[Dave Scheck]

We have used the same basic crab control on all of our robots since 2002 (I wasn't on the team prior to that, so I don't know how those were controlled).

The X-axis of the left stick controls the crab angle. Since we use a closed loop system, when the joystick is centered, the wheels point straight ahead.

The right stick is where the interesting stuff happens. If we are trying to crab (based on the value of crab stick X), only the Y-axis of the right stick is used, and it becomes our throttle. When we aren't trying to crab, the right stick acts as a single stick differential drive.

This setup is similar to a FPS video game control except we don't attempt to strafe and rotate at the same time.