The disclosure relates generally to the detection and identification of issues relevant to the health of railway components from a moving railway vehicle.
In railway operations, the condition of the track and of the wheels is an important safety concern. A damaged section of track or damaged wheel can result in a serious accident, even derailment. Even in the absence of an actual mishap, ride quality for passengers or freight is affected.
Track or wheel condition hazards often do not develop suddenly, but rather develop over a period of time. By monitoring track and wheel quality constantly, trending may be used to anticipate hazards before they become serious. This serves both to prevent accidents and to reduce repair costs. This monitoring may be done using optical techniques, vibration sensing, audio analysis, or other sensor techniques.
Track quality is currently assessed using specialized “geometry cars”, which scan the rails as they travel. While thorough, these cars can only scan the track by riding over it, which can't provide total coverage.
Wheel quality is currently assessed using wayside monitors, which optically scan the wheels as they pass a fixed location. For a given wheel, this provides only episodic coverage.
The present invention provides a mobile monitoring unit which is small and inexpensive enough to install on large numbers of rail cars. This provides continuous monitoring of the car's wheels over an extended time period. Moreover, installation of this unit on a large proportion of a rail fleet can provide rail quality monitoring over all track traversed by any of the cars.
The following application describes an on-board system which monitors train track, wheels, running gear, and other railway systems' component health by constantly listening in on the acoustic sounds as well as the vibrations emitted by various components. These sounds as well as vibrations are then processed to arrive at the track health data per track location, arrive at specific vehicle component health (e.g. wheel flatspots), and ride quality data from either passenger comfort or cargo damage protection of view. It is also shown that an alternative embodiment of the system may be based on the rails and/or supporting structures as well as on-board a rail vehicle.
Track Measurements: By using the described approach, the system gathers the sounds and then processes them to arrive at the following track attributes. All attributes are adjusted for the speed of the train at the time measurements are taken and also adjusted for track parameters to normalize the track sound data:
1. Peak noise level for the entire track segment under observation
2. Average noise level for various track segments based on a running average over a set distance
3. Compute track quality index (TQI) which calculates the instantaneous track noise with the average noise. TQI help prioritize rail grindings and verify rail noise reduction
4. Frequency content of the sound/noise data
Vibration Monitoring: Remote vibration monitoring units may be installed on rail vehicle components (e.g., axle boxes, railcar body, etc.), to measure both track and wheel quality. They would convey their collected data to the centralized acoustic monitoring unit for correlation and/or aggregation with the acoustic data. The data may be conveyed by wired or wireless communication. The units may be powered by wires, battery, or power harvesting.
Axle box vibration monitoring provides information directly from the track, without intervening suspension (called “unsprung” in the field) which can more easily allow detection of both wheel defects—flat spots, out of round, spalls—and track defects—squats, corrugation, and deteriorating welds.
Optical Scanning: By co-locating a laser-camera pair at the truck, and using structured light techniques, the surface of the rail may be scanned in real time for anomalies.
Deep learning to recognize track anomalies: Accurate automatic defect recognition can be performed with the help of deep learning algorithms. Deep learning consists of training an algorithm with a variety of data points (defects and non-defects) which learns important features from each class without being explicitly programmed by humans.
Deep learning techniques usually involve a form of Neural Network such as Artificial Neural Networks (ANNS), Convolutional Neural Networks (CNNs) and Long Short Term Memory (LSTM) networks. The latter can learn long-term temporal dependencies by utilizing special mechanisms called memory cells which is particularly important in the application of vibrational defect detection.
The deep learning process may consist of four stages: (1) collection of data in both defect and non-defect conditions; (2) pre-processing of vibrational data aimed at extracting characteristics of the train wheels and tracks (i.e. speed, wheel number, etc.); (3) training of Neural Networks (4) detection of defects in the wheels and tracks in current condition through the comparison between predicted and measured responses in real-time or near real-time.
These and other features of the disclosure will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various aspects of the invention.
It is noted that the drawings may not be to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings.
In
Wheelset axle box monitoring units 50 are mounted to the axle ends of at least one wheelset 60 to measure the unsprung vibration from the wheels and track. In the preferred embodiment, these units 50 are wireless, powered via batteries, power harvesting, or a combination thereof. This allows the units to be installed quickly, easily, and cheaply, with no requirement of installed power infrastructure in such locations. This also allows the present invention to be made available either as a product (monitoring devices) or a service (data gathering and analysis based on such devices).
At least one optical track measurement unit 70 is mounted to the car body 20 (sprung) in view of the track head. Such a unit 70 allows a direct examination of visible features (cracks, gouges, wear, etc.) on the track. In addition, axle box monitoring units 50 can monitor and extract vibration due to the track from the signals; this is feasible for a number of reasons, the most obvious being that track signals will not repeat in a cycle in-phase with the rotation of the wheels (or some particular ratio thereof, such as in the case of worn bearing signals).
Mounting near the middle of the car provides microphone reception fields 80 which can monitor all wheelsets 50. This is in addition to the reception of vibrations transmitted through the car body 20, providing an additional source of data for cross-checking received vibration signals, and also provides some directionality for signals, allowing specific vibration/acoustic signals to be assigned to particular wheels.
It should be noted that the system is modular in design. It could be implemented with vibration and acoustic monitoring units 50 alone, or with the optical units 70, or the units 50 could be implemented as solely vibration or solely acoustic devices.
The location processing unit 130 computes location based on available sources, which may include GNSS, IMU (dead-reckoning), or RFID tags, and conveys this location information to the computer processing unit 110. By tagging the data from the other sensors with geographic information, the location of a track anomaly can be deduced.
The remote interface unit 140 provides a wired or wireless link between the computer processing unit 110 and a data repository. In a preferred embodiment, the data will be passed over a wireless link, such as WiFi, to a network access point in a station or wayside unit. It is, however, also possible for the data to be conveyed via a direct connection (USB, Ethernet, removable memory card, etc.) whenever the vehicle is stopped in an appropriate location. The tri-axial accelerometer unit 150 provides vibration and impact detection which may be analyzed independently and/or correlated with detected acoustic signals. The power supply unit 160 stores and distributes power to the other components of the system. The remote axle box vibration units 170 convey axle box (unsprung) vibration data to the computer processing unit 110. The remote track condition optical units 180 convey data from their optical sensors to the computer processing unit 110. Primary acoustic data is gathered by the four directional microphones 190.
The fused data is analyzed for different properties. Thresholding 450 provides information for transient anomalies such as flawed joints and squats 480. Autocorrelation 460 detects rail corrugation and wheels which are flat or out of round 490. Spectral analysis 470 detects wheel/rail flanging and flat or out of round wheels 500.
There are numerous embodiments of this innovative system:
In a preferred embodiment, the system can be installed under a vehicle in the middle to allow easy capture of all sounds from wheel-rail interaction. The sounds are then processed by the system and correlated with the track position.
In another embodiment, the system can be installed inside a vehicle to allow easy capture of all sounds from wheel-rail interaction. By measuring the noise levels inside a vehicle, the relative loudness of the entire system can be gathered efficiently. The speed data is used to map the noise levels to specific locations on the system. The sounds are then processed by the system and correlated with the track position. In addition, gathering data from within a vehicle such as a passenger car will also provide data on ride quality.
In another embodiment, vibration detectors are mounted on the axle box (unsprung) and convey vibration data resulting from wheel or track anomalies to the aggregation node.
In one embodiment, the system uses 16-bit analog to digital conversion while in another embodiment, the system uses 24-bit or 32-bit A2D conversion to digitize sounds with very high fidelity.
In another embodiment, the sensor units 50 may be installed at a stationary location, such as on or just below the track surface, where vibrations, acoustic signals, and/or images (with or without laser lines) may be gathered from passing trains. This allows the system to gather short but useful segments of data on multiple railcars and long-term monitoring of the relevant section of rail.
In yet another embodiment, the described system may be incorporated into other large vehicles, such as commercial vehicles (trucks), and thus be used to monitor both the performance of components of the vehicle and the condition of the roadway surface over which the vehicle passes, with similar benefits for the vehicle owner and the maintainers of the road.
The foregoing description of various embodiments of this invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed and inherently many more modifications and variations are possible. All such modifications and variations that may be apparent to persons skilled in the art that are exposed to the concepts described herein or in the actual work product, are intended to be included within the scope of this invention disclosure.
The current application claims the benefit of U.S. Provisional Application No. 63/052,100, filed on 15 Jul. 2020, which is hereby incorporated by reference herein.
Number | Date | Country | |
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63052100 | Jul 2020 | US |