The detection of internal defects within railway tracks stands as a critical aspect of ensuring transport security, given its potential to precipitate severe accidents. Phased array ultrasonic testing methods have gained extensive usage in rail inspection owing to their remarkable precision and expansive coverage. Traditional ultrasonic inspection techniques typically require either a fixed relative position between the transducer and the specimens or a gentle movement of the transducer to beamform. However, the unavoidable vibration stemming from the vehicle–rail coupled interactions often results in time-variant media, significantly impacting the beamforming. This paper presents a refined wavenumber-domain plane wave imaging technique tailored to enable real-time dynamic imaging, specifically accommodating the vertical vibrational movement of the transducer. Real-time calculation of the transmission focal law is achieved by numerical fitting. The wavenumber-domain technique is utilized to realize real-time accurately reconstructed images. The efficacy of the proposed method is assessed through simulations and experiments performed on a convex cylindrical specimen and a rail head sample, respectively. It can be seen that this approach can achieve a frame rate of 83.3 fps with a pipeline architecture in this study, demonstrating the capability to reconstruct images in vibrating environments, such as during the high-speed inspection of railways.

中文翻译：

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用于高速铁路检测的超声动态平面波成像


铁路轨道内部缺陷的检测是确保运输安全的一个关键方面，因为它有可能引发严重事故。相控阵超声检测方法以其卓越的精度和广泛的覆盖范围在轨道检测中获得了广泛的应用。传统的超声波检测技术通常需要换能器和样本之间的固定相对位置，或者需要轻轻移动换能器以形成波束。然而，车辆-轨道耦合相互作用产生的不可避免的振动通常会导致介质随时间变化，从而显着影响波束形成。本文提出了一种改进的波数域平面波成像技术，旨在实现实时动态成像，特别是适应换能器的垂直振动运动。通过数值拟合实现了传输聚焦定律的实时计算。利用波数域技术实现实时精确重建图像。通过分别对凸圆柱形样本和轨头样本进行模拟和实验来评估所提出方法的有效性。可以看出，在本研究中，这种方法可以通过管道架构实现 83.3 fps 的帧速率，展示了在振动环境中重建图像的能力，例如在铁路高速检查期间。