Adaptive control of a robot manipulator in contact with a curved compliant surface

In this paper the problem of controlling the interaction of a robot manipulator with a compliant curved surface is considered. A task space is defined, where the control objective is specified in terms of one coordinate for the contact force, two coordinates for the end-effector position on the surface and a unit quaternion for the end-effector orientation. The controller design is carried out in a passivity framework and an adaptive algorithm is used to ensure force tracking when the stiffness coefficient of the environment is unknown. An experimental case study is developed on an industrial robot with open control architecture and a wrist force sensor.