Abstract:To solve the dynamic preemptive scheduling problem of a fuzzy uncertain task set under an unpredictable environment, a scheduling algorithm, by applying fuzzy rules and fuzzy scheduling theory, is presented based on fuzzy feedback control, and its corresponding scheduling structure, composed of a basic scheduler and a fuzzy feedback controller, is established. The fuzzy scheduling algorithm is used as the scheduling algorithm of the basic scheduler. By classifying tasks into different priority levels and scheduling the task with high priority level first, more critical tasks can be scheduled. A fuzzy controller constitutes the part of the fuzzy feedback control with the adjusting policy of task flow. Simulation results show that the proposed fuzzy feedback-control scheduling can effectively control the missed deadline rate of tasks, the scheduling problem with fuzzy characteristics or unpredictable environment can be solved, and the successful scheduling rate of critical tasks can be improved.