基于OCCT的激光立体成形CAM软件开发

发布时间：2018-05-31 19:34

本文选题：增材制造 + 激光立体成形　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：激光立体成形是基于送粉式激光熔覆技术发展起来的一种增材制造技术,至今已有20余年的历史。近年来,虽然该技术在工艺上得到了很大的发展,但是激光立体成形软件的质量却难以真正满足工艺开发者的应用需求。目前软件功能与工艺的匹配存在脱节,导致软件直接限制了该技术可加工零件的形状、加工零件的精度和加工过程的效率。因此,本文在充分依赖于激光立体成形工艺的基础上,为其开发了专业的CAM软件,并通过实际零件的制造验证了开发软件的实用性与可靠性。为了提高软件开发效率与软件鲁棒性,以面向对象的C++作为编程语言、以Qt开发图形用户界面(GUI)、以Open CASCADE Technology(OCCT)几何造型内核实现软件核心功能模块。激光立体成形CAM软件有5大功能模块:模型读取、模型显示、分层功能、路径规划功能、6轴机器人加工程序转换。其中,后3个模块与工艺直接相关,为了保证与工艺更好契合,本文为其开发了专门的算法。软件实现了STL格式文件的读取,将STL模型转换为边界表示法(B-rep)描述的模型。转换后的图形在窗口中显示,并且可以对显示的模型做平移、旋转、缩放等基本视图操作。分层功能和路径规划功能为核心功能。分层功能选用等距分层算法,使用OCCT中Face和Solid求交集(Common)的布尔运算方法实现,获得Face拓扑结构的分层面。路径规划功能根据零件制造工艺不同分为两类:厚壁零件路径和薄壁零件路径。为厚壁零件路径设计了外轮廓加内部Z字形填充路径的规划方式,使用OCCT中Face和Face求交线(Section)的布尔运算方法实现;为薄壁零件设计了常规轮廓路径和螺旋线路径两种路径规划算法,螺旋线算法可以实现加工过程仅开关激光一次就完成整个薄壁零件的制造。以KUKA 6轴机器人为应用对象,针对同轴送粉、旁轴送丝两种激光立体成形工艺,开发了两种机器人加工程序转换算法;基于KUKA离线编程的关键指令,采用罗德里格公式了推导激光头姿态欧拉角。最后,分别以316L不锈钢、Al Si10Mg铝合金两种材料,完成了薄壁变截面样件的激光立体成形制造,对激光立体成形CAM软件的算法和性能进行了验证。
[Abstract]:Laser solid forming is a kind of material increasing technology developed based on powder feeding laser cladding technology, which has a history of more than 20 years. In recent years, although the technology has been greatly developed, the quality of laser stereoscopic forming software is difficult to meet the application needs of process developers. At present, there is a disjoint between the function of the software and the process, which directly limits the shape of the machined parts, the precision of the machined parts and the efficiency of the machining process. Therefore, on the basis of fully relying on the laser stereoscopic forming process, this paper develops the professional CAM software for the laser solid forming process, and verifies the practicability and reliability of the development software through the manufacture of the actual parts. In order to improve the efficiency and robustness of software development, using object-oriented C as programming language, using QT to develop graphical user interface (GUI) and using Open CASCADE Technology (Occt) geometry modeling kernel to realize the core function module of software. The CAM software of laser stereoscopic forming has five function modules: model reading, model display, delamination function, path planning function and 6-axis robot machining program conversion. The latter three modules are directly related to the process. In order to ensure better agreement with the process, this paper develops a special algorithm for it. The software realized the reading of the STL format file, and converted the STL model into the model described by the boundary representation. The transformed graphics are displayed in the window, and the basic view operations such as translation, rotation, zoom and so on can be performed on the displayed model. Hierarchical function and path planning function are the core functions. The hierarchical function is implemented by using the algorithm of equidistant delamination, and the Boolean operation method of Face and Solid intersection in OCCT is used to achieve the hierarchical structure of Face. The function of path planning is divided into two categories according to the manufacturing process: thick wall part path and thin wall part path. For the thick wall part path, the external contour and the inner Z shape filling path are designed, and the Boolean operation method of Face and Face intersection line Sectionin OCCT is used. Two path planning algorithms, conventional contour path and spiral path, are designed for thin-walled parts. The helix algorithm can realize the fabrication of the whole thin-walled parts only once by switching laser. Taking the KUKA 6 axis robot as the application object, aiming at two laser stereoscopic forming processes of coaxial powder feeding and side wire feeding, two robot processing program conversion algorithms are developed, and the key instructions of off-line programming based on KUKA are developed. The attitude Euler angle of laser head is deduced by Rodrigo formula. Finally, laser stereoscopic forming of thin-walled samples with variable cross-section was completed using 316L stainless steel and Al Si10Mg aluminum alloy, and the algorithm and performance of CAM software for laser stereoforming were verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP311.52;TG665

【参考文献】