On the asymptotic stability of the hybrid position/force control scheme for robot manipulators

Conditions are presented for the global asymptotic stability of the hybrid position/force control of robot manipulators, using Lyapunov´s direct method. Although hybrid control schemes have been studied in depth, the stability problem has not been clarified completely. The authors deal with the stability of the hybrid control scheme in Cartesian coordinates of the work space, especially from the viewpoint of coupling between position and force control. Results show not only the global asymptotic stability conditions but also the physical interpretation or meaning of the stability conditions by citing an example of a two-degree-of-freedom manipulator