Robust Trajectory Tracking Control of Robot Manipulators for High Precision

We propose a design scheme for robust control which achieves precise trajectory tracking for robot manipulators. In the scheme, the nonlinearity of the manipulator is divided into two types : one is nonlinearity that can be formulated, such as centrifugal force and Coriolis force, and the other is nonlinearity that can't be formulated, such as fluid drag by the surrounding air and magnetic force of the surrounding servomotor. The influence of the unformulated nonlinearity for control precision is considered through the simulation of a 2-link manipulator and from the experimental results of tracking control for a desired trajectory.