一种变采样周期的网络控制系统控制与调度协同设计新方法

A new co-design method of control and scheduling for networked control systems with variable sampling period

针对存在时变时延与随机丢包的变采样周期网络控制系统,提出了一种鲁棒H控制与采样周期调度协同设计方法。运用模糊控制中的最大隶属度解模糊方法,依据系统误差大小使得采样周期在几个固定值之间切换。根据采样周期计算出满足H性能指标的状态反馈矩阵K,并按照当前的采样周期选择相对应的K来计算控制量。可以避免由同时考虑时变采样周期与时变时延所带来的强保守性。设计鲁棒H控制器时采用Markov链描述系统随机丢包,使得建模更贴近实际情况,运用标称点法确定由时延组成的系统不确定项的范数界,可以进一步减小保守性。最后,数值仿真结果验证了该协同设计方法的可行性与有效性。

For variable sampling period networked control systems with time-varying delay and random packet-dropouts, a collaborative design method of robust Hcontrol and sampling cycle scheduling is proposed. Using the maximum membership degree defuzzification method in fuzzy control, the sampling period is switched between several fixed values according to the size of system error, and the state feedback matrix K satisfying the Hperformance index under each sampling period is calculated respectively. The controller selects the corresponding feedback matrix according to the current sampling period to calculate the control quantity, which can avoid the strong conservatism caused by considering both time-varying sampling period and time-varying delay. When robust Hcontroller is designed, Markov chain is used to describe the random packet-dropouts of the system, which makes the modeling closer to the actual situation. Using the nominal point method to determine the norm bound of the system uncertainty composed of time delay can further reduce the conservatism. Finally, numerical simulation results verify the feasibility and effectiveness of the cooperative design method.