自由曲面接触式测量方法研究与原型系统研制

【作者】 兰诗涛；

【导师】 王文； 陈子辰；

【作者基本信息】 浙江大学 ， 精密仪器及机械， 2004， 硕士

【摘要】 现代制造业的产品具有信息模型和实物两种不同范畴的表现形式，而产品生产中最具创新和价值的部分被包含在产品信息模型中，对于在现代工业中得到广泛应用的自由曲面零件尤为如此。所以，对自由曲面零件进行三维几何形状测量、数学建模和数控加工及产品表面质量评定具有重要的现实意义。本文在分析国内外关于自由曲面测量方法、路径规划、碰撞检查及规避、测量数据处理等研究现状及发展趋势的基础上，综合利用机械、测量、CAD／CAM和计算机控制等技术，研制开发了基于开放式运动控制卡的接触式测量原型系统；并对接触式测量系统所涉及相关问题进行了深入的研究。 第一章综述了自由曲面测量方法、接触式测量路径规划、碰撞检查及规避、测点数据预处理等相关研究概况，分析该领域目前存在的问题，确定本论文主要研究内容。 第二章根据接触式测量系统的功能需求分析，提出了接触式测量系统的总体设计方案，包括硬件结构和软件组成功能两部分。 第三章研究自由曲面接触式测量路径规划问题，提出了未知曲面自适应测量的三角形细分法，实现测点的自适应分布；并通过仿真实验验证了该方法的有效性。然后探讨了接触式测量中测量路径的生成及其优化方法。 第四章探讨了CAD模型已知情况下的碰撞规避问题，主要包括扩张障碍物法和射线跟踪法。这些方法可以较好的解决接触式测量中已知CAD模型时的碰撞规避；而对于CAD模型未知情况下的碰撞规避，采用常用的“生成--测试”的方法，并对几种常见的碰撞情况进行了讨论。 第五章介绍了接触式测量数据的噪声处理和坏点剔除；然后详细论述了采用微平面法进行半径补偿处理的算法。另外还将测量得到的数据进行了IGES标准文件格式的转换，以利进行后续处理。 第六章介绍了接触式测量系统的实现及其开发的关键技术、主要的软件功能模块等；然后分析了影响该测量系统精度的主要因素，并进行了相关的实验研究。 第七章概括了全文研究的主要结论，并对接触式测量系统的后续研究提出了自己的看法，进行了展望。更多还原

【Abstract】 The products in the modern manufacturing have such two kinds of different representations as in information model and real model, while the most innovative and valuable part of the manufacturing is included in the former one. This is the case especially for the free-form surface parts widely used in modern industry. Thus such research work as the measuring, modeling, manufacturing and quality assessment of freeform surface parts is of great importance in modern manufacturing industry. In this dissertation, based on the survey of the present research situation and development trends at home and abroad of the free-form surface measurement methods, path planning, collision checking and avoiding, data processing, etc., by absorbing techniques of mechanics, measuring, CAD/CAM and computer control, etc., a contact measure prototype system based on open motion control card was developed, meanwhile the relevant problems on contact measuring were profoundly studied.In Chapter 1, the current study situation of measuring methods for free-form surface, path planning for contact measurement, collision checking and avoiding and the measure data processing is summarized and the problems on contact measurement are also pointed out. Then the main research work of the dissertation is made certain.In Chapter 2, the gross design including hardware structure and software for the contact measure system is brought forward, according to the function requirement analysis of the contact measure system.In Chapter 3, the problem about path planning of contact measure is studied. Triangle mesh method for the surface whose CAD model is unknown is brought forward to fulfill the self-adaptive distributing of measure dots, and the method is proved to be valid by simulated experiment. Then the path generating for contact measure and the methods to optimize it are discussed.In Chapter 4, the collision avoidance problem is discussed in the situation that the CAD model is known and there are two methods that can resolve the problem to some extend. The method of "generate-test" is often used in the situation that the CAD model is unknown, and some collisions that are frequently happened are discussed.In Chapter 5, the method of processing yawp and wrong data is introduced. Then arithmetic to compensating the probe radius error is discussed in detail. After that, the measure data is converted to IGES format in order for the subsequent processing.In Chapter 6, the fulfillment of the contact measure system, some several key technologies for the development and the main software function modules are introduced. Then some main factors that impact on the precision of the contact measure system are analyzed and some experiments are studied.In Chapter 7, the main conclusions of the dissertation are summarized, and the author’s ideas about the future work of the contact measure system are proposed.更多还原