Method and system for predicting wear life of caliper brake friction plate

Abstract

The invention relates to the technical field of data processing, and discloses a caliper brake friction plate wear life prediction method and system. The method comprises the following steps: synchronously acquiring braking times, a pressure peak value and a temperature peak value to construct a data recording group; setting an acquisition interval screening data record group according to the braking frequency; calculating a pressure deviation rate to inversely calculate the abrasion loss, and moving forward a braking frequency threshold value according to the abrasion rate; calculating accumulated abrasion loss and residual braking times according to the temperature peak value and the pressure peak value. According to the invention, the accuracy of wear life prediction and the utilization efficiency of data acquisition resources are improved.

Description

Technical Field

[0001] This application relates to the field of data processing technology, and in particular to a method and system for predicting the wear life of friction pads in caliper brakes. Background Technology

[0002] As a critical safety component of the cableway system, the wear condition of the friction pads in the cableway caliper brake directly affects braking performance and operational safety. Current technologies primarily employ a combination of empirical formulas and periodic inspections to predict friction pad wear life. The empirical formula method calculates the theoretical wear amount per braking action based on the wear coefficient of the friction pad material, the rated power of the brake, and the expected number of braking actions, using Arcard wear theory. This theoretical wear is then multiplied by the cumulative number of braking actions to estimate the total working time required for the friction pads to reach replacement standards. The periodic inspection method involves maintenance personnel conducting shutdown inspections at predetermined intervals, directly measuring the remaining thickness of the friction pads using measuring tools, comparing the measured value with the theoretical prediction, and correcting for any discrepancies. Replacement is scheduled when the remaining thickness falls below a safety threshold. Some systems install counters on the brakes to record the number of braking actions or use a PLC control system to read the number of braking commands as supplementary data for wear assessment.

[0003] Existing methods for predicting friction pad wear life suffer from incomplete and discontinuous data collection. Relying solely on periodic manual measurements of friction pad thickness fails to capture dynamic data such as pressure fluctuations and temperature changes during braking. In actual operation, the working pressure of cableway brakes deviates from the design value due to factors such as disc spring fatigue and hydraulic system fluctuations, while the temperature varies significantly depending on environmental conditions and braking frequency. These factors significantly affect the wear rate but cannot be captured by existing methods. Furthermore, the wear calculation formulas used in existing methods assume constant parameters, treating braking force and friction coefficient as constants in the calculations, which fails to reflect the complexity of actual operating conditions, resulting in a large discrepancy between predicted and actual life. In addition, existing methods rely on periodic manual inspections, which have long and delayed inspection cycles. This can lead to a sudden acceleration in friction pad wear between inspections, posing a safety hazard of exceeding the limit. Moreover, they lack real-time monitoring and proactive early warning capabilities. Summary of the Invention

[0004] This application provides a method and system for predicting the wear life of caliper brake friction pads, which solves the technical problem that existing wear life prediction methods cannot dynamically adjust the data acquisition strategy according to the actual wear process, resulting in resource waste or prediction lag. By using an adaptive adjustment mechanism that back-calculates the wear rate based on pressure data and moves the braking number threshold forward, the system switches to a dense acquisition mode in advance when wear accelerates, thereby improving the accuracy of wear life prediction and the utilization efficiency of data acquisition resources.

[0005] In a first aspect, this application provides a method for predicting the wear life of caliper brake friction pads, the method comprising: Step S1: Synchronously collect the number of braking events, peak hydraulic pressure, and peak friction pair temperature to construct a data record group containing the number of braking events, peak pressure, and peak temperature. Step S2: Set the data acquisition interval according to the number of braking cycles, and filter the data record group according to the data acquisition interval; Step S3: Calculate the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure. When the deviation rate exceeds the set value, calculate the current wear amount based on the average value of the pressure peaks. Calculate the actual wear rate based on the ratio of the current wear amount to the number of braking cycles. Move the braking cycle threshold forward based on the ratio of the actual wear rate to the theoretical wear rate, and shorten the data acquisition interval. Step S4: Calculate the cumulative wear based on the temperature peak and the pressure peak, and calculate the remaining number of braking cycles based on the cumulative wear.

[0006] Secondly, this application provides a caliper brake friction pad wear life prediction system, the caliper brake friction pad wear life prediction system comprising: The data acquisition module is used to simultaneously acquire the number of braking events, the peak hydraulic pressure, and the peak temperature of the friction pair, and to construct a data record group containing the number of braking events, the peak pressure, and the peak temperature. The filtering module is used to set the data acquisition interval according to the number of braking actions and filter the data record group according to the data acquisition interval. The analysis module is used to calculate the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure. When the deviation rate exceeds a set value, the current wear amount is calculated back based on the average value of the pressure peaks. The actual wear rate is calculated based on the ratio of the current wear amount to the number of braking cycles. The braking cycle threshold is moved forward based on the ratio of the actual wear rate to the theoretical wear rate, and the data acquisition interval is shortened. The calculation module is used to calculate the cumulative wear based on the temperature peak and the pressure peak, and to calculate the remaining number of braking cycles based on the cumulative wear.

[0007] The technical solution provided in this application constructs a data recording group by simultaneously collecting braking frequency, hydraulic pressure peak value, and friction pair temperature peak value. This solves the problem of incomplete information caused by relying on only a single parameter for prediction in existing technologies. Braking frequency provides a time reference for wear accumulation, pressure peak value reflects the disc spring load decay state, and temperature peak value reveals the frictional heat load level. The simultaneous collection of these three types of parameters enables the wear prediction model to comprehensively consider the coupling effect of mechanical wear and thermally accelerated wear, avoiding the one-sidedness of traditional methods that rely solely on braking frequency statistics or pressure monitoring. The segmented collection strategy, which sets the data collection interval based on the braking frequency and filters the data recording group according to the collection interval, employs sparse collection in the early stages of wear to reduce data storage. To improve monitoring accuracy in the later stages of wear, dense data acquisition is used to handle the load. Compared with a fixed acquisition frequency scheme, this saves system resources and ensures data integrity in critical stages. The mechanism calculates the deviation rate between the average peak pressure and the design pressure and triggers wear rate calibration based on the deviation rate. By back-calculating the current wear amount through pressure data, a direct correlation between the measured working condition and the wear state is established, overcoming the cumulative error caused by the reliance on theoretical formulas in traditional methods. When the actual wear rate exceeds the theoretical wear rate, the threshold number of braking times is advanced by shifting the wear acceleration factor and shortening the data acquisition interval. This achieves adaptive adjustment of the acquisition strategy to the actual wear process and avoids the lag response problem of the fixed threshold strategy under wear acceleration conditions. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of an embodiment of the method for predicting the wear life of caliper brake friction pads in this application. Figure 2 This is a schematic diagram comparing wear rates under different operating conditions in the embodiments of this application; Figure 3 This is a schematic diagram showing the changes in temperature acceleration correction coefficients for different materials in the embodiments of this application. Detailed Implementation

[0010] This application provides a method and system for predicting the wear life of caliper brake friction pads. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0011] For ease of understanding, the specific process of the embodiments of this application is described below. Please refer to [link / reference]. Figure 1 One embodiment of the method for predicting the wear life of caliper brake friction pads in this application includes: Step S1: Synchronously collect the number of braking events, peak hydraulic pressure, and peak friction pair temperature to construct a data record group containing the number of braking events, peak pressure, and peak temperature. Specifically, the data recording group is constructed and stored using a timestamp index method. The industrial control software triggers a data acquisition event each time it detects an increase in the value of the braking count counter. The pressure sensor sampling frequency is set to 100Hz to capture the transient pressure change characteristics during the opening process. The maximum value is extracted from the collected pressure time series as the pressure peak value. The temperature sensor synchronously collects the friction pair temperature and extracts the peak value. The three parameters of braking count, pressure peak value, and temperature peak value are associated and stored to form a data record.

[0012] Step S2: Set the data acquisition interval according to the number of braking cycles, and filter the data record groups according to the data acquisition interval; Specifically, the data acquisition interval is dynamically adjusted according to the braking number threshold. The first braking number threshold is calculated based on the basic wear coefficient and initial braking pressure, corresponding to the theoretical braking number of 1.5mm wear. The second threshold corresponds to 3mm wear, and the third threshold corresponds to 4mm wear. The industrial control software determines the acquisition interval parameter by judging the threshold range of the current braking number, and filters the data record group according to the set interval value, retaining only the records whose braking number identifier is divisible by the interval value for subsequent analysis.

[0013] Step S3: Calculate the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure. When the deviation rate exceeds the set value, calculate the current wear amount based on the average value of the pressure peaks. Calculate the actual wear rate based on the ratio of the current wear amount to the number of braking cycles. Move the braking cycle threshold forward based on the ratio of the actual wear rate to the theoretical wear rate and shorten the data acquisition interval. Specifically, the pressure deviation rate is calculated by averaging a fixed number of recently collected pressure peak data. 10 sets of data are taken in the early stage of wear, 20 sets in the middle stage, 50 sets in the later stage, and 100 sets in the final stage. When the average pressure is substituted into the pressure-wear amount relationship formula to back-calculate the current wear amount, the first opening pressure corresponding to zero wear and the second opening pressure corresponding to the preset wear amount form two endpoints of the linear relationship. The back-calculation is completed by multiplying the ratio of the pressure reduction amount to the pressure reduction benchmark amount by the preset wear amount. When the ratio of the actual wear rate to the theoretical wear rate exceeds 1.2, the remaining braking number of the next stage threshold is divided by this ratio to move the threshold forward.

[0014] Step S4: Calculate the cumulative wear based on the peak temperature and peak pressure, and calculate the remaining number of braking cycles based on the cumulative wear.

[0015] Specifically, the cumulative wear calculation involves multiplying the basic wear increment of each braking action by a pressure correction factor and a temperature acceleration correction factor. The pressure correction factor is determined by the ratio of the current average pressure to the design pressure to reflect the impact of disc spring pressure decay on wear. The temperature acceleration correction factor is calculated by dividing the difference between the average temperature rise value and the critical temperature rise threshold by the critical temperature rise threshold and then multiplying by the material's thermal sensitivity coefficient. The cumulative wear amount is obtained by summing the corrected wear increments of all previous braking actions. The remaining number of braking actions is obtained by subtracting the cumulative wear amount from the wear replacement standard of 5mm and dividing by the average wear rate of the most recent braking actions.

[0016] In one specific embodiment, step S1 includes: The real-time pressure value of the hydraulic opening cylinder is collected by a pressure sensor, and the peak value of the pressure value during each braking process is extracted as the hydraulic pressure peak value. The real-time temperature value of the friction pad contact surface is collected by a temperature sensor, and the peak temperature value during each braking process is extracted as the peak temperature of the friction pair. Read the on / off signal of the braking command solenoid valve. When the solenoid valve is detected to switch from the de-energized state to the energized state and then back to the de-energized state, the counter value is incremented once to obtain the number of braking operations. The number of braking operations, peak hydraulic pressure, and peak friction pair temperature are stored using timestamp indexing to construct a data record group.

[0017] Specifically, the pressure sensor is installed on the oil inlet pipe of the hydraulic opening cylinder, with a range set to 0-20MPa and a sampling accuracy of 0.01MPa. The sampling frequency of the data acquisition card is set to 100Hz to ensure that the transient changes in hydraulic pressure during braking are captured. The industrial control software searches for the maximum value from the collected pressure time series as the peak hydraulic pressure of that braking action. The temperature sensor uses a K-type thermocouple arranged 3-5mm on the back side of the contact surface between the friction pad and the brake disc, with a measurement range of -20℃ to 300℃ and a sampling accuracy of 0.1℃. The temperature change curve during braking is collected synchronously, and the peak value is extracted as the peak temperature of the friction pair. The on / off signal of the braking command solenoid valve is read through the PLC digital input module. The solenoid valve is energized to open the brake and de-energized to close the brake. A complete energization-de-energization cycle represents the completion of one braking action.

[0018] When the industrial control software detects that the solenoid valve has switched from being de-energized to energized, it initiates a data acquisition window. When the solenoid valve returns to the de-energized state, the acquisition window closes and data processing is triggered. The pressure time series and temperature time series within the acquisition window are extracted for peak values. At the same time, the current value of the braking count counter is read. The number of braking counts, the extracted hydraulic pressure peak value, the friction pair temperature peak value, and the corresponding system timestamp are encapsulated into a structured data record. The data record is stored in the real-time database in ascending order of timestamp. The timestamp is recorded with millisecond-level precision to facilitate rapid retrieval of braking data for a specific time period based on the time range. The storage format of the data record group supports two query methods: indexed by the number of braking counts and indexed by timestamp.

[0019] In one specific embodiment, step S2, which sets the data acquisition interval based on the number of braking cycles, includes: The wear life cycle of the friction plate is divided into the initial wear stage, the middle wear stage, the late wear stage, and the final wear stage, which correspond to the first braking number threshold, the second braking number threshold, the third braking number threshold, and the fourth braking number threshold, respectively. When the number of braking events is less than the first braking event threshold, the data collection interval is set to once every ten braking events. When the number of braking events is greater than or equal to the first braking event threshold and less than the second braking event threshold, the data collection interval is set to collect data once every five braking events. When the number of braking events is greater than or equal to the second braking event threshold and less than the third braking event threshold, the data collection interval is set to collect data once per braking event. When the number of braking events is greater than or equal to the third braking event threshold, the data acquisition interval is set to once per braking event and continuous temperature monitoring is initiated.

[0020] Specifically, the first braking frequency threshold is calculated based on the basic wear coefficient of the friction pad material, the single braking sliding distance, and the initial braking pressure of 120kN. The calculation formula is 1.5mm divided by the product of the basic wear coefficient, the initial braking pressure, and the sliding distance, and the result is taken as an integer as the threshold. The second braking frequency threshold is calculated by replacing 1.5mm with 3mm. The third braking frequency threshold is calculated by setting the wear amount to 4mm. The fourth braking frequency threshold is not involved in the acquisition interval adjustment but is only used as the basis for judging the end of wear. The four thresholds are calculated and stored based on the specific friction pad material parameters during the initialization of the industrial control software. In the early stage of wear, because the surface condition of the friction pad is stable and the disc spring pressure basically maintains the design value, the wear rate changes slowly. The sparse acquisition mode of acquiring data once every ten braking cycles can reduce the data storage and processing load.

[0021] After each braking action, the industrial control software reads the current braking count counter value and compares it with four thresholds to determine the current wear stage. Based on the threshold range, it sets the acquisition interval parameter, which determines whether to execute the data recording group storage operation. When the number of braking actions is divisible by the acquisition interval parameter, complete data acquisition and storage are performed; otherwise, only the counter is incremented and data recording is skipped. In the later stage of wear, the reduced thickness of the friction pads leads to a shortened heat conduction path, which may cause the temperature peak to rise. In the final stage of wear, in addition to maintaining the acquisition of each braking action, a continuous temperature monitoring mode is activated. During the braking action, the temperature change process is continuously recorded at a sampling frequency of 100Hz to analyze thermal characteristic parameters such as the duration of the temperature peak and the temperature decay rate.

[0022] In one specific embodiment, step S3, calculating the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure, includes: Determine the number of data sets to be extracted based on the current wear stage, and extract the corresponding number of pressure peak data sets from the data record sets in reverse chronological order. The average value of the extracted pressure peak data is obtained by summing the multiple sets of pressure peak data and dividing by the number of data sets. Subtract the design pressure from the average value of the peak pressure, divide by the design pressure, and then multiply by 100% to obtain the deviation rate.

[0023] Specifically, the industrial control software sets the number of pressure data extraction groups based on the wear stage of the current braking cycle: 10 groups for the initial wear stage, 20 groups for the middle wear stage, 50 groups for the late wear stage, and 100 groups for the final wear stage. The latest corresponding pressure peak data is extracted from the data records, sorted in descending order of timestamp. All extracted pressure peak values ​​are summed and divided by the number of extracted data groups to obtain the average pressure peak value. This average value reflects the average opening pressure level provided by the hydraulic system during recent braking processes. The average pressure peak value is subtracted from the design pressure of 9.55 MPa to obtain the absolute value of the pressure deviation. This absolute value is then divided by the design pressure and multiplied by 100% to complete the normalization process, yielding the deviation rate. A positive deviation rate indicates that the actual pressure is higher than the design value, while a negative deviation rate indicates that the actual pressure is lower than the design value. The absolute value of the deviation rate reflects the degree to which the current braking system pressure deviates from the design operating conditions.

[0024] In one specific embodiment, step S3, when the deviation rate exceeds a set value, involves calculating the current wear amount based on the average value of the pressure peak values, including: Establish a first correspondence between zero wear and the load of the first disc spring, and a second correspondence between the preset wear and the load of the second disc spring; Multiply the average value of the pressure peak by the effective area of ​​the piston to obtain the current hydraulic opening force; Subtract the current hydraulic opening force from the first disc spring load to obtain the current disc spring load; Subtract the current disc spring load from the first disc spring load to obtain the disc spring load reduction amount; Subtract the second disc spring load from the first disc spring load to obtain the disc spring load reduction reference amount; The current wear amount is obtained by dividing the decrease in disc spring load by the reference decrease in disc spring load and then multiplying it by the preset wear amount.

[0025] Specifically, the first correspondence establishes a disc spring load of 119.82 kN under zero wear conditions, and the second correspondence establishes a disc spring load of 88.10 kN under a preset wear level of 2 mm. Based on the NB100 brake's structural parameters, the effective piston area is 16886.06 square millimeters. Multiplying the average of the currently measured pressure peaks by the effective piston area yields the current opening force provided by the hydraulic system. Since the brake is in a force balance state, the braking force applied by the disc spring is equal in magnitude and opposite in direction to the hydraulic opening force. Therefore, subtracting the current hydraulic opening force from the first disc spring load gives the current disc spring load. Subtracting the current disc spring load from the first disc spring load of 119.82 kN yields... The reduction in disc spring load reflects the load attenuation caused by the decrease in compression due to wear of the friction plates. Subtracting the second disc spring load of 88.10kN from the first disc spring load of 119.82kN yields a baseline load reduction of 31.72kN. This baseline corresponds to a load change of 2mm for the preset wear amount. Dividing the disc spring load reduction by the baseline yields the wear progress ratio, which is then multiplied by the preset wear amount of 2mm to calculate the current actual wear amount. This method is based on the linear relationship between load and compression in the disc spring characteristic curve. Wear of the friction plates leads to a decrease in the disc spring compression, resulting in a linear decrease in the disc spring load, which is reflected in a reduction in the required opening pressure.

[0026] In one specific embodiment, step S3 calculates the actual wear rate based on the ratio of the current wear amount to the number of braking cycles, and advances the braking cycle threshold based on the ratio of the actual wear rate to the theoretical wear rate, including: Read the historical wear amount and historical braking number recorded during the last calibration from the database, subtract the historical wear amount from the current wear amount to obtain the wear increment, and subtract the historical braking number from the current braking number to obtain the braking number increment; The actual wear rate is obtained by dividing the wear increment by the braking number increment; the theoretical wear rate is obtained by multiplying the basic wear coefficient of the friction pad material, the single braking sliding distance, and the initial braking pressure. Divide the actual wear rate by the theoretical wear rate to obtain the wear acceleration factor; When the wear acceleration factor is greater than the preset acceleration threshold, the difference between the braking number threshold for the next stage and the current braking number is divided by the wear acceleration factor to obtain the corrected remaining number of braking times; the corrected remaining number of braking times is added to the current braking number of braking times to update the braking number threshold for the next stage.

[0027] Specifically, historical wear and braking frequency are stored in the calibration record data table of the industrial control software. Each time the wear rate calibration process in step S3 is executed, the currently calculated wear and corresponding braking frequency are written into the database as new calibration records, while the previous calibration record is retained as historical data. The wear increment between two calibrations is obtained by subtracting the historical wear from the current wear, and the braking frequency increment between two calibrations is obtained by subtracting the historical braking frequency from the current braking frequency. The wear increment is divided by the braking frequency increment to obtain the actual wear rate during this period. This rate reflects the average wear of each braking under real working conditions. The theoretical wear rate is calculated based on the performance parameters of the friction pad material. The basic wear coefficient is obtained from the material database in cubic millimeters per Newton-meter. The single braking sliding distance is calculated based on the brake structure parameters and braking stroke. The initial braking pressure is the 119.82 kN load provided by the disc spring in a zero-wear state. The product of the three parameters is the wear amount of each braking under theoretical conditions, i.e., the theoretical wear rate.

[0028] The wear acceleration factor is obtained by dividing the actual wear rate by the theoretical wear rate. A factor greater than 1 indicates that the actual wear is faster than the theoretical expectation, and a factor less than 1 indicates that the actual wear is slower than the theoretical expectation. When the wear acceleration factor is greater than the preset acceleration threshold of 1.2, it indicates that the actual working conditions are severe, resulting in a significant acceleration of wear. At this time, it is necessary to trigger the dense collection strategy for the next wear stage in advance. The difference between the braking number threshold for the next stage and the current braking number represents how many brakings are needed to reach the next stage according to the theoretical wear rate. Dividing this difference by the wear acceleration factor and correcting it, we get the true remaining number of brakings after considering the actual wear acceleration. Corrected remaining number of brakings = theoretical remaining number of brakings ÷ wear acceleration factor. Adding the corrected remaining number of brakings to the current braking number gives the new threshold position. The updated threshold will trigger earlier than the original threshold, thereby switching to a denser data collection interval and a more frequent calibration cycle in advance, avoiding prediction lag caused by wear acceleration.

[0029] In one specific embodiment, step S4, calculating the cumulative wear amount based on the peak temperature and peak pressure, includes: Extract the most recently collected sets of temperature peak data from the data record group, and subtract the corresponding initial temperature from each set of temperature peaks to obtain multiple temperature rise values. The average temperature rise is obtained by summing multiple temperature rise values ​​and then dividing by the number of temperature rise values. When the average temperature rise exceeds the critical temperature rise threshold, the average temperature rise is subtracted from the critical temperature rise threshold, divided by the critical temperature rise threshold, multiplied by the material's thermal sensitivity coefficient, and then one is added to obtain the temperature acceleration correction coefficient. Divide the average value of the pressure peak by the design pressure to obtain the pressure correction coefficient; multiply the basic wear coefficient of the friction pad material by the pressure peak of the current braking and the single braking sliding distance to obtain the basic wear increment. Multiply the base wear increment by the pressure correction factor and the temperature acceleration correction factor to obtain the actual wear increment; sum the actual wear increments of each braking operation to obtain the cumulative wear amount.

[0030] Specifically, multiple sets of recently collected temperature peak data are extracted from the data recording group in reverse chronological order. The number of data sets extracted is determined based on the current wear stage: 50 sets are extracted in the early wear stage, 100 sets in the middle wear stage, 200 sets in the late wear stage, and 500 sets in the late wear stage. Each data record contains the temperature peak and initial temperature of that braking action. The initial temperature is the friction pair temperature value collected by the temperature sensor before the braking action begins. The temperature rise value of that braking action is obtained by subtracting the corresponding initial temperature from the temperature peak in each data set. The temperature rise value reflects the temperature rise caused by frictional heat during a single braking process. The average temperature is obtained by summing all extracted temperature rise values ​​and dividing by the number of temperature rise values. The average temperature rise value reflects the recent thermal load level under braking conditions. The critical temperature rise threshold is determined according to the friction pad material type: 80℃ for copper-based powder metallurgy materials, 100℃ for resin-based composite materials, and 120℃ for carbon-based materials. When the average temperature rise value exceeds the critical temperature rise threshold, the material matrix undergoes thermal softening, resulting in a decrease in hardness. Subtracting the critical temperature rise threshold from the average temperature rise value yields the temperature rise exceeding the threshold. Dividing this by the critical temperature rise threshold completes the normalization process. Multiplying by the material's thermal sensitivity coefficient and adding one gives the temperature acceleration correction coefficient. The material's thermal sensitivity coefficient is obtained from a material database: 0.15 for copper-based materials, 0.25 for resin-based materials, and 0.10 for carbon-based materials.

[0031] The average value of the pressure peak is calculated in step S3. Dividing this average value by the design pressure of 9.55 MPa yields the pressure correction coefficient, which reflects the degree of attenuation of the current disc spring load relative to the initial load. The pressure peak value of the current braking is read from the data recording group. The basic wear coefficient of the friction pad material is multiplied by the pressure peak value of the current braking and the single braking sliding distance to obtain the basic wear increment. The basic wear increment represents the wear amount of the braking under ideal working conditions. The basic wear increment is multiplied by the pressure correction coefficient and the temperature acceleration correction coefficient to obtain the actual wear increment. When the pressure correction coefficient is less than 1, the wear amount is reduced; when the temperature acceleration correction coefficient is greater than 1, the wear amount is increased. The two coefficients work together to reflect the comprehensive influence of pressure attenuation and temperature acceleration on wear. The industrial control software sums up the actual wear increments of all braking actions from the initial state to the current moment to obtain the cumulative wear amount. This cumulative wear amount represents the total wear amount of the friction pad accumulated from the zero wear state to the current state. The wear replacement standard of 5 mm is subtracted from the cumulative wear amount to obtain the remaining wear margin. The actual wear increments of the most recent braking are extracted from the database to calculate the average wear rate. The remaining wear margin is divided by the average wear rate to obtain the remaining number of braking operations.

[0032] Figure 2 This is a schematic diagram comparing wear rates under different operating conditions in the embodiments of this application. Figure 2 The comparison between theoretical and actual wear rates is shown under four typical operating conditions: normal pressure and normal temperature, normal pressure and high temperature, low pressure and normal temperature, and low pressure and high temperature. The theoretical wear rate is 0.50 mm / thousand cycles under all conditions, while the actual wear rate is 0.52 mm / thousand cycles under normal pressure and normal temperature. Under normal pressure and high temperature, the actual wear rate increases to 0.68 mm / thousand cycles due to the temperature acceleration correction factor. Under low pressure and normal temperature, the actual wear rate decreases to 0.42 mm / thousand cycles due to the pressure correction factor. Under low pressure and high temperature, the actual wear rate is 0.55 mm / thousand cycles due to the combined effect of both correction factors. This comparison verifies the necessity and effectiveness of the present invention in correcting the basic wear increment using pressure correction factor and temperature acceleration correction factor.

[0033] Figure 3 This is a schematic diagram showing the changes in temperature acceleration correction coefficients for different materials in the embodiments of this application. Figure 3 The curves showing the relationship between the temperature acceleration correction coefficient βT and the average temperature rise for three friction pad materials—copper-based, resin-based, and carbon-based—are presented. The critical temperature rise thresholds are 80℃ for copper-based materials, 100℃ for resin-based materials, and 120℃ for carbon-based materials. When the average temperature rise is below their respective critical temperature rise thresholds, the correction coefficient βT remains at a baseline value of 1.0. Once the average temperature rise exceeds the critical temperature rise threshold, the correction coefficient begins to increase linearly with increasing temperature. The resin-based material exhibits the fastest increase in correction coefficient due to its maximum thermistor kT of 0.25, while the copper-based material falls in the middle with a thermistor kT of 0.15. The carbon-based material exhibits the slowest increase in correction coefficient due to its minimum thermistor kT of 0.10. Figure 2 The three vertical dashed lines in the figure mark the critical temperature rise threshold positions of the three materials, and the red horizontal dashed line marks the baseline βT=1.0. This figure verifies the rationality of the present invention in dynamically calculating the temperature acceleration correction coefficient based on different friction plate material types and actual temperature rise conditions.

[0034] The above describes the method for predicting the wear life of caliper brake friction pads in the embodiments of this application. The following describes the system for predicting the wear life of caliper brake friction pads in the embodiments of this application. One embodiment of the system for predicting the wear life of caliper brake friction pads in the embodiments of this application includes: The data acquisition module is used to simultaneously acquire the number of braking events, the peak hydraulic pressure, and the peak temperature of the friction pair, and to construct a data record group containing the number of braking events, the peak pressure, and the peak temperature. The filtering module is used to set the data acquisition interval according to the number of braking actions and filter the data record group according to the data acquisition interval. The analysis module is used to calculate the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure. When the deviation rate exceeds a set value, the current wear amount is calculated back based on the average value of the pressure peaks. The actual wear rate is calculated based on the ratio of the current wear amount to the number of braking cycles. The braking cycle threshold is moved forward based on the ratio of the actual wear rate to the theoretical wear rate, and the data acquisition interval is shortened. The calculation module is used to calculate the cumulative wear based on the temperature peak and the pressure peak, and to calculate the remaining number of braking cycles based on the cumulative wear.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting the wear life of friction pads in a caliper brake, characterized in that, The method includes: Step S1: Synchronously collect the number of braking events, peak hydraulic pressure, and peak friction pair temperature to construct a data record group containing the number of braking events, peak pressure, and peak temperature. Step S2: Set the data acquisition interval according to the number of braking cycles, and filter the data record group according to the data acquisition interval; Step S3: Calculate the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure. When the deviation rate exceeds the set value, calculate the current wear amount based on the average value of the pressure peaks. Calculate the actual wear rate based on the ratio of the current wear amount to the number of braking cycles. Move the braking cycle threshold forward based on the ratio of the actual wear rate to the theoretical wear rate, and shorten the data acquisition interval. Step S4: Calculate the cumulative wear based on the temperature peak and the pressure peak, and calculate the remaining number of braking cycles based on the cumulative wear.

2. The method for predicting the wear life of caliper brake friction pads according to claim 1, characterized in that, Step S1 includes: The real-time pressure value of the hydraulic opening cylinder is collected by a pressure sensor, and the peak value of the pressure value during each braking process is extracted as the hydraulic pressure peak value. The real-time temperature value of the friction plate contact surface is collected by a temperature sensor, and the peak temperature value during each braking process is extracted as the peak temperature of the friction pair. Read the on / off signal of the braking command solenoid valve. When the solenoid valve is detected to switch from a de-energized state to an energized state and then back to a de-energized state, increment the counter value once to obtain the number of braking operations. The number of braking operations, the peak hydraulic pressure, and the peak temperature of the friction pair are stored using a timestamp index to construct the data record group.

3. The method for predicting the wear life of caliper brake friction pads according to claim 1, characterized in that, Step S2, which involves setting the data acquisition interval based on the number of braking cycles, includes: The wear life cycle of the friction plate is divided into the initial wear stage, the middle wear stage, the late wear stage, and the final wear stage, which correspond to the first braking number threshold, the second braking number threshold, the third braking number threshold, and the fourth braking number threshold, respectively. When the number of braking events is less than the first braking event threshold, the data collection interval is set to once every ten braking events; When the number of braking events is greater than or equal to the first braking event threshold and less than the second braking event threshold, the data collection interval is set to collect data once every five braking events. When the number of braking events is greater than or equal to the second braking event threshold and less than the third braking event threshold, the data acquisition interval is set to once per braking event. When the number of braking events is greater than or equal to the third braking event threshold, the data acquisition interval is set to once per braking event and continuous temperature monitoring is initiated.

4. The method for predicting the wear life of caliper brake friction pads according to claim 1, characterized in that, Step S3, which calculates the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure, includes: The number of data sets to be extracted is determined based on the current wear stage, and the corresponding number of pressure peak data sets are extracted from the data record sets in reverse chronological order. The average value of the extracted pressure peak data is obtained by summing the multiple sets of pressure peak data and dividing by the number of data sets. The deviation rate is obtained by subtracting the design pressure from the average value of the pressure peaks, dividing by the design pressure, and then multiplying by 100%.

5. The method for predicting the wear life of caliper brake friction pads according to claim 4, characterized in that, In step S3, when the deviation rate exceeds a set value, the current wear amount is calculated back based on the average value of the pressure peak values, including: Establish a first correspondence between zero wear and the load of the first disc spring, and a second correspondence between the preset wear and the load of the second disc spring; Multiply the average value of the pressure peaks by the effective area of ​​the piston to obtain the current hydraulic opening force; Subtract the current hydraulic opening force from the first disc spring load to obtain the current disc spring load; Subtracting the current disc spring load from the first disc spring load yields the disc spring load reduction. Subtracting the second disc spring load from the first disc spring load yields the disc spring load reduction reference amount. The current wear amount is obtained by dividing the disc spring load reduction by the disc spring load reduction reference amount and then multiplying by the preset wear amount.

6. The method for predicting the wear life of caliper brake friction pads according to claim 5, characterized in that, In step S3, the actual wear rate is calculated based on the ratio of the current wear amount to the number of braking cycles, and the braking cycle threshold is shifted forward based on the ratio of the actual wear rate to the theoretical wear rate, including: The historical wear amount and historical braking number recorded during the last calibration are read from the database. The wear increment is obtained by subtracting the historical wear amount from the current wear amount, and the braking number increment is obtained by subtracting the historical braking number from the current braking number. The actual wear rate is obtained by dividing the wear increment by the braking number increment; the theoretical wear rate is obtained by multiplying the basic wear coefficient of the friction pad material, the single braking sliding distance, and the initial braking pressure. Divide the actual wear rate by the theoretical wear rate to obtain the wear acceleration factor; When the wear acceleration factor is greater than the preset acceleration threshold, the difference between the braking number threshold for the next stage and the current braking number is divided by the wear acceleration factor to obtain the corrected remaining number of braking times; the current braking number is added to the corrected remaining number of braking times to update the braking number threshold for the next stage.

7. The method for predicting the wear life of caliper brake friction pads according to claim 1, characterized in that, Step S4, which calculates the cumulative wear based on the peak temperature and the peak pressure, includes: Extract the most recently collected multiple sets of temperature peak data from the data record group, and subtract the corresponding initial temperature from each set of temperature peaks to obtain multiple temperature rise values. The average temperature rise value is obtained by summing the multiple temperature rise values ​​and dividing by the number of temperature rise values. When the average temperature rise exceeds the critical temperature rise threshold, the average temperature rise is subtracted from the critical temperature rise threshold, then divided by the critical temperature rise threshold, multiplied by the material's thermal sensitivity coefficient, and then one is added to obtain the temperature acceleration correction coefficient. Divide the average value of the pressure peak by the design pressure to obtain the pressure correction coefficient; multiply the basic wear coefficient of the friction pad material by the pressure peak of the current braking and the single braking sliding distance to obtain the basic wear increment; The actual wear increment is obtained by multiplying the basic wear increment by the pressure correction factor and the temperature acceleration correction factor; the cumulative wear amount is obtained by summing the actual wear increments of each braking operation.

8. A caliper brake friction pad wear life prediction system, characterized in that, For implementing the method for predicting the wear life of caliper brake friction pads as described in any one of claims 1-7, the caliper brake friction pad wear life prediction system comprises: The data acquisition module is used to simultaneously acquire the number of braking events, the peak hydraulic pressure, and the peak temperature of the friction pair, and to construct a data record group containing the number of braking events, the peak pressure, and the peak temperature. The filtering module is used to set the data acquisition interval according to the number of braking actions and filter the data record group according to the data acquisition interval. The analysis module is used to calculate the deviation rate between the average value of the pressure peaks in the data recording group and the design pressure. When the deviation rate exceeds a set value, the current wear amount is calculated back based on the average value of the pressure peaks. The actual wear rate is calculated based on the ratio of the current wear amount to the number of braking cycles. The braking cycle threshold is moved forward based on the ratio of the actual wear rate to the theoretical wear rate, and the data acquisition interval is shortened. The calculation module is used to calculate the cumulative wear based on the temperature peak and the pressure peak, and to calculate the remaining number of braking cycles based on the cumulative wear.

9. The system according to claim 8, characterized in that, Simultaneously collect braking frequency, hydraulic pressure peak value, and friction pair temperature peak value to construct a data record group containing braking frequency, pressure peak value, and temperature peak value, including: The real-time pressure value of the hydraulic opening cylinder is collected by a pressure sensor, and the peak value of the pressure value during each braking process is extracted as the hydraulic pressure peak value. The real-time temperature value of the friction plate contact surface is collected by a temperature sensor, and the peak temperature value during each braking process is extracted as the peak temperature of the friction pair. Read the on / off signal of the braking command solenoid valve. When the solenoid valve is detected to switch from a de-energized state to an energized state and then back to a de-energized state, increment the counter value once to obtain the number of braking operations. The number of braking operations, the peak hydraulic pressure, and the peak temperature of the friction pair are stored using a timestamp index to construct the data record group.

10. The system according to claim 9, characterized in that, The cumulative wear is calculated based on the peak temperature and the peak pressure, including: Extract the most recently collected multiple sets of temperature peak data from the data record group, and subtract the corresponding initial temperature from each set of temperature peaks to obtain multiple temperature rise values. The average temperature rise value is obtained by summing the multiple temperature rise values ​​and dividing by the number of temperature rise values. When the average temperature rise exceeds the critical temperature rise threshold, the average temperature rise is subtracted from the critical temperature rise threshold, then divided by the critical temperature rise threshold, multiplied by the material's thermal sensitivity coefficient, and then one is added to obtain the temperature acceleration correction coefficient. Divide the average value of the pressure peak by the design pressure to obtain the pressure correction coefficient; multiply the basic wear coefficient of the friction pad material by the pressure peak of the current braking and the single braking sliding distance to obtain the basic wear increment; The actual wear increment is obtained by multiplying the basic wear increment by the pressure correction factor and the temperature acceleration correction factor; the cumulative wear amount is obtained by summing the actual wear increments of each braking operation.

Images