Design of Fractional-Order Lag Network and Fractional-Order PI Controller for a Robotic Manipulator

Abstract

Motion control of robotic manipulators is frequently realized by independent control of the DC motors actuating robot joints. Namely, nonlinearities, coupling between actuators and other complex dynamics are neglected if high gear ratios between the actuators and robot joints are considered. This paper proposes a fractional-order lag network or a fractional-order PI controller to control the position of the actuators shafts. The introduced fractional compensators are designed by using the symmetrical optimum principle and by parameters optimization or by frequency-domain loop shaping, respectively. Simulation results and frequency response show effectiveness and robustness of the approach.