Capstone Spring 2009Preliminary Design Review

Cole Bendixen

Electrical and Computer Engineering

Erich Hanke

Electrical Engineering

Erik Larson

Electrical Engineering

Quang Than

Electrical Engineering

HAMSter

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HAMSter Project Overview

Mobile Servo Powered Cart Stereo-Vision Obstacle DetectionAutonomous NavigationFPGA Hardware / Software ControlIR Sensor “Failsafe” Collision Avoidance

HAMSter Purpose

To create an autonomous platform that can be used as a mounting point for various sensors and monitors to test remote locations without human

control.To advance hardware stereo-vision algorithms.

Cart Control Systems

IR

IR

IR

IR

IR

VIRTEX-5 FPGA

Cam0

Cam1ADC

BOARD

Opto-ElectricIsolation

COM1

ServoCntrl

Board

PowerPC440

Hardcore

Servo

Servo

Servo

Servo

Servo

Servo

Right Wheels

Camera tilt/pan

Left Wheels

COM 0

GPSReceiver

BRAM16Mb

Imageco-proc

DDR2256MB

GPS

Used for long range directional controlPolled GPS to periodically calculate a destination vectorHard coded destination

RF Transceivers

Beacon at destination pointMedium/Short range destination proximity sensorOverrides GPS when activeImplementation based on timeCould be achieved through stereo vision

Stereo Vision

2-NTSC cameras input 30fps image streamsImage processing detects obstaclesUse of parallax to determine distance

IR

Provides short range obstacle detectionHighest sensor interrupt level – acts as failsafe to avoid collision

30 cm

Sensor Interrupt Levels

IR Proximity Sensor

Frame Ready To Processes

Polled

Highest Priority

Lowest Priority

GPS

Computer Stereo-Vision

RF Beacon Detector

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Code Flow Diagram

Mobile Cart

Frame Grabber

ImageProcessing

SoftwareProcessing

Wheel Translation

ControlHardware Filter

Servo Control Board

Driver Interface

Green = Hardware Implementation Blue = Software ImplementationYellow = Hardware/Software interface

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Stereo Vision

Based upon the phenomena of parallax, where an observation at two locations along a baseline of a common object appears to cause an offset of the object. This offset can be used to determine relative distance to the object.

Camera One Camera Two

d1 d2

Point Spread FunctionSimple PSF is applied to the image to enhance edges.Parameterized sweeper size and intensity.Post convolution threshold filter applied.

HDL IMAGE CO-PROCESSOR

PPC HARDCORE PROCESSOR

DVI CONTROLLER

IMAGE PROCESSING

PPC REGINTERFACE

PLL

DATABUILDER

DVISIGNAL

GENERATOR

RAM BLOCK

SRAMCONTROL

CONTROLREGISTERS

DATABREAKER

CONVIMAGE

PowerPC 440

1,100 DMIPSUp to 550MHzOut of Order ProcessingBranch Prediction256MB DDR2 200MHz

I/O Control

Interrupt Enabled InputsIR SensorsObject Array stored in Block RAMPolled InputsGPS via COM0TransceiverOutputsServo Control Board via COM1

Path Determination

Initial direction of destination is determined using the GPS/transceiver data.Objects are then realized in software.Movement vector is determined based on direction and relative position of objects.IR sensors are then used to update path model due to “invisible objects.”

GPS Direction Determination

Given our current position (in the grid coordinate system) from the GPS, we calculate our north/south and east/west displacement from the destination position and use that to calculate a destination direction vector.We then calculate the deviation of our current direction from the destination direction and rotate the robot the required amount to correct this difference.

Transceiver Direction Determination

The transceiver will determine a direction and distance of the destination transceiver.We then calculate the deviation of our current direction from the destination direction and rotate the robot the required amount to correct this difference, just as with GPS.Transceiver is necessary because the GPS is only accurate to ~3m.

Object Realization

To realize objects we will create a matrix representing the relative visible area in the direction of the destination.Object input in the form of a distance and deflection will then be used to populate this matrix with objects.

Movement Vector Determination

First we determine acceptable directions to travel based on object positions.We then evaluate a vector in each valid direction space.The length of movement vectors will place the robot just past the nearest object.We then compare the valid vectors and choose the one that places the robot closest to the destination.Instructions are then given to the servos to correct direction and move forward the determined distance.

IR Recognition of 'Invisible' ObjectsIR interrupts cause immediate motion halt.Object is populated into matrix using IR sensor determined direction and distance.Path is then re-evaluated using updated object matrix.Motion continues.

FPGA

ADC

Camera IR Sensor

GPS

Battery 2

Opto-Isolator

Servo-Control Board

Servo Motors

Battery 1

Power Systems

GoalsCDRRobot that will move to a specified GPS location.Milestone1Object recognition hardware completed.Milestone2Robot that will move to a specified GPS location avoiding 'visible' objects.ExpoRobot that will move to a destination object, via GPS and transceiver, and avoid objects using video imaging and IR sensors.

Budget

Item Name / DescriptionUnit Price

Quantity Sub-Total After Donations

Xilinx ML507 Virtex 5-FX XC5VFX70T-2FF1136C $1,406.00 1 $1,406.00 DONATION

Agilent 1692A Logic Analyzer Mictor Probe $1,150.00 1 $1,150.00 DONATION

Servo-Continuous Rotation HSR-8498HB HMI Robot Servo CNT $79.99 8 $639.92 DONATION

Servo- Positional HSR-8498HB HMI Robot Servo $59.99 2 $119.98 DONATION

NiMH Battery Pack: Powerizer 7.2V 4200mAh with 12AWG wire $29.99 3 $89.97 $89.97

12 Channel Lassen IQ GPS Receiver with DGPS $59.95 1 $59.95 $59.95

Antenna GPS Ultra-Compact Embedded HFL for Lassen IQ $18.95 1 $18.95 $18.95

Sharp GP2Y0A21YK0F Distance Sensor $9.95 6 $59.70 $59.70

CMOS Camera Module 640x480 --SEN-08773 $34.95 4 $139.80 $139.80

Linx Transceiver $17.15 2 $34.30 $34.30

Transceiver Antenna $2.08 2 $4.16 $4.16

Cart Frame Aluminum / wheels / screws $80.00 1 $80.00 $80.00

Miscellaneous wires and parts $60.00 1 $60.00 $60.00

PCB Layout $33.00 3 $99.00 $99.00

Total $ $3,961.73 $645.83

Schedule

Division Of LaborErich H. Cole B. Quang T. Erik L.

Hardware

Cart Construction x x

Servos x x x

Servo Controller x x

GPS x x

Video Processing x x

Object Recognition x x

IR Sensors x x

Transceiver x

Power System x x

Software

Servo Control Code x

GPS data processing x x

Pathing code x x x

IR interrupt processing x

Transceiver data processing x

Documentation

Preliminary user's manual x

Final Technical Documentation x x x x

User's Manual x x x x

RISKS

ADC interface to the FPGA – Loading images into memoryWheels operating at same speedsInaccurate calculation of cart speed to judge distance traveledInterfacing to the RF transceiver (signal magnitude not direction)Cart frame parasitic to GPS or RF signals