A subsystem design approach to continuous-time performance of decentralized multirate sampled-data systems

A decentralized controller design is presented for multirate sampled-data systems, where stability and input-output performance are considered in terms of continuous-time signals. The design procedure consists of analysis for the overall system and controller synthesis for individual subsystems. For the subsystem designs, a unique technique of removing lifting operation which is used in the analysis is proposed. Robust performance and robust stability in terms of continuous-time signals can be achieved by using the proposed design. A numerical example shows that the design method results in satisfactory controllers which guarantee closed-loop stability and performance in continuous time.