capstone spring 2009 preliminary design review cole bendixen electrical and computer engineering...
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Capstone Spring 2009Preliminary Design Review
Cole Bendixen
Electrical and Computer Engineering
Erich Hanke
Electrical Engineering
Erik Larson
Electrical Engineering
Quang Than
Electrical Engineering
HAMSter
2
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
10
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
11
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