final presentation of “toolbot” eel 5666 intelligent machines design laboratory december 3, 2002...
TRANSCRIPT
Final Presentation of “Toolbot”
EEL 5666Intelligent Machines Design
LaboratoryDecember 3, 2002
Jeno Nagy
Abstract
Purpose of “Toolbot”Platform and DesignElectronics Systems for motion and deliveryOverview of each mechanismProblems and solutionsOverall performance
Purpose of “Toolbot”
Autonomous tool delivery systemDispenses proper sized sockets as neededFollows user and waits for commandsIdeally fits under vehicle and survives a garage type environment
Platform and Design
Two wheeled round bodyLarge battery tray between servos
Keeps center of gravity low
Huge battery
Elevated carousel for sockets with dispensing doorTop mounted camera
Vertically adjustable camera angle
Electronics
Power Pack YUASA NP2-12 12V
2.0Ah Lead-Acid Battery
Voltage regulation 4 5V
regulators Main controller
board Camera 2 servos
Electronics
Controller Microchips PIC 16F877
at 4Mhz 8K FLASH
Main Board Supporting Devices
EDE 702 Serial LCD Driver
Densitron LM2202A LCD Display
Altera 7032SLC44-10F CPLD
Systems for motion and delivery
Movement 2 GWS S03N BB servos
Motion/Behaviors Obstacle Avoidance
IR proximity sensors 2 Sharp GP2d12 forward
looking IR 4 contact bump ring with
voltage divider network
Systems for motion and delivery
Motion People tracking/following
CMUcam Vision Board SX28 microcontroller at 75 Mhz Digital data extraction from image Serial interface at 9600 Baud with PIC
Systems for motion and delivery
Delivery Carousel type
holder with 10 sockets One GWS 303N BB
servo for rotation Dispensing door
under carousel One GWS PICO BB
servo for door movement
Systems for motion and delivery
Delivery Voice command
recognition using Voice Direct 364 Board
RF headset for increased accuracy
Systems for motion and delivery
RF link Small transmission box
with headset Internals
Voice Direct 364 board Rentron TWS-434 RF
transmitter 433.92 MHz
PIC 16F84A at 4Mhz for serial transmission from voice board at 2400 Baud
All calculations done inside, serial data sent identifies location of socket to dispense
Systems for motion and delivery
RF link Transmitter Board Receiver
Rentron RWS-434 RF receiver
Serial link to main controller PIC at 2400 Baud
Systems at work
Color following using CMUcam
Follow yellow object Stop if confidence is
low and wait Search left-right if
found but unsure which way to go
Yellow LED array for feedback
Systems at work
Carousel Dispensing socket
upon voice command
Self alignment on startup using beam break
Wait for voice command
Dispense right socket
Systems at work
Carousel Dispensing socket Transmitter is shown Green blink indicator
shows key word recognized
Second red indicator blinks between 1 to 10 to show which command is sent
Problems and Solutions
Problem #1 CMUcam
Very sensitive to light conditions Works 100% on my desk Works 70% on kitchen table Works 0% on kitchen floor
LCD indicates a pixel level of 208 which causes software to sit and wait for command
Conclusion: Image gets flooded with light and tracks it. Fix: turn off and try again
Initially there was no color lock
Solution #1 Had software stop servos if pixel count was locked
instead of driving around in crazy rampage
Problems and Solutions
Solution #1 cont. Initialized CAM with stricter settings
and adjusted white-balance and auto-gain
Still affected by surroundings but better
Problems and Solutions
Problem #2 Carousel alignment
Direct driven by servo in center Attached to 4 inch “lazy susan” for stability The servo was off-center with respect to support Carousel would turn half way then get stuck
Solution #2 Have support free-spin under carousel. Not as stable as before but it turns 360 degrees
Problems and Solutions
Problem #3 Unreliable voice recognition
Low accuracy with words
Solution #3 RF link solved most of the problem Over 90% accuracy
Compromises in design
Inconsistent (jerky) motion due to PWM driving issuesSlow reaction to movement due to calculations needed to extract decimal values out of serial ASCII streamDelays in receiving dispense command due to SERIN command limitations
Overall Performace
All systems operate within specs except for the CMUcam which works in certain lightThe obstacle avoidance, tool delivery, RF link all function as neededThe CMUcam problem is outside the scope of the actual robot design. Experimenting with IR filtering might improve it.
Lessons Learned
Don’t use a PIC for anything needing servos with a 50Hz signal Hardware can’t generate it unless
clock speed is less then 1 Mhz
Stay away from products of other universitiesKeep it simple in design
Conclusion
The EndAny questions?
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