Linear and nonlinear PD-type control of robotic manipulators for trajectory tracking

This paper presents trajectory tracking of robot manipulators using linear and nonlinear proportional-derivative (PD) type controllers. It is shown that the controller gains which are nonlinear functions of system states can improve tracking performance and prevent actuator saturation. Furthermore, it is shown that global asymptotic stability of the closed-loop system can be achieved with the proposed PD-type controllers. Simulation results on a single-link robot and a typical two-degrees-of-freedom robot demonstrate excellent performance using the proposed control schemes.