Automobile brake cylinder fault detection method and system

Abstract

The invention discloses a method and system for detecting a fault of an automobile brake cylinder, and relates to the technical field of automobile safety. The main scheme is: real-time acquisition of multiple parameter data of the brake cylinder; calculating the pressure change rate and comparing it with a threshold to determine whether the brake cylinder pressure is abnormal; calculating the piston displacement stroke and the piston speed, comprehensively calculating the comprehensive index of the piston displacement, and comparing it with the threshold to determine whether the piston displacement is abnormal; calculating the temperature change rate and the current temperature change curve, calculating the temperature difference in combination with the normal temperature change curve, and comparing it with the threshold to determine whether the brake cylinder temperature is abnormal; calculating the comprehensive operation index, and comparing it with the threshold to determine whether the comprehensive operation state of the brake cylinder is abnormal, and triggering an alarm device to send a fault alarm signal if any abnormality occurs; this method can monitor multiple parameters of the brake cylinder in real time and comprehensively, comprehensively determine the brake cylinder fault, and effectively improve the safety and reliability of the automobile brake system.

Description

Technical Field

[0001] The invention relates to the technical field of automobile safety, and in particular to a method and system for detecting automobile brake cylinder faults. Background Art

[0002] The automobile braking system is a key component of automobile safety performance, and the normal operation of the brake cylinder as the core component of the braking system is crucial to ensure the safe braking of the automobile. During long-term use, the brake cylinder is prone to various faults due to factors such as frequent braking operations and complex working environments. These faults lead to reduced braking performance or even brake failure, which poses a great safety risk to drivers and passengers. Therefore, accurate and timely detection of brake cylinder faults is an important issue facing the field of automobile safety assurance.

[0003] In the prior art, the fault detection of automobile brake cylinders is mainly based on some traditional methods. A common method is to conduct regular manual inspections. Maintenance personnel use their experience and some simple tools to check the appearance of the brake cylinders, such as checking whether the pistons have obvious signs of wear. Another technical means is to set some simple sensors in the automobile braking system, such as pressure sensors, to monitor the hydraulic pressure in the brake cylinder. When the pressure exceeds the normal range, the electronic control unit of the car will receive a signal and determine that there is a fault. These methods can detect some relatively obvious brake cylinder faults to a certain extent.

[0004] However, the existing automobile brake cylinder fault detection technology still has many defects. Relying on a single pressure sensor to detect faults is not comprehensive enough. The failure of the brake cylinder is not only reflected in the abnormal pressure, but also the displacement of the piston and the temperature change of the brake cylinder during operation also have an important impact on the normal operation of the brake cylinder. Therefore, the existing brake cylinder fault detection technology cannot monitor the working status of the brake cylinder comprehensively and in real time, and it is difficult to meet the high requirements of modern automobiles for safety and reliability. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a method and system for detecting automobile brake cylinder faults. The method collects brake cylinder parameter data in real time, calculates the pressure change rate, the comprehensive index of piston displacement stroke and speed, the temperature change rate and the difference, and compares them with the threshold to determine abnormalities. The comprehensive operating index is calculated, and an alarm is triggered if there is an abnormality, thereby solving the problems of insufficient real-time monitoring, incomplete detection and lack of comprehensiveness in fault determination.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for detecting a fault in a brake cylinder of an automobile, comprising:

[0009] Real-time collection of pressure data, piston displacement data and real-time temperature change data of the automobile brake cylinder during operation;

[0010] Calculate the pressure change rate based on the brake cylinder pressure data ; Preset the pressure change rate threshold, and set the pressure change rate Compare with the pressure change rate threshold, and determine whether the brake cylinder pressure is abnormal based on the comparison result; according to the piston displacement data and pressure change rate , respectively calculate the piston displacement stroke and piston speed ; According to the piston displacement , piston speed And piston displacement data, calculate the comprehensive index of piston displacement , preset abnormal indicator threshold , the piston displacement comprehensive index and abnormal indicator threshold Perform a comparison, and determine whether the piston displacement is abnormal based on the comparison result;

[0011] Calculate temperature change rate based on real-time temperature change data ; Based on real-time temperature change data and temperature change rate Get the current temperature change curve ; Obtain historical temperature change data, and obtain the normal temperature change curve based on the historical temperature change data , calculate the temperature change curve And normal temperature change curve The temperature difference at the corresponding time point ; Preset temperature difference threshold , the temperature difference Temperature difference threshold Performing comparison, and determining whether the brake cylinder temperature is abnormal according to the comparison result;

[0012] According to the pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive operation index ; Preset operation indicator threshold , the comprehensive fault index Fault indicator threshold Compare and determine whether the comprehensive operating state of the automobile brake cylinder is abnormal according to the comparison result;

[0013] When it is determined that any abnormal condition exists in the automobile brake cylinder, the alarm device is triggered and a fault alarm signal is issued.

[0014] In the preferred embodiment of the above-mentioned method for detecting a fault in a brake cylinder of an automobile, the method for determining whether the pressure in the brake cylinder is abnormal is as follows:

[0015] Pressure data includes the current pressure value and the pressure value at the previous moment ;

[0016] According to the current pressure value and the pressure value at the previous moment , calculate the pressure change rate , the formula based on is: in, is the time interval between two pressure data collections; is the pressure value collected at the current moment, i.e., moment n; is the pressure value collected at the previous moment, that is, moment n-1; n is 2, 3, 4...m; m is the number of moments, and its value is a positive integer ≥2;

[0017] The pressure change rate threshold includes the pressure threshold and pressure threshold 2 ,and ;

[0018] when When , it is determined that the pressure in the brake cylinder is normal;

[0019] when or When the brake cylinder pressure is abnormal.

[0020] In the preferred embodiment of the above-mentioned method for detecting a fault in a brake cylinder of an automobile: calculating the piston displacement stroke The method is:

[0021] The piston displacement data includes the current piston position coordinates and the piston position coordinates at the previous moment ;

[0022] According to the pressure change rate , Piston position coordinates at the current moment and the piston position coordinates at the previous moment , calculate the piston displacement , the formula based on is: in, is a coefficient related to the brake cylinder structure, with a value of 0~1; The time consumed from the start of braking to the current moment; is the piston position coordinate collected at the current moment, i.e., moment n; is the piston position coordinate collected at the previous moment, that is, moment n-1; is the pressure change rate The baseline value of is the pressure change rate Adjustment factor for piston displacement stroke.

[0023] In the preferred embodiment of the above-mentioned method for detecting a fault in a brake cylinder of an automobile: calculating the piston speed The method is:

[0024] According to the pressure change rate , Piston position coordinates at the current moment and the piston position coordinates at the previous moment , calculate the piston speed , the calculation formula is: in, It is the time interval between two adjacent piston position data collections.

[0025] In the preferred embodiment of the above-mentioned automobile brake cylinder fault detection method, the method for determining whether the piston displacement is abnormal is:

[0026] The piston displacement data also includes the minimum displacement stroke , Maximum displacement stroke , minimum speed and maximum speed ;

[0027] According to the displacement stroke of the brake cylinder piston , piston speed And piston displacement data, calculate the comprehensive index of piston displacement , the calculation formula is: in, is the piston displacement The weight coefficient is between 0.4 and 0.6; is the piston speed The weight coefficient is between 0.5 and 0.6; ;

[0028] Preset abnormal indicator threshold ;

[0029] when When the brake cylinder piston displacement is determined to be abnormal;

[0030] when , it is determined that the brake cylinder piston displacement is normal.

[0031] In the preferred embodiment of the above-mentioned method for detecting a fault in a brake cylinder of an automobile: calculating the temperature change rate The method is:

[0032] Real-time temperature change data includes the time points of temperature data collected during braking and temperature value at time point ;

[0033] According to the real-time temperature change data time point and temperature value at time point , calculate the temperature change rate at adjacent time points , the formula based on is: in, To collect real-time temperature change data A point in time, To collect real-time temperature change data time point; Real-time temperature change data time point The corresponding temperature value, Real-time temperature change data time point The corresponding temperature value.

[0034] In the preferred embodiment of the above-mentioned automobile brake cylinder fault detection method: obtaining the current temperature change curve The method is:

[0035] The original formula for obtaining the temperature change curve is: ;in, is the time variable; is the intercept of the temperature change curve;

[0036] Will Substitution In, get , the formula is as follows: Will Substituting into the original formula, the current temperature change curve is: In the preferred embodiment of the above-mentioned method for detecting a fault in a brake cylinder of an automobile, the method for determining whether the temperature of the brake cylinder is abnormal is as follows:

[0037] Obtain historical temperature change data and determine the normal temperature change curve based on the historical temperature change data ;

[0038] Calculate the current temperature change curve And normal temperature change curve The temperature difference at the corresponding time point , the calculation formula is: Preset temperature difference threshold ;

[0039] when When the temperature change curve conforms to the trend of the normal temperature change curve, it is determined that the brake cylinder temperature is normal;

[0040] when When the temperature change curve does not conform to the trend of the normal temperature change curve, it is determined that the brake cylinder temperature is abnormal.

[0041] In the preferred embodiment of the above-mentioned method for detecting a fault in a brake cylinder of an automobile, the method for determining whether a fault exists in the brake cylinder of an automobile is as follows:

[0042] According to the pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive fault index , the calculation formula is: in, is the pressure change rate The weight coefficient is between 0.1 and 0.3; It is the comprehensive index of piston displacement The weight coefficient is 0.3~0.4; Temperature difference The weight coefficient is between 0.3 and 0.5; ;

[0043] Preset fault indicator threshold ;

[0044] when When the brake cylinder of the vehicle is judged to be faulty;

[0045] when When the car brake cylinder is determined to be normal.

[0046] The present invention also discloses a vehicle brake cylinder fault detection system, which is used to implement the above-mentioned vehicle brake cylinder fault detection method, comprising:

[0047] The data acquisition module is used to collect the pressure data, piston displacement data and real-time temperature change data of the automobile brake cylinder when it is working;

[0048] Data analysis module, used to calculate the pressure change rate based on the brake cylinder pressure data , preset the pressure change rate threshold, and set the pressure change rate Compare with the pressure change rate threshold, and determine whether the brake cylinder pressure is abnormal based on the comparison result; according to the piston displacement data and pressure change rate , respectively calculate the piston displacement stroke and piston speed ; According to the piston displacement , piston speed And piston displacement data, calculate the comprehensive index of piston displacement , preset abnormal indicator threshold , the piston displacement comprehensive index and abnormal indicator threshold Perform a comparison, and determine whether the piston displacement is abnormal based on the comparison result;

[0049] Temperature processing module, used to calculate the temperature change rate based on real-time temperature change data ; Based on real-time temperature change data and temperature change rate Get the current temperature change curve ; Obtain historical temperature change data, and obtain the normal temperature change curve based on the historical temperature change data , calculate the temperature change curve And normal temperature change curve The temperature difference at the corresponding time point ; Preset temperature difference threshold , the temperature difference Temperature difference threshold Performing comparison, and determining whether the brake cylinder temperature is abnormal according to the comparison result;

[0050] Comprehensive processing module for pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive operation index ; Preset operation indicator threshold , the comprehensive fault index Fault indicator threshold Compare and determine whether the comprehensive operating state of the automobile brake cylinder is abnormal according to the comparison result;

[0051] The fault determination module is used to trigger the alarm device and send out a fault alarm signal when it is determined that any abnormal situation exists in the automobile brake cylinder.

[0052] (III) Beneficial effects

[0053] The present invention provides a method and system for detecting a vehicle brake cylinder fault, which has the following beneficial effects:

[0054] (1) By collecting multiple parameter data such as pressure, displacement, and real-time temperature in real time, we can fully understand the operating status of the brake cylinder under different working conditions. This helps to timely discover potential fault hazards, so that maintenance measures can be taken in advance to avoid serious safety accidents such as brake failure during driving.

[0055] (2) The calculation and comparison of the pressure change rate can timely detect abnormal pressure in the brake cylinder, providing important protection for the safety of the brake system. Combined with the analysis of piston displacement data, not only the output effect of the brake cylinder is considered, but also the calculation of comprehensive indicators can more accurately determine whether the movement of the piston is normal. This method improves the accuracy and reliability of fault detection.

[0056] (3) The current temperature change curve obtained based on real-time temperature change data and temperature change rate can intuitively reflect the temperature dynamics of the brake cylinder under the current operating state, providing detailed information basis for accurate judgment; by comparing with the normal temperature change curve obtained from historical temperature change data, temperature abnormalities can be discovered in a timely manner, whether the temperature continues to rise, falls too slowly, or deviates too much from the normal curve, all of which can be quickly detected.

[0057] (4) By calculating the pressure change rate , Comprehensive index of piston displacement and temperature difference , it can achieve an overall grasp of the operating status of the brake cylinder; compared with the detection of a single factor, comprehensive consideration of multiple factors can more comprehensively reflect the actual working conditions of the brake cylinder, avoiding inaccurate assessment of the brake cylinder status due to misjudgment of a single factor; at the same time, the preset operating indicator threshold makes the judgment more objective and standardized, providing a clear basis for fault diagnosis.

[0058] (5) Through real-time monitoring and alarm of brake cylinder abnormalities, the incidence of vehicle failures caused by brake cylinder failures can be effectively reduced, and the reliability of the vehicle under various driving conditions can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 A schematic diagram of the steps of a method for detecting a brake cylinder fault of an automobile according to the present invention; DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] See also Figure 1 The present invention provides a method for detecting a fault in a brake cylinder of an automobile, comprising the following steps:

[0062] Step 1: Collect real-time pressure data, piston displacement data and real-time temperature change data of the automobile brake cylinder when it is working.

[0063] Step 101: Install a pressure sensor at the hydraulic oil input pipeline of the brake cylinder; install a displacement sensor on the outer wall of the brake cylinder piston and parallel to the movement direction of the piston; install a temperature sensor on the outer surface of the brake cylinder body near the area with the highest temperature when the brake cylinder is working.

[0064] Step 102: After the vehicle is started, during the operation of the brake system, multiple sensors are used to collect the pressure data, piston displacement data and real-time temperature change data of the brake cylinder in real time.

[0065] This method can provide comprehensive and accurate information for the status monitoring of the automobile braking system. The pressure data can be used to timely understand the pressure changes in the brake cylinder and judge the working intensity and effectiveness of the braking system; the piston displacement data can reflect the movement state of the piston, which helps to detect whether the piston is working normally and whether the braking stroke meets the requirements; the real-time temperature change data can indicate the thermal state of the brake cylinder to prevent overheating from causing failures. Real-time collection of this data can realize real-time monitoring of the brake cylinder, timely discover potential problems, provide a basis for fault diagnosis and preventive maintenance, improve the reliability and safety of the automobile braking system, and ensure driving safety.

[0066] Step 2: Calculate the pressure change rate based on the brake cylinder pressure data , preset the pressure change rate threshold, and set the pressure change rate Compare with the pressure change rate threshold, and determine whether the brake cylinder pressure is abnormal based on the comparison result; according to the piston displacement data and pressure change rate , respectively calculate the piston displacement stroke and piston speed ; According to the piston displacement , piston speed And piston displacement data, calculate the comprehensive index of piston displacement , preset abnormal indicator threshold , the piston displacement comprehensive index and abnormal indicator threshold A comparison is made and whether the piston displacement is abnormal is determined based on the comparison result.

[0067] Step 201: Based on the collected pressure data, obtain the pressure value at the previous moment and the pressure value at the previous moment .

[0068] According to the current pressure value and the pressure value at the previous moment , calculate the pressure change rate , the formula based on is: in, is the time interval between two pressure data collections; is the pressure value collected at the current moment, i.e., moment n; is the pressure value collected at the previous moment, that is, the n-1 moment; n is 2, 3, 4...m; m is the number of moments, and its value is a positive integer ≥2.

[0069] It should be noted that Represents the pressure value at two adjacent moments. The difference reflects the change in pressure between these two moments. If the pressure increases, the difference is positive; if the pressure decreases, the difference is negative. Then, the difference is squared. The purpose of squaring is to emphasize the magnitude of the pressure change, making larger pressure changes more prominent in the calculation. At the same time, the squaring operation can also prevent the positive and negative pressure differences from canceling each other out, ensuring that the direction of the pressure change does not affect the final result. Finally, the squares of the pressure differences at all adjacent moments are summed. In this way, the pressure changes at multiple time points can be comprehensively considered to obtain an overall pressure change amplitude index. is the time interval between two pressure data collections. This time interval determines the time scale of pressure change. represents the total number of adjacent time pairs. From n=2 to m, there are a total of m-1 pairs of adjacent time. Multiplying by the number of adjacent time pairs gives a total time span that is used to normalize the magnitude of the pressure change in the molecular part.

[0070] Step 202: Preset a pressure change rate threshold; the pressure change rate threshold includes a pressure threshold value and pressure threshold 2 ,and .

[0071] In a laboratory environment, various braking conditions are simulated, such as different vehicle speeds, braking intensities, load conditions, etc., and a large number of tests are performed on the brake cylinder. Pressure data is collected through the pressure sensor installed on the brake cylinder, and the changing patterns of these data under different conditions are analyzed. Focus on the pressure data under relatively safe and mild braking conditions. For example, under low-speed and light braking conditions, the pressure change is relatively small; perform statistical analysis on the pressure data under these low-pressure conditions, and calculate statistical quantities such as the mean, median, and percentile; comprehensively consider the safety margin and actual conditions, and select a relatively low pressure value as the pressure threshold. ; Continue to use the pressure data collected in the laboratory to simulate different braking conditions, and focus on analyzing the pressure data under more extreme and urgent braking conditions, such as high-speed emergency braking. In this case, the pressure changes will be large, and statistical analysis is performed on the pressure data under these high-pressure conditions, and statistical quantities such as the mean, median, and percentile are also calculated; Considering the safety performance and maximum tolerance of the braking system, a relatively high pressure value is selected as the pressure threshold value 2 ; Set the pressure change rate threshold based on this.

[0072] when When , it is determined that the pressure in the brake cylinder is normal;

[0073] when or When the brake cylinder pressure is abnormal.

[0074] Step 203: Based on the piston displacement data, obtain the piston position coordinates at the current moment and the piston position coordinates at the previous moment ;

[0075] According to the pressure change rate , Piston position coordinates at the current moment and the piston position coordinates at the previous moment , calculate the piston displacement , the formula based on is: in, is a coefficient related to the brake cylinder structure, with a value of 0~1; The time consumed from the start of braking to the current moment; is the piston position coordinate collected at the current moment, i.e., moment n; is the piston position coordinate collected at the previous moment, that is, moment n-1; is the pressure change rate The baseline value of is the pressure change rate Adjustment factor for piston displacement stroke.

[0076] It should be noted that Considering that the pressure change in the brake cylinder will directly affect the movement of the piston. It reflects the structural characteristics of the brake cylinder. Different brake cylinder structures will lead to different conversion relationships between pressure and displacement. Pressure change rate It measures how quickly the pressure in the brake cylinder changes. The faster the pressure changes, the stronger the push on the piston will be in theory. It represents the time consumed from the start of braking to the current moment. As time goes by, the continuous action of pressure will cause the piston to produce corresponding displacement. This part reflects the contribution of the cumulative effect of pressure and time to the piston displacement stroke. It represents the sum of the absolute values ​​of the piston position coordinate differences at adjacent moments. The change in the positions of two adjacent pistons is calculated, and the absolute value is taken to ensure that the magnitude of the position change can be correctly calculated regardless of whether the piston moves forward or backward. is the pressure change rate The baseline value, which serves as a reference standard to measure the current pressure change rate The degree of deviation from normal conditions. is the pressure change rate The adjustment coefficient for the piston displacement stroke determines the degree of influence of the pressure change rate on the piston displacement stroke calculation. Deviation from the baseline hour, This part generates an adjustment value, which is added to 1 to adjust the displacement calculated based on the piston position coordinates.

[0077] Step 204: According to the pressure change rate , Piston position coordinates at the current moment and the piston position coordinates at the previous moment , calculate the piston speed , the calculation formula is: in, It is the time interval between two adjacent piston position data collections.

[0078] It should be noted that It is the basic form of piston speed calculation. Among them, Indicates the difference between the current time n and the previous time The absolute value of the difference between the collected piston position coordinates reflects the distance the piston moves during this time interval. It is the time interval between two adjacent data collections. The average speed of the piston in this time period is obtained by dividing the two. This part reflects the effect of the pressure change rate on the piston speed. When the pressure in the brake cylinder changes, it will affect the movement of the piston. If the pressure is different, the driving force on the piston movement will also be different. and is a reference value related to the pressure change rate, through The calculation of can quantify the deviation of the pressure change rate from the reference value. By multiplying This factor adjusts the basic piston speed calculated based on the position coordinate difference. If the pressure change rate increases, then this factor will be greater than 1, thereby increasing the calculated piston speed; conversely, if the pressure change rate decreases, this factor may be less than 1, resulting in a corresponding decrease in piston speed.

[0079] Step 205: Determine the minimum value of the displacement stroke , maximum value , the minimum value of speed and maximum speed ; Repeatedly test multiple brake cylinders of the same model to ensure the reliability and consistency of the data. Statistical analysis of a large amount of test data is performed to determine the minimum displacement stroke. and maximum value .

[0080] On a special brake system test bench, the brake cylinder is tested under various working conditions. By controlling parameters such as brake pressure and brake frequency, different braking conditions are simulated and the speed change of the piston is measured. The speed data of the piston under different test conditions is recorded, and the distribution of these data is analyzed to determine the minimum speed value. and maximum speed .

[0081] Step 206: Calculate the minimum displacement stroke value obtained in step 205 , Maximum displacement stroke , minimum speed and maximum speed , combined with the brake cylinder piston displacement stroke , piston speed , calculate the comprehensive index of piston displacement , the calculation formula is: in, is the piston displacement The weight coefficient is between 0.4 and 0.6; is the piston speed The weight coefficient is between 0.5 and 0.6; .

[0082] It should be noted that and Respectively represent the maximum and minimum values ​​of the preset piston displacement stroke. The actual piston displacement stroke is calculated Normalization is performed so that its value is between 0 and 1. The purpose of this is to convert the displacement values ​​of different scales into a relative proportional value, which is convenient for comprehensive comparison with other parameters. is the piston displacement The weight coefficient reflects the importance of piston displacement relative to piston speed in the comprehensive index. If the piston displacement is considered to be more critical in judging the working state of the brake cylinder, then the weight coefficient can be appropriately increased. On the other hand, if the piston speed is considered more important, the The value of . and are the preset maximum and minimum values ​​of the piston speed respectively. The actual piston speed Normalized to between 0 and 1. is the piston speed The weight coefficient of , which ensures that the sum of the two weight coefficients is 1, so that the comprehensive indicator remains balanced when considering the two parameters. The value of can change the importance of piston speed in the comprehensive index according to actual conditions.

[0083] Step 207: Setting the abnormal indicator threshold ; Through in-depth research on the working principle of automobile brake cylinder, including the movement mechanism of the piston and the interaction with other components of the brake system. Based on these principles, a mathematical model is established to describe the relationship between the piston displacement stroke and speed of the brake cylinder under normal working conditions, as well as their impact on comprehensive indicators By inputting the piston displacement and speed data under abnormal working conditions into the mathematical model, a theoretical threshold range can be preliminarily determined to preset the abnormal indicator threshold. .

[0084] when When the brake cylinder piston displacement is determined to be abnormal;

[0085] when , it is determined that the brake cylinder piston displacement is normal.

[0086] This method can comprehensively and accurately monitor the operating status of the brake cylinder. By judging the pressure change rate, abnormal fluctuations in the brake cylinder pressure can be detected in time, effectively preventing brake failures caused by sudden changes in pressure. The multi-dimensional analysis of piston displacement takes into account the displacement stroke, speed and comprehensive indicators, and can capture abnormal conditions of piston movement in more detail. This not only improves the accuracy and reliability of fault detection, but also provides a specific diagnostic basis, making maintenance more targeted, helping to ensure the safe and stable operation of the vehicle's braking system and improving driving safety.

[0087] Step 3: Calculate the temperature change rate based on real-time temperature change data ; Based on real-time temperature change data and temperature change rate Get the current temperature change curve ; Obtain historical temperature change data, and obtain the normal temperature change curve based on the historical temperature change data , calculate the temperature change curve And normal temperature change curve The temperature difference at the corresponding time point ; Preset temperature difference threshold , the temperature difference Temperature difference threshold A comparison is made and whether the brake cylinder temperature is abnormal is determined based on the comparison result.

[0088] Step 301: Based on the real-time temperature change data, obtain the time point of the temperature data collected during the braking process and temperature value at time point .

[0089] According to the real-time temperature change data time point and temperature value at time point , calculate the temperature change rate at adjacent time points , the formula based on is: in, To collect real-time temperature change data A point in time, To collect real-time temperature change data time point; Real-time temperature change data time point The corresponding temperature value, Real-time temperature change data time point The corresponding temperature value.

[0090] It should be noted that the molecular part Represents two adjacent time points and The difference between the corresponding temperature values ​​reflects the change in temperature during this time interval. If the temperature rises, the difference is positive; if the temperature drops, the difference is negative. Represents the time interval between two adjacent time points. The length of this time interval determines the speed of temperature change. The shorter the time interval, the closer the calculated temperature change rate is to the instantaneous change rate. Dividing the temperature change by the time interval, the result is the average temperature change rate during this time interval. It reflects how fast the temperature changes over time.

[0091] Step 302: According to the concept of linear function, the original formula of the temperature change curve is obtained as follows: ;in, is the time variable; is the intercept of the temperature variation curve.

[0092] It should be noted that, in general, a linear function can be expressed as of the form, where is the independent variable, y is the dependent variable, and a and b are constants.

[0093] Step 302: Substitution In, get , the formula is as follows: We can get: Step 303: Substituting into the original formula, the current temperature change curve is: .

[0094] It should be noted that is the temperature change rate, which determines The degree of influence on the rate of temperature change. is a time variable, when When it increases, due to The existence of will cause the temperature change rate to increase accordingly in a linear relationship. The part is used as an adjustment item to correct the linear part; among them, is the temperature data time point The corresponding temperature value; is based on the pressure change rate and time variables A calculated value; through the temperature value minus , adjust the temperature change rate function to better adapt to the actual temperature changes.

[0095] Step 304: Obtain historical temperature data and determine a normal temperature change curve based on the historical temperature data .

[0096] Calculate the current temperature change curve And normal temperature change curve The temperature difference at the corresponding time point , the calculation formula is: .

[0097] Step 305: Preset the temperature difference threshold, and establish a heat transfer model for the automobile brake cylinder through the factory data of the brake cylinder, taking into account the heat generation, transfer and dissipation process. According to the material properties, size, working principle and ambient conditions of the brake cylinder, theoretical analysis is performed using physical principles such as the heat conduction equation and the law of conservation of energy; the theoretical range of change of the brake cylinder temperature under different braking conditions is calculated through the heat transfer model. For example, the heat generated during the braking process is calculated based on parameters such as braking power and friction coefficient, and the temperature rise and change rate are estimated in combination with factors such as the heat dissipation coefficient and ambient temperature; based on the calculation results, the temperature difference threshold is obtained. .

[0098] when , the temperature change curve conforms to the trend of the normal temperature change curve, and it is determined that the brake cylinder temperature is normal.

[0099] when When the temperature change curve does not conform to the trend of the normal temperature change curve, it is determined that the brake cylinder temperature is abnormal.

[0100] The temperature change rate reflects the temperature change trend over time, and the pressure change rate reflects the potential impact of pressure on temperature in the braking system, making the judgment of temperature anomalies more accurate and avoiding misjudgment caused by single temperature data. The normal temperature change curve is constructed using historical temperature data to provide a reliable reference for judgment, covering the normal state under different environments and working conditions, and potential faults can be discovered in time through comparison. The temperature difference is calculated and compared with the preset threshold, providing a clear quantitative standard, making fault detection more objective and scientific, and facilitating maintenance personnel to assess the severity of the fault and take targeted measures to effectively ensure the safe driving and stable operation of the vehicle.

[0101] Step 4: According to the pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive operation index ; Preset operation indicator threshold , the comprehensive fault index Fault indicator threshold A comparison is made, and whether the comprehensive operating state of the vehicle brake cylinder is abnormal is determined based on the comparison result.

[0102] Step 401: According to the pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive fault index , the calculation formula is: in, is the pressure change rate The weight coefficient is between 0.1 and 0.3; It is the comprehensive index of piston displacement The weight coefficient is 0.3~0.4; Temperature difference The weight coefficient is between 0.3 and 0.5; .

[0103] It should be noted that the pressure change rate A measure of how quickly the pressure in the brake cylinder changes. Abnormal pressure may be caused by hydraulic problems, leaks or other faults in the brake system. Assign a weighting factor , reflects the relative importance of pressure change in comprehensive fault assessment. The value of 0.1~0.3 indicates that although pressure change is an important factor, it may not be the most important factor in the comprehensive assessment. Piston displacement comprehensive index It comprehensively considers factors such as piston displacement stroke and speed, and reflects whether the piston movement is normal or not. The value is 0.3~0.4, which means that piston displacement plays a more important role in comprehensive fault assessment, and its importance is slightly higher than the pressure change rate. It is usually the difference between the actual temperature and the normal temperature range, reflecting the abnormal temperature of the brake cylinder. The value is 0.3~0.5, indicating that the temperature difference may be one of the most important factors in comprehensive fault assessment. This is because temperature abnormality is often an important manifestation of brake cylinder failure, and temperature changes are closely related to the working state of the brake cylinder.

[0104] Step 402: Preset fault indicator threshold ; Through various simulation tests on automobile brake cylinders in laboratory environments, including tests under different braking strengths, durations, ambient temperatures, etc. Various sensors are installed to collect data such as pressure, displacement, and temperature, and calculate comprehensive fault indicators By analyzing a large amount of test data, the critical value is selected as the fault indicator threshold .

[0105] when When the brake cylinder of the vehicle is judged to be faulty;

[0106] when When the car brake cylinder is determined to be normal.

[0107] As the core component of the braking system, the operating status of the automobile brake cylinder is directly related to the braking performance of the vehicle. The comprehensive operating index calculated by considering multiple key parameters can fully and accurately reflect the actual working status of the brake cylinder. Once an abnormality occurs, a warning will be issued in time, and countermeasures can be taken quickly, effectively avoiding traffic accidents caused by brake cylinder failures and greatly reducing driving risks.

[0108] Step 5: When it is determined that any abnormal condition exists in the automobile brake cylinder, the alarm device is triggered and a fault alarm signal is issued.

[0109] Step 501: The alarm signal includes:

[0110] Sound alarm: Use a buzzer to emit a sound signal of a specific frequency. The loudness of the sound is adjusted according to the actual situation to ensure that it can be clearly heard in various noise environments during vehicle driving.

[0111] Visual alarm: A special fault indicator light is set on the dashboard. When the brake cylinder has an abnormal condition, the indicator light comes on. A red indicator light indicates a serious fault and requires immediate stop and inspection; a yellow indicator light indicates a minor fault or potential problem and requires inspection and repair as soon as possible.

[0112] Tactile alarm: When the brake cylinder fails, the steering wheel or seat will vibrate slightly; the intensity of the vibration can be adjusted according to the severity of the fault. For serious faults, the vibration intensity is higher; for mild abnormalities, the vibration intensity is lower.

[0113] This method helps reduce vehicle damage. By getting an early warning of a brake cylinder anomaly, the vehicle can be repaired in time to prevent the fault from getting worse, thereby reducing damage to other components of the brake system and the overall structure of the vehicle. It also avoids potential traffic accidents.

[0114] On the other hand, the present invention also discloses a vehicle brake cylinder fault detection system, which is used to implement the above-mentioned vehicle brake cylinder fault detection method, and the specific steps include:

[0115] The data acquisition module is used to collect the pressure data, piston displacement data and real-time temperature change data of the automobile brake cylinder when it is working;

[0116] Data analysis module, used to calculate the pressure change rate based on the brake cylinder pressure data ; Preset the pressure change rate threshold, and set the pressure change rate Compare with the pressure change rate threshold, and determine whether the brake cylinder pressure is abnormal based on the comparison result; according to the piston displacement data and pressure change rate , respectively calculate the piston displacement stroke and piston speed ; According to the piston displacement , piston speed And piston displacement data, calculate the comprehensive index of piston displacement , preset abnormal indicator threshold , the piston displacement comprehensive index and abnormal indicator threshold Perform a comparison, and determine whether the piston displacement is abnormal based on the comparison result;

[0117] Temperature processing module, used to calculate the temperature change rate based on real-time temperature change data ; Based on real-time temperature change data and temperature change rate Get the current temperature change curve ; Obtain historical temperature change data, and obtain the normal temperature change curve based on the historical temperature change data , calculate the temperature change curve And normal temperature change curve Temperature difference at corresponding time points ; Preset temperature difference threshold , the temperature difference Temperature difference threshold Performing comparison, and determining whether the brake cylinder temperature is abnormal according to the comparison result;

[0118] Comprehensive processing module for pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive operation index ; Preset operation indicator threshold , the comprehensive fault index Fault indicator threshold Compare and determine whether the comprehensive operating state of the automobile brake cylinder is abnormal according to the comparison result;

[0119] The fault determination module is used to trigger the alarm device and send out a fault alarm signal when it is determined that any abnormal situation exists in the automobile brake cylinder.

[0120] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. A person of ordinary skill in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented in electronic hardware or in combination with computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution.

[0121] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0122] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for detecting a fault in a vehicle brake cylinder, characterized in that: include: Real-time collection of pressure data, piston displacement data and real-time temperature change data of the automobile brake cylinder during operation; Calculate the pressure change rate based on the brake cylinder pressure data ; Preset pressure change rate threshold value, set the pressure change rate The pressure is compared with the preset pressure change rate threshold, and the brake cylinder pressure is judged to be abnormal according to the comparison result; according to the piston displacement data and pressure change rate , respectively calculate the piston displacement stroke and piston speed; according to piston displacement stroke , piston speed And piston displacement data, calculate the comprehensive index of piston displacement ; Specifically: Piston displacement data includes the minimum displacement stroke , Maximum displacement stroke , minimum speed and maximum speed ; Calculate the comprehensive index of piston displacement The calculation formula is: in, is the piston displacement The weight coefficient is between 0.4 and 0.6; is the piston speed The weight coefficient is between 0.5 and 0.6; + =1; Preset abnormal indicator threshold , the piston displacement comprehensive index and preset abnormal indicator threshold Perform a comparison, and determine whether the piston displacement is abnormal based on the comparison result; Calculate temperature change rate based on real-time temperature change data ; Based on real-time temperature change data and temperature change rate Get the current temperature change curve ; Obtain historical temperature change data, and obtain the normal temperature change curve based on the historical temperature change data , calculate the temperature change curve And normal temperature change curve The temperature difference at the corresponding time point ; Preset temperature difference threshold , the temperature difference The temperature difference threshold Performing comparison, and determining whether the brake cylinder temperature is abnormal according to the comparison result; According to the pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive operation index , the calculation formula is: in, is the pressure change rate The weight coefficient is between 0.1 and 0.3; It is the comprehensive index of piston displacement The weight coefficient is 0.3~0.4; Temperature difference The weight coefficient is between 0.3 and 0.5; + + =1; Preset operating indicator thresholds , the comprehensive operating indicators and preset operating indicator thresholds Compare and determine whether the comprehensive operating state of the automobile brake cylinder is abnormal according to the comparison result; When it is determined that any abnormal condition exists in the automobile brake cylinder, the alarm device is triggered and a fault alarm signal is issued.

2. A method for detecting a vehicle brake cylinder fault according to claim 1, characterized in that: The method to determine whether the pressure in the brake cylinder is abnormal is: Pressure data includes the current pressure value and the pressure value at the previous moment ; According to the current pressure value and the pressure value at the previous moment , calculate the pressure change rate , the formula based on is: in, is the time interval between two pressure data collections; is the pressure value collected at the current moment, i.e., moment n; is the pressure value collected at the previous moment, that is, moment n-1; n is 2, 3, 4...m; m is the number of moments, and its value is a positive integer ≥2; The pressure change rate threshold includes the pressure threshold and pressure threshold 2 ,and ; when When , it is determined that the pressure in the brake cylinder is normal; when or When the brake cylinder pressure is abnormal.

3. A method for detecting a vehicle brake cylinder fault according to claim 2, characterized in that: Calculate piston displacement The method is: The piston displacement data also includes the current piston position coordinates and the piston position coordinates at the previous moment ; According to the pressure change rate , Piston position coordinates at the current moment and the piston position coordinates at the previous moment , calculate the piston displacement , the formula based on is: in, is a coefficient related to the brake cylinder structure, with a value of 0~1; The time consumed from the start of braking to the current moment; is the piston position coordinate collected at the current moment, i.e., moment n; is the piston position coordinate collected at the previous moment, that is, moment n-1; is the pressure change rate The baseline value of is the pressure change rate Adjustment factor for piston displacement stroke.

4. A method for detecting a vehicle brake cylinder fault according to claim 3, characterized in that: Calculate piston speed The method is: According to the pressure change rate , Piston position coordinates at the current moment and the piston position coordinates at the previous moment , calculate the piston speed , the calculation formula is: in, It is the time interval between two adjacent piston position data collections.

5. A method for detecting a vehicle brake cylinder fault according to claim 4, characterized in that: The method to determine whether the piston displacement is abnormal is: Preset abnormal indicator threshold ; when When the brake cylinder piston displacement is determined to be abnormal; when , it is determined that the brake cylinder piston displacement is normal.

6. A method for detecting a vehicle brake cylinder fault according to claim 5, characterized in that: Calculate the rate of temperature change The method is: Real-time temperature change data includes the time points of temperature data collected during braking and temperature value at time point ; According to the real-time temperature change data time point and temperature value at time point , calculate the temperature change rate at adjacent time points , the formula based on is: in, To collect real-time temperature change data A point in time, To collect real-time temperature change data time point; Real-time temperature change data time point The corresponding temperature value, Real-time temperature change data time point The corresponding temperature value.

7. A method for detecting a vehicle brake cylinder fault according to claim 6, characterized in that: Get the current temperature change curve The method is: The original formula for obtaining the temperature change curve is: ;in, is the time variable; is the intercept of the temperature change curve; Set v= Substitution In, get , the formula is as follows: Substituting d into the original formula, the current temperature change curve is: 。 8. The method for detecting a vehicle brake cylinder fault according to claim 7, characterized in that: The method to determine whether the brake cylinder temperature is abnormal is: Obtain historical temperature change data and determine the normal temperature change curve based on the historical temperature change data ; Calculate the current temperature change curve And normal temperature change curve The temperature difference at the corresponding time point , the calculation formula is: ,Will The temperature difference threshold For comparison: Preset temperature difference threshold ; when When the temperature change curve conforms to the trend of the normal temperature change curve, it is determined that the brake cylinder temperature is normal; when When the temperature change curve does not conform to the trend of the normal temperature change curve, it is determined that the brake cylinder temperature is abnormal.

9. The method for detecting a vehicle brake cylinder fault according to claim 7, characterized in that: The method to determine whether there is a fault in the automobile brake cylinder is: The comprehensive operating indicators and preset fault indicator threshold : when When the brake cylinder of the vehicle is judged to be faulty; when When the car brake cylinder is determined to be normal.

10. An automobile brake cylinder fault detection system, characterized in that: A method for detecting a fault in a brake cylinder of an automobile according to any one of claims 1 to 9, comprising: The data acquisition module is used to collect the pressure data, piston displacement data and real-time temperature change data of the automobile brake cylinder when it is working; Data analysis module, used to calculate the pressure change rate based on the brake cylinder pressure data ; Preset the pressure change rate threshold, and set the pressure change rate The pressure is compared with the preset pressure change rate threshold, and the brake cylinder pressure is judged to be abnormal according to the comparison result; according to the piston displacement data and pressure change rate , respectively calculate the piston displacement stroke and piston speed ; According to the piston displacement , piston speed And piston displacement data, calculate the comprehensive index of piston displacement , preset abnormal indicator threshold , the piston displacement comprehensive index and preset abnormal indicator threshold Perform a comparison, and determine whether the piston displacement is abnormal based on the comparison result; Temperature processing module, used to calculate the temperature change rate based on real-time temperature change data ; Based on real-time temperature change data and temperature change rate Get the current temperature change curve ; Obtain historical temperature change data, and obtain the normal temperature change curve based on the historical temperature change data , calculate the temperature change curve And normal temperature change curve The temperature difference at the corresponding time point ; Preset temperature difference threshold , the temperature difference The temperature difference threshold Performing comparison, and determining whether the brake cylinder temperature is abnormal according to the comparison result; Comprehensive processing module for pressure change rate , Comprehensive index of piston displacement and temperature difference , calculate the comprehensive operation index ; Preset operation indicator threshold , the comprehensive operating indicators and preset operating indicator thresholds Compare and determine whether the comprehensive operating state of the automobile brake cylinder is abnormal according to the comparison result; The fault determination module is used to trigger the alarm device and send out a fault alarm signal when it is determined that any abnormal situation exists in the automobile brake cylinder.

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