Wei Yuchen, Weng Jiechun, Chen Bing, Gao Zeren, Miao Hong, Yu Qifeng, Fu Yu
Opt Express. 2024 Jun 3;32(12):20742-20761. doi: 10.1364/OE.521211.
Digital Image Correlation (DIC) is a crucial noncontact full-field optical measurement method used in various fields. However, in practical applications, DIC is affected by systematic and random noises, leading to experimental resolutions lower than theoretical ones. In this study, we proposed a laser Doppler vibrometer guided DIC to perform vibration measurements. 3D-DIC obtains a sequence of out of displacement field initially. A three-dimensional frequency domain collaborative filtering (3D-FDCF) method that utilizes Laser Doppler vibrometer (LDV) single-point data to assist in processing of the displacement field sequence pixel-wise is adopted. The 3D-FDCF method combines lowpass filtering in the spatial frequency domain with LDV-guided bandpass filtering in the temporal frequency domain. The effectiveness of the 3D-FDCF method is demonstrated through a comparison among DIC data, the filtered DIC data, and continuously scanning LDV data. The experiment results demonstrate the 3D-FDCF method's capability in measuring vibration amplitudes of several hundred nanometers with the size of a test sample of about 100 mm × 100 mm, supporting the statement of interferometric scale full-field vibration measurement by DIC with the guidance of the LDV data.
数字图像相关（DIC）是一种在各个领域中使用的关键非接触式全场光学测量方法。然而，在实际应用中，DIC会受到系统噪声和随机噪声的影响，导致实验分辨率低于理论分辨率。在本研究中，我们提出了一种激光多普勒振动计引导的DIC来进行振动测量。三维数字图像相关（3D-DIC）最初获得一系列位移场。采用一种利用激光多普勒振动计（LDV）单点数据逐像素辅助处理位移场序列的三维频域协同滤波（3D-FDCF）方法。3D-FDCF方法将空间频域中的低通滤波与时间频域中LDV引导的带通滤波相结合。通过对DIC数据、滤波后的DIC数据和连续扫描的LDV数据进行比较，证明了3D-FDCF方法的有效性。实验结果表明，3D-FDCF方法能够在测试样品尺寸约为100mm×100mm的情况下测量几百纳米的振动幅度，支持了在LDV数据引导下通过DIC进行干涉尺度全场振动测量的说法。
