以幂次趋近的离散变结构重复控制

Discrete-time variable-structure repetitive control with power-rate reaching

本文提出一种离散变结构重复控制器设计方法,在趋近律中"嵌入"扰动抑制措施,构造理想切换动态,并据此导出重复控制器.为了进行控制器参数整定和刻画闭环系统的收敛性能,文中推导出准滑模带、单调收敛层和绝对收敛层边界的表达式.设计的离散变结构重复控制器能够完全抑制周期性扰动,控制器设计方法也适用于常值扰动下的定位控制.数值仿真及实验结果验证了所提出控制方案的有效性.

We present a discrete-time variable-structure repetitive controller; in which a measure of disturbance-rejection is embedded in the reaching law to form the ideal dynamics of switching, thus developing the repetitive controller. For the convenience in adjusting the control parameters and describing the convergent performance of the closed-loop system, we derive the expressions for the range of the quasi-sliding-mode and the boundary between the monotonic convergence layer and the absolute convergence layer. The developed repetitive controller is not only effective in perfect rejection of periodic disturbances, but also applicable to position control with constant disturbances. Both numerical simulation and experiment results demonstrate the effectiveness of the proposed repetitive control scheme.