Improved Intruder Detection Using Seismic Sensors and Adaptive Noise Cancellation

Transcription

1 Improved Intruder Detection Using Seismic Sensors and Adaptive Noise Cancellation Human, Light Vehicle, and Tunnel Detection Workshop June 16, 2009 William Audette, David Kynor, Jed Wilbur, and John Gagne Creare, Inc. Dr. Lindamae Peck ERDC-CRREL SBIR Data Rights Contract No. W912HZ-09-C-0023 Creare Inc., 16 Great Hollow Road, P.O. Box 71, Hanover, NH Expiration of SBIR Data Rights Period: December 19, 2014 The Government's rights to use, modify, reproduce, release, perform, display, or disclose technical data or computer software marked with this legend are restricted during the period shown as provided in paragraph (b)(4) of the Rights in Noncommercial Technical Data and Computer Software--Small Business Innovative Research (SBIR) Program clause contained in the above identified contract. No restrictions apply after the expiration date shown above. Any reproduction of technical data, computer software, or portions thereof marked with this legend must also reproduce the markings. An unpublished work. All rights reserved. MTG /

2 Program Overview Overall Program Goal: Develop a seismic perimeter monitoring system for walking intruders that overcomes some of the limitations of existing systems (range, interference) Funding: Small Business Innovative Research (SBIR) contract through the U.S. Army ERDC-CRREL Technical Monitor is Dr. Lindamae Peck An unpublished work. All rights reserved. MTG /

3 Outline Approach to intruder detection Performance in a quiet environment Impact of machinery noise Performance using adaptive noise cancellation (ANC) algorithms Comparison to commercially available systems Discrimination of Human vs. Animal Activity An unpublished work. All rights reserved. MTG /

4 Intruder Detection Approach Focus on detecting walking intruders for perimeter security Use common geophones and apply proprietary signal processing algorithms Creare Algorithms Geophone Adaptive Noise Cancellation C Individual Footstep Detection Intruder Detection (Cadence) Alert Key difference is in detecting individual footsteps An unpublished work. All rights reserved. MTG /

5 Example Footstep Data Geophone Data from For Walker at 5 ft to 165 ft Signal Amplitude Raw Data From CRREL SNR of Signal Envelope for Detecting Individual Footsteps SNR (db) Time (sec) An unpublished work. All rights reserved. MTG /

6 Footstep Detection in Quiet Automated Footstep Detection Trial 1 Trial 2 Raw Data From CRREL: Single-Axis, 4.5Hz Geophone Quiet, Rural Pasture in NH Single Walker Trial 3 An unpublished work. All rights reserved. MTG /

7 Adding Interference Diesel Engine Max Range is 168 ft Tractor Off, Footsteps at 100ft Power Spectral Density (db/bin) Frequency (Hz) Time (sec) Tractor On, Footsteps at 100ft Power Spectral Density (db/bin) 100 Frequency (Hz) Time (sec) An unpublished work. All rights reserved. MTG /

8 Footstep Detection Despite Tractor Noise Automated Footstep Detection Raw Data From Creare: Horse Riding Arena, frozen ground, 4.5 Hz geophone Interference from a stationary diesel tractor Tractor is 16.5 feet from the geophone An unpublished work. All rights reserved. MTG /

9 Variable Interference Gasoline Generator Gasoline generator 20 feet from geophone Walker on 40 foot circle Tested with fixed and variable generator speeds 60 Raw Data of Walking While Varying the Generator Speed Frequency (Hz) I II III IV Time (sec) An unpublished work. All rights reserved. MTG /

10 Footstep Detection Despite Generator Noise Automated Footstep Detection Percent of Footsteps Detected 100% 75% 50% 25% 0% 100% 13% 91% 91% 6% 5% No ANC ANC 81% Generator Off Generator Low Generator High Generator Varying Speed Single walker at a radius of 40 feet. Gasoline generator at a distance of 20 feet. An unpublished work. All rights reserved. MTG /

11 Comparison With Commercial Systems Added a cadence detector to finish our algorithm stack Creare Algorithms Geophone Adaptive Noise Cancellation C Individual Footstep Detection Intruder Detection (Cadence) Alert Performed additional field trials to measure range to walker when intruder alert is issued Compared to alerts from commercial systems An unpublished work. All rights reserved. MTG /

12 Test Site 1: Former Riding Field Rural Vermont, May 2009 Ledge, Gravel, Sparse Grass Very Low Background Noise Two Different Walkers 300 ft Walker 250 ft Walking Path R Walking Path L Line of Sensors 13 ft Creare Qual-Tron Left Gain 4,6,9 Qual-Tron Creare Gain 8 Right REMBASS II Gain High Diesel Tractor (stationary, 40 ft back) An unpublished work. All rights reserved. MTG /

13 Test Site 2: Former Pasture ( Swale ) Rural Vermont, May 2009 Thick Soil (for Vermont), Heavy Grass Very Low Background Noise One Walker Walker at 250 ft Walking Path Line of Sensors (as before) Gasoline Generator (40 ft behind sensors) An unpublished work. All rights reserved. MTG /

14 Intruder Detection Quiet Conditions Ins Automated Processing Strongly Influenced By Gain Setting This is at Maximum Gain Test Site 1, Walker B, 2 Trials Test Site 2, Walker D, 3 Trials No Creare Right at Site 2 Five Trials Total An unpublished work. All rights reserved. MTG /

15 Intruder Detection Generator Noise Automated Processing Shows Reduced Range Nuisance Alarms at High Gain No Detections Generator is 40 ft from Sensors Test Site 2, Walker D Three Trials Total An unpublished work. All rights reserved. MTG /

16 Intruder Detection Tractor Noise Excellent Performance Severely Desensitized Tractor is 40 ft from Sensors Test Site 1, Path R, Walker C Two Trials Total An unpublished work. All rights reserved. MTG /

17 Summary Developed approach based on detecting individual footsteps Developed ANC algorithms to restore performance despite machinery noise Detection range compares very favorably to existing commercial systems Other Development Areas... An unpublished work. All rights reserved. MTG /

18 Animal vs. Human Discrimination Winston Individual Footstep Detection Individual Footstep Extraction Measure Morphology 80% of Horse Steps Identified 94% of Human Steps Identified An unpublished work. All rights reserved. MTG /