Scheduling algorithm for tasks and messages in asynchronous networked control systems

Abstract

There are a large quantity of control loops in an Networked Control Systems (NCSs) and a control loop consists of two message tasks and a control task which are interactional and interrelated and run on different kinds of resources. For asynchronous NCS, a new algorithm is presented in this paper to schedule these tasks. In our algorithm, the precedence constraints among the subtasks of a loop can be met by controlling their start times and finish times. And the second message tasks of all the loop tasks are arranged according to backward non-preemptive EDF. The first message tasks of all loop tasks are scheduled according to non-preemptive EDF. The algorithm for assigning control tasks to processors is designed and control tasks are scheduled according to their available times. The experiment results show that the algorithm can schedule message tasks and control tasks effectively.