复合驱动并联机构的动力学建模与仿真分析

Dynamics modeling and simulation analysis of hybrid-drive parallel mechanism

针对一种PUU-2PRRS 5自由度复合驱动并联机构的刚体动力学建模问题,采用拉格朗日法结合虚功原理建立刚体动力学模型并进行仿真分析。首先,在考虑存在次闭环的情况下,采用闭环矢量法对并联机构进行运动学分析,推导出机构各构件质心的线速度和角速度;其次,采用拉格朗日法结合虚功原理建立复合驱动并联机构的刚体动力学模型,为复合驱动并联机构驱动力的求解及后续动力学仿真分析奠定了基础;最后,基于MATLAB软件和ADAMS软件对该并联机构进行动力学仿真分析,在给定相同末端轨迹的情况下,对比两种软件得到的驱动力变化曲线,仿真结果验证了所建动力学模型的正确性。文中不仅为PUU-2PRRS 5自由度复合驱动并联机构控制系统的搭建打下了基础,也为其他复合驱动并联机构的动力学建模分析提供了理论依据。

In this article,in order to realize the rigid-body dynamics modeling of a PUU(prismatic pairs-universal joints-uni-versal joints)-2PRRS(prismatic pairs-revolution joints-revolution joints-spherical joints)5-DOF hybrid-drive parallel mecha-nism,the rigid-body dynamics model is set up with the help of the Lagrange method and the virtual work principle,and then the simulation analysis is carried out.Firstly,with the sub-closed loop taken into consideration,the closed-loop vector method is used to conduct the kinematic analysis on the parallel mechanism,so as to identify the linear velocity and the angular velocity at the centroid of the mechanism's each component.Secondly,both the Lagrange method and the virtual work principle are adopted to set up the hybrid-drive parallel mechanism's rigid-body dynamics model,which lays a foundation for solving the hybrid-drive par-allel mechanism's driving force and conducting the dynamics simulation analysis subsequently.Finally,the dynamics simulation analysis is conducted on the parallel mechanism based on the software MATLAB and ADAMS.In the case of the same trajectory,the driving-force curves obtained by the software are compared,in order to verify whether the dynamics model is correct.This study not only lays a foundation for setting up the control system of the PUU-2PRRS 5-DOF hybrid-drive parallel mechanism,but also provides theoretical basis for the dynamic modeling analysis on other hybrid-drive parallel mechanisms.