基于改进萤火虫算法的航发叶片3D采样方法研究
Research on Aero-engine Blade 3D Sampling Method Based on Improved Firefly Algorithm
作者：黄智(电子科技大学 机械电子工程学院, 四川 成都 611731)；李凯(电子科技大学 机械电子工程学院, 四川 成都 611731)；李超(电子科技大学 机械电子工程学院, 四川 成都 611731)；王洪艳(电子科技大学 机械电子工程学院, 四川 成都 611731)；宋瑞(电子科技大学 机械电子工程学院, 四川 成都 611731)
Author：HUANG Zhi(School of Mechatronics Eng., Univ. of Electronic Sci. and Technol. of China, Chengdu 611731, China)；LI Kai(School of Mechatronics Eng., Univ. of Electronic Sci. and Technol. of China, Chengdu 611731, China)；LI Chao(School of Mechatronics Eng., Univ. of Electronic Sci. and Technol. of China, Chengdu 611731, China)；WANG Hongyan(School of Mechatronics Eng., Univ. of Electronic Sci. and Technol. of China, Chengdu 611731, China)；SONG Rui(School of Mechatronics Eng., Univ. of Electronic Sci. and Technol. of China, Chengdu 611731, China)
收稿日期：2017-09-08 年卷（期）页码：2018,50(4):260-265
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：叶片;轮廓测量;三坐标测量机;截面曲线;采样;改进萤火虫算法
Key words：blade;contour measurement;coordinate measurement machine;cross-section;sampling;improved firefly algorithm
基金项目：国家自然科学基金资助项目（51275078）；四川省科技支撑计划资助项目（2016GZ0004）；中央高校基本科研业务费资助项目（ZYGX2015J086）
中文摘要
航发叶片是航空发动机的重要零件，其加工精度将直接影响航空发动机的使用性能与寿命。对叶片加工精度的评价通常采用3D轮廓测量方式实现。由于作为典型自由曲面代表的叶片结构复杂，存在较大的空间扭曲度，不仅导致其加工困难，也加剧了测量的难度。三坐标测量机是目前叶片轮廓测量精度最高的检测方式，受制于叶片型面复杂度和目前触点式三坐标测量技术限制，需要采集大量的表面数据点才能全面地表征叶片表面特征，使得测量效率极低。从曲面3D模型采样的角度出发，提出了基于改进萤火虫算法的采样点提取方法，首先提取叶片各截面曲线，其次对提取曲线分段并以等弧长方法均匀采点，按顺序提取的初始点位置数据模拟建立小型萤火虫群落，计算群落内点曲率关系并确定目标位置点的移动方向以及步长，实现已知分布点的点位自动更新，最终得到叶片表面所有关键特征采样点。本文算法可实现测量点数自由配置，通过该方式达到调整测量效率的目的，再代入算法实现了采样点还原精度的提升，通过对比等弧长采样算法以及等参数采样算法采样结果，拟合曲线与原始曲线的轮廓偏差、最大位置偏差、平均位置偏差，确定本文采样算法结果明显优于前两种算法。
英文摘要
The aero blade is an important part of the aero engine. Its machining accuracy directly affects the performance and life of the aero engine. 3D contour measurement is usually use to value the machining accuracy. As a typical free surface, the blade has complex surface structure which leads to processing difficulties, also exacerbates the measurement difficulty. Coordinate measuring machine is the highest accuracy contour measuring method, but limited to the blade surface complexity and the current CMM contact measurement technology, it has to collect a large number of surface data points in order to fully show the surface characteristics of the blade and make the measurement efficiency very low. Based on the 3D blade model, a sampling method was proposed based on improved firefly algorithm. Firstly, the curves of the blade sections were extracted, and then the points obtained by equal arc-length method of the cross-section were collected. The initial point position data were used to simulate a small firefly community. Calculating the curvature relationship between the points in the community and determining the moving direction and the step length of the target point were helpful to the automatic updating of the distribution points' positions. Finally, all the sampling points of the blade surface were obtained. The algorithm could achieve the free number configuration of the measurement points so that the purpose of adjusting the measurement efficiency was achieved. And then the algorithm was useful for improving the precision of the sampling points. By comparing the contour deviation, the maximum position deviation and the average position deviation of the fitting curve and the original curve with equal arc-length sampling algorithm and the equal parameters sampling algorithm, the proposed sampling algorithm showed its better sampling quality than the other two algorithms. It laid a technical foundation for the high efficiency measurement of the blade.
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