An optimal general purpose scheduler for Networked Control Systems

The network-induced time delay is one of the major challenges that appear when the design or the analysis of any Networked Control System (NCS) is needed. The delay can be tackled in the network level by performing control of network actions. Since the process of prioritizing the network access is the main contributor of the network-induced time delay, then the efficient way to control the time delay is to improve the scheduling criterion. This paper proposes an optimal scheduling criterion that improves the quality of service for each node in the network and at the same time maintains the stability of the control system. The proposed optimal scheduling protocol is a hybrid scheduling criterion that combines the advantages of the dynamic and the static scheduling protocols. First, the algorithm of the optimal scheduling is discussed. Second, the optimal control-scheduling problem is formulated. The mixed logical-dynamical optimization problem is then solved. Finally, numerical examples and simulation results are introduced and discussed.