Performance of Camera-Based Vibration Monitoring Systems in Input-Output Modal Identification Using Shaker Excitation
Performance of Camera-Based Vibration Monitoring Systems in Input-Output Modal Identification Using Shaker Excitation
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DOI：
10.3390/rs13173471
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发表时间：
2021-09-01
期刊：
影响因子：
5
通讯作者：
Nikitas, Nikolaos
中科院分区：
文献类型：
--
作者：
Kalybek, Maksat;Bocian, Mateusz;Nikitas, Nikolaos
尽管在过去的几十年里，高分辨率数码相机的发展取得了重大进展，但在输入输出模态识别的背景下，它们的潜力在很大程度上仍未被探索。然而，这些遥感器可以大大提高土木工程结构的实验动态特性的功效。为此，本研究提供了早期的证据，基于摄像机的振动监测系统的适用性，在经典的实验模态分析使用机电振动台。一个伪随机和正弦啁啾激励施加到一个比例模型的斜拉桥在不同的强度水平。振动监测系统的性能，包括消费级数码相机和两种图像处理算法，分析相对于基于加速度计的系统。在这个过程中，一个完整的模态参数，包括模态频率，阻尼，质量和模态振型。结果表明，基于摄像机的振动监测系统可以提供高精度的结果，虽然他们的有效应用需要考虑的一些问题的灵敏度，性质的激振力，以及信号和图像处理。基于这些研究结果，最佳实践的建议，以帮助实施基于摄像机的振动监测系统的实验模态分析。
Despite significant advances in the development of high-resolution digital cameras in the last couple of decades, their potential remains largely unexplored in the context of input-output modal identification. However, these remote sensors could greatly improve the efficacy of experimental dynamic characterisation of civil engineering structures. To this end, this study provides early evidence of the applicability of camera-based vibration monitoring systems in classical experimental modal analysis using an electromechanical shaker. A pseudo-random and sine chirp excitation is applied to a scaled model of a cable-stayed bridge at varying levels of intensity. The performance of vibration monitoring systems, consisting of a consumer-grade digital camera and two image processing algorithms, is analysed relative to that of a system based on accelerometry. A full set of modal parameters is considered in this process, including modal frequency, damping, mass and mode shapes. It is shown that the camera-based vibration monitoring systems can provide high accuracy results, although their effective application requires consideration of a number of issues related to the sensitivity, nature of the excitation force, and signal and image processing. Based on these findings, suggestions for best practice are provided to aid in the implementation of camera-based vibration monitoring systems in experimental modal analysis.