A novel method is proposed for rail fastener detection based on millimetre-wave (mmWave) radar, mmWave radar fastener counter (MMW-FC), which can accurately detect and record the fasteners in real-time as the train traverses its route. Under circumstances where GNSS signals remain unavailable for prolonged durations, precise train localisation can be accomplished by correlating the number of fasteners derived from this method with the corresponding track map. Initially, MMW-FC utilises fast Fourier transform and adaptive beamforming to focus the energy reflected from fasteners. Subsequently, it applies an adaptive template-matching algorithm to detect each fastener. Furthermore, by leveraging known fastener spacing and the average time for trains to pass adjacent fasteners, the Kalman filter can execute precise speed tracking, used as a speed reference when adjusting the matching template adaptively. The experimental results indicate that the proposed method can precisely count the fasteners the train encounters in diverse road and speed conditions. The fastener counter maintains the Counting Error less than 0.067%, the speed error stays below 1.8 km/h, and the maximum values of the mean absolute error and root mean square error for speed are 0.7337 and 0.9584 km/h, respectively.

中文翻译：

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MMW-FC：一种基于毫米波雷达的列车定位新型铁路扣件检测方法

提出了一种基于毫米波（mmWave）雷达的钢轨扣件检测新方法——毫米波雷达扣件计数器（MMW-FC），可以在列车行驶过程中实时准确地检测和记录扣件。在 GNSS 信号长时间无法使用的情况下，可以通过将从此方法得出的紧固件数量与相应的轨道图相关联来实现精确的列车定位。最初，MMW-FC 利用快速傅立叶变换和自适应波束形成来聚焦从紧固件反射的能量。随后，它应用自适应模板匹配算法来检测每个紧固件。此外，通过利用已知的扣件间距和列车通过相邻扣件的平均时间，卡尔曼滤波器可以执行精确的速度跟踪，作为自适应调整匹配模板时的速度参考。实验结果表明，该方法可以精确统计列车在不同道路和速度条件下遇到的紧固件。紧固件计数器保持计数误差小于0.067%，速度误差保持在1.8 km/h以下，速度的平均绝对误差和均方根误差最大值分别为0.7337和0.9584 km/h。