复杂曲面零件激光熔覆的路径规划研究

发布时间：2018-06-24 01:24

本文选题：激光熔覆 + 逆向工程　；参考：《新疆大学》2017年硕士论文

【摘要】：激光熔覆技术作为近年来发展起来的高新技术,具有节约能源、基变形小、产品成品率高、可获得高性能冶金结合熔覆涂层等特点,被广泛应用于破损零部件的修复、表面强化处理以及零件的直接制造等方面。曲面因具有高的自由度,良好的流体热力学和动力学等特性,曲面造型的零部件日趋被广大工业领域所引用。随着CAD软件和专业CAM系统的迅速发展,复杂曲面零件的建模精度越来越高,曲面零件激光熔覆加工逐渐成为零部件修复的发展方向,但由于受其工艺条件的限制,使得复杂曲面表面熔覆层质量很难得到保证。在曲面零件的激光熔覆再制造加工过程中,熔覆路径的规划至关重要,它直接影响着工件表面的熔覆层质量。本文结合了激光熔覆的工艺特性,对曲面零件进行路径规划,在提高曲面零件加工效率的基础上,改善熔覆层质量,并对规划的路径进行仿真和实验,证明了该方法的合理性。(1)论文首先结合逆向工程技术获取曲面零件表面的点云数据,并对其进行处理,得到偏差值小,密度适中,轮廓清晰的点云,对点云特征进行分析,选定特征点领域的算法,采用拟合局部NURBS曲面的方法,分析曲面微分几何特性,求出特征点的法向矢量,为后续熔覆加工打下基础。(2)论文采用点云切片技术生成熔覆加工路径,并根据点云密度进行切片厚度的计算,结合曲面的特性引入人工交互手段确定熔覆扫描方向,着重考虑熔覆的搭接特点进行切片间距的计算,分析熔覆的工艺特点以及曲面的特征,运用等弓高稀疏加工点的方法进行熔覆加工插补点的计算,进而获取激光枪头运行轨迹。(3)论文根据得到的熔覆轨迹进行仿真及实验。因机器人具有较大的加工自由度,可进行柔性熔覆加工等特点,首先对规划好的熔覆路径进行坐标转换以及机器人运动路径生成,得到最终熔覆程序,并根据所得的熔覆程序进行实验,最后定性和定量分析所得熔覆层质量,从而验证了该方法的合理性。
[Abstract]:Laser cladding technology, as a new technology developed in recent years, is widely used in repairing damaged parts because of its advantages of saving energy, low base deformation, high product yield, high performance metallurgical cladding coating and so on. Surface strengthening treatment and direct manufacturing of parts, etc. Due to its high degree of freedom, good fluid thermodynamics and dynamics, surface modeling parts are increasingly used in industrial fields. With the rapid development of CAD software and professional CAM system, the modeling accuracy of complex curved surface parts is getting higher and higher. Laser cladding machining of curved surface parts has gradually become the development direction of parts repair, but due to the limitations of its technological conditions, It is difficult to ensure the quality of the cladding layer on the surface of complex surface. The planning of cladding path is very important in the process of laser cladding and remanufacturing of curved surface parts, which directly affects the quality of the cladding layer on the surface of workpiece. In this paper, based on the process characteristics of laser cladding, the path planning of curved surface parts is carried out. On the basis of improving the machining efficiency of curved surface parts, the quality of cladding layer is improved, and the planned path is simulated and experimented. It is proved that this method is reasonable. (1) the point cloud data of curved surface are obtained by reverse engineering, and the point clouds with small deviation value, moderate density and clear contour are obtained, and the point cloud features are analyzed. The method of fitting local Nurbs surface is used to analyze the differential geometric characteristics of the surface, and the normal vector of the feature point is obtained, which lays the foundation for the subsequent cladding machining. (2) Point cloud slicing technique is used to generate the cladding path in this paper. The slice thickness is calculated according to the point cloud density, and the manual interactive method is introduced to determine the scanning direction of cladding, and the cladding space is calculated by considering the overlap characteristics of cladding. The characteristics of cladding process and surface are analyzed, and the interpolation point of cladding process is calculated by using the method of equiarched high sparse machining point. (3) the simulation and experiment are carried out according to the obtained cladding path. Because the robot has a large degree of freedom, it can be used for flexible cladding machining. Firstly, coordinate transformation of the planned cladding path and robot motion path generation are carried out, and the final cladding procedure is obtained. Finally, the quality of cladding layer is qualitatively and quantitatively analyzed according to the cladding procedure, which verifies the rationality of the method.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

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