Nooby question here. I know PID (proportional-integral-derivative) control is a math based algo that help you, have a tight control over motors. http://en.wikipedia.org/wiki/PID_controller
But am a little confused about in which situation a robot can be controlled through PID? Or in other words what these PID gain do on motors, does not the motors do that automatically? And do we need the PID gains in a situation when robot needs a lot more torque to regain its balance?
Any guide will be highly appreciated.