基于运动放大的振动结构的模态识别  

Modal Identification of Vibration Structure Based on Motion Magnification

作　　者：李丽霞 陈海卫 Li Lixia, Chen Haiwei(School of Mechanical Engineering, Jiangnan University, Wuxi 214122, Chin)

机构地区：[1]江南大学机械工程学院,江苏无锡214122

出　　处：《计算机测量与控制》2018年第9期163-167,共5页Computer Measurement &Control

基　　金：国家自然科学基金资助项目(51205166)

摘　　要：快速准确地获取结构的振动信息是确定结构模态参数的关键;随着计算机视觉和高速相机技术的发展,视觉测量振动逐渐受到人们的重视;运动放大技术是一种可检测结构微小运动的计算机视觉技术,相比其他视觉测量技术,采用运动放大技术进行振动结构的模态识别,其优势在于:可在不提取位移的情况下直接展示振动结构的模态特征;为了验证提出方法的可行性,以悬臂梁为例搭建了加速度计和高速相机的模态识别实验系统,并依据理论模态对其实验数据进行模态置信准则(MAC)检验;实验结果表明:采用运动放大技术识别的模态结果与理论结果之间的MAC值最相关可达98.3%,提出的方法可以准确识别振动结构的模态参数。Modal analysis of structures depends on the accurate and swift collection of data from a vibrating structure so the data can be analyzed to determine the modal characteristics.With the development of computer vision techniques and high-speed camera techniques,vision measurement vibration is gradually attended by people.This paper researches a motion magnification technique based on computer vision,which can detect the small sub-pixel motion in vibration structure.Comparing with other vision measurement technology,use motion magnification algorithm to identify mode of vibration structure which can determine directly the modal characteristics without extracting displacements.Taking the cantilever beam as a model,and setting the accelerometer measurements and high-speed camera modal identification experimental systems for verification on the method we proposed is viable,and verifying the test results based on modal assurance criterion（MAC）.The results demonstrate the method we researched compared with theoretical value,the best value can reach 98.3% to identify the mode of vibration structure and can be applied to modal identification of vibration structure.

关 键 词：运动放大 里斯变换 高速相机 模态识别 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] O329[自动化与计算机技术—计算机科学与技术]