基于关键点检测的航空发动机螺栓安装缺陷自动化检测方法  

An automatic detection method of aero-engine bolt installation defects based on key points detection

作　　者：辛佳雯 王睿[1] 谢艳霞 孙军华[1] Xin Jiawen;Wang Rui;Xie Yanxia;Sun Junhua(Laboratory of Precision Opto-mechatronics Technology,Ministry of Education,Institute of Instrumentation Science and Opto-Electronics Engineering,Beihang University,Bejing 100191,China)

机构地区：[1]北京航空航天大学仪器科学与光电工程学院精密光机电一体化教育部重点实验室,北京100191

出　　处：《仪器仪表学报》2023年第3期98-106,共9页Chinese Journal of Scientific Instrument

摘　　要：针对航空发动机螺栓存在背景复杂、目标小、且精细特征不明显的问题,本文研究了一种基于关键点检测的航空发动机螺栓安装缺陷的自动化检测方法。首先设计了基于Faster RCNN和改进CPN(AD-CPN)的级联卷积神经网络,实现了图像中螺栓及二维关键点的检测,可判断该螺栓是否脱落、漏装。为进一步检测螺栓的三维安装缺陷,通过欧氏距离选择策略对已检测出的关键点进行双目匹配、筛选以获得检测点对,最后对检测点对三维重构,并计算出螺栓的实际长度,从而判断螺栓是否错装。实验结果表明,相较于CPN,AD-CPN的mAP、AP50、AP75分别提升了2.9%、3.3%、4%;螺栓测量长度的相对平均误差约为3.0%,可见该方法具有较高的缺陷检测准确率,有效保障了航空发动机的安全运行。In view of the problems of complex background,small target and inconspicuous fine features of aero-engine bolts,an automated detection algorithm of aero-engine bolt installation detection based on key points detection is proposed.First,a cascaded convolutional neural network based on the Faster RCNN and the improved CPN(AD-CPN)is proposed to achieve the detection of bolts and 2D key points which can determine whether the bolt has fallen off or missed.To further detect the 3D installation detection of the bolt,the Euclidean distance selection strategy is introduced to match and screen the key points to obtain the detected point pairs.Finally,the 3D coordinates of the key points are calculated by using binocular stereo vision technology.In this way,it can judge whether the bolt is wrongly installed.Compared with CPN,the mAP,APso,and APrs of AD-CPN are improved by 2.9%,3.3%,and 4%,respectively.In addition,the relative average error of bolt measurement length is approximately 3.0%.It can be seen that the algorithm could enhance the accuracy of detection,and ensure the safe operation of aero-engines,which has great practical significance.

关 键 词：缺陷检测 关键点检测 深度学习 双目立体视觉 

分 类 号：TH862[机械工程—仪器科学与技术] TP391.4[机械工程—精密仪器及机械]