Reetz Susanne, Najeh Taoufik, Lundberg Jan, Groos Jörn
Institute of Transportation Systems, German Aerospace Center (DLR), 38108 Braunschweig, Germany.
Department of Civil, Environmental and Natural Resources Engineering, Division of Operation, Maintenance and Acoustics, Luleå University of Technology, 97187 Luleå, Sweden.
Sensors (Basel). 2024 Jan 12;24(2):477. doi: 10.3390/s24020477.
Switches are an essential, safety-critical part of the railway infrastructure. Compared to open tracks, their complex geometry leads to increased dynamic loading on the track superstructure from passing trains, resulting in high maintenance costs. To increase efficiency, condition monitoring methods specific to railway switches are required. A common approach to track superstructure monitoring is to measure the acceleration caused by vehicle track interaction. Local interruptions in the wheel-rail contact, caused for example by local defects or track discontinuities, appear in the data as transient impact events. In this paper, such transient events are investigated in an experimental setup of a railway switch with track-side acceleration sensors, using frequency and waveform analysis. The aim is to understand if and how the origins of these impact events can be distinguished in the data of this experiment, and what the implications for condition monitoring of local track discontinuities and defects with wayside acceleration sensors are in practice. For the same experimental configuration, individual impact events are shown to be reproducible in waveform and frequency content. Nevertheless, with this track-side sensor setup, the different types of track discontinuities and defects (squats, joints, crossing) could not be clearly distinguished using characteristic frequencies or waveforms. Other factors, such as the location of impact event origin relative to the sensor, are shown to have a much stronger influence. The experimental data suggest that filtering the data to narrow frequency bands around certain natural track frequencies could be beneficial for impact event detection in practice, but differentiating between individual impact event origins requires broadband signals. A multi-sensor setup with time-synchronized acceleration sensors distributed over the switch is recommended.
道岔是铁路基础设施中至关重要且关乎安全的部分。与开放式轨道相比，其复杂的几何形状会导致过往列车对轨道上部结构的动态载荷增加，从而产生高昂的维护成本。为提高效率，需要针对铁路道岔的状态监测方法。一种常见的轨道上部结构监测方法是测量车辆与轨道相互作用引起的加速度。例如由局部缺陷或轨道不连续导致的轮轨接触局部中断，在数据中表现为瞬态冲击事件。在本文中，利用频率和波形分析，在配备轨道旁加速度传感器的铁路道岔实验装置中对这类瞬态事件进行了研究。目的是了解在该实验数据中能否以及如何区分这些冲击事件的起源，以及在实际中使用路旁加速度传感器对局部轨道不连续和缺陷进行状态监测有哪些影响。对于相同的实验配置，单个冲击事件在波形和频率成分上是可重现的。然而，使用这种轨道旁传感器设置，无法通过特征频率或波形清晰区分不同类型的轨道不连续和缺陷（轨底坡、接头、道岔）。结果表明，其他因素，如冲击事件起源相对于传感器的位置，具有更强的影响。实验数据表明，在实际中对数据进行滤波以在某些固有轨道频率周围的窄频带内处理，可能有利于冲击事件检测，但区分单个冲击事件的起源需要宽带信号。建议采用在道岔上分布有时间同步加速度传感器的多传感器设置。
