Robust Control of a Serial Variable Stiffness Actuator Based on Nonlinear Disturbance Observer (NDOB)

摘要

This paper focuses on the difficulty of designing control strategy for a Serial Variable Stiffness Actuator (SVSA) because of the disturbances in such as spring deflection, model uncertainty and load disturbance. A nonlinear disturbance observer based composite controller (NDOBC) is developed to reject the load disturbance and improve the performance in disturbance rejection. This NDOBC is proposed to control both stiffness and position of the SVSA. Compared to other nonlinear controller for SVSA, the proposed control method can guarantee the robust stability and performance against load disturbance. The effectiveness of the proposed controller is experimentally verified on the SVSA.