Adaptive Backstepping Sliding Mode Control for Robotic Manipulator with Nonlinear Disturbance Observer

A new adaptive backstepping sliding mode control for robotic manipulator position tracking using nonlinear disturbance observer（NDO） is proposed. Nonlinear disturbance observer is used to observe the observable part of disturbance on line. By selecting the design parameters, the nonlinear disturbance observer can converge exponentially. Subsequently, an adaptive backstepping sliding mode controller is designed for the system with nonlinear disturbance observer. The proposed controller can guarantee the stability of the closed-loop system. By designing the adaptive law, the unobservable disturbance is compensated, which improves the position tracking performance of robotic manipulator. The simulation results show that the control strategy has perfect control performance to overcome the uncertainties and random disturbances, and improves the control performance of system.