Re: Project Proposal for Selective Noise Canceling Headphone System

Transcription

1 Jan 25, 2016 Dr. Andrew Rawicz School of Engineering Science Simon Fraser University Burnaby, British Columbia V5A 1S6 Re: Project Proposal for Selective Noise Canceling Headphone System Dear Dr. Rawicz Attached you will find the document Proposal for a Selective Noise Canceling Headphone System, which outlines our project for ENSC 440W. Our goal is to design a system protocol to allow workers in noisy industrial settings to remain safe and work efficiently while protecting their hearing. The proposal describes the problem to be solved and details our solution, including design plan, budget, and timeline. This document also describes the prototype system which is to be developed in the next three months which will demonstrate the functionality of the full system. Ekho Systems is made of four fourth year engineering students with previous work experience: Russell McLellan, Taylor Robson, Gordon Ho, and Adrian Tanskanen. If you have any questions or concerns, please contact us my at rmclella@sfu.ca. Sincerely, Russell McLellan President Ekho Systems

2 Proposal for a Selective Noise Canceling Headphone System Group 18: Russell McLellan Taylor Robson Gordon Ho Adrian Tanskanen Contact Person: Russell McLellan Submitted: January 21, 2016

3 1 EXECUTIVE SUMMARY Catastrophe can strike in loud manufacturing plants if workers remain blissfully unaware of alarms. The cacophony of noise in these situations makes auditory alarms inadequate, leaving the critical alarm systems as a flashing blue light. But can safety be trusted to visuals? If employees are deeply immersed in work, a visual alarm may go unnoticed and a serious accident can occur. And worse if a worker is injured in a high noise environment, signaling for help could be impossible. A system is needed for workers to use their sense of hearing to remain safe. Many construction sites have only auditory alarm systems, as it is impractical to setup visual alarms when the building is being erected. The use of power tools, the use of hearing protection, and the obstructions between employees and where the alarm is sounding can lead to alarms going unheard. This can lead to a hazardous worksite, or time and money spent to improve the alarms or to provide visual alarms. We at Ekho Systems has a revolutionary new product idea - Selective Noise Cancelling Headphones that seeks to resolve these issues at a relatively low cost to the employer. This product is still in the development stage but looks to offer much functionality that is currently unavailable or is too costly to implement. These headphones would be encased in earmuffs for reducing noise and also have a noise cancelling system as well to provide a quieter environment for the user. These headphones will have a microphone that filters out all noise other than the frequency of the alarms and sends the auditory alarm signal through to the user. In addition to passing the alarm through to the user, add-ons will eventually be available. One such add-on is a proximity-based sensor to allow employees within a certain range to talk to each other. Based on how loud a person speaking the range that their voice is projected will change. For example, if someone is to injure themselves and yell, their voice will be projected to the majority of the site, whereas if someone speaks at a conversational level their voice will only be projected to people that are close to them. The design of the main system, which includes the research, proposal, design, implementation and testing, is to take place between January 1, 2016 and April 11, 2016.The budget to create a working prototype is approximately $765. We are four engineering science students, who between us have worked on construction sites, observed the limitations of alarm systems, and are trained in the use of microcontrollers, sensors, and signal processing. With this knowledge we seek to make hazardous work environments significantly safer by providing more methods of interaction and extending the functionality of current alarm systems. ii

4 Table of Contents EXECUTIVE SUMMARY TABLE OF CONTENTS LIST OF FIGURES II III IV INTRODUCTION 1 WORKPLACE SAFETY AND CURRENT SOLUTIONS 3 PROPOSED DESIGN, SCOPE AND BENEFITS 4 LIABILITIES, RISKS AND HAZARDS 6 PROTOTYPE 7 BUDGET 8 COMPETITION 9 SCHEDULE 11 DESIGN TEAM 12 CONCLUSION 13 REFERENCES 13 iii

5 List of Figures Figure 1. Sound levels in decibels (dbs) of various noises, some common to work place settings [2]. 2 Figure 2. Example of emergency protocol from an industrial setting [4]. 3 Figure 3. The proposed Ekho Systems solution with two workers. 4 Figure 4. Active filtering applied to an alarm signal with random excess noise generated from an industrial environment [3]. 5 Figure 5. The prototype system. 7 Figure 6. Schedule for the design and fabrication of a full set of selective noise cancelling head phones with voice volume controlled wireless communication add-on. 11 iv

6 2 INTRODUCTION Industrial workplaces are extremely hazardous if certain safety precautions are not adhered to. In many metal working plants employees are required to wear respirators, face shields, hearing protection, hard hats, high visibility vests, steel-toed boots and a plethora of other equipment. Ekho Systems looks to make the items that workers already use more functional. According to the Association of Workers Compensation Boards of Canada, there were approximately 36,000 injuries that resulted in time off work in manufacturing during 2013, 27,000 injuries that resulted in time off work in construction during 2013, and 2,000 injuries that resulted in time of work in mining, quarrying and oil wells [1]. Between these three industries, in 2013 there were an estimated 65,000 injuries and 480 fatalities [1]. Considering the number of injuries and fatalities, improved response and notification systems will drastically reduce the time employees are off work, the number of injured employees, and the number of fatalities. The main objective of our project is to enhance current safety equipment to make working and communicating in loud industrial environments less hazardous. Some of the benefits of our product include decreasing the response time getting to injured employees and make employees notice alarms almost instantaneously. Just improving these safety concerns is not enough, as we want to adapt the current equipment to be more functional so that employee production does not deteriorate due to too many restrictions caused by personal protective equipment (PPE). Hearing protection blocks out worker to worker communication as well as industrial noise, causing communication problems. If properly implemented the system should reduce the number of injuries, which will lead to fewer claims, less money paid out by insurance companies, and therefore lower rates for companies. These lower rates for insuring employees will offset some, or even all, of the cost of buying this system. Our design deals specifically with the industrial dangers caused by the constant loud background noise from heavy machinery or power tools. The National Institute for Occupational Safety and Health (NIOSH) recommends no more than two hours of exposure each day to noises on the intensity level of 100dB or no more than eight hours exposure each day to noises on the level of 85dB in order to prevent permanent hearing damage [2]. Figure 1 shows a variety of noise levels common to loud workplace settings. 1

7 Figure 1. Sound levels in decibels (dbs) of various noises, some common to work place settings [2]. Figure 1 illustrates how noises common to work place settings often exceed the thresholds set by NIOSH. With Ekho Systems technology, workers will be able to operate and communicate safely in job sites ranging from construction to airplane hangars without any loss of hearing from the prolonged exposure to these dangerous sound waves. By doing this, employers can maximize worker production and employees can work without concern of the permanent damage that would otherwise be inevitable. This proposal covers the current alarm systems, our proposed design and its limitations, the schedule for completing a prototype as well as sources of funding. Potential liabilities and hazards our product may have are also included. 2

8 3 WORKPLACE SAFETY AND CURRENT SOLUTIONS There are a wide variety of alarm systems and warning systems that currently used in industry. These can go from simple systems such as an air horn to extremely complex systems that have bells, speakers and flashing lights. The simplest alarm system typically used on a construction site is having stations setup with air horns and a sign that tells what each sequence of blasts indicates. An example of this sign is shown in Figure 2. This system is used in construction sites because the cost of installing alarms and sensors in a building is not justifiable while erecting the building. Limitations of this system are that an injured person may not be able to make it to an air horn station to signal when they need help, or others may not hear the air horn if they are across the site with power tools running and hearing protection in. Figure 2. Example of emergency protocol from an industrial setting [4]. A second system is a built-in, automatic auditory alarm system. These systems usually have sensors to trigger automatically if there is a fire or a handle for manual triggering. These systems do not allow for different messages to be conveyed; they can only signal that there is a safety issue. The previous two alarm systems were only auditory, which means that workers with hearing protection may not be able to hear them. Since this shortfall is well known, louder industrial plants use visual alarms as well. These are required in certain buildings by fire and building codes. The use of visual alarms is becoming more common as designers and builders are taking hearing impaired persons into account. Visual alarms are required to have a certain light intensity, which differs by region and code, projected onto the majority of surfaces in a room. This is adequate in most situations, but these alarms can be overlooked or missed if someone is not facing the correct direction. Current alarm systems work for the majority of public spaces but can be severely lacking in industrial and commercial plants. Multiple alarm systems can be costly to install, so they are not always implemented when necessary. Relying on the alarms in an industrial setting runs the risk of workers not noticing the emergency signal. Ekho Systems wants to ensure that no alarm goes unnoticed. 3

9 4 PROPOSED DESIGN, SCOPE AND BENEFITS We at Ekho Systems seek to remedy all of the issues associated with industrial alarm and safety systems as outlined in section 3. We propose an all-purpose set of safety headgear that integrates a set of Selective Noise Cancelling Headphones with a hands free voice controlled communications system. By combining these two technologies, workers will no longer have to fear missing potentially lifesaving alarms. Additionally, the system will allow for seamless communication between workers, regardless of the setting, without the confusion associated with attempting to communicate with an individual on a walkie-talkie while everyone is on the same frequency. Since hearing protection is required for loud industrial sites, our system looks to integrate additional features into current safety standard hearing protection. The system will incorporate active noise cancelling headphones built into noise reducing earmuffs, a microphone that can filter out alarms and pass the alarm through the headphones, and add-ons such as a volume controlled voice projection system that allows the user to communicate with others at different distances based on how loud they speak. A block diagram of the proposed system with two workers is shown in Figure 3. Figure 3. The proposed Ekho Systems solution with two workers. 4

10 Since many companies such as Sony, Bose, or Beats already have high quality noise cancelling headphones our product will utilize their design. These headphones are usually good for reducing or completely eliminating low frequency noises. However, since industrial applications can have high levels of higher frequency noises, pairing active noise cancelling headphones with earmuffs is necessary. Ear muffs are better at reducing high frequency noises but are not always a great solution as a buzzing can usually still be heard. Through combining both of these existing products, employees should be able to focus on their work without fear of damaging their ears regardless of how loud the environment is. Our solution to allow workers to hear auditory alarms is to integrate an innovative electrical system into protective headgear so as to bypass important emergency signals to the user regardless of the amount of exterior noise. To achieve this, a microphone will be placed outside of the headphones in order to measure all sound from the workplace. The sound will be send to a microprocessor integrated into the headphones. The microprocessor will then actively filter out all frequencies other than the alarm and pass the sound of the alarm through to the headphones, as seen in Figure 4. Figure 4. Active filtering applied to an alarm signal with random excess noise generated from an industrial environment [3]. In addition to alarms, the headphones will have a voice volume controlled wireless communication microphone add-on. This device will allow the user to wirelessly project their voice to other headsets in a certain range determined by how loud they speak into the microphone. This works by the user speaking into a microphone attached to the system microcontroller; the microcontroller will then process the users voice and then relay the voice signal to all other sets of headphones within a range proportional to the intensity of the users voice. The receiving processor will read the signal, decipher the distance away the microphone sending the signal is and then will relay the voice signal through to the headphones. The intensity of the sound signal sent to the headphones will decrease the further the two people are from each other and will increase if the person speaking into the microphone talks louder. As a safety device, this add-on vastly improves upon devices such as the walkie-talkie by removing the necessity to push a button or change settings to communicate with certain people. Instead, if the user is in an emergency situation, or even simply has their hands full and is in need of help, he need only raise his voice to call for help. This design will allow for easier communication, and reduce the chance of missednalarms. It augments current PPE but there will be minimal additional equipment employees are required to wear. 5

11 5 LIABILITIES, RISKS AND HAZARDS The United States Department of Labour states that hearing protection is manditory on a job site for an 8 hour work day when the environment exceeds noise levels of 85dB [2]. What Ekho Systems seeks to offer is an augmentation to current safety standards in a workplace environment. If any part of Ekho Systems Selective Noise Cancelling headphones is not certified to pass safety standards, it cannot be used in worksites. The main hazard associated with our design is the use of potentially sensitive microelectronics in a heavy industrial setting. The main issue with this results from the chance that if the electronics in the noise cancelling headphones fail, they may no longer act as adequate hearing protection. For this reason our final design will be integrated in such a way as to bypass the sound proofing or noise cancelling of a pair of certified hearing protection. Because of this, should the electronics that produce the active selective noise cancelling fail, an Ekho Systems headset will still act as certified hearing protection. Additional hazards that may arrise through use of our product involves the failure of the communications element of the headset. Until our system becomes certified, the Ekho Systems Selective Noise Cancelling Headset is not a replacement for current safety standard equipment required on a job site, rather it serves to augment and improve upon the current available equipment. Should the communications device encounter a catastrophic failure, the worker should resort to the standard given equipment. 6

12 6 PROTOTYPE Before the full system is manufactured, a prototype will be developed. The prototype will consist of two microcontrollers demonstrating all aspects of the system. The prototype is shown in a block diagram in Figure 5. Figure 5. The prototype system. The prototype system consists of two microcontrollers. The powerful primary device will do most of the audio processing and send the audio data to the headphones. The cheaper secondary device will simply read in speech from a microphone and send the audio data to the primary device. The system will use a SONAR-like system of ultrasonic sound waves to determine the distance between the two devices to operate the proximity filter. One device will send out a signal, and the other device will respond. The time taken for the response to be measured will give the distance between the two devices. An overview of the devices used in the prototype is given below. Noise Cancelling Headphones Noise cancelling headphones work by having a microphone on the outside that captures the noise. An algorithm makes an equal and opposite frequency noise that is broadcast through the speaker and then another microphone on the inside of the headphone is used to measure how well the noise was cancelled. For this project, the Sony Active Noise cancelling headphones will be used due to their reasonable price, which is approximately $220. Other headphones, such as Beats Studio, retail for $250, 7

13 which increases the overall product by a larger percentage making the increase in quality not worth the monetary loss. Microphones There are many microphones on the market. For the microphone used to sense the alarm an accurate and clear microphone will be required so that individual frequencies are able to be retrieved. For the prototype, we will be integrating a Motorola NNTN8382 Noise Cancelling Microphone which is priced at around $200. Microcontrollers This project requires the use of an Arduino microcontroller to actively filter out selective noises. Typically, these microcontrollers cost from $30 to $100. To optimize the conversion of sound into digital data, the fastest model will be required. We have determined the Intel Galileo Gen 2 Arduino to be the model best suited for our applications due to its high speed and large memory. In addition to the Intel Galileo, a second microcontroller will be used for application in our voice controlled proximity sensor. This microcontroller is necessary in order to interact with the main board to provide wireless communication. We intend on using the Genuino Uno Rev3 Microprocessor, which is less powerful and expensive than the Intel Galileo. Other Input/Output devices Several smaller input/output devices are needed for the prototype. The ultrasonic transducers and the receiver-transmitter pair shown in Figure 5 add cost to the prototype. The price of these components is small when compared to the microcontrollers and audio equipment. 7 BUDGET Table 1 below shows the estimated costs for the materials and systems required to build a functioning set of Ekho Systems Selective Noise Cancelling Headphones with a Voice Volume Controlled Wireless Communication add-on. Unforeseen costs have been added onto the total cost because large portions of the design process of this product are only possible upon receiving the majority of the components and testing their capabilities. 8

14 Table 1- Budget List for Ekho Systems Selective Noise Cancelling Headphones with a Voice Controlled Proximity Communication Add-On Equipment List Unit Cost 1x Intel Galileo Gen 2 Microprocessor $100 1x Sony 10RNC Noise Cancelling Headphones $220 1x Motorola NNTN8382 Noise Cancelling Microphone $200 2x Murata Electronics MA40S4S Ultrasonic Transducer $10 1x Genuino Uno Rev3 Microprocessor $25 1x Wenshing RWS-374 Wireless Receiver $5 1x Wenshing TWS-BS Wireless Transmitter $5 Unforeseen Costs $200 Total Cost $765 Justification for the components required for the prototype is found in section 5 of this proposal. Funding This budget primarily outlines the costs of designing and constructing a prototype headset. As with any product, the price of manufacturing reduced with the number of units being constructed. Should the prototype be successful, each of the microcontrollers used for this project will be replaced with chips specifically designed for this application. In addition, the headphones required for a final manufactured product would be designed by Ekho Systems, rather than ones designed by Sony. The combination of digital chips as well as Ekho Systems designed headphones would likely reduce the total components cost to under $300 per unit to manufacture. In the case that the prototype is received successfully we will be seeking funding from sources such as WorkSafe BC and various heavy industry companies. We would also seek funding from trade schools such as BCIT and Vancouver Community College. For the prototype, we will be seeking funding from various grants, such as the ESSEF grant offered by the ESSS at SFU school of engineering science. The remainder of the project shall be self-funded unless we become sponsored by interested parties. 8 COMPETITION We at Ekho Systems are positive that we are set to deliver a product that will revolutionize industrial workplace safety. With our Selective Noise Cancelling Headphones and wireless voice controlled communications systems we seek to displace two separate products used by the tireless men and women found working in loud, dangerous work sites all over British Columbia. The competition for the selective noise cancelling headphones part of our design includes the following: i. Industrial Earmuffs These are the safety standard for worksites all over North America. Ear muffs are ideal for reducing high frequency noises but are not always a great solution as a buzzing can usually still be heard. Earmuffs typically cost $20. 9

15 ii. Noise Cancelling Headphones- Actively cancels outside noise through use of electrical components. These headphones are usually good for reducing or completely eliminating low frequency noises. These often sell for up to $300 per unit. As for our voice controlled communication system the competition is documented below. i. Motorola Noise Cancelling Microphone- These are for specific use in loud factory settings. Actively cancels out noise other than voices, including all manner of industrial noises. These sell for $200. ii. Hands Free Bluetooth- These allows for hands free voice communication, but do not filter out any background sound. A good quality Blue Tooth Headset sells for up to $150. The brilliance behind our design is that it incorporates the technologies of the primary competitions into a single system. By bypassing a set of industrial earmuffs with active noise cancelling technology, both low and high frequency noises will be unnoticeable. Additionally, ours is the only product that allows emergency alarms to be heard. As for the voice controlled communication, the Noise Cancelling Microphone does not allow for hands free communication and Bluetooth microphones are not set up for industrial settings. Our product also offers the use of voice volume controlled communication, which is a novel new technology that will be brought to work places all over by Ekho Systems. We hope that our complete system will become the standard for workplace safety. With the help of WorkSafe BC, Ekho Systems seeks to raise the bar and ensure that no alarm will go unheard. For the unit price of approximately $300, workers on a large industrial site will be able to operate as if they were working in a quiet office. We will also be selling our product to individual factories and workplaces as a means of augmenting their current systems. As mentioned before, the increased safety and communication should rapidly increase worker productivity as well as enhance the ability for managers to ensure the job site runs smoothly. 10

16 9 SCHEDULE The schedule for the fabrication of the prototype is shown below in Fig 6. Figure 6. Schedule for the design and fabrication of a full set of selective noise cancelling head phones with voice volume controlled wireless communication add-on. 11

17 10 DESIGN TEAM Russell McLellan President I am a fourth year engineering physics student with research experience. I have background in modelling, analyzing, and controlling complex systems, specifically an automotive fuel cell powertrain. While this project does not have challenges that a fuel cell powertrain does, my experience translating models into prototypes and analyzing the resulting system will prove invaluable. From my SFU coursework, I have gained proficiency in both signal processing and in the physics underlying this project. Taylor Robson Chief Executive Officer I am a fourth year systems engineering student minoring in business. I have a background in carpentry, mechanics, and consulting engineering. Through my previous experience I am well versed on current standards in construction from required PPE to the opinions of workers that are wearing it. Having a background in business will help ensure the marketability and profitability of this product. Experience programming on a microprocessor, Zedboard, in previous classes will help with programming all of the communication protocols between the components of the system. Gordon Ho Senior Software Engineer I am a fourth year systems engineering student at SFU. I have a strong background in robotics, and have won many competitions in the past. My first co-op gave me much experience in rapid prototyping with 3D printers, Arduino microcontrollers, and small actuators. My recent co-op was software based and I gained valuable experience in programming in a multi-project environment. I have experience in using source tree and other various tools needed for a complex environment setup. In my spare time, I have also built an electric longboard, 3D printer, and a quadcopter. My hand-on experience will definitely be an asset to this project. Adrian Tanskanen Senior Product Design and Verification Engineer I am a fourth year engineering physics student specialized in microelectronic system design. Over the last eight months, I have not only delivered outstanding results and developing CMOS analog integrated circuits, but have continued to consistently excel at my schoolwork, as well as act as a mentor to many of my colleagues. This trend towards excellence has its roots in years of hard work in everything I put my mind to, and has lead me to compiling an extensive skills set to aid in project design, ranging from expertise in electrical engineering to a strong understanding of methods of theoretical and experimental physics. 12

18 11 CONCLUSION Ekho Systems Selective Noise Cancelling Headphones provides an elegant improvement on workplace safety through use of a convenient portable device. We are committed to engineering safety and communication equipment to the highest standard in order to ensure the safety of the men and women working in heavy industrial zones throughout North America. Through our innovative new set of protective headgear, we hope to alleviate the issues surrounding communicating in industrial environments while ensuring that lifesaving alarms don t go unheard. Our innovative design hopes to augment the industrial work place in such a way as to enable seamless communication between workers as if there was no industrial noise. The Ekho Systems Selective Noise Cancelling Headphones uses advanced signal processing technologies to allow for alarms and other desired sounds to bypass the necessary hearing protection found on all job sites. This is done by actively reading the sound waves of an industrial site and selectively allowing the noise signals of alarms to be projected to the user. Our system will also include a communication system that projects a user s voice to other headsets depending on how loud the user talks. By doing this the user can communicate with nearby workers without fear of interfering with people working on other parts of the job site. It also allows for the added safety feature that should the user end up being injured, they need only raise their voice in order to notify the entire job site of their distress. We at Ekho Systems are passionate about workplace safety. We hope to integrate our innovative new technology to aid the on-going workplace safety movement while also enhancing worker performance. Preliminary research predicts that this project should be fully completed by early April and we are eager to present the product to potential users. 12 References [1] Association of Workers' Compensation Boards of Canada (2015). Detailed Key Statistical Measures Report [Online]. Available FTP. [2] United States Department of Labor (2011). Occupational Noise Exposure [Online]. Available FTP. [3] Véronique Vaillancourt, Hugues Nélisse, Chantal Laroche, Christian Giguère, Jérôme Boutin, Pascal Laferrière (2015). Comparison of sound propagation and perception of three types of backup alarms with regards to worker safety [Online]. Available FTP. epage=436;aulast=vaillancourt [4] Digital Print Imaging Canada (2016) SITE: AIR HORN 3 BLAST FOR FIRST AID 1 LONG BLAST FOR FIRE [Online]. Available FTP. 13