Relay valve fault diagnosis method and system
By collecting the displacement data of the relay valve spool and valve stem, the displacement characteristics are generated and compared with the normal working state, the problem of poor accuracy in judging slight performance degradation in the prior art is solved, and high-precision fault diagnosis and performance are achieved predict.
Patent Information
- Application Number
- CN202411626004.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-02-18
AI Technical Summary
The prior art has poor accuracy when judging that the relay valve has slight decline in performance, and the external pressure signal is affected by a variety of factors, resulting in complex fault judgments.
By collecting the displacement data of the relay valve spool and valve stem in real time, the displacement characteristics are generated and compared with the characteristics of the normal working state, fault diagnosis and performance prediction are achieved.
This method can automatically and in real-time diagnosis during train operation, reducing the impact of factors on pressure values, improving judgment accuracy, and saving manpower.
Smart Images
Figure CN119459645A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fault diagnosis, and in particular to a relay valve fault diagnosis method and system. Background Art
[0002] The relay valve in the rail vehicle braking system outputs the corresponding brake cylinder pressure according to the pre-control pressure and amplifies the flow. The brake cylinder pressure transmits the braking force to the basic braking device through the lever action, so that the brake pad and brake disc fit according to the force calculated by the brake control unit to achieve the braking effect.
[0003] The relay valve is one of the most important pneumatic components in the rail vehicle braking system. The performance of the relay valve directly determines whether the braking system can function normally. If there is a large leakage in the relay valve, it may cause insufficient pressure output to the brake cylinder, thereby affecting the braking force. If the relay valve core or valve stem is stuck, it may cause the output braking force to be too large or insufficient. In severe cases, there will be no braking force or a fault that cannot be relieved after braking.
[0004] During the use of the relay valve, the performance is gradually declining with the aging of rubber seals, wear of metal parts, and attenuation of springs. When the loss of internal parts of the relay valve accumulates to a certain extent, it will cause relay valve failure and have serious consequences. Therefore, the performance attenuation trend of the relay valve is predicted based on the characteristic parameters during the operation of the relay valve, and repair or replace it before the performance attenuates to a certain extent, which can effectively avoid the relay valve from having failures that affect the safe operation of the train.
[0005] At present, there are many methods for predicting and diagnosing relay valve faults through relay valve characteristic parameters. One of them is to judge whether the characteristic parameters exceed the range of the characteristic parameters of the relay valve in the simulation state through the pressure value of the air filling line starting point on the hysteresis loop of the relay valve, the slope of the air filling line, the slope of the exhaust line and the terminal pressure difference, and then judge whether the relay valve has a fault. Another method is to obtain the pressure time series of the main air cylinder, the balancing air cylinder and the train pipe when the relay valve has different fault types from the real train balancing module and the train balancing module simulation platform, extract the pressure characteristic value from it, train the neural network model, obtain the fault diagnosis model, and use the fault diagnosis model to diagnose the fault type of the relay valve to be tested. Another method is to perform normal distribution statistics on the brake cylinder response time, the brake cylinder pressure rise time, the pre-control pressure response time, and the pre-control pressure rise time, calculate the expectation and variance, and then obtain the operating time threshold of each component for fault warning. The above methods all use the pressure signals of the pre-control, brake cylinder, main air cylinder, balancing air cylinder and other positions outside the relay valve as characteristic parameters for fault prediction and diagnosis. Since the pressure of external pipelines and air cylinders is related to the leakage of pipelines and air cylinders, the altitude and temperature of the train, the flow state of compressed air in the pipelines and air cylinders will also cause pressure fluctuations, and the installation position of the pressure sensor on the pipeline and air cylinder will also cause the pressure value to be inconsistent with the fault diagnosis model. Therefore, the above method is more effective for judging more obvious performance degradation and faults, but has poor accuracy for judging minor performance degradation. Summary of the invention
[0006] In response to the problems in the prior art, the embodiments of the present application provide a relay valve fault diagnosis method and system, which can at least partially solve the problems in the prior art.
[0007] On the one hand, an embodiment of the present application provides a relay valve fault diagnosis method, comprising:
[0008] Collect the displacement data of the relay valve core and the valve stem in real time;
[0009] Generating a displacement feature of the valve core and a displacement feature of the valve stem according to the displacement data of the valve core and the displacement data of the valve stem;
[0010] The displacement characteristics of the valve core and the valve stem are compared with the displacement characteristics of the valve core and the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve.
[0011] In some embodiments, a first through hole is provided on the housing of the relay valve at a position close to the first end of the valve core and opposite to the first end of the valve core, and a first displacement sensor is installed on the outer side of the housing so that the first displacement sensor collects displacement data of the valve core through the first through hole, wherein the first end of the valve core refers to an end away from the valve stem; and / or
[0012] A second through hole is provided on the housing of the relay valve near the first end of the valve stem and opposite to the first end of the valve stem, and a second displacement sensor is installed on the outside of the housing so that the second displacement sensor collects displacement data of the valve stem through the second through hole, wherein the first end of the valve stem refers to an end away from the valve core.
[0013] In some embodiments, the displacement characteristic comprises at least one of the following: a displacement-time curve, a velocity, an acceleration.
[0014] In some embodiments, generating the displacement characteristics of the valve core and the displacement characteristics of the valve stem according to the displacement data of the valve core and the displacement data of the valve stem comprises:
[0015] Generating a displacement-time curve of the valve core according to the displacement data of the valve core;
[0016] A displacement-time curve of the valve stem is generated according to the displacement data of the valve stem.
[0017] In some embodiments, the displacement characteristics of the valve core and the valve stem are compared with the displacement characteristics of the valve core and the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve, including:
[0018] Comparing the displacement-time curve of the valve core with the displacement-time curve of the valve core of the relay valve in a normal working state to obtain a first comparison result;
[0019] Comparing the displacement-time curve of the valve stem with the displacement-time curve of the valve stem of the relay valve in a normal working state to obtain a second comparison result;
[0020] A fault diagnosis result of the relay valve is generated according to the first comparison result and the second comparison result.
[0021] In some embodiments, the first comparison result includes: the displacement value corresponding to the stabilization of the valve core position is greater than the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state;
[0022] Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes:
[0023] If the difference between the displacement value corresponding to the stabilization of the valve core position and the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state is greater than a first threshold, it is determined that leakage occurs between the valve core of the relay valve and the charging valve port and the exhaust valve port, and the relay valve is in a fault stage;
[0024] If the difference between the displacement value corresponding to the stabilization of the valve core position and the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state is less than or equal to the first threshold, it is determined that leakage occurs between the valve core of the relay valve and the charging valve port and the exhaust valve port, and the relay valve is in a stage of performance degradation.
[0025] In some embodiments, the first comparison result includes: the maximum displacement of the valve core is smaller than the maximum displacement of the valve core of the relay valve in the normal working state, and / or the movement speed of the valve core is smaller than the movement speed of the valve core in the normal working state at the same time;
[0026] Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes:
[0027] If the difference between the maximum displacement of the valve core and the maximum displacement of the valve core of the relay valve in the normal working state is greater than a second threshold, or the difference between the movement speed of the valve core and the movement speed of the valve core in the normal working state at the same time is greater than a third threshold, it is determined that the valve core of the relay valve is mechanically stuck and the relay valve is in a fault stage;
[0028] If the difference between the maximum displacement of the valve core and the maximum displacement of the valve core of the relay valve in the normal working state is less than or equal to the second threshold, or the difference between the movement speed of the valve core and the movement speed of the valve core in the normal working state at the same time is less than or equal to the third threshold, it is determined that the valve core of the relay valve is mechanically stuck and the relay valve is in a performance degradation stage.
[0029] In some embodiments, the first comparison result includes:
[0030] The time when the valve core starts to move is later than the time when the valve core of the relay valve in the normal working state starts to move;
[0031] Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes:
[0032] If the difference between the time when the valve core starts to move and the time when the valve core of the relay valve in the normal working state starts to move is greater than a fourth threshold, it is determined that the sensitivity of the relay valve decreases and the relay valve is in a fault stage;
[0033] If the difference between the time when the valve core starts to move and the time when the valve core of the relay valve in the normal working state starts to move is less than or equal to the fourth threshold, it is determined that the sensitivity of the relay valve decreases and the relay valve is in a performance degradation stage.
[0034] In some embodiments, the displacement characteristics of the valve core and the valve stem of the relay valve in the normal working state are generated according to the displacement data of the relay valve under various working conditions collected in real time by the displacement sensor after a displacement sensor is installed on the relay valve in the normal working state; or
[0035] The displacement characteristics of the valve core and the valve stem of the relay valve in the normal working state are obtained by modeling the relay valve in the normal working state using a simulation method and simulating the actions of the relay valve under various working conditions using the simulation model.
[0036] On the other hand, an embodiment of the present application provides a relay valve fault diagnosis system, including:
[0037] Relay valves, installed in rail vehicle braking systems;
[0038] A displacement sensor is installed on the relay valve to detect the displacement data of the valve core and the valve stem of the relay valve in real time;
[0039] A data acquisition device connected to the displacement sensor, collecting displacement data of the relay valve core and the valve stem detected by the displacement sensor, and sending the displacement data of the relay valve core and the valve stem to a fault diagnosis device;
[0040] A fault diagnosis device is connected to the data acquisition device, and generates displacement characteristics of the valve core and the valve stem according to the displacement data of the valve core and the displacement data of the valve stem, and compares the displacement characteristics of the valve core and the displacement characteristics of the valve stem with the displacement characteristics of the valve core and the displacement characteristics of the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve.
[0041] The relay valve fault diagnosis method and system provided in the present application can perform automatic real-time diagnosis during train operation by collecting valve core displacement and valve stem displacement and comparing them with data in a database, without the need for human intervention, thus saving a lot of manpower. Compared with the method of diagnosing relay valve faults based on pressure information, the present method performs fault diagnosis and performance prediction by directly collecting displacements that reflect the motion characteristics of the valve core and valve stem, thereby eliminating the influence of factors such as pipeline and air cylinder leakage, the altitude and temperature of the train, the flow state of compressed air in the pipeline and air cylinder, and the installation position of the pressure sensor on the pipeline and air cylinder on the pressure value, thereby reducing the complexity of fault judgment and performance prediction and improving the accuracy of judgment. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:
[0043] Figure 1a It is a structural diagram of the relay valve in the relief state.
[0044] Figure 1b It is a structural diagram of the relay valve in the braking state.
[0045] Figure 1c It is a structural diagram of the relay valve in the pressure maintaining state.
[0046] Figure 2 It is a flow chart of a relay valve fault diagnosis method provided in one embodiment of the present application.
[0047] Figure 3 This is a schematic diagram of the installation position of the displacement sensor on the relay valve provided in one embodiment of the present application.
[0048] Figure 4 It is a partial flow chart of a relay valve fault diagnosis method provided in one embodiment of the present application.
[0049] Figure 5 It is a schematic diagram of a leakage fault example provided by an embodiment of the present application.
[0050] Figure 6 It is a schematic diagram of an example of a mechanical jamming failure provided in an embodiment of the present application.
[0051] Figure 7 It is a schematic diagram of an example of sensitivity reduction provided by an embodiment of the present application.
[0052] Figure 8 It is a structural schematic diagram of a relay valve fault diagnosis system provided in one embodiment of the present application.
[0053] Reference numerals:
[0054] a, main air valve seat; b, main air outlet sleeve; c, upper hook shell; d, lower hook shell; e, return spring; f, main air spring; MR, main air chamber; BC, output chamber; AC1, emergency brake chamber; AC2, common brake chamber; O, exhaust port; 10, charging valve port; 20, exhaust valve port; 30, valve core; 40, valve stem; 50, first displacement sensor; 60, second displacement sensor. DETAILED DESCRIPTION
[0055] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not intended to limit the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily arranged with each other.
[0056] The terms “first”, “second”, etc. used in this document do not specifically refer to an order or sequence, nor are they used to limit this application. They are only used to distinguish elements or operations described with the same technical terms.
[0057] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.
[0058] As used herein, "and / or" includes any and all permutations of the items described.
[0059] In order to better understand the present application, the research background of the present application is briefly introduced below.
[0060] The working principle of the relay valve can be referred to Figure 1a to Figure 1c , the relay valve is initially in the relief position, that is, the valve core contacts the air charging valve port, the air charging valve port is closed, the air path from the total air chamber MR to the output chamber BC is disconnected, the valve stem leaves the valve core under the action of the valve stem return spring, the exhaust valve port is in an open state, the air path of the output chamber is connected with the exhaust port, and the pressure of the output chamber is 0. When the train applies the brake, the pre-control pressure Cv enters the pre-control chamber, acts on the upper hook shell body c and the lower hook shell body d, and pushes the valve core through the valve stem to open the air charging valve port, the exhaust valve port is closed, the total air chamber is connected with the output chamber, and the output pressure rises. When the output pressure chamber reaches the target pressure, under the feedback action of the valve inside, the valve stem moves downward, the air charging valve port and the exhaust valve port are both closed, and the pressure of the output chamber remains stable and enters the pressure holding state. When the pre-control pressure Cv increases or decreases, the pressure holding state will be destroyed, and the air charging state or exhaust state will be entered until a new balance is reached.
[0061] According to the working principle of the relay valve, the charging valve port and the exhaust valve port are opened or closed under the combined force of the thrust of the air pressure on the piston, the spring force, and the resistance of each part. The valve core displacement s1 and the valve stem displacement s2 directly determine the flow area of the charging valve port and the flow area of the exhaust valve port. Taking the charging valve port as an example, under the condition of constant upstream pressure, the flow area of the charging valve port and the rate of change of the flow area determine the gas flow characteristics from the total air chamber to the output chamber, such as the pressure value rising slope of the output pressure, the time when the pressure value starts to rise, the stable value of the output pressure and other parameters. When the downstream pipeline and volume, and the upstream total air chamber air supply pressure are fixed (in the actual rail transit braking system, these parameters have been determined after the design is finalized), the flow area of the charging valve port is obtained by multiplying the circumference of the valve port and the valve core opening. The circumference of the valve port has been determined after the design is finalized. Therefore, the downstream output pressure characteristics are determined by and only by the displacement s1 and the valve core movement speed v1 and acceleration a1 calculated based on the displacement s1. Similarly, the valve stem displacement s2 and the calculated valve stem movement speed v2 and acceleration a2 determine the gas movement characteristics from the output chamber to the exhaust port.
[0062] Therefore, by monitoring the displacement s1 of the valve core and the displacement s2 of the valve stem, the air tightness, braking performance, and relief performance of the relay valve can be monitored and faults can be diagnosed. In addition, since the relay valve is a mechanical pneumatic product, its essence is the thrust formed by the gas pressure acting on the piston and the rubber diaphragm, the resistance of each part (including the friction between metal parts and the friction between rubber seals and metal parts, the impedance of the diaphragm, etc.), and the spring force. The combined force moves to open or close the valve port to achieve functions such as filling, maintaining pressure, and exhausting. Therefore, the displacement s1, s2 of the valve core and the valve stem, the speed v1, v2, and the acceleration a1, a2 are determined by the combined force formed by the various components in the valve. By monitoring the displacement s1, s2, the overall motion characteristics of the internal parts of the valve body can be obtained, and it can be judged in advance whether the motion state of the internal parts is normal.
[0063] Figure 2 FIG. 1 is a flow chart of a relay valve fault diagnosis method provided in an embodiment of the present application. Figure 2 As shown, the relay valve fault diagnosis method provided in the embodiment of the present application includes:
[0064] S101, collecting displacement data of the valve core and the valve stem of the relay valve in real time;
[0065] S102, generating a displacement feature of the valve core and a displacement feature of the valve stem according to the displacement data of the valve core and the displacement data of the valve stem;
[0066] S103, comparing the displacement characteristics of the valve core and the valve stem with the displacement characteristics of the valve core and the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve.
[0067] Specifically, based on the relationship between the valve core and valve stem displacements s1 and s2 and the relay valve performance, a displacement sensor can be installed on the relay valve to collect the valve core displacement and valve stem displacement in real time. The collected displacement information is processed in a computer to obtain at least one of the following characteristic parameters: displacement s, velocity v and acceleration a. The characteristic parameters are compared with the characteristic parameters in the relay valve characteristic parameter library. If the characteristic parameters exceed the threshold range, it can be determined that the relay valve has performance degradation or failure.
[0068] The relay valve fault diagnosis method provided in the present application can perform automatic real-time diagnosis during train operation by collecting valve core displacement and valve stem displacement and comparing them with data in a database, without the need for human intervention, thus saving a lot of manpower. Compared with the method of diagnosing relay valve faults based on pressure information, the present method performs fault diagnosis and performance prediction by directly collecting displacements that reflect the motion characteristics of the valve core and valve stem, thereby eliminating the influence of factors such as pipeline and air cylinder leakage, the altitude and temperature of the train, the flow state of compressed air in the pipeline and air cylinder, and the installation position of the pressure sensor on the pipeline and air cylinder on the pressure value, thereby reducing the complexity of fault judgment and performance prediction and improving the accuracy of judgment.
[0069] Specifically, the displacement data can be collected using a displacement sensor. Since the displacement sensor has the characteristics of high precision and high sensitivity, it can collect tiny changes in the displacement signals of the valve core and valve stem. Therefore, the ability to diagnose faults can be more advanced and accurate than judging through external pressure.
[0070] like Figure 3 As shown, in some embodiments, a first through hole is provided on the housing of the relay valve at a position close to the first end of the valve core 30 and opposite to the first end of the valve core 30, and a first displacement sensor 50 is installed on the outer side of the housing so that the first displacement sensor 50 collects displacement data of the valve core 30 through the first through hole, wherein the first end of the valve core 30 refers to an end away from the valve stem 40; and / or
[0071] A second through hole is opened on the housing of the relay valve near the first end of the valve stem 40 and opposite to the first end of the valve stem 40, and a second displacement sensor 60 is installed on the outside of the housing so that the second displacement sensor 60 collects displacement data of the valve stem 40 through the second through hole, wherein the first end of the valve stem 40 refers to the end away from the valve core 30.
[0072] In some embodiments, the displacement characteristic comprises at least one of the following: a displacement-time curve, a velocity, an acceleration.
[0073] In some embodiments, generating the displacement characteristics of the valve core and the displacement characteristics of the valve stem according to the displacement data of the valve core and the displacement data of the valve stem comprises:
[0074] Generating a displacement-time curve of the valve core according to the displacement data of the valve core;
[0075] A displacement-time curve of the valve stem is generated according to the displacement data of the valve stem.
[0076] like Figure 4 As shown, in some embodiments, the displacement characteristics of the valve core and the valve stem are compared with the displacement characteristics of the valve core and the valve stem of the relay valve in a normal working state to obtain the fault diagnosis result of the relay valve, including:
[0077] S1031, comparing the displacement-time curve of the valve core with the displacement-time curve of the valve core of the relay valve in a normal working state to obtain a first comparison result;
[0078] S1032, comparing the displacement-time curve of the valve stem with the displacement-time curve of the valve stem of the relay valve in a normal working state to obtain a second comparison result;
[0079] S1033. Generate a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result.
[0080] The following is an example to illustrate the fault diagnosis process in the above embodiment.
[0081] In some embodiments, the first comparison result includes: the displacement value corresponding to the stabilization of the valve core position is greater than the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state;
[0082] Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes:
[0083] If the difference between the displacement value corresponding to the stabilization of the valve core position and the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state is greater than a first threshold, it is determined that leakage occurs between the valve core of the relay valve and the charging valve port and the exhaust valve port, and the relay valve is in a fault stage;
[0084] If the difference between the displacement value corresponding to the stabilization of the valve core position and the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state is less than or equal to the first threshold, it is determined that leakage occurs between the valve core of the relay valve and the charging valve port and the exhaust valve port, and the relay valve is in a stage of performance degradation.
[0085] Specifically, taking the common sealing performance degradation of relay valves as an example, see Figure 5 As shown in the figure, the solid curve is the valve core displacement curve under the braking condition in the database, and the dotted curve is the valve core displacement curve under the actual braking condition collected. It can be seen from the figure that after the valve core stabilizes, the valve core does not return to the initial position, and there is a small gap Δs with the valve port position. This gap reflects the leakage between the valve core and the valve port. The size of the gap can be used to determine whether the poor sealing is in the performance degradation stage or the failure stage.
[0086] In some embodiments, the first comparison result includes: the maximum displacement of the valve core is smaller than the maximum displacement of the valve core of the relay valve in the normal working state, and / or the movement speed of the valve core is smaller than the movement speed of the valve core in the normal working state at the same time;
[0087] Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes:
[0088] If the difference between the maximum displacement of the valve core and the maximum displacement of the valve core of the relay valve in the normal working state is greater than a second threshold, or the difference between the movement speed of the valve core (i.e., the slope of the displacement) and the movement speed of the valve core in the normal working state at the same time is greater than a third threshold, it is determined that the valve core of the relay valve is mechanically stuck and the relay valve is in a fault stage;
[0089] If the difference between the maximum displacement of the valve core and the maximum displacement of the valve core of the relay valve in the normal working state is less than or equal to the second threshold, or the difference between the movement speed of the valve core and the movement speed of the valve core in the normal working state at the same time is less than or equal to the third threshold, it is determined that the valve core of the relay valve is mechanically stuck and the relay valve is in a performance degradation stage.
[0090] Specifically, Figure 6 The figure shows a curve diagram of a mechanical jam fault. During the braking stage, if a mechanical moving part in the valve is mechanically jammed, additional resistance will be involved in the movement of the valve core, which will eventually be reflected in the displacement curve. Figure 6The solid curve in the middle is the displacement curve of the brake valve core in the database, and the dotted curve is the displacement curve of the valve core when the jam occurs. It can be seen that there is a difference of Δs between the maximum displacement value when the jam occurs and the maximum value of the normal curve. By judging that Δs is in the performance degradation area or the fault area, it can be judged that the mechanical jam is in the normal performance degradation range or the fault range. Due to the existence of mechanical resistance, the movement speed of the valve core, that is, the rising slope of the displacement curve is also smaller than the rising slope of the normal displacement curve. Combined with Δs, it can be judged that the mechanical jam is in the normal performance degradation range or the fault range.
[0091] In some embodiments, the first comparison result includes:
[0092] The time when the valve core starts to move is later than the time when the valve core of the relay valve in the normal working state starts to move;
[0093] Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes:
[0094] If the difference between the time when the valve core starts to move and the time when the valve core of the relay valve in the normal working state starts to move is greater than a fourth threshold, it is determined that the sensitivity of the relay valve decreases and the relay valve is in a fault stage;
[0095] If the difference between the time when the valve core starts to move and the time when the valve core of the relay valve in the normal working state starts to move is less than or equal to the fourth threshold, it is determined that the sensitivity of the relay valve decreases and the relay valve is in a performance degradation stage.
[0096] Specifically, Figure 7 The figure shows the sensitivity reduction curve. During the braking stage, the friction resistance increases due to the aging and wear of the rubber parts, which will cause the initial sensitivity of the relay valve to decrease, that is, the valve port opens slowly. The curve shows that there is a difference Δt in the valve core action time between normal working conditions and sensitivity reduction working conditions. By judging whether Δt is in the performance reduction area or the fault area, it can be determined whether the relay valve performance is reduced or a fault occurs.
[0097] The above embodiment provides a process of performing fault diagnosis after obtaining the first comparison result. The process of performing fault diagnosis after obtaining the second comparison result is similar. Those skilled in the art can implement it specifically under the inspiration of the above embodiment, which will not be described in detail here.
[0098] In summary, by collecting the valve core displacement and valve stem displacement and comparing them with the data in the database, it can be determined whether the relay valve performance has degraded or failed, and the fault type can be determined.
[0099] In some embodiments, the displacement characteristics of the valve core and the valve stem of the relay valve in the normal working state are generated according to the displacement data of the relay valve under various working conditions collected in real time by the displacement sensor after a displacement sensor is installed on the relay valve in the normal working state; or
[0100] The displacement characteristics of the valve core and the valve stem of the relay valve in the normal working state are obtained by modeling the relay valve in the normal working state using a simulation method and simulating the actions of the relay valve under various working conditions using the simulation model.
[0101] Specifically, the relay valve characteristic parameter library, which serves as a fault judgment standard, contains the relay valve core and stem displacements s1 and s2 in normal working conditions, which can be obtained by the following methods: 1. Actual measurement method. That is, prepare a relay valve with normal functions, install the displacement acquisition equipment, and perform various working conditions such as braking, pressure maintenance, and relief. The collected displacements s1 and s2, the calculated velocities v1 and v2, and the accelerations a1 and a2 can be used as judgment indicators. 2. Simulation method. Simulate and model the relay valve. The modeling can be performed on the AMEsim or Simulink simulation platform or other similar functional platforms. The model should be calibrated according to the measured data to ensure the accuracy of the simulation. Perform virtual experiments on the simulation platform to simulate the relay valve operation under various working conditions, read the displacements s1 and s2, velocities v1 and v2, and accelerations a1 and a2, and store them as judgment indicators.
[0102] Figure 8 is a schematic diagram of the structure of a relay valve fault diagnosis system provided by an embodiment of the present application, such as Figure 8 As shown, the relay valve fault diagnosis system provided by the embodiment of the present application includes:
[0103] Relay valves, installed in rail vehicle braking systems;
[0104] A displacement sensor is installed on the relay valve to detect the displacement data of the valve core and the valve stem of the relay valve in real time;
[0105] A data acquisition device connected to the displacement sensor, collecting displacement data of the relay valve core and the valve stem detected by the displacement sensor, and sending the displacement data of the relay valve core and the valve stem to a fault diagnosis device;
[0106] A fault diagnosis device is connected to the data acquisition device, and generates displacement characteristics of the valve core and the valve stem according to the displacement data of the valve core and the displacement data of the valve stem, and compares the displacement characteristics of the valve core and the displacement characteristics of the valve stem with the displacement characteristics of the valve core and the displacement characteristics of the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve.
[0107] Specifically, the relay valve is a typical relay valve in the rail vehicle braking system with braking, relief and pressure holding functions; the displacement sensor can be a Baumer OM20 laser displacement sensor, see Figure 3 , the sensor is installed on the valve body through the fixing plate, and a detection hole is punched on the valve body so that the displacement sensor can detect the displacement of the valve core and the valve stem; Figure 8 As shown; the displacement sensor is connected to the data acquisition device, which is used to collect the current signal of the displacement sensor. The data acquisition device can select the CANSAS measurement module of imc company; the data acquisition device is connected to the fault diagnosis device, which is a portable computer, connected to the data acquisition device through a network cable, and the current or voltage signal collected by the data acquisition device is transmitted to the computer, and converted into a displacement signal, a velocity signal, and an acceleration signal in the computer. In the fault diagnosis program, the displacement signal, the velocity signal, and the acceleration signal are compared with the data in the database, and the result is output.
[0108] This application has at least the following advantages:
[0109] By collecting the valve core displacement s1 and valve stem displacement s2 data of the relay valve for non-destructive fault diagnosis and performance degradation prediction, automatic real-time diagnosis and prediction can be performed during train operation without human intervention, saving a lot of manpower;
[0110] Compared with the method of performing relay valve fault diagnosis and performance prediction based on pressure information, this method performs fault diagnosis and performance prediction by directly collecting the displacements s1 and s2 reflecting the motion characteristics of the valve core and valve stem, thereby eliminating the influence of factors such as pipeline and air cylinder leakage, the altitude and temperature of the train, the flow state of compressed air in the pipeline and air cylinder, and the installation position of the pressure sensor on the pipeline and air cylinder on the pressure value, thereby reducing the complexity of fault judgment and performance prediction and improving the judgment accuracy.
[0111] Since the displacement sensor has the characteristics of high precision and high sensitivity, it can collect small changes in the valve core and valve stem displacement signal, so the prediction of performance degradation can be more advanced and accurate than judging by external pressure.
[0112] In the description of this specification, the description with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0113] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.
Claims
1. A relay valve fault diagnosis method, characterized in that: include: Collect the displacement data of the relay valve core and the valve stem in real time; Generating a displacement feature of the valve core and a displacement feature of the valve stem according to the displacement data of the valve core and the displacement data of the valve stem; The displacement characteristics of the valve core and the valve stem are compared with the displacement characteristics of the valve core and the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve.
2. The method according to claim 1, characterized in that A first through hole is provided on the housing of the relay valve at a position close to the first end of the valve core and opposite to the first end of the valve core, and a first displacement sensor is installed on the outer side of the housing so that the first displacement sensor collects displacement data of the valve core through the first through hole, wherein the first end of the valve core refers to an end away from the valve stem; and / or A second through hole is provided on the housing of the relay valve near the first end of the valve stem and opposite to the first end of the valve stem, and a second displacement sensor is installed on the outside of the housing so that the second displacement sensor collects displacement data of the valve stem through the second through hole, wherein the first end of the valve stem refers to an end away from the valve core.
3. The method according to claim 1, characterized in that The displacement characteristic includes at least one of the following: displacement-time curve, velocity, acceleration.
4. The method according to claim 3, characterized in that The generating the displacement characteristics of the valve core and the displacement characteristics of the valve stem according to the displacement data of the valve core and the displacement data of the valve stem comprises: Generating a displacement-time curve of the valve core according to the displacement data of the valve core; A displacement-time curve of the valve stem is generated according to the displacement data of the valve stem.
5. The method according to claim 4, characterized in that The step of comparing the displacement characteristics of the valve core and the valve stem with the displacement characteristics of the valve core and the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve includes: Comparing the displacement-time curve of the valve core with the displacement-time curve of the valve core of the relay valve in a normal working state to obtain a first comparison result; Comparing the displacement-time curve of the valve stem with the displacement-time curve of the valve stem of the relay valve in a normal working state to obtain a second comparison result; A fault diagnosis result of the relay valve is generated according to the first comparison result and the second comparison result.
6. The method according to claim 5, characterized in that The first comparison result includes: the displacement value corresponding to the stabilization of the valve core position is greater than the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state; Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes: If the difference between the displacement value corresponding to the stabilization of the valve core position and the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state is greater than a first threshold, it is determined that leakage occurs between the valve core of the relay valve and the charging valve port and the exhaust valve port, and the relay valve is in a fault stage; If the difference between the displacement value corresponding to the stabilization of the valve core position and the displacement value corresponding to the stabilization of the valve core position of the relay valve in the normal working state is less than or equal to the first threshold, it is determined that leakage occurs between the valve core of the relay valve and the charging valve port and the exhaust valve port, and the relay valve is in a stage of performance degradation.
7. The method according to claim 5, characterized in that The first comparison result includes: the maximum displacement of the valve core is smaller than the maximum displacement of the valve core of the relay valve in the normal working state, and / or the movement speed of the valve core is smaller than the movement speed of the valve core in the normal working state at the same time; Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes: If the difference between the maximum displacement of the valve core and the maximum displacement of the valve core of the relay valve in the normal working state is greater than a second threshold, or the difference between the movement speed of the valve core and the movement speed of the valve core in the normal working state at the same time is greater than a third threshold, it is determined that the valve core of the relay valve is mechanically stuck and the relay valve is in a fault stage; If the difference between the maximum displacement of the valve core and the maximum displacement of the valve core of the relay valve in the normal working state is less than or equal to the second threshold, or the difference between the movement speed of the valve core and the movement speed of the valve core in the normal working state at the same time is less than or equal to the third threshold, it is determined that the valve core of the relay valve is mechanically stuck and the relay valve is in a performance degradation stage.
8. The method according to claim 5, characterized in that The first comparison result includes: The time when the valve core starts to move is later than the time when the valve core of the relay valve in the normal working state starts to move; Generating a fault diagnosis result of the relay valve according to the first comparison result and the second comparison result includes: If the difference between the time when the valve core starts to move and the time when the valve core of the relay valve in the normal working state starts to move is greater than a fourth threshold, it is determined that the sensitivity of the relay valve decreases and the relay valve is in a fault stage; If the difference between the time when the valve core starts to move and the time when the valve core of the relay valve in the normal working state starts to move is less than or equal to the fourth threshold, it is determined that the sensitivity of the relay valve decreases and the relay valve is in a performance degradation stage.
9. The method according to claim 1, characterized in that: The displacement characteristics of the valve core and the valve stem of the relay valve in the normal working state are generated according to the displacement data of the relay valve under various working conditions collected in real time by the displacement sensor after the displacement sensor is installed on the relay valve in the normal working state; or The displacement characteristics of the valve core and the valve stem of the relay valve in the normal working state are obtained by modeling the relay valve in the normal working state using a simulation method and simulating the actions of the relay valve under various working conditions using the simulation model.
10. A relay valve fault diagnosis system, characterized in that: The system comprises: Relay valves, installed in rail vehicle braking systems; A displacement sensor is installed on the relay valve to detect the displacement data of the valve core and the valve stem of the relay valve in real time; A data acquisition device connected to the displacement sensor, collecting displacement data of the relay valve core and the valve stem detected by the displacement sensor, and sending the displacement data of the relay valve core and the valve stem to a fault diagnosis device; A fault diagnosis device is connected to the data acquisition device, and generates displacement characteristics of the valve core and the valve stem according to the displacement data of the valve core and the displacement data of the valve stem, and compares the displacement characteristics of the valve core and the displacement characteristics of the valve stem with the displacement characteristics of the valve core and the displacement characteristics of the valve stem of the relay valve in a normal working state to obtain a fault diagnosis result of the relay valve.