Method for identifying the sequence of vehicles on a train and control device for a railway vehicle

Abstract

The invention relates to a method for determining the order of rail vehicles connected to a locomotive on a train and to a control device for a rail vehicle, the rail vehicle control device comprising a pressure sensor for detecting a pressure change in a brake pipe connected to the locomotive, the rail vehicle control device being configured to decode an identification code encoded in the pressure change by a control device of the locomotive, the rail vehicle control device further comprising a communication unit for communicating on a wireless communication network, and the rail vehicle control device being configured to respond to a request from the locomotive only if an identification code transmitted with the request corresponds to the identification code decoded from the pressure change.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for determining the order of rail vehicles connected to a locomotive on a train, wherein a control device of the locomotive is connected via a brake pipe to a rail vehicle comprising a control device and the control device of the locomotive and the control device of the rail vehicle are able to exchange messages via a fast network. Furthermore, the invention relates to a control device for a rail vehicle. BACKGROUND

[0002] Such a method is known from US 2002 / 0139181 A1, wherein a brake test is performed in order to determine a continuity test of the pneumatic brake pipe.

[0003] Furthermore, such a method is known from DE 202012 012558 U1, wherein the pressure change acting at the locomotive and the time between its arrival at the rail vehicle are measured in order to determine the order of vehicles on the train.

[0004] In EP 3 081 445 A1, the determination of the order of vehicles on the train is triggered by a predetermined sequence of pressure changes, which are recorded only when the rail vehicle is at standstill. When the determination of the order of vehicles is triggered, a GPS positioning is used to determine the order of the rail vehicles.

[0005] Some of the above-mentioned methods can be triggered at the same time on multiple trains when the trains are very close, which would lead to multiple rail vehicles responding to brake test signals from a locomotive not connected to these rail vehicles. For example, when two trains are side by side and both locomotives start the method for identifying the order of vehicles, it is not possible to determine which rail vehicles respond to which locomotive.

[0006] Other methods require an electrical communication connection between the rail vehicles, which can not be feasible when some rail vehicles are equipped with these devices and others are not. SUMMARY

[0007] It is an object of the invention to solve the above-mentioned problems of the prior art.

[0008] As a solution, a method according to claim 1 is proposed. Advantageous embodiments are contained in the dependent claims.

[0009] To solve the above problems, a method for determining the order of rail vehicles connected to a locomotive on a train is proposed, wherein a control device of the locomotive is connected to a rail vehicle comprising a control device via a brake pipe, the control device of the locomotive and the control device of the rail vehicle are able to exchange messages via a wireless fast network, and the method comprises the following steps: transmitting, by the control device of the locomotive, a unique identification code to the control device via a slow network constituted by the brake pipe; transmitting, by the control device of the locomotive, a message on the fast network indicating the current state of the transmission achieved via the slow network, wherein the message comprises the unique identification code; determining, by the control device, a time delay between the state of the transmission received from the control device and the state of the transmission measured on the slow network; calculating, from the time delay and the propagation speed of the slow network, the distance of each rail vehicle to the locomotive; requesting, by the control device of the locomotive, a report related to the calculated distance and / or the measured time delay from each rail vehicle; sending the report by the control device in response to the above request if the identification code in the request matches the identification code received via the slow network; and ordering the rail vehicles according to the distance of the rail vehicles to the locomotive.

[0010] Thus, the rail vehicles will only respond to the locomotive having the same unique identification code as received on the brake pipe. In this way, even if two or more trains are side by side, each locomotive will only receive distance reports from the rail vehicles actually connected to that locomotive. Furthermore, the method is applicable even when some rail vehicles are not equipped with a control device.

[0011] In yet another embodiment, the transmission step by the control device of the locomotive comprises generating a pressure variation in the brake pipe in order to encode the identification code for the transmission, wherein the state of the transmission is the pressure generated in the brake pipe at the locomotive by the brake control unit.

[0012] This is one of the simplest methods to encode the identification code. It can be implemented with low equipment cost.

[0013] In yet another embodiment, determining the time delay between the state of the transmission received from the control device and the state of the transmission measured on the slow network can comprise the following steps: measuring, by a pressure sensor associated with the control device, the pressure in the brake pipe at the rail vehicle; taking a first time derivative of the measured pressure in the brake pipe at the rail vehicle; taking a second time derivative of the measured pressure in the brake pipe at the locomotive; and determining the time delay as the time delay between the respective positive and negative variations of the first and second time derivatives.

[0014] In this way, the absolute pressure in the brake pipe is less important. Especially on long trains, the pressure at the last rail vehicle can be much lower than at the head of the train. By measuring only the pressure change and interrogating the change in the time derivative of the pressure, the communication of the identification code becomes more flexible.

[0015] In yet another embodiment, the step of transmitting, by the control device of the head of the train, a message indicative of the current state of the transmission can comprise the steps of: measuring, by a pressure sensor associated with the control device of the head of the train, the pressure in the brake pipe at the head of the train; calculating a second time derivative from the pressure measured in the previous step; sending the second time derivative value to the control device on the fast network as a message indicative of the current state of the transmission achieved via the slow network; and wherein the step of obtaining the second time derivative comprises receiving the message comprising the second time derivative.

[0016] Thus, the control device of the rail vehicle only needs to calculate the time derivative of its own measurement, thereby reducing the power consumption.

[0017] In yet another embodiment, the message sent on the slow network is split into a plurality of symbols and transmitted by a change in pressure in the brake pipe, wherein each symbol is transmitted over a predetermined number of time frames, wherein a first symbol of the transmission is transmitted such that: during a first time frame, the pressure in the brake pipe increases by a first predetermined amount; during a second frame, the pressure in the brake pipe decreases by a second predetermined amount, wherein a second symbol of the transmission is transmitted such that: during a first time frame, the pressure in the brake pipe decreases by a third predetermined amount; during a second frame, the pressure in the brake pipe (22) increases by a fourth predetermined amount, wherein one of the first symbol and the second symbol represents a binary 0 and the other of the first symbol and the second symbol represents a binary 1.

[0018] This encoding into a change in pressure value over time is clearly different from normal operation on the brake pipe.

[0019] In yet another embodiment, during a third time frame, the pressure in the brake pipe returns to the base pressure that existed in the brake pipe before the first time frame.

[0020] This constitutes a stop bit and allows the pressure to return to a predetermined normal value.

[0021] In yet another embodiment, the method can comprise the step of determining whether there are rail vehicles in the train that are not equipped with a control device, wherein this step comprises the steps of comparing the known length of the rail vehicles with the relative distances of these rail vehicles to the head of the train and determining which of the relative distances between the rail vehicles and / or the head of the train are greater than the known length of the rail vehicles there between.

[0022] It is thus possible to consider rail vehicles which are not equipped with a control device and / or a communication device.

[0023] The problem is also solved by a rail vehicle comprising a control device, wherein the control device comprises a pressure sensor for detecting a pressure change in a brake pipe, the control device is configured to decode an identification code encoded in the pressure change by the vehicle head, the control device further comprises a communication unit for communicating on a wireless communication network, and the control device is configured to respond to a request from the vehicle head only if the identification code transmitted with the request corresponds to the identification code decoded from the pressure change.

[0024] Thus, the rail vehicles will only respond to a vehicle head having the same unique identification code as received on the brake pipe. This way, even if two or more trains are side by side, each vehicle head will only receive distance reports from the rail vehicles actually connected to that vehicle head. BRIEF DESCRIPTION OF DRAWINGS

[0025] These and other objects, advantages, and novel features of the present application will become apparent to those skilled in the art from the following detailed description of the application when considered in conjunction with the accompanying drawings.

[0026] In the schematic drawings:

[0027] Figure 1 a schematic diagram of a train configuration for implementing the method according to an embodiment of the present application is shown, and

[0028] Figure 2 a schematic diagram representing a pressure change signal according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] As Figure 1 shown, a train 10 can comprise a vehicle head 12 and a plurality of rail vehicles 14, 16, 18, 20. The vehicle head 12 and the rail vehicles 14, 16, 18, 20 are connected to a brake pipe 22. The brake pipe 22 carries a pneumatic pressure from the vehicle head 12 to each of the rail vehicles 14, 16, 18, 20. Each of the rail vehicles 14, 16, 18, 20 is provided with a brake unit which brakes the rail vehicle 14, 16, 18, 20 when the pneumatic pressure in the brake pipe 22 is too low. Thus, if, for example, a leak occurs in the brake pipe 22, the brake units will stop the train.

[0030] The locomotive 12 comprises a control device 28 and each of the rail vehicles 14, 16, 20 comprises a control device 30, 32, 34. The rail vehicle 18 does not comprise a control device. Each of the control devices 28, 30, 32, 34 can be different. In particular, the control device 28 of the locomotive 12 can be configured to output messages and to receive commands from the human-machine interface device 26 and can be configured to control the brake control unit 24.

[0031] The brake control unit 24 controls the pneumatic pressure inside the brake pipe 22. The control device 28 can control the brake control unit 24 based on user input received via the human-machine interface device 26 and / or from other inputs, e.g. from sensors.

[0032] Each of the locomotive 12 and the rail vehicles 14, 16, 20 comprises a pressure sensor 36, 38, 40, 42 which senses the pneumatic pressure inside the brake pipe 22 at the sensor location. The brake control unit 24 can control the pneumatic pressure inside the brake pipe 22 in order to transmit digital messages from the locomotive 12 to the rail vehicles 14, 16, 20.

[0033] Each of the control devices 28, 30, 32, 34 comprises a communication unit 44, 46, 48, 50, each communication unit comprising an antenna. The communication units 44, 46, 48, 50 can be connected to each other and / or transmit messages to each other via a wireless communication network 52.

[0034] Each of the control devices 28, 30, 32, 34 comprises a predetermined unique identification code, the unique identification code comprising a plurality of information bits and can be used to identify each control device 28, 30, 32, 34 and / or can be used to address a message to one specific other control device 28, 30, 32, 34 and / or to determine the origin of a received message.

[0035] The control device 28 of the locomotive 12 can transmit its identification code to all control devices 30, 32, 34 having a pressure sensor 38, 40, 42 on the brake pipe 22. In order to transmit the bits of its identification code, the control device 28 represents these bits as symbols by controlling the brake control unit 24, the symbols being encoded as a sequence of pressure changes to be generated in the brake pipe 22. The message comprising the whole identification code of the control device 28 can be sent and re-sent in a loop via the brake pipe 22. By detecting the pressure changes and receiving the message, the control devices 30, 32, 34 are able to identify the control device 28 of the locomotive 12 they are connected to.

[0036] Since the pressure changes inside the brake pipe 22 propagate through the brake pipe 22 at a relatively slow speed (e.g. 280 m / s), the brake pipe 22 constitutes a slow network, while the wireless communication network 52 constitutes a fast network.

[0037] In addition, the control device 28 can broadcast its identification code and / or the brake pipe 22 pressure measured by its own pressure sensor 36 over the network 52. As the pressure change within the brake pipe 22 propagates at the speed of sound, each control device 30, 32, 34 can determine its distance to the locomotive 12 by measuring the time delay between the pressure change detected by the pressure sensors 38, 40, 42 and the pressure change broadcasted by the control device 28. The pressure change broadcasted by the control device 28 serves as a reference signal for the delay measurement.

[0038] In yet another embodiment of the application, the control device 28 can for example calculate the time derivative of the pressure measured by its own pressure sensor 36 and can broadcast the time derivative over the network 52.

[0039] In yet another embodiment of the application, the control devices 30, 32, 34 can determine a first time derivative of the pressure measured in the brake pipe 22 at their location and can determine a second time derivative of the pressure measured in the brake pipe 22 at the locomotive 12 from the pressure change broadcasted by the control device 28. To determine the time delay between the detected pressure change and the broadcasted pressure change, the control devices 30, 32, 34 determine the positive and negative changes of the time derivative. When the respective positive and negative changes of the time derivative are detected within the first and second time derivative, the time delay is determined as the time delay between the respective positive and negative changes.

[0040] The control device 28 can send a message over the network 52 requesting the time delay and / or the calculated distance from any one or all of the control devices 30, 32, 34. Although control devices not connected to the train can receive the message, only those control devices 30, 32, 34 connected to the same brake pipe 22 as the locomotive 12 have received the identification code of the control device 28 before. Therefore, only those control devices 30, 32, 34 will respond to the message requesting the time delay and / or the calculated distance. In this way, the locomotive 12 is able to determine which rail vehicles 14, 16, 20 are connected to the locomotive.

[0041] The distance of each rail vehicle 14, 16, 20 to the locomotive 12 can be calculated from each time delay and the speed of sound within the brake pipe 22. The calculation can be performed by the control device 28 of the locomotive 12 and / or by the control devices 30, 32, 34 of the rail vehicles 14, 16, 20.

[0042] As the actual physical length of the locomotive 12 and the rail vehicles 14, 16, 20 is known, the rail vehicle 18 without a control device can be detected, because the distance measured between the rail vehicle 16 and the rail vehicle 20 is too large.

[0043] In yet some embodiments of the application, in order to increase the reliability of the transmission of the identification code of the control device 28 via the brake pipe 22, each bit can be represented, for example, by a symbol encoded as a sequence of pressure increase and / or pressure decrease. Figure 2 One example of such an encoding is shown. The binary values 0 and 1 are encoded as a sequence of deviations from a base pressure P0. Each symbol extends over a plurality of time frames T1, T2, T3, T4, T5, T6. Figure 2 The sequence shown in Fig. 3 comprises a binary value 0 encoded in time frames T1 and T2 and a binary value 1 encoded in time frames T5 and T6.

[0044] In particular, a binary value 0 is encoded by raising the pressure in the brake pipe 22 by a first predetermined amount as shown in time frame T1, then lowering the pressure in the brake pipe 22 by a second predetermined amount during time frame T2, then increasing the pressure in the brake pipe 22 to a base pressure P0 at the beginning of time frame T3, said base pressure being also the pressure present in the brake pipe 22 before the first time frame T1. In a similar manner, a binary value 1 is encoded by first lowering the pressure by a third predetermined amount during time frame T5, then increasing the pressure by a fourth predetermined amount during time frame T6 and returning to the base pressure P0 after time frame T6.

[0045] In yet some embodiments of the application, the binary values can be represented differently. For example, one symbol can comprise at least two time frames during which different pressure variations can be used to encode the symbol. In yet another example, one symbol can represent more than one binary digit. In yet another example, a plurality of symbols can be used to represent the same binary value (e.g. 4B5B encoding).

[0046] In yet another embodiment of the application, the base pressure P0 can be determined as the pressure present in the brake pipe 22 at the vehicle head 12 just before the beginning of time frame T1.

[0047] In yet another embodiment of the application, the identification code generated on all control devices can be unique.

[0048] The application thus allows to safely identify the vehicles connected to the train and is also applicable when some of the rail vehicles 18 are not equipped with a control device.

[0049] List of reference signs

[0050] 10 train

[0051] 12 vehicle head

[0052] 14 rail vehicle

[0053] 16 rail vehicle

[0054] 18 rail vehicle

[0055] 20 rail vehicle

[0056] 22 brake pipe (slow network)

[0057] 24 brake control unit

[0058] 26 human-machine interface device

[0059] 28 control device

[0060] 30 control device

[0061] 32 control device

[0062] 34 control device

[0063] 36 pressure sensor

[0064] 38 pressure sensor

[0065] 40 pressure sensor

[0066] 42 pressure sensor

[0067] 44 communication unit

[0068] 46 communication unit

[0069] 48 communication unit

[0070] 50 communication unit

[0071] 52 wireless communication network (fast network)

[0072] T1 time frame

[0073] T2 time frame

[0074] T3 time frame

[0075] T4 time frame

[0076] T5 time frame

[0077] T6 time frame

Claims

1. A method for determining an order of rail vehicles (14, 16, 18, 20) connected to a locomotive (12) on a train (10), wherein, The head control device (28) of the head (12) is connected to the rail vehicle control devices (30, 32, 34) comprised in the rail vehicles (14, 16, 20) via the brake pipe (22), the head control device (28) of the head (12) and the rail vehicle control devices (30, 32, 34) of the rail vehicles (18, 16, 20) being able to exchange messages via a wireless fast network (52), characterized by the following steps: a) transmitting, by the control device (28) of the head (12), a unique identification code to the control devices (30, 32, 34) via the slow network constituted by the brake pipe (22); b) transmitting, by the head control device (28) of the head (12), a message on the fast network indicating the current state of the transmission effected via the slow network, wherein the message comprises the unique identification code; c) determining, by the rail vehicle control devices (30, 32, 34), the time delay between the state of the transmission received from the head control device (28) and the state of the transmission measured on the slow network; d) calculating, from the time delay and the propagation speed of the slow network, the distance of each rail vehicle (14, 16, 20) to the head (12); e) requesting, by the head control device (28) of the head (12), a report from each rail vehicle (14, 16, 20) relating to the calculated distance and / or the measured time delay; f) sending the report in response to the above request by the rail vehicle control devices (30, 32, 34) if the identification code in the request matches the identification code received via the slow network; and g) ordering the rail vehicles according to their distance to the head (12).

2. The method of claim 1, wherein, Step a) comprises generating a pressure variation in the brake pipe (22) so as to encode the identification code for the transmission, wherein the state of the transmission is the pressure generated by the brake control unit (24) in the brake pipe (22) at the head (12).

3. The method of claim 2, wherein, Step c) comprises the following steps: c1) measuring, by a pressure sensor (38, 40, 42) associated with the rail vehicle control device (30, 32, 34), the pressure in the brake pipe (22) at the rail vehicle (14, 16, 20); c2) taking the first time derivative of the measured pressure in the brake pipe (22) at the rail vehicle (14, 16, 20); c3) taking the second time derivative of the measured pressure in the brake pipe (22) at the head (12); and c4) determining the time delay as the time delay between the respective positive and negative variations of the first and second time derivatives.

4. The method of claim 3, wherein, Step b) comprises the following steps: b1) measuring, by a pressure sensor (36) associated with the head control device (28) of the head (12), the pressure in the brake pipe (22) at the head (12); b2) calculating the second time derivative from the pressure measured in the preceding step; b3) sending the second time derivative to the rail vehicle control device (30, 32, 34) over the fast network, the second time derivative value as a message indicating the current status of the transmission achieved via the slow network; and wherein step c3) comprises receiving a message comprising the second time derivative.

5. The method according to any one of claims 2 to 4, characterized in that, The message to be sent over the slow network is divided into a plurality of symbols and sent by means of pressure variations in the brake pipe (22), wherein each symbol is sent over a predetermined number of time frames, wherein a first symbol of the transmission is transmitted so that: during a first time frame, the pressure in the brake pipe (22) is increased by a first predetermined amount; during a second frame, the pressure in the brake pipe (22) is decreased by a second predetermined amount, wherein a second symbol of the transmission is transmitted so that: during a first time frame, the pressure in the brake pipe (22) is decreased by a third predetermined amount; during a second frame, the pressure in the brake pipe (22) is increased by a fourth predetermined amount, wherein one of the first symbol and the second symbol represents a binary 0 and the other of the first symbol and the second symbol represents a binary 1.

6. The method of claim 5, wherein, during a third time frame, the pressure in the brake pipe (22) returns to the base pressure that existed in the brake pipe (22) before the first time frame.

7. The method according to any one of claims 1 to 4, characterized by the following steps: h) determining whether there is a rail vehicle (18) in the train (10) which is not equipped with a rail vehicle control device (30, 32, 34), wherein This step comprises the following steps: hi) comparing the known length of the rail vehicle (14, 16, 20) with the calculated relative distances of the rail vehicle (14, 16, 20) to the locomotive (12); and h2) determining which of the calculated relative distances between the rail vehicle (14, 16, 20) and / or the locomotive (12) are greater than the known length of the rail vehicle therebetween.

8. A rail vehicle control device (30, 32, 34) for a rail vehicle (14, 16, 20), wherein The rail vehicle control device (30, 32, 34) comprises a pressure sensor (38, 40, 42) for detecting pressure variations in a brake pipe (22) connected to a locomotive (12), the rail vehicle control device (30, 32, 34) being configured to decode an identification code encoded in the pressure variations by a locomotive control device (28), the rail vehicle control device (30, 32, 34) further comprising a communication unit (46, 48, 50) for communicating on a wireless communication network (52), and the rail vehicle control device (30, 32, 34) being configured to respond to a request from the locomotive control device (28) via the wireless communication network (52) only if the identification code sent with the request corresponds to the identification code decoded from the pressure variations.

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