Observer-based impedance control of robot manipulators

In this paper, an observer-based impedance controller for robot manipulators during a constrained motion is developed. The proposed controller requires the measurements of link position and interaction force. A filtering technique is applied to eliminate the need for link velocity measurements. The proposed control strategy provides semiglobal asymptotic tracking performance for the end-effector position and compliant interaction force between the environment and the robot end-effector. In order to verify the effectiveness of the proposed controller, a numerical simulation for a two-link planar robot is also provided.