Robust control of a robot manipulators using fractional order lag compensator

Abstract

In this paper a fractional order lag compensator is introduced for the control of robot manipulators. Mathematical model of the robotic system is derived using the Rodriquez approach which, due to a high gear ratio between the actuators and robot joints, reduces to a linear model. Then, fractional order compensator is designed according to the symmetrical optimum principle. Optimal values of controller parameters give good performance characteristics and high robustness of the system, together with an iso-damping property of the closed loop reference response. The effectiveness of the proposed method is illustrated through the control simulation of three degrees of freedom robot manipulator.