Optimal Tasks and Messages Scheduling for Asynchronous Networked Control Systems

Considering the execution order restriction of control tasks and message tasks in asynchronous networked control system (NCS), this paper proposes a hybrid scheduling scheme based on earliest deadline first (EDF) algorithm and genetic algorithm (GA). GA is used to allocate control tasks on multiprocessors in order to achieve load balance. For the purpose of meeting message deadlines and maximizing network utilization, non-preemptive EDF is used for the transmission of messages on networks. Finally, a tasks and messages scheduling paradigm is constructed within a least common multiple (LCM) which contains information about execution time and resource allocation of messages and tasks. Simulation results show that execution order restriction and timing constraints can be satisfied and a considerable high resource utilization rate can be achieved through our scheduling scheme.