H∞ smith predictor design for time-delayed MIMO systems via convex optimization

A new method for robust fixed-order H_∞ controller design for uncertain time-delayed MIMO systems is presented. It is shown that the H_∞ robust performance condition can be represented by a set of convex constraints with respect to the parameters of a linearly parameterized primary controller in the Smith predictor structure. Therefore, the parameters of the primary controller can be obtained by convex optimization. The proposed method will be applied to stable MIMO models with uncertain dead-time and with multimodel and frequency-dependent uncertainty. The performance of this method is illustrated by simulation examples of industrial processes.