Based on a decomposition of the rigid robot system with motor dynamics, a novel sliding-adaptive controller is developed which can achieve robustness to parameter variations in both manipulator and motor. When the system is in sliding mode, force, position, and redundant joint velocity errors will approach zero irrespective of parametric uncertainties, Unlike conventional sliding techniques which are only robust to matched uncertainties, the proposed sliding method is robust to both matched and mismatched uncertainties. Hence the scope of applications of sliding mode method can be broadened to nonlinear systems with mismatched parameter variations. No joint acceleration measurement is needed.