[foxglacier]

Closed loop control systems! I'd say that's a common requirement of any robot. I wouldn't spend a lot of time on theory though, just look up the concept of PID and implement it. It's easy. No library needed. There are lots of ways for control loops to perform badly and there's all the theory of that but you can also intuit a lot of it by playing around with motors, encoders, and microcontrollers.