Deterioration determination device and method

Description

[Technical field]

[0001] The present disclosure relates to a deterioration determination device and a deterioration determination method. [Background technology]

[0002] A control device that controls on-board devices mounted on a railway vehicle has multiple boards on which various control circuits are formed. The control device may be installed in an environment where it comes into contact with corrosive gas that corrodes the metal forming the wiring pattern of the board, such as under the floor or on the roof of a car body. Patent Document 1 discloses an example of a detection device that detects metal corrosion to prevent failure of the control device. The corrosion monitoring device disclosed in Patent Document 1 has an exposed copper pattern and is equipped with a sensor that determines whether the pattern has corroded and broken.

[0003] The corrosion monitoring device disclosed in Patent Document 1 detects when the exposed copper pattern of the sensor corrodes and breaks, making it possible to detect deterioration of the board before the wiring pattern covered with the solder resist and coating material corrodes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-358429 A Summary of the Invention [Problem to be solved by the invention]

[0005] Since the progress of metal corrosion caused by a corrosive gas varies depending on the concentration of the corrosive gas, it is preferable to detect the concentration of the corrosive gas in order to accurately detect signs of corrosion before the corrosion of the wiring pattern occurs. The corrosion monitoring device disclosed in Patent Document 1 can detect the occurrence of disconnection of the exposed copper pattern, which occurs before the corrosion of the wiring pattern, but cannot obtain the concentration of the corrosive gas.

[0006] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a deterioration determination device and a deterioration determination method that accurately determine the presence or absence of signs of deterioration in a substrate by estimating the concentration of a corrosive gas. [Means for solving the problem]

[0007] In order to achieve the above object, the deterioration determination device of the present disclosure includes a corrosion amount acquisition unit, a concentration estimation unit, and a deterioration determination unit. The corrosion amount acquisition unit acquires the amount of reduction in thickness of a metal thin film formed of a metal member that corrodes upon contact with a corrosive gas and is provided on any one of a number of substrates of an electronic device mounted on the railway vehicle, during an estimated period beginning from the start of operation of the railway vehicle. The concentration estimation unit estimates the amount of reduction in thickness of the metal thin film during the estimated period acquired by the corrosion amount acquisition unit, and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member. , rot The deterioration determination unit determines whether or not there is a sign of deterioration of a circuit board of the electronic device based on the length of the estimation period and the concentration of the corrosive gas estimated by the concentration estimation unit. Effect of the Invention

[0008] A deterioration determination device according to the present disclosure estimates a concentration of a corrosive gas. The deterioration determination device determines whether or not there is a sign of deterioration of a board of an electronic device based on the length of an estimation period and the concentration of the corrosive gas, thereby making it possible to accurately determine whether or not there is a sign of deterioration of the board. [Brief description of the drawings]

[0009] [Figure 1] Block diagram of a deterioration determination device according to a first embodiment. [Diagram 2] FIG. 1 is an exploded perspective view of an electronic device including a substrate that is to be discriminated by the deterioration discriminating device according to a first embodiment; [Diagram 3] FIG. 1 is a diagram showing an example of implementation of a deterioration determination device according to a first embodiment. [Figure 4] FIG. 1 is a diagram showing a hardware configuration of a deterioration determination device according to a first embodiment. [Diagram 5]1 is a flowchart showing an example of the operation of a deterioration sign determination process performed by the deterioration determination device according to the first embodiment. [Figure 6] FIG. 1 is a diagram showing an example of changes over time in the concentration of a corrosive gas and the thickness of a metal in the first embodiment. [Figure 7] FIG. 1 is a diagram showing an example of a monitoring device that outputs a determination result of the deterioration determination device according to the first embodiment. [Figure 8] FIG. 13 is a diagram showing an example of implementation of a deterioration determination device according to a second embodiment. [Figure 9] FIG. 13 is a diagram showing a modification of the hardware configuration of the deterioration determination device according to the embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A deterioration determination device and a deterioration determination method according to embodiments of the present disclosure will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0011] (Embodiment 1) An example of an electronic device having a substrate on which a wiring pattern is formed is a control device that controls on-board devices mounted on a railway vehicle. One example of the control device is a device that converts supplied power into power for supplying to an electric motor and controls a power converter that supplies the converted power to the electric motor. The control device is installed in a location exposed to the outside air, such as under the floor or on the roof of the railway vehicle.

[0012] When the outside air contains a corrosive gas that corrodes metal, the wiring pattern formed on a board of a control device that is installed in a location exposed to the outside air may corrode. Since deterioration of the board, including corrosion of the wiring pattern, is one of the causes of failure of the control device, the deterioration determination device 1 according to the first embodiment shown in FIG. 1 determines whether there is a sign of deterioration of the control device.

[0013] The deterioration determination device 1 includes a corrosion amount acquisition unit 11 that acquires the amount of reduction in the thickness of the metal thin film during an estimation period from the measurement value of a corrosion sensor 10 provided on a board included in the control board, a concentration estimation unit 12 that estimates the concentration of corrosive gas around the railcar from the amount of reduction in the thickness of the metal thin film, and a deterioration determination unit 13 that determines the presence or absence of signs of deterioration of the board from the length of the estimation period and the concentration of the corrosive gas. The deterioration determination device 1 sends the determination result of the deterioration determination unit 13 to a monitoring device 71 provided in, for example, the driver's cab.

[0014] An example of a control device for which the deterioration determination device 1 determines whether or not there is a sign of deterioration is shown in Fig. 2. The control device 50 includes a subrack 51 fixed to an underfloor of a railway vehicle by a fixing member (not shown), and a backplane 52 accommodated in the subrack 51. The subrack 51 has a box-like shape with an opening formed on one side. A plurality of slots 53, 54, 55, and 56 are formed in the backplane 52. The slots 53, 54, 55, and 56 are connected to each other by power supply lines, signal lines, etc. (not shown).

[0015] The control device 50 further includes plug-in units 61, 62, 63, and 64 respectively connected to the slots 53, 54, 55, and 56. The plug-in units 61, 62, 63, and 64 each include front panels 61a, 62a, 63a, and 64a to which cables (not shown) are connected, connectors 61b, 62b, 63b, and 64b attached to the slots 53, 54, 55, and 56, and substrates 61c, 62c, 63c, and 64c on which electronic circuits are mounted.

[0016] It is preferable that the deterioration determination device 1 determines the presence or absence of signs of deterioration for boards 62c, 63c, 64c according to the measurement value of the corrosion sensor 10 provided on the plug-in unit located at the end in the arrangement direction of the plug-in units 61, 62, 63, 64, for example, board 61c of the plug-in unit 61. In this case, board 61c is a board provided for deterioration determination, and the other boards 62c, 63c, 64c are boards on which control circuits for controlling in-vehicle devices are formed.

[0017] 3, the deterioration determination device 1 is realized by a deterioration determination module 2 formed on a substrate 61c. The corrosion sensor 10 is provided on the substrate 61c. The corrosion sensor 10 has a thin metal film 21 formed on the substrate 61c, a resistor 22 connected in series to the thin metal film 21 on the substrate 61c, and a resistance determination circuit 23 that determines a combined resistance value of the thin metal film 21 and the resistor 22.

[0018] The thin metal film 21 is made of a metal member, such as silver, that corrodes when it comes into contact with a corrosive gas, such as hydrogen sulfide. The thickness of the thin metal film 21 is thinner than the thickness of the metal member forming the wiring patterns provided on the boards 62c, 63c, and 64c of the other plug-in units 62, 63, and 64, specifically, the thickness of the silver plating, and is, for example, 100 nm.

[0019] The resistor 22 is made of a material having higher resistance to corrosive gases than the thin metal film 21, for example, copper whose surface is plated with tin, nickel, or the like.

[0020] The resistance determination circuit 23 has a power source, for example a constant current source, and passes a current through a circuit formed by the metal thin film 21 and resistor 22 connected in series, and determines a combined resistance value of the metal thin film 21 and resistor 22 from the voltage applied to the circuit and the current flowing through the circuit. The resistance determination circuit 23 sends the determined combined resistance value to the corrosion amount acquisition unit 11.

[0021] When the concentration of corrosive gas is significantly different between the area where the manufacturing factory of the railway vehicle is located and the area where the railway vehicle actually runs, it is preferable to determine the presence or absence of signs of deterioration of the substrates 62c, 63c, 64c according to the concentration of the corrosive gas after the railway vehicle moves to the running area. Therefore, the corrosion amount acquisition unit 11 obtains the amount of reduction in the thickness of the metal thin film 21 during an estimated period starting from the start of operation of the railway vehicle. The start of operation of the railway vehicle is, for example, the time when a switch for instructing the start of operation, which is provided in the driver's cab, is operated after the railway vehicle is transported from the factory to the running area. When the corrosion amount acquisition unit 11 receives an operation start signal that is output in response to the operation of the switch and instructs the start of operation, it regards the time when the operation start signal was received as the start of the estimated period. The corrosion amount acquisition unit 11 obtains the length of time from the time when the operation start signal was received to the current time, and sends it to the concentration estimation unit 12 and the deterioration determination unit 13 as the length of the estimated period.

[0022] Since the combined resistance value of the metal thin film 21 and resistor 22 varies depending on the cross-sectional area of ​​the metal thin film 21, the corrosion amount acquisition unit 11 estimates the thickness of the metal thin film 21 from the combined resistance value acquired from the resistance determination circuit 23. The corrosion amount acquisition unit 11 obtains the amount of reduction in the thickness of the metal thin film 21 during the estimated period, which is the difference between the thickness of the metal thin film 21 at the time of its formation and the thickness of the metal thin film 21 estimated from the combined resistance value. Note that the corrosion amount acquisition unit 11 previously holds information about the thickness of the metal thin film 21 at the time of its formation.

[0023] The concentration estimation unit 12 estimates the concentration of the corrosive gas around the railway vehicle from the amount of decrease in the thickness of the thin metal film 21 during the estimation period acquired from the corrosion amount acquisition unit 11 and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member that forms the thin metal film 21. The concentration estimation unit 12 sends the estimated concentration of the corrosive gas to the deterioration determination unit 13.

[0024] The deterioration determination unit 13 determines whether or not there is a sign of deterioration for the boards 62c, 63c, 64c, based on the length of the estimated period obtained by the corrosion amount acquisition unit 11 and the concentration of the corrosive gas estimated by the concentration estimation unit 12. In detail, the deterioration determination unit 13 determines whether or not there is a sign of deterioration for the boards 62c, 63c, 64c, based on the thickness of the metal members forming the wiring patterns provided on the boards 62c, 63c, 64c, the length of the estimated period obtained by the corrosion amount acquisition unit 11, and the concentration of the corrosive gas estimated by the concentration estimation unit 12. The deterioration determination unit 13 outputs the determination result to the monitoring device 71 shown in FIG. 1.

[0025] The hardware configuration of the deterioration determination device 1 having the above-mentioned configuration is shown in Fig. 4. The deterioration determination device 1 includes a processor 91, a memory 92, and an interface 93. The processor 91, the memory 92, and the interface 93 are connected to one another via a bus 90. The functions of each part of the deterioration determination device 1 are realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory 92. The processor 91 reads out and executes the programs stored in the memory 92, thereby realizing the functions of each part described above. That is, the memory 92 stores programs for executing the processing of each part of the deterioration determination device 1.

[0026] The memory 92 includes, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read-Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable and Programmable Read-Only Memory), magnetic disks, flexible disks, optical disks, compact disks, mini disks, DVDs (Digital Versatile Discs), etc.

[0027] The deterioration determination device 1 is connected to the corrosion sensor 10 and the monitoring device 71 via an interface 93. The interface 93 has an interface module that complies with one or more standards depending on the connection destination.

[0028] The deterioration determination device 1 is realized by providing a microprocessor including a processor 91, a memory 92, and an interface 93 on a board 61c.

[0029] The deterioration determination device 1 having the above configuration performs a process of determining signs of deterioration shown in Fig. 5 during operation of a railway vehicle. For example, when a start switch provided in the driver's cab is operated to electrically connect the current collector to a power supply line and the deterioration determination device 1 receives a supply of power from the current collector via a power supply device (not shown), the deterioration determination device 1 starts the process of determining signs of deterioration shown in Fig. 5.

[0030] The corrosion amount acquisition unit 11 obtains the length of the estimated period, which is the length of time from the time when the operation start signal is received to the current time (step S11). In detail, the corrosion amount acquisition unit 11 stores the time when the operation start signal instructing the start of operation is received as the start time of the estimated period. The corrosion amount acquisition unit 11 obtains the length of the estimated period, which is the time from the start time of the estimated period to the current time, by using, for example, an internal timer of a CPU (Central Processing Unit), which is an example of the processor 91.

[0031] The corrosion amount acquisition unit 11 acquires a combined resistance value of the thin metal film 21 and the resistor 22 from the corrosion sensor 10, and determines the amount of reduction in the thickness of the thin metal film 21 during the estimation period from the combined resistance value (step S12). The corrosion amount acquisition unit 11 sends the length of the estimation period determined in step S11 to the concentration estimation unit 12 and the deterioration determination unit 13, and sends the amount of reduction in the thickness of the thin metal film 21 determined in step S12 to the concentration estimation unit 12.

[0032] When the metal thin film 21 is broken, no current flows through the circuit formed by the metal thin film 21 and the resistor 22, and the combined resistance value of the metal thin film 21 and the resistor 22 obtained by the resistance determination circuit 23 increases rapidly. Therefore, when the combined resistance value obtained from the resistance determination circuit 23 becomes equal to or greater than the resistance threshold value, the corrosion amount acquisition unit 11 considers that the amount of reduction in the thickness of the metal thin film 21 matches the thickness of the metal thin film 21 at the time of its formation. The resistance threshold value may be any value that is greater than the upper limit of the value that the combined resistance value can take when a current flows through the circuit formed by the metal thin film 21 and the resistor 22.

[0033] In the first embodiment, the corrosion amount acquisition unit 11 outputs the length of time from the time when an operation start signal instructing the start of operation is received to the time when the combined resistance value becomes equal to or greater than the resistance threshold value as the length of the estimated period to the concentration estimation unit 12 and the deterioration determination unit 13, and outputs the thickness of the metal thin film 21 at the time of its formation as the amount of decrease in the thickness of the metal thin film 21 during the estimated period to the concentration estimation unit 12. Note that the corrosion amount acquisition unit 11 holds in advance information about the thickness of the metal thin film 21 at the time of its formation.

[0034] The concentration estimation unit 12 estimates the concentration of the corrosive gas around the railway vehicle from the amount of decrease in the thickness of the thin metal film 21 during the estimation period and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member forming the thin metal film 21 (step S13). The concentration estimation unit 12 sends the estimated concentration of the corrosive gas to the deterioration determination unit 13.

[0035] The concentration estimation unit 12 holds in advance the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal forming the metal thin film 21, as shown in FIG. 6, for example. FIG. 6 shows the relationship between the concentration of hydrogen sulfide, which is an example of a corrosive gas, the thickness of silver, which is an example of a metal corroded by hydrogen sulfide, at the time of formation, and the exposure period, which is the period required for the amount of reduction in the thickness of silver in contact with hydrogen sulfide to reach the thickness at the time of formation. The exposure period corresponds to the time required for a break in the silver in contact with hydrogen sulfide to occur. The concentration is expressed in units of ppb (parts per billion), the metal thickness is expressed in units of nm (nanometer), and the exposure period is expressed in units of days.

[0036] Specifically, the example data in the first row of Fig. 6 indicates that when silver having a thickness of 160 nm is exposed to hydrogen sulfide at a concentration of 200 ppb, a break occurs in 30 days. The relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member forming the thin metal film 21 shown in Fig. 6 is assumed to have been obtained in advance by a test, a simulation, or the like in which the metal is exposed to the corrosive gas.

[0037] The concentration estimation unit 12 estimates the concentration of the surrounding corrosive gas from the length of the estimation period and the amount of reduction in the thickness of the metal thin film 21 using the relationship shown in Fig. 6. As an example, when the thickness of the metal thin film 21 at the time of formation is 160 nm, and the estimation period, which is the length of time from the time of receiving an operation start signal instructing the start of operation to the time of the combined resistance value becoming equal to or greater than the resistance threshold, is 80 days, the concentration estimation unit 12 estimates the concentration of the corrosive gas to be 100 ppb. As another example, when the thickness of the metal thin film 21 at the time of formation is 160 nm, and the estimation period is 60 days, the concentration estimation unit 12 estimates the concentration of the corrosive gas to be 150 ppb.

[0038] The deterioration determination unit 13 determines whether there is a sign of deterioration of the boards 62c, 63c, and 64c based on the length of the estimated period calculated in step S11 of Fig. 5 and the concentration of the corrosive gas estimated in step S13. In detail, the deterioration determination unit 13 determines whether the concentration of the corrosive gas is equal to or higher than a concentration threshold (step S14). The concentration threshold is determined according to the thickness of the metal members forming the wiring patterns provided on the boards 62c, 63c, and 64c, and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal members forming the wiring patterns, and is the concentration of the corrosive gas that can cause corrosion of the wiring patterns during the operation of the railway vehicle over several decades. The deterioration determination unit 13 holds information about the concentration threshold in advance.

[0039] If the concentration of the corrosive gas is less than the concentration threshold value (step S14; No), the deterioration determination unit 13 outputs a determination result indicating that there is no sign of deterioration to the monitoring device 71 (step S17). When the process of step S17 is completed, the above-mentioned process is repeated from step S11.

[0040] If the concentration of the corrosive gas is equal to or greater than the concentration threshold (step S14; Yes), the deterioration determination unit 13 determines whether the estimated period is equal to or greater than the period threshold (step S15). The period threshold is a threshold that changes depending on the concentration of the corrosive gas, and is determined according to the corrosion rate of the metal member forming the wiring pattern provided on the substrates 62c, 63c, and 64c when the metal member comes into contact with the corrosive gas. In detail, the period threshold is determined according to the thickness of the metal member forming the wiring pattern provided on the substrates 62c, 63c, and 64c and the corrosion rate of the metal member depending on the concentration of the corrosive gas.

[0041] The corrosion rate is derived from the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member forming the metal thin film 21 shown in FIG. 6. The deterioration determination unit 13 holds information on the corrosion rate of the metal member forming the wiring pattern provided on the substrates 62c, 63c, and 64c in advance. For example, if the concentration of the corrosive gas is 200 ppb, the corrosion rate is 160 nm / 30 days, and the thickness of the silver plating forming the wiring pattern is 80 nm, the silver plating will corrode by 80 nm in 15 days, affecting the operation of the control circuit. In this case, by setting the period threshold to a period shorter than 15 days, for example, 10 days, the deterioration determination unit 13 can detect signs of deterioration of the substrates 62c, 63c, and 64c before the operation of the control circuit is affected.

[0042] If the estimated period is less than the period threshold value (step S15; No), the deterioration determination unit 13 sends a determination result indicating that there is no sign of deterioration to the monitoring device 71 (step S17). When the process of step S17 is completed, the above-mentioned process is repeated from step S11.

[0043] If the concentration of the corrosive gas is equal to or greater than the concentration threshold and the estimated period is equal to or greater than the period threshold (step S14; Yes, step S15; Yes), the deterioration determination unit 13 outputs a determination result indicating that there is a sign of deterioration to the monitoring device 71 (step S16). When the process of step S16 is completed, the above-mentioned process is repeated from step S11.

[0044] While power is being supplied from the power supply device, the deterioration determination device 1 repeats the above-mentioned process for a fixed period of time, for example, every 200 milliseconds.

[0045] The monitoring device 71, which acquires the discrimination result from the deterioration discrimination unit 13 included in the deterioration discrimination device 1, outputs the discrimination result on a display screen 72 as shown in FIG. 7. In the example of FIG. 7, a plurality of deterioration discrimination devices 1 are mounted on a railway vehicle. The deterioration discrimination targets of the plurality of deterioration discrimination devices 1 are different from one another. The discrimination results of each deterioration discrimination device 1 are displayed on the display screen 72. In the example of FIG. 7, the absence of signs of deterioration is shown as normal, and the presence of signs of deterioration is shown as abnormal.

[0046] The display screen 72 is a touch panel and is provided with an on-screen button 73 that serves as a switch for instructing the start of operation of the railway vehicle. When the button 73 is operated, an operation start signal is sent to the deterioration determination device 1.

[0047] As described above, the deterioration determination device 1 according to the first embodiment estimates the concentration of the corrosive gas, and determines whether or not there is a sign of deterioration of the boards 62c, 63c, 64c of the control device 50 that controls the on-board equipment, based on the length of the estimated period starting from the time the railcar starts operating and the concentration of the corrosive gas. By using the length of the estimated period and the concentration of the corrosive gas, it becomes possible to accurately determine whether or not there is a sign of deterioration of the boards 62c, 63c, 64c of the control device 50 that controls the on-board equipment.

[0048] (Embodiment 2) The implementation of the deterioration determination device is not limited to the above-mentioned examples. The configuration of the deterioration determination device 1 according to the second embodiment is the same as that of the deterioration determination device 1 according to the first embodiment. Unlike the first embodiment, in the control device 50 that is the object of determination by the deterioration determination device 1, a control circuit for controlling the in-vehicle devices is formed on each of the boards 61c, 62c, 63c, and 64c. In the second embodiment, the deterioration determination device 1 is provided on the board 61c on which the control circuit for controlling the in-vehicle devices is formed.

[0049] 8, a corrosion sensor 10 is provided on a substrate 61c. A power conversion control module 31 that controls a power conversion device mounted on a railway vehicle is formed on the substrate 61c. The deterioration determination device 1 is realized by a deterioration determination module 2 that is one function of the power conversion control module 31.

[0050] The operation of the deterioration determination device 1 according to the second embodiment is similar to that of the first embodiment. The deterioration determination device 1 determines the presence or absence of signs of deterioration of the board 61c on which the deterioration determination device 1 is mounted, as well as the boards 62c, 63c, and 64c included in the same control device 50, from the length of the estimated period and the concentration of the corrosive gas. The thickness of the thin metal film 21 may be thinner than the thickness of a metal member forming the wiring pattern of the power conversion control unit 32 provided on the board 61c, for example.

[0051] As described above, the deterioration determination device 1 according to the second embodiment is provided on the board 61c on which the control circuit for controlling the in-vehicle devices is formed. By mounting the deterioration determination device 1 on an existing board, even when the number of slots for the control device 50 is limited, it becomes possible for the deterioration determination device 1 to determine whether or not there is a sign of deterioration of the boards 61c, 62c, 63c, and 64c.

[0052] The present disclosure is not limited to the above-described embodiment. The above hardware configuration and flowchart are merely examples, and can be changed or modified as desired.

[0053] In the above example, the concentration estimation unit 12 holds in advance the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal forming the metal thin film 21 shown in Fig. 6, but the way of expressing the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member forming the metal thin film 21 is not limited to the above example. As an example, the concentration estimation unit 12 may hold a calculation formula indicating the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member forming the metal thin film 21, which is obtained in advance by a test in which the metal member is exposed to the corrosive gas, a simulation, or the like.

[0054] As another example, the concentration estimation unit 12 may hold a concentration estimation model obtained by learning the thickness of the metal member at the time of formation, the concentration of the corrosive gas, and an exposure period that is the period from when the metal member starts to come into contact with the corrosive gas until the amount of reduction in the thickness of the metal member reaches the thickness of the metal member at the time of formation. The concentration estimation model may be any model that indicates the concentration of the corrosive gas when the amount of reduction in the thickness of the metal member during the estimation period and the length of the estimation period are input.

[0055] As another example, the concentration estimation unit 12 may use a regression analysis in which the concentration of the corrosive gas is used as a target function and the amount of reduction in thickness of the metal component during the estimation period and the length of the estimation period are used as independent variables to determine a model indicating the concentration of the corrosive gas when the amount of reduction in thickness of the metal component during the estimation period and the length of the estimation period are input.

[0056] The deterioration determination device 1 may be implemented as one function of a train information management system. The deterioration determination device 1 may be provided, for example, in a train operation control center without being mounted on a railway vehicle.

[0057] The core part having the processor 91, memory 92, and interface 93 and performing control processing can be realized by using a normal computer system, not a dedicated system. For example, the deterioration determination device 1 that performs the above-mentioned processing may be realized by storing and distributing a computer program for performing the above-mentioned operations on a computer-readable recording medium (such as a flexible disk, a CD-ROM (Compact Disc-Read Only Memory), or a DVD-ROM (Digital Versatile Disc-Read Only Memory)), and installing the computer program on a computer. Also, the deterioration determination device 1 may be realized by storing the computer program in a storage device of a server device on a communication network, and downloading it by a normal computer system.

[0058] When the functions of the deterioration determination device 1 are realized by sharing between an OS (Operating System) and an application program, or by cooperation between the OS and the application program, only the application program portion may be stored in a recording medium or storage device.

[0059] It is also possible to superimpose a computer program on a carrier wave and distribute it via a communication network. For example, the computer program may be posted on a bulletin board (BBS: Bulletin Board System) on the communication network and distributed via the communication network. Then, the computer program may be started and executed under the control of the OS in the same way as other application programs, thereby executing the above-mentioned processing.

[0060] The deterioration determination device 1 may be realized by a processing circuit 94 as shown in FIG. 9. The processing circuit 94 is connected to the corrosion sensor 10 and the monitoring device 71 via an interface circuit 95. When the processing circuit 94 is a dedicated hardware, the processing circuit 94 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each part of the deterioration determination device 1 may be realized by an individual processing circuit 94, or each part of the deterioration determination device 1 may be realized by a common processing circuit 94.

[0061] Some of the functions of the deterioration determination device 1 may be realized by dedicated hardware, and the other parts may be realized by software or firmware. For example, the corrosion amount acquisition unit 11 may be realized by a processing circuit 94 shown in Fig. 9, and the concentration estimation unit 12 and the deterioration determination unit 13 may be realized by a processor 91 shown in Fig. 4 reading and executing a program stored in a memory 92.

[0062] The method of calculating the length of the estimated period is not limited to the above example. As an example, the start point of the estimated period is not limited to the time when the corrosion amount acquisition unit 11 receives the operation start signal, but may be the time when the commercial operation of the railway vehicle is first started by a start signal, the time when the railway vehicle first starts running after the test run is completed, etc.

[0063] As another example, the length of the estimation period may be obtained by multiplying the number of times that the deterioration sign determination process shown in Fig. 5 has been performed by the deterioration determination device 1 since the railway vehicle started operation by the cycle of repeating the deterioration sign determination process shown in Fig. 5. As another example, the corrosion amount acquisition unit 11 acquires time information from an external device, and obtains the length of the estimation period from the difference between the time when the operation start signal was received and the time when the estimation period is obtained.

[0064] The control device 50 is not limited to a subrack device, but may be any electronic device having a metal that corrodes when it comes into contact with a corrosive gas. As an example, the control device 50 may be provided in a cab.

[0065] The deterioration determination device 1 may output the determination result to any output device, not just the monitoring device 71. As an example, the deterioration determination device 1 may output the determination result to an LED device provided on the front panel 61a of the substrate 61c. The LED device may be turned on when the determination result indicates that there is a sign of deterioration, and turned off when the determination result indicates that there is no sign of deterioration.

[0066] Because the resistance value of a metal changes depending on the cross-sectional area of ​​the metal, the corrosion amount acquisition unit 11 may obtain the amount of reduction in thickness due to corrosion of the metal thin film 21 from the relationship between the previously stored combined resistance value and the thickness of the metal thin film 21 and the combined resistance value acquired from the corrosion sensor 10 before a disconnection occurs due to corrosion of the metal thin film 21. At this time, the concentration estimation unit 12 can estimate the concentration of the corrosive gas from the amount of reduction in thickness due to corrosion of the metal thin film 21 obtained by the corrosion amount acquisition unit 11 and the length of the estimation period.

[0067] The metal forming the wiring pattern is not limited to silver, but may be copper, iron, tin, zinc, aluminum, nickel, or other metal that corrodes when it comes into contact with a corrosive gas.

[0068] The corrosive gas whose concentration is estimated by the deterioration determination device 1 is not limited to hydrogen sulfide, but may be any gas that corrodes metals, such as sulfur dioxide, nitrogen oxides, chlorine, and ammonia.

[0069] The deterioration determining unit 13 may store in advance, for each combination of a metal member and a corrosive gas, a relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member forming the metal thin film 21, for a plurality of types of metal members and a plurality of types of corrosive gases. This allows the deterioration determining unit 13 to determine the presence or absence of signs of deterioration of the substrates 61c, 62c, 63c, 64c, based on the concentrations of the plurality of types of corrosive gases. Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) a corrosion amount acquisition unit that acquires an amount of reduction in thickness of a metal thin film that is provided on any one of a plurality of substrates of an electronic device mounted on the railway vehicle and is made of a metal member that corrodes upon contact with a corrosive gas, during an estimated period starting from a start time of operation of the railway vehicle; a concentration estimation unit that estimates a concentration of the corrosive gas based on the amount of reduction in the thickness of the metal thin film during the estimation period acquired by the corrosion amount acquisition unit and a relationship between the concentration of the corrosive gas and a change in the thickness of the metal member over time; a deterioration determination unit that determines whether or not there is a sign of deterioration of the board of the electronic device based on the length of the estimation period and the concentration of the corrosive gas estimated by the concentration estimation unit; A deterioration determination device comprising: (Appendix 2) the corrosion amount acquisition unit acquires a reduction in thickness of the metal thin film, the metal thin film being formed on a substrate on which a control circuit for controlling the on-board equipment is provided, among the plurality of substrates included in the electronic device, which is a control device for controlling on-board equipment mounted on the railway vehicle, and having a thickness at the time of formation that is thinner than a thickness at the time of formation of the metal member forming a wiring pattern provided on the substrate on which the control circuit is formed; 2. The deterioration determination device according to claim 1. (Appendix 3) the corrosion amount acquisition unit acquires a reduction in thickness of the metal thin film, the metal thin film being formed on a substrate other than the substrate on which a control circuit for controlling the on-board equipment is provided, among the plurality of substrates included in the electronic device, which is a control device for controlling on-board equipment mounted on the railway vehicle, and having a thickness at the time of formation that is thinner than a thickness at the time of formation of the metal member forming a wiring pattern provided on the substrate on which the control circuit is formed; 2. The deterioration determination device according to claim 1. (Appendix 4) the corrosion amount acquisition unit acquires an operation start signal that instructs the start of operation of the railway vehicle, and acquires an amount of reduction in thickness of the metal thin film during the estimated period that starts from a time point when the operation start signal instructs the start of operation of the railway vehicle. 4. A deterioration determination device according to any one of claims 1 to 3. (Appendix 5) the corrosion amount acquisition unit calculates an amount of reduction in the thickness of the metal thin film during the estimation period based on a measurement value of a combined resistance acquired from a corrosion sensor that measures a combined resistance value of the metal thin film and a resistor that is connected in series to the metal thin film and is made of a material having higher resistance to the corrosive gas than the metal thin film; 5. A deterioration determination device according to any one of claims 1 to 4. (Appendix 6) when the amount of reduction in the thickness of the metal thin film during the estimation period acquired by the corrosion amount acquisition unit coincides with the thickness of the metal thin film at the time of its formation, the concentration estimation unit estimates the concentration of the corrosive gas from the length of the estimation period, the thickness of the metal thin film at the time of its formation, and a relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member. 6. A deterioration determination device according to any one of claims 1 to 5. (Appendix 7) the deterioration determination unit determines that deterioration of the substrate is occurring when the concentration of the corrosive gas estimated by the concentration estimation unit is equal to or greater than a concentration threshold determined according to the thickness of the metal member forming the wiring pattern formed on the substrate and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member, and when the length of the estimation period is equal to or greater than a period threshold determined according to the corrosion rate of the metal member in contact with the corrosive gas, which is a threshold that changes depending on the concentration of the corrosive gas. 7. A deterioration determination device according to any one of claims 1 to 6. (Appendix 8) the corrosion amount acquisition unit is accommodated in the electronic device formed by a subrack device including a backplane in which a plurality of slots are formed and a subrack that accommodates the backplane, and acquires a reduction amount, during the estimated period, in thickness of the metal thin film formed on the substrate of a plug-in unit connected to a slot located at an end in an arrangement direction of the plurality of slots among the plurality of slots; 8. A deterioration determination device according to any one of claims 1 to 7. (Appendix 9) The deterioration determination unit outputs a determination result as to whether or not there is a sign of deterioration of the substrate to a monitoring device mounted on the railway vehicle. 9. A deterioration determination device according to any one of appendix 1 to 8. (Appendix 10) acquiring an amount of reduction in thickness of a metal thin film, the metal thin film being provided on any one of a plurality of substrates of an electronic device mounted on the railway vehicle and made of a metal member that corrodes upon contact with a corrosive gas, during an estimated period starting from a start time of the operation of the railway vehicle; estimating a concentration of the corrosive gas from a reduction in thickness of the metal thin film during the estimation period and a relationship between the concentration of the corrosive gas and a change in thickness of the metal member over time; determining whether or not there is a sign of deterioration of the substrate of the electronic device based on the length of the estimated period and the estimated concentration of the corrosive gas; Deterioration determination method.

[0070] Various embodiments and modifications of the present disclosure are possible without departing from the broad spirit and scope of the present disclosure. The above-described embodiments are for explaining the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and the scope of the disclosure equivalent thereto are considered to be within the scope of the present disclosure. [Explanation of symbols]

[0071] 1 Deterioration determination device, 2 Deterioration determination module, 10 Corrosion sensor, 11 Corrosion amount acquisition unit, 12 Concentration estimation unit, 13 Deterioration determination unit, 21 Metal thin film, 22 Resistor, 23 Resistance determination circuit, 31 Power conversion control module, 32 Power conversion control unit, 50 Control device, 51 Subrack, 52 Backplane, 53, 54, 55, 56 Slot, 61, 62, 63, 64 Plug-in unit, 61a, 62a, 63a, 64a Front panel, 61b, 62b, 63b, 64b Connector, 61c, 62c, 63c, 64c Board, 71 Monitoring device, 72 Display screen, 73 Button, 90 Bus, 91 Processor, 92 Memory, 93 Interface, 94 Processing circuit, 95 Interface circuit.

Claims

1. A corrosion amount acquisition unit that acquires a decrease amount in the thickness of a metal thin film formed of a metal member provided on any of a plurality of substrates included in an electronic device mounted on the railway vehicle and corroded by contact with a corrosive gas during a predicted period starting from the start point of operation of the railway vehicle; A concentration estimation unit that estimates the concentration of the corrosive gas from the decrease amount in the thickness of the metal thin film during the predicted period acquired by the corrosion amount acquisition unit and the relationship between the concentration of the corrosive gas and the temporal change in the thickness of the metal member; A deterioration determination unit that determines the presence or absence of signs of deterioration of the substrate included in the electronic device from the length of the predicted period and the concentration of the corrosive gas estimated by the concentration estimation unit; A deterioration determination device comprising the above.

2. The corrosion amount acquisition unit is formed on the substrate provided with a control circuit for controlling the in-vehicle device among the plurality of substrates included in the electronic device which is a control device for controlling the in-vehicle device mounted on the railway vehicle, and the thickness at the time of formation is thinner than the thickness at the time of formation of the metal member forming the wiring pattern provided on the substrate on which the control circuit is formed, and acquires the decrease amount in the thickness of the metal thin film. The deterioration determination device according to Claim 1.

3. The corrosion amount acquisition unit is formed on a substrate different from the substrate provided with a control circuit for controlling the in-vehicle device among the plurality of substrates included in the electronic device which is a control device for controlling the in-vehicle device mounted on the railway vehicle, and the thickness at the time of formation is thinner than the thickness at the time of formation of the metal member forming the wiring pattern provided on the substrate on which the control circuit is formed, and acquires the decrease amount in the thickness of the metal thin film. The deterioration determination device according to Claim 1.

4. The corrosion amount acquisition unit acquires an operation start signal instructing the start of operation of the railway vehicle, and acquires the decrease amount in the thickness of the metal thin film during the predicted period starting from the time when the operation start signal instructs the start of operation of the railway vehicle. The deterioration determination device according to any one of Claims 1 to 3.

5. The corrosion amount acquisition unit obtains the decrease amount in the thickness of the metal thin film during the predicted period based on the measured value of the combined resistance acquired from a corrosion sensor that measures the combined resistance value of the metal thin film and a resistor formed of a member connected in series to the metal thin film and having higher resistance to the corrosive gas than the metal thin film. The deterioration determination device according to any one of Claims 1 to 3.

6. When the amount of decrease in the thickness of the metal thin film during the estimation period acquired by the corrosion amount acquisition unit matches the thickness of the metal thin film at the time of formation of the metal thin film, the concentration of the corrosive gas is estimated from the length of the estimation period, the thickness of the metal thin film at the time of formation, and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member. The deterioration determination device according to any one of claims 1 to 3.

7. When the concentration of the corrosive gas estimated by the concentration estimation unit is equal to or higher than a concentration threshold determined according to the thickness of the metal member forming the wiring pattern formed on the substrate and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member, and the length of the estimation period is a threshold value that changes according to the concentration of the corrosive gas and is equal to or longer than a period threshold determined according to the corrosion rate of the metal member in contact with the corrosive gas, it is determined that deterioration of the substrate has occurred. The deterioration determination device according to any one of claims 1 to 3.

8. The corrosion amount acquisition unit is housed in the electronic device formed by a subrack device including a backplane in which a plurality of slots are formed and a subrack that houses the backplane, and acquires the amount of decrease in the thickness of the metal thin film formed on the substrate of the plug-in unit connected to the slot located at the end in the arrangement direction of the plurality of slots among the plurality of slots during the estimation period. The deterioration determination device according to any one of claims 1 to 3.

9. The deterioration determination unit outputs the determination result of the presence or absence of signs of deterioration of the substrate to a monitoring device mounted on the railway vehicle. The deterioration determination device according to any one of claims 1 to 3.

10. Obtain the amount of decrease in the thickness of the metal thin film formed of a metal member that is provided on any of the plurality of substrates of the electronic device mounted on the railway vehicle and corrodes by contacting a corrosive gas during an estimation period starting from the start time of operation of the railway vehicle. Estimate the concentration of the corrosive gas from the amount of decrease in the thickness of the metal thin film during the estimation period and the relationship between the concentration of the corrosive gas and the change over time in the thickness of the metal member. Determine the presence or absence of signs of deterioration of the substrate of the electronic device from the length of the estimation period and the estimated concentration of the corrosive gas. Deterioration determination method.

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