Group 8 David Morrow Ricardo Rodriguez Shane Theobald Nick Bauer University of Central Florida College of Electrical Engineering and Computer Science Senior Design Fall 2011 Wanted to gain experience in many different engineering disciplines ◦ ◦ ◦ ◦ C# - GUI Optics – Laser Range Finder Wireless Communication Controlling Peripheral Devices via Microcontroller Calculate the GPS coordinates of a user specified target using the following components. ◦ ◦ ◦ ◦ Wireless Camera Laser Rangefinder Digital Compass GPS Module Minimize ◦ Cost ◦ Weight ◦ Power Consumption Target Specs ◦ 5m minimum distance ◦ 100m maximum distance ◦ 10m x 10m minimum target size Accuracy ◦ Rangefinder distance within ±10m ◦ Self GPS coordinates within 5m radius of true location ◦ Compass heading within ±1° of true heading ◦ Final target GPS coordinates within 50m radius of true location Methods of Laser Rangefinding ◦ Triangulation Easiest method both conceptually and design Based on geometry Increasingly less accurate as range increases ◦ Interferometry Most accurate method of laser rangefinding Can measure small distances on order of wavelengths ◦ Time-of-flight Can measure very large distances with great accuracy This is the approach that we will implement Photodetector HV Power Supply Front End Amplifier (Transimpedance Amp) NIR optical filter Receiver Lens Pros ◦ Highly Sensitive Photodetectors ◦ Make use of avalanche multiplication for increased gain ◦ High Speed ◦ Designed for rangefinder applications ◦ Allows for larger maximum range detection Cons ◦ Require HV reverse bias to get maximum gain ◦ Exhibit higher dark current than alternatives ◦ Small active area makes alignment difficult Peak Spectral Response Cost and Availability Minimum Dark Current Required Bias Voltage Enhanced for NIR detection at 900nm Spectral Response at M = 100 Low noise equivalent power = 10fW/√Hz TO-52 Package allows for easy mounting Proportional Input/Output Voltage 250VDC when full 5V input applied Low peak-to-peak ripple (<1%) Maximum Output Current 4mA Low turn on voltage of 0.7V Converts photocurrent into voltage High Slew Rate at 290V/µs Low Input Noise Voltage 7nV/√HZ FREE—Sampled 0.9 0.8 0.7 Transmission 0.6 0.5 0.4 0.3 0.2 0.1 0 860 870 880 890 900 910 920 930 940 950 Wavelenth in nm Filter Specs ◦ ◦ ◦ ◦ 2 in X 2in X .1in CWL 905.9nm BBW 54.0nm Peak transmission 79% Lens Tube Assembly Receiver Electronics Prevent False Alarms ◦ Capture as much energy as possible ◦ Keep noise floor low ◦ Set threshold Output Power—Need high power laser diode to meet maximum range criterion Pulsewidth—Must have short pulsewidth to have high axial (range) resolution (V x τp) Wavelength—Transmitter near peak responsivity of photodetector. Beam Divergence—low divergence angle to ensure maximum energy on target HA! SPL-PL-90_3 ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ TO-18 Package Divergence 9 x 25 gradient degrees Minimum Rise/Fall time 1ns Threshold Current 0.75A Peak wavelength 905nm Power output 75W Peak Current 40A Typical Voltage 9V Pulsewidth 5-100ns 5mm 5.9mm Pros ◦ ◦ ◦ ◦ Very small in size at 1”x2.5” Produces fixed pulsewidth at 15ns Can produce up to 50A diode drive current Diode mounts easily to CCA. (Radial or Axial options) Cons ◦ Also requires high voltage source ◦ 33ns propagation delay ◦ Difficult T-zero capture Supply Current ◦ Ips = (Cpfn + Cfet + Cstray) * Vin * f ◦ Ips = (4000pF + 120pF + 430pF) *195V *1Hz =0.9µA Output Current ◦ Directly dependent on HV supply (195V is max) JP1 Connection Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 10 Ground 15V @ 1mA (support power) Ground Gate (Trigger) 5V Ground HV in (0 - 195V @ Ips) Transmitter Electronics High Voltage 15V 10-13V ±5V 5V 3.3V ◦ Diode Driver Board – 195Vmax ◦ Avalanche Photodiode – 230V ◦ Diode Driver Board ◦ Camera System ◦ Comparator ◦ Op Amps ◦ High Voltage Power Supply ◦ Microprocessor ◦ TDC Designed and Build using ExpressPCB Creates a digital value for the laser pulses time of flight from the transmitter to the receiver. ◦ ◦ ◦ ◦ ◦ ◦ ◦ 2 channels with 50 ps rms resolution Measurement from 3.5ns to 1.8ms Fire pulse generator I/O voltage 1.8v – 5.5v Core voltage 1.8 – 3.6v 4 wire SPI interface QFN 32 Package 5mm 5mm Microcontroller ◦ Programming Language: C ◦ Development Environment: Arduino Uno IDE ◦ Handles data collection and peripheral control GUI ◦ Programming Language: C# ◦ Development Environment: MS Visual Studio ◦ Receives user input and displays relevant information GPS Compass MCU XBee TDC Pan & Tilt Clock Speed Core Size I/O Pins Package Size Memory UART/I2C/SPI/PMW Operating Voltage Price • • 16 MHz 8 bit 14 DIP 28 32 kB 2/1/2/6 1.8 – 5.5V $6.27 Mounted on Arduino development board Arduino Uno development environment compatibility • • • • C Programming language Allows for flexible troubleshooting Large support community SPI, I2C, & Serial libraries Input Voltage Input Current Baud Rate C/A code Comm. Protocol Accuracy Price 4.5 – 6.5V 44 mA 4800 1.023 MHz UART; RS-232 5m WAAS $59.95 5cm 5cm Input Voltage Input Current Field Range Resolution Comm. Protocol Weight Price • • 2.7 – 3V 2 – 10mA 0.1 gauss 0.5 degrees I2C 0.14 grams $34.95 Two axis digital compass Provides heading in degrees from magnetic north 100ft radial distance Omni-directional link Low Power Consumption Input Voltage RX/TX Current Transmit Power TX Sensitivity RF Data Rate Baud Rate Frequency Band Indoor Range Outdoor Range Protocol Antenna Price 2.8 – 3.6V 40 mA 2 mW (+3 dBm) -98 dBm 250 Kbps 1200 – 1 Mbps 2.4 GHz 133ft 400ft Zigbee (802.15.4) Whip (dipole) $25.95 (X2) 3cm 3cm Operating Voltage Operating Speed (6V) Stall Torque Operating Angle Current Drain (6V) Motor Type Weight Price 4.8 – 6V .18 sec/600 83.3 oz*in 450 8.8 mA / 180 mA 3 Pole Ferrite 1.59 oz $16.99 Weight (w/o servos) Tilt Swing Max. Payload Price 5.5 oz 135o 2 lbs $45.99 DIY Security Camera Kit ◦ NTSC format ◦ 510x492 pixels 900MHz Tx/Rx combo Connect to XBee and Video Open GUI no Poll GPS User Input yes Fire Laser Poll Compass Display Info Move Camera PositionalData Target RangeFinder - double CompassHeading + PositionalData targetData + PositionalData Info - double latitude + RangeFinder rangefinderData + int distance - CalculateGPS() - PollGPS() - DisplayData() - PollCompass() - string LatitudeHeading - double longitude - string LongitudeHeading - PollLaser() - DisplayData() Given: ◦ Self GPS Coordinates Latitude (N/S ddmm.mmmm) Longitude (E/W ddmm.mmmm) ◦ Distance to target (m) ◦ Heading clockwise from magnetic north (deg) Calculate: ◦ Target GPS Coordinates Latitude (N/S ddmm.mmmm) Longitude (E/W ddmm.mmmm) Spherical Law of Cosines lat2 = sin-1[ sin(lat1)*cos(d/R) + cos(lat1)*sin(d/R)*cos(Θ) ] lon2 = lon1 + tan-12 cos(lat1)*sin(d/R)*sin(Θ) cos(d/R) - sin(lat1)*sin(lat2) [ ◦ ◦ ◦ ◦ ◦ Self GPS coordinates (lat1, lon1) Distance to target (d) Heading (Θ) Radius of the earth (R) Target GPS coordinates (lat2, lon2) ] Subsystem Cost Analysis Budget Laser System Time to Digital Conversion Camera System Compass Module GPS Module Wireless System Microcontroller Power System Mounting Fixture and Servo Motors PCB Construction TOTALS: $770.29 $70.00 $0.00 $35.00 $79.99 $50.00 $45.00 $200.00 $75.00 $115.00 $1,440.28 $850.00 $50.00 $100.00 $50.00 $100.00 $100.00 $50.00 $25.00 $100.00 $75.00 $1,500.00 Rangefinder Components Quantity 2 1 1 1 1 1 1 2 1 1 Part Name Laser Diode OSRAM SPL PL 90_3 Diode Driver IXYS PCO 7110-50-15 APD Pacific Silicon AD230-9 TO52-S1 Optical Band Pass Filter Laser Diode Collimation Tube Receiver Extension Tube Receiver Lens HV Power Supply EMCO A025 Op-Amp TI OPA656 Assorted Resistors/Capacitors Cost $55.00 $207.20 $92.53 $30.00 $15.00 $140.00 $34.00 $65.78 $0.00 $10.00 Total $110.00 $207.20 $92.53 $30.00 $15.00 $140.00 $34.00 $131.56 $0.00 $10.00 Component/Task Critical Design Review Condensed Final Report Final Presentation Due Date 20-Sep 2-Dec 2-Dec David X X X Responsibilities Ricardo Nick X X X Shane % Complete X X X 100% 0% 0% X X X PHASE 1 - Components 97% GPS 100% Microcontroller Communication 4-Sep Data Manipulation in GUI 4-Sep X 100% X 100% Compass Microcontroller Communication Data Manipulation in GUI 100% 11-Sep 11-Sep X 100% 100% X Camera Wireless Communication Video in GUI Optics 100% 18-Sep 18-Sep 18-Sep X 100% 100% 100% X X Servos Microcontroller Communication Hardware Setup 100% 25-Sep 25-Sep X 100% 100% X Wireless System Microcontroller Interface GUI Interface 100% 30-Sep 30-Sep X X 30-Sep X 100% 100% Power System Hardware Setup 100% X X X Laser Tx Hardware Setup Optics Calibration 11-Sep 11-Sep 11-Sep X X X X X X 100% 100% 100% 25-Sep 25-Sep 25-Sep X X X X X X 100% 100% 10% Laser Rx Hardware Setup Optics Calibration 70% Time to Digital Microcontroller Communication Calibration 100% 100% 100% 2-Oct 2-Oct X X X David Ricardo 100% 100% Nick Shane PHASE 2 - System Integration 100% GUI 100% Target GPS Algorithm Live Video Servo Control Laser Control 9-Oct 16-Oct 23-Oct 30-Oct X X X X Camera, Laser Tx/Rx Alignment Properly mounted components Compact Design 16-Oct 23-Oct 30-Oct X X X Designed Manufactured 16-Oct 30-Oct X X 100% 100% 100% 100% X X X X X X X X X X X X X X X X X X Housing 100% 100% 100% 100% PCB 100% 100% 100% PHASE 3 - Testing 79% Testing Rangefinder GPS Compass Servo Control Algorithm GUI 79% 13-Nov 6-Nov 6-Nov 6-Nov 6-Nov 13-Nov X X X X X X X 50% 75% 75% 75% 100% 100% X X X David Ricardo Nick Shane Environmental conditions Laser transmitter and receiver alignment Divergence t0 Timing Cost ◦ Replacing broken parts Compass and GPS polling Noise QUESTIONS?