一类不确定仿射非线性系统的自适应变结构控制

研究非匹配不确定仿射非线性系统的输出跟踪问题．针对系统中的参数不确定性，基于李亚普诺夫稳定性理论提出了一种分段控制方案，当控制误差大于一定范围时，采用自适应变结构控制方案，使得闭环跟踪系统全局渐近稳定，参数估计值收敛，系统信号保持有界，控制误差减小到零域附近时，切断变结构控制，避免了颤振现象的出现．理论研究和仿真结果证实了理论结果的正确性和有效性．

An adaptive variable structure controller for affine nonlinear systems with uncertainties

The output tracking of a class of affine nonlinear systems with unmatched-uncertainties was discussed. In respect that the parameters of system are uncertainty, a control scheme based on the theory of Lyapunov stability is proposed. When system error is bigger then a certain value, adaptive design method is combined with variable structure control to design a adaptive VS controller, in which the closed loop system is globally stable, parameter estimation is convergent, the signal of system keeps limitary, and the VSC is forbidden when system error close to zero, so the chattering phenomenon is avoided. Academic study and simulation results confirm that the adaptive VS controller is correct and effective.