本文提出一种基于反馈机理的网络控制系统动态调度器的设计方法.首先利用网络监测器在线获取当前的网络带宽和网络传输误差,预测下一监测器采样周期内可利用的网络带宽.然后利用网络带宽预测值和网络传输误差确定各控制回路采样周期的调节规律,并给出反馈调度器的可调度性约束.当数据包传输发生冲突时,采用MEF(Maximum Error First)作为辅助调度策略,确定数据包的发送优先级.最后通过一组仿真结果验证了所设计的反馈调度器的有效性.
A dynamic scheduler based on feedback control is designed to solve the problem of limited network resource sharing in networked control systems (NCSs).Current network bandwidth and network-induced transfer error is obtained by a network QoS(Quality of Service)monitor. Then the new bandwidth is computed based on the known QoS. The sample periods are dynamically changed according to the network-induced error.At the same time,MEF scheduling policy is adopted to decide the priority of data packets when there has conflicts. Finally, the simulation validates the effectiveness of the proposed co-design method.