Robust Computed Torque Control of Mechchanical Manipulators: Non-Adaptive vs. Adaptive

Abstract

We consider the tracking control problem of mechanical manipulators in the presence of uncertainty. Two classes of control algorithms are proposed. If the possible bound of the uncertainty is known, a class of non-adaptive robust computed torque control schems is used. The control guarantees the tracking error to be confined within a specified region after a finite time. If the bound of uncertainty is unknown, a class of adaptive robust computed torque control schemes is used. The control guarantees the tracking error to converge to zero. Both classes of controls are continous and no statistical information on the uncertainty is ever assumed, nor is such information used. Use of the controls is illustrated by a two-link planar robot manipulator. The resulting system performance is compared with that of the manipulator when the traditional computed torque control scheme is employed.