Trajectory-tracking in finite-time for robot manipulators with bounded torques via output-feedback

In this paper we propose a novel output-feedback controller for robot manipulators that exhibit actuator saturation. This proposal ensures trajectory-tracking in finite-time provided that the desired velocity and acceleration are sufficiently slow. The scheme consists of a continuous dynamic nonlinear Proportional-Derivative (PD)-like control plus a feed-forward compensation term and global uniform finite-time stability of the tracking error is established designing novel strict Lyapunov functions. Further, in presence of small uncertainties in the dynamic model of the robot, we establish global uniform ultimate boundedness of the trajectory tracking error. Simulations are shown to validate the theoretical findings.