基于观测器的一类不确定非线性系统自适应输出反馈控制

针对一类不确定非线性系统,基于非线性状态观测器采用回馈递推(Backstepping)设计方法提出了一种鲁棒自适应L2增益控制方案。该控制方案首先对系统的不可观测状态设计非线性状态观测器,在此基础上通过多步递推得到系统的控制律并设计了未知干扰的参数自适应律,使系统具有L2增益性能。同时把采用常规设计方法需要对过多参数进行辨识问题简化为只需对与未知干扰个数相同的参数进行辨识的问题,简化了控制器结构。最后通过仿真算例验证了所设计控制方案的有效性。

Adaptive output feedback control based on observer for a class of uncertain nonlinear systems

A new robust adaptive L_2 gain controller using backstepping design method for a class of nonlinear uncertain systems based on nonlinear state observeris presented in this paper. The nonlinear state observer is designed for the unobservable state of the nonlinear system. Based on the nonlinear state observer, the control law is obtained by backstepping design method and the parameter adaptive law of the uncertain disturbance is designed. The designed controller renders the system L_2 gain performance. Meanwhile, the number of estimators of disturbance in this method is smaller than that of the conventional designed method and as many as the number of the disturbances, thus the structure of the designed controller is simplified. Finally, an example is given to demonstrate the effectiveness of the proposed control method.