Adaptive compliant control of robot manipulators

An adaptive compliant control for robot manipulators is presented in this paper. The control law is designed in the task space and contains a nonlinear model-based term and a linear compensator action. This is obtained as a combination of the position error, the velocity error and the integral of the force error. The scheme is made adaptive with respect to the dynamic parameters of the model of the robot manipulator. By using the classical Lyapunov method, it is demonstrated that the proposed control law ensures tracking of the unconstrained components of the desired end-effector trajectory, with regulation of the desired contact force along the constrained direction. Experiments are developed for an industrial robot manipulator in contact with an elastic surface.