Fixed-time adaptive sliding mode control for manipulators based on disturbance observer

Aiming at the trajectory tracking problem of multi-node robot manipulator system with external disturbances and internal parameter uncertainties, a fixed-time adaptive sliding mode control strategy based on a disturbance observer is proposed. First, the external disturbances and internal uncertainties of the robot manipulator system are estimated by a disturbance observer in order to achieve feedforward compensation for the system. Second, to address the chattering and slow convergence issues of sliding mode control strategies, a controller based on a fixed-time adaptive sliding surface and a piecewise reaching law is designed, and the stability of the system is proven using Lyapunov theory. Finally, simulation experiments on the robotic arm verify the effectiveness of the proposed control strategy.