STFT-IP时频特征提取技术的螺栓松动识别方法  

Identification Method of Bolt Looseness Using STFT-IP Time-frequency Feature Extraction Technology

作　　者：王九龙 盛俊杰[1] 蒋家勇[1] 温金鹏[1] 肖世富[1] 张周锁[2] WANG Jiulong;SHENG Junjie;JIANG Jiayong;WEN Jinpeng;XIAO Shifu;ZHANG Zhousuo(Institute of Systems Engineering,China Academy of Engineering Physics,Mianyang 621999,Sichuan,China;School of Mechanical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]中国工程物理研究院总体工程研究所,四川绵阳621999 [2]西安交通大学机械工程学院,西安710049

出　　处：《噪声与振动控制》2021年第3期108-112,共5页Noise and Vibration Control

基　　金：科学挑战专题资助项目(TZ2018007)。

摘　　要：针对机械连接结构中常见的螺栓松动识别问题,利用短时傅里叶变换(STFT,Short-time Fourier transform)处理振动信号获得时频图,通过分析时频图发现不同预紧状态螺栓联接结构的振动响应时频特征,凝练STFT-IP(Image Pixel)特征指标,并提出基于STFT-IP时频特征的螺栓松动识别方法。首先通过短时傅里叶变换得到振动响应信号的时频图,然后结合图像处理技术对时频矩阵进行二值化处理,并建立STFT-IP序列,利用不同预紧状态STFT-IP序列与初始序列之间的欧式氏距离作为松动评估指标。通过实验验证所提时频特征提取技术的有效性,STFT-IP指标可有效表征螺栓连接结构不同预紧状态,研究结果可为螺栓松动识别提供新的技术途径和解决问题的思路。The common problem of bolt looseness recognition in mechanical connection structures was studied.The short time Fourier transform(STFT)was used to analyze the time-frequency distribution of vibration response to obtain the time-frequency diagram.The time-frequency characteristics of the vibration response of the bolted connection structures in different pre-tightened states were found,and the characteristic indexes of the STFT-IP were condensed.A bolt looseness recognition method based on the STFT-IP time-frequency was presented.First of all,the time-frequency diagram of the vibration response signal was obtained by the STFT.Then,the time-frequency matrix was treated by binary value processing combined with the image processing technique.And the STFT-IP sequence was established.Finally,the Euclidean distance between the STFT-IP sequence in different preload states and the initial sequence was used as the evaluation index for bolt looseness identification.Experiment has verified the effectiveness of the proposed time-frequency feature extraction technology,and the STFT-IP feature can effectively represent different preload state of the bolt connection structure.The research provides a new technical approach and solution for bolt looseness recognition.

关 键 词：振动与波 螺栓松动 振动响应 短时傅里叶变换 图像处理 STFT-IP时频特征 

分 类 号：TH113.1[机械工程—机械设计及理论]