Fault-tolerant and optimal scheduling algorithm for a class of distributed control system

On the basis of analysis on the character of the synchronous sampling distributed control system, a novel fault-tolerant scheduling algorithm was given. Firstly, a scheduling sequence (including primary copies and backup copies) was designed in a sampling period. Then heuristic static algorithm for assigning tasks to processors has been adopted and the primary copy and backup copy of a real-time task are assigned to different processors. The tasks assigned to a processor are executed according to their orders in scheduling sequence. Because the performance of control system is influenced on by sampling period and control delay, genetic algorithm based on integer coding was applied to optimized scheduling sequence. Simulation result show the scheduling algorithm can guarantee that real-time tasks are fault-tolerant schedulable and the performance of control system is improved.