基于绝对节点坐标法的空间并联机构刚柔耦合动力学建模  

Rigid Flexible Coupling Dynamic Modeling of Spatial Parallel Mechanism Based on Absolute Node Coordinate Formulation

作　　者：陈修龙[1] 崔梦强 CHEN Xiulong;CUI Mengqiang(College of Mechanical and Electronic Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学机械电子工程学院,青岛266590

出　　处：《农业机械学报》2021年第4期392-401,共10页Transactions of the Chinese Society for Agricultural Machinery

基　　金：山东省重点研发计划(公益类)科技攻关项目(2019GGX104011)。

摘　　要：为研究柔性杆件对空间并联机构动力特性的影响,以具有结构冗余的3-RRPaR空间并联机构为研究对象,提出建立冗余空间并联机构刚柔耦合动力学模型的通用方法。基于绝对节点坐标法建立了三维二节点梁单元模型,分析了机构的结构特征,利用拉格朗日乘子法推导了机构的刚柔耦合动力学方程,采用广义α方法在Matlab中对其动力学方程进行数值求解,得到不同弹性模量下的动力学响应曲线。结果表明,柔性杆件对机构输出特性产生重要的影响,弹性模量越小,对机构的影响越大,且弹性模量对动平台加速度的影响最为显著。本研究为空间并联机构的刚柔耦合动力学建模提供了研究思路。In order to study influence of flexible rod on the dynamic characteristics of the spatial parallel mechanism,the 3-RRPaR spatial parallel mechanism with structural redundancy was taken as the research object,and a general method for establishing rigid flexible coupling dynamic model of redundant spatial parallel mechanism was proposed. A three-dimensional two node beam element model was established based on the absolute node coordinate method. The structural characteristics of the mechanism were studied,and the rigid flexible coupling dynamical equation of the mechanism was derived by Lagrange multiplier method. The generalized α method was used to solve the dynamic equation in Matlab,and the dynamical responses curves of the mechanism under different elastic modulus were obtained. It can be concluded that the flexible rod had an important influence on the output characteristics of the mechanism. The smaller the elastic modulus was,the greater the influence on the mechanism was,and the impact on the acceleration of the moving platform was the most significant. The research can provide a modeling method and idea for other rigid flexible coupling dynamics of other spatial parallel mechanisms,and also can lay a foundation for the dynamic modeling of the mechanism considering joint clearance and flexible rod at the same time.

关 键 词：空间并联机构 绝对节点坐标法 拉格朗日乘子法 刚柔耦合动力学 

分 类 号：TH112[机械工程—机械设计及理论]