一种含有闭环支链的5-DOF并联机械臂的动力学建模与分析

Dynamics Modeling and Analysis of a 5-DOF Parallel Manipulator Arm with Closed Loop Branch Chain

提出一种双闭环5-DOF机械臂,该机械臂在((2-UPS)+U)PU构型的基础上增加闭环结构,得到新的拓扑构型2-UPS+((2-UPS)+U)PU,闭环结构的引入使得机构获得更高的承载能力且为拓扑新的构型提供了新思路。应用矢量链法,建立了机构的位置模型;推导了支链驱动速度、支链摆动角速度与运动平台广义速度Vo的映射,建立了机构的独立变量q与运动平台广义速度Vo之间的解耦矩阵;建立了机构支链中的摆动杆、伸缩杆质心速度与运动平台广义速度Vo之间映射,并基于虚功原理建立了机构的动力学模型,将推导的动力学模型变换成具有Lagrange动力学形式的动力学模型;在Adams仿真软件中建立该机构的虚拟样机模型,通过仿真验证了推导的动力学模型的正确性。

A double closed loop 5-DOF manipulator arm is proposed,which adds a closed loop structure on the basis of((2-UPS)+U)PU configuration to obtain a new topology configuration 2-UPS+((2-UPS)+U)PU.The introduction of the closed loop structure enables the mechanism to obtain a higher carrying capacity and provides a new idea for the new topology configuration.The mapping of the velocity of the branch drive,the velocity of the swing angle of the branch and the generalized velocity Vo of the moving platform is derived.The decoupling matrix between the independent variable q̇of the mechanism and the generalized velocity Vo of the moving platform is established.The mapping between the velocity of the center of mass of the swing bar,the expansion bar and the generalized velocity Vo of the moving platform in the branch chain of the mechanism is established.Based on the principle of virtual work,the dynamics model of the mechanism is established and transformed into a dynamics model with Lagrange dynamic form.The virtual prototype model of the mechanism is established in Adams simulation software,and the correctness of the derived dynamics model is verified by simulation.