双端虎克铰型六自由度并联机构的动力学模型

Dynamic model of a 6-DOF parallel mechanism with Hooke's joints at both chain ends

为对支链两端为虎克铰型的并联机构进行优化设计及运动仿真,建立了六自由度的该类并联机构的动力学模型。基于运动学分析推导了机构的几何Jacobi矩阵,采用Newton-Euler法建立了所有构件的动力学方程,根据D'Alembert原理的约束理想性条件并利用几何Jacobi矩阵消去各方程中的未知约束反力,最终得到了各主动副驱动力的表达式。以一个六自由度运动平台为例进行计算,验证了该模型的正确性。该模型可用于实际的支链两端为虎克铰型的并联机构的分析和设计。

A dynamic model developed for a six degrees of freedom (DOF) mechanism was used to optimize the design and motion simulation of a parallel mechanism with Hooke's joints at both chain ends. The Jacobian matrix of the mechanism geometry was derived from a kinematics analysis. The dynamic equations for each part were deduced using the Newton-Euler method. The ideal constraint condition of the D'Alembert principle was used to eliminate the unknown constraint counterforce terms in the equations from the Jacobian to calculate the driving forces of the active joints. A 6-DOF motion simulation platform was taken as an example to verify the model. The results show that the model can be used to design and analyze practical parallel mechanisms with Hooke's joints at both chain ends.