A PHM-based metro equipment dynamic fatigue early warning method, device and medium

Abstract

The application discloses a rail transit equipment dynamic fatigue early warning method and device based on PHM and a medium, relates to the technical field of rail transit monitoring, and comprises the following steps: collecting control instruction values of rail transit equipment corresponding to vehicles, current speeds of the vehicles, strain values of first strain measuring points and strain values of second strain measuring points, reading light yielding constraint data, and determining light yielding judgment data; identifying a light yielding allowable period according to the current speeds of the vehicles, a protection prohibition sign and a control instruction stable state, reducing the control instruction values and restoring the control instruction values to form effective light yielding detection actions; determining a main release section based on strain release changes of the first strain measuring points, searching for a same-direction receiving section in the second strain measuring points, and calculating release receiving delay values and release receiving missing values according to a starting interval and a release amplitude; judging a fatigue inducing state according to the release receiving delay values and the release receiving missing values, and generating dynamic fatigue early warning data. The application realizes early dynamic fatigue risk appearance and improves early warning accuracy.

Description

Technical Field

[0001] This invention relates to the field of rail transit monitoring technology, and in particular to a method, equipment and medium for early warning of dynamic fatigue of rail transit equipment based on PHM. Background Technology

[0002] Rail transit equipment is subjected to cyclic dynamic loads over long periods under traction, braking, curve passage, and alternating loads. Load-bearing structures such as bogie frames, traction connections, and brake installations typically require operational status monitoring and health assessment. Existing PHM methods for rail transit equipment primarily involve collecting operational data such as strain, vibration, speed, and control status, combined with fatigue load analysis, threshold judgment, or health status evaluation models, to identify fatigue risks during equipment service and provide data support for maintenance.

[0003] In the above methods, on the one hand, fatigue risk identification relies heavily on the load response generated during the natural operation of the vehicle, lacking a low-disturbance active detection method that is coordinated with the vehicle control process, making it difficult to induce and manifest early fatigue anomalies in a timely manner; on the other hand, conventional judgments focus more on the peak strain at a single point or the difference in values ​​at multiple measurement points, failing to adequately characterize the release and connection relationship between the main force-bearing position and the adjacent force-transmitting position after the control yields slightly, making it difficult to accurately distinguish between normal release hysteresis and force transmission anomalies. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a dynamic fatigue early warning method for rail transit equipment based on PHM to solve the problems of the difficulty in timely inducing and manifesting early dynamic fatigue risks and the insufficient granularity of force transmission and release anomaly judgment in the existing technology.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a dynamic fatigue early warning method for rail transit equipment based on PHM (Prognostics and Hygiene Management), comprising: collecting control command values, current vehicle speed, strain values ​​at a first strain measuring point, and strain values ​​at a second strain measuring point of the target rail transit equipment; reading light yield constraint data and determining light yield judgment data; identifying a light yield allowable period based on the current vehicle speed, protection prohibition sign, and the continuous stable state of the control command value; briefly reducing the control command value within the light yield allowable period according to the allowable adjustment range of vehicle control during the light yield allowable period; and restoring the control command value to the light yield allowable period after the light yield holding time ends. Before yielding, control the level to form an effective light yielding detection action; based on the continuous strain release change of the first strain measuring point under the effective light yielding detection action, determine the main release segment; in the second strain measuring point, search for the same-direction receiving segment that is consistent with the release direction of the main release segment; and calculate the release receiving delay value and release receiving missing value according to the starting interval between the main release segment and the same-direction receiving segment, the release amplitude of the main release segment and the release amplitude of the same-direction receiving segment, and generate fatigue induction judgment data; determine the light yielding fatigue induction state according to the fatigue induction judgment data, and generate dynamic fatigue early warning data for the target rail transit equipment.

[0007] As a preferred embodiment of the dynamic fatigue early warning method for rail transit equipment based on PHM described in this invention, the determination of the minor yielding judgment data includes: arranging a first strain measuring point and a second strain measuring point on the target rail transit equipment; reading the traction command value and the braking command value that are in an effective output state as the control command value, and normalizing the control command value; storing the control command value, the current vehicle speed, the strain value of the first strain measuring point, the strain value of the second strain measuring point, and the minor yielding constraint data to obtain the minor yielding judgment data; the first strain measuring point is set at the main stress position of the target rail transit equipment; the second strain measuring point is set at a position adjacent to the first strain measuring point that has a structural force transmission relationship.

[0008] As a preferred embodiment of the dynamic fatigue early warning method for rail transit equipment based on PHM described in this invention, the identification of the light yielding allowable period includes: obtaining the maximum, minimum, and average values ​​of the control command value within a continuous and stable observation period, and determining whether the control command value is in a continuous and stable state based on the proportion of the fluctuation range between the maximum and minimum values ​​relative to the average value; when the vehicle's current speed is in a stable operating state, the control command value is in a continuous and stable state, the protection prohibition sign does not display a protection state, and the vehicle control allowable adjustment range shows that the control command value has a range that can be reduced, the corresponding continuous operating period is determined as the light yielding allowable period.

[0009] As a preferred embodiment of the dynamic fatigue early warning method for rail transit equipment based on PHM described in this invention, the step of forming an effective light yielding detection action includes: determining the light yielding amplitude according to the allowable adjustment range of vehicle control, and determining the light yielding holding time according to the strain sampling period; reducing the control command value according to the light yielding amplitude during the allowable light yielding period, and maintaining the reduced control command value during the light yielding holding time; restoring the control command value to the control level before the light yielding after the light yielding holding time ends; and recording the start time of the light yielding action, the end time of the light yielding action, the light yielding amplitude, the light yielding holding time, and the control level before the light yielding, thereby forming an effective light yielding detection action.

[0010] As a preferred embodiment of the dynamic fatigue early warning method for rail transit equipment based on PHM described in this invention, the determination of the main release segment includes: based on the effective light yielding detection action, according to the start time of the light yielding action and the light yielding holding time, extracting continuous strain data of the first strain measuring point before the start of the light yielding action and during the light yielding holding time to obtain the first strain release data segment; determining the stable strain level of the first strain measuring point before the light yielding based on the continuous stable sampling period before the start time of the light yielding action; determining the continuous sampling segment in which the first strain measuring point undergoes continuous release changes relative to the stable strain level before the light yielding action after the start of the light yielding action, and the release change amplitude exceeds the strain sampling noise boundary, as the main release segment; determining the release amplitude of the main release segment according to the start time and end time of the main release segment, and determining the release direction of the main release segment according to the sign of the release amplitude of the main release segment.

[0011] As a preferred embodiment of the dynamic fatigue early warning method for rail transit equipment based on PHM described in this invention, the calculation of the release bearing delay value and the release bearing missing value includes: based on the start time of the light yielding action and the light yielding holding time, extracting continuous strain data of the second strain measuring point before the start of the light yielding action and during the light yielding holding time to obtain a second strain release data segment; in the second strain release data segment, determining the continuous sampling segment where the second strain measuring point produces continuous release changes after the start time of the main release segment, and the direction of the release change is consistent with the release direction of the main release segment, and the release change amplitude exceeds the strain sampling noise boundary, as a co-directional bearing segment; the ratio of the time difference between the start time of the co-directional bearing segment and the start time of the main release segment to the light yielding holding time as the release bearing delay value; and the ratio of the amplitude difference between the release amplitude of the main release segment and the release amplitude of the co-directional bearing segment to the release amplitude of the main release segment as the release bearing missing value.

[0012] As a preferred embodiment of the dynamic fatigue early warning method for rail transit equipment based on PHM described in this invention, the release amplitude of the same-direction bearing section includes: when the second strain measuring point does not form a same-direction bearing section within the light yielding holding time, the start time of the same-direction bearing section is recorded as the end time of the light yielding holding time, and the release amplitude of the same-direction bearing section is recorded as zero.

[0013] As a preferred embodiment of the PHM-based dynamic fatigue early warning method for rail transit equipment described in this invention, the generation of dynamic fatigue early warning data for the target rail transit equipment includes: when the release acceptance delay value is lower than the delay allowable boundary, and the release acceptance deficiency value is lower than the acceptance deficiency allowable boundary, the target rail transit equipment is determined to be in a normal acceptance state; when the release acceptance delay value is not lower than the delay allowable boundary, and the release acceptance deficiency value is lower than the acceptance deficiency allowable boundary, the target rail transit equipment is determined to be in a release acceptance delay state; when the release acceptance delay value is lower than the delay allowable boundary, and the release acceptance deficiency value is lower than the acceptance deficiency allowable boundary, the target rail transit equipment is determined to be in a release acceptance delay state; when the release acceptance delay value is lower than the delay allowable boundary, and the release acceptance deficiency value is lower than the release acceptance deficiency allowable boundary, the target rail transit equipment is determined to be in a release acceptance delay state. When the release bearing deficiency value is not lower than the allowable bearing deficiency boundary, the target rail transit equipment is determined to be in a state of insufficient release bearing; when the release bearing delay value is not lower than the delay boundary and the release bearing deficiency value is not lower than the bearing deficiency boundary, the target rail transit equipment is determined to be in a state of fatigue induction, and dynamic fatigue warning data is generated; the dynamic fatigue warning data includes the name of the target rail transit equipment, the location of the first strain measuring point, the location of the second strain measuring point, the start time of the light yielding action, the light yielding amplitude, the release bearing delay value, the release bearing deficiency value, and the light yielding fatigue induction state.

[0014] In a second aspect, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the computer program, when executed by the processor, implements any step of the PHM-based dynamic fatigue early warning method for rail transit equipment as described in the first aspect of the present invention.

[0015] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements any step of the PHM-based dynamic fatigue early warning method for rail transit equipment as described in the first aspect of the present invention.

[0016] The beneficial effects of this invention are as follows: by performing an effective light yielding detection action, the early dynamic fatigue risk is actively induced and manifested; by identifying the correspondence between the main release segment and the same-direction receiving segment, the abnormality of force release is accurately judged; and by coordinating the determination of the release receiving delay value and the release receiving missing value, the accuracy of dynamic fatigue early warning is improved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a dynamic fatigue early warning method for rail transit equipment based on PHM.

[0019] Figure 2 This is a schematic diagram illustrating the formation of a gentle yielding allowance and an effective gentle yielding detection action.

[0020] Figure 3 A schematic diagram showing the corresponding identification of the main release segment and the same-direction receiving segment.

[0021] Figure 4 A schematic diagram for determining and outputting early warnings of fatigue-induced states during light yielding. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0025] Reference Figures 1-4 As one embodiment of the present invention, this embodiment provides a dynamic fatigue early warning method for rail transit equipment based on PHM, comprising the following steps: S1. Collect the control command value, current speed, strain value of the first strain measuring point and strain value of the second strain measuring point of the target rail transit equipment corresponding to the vehicle, and read the light yield constraint data to determine the light yield judgment data.

[0026] After rail transit vehicles enter online operation, a target rail transit equipment is selected as the object of dynamic fatigue early warning.

[0027] The target rail transit equipment is one of the following: the bogie frame welding connection area, the traction rod seat, the brake caliper mounting seat, the axle box connection area, or the car body traction connection area.

[0028] It should be noted that the selection of target rail transit equipment is determined by the frequency of fatigue cracks, the frequency of connection loosening records, and the location of strain concentration in the vehicle maintenance records. The load-bearing connection location with the highest frequency of fatigue cracks or the highest frequency of connection loosening records is selected as the target rail transit equipment.

[0029] Furthermore, a first strain measuring point and a second strain measuring point are arranged on the target rail transit equipment, and the strain values ​​of the first strain measuring point and the strain values ​​of the second strain measuring point are collected.

[0030] The first strain measuring point is set at the main stress location of the target rail transit equipment.

[0031] The location of the main force is determined by the location of the traction force, braking force, or vertical load transmitted in the design force diagram of the target rail transit equipment.

[0032] The second strain measuring point is set at a location adjacent to the first strain measuring point where there is a structural force transmission relationship.

[0033] The adjacent location is determined by the connection direction of the target rail transit equipment structure, and it is ensured that there are no flexible vibration isolation components between the first strain measuring point and the second strain measuring point.

[0034] It should be noted that the first strain measurement point is used to collect the strain release changes at the main force-bearing location, and the second strain measurement point is used to collect the strain release changes at the adjacent force-transmitting location.

[0035] Furthermore, the vehicle controller reads the traction command value and the braking command value that are in a valid output state as the control command value.

[0036] The control command value is normalized using the maximum permissible output normalization method (for example, the traction command value is divided by the current speed and the maximum permissible traction output value under the current operating mode to obtain the normalized traction command value). A control command value of 0 indicates no traction output or no braking output, and a control command value of 1 indicates the maximum permissible traction output or maximum braking output under the current operating mode.

[0037] The vehicle speed acquisition device reads the current vehicle speed, and the strain acquisition device simultaneously reads the strain values ​​of the first strain measuring point and the strain values ​​of the second strain measuring point.

[0038] The vehicle controller, vehicle speed acquisition device, and strain acquisition device use vehicle network time for time alignment, and the time alignment error does not exceed one strain sampling cycle.

[0039] Furthermore, obtain the light yield constraint data.

[0040] The light yield constraint data includes control adjustable limit, protection prohibition sign and sampling coordination parameters.

[0041] It should be noted that the control adjustable limit is determined by the range of control commands that the vehicle controller can reduce under the current operating mode, current vehicle speed, and current vehicle load conditions; the protection prohibition sign is obtained by reading the protection status corresponding to emergency traction, emergency braking, precise parking at the station, low adhesion protection, and speed limit protection from the vehicle controller; the sampling coordination parameters include the control sampling period, strain sampling period, and the shortest stable output time of the vehicle controller.

[0042] The control command value, the vehicle's current speed, the strain value at the first strain measuring point, the strain value at the second strain measuring point, and the minor yielding constraint data are stored according to the sampling time to determine the minor yielding judgment data.

[0043] S2. Identify the permitted period for light yielding based on the vehicle's current speed, the protection prohibition sign, and the continuous stable state of the control command value. During the permitted period for light yielding, briefly reduce the control command value according to the vehicle's control adjustment range, and restore it to the control level before light yielding after the light yielding holding time ends, thus forming an effective light yielding detection action.

[0044] Furthermore, the vehicle controller identifies whether the target rail transit equipment's corresponding vehicle is in a period of light yielding based on the vehicle's current speed, control command value, control adjustable limit, protection prohibition sign, and sampling coordination parameters.

[0045] The permitted period for light yielding refers to the continuous operating period during which the vehicle is in a stable traction output state or a stable braking output state, and the vehicle controller still has a safety margin for slightly reducing the control command value.

[0046] Specifically, the vehicle controller first reads the protection prohibition sign. When the protection prohibition sign indicates that the vehicle is in emergency traction, emergency braking, precise parking in the station, low adhesion protection, or speed limit protection, the vehicle controller stops the current light yield permission judgment and does not execute the control light yield detection action. When the protection prohibition sign does not have any protection status, the vehicle controller continues to read the current vehicle speed and control command value, and determines whether the current vehicle speed is in a stable operating state.

[0047] Among them, the stable operating state is determined by the change of the vehicle's current speed within the continuous control sampling period. When the speed change of the vehicle's current speed within the continuous control sampling period does not exceed the comfort speed fluctuation range allowed by the vehicle operation control, the vehicle's current speed is judged to be in a stable operating state.

[0048] It should be noted that the comfort speed fluctuation range is obtained by statistically analyzing the smooth operating speed fluctuation data that did not cause traction braking control correction or trigger ride comfort alarms during the vehicle commissioning phase or operation records, with a value range of 0.02m / s to 0.20m / s.

[0049] Furthermore, to avoid the accidental triggering of the yield detection due to instantaneous fluctuations in the control command value, the vehicle controller reads the maximum, minimum, and average values ​​of the control command value during a continuous and stable observation period, and judges whether the control command value is stable based on the proportion of the fluctuation between the maximum and minimum values ​​relative to the average value.

[0050] When the fluctuation range of the control command value is lower than the allowable boundary for command stability, the control command value is determined to be in a continuous stable state.

[0051] When the fluctuation range of the control command value is not lower than the allowable boundary of command stability, the control command value is determined to be in a non-continuous stable state. The vehicle controller does not generate a light yield allowance period and maintains continuous and stable observation of the control command value.

[0052] It should be noted that the continuous stable observation time is the sampling period used to confirm the stable maintenance of traction output or braking output after the most recent change in the control command value. It is obtained according to the minimum stable output requirement of the vehicle controller and has a value range of 0.3s to 3s. The command stability allowable boundary is obtained according to the minimum executable adjustment amount of the vehicle controller and the control sampling noise, and has a value range of 0.01 to 0.05.

[0053] Furthermore, the vehicle controller calls upon the continuous stable state of the control command value in the yield determination data, and combines the vehicle's current speed, control adjustable limit, and protection prohibition sign to identify the permitted yield period.

[0054] When the vehicle's current speed is stable, the control command value is continuously stable, the protection prohibition sign does not display the protection status, and the control adjustable limit display control command value has a range that can be reduced, the vehicle controller will determine the current continuous running period as the light yielding allowable period.

[0055] It should be noted that the control adjustable limit is obtained through the control command range that the vehicle controller is allowed to reduce under the current operating mode, current vehicle speed, and current vehicle load conditions; when the reduction range corresponding to the control adjustable limit is less than the minimum executable adjustment amount of the vehicle controller, the vehicle controller does not generate a light yield allowance period.

[0056] Furthermore, during the permitted period of light yielding, the vehicle controller generates a light yielding detection action based on the control adjustable limit and sampling coordination parameters.

[0057] The control of the light yield detection action includes briefly reducing the control command value, maintaining the reduced control command value, and restoring the control level before the light yield.

[0058] It should be noted that the yield amplitude is selected from the range that can be reduced corresponding to the adjustable limit of the control, and the yield amplitude is not lower than the minimum executable adjustment amount of the vehicle controller, while not exceeding the control adjustment amount of the vehicle controller that does not cause a significant change in vehicle acceleration under the current operating state; the yield holding time is determined according to the strain sampling period in the sampling coordination parameters and the shortest stable output time of the vehicle controller, and the yield holding time is guaranteed to cover multiple (e.g., 3) strain sampling periods, so that the first strain measuring point and the second strain measuring point can form a continuous strain release record.

[0059] When the control command value is the control command value under the traction-dominant state, the vehicle controller briefly reduces the control command value corresponding to the traction output during the light yielding allowance period, and restores it to the control level before the light yielding after the light yielding hold time ends; when the control command value is the control command value under the braking-dominant state, the vehicle controller briefly reduces the control command value corresponding to the braking output during the light yielding allowance period, and restores it to the control level before the light yielding after the light yielding hold time ends.

[0060] The process of reducing and restoring the control command value both employ the original slope limiting method of the vehicle controller, ensuring that the longitudinal acceleration of the vehicle remains within the comfort control range.

[0061] When the vehicle controller performs a light yielding detection action, it simultaneously records the start time of the light yielding action, the end time of the light yielding action, the light yielding magnitude, the light yielding holding time, and the control level before the light yielding, thus forming an effective light yielding detection action.

[0062] S3. Based on the continuous strain release change of the first strain measuring point under the effective light yielding detection action, determine the main release segment. In the second strain measuring point, search for the same direction bearing segment that is consistent with the release direction of the main release segment. Based on the starting interval between the main release segment and the same direction bearing segment, the release amplitude of the main release segment and the release amplitude of the same direction bearing segment, calculate the release bearing delay value and the release bearing missing value to generate fatigue induction judgment data.

[0063] Furthermore, based on the effective yielding detection action, the strain acquisition device extracts continuous strain data from the first strain measurement point and the second strain measurement point before the start of the yielding action and during the yielding holding time, respectively, according to the start time of the yielding action and the yielding holding time, to form the first strain release data segment and the second strain release data segment.

[0064] The first strain release data segment is used to characterize the direct force release process of the main force-bearing position after a short-term reduction in control command, and the second strain release data segment is used to characterize the force release process of adjacent force-transmitting positions under the same control yielding action.

[0065] Specifically, the strain acquisition device first determines the stable strain level before the first strain measurement point and the stable strain level before the second strain measurement point.

[0066] Specifically, the stable strain level of the first strain measuring point before the slight yielding is obtained by reading the average strain value of the first strain measuring point during the continuous stable sampling period before the start of the slight yielding action; the stable strain level of the second strain measuring point before the slight yielding is obtained by reading the average strain value of the second strain measuring point during the continuous stable sampling period before the start of the slight yielding action; the continuous stable sampling period is intercepted backward from the start of the slight yielding action, and ensures that it covers the continuous strain sampling period, and the corresponding control command value is in a continuous stable state.

[0067] Furthermore, the strain acquisition device determines the main release segment based on the first strain release data segment.

[0068] The main release segment is a continuous sampling segment in which the first strain measuring point continuously releases and changes its strain relative to the stable strain level before the slight yielding action begins, and the magnitude of the release change exceeds the strain sampling noise boundary.

[0069] The start time of the main release segment is the sampling time when the release change of the first strain measuring point first exceeds the strain sampling noise boundary, and the end time of the main release segment is the first sampling time when the release change of the first strain measuring point enters the local holding state; if the local holding state is not formed within the light yielding holding time, the end time of the light yielding holding time is taken as the end time of the main release segment.

[0070] The release amplitude of the main release segment is obtained by the difference between the strain value of the first strain measuring point at the end of the main release segment and the strain value of the first strain measuring point at the beginning of the main release segment, and the release direction of the main release segment is determined according to the sign of the difference.

[0071] It should be noted that the strain sampling noise boundary is obtained through the stable holding sampling period before the start of the slight yielding action. Specifically, the strain fluctuation distribution of the first strain measurement point and the second strain measurement point is read during the continuous stable sampling period, and the strain change amplitude that can cover the normal sampling fluctuation within the stable holding sampling period is taken as the strain sampling noise boundary. This is used to eliminate false release changes caused by strain acquisition noise. The preferred value range of the strain sampling noise boundary is 2με to 20με.

[0072] Furthermore, the strain acquisition device retrieves the same-direction connection segment in the second strain release data segment.

[0073] Among them, the same-direction receiving segment is a continuous sampling segment in which the second strain measuring point produces continuous release changes after the start time of the main release segment, and the direction of the release changes is consistent with the release direction of the main release segment, and the amplitude of the release changes exceeds the strain sampling noise boundary.

[0074] The starting time of the same-direction bearing segment is the sampling time when the direction of the release change of the second strain measuring point is consistent with the release direction of the main release segment and exceeds the strain sampling noise boundary for the first time. The ending time of the same-direction bearing segment is the first sampling time when the release change of the second strain measuring point enters the local holding state. If the second strain measuring point does not form a same-direction bearing segment within the light yielding holding time, the starting time of the same-direction bearing segment is recorded as the ending time of the light yielding holding time, and the release amplitude of the same-direction bearing segment is recorded as zero.

[0075] In this system, the first strain gauge is no longer used as a general comparison point, but as the main release trigger point under a light yielding action; the second strain gauge is no longer used only for numerical difference comparison, but is used to determine whether the release change generated at the main force position completes the same-direction connection along the adjacent force transmission position; when the target rail transit equipment is in a healthy state, the second strain gauge can form a same-direction connection section with consistent direction and commensurate amplitude after the main release section; when the target rail transit equipment has reduced stiffness in the welded connection area, loose connection, or early fatigue cracks, the same-direction connection section is prone to starting lag, inconsistent release direction, or insufficient release amplitude.

[0076] Furthermore, based on the start time of the main release segment, the start time of the same-direction receiving segment, and the light yielding holding time, the release receiving delay value is calculated, expressed as: ; in, To release the slow acceptance value, The start time of the main release segment. This is the starting time of the same-direction continuation segment. To allow for a slight retreat and maintain the duration.

[0077] It should be noted that the release and acceptance delay value is used to characterize the degree of delay in the release and following of the adjacent force transmission position relative to the main force receiving position. The larger the release and acceptance delay value, the more difficult it is for the adjacent force transmission position to form a release and acceptance in the same direction in a timely manner after the main force receiving position undergoes a release change.

[0078] Furthermore, based on the release amplitude of the main release segment and the release amplitude of the same-direction receiving segment, the missing value of the release and receiving segment is calculated, expressed as: ; in, To release the missing values, The release amplitude of the main release segment. This refers to the release range of the same direction receiving segment.

[0079] It should be noted that the release bearing deficiency value is used to characterize the degree of insufficient bearing of the release amplitude of the main force position by the adjacent force transmission position. The larger the release bearing deficiency value, the weaker the bearing of the amplitude of the release change of the first strain measurement point by the second strain measurement point.

[0080] The start time of the main release segment, the start time of the same-direction receiving segment, the release amplitude of the main release segment, the release amplitude of the same-direction receiving segment, the release receiving delay value, and the release receiving missing value are stored accordingly to generate fatigue induction judgment data.

[0081] S4. Determine the fatigue induced state based on the fatigue induced judgment data, and generate dynamic fatigue early warning data for the target rail transit equipment.

[0082] Furthermore, the fatigue-induced state of the target rail transit equipment under light yielding was determined.

[0083] Among them, the light yield fatigue induced state is used to characterize whether the strain release change formed at the main force position of the target rail transit equipment under minimal control light yield can be timely, in the same direction and with full amplitude received by the adjacent force transmission position.

[0084] Furthermore, when the release delay value is lower than the delay allowable boundary, and the release missing value is lower than the missing acceptance boundary, the target rail transit equipment is determined to be in a normal acceptance state.

[0085] The normal bearing state means that after the first strain measuring point forms the main release section under the control of the light yielding action, the second strain measuring point can form the same-direction bearing section within the allowable time range, and the release amplitude of the same-direction bearing section can meet the requirements of healthy force transmission release.

[0086] The vehicle controller maintains the normal dynamic fatigue monitoring frequency under normal operating conditions and writes the data from this minor yielding detection into the online monitoring record of the target rail transit equipment.

[0087] Furthermore, when the release delay value is not lower than the delay allowable boundary, and the release missing value is lower than the missing boundary, the target rail transit equipment is determined to be in a release delay state.

[0088] Among them, the delayed release state indicates that the second strain measuring point can still form a unidirectional bearing segment, but the unidirectional bearing segment starts significantly later than the main release segment.

[0089] When the vehicle controller is in a slow release state, it increases the frequency of light yielding detection and generates a visual inspection prompt for the target rail transit equipment entering the warehouse. The inspection focus is on the connection transition area between the first strain measuring point and the second strain measuring point.

[0090] Furthermore, when the release delay value is lower than the delay allowable boundary, and the release missing value is not lower than the missing boundary, the target rail transit equipment is determined to be in a state of insufficient release.

[0091] Among them, the insufficient release state indicates that the second strain measuring point can form a unidirectional support segment in time, but the release amplitude of the unidirectional support segment does not fully correspond to the release amplitude of the main release segment.

[0092] When the vehicle controller is in a state of insufficient load release, it generates a local force transmission abnormality warning and generates a fastening check command and a strain retest command. The inspection focuses on the bolt connection position, welded connection position and load transfer transition position of the target rail transit equipment.

[0093] Furthermore, when the release delay value is not lower than the delay allowable boundary, and the release missing value is not lower than the missing boundary, the target rail transit equipment is determined to be in a fatigue-induced state.

[0094] Among them, the fatigue-induced state indicates that the target rail transit equipment simultaneously exhibits a slow release and insufficient release and acceptance timing and a insufficient release and acceptance amplitude under minimal control and light yielding action, indicating that the force transmission and release relationship between the main force-bearing position and the adjacent force-transmitting position has become abnormal.

[0095] The vehicle controller generates dynamic fatigue warning data under fatigue induced state and sends smooth traction or smooth braking suggestions to the vehicle controller, while generating non-destructive testing instructions for the target rail transit equipment.

[0096] It should be noted that both the allowable delay boundary and the allowable failure boundary are obtained through low-amplitude light yielding calibration data. The low-amplitude light yielding calibration data comes from the initial operation phase after the target rail transit equipment has passed maintenance. Multiple light yielding calibrations are performed under the same measuring point layout and the same light yielding amplitude range. The stable distribution of release yielding delay value and release yielding failure value under healthy calibration state is extracted. The values ​​that can cover healthy and stable fluctuations and are lower than the initial distribution of confirmed abnormal samples are used as the allowable delay boundary and the allowable failure boundary. The value range of the allowable delay boundary is 0.10 to 0.35, and the value range of the allowable failure boundary is 0.15 to 0.45, so that the online light yielding detection only triggers dynamic fatigue warning when the release yielding sequence or release yielding amplitude exceeds the healthy and stable range.

[0097] Furthermore, the dynamic fatigue early warning data includes the name of the target rail transit equipment, the location of the first strain measuring point, the location of the second strain measuring point, the start time of the light yielding action, the magnitude of the light yielding action, the release and acceptance delay value, the release and acceptance missing value, and the fatigue-induced state of the light yielding action.

[0098] This embodiment also provides a computer device applicable to the dynamic fatigue early warning method for rail transit equipment based on PHM, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the dynamic fatigue early warning method for rail transit equipment based on PHM as proposed in the above embodiment.

[0099] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0100] This embodiment also provides a storage medium storing a computer program. When executed by a processor, the program implements the dynamic fatigue early warning method for rail transit equipment based on PHM as proposed in the above embodiments. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0101] In summary, this invention achieves proactive induction and manifestation of early dynamic fatigue risk by executing effective light yielding detection actions; it achieves accurate judgment of force release anomalies by correspondingly identifying the main release segment and the same-direction receiving segment; and it improves the accuracy of dynamic fatigue early warning by collaboratively determining the release receiving delay value and the release receiving missing value.

[0102] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A dynamic fatigue early warning method for rail transit equipment based on PHM, characterized in that, include: Collect the control command value, current speed, strain value of the first strain measuring point and strain value of the second strain measuring point of the target rail transit equipment corresponding to the vehicle, and read the light yield constraint data to determine the light yield judgment data; Based on the vehicle's current speed, the protection prohibition sign, and the continuous stable state of the control command value, the light yielding permission period is identified. During the light yielding permission period, the control command value is briefly reduced according to the vehicle's control adjustment range, and after the light yielding holding time ends, it is restored to the control level before the light yielding, thus forming an effective light yielding detection action. Based on the continuous strain release change of the first strain measuring point under the effective light yielding detection action, the main release segment is determined. In the second strain measuring point, the same direction bearing segment that is consistent with the release direction of the main release segment is retrieved. Based on the starting interval between the main release segment and the same direction bearing segment, the release amplitude of the main release segment and the release amplitude of the same direction bearing segment, the release bearing delay value and the release bearing missing value are calculated to generate fatigue induction judgment data. The fatigue induced state is determined based on the fatigue induced judgment data, and dynamic fatigue early warning data of the target rail transit equipment is generated.

2. The dynamic fatigue early warning method for rail transit equipment based on PHM as described in claim 1, characterized in that, The data used to determine the minor concession includes: First and second strain measuring points are arranged on the target rail transit equipment; Read the traction command value and the braking command value that are in a valid output state as the control command value, and normalize the control command value; The control command value, the current vehicle speed, the strain value of the first strain measuring point, the strain value of the second strain measuring point, and the minor yielding constraint data are stored to obtain the minor yielding judgment data. The first strain measuring point is set at the main stress position of the target rail transit equipment; The second strain measuring point is located at a position adjacent to the first strain measuring point where there is a structural force transmission relationship.

3. The dynamic fatigue early warning method for rail transit equipment based on PHM as described in claim 1 or 2, characterized in that, The period for receding minor concessions includes: Within a continuous and stable observation period, the maximum, minimum, and average values ​​of the control command values ​​are obtained, and the control command values ​​are judged to be in a continuous and stable state based on the proportion of the fluctuation between the maximum and minimum values ​​relative to the average value. When the vehicle's current speed is in a stable operating state, the control command value is in a continuous stable state, the protection prohibition sign does not show a protection state, and the vehicle control allowable adjustment range shows that the control command value has a range that can be reduced, the corresponding continuous operating period is determined as the light yield allowable period.

4. The dynamic fatigue early warning method for rail transit equipment based on PHM as described in claim 3, characterized in that, The effective yielding detection action includes: The yielding amplitude is determined based on the vehicle control's allowable adjustment range, and the yielding holding time is determined based on the strain sampling period; During the allowable period of slight yielding, the control command value is reduced according to the slight yielding magnitude, and the reduced control command value is maintained during the light yielding holding period; After the light yield hold time ends, the control command value is restored to the control level before the light yield; Record the start time, end time, amplitude, duration, and control level before the slight yielding action to form an effective slight yielding detection action.

5. The dynamic fatigue early warning method for rail transit equipment based on PHM as described in claim 4, characterized in that, The determination of the main release segment includes: Based on the effective yielding detection action, according to the start time of the yielding action and the yielding holding time, the continuous strain data of the first strain measuring point before the start of the yielding action and during the yielding holding time are extracted to obtain the first strain release data segment; Based on the continuous stable sampling period before the start of the slight yielding action, determine the stable strain level of the first strain measuring point before the slight yielding; The continuous sampling segment in which the first strain measuring point continuously releases its strain relative to the stable strain level before the first strain measuring point's slight yielding action begins, and the amplitude of the release change exceeds the strain sampling noise boundary, is determined as the main release segment. The release amplitude of the main release segment is determined based on the start and end times of the main release segment, and the release direction of the main release segment is determined based on the sign of the release amplitude.

6. The dynamic fatigue early warning method for rail transit equipment based on PHM as described in claim 5, characterized in that, The calculation of the release delay value and the release missing value includes: Based on the start time and holding time of the gentle yielding action, continuous strain data of the second strain measuring point before the start of the gentle yielding action and during the holding time of the gentle yielding action are extracted to obtain the second strain release data segment; In the second strain release data segment, the continuous sampling segment in which the second strain measurement point produces continuous release changes after the start time of the main release segment, and the direction of the release change is consistent with the release direction of the main release segment, and the amplitude of the release change exceeds the strain sampling noise boundary, is determined as the same direction continuation segment. The ratio of the time difference between the start time of the same-direction receiving segment and the start time of the main release segment to the light yielding holding time is used as the release receiving delay value. The ratio of the difference between the release amplitude of the main release segment and the release amplitude of the same-direction receiving segment to the release amplitude of the main release segment is taken as the missing value of release receiving segment.

7. The dynamic fatigue early warning method for rail transit equipment based on PHM as described in claim 1 or 6, characterized in that, The release amplitude of the same-direction bearing segment includes: when the second strain measuring point does not form a same-direction bearing segment within the light yielding holding time, the start time of the same-direction bearing segment is recorded as the end time of the light yielding holding time, and the release amplitude of the same-direction bearing segment is recorded as zero.

8. The dynamic fatigue early warning method for rail transit equipment based on PHM as described in claim 7, characterized in that, The dynamic fatigue early warning data for the target rail transit equipment includes: When the release acceptance delay value is lower than the delay allowable boundary, and the release acceptance missing value is lower than the acceptance missing boundary, the target rail transit equipment is determined to be in a normal acceptance state. When the release delay value is not lower than the delay allowable boundary, and the release missing value is lower than the missing boundary, the target rail transit equipment is determined to be in a release delay state. When the release and acceptance delay value is lower than the delay allowable boundary, and the release and acceptance deficiency value is not lower than the acceptance deficiency allowable boundary, the target rail transit equipment is determined to be in a state of insufficient release and acceptance. When the release delay value is not lower than the delay allowable boundary and the release missing value is not lower than the missing boundary, the target rail transit equipment is determined to be in a fatigue-induced state, and dynamic fatigue early warning data is generated. The dynamic fatigue early warning data includes the target rail transit equipment name, the location of the first strain measuring point, the location of the second strain measuring point, the start time of the light yielding action, the light yielding amplitude, the release and acceptance delay value, the release and acceptance missing value, and the light yielding fatigue induction state.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the PHM-based dynamic fatigue early warning method for rail transit equipment as described in any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the PHM-based dynamic fatigue early warning method for rail transit equipment as described in any one of claims 1 to 8.

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