鲁棒自适应滑模虚拟执行器设计

为了解决具有不确定性的非线性系统发生执行器故障后的安全运行问题,针对未建模动态、外界扰动和参数不确定等各种不确定性的综合影响,提出了一种鲁棒自适应滑模虚拟执行器控制重构策略.该方法利用滑模控制具有鲁棒性的特点消除不确定性的影响,采用参数自适应方法使得无须己知不确定项的上界,同时具有虚拟执行器不改变标称控制器结构和参数的特点.采用李雅普诺夫稳定性理论证明了闭环系统的稳定性和鲁棒性.通过动力定位船仿真验证了该方法的有效性.

Design of virtual actuator with robust adaptive sliding mode

To maintain the safe operation for uncertain nonlinear systems after actuator failure, we consider the total effect from un-modeled dynamics, external disturbances and uncertain parameters, etc., and propose a virtual actuator control reconfiguration strategy with robust-adaptive sliding-mode. The robustness of sliding mode control is used to eliminate effects of uncertainties. Because of the parameter adaptive method, a priori knowledge of the uncertainty boundary is not required. The structure and parameters of nominal controller are unchanged by means of a virtual actuator. The stability and robustness of the closed-loop system is proved by using the Lyapunov stability theory. The validity of the proposed approach is investigated in the simulation of a dynamic positioning vessel.