An adaptive compliant motion controller for robot manipulators based on damping control

An investigation is reported of the design and implementation of a compliant control scheme based on damping control that can be used to perform position and force control of robot manipulators in teleoperation or autonomous control. The dynamic performance of such a system in constrained situations is very dependent on the environmental parameters. An adaptive controlled based on the model reference adaptive controller (MRAC) approach is developed for a single-axis manipulator model and is further extended to the multiaxis case using the concept of directional adaptation: the MRAC and the compliance are active only in the direction of the force constraints, thus allowing near-perfect velocity and force tracking in all directions. Simulation results show that the adaptive scheme can significantly improve the performance in force tracking and enhance stability at high stiffness by rendering the behavior independent of the environment and robot parameters. Some experimental implementation concerns are presented in light of a series of preliminary tests with a PUMA 560 manipulator