URSA: Encoders

One of the specs I wanted for URSA is accurate movements to navigate it's unknown environment. Using stepper motors would certainly do that, but they are quite power hungry! The answer is using 'standard' motors with axle encoders mounted that will allow fairly accurate tracking. Dagu has a relatively inexpensive Simple Encoder kit consisting of an 8 pole magnetic disc and a hall-effect sensor to read the pole changes as the axle rotates. I have attached the disc to each of URSA's drive axles:

...and the sensors (making sure you have the smaller side of the sensor facing the disc!) were attached to the robot body using wire ties:

Finally, a quick test to insure the sensors are picking up the pole changes on the disc as it rotates by connecting the motors and sensors to a power source and an LED to the hall-effect sensor's output: Mount and Test Dagu Simple Encoders