The Dynamics Modeling And Vibration Sup Pression Research Off Lexible Joint-Flex Ible Link Manipulators

With the rapid development of aerospace science and human exploration in space, the space robot technology will play an increasingly important role.Restricted by the firing conditions, the quality of space manipulator should be as light as possible. And to reach the large operating space, the design size of manipulator links are generally long which lead to the non-ignorable flexibilityof manipulator.The flexibility of the manipulators will lead to the vibration of the manipulator’s end-effector, which not only affecting the execution of the task but also creating the safety problems.In this paper, the dynamics models and the vibration characteristic analysis of the flexible link-flexible joint space manipulator is studied and then study the control methods of the vibration suppression.Space manipulator consists of the joints and the links, the deformation of which will both cause the vibration of the end of the actuator. According to the different design of manipulator, the influence of flexible joints and the flexible link is different, so the actual flexible space manipulator is divided into three types of flexible joints-rigid link, rigid joint-flexible link and flexible joint-flexible link, and the corresponding dynamic model is deduced. In the process of modeling, the flexible joint is equivalent to a linear spring, using Euler Bernoulli beam to simulate the flexible link and its deformation is described by the assuming modal method. Then the dynamic equations of the above three types of flexible manipulator are deduced based on the Lagrange method. After that, the dynamics equation is solved and the vibration equation of the joints and the end of link is deduced, and analyzed the vibration characteristic under the condition of different parameters, to provide theoretical basis for the design and control of the manipulator.Study the method of parameter identification and vibration suppression of the flexible manipulator based on the established dynamic model and the vibration analysis. Transform the problem of parameter identification into a nonlinear optimization problem, and then using particle swarm optimization algorithm to finish the identification of joint stiffness coefficient, moment of inertia of the flexible joint, and the elastic modulus and moment of inertia of the link. Combination with the parameters identified above, the vibration control algorithm based on input shaping is developed. Finally, the flexible robot prototype and its experimental system of the single joint single link is developed, and through the prototype experiments. Then the experimental data of joint vibration, link vibration and terminal position are used for the flexible parameter identification, and the developed control algorithm of vibration suppression is verified on the experiment system which is proved to be effective.