Dynamic Characteristic Analysis of Flexible-Joint Flexible-Link Space Manipulator with Joint Friction

Research on motion characteristics of the flexible-joint flexible-link space manipulator is investigated. The dynamic equations of the N degree of freedom (DOF) flexible manipulator is modeled by means of the Newton-Euler iteration equations and finite segment method to discretize the flexible slender links which considering both computational efficiency and accuracy. The genetic algorithm is utilized to identify the twist stiffness and damping related to link flexibility in finite segment models. The derived model involves the dynamic factors, such as joint and link flexibility, joint friction and the end concentrated mass of the link. Then the spatial motion of a two flexible-joint flexible-link robotic arm are carried out with different joint frictions. The results show that the established models can properly describe the spatial motions of the flexible manipulator, and the vibrations of the active joint angles, flexible links and end position/orientation of the manipulator can be reduced by increasing the joint friction. It lays the foundation for the reliability analysis and vibration suppression controller design of the flexible-joint flexible-link space manipulator for engineering applications.