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ECE 477 Design Review Team 08 Spring 2010. Greg. Ananya. Seraj. Beau. Outline. Project overview Project-specific success criteria Block diagram Component selection rationale Packaging design Schematic and theory of operation PCB layout Software design/development status
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ECE 477 Design Review Team 08 Spring 2010 Greg Ananya Seraj Beau
Outline • Project overview • Project-specific success criteria • Block diagram • Component selection rationale • Packaging design • Schematic and theory of operation • PCB layout • Software design/development status • Project completion timeline • Questions / discussion
Project Overview • Autonomous robot • Simulates behavior of dog fetching • Tracks a thrown object, picks it up, and returns it to thrower • Able to avoid obstacles • Computer vision • Able to recognize an object using a camera • Follows object using computer vision algorithms (SIFT)
Project-Specific Success Criteria • An ability to identify a target object within a captured image • An ability to control vehicle direction and speed • An ability to recognize nearby objects in anticipation of avoiding said objects • An ability to pick up an object autonomously • An ability to record a GPS location in order to verify that DOG has returned to this location
Component Selection Rationale • Microcontroller • Freescale MC9S12A • 8-channel PWM • Dual SCI • Familiar architecture • Chassis • Self-designed and built • Cheapest • Greatest flexibility for designing neck/arm
Component Selection Rationale • Vision processor • Intel Atom board • Available for free • Ability to use high-level languages • H-bridges • VNH3SP30 • 30A capable • PWM drive
Component Selection Rationale • Motors • Planetary gear motor • High torque • Stall torque 152 oz-in (x4) • Ample speed • No load 1023 RPM • GPS • PMB-248 • Accuracy of ±2m • 1 second refresh rate
Component Selection Rationale • Sonar Sensors • LV-MaxSonar-EZ3 • 6” to 254” range with 1” resolution • 3 ¼” diameter dowel
Packaging Design • Chassis • House electrical components • Neck • Extends to reach out and grab object • Head • Top mounted camera for maximum field of view • Tail • Aesthetics (possible GPS mounting position)
Packaging Design Camera GPS (tail?) Servos (TBA) Ultrasonic Sensors Motors Batteries Atom Head Neck Body
Schematic/Theory of Operation • LM2675 • Input: 14.4V • Output: 5.0V • Drives: Micro, Servos, Sensors, GPS, Level Translator • AP1509 • Input: 14.4V • Output: 12.0V (2.0A) • Drives: Atom board
Schematic- H-Bridge • VNH3SP30 • Power Input: 8.4V @ 30 A • Logic Input: PWM, Direction and Enabling I/O @ 5.0V • Drives: Motor(x2) Test Points µC PWM Pin Enable and direction pins 8.4V @ 30A GND Battery
Schematic-Level Translators • MAX3232 • Input: TTL Rx/Tx • Output: RS-232 Rx/Tx • Allows for serial communication
Schematic - Microcontroller • MC9S12A • 8-Ch PWM • Motor Drivers (x2) • Servos (x6) • 8-Ch ATD • Sonar Sensors (x3) • 24-Ch I/O • Motor Drivers (x8) • LEDs (x4) • Push Buttons (x3) • 2-Ch Serial • Atom Board (x1) • GPS (x1) H-Bridges
Schematic-Oscillator and BDM • 6 MHz quartz crystal • Pierce oscillator • BDM connector • Used for debugging • Reset • BKGND (signal) • Power / Ground
PCB Layout – H Bridge • Wide traces/ multiple traces for power rails • Drill holes for soldering • Heat sinkdrill holes • Output headers connected through thick traces to the motor
PCB Layout – Oscillator • Very close to microcontroller • No traces allowed underneath
PCB Considerations-1 • High power circuitry, digital and analog subsystems are separated and placed in different sections • Bypass capacitors placed close to the microcontroller • Peripherals and connectors are oriented on the edges for easy accessibility High current part Digital Part Bypass Capacitors
PCB Considerations-2 • One main Power and Ground system • Bulk capacitors between the power terminals • Ground and power traces run parallel • 8.4v power supply runs on 150 mils power and ground traces • 14.4v power supply runs on 22 mils power and ground traces Bulk Capacitors Power Ground
Software Design/Development Status • Complete • Tested functionality of GPS, Servos, Sonar, Atom, Motors, Micro • Tested Vision tracking and the use of SIFT • Prototype interfaces with Servos, Sonar, Micro • Layout of all chassis parts • Incomplete • Machining of all chassis parts • Chassis assembly • Software development • Integration