Research on the motion characteristics of a flexible joint-flexible link space manipulator

Abstract

Research on motion characteristics of the space flexible-joint flexible-link manipulator is investigated. The motion equations of the N degree of freedom (DOF) flexible manipulator are established by means of the Newton-Euler method and finite segment method considering both computational efficiency and accuracy. The genetic algorithm is used to identify the parameters of the torsional stiffness and damping related to the link flexibility. The derived model involves the dynamic factors, such as joint and link flexibility, joint friction and the end lumped mass of the link. Then the joint critical stiffness is adopted to decide whether to consider joint flexibility. After that, spatial motions of a two flexible-joint flexible-link manipulator are performed with different joint stiffness and friction. The results show that the spatial vibration of the flexible manipulator can be reduced by increasing both the joint stiffness and friction, and the vibration can be effectively suppressed when the joint stiffness is greater than the critical value. Meanwhile, the validity of the presented model is verified. It lays the foundation for the reliability analysis and controller design of the flexible-joint flexible-link space manipulator.