非匹配的不确定时滞离散系统的滑模控制

Sliding Mode Control for Time-delay Discrete Systems with Unmatched Uncertainty

针对一类不确定离散时滞系统,研究了其滑模控制问题。所考虑的系统是变时滞的,并且含有非匹配的时变参数不确定项。通过非奇异矩阵变换将其转化为两部分,一部分满足传统的匹配条件;另一部分是非匹配,但是满足范数有界的条件。利用变结构控制方法,设计了满足到达条件的滑模控制器,使系统状态在有限时间内到达滑模面,并且在控制器的作用下保持在滑模面上,从而使系统具有稳定的滑动模态,克服了传统滑模控制方法中不确定项需满足匹配条件的保守性。

According to a class of uncertain time-delay discrete systems, the sliding mode control problem is discussed. The delay of the system is time varying and the uncertainty is unmatched. The uncertainty is transferred into the matched part and the unmatched part by a nonsingular matrix transformation, the unmatched uncertainty is needed to satisfy the norm bounded condition. The sliding mode controller satisfied the hitting condition is designed by variable structure control method which make the state of the system hit the sliding mode surface in finite time and stay on it subsequently, so the system can derive stable sliding mode. The conservative feature is overcome in the traditional sliding mode control approach which needs matched uncertainty.