State-space approach to the combined sensitivity and complementary sensitivity problem

The Combined Sensitivity and Complementary Sensitivity (CSCS) problem is concerned with simultaneously minimizing the effects of disturbances from two independent sources on a closed-loop, output feedback, control system. Recent papers have dealt with the SISO problem; we consider the more general MIMO case. We shall present a method of transforming a MIMO CSCS problem into a standard H∞ control problem. We are able to use existing techniques and relevant computer software packages to construct numerical solutions of the MIMO CSCS problem. An example illustrating our procedure is also presented.