Structural Properties of Multirate Sampled-Data Systems

The application of Networked Control Systems (NCS) in which sensory and control signals are transmitted via shared data communication networks, is growing significantly and these systems have been the subject of research during the last decade. On the other hand, multirate sampled data systems have been investigated since a long time. In this paper, conditions under which a networked control system could be modeled as a multi rate sampled data system are provided. After that, using recent results in the field of networked control systems, existing results for controllability and stabilizability of multi rate sampled data systems are enhanced. For this purpose, sufficient conditions are provided based on the system eigenvalues, to preserve controllability (stabilizability) of a multi rate sampled data system. The results are compared to the existing results in the literature. A numerical example is included as well for clarification and comparison.