基于时空域分析影像云纹的低频振动测量  

Low-Frequency Vibration Measurement Based on Spatiotemporal Analysis of Shadow Moiré

作　　者：史红健[1] 朱飞鹏[1] 何小元[1] 

机构地区：[1]东南大学工程力学系,江苏南京210096

出　　处：《光学学报》2011年第4期120-124,共5页Acta Optica Sinica

基　　金：国家自然科学基金(10727201;10972054)资助课题

摘　　要：实现了一种基于时空域分析影像云纹的振动测量方法。在此方法中,一个正弦光栅放置在低频振动物体的正前方。光栅及其影像相互干涉产生的云纹图像由高速摄像机采集并保存。序列云纹图像的联合时空域信息将同时被三维傅里叶变换处理,而不是各自分开处理。通过过滤三维频谱和三维反傅里叶变换,得到三维复相位矩阵,从而获取运动物体在不同时刻的形貌和位移。连续振动悬臂梁的测量实验结果表明,影像云纹结合时空域分析能够用于动态测量,证实了该方法的有效性。A method for vibration measurement of an object based on spatiotemporal analysis of shadow Moire fringes is discussed. In this method, a sinusoidal grating is closed to a vibrating object. The Moire fringes patterns generated by the interference of grating lines and shadow lines are captured by a high-speed camera. The joint spatial and temporal information of the fringe sequences is processed by the 3D Fourier transform simultaneously rather than separately. A 3D space-time phase distribution can be obtained from the filtered spatiotemporal spectra and 3D inverse Fourier transform. From the phase values, the surface profile and displacement of the object at different time can be retrieved. The measurement experiment of a vibrating cantilever beam demonstrated the validity of this method. The results show that shadow Moire with spatiotemporal analysis can be applied to dynamic measurement.

关 键 词：振动测量 时空域分析 影像云纹 

分 类 号：O438[机械工程—光学工程]