一类非线性系统的微分平滑反步自适应输出反馈控制

研究了一类含不确定参数且存在未知扰动的严反馈非线性系统输出反馈控制问题,设计了一种新型的反步递推(Backstepping)自适应控制器.为实现输出反馈,设计过程引入了虚拟的全维状态观测器.由于Backstepping的虚拟控制量与未知参数逼近值及其高阶导数有关,为此通过微分平滑算法对原系统进行相应的动态扩展.在稳定性分析中,利用Lyapunov定理,得到了系统全局一致有界稳定的条件,并求出系统的稳态跟踪误差.最后给出的仿真算例验证了本文方法的有效性和可行性.

Differential flatness adaptive backstepping output feedback control for a class of nonlinear systems

A novel adaptive backstepping output feedback control approach is presented for a class of strict-feedback nonlinear systems with uncertain parameters and unknown disturbances.In order to realize the output feedback control,the virtual full-dimensions state observer is introduced in the design.Given the fact that the virtual controllers in backstepping procedure are the functions of the parameter estimates and their higher derivatives,the differential flatness algorithm is used to expand the dynamics of original systems.In the stability analysis,based on the Lyapunov theory,some conditions are derived for global uniform ultimate boundedness of systems,while the stable tracking error is provided.Finally,the simulation example is given to demonstrate the feasibility and effectiveness of the proposed method.