Manipulator Control with an Exponentially Stable Velocity Observer

In this paper, a reduced order manipulator velocity observer is presented. The observer is used to provide a smooth velocity estimate for a computed torque controller. By using a Lyapunov approach, it is shown that the modified computed torque controller is locally asymptotically stable for trajectory tracking. Experimental results obtained through implementation on the second and third link of the PUMA-560 agree strongly with the theory.