High performance robust motion control of industrial robot parameter identification based on resonant frequency

Controller design for industrial robots is normally based on the model of the mechanical system. The proper parameters of the model cannot be obtained by the parameter identification based on only manipulator force and motion measurements. In this paper, the resonant frequency characteristic of the flexible joint is employed to identify the proper parameters of the two-inertia model of each joint of the robot. These parameters are used in independent-joint controller design for conventional PD control scheme and robust control scheme. The nominal inertia and the nominal spring constant based on the proposed identification method contributes more control accuracy in comparison with the conventional identification method which uses both the constant speed test and the acceleration speed test. Moreover, the two control schemes, which are the proposed robust motion control method and the conventional motion control method, are applied to the tested robot manipulator to comparing the efficiency of the identified parameters and implemented control schemes.