Diagnosis of excessive flow in train brake pipes

Abstract

The brake pipe pressure monitoring system evaluates the pressure flow in the brake pipe and alerts the train operator if the brake pipe flow indicates a brake system malfunction. The system includes a brake pipe pressure module, coupled to the computer-controlled brakes, as well as a brake pipe pressure transducer, a main reservoir pressure transducer, and a flow transducer. The module determines the pressure flow from the main reservoir to the brake pipe. The module is programmed to calculate and track the flow rate in the brake pipe over time and determine whether the flow rate exceeds a predetermined threshold. If the flow rate exceeds the predetermined threshold, the computer-controlled brakes signal the train operator to indicate a malfunction.

Description

Background Art 1. Technical Field

[0002] The present invention relates to train braking systems, and more particularly, to a system and method for monitoring a train brake pipe for excess flow when automatic train brakes are applied.

[0003] 2. Description of Related Technology

[0004] The braking power of a train is often the subject of strict government requirements designed to ensure the safe operation of the train. For example, each train undergoes a terminal test before departure to confirm that the entire braking system is operating properly. Additionally, if the braking power of a train falls below a predetermined threshold during travel, the train must be stopped. One problem that can arise is a faulty railcar brake control valve. Leakage from a faulty railcar control valve can impair train braking performance because a railcar with a leaking control valve will not respond to a decrease in brake pipe pressure with the appropriate amount of brake cylinder pressure, thereby failing to properly apply the railcar brakes. Therefore, there is a need in the art for a method for determining and monitoring brake pipe flow to detect and diagnose brake system problems. Summary of the Invention

[0005] The present invention includes a brake pipe pressure monitoring system that can evaluate brake pipe pressure flow and alert a train operator when the brake pipe flow rate drops above a predetermined threshold, indicating damage to the operating train's brakes. More specifically, the brake pipe pressure monitoring system includes a computer-controlled brake system, the brake system including a controller programmed to implement at least one brake system input from the train operator. A brake pipe pressure module is associated with the computer-controlled brake system. A brake pipe pressure transducer is interconnected with the brake pipe pressure module and configured to provide a measure of pressure in a brake pipe coupled to the brake pipe pressure module. A master reservoir pressure transducer is interconnected with the brake pipe pressure module and configured to provide a measure of pressure in a master reservoir coupled to the brake pipe pressure module. A flow transducer is interconnected with the brake pipe pressure module and configured to provide the brake pipe pressure module with information on flow from the master reservoir to the brake pipe. The brake pipe pressure module is programmed to calculate and track the flow rate in the brake pipe over time and determine whether the flow rate in the brake pipe over time exceeds a predetermined threshold. The brake pipe pressure module is further configured to cause the computer controlled brakes to alert the train operator if flow in the brake pipe exceeds a predetermined threshold.

[0006] In one embodiment, the present invention is a system for monitoring excessive pressure loss from a train brake pipe, comprising: a computer-controlled brake having an electro-pneumatic control unit programmed to modify the amount of pressure in the brake pipe in response to user input; a brake pipe pressure flow node associated with the electro-pneumatic control unit, wherein the brake pipe pressure flow node includes a brake pipe pressure transducer configured to provide the amount of pressure in the brake pipe to the brake pipe pressure flow node, a main reservoir pressure transducer configured to provide the amount of pressure in the main reservoir to the brake pipe pressure flow node, and a flow transducer configured to provide the amount of flow in the brake pipe from the main reservoir, wherein the brake pipe pressure flow node is programmed to determine the flow in the brake pipe to determine whether the flow in the brake pipe exceeds a predetermined threshold and to indicate to the train operator on a locomotive display if the flow in the brake pipe exceeds the predetermined threshold. The brake pipe pressure flow node may be programmed to determine whether the flow in the brake pipe exceeds the predetermined threshold based on a comparison of the flow in the brake pipe when the brake pipe is in a brake-released pressure state and a brake-applied pressure state. The brake pipe pressure flow node can be programmed to determine whether the flow in the brake pipe exceeds a predetermined threshold based on whether the flow in the brake pipe with the brakes applied minus the flow in the brake pipe with the brakes released exceeds a predetermined threshold. The predetermined threshold may represent the flow in the brake pipe that would occur if thirty-five percent of all truck control valves coupled to the computer-controlled brakes had a malfunction. The brake pipe pressure flow node can be programmed to determine whether the flow in the brake pipe exceeds a predetermined threshold based on whether the flow in the brake pipe in the brake applied state exceeds the predetermined threshold. The predetermined threshold may represent the brake flow in the brake pipe that would occur if thirty-five percent of all truck control valves coupled to the computer-controlled brakes had a malfunction.

[0007] In another embodiment, the present invention is a method for monitoring a train braking system, the train braking system including a computer-controlled brake having an electro-pneumatic control unit programmed to modify the amount of pressure in a brake pipe in response to user input. In a first step, a brake pipe pressure flow node is associated with the electro-pneumatic control unit of the computer-controlled brake, wherein the brake pipe pressure flow node includes a brake pipe pressure transducer configured to provide the amount of pressure in the brake pipe to the brake pipe pressure flow node, a main reservoir pressure transducer configured to provide the amount of pressure in the main reservoir to the brake pipe pressure flow node, and a flow transducer configured to provide the flow rate in the brake pipe from the main reservoir. In another step, the brake pipe pressure flow node is used to determine the flow rate in the brake pipe. In another step, the brake pipe pressure flow node is used to determine whether the flow rate in the brake pipe exceeds a predetermined threshold. In another step, if the flow rate in the brake pipe exceeds the predetermined threshold, the brake pipe pressure flow node is used to provide an indication to the train operator on a locomotive display. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present invention will be more fully understood and appreciated by reading the following detailed description in conjunction with the accompanying drawings, in which:

[0009] Figure 1 is a schematic diagram of a locomotive computer controller brake for controlling a braking system of a locomotive and a series of railcars coupled to the locomotive in accordance with the present invention;

[0010] Figure 2 is a flow chart of a monitoring system for a computer controller brake according to the present invention;

[0011] Figure 3 is a schematic diagram of a monitoring system for a computer-controlled brake according to the present invention; and

[0012] Figure 4 is a flow chart of excess brake pipe flow determination according to the present invention. DETAILED DESCRIPTION

[0013] Referring to the drawings, wherein like numerals refer to like parts throughout, Figure 1As seen in FIG, train 10 includes at least one locomotive 12 coupled to a series of railcars 14. Locomotive 12 includes computer-controlled brakes 16 that interface with the locomotive's existing automatic brakes 18 and independent brakes 20 that control locomotive brake pressure 22 and brake pipe pressure 24, with brakes 16 signaling to apply and release the automatic brakes of railcars 14 pulled by locomotive 12. Computer-controlled brakes 16 are locomotive devices that respond to train operator input by executing or commanding brake settings, such as those selected by the train operator, such as CCBs available from New York Air Brake Co., Inc. of Watertown, New York. Computer Controlled Brakes. As is known in the art, computer controlled brakes 16 receive signals generated by automatic brake handles 26 and independent brake handles 28 of electronic brake valves 32 located in the cab of locomotive 12 and are responsible for converting user handle inputs into brake system commands, such as changes in brake pipe pressure 24 for selectively applying and releasing the brakes of attached railcars 14 and changes in locomotive brake pressure 22 for selectively applying and releasing the locomotive brakes.

[0014] refer to Figure 2 , the primary monitoring and control functions of the computer controlled brakes 16 are performed by an electro-pneumatic control unit (EPCU) 40. The EPCU 40 manages the pneumatic interface of the train braking system and the electronic brake valve 32. The EPCU 40 is programmed to implement train operator inputs via the pneumatic and electro-pneumatic components of the computer controlled brakes 16. For example, the EPCU 40 may be programmed with a separate brake application module 34 and an automatic brake application module 36. The EPCU 40 also communicates with a CCB processor module 42 that manages the electronic interface and interfaces with a user locomotive display 44 located in the cab of the locomotive 12, such as CCA or FIRE control system.

[0015] refer to Figure 3 , the present invention can be implemented in the EPCU 40 as a BP LRU node 50. The BP LRU node 50 includes programmable logic that communicates with the pneumatic components of the train braking system. Figure 3 As can be seen, the BP LRU node 50 has access to a brake pipe pressure transducer (BPT) 52, a main reservoir pressure transducer (MRT) 54, and a flow transducer (FLT) 56. Using the BPT, MRT, and FLT sensors, the flow in the brake pipe 24 can be calculated and monitored in real time by the BP LRU node 50. The calculated brake pipe flow can be tracked over time to identify whether the brake system is operating properly or if there are issues that compromise the train's braking integrity. Leakage is typically measured in cubic feet per minute (CFM), but it should be appreciated that the units may vary depending on the location.

[0016] refer to Figure 4 BP LRU node 50 can retrieve sensor data 60 from brake pipe pressure transducer BPT 52, master reservoir pressure transducer MRT 54, and flow transducer FLT 56. The retrieved data is then used to determine brake pipe flow 62. The calculated brake pipe flow is then checked 64 to determine whether it exceeds a predetermined threshold, thereby indicating excessive leakage. If check 64 indicates excessive leakage, an indication 68 is made, such as providing an alarm or alert to a user via a user display. Thus, BP LRU node 50 is programmed to identify a brake pipe flow exceeding a predetermined threshold as an indication of excessive brake pipe flow and to indicate the excessive brake pipe flow condition to the user.

[0017] As explained above, the BP LRU node 50 can be programmed to determine excess brake pipe flow (EBPF) by using a predetermined threshold (identified as X). The threshold X can be set according to railroad regulations or any user-defined lever used to provide an indication of excess flow. For example, in some jurisdictions, a brake pipe leakage flow equivalent to 35% of freight car valves exhibiting a malfunction is considered an appropriate level for compliance with regulations. Thus, in a 120-car train, a brake pipe leakage flow equivalent to 42 of the 120 cars having a malfunction can be used as the threshold for determining excess leakage. The flow in the brake pipe can be evaluated in both the brake released state (pre-brake application with the brake pipe at standard pressure) and the brake applied state (brake application via an appropriate brake pipe pressure reduction).

[0018] The number of cars in a train can be determined on a case-by-case basis because specific composition information can be entered for each car 10 prior to leaving the terminal on a given route, or retrieved from an onboard system (such as a train control system located in the cab of a locomotive 12) that has been programmed with the current train configuration. Figure 4 In the illustrated method, component information 66 may be retrieved for use in determining thresholds to be applied in check 64. For example, BP LRU node 50 may be programmed to determine excess brake pipe flow (EBPF) in check 64 based on one or more predetermined conditions, such as:

[0019] 1.EBPF = Applied Brake Pipe Flow – Pre-Applied BP Flow > (X)

[0020] or

[0021] 2.EBPF=Applied brake pipe flow>60CFM+(X)

[0022] The results of the excess brake pipe flow determination, or a real-time indication of whether the current brake pipe flow is excessive, may be indicated to the user via the CCB processor module 42 to provide the results on a user display 44 located in the cab of the locomotive 12 .

[0023] As described above, the present invention can be a system, method and / or computer program associated therewith, and is described in this article with reference to the flowchart and block diagram of method and system. Flowchart and block diagram illustrate the architecture, function and operation of the possible embodiments of the system, method and computer program of the present invention. It should be understood that each frame of the flow chart and block diagram can be implemented by computer-readable program instructions in software, firmware or special analog or digital circuits. These computer-readable program instructions can be implemented on a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine that implements part or all of any frame in the flow chart and block diagram. Each frame in the flow chart or block diagram can represent a module, segment or partial instruction, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that each frame illustrated in the block diagram and flow chart, or the combination of the frames in the block diagram and process, can be implemented by a system based on dedicated hardware that performs a specified function or action or performs a combination of dedicated hardware and computer instructions.

Claims

1. A system for monitoring excessive pressure loss from a train brake pipe, comprising: a computer-controlled brake having an electro-pneumatic control unit programmed to modify the amount of pressure in the brake pipe in response to user input; a brake pipe pressure flow node associated with the electro-pneumatic control unit, wherein the brake pipe pressure flow node includes a brake pipe pressure transducer configured to provide a pressure amount in the brake pipe to the brake pipe pressure flow node, a main reservoir pressure transducer configured to provide a pressure amount in a main reservoir to the brake pipe pressure flow node, and a flow transducer configured to provide a flow rate in the brake pipe; and wherein the brake pipe pressure flow node is programmed to determine the flow in the brake pipe to determine whether the flow in the brake pipe exceeds a predetermined threshold, and to indicate to the train operator on a locomotive display if the flow in the brake pipe exceeds the predetermined threshold.

2. The system according to claim 1, wherein: The brake pipe pressure flow node is programmed to determine whether the flow in the brake pipe exceeds the predetermined threshold based on a comparison of the flow in the brake pipe when the brake pipe is in a brake release pressure state and a brake apply pressure state.

3. The system according to claim 2, wherein: The brake pipe pressure flow node is programmed to determine excess flow in the brake pipe based on whether flow in the brake pipe with the brakes applied minus flow in the brake pipe with the brakes released exceeds the predetermined threshold.

4. The system according to claim 3, wherein: The predetermined threshold represents the flow in the brake pipe that would occur if thirty-five percent of all truck control valves coupled to the computer-controlled brakes had a malfunction.

5. The system according to claim 1, wherein: The brake pipe pressure flow node is programmed to determine whether the flow in the brake pipe exceeds the predetermined threshold based on whether the flow in the brake pipe exceeds the predetermined threshold in a brake applied state.

6. The system according to claim 5, wherein: The predetermined threshold represents the brake flow in the brake pipe that would occur if thirty-five percent of all truck control valves coupled to the computer controlled brakes had failed.

7. A method of monitoring a train braking system including computer-controlled brakes having an electro-pneumatic control unit programmed to modify the amount of pressure in a brake pipe in response to user input, the method comprising the steps of: associating a brake pipe pressure flow node with the electro-pneumatic control unit of the computer-controlled brake, wherein the brake pipe pressure flow node includes a brake pipe pressure transducer configured to provide a quantity of pressure in the brake pipe to the brake pipe pressure flow node, a master reservoir pressure transducer configured to provide a quantity of pressure in a master reservoir to the brake pipe pressure flow node, and a flow transducer configured to provide a flow in the brake pipe; determining a flow rate in the brake pipe using the brake pipe pressure-flow node; using the brake pipe pressure flow node to determine whether a flow rate in the brake pipe exceeds a predetermined threshold; and If the flow in the brake pipe exceeds the predetermined threshold, an indication is provided to the train operator on a locomotive display.

8. The method according to claim 7, wherein: The brake pipe pressure-flow node determines whether the flow rate in the brake pipe exceeds the predetermined threshold based on a comparison of the flow rate in the brake pipe when the brake pipe is in a brake release pressure state and a brake apply pressure state.

9. The method according to claim 8, wherein The brake pipe pressure determines excess flow in the brake pipe based on whether the flow in the brake pipe with the brakes applied minus the flow in the brake pipe with the brakes released exceeds the predetermined threshold.

10. The method according to claim 9, wherein: The predetermined threshold represents an amount of braking in the brake pipe that would occur if thirty-five percent of all truck control valves coupled to the computer controlled brake had a faulty function.

11. The method according to claim 7, wherein: The brake pipe pressure-flow node determines whether the flow rate in the brake pipe exceeds the predetermined threshold based on whether the flow rate in the brake pipe in a brake applied state exceeds the predetermined threshold.

12. The method according to claim 11, wherein The predetermined threshold represents the flow in the brake pipe that would occur if thirty-five percent of all truck control valves coupled to the computer-controlled brakes had a malfunction.

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