WET AND DRY ROBOTIC VACUUM CLEANER NAZLI EIDMOHAMMADI A CONCEPT DEVELOPMENT PROCESS MASTER OF SCIENCE THESIS IN THE PRODUCT DEVELOPMENT

Transcription

1 WET AND DRY ROBOTIC VACUUM CLEANER A CONCEPT DEVELOPMENT PROCESS MASTER OF SCIENCE THESIS IN THE PRODUCT DEVELOPMENT PROGRAMME, ON BEHALF OF VORWERK NAZLI EIDMOHAMMADI DEPARTMENT OF PRODUCT AND PRODUCTION DEVELOPMENT CHALMERS UNIVERSITY OF TECHNOLOGY GOTHENBURG, SWEDEN, 2014

2 Master of Science Thesis Wet and Dry Robotic Vacuum Cleaner A concept development process NAZLI EIDMOHAMMADI Supervisors: Dr. Sabrina Hoffman, Professor Hans L. Johannesson Examiner: Professor Hans L. Johannesson NAZLI EIDMOHAMMADI, 2014 Published by: Department of Product and Production Development Division of Product Development Chalmers University of Technology SE Gothenburg, Sweden Telephone: (0) Web: Cover: A design suggestion for the project s conceptual solution.

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4 ABSTRACT Households of today are becoming smarter and more automated. Home automation delivers convenience and creates more time for people. Domestic robots are entering the homes and people s daily lives, but it is yet a relatively new and immature market. However, a growth is predicted and the adoption of domestic robots is evolving. Several robotic vacuum cleaners are available on the market but only few ones implement wet cleaning of floors. The Master s Thesis Wet and Dry Robotic Vacuum Cleaner was carried through on behalf of the German corporation, Vorwerk, at the Kobold Vacuum Cleaners Division, in Wuppertal. It was a module within the Product Development Master s Programme at Chalmers University of Technology (Department of Product and Production Development). The goals were to present a conceptual solution that provides the user with automated vacuum cleaning and mopping of floors and to create a working prototype that demonstrates the solution. The project followed a product development process, which included the stages of project planning, market research, setting a requirement specification, concept generation, concept evaluation and selection and embodiment design. The developed concept carries a dry cleaning mechanism in the front and a wet cleaning mechanism in the back. First large particles and debris are suctioned, afterwards clean water is applied to a rotating cylindrical brush that scrubs the floor and lastly the dirty water is suctioned and removed from the floor. It holds a square design to enhance reachability of cleaning areas and a one-stroke strategy to implement both cleaning procedures in one sweep. The constructed prototype served as a learning tool, which facilitated in revealing new aspects and recognising features that the robot should carry. A technology-intensive product of this kind requires the market to adapt a new technology. Therefore it is strongly recommended that a user-centred approach is applied, since it is the users who determines the market success or failure of a product. Keywords: domestic, mopping, product development, robot, scrubbing, vacuum cleaner.

5 TABLE OF CONTENTS ABSTRACT INTRODUCTION About Vorwerk Background Problem Description Purpose Goals and Objectives Scope and Limitations Thesis Outline THEORETICAL FRAMEWORK Adoption of New Technology Kano Model The Bernoulli Equation Introduction to Vacuum Cleaners Introduction to Robotic Vacuum Cleaners PROCESS AND METHODS Product Development Process Methods and Tools MARKET RESEARCH Market Analysis of Cleaning Robots Identifying Customer Needs REQUIREMENT SPECIFICATION CONCEPT GENERATION Establishing Function Structures Searching Externally Searching Internally Combining Working Principles CONCEPT EVALUATION AND SELECTION Determining the Cleaning Strategy Morphological Matrix Concept Elimination Conceptual Solutions... 55

6 7.5 Concept Screening Concept Scoring Chosen Cleaning Procedure and Concept EMBODIMENT DESIGN Prototyping Learning Outcomes Internal Product Architecture PRODUCT CONCEPT Concept Description and Depiction DISCUSSION Pursued Product Development Process Applied Methods Achieved Results CONCLUSION RECOMMENDATIONS BIBLIOGRAPHY APPENDICES Appendix I - Gantt Chart Appendix II - Product Comparison Chart Appendix III - Competitor Benchmarking Appendix IV - Customer and Need Statement List Appendix V - Interview Guide Appendix VI - Interview Notes Appendix VII - Water Usage of Floor Scrubber Appendix VIII - Morphological Matrices Appendix IX - Elimination Matrices Appendix X - Pugh Matrix Appendix XI - Weight Decision Matrix Appendix XII - Pictures of CAD-Models Appendix XIII - Pictures of Prototype

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8 1. INTRODUCTION This chapter is an introduction to the Master s Thesis Wet and Dry Robotic Vacuum Cleaner. First, a brief description of the company that assigned the study is presented. This is followed by declaring the project s background and problem description, defining its purpose and specifying its goals and objectives. Subsequently, the project scope is explicated and to provide a clear overview of the content a thesis outline is conveyed in the end of the chapter. 1.1 About Vorwerk Vorwerk & Co. KG (Compagnie Kommanditgesellschaft 1 ) is a German global corporate group with products in diverse fields, from vacuum cleaners to cosmetics. However, their main product category is the household appliances. The company was founded in 1883 as a family enterprise, a carpet factory, in Wuppertal, Germany. Later, Vorwerk extended their product portfolio and started sales of gramophones. In 1920, the radio gained a large market share and the sales dropped. This situation was the root to the technical sensation, the Kobold hand-held vacuum cleaner. The chief engineer used a gramophone motor to create this vacuum cleaner. With its mere size, for the time being, customers had difficulties believing that something so small could be so efficient. Thus, in 1930, Vorwerk started with a new sales system: direct sales. This meant that the customer could experience the efficiency and quality of the products in their own homes. The company still uses direct sales as its main distribution channel and the benefits are clearly shown in their revenues (Vorwerk & Co. KG [A], 2014). FIGURE VORWERK'S LOGOTYPE (VORWERK KOBOLD [A], 2014). Today, Vorwerk is still a family enterprise and since then the corporation has expanded to 70 countries and has more than half a million employees. With principles like customer focus, exceptional quality and sustainability it is evident what Vorwerk values and their mission statement emphasises this even more: As a trusted family business, we empower people across the globe to be successful with our exceptional products and services. (Vorwerk & Co. KG [B], 2014) 1 The German name for limited partnership business entity. 1. INTRODUCTION 1

9 1.2 Background This project was assigned by the Kobold Vacuum Cleaners Division, which is the best-selling division within the corporation. The division has since 1930 been supplying vacuum cleaners with high quality. Their product platform includes upright, handheld and robotic versions. The robotic cleaner, VR100 (See Figure 1.2), is the newest addition. It works with an innovative laser room scanner, which maps the room and then cleans it systematically. This differentiates it from most of its competitors since other robots navigate around the room in arbitrary patterns. The robot can either be started with the push of a button or be pre-scheduled to start at a given time (Vorwerk Kobold [B], 2013). FIGURE VORWERK'S ROBOTIC VACUUM CLEANER, VR100 (VORWERK KOBOLD [C], 2014). The world s first robotic vacuum cleaner was introduced by Electrolux in 2001 (Hanlon, 2013). Since then there is an abundance of different robotic vacuum cleaners on the market. The hectic lifestyles of today and the use of advanced technology have developed a need for this type of product. People want to waste less time and effort on cleaning and desire easy and convenient solutions. The VR100 provides this, but in order to meet the customer s needs additionally a product that offers wet cleaning of the floors is required. 1.3 Problem Description The given problem description was to design a conceptual solution for a domestic cleaning robot that vacuum cleans and wet cleans the floors and to build a working prototype to demonstrate the solution, which also were the main goals of this project. There are several problem areas that are required to be solved to introduce this type of product on the market e.g. path planning, detecting obstacles or the maintenance in between cleaning cycles, while keeping the robot as small as possible to enable its mobility in the use environment. Not only does it require achieving this, but it also must achieve a proper cleaning result. However, the main focus of this project is to manage the actual cleaning procedure. Currently, Vorwerk holds a working prototype but it does not meet all the necessary requirements to serve as wet and dry cleaning robot, since there are problem areas that not yet have been concerned or solved. 2 WET AND DRY ROBOTIC VACCUM CLEANER

10 1.4 Purpose The purpose of the project is to implement an automated wet and dry cleaning system to Vorwerk s product platform. The system requires to: 1. Remove the debris and large particles from the floor. 2. Wet clean the floor with fresh water. 3. Remove the dirty water and leave the floor as dry as possible. This type of product must enhance the convenience for the customers using it while providing them with a proper cleaning result. This implies that the system is required work with minimal human intervention. At the moment, there are only a few products on the market that offer this solution. This indicates a difficulty and complexity in solving the task in an efficient and satisfactory way. 1.5 Goals and Objectives One of the goals of this project was to present a concept, which represents a system solution and the cleaning strategy of a product that provides the customer with automated dry and wet cleaning of floors. This development project is in the early stages of the development process; therefore an additional goal was for this thesis to be a research project so it could lay the foundation for the future development work at Vorwerk. In order to reach these goals four objectives were set, which also can be accounted as the deliverables of this project:! Objective 1: Conduct a market research.! Objective 2: Deliver a requirement specification, which will be the foundation in the development of this product.! Objective 3: Deliver a number of possible solutions and the further development of a chosen concept.! Objective 4: Deliver a working prototype, which demonstrates the cleaning strategy. 1.6 Scope and Limitations This project was carried out at the department of Advanced Technology Development, which also sets the scope of the project. Few limitations were specified by the company since the desire was to search for and examine a wide range of different solutions. Consequently, this thesis was seen as research and development project to provide learning aspects and to reduce uncertainty to the departments own development process. 1. INTRODUCTION 3

11 The development of a combined dry and wet cleaning robot has been divided into different subtasks within the company and, thus it is of importance to define the scope of this project and set the limitations of it. Main focus has been to find a system solution and solving the main problem area: implementing a wet cleaning system. Therefore, all problem areas regarding this product are not addressed. The goal was to achieve a working prototype that will prove the cleaning procedure and not to obtain a fully developed prototype for the entire robot. This means that for instance software and manufacturing methods were not considered. Thus, it only demonstrates how the robot is cleaning the floors. Driving strategy and operating features are considered for the concept but not how they could be implemented. Material selection was only considered for the parts associated to the cleaning, where the choice can increase the cleaning efficiency. However, the market research concerned the all areas since this material would be of value for the company in the further development process. Assistance was received from Vorwerk in the development of the prototype. This is due to limited knowledge in the field of electronics. Additionally, the fact that this project is about recognising new ideas costs were not a primary concern for the development of the concept. 1.7 Thesis Outline Chapter 1: Introduction introduces this Master s Thesis with a description of the company and a declaration of the project s background. It includes a definition of its purpose, goals, objectives and limitations. Chapter 2: Theoretical Framework provides theory regarding the subject, which is applied to justify choices in the development process. Also, an introduction to vacuum cleaners and robotic vacuum cleaners are given. Chapter 3: Process and Methods explains the followed product development process and argues the reasons for and the importance of each conducted phase. Furthermore, it describes the methods and tools that were applied throughout the project. Chapter 4: Market Research presents the result of the market research for the cleaning robot, which contains a market analysis and an identification of customer needs. 4 WET AND DRY ROBOTIC VACCUM CLEANER

12 Chapter 5: Requirement Specification holds the established requirement specification, which regards requirements such as safety issues, cleaning result, maintenance and how the robot is required to operate. Chapter 6: Concept Generation provides a deeper understanding of the problem and the procedure to attain solutions. Here, the general ideas are being can be found. Chapter 7: Concept Evaluation and Selection determines the robot s cleaning strategy and presents the conceptual solution. It also denotes results from the concept screening and scoring procedures and concludes with presenting the selected concept. Chapter 8: Embodiment Design explains the stage of prototyping the selected concept, the learning outcomes and ideas regarding the internal architecture. Chapter 9: Product Concept presents the established concept. It describes and depicts the concept, its cleaning strategy and its mechanisms. Chapter 10: Discussion examines the pursued development process, the applied methods and the achieved result. Aspects that have affected the result are being deliberated and the result s reliability and validity are discussed. Chapter 11: Conclusion provides a summary of the most significant conclusions that were drawn throughout this Master s Thesis. Chapter 12: Recommendations is a list of suggestions to Vorwerk. The list can be used for the future development of the wet and dry cleaning robot. 1. INTRODUCTION 5

13 2. THEORETICAL FRAMEWORK The following sections are being presented to give the reader an insight to relevant and significant knowledge that concerns this study. This framework also provides theory that is applied to justify choices in the product development process. Conclusively, an introduction to and the terminology of vacuum cleaners and robotic vacuum cleaners are presented. 2.1 Adoption of New Technology The adoption of new technologies is an important aspect to consider when introducing this sort of technology-intensive product to the market, since the decision of adopting a product ultimately determines the market success. Therefore, the diffusion of innovations has been deliberated in this development process Diffusion of Innovations A new innovation requires the consumers to adopt a technology. Rogers (2003) defines diffusion as the process by which an innovation (1) is communicated through certain channels (2) over time (3) among the members of a social system (4). These four main elements determine the diffusion of innovations: 1. The innovation The innovation itself has different characteristics and these help explaining the adoption rates:! Relative Advantage. The user s perceived benefits of the innovation when comparing to other already existing solutions.! Compatibility. The innovation s compatibility with existing norms and social standards in the social system where innovation is to be diffused.! Complexity. The perceived difficulty to understand the product and how to use it.! Trialability. The degree the user can experiment and test the innovation to reduce uncertainty of it.! Observability. The degree to which the results of utilising the innovation can be observed (Rogers, 2003). 2. Communication Channels A communication channel is what is used to provide a message from one individual to another. These are used to present the innovation to the customers, e.g. mass media, social media or face-to-face interaction (Rogers, 2003). 6 WET AND DRY ROBOTIC VACUUM CLEANER

14 3. Time Time is an important aspect in the diffusion theory. The rate of adoption is the time that is required for certain members of a social system to adopt an innovation. Figure 2.1 shows the distribution of different adopter categories in a society and are categorised accordingly:! Innovators represent the members that purchase and try innovation just because the innovation is new. They usually have financial resources and are willing to take risks.! Early Adopters decreases the degree of uncertainty in a product and the potential adopters look to this adoption category before a decision.! Early Majority adopts and is wiling to adopt innovations before the average member of a social system. However, they do not want to be the first ones and neither the last ones to try an innovation.! Late Majority is a category that is sceptical. The pressure of peers of the social system is required to result in adoption.! Laggards are the last ones to adopt an innovation and are usually traditional and isolated (Rogers, 2003). FIGURE INNOVATION ADOPTION CURVE. THE CURVE ILLUSTRATES THE RATE OF ADOPTION AND THE DIFFERENT ADOPTER CATEGORIES DISTRBUITION IN A SOCIETY (GLOVER, 2013). 4. A social system A social system refers to the rules, norms and structures of the system. This also impacts the diffusion of an innovation (Rogers, 2003). 2.2 Kano Model Noriaka Kano is the developer of this two dimensional model referred to as the Kano model. It explains the influence on customer satisfaction when fulfilling different product requirements (Kano, 1984). 2. THEORETICAL FRAMEWORK 7

15 FIGURE 2.2 KANO MODEL. ILLUSTRATES THE RELATIONSHIP BETWEEN CUSTOMER SATISFACTION AND PRODUCT REQUIREMENTS (MATZLER, 1996). In Figure 2.2 the horizontal axis represents how well a product requirement is implemented, i.e. the absence or the presence of a feature. The vertical axis represents the degree of customer satisfaction. The model divides requirements into three categories:! Must-be requirements: These requirements are fundamental; the absence of these features results in extreme dissatisfaction while the presence does not enhance the customer satisfaction. When these requirements have reached a satisfactory level an improvement of them is not necessary, since this will not enhance the customer experience. Thus, resources can be utilised to fulfil the other requirement types instead.! One-dimensional requirements: The customer satisfaction is seen as a linear function of the product requirement fulfilment. The satisfaction rises with the implementation.! Attractive requirements: These requirements are the delighters ; the absence of these features does not result in dissatisfaction while the presence provides the highest influence on customer satisfaction (Kano, 1984). This implies that all features do not have the same value and that some features create higher levels of customer satisfaction. The classification enhances the understanding of the product requirements, improves the distribution of resources and assist in trade-offs situations (Kano, 1984). 8 WET AND DRY ROBOTIC VACUUM CLEANER

16 2.3 The Bernoulli Equation This principle is an equation that states a relationship between pressure, velocity and position or elevation in a flow field. The Bernoulli equation for a steady, incompressible flow along a streamline with no friction is: where: p is pressure at a specific point, ρ is density (constant all over the fluid), V is fluid flow speed at the specified point, g is the acceleration due to gravity, z is the elevation level.!! +!! +!" =!"#$%&#% 2 The equation demonstrates that if the fluid flow speed is increased at a certain point a pressure drop is created in order to maintain the constant (Janna, 2010). 2. THEORETICAL FRAMEWORK 9

17 2.5 Introduction to Vacuum Cleaners When familiarising with the topic of this study it is important to understand the mechanism of vacuum cleaners. It can be explained with sipping soda out of a straw. The sipping creates a pressure difference between the bottom and the top of the straw and the fluid is pushed from the high-pressure area to the low-pressure area. Vacuum cleaners work in the same manner, since the particles are being suctioned due to the pressure difference (Harris, 2014). The main components that vacuum cleaners consist of are: an intake port, an exhaust port, an electric motor, a fan, a filter and a dust compartment (See Figure 2.3). When the motor that is attached to the fan creates the wanted pressure drop at the exhaust port the ambient air is pushed into the vacuum cleaner through the intake port and the particles are suctioned into the dust compartment. The filter contains holes, which are small enough to stop the particles, but large enough to let the air go through. The dirty air is filtered and flows through the exhaust port (Harris, 2014). FIGURE INSIDE VACUUM CLEANERS (HOWSTUFFWORKS, 2001). What determines the suction power is the power of the fan, the shape of the air passageway and the size of the intake port s opening. The fan generates the pressure difference, but if the air passageway contains obstacles that block the path the resistance will result in reduced suction power due to reduced air speed. The resistance can be a consequence of a full dust bag or a poorly designed passageway. The airflow rate (litre/second) that the fan generates is constant, which means that the amount of air that passes through per unit of time is constant. However, the air speed varies throughout the system and with a smaller nozzle size the speed can be increased at the intake port. The increased airspeed provides a pressure drop, due to the Bernoulli equation (See Section 2.3), which results in a greater suction power (Harris, 2014). 10 WET AND DRY ROBOTIC VACUUM CLEANER

18 2.6 Introduction to Robotic Vacuum Cleaners The robotic vacuum cleaners aim to achieve vacuum cleaning with minimal human interaction. The cleaners operate with the same suction system as regular vacuum cleaners but in order to avoid the human interaction a self-navigation system is required. With a press of a button or a pre-scheduling feature the cleaning robot starts operating through the room (irobot [A], 2014). The robots conventionally start their cleaning route by mapping the room to obtain the room size, either with an infrared signal or with a laser scanner as the VR100. Algorithms that determine the cleaning path make them run in arbitrary patterns to finally ensure full coverage. The VR100, however, works more systematically and creates a square of the room and operates methodically within the square. During the cleaning cycle the robots recognise obstacles with bumpers in the front (Vorwerk Kobold [B], 2014). Figure 2.4 shows different robot vacuum cleaners currently available on the market. FIGURE ROBOT VACUUM CLEANERS. NAVIBOT S ROBOT VACUUM FROM SAMSUNG (SAMSUNG [A], 2014), ROBOTIC SQUARE VACUUM CLEANER FROM LG (LG [A], 2014), ROOMBA 880 FROM IROBOT (IROBOT [B], 2014). The particle suction is enhanced through using one or more brushes (See Figure 2.5). Usually, the cleaning robots carry a roller brush (Samsung [A], 2014). However, several also have side brushes to enhance corner and edge cleaning (LG [B], 2014). The VR100 has one side brush one the right side, which is the side that is programed to follow edges. Most of the cleaners have cliff sensors that prevent them from falling from heights, such as stairs (Samsung [A], 2014). The user can also place virtual walls in the home to prevent it from entering unwanted areas (irobot [A], 2014). FIGURE 2.5 BOTTOM VIEW OF NAVIBOT S FROM SAMSUNG (SAMSUNG [B], 2014). 2. THEORETICAL FRAMEWORK 11

19 The robots are powered by rechargeable batteries whose capacity determines the cleaning time. If the desired cleaning area is not finished within the battery time they return to their base station to recharge and afterwards the robot continues the cleaning where it stopped (Vorwerk Kobold [B], 2014). The low height of the robots increases the mobility and accessibility for them so they are able to cover larger areas. Other features the cleaners carry are UV-light to disinfect or dirt detection sensors to enhance the cleaning (Infinuvo, 2014). Some can even empty the dustbin at the base station automatically (Kärcher [A], 2014). All of this is to ensure minimal involvement by the user. Nevertheless, regarding cleaning performance the robotic vacuum cleaners have not advanced enough to replace regular vacuum cleaners yet. Therefore, the main purpose of use can be seen as a compliment to the regular vacuum cleaner for daily touch ups. 12 WET AND DRY ROBOTIC VACUUM CLEANER

20 3. PROCESS AND METHODS This chapter explains the followed product development process and argues the reasons for and the importance of each conducted phase (See Section 3.1). Furthermore, it describes the methods and tools that were applied throughout the project (See Section 3.2). 3.1 Product Development Process The flow diagram below demonstrates the process that was followed throughout this project and in chapters 4-9 the results are being presented. The loop shows the action of iteration that was essential to apply when developing and prototyping the concept. This denotes that modifications were made to the concept when unknown problems were encountered during the different phases. The aim was to keep these iterations as small as possible to achieve an effective and efficient design process. The work procedure was adapted and adjusted from the books Product Design and Development and Engineering Design: A Systematic Approach to properly suit the nature of this project (Pahl, 2007; Ulrich, 2012). The process is explained more closely in the upcoming sections and the methods and tools are denoted with bold text throughout the description. The applied tools and methods are later explained in Section 3.2. FIGURE PRODUCT DEVELOPMENT PROCESS. ADAPTED FROM PAHL (2007) AND ULRICH (2012) Project Planning The project was initiated with a planning phase and it concerned activity planning and the scheduling of these activities (Pahl, 2007). This was carried out in order to establish the project s scope and to create an overview of the upcoming work, since with clear project goals and objectives set the project work would become easier to manage. The time plan was presented as a Gantt chart, which can be found in Appendix I. 3. PROCESS AND METHODS 13

21 3.1.2 Market Research The market research is a crucial initiating step in any product development process (Johannesson, 2004). Marketing is about identifying and meeting human and social needs. The financial success of a company often depends on their marketing abilities (Kotler, 2012). Without a proper market research, as a foundation for a development process, the result could be overlooking important product attributes the customers require. Thus, a market research can provide the company with a competitive advantage on the market. In this day and age, companies encounter a tough challenge of competition. It is not only about meeting the customer s needs anymore; it is also about exceeding them. In order to provide this to the customers it is of importance to truly understand them and get into their heads (Kotler, 2012). McQuarrie (2012) defines market research as techniques for gathering information from and about customers to support a business decision. He denotes that there are only two types of market research: exploratory or confirmatory. This study followed an exploratory research, due to the fact that it is in the beginning of a product development process and that no market research yet had been conducted. In later stages of the development process a confirmatory research can be applied to verify the use of the developed product. Market Analysis of Cleaning Robots The exploratory research started out with creating a product comparison chart, which can be found in Appendix II. By comparing competing products the competitors could be identified. The chart also provided the ability to identify what the robots must fulfil and offered inspiration. Furthermore, a company benchmarking was conducted to recognise the largest competitors (See Appendix III). Identifying Customer Needs The customer needs identification is an integral part in developing products. This ensures that the product to be developed is focused on what the customer wants. It also provides the foundation for the product specification, which the development team follows. Furthermore, it ensures that no critical customer need is overlooked or neglected (Ulrich, 2012). This investigation enabled The Use System to be described so an understanding can be reached in what type of product is required (See Section 4.2.1). 14 WET AND DRY ROBOTIC VACUUM CLEANER

22 In order to perform an exploratory research and to gather raw data from customers Interviews (See Section 4.2.2), Observations and Secondary Research were conducted (See Section and 4.2.4). All the collected data was gathered and categorised in a Customer Statement List (See Appendix IV). It is of importance to have in mind that the customers might not always express or even know what they need, so it is important to be able to interpret what they actually need. This can be explained with a quote that Henry Ford once supposedly stated: - If I had asked my customers what they wanted they would have said a faster horse. If Ford indeed expressed this or not can be discussed, but the fact still remains that needs must be interpreted by the product developers (QuoteInvestigator, 2011). Thus, the interpretation and translation were collected in a Need Statement List (See Appendix IV) Requirement Specification The goal in this step was to establish a requirement specification by using the results from the market research. This provided a specific guidance about how to design and engineer the product. Due to the fact that the product to be developed is technology-intensive and it concerns plenty of uncertainty, it is rarely possible to establish only one requirement specification that is will be followed throughout the entire process. Therefore, a Target Specification was established, which represents the aim to achieve with the final product (See Chapter 5). In the development when new information were acquired the specification was revised and updated. The final product specification is set when all the trade-offs have been carried out in between different desired characteristics (Ulrich, 2012) Concept Generation The concept generation phase is generally the most creative stage of the development process. Despite this, a systematic approach was followed in order to ensure the coverage of a solution space as large as possible. Furthermore, it ensured that a wide selection of solutions and alternatives were examined and evaluated (Johannesson, 2004). The goal of this phase was to generate a number of conceptual solutions that fulfil the requirement specification. Later, these solutions were evaluated and in between them the most favourable concept was selected. The systematic approach was adapted from the concept generation approaches used in Johannesson (2004), Pahl (2007) and Ulrich (2012) and the structure is presented below. 3. PROCESS AND METHODS 15

23 Abstracting to Identify the Essential Problem Abstraction is a procedure that is used when not wanting to be influenced by or fixed to conventional ideas. The phrase in Pahl (2007) expresses this perfectly: This means ignoring what is particular or incidental and emphasising what is general and essential. Such generalisation leads straight to the crux of the task. When the crux of the task has been identified the problem formulation can be broadened so it is of solution neutral character (Pahl, 2007). Establishing Function Structures This phase had the goal to generate different solutions to the problem, but before being able to solve a problem it is required to really understand it. This can be achieved by decomposing a complex problem into simpler smaller problems (Ulrich, 2012). The applied method was conducting a function analysis and in the analysis a Function Diagram (See Section 6.1.1) was created to obtain an overview of the overall function and a Function-Means Model (See Section 6.1.2)was mapped to identify the subfunctions (Johannesson, 2004). This resulted in the division of the main problem into subproblems, which then could be attacked individually. Searching Externally External material can be used in the product development process for several types of aspects, but the main aim of the search is to find existing solutions. If existing solutions are used the creativity can be focused on critical subproblems instead. The information can be found by interviewing lead users, consulting experts, searching patents, searching in published literature and benchmarking related products (See Section 6.2) (Ulrich, 2012). Searching Internally The search uses internal knowledge and creativity to generate ideas and the method is commonly referred to as Brainstorming (See Section 6.1.3). In order to convey the found ideas sketching can be used as a mediating tool. This internal search can be carried out both individually and in group-sessions, and both techniques are seen as useful. The individual has the ability to produce more and better concepts than a group working during the same amount of time. However, the group s work can help to build consensus and refine the concepts of the individual s work (Ulrich, 2012). With this reasoning both an individual and a group session was held (See Section 6.3). 16 WET AND DRY ROBOTIC VACUUM CLEANER

24 Combining Working Principles When establishing all the research it is of importance to explore all the solutions systematically and combine them into working principles (Ulrich, 2012; Pahl, 2007). The applied method that was made use of was a classification scheme named Morphological Matrix (See Section and 7.2). In this matrix the solutions were categorised according to the subfunctions from the function analysis. These solutions were later combined into overall concept solutions, which could be evaluated and selected among (Pahl, 2007) Concept Evaluation and Selection The evaluation and selection process can follow different procedures according to company commodity or the character of a project. Either route, the evaluation must be carried out with respect to the customer s needs and requirements (Ulrich, 2012). It is of importance to emphasise the difficulty of this phase since the evaluation requires determining the concepts value or quality, which surely can be a subjective procedure (Johannesson, 2004). However, a structured method can be the guide to achieve objectivity throughout it and several benefits could be gained, e.g. a customer-focused product, a competitive design and documentation of the decision process (Ulrich, 2012). The applied concept selection process followed the steps presented beneath (Johannesson, 2004): 1. Concept Elimination: Elimination Matrix 2. Concept Screening: Pugh Matrix 3. Concept Scoring: Kesselring Matrix In the evaluation and selection process new conceptual solutions might be encountered and added to the collection of concepts (See Figure 3.2) (Johannesson, 2004). The selection process was carried out with advice from the company in order to maintain the right aim. Furthermore, tests were conducted in order to collect material to support the decisions of the process. FIGURE 3.2 A DEPICTION OF THE CONCEPT SELECTION AND EVALUATION PROCESS FROM ULRICH (2012). 3. PROCESS AND METHODS 17

25 3.1.6 Embodiment Design The goal of this stage was to initiate the embodiment design of the chosen product. This concerns how it should operate and what features were required, thus developing the selected concept from the previous stage further. This was carried out by creating and testing a prototype. Prototyping and Testing The goals of building the prototype were to gain knowledge about constructing the product and to verify the cleaning strategy of selected concept. Hence, the purpose of the prototype was learning and communicating the product concept (Ulrich, 2012). The CAD-modelling software NX, developed by Siemens, was utilised to create desired parts to the prototype and other material was retrieved from the company workshop or purchased. 3.2 Methods and Tools This section explains the applied methods and tools that have been used in this study. The previous section, in which the work procedure was explained, the applied practices were denoted with bold text and are now presented in the same order as previously Project Planning Gantt Chart The Gantt chart is a widely used project management tool for project planning. Projects have a start- and end date and the main purpose for utilising this tool is to manage the time resource in a given time span. The activities for the project are listed and each activity s duration is represented with a horizontal bar along a time axis. This graphical representation gives a comprehensive overview of what is required to be completed and when (Gantt.com, 2012). The Gantt chart for this project can be found in Appendix I Market Research Benchmarking Benchmarking is used to improve performance through studying the best practice companies (Kotler, 2012). It is a tool that measures the quality of a company s e.g. policies, products and strategies in comparison to their competitors. It can aid in determining where improvements are required and to recognise how the competitors achieve high performance (BusinessDictionary.com, 2014). In this project a number of evaluation parameters were specified and the companies were compared according to these. Each company was assigned different values for each parameter, thus resulting in the companies obtaining different rankings. 18 WET AND DRY ROBOTIC VACUUM CLEANER

26 The User-Product-Goal-Context System ( The Use System ) Identification of usage needs requires a comprehension of the whole system as an entity and this is the reason why this system model was applied. It enables development teams to consider all factors and to recognise how they influence each other. The system consists of the user, the product, the task/goal and the environment (See Figure 3.3). Then the question can be asked if one of the elements is changed will the requirements of the system alter. This method can enable the recognition of further needs. Also then it is possible to design a product that suits different users or environments (Karlsson, 2012; Kaulio, 1996). Interviews FIGURE THE USE SYSTEM (MODIFIED FROM KARLSSON, 2012; KAULIO, 1996). Interviewing is a data-gathering tool that is performed to collect raw data from customers. The discussion regards the customer needs and is usually conducted in the customer s environment (Ulrich, 2012). When gathering raw data from customers different approaches can be used and the one applied in this study was the semi-structured approach. This means that an interview guide (See Appendix V) was designed and followed to assure that certain questions were addressed but the topic was still discussed in a free manner to identify unrecognised problem areas (Lantz, 2007). Observations Observing is a research technique that can be utilised to understand how a product is being used. The purpose is to watch the customer use the product in its natural environment in order to reveal and recognise details about the customer needs. It can be carried out passively or with some interaction from the observer (Ulrich, 2012). This technique was applied by watching video reviews created by users and also by using and testing cleaning robots. Secondary Research Secondary research refers to any data on the subject collected by others that is relevant to the project e.g. sales reports or customer databases (McQuarrie, 2012). This tool was the main data collection tool of this report due to the fact that it is a rapid and simple procedure to collect information in a short period of time. Customer reviews of robotic vacuum cleaners and published articles were examined and analysed to collect the required material. 3. PROCESS AND METHODS 19

27 Customer Statement List A customer statement list is a tool for documenting and reviewing expressed needs from customers. In a spreadsheet all the statements, which represent the raw data, are organised in categories and documented with the customer s own words. It is vital to maintain the customer s own expressions with regard to not losing any information (Ulrich, 2012). This tool was utilised to document the information found in online customer reviews. Need Statement List The need statement list is created through translating and interpreting the customer statement list and it was applied by pursuing the following guidelines given by Ulrich (2012):! Express the need in terms of what the product has to do, not in terms of how it might do it to avoid limiting the concept generation to certain solutions.! Express the need as specifically as the raw data to avoid data loss.! Preferably use, positive not negative, phrasing! Express the need as an attribute of the product.! Avoid the words must and should. Customer Statement List! Need Statement List! The customer's own words" The interpreted need" FIGURE TRANSLATION FROM CUSTOMER STATEMENTS INTO NEED STATEMENTS Requirement Specification Target Specification The requirement specification is established with the result from the market research. All found customer needs and requirements are formulated and given a measurable metric to the possible extent (Ulrich, 2012). The metric is given to be able to investigate if the need is fulfilled and to have a distinctly expressed aim. According to Johannesson (2004) the requirements can be classified in two main categories: functional requirements and constraining requirements. The functional requirements are the criteria related to the product s anticipated function such as carry load or transmit signals. The constraining requirements are the criteria that limit the sought solution like cost or weight. An additional grouping is to divide the requirements into demands and wishes. Demands are what the solution must fulfil while wishes are optional. The wishes can however have an importance level so they can be prioritised when being implemented. 20 WET AND DRY ROBOTIC VACUUM CLEANER

28 3.2.4 Concept Generation Function Diagram The function diagram divides the overall function into subfunctions and this illustrates how the complex overall function operates. It also depicts how the subfunctions interact and it enables the development team to find solutions to each subtask instead of tackling the entire problem (Johannesson, 2004). Function-Means Modelling This model is a graphical representation, which carries the desired product s functions (Functional Requirements) and its means to apply the function (Design Parameters). It is a hierarchical structure that alternates from the functional domain where the what is defined to the physical domain where the how is defined. Hence, this method helps to decompose the subfunctions additionally and better understanding can be achieved (Johannesson, 2004). Brainstorming This idea generation method is seen as the most creative task in the development process and where as many ideas as possible are generated. The session should be suspended of all judgement and ideas that may seem unfeasible should be welcomed. This is in order to find innovative solutions and to not restrict the minds of the development group (Ulrich, 2012). Morphological Matrix A morphological matrix gathers the different solutions found during the internal and external search. The identified subfunctions from the function analysis are used as categories and the different subsolutions are presented. The reason for creating this matrix is to be able to combine various subsolutions to possibly identify an overall solution that has not yet been considered. Consequently, it provides the investigation of a wider solution space (Johannesson, 2004) Concept Evaluation and Selection Elimination Matrix The elimination matrix is utilised to clarify that the solution e.g. solves the main problem, fulfils the requirements and is within the margin of expenditure etc. (Johannesson, 2004). This matrix can be seen as a form of checklist to quickly eliminate solutions that not are suitable to pursue. 3. PROCESS AND METHODS 21

29 Pugh Matrix Important requirements are set as the selection criteria and the remaining concepts are compared with one reference concept. This evaluation method shows if a concept fulfils the criteria better (+), equally (0) or worse (-) than the reference concept (or a competitor s product). The net value of the comparison determines if the concepts should be further evaluated. After this stage, it can be identified where a certain concept has to be improved in order to continue in selection process. Therefore, this decision matrix can yield in new stronger concepts (Johannesson, 2004). Kesselring Matrix In a Kesselring matrix conceptual solutions are evaluated according to different criteria. These criteria are assigned weight factors to show the importance of each criterion. The weight factors, w, are allocated through the implementation of a weight decision matrix (See Appendix XI), which enables each criterion to be assessed against all other criterion. This structured manner helps to maintain an objective view in the evaluation process. The solutions are evaluated according to each criterion and given a value, v, between 1-5 to show how well the criterion is fulfilled. The value, v, is then multiplied with the assigned weight factor, w, resulting in the product, t:!! =!! All t i -values are added for each concept, hence giving each concept a total value, T:! =!! The ideal concept would fulfil all criteria fully, thus achieving T max. A normalised total merit value is calculated for each concept, to show how well it fulfils the criteria:! =!/!!"# Therefore, the ideal value equals to 1 and the closer the evaluated concepts are to the ideal the better. The result of this decision matrix should be one final concept. It can also be evaluated how close the final concept is to the ideal solution and if changes can be made to achieve a better solution (Johannesson, 2004). 22 WET AND DRY ROBOTIC VACUUM CLEANER

30 4. MARKET RESEARCH This chapter presents the result of the market research that was conducted in this project. First a market analysis is provided, followed by a benchmarking of the main competitors and their competing products. Subsequently, the results from identifying of customer needs are portrayed by describing The Use System, summarising the interviews and customer reviews and presenting findings from related articles. 4.1 Market Analysis of Cleaning Robots The households of today are becoming smarter and more automated. Home automation is used to provide convenience and to create more time for people. Household chores are seen as time-consuming and repetitive tasks and if there is a product that simplifies or even eliminates these chores a demand will occur. People have a positive attitude toward adopting technological solutions that makes life more comfortable (Mert, 2008; Winter Green Research, 2012). Dishwashers and washing machines as mature technologies have become a common household product. However, cleaning robots have not yet reached this maturity in people s daily lives but a growth is predicted. In 2011 the sales revenues of household robots reached 500 million and it is forecasted for it to reach 1,3 billion by 2018, which implies more than doubling the market shares (Winter Green Research, 2012). Sung et. al. (2008), also states the adoption of domestic robots is growing. It is believed that the market growth is due to the increase of workingwomen and the sharing of household chores. Additionally, there is a need to keep older people in their homes longer. Thus, automation of manual processes also functions as a market driver (Winter Green Research, 2012). Currently, there are only a few products on the market that offer a solution for automated wet and dry cleaning of floors Competitor Benchmarking Cleaning performance, battery time and price are different technical details that are used to parallel the quality of cleaning robots. These technical details were collected in a Product Comparison Chart to have the ability to easily compare the different products available on the market (See Appendix II). The chart gave an impression of companies that might be worth observing closer due to which functions they have implemented and how advanced their robots are. 4. MARKET RESEARCH 23

31 Thus, nine important competitors were identified and they were evaluated and benchmarked according to ten criteria in order to recognise the main competitors. The full evaluation can be found in Appendix III and the main competitors are presented below. Neato Robotics is a popular and well-known robot vacuum cleaner company and Vorwerk owns the majority of this enterprise. Because of the companionship the company is not presented as one of the competitors. irobot The company irobot is an American corporation within the field of robotics with over 500 employees. It was founded in 1990 by MIT roboticists that wanted to make practical robots a reality. Today, they offer mostly cleaning FIGURE IROBOT'S LOGOTYPE (IROBOT [C], 2014). robots for domestic use but also provide military and space robots. Their sales revenue of 2011 reached 344 million and 323 in 2012 (irobot, 2011; irobot [D], 2014). The benchmarking of the competitors combined with what was expressed by user in online reviews indicates that this is Vorwerk s main competitor in the cleaning robot category. Furthermore, irobot is the only company that provides an advanced solution for a wet and dry cleaning robot, which enhances this statement further. Kärcher The German company Kärcher is a global market leader within cleaning technology. Alfred Kärcher founded it in 1935 and it is like Vorwerk a family owned enterprise. The company is known for its wide range of cleaning equipment FIGURE KÄRCHER'S LOGOTYPE (KÄRCHER [B], 2014). for home and professional use. In 2012 the sales revenue for Kärcher was over 1.9 billion and their workforce had a size of approximately employees (Kärcher [C], 2014). Kärcher shares numerous similarities with Vorwerk such as the industry and the German market. The organisation holds several innovative appliances for cleaning with water; as highpressure washers, wet and dry vacuum cleaners and window cleaners. Additionally, the company has a vacuum cleaning robot with an advanced technology for automatic emptying (Kärcher [A], 2014). The robot empties its dustbin to the base station and therefore the user is not required to manually empty the robot. Their current knowledge within the field could surely be implemented in a wet and dry cleaning robot and it can be assumed that the company is considering a solution for it (Kärcher [C], 2014). 24 WET AND DRY ROBOTIC VACUUM CLEANER

32 Moneual Moneual is a South Korean company that was founded in The headquarter is located in Seoul but still the company has locations all over the world such as North America, Europe (Eschborn, Germany), FIGURE MONEUAL'S LOGOTYPE (MONEUAL EU [A], 2014). China and Japan. The organisation develops IT technologies for home and office environments and they have an eco- and user-friendly approach. The company also states their focus on innovation and has won several innovation awards (Moneual KR, 2014). The European subsidiary has products such as PCs, UV handheld vacuum cleaners and the cleaning robots (Moneual EU [B], 2014). Their new product launch in the cleaning robot category shows that the company is trying to enter the market for wet and dry cleaning robots, and with this in mind this company should be held under observation. Details Vorwerk irobot Kärcher Moneual Country Germany USA Germany Korean (European) Sales Revenue [ ] 2.4 billion 344 million 1.9 billion n/a Employees Founded (2012) TABLE 4.1 AN OVERVIEW OF THE MAIN COMPETITORS Competing Products The cleaning robots compete in a wide range of diverse features like appearance, ease of use, maintainability, reliability and quality (Winter Green Research, 2012). The main constraint that must be regarded in the development of a cleaning robot is the size, since without a minimal size it will not maintain its mobility. While sustaining the small size the robot must deliver a proper cleaning result with minimal human intervention. The size limitation results in challenging tradeoffs that is necessary to acknowledge. This complexity is mirrored by the circumstance that there are only a few products on the market that offer an automated wet and dry cleaning product. The products that do have this solution are being presented below. 4. MARKET RESEARCH 25

33 Wet and Dry Cleaning Robots Scooba 390 irobot The Scooba 390 follows a four-stage cleaning process: It starts with preparing the floor by suctioning large particles and debris, then it applies cleaning solution on the floor, subsequently the floor is being scrubbed with a rotating brush and finally the dirty water is squeegee vacuumed into the robot (See Figure 4.4). It passes one area at least three times to ensure proper cleaning. The robot avoids carpets and has the ability to clean an area of 40 m 2 with one water tank. The clean and dirty water tank utilises the same space, approximately 1000 ml. It is a two-chambered tank that separates clean and dirty water with a flexible membrane. After the cleaning cycle the water tank has to be emptied and rinsed. The user cannot choose to only vacuum clean the floor with this device (Robot Buying Guide, 2014). However, the cleaning robot has been replaced by a new model and is no longer available through irobot s web shop. FIGURE SCOOBA 390 (EXPANSYS, 2014). Scooba 450 irobot The latest Scooba was released in January 2014 and irobot has altered the cleaning strategy for the floorscrubbing robot (See Figure 4.5). It still prepares the floor by initially suctioning debris but it also prepares the floor with the new feature called Pre-soak technology, which means that it leaves the floor wet. Next cycle it scrubs and suctions the dirty water of the floor and the third time around it squeegees the floor. This requires the robot to cross the same area multiple times to achieve the wanted cleaning result. FIGURE SCOOBA 450 (IROBOT [E], 2014). The handling of the water tank seems to be easier to manage than its predecessor. It runs in cycles of 20 or 40 minutes and covers 14 or 28 m 2, respectively. The size of the tank has unfortunately not been given by irobot. The option for only vacuum cleaning the floor has still not been provided (irobot [F], 2014). 26 WET AND DRY ROBOTIC VACUUM CLEANER

34 Hybrid Robot Vacuum Cleaner MR6800M Moneual This hybrid robot vacuum cleaner was released in December 2013 and works as a regular vacuum cleaning robot but it can be used as wet and dry one by attaching a water tank to the it (See Figure 4.6). The water tank distributes clean water to a microfiber cloth, which can be attached underneath, and contains 180 ml of fresh water. It has a feature called Shadow-cleaning mode, which means that it activates a more thorough cleaning in these areas, such as under the bed or couch (Moneual EU [B], 2014). Braava 380 irobot FIGURE HYBRID VACUUM CLEANER MR6800M (MONEUAL EU [C], 2014). Braava is not a wet and dry cleaning robot but a mopping robot and certainly is worth mentioning. It was produced by the company Evolution Robotics and launched in The company was in 2012 acquired by irobot and is now sold under irobot s name (Biggs, 2012). This floor-mopping robot uses disposable cleaning cloths or washable microfiber cloths, which can be used for dry or damp mopping. The dry mopping can cover 92 m 2 and the damp mopping an area of 32 m 2. To utilise the damp mopping function the cloth must be presoaked and then it starts cleaning with a different cleaning pattern (irobot [H], 2014). FIGURE BRAAVA 380 (IROBOT [G], 2014). 4. MARKET RESEARCH 27

35 Overview of Technical Details The table below presents the technical details of the competing products Braava 380, Scooba 390, Scooba 450 and Hybrid Robot Vacuum Cleaner MR6800M. Technical Details Braava 380 Scooba 390 Scooba 450 Hybrid RVC MR6800M Manufacturer irobot irobot irobot Moneual Automatic Charging No No No Yes Bin Capacity [l] No dust bin No dust bin No dust bin 0.6 Charging Time [h] 4 3 n/a 1-2 Cleaning Area [m²] Dry: 92, Damp: / Climb Obstacles [mm] Avoids carpets Avoids carpets Avoids carpets n/a Dimensions (WxDxH) [mm] 216x216x79 374x374x90 365x365x92 350x350x86 Dirt Detection No No No No Full Bin Indicator - Empty Tank n/a No HEPA-Filters - No No Yes Noise Level [db] "Whisper Quiet" n/a n/a 60 Price [ ] Run Time [min] Dry: 240 Damp: (+ Docking: 79) /40 cycles 399 Dry: Wet: 50 Scheduled Cleaning No No No No Side Brushes No No No 2 Suction Power [W] - n/a n/a n/a UV Lamp No No No No Weight [kg] Other Water tank: 1000 ml 600 rpm scrubbing brush TABLE AN OVERVIEW OF THE COMPETING PRODUCTS' TECHNICAL DETAILS. Water Tank: 180 ml 28 WET AND DRY ROBOTIC VACUUM CLEANER

36 4.2 Identifying Customer Needs This section of the market research demonstrates the acquired result of what the customer needs and requires. The main data collection tool was secondary research and it aimed to collect information from written reviews, blogs and user forums, where the customers express their needs. The obtained result includes the mapped The Use System, findings from interviews, observations and reviews, and the outcome from relevant articles The Use System The model aided to create an understanding for the entire use system and to map what factors impact the product that is to be developed (See Figure 4.8). The product in this model is presented as a question mark since this is what has to be developed. The task of the wanted product is to achieve an automated cleaning system that vacuums and mops the floor with no human intervention during the cleaning process. The customer and environment is FIGURE THE USE SYSTEM OF THE PROSPECTED PRODUCT. described and presented in the sections below. Customer Description The customer of this product is the person who makes the purchases for an entire household, while the users are the entire household. This means that the end-user could practically be anyone. However, the maturity of this product is still in the phase of the innovators and the early-adopters, which according to Rogers (2003) corresponds to around 16% of the population (See Section 2.1.1). In order to penetrate the market with this product it is important to intrigue these customers to purchase. It is these adoption categories that will spread the word-of-mouth to the rest of the population by writing reviews or talking to friends and family. Rogers (2003) states the importance of determining the target market of products, because it will be the innovators and early adopters that will influence the adoption of others. Therefore, the development of this product requires a user-centred approach. 4. MARKET RESEARCH 29

37 Sung et al. (2008) conducted a study to map the user profile of robotic vacuum owners. 379 Roomba owners were observed and their demographics and usage trends were identified. The main users were people between that had a higher education and technical knowledge. Users were, surprisingly, equally likely to be men and women. Additionally, households with children or pets expressed a greater satisfaction. More than the majority of the users also lived with another person, which indicates that the household composition also has an influence in acquiring a robotic vacuum cleaner. The reason could be that the common household chores should be made easier and the fact that more money can be spend on these products. Currently, target market is the German household. Facts and figures about the average household were gathered from Statistisches Bundesamt, the Federal Statistical Office of Germany. The majority of the households are oneperson or two-person households (See Figure 4.8) (Statistisches Bundesamt [A], 2014). Therefore the advantages of using this product must be brought forward to this customer group. In 2012 the gross income of a one-person household was and in a two-person household (Statistisches FIGURE GERMAN HOUSEHOLDS BY SIZE. (STATISTISCHES BUNDESAMT [B], 2014) Bundesamt [C], 2014) so the pricing of the product should take the average household incomes and expenditures into account in order to reach the market. Environment Description The environment varies widely in between households and the goal is that this domestic robot should be applicable for all households. The environment that the product is will be used in is a mixture of hard floor and carpeted floors. Here, the robot should be able to move freely without the user needing to interact. In Germany, the average living space per dwelling was in 2012; 90.6 m 2 and the rooms per dwelling was 4.4 (Statistisches Bundesamt [D], 2014). An average room size would then correspond to around 20 m 2, which could be seen as a guideline for the minimal cleaning area. Furthermore, this states the importance of the robot s ability to move from room to room. 30 WET AND DRY ROBOTIC VACUUM CLEANER

38 4.2.2 Interviews The performed interviews were conducted with six interview persons between the ages of 22 and 31. The sample consisted of one woman and five men and four of them had at some time previously operated a vacuum cleaning robot. Questions regarding how they would utilise this type of product were asked, and the mean usage of the vacuum cleaning function would be every two days and for the mopping function it would be once a week. Their average expected cleaning area was approximately 60 m 2 and the cleaning cycle should not require more than one hour or one charge (the run time of a full battery), so the robot not has to charge in the middle of the cleaning cycle. They expected to clean manually around once a month with this product and the maintenance should not exceed 3,5 min/day or 25 min/week. All the interviewees shared the same opinion that they did not want to have two robots, one for vacuum cleaning and one for mopping, and that they wanted the robot to only carry reusable parts, since using disposable parts is time consuming and they are troublesome to purchase. The interviews gave an interpretation of how the product would be used and what would be expected of it. The table below shows a quick overview and summarises their answers. Questions IP1 M27 IP2 M22 IP3 F27 IP4 M22 IP5 M31 IP6 M24 Used a Robot Vacuum Cleaner Before? Dry Function [times/week] Wet Function [times/week] Cleaning Area [m 2 ] Cleaning Time [hours] Charging Time [hours] How often can you expect to clean yourself? [times/month] Maintenance [min/day] Yes Yes Yes No No Yes Max 8 1 Does not matter One charge One charge Does not matter One charge Does not matter ,5 TABLE SUMMARY OF THE INTERVIEWEES' ANSWERS. 4. MARKET RESEARCH 31

39 4.2.3 Customer Reviews The Scooba 390 model is often negatively discussed and there are several complaints about this product, e.g. that the floor is excessively wet when using it, that it leaves track marks or that it leaves puddles when it is stuck. All of these customer needs have been inserted in the requirement specification, so these problems can be addressed. Since the quality of the Scooba is poor it is often stated that the Braava is preferred instead. The Scooba 450 and the Moneual Hybrid were recently launched and thus no information was available at the time of this research. However, it would be of interest to investigate this matter for future development. Customer statements have been collected from online reviews, forums and blogs regarding: General Use, Cleaning Efficiency, Battery, Maintenance and Appearance. This collection is presented in the Customer Statement List, which can be found in Appendix IV. All the statements were interpreted and the interpretations are being presented in the same Appendix as the Need Statement List Findings in Published Articles The secondary research acquired four articles that are of relevance to the development of this product. Three of them were published in International Journal of Social Robots and one was a proceeding from an international conference. The significant information is presented beneath and the identified customer needs were included in the requirement specification. Domestic Robot Ecology (Sung, 2010) An Initial Framework to Unpack Long-Term Acceptance of Robots at Home This article covers a 6-month study that observed the use of different Roomba models (irobot) in 30 households in the US. The study resulted in a framework called Domestic Robot Ecology and represents the holistic view on the long-term interaction with robots. It also demonstrates that the interaction pattern changes over time and that this can be a useful tool when designing for long-term acceptance. The study reveals four steps that householders experience while accepting a robot in their homes and how the interaction differs in each step: Pre-adoption, adoption, adaption and use (Sung, 2010). In order to design a robot from a human-machine-interaction perspective it is important to consider that the robot meets the users needs during all these stages. A few of the given design guidelines in the article are the following: 32 WET AND DRY ROBOTIC VACUUM CLEANER

40 ! Define environmental context, user profiles, task characteristics and interaction scenarios. This enables, as The Use System, to achieve a greater understanding.! Articulate a detailed list that covers all the obstacles the robot can encounter so the robot can operate autonomously and independently.! Implement entertainment value and the ability for the robot to express motions or have speech recognition, since the domestic robots are not only seen as utilitarian tools but also as social agents.! Implement the ability to map the entire house so the user can select if the entire house needs to be cleaned or only a certain room or area. The users showed a routine of rotating the cleaning areas and this could be implemented autonomously.! Design the robots exterior in a manner so it can be customised by the user or for it to blend into the environment, since this is an appliance that is will be placed in visible places of the home. The users sought a place for the robot that was less obtrusive but still visible enough to remind them of it (Sung, 2010). Living with a Vacuum Cleaning Robot (Fink, 2013) A 6-month Ethnographic Study This study was carried out in nine households in Switzerland and it was also observed with the 500 series Roomba. The conclusions drawn about achieving acceptance of the domestic robots relevant for this project are the following (Fink, 2013):! People are curious to try out a robot in their homes.! Cleaning strategies are deeply rooted habits, which mean that some people are not compatible with this type of domestic appliance. This implies the importance of defining the target market.! The robot does not replace the regular vacuum cleaner (yet).! Attitudes and beliefs are more important than the environmental context and thus, main priority for the robot is that it must be practical in the eye of the user. Robot Vacuum Cleaner Personality and Behaviour (Hendricks, 2011) This article reports how users experience the behaviour of robot vacuum cleaners and what they want to experience from this type of cleaning appliance. The investigation shows that people have a tendency to anthropomorphise the robotic vacuum cleaners and thus, the robots are given personal characteristics and are often referred to as a gender. Sung (2012) also identified this because almost half of the households even gave the robot a name. The owners that create a bond to their vacuuming cleaner are also more likely to express higher customer satisfaction (Sung, 2008). 4. MARKET RESEARCH 33

41 Furthermore, the desired personality that resulted from this study was for the robot to be calm, withdrawn and to like routines while it also should be friendly, systematic and efficient. The authors mean that designers can exploit the desire users have of certain behaviours and therefore to apply a personality model is recommended as a development tool. Hendriks (2010) additionally articulates that designing the personality will be beneficial to enhance the user experience since it helps to form an impression of the robot. This implies that it will also impact the perceived usefulness, thus the customer satisfaction. Housewives or Technophiles?: Understanding Domestic Robot Owners (Sung, 2008) This publication states the main reasons for purchasing a domestic robot. Since there still is some uncertainty in this type of product it is clearly shown that the main reason is through experience (Sung, 2008). This shows that Vorwerk most definitely should utilise their direct sales channel in order to reach the market with this new technology. Purchase Motivation for First Roomba (N=379) Responses Through my or other s experience (demonstrated, recommended, gifted) 188 Interested in new technology 173 Hate vacuuming 171 Curiosity 152 Always wanted to own robots (childhood dream) 79 Overwhelming amount of cleaning. Need assistance 63 To workaround physical difficulties 44 TABLE MOTIVATION FOR FIRST ROOMBA OWNERSHIP (SUNG, 2008). 34 WET AND DRY ROBOTIC VACUUM CLEANER

42 5. REQUIREMENT SPECIFICATION This chapter holds the established requirement specification. This is a target specification, due to the fact that the development process is in the early stages. It regards requirements such as safety issues, cleaning result, maintenance and how the robot is required to operate. The market research identified and gathered all customer needs and requirements for the product that is to be developed. The target specification works as a recommendation and a foundation for the entire development process. This specification represents what should be aimed for, since what constrains the product technology will be encountered later on in the process (Ulrich, 2012). Further in the development process the final specification can be established and will require certain trade-offs to be made. The marginal values that are given represent what least is expected of the wanted product and is based on what already is offered on the market. Some values have not yet been defined, since they do not lie within the scope of this project. However, they can be seen as reminders to consider these aspects later. The aim of this project has been to assure the cleaning procedure and therefore the concept development has mainly focused on and used the critical requirements regarding the cleaning procedure. The requirements were allocated into different categories in order to recognise what type of requirement it is and also to distinguish what type of resource it requires. The requirements were grouped in the previously explained categories (See Section 3.2.3): Functional requirements/constraining requirements and Demands/Wishes. An additional grouping has been carried out to illustrate where the innovative effort must be localised. The accomplished grouping was implemented according to the KANO-model (See Section 2.2) with must-be, onedimensional, attractive requirements. The categories abbreviations are denoted below:! FR: Functional requirements! C: Constraining requirements! D: Demands! W: Wishes (Imp: Importance level 1-5)! M: Must-be requirements! O: One-dimensional requirements! A: Attractive requirements 5. REQUIREMENT SPECIFICATION 35

43 FR/C D/W IMP. M/O/A Requirements 1. Geometry Marginal Values and Metrics C D - M Depth 315 ± 30 [mm] C D - M Does not have a shape that easily is stuck under furniture, like a wedge shape C D - M Height 100 [mm] C D - M Width 330 ± 40 [mm] - 2. Kinematics C D - M Dry cleaning velocity? [m/s] C D - M Wet cleaning velocity? [m/s] 3. Forces C D - M Weight 5000 ± 3000 [g] 4. Energy C D - M Working temperature? [ C] 5. Material C D - M Exterior material that not leaves marks when encountering obstacles - C D - M Scrubbing material that enables easy rinsing - C D - M Wheel material that is able to drive on a wet floor without loosing grip - 6. Signals FR D - O Informs the user when in need of emptying - FR D - O Informs the user when in need of water refill - FR W 5 A Informs the user when in need of maintenance - 7. Safety FR D - M Does not affect the floor after a cleaning cycle, when in standby - FR D - M Does not leak - FR D - M Does not leave marks on furniture or walls after cleaning - FR D - M Does not require monitoring by user - FR D - M Does not scratch the floor or leave marks - FR D - M Keeps the electronics isolated from water - FR D - M Recognises heights and avoids them - FR D - M Recognises if it is stuck and stops cleaning - FR D - M Recognises if operating on a carpet and immediately stops wet cleaning - FR W 5 M Recognises when cables, wires or curtains tangle and detangles them - FR W 2 M Recognises if it suctions metal and informs the user - 8. Cleaning Result FR D - O Allows dry and wet cleaning along edges, as close as 10 ± 5 [mm] FR D - O Allows dry and wet cleaning of corners, with the angle FR D - O Cleans floor seams in floors, with the depth 5 ± 2 [mm] FR D - O Does not drop dust in changes in height, e.g. when it drives down from a carpet FR D - M Does not leave streak marks after wet cleaning - FR D - O Does not leave water in floor seams WET AND DRY ROBOTIC VACUUM CLEANER

44 FR D - M Does not require pre-treatment of floor - FR D - M Dries the floor sufficient enough Subjective FR D - O Handles dried in stains - C D - O Has the equivalent or better suction power than the VR100 [W] FR D - O Meets HEPA-standard - C D - O Obtains a sufficient cleaning result Subjective FR D - O Removes debris before wet cleaning - FR D - O Removes pet hair sufficiently - FR D - O When wet cleaning, the floor dries in 10 [min] FR W 5 A Reaches all possible cleaning areas - FR W 4 O Removes allergens - FR W 4 O Removes bacteria (disinfects) - 9. Operation FR D - M Allows cleaning of all types of floors including carpets, entire indoor area - FR D - O Allows navigation in rooms absent of light - FR D - O Is able to climb thresholds and carpets with a minimum height of 15 mm FR D - O Is resistant to ware - C D - A Is usable with any type of detergent - C D - O One tank of water enables a wet cleaning area of 30 ± 10 [m 2 ] C D - O Operation sound level 70 db FR D - M Provides an even water distribution when wet cleaning - FR D - A Recognises obstacles before bumping into them - FR D - M Requires minimal adjustments of the home - FR D - A Returns to its docking station after finishing a cleaning cycle - FR W 5 A Is able to release itself if it is stuck - FR W 4 A Recognises dirtier areas and cleans them more extensively - FR W 1 A Detects dirty areas from a distance - FR W 1 A Remembers the cleaning path from previously cleaned rooms - FR D - A 10. Battery Automatic resume of where it was cleaning, if cleaning cycle was not finished FR D - O Automatic charging - C D - O Dry cleaning area in one charge, carpeted floor 50 [m²] C D - O Dry cleaning area in one charge, non carpeted floor 60 [m²] C D - O Recharges the battery in 3 [h] C D - O Run time 100 [min] C D - O Wet & dry cleaning area in one charge, non carpeted floor 20 [m²] Features FR D - O Allows scheduled cleaning for both wet and dry cleaning - FR D - M Allows software updates when new software is released - FR D - O Spot cleaning Capacity FR D - M Everyday use - C D - O Has a dust bin capacity of 0.6 [litres] C D - O Water tank, corresponding to the desired cleaning area 300 [ml] 5. REQUIREMENT SPECIFICATION 37

45 13. Maintenance FR D - M Allows easy replacement of worn parts - FR D - M Easy to assemble and disassemble - FR D - M Easy to empty - FR D - M Easy to recognise parts that needs maintenance - FR D - M Easy to refill - FR D - M Easy to remove tangled hair from parts - FR D - M Easy to set up for start - FR D - M No hairs are tangled in the wheels - FR D - M Releases the minimum amount of dust back into the air when emptying - C D - M Time for maintenance 3.5 min/day 14. Recycling C D - M Has a lifetime of 3 years 15. Costs C D - M Affordable - C D - M Affordable replacement parts - C D - M Free software updates Appearance C W 5 A Is discrete and blends into its environment Subjective C W 5 A The appearance is suited so the user can have it out all the time Subjective C W 2 A Is possible to customise Subjective 17. Behaviour C W 5 A Enhance perceived intelligence of robot - C W 5 A Portrays trustworthiness and calmness - C W 5 A Utilises a structured cleaning pattern Ergonomics C D - M Enables a comfortable grip when moving Docking station C D - M Does not require a large space - C D - O Long enough cord for the charging base User Interaction C D - A Has an intuitive user interface and is easy to program - C D - M Minimal human intervention - FR W 3 A Speech recognition - TABLE TARGET SPECIFICATION. 38 WET AND DRY ROBOTIC VACUUM CLEANER

46 6. CONCEPT GENERATION This chapter includes a function analysis to reach a deeper understanding of the problem. It also presents an external search, a patent search and an internal search, which aided in generating ideas and conceptual solutions. The general ideas are being presented in this chapter, and the conceptual solutions can be found in the upcoming chapter (See Section 7.4). 6.1 Establishing Function Structures The concept generation stage was initiated by performing a function analysis in order to grasp the core of the problem through mapping a function diagram and a Function-Means Model. The first step was to utilise an abstraction procedure so the crux of the task could be identified. It resulted in the following problem formulation to be defined and it enabled the essential problem to be observed and attacked in a solution neutral manner: Design an automated cleaning system that removes dirt and debris from the floor and cleans the floor with clean water. While doing this, the solution is required to obtain a sufficient cleaning result Function Diagram The product to be developed requires a transforming function, which converts the floor from a dirty to a clean state. The process to achieve this state and properly clean a floor can be broken down into a sequence of steps. Figure 6.1 illustrates this procedure and it is this course of action the prospected product is intending to apply. Firstly, the large particles and debris must be removed and then tougher dust and dirt, such as stubborn stains, must be separated from the floor. The separation can be carried out with different means but the substantial element to be used for this procedure is water, as for regular mopping. All the dust, dirt and debris are then transported into a container, which later can be emptied. When the procedure is completed a clean floor state will be reached. 6. CONCEPT GENERATION 39

47 FIGURE FUNCTION DIAGRAM. THE FUNCTIONS THAT TRANSFORM THE FLOOR FROM A DIRTY TO A CLEAN STATE Function-Means Model The Function-Means Model was applied to be able to divide the main problem into smaller and more manageable categories. The first functional requirement (FR) of this hierarchical topdown structure is clean floor and its design parameter (DP) is an automated wet and dry cleaning robot. The next level of the model corresponds to the functions in the previously obtained function structure (See Figure 6.2). The design parameter of separating the dust and dirt from the floor is required to utilise a wet cleaning mechanism due to the designated purpose of this project. The mechanism has been fragmented into supplementary functional requirements in order to simplify the development process. This overview gives Vorwerk an insight in where and how the resources can be allocated and divided in the upcoming development processes. In pursuance of this project, the model assisted in performing the idea generation phase and various solutions for each functional requirement were sought. Due to the fact that the wet cleaning mechanism requires most innovative work at Vorwerk, most effort was also concentrated on solving this task. 40 WET AND DRY ROBOTIC VACUUM CLEANER

48 FIGURE FUNCTION-MEANS MODEL. FR: FUNCTIONAL REQUIREMENT, DP: DESIGN PARAMETER. 6. CONCEPT GENERATION 41

49 6.2 Searching Externally The aim of the external search was to find already existing concepts and investigate related products for inspiration. Upright wet and dry cleaners floor scrubbers were explored in order to find functions from these products that could be possible to implement. Vacuum cleaning robots investigated during the market research and the material can be found in the Product Comparison Chart (See Appendix II). The significant material is presented below. Furthermore, a patent search was also carried out at this stage to collect additional information Wet and Dry Vacuum Cleaners The system for the wet and dry vacuum cleaners is operated with one fan generating the suction. The intake port suctions both water and dirt simultaneously. When the air stream reaches the bucket, the area is wider, thus the air speed slows down and particles and water fall down into the bucket (See Figure 6.3) (Harris, 2014). This method could be implemented for the future product, but it might require a more powerful motor than the VR100. Therefore it must be investigated if this solution is FIGURE WET AND DRY VACUUM CLEANER (HOWSTUFFWORKS, 2006). implementable in a robotic cleaner Floor Scrubbers Floor scrubbers utilise a method that could be required for the prospected product, but in a significantly larger scale (See Figure 6.4). Inspirations from this product can be collected if a function similar to this is to be designed. It has been recognised that several scrubbers of this type carry a curved water suction nozzle, which could be implemented. Moreover, the water usage was investigated for a few products to obtain a comprehension of how much water is required to clean a certain area. FIGURE FLOOR SCRUBBER FROM TENNANT (TENNANT, 2014). 42 WET AND DRY ROBOTIC VACUUM CLEANER

50 These products are mainly used for industrial purposes and therefore it can be assumed that they will be operated in tougher environments, thus also require larger amounts of water. The scrubbers clean approximately m 2 with one litre of water. If the assumption is made that an indoor environment would need less amounts of water, hopefully the same area could be cleaned with around ml. The compared products are presented in Appendix VII Patent Search A patent search was acquired through the databases United States Patent and Trademark Office (USPTO), the European Patent Office (EPO), and the World Intellectual Property Organization (WIPO). A general search was performed to discover patents for automated wet cleaning robots and an investigation of the main competitors was also carried out. The general search resulted in finding several different patents in this field. However, a large amount of them were only filed in China (Guangxi University, 2012; Kunshan Industrial Technology Research Institute Co., Ltd., 2012) and Korea (Kim, 2012), which is a beneficial aspect for Vorwerk. The competitor LG has filed a Korean patent for a Cleaning robot capable of wet cleaning in 2002 (LG Electronics Inc., 2004) and one patent for a robotic steam cleaner (LG Electronics Inc., 2008). Four patents from Samsung were found considering wet cleaning robots and the earliest one was filed in 2003 in the US (See Figure 6.5) (Samsung Gwangju Electronics Co., Ltd. [A], 2005; Samsung Gwangju Electronics Co., Ltd. [B], 2005; Samsung Gwangju Electronics Co., Ltd. [C], 2005; Samsung Gwangju Electronics Co., Ltd., 2008). One of the patents affirms that the product is supposed to recognise carpets when wet cleaning, to prevent damaging (Samsung Gwangju Electronics Co., Ltd., 2008). This ascertains that the competitors LG and Samsung are also investigating solutions for wet cleaning robots. FIGURE ILLUSTRATION FROM SAMSUNG PATENT (SAMSUNG GWANJU ELECTRONICS CO., LTD. [A], 2005). irobot has a large number of patents concerning their robots. Autonomous surface cleaning robot for wet and dry cleaning is the patent for the Scooba 390 (irobot Corporation, 2006). The patent claims the robot s cleaning procedure and it was filed the 21 st of February It is an international application and it was granted by the European Patent Office the 19 th of May 2010, thus also including Germany. It is recommended that a wider search should be carried out regarding the patents of this corporation, due to the large amounts they are holding. 6. CONCEPT GENERATION 43

51 Kärcher has one patent for their cleaning robot (Alfred Kärcher GmbH & Co. Kg, 2006) and fortunately no patent for a wet cleaning device was found in this research. Moneual declares that they hold a patent for a detachable mop-cleaning device (Moneual EU [D], 2014). In the research this patent was not found in the databases mentioned previously, but the Korea Intellectual Property Rights Information Service (KIPRIS) database presents a patent named Robot vacuum cleaner have a rag mounting structure (Moneual Inc., 2011). This patent has only been found as a Korean patent. A depiction from it is showed in Figure 6.6. The invention relates to the robot having a mopping structure and that the robot recognises whether it is attached or not. It can be assumed that this feature is implemented due to the need of changing the driving strategy according to the cleaning mode. The search discovered no claims regarding the newly released Moneual Hybrid (MR6800M), which FIGURE 6.6 ILLUSTRATION FROM carries an attachable water tank. MONEUAL PATENT (MONEUAL INC., 2011). The patent research does reveal important information, but since this development process still is in the early stages the results will not constrain the idea generation. This is because patents will expire or ways around them can be recognised. Thus, patent issues should be addressed further on in the development process. 44 WET AND DRY ROBOTIC VACUUM CLEANER

52 6.3 Searching Internally The collective brainstorming session that was held were with mechanical- and electrical engineering interns and it led to the generation of several different ideas. The session regarded all ideas that would be of use for this type of product, so the topic was discussed freely in a group. Several thoughts and ideas were formed during this session, but also questions that had not been concerned arouse. Figure 6.7 denotes some of them. The generated ideas were after the session noted and illustrated (See Figure 6.8) Should the user have the option of only choosing wet cleaning?" Should it clean carpets during wet cleaning cycles?" What driving strategy should be implemented?" Automated Wet & Dry Cleaning" How to reach the edges and corners with both wet and dry cleaning parts?" What cleaning procedure should it utilise?" Is suctioning the dirty water a requirement?" FIGURE QUESTIONS THAT AROSE DURING THE BRAINSTORMING SESSION. FIGURE A FEW SKETCHES OF THE GENERATED IDEAS. 6. CONCEPT GENERATION 45

53 6.4 Combining Working Principles The internal and external research resulted in numerous different ideas and conceptual solutions. In order to enable a structural arrangement the ideas were collected in a Morphological Matrix. One matrix was created for the dry cleaning mechanism and one for the wet cleaning mechanism. Remaining ideas did not suit any of the matrices, and therefore they were collected in a table for general ideas, which is presented below General Ideas # Name Depiction Description 1 Systematic Cleaning The cleaning mechanism will work in one sweep. Firstly, dry cleaning and then wet cleaning. The wet cleaning will be located after the wheels to avoid track marks. 2 Upright Handle This idea suggests that a handle is stored at the base station and if the user wants to utilise the cleaning equipment manually, they have the ability to. 3 Exchangeable Units The robot is able to change the front unit from a dry cleaning unit to a wet cleaning unit. An automatic change will then be carried out at the docking station. 4 Attachable Wet Cleaning Unit The users will, in most cases, use the wet cleaning function less frequently than the vacuum cleaning function. In order to meet this usage requirement a possible solution is to attach a wet cleaning unit when this feature is desired. 5 One Suction Channel One brush roller for dry cleaning and one microfiber roller for wet cleaning and the debris and dirty water is suctioned through the same channel and collected in one container. 46 WET AND DRY ROBOTIC VACUUM CLEANER

54 6 Dust to Water - This proposes that the dustbin is changed at the docking station in docking station to water tank. 7 Docking Station Furniture - The docking station is a piece of furniture and covers the robot when not in use. Thus the station will not only be a charging station, but also provide the user with an additional function. Nevertheless, it will be a decoration. 8 Reuse Water - Filter the applied water from dirt so the cleaner can use it again. 9 Phone Application - Remote control, starting when the user is not at home if forgotten TABLE GENERAL IDEAS 6. CONCEPT GENERATION 47

55 6.4.2 Morphological Matrices The functional requirements that were utilised in the morphological matrices corresponded to the lowest level of the hierarchical structure in the Function-Means Model. In order to minimise the number of combinations one matrix was created for each cleaning mechanism. The tables represent the matrices subproblems and the number of generated solutions: # Subproblems Dry Cleaning Matrix Number of solutions D1 Collect debris 6 D2 Lift debris 6 D3 Transport the dust, dirt and debris 2 D4 Contain dust, dirt and debris 5 D5 Empty contained dust, dirt and debris 2 Number of Combinations: 720 TABLE NUMBER OF SOLUTIONS FOR EVERY SUBPROBLEM IN THE DRY CLEANING MATRIX. # Subproblems Wet Cleaning Matrix Number of solutions W1 Contain water 6 W2 Apply water 5 W3 Apply pressure (Cleaning tool, Water Suction) W4 Use cleaning motion 5 W5 Clean with applied water 10 W6 Remove dirty water from floor 4 W7 Dry floor 4 Number of Combinations: TABLE NUMBER OF SOLUTIONS FOR EVERY SUBPROBLEM IN THE WET CLEANING MATRIX. Of course all solution fragments collected in the morphological matrices are not possible to combine, some solutions might not be possible to implement and others might not meet the requirement specification. Therefore, the evaluation and selection process was necessary to conduct. The complete matrices are presented in Appendix VIII and the reduced versions will follow in the next chapter. It is important to state that all subproblems are not to be solved within the scope of this project, but the subproblems that concern the cleaning procedure WET AND DRY ROBOTIC VACUUM CLEANER

56 7. CONCEPT EVALUATION AND SELECTION This chapter is initiated with the determination of the robot s cleaning strategy followed by an explanation of the conceptual solutions. Afterwards the results from the concept screening and scoring procedures are denoted. Conclusively, the selected concept is presented. The morphological matrix that concluded the previous step of the development process presented the categorised subproblems. In an evaluation process it is the overall product concepts that are to be assessed and thus the subsolutions were combined into total solutions. Different concepts require different cleaning motions, cleaning modes and driving patterns. Ultimately, the cleaning strategy decides the entire product solution. In order to be able to determine which concept that would meet the target specification in the most optimum way, the first issue to be evaluated was the cleaning strategy. 7.1 Determining the Cleaning Strategy When the VR100 is turned on the laser scanner first scans the room, then it maps up a square area and afterwards it methodically works within this square. A wet cleaning robot would require accomplishing the equivalent thing while carrying out two cleaning procedures: the particle suction (dry) and the mopping (wet). The requirement is that the robot must use water to clean the hard floors. Consequently, this means that three types of strategies can be considered when operating a wet and dry cleaning robot: Wet Cleaning, Dry and then Wet Cleaning and Dry and Wet Cleaning. The three strategies are explained more closely below Wet Cleaning The first strategy requires a robot that solely bares the task of wet mopping the floor, which means that no particle suction would be performed by this robot. The robot would only work on hardfloor surfaces and would be able to acquire information regarding the driving pattern from Vorwerk s vacuum cleaning robot, if this was operated previously. FIGURE WET CLEANING STRATEGY. 7. CONCEPT EVALUATION AND SELECTION 49

57 7.1.2 Dry and then Wet Cleaning A robot that follows the second strategy would first perform one cycle of dry particle suction and later follow the same route and perform the wet mopping. In the wet cleaning cycle the robot would avoid carpeted areas and this cleaning path would be recognised and remembered by the previous driving cycle Dry and Wet Cleaning The third one-stroke strategy would imply that both cleaning procedures FIGURE DRY AND THEN WET CLEANING STRATEGY. are achieved in one motion and when the robot passes a certain part of the floor it would be both vacuumed and mopped. This strategy would either climb carpets and turn off the wet cleaning mechanism or not climb carpets at all. If it is to climb carpets it could be implemented that the carpet cleaning is carried out first and then the hard floor cleaning Evaluation The evaluation of the strategies was accomplished by assessing the FIGURE DRY AND WET CLEANING STRATEGY. advantages and the disadvantages of them. The reasoning and the arguments are explained in the table below. # Advantages Disadvantages 1! Is able to carry a larger water tank, thus wet clean larger areas.! The cleaning result does not require to be compromised, in order to fit parts for the dry cleaning.! Demands the user to clean before usage.! Might scratch the floor if large particles are not removed.! Implies that two robots are required, if dry cleaning is wanted. 2! Is able to empty the dustbin or have a water refill from the docking station.! The robot s wet cleaning pattern can be preplanned.! The cleaning time is longer than the other strategies.! The user might disturb the dry cleaning cycle and this could result in new debris on the floor. 3! Ensures removal of big particles before wet cleaning and thus protects the floor from being damaged.! The cleaning result can be seen immediately.! The cleaning time of an area is shorter than the second strategy.! The robot must change between dry & wet cleaning mode and dry cleaning mode where there are carpets. This might lead to accidentally soaking the carpets.! The tank size must be compromised. TABLE ADVANTAGES AND DISADVANTAGES OF THE DIFFERENT CLEANING STRATEGIES: (1) WET CLEANING, (2) DRY AND THEN WET CLEANING, (3) DRY AND WET CLEANING. 50 WET AND DRY ROBOTIC VACUUM CLEANER

58 The cleaning strategies were further evaluated with an evaluation matrix according to different parameters, which is presented in Table points were distributed in between the parameters and the ones with higher importance were issued more points, thus representing their weight factors. Parameters Weight Factor Rating Strategy 1 Strategy 2 Strategy 3 Weighted Score Rating Weighted Score Rating Weighted Score Cleaning Result Cleaning Time Ease of Use Easy Maintenance Floor Damaging Protection Meets the Requirements Simplicity Size of the Product Solves the Main Problem Rank TABLE EVALUATION MATRIX FOR CLEANING STRATEGY. The strategy was then given a rating in how well a parameter was fulfilled. For instance, the strategies cleaning result was given a rating between 0-14 and cleaning time between 0-6. The ratings were multiplied with the weight factor, which resulted in the weighted score. The scores were finally added and the strategy with the highest score was the strategy to be chosen. This method was applied to be able to take the importance level of the parameters into account and also to view the strategies in an objective manner. The outcome of the evaluation of the cleaning strategies consequently was the selection of the third strategy. It is believed that this decision is the best approach for a wet and dry cleaning robot; essentially because it will at all times ensure the removal of large particles. Protecting the floor from damaging is a fundamental user expectation and must be provided. When implementing this strategy, it will also provide the user with direct feedback regarding the cleaning result; hence they can assess the usefulness of the product immediately. This shapes the attitude toward using the product and in the end determines if the product will be used or not. 7. CONCEPT EVALUATION AND SELECTION 51

59 7.2 Morphological Matrix The decision of the cleaning strategy allowed the morphological matrix to be reduced. Solutions were also excluded if they were implausible or did not meeting the requirement specification. The goal of this project was to determine the cleaning strategy while obtaining a proper cleaning result. Therefore, the subfunctions that did not concern this were excluded from the matrix and to be decided later on in the process, when the cleaning procedure was decided. An example is that the cleaning motion is decided by the cleaning tool s shape, which means that the motion cannot be selected until the tool is determined. The reduced matrices are presented in the following sections and the complete matrix can be found in Appendix VIII Dry Cleaning Matrix The subfunctions that remained in the dry cleaning matrix were the first two: Collect debris and Lift debris. When removing the improbable solutions the reduced matrix could be combined into five different conceptual solutions, which are presented in Table 7.3. Solutions # Subfunctions A B C D1 Collect debris D2 Lift debris Rotating brush One small suction channel TABLE DRY CLEANING MATRIX. Scraper One large wide suction channel Only a rotating brush to lift the debris to a compartment, so no suction is used Wet Cleaning Matrix Three subfunctions were excluded from the wet cleaning matrix and thus it contained: Apply water, Clean with applied water, Remove dirty water from floor and Dry floor (See Table 7.4). The reduced wet cleaning matrix contained 42 possible combinations. 52 WET AND DRY ROBOTIC VACUUM CLEANER

60 Solutions # Subfunctions A B C D E F W2 Apply water Apply on floor Apply on cleaning tool Apply in cleaning tool W5 Clean with applied water Microfiber Roller Rotating brush Two counterrotating brushes Microfiber pad W6 Remove dirty water from floor Suction and squeegee No removal Rotating cloth Like SP530 (Vorwerk Kobold [D], 2014) W7 Dry floor Use the outlet air No drying TABLE WET CLEANING MATRIX. 7. CONCEPT EVALUATION AND SELECTION 53

61 7.3 Concept Elimination The possible combinations were evaluated in two elimination matrices, one for each cleaning mechanism. The evaluation was performed with respect to general parameters and it helped eliminating the total solutions that did not met the following criteria:! Solves the main problem! Fulfils all the requirements! Realisable! Proper cleaning result! Suitable for the company! Maintenance! Easy to use When evaluating the concepts the difficulty of assessing the cleaning result emerged. For instance, the question if the way of applying the water influenced the cleaning result arose. Therefore, it was decided to conduct a cleaning test to gather material for the next evaluation step. The subfunctions Apply water and Dry floor were decided to be evaluated with test, hence resulting in leaving them out from this evaluation step. During the elimination process the concept with no particle suction for the dry cleaning was ruled out, due to the fact that the large particles must be removed properly. Furthermore, the rotating cloth concept was eliminated with the reasoning that the maintenance issues of this concept could be a problem. If the user neglects to change the cloth after usage the dirty cloth would be reused. Also, a used wet cloth is in risk of moulding if it is not ventilated after usage. The concept with the SP530, one of Vorwerk s current products, was also excluded. The product oscillates a pre-soaked microfiber cloth to wet clean floors. The motivation was that the oscillation could disturb the manoeuvring of the cleaning robot. After the elimination matrix was performed four concepts for the dry cleaning mechanism and eight for the wet cleaning mechanism remained. The elimination matrices can be found in Appendix IX. Along the process a new concept also emerged and thus it was also included in the evaluation. 54 WET AND DRY ROBOTIC VACUUM CLEANER

62 7.4 Conceptual Solutions The solutions from the morphological matrices were combined into entire conceptual solutions. The result was eight different concepts, which are described and depicted below The Step-by-Step This concept works its way through the desired cleaning area in five steps. Firstly, particles are suctioned, then water is applied and scrubbed with a brush, afterwards the water is suctioned and finally the floor is dried with the outlet air. The back can be detached to empty and rinse all dust, dirt and debris, which contain the dustbin and the water tank. FIGURE CONCEPT 1: THE STEP-BY-STEP The Scrubber This solution suctions the large particles and debris off the ground. Then is utilises two circular brushes to separate the dirt from the floor and lastly the dirty water is suctioned. FIGURE CONCEPT 2: THE SCRUBBER. 7. CONCEPT EVALUATION AND SELECTION 55

63 7.4.3 The Fishtail This concept is based on the rear side of the cleaning robot being flexible. The tail suctions particles, scrubs the floor and suctions the dirty water. The flexibility is to provide better corner and edge cleaning. FIGURE CONCEPT 3: THE FISHTAIL The Buffer This solution carries a rotating circular microfiber pad that mops the floor. It also holds a particle suction channel as well as a water suction channel. Conclusively, it dries the floor with the outlet air. FIGURE CONCEPT 4: THE BUFFER. 56 WET AND DRY ROBOTIC VACUUM CLEANER

64 7.4.5 The Combined Suction This cleaning robot utilises two cleaning tools: one collecting brush and one scrubbing brush. The robot also has two suction inlets: one for particles and one for water. Both inlets are later combined into one channel providing the ability to combine the containing of debris and dirty water in one tank. FIGURE CONCEPT 5: THE COMBINED SUCTION The Tank-in-Roller This conceptual solution cleans with a microfiber roller. Inside the roller there is a build in water tank, which contains both clean and dirty water. By suctioning the water and drying the floor the aim is leave the floor as dry as possible. FIGURE CONCEPT 6: THE TANK-IN-ROLLER. 7. CONCEPT EVALUATION AND SELECTION 57

65 7.4.7 The Square This conceptual solution has the dry cleaning mechanism placed in the front while the dry cleaning mechanism is placed on the robot s rear side. The wet cleaning mechanism holds a rotating scrubbing brush and a water suction nozzle The No Water Suction FIGURE CONCEPT 7: THE SQUARE. This concept differs from the rest due to the fact that it does not suction the dirty water. A damp microfiber roller is used to mop the floor and the outlet air is utilised to dry the floor. FIGURE CONCEPT 8: THE NO WATER SUCTION. 58 WET AND DRY ROBOTIC VACUUM CLEANER

66 7.5 Concept Screening The screening procedure was accomplished with findings from the performed cleaning test. Firstly, the test procedure is declared and then the attained conclusions are presented. Lastly, the concepts were compared with one reference concept in a Pugh Matrix Cleaning Test The purpose of this assessment was to compare the cleaning result of different cleaning mechanisms. The wet cleaning mechanism was the only mechanism that was tested. The motive for this was that Vorwerk already holds the knowledge of how to obtain a proper result for dry cleaning. It is the wet cleaning field that is unfamiliar and of value for Vorwerk, hence also requiring more research. The test was constructed to identify which of the remaining wet cleaning concepts from the morphological matrix offered an enhanced cleaning result. The subproblems that previously were omitted from the morphological matrix Apply water and Dry floor were also to be tested. Figure 7.13 shows pictures from the cleaning test. FIGURE PICTURES FROM THE CLEANING TEST. Before the screening process was initiated the concepts were discussed in a company meeting. During this briefing thoughts surfaced regarding cleaning procedures the concepts would implement. These questions were also evaluated with the test and the main issue was to examine how different cleaning motions or tools affect the water. It was inspected how the water scatters with the different techniques mainly the circular brushes. This is important because the product s precondition is to not damage the environment it is being operated in. Different cleaning tools were constructed and drilling machines were used to create the motion. The water suction was implemented with a window cleaner, which is shown in Figure Floor tiles were prepared with a dirt solution containing fine dust (See Figure 7.13). The Dry Floor subsolution was tested by utilising a hair dryer. FIGURE WINDOW CLEANER FROM KÄRCHER (KÄRCHER [D], 2014). 7. CONCEPT EVALUATION AND SELECTION 59

67 7.5.2 Test Results The result was assessed with what could be observed with the bare eye and if it was not obvious to see a white cloth was rubbed against the tile. The cleaning techniques were given the following valuations: Very effective, Effective, Poor and Very poor. Combinations of the subfunctions 5 and 6 Depiction and Description Result AA Microfiber Roller + Suction Very effective AB Microfiber Roller + No Suction Effective BA Rotating Brush + Suction Very effective BB Rotating Brush + No Suction Very poor CA Two brushes + Suction Very effective CB Two brushes + No Suction Very poor DA Microfiber Pad + Suction Very effective DB Microfiber Pad + No Suction Effective TABLE TEST RESULTS FROM CLEANING TEST. The test revealed important aspects in how to reach a proper cleaning result. When comparing microfiber-cloths and brushes both provided almost the same cleanliness, but the brushes loosened tougher dirt more efficiently. Therefore, floor seams and grout lines will be reached better when utilising brushes. It was also realised that using a scrubbing brush cannot be used without implementing water suction. The reason is that brushes are not able to contain dirt, while microfiber cloths are. However, the cloths will reach a limit were no more dirt can be contained. The SP530 operates a cloth with a size of 31x16 cm and with this it is able to clean an area around 20 m 2. Implying that if a larger area is to be cleaned, a larger cloth will be required. Regarding maintenance matters the user must wash a microfiber cloth before reusing it, while a brush can be quickly rinsed under tap water. If the user has forgotten to wash the cloth before using it a hinder might emerge for operating the wet cleaning function at all. Therefore, it is believed that the proper cleaning tool for this product is a tool that does not contain dirt. 60 WET AND DRY ROBOTIC VACUUM CLEANER

68 The focus of this project was to achieve a sufficient cleaning result, so when deciding to utilise a brush it meant that it had to be combined with water suction. Additionally, the cleaning result was always enhanced when using the suction. With this reasoning it was decided that a brush combined with suction would be used. It was recognised that the circular brushes are easier to rinse from tangled hair than the cylindrical brushes. Regarding the scattering of water it was seen that the circular brushes do not spread the water while the cylindrical brushes spreads the water as seen in Figure However, the cylindrical brush will attain a cleaning width with one tool while several circular brushes must be used to cover the same width (See Figure 7.15). This results in the robot carrying more parts, which enhances the maintenance. Containing two large circular brushes FIGURE WATER SCATTERING DIRECTIRON WHEN USING A ROTATING CYLINDRICAL BRUSH. would infer them taking up more space. Concerning the water application, no evident conclusion could be drawn. Therefore, it was decided to implement the solution that was FIGURE CIRCULAR BRUSHES. suitable for the selected concept. A test must be conducted to able to determine this. When testing to dry the floor it was realised that dust and debris were blown away to areas that already have been cleaned and therefore this subsolution was excluded. Conclusion Completing the cleaning test resulted in attaining more understanding and knowledge in this area. With this the following conclusions could be drawn: # Subproblems Decision W2 Apply water Difficult to see a difference in result. The most suitable application will be implemented. W5 Clean with applied water Rotating Brush (Cylindrical) W6 Remove dirty water from floor Water suction W7 Dry floor No drying TABLE DRAWN CONCLUSIONS FOR SUBPROBLEMS. 7. CONCEPT EVALUATION AND SELECTION 61

69 7.5.3 Pugh Matrix The results from the cleaning test were presented and the evaluation was carried out with input from the company. The selection matrix reduced the number of concepts from eight to five. The Buffer was discarded because of its inability to reach corners and The Tank-in-Roller because of its maintenance issues. The No Water Suction was also excluded due to the results from test. The evaluation matrix is presented in Appendix X. 7.6 Concept Scoring When implementing a wet and dry cleaning robot the navigation must be altered to suit the cleaning mechanism. The mobility of the robot is depending on its shape; therefore different forms of the robot were also examined. In order to be able to assess these issues miniature models were created of the concepts to obtain a comprehension of the reachability of the cleaning mechanisms. Additionally, plastic plates with different shapes were attached to a remotecontrolled car to observe how the shape impacts the navigation. After the investigations the Kesselring Matrix was applied to perform the scoring process and to be able to select the final concept among the five remaining ones Reachability Analysis A complex problem that was identified was the ability for the cleaning robot to reach all areas with both cleaning mechanisms. The robot is required to perform the dry cleaning before the wet cleaning of a floor. When the particle suction is located in the front of the robot, as it is for the VR100, it would infer that the wet cleaning mechanism would be placed behind it. When the cleaning robot reaches a corner it would mean that it is not able to reach with the wet cleaning mechanism in that corner, because of its own body (See Figure 7.16). Another similar issue is that the water suction must be able to FIGURE 7.16 CORNER REACHABILITY. reach all areas where water is applied, and reaching a corner would also cause this problem. Consequently, the reachability is an important aspect that must be considered in the development. 62 WET AND DRY ROBOTIC VACUUM CLEANER

70 7.6.2 Shape Analysis In this phase different shapes for the robot were analysed and these are being presented in Figure The most dominating shape on the market is round cleaning robots. The main reason for this is that it enhances the mobility, but it also reduces the ability to FIGURE DIFFERENT SHAPES THAT WERE reach corners and edges. The D-shape that the EVALUATED. VR100 carries is a compromise of these two aspects. When the robot reaches a corner the front square shape will provide corner cleaning and the rounded back will enable it to turn on the spot. The reachability problem can be addressed by locating the wet cleaning mechanism in the back of the robot. Doing this while wanting it to be able reach a corner would infer that the robot s rear is also square shaped; hence the robot is not able to turn on the spot. Therefore, it will require a changing of the driving strategy. The strategy is presented in Figure An important trade off that has to be made is between the ease of driving and the wet cleaning of edges and corners. Since the focus of this study lies on the cleaning result the square shape was seen as advantageous since it ensures the reachability of all areas. However, if the mobility problem cannot be resolved the D-shape can still be implemented. This will mean that the cleaning of edges and corners will be compromised. Therefore, it must be determined what is more important. FIGURE CLEANING STRATEGY. The square shape can constrain the mobility but it is the technology of the navigation system will most definitely have progressed in the near future. Furthermore, there is a square robot on the market from LG, which implies that this problem already can be resolved (LG [C], 2014). The Fish-tail concept would be able to reach all wanted areas, but would require that the front of the robot is thinner otherwise the reachability will be constrained by the front. It is also believed that the tail would require an active control of the tail. 7. CONCEPT EVALUATION AND SELECTION 63

71 7.6.3 Wet and Dry Cleaning Operation When the wet and dry cleaning mode of the robot is operated an issue to address is how the robot reacts when it encounters a carpet. It could either climb it and turn off the wet cleaning mechanism or not climb it at all during this mode. The safety of the operating environment is a prerequisite and therefore it is considered that this mode only should be operated on hard floors. When the robot is wet cleaning, the climbing feature should hence be turned off. Furthermore, the usage frequency of the dry cleaning mode will be greater than the wet cleaning mode. This indicates that vacuuming cleaning of the carpets will be carried out sufficiently so it is not required to include this area for this mode Kesselring Matrix The coverage and shape analysis enabled the Kesselring evaluation to be accomplished. Important criteria were selected from the requirement specification and assessed in a weight decision matrix to objectively assign weight factors. The matrix is presented in Appendix XI. The matrix is presented on the following page and it resulted in selecting the fifth conceptual solution, The Square. See Section Concept Evaluation and Selection - Kesselring Matrix for an explanation of the applied method. Cleaning efficiency and Floor safety have been the two most important aspects followed by Ease of maintenance and Ease of use. The Step-by-Step was the next best concept. However, the losses were the corner cleaning and the reachability. The Scrubber came next and faced similar issues. Additionally, this concept was assessed to less convenient to maintain due to having two cleaning tools clean. The Combined Suction s main drawback was to attain the desired water suction when the suction channel is combined, since air tends to take the easiest passage. Therefore, this could result in loosing the desired water suction. Nevertheless, the idea was still kept in mind for further development since the combination could result in addressing the size issue. The Fishtail concept attained the lowest score due to the main body constraining the aspiration of enhanced corner and edge cleaning. This could be addressed with minimising the front as mentioned in the shape analysis. Furthermore, it was realised that this concept could be too complex since an active control of the tail would be required to achieve the desired result. 64 WET AND DRY ROBOTIC VACUUM CLEANER

72 Concepts Ideal The Step-by- Step The Scrubber The Fishtail The Combined Suction The Square Criteria w v t v t v t v t v t v t Allows cleaning of all floor types Cleaning efficiency Cleans floor seams Compactness of device Corner cleaning Does not leave water in floor seams Dries the floor sufficient enough Easy to maintain Easy to set up Edge cleaning Floor safety Reachability of cleaning T= ti Q=T/Tmax 1,00 0,85 0,82 0,69 0,71 0,89 Rank TABLE KESSELRING MATRIX. 7. CONCEPT EVALUATION AND SELECTION 65

73 7.7 Chosen Cleaning Procedure and Concept The selection and evaluation procedure enabled the cleaning mechanism to be decided. The Dry Cleaning Mechanism was chosen to not contain a collecting tool, to be able to sustain the product s minimal size. This resulted in a suction nozzle that must be designed to achieve the desired suction. The Wet Cleaning Mechanism will utilise a cylindrical cleaning brush and the applied water is will be suctioned (See Figure 7.19). FIGURE WET CLEANING MECHANISM. The square concept locates the particle suction in the front of the cleaning robot and the water suction nozzle is located in the back of the robot. This geometrical layout will ensure that the robot can perform vacuum cleaning and wet mopping in all desired areas, with the suggested driving strategy. FIGURE THE SELECTED CONCEPT: THE SQUARE. 66 WET AND DRY ROBOTIC VACUUM CLEANER

74 8. EMBODIMENT DESIGN This chapter explains the stage of prototyping the selected concept. The learning outcomes from this procedure gave an addition to the requirement specification, which also is included. It also contains ideas regarding the internal product architecture. The preceding phase was concluded with selecting one concept that was to be further developed. The embodiment and the geometric layout of a technology-intensive product of this type is a complex task to solve, hence requiring a substantial amount of effort. The scope of this project was to initiate this embodiment stage. This was established by constructing and testing a prototype and considering the product s architecture. The product concept that is presented in the upcoming chapter is the result of these two activities. The first section explains how the prototype was built and what knowledge was gained through this endeavour. The subsequent section regards the internal architecture of the product. 8.1 Prototyping Obtaining a working prototype of the selected product concept was the goal of this phase and it was created by utilising already existing products and by modifying them. The utilised products were Vorwerk s robotic vacuum cleaner (VR100), a radio-controlled excavator from Carson and a window cleaner from Kärcher (See Figure 8.1). FIGURE PRODUCTS USED FOR PROTOTYPING: VR100 (VORWERK KOBOLD [C], 2014), RADIO- CONTROLLED EXCAVATOR (CARSON MODEL SPORT, 2014), WINDOW CLEANER (KÄRCHER [D], 2014). The VR100 was disassembled in order to utilise components such as the fan or the dustbin. A radio-controlled excavator was used to be able to simulate the movement of a robot. The excavator would be able to imitate the robot s motions due to the fact that it can turn on the spot, which for instance radio-controlled cars cannot. 8. EMBODIMENT DESIGN 67

75 Vorwerk had, in a previous project, prototyped parts that enabled the utilisation of the window cleaner. The already created parts were also used to build this prototype. The parts were a stand for the motor and propeller, a water tank and a water and air divider. Furthermore, the electrical components were created and implemented with assistance from the company. An initial schematic of the layout was created (See Figure 8.2), which is presented in the figure below. The layout was strongly limited by the already existing product s shapes and dimensions, so the 3D-modelled parts were constructed around them. The schematic aided in designing the parts to be modelled and to determine the required dimensions. FIGURE PROTOTYPE LAYOUT. The prototyping facilitated in identifying unanticipated problems, understanding different aspects that still were uncertain and aided in recognizing features the robot should carry. Due to the uncertainty, the prototype only implemented the cleaning strategy; hence it does not have the optimal geometrical layout. Therefore, it is of importance to emphasize that the prototype served as a proof of principle for the cleaning strategy and that the actual product architecture is to be discovered in the future development. 68 WET AND DRY ROBOTIC VACUUM CLEANER

76 8.1.1 Driving Base The driving base constituted the foundation of the prototype and the assembly of all other components was dependent of its shape and construction. With it being the central part of the prototype this component was the part to be constructed first. The upper part of the excavator was removed and redundant electronics detached. Later, a plastic plate was placed on top in order to be able to attach all created parts. Figure 8.3 depicts the transformation of the excavator FIGURE DRIVING BASE Dry Cleaning Mechanism The creation of the particle suction was established through utilising parts from the VR100. The extracted parts were a motor, a fan and a dust compartment, which were placed on top of the driving base. A nozzle was designed in CAD and connected to the dust compartment to obtain the dry cleaning mechanism (See Figure 8.4). The asymmetry of the nozzle is due to other parts constraining its location. It was anticipated that the suction power would be less on the nozzle s left than right side, but from a learning perspective this was regarded as a sufficient solution. FIGURE DRY CLEANING MECHANISM. CAD-MODEL AND PHYSICAL MODEL Wet Cleaning Mechanism This procedure of the cleaning process requires applying water, scrubbing the floor and lastly suctioning the dirty water. These elements are described below, but first the water tank system is introduced. Water Tank System The water tank system was one of the components already created to be able to utilise the Kärcher s window cleaner. Figure 8.4 depicts how the system functions. 8. EMBODIMENT DESIGN 69

77 The tank is a container for both clean and dirty water, which has a flexible membrane that divides it into two chambers. With this technique the same space can be utilised for both clean and dirty water. The water outlet from the clean water chamber is a hole, where a tube can be attached, and the inlet to the dirty water tank is located at the top of the tank (See Figure 8.5). When suctioning water the principle is almost the same as for vacuum cleaners (See Section 2.1). However, the difference is that a separation of water and air must be performed to be able to contain the water and to preserve the electrical components. The separator has walls that collect the water while letting the air pass through, so the collected droplets fall into the container. When the water is removed from the air stream the stream reaches the outlet, resulting in only releasing air. FIGURE WATER TANK SYSTEM WITH FLEXIBLE MEMBRANE TO UTLISE THE SAME SPACE FOR CLEAN AND DIRTY WATER. Water Application Clean water is applied by using a pump, which transports water from the reservoir to a tube located above the rotating brush (Figure 8.5). The tube was pierced with a needle to create three small holes for the water to be applied through. The size of the holes was small enough to obtain a spraying function. Figure 8.6 demonstrates how the water is applied. FIGURE PUMP. FIGURE WATER APPLICATION. 70 WET AND DRY ROBOTIC VACUUM CLEANER

78 A constant application of water was recognised to be too extensive. Thus, less water had to be applied by giving the pump an application frequency. The created circuit board enabled the pump to spray water every fourth second, providing a more suitable amount of water to be applied. Rotating Brush The cleaning tool was placed behind the wheels of the excavator and required a casing to carry the brush. The part also required to hold the motor that generates the brush s rotation and to be attached to the back of the driving base. Therefore, a roller holder was created in CAD, with inspiration from the VR100 (See Figure 8.6). FIGURE ROLLER HOLDER. CAD-MODEL AND PHYSICAL MODEL. The component carries a placment for the motor and a cavity to place the water appication tube in. The brush used for the prototype was the original Vorwerk VR100 brush (See Figure 8.7), with a small modification: the plastic collectors were exchanged to bristles. Further on in the development process different brushes can be created and tested with the prototype, since other materials or constructions could achieve a more sufficient result. FIGURE BRUSH FROM VR100 (VORWERK KOBOLD [E], 2014). 8. EMBODIMENT DESIGN 71

79 Water Suction The water suction nozzle from the window cleaner was utilised and also the electronics of it. In order to be able to attach a tube from the nozzle to the water tank system an attachment was modelled with the CAD program. The attachment served as a connector between the nozzle and the tube. The angle of the water suction nozzle and the required pressure had to be decided to obtain the desired suction. It was decided through tests and the results are presented in the learning outcomes. FIGURE WATER NOZZLE ATTACHMENT. CAD-MODEL AND PHYSICAL MODEL Prototype Figure 8.9 displays the assembly of all parts. It is started with turning on the driving base and the remote control. Four buttons start the different mechanisms of the cleaning robot: 1. Particle Suction 2. Water Application 3. Rotation of Roller 4. Water Suction More pictures of the prototype are shown in the Appendix XIII. FIGURE CONSTRUCTED PROTOTYPE. 72 WET AND DRY ROBOTIC VACUUM CLEANER

80 8.1.5 Prototype Testing The task of testing the prototype was carried out to confirm the cleaning procedure while gaining new knowledge. During the test different mechanisms were turned on and off to see how they impacted the cleaning procedure. For instance, running the robot without the dry cleaning mechanism or the water suction nozzle. Figure 8.10 shows a before and after picture of when the prototype has cleaned the floor. Constructing and testing the prototype revealed unknown areas that would not have been discovered without the implementation of this method. These are being presented in the subsequent section. FIGURE CLEANING RESULT. BEFORE AND AFTER PICTURE. 8.2 Learning Outcomes When constructing and testing the prototype different unknown and unanticipated areas were discovered. Due to the fact that this is a first generation prototype of this concept, it is important to recognise that this prototype was not developed to perform confirmatory testing, but rather an exploratory testing. These outcomes were documented and are presented below General Findings! Importance of removing large particles. Large particles and debris that were not suctioned properly were stuck in the water suction nozzle between the two rubber blades. Small rocks that were caught were then scraped along the floor, which for sensitive floors can be disastrous. Therefore, a utilisation of only the wet cleaning mechanism without the particle suction should not be provided.! Cleaning parts become extremely soiled. It was observed that all parts concerning the actual cleaning procedure such as nozzles, tubes and containers and the bottom surface of the robot came to be tremendously dirty when utilising it. Therefore, these parts must be possible to rinse in an easy manner. Due to the fact that the product will carry several parts that will require maintenance the ease of it is an aspect that must be addressed. 8. EMBODIMENT DESIGN 73

81 ! Seek simplicity. This product includes several physical elements while it is required to maintain its minimal size. Hence, simplicity should be a target in the further development of this prototype.! Will require two different driving strategies for each cleaning mode. The cleaning robot must operate according to its cleaning mode. For instance, the robot should reduce its cleaning velocity when using the mopping function, to ensure proper cleaning. Therefore, different driving strategies must be examined and implemented for each cleaning mode Dry Cleaning Mechanism The dry cleaning mechanism is about achieving a sufficient suction power. As previously mentioned (See Section 2.1), the suction power depends on the airflow rate, the shape of the air passageway and the size of the intake port s opening. Due to several factors impacting the suction power it is believed that an extensive test of each factor must be conducted.! Airflow rate. Due to the absence of a collecting tool, like a rotating roller brush, the airflow rate from the VR100 might not be sufficient enough to lift debris. The airflow rate could be sufficient if the other two factors are designed properly. At this stage it is not possible to draw a conclusion regarding the sufficiency.! Air passageway shape. The height of the nozzle was too tall to be able to lift all debris with this flow rate. Therefore, when designing the passageway the height should be kept as minimal as possible.! Intake port. A smaller intake port results in a greater suction power and this was the main thought behind creating the guiding channels. However, the applied design was not optimal.! Too narrow guiding channels. The width (4 mm) of the guiding channels (See Figure 8.11) was too narrow for larger debris to pass through. Additionally, the closed front resulted in some particles being dragged along the nozzle front instead of being suctioned. FIGURE GUIDING CHANNELS. 74 WET AND DRY ROBOTIC VACUUM CLEANER

82 ! Channelise debris to intake port. Since no collecting tool is used to lead the debris to the intake port it must somehow be directed to the intake port instead.! The nozzle shaped solution is not optimal. The closed front could also be a hinder when the robot needs to climb obstacles.! With this obtained knowledge it is considered that intake ports should be close to the ground and have an open front. Directing walls to the intake port should be implemented. The following figure explains how this could be designed. FIGURE SUGGESTION FOR DESIGN OF PARTICLE SUCTION Wet Cleaning Mechanism! Water application.! Application frequency. The water application frequency depends on the robot s velocity, and therefore these two parameters must be harmonised.! Spray water. Spraying water provides a more even distribution in comparison to dripping the water. Therefore, less water is required to moist the same area when it is sprayed. The conclusion can be drawn that if the water is utilised better a larger area can be cleaned with the same amount of water.! Rotating brush.! Stiffer bristles. The bristles from the brush are too flexible to scrub tougher stains. The bristles should therefore be of a stiffer material.! Water distribution. The rotating brush helps in distributing the water evenly. However, it also scatters the water backwards. It must be made sure that this scattering of water does not reach the surrounding environment.! Tangled hair. Long hair becomes tangled incredibly easy in the roller brush, which creates a maintenance issue. However, if the particle suction is sufficient enough less hair will be tangled but it is believed that the tangling of hair with this type of brush is inevitable. Therefore, the design of the scrubbing tool should address this manner. The latest Roomba model uses rubber rollers, which claim to make them tangle-free. This solution could be examined if it solves this problem (irobot [A], 2014).! Diameter of brush. The diameter of the brush can be made smaller to save space.! Water suction efficiency. It was recognised that the water suction efficiency depended on the following factors.! Robot velocity. The water suction is more efficient in a slower velocity. Hence, the speed of the robot must be adjusted to this cleaning mode. 8. EMBODIMENT DESIGN 75

83 ! Angle of water suction nozzle. The nozzle requires pressure towards the ground. When the window cleaner was placed on a flat surface and only dragged forward it could be observed that the nozzle required pressure towards the ground. With this placement it the angle that was obtained between the nozzle and the floor was 45. To determine the required vertical force the window cleaner was pushed with a dynamometer at the angle of 30 (See Figure 8.12). Three measurements gave F: 8,6 N, 9,1 N and 9,5 N, so the values were approximated to 9 N and the following calculation was made: sin α =!!!! =! sin! = 9 sin 30 = 4,5! 450! Therefore, when the nozzle angle is 45 it requires a weight of around 450 grams to obtain a sufficient pressure. FIGURE MEASUREMENT OF THE REQUIRED FORCE TO OBTAIN A SUFFICIENT SUCTION.! Backwards motion. In the backwards motion the rubber lip created a resistance. Lifting the nozzle slightly in the backward motion could possibly solve this.! Stop applying water.! Turn off the water application before the water suction and drive the robot the distance that is required to suction the applied water.! Stop applying water in the backwards motion, to ensure that all applied water is being suctioned. When the robot is reversing it might change its route in the forward motion, resulting in leaving water on the floor.! Stop the water application when the robot has difficulties leaving cluttered areas or is stuck.! The vibrations from the cleaning tool must be isolated. When the cleaning tool oscillates it created a vibration. This vibration must be isolated from the water suction nozzle, so the water suction efficiency is not impacted.! Water transportation channel. The prototype had a curvature in the transportation tube from the floor to the container. In this curvature water was gathered and when the suction was turned off this gathered water seeped back on the floor. Therefore, the transportation channel requires a smooth transition. 76 WET AND DRY ROBOTIC VACUUM CLEANER

84 ! Height of lifting the water. The height caused problems here as it did for the particle suction. Which means that the suction power must be more powerful. Therefore, the height should be considered in the further development.! Placement of wheels. Placing the wet cleaning mechanism behind the wheels results in them not disturbing the cleaning. However, the water suction must be sufficient enough otherwise it will leave streak marks if it passes an already wet cleaned area Additional Requirements to Target Specification In Chapter 3 it was mentioned that during a development process a requirement specification is updated and revised, due to new acquired knowledge. The learning outcomes from the prototype construction and testing aided in recognising additional requirements for the target specification. Furthermore, the selected concept contributed to the addition of requirements. These are presented in the Table 8.1 and have been categorised in the same manner as previously. FR/C D/W IMP. M/O/A Requirements Marginal Values Cleaning Tool C D - M Material is stiff enough to scrub the floor, without damaging the floor - Operating Features FR D - O All modes are possible to schedule - FR D - M Allows dry cleaning - FR D - M Allows dry and wet cleaning, simultaneously - FR D - M Does not climb carpets during wet cleaning - Robot Velocity C D - O Dry cleaning mode velocity > Dry and wet cleaning mode velocity? [m/s] Water Application FR D - M Water application? [ml/application] FR D - M Water application frequency? [applications/minute] FR W 1 A Apply more water when tougher stains are recognised - Water Suction FR D - M Assure that all applied water is suctioned - FR D - M Hinder water from seeping back on the floor, when the device stop operating FR D - M Isolate vibrations from other mechanism - C D - M Nozzle angle [ ] C D - M Nozzle pressure against floor? [Pa] - Water Tank FR D - M Allow easy rinsing of dirty water tank - TABLE ADDITIONS RO REQUIREMENT SPECIFICATION. 8. EMBODIMENT DESIGN 77

85 8.3 Internal Product Architecture The scope of this project was not to obtain the product s architecture but to decide physical elements concerning the cleaning procedure. However, in the construction of the prototype it was inevitable not regarding this matter. The considered thoughts and ideas can be useful in the future development process and therefore it is being presented below. When building the prototype it was realised that the size constraint truly will be a challenge, due to the fact of the amount of functional elements that must be included. It was reflected on what parts were redundant and how the solution could be simplified. The curiosity arose how the cleaning robot from irobot, Scooba 390, operates. Their patent was studied (irobot Corporation, 2013) and the cleaning robot was disassembled. It was found that the cleaning robot utilises one suction generator (one motor and one fan) to obtain both particle suction and water suction. The illustration below is extracted from the patent and it shows how the product operates. The suction (830) is generated by the rotating fan (502). 562 is a plenum located in the water tank which divides the suction (830) into three channels (832, 834, 836). Suction 834 and 836 is the water suction of the cleaning robot and suction 832 is the particle suction. The outlet air from the suction generator (502) comes out from 554 and pushes dirt towards the intake port (558). The dirt and debris is collected in a small filter at (557). Hence, the cleaning robot does not have a dustbin to contain dust and debris, but only a filter that collects it. Testing the Scooba 390 showed that the water suction FIGURE INTERNAL PRODUCT ARCHITECTURE OF SCOOBA 390 (IROBOT CORPORATION, 2013). was not effective and a large amount of water was left to dry on the floor. After studying the Scooba it was considered how the suction for both debris and water could be obtained with one suction generator. Two ideas that arose are presented below. 78 WET AND DRY ROBOTIC VACUUM CLEANER

86 8.3.1 Two Nozzles Attached to One Tank The idea suggests that one suction generator is connected to one tank (See Figure 8.15). A fluid dynamic expert was consulted at the company and he stated that this could be achieved as long as the motor is powerful enough. The question is how powerful it would require to be, which is an aspect that ought to be tested. One tank also enables the possibility to contain both debris and dirty water in the same place, which addresses the size issue. Another advantage is that the dust is contained in water, which is a positive aspect when emptying the dirty container. The reason is that the dust is not released back into the air when emptying. FIGURE TWO NOZZLES ATTACHED TO ONE TANK. 8. EMBODIMENT DESIGN 79

87 9. PRODUCT CONCEPT This chapter is a presentation of this product development process s established concept. It describes and depicts the developed concept, its cleaning strategy and its mechanisms. 9.1 Concept Description and Depiction The development process resulted in achieving a concept that implements a cleaning strategy for a wet and dry cleaning robot. The main requirements that have been focused on throughout this project have been Cleaning efficiency, Floor safety, Ease of use and maintenance and the device s Reachability. The product concept is an automated wet and dry cleaning robot. The sections below present the developed concepts cleaning strategy, dry and wet cleaning mechanism, driving strategy and operating features. It carries a square shape to enhance the reachability, which ensures dry and wet cleaning of corners and edges. The illustration below depicts a design suggestion of the cleaning robot s appearance (See Figure 9.1). The curvatures have been placed in this manner to provide an indication of the robot s driving direction. FIGURE DESIGN SUGGESTION OF PRODUCT CONCEPT. 80 WET AND DRY ROBOTIC VACUUM CLEANER

88 9.1.1 Cleaning Strategy The developed concept utilises a one-stroke strategy and implements both the dry and wet cleaning procedures simultaneously. The robot acquires two different cleaning modes; one dry cleaning mode, in which it vacuum cleans the floor and one wet and dry cleaning mode, in which it vacuum cleans and mops the floor. The cleaning robot first suctions larger particles and debris from the floor (See Figure 9.2). Afterwards, fresh water is applied to a rotating cylindrical brush that scrubs the floor. The dirty water is then suctioned off the floor. This means that only fresh water will be utilised to clean the floors, which provides an enhanced cleaning result. The wheels of the robot are placed in front of the wet cleaning mechanism so that the robot does not disrupt the scrubbing of the floor. FIGURE CLEANING STRATEGY Dry Cleaning Mechanism The dry cleaning mechanism has an intake port closely located to the floor. It carries V-shaped (See Figure 9.3) directing walls that guide the debris to the intake port in the forward motion. All the suctioned particles are later collected in a dustbin, which after the cleaning cycle can be emptied. FIGURE BOTTOM VIEW OF PRODUCT CONCEPT. 9. PRODUCT CONCEPT 81

89 9.1.3 Wet Cleaning Mechanism The wet cleaning mechanism carries three main parts: a water tank, a cleaning tool and a water suction nozzle. A flexible membrane inside the tank creates two chambers, which enables the same space to be utilised for both clean and dirty water. Small spraying nozzles, located above the rotating roller brush, apply water on the brush and the rotating cleaning motion of the cylindrical brush scrubs the floor. This results in separating dirt from hardfloors. The water suction nozzle with rubber lips suctions the dirty water off the floor and stores it in the water tank. When the cleaning robot has finished its cleaning cycle the water tank can be emptied leaving a both vacuum cleaned and scrubbed floor Driving Strategy A laser navigation system scans the room to recognise the optimum path and the cleaning is carried out methodically and systematically. When the cleaning robot reaches a corner the square front assures the vacuum cleaning of it. It later reverses into the same corner with its rear side to operate the mopping mechanism. The illustrations below demonstrate the driving pattern when a corner is encountered. Furthermore, the cleaning robot is designed so it is one side that follows the wall. This means that the edge cleaning is enhanced as well. FIGURE DRIVING STRATEGY Operating Features The user can choose between the two different cleaning modes: dry cleaning or wet and dry cleaning. This gives the user the option to choose what type of cleaning is desired. In the latter mode the cleaning robot does not climb carpets, thus assuring that carpeted areas will be secured. Additionally, the user can also schedule the cleaning for both modes. The cleaning robot also assures that all applied water is suctioned, which is carried out by regulating the water application. The application of water is switched on or off contingent upon different scenarios. It stops applying in the backwards motion, since the robot can alter its direction after reversing. Also, at the end of a cleaning cycle the water suction operates for a longer distance than the application so the applied water is suctioned. 82 WET AND DRY ROBOTIC VACUUM CLEANER

90 In the backwards motion the robot lifts the water suction nozzle, so that it does not push dirt backwards if it is stuck and the rubber lip does not become bent in the wrong direction Wet Cleaning Attachment One of the general ideas that were brainstormed during the concept generation phase was the wet cleaning attachment (See Figure 9.5). This idea would be implementable to the developed concept. The attachment would suggest that when the mopping feature is desired the user attaches the wet cleaning mechanism. Due to the fact that the wet cleaning mechanism will not be utilised as often as the dry cleaning mechanism it would be beneficial for this part to be removed and stored when it is not used. Thus, the robot will not require too much space in its use environment. FIGURE WET CLEANING ATTACHMENT. An implementation of this would provide several advantages. In the matter of maintenance, the user will be able to detach this part to rinse it and refill/empty the water tank without needing to lift and manage the entire robot. In the matter of product architecture, if change is anticipated in certain parts these are often clustered together (Ulrich, 2012), thus, locating all wet cleaning parts together could provide ease in upgrading the product. Because of the novelty of this product it can be expected that changes will be required after product release. Furthermore, an attachment provides the ability to sell the wet cleaning mechanism as an add-on providing the user with flexibility in use. Of course, technical difficulties with this implementation could be encountered, but it is strongly recommended that this suggestion ought to be examined. 9. PRODUCT CONCEPT 83

91 10. DISCUSSION This chapter discusses the pursued development process, the applied methods and the achieved result. Aspects that have affected the result are being deliberated and finally the result s reliability and validity are discussed Pursued Product Development Process The followed development process was adjusted to suit the character of the prospected product. The project plan was pursued to a large extent, but as in any project accustomed slightly when unanticipated problems were encountered. The evaluation and selection process was the stage that required longer time than foreseen. It is believed that the reason was the amount of uncertainty the project had to face. Few product requirements were specified and known before the initiation; hence several assessments required substantial amounts of deliberation and research to be able to support the decisions-making processes. The choice of process has been advantageous for this project due to the fact that it still is in the early stages of development. It aided in defining the problem and what was required to be achieved. This resulted in giving a solid foundation for the remaining work. Another beneficial aspect was that the project was carried out at the company, since this established a close communication and collaboration. The available resources, such as tools and materials for prototyping and having a 3D-printer at hand, also helped in enhancing this aspect. Two main difficulties throughout the project have been the complexity of the task along with carrying out the project individually. The task itself requires the cooperation of several fields such as electrical engineering, software engineering, mechanical engineering and human-machineinteraction, which confirms the technology-intensity of this product. Furthermore, the market clearly presents the difficulty of solving this problem due to the absence of this type of device. The struggles state that working in cross-functional teams would be of desire when solving this task. Despite the fact that this was an individual project discussions with employees from different fields gave their input, which contributed and enriched the result. It can be stated that a different result could have been achieved in other circumstances. However, it is considered that the study examined a wide range of aspects, thus reducing the uncertainty of the company s project initiation and it lays the foundation for the upcoming work. 84 WET AND DRY ROBOTIC VACUUM CLEANER

92 10.2 Applied Methods The applied methods have been valuable for this course of work and provided a systematic approach in solving the task. The methods enabled the recognition of unidentified problem areas while enhancing the knowledge within the field. The methods achieving the market research gathered important information to be able to set the requirement specification. Since customer and usage data have been collected from a variety of sources it can be stated that the target specification will provide a deeper understanding for what must be solved. Moreover, the online reviews were seen as a powerful tool and it is strongly recommended for collecting data. This enabled the reach of users at their conditions. The comfort made the reviewers utter the requirements in a natural environment and discuss the topic in a relaxed manner, for instance in the comfort of their own homes. This setting for expressing needs supports users in giving their honest opinions. The methodology for the requirement specification was slightly modified where an extra categorisation was added in order to provide more knowledge in how to tackle the problems and how to allocate the available resources for future work. Another alteration was implemented during the concept generation phase, in which the subsolutions were combined. Subsolutions that did not concern the cleaning procedure were excluded, since these aspects did not lie within the scope of the project. It is the cleaning efficiency users will be assessing instantly, which will form their opinion and attitude. Therefore, it is considered that this focus was advantageous at this stage of the development. The concept generation and concept evaluation and selection followed the same structured approach, which attained the coverage of a large solution space and a careful examination of the possible outcomes Achieved Results Segments of the achieved results have been discussed with the presentation of the results in Chapters 4-9. In the following sections the major findings are highlighted and possible limitations of the results are denoted Market Research The market analysis and the identification of customer needs contributed in revealing a wide ratio of problem areas. The research proved that the market of cleaning robots is evolving and stated the major competitors and their competing products. 10. DISCUSSION 85

93 The result defined the target market, described the usage of the prospected product and provided a comprehension of the needs and requirements. It is suggested that a more extensive market research is conducted and that users are interviewed to identify their needs additionally. It must be emphasized that this is an important aspect since the product still is in the early stages of the diffusion of innovations. In order to achieve market penetration it is the innovators and the early adopter must be persuaded; hence understanding their requirements are essential. The lack of not meeting real users was addressed with examining and researching online reviews widely, which enabled to compensate this to an extent. Online reviews represent the early majority will acquire their knowledge about the product, which furthermore expresses the importance of meeting the innovators and early adopters needs Requirement Specification The specification has been updated continuously throughout the project, since the art of the project has been exploratory and new requirements have emerged along the path. The result provides a structured overview for when the development project will be initiated at the company and it will in allocating resources accordingly. However, it is recommended that the specification should be updated with input from other disciplines Concept Generation This stage enabled to grasp the problem in solution-neutral manner in order to not constrain the generation process. The defined function structures provide a clear view of the problem. It should be recognised that a wide solution space has been covered, by giving this stage the time of creativity it requires. As previously mentioned, input from other fields could have been of use. However, the scope of this project focused on the system solution and the cleaning procedure so it can be stated that the knowledge was sufficient for the sought solutions Concept Evaluation and Selection The main establishment of this stage was deciding the cleaning strategy, which has been a difficult question to tackle. The careful evaluation process ascertained, by gathering decision material through testing, that no essential requirements have been neglected and a variety of trade-offs have been addressed. Without this procedure, the identified problem areas would not have emerged, thus revealing the importance of thoroughness of this stage. 86 WET AND DRY ROBOTIC VACUUM CLEANER

94 Embodiment Design The embodiment design resulted in a prototype, which demonstrated the chosen concept s cleaning strategy. With the decided cleaning mechanisms it has been proven that the floor can be dry and wet cleaned with the one-stroke strategy. Also the reachability issue has been addressed. Despite limited knowledge within the field of electronics a working prototype was constructed, which was able to provide learning outcomes of significance in the future development Product Concept The developed product concept meets the requirement specification. However, it must be investigated that it is able to meet all the requirements in practice, e.g. requirement regarding the operating features must be tested. The requirements regarding the cleaning strategy and procedure have been met, which has been proven with the established prototype. Therefore, the product concept is valid according to its predefined scope. Implementing different cleaning modes is an aspect that should be a strong aim. The ability to chose between dry cleaning or wet cleaning is a desirable requirement that should be applied. The Scooba (irobot) does not provide this option, while the Hybrid Robot Vacuum Cleaner (Moneual) does. However, Moneual s robot does not utilise water suction. Neither a scheduling function is given to the wet cleaning robots. Therefore, Vorwerk has the opportunity to provide users with these abilities, which will give the company a competitive advantage on a yet immature market. A central concern has been the cleaning robot s reachability issue. It can be argued that a square design constrains the robot s mobility, but the LG robot proves that this is a problem that can be tackled. Furthermore, robot technology is advancing and developing, which also will aid in addressing this issue. Consequently, it is considered that selected concept is possible to implement. If the fact remains that the square shape does decrease the mobility, the rear side can be altered by giving it a rounded edge. This trade-off would imply that the corners would be vacuum cleaned but not scrubbed, which actually will not impact the cleaning result substantially. 10. DISCUSSION 87

95 The Study s Width and Depth The arrangement of the study gave the ability to accomplish a large part of the development process during a compressed period of time. This has been beneficial due to the amount of ambiguity the project was initiated with. The result contributed with learning aspects in several different areas rather than focusing on one single issue; hence denoting that the result became wide and diverse rather than in-depth and specific. In the early stages it is considered that this approach gives a stronger overview of the task and an enhanced ability to mange the project. Therefore, it can be stated that the provided result is valuable and relevant for the current stage of development The Result s Reliability and Validity The selected methods and the manner of their applications have affected the result s reliability. The methods provided the task to be accomplished with a structured approach, which has been beneficial due to the product s technology-intensity and complexity. The approach enabled a careful scrutinisation and identification of several problem areas and aspects that presumably would not have been discovered with an unstructured approach. The structure provides thoroughness, which is a desirable characteristic in a development process of this type because it offers the revelation of important factors and the deliberation of essential trade-offs. Utilising the methods also has contributed in preserving an objective view throughout the project, hence minimising biasing opinions. The methods have been implemented by common procedure and the alterations are regarded as too minor to have a substantial impact on the result. Furthermore, it can be stated that the applied methods hold trusted knowledge and are widely applied within the discipline of product development. Subsequently, with these aspects in concern the established results are regarded to have a strong reliability. The project has maintained its initial goals, objectives and purpose. However, it can be stated that the definition of the task was defined in a more vague manner in the initiation and has become more specified throughout the course of the project. The validity of the results are conveyed through the project s objectives below:! Conduct a market research. Chapter 4 Market Research maps the market and identifies the main competitors and competing products. Moreover, through interviews, observation and secondary research the customer needs have been identified and the customers and their use environment have been described. 88 WET AND DRY ROBOTIC VACUUM CLEANER

96 ! Deliver a requirement specification. Chapter 5 Requirement Specification provides this deliverable in a categorised and structured manner. This gave the development process the foundation it required.! Deliver a number of possible solutions and the further development of a chosen one. Chapter 6 Concept Generation, Chapter 7 Concept Evaluation and Selection and Chapter 9 Product Concept confirm this objective by generating conceptual solutions for the problem, assessing and choosing a concept according to the requirement specification and further developing the Square Concept.! Deliver a working prototype, which demonstrates the cleaning strategy. Chapter 8 Embodiment Design validates the final objective by attaining knowledge through prototype constructions and examining internal parts for the product architecture. This argues that the desired results have been accomplished and are of relevance for the given task; hence providing results with its validity. 10. DISCUSSION 89

97 11. CONCLUSION This chapter provides a summary of the most significant conclusions that were made throughout this Master s Thesis. The following aspect presents a linkage from the beginning to the end of this development project and the drawn conclusions are listed below:! The technology-intensity and complexity of this product reveals the importance of combining different competencies. It is essential for different departments and disciplines to have a close collaboration and communication to achieve an innovative product with a strong competitive advantage. Therefore, a cross-functional development team will provide its benefits in the development of this innovation.! It can be stated that a one-stroke strategy is regarded as the optimal cleaning strategy for the implementation of this product. Additionally, the utilisation of a scrubbing tool and a water suction provided the most effective cleaning result. The placement of the dryand wet cleaning mechanisms enabled the reachability without the robot s own body as a hinder. With this cleaning strategy the user will be able to assess the cleaning efficiency immediately, which consequently will shape the attitude towards purchase.! The product must be practical in the eye of the user, which shows that a strong emphasise must be placed on usability issues e.g. ease of use and ease of maintenance. The usefulness will also be assessed by the robot behaviour, which shows the importance of the robot to communicate a trustworthy, calm and structured impression.! The implementation of this product will require the adoption of a new technology. The diffusion of innovations shows the essentiality in defining the target market, which will be the innovators and early adopters. It is important to meet these target groups so they can influence the rest of the population, thus a user-centred approach must be enforced.! A strong purchase motivation is through demonstration and recommendation. This indicates the importance and value of Vorwerk s direct sales channel and utilising the word-of-mouth. This will aid in attaining the enterprise s place on the market. This master s thesis has developed a system solution of the cleaning strategy for an automated wet and dry cleaning robot and has provided a foundation for further development. Thus, it has initiated the implementation of this product to Vorwerk s product platform. Therefore, it can be declared that this project has reached its goals and fulfilled its purpose. 90 WET AND DRY ROBOTIC VACUUM CLEANER

98 12. RECOMMENDATIONS This chapter is a list of recommendations to Vorwerk. The list can be used for the future development of the wet and dry cleaning robot. The complexity and technology-intensity of this development project indicates that still a long development process lies ahead. The following points indicate suggestions for the future work:! Define the target market to determine who the user is. Furthermore, interview users of this market segment to update the requirement specification! Update the requirement specification with involvement from other disciplines.! Design different particle suctions that can compensate for not utilising a collecting tool or roller brush and see if it possible to attain the equivalent suction power of the VR100 without the tool. Additionally, investigate if a v-shaped directing channel can replace the rotating side brush.! Explore what amount of water is required to be applied to clean a certain area and with what frequency. Also, study when and how the application should be regulated.! Examine what velocity the robot should move in and design the driving strategy.! Optimise the cleaning tool and develop different cleaning tools for different floors.! Test exactly what pressure and what angle provides the best cleaning result.! Investigate how this pressure could be applied and how the nozzle can be lifted in the backwards motion.! Research different driving strategies for the different cleaning modes and what other cleaning modes could be implemented to suit the user.! Further investigate the product architecture and how to design the internal system.! Create a fully functioning prototype and test it among users to obtain feedback prior to market introduction. 12. RECOMMENDATIONS 91

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105 APPENDICES Appendix I Gantt Chart! List of Activities Start Dur Project Work Project Planning 1 2 Market Research 3 3 Requirement Specification 6 2 Concept Generation 7 4 Concept Evaluation & Selection 9 5 Embodiment Design 12 9 Prototyping Documentation Planning Report 1 3 Writing of Thesis WET AND DRY ROBOTIC VACUUM CLEANER

106 Appendix II Product Comparison Chart APPENDICES 99

107 100 WET AND DRY ROBOTIC VACUUM CLEANER

108 APPENDICES 101

109 Appendix III Competitor Benchmarking 102 WET AND DRY ROBOTIC VACUUM CLEANER

110 APPENDICES 103

111 Appendix IV Customer and Need Statement List These statements were gathered from online reviews. General Use Customer Statement Our favourite feature is the ability to schedule a cleaning. Con - Doesn t have multi-room navigation functionality. (The robotic vacuum is able to travel from room to room without needing any human assistance.) If carpet is your floor covering of choice, we d choose a different automatic vacuum cleaner. Pro, About Trilobite - It doesn t bump into things, it turns around right before it bumps. Doesn t get over threshold that are 1 cm high. Con - The SR8895 worked fine for the first two minutes, but then got totally lost when we switched off the lights. It is round and, in consequence, cannot get fully into square corners. It doesn t actually remember the layout of your place. That would have been awesome Anti-tangle worked well when confronted by cables and curtains, except for very thin phone wires which were dragged along. Less confident in Neato because they are delaying the release of the new software. But to memory the Deepoo D76 can empty his tray to its base thereby increasing its capacity of 0.95 l! Hair is always bound around the bearings which will lead to long term damage if not removed each time. IRobot says the Roomba 780 uses both acoustic and optical sensors to detect dust and dirt. Customer asking - Can it handle dried-on stains? Interpreted Need The CR 1 has the ability for scheduled cleaning The CR is able to travel from one room to another, without needing human assistance. The CR can vacuum carpets. The CR recognises obstacles before bumping into them. The CR can get over threshold that are minimum 1 cm high. The CR is able to navigate in the absence of light. The CR can clean square corners. The CR remembers the layout of previously cleaned rooms. The CR does not tangle into cable, wires or curtains. The CR is able to be updated with new software through new releases. The CR has a large dirt capacity. The CR does not tangle hair in its mechanisms. The CR can detect where there is more dust and dirt. The CR can handle dried-in stains. Eliminate low-lying floor dust and allergens to help allergy sufferers. Little more, the robot is also an air purifier in its topof-the-range version thanks to his ionizer which destroys bacteria and allergens to the ground. About Rowenta The CR cleans to the extent that it helps allergy sufferers. The CR removes allergens and bacteria. 1 Cleaning Robot 104 WET AND DRY ROBOTIC VACUUM CLEANER

112 Cleaning Efficiency Customer Statement The only thing we would have liked to see was HEPA filters replace the standard filters. About Neato XV-21 Pro - A UV disinfecting light kills bacteria while vacuuming the room. Pro - An acoustic sensor to sense excessively dirty areas. When the automatic vacuum cleaner detects a particularly dirty spot, it goes into spot mode, giving the area a little more attention. Doesn t clean along the edges, which means that 1-2cm from the wall remains uncleaned. Con - Suction isn't powerful enough to clean cracks and crevices in wood floors Interpreted Need The CR removes (from the air that passes through) 99.97% of particles that have a size of 0.3 micrometres. (HEPA Standard) The CR kills bacteria and disinfects. The CR senses more dirty areas and cleans them more extensively. The CR cleans along the edges. The CR cleans cracks in floors. Battery Customer Statement We love that this robot vacuum knows when its battery is getting low and will head back home to recharge. Best of all, when it needs to be recharged, it takes care of itself, returning home to its charging base. Pro It can run for 90 minutes before it needs to be recharged. Pro It can run for 70 minutes before it needs to be recharged. Interpreted Need The CR recharges itself when the battery is running low. The CR recharges itself when the battery is running low. The CR has running time of at least 90 min. The CR has running time of at least 70 min. Maintenance Customer Statement All of the parts that should be removed regularly and cleaned are yellow. Doesn t have a full dustbin indicator, so you ll need to be diligent in keeping the unit clean on your own. Although the filters aren t HEPA, we do like how they can be cleaned instead of needing frequent replacements. Con - It only comes with a six-month warranty. Unless one uses disposable cleaning cloths, removing and washing the microfiber textile is a dirty and unpleasant task. People said that automatic charging and scheduling is worthless, if the robot needs to be taken care of anyways. It's more convenient to have a robot with a larger bin. Interpreted Need The parts of the CR that needs to be maintained are easily detected The CR indicates when it needs to be emptied. The CR has filters that can be reused. The CR has an acceptable warranty length. The CR maintenance is not a pleasant task. The CR need little maintenance. The CR does not need to be emptied often. APPENDICES 105

113 Appearance Customer Statement The colour of the robot is definitely a love it or hate it question. It catches everyone s eye visiting the house, and to be honest most of them didn t like the colour. About a colourful Deepoo The shiny white robot is elegant, trendy and definitely unique among consumer robots. About Braava Likes VR100 Customer Statement I have bought the Neato a while back but I regret it that I haven't bought the Kobold. Mainly because of the absence of a side brush. Yeah I m missing the side brush too, otherwise its perfect robot for me. Interpreted Need The CR has a discrete appearance and blends in to the home environment. The CR has an elegant and trendy appearance. Interpreted Need The CR cleans well in corners and by the edge of the wall. The CR cleans well in corners and by the edge of the wall. Dislikes VR100 Customer Statement As indeed it should for 650 notes. Has a less than ideal battery life. The only shortfall is you need to empty the dirt bin after each vacuum but I feel this is testament to the cleaning power of the device. The revolving side brush [why is there only one?] The dust compartment can indeed be very easy to open, but not the containers contained therein. To install the update, however, each time you require service. Importing updates itself, unfortunately, does not work. For the price of the robot, one may regret the lack of accessories. The side brush improves the cleaning of borders but not the corners. I would have appreciated an extra filter or a brush. His appearance. Interpreted Need The CR is worth the price with giving a superior cleaning, features, and accessories. The CR has a sufficient battery time. The CR does not need to be emptied after each cleaning. The CR cleans the sides of the wall well. The containers in the dustbin are easy to maintain. The customer is able to update the software herself. The CR is worth the price with giving a superior cleaning, features, and accessories. The CR cleans properly in corners. The CR is provided with extra parts for changing maintenance. The CR has a pleasant appearance. Suggested Improvements VR100 Customer Statement A much easier emptying of the dust container (e.g. via a suction), or a larger side brush that comes in would corners as points. Interpreted Need The CR is easy to empty. The CR reaches in corners. 106 WET AND DRY ROBOTIC VACUUM CLEANER

114 Likes Scooba Customer Statement At the end of its cycle it goes into internal drying mode to eliminate the water in its systems. Thanks to the sensors, the robot smartly avoids rugs and stairs as well as places where it may fall. The Mint is easier to set up compared to the Scooba, but I prefer the Scooba that it actually scrubs the floor and grout lines. Dislikes - Scooba Customer Statement An hour later saw me with my good old mop and bucket cleaning up after the Scooba that had contrived to leave dirty streaks all over my (vacuumed and relatively clean) white tiles. Before starting its cleaning cycle you must clear the floor of dirt. This may pose a problem if the floor is exceptionally dirty as the robot can hold a small amount of dust in its first cycle. It is important to note that the Scooba 390 cannot replace a vacuum cleaner robot. It is also important to note not to use other brands of detergent as they will damage the Scooba. The cleaning of the filters and overall of the robot will be more long and tedious if you do not take the trouble to use a vacuum cleaner before. When the robot has completed its cycle, I recommended that it should not be left on the floor because the humidity present under the robot may cause mould to grow. On the other hand, due to its design it cannot clean corners. The weakest point of the design is the lock for opening the appliance as it can be released by pressing a handle that is used both for opening and picking up the device which is difficult to use because in order to open the robot the flippable handle should be pushed down, just in the opposite direction, this solution worked well for the first few times of use but since then it sometimes works, sometimes doesn't. Got stuck under a furniture, which resulted in a big water puddle on the parquet. No scheduling! You always have to start it manually. I want this to be done automatically while we are at work. It won't work well with very hairy floor. Leaves tire track lines/line segments. It's subpar at edge cleaning. Any edge cleaning will still need to be done by hand. Interpreted Need The CR is able to dry internal parts after use. The CR recognises rugs. The CR recognises stairs. The CR is easy to set up. The CR thoroughly wet cleans the floor. Interpreted Need The CR does not leave streak marks. The CR cleans the floor sufficiently of dirt before stating the wet cleaning. The CR is able to replace a vacuum cleaning robot. The CR is useable with any type of detergent. The CR maintenance time is little enough to make not vacuuming yourself worth it. The CR is able to stay on the floor after a cleaning cycle without affecting the floor. The CR can clean in corners. The CR can is resistant to ware. The CR does not get stuck under furniture. The CR does not leave amounts of water behind on the floor, The CR is possible to schedule. The CR removes hair from the floor. The CR does not leave track marks after its cleaning. The CR does clean the edges sufficiently, so the customer does not have to do it herself. APPENDICES 107

115 It is barely useable on distressed hardwood floors as it cannot suck the water out of the recesses. As a result, when it is done, the floor is left with dirty water everywhere, in every nook and cranny of the recessed floor. That caused me to return the thing. The Scooba is also substantially louder than a Roomba and more of a pain to fill and clean than a Roomba. I miss having a 'spot clean' function as Roomba provides, covering about a 3' area The CR can remove the excess water in cracks in floors. The CR has an acceptable sound level. The CR is able to clean a certain spot. Likes Mops Customer Statement Interpreted Need Unit is whisper quiet. - Braava The CR is quite. Because it just damp mops, the floor dries quickly. The CR leaves the floor with very little drying time. Easy to assemble and use. - Braava The Mint lasts about 3 hours on a charge according to the manual, which seemed about right to me. Mint definitely figured out how to keep hair from getting twisted up around the Mint Cleaner s wheels. This is awesome! Dislikes Mops Customer Statement I used both the included reusable cloth wet mop and a disposable one. They both performed the same, and unfortunately neither would remove yogurt and other liquids that the kids spilled. I had to resort to a manual mop and elbow grease to clean several spots. I also ran into an issue with the Mint s wedge shape. It jammed itself under the dishwasher and couldn t back out. I had to pull it out. I also found that the device is too large to get in smaller spaces and I completed the cleaning job with a hand mop. To be perfectly frank, in the time it takes the Mint to clean one of my rooms, I can do all the solid floors in my house with the Swiffer. This is a great device to use for daily touch ups, however, it s no substitute for using a vacuum and regular mop. I had to get up a couple of times to make sure it wasn't stuck somewhere. Does not return to its charging dock, it stops when it thinks it has finished the room. Mopping my kitchen took over two hours. (Too long) The machine takes forever and the wet option the cloth dries up quickly and did not a good job on my hardwood floors. The CR is able to clean a sufficiently large area in one charge. The CR s wheels do not tangled with hair. Interpreted Need The CR is able to remove dried in stains, so the customer does not need to do this manually. The CR does not have a shape that gets stuck under furniture. The CR can get into smaller places. The CR s cleaning time does not exceed the time of cleaning it yourself substantially. The CR is a substitute for using the vacuum and a regular mop. The CR does not get stuck. The CR returns to the charging dock when it is finished. The CR does not take more than 2 hours to clean a room. The CR provide enough moist on the floor to wet clean. 108 WET AND DRY ROBOTIC VACUUM CLEANER

116 My biggest complaint with the thing is that every time I go to use it, I have to charge it for six hours in order to use it. A fully charged battery only lasts for 45 min-1 hour. The instructions say it should last 2 hours or more. If you're using it to mop it dries out way too fast. Any spots you don't pre-treat, don't get cleaned. My Mint cleans very well but I have to recharge the unit twice before it finishes my living room The mopping does pick up a lot of dirt, but it ends up going back and forth against the grain at some points which ends up streaking the hardwoods. It requires too much monitoring. The CR does not require a long charging time. The CR battery time is long enough to clean the wanted area. The CR s washing cloth does not dry out. The CR does not require pre-treatment of spots on the floor. The CR is able to clean the wanted cleaning are in one charge. The CR does not scratch the floor with big particles. The CR requires no monitoring. APPENDICES 109

117 Appendix V Interview Guide 1. Have you tried or used VR100? Or any other robot vacuum cleaners? 2. What do you think is important in robot vacuum cleaner? a. What features are important? b. What kind of feature would you like it to have? Not have? c. What improvements does it need? d. What do you think about the side brush? 3. How would you use a dry and wet cleaning robot? a. Would you want to use it when you are home or not? b. Would you like to be able to use it for each purpose separately? c. What do you think are some requirements for this type of robot? 4. How much does the vacuum cleaner need to clean in one run for you to be satisfied? a. How many rooms or in how many hours? 5. How often is it acceptable to maintain it? a. How long each time? 6. How much can you expect to clean yourself when using this robot? How often to vacuum and mopping manually? 7. What would you think about having two robots? One for each task? 8. What do you prefer: disposable microfiber cloth or reusable? 9. How important is the charging time for you? a. How long is the maximum charging time? 10. What is an acceptable warranty length? 11. What would be the perfect scenario in the use of this device, in your opinion? 12. Anything I haven t asked? 110 WET AND DRY ROBOTIC VACUUM CLEANER

118 Appendix VI Interview Notes Interview Person 1 M27 Have tried the VR100, but only the lab version. It has issues with the sensor but this might not be a problem be the VR200 or the actual VR100. It is very important that the sensors can detect carpets and cables. And also that they are sensitive enough to fulfil its task. It should not get dirty very fast so it needs to be maintained because it cannot clean because of dirty sensors. The side brush is good and should be kept, also scheduling is needed because I want it to clean when I am away. It has some problem with getting close enough to table legs. But this is a minor issue as long as it cleans well every where else. Cleans quite well in the edges and corners and the wet cleaning should be able to the same. Maybe it could have a wet side brush. It should be able to clean my entire apartment (68m 2 ) during the time I am away (8h). I does not matter how often it has to charge or for how long as long as it has cleaned the apartment when I get back home. At least 1 hour of run time in one charge. The sensors should not be affected by water on them, so it should have some kind of shielding. The one I used I, the sensors were quite sensitive to dust and should not be, as well as for water. 2-3 days/week for wet cleaning and more often for dry cleaning. Acceptable maintenance: 5 min/day I would clean myself once a month. Waste as little water as possible to clean as much area as possible! Cleaning efficiency vs. water supply. Don t like the idea of having two robots, would prefer having all in one. The microfiber cloth: If there is not any difference in cleaning efficiency I would prefer reusable ones. At least 2 years warranty, I would expect. I would prefer a robot with a discrete appearance but the appearance does not matter as long as the cleaning efficiency is sufficient. I believe that internally the path planning of the robot could be improved sufficiently. About cleaning noise being connected to cleaning efficiency with regular vacuum cleaners: I am not sure that this will be the same, since it is a robot and it is not you that does the cleaning. It would be cool if it could notify me on my phone if it s stuck and I could manoeuvre the robot with my phone. APPENDICES 111

119 Interview Person 2 M22 The robot needs to work perfectly in order for me to leave it to clean when I am out. I think the robot is too expensive, I would pay 350 and 700 for a wet and dry cleaning unit. Cleaning of the edges are very important. 50m 2 should not take more than 1 hour to clean. And also one tank should at least clean that area. If it does not I can do it faster myself and therefor I don t need a robot vacuum cleaner. The speed also matters since I don want to walk around the apartment with a high pitched noise during the cleaning time. So the noise level matters. And for instance I would like to use it during the weekends when I am home. I would use the dry cleaning every day and the wet cleaning every 3 days. Maintenance time should not exceed 10 minutes every two days. When buying this device I expect to not need to clean my home manually. That would be optimal. If you need to clean after the robot than the purpose of having it is useless. I don t like the idea of having two robots, since it takes more space. It doubles the cleaning time and the energy. It is inefficient to do a route of dry cleaning first and then wet cleaning. The charging time is too long. I think it should be able to charge in maximum 1.5 hours. I would prefer reusable parts because I don t need to think about going and buying new ones and it s more environmental. The robot should recognise my rooms and I want to be able tell it which rooms to avoid and which to clean. It is okay if it makes a quick map every time but it does not need to be so thorough ever clean. Then he would know where there are obstacle in advance and optimise the cleaning time. So it can plan the route better. Long hairs is a big problem for the brush, and it is very difficult to clean them. I prefer the wet cleaning with fresh water all the time instead of damp mopping. I would like it to have a remote control, if I spill something it can come and clean. I think the charging station is too big, it could be a lot smaller or have like an inductive carpet for charging. I think the cleaning noise is too loud. If it takes too much time to clean my apartment (and it s really large or I have two floors) I would want to have two so it goes faster. And in this case I would want them to be able to communicate so they know who is doing what. If it has a camera it can also be a surveillance camera. It should definitely leave no puddles of water on the floor. 112 WET AND DRY ROBOTIC VACUUM CLEANER

120 Interview Person 3 F27 I liked the scheduling feature. And would like to have the same possibility for wet cleaning. It has a too long charging time, I think 30 min for charging would be optimal. Then it should work for about 1 hour. Right now it had to charge after every room and I don t think that is very good. It should be able to clean 100m 2 in one cleaning cycle. I don t think that the side brush should be removed, I think it s essential for cleaning close to the edges. I would use it for dry cleaning every 2 nd day and wet cleaning once a week. Maintenance should not be longer than 10 minutes every week. If I have I robot I would never want to clean manually, but if I have to it would be maximum once a month. I would pay 600 for dry cleaning and for both 800. I don t like the idea of having two robots. It would require two docking station, more space and I would have to clean both. I would like to have reusable cloths, because I don t want to have too much garbage. I prefer that it just uses fresh water, because the cleaning result will be better. Don t like damp mopping at all. I think it should have a warranty length of at least 3 years. I would not like if the wet cleaning has a scrubbing brush since I would think that it might scratch my floors. I would prefer a microfiber roller or cloth instead. I would leave the robot to do dry cleaning and wet cleaning and I would trust that it would do its job, since it s a product from Vorwerk. Interview Person 4 M22 I have never used a cleaning robot. I would like to be able to schedule it because I have heard that the robot is very load. And if it is very load I would not want to be at home when it s running. The cleaning of edges is very important so therefore so I think the side brush should stay there. It should at least be able to clean room in one charge. I would use it for dry cleaning every third day and wet cleaning once a week. The cleaning speed is not very important as long as the cleaning result id good. It should not take more than 2-3 hours to charge it. I would like to have the option to set it to dry cleaning only or wet cleaning or both. In one week I can clean it for maximum 30 min. I wouldn t like to clean if I had one but if I have maximum 1 a month. I think it s a bad idea to have 2 robots, because then I have 2 robots to maintain and handle, they take more space, and energy. I would prefer reusable parts because otherwise I have to spend more money. The warranty should be at least for 2 years or maybe even 5 years. APPENDICES 113

121 Interview Person 5 M2? I have never used a cleaning robot before. It should be able to clean well and clean around corner and recognise obstacles. The side brush is not very integral for the cleaning I would say. But of course the result is better with one. I would like to use the scheduling but the first times I would like try out how it works and if it does a good job. If I am satisfied and I don t need to check up on it I would schedule it. In one charge it should clean for 1 hour. Of course the cleaning area depends on how many obstacles you have on the floor. If it s an empty room it should at least clean 50m 2. It s okay if it charges in between, when it is cleaning as long as I am not home. As long as 80% of the cleaning is done when I come home. I would use dry cleaning once a week and dry cleaning once week. Maintenance should also be one week for 15 minutes or less. Otherwise it would be no need for me to use it. I can clean manually every 2-3 weeks for maybe 40 minutes. I don t like the idea of having 2 robots. You don t have time to maintain 2 robots. But if they are very easy to set up it could work. But I would say that it is optimal to have it all in one motion. It s not good to use damp mopping if you have very dirty floors because then you will only spread the dirt around. And I also know that this way will require more water because it s absorbed in the cloth. I would prefer reusable parts. Isn t that obvious? Warranty time should be at least 2 years. I would like to have indicators telling me when the dustbin is full or when I need to fill it with water. Interview Person 6 M24 Yes I have used one and the best advantage is that you don t have to clean yourself. The bad part is that you have to prepare your home so much before. Remove chairs, carpets open door. And with opened doors it can t clean behind the door. It has big problem with cables. One tank should last for m 2 and about 40-50m 2 should be done with one charge. Cleaning time would not matter so much because I wouldn t be home when using it. I would like to clean it myself every third cleaning and maximum 5 min every time. I would schedule it for dry cleaning once every week and wet cleaning once every month. I would clean myself once a week because I know that it can t clean on top of furniture and that there would be places where it can t reach. I would prefer reusable, because it s faster to clean them yourself than going and buying them. The charging time does not matter too much since when it is not cleaning it is in the charging station. I would prefer the use of fresh water since then you could use some specific chemical to get a better cleaning result. I would want a warranty of 2-3 years. 114 WET AND DRY ROBOTIC VACUUM CLEANER

122 Appendix VII Water Usage of Floor Scrubbers APPENDICES 115

123 Appendix VIII Morphological Matrices The Faded one are the ones that have been excluded. Dry Cleaning Matrix 116 WET AND DRY ROBOTIC VACUUM CLEANER

124 Wet Cleaning Matrix APPENDICES 117

125 118 WET AND DRY ROBOTIC VACUUM CLEANER

126 Appendix IX Elimination Matrices Dry Cleaning Matrix Wet Cleaning Matrix APPENDICES 119

127 Appendix X Pugh Matrix 120 WET AND DRY ROBOTIC VACUUM CLEANER

128 Appendix XI Weight Decision Matrix Each criterion were compared with the other criteria and assigned a value 0, 0.5 or 1. The value represents if the criterion is less important, equally important or more important than the criterion it is being compared with. The values for each criterion were added and are shown in the Sum-column. The sums were divided with the total value and are shown in the next column (σ i ). Later, the following formula was applied to obtain the weight factors.!! = (!!!!,!"# )!!,!"# This method provides an objective approach in assigning weight factors (Johannesson, 2004). APPENDICES 121

129 Appendix XII Pictures of CAD-Models Particle Nozzle Roller Holder 122 WET AND DRY ROBOTIC VACUUM CLEANER

130 Attachment APPENDICES 123

131 Appendix XIII Pictures of Prototype 124 WET AND DRY ROBOTIC VACUUM CLEANER

132 APPENDICES 125