Final Presentation of “Toolbot” EEL 5666 Intelligent Machines Design Laboratory December 3, 2002 Jeno Nagy

Abstract Purpose of “Toolbot” Platform and Design Electronics Systems for motion and delivery Overview of each mechanism Problems and solutions Overall performance

Purpose of “Toolbot” Autonomous tool delivery system Dispenses proper sized sockets as needed Follows user and waits for commands Ideally fits under vehicle and survives a garage type environment

Platform and Design Two wheeled round body Large battery tray between servos Keeps center of gravity low Huge battery Elevated carousel for sockets with dispensing door Top mounted camera Vertically adjustable camera angle

Electronics Power Pack YUASA NP V 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 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 issues Slow reaction to movement due to calculations needed to extract decimal values out of serial ASCII stream Delays in receiving dispense command due to SERIN command limitations

Overall Performace All systems operate within specs except for the CMUcam which works in certain light The obstacle avoidance, tool delivery, RF link all function as needed The 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 universities Keep it simple in design

Conclusion The End Any questions? =