Qualitative analysis of worst-case performance for general deterministically nonsynchronous controllers

This paper considers multirate sample-data systems with deterministically nonsynchronous controllers. Samplers and hold mechanisms in different channels do not update their signals at the same time. Phases of discrete-time events are independent of each other. This paper focuses on the effect of the nonsynchronous phase distribution on L^p worst-case performance. Qualitative analysis of performance degradation or improvement caused by the nonsynchronism is presented. In particular, the worst-case performance measure is shown to be a continuous function of the phase shift. This paper extends the result [4] of decentralized control to general nonsynchronous systems with centralized controllers. Noticeable differences between the behaviors of centralized and decentralized nonsynchronous controllers are described.