Uncertain Double Pendulum with All-Pass: Stabilization and Disturbance Rejection

A Hinf controller has been designed for the nominal double pendulum and beside stabilization the task of the controller is to reject a strong current pulse. For the nominal plant, the controller perfectly rejects this disturbance but when an all-pass is added, the closed-loop system get an oscillatory behavior. This can be observed in the first part of the film. The Hinf controller will be robustified with the D-K iteration. The resulting mue controller has no oscillatory behavior and almost no performance degradation occurs. This can will be demonstrated by the second part of the film.