基于扰动补偿趋近律的非匹配离散广义准滑模控制

QUASI-SLIDING MODE CONTROL FOR MISMATCHED DISCRETE SINGULAR SYSTEMS BASED ON REACHING LAWS WITH DISTURBANCE COMPENSATOR

研究了非匹配不确定离散广义系统准滑模控制策略的综合问题.给出了具有前级状态向量的动态切换函数,使得系统能够在切换带内稳定.设计了两种带有扰动补偿的离散广义趋近律,消除了常规滑模控制策略中不确定项必须有界的限制,且不必满足匹配条件.给出了系统准滑动模态保持逐步穿越切换面的必要条件,减小了准滑动模态切换带的带宽.所设计的滑模控制器在有限时间内可达切换面,削弱了系统抖振,有效地改善了系统动态品质.最后,数值算例验证了该控制策略的可行性.

The synthesis problem of quasi-sliding mode control strategies for mismatched discrete singular systems with internal parameter perturbation and external disturbance is considered. A dynamic switching function with last step state vector is given to guarantee the stability of the control system in the switching band. Two types of discrete singular reaching laws with disturbance compensator are designed to eliminate the restriction that the system uncertainties is bounded and must satisfy matching conditions compared with conventional sliding mode control strategy. Necessary conditions for quasi-sliding mode to cross the switching plane step by step are provided, and the switching band of quasi-sliding mode is reduced. Two types of discrete singular sliding mode controllers are designed by applying the reaching laws, which can guarantee the system to reach the switching plane in finite time, decrease the system chattering and enhance the dynamic quality of the system effectively. Finally, a numerical example illustrates the feasibility of the proposed control strategies.