A class of global regulators with bounded control actions for robot manipulators

Motivated by the energy shaping pins damping injection methodology for robot regulator design, in this paper we characterize a class of global regulators which achieve this goal keeping the control actions bounded regardless the initial conditions. This is obtained by the kind of artificial potential energies and energy dissipation functions whose gradients are bounded. As an important practical outcome, for such class of regulators we derive conditions to yield a globally asymptotically stable closed-loop system by maintaining the applied torques inside prescribed torque actuator limits. The performance of a regulator of this class is illustrated via experiments on a two degrees-of-freedom direct drive robot arm.