基于激光跟踪仪的大型五轴数控机床空间精度检测及建模

发布时间：2018-05-28 06:05

本文选题：大型五轴机床 + 空间精度　；参考：《电子科技大学》2017年硕士论文

【摘要】：在航空航天制造业中,存在着大量不同类型的大尺寸复杂零件,相对于小型机床而言,大型五轴数控机床由于其工作空间范围大、结构灵活,在加工这类零件时具有明显的优势。然而大型机床往往受到自身制造、装配等精度的限制,导致其在进行超精密加工时无法满足精度要求,而机床空间精度作为各误差源在机床系统中的综合体现,能很好的反映大型机床在全工作空间域的精度,并为机床精度补偿提供依据。因此,本文以提高大型五轴数控机床空间精度为目的,开展了空间精度的检测、建模等相关研究。具体内容如下:(1)首先开展空间误差源分析,定义了空间精度的表示方法。结合大型五轴机床工作空间特征,选择API激光跟踪仪作为检测仪器,研究其相关检测原理,包括三维位置坐标测量原理以及转站测量原理等。根据五轴机床空间精度特征,设计了空间位姿精度的检测方案。借用机器人学中工作空间的概念,采用蒙特卡洛法,分析了五轴数控机床的工作空间。(2)基于GPS原理,采用激光跟踪仪,设计了五轴数控机床“多站法”空间位姿精度优化检测方案。在工作空间分析的基础上,研究了空间测点生成算法,获得了机床工作空间的测点。基于遗传算法分别优化了激光跟踪仪在测量过程中的设站和空间位姿检测路径,保证了测量精度,并提高了测量效率。(3)采用多项式函数拟合出各单项误差在机床各轴任意位置处的误差值,结合多体运动学建立的机床空间位姿模型,计算出特定位置的机床位姿向量,与激光跟踪仪检测出的相应位置处的位姿数据相比较,得到差异向量,运用LM算法,辨识出了各单项误差拟合多项式系数,预测了五轴机床在全工作空间域的位姿精度。实现了大型五轴数控机床空间精度建模。(4)基于MATLAB GUI开发了大型五轴机床空间精度建模及预测软件,设计出不同的功能模块,实现了算法的软件化应用。
[Abstract]:In the aerospace manufacturing industry, there are a large number of large and complex parts of different types. Compared with small machine tools, large five-axis CNC machine tools have a wide workspace and flexible structure. There are obvious advantages in processing this kind of parts. However, large machine tools are often limited by their own manufacturing, assembly and other precision, resulting in their ultra-precision machining can not meet the accuracy requirements, and the machine tool spatial accuracy as a comprehensive reflection of the error sources in the machine tool system. It can well reflect the precision of large machine tool in the whole workspace, and provide the basis for the accuracy compensation of machine tool. Therefore, the purpose of this paper is to improve the spatial accuracy of large five axis CNC machine tools, and research on spatial accuracy detection and modeling is carried out. The main contents are as follows: 1) first, the spatial error source analysis is carried out, and the representation method of spatial precision is defined. Based on the workspace characteristics of a large five-axis machine tool, API laser tracker is selected as the testing instrument, and the related detection principles, including the three-dimensional position coordinate measurement principle and the transfer station measurement principle, are studied. According to the spatial accuracy characteristics of five-axis machine tools, the detection scheme of spatial pose accuracy is designed. Based on the concept of workspace in robotics and the Monte Carlo method, the workspace of five-axis CNC machine tool is analyzed. Based on the principle of GPS, the laser tracker is used. In this paper, a five-axis NC machine tool "multi-station method" is designed to optimize the precision of position and pose. On the basis of workspace analysis, the algorithm of generating space measurement points is studied, and the measuring points of machine tool workspace are obtained. Based on genetic algorithm, the station setting and space pose detection path of laser tracker in the measurement process are optimized, and the measurement accuracy is ensured. The measurement efficiency is improved. The polynomial function is used to fit the errors at any position of each axis of the machine tool, and the position and pose vector of the machine tool at a specific position is calculated by combining the space pose model of the machine tool established by multi-body kinematics. Compared with the position and pose data of the corresponding position detected by laser tracker, the difference vector is obtained. By using LM algorithm, the fitting polynomial coefficients of each single error are identified, and the pose accuracy of the five-axis machine tool in the whole workspace domain is predicted. The spatial precision modeling and prediction software of large five-axis CNC machine tool is developed based on MATLAB GUI. Different function modules are designed and the software application of the algorithm is realized.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG659

【相似文献】