A new operational space trajectory tracking controller for manipulators by using only position measurements

Many robotic tasks are specified in terms of the position and orientation (pose) of the robot end-effector. The operational space is defined by a set of generalized coordinates to describe the end-effector pose. The main contribution of this paper is a new operational space trajectory tracking controller, which does not require any velocity measurement. A rigorous stability analysis based on Lyapunov's direct method is presented. The practical viability of the proposed algorithm is explored through real-time experiments in an horizontal planar direct-drive arm with two degrees-of-freedom.