Hybrid position/force control of constrained manipulators in presence of uncertainties

Abstract

In this paper the problem ofthe hybrid position/force control of constrained robots is discussed. 1be analysis is based on the decoupling of singular dynamic systems, representing the constrained dynamics. In particular the existence of a class of coordinate transfonnations, allowing the decoupling of the equations describing the motion in a neighbour of a reference trajectory, from those representing the reaction forces, is discussed. Then a position/velocity feedback control law is proposed guaranteeing boundedness of both position and force tracking errors. Finally the robustness of the control scheme, with respect to uncertainties in the constraints geometry, and robot inertial characteristics, is analysed.