Ferromagnetic Material Launcher Senior Design II Report Group 1 Group Members Austin Akey Joshua Sanchez Donald Freeman Brett Oden Summer 2014 Table of Contents 1.0 Executive Summary ..................................................................... 1 2.0 Project Description ....................................................................... 3 2.1 Motivation for the Project .................................................... 3 2.2 Project Goals and Objectives .............................................. 4 2.3 Project Specifications and Requirements ............................ 5 2.3.1 Coil Components Specifications ............................. 5 2.3.2 Control System Specifications ................................ 6 2.3.3 Software Specifications .......................................... 7 2.3.4 Power Specifications .............................................. 8 3.0 Background/Research ............................................................... 10 3.1 Similar Projects ................................................................. 10 3.1.1 Coilgun Projects ................................................... 10 3.1.2 Automated Turret Projects .................................... 13 3.1.3 Accelerometer Control Apps ................................. 16 3.2 Related Technology .......................................................... 17 3.2.1 FPGA/Microcontroller ........................................... 17 3.2.2 Wireless Communications .................................... 19 3.2.3 Motors .................................................................. 20 3.2.3.1 Servo Motors ............................................ 20 3.2.3.2 Stepper Motors ......................................... 21 3.2.4 Optics ................................................................... 23 3.2.5 Design Software ................................................... 25 3.3 Projectile ........................................................................... 25 3.4 Barrel ................................................................................ 26 3.5 Magnetic Field .................................................................. 27 3.5.1 External Iron .......................................................... 28 3.6 Heat Dissipation................................................................ 29 3.7 Automatic Reload ............................................................. 30 3.8 Velocity Detection ............................................................. 31 3.8.1 Experimental Methods .......................................... 32 3.8.2 Real Time Methods ............................................... 33 3.9 Capacitor Type ................................................................. 34 3.10 Power Sources ............................................................... 36 3.10.1 Batteries ............................................................. 36 3.11 Power Conversion .......................................................... 36 3.11.1 AC/DC Conversion ............................................. 36 3.11.1.1 AC Step-up .............................................. 39 i 3.11.1.2 DC Step-up ............................................. 40 3.11.1.3 DC Step-down ......................................... 41 4.0 Design ....................................................................................... 43 4.1 Projectile ........................................................................... 43 4.1.1 Magnetic Properties .............................................. 43 4.1.2 Projectile Fabrication ............................................ 44 4.2 Barrel ................................................................................ 45 4.3 Force and Energy Characteristics ..................................... 46 4.4 Coil ................................................................................... 49 4.4.1 Dimensions ........................................................... 50 4.4.1.1 Diameters ................................................. 50 4.4.1.2 Length ...................................................... 51 4.4.2 Conductor ............................................................. 52 4.4.2.1 Conductor Type ........................................ 52 4.4.2.2 Insulation Type ........................................ 52 4.4.2.3 Conductor Sizes ....................................... 53 4.4.3 Coil Simulations .................................................... 55 4.4.3.1 Inductor Simulator ..................................... 55 4.4.3.2 RLC Simulator .......................................... 56 4.4.4 Heat Dissipation .................................................... 58 4.5 Magnetic Field .................................................................. 59 4.6 Automatic Reload ............................................................. 61 4.7 Velocity Detection ............................................................. 61 4.8 Automated Turret .............................................................. 62 4.8.1 Power and Control ................................................ 63 4.8.2 Mounting Hardware .............................................. 65 4.8.3 Position Feedback ................................................ 66 4.9 PCB Components ............................................................. 67 4.9.1 Wireless and USB ................................................. 67 4.9.2 GPIO Pins ............................................................. 69 4.9.2.1 Input ......................................................... 69 4.9.2.2 Output ....................................................... 69 4.9.3 Microcontroller ...................................................... 71 4.9.3.1 Hardware .................................................. 71 4.9.3.2 Software ................................................... 72 4.9.4 Power ................................................................... 73 4.10 Optics ............................................................................. 74 4.11 Software Implementation ................................................ 75 4.11.1 Software Block Diagram ..................................... 75 4.11.2 Android vs. IOS ................................................... 76 ii 4.11.3 User Interface ..................................................... 77 4.11.4 Wi-Fi P2P Communication .................................. 79 4.11.4.1 Camera Feed .......................................... 80 4.11.4.2 Password protected launch ..................... 81 4.12 Capacitor Charge and Discharge .................................... 82 4.12.1 Mode 1 ............................................................... 85 4.12.2 Mode 2 ............................................................... 86 4.12.3 Mode 3 ............................................................... 87 4.13 Power Supply ................................................................. 88 4.13.1 Energy Source .................................................... 88 4.13.1.1 Batteries ................................................. 88 4.13.1.2 Wall Outlet .............................................. 89 4.13.2 Turret Power ....................................................... 90 4.13.3 Control Power ..................................................... 90 4.13.4 Coil Power .......................................................... 90 4.13.5 Circuit Protection ................................................ 91 4.13.6 User Safety ......................................................... 91 5.0 Design Summary ....................................................................... 94 5.1 Final Gun Design .............................................................. 94 5.2 Final PCB Microcontroller Design ..................................... 95 5.2.1 Schematic and PCB Layout .................................. 95 5.2.2 Microcontroller Software ....................................... 98 5.3 Final Turret Design ........................................................... 99 5.4 Final User Interface Design ............................................ 100 5.5 Final Power Design ......................................................... 102 5.5.1 High Voltage ....................................................... 102 5.5.2 Low Voltage ........................................................ 103 5.6 Project Operation and User’s Manual ............................. 104 6.0 Prototype Construction ............................................................ 106 6.1 Gun Components ............................................................ 106 6.2 Microcontroller Prototype ................................................ 108 6.2.1 Breadboard Microcontroller ................................. 108 6.2.2 PCB Microcontroller ............................................ 109 6.3 Supply Power ................................................................. 110 6.3.1 Equipment Housing ............................................ 110 6.3.2 Wiring Harnesses ............................................... 111 7.0 Prototype Testing ..................................................................... 113 7.1 Bench Testing ................................................................. 113 7.1.1 Charging Circuit .................................................. 113 7.1.2 Gun Components ............................................... 114 iii 7.1.2.1 Coil and Projectile ................................... 114 7.1.2.2 Firing Position ........................................