Adaptive Hybrid Impedance Control of robotic manipulators

In this paper, the problem of position and force control of a robotic manipulator in contact with the environment is considered. The Hybrid Impedance Control (HIC) methodology is employed to control the position of the end-effector in such a way that the robot exhibits a desired dynamic property and hence desired Impedance which in turn results in tracking the interaction force. It is assumed that the robot has unknown dynamics, hence an adaptive HIC is used to control the robot manipulator. The environment is modeled as a spring to be used in the force control directions. The Lyapunov´s theorem is used to show the stability of the closed-loop system obtained by the proposed adaptive law. The effectiveness of the proposed approach is demonstrated via simulations performed on a three-link articulated manipulator.