Team GPS RoverTeam GPS RoverAlex WaskiewiczAndrew BouskyBaird McKevittDan Regelson

Zach Hornback

OverviewOverview

Project Main ObjectivesOutline of ApproachImplementation of Sub-SystemsDivision of Labor and ResponsibilitiesScheduleRisks and Contingency Plan

PROJECT MAIN PROJECT MAIN OBJECTIVESOBJECTIVES

Baseline Functional DescriptionBaseline Functional Description

The human user will be able to drive the rover Rover will calculate its location and bearing Rover will transmit telemetry to the user The user will command the rover Rover will sense and avoid obstacles Rover will autonomously maneuver to its assigned

destination

Extended Functional DescriptionExtended Functional Description

Rover could have onboard camera(s) providing visual feedback to user.

Rover could be able to carry and deploy instrumentation packages– Rocket launch platform– Environmental sensors– Mechanical Manipulator

Drive

OUTLINE OF APPROACHOUTLINE OF APPROACH

VEHICLEVEHICLE Traxxas Rustler

– 445x311x178 mm– 1.69 kg– Top Speed 35 mph– $203 with batteries– High Load Capacity– Replaceable parts

Electronics Platform– Attaches to the chassis– Carries electronics, sensors, and batteries– Interfaces directly with car controls– Weight and Size are constraints

ELECTRONICSELECTRONICSGPS moduleDigital compassProximity sensors RPM monitorsControl block 2-way RF

communication linkPower system

Block DiagramBlock Diagram

Control Block

DigitalCompass

GPSModule

RF Link

ProximitySensors

WheelEncoders Motor

Laptop PC

SOFTWARESOFTWARE Vehicle control GPS Interface Coordinate Tracking Pathfinding Collision Avoidance & Sensors Communication Possible Reprogramability

– Preserve stop functionality & remote programming – Receiver Transmitter Pairs

IMPLEMENTATION OF IMPLEMENTATION OF SUB-SYSTEMSSUB-SYSTEMS

GPS PartsGPS Parts Requires

transmitter/receiver and interface board.

EM406 SiRF III Evaluation Board - RS232 - $30

20 Channel EM-406 SiRF III Receiver with Antenna - $60

Concerns: Interfacing eval board with PC & resolution of GPS (10meters listed)

RF LinkRF Link

4800bps UART Analog or digital

modes $15 Variable range with

transmitted voltage Sparkfun

Digital CompassDigital Compass

$60 ½ degree resolution I2C interface Provides excellent

tracking coordination with GPS sensor

http://www.sparkfun.com/commerce/product_info.php?products_id=7915

RPM Monitors

Measure speed and distance traveledAlong with Digital Compass provides

backup and coordination with GPS trackingBuy or Build?Optical Encoder

– Black and white “spokes” on inside of wheel

                            

                                                  

Programmable Logic

Xilinx CPLD or FPGA to sample sensors and place sensor data in external memory

May use extra logic to control motors if PWM block is inaccessible

Sensor 3

Logic

External RAM

Microcontroller

Sensor 2Sensor 1

Microcontroller

Required– Dedicated data and address busses to external memory

Wishlist: ability to “easily” interface with peripherals– Onboard ADC(s)– Onboard PWM– Onboard I2C module, or other serial communication

protocol

SensorsSensors Use: 2 sensors, one forward, one downward

– Provides obstacle avoidance and drop-off detection Options:

– Ultrasonic: Devantech SRF08 Ranger ($62) 6m range I2C interface

– IR: Sharp GP2Y0A21YK ($12) 80cm range Analog interface

Sensor configuration

                  

  

Power SubsystemPower Subsystem

2.5V, 3.3V, 5V systems (potentially)Use of two 9V batteries in parallel:

– Won’t need more than 9V, will provide sufficient energy

Use of 3 voltage regulators– Simple and cheap

DIVISION OF LABOR AND DIVISION OF LABOR AND RESPONSIBILITIESRESPONSIBILITIES

ALEX ANDREW BAIRD DAN ZACH

•Car Interface

•GPS

•CPLD

•Software

•Chassis Mount

•Perf Board

•RF Link

•Power

•Car Interface

•Chassis Mount

•Sensors

•Organize Documents

•Car Interface

•Power

•RPM Monitors

•Digital Compass

•GPS

•Sensors

•CPLD

•Digital Compass

•Software

SCHEDULESCHEDULE

DoneIn progressNot started

RISKS AND CONTINGENCY RISKS AND CONTINGENCY PLANPLAN

Risks and Contingency PlansRisks and Contingency Plans

Parts availability and shipping timesCostInterfacing with the CarProviding sensor data to the microcontrollerRF communicationComponent failure

Questions?Questions?