[Ken Streeter]

I would suggest installing a position sensor on the steering arm to be used for "closed loop" control to set the position of the steering arm.

A few possible options for the sensor:

• if using a pitman arm to move the steering arm, install a potentiometer directly to the motor shaft
• if using a rack/pinion or lead screw to move the steering arm, use a multi-turn potentiometer or an encoder
• if the steering arm doesn't move particularly far, you could install a slide potentiometer directly to the steering arm.

With the above approach, the robot controller will be able to query the sensor to determine the "current position" of the steering arm.

The operator interface would then be used to set the "desired position" via the joystick, steering wheel, or whatever you use in the OI.

The robot controller could use a PID control loop to force the "current position" to match the "desired position".

Best Regards,
--ken