WORCESTER POLYTECHNIC INSTITUTE Body Armor Impact Map System The research, design, and development of a ballistic impact detection, mapping, and biotelemetry system for body armor. PATENT PENDING U.S. PATENT APPLICATION 62/306,295 Filed March 10, 2016 A Major Qualifying Project Report Completed in Partial Fulfillment of Requirements for the Bachelor of Science Degree in: Electrical and Computer Engineering, Mechanical Engineering, and Computer Science at Worcester Polytechnic Institute, Worcester, MA Report Submitted by Authors & Inventors: Carolyn Keyes, Mechanical Engineering Nicholas Potvin, Electrical & Computer Engineering Zachary Richards, Computer Science Christopher Tolisano, Mechanical Engineering April 27, 2016 Report Submitted to the Faculty and Advisors: Professor William Michalson, Electrical & Computer Engineering Professor John Sullivan, Mechanical Engineering This report represents work of WPI undergraduate students submitted to the faculty as evidence of a degree requirement. WPI routinely publishes these reports on its website without editorial or peer review. For more information about the projects program at WPI, see http://www.wpi.edu/Academics/Projects. Table of Contents Abstract ......................................................................................................................................................... 6 Acknowledgements ....................................................................................................................................... 7 1. Introduction ............................................................................................................................................... 8 2. Background ............................................................................................................................................. 10 2.1 Overview of Current Body Armor .................................................................................................... 10 2.2 Law Enforcement and Military Body Armor Statistics .................................................................... 11 2.3 Prior Art ............................................................................................................................................ 12 2.3.1 Patent Application: Bullet-Proof Vest Bullet Hit Detection System ......................................... 13 2.3.2 Patent: Bullet-Proof Vest with Distress Signaling System ........................................................ 14 2.4 Physiological Effects of Behind Armor Blunt Trauma ..................................................................... 15 2.5 Triage of Gunshot Victims ................................................................................................................ 17 3. Methodology ........................................................................................................................................... 18 3.1 Systems Level Design ....................................................................................................................... 18 3.2 Materials ........................................................................................................................................... 23 3.2.1 Piezoelectric Materials ............................................................................................................... 23 3.2.2 Conductive Fabric ...................................................................................................................... 24 3.2.3 Mesh Interlayer .......................................................................................................................... 26 3.3 Monitoring Subsystem Design & Architecture ................................................................................. 27 3.3.1 Analog to Digital Converter (ADC) ........................................................................................... 27 3.3.2 Field-Programmable Gate Array (FPGA) .................................................................................. 29 3.3.2.1 Control Logic & Memory Architecture .................................................................................. 29 3.3.2.2 Clock Dividers ........................................................................................................................ 30 3.3.2.3 Circular Memory Buffer ......................................................................................................... 31 3.3.2.4 Detecting a Threshold Exceedance ......................................................................................... 34 3.3.2.5 Circuit Behavior upon Threshold Exceedance ........................................................................ 35 3.3.4 Wireless Data Transmission ....................................................................................................... 36 3.3.5 Constructing a Matrix from Strip Values ................................................................................... 36 3.3.6 Android Smartphone Application .............................................................................................. 37 3.3.7 User Monitoring and Data Aggregation Subsystem .................................................................. 38 3.3.8 Power Specifications and Analysis ............................................................................................ 39 4. Results ..................................................................................................................................................... 40 4.1 LabVIEW High Speed Data Collection ............................................................................................ 40 4.2 Construction of Sensor Grid ............................................................................................................. 40 4.3 Small-Scale Sensor Testing .............................................................................................................. 42 4.4 Velostat Testing Without Applied Voltage ....................................................................................... 46 4.5 Drop Tests ......................................................................................................................................... 48 4.5.1 Drop Test Set-up ........................................................................................................................ 48 4.5.2 Drop Test: Modeled .22 LR ....................................................................................................... 51 4.5.3 Drop Test: Modeled 9x19 .......................................................................................................... 55 4.5.4 Drop Test: Modeled .357 Magnum ............................................................................................ 58 2 ©2016 C. Keyes, N. Potvin, Z. Richards, C. Tolisano. All rights reserved. 4.6 First Round of Live-Fire Testing ...................................................................................................... 61 4.6.1 Set up and Plan ........................................................................................................................... 62 4.6.2 Slope Threshold Validation ....................................................................................................... 62 4.6.3 Results ........................................................................................................................................ 63 4.6.4 Strip Construction Performance ................................................................................................. 68 4.7 Worcester Police Live-Fire Testing .................................................................................................. 68 4.8 Third Round Live-Fire Testing ......................................................................................................... 72 4.9 Voltage Threshold Exceedance Calculation ..................................................................................... 77 5.0 Future Development .............................................................................................................................. 80 6.0 Appendix ............................................................................................................................................... 81 6.1 Impact Drop Test Calculations ......................................................................................................... 81 6.2 First Round Live-Fire Test Plan........................................................................................................ 82 6.3 Worcester PD Live-Fire Test Plan .................................................................................................... 83 6.4 Third Round Live-Fire Test Plan ...................................................................................................... 85 References ................................................................................................................................................... 87 3 ©2016 C. Keyes, N. Potvin, Z. Richards, C. Tolisano. All rights reserved. Table of Figures Figure 1: Ballistic Vest Types4 ................................................................................................................... 10 Figure 2: Ballistic Armor Plates7 ................................................................................................................ 11 Figure 3: Patent Application Vest Diagram17 ............................................................................................