State determination device, state determination method, and state determination program

Abstract

This technology provides a way to determine the state of air control valves and flow paths used in vehicle brakes without requiring any special operation. [Solution] The state determination device 100 is a state determination device 100 that determines the state of at least one of an air control valve and a flow path used in a vehicle brake, and the air control valve includes an acquisition unit 110 that discharges air at an output pressure corresponding to the input pressure, which is the pressure of the introduced air, into a supply flow path to the brake cylinder, acquires first measured values ​​of the input pressure and output pressure at one or more timings during the pressure-increasing period when the input pressure increases, and acquires second measured values ​​of the input pressure and output pressure at one or more timings during the pressure-reducing period when the input pressure decreases, a calculation unit 120 that calculates the difference between at least one of the input pressure and output pressure during the pressure-increasing period and the pressure-reducing period based on the first measured value and the second measured value, and a determination unit that determines the state of at least one of the air control valve and the flow path according to the difference.

Description

Technical Field

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[0001] The present invention relates to a state determination device, a state determination method, and a state determination program.

Background Art

[0002] In a braking device for a vehicle such as a railway vehicle, it is required to operate the brake safely and reliably. Therefore, it has been necessary to grasp the state of the flow path from the compressed air supply source to the brake cylinder and the state of the air control valve provided in the middle of the flow path. Further, Patent Document 1 describes a technique for correcting the hysteresis characteristics generated in the air control valve and maintaining a constant brake pressure with respect to a brake command.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, in order to perform inspection work on an air control valve or a flow path, it has been necessary to stop the operation of the vehicle, and the inspection work has required special operations such as opening and closing operations of a brake cock.

[0005] In view of the above problems, an object of the present invention is to provide a technique for determining the state of an air control valve and a flow path used in a vehicle brake without requiring special operations.

Means for Solving the Problems

[0006] To solve the above problems, a state determination device in one aspect of the present invention is a state determination device for determining the state of at least one of an air control valve and a flow path used in a vehicle brake, wherein the air control valve discharges air at an output pressure corresponding to an input pressure, which is the pressure of the introduced air, into a supply flow path to a brake cylinder, and acquires first measured values ​​of the input pressure and the output pressure at one or more timings during a pressure-increasing period in which the input pressure increases, and acquires second measured values ​​of the input pressure and the output pressure at one or more timings during a pressure-reducing period in which the input pressure decreases; a calculation unit calculates the difference between at least one of the input pressure and the output pressure during the pressure-increasing period and the pressure-reducing period based on the first measured value and the second measured value; and a determination unit determines the state of at least one of the air control valve and the flow path according to the difference.

[0007] To solve the above problems, a state determination method in one aspect of the present invention is a state determination method in which a state determination device determines the state of at least one of an air control valve and a flow path used in a vehicle brake, wherein the air control valve discharges air at an output pressure corresponding to an input pressure, which is the pressure of the introduced air, into a supply flow path to a brake cylinder, and acquires first measured values ​​of the input pressure and the output pressure at one or more timings during a pressure-increasing period in which the input pressure increases, and acquires second measured values ​​of the input pressure and the output pressure at one or more timings during a pressure-reducing period in which the input pressure decreases, and calculates the difference between at least one of the input pressure and the output pressure during the pressure-increasing period and the pressure-reducing period based on the first measured value and the second measured value, and determines the state of at least one of the air control valve and the flow path according to the difference.

[0008] A state determination program in one embodiment of the present invention is a program for determining the state of at least one of an air control valve and a flow path used in a vehicle brake, wherein the air control valve discharges air at an output pressure corresponding to an input pressure, which is the pressure of the introduced air, into a supply flow path to a brake cylinder, and the program causes a computer to perform the following steps: acquire first measured values ​​of the input pressure and the output pressure at one or more timings during a pressure-increasing period when the input pressure increases, acquire second measured values ​​of the input pressure and the output pressure at one or more timings during a pressure-reducing period when the input pressure decreases; calculate the difference between at least one of the input pressure and the output pressure during the pressure-increasing period and the pressure-reducing period based on the first measured value and the second measured value; and determine the state of at least one of the air control valve and the flow path according to the difference.

[0009] Furthermore, any combination of the above, or any substitution of the components or expressions of the present invention between methods, apparatus, programs, temporary or non-temporary storage media recording programs, systems, etc., are also valid embodiments of the present invention. [Effects of the Invention]

[0010] According to the present invention, a technology can be provided to determine the state of air control valves and flow paths used in vehicle brakes without requiring any special operations. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic side view showing a railway vehicle to which the brake control device according to this embodiment is applied. [Figure 2] This diagram schematically shows an example of a configuration related to the flow path in the brake system of a railway vehicle. [Figure 3] This is a block diagram showing the configuration of a brake control device and a state determination device. [Figure 4] This figure shows examples of the first and second measured values. [Figure 5] This figure shows other examples of the first and second measurement values. [Figure 6] This figure shows yet more examples of the first and second measurements. [Figure 7] This figure shows an example of a method for acquiring the first and second measurement values ​​by the acquisition unit. [Figure 8] This figure shows an example of how the difference changes over time. [Figure 9] This flowchart shows an example of a state determination process performed by a state determination device. [Figure 10] This flowchart shows an example of the process by which the state determination device determines the first and second thresholds. [Figure 11] This flowchart shows an example of the process for determining the degree of air leakage by a condition assessment device. [Figure 12] This diagram illustrates the judgment process shown in Figure 11. [Modes for carrying out the invention]

[0012] Among the embodiments disclosed herein, those composed of multiple objects may be integrated, and conversely, those composed of a single object may be divided into multiple objects. Whether or not they are integrated, the invention can be constructed in a way that achieves its objective.

[0013] In the embodiments disclosed herein, those in which multiple functions are provided in a distributed manner may have some or all of those multiple functions integrated into a single unit, and conversely, those in which multiple functions are integrated may have some or all of those functions provided in a distributed manner. Whether the functions are integrated or distributed, the configuration should be such that the objective of the invention can be achieved.

[0014] In addition, for separate constituent elements having common points, "first", "second", etc. are attached to the beginning of the name for distinction, and these are omitted when collectively referred to. Also, terms including ordinal numbers such as first and second are used to describe various constituent elements, but this term is used only for the purpose of distinguishing one constituent element from other constituent elements, and the constituent elements are not limited by this term.

[0015] Hereinafter, the present invention will be described with reference to each drawing based on preferred embodiments. In the embodiments and modified examples, the same or equivalent constituent elements and members are denoted by the same reference numerals, and repeated explanations are appropriately omitted. Also, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. In addition, some members that are not important for explaining the embodiments in each drawing are omitted from the display.

[0016] Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a side view schematically showing a railway vehicle 1 to which a brake control device for railway vehicles (hereinafter referred to as "brake control device 50") according to an embodiment is applied. First, an overview of the railway vehicle 1 will be described.

[0017] Each functional block shown in each figure including FIG. 1 can be realized hardware-wise by electronic elements and electronic circuits such as a computer's CPU and memory, and mechanical parts, and can be realized software-wise by a computer program or the like. Here, however, functional blocks realized by their cooperation are depicted. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by a combination of hardware and software.

[0018] As shown in Figure 1, the railway vehicle 1 mainly comprises a driver's cab 2, a first bogie 4, a second bogie 6, a brake mechanism 16, a compressed air supply source 8, a brake control device 50, a state determination device 100, and a pressure sensor 80. The driver's cab 2 is located at the front of the vehicle in the direction of travel. The first bogie 4 is located towards the front of the lower part of the vehicle. The second bogie 6 is located towards the rear of the lower part of the vehicle. The brake mechanism 16 is provided on both the first bogie 4 and the second bogie 6. The pressure sensor 80 is a collective term for the first pressure sensor 80a to the fourth pressure sensor 80d, which will be described later.

[0019] The compressed air supply source 8 is a tank that supplies compressed air, and the pressure inside the tank is maintained within a predetermined range by an air pump. The compressed air supply source 8 is connected to the flow path 20 (see Figure 3) and functions as a supply source that supplies compressed air to the flow path 20. The compressed air supply source 8 is an example of a fluid supply source, and the pressurized fluid supplied by the fluid supply source may be a gas such as air, nitrogen, or an inert gas, or a liquid such as water or oil. In the following explanation, compressed air will be used as the pressurized fluid.

[0020] The brake control device 50 comprises a control unit 52 and a brake pressure adjustment mechanism 54 that adjusts the pressure of the compressed air supplied to the brake mechanism 16 (hereinafter referred to as "brake pressure"). The control unit 52 controls the brake pressure adjustment mechanism 54 based on brake commands from the driver's cab 2. The brake control device 50 also transmits the measured value of a pressure sensor 80, which measures the pressure of the compressed air in the flow path 20, to a state determination device 100. Details of the brake control device 50 will be described later.

[0021] The first bogie 4 and the second bogie 6 each have two axles 10 spaced apart in the longitudinal direction. Wheels 12 are attached to both ends of the axles 10. The brake mechanism 16 operates in response to the applied brake pressure. The brake mechanism 16 includes a friction material 16s that generates braking force on the wheels 12 and a brake cylinder 16t that drives the friction material 16s.

[0022] The friction material 16s is, for example, a brake pad. The brake cylinder 16t is connected to the flow path 20 (see Figure 3). Compressed air with brake pressure is supplied through the flow path 20, causing the brake cylinder pressure to rise and the brake cylinder 16t to operate. When the brake cylinder 16t operates, the friction material 16s is pressed against the tread surface of the wheel 12, generating a braking force on the wheel 12.

[0023] The state determination device 100 determines the state of at least one of the air control valves and flow paths 20 used in railway vehicle brakes based on the measurement values ​​from the pressure sensor 80. The air control valves whose state is determined by the state determination device 100 are, for example, the load-sensitive valve 24 (see Figure 3) and the relay valve 28 (see Figure 3). Details of the state determination device 100 will be described later.

[0024] Figure 2 is a schematic diagram showing an example of the configuration related to the flow path 20 of the brake system of the railway vehicle 1. The flow path 20 is a supply passage for supplying compressed air. The flow path 20 is divided, for example, by a pipe made of metal or the like that partitions most of the flow path 20, and an air hose made of flexible resin or the like that connects the pipe to the brake cylinder 16t.

[0025] In addition to the compressed air supply source 8 and brake cylinder 16t mentioned above, the flow path 20 is connected to an air spring 22, a load-sensitive valve 24, a service brake control valve 14a, an emergency brake control valve 14b, a double check valve 26, and a relay valve 28. Furthermore, first pressure sensors 80a to fourth pressure sensors 80d are provided to measure the compressed air pressure at each position in the flow path 20.

[0026] The load-sensitive valve 24 generates a load-sensitive pressure using compressed air pressure supplied from the compressed air supply source 8, based on the pressure of the air springs 31 that support the railway vehicle 1. This load-sensitive pressure corresponds to the total weight of the railway vehicle 1, including the weight of the passengers. The load-sensitive valve 24 outputs compressed air with an output pressure corresponding to the input pressure, which is the pressure of the compressed air introduced from the air springs 31, to the supply passage for the emergency brake control valve 14b. There is a positive correlation between the input pressure to the load-sensitive valve 24 and the output pressure from the load-sensitive valve 24. That is, the larger the input pressure to the load-sensitive valve 24, the larger the output pressure from the load-sensitive valve 24, and the smaller the input pressure to the load-sensitive valve 24, the smaller the output pressure from the load-sensitive valve 24.

[0027] Based on the brake signal described later, the service brake control valve 14a generates a brake command pressure using compressed air supplied from the compressed air supply source 8 to generate the target braking force specified in the service brake command described later, and supplies it to the double check valve 26.

[0028] The emergency brake control valve 14b, in response to the cessation of the supply of the excitation signal described later, supplies the load-responsive pressure of the load-responsive valve 24 to the double check valve 26 as the emergency brake pressure to generate braking force for the emergency brake. The emergency brake control valve 14b in this embodiment is a valve that switches the internal air passage by energizing and demagnetizing an electromagnetic coil. Normally, the emergency brake control valve 14b is energized in response to the excitation signal described later, and the supply of load-responsive pressure from the load-responsive valve 24 is cut off. On the other hand, the emergency brake control valve 14b is demagnetized when the supply of the excitation signal from the brake control unit 58 of the brake control device 50 is stopped. As a result, the load-responsive pressure of the load-responsive valve 24 is supplied to the double check valve 26 as the emergency brake pressure through the emergency brake control valve 14b.

[0029] The double check valve 26 is a valve having two input ports and one output port. The double check valve 26 is configured to output the higher pressure to the output port when fluids of different pressures are supplied to each of the two input ports. One input port of the double check valve 26 is connected to the service brake control valve 14a, and the other input port is connected to the emergency brake control valve 14b. Therefore, the output port of the double check valve 26 outputs the higher of the brake command pressure from the service brake control valve 14a and the emergency brake pressure from the emergency brake control valve 14b.

[0030] The relay valve 28 uses compressed air from the compressed air supply source 8 to amplify the capacity of the brake command pressure or emergency brake pressure supplied via the double check valve 26. As a result, the amplified brake command pressure or emergency brake pressure is output. The brake pressure output from the relay valve 28 is supplied to the brake cylinder 16t via a sliding control valve (not shown), etc. The relay valve 28 outputs compressed air with an output pressure corresponding to the input pressure, which is the pressure of the compressed air introduced from the double check valve 26, to the supply passage to the brake cylinder 16t. There is a positive correlation between the input pressure to the relay valve 28 and the output pressure from the relay valve 28. That is, the larger the input pressure to the relay valve 28, the larger the output pressure from the relay valve 28, and the smaller the input pressure to the relay valve 28, the smaller the output pressure from the relay valve 28. Note that the relay valve 28 may be provided for each axle of the wheels 12.

[0031] The first pressure sensor 80a measures the pressure of the compressed air introduced into the load-sensitive valve 24. In the illustrated example, the first pressure sensor 80a is located in the flow path 20 between the air spring 22 and the load-sensitive valve 24. The second pressure sensor 80b measures the pressure of the compressed air discharged from the load-sensitive valve 24. In the illustrated example, the second pressure sensor 80b is located in the flow path 20 between the emergency brake control valve 14b and the double check valve 26. The third pressure sensor 80c measures the pressure of the compressed air introduced into the relay valve 28. In the illustrated example, the third pressure sensor 80c is located in the flow path 20 between the double check valve 26 and the relay valve 28. The fourth pressure sensor 80d assumes the pressure of the compressed air discharged from the relay valve 28. In the illustrated example, the fourth pressure sensor 80d is located in the flow path 20 between the relay valve 28 and the brake cylinder 16t.

[0032] Figure 3 is a block diagram showing the configuration of the brake control device 50 and the state determination device 100. As shown in Figure 3, the control unit 52 of the brake control device 50 includes a receiving unit 56, a brake control unit 58, and a transmitting unit 60. The brake pressure adjustment mechanism 54 includes a brake control valve 14. The brake control valve 14 is a collective term for the service brake control valve 14a and the emergency brake control valve 14b. The brake pressure adjustment mechanism 54 may further include other valves such as a slip control valve. The slip control valve is a valve mechanism that eliminates slippage by discharging air outside the flow path 20 to reduce the brake pressure when slippage occurs in the wheel 12 while the railway vehicle 1 is being braked by the brake mechanism 16.

[0033] The receiving unit 56 receives service brake commands and emergency brake commands as brake commands from the driver's cab 2. The service brake command is a command to operate the brake mechanism 16 so as to generate a specified target braking force in response to the brake operation. The emergency brake command is a command to operate the brake mechanism 16 in an emergency. The emergency brake command is supplied to the receiving unit 56 from the driver's cab 2 of the railway vehicle 1 in response to, for example, a brake operation by the driver or the reception of an emergency stop signal from an external device of the railway vehicle 1.

[0034] The receiving unit 56 further receives the pressure value of the compressed air in the flow path 20, which is a measurement value from the pressure sensor 80.

[0035] The brake control unit 58 responds to a service brake command by setting a target braking force and controlling the brake control valve 14 to generate that target braking force. For example, the brake control unit 58 sets the braking force specified in the service brake command as the target braking force and supplies a brake signal to the service brake control valve 14a to generate this set target braking force. When the brake control unit 58 has not received an emergency brake command, it supplies an excitation signal to the emergency brake control valve 14b, thereby exciting the emergency brake control valve 14b and shutting off the supply of emergency brake pressure to the brake cylinder 16t at the emergency brake control valve 14b. The brake control unit 58 responds to an emergency brake command by setting a predetermined braking force as the target braking force and controlling the brake control valve 14 to generate that target braking force. For example, in response to an emergency brake command, the brake control unit 58 demagnetizes the emergency brake control valve 14b by stopping the supply of an excitation signal to the emergency brake control valve 14b, thereby supplying the amplified emergency brake pressure to the brake cylinder 16t via the emergency brake control valve 14b. This sets a predetermined braking force for emergency braking as the target braking force.

[0036] The transmitting unit 60 transmits the measurement values ​​from the pressure sensor 80 received by the receiving unit 56 to the state determination device 100.

[0037] The state determination device 100 comprises an acquisition unit 110, a calculation unit 120, a determination unit 130, and a storage unit 140.

[0038] The acquisition unit 110 acquires the measured values ​​of the pressure sensors 80. Specifically, the acquisition unit 110 acquires the measured value of the first pressure sensor 80a as the input pressure to the load-sensitive valve 24, and the measured value of the second pressure sensor 80b as the output pressure from the load-sensitive valve 24. The acquisition unit 110 also acquires the measured value of the third pressure sensor 80c as the input pressure to the relay valve 28, and the measured value of the fourth pressure sensor 80d as the output pressure from the relay valve 28. Hereafter, the measured value of the first pressure sensor 80a, which is the input pressure to the load-sensitive valve 24, will be simply referred to as the input pressure, and the measured value of the second pressure sensor 80b, which is the output pressure from the load-sensitive valve 24, will be simply referred to as the output pressure. The same applies to the measured value of the third pressure sensor 80c, which is the input pressure to the relay valve 28, and the measured value of the fourth pressure sensor 80d, which is the output pressure from the relay valve 28.

[0039] The acquisition unit 110 acquires measured values ​​of input pressure and output pressure (hereinafter referred to as "first measured values") at one or more timings during the pressure-boosting period when the input pressure increases. The acquisition unit 110 also acquires measured values ​​of input pressure and output pressure (hereinafter referred to as "second measured values") at one or more timings during the pressure-reducing period when the input pressure decreases. The pressure-boosting period may be a period in which the input pressure increases continuously or a period in which it increases intermittently. Similarly, the pressure-reducing period may be a period in which the input pressure decreases continuously or an intermittent period. As described above, there is a positive correlation between input pressure and output pressure, so the output pressure also increases during the pressure-boosting period and decreases during the pressure-reducing period.

[0040] The calculation unit 120 calculates the difference between at least one of the input pressure and output pressure during the pressure-increasing period and the pressure-reducing period, based on the first and second measurement values ​​obtained by the acquisition unit 110. Then, the determination unit 130 determines the state of at least one of the relay valve 28 and the flow path 20 according to the difference calculated by the calculation unit 120. Details of the calculation unit 120 and the determination unit 130 will be described later.

[0041] The storage unit 140 stores various types of data. For example, the storage unit 140 stores the first measured value, the second measured value, the difference calculated by the calculation unit 120, etc. The storage unit 140 also stores the first threshold and the second threshold, which will be described later. In addition to the above data, the storage unit 140 may also be a data logger that monitors and records various data related to brake operation in real time, such as brake operation history, brake pressure, temperature, speed, and acceleration.

[0042] Here, we will explain examples of the first and second measured values ​​with reference to Figures 4 to 6. Figure 4 shows an example of the first measured values ​​92a to 92f and the second measured values ​​94a to 94f. In Figure 4, the horizontal axis represents the input pressure Pin, and the vertical axis represents the output pressure Pout. This is also the case for Figures 5 and 6. Hereafter, the first measured values ​​92a to 92f will be collectively referred to as the first measured value 92, and the second measured values ​​94a to 94f will be collectively referred to as the second measured value 94.

[0043] Each of the first measurement values ​​92a to 92f is acquired at different timings during the pressure-boosting period. That is, the acquisition unit 110 acquires the first measurement value 92 at multiple timings during the pressure-boosting period. Similarly, each of the second measurement values ​​94a to 94f is acquired at different timings during the pressure-reducing period. That is, the acquisition unit 110 acquires the second measurement value 94 at multiple timings during the pressure-reducing period. The multiple timings at which the first measurement value 92 and the second measurement value 94 are acquired may be different timings in a single operation, or they may be predetermined timings in different operations. For example, the acquisition unit 110 may acquire one first measurement value 92 during the pressure-boosting period and one second measurement value 94 during the pressure-reducing period in a single operation, and acquire multiple first measurement value 92 and second measurement value 94 over multiple operations. Furthermore, the acquisition unit 110 may acquire the first measurement value 92 and the second measurement value 94 in accordance with normal brake operation, or when executing an operation mode for data acquisition.

[0044] As shown in Figure 4, the calculation unit 120 calculates the difference D based on the first approximation line 96, which is the approximation line for the first measurement value 92, and the second approximation line 98, which is the approximation line for the second measurement value 94. The first approximation line 96 is calculated, for example, by the least squares method for the first measurement values ​​92a to 92f. Similarly, the second approximation line 98 is calculated, for example, by the least squares method for the second measurement values ​​94a to 94f. The difference D is the difference between the first approximation line 96 and the second approximation line 98, and in the example shown in Figure 4, it is the difference in output pressure Pout when the input pressure Pin takes a predetermined value in the first approximation line 96 and the second approximation line 98. The difference D may also be the difference in input pressure Pin when the output pressure Pout takes a predetermined value in the first approximation line 96 and the second approximation line 98. Alternatively, the difference D may be the shortest distance between the first approximation line 96 and the second approximation line 98.

[0045] Here, we will explain the difference D. As shown in Figure 4, the first approximate line 96, which is an approximate line of the first measurement value 92 obtained during the pressure-boosting period, has a smaller output pressure Pout for the same input pressure Pin than the second approximate line 98, which is an approximate line of the second measurement value 94 obtained during the pressure-reducing period. This is because the response of the output pressure Pout to the change in input pressure Pin is delayed due to the influence of the operating resistance of the movable part of the load-sensitive valve 24. In other words, during the pressure-boosting period, the increase in output pressure Pout lags behind the increase in input pressure Pin, whereas during the pressure-reducing period, the decrease in output pressure Pout lags behind the decrease in input pressure Pin, and this difference appears as the difference D. This property is also called hysteresis characteristic. The same applies to the relay valve 28.

[0046] Figure 5 shows other examples of the first measurement value 92 and the second measurement value 94. Explanations of points common to Figure 4 will be omitted as appropriate. In the example shown in Figure 5, the difference D is smaller than in the example shown in Figure 4. This is thought to be because air leakage occurs in the flow path 20, which reduces the pressure applied to the load-sensitive valve 24, and the difference in the movement of the load-sensitive valve 24 during the pressure-increasing process and the pressure-decreasing process becomes smaller, thereby reducing the hysteresis characteristics of the load-sensitive valve 24.

[0047] Figure 6 shows yet another example of the first measurement value 92 and the second measurement value 94. Explanations of matters common to Figure 4 will be omitted as appropriate. In the example shown in Figure 6, the difference D is larger than in the example shown in Figure 4. This is thought to be because stiffness occurs in the load-sensitive valve 24, increasing the operating resistance of the load-sensitive valve 24 and thus increasing the hysteresis characteristics of the load-sensitive valve 24. Here, stiffness refers to a state in which smooth movement is hindered due to the sticking of the movable part of the air control valve.

[0048] The properties described above using Figures 4 to 6 can be used in the determination of the determination unit 130. Figure 4 assumes that the first measurement value 92 and the second measurement value 94 are normal for the flow path 20 and the load-sensitive valve 24. In this case, since the difference D in Figure 4 is a normal value, the determination unit 130 may determine that air leakage has occurred in the flow path 20 if the difference D is less than a predetermined value (referred to as the "first threshold") which is smaller than the normal value, as shown in Figure 5, for example. Alternatively, the determination unit 130 may determine that stiffness has occurred in the load-sensitive valve 24 if the difference D is greater than a predetermined value (referred to as the "second threshold") which is larger than the normal value, as shown in Figure 4, for example. The first threshold and the second threshold can be set arbitrarily.

[0049] As a normal value for difference D, for example, a difference D based on a first measurement value 92 and a second measurement value 94 acquired over a predetermined period, for example several months, starting from immediately after use, maintenance, or replacement of the load-sensitive valve 24 and the flow path 20 can be used. Then, in a subsequent period, the determination unit 130 may determine whether the difference D based on the first measurement value 92 and the second measurement value 94 acquired over the most recent predetermined period, for example several months, is smaller than the first threshold or larger than the second threshold.

[0050] Figure 7 shows an example of a method for acquiring first measurement values ​​92 and second measurement values ​​94 by the acquisition unit 110. In Figure 7, the horizontal axis represents time, and the vertical axis represents the target braking force of the service brake command. In the example shown in Figure 7, during the pressure-boosting period in which the target braking force is increased in stages, the acquisition unit 110 acquires the first measurement value 92 at the timing of each stage. Subsequently, during the pressure-reducing period in which the target braking force is decreased in stages, the acquisition unit 110 acquires the second measurement value 94 at the timing of each stage. This makes it possible to acquire multiple first measurement values ​​92 and multiple second measurement values ​​94 in a single cycle of pressure-boosting and pressure-reducing periods.

[0051] Furthermore, the acquisition unit 110 may acquire the first measurement value 92 and the second measurement value 94 at each timing shown in Figure 7 when the railway vehicle 1 is released from the depot. Since the departure of the railway vehicle 1 is likely to be approximately on schedule, the influence of environmental factors such as temperature on the acquired first measurement value 92 and second measurement value 94 can be reduced. The example shown in Figure 7 may be performed by braking by the driver, or it may be a mode that is automatically executed for data acquisition by the acquisition unit 110.

[0052] The acquisition unit 110 may acquire the first measurement value 92 and the second measurement value 94 when the railway vehicle 1 is moving at a predetermined speed or less. In this way, when the railway vehicle 1 is operating at a low speed, the brake pressure tends to be relatively stable, so the variation in the first measurement value 92 and the second measurement value 94 can be reduced.

[0053] Figure 8 shows an example of the time change of difference D. In Figure 8, the horizontal axis represents time, and the vertical axis represents difference D. When difference D based on the first measurement value 92 and the second measurement value 94 acquired over a predetermined period, for example several months, is repeatedly stored in the storage unit 140, multiple difference D values ​​can be plotted at different positions on the time axis, as shown in Figure 8. In the example shown in Figure 8, the difference D, which is initially located near the reference value, gradually decreases over time and falls below the first threshold. In this case, the determination unit 130 determines that an air leak has occurred in the flow path 20 when the difference D falls below the first threshold. Note that since the difference D has been gradually decreasing since before it fell below the first threshold, the determination unit 130 may also determine that an air leak is likely to occur in the flow path 20 based on the change in difference D, even before the difference D falls below the first threshold. Similarly, if the difference D is gradually increasing, the determination unit 130 may also determine that stiffness is likely to occur in the load-sensitive valve 24 based on the change in difference D, even before the difference D exceeds the second threshold.

[0054] Figure 9 is a flowchart showing an example of the state determination process by the state determination device 100. The acquisition unit 110 acquires the first measurement value 92 and the second measurement value 94 and stores them in the storage unit 140 (S10). The timing of the acquisition unit 110 acquiring the first measurement value 92 and the second measurement value 94 is as described above.

[0055] If it is not time for the determination unit 130 to make a determination (N in S12), the process returns to step S10. In other words, until it is time for the determination unit 130 to make a determination, the acquisition unit 110 acquires the first measurement value 92 and the second measurement value 94, and stores them in the storage unit 140. The timing for the determination unit 130 to make a determination may be at predetermined intervals, for example, every few months, or when a certain number of measurement values ​​have been accumulated, or when there is an operation by the driver. When it is time for the determination unit 130 to make a determination (Y in S12), the process proceeds to step S14.

[0056] The calculation unit 120 calculates a first approximate line 96, which is an approximate line of the first measurement value 92, and a second approximate line 98, which is an approximate line of the second measurement value 94 (S14). Here, the first measurement value 92 and the second measurement value 94 used in calculating the first approximate line 96 and the second approximate line 98 may be measurement values ​​obtained since the previous state determination process. That is, the state determination process is performed on measurement values ​​obtained in the most recent predetermined period.

[0057] The calculation unit 120 calculates the difference D based on the first approximation line 96 and the second approximation line 98 (S16). The determination unit 130 determines that an air leak has occurred in the flow path 20 if the difference D is less than the first threshold (Y in S18) (S20). On the other hand, the determination unit 130 determines that a sticking has occurred in the air control valve if the difference D is greater than or equal to the first threshold (N in S18) and greater than or equal to the second threshold (Y in S22) (S24). The determination unit 130 determines that the flow path 20 and the air control valve are normal if the difference D is greater than or equal to the first threshold (N in S18) and less than or equal to the second threshold (N in S22) (S26).

[0058] Figure 10 is a flowchart showing an example of the process for determining the first and second thresholds by the state determination device 100. The acquisition unit 110 acquires the first measurement value 92 and the second measurement value 94 and stores them in the storage unit 140 (S40). The first measurement value 92 and the second measurement value 94 used in this determination process may be the same measurement values ​​as the first measurement value 92 and the second measurement value 94 used to calculate the normal value of the difference D described above. That is, the first measurement value 92 and the second measurement value 94 are acquired during a period in which there is a high probability that the flow path 20 and the air control valve are normal.

[0059] If it is not time for the calculation unit 120 to calculate the threshold (N in S42), the process returns to step S40. In other words, until it is time for the calculation unit 120 to calculate the threshold, the acquisition unit 110 acquires the first measurement value 92 and the second measurement value 94, and these are stored in the storage unit 140. The timing for the calculation unit 120 to calculate the threshold may be after a predetermined period, for example, several months, or when a certain number of measurement values ​​have been accumulated, or when there is an operation by the driver. When it is time for the calculation unit 120 to calculate the threshold (Y in S42), the process proceeds to step S44.

[0060] The calculation unit 120 calculates a first approximation line 96, which is an approximation line for the first measurement value 92, and a second approximation line 98, which is an approximation line for the second measurement value 94 (S44). The calculation unit 120 calculates the difference D based on the first approximation line 96 and the second approximation line 98 (S46). Then, the calculation unit 120 takes the difference D calculated in step S46 as the normal value and determines the first threshold and the second threshold based on this difference D (S48). In other words, as described above, the first threshold is a value smaller than the difference D, and the second threshold is a value larger than the difference D.

[0061] Figure 11 is a flowchart showing an example of the process for determining the degree of air leakage by the condition determination device 100. This process is executed after the determination unit 130 determines that air leakage is occurring in the flow path 20.

[0062] First, based on the brake command, the system transitions from a depressurization period in which the input pressure Pin decreases to a period in which the system stabilizes at a predetermined input pressure Pin_1 (S60). Subsequently, the state determination device 100 monitors the time change of the output pressure Pout while the system is stabilizing at the input pressure Pin_1 (S62). The determination unit 130 determines the degree of air leakage in the flow path 20 based on the time change of the output pressure Pout.

[0063] Figure 12 is a diagram illustrating the determination process in Figure 11. In Figure 12, the horizontal axis represents time, and the vertical axis represents the output pressure Pout. In Figure 12, the state change explained in step S60 is shown with a dashed line, and the state change from the pressure-boosting period to the period of stabilization at input pressure Pin_1 is shown with a solid line for comparison. As shown in Figure 12, the output pressure Pout immediately after transitioning from the pressure-reducing period to the period of stabilization at input pressure Pin_1 is greater than the output pressure Pout immediately after transitioning from the pressure-boosting period to the period of stabilization at input pressure Pin_1 due to the influence of hysteresis characteristics. However, when transitioning from the pressure-reducing period to the period of stabilization at input pressure Pin_1, the output pressure Pout gradually decreases due to air leakage. The determination unit 130 can then determine that the shorter the time until the output pressure Pout in both states becomes equal, the greater the degree of air leakage. This allows for the determination of urgency according to the degree of air leakage.

[0064] As described above, the state determination device 100 of this embodiment is a state determination device 100 that determines the state of at least one of an air control valve and a flow path 20 used in a vehicle brake, and the air control valve includes an acquisition unit 110 that discharges air with an output pressure Pout corresponding to an input pressure Pin, which is the pressure of the introduced air, into a supply flow path to a brake cylinder 16t, acquires first measured values ​​92 of the input pressure Pin and output pressure Pout at one or more timings during a pressure-increasing period when the input pressure Pin increases, and acquires second measured values ​​94 of the input pressure Pin and output pressure Pout at one or more timings during a pressure-reducing period when the input pressure Pin decreases, a calculation unit 120 that calculates the difference D of at least one of the input pressure Pin and output pressure Pout during the pressure-increasing period and the pressure-reducing period based on the first measured value 92 and the second measured value 94, and a determination unit 130 that determines the state of at least one of the air control valve and the flow path 20 according to the difference D.

[0065] This makes it possible to determine the state of at least one of the air control valve and the flow path 20 used in vehicle brakes simply by acquiring measurement values ​​during the pressure-increasing period and the pressure-reducing period, without requiring any special operations.

[0066] In the state determination device 100, the acquisition unit 110 may acquire a first measurement value 92 at multiple timings during the pressure increase period and a second measurement value 94 at multiple timings during the pressure decrease period, and the calculation unit 120 may calculate the difference D based on a first approximate line 96 for the first measurement value 92 and a second approximate line 98 for the second measurement value 94 in a coordinate plane with input pressure Pin and output pressure Pout as two axes. As a result, since the difference D is calculated based on the first measurement value 92 and the second measurement value 94 acquired at multiple timings, the influence of measurement variability and measurement errors can be reduced compared to calculating the difference D based on the first measurement value 92 and the second measurement value 94 acquired at a single timing. Therefore, the accuracy of the determination can be further improved.

[0067] In the state determination device 100, the determination unit 130 may determine that an air leak has occurred in the flow path 20 if the difference D is less than the first threshold. This allows for accident prevention by taking measures against air leaks, such as repairing the piping.

[0068] In the state determination device 100, the determination unit 130 may determine that the air control valve is stuck if the difference D exceeds the second threshold. This allows for the prevention of accidents by taking measures against the air control valve's stuckness, such as replacing the air control valve.

[0069] The state determination device 100 may further include a storage unit 140 that stores and stores the difference D calculated by the calculation unit 120. This allows the storage unit 140 to store the difference D and use it for analysis of the change in the difference over time, etc.

[0070] In the state determination device 100, the acquisition unit 110 may acquire the first measurement value 92 and the second measurement value 94 when the railway vehicle 1 is being taken out of the depot or when the railway vehicle 1 is moving at a predetermined speed or below. If the data is acquired when the railway vehicle 1 is being taken out of the depot, for example, environmental factors such as temperature will be similar if the vehicle is taken out at a fixed time every day, thus reducing the influence of environmental factors on the measurement values. Also, if the data is acquired when the railway vehicle 1 is moving at a predetermined speed or below, the brake pressure tends to be relatively stable, thus reducing the variability of the measurement values.

[0071] The embodiments of the present invention have been described in detail above. The embodiments described above are merely examples of how to implement the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes, such as changes, additions, and deletions of components, are possible as long as they do not depart from the spirit of the invention as defined in the claims. In the embodiments described above, such design changes are described with notations such as "of the embodiments" or "in the embodiments," but design changes may also be permitted in contents without such notations.

[0072] [Differentiation] The following describes modified examples. In the drawings and descriptions of the modified examples, components and parts that are the same or equivalent as those in the embodiments are denoted by the same reference numerals. Descriptions that overlap with those in the embodiments will be omitted as appropriate, and the descriptions will focus on the configurations that differ from those in the embodiments.

[0073] In the description of the embodiment, an example was shown in which one brake control device 50 and one state determination device 100 are provided for each railway vehicle 1, but the invention is not limited to this. For example, multiple brake control devices 50 and multiple state determination devices 100 may be provided for each railway vehicle 1. Also, one state determination device 100 may be provided for multiple railway vehicles 1, in which case it may receive measurement values ​​from the pressure sensor 80 from each of the multiple brake control devices 50.

[0074] Furthermore, the state determination device 100 may be provided as a function of the control unit 52 of the brake control device 50. In this case, the control unit 52 does not need to include the transmission unit 60.

[0075] Furthermore, the first and second thresholds of the difference D do not necessarily have to be determined based on the first measurement value 92 and the second measurement value 94. For example, the first and second thresholds may be values ​​that have been prepared in advance before the state determination device 100 was shipped.

[0076] The modifications described above produce the same functions and effects as each embodiment.

[0077] Any combination of the embodiments and modifications described above is also useful as an embodiment of the present invention. The new embodiments resulting from these combinations possess the combined effects of the respective embodiments and modifications.

[0078] In the embodiments disclosed herein, those in which multiple functions are provided in a distributed manner may have some or all of those multiple functions integrated into a single unit, and conversely, those in which multiple functions are integrated may have some or all of those functions provided in a distributed manner. Whether the functions are integrated or distributed, the configuration should be such that the objective of the invention can be achieved. [Explanation of Symbols]

[0079] 1 Railway vehicle, 8 Compressed air supply source, 16t Brake cylinder, 20 Flow path, 24 Load-sensitive valve, 28 Relay valve, 50 Brake control device, 80 Pressure sensor, 92 First measurement value, 94 Second measurement value, 96 First approximate straight line, 98 Second approximate straight line, 100 State determination device, 110 Acquisition unit, 120 Calculation unit, 130 Determination unit, 140 Storage unit.

Claims

1. A condition determination device for determining the state of at least one of an air control valve and a flow path used in vehicle brakes, The aforementioned air control valve discharges air at an output pressure corresponding to the input pressure, which is the pressure of the introduced air, into the supply passage to the brake cylinder. An acquisition unit that acquires first measured values ​​of the input pressure and the output pressure at one or more timings during the pressure-boosting period when the input pressure increases, and acquires second measured values ​​of the input pressure and the output pressure at one or more timings during the pressure-reducing period when the input pressure decreases, A calculation unit that calculates the difference between at least one of the input pressure and the output pressure during the pressure-increasing period and the pressure-reducing period, based on the first measurement value and the second measurement value, A determination unit that determines the state of at least one of the air control valve and the flow path according to the difference, A state determination device equipped with the following features.

2. The acquisition unit acquires the first measurement value at multiple timings during the pressure-increasing period and acquires the second measurement value at multiple timings during the pressure-reducing period. The calculation unit calculates the difference based on the approximate straight line of the first measurement and the approximate straight line of the second measurement in a coordinate plane with the input pressure and output pressure as two axes. The state determination device according to claim 1.

3. The determination unit determines that if the difference is less than the first threshold, an air leak has occurred in the flow path. The state determination device according to claim 1.

4. The determination unit determines that if the difference exceeds the second threshold, then stiffness has occurred in the air control valve. The state determination device according to claim 1.

5. The system further includes a storage unit that stores and stores the difference calculated by the calculation unit. The state determination device according to claim 1.

6. The acquisition unit acquires the first measurement value and the second measurement value when the vehicle leaves the parking lot or when the vehicle is moving at a predetermined speed or less. The state determination device according to claim 1.

7. If the determination unit determines that an air leak has occurred in the flow path, it determines the degree of air leak based on the time change of the output pressure after transitioning from the depressurization period to the period during which the input pressure is stabilized at a predetermined level. The state determination device according to claim 3.

8. A condition determination method in which a condition determination device determines the state of at least one of an air control valve and a flow path used in a vehicle brake, The aforementioned air control valve discharges air at an output pressure corresponding to the input pressure, which is the pressure of the introduced air, into the supply passage to the brake cylinder. The steps include: acquiring first measured values ​​of the input pressure and output pressure at one or more timings during the pressure-boosting period when the input pressure increases, and acquiring second measured values ​​of the input pressure and output pressure at one or more timings during the pressure-reducing period when the input pressure decreases; A step of calculating the difference between at least one of the input pressure and the output pressure during the pressure-increasing period and the pressure-reducing period, based on the first measurement value and the second measurement value. A step of determining the state of at least one of the air control valve and the flow path according to the difference, A method for determining the state, including the following.

9. A state determination program for determining the state of at least one of an air control valve and a flow path used in vehicle brakes, The aforementioned air control valve discharges air at an output pressure corresponding to the input pressure, which is the pressure of the introduced air, into the supply passage to the brake cylinder. The steps include: acquiring first measured values ​​of the input pressure and output pressure at one or more timings during the pressure-boosting period when the input pressure increases, and acquiring second measured values ​​of the input pressure and output pressure at one or more timings during the pressure-reducing period when the input pressure decreases; A step of calculating the difference between at least one of the input pressure and the output pressure during the pressure-increasing period and the pressure-reducing period, based on the first measurement value and the second measurement value. A step of determining the state of at least one of the air control valve and the flow path according to the difference, A state determination program to cause a computer to execute a command.

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