【作者】 张艳；

【导师】 郑鹏； 商向东；

【作者基本信息】 沈阳工业大学 ， 机械制造及其自动化， 2004， 硕士

【摘要】 反求工程指在没有技术资料的情况下获得产品初始设计意图的技术过程。本文在全面总结和分析目前制造业领域中反求工程的基本理论及关键技术、研究及应用状况的基础上，结合电话听筒外壳型面及其它实例，对目前复杂曲面反求工程的全过程及其关键技术进行了研究和探索，内容包括数据测量、数据处理、曲面重构和数控加工编程。本论文的主要工作在以下几个方面： 分析与比较了目前常用的数字化测量方法及各种三维数字测量设备，着重介绍了本课题所用到的LK G90CS15.10.8型三坐标测量机的机械结构、软硬件配置、规格参数及环境要求，并用该机器对某电话机听筒外壳的三维表面进行扫描测量； 阐述了反求工程的测量数据类型及各种数据点的处理方法，提出了利用Coons曲面原理剔除噪声点的方法，采用中值滤波方法对测量数据进行平滑，提出了用弦高差等方法和特征曲率法对电话听筒外壳数据进行了数据点的精简和特征点的提取的方法； 论述了曲面造型技术的发展过程，比较了自由曲面和各种生成算法，应用NURBS算法重构了电话听筒的外壳曲面，并利用特征线对生成曲面进行了裁剪； 分析比较了复杂曲面数控加工的切削方式、切削用量、走刀方式进退刀方式、编程零点和加工坐标系的确定，推导出用残留刀痕法来控制加工步长的关系式，阐述了在MasterCAM环境下如何选定待加工曲面的切削参数和刀具参数，并根据所选刀具和切削参数分别生成了电话听筒外壳型面的粗加工和精加工过程的刀具路径。更多还原

【Abstract】 Reverse Engineering (RE) refers to the process of acquiring the original technical information of the product without any technical data. In this thesis, basic theory, key technique, present research and applying status of RE in manufacture field are comprehensively summarized and analyzed, on the basis of which the whole process and key technique of complex surface’s RE are researched, including data measuring, data processing, surface reconstruction and numerical control machining, taking the telephone hand-receiver as example. Main work is as following:The digitized measuring methods and devices that are generally used at present are analyzed and compared. Among them, the mechanical structure, the configuration of hardware and software, the specification parameter and the environmental request of LK G90CS15.10.8 thiee-CMM mat are used in this thesis are introduced specially. By using LK G90CS15.10.8 three-CMM, the measuring data of the telephone hand-receiver are acquired.The types and the processing methods of measured data are discussed. Aiming at the error points in points data, a method using Coons surface is put forward. Filtration is commonly used in data smoothing, and median method is adopted in this article. Moreover, the chord method and the curvature method are used here to compress the data and extract the feature points of the telephone hand-receiver measured data.The developing process of surface molding is introduced and the formation algorithm of free-form surfaces is compared By using NURBS algorithm in mis article, the telephone hand-receiver surface is reconstructed. In addition, the surface of the telephone hand-receiver is cut according to the feature curve created by the feature points.The craft of numerical control machining program of complex surface is analyzed and compared. These craft are machining method, cutting dosage, machining remainder, cuter walking mode, the cuter advance, the retreat mode, programming zero, and machiningcoordinate so on. The conclusion that the layer cutting is fitter for rough machining is made. The formula of scallop-height method controlling machining step is deduced. Finally, the cutting and cutter parameter for rough machining and finish machining of complex surface is put forward in the MasterCAM software, according to which the cutter route for rough machining and finish machining are produced respectively.更多还原