Oberving and Controlling Plants using their Delayed and Sampled Outputs

This article deals with linear plants whose outputs are not available directly, but only via digital sensors which deliver them in a delayed and sampled format. First, we reconstitute the plant's state by using a Lyapunov-Krasovskii based observer. A sampled tracking control strategy is then proposed by combining the observer with a particular controller that belongs to a class of piecewise continuous systems. Computer simulation examples are presented so as to enhance the theoretical aspect. The method shows reliability and robustness against slight time-variations of the plant's parameters