Dynamic hybrid position/force control of robot manipulators: online estimation of unknown constraint

The problem of dynamic hybrid control with unknown end-effector constraints is studied. Assuming that the force exerted on the constraint surface by the end effector is measurable, an algorithm is proposed for online estimation of the local shape of the constraint surface from the data position and force. It has been shown by experiments using a SCARA robot that the combination of the estimation algorithm with the dynamical hybrid control method works well. This approach saves the operator from the task of giving precise constraint hypersurfaces to the robot controller