WoMAN (Work-Oriented Mobile Autonomous Neat-freak) University of Florida Department of Electrical and Computer Engineering Intelligent Machines Design Laboratory Eric Donnelly 8/6/02

Who wants to clean? Problem: The chore of vacuuming is time-consuming and boring. Solution: Have something do it for you! -WOMAN is a small, relatively quiet robot which can vacuum unassisted continuously.

WoMAN outlined

Hardware  Atmel ATmega163 microcontroller  MegaAVR development board  12V, 83 CPM, 35 dB noise DC fan  2 Hacked Futaba Servos  16 Rechargable batteries (NiCad)  2 GP2D12 IR sensors  2 CdS cells  2 LM 35 temperature sensors

Infrared  Cross-eyed approach  GP2D12s have 40 degrees coverage  Mount sensors 20 degrees inward

Bump Switches  6 N.O. bump switches  Tied to ground and Port B with internal pull-up Exposed copper

CdS Cells Uses voltage divider network with 33kΩ resistors Mounted in Pen caps, provide very directional light detection. Using two can provide information of where the light is coming from.

CdS Data degrees right 40 degrees right 20 degrees left 40 degrees left feet awayLeftRightLeftRightLeftRightLeftRightLeftRight Note: the ambient room lighting gave values of 186 and 189, respectively.

Temperature Sensors  Provide 10mV output per 1 degree C above 0.  With A/D with 5V reference, resolution is 2 degrees C.  Mounted with heat sink compound

Temperature Data

Charge Contact Placement  2-D motion  Z-plane constant  Allows for predictable points of contact  Polarity preserved Ground Positive

Charging circuitry

How WoMAN Cleans… Fan = on Roam If battery voltage < Threshold Then Fan = off bridge = on search for home If found home = true ThenRecharge If Temperature > Threshold Then bridge = off Fan = on Roam

“Dizzy Search” CdS cells = on Look for light If time up Then spin in place look for light Follow light Note: 360 degree rotation takes 2 seconds. light interrupt every 10ms. So 360/200 = 1.8 degrees resolution

Room for Improvement  Lower bumper rim positioning  Encapsulate/protect circuitry  Thicker battery packs  Quieter servos/motors

Conclusion WoMAN modestly accomplishes all the task aimed for….  Vacuuming  Obstacle avoidance  Self-recharging ability This robot was a success for a first attempt. Improvements can always be made as lessons are learned throughout the design process. A robust, autonomous robot vacuum is definitely feasable and predicted to enter the commercial market in the future, as foreseen on the Jetsons.