A robust adaptive approach for force/motion control of manipulators under holonomic constraints

This paper deals with the sliding mode position/force control of constrained manipulators systems, in which, the constraints are supposed to be holonomic. An adaptive version of the controller is used for an on-line estimation of the unknown parameters. Because of this, no apriori knowledge about the bounds of unknown parameters is required. The algorithm guarantees asymptotic stability of the global system, a zero tracking error for both position and force vectors and robustness against parameters uncertainties and external disturbances, if the model of the system is well known, the force feedback is not necessary to achieve the zero error force convergence. With a small modification of the control law, the chattering phenomenon is avoided from the applied joints torques