Abstract
By using a state observer a new robust trajectory tracking control scheme is developed in this paper for flexible joint manipulators. A precompensator including an integrator is introduced in order to ensure asymptotical stability of tracking error between link angles and constant desired trajectories. Then, to ease the development of a controller achieving good robust tracking performance, a new representation of flexible joint robot dynamics with the precompensator is introduced. The developed controller based on the new representation has the following features; i) The configuration of the proposed controller becomes very simple compared with regressor based adaptive controllers. ii) The Euclid norm of tracking errors arrives to any small closed region with any convergent rate by setting design parameters. Especially for the desired trajectories converging to constant ultimate values, tracking errors converge to zero.
