Robust task space position constraint control of kinematically redundant manipulators: A barrier Lyapunov approach

Abstract

This study introduces a novel robust control strategy for kinematically redundant robotic manipulators, aimed at maintaining task space position errors within predefined constraints. The proposed design ensures that the tracking errors for both the end-effector's position and sub-tasks are uniformly ultimately bounded, despite dynamic uncertainties. It also guarantees that the position error of the end-effector stays within a predetermined safe region and achieves predictable overshoot and transient performance, provided the initial error is bounded within this safe area. The incorporation of a BLF into our stability analysis is the cornerstone of our methodological advancement, which is crucial for imposing predefined constraints on task space position errors. Simulations and experiments confirm the controller's effectiveness, showing consistent error maintenance, stability of error terms, and boundedness of closed-loop signals. Tighter constraints increased control effort but led to faster convergence and improved tracking performance.