Robust Adaptive Position/Force Hybrid Control for Constrained Robotic Manipulators

A robust adaptive control strategy was proposed for position/force hybrid control of robotic manipulators. The adaptive law updates the unknown parameters on line and the dead zone is employed to prevent the drifts of the estimated parameters and strengthen the robustness of the adaptive control when the robot system is subjected to external disturbances. The sliding mode control can not only eliminate the drawback of the dead zone adaptive control, but reject the external disturbances effectively. So this control strategy can guarantee the tracking accuracy of the position and force and make the end-effector move along the constraint surface with a desired contact force. Simulation studies of 2-links manipulators show the validity of the algorithm.