Multilevel control under communication constraints

The performance of distributed control systems, apart from the sampling period, depends on many parameters, such as the control loop execution time, jitter and communication parameters of data transmission channels. Limited throughput of transmission channels, combined with non-optimized hardware and software components introduce non-determinism in the real-time control system. Additionally, some control loops can be handle not only by local, device - level controllers, but also by the supervisory controllers in a multilevel, vertical control hierarchy. In this paper we propose a design method for a networked, multilevel control system, which can be used to select proper values of the of the design parameters. In the paper some control techniques improving the temporal robustness of networked control systems are analysed.