Eddy current testing (ECT) has been employed as a traditional non-destructive testing and evaluation (NDT&E) tool for many years. It has developed from single frequency to multiple frequencies, and eventually to pulsed and swept-frequency excitation. Recent progression of wireless power transfer (WPT) and flexible printed devices open opportunities to address challenges of defect detection and reconstruction under complex geometric situations. In this paper, a transmitter–receiver (Tx–Rx) flexible printed coil (FPC) array that uses the WPT approach featuring dual resonance responses for the first time has been proposed. The dual resonance responses can provide multiple parameters of samples, such as defect characteristics, lift-offs and material properties, while the flexible coil array allows area mapping of complex structures. To validate the proposed approach, experimental investigations of a single excitation coil with multiple receiving coils using the WPT principle were conducted on a curved pipe surface with a natural dent defect. The FPC array has one single excitation coil and 16 receiving (Rx) coils, which are used to measure the dent by using 21 C-scan points on the dedicated dent sample. The experimental data were then used for training and evaluation of dual resonance responses in terms of multiple feature extraction, selection and fusion for quantitative NDE. Four features, which include resonant magnitudes and principal components of the two resonant areas, were investigated for mapping and reconstructing the defective dent through correlation analysis for feature selection and feature fusion by deep learning. It shows that deep learning-based multiple feature fusion has outstanding performance for 3D defect reconstruction of WPT-based FPC-ECT. This article is part of the theme issue ‘Advanced electromagnetic non-destructive evaluation and smart monitoring’.

中文翻译：

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使用柔性印刷线圈阵列的基于无线电力传输的涡流无损检测

多年来，涡流检测 (ECT) 一直被用作传统的无损检测和评估 (NDT&E) 工具。它已经从单频发展到多频，并最终发展到脉冲和扫频激励。无线电力传输 (WPT) 和柔性印刷设备的最新进展为解决复杂几何情况下的缺陷检测和重建挑战提供了机会。在本文中，首次提出了使用具有双谐振响应的 WPT 方法的发射器-接收器 (Tx-Rx) 柔性印刷线圈 (FPC) 阵列。双共振响应可以提供样品的多个参数，例如缺陷特性、剥离和材料特性，而灵活的线圈阵列允许复杂结构的区域映射。为了验证所提出的方法，使用 WPT 原理在具有自然凹痕缺陷的弯曲管道表面上对具有多个接收线圈的单个励磁线圈进行了实验研究。FPC 阵列有 1 个单励磁线圈和 16 个接收 (Rx) 线圈，用于通过使用专用凹痕样品上的 21 个 C 扫描点来测量凹痕。然后将实验数据用于在定量 NDE 的多特征提取、选择和融合方面对双共振响应进行训练和评估。通过深度学习的特征选择和特征融合的相关分析，研究了四个特征，包括两个谐振区域的谐振幅度和主成分，用于映射和重建缺陷凹痕。这表明基于深度学习的多特征融合对于基于 WPT 的 FPC-ECT 的 3D 缺陷重建具有出色的性能。本文是主题问题“高级电磁无损评估与智能监测”的一部分。