Train emergency braking system state evaluation method, device, and storage medium

Abstract

This application provides a method, device, and storage medium for assessing the condition of a train emergency braking system. The method involves acquiring the BDP curve of the emergency braking process during daily train operation; determining the acquisition segment within the BDP curve; dividing the emergency braking process into stages based on the acquisition segment; extracting features from each stage; determining the score and weight of each feature; and assessing the condition of the train emergency braking system based on the product of all feature scores and weights. This application assesses the condition of the train emergency braking system solely based on the BCP process value of the emergency braking process during daily train operation, without requiring knowledge of the internal structure and implementation principles of the braking system. The assessment process is simple, the results are accurate and reliable, and it possesses flexibility and adaptability. It can provide personalized, component-level, detailed condition assessments for the braking systems of different trains, meeting the needs of modern rail transit systems for braking system condition monitoring and maintenance management.

Description

Technical Field

[0001] This application relates to the field of rail transit technology, and in particular to a method, device, and storage medium for assessing the condition of a train emergency braking system. Background Technology

[0002] In modern railway transportation systems, emergency braking is fundamental to the safe operation of subway trains. It ensures the safe and reliable deceleration and stopping of trains in emergency situations, guaranteeing operational safety. The emergency braking process involves the train control system issuing an emergency braking command. The emergency braking system uses compressed air supplied by the compressed air supply system to control the magnitude of the train's braking force and monitor the pressure value. (See diagram below.) Figure 1 As shown.

[0003] Emergency braking is triggered by the train's emergency braking loop, which typically includes the following components:

[0004] 1. Emergency Brake Switch: This is a button or switch on the train that is manually activated by the crew or a passenger. Once pressed, the emergency brake switch sends an emergency braking signal to the train's braking system.

[0005] 2. Emergency Brake Valve: Upon receiving an emergency braking signal, the emergency brake valve opens, allowing compressed air to enter the braking system. This rapidly increases the force applied by the brakes, achieving emergency braking of the train. Once emergency braking is triggered, the compressed air controls the pressure changes in the brake cylinders via the BCU (Brake Control Unit) to implement emergency braking.

[0006] 3. Brakes: Brakes are the actuators in the braking system that apply force to slow down or stop the train. In emergency braking situations, the brakes will quickly apply greater force to achieve the emergency braking effect.

[0007] 4. Braking System Monitoring: The emergency braking loop also includes a braking system monitoring function. Once emergency braking is triggered, the braking system monitor will detect the normal operation of the braking system and provide warnings or take appropriate measures when a fault or abnormality is detected.

[0008] A simplified emergency braking pneumatic structure centered on the brake cylinder within the brake control unit (BCU) of the train's emergency braking loop, such as... Figure 2 As shown:

[0009] However, long-term train operation involves numerous braking operations and environmental changes. The materials of equipment components involved in the train's emergency braking circuit, such as valves, brake shoes, springs, brake air cylinders, and brake cylinders, undergo qualitative changes and wear, which may lead to a decline in the performance of the emergency braking system or malfunctions. This can affect the train's braking effect and pose safety hazards. Therefore, it is necessary to dynamically assess the status of the emergency braking system to avoid the occurrence of emergency braking accidents. Summary of the Invention

[0010] To address one of the aforementioned technical deficiencies, this application provides a method, device, and storage medium for assessing the condition of a train emergency braking system.

[0011] The first aspect of this application provides a method for assessing the condition of a train emergency braking system, the method comprising:

[0012] Collect the brake cylinder pressure (BCP) process value during the emergency braking process in daily train operation;

[0013] Based on the BCP process value, a BDP curve is generated, with the horizontal axis of the BDP curve representing the acquisition time and the vertical axis representing the BDP process value.

[0014] Identify the acquisition segment in the BDP curve;

[0015] Based on the collected footage, the emergency braking process was divided into stages;

[0016] Extract features from each stage;

[0017] Determine the score and weight of each feature;

[0018] The status of the train's emergency braking system is assessed by producting the scores of all features with their weights.

[0019] Optionally, the acquisition segment in the BDP curve is determined, including:

[0020] Determine the slope value corresponding to each acquisition time in the BDP curve;

[0021] The first acquisition time is used as the initial time, and a time window is formed with a preset value as the length;

[0022] Determine the distance between the slope vector and the zero vector within the current time window; where the slope vector consists of the slope values ​​corresponding to the acquisition times within the current time window, and the length of the zero vector is a preset value;

[0023] If the distance is not greater than the preset distance threshold, the initial time of the current time window is recorded. If the distance is greater than the preset distance threshold, all initial times that were recorded but not yet formed into a collection segment are formed into a collection segment.

[0024] The sliding time window is repeatedly executed, including the steps of determining the distance between the slope vector and the zero vector within the current time window and subsequent steps, until the initial time of the time window slides out of the BDP curve. The length of the sliding time window remains unchanged, and the initial time is the next acquisition time after the initial time of the current time window.

[0025] Optionally, based on the collected segments, the emergency braking process can be divided into stages, including:

[0026] The longest segment among the collected data is taken as the stable phase of the emergency braking process;

[0027] Identify the standard phases within the acquired segments;

[0028] The rising phase is formed by taking the end time of the adjacent acquisition segment before the standard phase as the initial time of the rising phase and taking the initial time of the stable phase as the end time of the rising phase.

[0029] Optionally, standard phases in the acquired segments are determined, including:

[0030] If the train maintains braking when the train control system issues an emergency braking command, then the standard phase in the collected segment is determined to be the stable phase.

[0031] If the train is in a state of maintaining braking when the train control system issues an emergency braking command, then the standard stage in the data acquisition segment is determined to be the maximum value stage; the maximum value stage is the data acquisition segment with the largest average value of the BDP process.

[0032] Optionally, the phases can be divided into an upward phase and a stable phase;

[0033] Extract features from each stage, including:

[0034] For the rising phase, extract the pressure rise time, the inflation rate of the brake cylinder pressure, and the pressure rise rate.

[0035] For the stable phase, extract the stable value, standard deviation, maximum value, and minimum value;

[0036] Among them, the pressure rise time is the time required for the brake cylinder pressure to rise to k% of the emergency braking target pressure after the emergency braking command is issued, where k is a preset value.

[0037] The inflation rate of the brake cylinder pressure is the slope corresponding to the preset pressure segment during the inflation time of the brake cylinder pressure.

[0038] The rate of pressure rise is the speed at which pressure increases.

[0039] The stable value is the BDP process value that appears most frequently during the stable phase.

[0040] The standard deviation is the standard deviation of all BDP process values ​​during the steady-state phase;

[0041] The maximum value is the maximum value of all BDP process values ​​during the steady-state phase;

[0042] The minimum value is the minimum value of all BDP process values ​​during the steady-state phase.

[0043] Optionally, k is 90;

[0044] The preset pressure range is 50 kPa to 70 kPa.

[0045] Optionally, the scores and weights of each feature are determined, including:

[0046] Determine the baseline values ​​for each feature. Standard deviation σ i and the change threshold K i Where i is the feature identifier;

[0047] Determine the values ​​f of each feature in the BDP curve. i ;

[0048] Calculate the score for each feature.

[0049] Calculate the weights of each feature. in,

[0050] Optionally, a baseline value for each feature is determined. Standard deviation σ i and the change threshold K i ,include:

[0051] Obtain multiple BDP sample curves;

[0052] Determine the values ​​of each feature in each BDP sample curve;

[0053] The mean of all values ​​for each feature is used as the baseline value for that feature.

[0054] The standard deviation of all values ​​for each feature is defined as the standard deviation σ of that feature. i ;

[0055] The change threshold K of each characteristic was obtained from the train's factory braking system design specification. i Alternatively, the threshold K for each feature can be obtained by statistically analyzing the changes of each feature under normal conditions. i .

[0056] A second aspect of this application provides an electronic device, comprising:

[0057] Memory;

[0058] Processor; and

[0059] Computer programs;

[0060] The computer program is stored in the memory and configured to be executed by the processor to implement the method described in the first aspect above.

[0061] A third aspect of this application provides a computer-readable storage medium having a computer program stored thereon; the computer program is executed by a processor to implement the method described in the first aspect above.

[0062] This application provides a method, device, and storage medium for assessing the condition of a train emergency braking system. The method involves acquiring the BDP curve of the emergency braking process during daily train operation; determining the acquisition segment within the BDP curve; dividing the emergency braking process into stages based on the acquisition segment; extracting features from each stage; determining the score and weight of each feature; and assessing the condition of the train emergency braking system based on the product of all feature scores and weights. This application assesses the condition of the train emergency braking system solely based on the BCP process value of the emergency braking process during daily train operation, without requiring knowledge of the internal structure and implementation principles of the braking system. The assessment process is simple, the results are accurate and reliable, and it possesses flexibility and adaptability. It can provide personalized, component-level, detailed condition assessments for the braking systems of different trains, meeting the needs of modern rail transit systems for braking system condition monitoring and maintenance management. Attached Figure Description

[0063] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0064] Figure 1 This is a schematic diagram of the existing emergency braking process;

[0065] Figure 2 This is a simplified schematic diagram of an existing emergency braking pneumatic structure.

[0066] Figure 3 This is a schematic diagram of the train emergency braking system status assessment method provided in an embodiment of this application;

[0067] Figure 4 This is a schematic diagram of the BDP curve change process provided in an embodiment of this application;

[0068] Figure 5 A schematic diagram illustrating the BDP curve change process under operating condition a51 provided in this application embodiment;

[0069] Figure 6 A schematic diagram of the BDP curve change process under 550 operating conditions provided in this application embodiment;

[0070] Figure 7 A schematic diagram illustrating the stages under the a51 operating condition provided in this application embodiment;

[0071] Figure 8 A schematic diagram illustrating the stages under the 550 operating condition provided in this application embodiment;

[0072] Figure 9 This is a schematic diagram of feature extraction under the a51 operating condition provided in an embodiment of this application;

[0073] Figure 10 This is a schematic diagram of feature extraction under a 550 operating condition provided in an embodiment of this application;

[0074] Figure 11 This is a schematic diagram of the evaluation results under the a51 operating condition provided in an embodiment of this application;

[0075] Figure 12 This is a schematic diagram of the evaluation results under the 550 operating condition provided in the embodiments of this application. Detailed Implementation

[0076] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0077] In the process of developing this application, the inventors discovered that long-term train operation involves a large number of braking operations and environmental changes. The materials of the equipment components involved in the train's emergency braking circuit, such as valves, brake shoes, springs, brake air cylinders, and brake cylinders, undergo qualitative changes and wear, which may lead to a decrease in the performance of the emergency braking system or malfunction, thereby affecting the train's braking effect and posing a safety hazard. It is necessary to dynamically assess the status of the emergency braking system to avoid the occurrence of emergency braking accidents.

[0078] To address the aforementioned issues, this application provides a method, device, and storage medium for assessing the status of a train emergency braking system. The method involves acquiring the BDP curve of the emergency braking process during daily train operation; determining the acquisition segment within the BDP curve; dividing the emergency braking process into stages based on the acquisition segment; extracting features from each stage; determining the score and weight of each feature; and assessing the status of the train emergency braking system based on the product of all feature scores and weights. This application assesses the status of the train emergency braking system solely based on the BCP process value of the emergency braking process during daily train operation, without requiring knowledge of the internal structure and implementation principles of the braking system. The assessment process is simple, the results are accurate and reliable, and it possesses flexibility and adaptability. It can provide personalized, component-level, fine-grained status assessments for the braking systems of different trains, meeting the needs of modern rail transit systems for braking system status monitoring and maintenance management.

[0079] See Figure 3 The implementation process of the train emergency braking system status assessment method provided in this embodiment is as follows:

[0080] 301. Collect the BCP (Brake Cylinder Pressure) process value during the emergency braking process of the train in daily operation.

[0081] This step can be achieved using a pressure sensor installed on the brake cylinder.

[0082] For example,

[0083] 1. Install a pressure sensor on the brake cylinder beforehand.

[0084] The sensor can be a pressure sensor or a specific sensor called a brake cylinder sensor. It is important to ensure that the sensor is correctly connected and securely installed.

[0085] 2. Connect the sensor to the data acquisition system.

[0086] The connection can be a cable connection or a wireless connection, depending on the type of sensor and data acquisition system.

[0087] 3. Data collected by the sensor is transmitted via connection.

[0088] 4. Use an appropriate data acquisition system to receive and record the BCP process value during emergency braking in real time during daily train operation.

[0089] The data acquisition system can be a dedicated recording device, computer, or data acquisition unit, etc.

[0090] In addition, the collected BCP process values ​​will also be stored. For example, they may be stored in the TCMS (Train Control and Monitoring System).

[0091] 302. Based on the BCP process value, the BDP curve is generated.

[0092] In this curve, the horizontal axis represents the acquisition time, and the vertical axis represents the BDP process value.

[0093] The collected BCP process values ​​can be visualized as BDP curves, which are line graphs describing the change of brake cylinder pressure (unit: kPa) over time. They can intuitively reflect the changes in brake cylinder output pressure during the emergency braking process.

[0094] For a complete emergency braking process, the plotted BDP curve often undergoes a series of changes, including: initial braking application, brake stabilization, and pressure changes during brake release, such as... Figure 4 As shown.

[0095] A single complete emergency braking action will generate one BDP curve, and multiple complete emergency braking actions will generate multiple BDP curves.

[0096] The following example demonstrates real brake cylinder pressure data collected under different train operating conditions.

[0097] The train operating conditions are classified based on the level of emergency braking command and whether the train maintains braking application when the train control system issues an emergency braking command.

[0098] The first operating condition is: the emergency braking command level is a5 and there is a holding brake being applied. For ease of description, this operating condition will be referred to as a51 below.

[0099] The second scenario is: the emergency braking command level is 55, and there is no application of sustained braking. For ease of description, this scenario will be represented by 550 below.

[0100] For the emergency braking process of the vehicle under operating condition A51, the following results are obtained: Figure 5 The graph shows 10 BDP curves. The horizontal axis represents the acquisition time (i.e., sampling point), and the vertical axis represents the BCP process value (i.e., brake cylinder output pressure value). The time intervals between the acquisition times of different curves are different. Under this operating condition, the emergency braking command level is relatively low, and the pressure value remains at around 228 kPa during the brake stabilization phase. Due to the presence of brake holding, the initial braking application starts from a brake cylinder pressure value of 120 kPa, and the pressure value rises until it stabilizes. Subsequently, after the emergency braking command is released, the brake is released until the pressure value returns to 120 kPa.

[0101] For the emergency braking process of vehicles operating at speeds below 550 km / h, the following results are obtained: Figure 6 The graph shows 10 BDP curves. The horizontal axis represents the acquisition time (i.e., sampling point), and the vertical axis represents the BCP process value (i.e., brake cylinder output pressure value). The time intervals between the acquisition times of different curves are different. Under this operating condition, the emergency braking command level is high, and the pressure value remains at around 278 kPa during the brake stabilization phase. There is no sustained braking application under this condition, so the initial braking application starts from the brake cylinder pressure value of 0 kPa. The pressure value rises rapidly to around 290 kPa, stabilizes at this pressure value for a period of time, and then drops back to around 278 kPa, exhibiting a long period of stability. Subsequently, after the emergency braking command is released, the braking is relieved until the pressure value returns to 0 kPa.

[0102] 303, Determine the acquisition segment in the BDP curve.

[0103] The implementation process of this step is as follows:

[0104] 303-1, Determine the slope value corresponding to each acquisition time in the BDP curve.

[0105] 303-2, take the first acquisition time as the initial time, and form a time window with a preset value as the length.

[0106] 303-3, Determine the distance between the slope vector and the zero vector within the current time window.

[0107] The slope vector consists of the slope values ​​corresponding to the acquisition time within the current time window, and the length of the zero vector is a preset value.

[0108] 303-4. If the distance is not greater than the preset distance threshold, the initial time of the current time window is recorded. If the distance is greater than the preset distance threshold, all initial times that were recorded but not yet formed into a collection segment are formed into a collection segment.

[0109] 303-5, Slide the time window, and repeat the step of determining the distance between the slope vector and the zero vector within the current time window (i.e., 303-3) and subsequent steps until the initial time of the time window slides out of the BDP curve.

[0110] The length of the sliding time window remains unchanged, and the initial time is the next acquisition time after the initial time of the current time window.

[0111] For example: After determining the slope value corresponding to each acquisition time in the BDP curve, starting from the first acquisition time, perform the following steps for each acquisition time until the last acquisition time.

[0112] Set a time window, with its start time being the current acquisition time and its size being a preset value, such as M. Then, construct a slope vector from the slope values ​​of all acquisition times within the current time window. Obtain the zero vector of length M Calculate the slope vector With the zero vector The L2 norm *dis* of the difference between the slope vector and the zero vector is used as the distance between the slope vector and the zero vector. If *dis* ≤ N, the initial moment of the current time window is recorded (i.e., the acquisition moment is recorded), and the next acquisition moment is executed. Otherwise, all initial moments that are recorded but not yet formed into acquisition segments are formed into acquisition segments, and then the next acquisition moment is executed.

[0113] Where N is the distance threshold,

[0114] In all the initial moments that were recorded but not formed into acquisition segments, the slope of the braking curve was close to 0, which was considered as extracting a relatively stable stage.

[0115] After all the data collection is completed, multiple sampling point segments can be obtained, which are multiple candidate stable phases.

[0116] 304. Based on the collected footage, the emergency braking process is divided into stages.

[0117] The execution process for this step is as follows:

[0118] 304-1, the longest segment in the collected data is taken as the stable phase of the emergency braking process.

[0119] Among all the acquired segments, the longest segment (i.e. the segment with the longest pressure stability) is defined as the stable phase of the entire braking process.

[0120] 304-2, Determine the standard stage in the acquired segment.

[0121] The standard stage varies depending on whether the train maintains the applied braking state when the train control system issues an emergency braking command.

[0122] If the train maintains braking when the train control system issues an emergency braking command, then the standard phase in the collected segment is determined to be the stable phase.

[0123] If the train is in a state of maintaining braking when the train control system issues an emergency braking command, then the standard stage in the collected segment is determined to be the maximum value stage.

[0124] Therefore, for trains that maintain braking application when the train control system issues an emergency braking command, the maximum value stage will be determined after executing step 304-1 and before executing step 304-3. That is, the maximum value stage is the acquisition segment with the largest average value of the BDP process.

[0125] For example, the average value of all collected segments is calculated, and the segment with the largest average value (i.e., the segment with the largest stable pressure value) is defined as the maximum value stage of the entire braking process.

[0126] 304-3, the end time of the adjacent acquisition segment before the standard phase is taken as the initial time of the rising phase, and the initial time of the stable phase is taken as the end time of the rising phase, thus forming the rising phase.

[0127] The following explanation uses a51 and 550 as examples to illustrate step 304-3.

[0128] For a51, there is a holding brake application, so the standard phase is the stable phase. In step 304-3, the end time of the adjacent acquisition segment before the stable phase is taken as the initial time of the rising phase, and the initial time of the stable phase is taken as the end time of the rising phase, thus forming the rising phase. That is, for a51, the adjacent phase before the stable phase is extracted as the holding brake or the pressure value is always 0 phase before the pressure value rises. The end time of this phase (i.e., the end time of the stable phase before the pressure rises) is defined as the pressure value starts to rise time. The time between this time and the first time the stable phase is reached is defined as the rising phase of the entire braking process.

[0129] by Figure 5 Taking curve 0 as an example, this emergency braking process was divided into an ascending phase and a stabilizing phase, as shown in the following... Figure 7 As shown.

[0130] For 550, there is no sustained braking application, so the standard phase is the maximum value phase. In step 304-3, the end time of the adjacent acquisition segment before the maximum value phase is taken as the initial time of the rising phase, and the initial time of the stable phase is taken as the end time of the rising phase, thus forming the rising phase. That is, for 550, the phase adjacent to the maximum value phase is extracted as the sustained braking or pressure value always being 0 phase before the pressure value rises. The time of the last sampling point of this phase (i.e., the end time of the stable phase before the pressure rise) is defined as the pressure value starting to rise time. The time between this time and the first time the stable phase is reached is defined as the rising phase of the entire braking process.

[0131] by Figure 6 Taking curve 3 as an example, this emergency braking process was divided into an ascending phase, a maximum value phase, and a stable phase, as shown in the following diagram. Figure 8 As shown.

[0132] 305. Extract features from each stage.

[0133] As shown in step 305, the divided stages must include an ascent stage and a stabilization stage. Therefore, this step extracts the pressure rise time, the cylinder inflation rate, and the pressure rise rate for the ascent stage. For the stabilization stage, it extracts the stable value, standard deviation, maximum value, and minimum value.

[0134] in,

[0135] 1. Pressure rise time

[0136] The pressure rise time is the time required for the brake cylinder pressure to rise to k% of the emergency braking target pressure after an emergency braking command is issued.

[0137] k is a preset value, for example, k is 90.

[0138] For example, the pressure rise time is the time required for the brake cylinder pressure to rise to the specified pressure (90% of the target pressure) after an emergency braking command is issued.

[0139] 2. Brake cylinder pressure inflation rate

[0140] The inflation rate of the brake cylinder pressure is the slope corresponding to the preset pressure segment during the inflation time of the brake cylinder pressure.

[0141] The preset pressure range is from 50 kPa to 70 kPa.

[0142] For example, in the inflation time of the brake cylinder pressure, a special slope range of 50kPa-70kPa is selected. This range reflects the inflation speed of the vehicle, and the brake cylinder pressure data at this time represents a series of actions of the braking system.

[0143] 3. Pressure rise rate

[0144] The rate of pressure rise is the rate of pressure increase.

[0145] The rate of pressure rise can reflect the overall rate of pressure increase during the rising phase.

[0146] 4. Stable value

[0147] The stable value is the BDP process value that appears most frequently during the stable phase.

[0148] When the brake cylinder pressure is established, the actual output pressure value is based on the target pressure. The actual output value differs from the target set value. During the stabilization phase, due to the system's dynamic characteristics, the actual brake cylinder pressure is real-time. In a single braking operation, if the vehicle's brake cylinder pressure output value becomes abnormally high or low, using the mean value might be affected by the abnormal data. Therefore, this embodiment selects the single mode value (i.e., the most frequent occurrence) of the data segment as the stable value for the brake cylinder pressure stabilization phase. In other words, the BDP process value that occurs most frequently during the stabilization phase is selected as the normal actual output value (i.e., the stable value).

[0149] 5. Standard deviation

[0150] The standard deviation is the standard deviation of all BDP process values ​​during the steady-state phase.

[0151] Standard deviation is the square root of the arithmetic mean of the squared deviations from the mean. It reflects the level of dispersion of a dataset and is one of the most frequently used quantitative indicators of the degree of dispersion of a set of data; it is a primary indicator of accuracy. For brake cylinder pressure in a stable phase, the normal value is constant, but the actual output usually fluctuates. Standard deviation can be used to represent the degree of fluctuation in brake cylinder pressure, thereby monitoring the stability of the system output.

[0152] 6. Maximum value

[0153] The maximum value is the maximum value of all BDP process values ​​during the steady-state phase, and this maximum value is the actual maximum value.

[0154] When the brake cylinder pressure is unstable and exhibits abnormal output, it is necessary to monitor the actual maximum output pressure. Excessive brake contact surface pressure will cause the wheels to lock up, thereby affecting braking performance.

[0155] 7. Minimum value

[0156] The minimum value is the minimum value of all BDP process values ​​during the steady-state phase, and this minimum value is the actual minimum value.

[0157] When the braking system malfunctions, such as leakage in the relay valve or brake cylinder, the brake cylinder pressure will continuously decrease after rising to the target pressure due to ongoing leakage. The minimum value during the stabilization phase is used to monitor for potential abnormalities.

[0158] The following example, using a51 and 550, illustrates the feature extraction process.

[0159] For a51, Figure 5Taking curves 0-9 (a total of 10 curves) as an example, the following data shows the 90%T (pressure rise time), special slope time periods (charge rate of brake cylinder pressure), stable values, standard deviations, significant maximum values, and significant minimum values ​​for each stage: Figure 9 As shown.

[0160] For 550, Figure 6 Taking curves 0-9 (a total of 10 curves) as an example, the following data shows the 90%T (pressure rise time), special slope time periods (charge rate of brake cylinder pressure), stable values, standard deviations, significant maximum values, and significant minimum values ​​for each stage: Figure 10 As shown.

[0161] 306. Determine the score and weight of each feature.

[0162] The implementation process of this step is as follows:

[0163] 306-1, Determine the baseline values ​​for each feature. Standard deviation σ i and the change threshold K i .

[0164] Where i is the feature identifier.

[0165] 1. Baseline values ​​for each feature and standard deviation σ i

[0166] Baseline values ​​for each feature and standard deviation σ i It is based on sample data.

[0167] In other words, before executing step 306-1,

[0168] 1) Obtain multiple BDP sample curves.

[0169] The BDP sample curve here can be generated by taking the historical BCP process values ​​of each train. The data collection scheme is similar to the implementation process of step 301, except that the data collection objects are different, so it will not be repeated here.

[0170] 2) Determine the values ​​of each feature in each BDP sample curve.

[0171] After acquiring the BDP sample curve, the acquisition segment in the BDP sample curve is determined; based on the acquisition segment, the emergency braking process is divided into stages; the features of each stage are extracted; and then the values ​​of each feature in each BDP sample curve are obtained.

[0172] The specific implementation plan described above is similar to steps 303 to 305, except that the curves processed are different, so it will not be repeated here.

[0173] For example, there are n BDP sample curves and m features. For any feature i (i = 1, 2, ..., m) among the m features, the value of each feature in the BDP sample curve is...

[0174] 3) Determine the mean of all values ​​for each feature as the baseline value for each feature.

[0175] For example, for any feature i,

[0176] 4) Determine the standard deviation of all values ​​for each feature as the standard deviation σ of each feature. i .

[0177] For example, for any feature i,

[0178] 2. Change threshold K i

[0179] Change threshold K i It is based on design specifications or statistics.

[0180] For example, the change threshold K of each feature can be obtained from the train's factory braking system design specifications. i Alternatively, the threshold K for each feature can be obtained by statistically analyzing the changes of each feature under normal conditions. i .

[0181] 306-2, Determine the values ​​f of each characteristic in the BDP curve. i .

[0182] 306-3, Calculate the score for each feature.

[0183] 306-4, Calculate the weights of each feature.

[0184] Among them, V i The coefficient of variation is 1.

[0185] 307. Evaluate the status of the train's emergency braking system based on the product of all feature scores and weights.

[0186] For example, evaluation results

[0187] The following example uses a51 and 550 to illustrate the evaluation results.

[0188] Ten curves under operating condition a51 were scored, and the statistical results of the curve scores are as follows: Figure 11 As shown.

[0189] Ten curves under operating condition 550 were scored, and the statistical results of the curve scores are as follows: Figure 12 As shown.

[0190] Figure 12 Compared to the score Figure 11 Overall, it's too low; consider starting from... Figure 5 and Figure 6 The comparison reveals the following reasons: Condition A51 is more common in daily train operation, resulting in more recorded data, and the brake cylinder pressure curve maintains a relatively regular change. Condition 550, on the other hand, represents the maximum braking command level, with fewer recorded data, less obvious patterns, and lower resistance to time-related interference during the brake cylinder pressure rise from 0 compared to condition A51. Furthermore, Condition 550 is often issued at high speeds, requiring a large braking force to urgently decelerate or stop the train in a short time. Due to the influence of high speed, the fluctuations in the emergency braking curve are greater each time, making it difficult for the curve to follow a uniform pattern of change over time.

[0191] Through the above steps 301 to 307, the brake cylinder pressure BCP process value of an emergency braking process can be input to generate a BDP curve. Then, the BDP curve is subjected to segment determination, stage division, and feature extraction to obtain the weight and score of each feature (the feature score is related to the feature extracted from the brake cylinder curve to be evaluated). Finally, the status of the train emergency braking system is comprehensively evaluated based on the weight and score.

[0192] The train emergency braking system status assessment method provided in this embodiment assesses the current status of the train emergency braking system by collecting and analyzing changes in brake cylinder pressure during emergency braking. Throughout the process, the emergency braking system is treated as a black box, focusing only on its inputs and outputs and disregarding its internal structure.

[0193] This embodiment provides a method for assessing the status of a train emergency braking system. The method involves collecting the BDP curve of the emergency braking process during daily train operation; determining the data acquisition segments within the BDP curves; dividing the emergency braking process into stages based on the data acquisition segments; extracting features from each stage; determining the score and weight of each feature; and assessing the status of the train emergency braking system based on the product of all feature scores and weights. This application assesses the status of the train emergency braking system solely based on the BCP process values ​​of the emergency braking process during daily train operation. It does not require a clear understanding of the internal structure and implementation principles of the braking system. The assessment process is simple, the results are accurate and reliable, and it possesses flexibility and adaptability. It can provide personalized, component-level, detailed status assessments for the braking systems of different trains, meeting the needs of modern rail transit systems for braking system status monitoring and maintenance management.

[0194] Based on the same inventive concept as the train emergency braking system status assessment method, this embodiment provides an electronic device, which includes: a memory, a processor, and a computer program.

[0195] The computer program is stored in memory and configured to be executed by a processor to implement the above-mentioned train emergency braking system status assessment method.

[0196] Specifically,

[0197] The brake cylinder pressure (BCP) process value was collected during the emergency braking process of the train in daily operation.

[0198] Based on the BCP process value, a BDP curve is generated, with the horizontal axis of the BDP curve representing the acquisition time and the vertical axis representing the BDP process value.

[0199] Identify the acquisition segment in the BDP curve.

[0200] Based on the collected footage, the emergency braking process was divided into stages.

[0201] Extract features from each stage.

[0202] Determine the score and weight of each feature.

[0203] The status of the train's emergency braking system is assessed by producting the scores of all features with their weights.

[0204] Optionally, the acquisition segment in the BDP curve is determined, including:

[0205] Determine the slope value corresponding to each acquisition time in the BDP curve.

[0206] The first acquisition time is taken as the initial time, and a time window is formed with a preset value as the length.

[0207] Determine the distance between the slope vector and the zero vector within the current time window. The slope vector consists of the slope values ​​corresponding to the acquisition times within the current time window, and the length of the zero vector is a preset value.

[0208] If the distance is not greater than the preset distance threshold, the initial time of the current time window is recorded. If the distance is greater than the preset distance threshold, all initial times that were recorded but not yet formed into a collection segment are formed into a collection segment.

[0209] The sliding time window is repeatedly executed, following the steps of determining the distance between the slope vector and the zero vector within the current time window, and subsequent steps, until the initial time of the time window slides off the BDP curve. The length of the sliding time window remains unchanged, and the initial time is the next acquisition time following the initial time of the current time window.

[0210] Optionally, based on the collected segments, the emergency braking process can be divided into stages, including:

[0211] The longest segment among the collected data is taken as the stable phase of the emergency braking process.

[0212] Identify the standard phases within the acquired segments.

[0213] The rising phase is formed by taking the end time of the adjacent acquisition segment before the standard phase as the initial time of the rising phase and taking the initial time of the stable phase as the end time of the rising phase.

[0214] Optionally, standard phases in the acquired segments are determined, including:

[0215] If the train maintains braking when the train control system issues an emergency braking command, then the standard phase in the collected segment is determined to be the stable phase.

[0216] If the train maintains applied braking when the train control system issues an emergency braking command, then the standard phase in the data acquisition segment is determined to be the maximum value phase. The maximum value phase is the data acquisition segment with the highest average BDP process value.

[0217] Optionally, the phases can be divided into an upward phase and a stable phase.

[0218] Extract features from each stage, including:

[0219] For the rising phase, extract the pressure rise time, the inflation rate of the brake cylinder pressure, and the pressure rise rate.

[0220] For the stable phase, extract the stable value, standard deviation, maximum value, and minimum value.

[0221] The pressure rise time is the time required for the brake cylinder pressure to rise to k% of the emergency braking target pressure after an emergency braking command is issued, where k is a preset value.

[0222] The inflation rate of the brake cylinder pressure is the slope corresponding to the preset pressure segment during the inflation time of the brake cylinder pressure.

[0223] The rate of pressure rise is the rate of pressure increase.

[0224] The stable value is the BDP process value that appears most frequently during the stable phase.

[0225] The standard deviation is the standard deviation of all BDP process values ​​during the steady-state phase.

[0226] The maximum value is the maximum value of all BDP process values ​​during the steady-state phase.

[0227] The minimum value is the minimum value of all BDP process values ​​during the steady-state phase.

[0228] Optionally, k is 90.

[0229] The preset pressure range is 50 kPa to 70 kPa.

[0230] Optionally, the scores and weights of each feature are determined, including:

[0231] Determine the baseline values ​​for each feature. Standard deviation σ i and the change threshold K i , where i is the feature identifier.

[0232] Determine the values ​​f of each feature in the BDP curve. i .

[0233] Calculate the score for each feature.

[0234] Calculate the weights of each feature. in,

[0235] Optionally, a baseline value for each feature is determined. Standard deviation σ i and the change threshold K i ,include:

[0236] Obtain multiple BDP sample curves.

[0237] Determine the values ​​of each feature in each BDP sample curve.

[0238] The mean of all values ​​for each feature is used as the baseline value for that feature.

[0239] The standard deviation of all values ​​for each feature is defined as the standard deviation σ of that feature. i .

[0240] The change threshold K of each characteristic was obtained from the train's factory braking system design specification. i Alternatively, the threshold K for each feature can be obtained by statistically analyzing the changes of each feature under normal conditions. i .

[0241] The electronic device provided in this embodiment has a computer program executed by a processor to perform a status assessment of the train's emergency braking system based solely on the BCP process value during the emergency braking process in daily train operation. It does not require a clear understanding of the internal structure and implementation principle of the braking system. The assessment process is simple, the assessment results are accurate and reliable, and it is flexible and adaptable. It can provide personalized component-level fine status assessments for the braking systems of different trains, meeting the needs of modern rail transit systems for braking system status monitoring and maintenance management.

[0242] Based on the same inventive concept as the train emergency braking system condition assessment method, this embodiment provides a computer-readable storage medium on which a computer program is stored. The computer program is executed by a processor to implement the aforementioned train emergency braking system condition assessment method.

[0243] Specifically,

[0244] The brake cylinder pressure (BCP) process value was collected during the emergency braking process of the train in daily operation.

[0245] Based on the BCP process value, a BDP curve is generated, with the horizontal axis of the BDP curve representing the acquisition time and the vertical axis representing the BDP process value.

[0246] Identify the acquisition segment in the BDP curve.

[0247] Based on the collected footage, the emergency braking process was divided into stages.

[0248] Extract features from each stage.

[0249] Determine the score and weight of each feature.

[0250] The status of the train's emergency braking system is assessed by producting the scores of all features with their weights.

[0251] Optionally, the acquisition segment in the BDP curve is determined, including:

[0252] Determine the slope value corresponding to each acquisition time in the BDP curve.

[0253] The first acquisition time is taken as the initial time, and a time window is formed with a preset value as the length.

[0254] Determine the distance between the slope vector and the zero vector within the current time window. The slope vector consists of the slope values ​​corresponding to the acquisition times within the current time window, and the length of the zero vector is a preset value.

[0255] If the distance is not greater than the preset distance threshold, the initial time of the current time window is recorded. If the distance is greater than the preset distance threshold, all initial times that were recorded but not yet formed into a collection segment are formed into a collection segment.

[0256] The sliding time window is repeatedly executed, following the steps of determining the distance between the slope vector and the zero vector within the current time window, and subsequent steps, until the initial time of the time window slides off the BDP curve. The length of the sliding time window remains unchanged, and the initial time is the next acquisition time following the initial time of the current time window.

[0257] Optionally, based on the collected segments, the emergency braking process can be divided into stages, including:

[0258] The longest segment among the collected data is taken as the stable phase of the emergency braking process.

[0259] Identify the standard phases within the acquired segments.

[0260] The rising phase is formed by taking the end time of the adjacent acquisition segment before the standard phase as the initial time of the rising phase and taking the initial time of the stable phase as the end time of the rising phase.

[0261] Optionally, standard phases in the acquired segments are determined, including:

[0262] If the train maintains braking when the train control system issues an emergency braking command, then the standard phase in the collected segment is determined to be the stable phase.

[0263] If the train maintains applied braking when the train control system issues an emergency braking command, then the standard phase in the data acquisition segment is determined to be the maximum value phase. The maximum value phase is the data acquisition segment with the highest average BDP process value.

[0264] Optionally, the phases can be divided into an upward phase and a stable phase.

[0265] Extract features from each stage, including:

[0266] For the rising phase, extract the pressure rise time, the inflation rate of the brake cylinder pressure, and the pressure rise rate.

[0267] For the stable phase, extract the stable value, standard deviation, maximum value, and minimum value.

[0268] The pressure rise time is the time required for the brake cylinder pressure to rise to k% of the emergency braking target pressure after an emergency braking command is issued, where k is a preset value.

[0269] The inflation rate of the brake cylinder pressure is the slope corresponding to the preset pressure segment during the inflation time of the brake cylinder pressure.

[0270] The rate of pressure rise is the rate of pressure increase.

[0271] The stable value is the BDP process value that appears most frequently during the stable phase.

[0272] The standard deviation is the standard deviation of all BDP process values ​​during the steady-state phase.

[0273] The maximum value is the maximum value of all BDP process values ​​during the steady-state phase.

[0274] The minimum value is the minimum value of all BDP process values ​​during the steady-state phase.

[0275] Optionally, k is 90.

[0276] The preset pressure range is 50 kPa to 70 kPa.

[0277] Optionally, the scores and weights of each feature are determined, including:

[0278] Determine the baseline values ​​for each feature. Standard deviation σ i and the change threshold K i , where i is the feature identifier.

[0279] Determine the values ​​f of each feature in the BDP curve. i .

[0280] Calculate the score for each feature.

[0281] Calculate the weights of each feature. in,

[0282] Optionally, a baseline value for each feature is determined. Standard deviation σ i and the change threshold K i ,include:

[0283] Obtain multiple BDP sample curves.

[0284] Determine the values ​​of each feature in each BDP sample curve.

[0285] The mean of all values ​​for each feature is used as the baseline value for that feature.

[0286] The standard deviation of all values ​​for each feature is defined as the standard deviation σ of that feature. i .

[0287] The change threshold K of each characteristic was obtained from the train's factory braking system design specification. i Alternatively, the threshold K for each feature can be obtained by statistically analyzing the changes of each feature under normal conditions. i .

[0288] The computer-readable storage medium provided in this embodiment has a computer program thereon that is executed by a processor to perform a status assessment of the train's emergency braking system based solely on the BCP process value during the emergency braking process in daily train operation. This does not require a clear understanding of the internal structure and implementation principle of the braking system. The assessment process is simple, and the assessment results are accurate, reliable, flexible, and adaptable. It can provide personalized, component-level, detailed status assessments for the braking systems of different trains, meeting the needs of modern rail transit systems for braking system status monitoring and maintenance management.

[0289] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0290] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0291] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0292] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0293] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0294] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for assessing the condition of a train emergency braking system, characterized in that, The method includes: Collect the brake cylinder pressure process value during the emergency braking process of the train in daily operation; Based on the brake cylinder pressure process value, a BDP curve is generated. The horizontal axis of the BDP curve represents the acquisition time, and the vertical axis represents the BDP process value. The BDP curve is a line graph describing the change of brake cylinder pressure value over time. Determining the acquisition segment in the BDP curve includes: determining the slope value corresponding to each acquisition moment in the BDP curve; taking the first acquisition moment as the initial moment and forming a time window with a preset value as the length; determining the distance between the slope vector and the zero vector within the current time window; wherein the slope vector is composed of the slope values ​​corresponding to the acquisition moments within the current time window, and the length of the zero vector is the preset value; if the distance is not greater than a preset distance threshold, then the initial moment of the current time window is recorded; if the distance is greater than the preset distance threshold, then all initial moments that were recorded but did not form an acquisition segment are formed into an acquisition segment; sliding the time window, repeatedly executing the step of determining the distance between the slope vector and the zero vector within the current time window and subsequent steps, until the initial moment of the time window slides out of the BDP curve; wherein the length of the time window after sliding remains unchanged, and the initial moment is the next acquisition moment after the initial moment of the current time window; Based on the acquired data, the emergency braking process is divided into stages, including an ascent stage and a stabilization stage. Features for each stage are extracted, including: for the rising stage, pressure rise time, brake cylinder inflation rate, and pressure rise rate; for the stabilization stage, stable value, standard deviation, maximum value, and minimum value are extracted; where, pressure rise time is the time from the emergency braking command to the brake cylinder pressure rising to the emergency braking target pressure. The time required The preset value is used for the following parameters: the inflation rate of the brake cylinder pressure is the slope corresponding to the preset pressure segment during the inflation time of the brake cylinder pressure; the pressure rise rate is the rate at which the pressure rises during the pressure rise time; the stable value is the BDP process value that appears most frequently in the stable phase; the standard deviation is the standard deviation of all BDP process values ​​in the stable phase; the maximum value is the maximum value of all BDP process values ​​in the stable phase; and the minimum value is the minimum value of all BDP process values ​​in the stable phase. Determine the score and weight of each feature, including: determining the baseline value for each feature. Standard deviation and change threshold ,in, As feature identifiers; determine the values ​​of each feature in the BDP curve. ; Calculate the score for each feature ; Calculate the weights of each feature ,in, ; The status of the train's emergency braking system is assessed by producting the scores of all features with their weights.

2. The method according to claim 1, characterized in that, The step of dividing the emergency braking process into stages based on the acquired segments includes: The longest segment among the collected data is taken as the stable phase of the emergency braking process; Determine the standard phase in the acquired segment; The rising phase is formed by taking the end time of the adjacent acquisition segment before the standard phase as the initial time of the rising phase and taking the initial time of the stable phase as the end time of the rising phase.

3. The method according to claim 2, characterized in that, Determining the standard phase in the acquired segment includes: If the train maintains braking when the train control system issues an emergency braking command, then the standard phase in the collected segment is determined to be a stable phase.

4. The method according to claim 3, characterized in that, The It is 90; The pressure of the preset pressure range is 50 kPa to 70 kPa.

5. The method according to claim 1, characterized in that, The reference values ​​for determining each feature Standard deviation and change threshold ,include: Obtain multiple BDP sample curves; Determine the values ​​of each feature in each BDP sample curve; The mean of all values ​​for each feature is used as the baseline value for that feature. ; The standard deviation of all values ​​for each feature is defined as the standard deviation of that feature. ; The threshold values ​​for each feature were obtained by statistically analyzing the changes of each feature under normal conditions. .

6. An electronic device, characterized in that, include: Memory; processor; as well as Computer programs; The computer program is stored in the memory and configured to be executed by the processor to implement the method as described in any one of claims 1-5.

7. A computer-readable storage medium, characterized in that, It stores a computer program thereon; the computer program is executed by a processor to implement the method as described in any one of claims 1-5.

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