Modified position-force control for a manipulator geometrically constrained by round obstacles

This paper addresses the problem of position-force control for robot manipulators under geometric endpoint constraints defined as round obstacles. Considerations are based on hybrid position-force control and use modified Arimoto algorithm with the principle of ”orthogonalisation”. To achieve so-called joint space orthogonalisation, where motion signals are orthogonal to force vectors and the direction selection is performed in the joint space, projection matrix is utilized. The convergence of tracting and force errors is proved.