Adaptive Cartesian Position Control with a Switching Strategy for Robotic Manipulator with Mixed Rigid-Elastic Joints

Abstract

With the increasing demand for safe and efficient human-robot interaction in industrial applications, robotic manipulators with mixed rigid-elastic joints have gained significant attention, yet their control remains challenging due to inherent parameter uncertainties and complex dynamics. In this paper, an adaptive Cartesian position control for robotic manipulators with mixed rigid-elastic joints is presented. Adaptive controllers are designed to deal with uncertainties in the parameters of the motors, while robust control signals effectively cope with uncertainties of the links and stiffness of the elastic joints. Furthermore, a switching strategy between Cartesian space position control and joint space position control when the end-effector comes into the vicinity of the target point is proposed. This switching strategy helps to keep the pose of the robotic manipulator stable when the end-effector has approached the target point. Simulation results on a 6-DOF robotic manipulator demonstrate that the proposed control scheme can achieve the desired accuracy in position and maintain a stable pose when the end-effector reaches the target.