Abstract: Ball and beam system is a benchmark system to study various control algorithms. It consists of a beam that can be tilted by a DC servo motor and a ball rolling back and forth on the top of the beam. The main reason for its acceptance in labs across the globe is its property that it is open loop unstable. It can serve as a conventional tool for implementation of many classical and modern control system design method. In the paper, the theory of H-infinity control is used to design a control system for the ball and beam system. The theory of Robust control is extended to design a robust PID controller. Controller parameter values for PID controller i.e. gains are found from the robust controller designed.

Keyword: Robust controller, Robust PID, H-infinity, Ball and Beam.