An optimal robust controller with multi-rate output feedback by using symbolic computation

This paper considers a robust discrete-time multirate output feedback. The feedback is robust to measurement noise in outputs. So far, there exists a method to robust to measurement noise by adding more inter-sampling outputs and selecting values of additional parameters in estimation of state feedback. But the selection is obtained by try-and-error method and is sometimes not optimal. In this paper, proposed is to obtain mathematical expression for an index of sum of errors caused by measurement noise using symbolic computation software. And by the expression an optimal parameter values are obtained.