Active vibration adaptive fuzzy backstepping control of a 7-DOF dual-arm of humanoid robot with input saturation

Abstract

This paper proposes a new controller based on the torque compensation method for the control of a 7-DOF dual-arm of a humanoid robot with input saturation residual vibration of the end-effector. Through theoretical and experimental analysis, an adaptive fuzzy backstepping control strategy was designed for the 7-DOF dual-arm control system. This strategy can be used to suppress the time-varying nonlinear residual vibration of the end-effector caused by inertia variations in the serial robot. Firstly, a boundary feedback controller was designed to asymptotically stabilize the closed-loop system based on the C₀-semigroup theory, which also proves the efficacy of the closed-loop system solution. Lyapunov stability analysis proved that the closed-loop demonstrated globally asymptotic stability. Secondly, an adaptive fuzzy backstepping method was designed for the dynamic compensator with a tracking filter for the control system of the 7-DOF dual-arm of the humanoid robot. The primary difference between this new method and conventional methods is that the new method does not require complex computation. In addition, this method improves the limit of computing power and memory space for the controllers. Finally, the effectiveness of the torque compensation strategy and the new method’s ability to suppress the residual vibration are demonstrated via simulation and experiments.