基于铣削力控制的曲面加工轨迹规划方法研究

发布时间：2018-03-21 02:39

本文选题：汽车覆盖件　切入点：曲面划分　出处：《哈尔滨理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：社会经济的飞速发展带动了汽车制造业的发展,为了满足汽车外形美观度及性能的要求,汽车覆盖件模具的更新速度逐步加快。但是,由于汽车覆盖件模具具有外形结构较大、曲率变化不均匀等特性,若模具整体采用一种加工方式进行加工则会导致表面质量差及加工效率低等问题,同时,也增大了汽车覆盖件模具数控加工编程的难度。为此,本文针对汽车覆盖件模具的曲面划分、铣削力建模及刀具路径规划等方面展开研究。针对汽车覆盖件整体加工存在的加工质量问题,采用计算曲面离散型值点的主曲率、平均曲率和高斯曲率及K-means聚类算法对复杂曲面进行划分,并结合Voronoi图算法对曲面边界进行提取,完成整体复杂曲面的分片划分。针对球头刀数控铣削加工过程,以瞬时刚性力学模型为基础,通过求解瞬时刚性力学模型中的未知量,建立刀具-工件切触区域模型,并采用MATLAB软件对刀具-工件切触区域进行仿真,结合坐标变换建立铣削力模型。针对传统刀具路径规划算法仅仅考虑刀具与工件之间几何位置之间的关系,忽略物理因素对整个加工过程的影响这一问题,采用TSP问题来解决刀路轨迹规划问题,并采用遗传算法来解决TSP问题,选择铣削力变动相对小的方向为加工方向,得到了规划的刀具路径,并采用MATLAB软件对规划的刀具路径进行仿真。通过传统加工方法与优化算法的对比实验验证了优化算法规划刀具路径的正确性、可行性,并证明优化算法规划的刀具路径加工的工件表面光顺性更好,加工过程中所承受的平均铣削力更小。
[Abstract]:The rapid development of social economy has led to the development of automobile manufacturing industry. In order to meet the requirements of the beauty and performance of automobile appearance, the renewal speed of automobile panel die has been accelerated gradually. However, because of the larger shape and structure of automobile panel die, If the die adopts a machining method, it will lead to the problems of poor surface quality and low machining efficiency. At the same time, it also increases the difficulty of NC machining of automobile panel die. In this paper, the surface partition of automobile panel die, milling force modeling and tool path planning are studied. In view of the machining quality problem existing in the whole machining of automobile panel, the principal curvature of discrete value points of surface is calculated. The mean curvature, Gao Si curvature and K-means clustering algorithm are used to partition the complex surface, and the Voronoi graph algorithm is used to extract the boundary of the surface to complete the partition of the whole complex surface. Based on the instantaneous rigid mechanics model and by solving the unknown quantity in the instantaneous rigid mechanics model, the contact region model of the cutter and workpiece is established, and the MATLAB software is used to simulate the contact region of the cutting tool to the workpiece. Based on coordinate transformation, the milling force model is established. Aiming at the problem that the traditional tool path planning algorithm only considers the relationship between the geometric position of the tool and the workpiece, and neglects the influence of physical factors on the whole machining process. The TSP problem is used to solve the path planning problem, and the genetic algorithm is used to solve the TSP problem. The cutter path is obtained by selecting the direction in which the milling force is relatively small. The tool path is simulated by MATLAB software. The correctness and feasibility of the optimization algorithm are verified by comparing the traditional machining method with the optimization algorithm. It is proved that the workpiece surface smoothness is better and the average milling force is smaller when the tool path is processed by the optimized algorithm.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U466;TG547

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