8803 , CSSE - 14 April 6 , 2001 Improving performance of deadbeat servomechanism by means of multirate input control

In this paper, an state-space approach to deadbeat servomechanism design is proposed using multirate input control. This paper focuses advantage of multirate control over conventional single-rate control. To achieve settling time specified, multirate controllers require less frequent sampling of measurement than single-rate ones. Multirate input mechanism can yield shorter settling time than single-rate control using the same frequency of sampling. However, multirate control often exhibits intersample ripple. Nevertheless, this paper demonstrates that the undesirable effect of multirate input on the steady-state response can be removed completely to accomplish ripple-free deadbeat, keeping the settling time short using multirate mechanism at the same time. Furthermore, the paper proposes a design method for multirate ripple-free deadbeat control which guarantees robustness against continuous-time model uncertainty and disturbance.