A nonlinear controller based on an extended second-order disturbance observer is presented to track desired position for an electro-hydraulic single-rod actuator in the presence of both external disturbances and param...A nonlinear controller based on an extended second-order disturbance observer is presented to track desired position for an electro-hydraulic single-rod actuator in the presence of both external disturbances and parameter uncertainties. The proposed extended second-order disturbance observer deals with not only the external perturbations, but also parameter uncertainties which are commonly regarded as lumped disturbances in previous researches. Besides, the outer position tracking loop is designed with cylinder load pressure as output; and the inner pressure control loop provides the hydraulic actuator the characteristic of a force generator. The stability of the closed-loop system is provided based on Lyapunov theory. The performance of the controller is verified through simulations and experiments. The results demonstrate that the proposed nonlinear position tracking controller, together with the extended second-order disturbance observer, gives an excellent tracking performance in the presence of parameter uncertainties and external disturbance.展开更多
Based on Lyapunov stability theory, a design method for the robust stabilization problem of a class of nonlinear systems with uncertain parameters is presented. The design procedure is divided into two steps: the firs...Based on Lyapunov stability theory, a design method for the robust stabilization problem of a class of nonlinear systems with uncertain parameters is presented. The design procedure is divided into two steps: the first is to design controllers for the nominal system and make the system asymptotically stabi1ize at the expected equilibrium point; the second is to construct closed-loop nominal system based on the first step, then design robust controller to make the error of state between the origina1 system and the nominal system converge to zero, thereby a dynamic controller with the constructed closed-loop nominal system served as interior dynamic is obtained. A numerical simulation verifies the correctness of the design method.展开更多
基金Project(51221004)supported by the Science Fund for Creative Research Groups of National Natural Science Foundation of ChinaProject(2012AA041801)supproted by the High-tech Research and Development Program of China
文摘A nonlinear controller based on an extended second-order disturbance observer is presented to track desired position for an electro-hydraulic single-rod actuator in the presence of both external disturbances and parameter uncertainties. The proposed extended second-order disturbance observer deals with not only the external perturbations, but also parameter uncertainties which are commonly regarded as lumped disturbances in previous researches. Besides, the outer position tracking loop is designed with cylinder load pressure as output; and the inner pressure control loop provides the hydraulic actuator the characteristic of a force generator. The stability of the closed-loop system is provided based on Lyapunov theory. The performance of the controller is verified through simulations and experiments. The results demonstrate that the proposed nonlinear position tracking controller, together with the extended second-order disturbance observer, gives an excellent tracking performance in the presence of parameter uncertainties and external disturbance.
文摘Based on Lyapunov stability theory, a design method for the robust stabilization problem of a class of nonlinear systems with uncertain parameters is presented. The design procedure is divided into two steps: the first is to design controllers for the nominal system and make the system asymptotically stabi1ize at the expected equilibrium point; the second is to construct closed-loop nominal system based on the first step, then design robust controller to make the error of state between the origina1 system and the nominal system converge to zero, thereby a dynamic controller with the constructed closed-loop nominal system served as interior dynamic is obtained. A numerical simulation verifies the correctness of the design method.
