Tracking and Disturbance Rejection for an Uncertain System Using Fast Output Sampling

Abstract

It is shown how a recently proposed sampled-data, multi-rate output feedback controller can be designed to realise the effect of robust state feedback, so that when applied simultaneously to a family of linear plants, the closed-loop eigenvalues are retained. This is not possible when a Luenberger observer is used to realise state feedback. The multirate control law proposed here is useful because it allows to utilise previously developed LMI methods for robust state feedback design when the full state is not available for feedback. A practical design example is presented, and experimental results show that, using the same state feedback design, the multirate controller gives peiformance superior to that achieved with an observer.