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| LDV辅助下的全场振动测量(1): 3D-DIC测量分辨率提升方法 |
| LDV-assisted full-field vibration measurements (1): 3D-DIC resolution enhancement method |
| 投稿时间：2024-04-18 修订日期：2024-06-03 |
| DOI： |
| 中文关键词: 振动测量，数字图像相关，全场测量，激光多普勒测振技术 |
| 英文关键词:Vibration measurement 3D-DIC Laser Doppler vibrometry whole-field measurement. |
| 基金项目:国家自然科学基金（12102423）、深圳市科技创新委项目（20231120175055001)、深圳大学专项项目(2023YQ011) |
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| 中文摘要: |
| 进入二十一世纪之后，随着计算机处理能力的快速提升，基于高速相机的三维数字图像相关(3D-DIC)测振技术开始逐步应用于不同的科研和工程领域。其优点是能实现全场振动测量，对测量环境的要求比较低，但在时间采样率和测量分辨率上无法满足大部分的振动测量需求。另外一类成熟的振动测量方法是基于单像素光电探测器的激光多普勒测振技术（LDV）。这类基于干涉的测量技术具有极高的时间采样率和测量分辨率，测量时对隔振要求也不高，但主要的问题是在空间域上只能实现单点或者少量稀疏点的测量。激光多普勒测振技术在应对稳态振动时，虽然可以采用扫描的方式，但受限于设备的光学景深，扫描范围非常有限，其空间采样率远不如基于图像的方法。本文提出了一种新型的振动测量方法，即利用LDV辅助3D-DIC实现全场振动测量，利用两者各自在测量分辨率和全场测量上的优势，从硬件和数据处理两个方面提升全场3D-DIC的振动测量分辨率，由特征尺寸的10-4量级提升至10-6-10-7量级。所提方法在采用普通帧率相机和没有隔振措施的情况下仍然可以实现干涉量级的全场振动测量，满足大部分结构振动测量的需求。 |
| 英文摘要: |
| After entering the 21st century, with the rapid improvement of computer processing capabilities, 3D digital image correlation (3D-DIC) based on high-speed cameras has gradually been applied to various scientific research and engineering fields. Its advantages are that it can provide full-field vibration measurement and has relatively low requirements for the measurement environment. However, in terms of time sampling rate and measurement resolution, it cannot meet the general requirements of vibration measurement. Another mature vibration measurement method is the laser Doppler vibrometry (LDV) based on single-pixel photodetectors. This type of interference-based measurement technique has an extremely high time sampling rate and measurement resolution, and the requirements for isolation are also not high. But the main problem is that in the spatial domain, it can only achieve single-point or sparse-point measurement. For stationary vibration, although scanning can be used, the scanning range is limited due to the optical depth of field of the equipment, resulting in low spatial sampling rate. This paper proposes a new vibration measurement method, namely LDV-assisted full-field vibration measurements by 3D-DIC. By utilizing the advantages of the two methods in measurement resolution and full-field measurement, the vibration measurement resolution of full-field DIC can be improved to the 10-6 - 10-7 scale of characteristic size in both hardware and data processing aspects. Even without using a high-speed camera and vibration isolation measures, it is still possible to achieve interferometric-level full-field vibration measurement, which meets the requirements of most structural vibration measurements. |
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