分布式网络化控制系统优化协同设计

Optimal Co-design of Networked LQR Controller and Bandwidth Schedule Based on CAN-bus

网络化控制系统的性能不仅与控制器的设计有关还与网络QoS有密切的联系;针对基于CAN总线协议的多闭环控制系统共享网络带宽的控制与资源调度协同设计问题,首先给出连续控制系统性能指标与传输延迟、采样周期的近似线性关系,然后以此为目标函数,以不可抢占RM可调度性和控制系统稳定性为约束条件,分配网络带宽,使控制系统整体性能最优,并对得到的传输周期进行谐调化处理,提高网络利用率;采用资源预留方法在不影响周期数据实时性的前提下,保证非周期数据的平均响应时间;最后将协调设计结果应用于某基于CANopen协议的分布式控制实验系统,控制3组倒立摆,通过研究脉冲响应并已有的调度策略比较说明了所提出策略可以有效提高控制系统性能及带宽利用率。

The performance of networked control system is not only determined by controller, but also by network QoS. In this paper, aiming at the bandwidth scheduling problem of multiple closed loop control system, an approximate linear function of continuous system per- formance with delay and sample period is proposed firstly, and then the optimal scheduling algorithm under both non--preemptive rate monotonic （RM） schedulability constraint and NCS stability constraint is proposed which is to optimize the overall performance of NCS. Moreover, an algorithm of sample periods harmonization is present to improve the bandwidth utilization. A reservation--based schedule of non--pe- riod data is also taken into account. Finally, an integrated experiment platform based on CANopen protocol is present, and the experimental results show that the scheme is more effective than the former ones.