3T各向同性并联机构的弹性动力学建模与特性分析

为了提升并联机构的运动精度,研究并总结了3T各向同性并联机构在运动过程中由支链产生的柔性变形对其运动轨迹的影响。首先,根据该并联机构的结构分析了其运动学特性。其次,利用空间梁单元的弹性动力学模型、拉格朗日方程、有限元理论以及各条支链的运动学和动力学的约束,对3条支链都在柔性变形情况下建立其弹性动力学方程,并基于Newmark方法进行求解。最后,联立ANSYS与ADAMS软件对该并联机构进行弹性动力学仿真。通过理论计算值与机构模型仿真值的对比,发现3条支链在柔性变形条件下对3T并联机构的运动特性产生了重要的影响,进一步证明了该并联机构弹性动力学模型的可靠性,为其以后的研究与应用提供了重要的理论基础。

Elastic Dynamics Modeling and Characteristic Analysis of a 3T Isotropy Parallel Mechanism

In order to improve the motion accuracy of the parallel mechanism,the influence of the flexible deformation produced by the branched chain on the motion trajectory of the 3T isotropic parallel mechanism during the movement is studied and summarized. Firstly,according to the structure of the parallel mechanism,its kinematics characteristics are analyzed. Secondly,by using the elastic dynamics model of the space beam element,the Lagrange equation,the finite element theory and the kinematics and dynamics constraints of each branch chain,the elastic dynamics equations of the three branches are established under the flexible deformation condition,and the solution is solved based on the Newmark method. Finally,the ANSYS and ADAMS software are used to carry out the elastic dynamics simulation of the parallel mechanism.Through the comparison of the theoretical value and the simulation value of the mechanism model,it is found that the three branched chains have an important influence on the kinematic characteristics of the 3T parallel mechanism under the flexible deformation conditions,and further prove the reliability of the elastic dynamics model of the parallel mechanism,which provides an important theoretical basis for the future research and application.