变结构控制的抖振问题研究

Research on Chattering Reduction in Variable Structure Control

变结构控制是一种鲁棒控制方法,它对系统参数的变化和外部干扰具有理论上的完全鲁棒性,然而,变结构控制系统在滑模面上的高频抖振是其工程应用的主要障碍。该文将抖振削弱方法分为两类:一类是传统控制方法,它通过改变变结构控制器的构造方式来削弱抖振;另外一类是组合控制方法,它通过引入其他先进控制理论(如智能控制、自适应控制等)来削弱抖振。目前,多种组合控制方法被广泛采用,但缺乏对结合方式的系统性分析,本文以模糊变结构组合控制方法为例,详细探讨了多种形式的结合方式。最后指出了处理抖振问题的发展方向。

Variable structure control （VSC） has been known theoretically as a powerful control technique capable of providing very robust control, even invariant under certain condition, with respect to system parameter variations and external disturbances. However, chattering on the sliding mode is an obstacle in an engineering system. In this paper, chattering reduction strategies are classified into two kinds： traditional strategy and combined control strategy. The former concentrates on a different structure of VSC, while the latter makes use of other advanced control theories （Intelligent Control, Adaptive Control etc. ） to reduce chattering. So far, different combined control strategies are widely adopted, but it is lacking in systemic study using ways of combination. In this paper, Fuzzy Variable Structure Control （FVSC） is emphasized, where different combinations of Fuzzy control and VSC are deeply discussed in detail. At the end of this survey,the future directions of chattering reduction is provided.