A Variable-period Dynamic Scheduling Strategy for Networked Control Systems

A design method based on current network running performance is presented for the dynamic scheduler of networked control systems.Firstly,a monitor is used to acquire current network utilization,network-induced error and the execution time of data packets,and the network utilization and data packet execution time in next period are predicted based on the acquired network information.Secondly,according to the demands of both control performance and network performance,the network resources are allocated and the new sampling periods of the control systems are computed based on the network utilization and the data packet execution time.When conflicts occur in data packet transmission,MEF(Maximum Error First) is adopted as an auxiliary scheduling strategy to determine sending priority of the data packets.Finally,simulation results are given to validate the effectiveness of the proposed dynamic scheduler.