Balancing Robot

This is my latest robot – it’s an inverted pendulum 2 wheel balancing robot. These photos and video are actually about a year old and were taken during initial development. I have made many improvements since these were taken, and will update with new pictures and videos showing the improvements and enhanced capabilities soon.

The robot has six PIC processors from Microchip Technology (http://www.microchip.com/) to handle the various functions:

• The master processor board has two PICs – the receiver PIC decodes the RC receiver’s PWM outputs and passes the results to the master PIC which controls the whole system.
  

• The IMU (Inertial Measurement Unit) processor board has a PIC that implements a Kalman filter to process inputs from a solid state SEN-008413 three degree of freedom module. The module is from Sparkfun Electronics (http://www.sparkfun.com/) and uses an ADXL320 accelerometer in combination with an ADXRS401 gyro rate sensor.
  

• The Sensor processor board has two PICs – one to capture data from a couple slotted encoders from an old wheel mouse to provide position feedback (but not balance information). The other PIC on this board handles communication with the CMUcam1 camera module (http://www.cs.cmu.edu/~cmucam/home.html) and LV-EZ4 ultrasonic rangefinder from Sparkfun Electronics (http://www.sparkfun.com/).
  

• Finally, the Speech processor board has a PIC that handles control of an old SP0256-AL2 allophone based speech chip.
  

There is also an H-Bridge motor controller board to take PWM commands from the master processor to control the two drive motors.

All software was written in PIC assembly language.

This video shows the robot balancing and moving around. The forward and turning inputs come from one joystick on a standard radio control (the same one I used on my snake robot). The head movement is controlled by the other joystick on the RC control. This video demonstrates the manual head movement mode, the head actually has a color tracking mode that I will show and describe in a future posting.