On The Non-Linear Joint And Dynamic Simulation Of Flexible Manipulators

In the study of flexible manipulator, the flexible joint has an important effect on the dynamic character of manipulators. In the most of works, the flexible joint is only predigested as a linear torsion spring. This is not sufficient to represent the dynamic character of flexible joint manipulator because of the complexity of actual joint. In this thesis, an attempt at considering the flexible joint as non-linear torsion spring has been made.First, the dynamic equations of a manipulator with rigid links and non-linear torsion springs are established. A numerical simulation of a planar 3R manipulator is performed. The results show that the non-linear torsion springs have important influences on the joint error and tip error of manipulators. Moreover, the influences of linear part of non-linear, the lumped mass of the rigid links and the angular acceleration of joint actuators on the non-linear dynamic character of flexible joint manipulator are discussed.Second, the dynamic equations of a manipulator with flexible links and non-linear torsion springs are developed by using flexible rotor beam element. Through a numerical simulation of a planar 3R manipulator, it is shown that the non-linear torsion springs have more important influences on the joint error and tip error of manipulators. Comparing with the flexible joint manipulators with rigid links, the delay in change of the dynamic character of flexible joint manipulators with flexible links is shown. Then, the discussion of the influence of linear part, the lumped mass of the rigid links and the angular acceleration of flexible joint actuators on the non-linear dynamic character of flexible joint manipulator with flexible links is done.At last, using the two famous CAE software ADAMS and ANSYS, the simulation models of flexible joint manipulator with rigid links and flexible joint manipulators with flexible links are established on the basis of the actual structure. The flow chart of the simulation arithmetic is then presented and two numerical examples are given. In comparison of the simulation results and calculation results, the utility of the calculation model and simulation model have been illustrated.