MODEL-BASED FEEDFORWARD PRECOMPENSATION AND VS-TYPE ROBUST NONLINEAR POSTCOMPENSATION FOR UNCERTAIN ROBOTIC SYSTEMS WITH WITHOUT KNOWLEDGE OF UNCERTAINTY BOUNDS .1./

In this paper, a robust motion tracking control algorithm for robotic manipulators is proposed where the higher-order system uncertainties a re taken into account. The control structure consists of two main part s: a model-based precompensation part and a robust nonlinear controlle r one. Specifically, with knowledge of possible upper bounds on uncert ainties, we propose the nonadaptive version of robust controller. Stab ility and robustness issues of the controllers have been investigated via a Lyapunov method and it is shown that the proposed control algori thms are highly robust in the presence of significant system uncertain ties. Finally, the computer simulation results are presented to valida te the proposed algorithm.