【作者】 王世军；

【导师】 黄玉美；

【作者基本信息】 西安理工大学 ， 机械工程， 2004， 博士

【摘要】 并联机床是一种具有良好应用前景的新一代制造装备，是机器人技术在机床领域的延伸，是传统机床与现代机器人技术相结合的产物。在机器人应用领域迅速扩大的同时，机器人领域内知识也在不断更新。当前的机器人研究不少是以刚体动力学为根本理论的前提下进行研究的，或者只考虑构件的弹性变形，而未考虑关节结合部的变形。但是，用作机床的机器人系统则向着高速、重载、高刚度，部件向着轻质的方向发展，构件的弹性变形增大，造成了其与机器人运动平稳性、准确性的矛盾，从而突出了机器人各部件弹性变形的影响。因此，传统的机器人的研究方法显然已经不适合于当前并联机床的研究。 并联机床的研究才刚刚展开，目前主要的研究内容涉及刚体动力学、弹性体动力学、加工过程稳定性、加工精度等几个方面。其中并联机床中并联机构动态特性的研究具有紧迫的现实意义，是并联机床在工程应用中亟待解决的关键技术问题之一。6PM2是西安理工大学自动化研究所开发的一台混联机床，是在并联机床基础上研制的新型机床，3-RPS并联机构是其核心部件。本文结合该机床主要进行了以下几个方面的研究工作： 1．建立了基于梁模型的并联机构的模型，以及非线性弹性关节刚度和载荷的测量方法，在此基础上分析了在不同载荷作用下的关节受力。 2．建立了计及接触非线性弹性的关节实体建模方法，并建立了相应的接触单西安理工大学博士学位论文 元刚度矩阵。该单元能够利用现有的结合部实验数据建立实体模型，能够 计及法向的非线性刚度和剪切刚度与法向面压的祸合关系。 3.建立了具有圆柱接触表面的转动关节实体建模方法，研究了曲面接触由于 数值离散而产生的剪涨特性并提出了相应的解决方案。 4.建立了计及关节非线性.弹性接触的并联机构的有限元模型，分析比较了使 用三种不同关节模型建立的整机模型静态、动态特性的差异:不考虑关节 接触特性的固结模型，考虑关节接触的刚性接触模型和考虑关节非线性弹 性接触的弹性接触模型。对并联机构的刚度进行了实验研究，并将实验结 果与不同模型的计算结果做了比较。关键词:混联机床，关节，非线性，整机分析，有限元，接触更多还原

【Abstract】 Serial-parallel machine tool is a new kind of machining equipment, which is a kind of robot in machine tools and a combination between traditional machine tools and modern robot. When robot technology is uesed in machine tools, robot technology is being updated itself consequently. Some of current study on robot is based on rigid body dynamics theory. In the others, elastic deformation of components is considered but the deformation of joint is not considered. The robots as machine tools become more and more of high speed, light weight, high load and high stiffness, which make elastic deformation of component increase. The elastic deformation lows robot movement stability and accuracy. Therefore, elastic deformation of joint of serial-parallel machine tools cannot ingored. Traditional study method on rigid robot evidently cannot be used in parallel machine tools.Study on serial-parallel machine tool just begins. Main contents involve rigid body dynamics, elastic body dynamics, stability in machining process and machining precision, et al. In the contents, dynamic characteristic of machine tools is most emergent and practical, which is a key technology in engineering application. 6PM2 is a new serial-parallel machine tool, which is developed by the Institute of Mechanism andAutomation of Xi’an University of Technology. 3 - RPS parallel machanism is its key component. Based on the machine tool, the research efforts have finished in this thesis as follow:1. Based on beam theory, a model for a nonlinear parallel machanism is established. Nonlinear joint stiffnesses and load are computed by measurement data of workbench and finite elment result of machine tool.2. A method is presented, in which solid joint with nonliear elasticity is modeled, and stiffness matrix of contact element is established. This kind of element can make use of joint experiment data to build solid joint model and can include normal nonlinear stiffness and coupling between shear stiffness and normal pressure.3. A method modeling solid joint with column contact surfaces is presented. Shear-expanded effect is studied, owning to numerical dispersion and a solution is presented.4. A global finite element model for serial-parallel machine tool is established, which involve in joint contact and nonlinear elasticity. Static and dynamic characteristic of global models with three kinds of joint analyzed and compared, which are concretion model not involving in joint contact, rigid contact model involving in joint contact and elastic contact model involving in joint contact with nonliear elasticity. Global stiffness of machine tool is studied in experiment and experimental results and computing result sare compared.更多还原