Transcript Team GPS Rover

Team GPS Rover
Alex Waskiewicz
Andrew Bousky
Baird McKevitt
Dan Regelson
Zach Hornback
Overview

Project Main Objectives
 Outline of Approach
 Implementation of Sub-Systems
 Division of Labor and Responsibilities
 Schedule
 Risks and Contingency Plan
PROJECT MAIN
OBJECTIVES
Baseline Functional Description
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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 Description
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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 APPROACH
VEHICLE
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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
ELECTRONICS
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GPS module
 Digital compass
 Proximity sensors
 RPM monitors
 Control block
 2-way RF
communication link
 Power system
Block Diagram
Digital
Compass
Laptop PC
RF Link
GPS
Module
Control Block
Wheel
Encoders
Motor
Proximity
Sensors
SOFTWARE
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Vehicle control
GPS Interface
Coordinate Tracking
Pathfinding
Collision Avoidance & Sensors
Communication
Possible Reprogramability
– Preserve stop functionality & remote programming
– Receiver Transmitter Pairs
IMPLEMENTATION OF
SUB-SYSTEMS
GPS Parts
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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 Link
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4800bps
UART
Analog or digital
modes
$15
Variable range with
transmitted voltage
Sparkfun
Digital Compass
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$60
 ½ degree resolution
 I2C interface
 Provides excellent
tracking coordination
with GPS sensor
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http://www.sparkfun.com/commerc
e/product_info.php?products_id=79
15
RPM Monitors
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Measure speed and distance traveled
 Along with Digital Compass provides
backup and coordination with GPS tracking
 Buy or Build?
 Optical Encoder
– Black and white “spokes” on inside of wheel
Programmable Logic
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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 1
Sensor 2
Sensor 3
Logic
External RAM
Microcontroller
Microcontroller
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Required
– Dedicated data and address busses to external memory
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Wishlist: ability to “easily” interface with
peripherals
– Onboard ADC(s)
– Onboard PWM
– Onboard I2C module, or other serial communication
protocol
Sensors
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Use: 2 sensors, one forward, one downward
– Provides obstacle avoidance and drop-off detection
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Options:
– Ultrasonic: Devantech SRF08 Ranger ($62)
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6m range
I2C interface
– IR: Sharp GP2Y0A21YK ($12)
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80cm range
Analog interface
Sensor configuration
Power Subsystem
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2.5V, 3.3V, 5V systems (potentially)
 Use of two 9V batteries in parallel:
– Won’t need more than 9V, will provide
sufficient energy
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Use of 3 voltage regulators
– Simple and cheap
DIVISION OF LABOR AND
RESPONSIBILITIES
ALEX
ANDREW
BAIRD
DAN
ZACH
•Car
Interface
•Chassis
Mount
•Car
Interface
•Car
Interface
•GPS
•GPS
•Perf
Board
•Chassis
Mount
•Power
•RF Link
•Sensors
•RPM
Monitors
•Power
•Organize
Documents
•Digital
Compass
•CPLD
•Software
•Sensors
•CPLD
•Digital
Compass
•Software
SCHEDULE
Done
In progress
Not started
RISKS AND CONTINGENCY
PLAN
Risks and Contingency Plans
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Parts availability and shipping times
 Cost
 Interfacing with the Car
 Providing sensor data to the microcontroller
 RF communication
 Component failure
Questions?