非线性不确定系统的非奇异快速终端滑模控制

针对存在非匹配干扰的非线性系统,设计了一种基于干扰观测器和反步法的非奇异快速终端滑模控制.引入非线性干扰观测器估计系统的不确定性,利用反步的思想处理高阶非线性系统,从而可以将非线性干扰观测器估计的干扰值引入反步法的虚拟控制量中,同时设计一种新颖的非奇异快速终端滑模控制律保证系统的收敛速度和精度.利用Lyapunov函数从理论上证明了所设计的控制器可以保证闭环系统的有限时间收敛.最后通过数值仿真验证了所设计的控制方法的有效性.

A novel non-singular fast terminal sliding mode control ofnonlinear systems with uncertain disturbances

A novel control scheme of non-singular fast terminal sliding mode control (NFTSMC) based on nonlinear disturbance observer (NDO) and back-stepping method is proposed for a class of nonlinear system with multiple uncertain disturbances. The uncertainty of the system can be estimated by nonlinear disturbance observer online. And the backstepping method is used to deal with high order nonlinear systems with uncertainties. A novel non-singular fast terminal sliding controller is designed for the last step which can promise the finite time convergence and improve the steady state precision. Also, all of the disturbances estimated by the NDO are introduced into the design of virtual control laws in each step to compensate the uncertain disturbances. Under the proposed terminal sliding mode control method, the finite time convergence of all closed-loop signals is guaranteed via Lyapunov analysis. Finally, a simulation example is applied to demonstrate the efficacy of the proposed composite control method.