Partial State Feedback Control System Synthesis Method with Preview Feedforward Compensation

A new synthesis method for digital multi-input multi-output partial state feedback control system with preview feedforward compensation is proposed. The preview feedforward compensation is discussed from two different points of view. (1) a preview feedforward compensation which minimizes a same performance index as that for the optimal feedback control system, (2) another preview feedforward compensation which minimizes a different performance index from that for the optimal feedback control system in order to improve the transient response. The performance index value is analytically derived when applying these preview feedforward compensations. In simulation and experimental studies, it is shown that the performance index value considerably decreases and the smooth transient response of the control system is attained by making used of the former preview feedforward compensation. It is also shown that the transient response is fairly improved by making use of the latter preview feedforward compensation. When some of the state variables are not directly detectable, the full state feedback control system with these feedforward compensations is transformed into the partial state feedback control system by using the straightforward method without designing an observer.