Adaptive force-motion control of coordinated robots interacting with geometrically unknown environments

Most studies on adaptive coordination of multi-robot systems assume exact knowledge of system kinematics and deal with dynamic uncertainties. However, many industrial applications involve tasks in which a multi-robot system interacts with geometrically unknown environments. In this paper we consider a multi-robot system grasping a rigid object which is in contact with a frictionless surface with unknown geometry. The proposed adaptive hybrid force-motion controller guarantees asymptotic tracking of desired motion and force trajectories while ensuring exact identification of tangential and normal directions to the constraining surface without persistency of excitation condition. The control signal is smooth and no projection is used in parameter update law. A simulation example is presented to illustrate the results.