非匹配条件不确定非线性系统的变结构控制

研究不确定非线性系统的输出跟踪问题。针对系统中的未建模动态和广义的不确定性，基于李亚普诺夫稳定性理论提出了一种变结构控制方案，它不要求系统的不确定性满足匹配条件，仅要求已知不确定性的有界约束。从理论上证明了闭环跟踪系统全局渐近稳定，系统信号保持有界。仿真实例证实了理论结果。

Variable Structure Control of Nonlinear System with Unmatched Uncertainties

In this paper, the robust output tracking control problem for nonlinear systems with unmatched uncertainties is discussed. In order to obtain such robustness, we adopt the variable structure (VS) control scheme based on Lyapunov theory. Dealing with the matched and unmatched uncertainties separately, we design the VS controller and it can ensure that the closed - loop system be globally stable and satisfy the sliding reachable condition.It is shown that the VS controller can ensure the tracking errors to converge to zero despite the uncertainties. At last, simulation results confirm preliminarily that the performance of the proposed VS controller is satisfactory.