A monitoring system for a rail freight wagon

Abstract

A monitoring system for a rail freight wagon (2, 3, 4), in which an axle end generator (5) is provided on an axle (aa, bb) of the freight wagon to provide an electrical supply to a mechatronic brake valve (6) for controlling brake pressures to the axle. The system further comprises a wheel speed sensor (17) and a brake pressure sensor (7) and a gateway (21) configured to transmit the data from the sensors off of the freight wagon. The mechatronic valve of the axle monitoring system enables brake pressure to be released when an axle locks to prevent wheel slide. This reduces the incidence of wheel flats and extends the life of the wheels and axles.

Description

[0001] A MONITORING SYSTEM FOR A RAIL FREIGHT WAGON

[0002] The invention relates to an axle monitoring system for use on freight wagons.

[0003] Railway vehicle braking systems are typically air brakes^ Such systems incorporating wheel slide control and wheel spin control have established themselves in recent years in the passenger train market. Both wheel slide and wheel spin stem from low wheel to rail adhesion. Wheel slide typically occurs when braking a railway car and is a major cause of wheel damage, which in turn can lead to track damage.

[0004] A typical wheel slide control system comprises a sensor on each axle of the vehicle, which measure the speed of rotation of the axle. In use, the outputs of the sensors are then fed to the brake control unit, which compares the values with those of adjacent axles and if the difference exceeds a pre-determined limit, releases and re-applies the brake pressure until the axle speed falls within acceptable limits. This system has proven itself in practice and improves braking performance and reduces the probability of damage to wheels and track. The damage to wheels on freight train has greater impact on the railhead due to high wagon weights and increased environmental noise due to wheel flat impacts on rotation. Wheel flat repair is also an expensive process and a cost burden to the maintainer as well as reducing asset availability from the wagon owner perspective.

[0005] Most freight wagons do not have an autonomous electrical power supply, which effectively has prevented the widespread adoption of wheel slide protection in freight trains. Wheel slide will cause wheels inevitably to acquire flats, pits or suffer from metallurgical change and so require “turning” in which the wheel is re-machined to an acceptable condition. This is an expensive process as the wheel often need to be removed from the wagon to enable the maintenance and this process can easily happen 3-4 times a year during which time the wagon is out of service.

[0006] GB2529479 discloses an axle end generator which provides an autonomous electrical power supply for a freight wagon. EPl 115603 discloses the use of an air driven generator, which uses the pressure in the brake pipe to generate electricity. EP3619082 discloses a method for carrying out an automatic brake test on a train which comprises a number of carriages or wagons equipped with pneumatically mechanical brakes. The pneumatically mechanical brakes have a brake control valve which is controlled by a main air line (HL) and a pneumatically operated brake cylinder, the brake cylinder pressure of which is controlled by the brake control valve. The brake cylinder transmits the brake cylinder pressure to a brake lining, in particular a brake pad or brake jaws, via mechanical components of the brake, such as a brake linkage for example, and thereby generates the braking force of the brake. Each carriage or wagon is equipped with an analysis unit. The brake cylinder pressure is sensed and the braking force produced by the brake cylinder pressure can be calculated are sensed on each carriage, analysed by the analysis unit, and transmitted to a central device.

[0007] According to the invention there is provided a brake system for a freight wagon having an axle, which axle is provided with an axle end generator, which axle end generator is adapted to provide an electrical supply to a mechatronic valve for controlling brake pressures to the axle, wherein the system further comprises wheel speed sensors and brake pressure sensors, the system being further provided with communication means, which communication means are adapted to transmit outputs of the wheel speed sensors and brake pressure sensors to a receiver.

[0008] Preferably, the system checks the status of the parking brake and transmits this status. Preferably the receiver is located off of the train.

[0009] Advantageously the system can add to standard operating procedures to improve safe release of the trains (parking brake check - brake pressure check) to assist with the confidence of the depot release and also to save some depot staff time.

[0010] The arrangement of the invention is advantageous as the monitoring of axle rotation enables per wagon data acquisition and for this to be transmitted off the train during normal service. It would be possible for this to be undertaken whenever a data signal is present but it could also be undertaken at less frequent intervals such as at train stops. The mechatronic valve of the axle monitoring system enables brake pressure to be released when an axle locks to prevent wheel slide. This reduces the incidence of wheel flats and extends the life of the wheels and axles. The monitoring of the axle rotation also enables the rapid detection of a persistent axle lock, which may or may not be brake related and which can lead to derailment of the wagon and enables an alert to be transmitted to the driver or the operator so that early mitigation can be implemented.

[0011] In a further aspect of the invention the condition of the brakes is monitored. The brake system monitors the input and output pressures of the brake system during normal operation. These brake pressures can be transmitted off train to provide a regular or continuous health check of the brake system and reduce the need for out of service brake tests.

[0012] Exemplary embodiments of the invention will now be described in greater detail with reference to the drawings in which:

[0013] Fig. 1 shows a schematic partial view of a freight train;

[0014] Fig. 2 shows a functional diagram of an axle monitoring system and

[0015] Fig. 3 shows a networked train rake

[0016] Figure 1 shows a schematic partial view of a freight train comprising a locomotive 1 with three wagons 2, 3, 4. Each wagon has two bogies a, b with two axles aa, bb each. Each wagon is provided with a wagon ID. An axle end generator 5 is installed on each axle. Each axle or wheel-end is provided with wheel speed sensors Brake pressure into braking devices on each axle is controlled by a respective mechatronic (freight) valve 6 on each bogie a, b. The mechatronic valve 6 can be provided with the wagon ID of the wagon it is located on. Each wagon is further provided with sensors 7, in particular to measure the brake pressures on the wagon and / or in the main brake pipe and an interface 8 to enable wireless data transfer off of the wagon. A mobile data signal is the preferred data transfer protocol but in principle it would be possible to use other protocols, in particular when stationary, such as Bluetooth ® or IEEE 802.11 depending on the available infrastructure. The data transmitted off the wagon can then be transmitted to the train owner or operator, including the locomotive driver, or the network operator. Sensors on the wagon can be connected to the on board gateway or freight valve by various means including direct wired connection Bluetooth or LoRaWan. Sensor data can be harvested via the gateway to the cloud for further analysis.

[0017] The mechatronic valve 6 limits wheel slide and consequential damage to the wheel. Damage can be flats, pits, metallurgic change etc. and therefore the life of the wheels is extended and they will not need to be turned as often. As wheel slide event data can be transmitted off the train in use (or at frequent intervals), to the operator, it becomes possible to analyse wheel maintenance and wheel lifespan or the anticipated maintenance intervals. The operator will therefore know how frequently wheels need turning against actual in service wheel slide activity. This enables more efficient management of wheel turning and wheel turning facilities.

[0018] Figure 2 shows a functional diagram of an axle monitoring system. Shown schematically, the main brake pipe 10 is supplied to the distributor 11, which is connected to the auxiliary reservoir 12. The distributor controls the pressure in the brake cylinders 13, which can be modified depending on the pressure output of the load sensing valve 14. The system is suitable for both twin and single pipe applications. In single pipe applications an air supply valve 15 can be used to control the charging of the supplementary reservoir 16 which is used to provide the additional air supply to support wheel flat protection when the auxiliary reservoir is not fed during braking.

[0019] Shown schematically are the two pairs of axles associated with each bogie. Each bogie is provided with a respective mechatronic valve 6, which receives an electrical supply from first and second axle end generators 5 shown on opposed sides of the bogie. Wheel speed sensors 17 are provided on each axle. The mechatronic valve 6 has energy storage capability so the system can be powered for low power monitoring activities and status reporting updated when the wagon is not moving.

[0020] The mechatronic valves 6 are associated with a respective GPS antenna 18 and are provided with a GPS module 19 to process the GPS signals received. The mechatronic valve is able to measure the brake pressure in the connection from the distributor 11. The parking brake mechanical position is monitored and hence the status of the parking brake can be reported. The outputs of all of the sensors are transmitted to a sensor node 20 and can then transmitted off the train via gateway 21. A mobile data signal is the preferred data transfer protocol but in principle it would be possible to use other protocols such as Bluetooth ® or IEEE 802. 11 depending on the available infrastructure. The gateway could also communicate directly with a device controlled by the driver with which it has been previously paired.

[0021] In a first embodiment of the invention, the system of the invention can be used for a departure check. In a first aspect of this embodiment, the status of the parking brake on each wagon is determined and then this status together with the wagon ID is transmitted off the train by the gateway 21 to a cloud server. The cloud server can then serve the data to a handheld device such as a mobile telephone or tablet of the driver who can then easily see the status of each parking brake on the rake .

[0022] In a second aspect of this embodiment, the brake pressure at the distributor or in the main brake pipe is measured and transmitted off the train. The train comprises a rake typically having a plurality of freight wagons including a first wagon and a last wagon with the last wagon being located furthest from the locomotive. The driver can identify the wagon ID of the last wagon on the rake and determine the brake pressure there. If the brake pressure at the last wagon on the rake is within a predetermined tolerance as the brake pressure of the locomotive, then the driver can be assured that all of the wagons in the rake are connected properly to the main brake supply.

[0023] These aspects partially automate the train departure and significantly speed up the departure process.

[0024] In a third aspect of the invention, brake condition monitoring can be implemented. The axle monitoring system measures system pressures, such as the brake pipe pressure, brake cylinder pressure and the variable load valve pressure setting and this measurement is ongoing during operation of the wagon as the pressures are monitored for the correct operation of the air brake system. The pressures can each be monitored by the mechatronic valve 6. It is standard practice is for each brake system to undergo an annual brake test to check the brake operation. The invention provides for week to week condition monitoring; periodic manual brake checks are a current procedural requirement. The condition monitoring may be able to be utilised to remove the need for the annual brake check. The data transmitted off the train enables an exceptions check if parameters are out of specification. This will not only save on the annual test but also facilitates the detection of failures between the normal test regime.

[0025] In a fourth aspect of the invention, the axle monitoring system enables the identification of low adhesion hotspots on the network. The system transmits the brake pressure information from the brake pressure sensors together with location data from the GPS system. This data is then compared to previous data on the same sections of track / the same location. It therefore becomes possible to identify areas of the network where low adhesion is a problem. This may be either due to problems with the infrastructure at this point, eg track damage or it may be related to weather or leaf fall.

[0026] In a fifth aspect of the invention, the axle monitoring system provides for brake performance monitoring. Regular use of wheel flat protection (WFP) or if the wagon has been in a deep slide or if there has been a persistent axle lock, may lead to degradation of the brakes or damage to the wheel. When a wheel develops a wheel flat, the wheel will generally vibrate in use and this vibration can be detected by a vibration sensor on the axle. Together with the outputs of the other sensors, this information can be used to schedule maintenance or to identify areas of track damage on the network.

[0027] In a further aspect, decoupled wagons due to various failures such as the coupler, pins breaking etc is a known problem. As the brake pipe pressure is monitored on each wagon, the system will be able to detect any significant air loss which would occur when there is a decouple. If a significant air loss is detected, the system can arise an alert to the driver and / or operator to alert them to the potential decouple. The GPS data from wagons in the rake (the originally connected wagons) will also show that the GPS signal from one or more wagons has changed compared to the GPS signals from the locomotive and any wagons still connected to the locomotive. Figure 3 shows a further aspect of the invention which provides for an option of a direct to driver communication method independent of the mobile cellular network connection. This is achieved by the generation of a mesh network that connects wagons 2, 3, 4 to each other wirelessly using LoraWAN protocol via gateways 21 (or by other wireless protocols) which in turn is connected to the same network on the locomotive to allow notification of a detected issue to the driver e.g. locked axle alert, parking brake on / partially on alert or a severe pressure loss alert. The notification may be provided to a handheld device such as a mobile telephone 30.

[0028] RECTIFIED SHEET (RULE 91) ISA / EP

Claims

Claims1. A monitoring system for a rail freight wagon, the freight wagon having an axle, which axle is provided with an axle end generator, which axle end generator is adapted to provide an electrical supply to a mechatronic valve for controlling brake pressures to the axle, wherein the axle monitoring system further comprises a wheel speed sensor and a brake pressure sensor, the axle monitoring system being further provided with communication means, which communication means are adapted to transmit outputs of the wheel speed sensor and brake pressure sensor to a receiver.

2. A monitoring system according to Claim 1, wherein the system checks the status of the parking brake and transmits this status to the receiver.

3. A monitoring system according to Claim 1 or Claim 2, wherein the mechatronic valve of the axle monitoring system enables release of brake pressure when the sensor outputs indicate an axle lock to thereby prevent wheel slide.

4. A monitoring system according to any one of Claims 1 to 3, wherein axle rotation is monitored to determine whether a persistent axle lock is present and if a persistent axle lock is detected, the system generates an alert for transmission to a driver or operator of the rail freight wagon.

5. A monitoring system according to any one of Claims 1 to 4, wherein the system monitors the input and output pressures of the brake system during normal operation to determine the condition of the brake system.

6. A monitoring system according to any one of Claims 1 to 5, wherein the receiver is located off of the train of which the freight wagon is a part.

7. A monitoring system according to any one of Claims 2 to 6, wherein the freight wagon is part of a rake and the status of the parking brake on each wagon is determined and then this status together with a wagon ID is transmitted off the train via the communication means to a cloud server, which cloud server can then serve the data toa handheld device of the driver to thereby enabling the driver to see the status of each parking brake on the rake .

8. A monitoring system according to any one of Claims 1 to 7, wherein the brake pressure at the or each distributor or in the main brake pipe is measured and transmitted off the train together with the wagon ID to thereby enable the driver to identify the brake pressure of the last wagon on the rake.

9. A monitoring system according to any one of Claims 1 to 8, wherein the brake pipe pressure, brake cylinder pressure and the variable load valve pressure setting are monitored in an ongoing manner during operation of the freight wagon.

10. A monitoring system according to any one of Claims 1 to 9, wherein the system transmits the brake pressure information from the brake pressure sensors together with location data from the GPS system to enable comparison with previous data on the same location.

11. A monitoring system according to any one of Claims 1 to 10, wherein the axle monitoring system comprises a vibration sensor on the axle.

12. A monitoring system according to any one of Claims 1 to 11, wherein the brake pipe pressure is monitored on each wagon, wherein if a significant reduction in brake pipe pressure is detected, the system sends an alert to the driver and / or operator to alert them to a potential decouple.

13. A monitoring system according to any one of Claims 1 to 12, wherein the system further comprises location functionality, wherein location data is transmitted from the freight wagon to thereby enable a comparison of the location data of different wagons in the rake with the location of the locomotive.

14. A monitoring system according to any one of Claims 1 to 13, wherein in a rake a mesh network is generated to connects wagons to each other wirelessly using LoraWAN protocol via the communication means.

15. A monitoring system according to Claim 14, wherein the mesh network is connected to the same network on the locomotive to allow notification of a detected issue to the driver.

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