Prescribed Performance Fixed-time Control of Manipulator Based on Disturbance Observer
In order to solve the problems of external disturbance,internal parameter uncertainty and tracking error constraint in the multi-degree-of-freedom manipulator system,a prescribed performance fixed-time sliding mode control tactics based on disturbance observer was devised.Firstly,by using the disturbance observer,the external uncertainty and internal uncertainties of the system were estimated,and the total disturbance estimated by the observer was brought into the controller to achieve feed-forward compensation.Secondly,the error con-version technology based on the preset performance function was adopted to constrain the tracking error within the preset range,which solved the error constraint problem and hoists the steady-state performance and transi-ent performance of the total system.Then,a fixed-time sliding mode controller was designed based on the con-verted error,and using the Lyapunov stability theory to confirm the fixed-time convergence of the system.Fi-nally,simulations were implemented to compare several common control methods,which verified that control method devised by this paper could hoist the control performance of the system.