Real-time prediction method and system for residual service life of silicon carbide brake disc

Abstract

The invention relates to the technical field of brake disc service life prediction, and discloses a real-time prediction method and system for the residual service life of a silicon carbide brake disc. The invention aims to solve the technical problem that an existing brake disc service life prediction method is difficult to realize accurate prediction. According to the invention, the synchronous and quantitative diagnosis of the physical wear of the brake disc and the material performance degradation is realized by deeply fusing the data of the multi-dimensional sensor. The core of the method is that a double-domain health model fusing macroscopic physical wear and microcosmic performance degradation is constructed, and all non-standard braking working conditions are uniformly converted into accumulative equivalent consumption through an energy dissipation principle. According to the method, a closed-loop diagnosis system from data acquisition, state evaluation to life prediction is constructed, so that the prediction accuracy and reliability of the residual service life of the silicon carbide brake disc are remarkably improved, and the active safety early warning and predictive maintenance capabilities of parts are greatly enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake disc life prediction, in particular to a real-time prediction method and system for the residual service life of a silicon carbide brake disc. BACKGROUND

[0002] Silicon carbide brake discs, commonly known as carbon fiber reinforced silicon carbide ceramic composite material brake discs, are a key component that has been increasingly widely used in the field of component brake disc life prediction systems in recent years. Compared with traditional gray cast iron brake discs, they have extremely low density, making them much lighter than metal discs of the same size, which can reduce the unsprung mass of the vehicle, improve handling response and fuel economy; they also have extremely high thermal stability and excellent thermal conductivity, allowing them to maintain a stable friction coefficient even under continuous and high-intensity braking conditions, effectively resisting the phenomenon of thermal degradation caused by high temperatures; in addition, their ultra-high hardness and wear resistance give them a much longer service life than traditional brake discs. Silicon carbide brake discs have become a standard configuration for high-performance sports cars, racing cars, and some high-end new energy vehicles.

[0003] By accurately estimating the residual life of the brake disc, it is possible to transition from traditional preventive maintenance based on fixed mileage or time to predictive maintenance based on the actual health status of the component. Not only can it ensure that the driver is warned in time before the brake disc performance deteriorates to the point where it affects safety, thereby minimizing the risk of serious accidents caused by brake system failure; but also effectively avoids the premature replacement of the brake disc when it still has considerable service life, making full use of its high-value components and significantly reducing the maintenance cost of the vehicle throughout its life cycle, improving the availability and economy of the vehicle.

[0004] Existing wear monitoring techniques ignore the invisible but crucial damage mode of internal material performance degradation caused by repeated thermal shock. They do not comprehensively consider physical wear and material performance degradation, and cannot provide a scientific and quantitative real-time life prediction method that truly reflects the wear and tear, which makes the maintenance and replacement strategy of silicon carbide brake discs still at a relatively rough and passive stage, posing a huge safety risk and economic waste. SUMMARY

[0005] In view of the above existing problems, the present application is proposed.

[0006] Therefore, the present application provides a real-time prediction method for the residual service life of a silicon carbide brake disc, which solves the technical pain points of existing brake disc life prediction methods that result in severely distorted prediction results due to the single evaluation dimension and the inability to quantify real wear and tear.

[0007] To solve the above technical problems, the present application provides the following technical solutions: The application provides a real-time residual service life prediction method for a silicon carbide brake disc, which comprises the following steps, S1: initialization calibration of the brake disc is performed after vehicle maintenance, and a full-cycle reference model containing state parameter reference values and an initial total equivalent consumption amount is established; S2: in a use cycle of the brake disc, multi-dimensional braking data associated with a braking event are collected in real time in response to the braking event; S3: real-time state parameters for characterizing physical wear and material performance of the brake disc are calculated based on the dynamic multi-dimensional braking data, and an equivalent consumption amount consumed by the braking event is calculated; S4: the full-cycle reference model is iteratively updated in combination with the real-time state parameters and the equivalent consumption amount; S5: a diagnosis report is output in the case that the health state of the brake disc is poor after comprehensive diagnosis of the health state of the brake disc is performed based on the updated model.

[0008] As a preferred scheme of the real-time residual service life prediction method for the silicon carbide brake disc, in the step S1, the process of establishing the full-cycle reference model specifically comprises the following steps: measuring a caliper piston zero position reference value for calculating a total wear stroke, an initial resistance reference value of a brake pad wear sensor for calculating an independent wear amount of the brake pad, and an equivalent capacitance reference value for subsequent calibration of a real-time effective thickness of a disc body, and storing the zero position reference value, the initial resistance reference value and the equivalent capacitance reference value as state parameter reference values; loading a preset standard thermal response model describing a standard temperature rise and fall rate of a brand new disc body under different braking conditions and a capacitance temperature drift characteristic reference describing a temperature change rule of a capacitance value of the brand new disc body into the full-cycle reference model; The initial total equivalent consumption amount is an initial total life amount converted into a dimensionless value according to a standard aging test environment based on a total number of design braking cycles of the brake disc.

[0009] As a preferred scheme of the real-time residual service life prediction method for the silicon carbide brake disc, in the step S2, the multi-dimensional braking data comprises the following data: real-time caliper piston stroke data collected by a high-precision displacement sensor, used for calculating a total wear amount including wear of the brake disc and the brake pad; real-time resistance data of the brake pad wear sensor, used for calculating a current wear amount of the brake pad; dynamic equivalent capacitance measurement data collected by a capacitance measurement circuit, a data change rate in a process in which the brake pad approaches is used for sensing a clearance closing process, and a drift amount after braking contact can assist in evaluating a temperature-induced characteristic change of a disc body material. The real-time temperature curve data of the braking process collected by the temperature sensor is used as the temperature reference for comparison with the standard thermal response model, and helps to analyze the degree of thermal property degradation of the disc material. Braking pressure data, obtained from the vehicle bus, is used to characterize braking intensity, and current vehicle speed data is used to define the initial braking state, serving as braking condition data.

[0010] As a preferred embodiment of the real-time prediction method for the remaining service life of the silicon carbide brake disc according to the present invention, the process of calculating the physical wear of the brake disc in step S3 specifically includes: calculating the difference between the real-time caliper piston stroke data and the zero-point position reference value as the total wear stroke; calculating the difference between the real-time resistance data solution and the initial resistance reference value to calculate the independent wear amount of the brake pad; and subtracting the independent wear amount from the total wear stroke to obtain the preliminary mechanical wear amount of the brake disc. Under non-braking steady-state conditions, the thickness of the air medium in the equivalent capacitance reference value is increased according to the independent wear amount to obtain a reference equivalent capacitance characterizing the independent wear amount. The difference between the reference equivalent capacitance and the dynamic measurement data of the equivalent capacitance is calculated. The preliminary electrical wear amount is calculated based on the difference between the pre-stored brake disc and the air dielectric constant. The actual wear of the brake disc is obtained by comprehensively evaluating the preliminary mechanical wear and the preliminary electrical wear.

[0011] As a preferred embodiment of the real-time prediction method for the remaining service life of the silicon carbide brake disc described in this invention, the process of calculating the real-time state parameters of the material properties of the brake disc in step S3 specifically includes: extracting temperature data within the braking time period from the real-time temperature curve data of the braking process, calculating the time slope to obtain the actual heating rate and the actual cooling rate; retrieving and matching the standard heating rate and the standard cooling rate under the corresponding working condition in the standard thermal response model; and obtaining the thermal characteristic degradation factor characterizing the deterioration of the disc's thermal conductivity and heat dissipation capacity by comprehensively evaluating the ratio of the actual heating rate to the standard heating rate and the ratio of the actual cooling rate to the standard cooling rate. The time frame of the temperature data and the equivalent capacitance dynamic measurement data is unified. The temperature data is substituted into the capacitance temperature drift characteristic reference to obtain the theoretical capacitance dynamic measurement data. The deviation between the equivalent capacitance dynamic measurement data and the theoretical capacitance dynamic measurement data is calculated. The electrical property degradation factor characterizing the change of internal electrical properties of the material is obtained by integration. By comprehensively evaluating the thermal property degradation factor and the electrical property degradation factor, a comprehensive material health index is obtained.

[0012] As a preferred embodiment of the real-time prediction method for the remaining service life of the silicon carbide brake disc of the present invention, the process of calculating the equivalent consumption of the braking event loss in step S3 specifically includes: Based on the comprehensive material health index, an adaptive specific heat capacity matching the current disc condition is looked up in a preset lookup table containing the comprehensive material health index and corresponding specific heat capacity values. A dynamic temperature difference compensation value is calculated based on the thermal characteristic degradation factor. This dynamic temperature difference compensation value characterizes the difference between the surface temperature and the average temperature of the effective friction zone. The average temperature rise of the effective friction zone is calculated by combining the real-time temperature curve data and the dynamic temperature difference compensation value. The total heat energy absorbed by the brake event during a single braking event is calculated by combining the adaptive specific heat capacity, the average temperature rise of the effective friction zone, and a preset constant representing the mass of the effective friction zone of the brake disc. The total heat energy absorbed by the single braking event is divided by the standard energy loss under standard test conditions, and then exponentially calculated using a damage aggravation index used to characterize the nonlinear cumulative effect of damage. Finally, the equivalent energy consumption of this braking event is calculated.

[0013] As a preferred embodiment of the real-time prediction method for the remaining service life of the silicon carbide brake disc described in this invention, the process of iteratively updating the full-cycle benchmark model in step S4 specifically includes: After the full-cycle benchmark model is established, a real-time working copy of the full-cycle benchmark model is created. After a braking event occurs, the parameters of the real-time working copy are updated using the real-time status parameters. The equivalent consumption is subtracted from the remaining equivalent consumption of the real-time working copy to obtain the latest remaining equivalent consumption, thus completing the iterative update of the real-time working copy.

[0014] As a preferred embodiment of the real-time prediction method for the remaining service life of the silicon carbide brake disc according to the present invention, the process of comprehensively diagnosing the current health status of the brake disc in step S5 specifically includes: The cumulative performance deviation is calculated by comparing the real-time status parameters with the baseline value of the status parameters; if the cumulative performance deviation exceeds the preset performance warning threshold, the current state of the brake disc is diagnosed as significantly deteriorated. If the remaining equivalent total consumption is lower than the preset wear warning threshold, the current state of the brake disc is marked as wear approaching the limit.

[0015] As a preferred embodiment of the real-time prediction method for the remaining service life of silicon carbide brake discs according to the present invention, the diagnostic report in step S5 specifically includes: brake disc replacement recommendations, potential risk parameters that lead to poor health status, and potential braking risks that the potential risk parameters may cause.

[0016] The present invention also provides a real-time prediction system for the remaining service life of silicon carbide brake discs, for performing the above method, specifically including the following modules: Model management module: retains the full-cycle baseline model, creates a real-time working copy based on the full-cycle baseline model, and updates the real-time working copy after the braking event ends; Time synchronization module: Receives multi-dimensional data streams transmitted from sensors and assigns a unified timestamp to the multi-dimensional data streams; Wear calculation module: Calculates the preliminary mechanical wear and preliminary electrical wear through the multi-dimensional data stream, and extrapolates the actual wear of the brake disc; Material evaluation module: Calculates the thermal property degradation factor and electrical property degradation factor through the multi-dimensional data stream, and deduces the comprehensive material health index of the brake disc; Equivalent Consumption Quantification Module: Receives the material comprehensive health index from the material evaluation module and converts the losses from braking events into equivalent consumption. Health status diagnosis module: compares the real-time working copy with the full-cycle benchmark model and the preset warning threshold to make independent diagnostic judgments on the performance degradation and physical wear status of the brake disc. Report generation module: Receives the health status determination result of poor health status from the health status diagnosis module, generates the corresponding diagnostic report and sends it to the vehicle display device.

[0017] The beneficial effects of this invention are as follows: By combining mechanical displacement differential calculation with capacitive sensing calibration, this invention accurately separates and quantifies the physical wear of the brake disc itself; by analyzing thermal response characteristics and capacitive temperature drift, it incorporates the degradation of material microstructure into the evaluation system. This achieves a multi-dimensional and comprehensive diagnosis of brake disc physical wear and performance degradation, resulting in more accurate and comprehensive predictions. By calculating and accumulating the total energy dissipated in each braking event, all non-standard and complex driving behaviors are scientifically and fairly converted into a unified unit of lifespan consumption. This allows lifespan prediction to truly adapt to and reflect the driving habits of different users, achieving personalized and high-precision lifespan management. An equivalent consumption quantification model based on energy dissipation is constructed, enabling scientific assessment of lifespan loss under different driving conditions. When issuing a warning, this invention can clearly distinguish and point out the root cause of the warning and clearly explain the specific potential risks that the cause may cause, providing a penetrating diagnostic report from root cause to risk, improving the guidance and safety of warning information. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 Flowchart of a method for real-time prediction of the remaining service life of silicon carbide brake discs.

[0020] Figure 2 The flowchart for calculating the core parameters.

[0021] Figure 3 This is a flowchart for diagnosis and reporting.

[0022] Figure 4 This is a module diagram of a real-time prediction system for the remaining service life of silicon carbide brake discs. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "example" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. An embodiment appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments.

[0026] Example 1 Reference Figures 1-3 As one embodiment of the present invention, this embodiment provides a method for real-time prediction of the remaining service life of a silicon carbide brake disc, comprising the following steps: S1: After vehicle maintenance, perform brake disc initialization calibration to establish a full-cycle benchmark model that includes state parameter benchmark values ​​and initial equivalent total consumption. A full-cycle benchmark model is established, and the zero-point position benchmark value of the caliper piston used to calculate the total wear stroke, the initial resistance benchmark value of the brake pad wear sensor used to calculate the independent wear amount of the brake pad, and the equivalent capacitance benchmark value used to calibrate the real-time effective thickness of the disc are measured. The zero-point position benchmark value, the initial resistance benchmark value, and the equivalent capacitance benchmark value are stored as state parameter benchmark values. The preset standard thermal response model, which describes the standard heating and cooling rate of the new disc under different braking conditions, and the capacitance temperature drift characteristic benchmark, which describes the law of capacitance value change with temperature, are loaded together into the full-cycle benchmark model. The initial equivalent total consumption is the total number of design braking cycles of the brake disc, converted into a dimensionless initial lifespan based on the standard aging test environment.

[0027] After the vehicle has completed its inspection, the baseline model parameters are updated for the brake discs that have been maintained or replaced.

[0028] Maintenance personnel first operate the vehicle's brake control unit to perform a piston return self-test procedure, releasing the hydraulic pressure on the brake calipers. The piston, under the action of the return spring, retracts to its maximum rearward position allowed by its mechanical structure. After stabilizing in position, the reading from the displacement sensor mounted on the caliper is taken as the reference value for the caliper piston's zero-point position. The caliper is then moved until it contacts the brake disc, and the distance traveled is taken as the initial brake clearance travel reference value. Next, the actual resistance value after this maintenance is read by a multi-stage resistive wear sensor integrated inside the brake pad friction block, serving as the initial resistance reference value for the brake pad wear sensor. Finally, a precise capacitance value is measured using a capacitance measurement circuit. This capacitor consists of the inner and outer brake pad backplates as electrodes, the new silicon carbide brake disc sandwiched in the middle, and the air in the gap between them as the dielectric. The measurement result is stored as the equivalent capacitance reference value.

[0029] After measuring and storing the baseline values ​​of the state parameters, maintenance personnel access the database based on the model of the silicon carbide brake disc to obtain the corresponding standard thermal response model and capacitor temperature drift characteristic baseline. The standard thermal response model, in tabular or functional form, details the standard temperature rise curve and standard temperature drop curve of the surface temperature of the new disc model under various preset braking conditions (defined by different combinations of initial vehicle speed, braking pressure, ambient temperature, etc.). The capacitor temperature drift characteristic baseline is a set of curves that precisely depict how the dielectric constant of the disc model changes systematically with increasing temperature. Then, based on the actual parameters of the disc after maintenance, the standard thermal response model and capacitor temperature drift characteristic baseline are corrected and stored.

[0030] If the maintenance confirms the installation of a brand new brake disc, the maintenance personnel will select the "New Components" option on the diagnostic tool interface. The total design cycle count provided by the brake disc manufacturer can be directly used as the initial equivalent total energy consumption. If the manufacturer provides the total energy dissipation over the design life, it needs to be divided by the energy loss per standard cycle (i.e., the heat energy absorbed during one standard braking cycle) to convert it into the total design cycle count before storage.

[0031] This overhaul involves maintaining the brake discs that have already been used. Therefore, it is necessary to remeasure the actual parameters of the brake discs, calculate the difference between the new parameters and the actual parameters as the wear value, and subtract the number of cycles with the corresponding wear value obtained based on the experimental environment from the total number of designed cycles to obtain the initial equivalent total wear after this update.

[0032] S2: During the service life of the brake disc, in response to braking events, multi-dimensional braking data associated with the braking events are collected in real time. Multidimensional braking data, which is real-time caliper piston stroke data collected by a high-precision displacement sensor, is used to calculate the total wear, including the wear of the brake disc and brake pads. Real-time resistance data collected by the brake pad wear sensor to calculate the current wear of the brake pads; The dynamic measurement data of equivalent capacitance collected by the capacitance measurement circuit, the rate of change of data during the approach of the brake pad is used to sense the gap closing process, and the drift after brake contact can help evaluate the temperature-induced changes of the disc material. The real-time temperature curve data of the braking process collected by the temperature sensor is used as a temperature reference for comparison with the standard thermal response model, and helps to analyze the degree of thermal property degradation of the disc material. Braking pressure data, obtained from the vehicle bus, is used to characterize braking intensity, and current vehicle speed data is used to define the initial braking state, serving as braking condition data.

[0033] During vehicle operation, a braking event is triggered when the driver presses the brake pedal.

[0034] As the brake pedal is pressed, the piston inside the brake caliper moves forward. The displacement sensor mounted on the caliper (such as a linear displacement sensor based on the Hall effect) records the real-time displacement value relative to its mounting position. The difference between this value and the zero-point reference value of the caliper piston is the real-time total piston stroke. Subtracting the initial brake clearance stroke reference value from the real-time total piston stroke gives the total wear stroke caused by the wear of the brake disc and brake pads.

[0035] A multi-stage resistive wear sensor integrated within the brake pad friction material consists of multiple conductive contacts or conductive layers embedded at different depths. As the brake pad wears down normally, these conductive layers are gradually worn away, causing a step change in the total resistance of the sensor's entire circuit. By reading the current resistance value and subtracting it from the initial resistance reference value of the brake pad wear sensor, the amount of wear can be roughly estimated.

[0036] A capacitance measurement circuit connected to the backplates of both the inner and outer brake pads is set up, and the measurement begins after a braking event is triggered. It calculates the capacitance value of the equivalent capacitor formed by the brake disc and air gap in real time by applying a high-frequency AC excitation signal to the electrodes (brake pad backplates) and measuring their response. During the process from before contact to complete compaction of the brake pads, the capacitance value rises sharply due to the rapid reduction of the air gap; this rise curve is recorded. After the brake pads compact with the disc and begin to heat up rapidly, the capacitance value drifts due to the change in the dielectric constant of the silicon carbide disc with temperature; this drift trajectory is continuously recorded to form a dynamic time series of capacitance measurement data.

[0037] Temperature sensors (such as thermocouples or infrared sensors) installed in the non-working area of ​​the brake pads or on the caliper near the disc body will start recording the temperature at their location after braking begins and heat accumulates and rises, until the disc body temperature stops changing over time after braking ends, thus recording the complete process of brake disc temperature change.

[0038] Braking condition data is obtained by accessing the vehicle's Controller Area Network (CAN bus). Braking pressure data is obtained by reading master cylinder pressure or wheel cylinder pressure data; after a braking event occurs, complete vehicle speed data during the entire braking process is read from messages from the Electronic Stability Program (ESP) or the instrument cluster module.

[0039] S3: Based on dynamic multidimensional braking data, calculate the real-time state parameters used to characterize the physical wear and material properties of the brake disc, and calculate the equivalent consumption of braking event losses. The physical wear of the brake disc is calculated by determining the difference between the real-time caliper piston stroke data and the zero-point position reference value, which is taken as the total wear stroke. The difference between the real-time resistance data solution and the initial resistance reference value is calculated to determine the independent wear of the brake pads. The initial mechanical wear of the brake disc is obtained by subtracting the independent wear from the total wear stroke. Under non-braking steady-state conditions, the thickness of the air dielectric in the equivalent capacitance reference value is increased according to the independent wear amount to obtain a reference equivalent capacitance characterizing the independent wear amount. The difference between the reference equivalent capacitance and the dynamic measurement data of the equivalent capacitance is calculated. The preliminary electrical wear amount is calculated based on the difference between the pre-stored brake disc and the air dielectric constant. The actual wear of the brake disc is obtained by comprehensively assessing the preliminary mechanical wear and preliminary electrical wear. The real-time state parameters of the brake disc material properties are calculated. Temperature data during the braking period are extracted from the real-time temperature curve data of the braking process, and the actual heating rate and actual cooling rate are obtained by calculating the time slope. The standard heating rate and standard cooling rate under the corresponding working conditions are retrieved and matched in the standard thermal response model. By calculating the ratio of the actual heating rate to the standard heating rate and the ratio of the actual cooling rate to the standard cooling rate, the thermal characteristic degradation factor that characterizes the deterioration of the disc's thermal conductivity and heat dissipation capacity is obtained by comparing the values. A unified time frame for temperature data and equivalent capacitance dynamic measurement data is established. Temperature data is substituted into the capacitance temperature drift characteristic reference to obtain theoretical capacitance dynamic measurement data. The deviation between equivalent capacitance dynamic measurement data and theoretical capacitance dynamic measurement data is calculated. By integration, the electrical property degradation factor characterizing the changes in the internal electrical properties of the material is obtained. A comprehensive evaluation of thermal property degradation factors and electrical property degradation factors yields a comprehensive material health index. The equivalent consumption of braking event losses is calculated by referring to a pre-set lookup table containing the material comprehensive health index and its corresponding specific heat capacity values ​​to find the adaptive specific heat capacity that matches the current disc condition. A dynamic temperature difference compensation value is calculated based on the thermal characteristic degradation factor. This value characterizes the difference between the surface temperature and the average temperature of the effective friction zone. The average temperature rise of the effective friction zone is calculated by combining real-time temperature curve data and the dynamic temperature difference compensation value. The total heat energy absorbed by the braking event during a single braking event is calculated by combining the adaptive specific heat capacity, the average temperature rise of the effective friction zone, and a pre-set constant representing the mass of the effective friction zone of the brake disc. This total heat energy is divided by the standard loss energy under standard test conditions and then exponentially calculated using a damage aggravation index that characterizes the nonlinear cumulative effect of damage. Finally, the equivalent consumption of this braking event is calculated.

[0040] The process begins by calculating the physical wear of the brake disc. This is achieved by subtracting the real-time caliper piston stroke data from the caliper piston zero-point position reference value, yielding the total piston stroke, which includes the brake clearance and the total wear of all components. Next, the initial brake clearance stroke reference value is subtracted from the total piston stroke to obtain the total wear stroke resulting from the combined wear of the disc and brake pads. Then, the difference between the real-time resistance data and the initial resistance reference value of the brake pad wear sensor is calculated. Using a lookup table stored in memory that precisely correlates the resistance value and remaining thickness of the brake pad for that model, the independent wear amount of the brake pad is calculated. Finally, the total wear stroke is subtracted from the independent wear amount; the difference represents the preliminary mechanical wear amount of the brake disc, calculated purely from mechanical displacement.

[0041]

[0042] in, Indicates the amount of mechanical wear on the brake disc; This indicates real-time caliper piston stroke data; This indicates the reference value at the zero point position of the caliper piston; This indicates the initial braking clearance travel reference value; This indicates real-time resistance data; This indicates the initial resistance reference value of the brake pad wear sensor; The change in resistance value is converted into the independent wear of the brake pads using a lookup table.

[0043] When the vehicle is not braking, the total amount of increase in air gap in the capacitor due to brake pad wear is added to the amount of independent wear. Based on the physical formula of the capacitor, the theoretical decrease in capacitance caused by this increase in air gap is subtracted from the equivalent capacitance reference value to obtain the reference equivalent capacitance that the system should measure when only the brake pads are worn and the disc is intact.

[0044] The capacitance difference is calculated by subtracting the equivalent capacitance from the dynamic measurement data of the equivalent capacitance actually acquired by the current capacitance measurement circuit. This difference physically originates primarily from the wear of the brake disc itself; that is, a portion of the silicon carbide dielectric with a high dielectric constant is worn away and replaced by air, which has an extremely low dielectric constant. Combining this with the pre-stored dielectric constant difference between this type of silicon carbide material and air, a preliminary electrical wear amount is calculated.

[0045]

[0046] in, Indicates the initial electrical wear amount; The geometric conversion factor is determined by geometric parameters such as the effective plate area of ​​the equivalent capacitor formed by the brake disc and brake pads, and is a constant calculated during the initialization process. Indicates the reference equivalent capacitance; This represents the dynamic measurement data of the equivalent capacitance under non-braking steady-state conditions. This represents the dielectric constant of the pre-stored silicon carbide material; This represents the dielectric constant of air.

[0047]

[0048] Next, measure the mechanical wear of the brake disc. and preliminary electrical wear Weighted calculations are performed (because electrical measurement methods can better eliminate interference from environmental factors such as thermal expansion and contraction, resulting in higher accuracy and stability of the results; the weighting coefficients can be set to a specific value). = 0.3、 = 0.7), to obtain the actual wear amount, and save the wear amount to the capacitor parameters.

[0049] The real-time temperature curve data during braking is differentiated and averaged to obtain the actual heating rate and actual cooling rate. Using braking condition data as initial values, a standard thermal response model is used to determine the standard heating rate and standard cooling rate that a brand-new disc should possess under identical operating conditions. A heating deviation ratio is obtained by dividing the actual heating rate by the standard heating rate, and a cooling deviation ratio is obtained by dividing the actual cooling rate by the standard cooling rate. Since material degradation typically leads to faster heating (ratio > 1) and slower cooling (ratio < 1), these two ratios are combined using a preset evaluation function to calculate a dimensionless value greater than 1 that quantifies the degree of decline in the disc's thermal conductivity and heat dissipation capacity—the thermal characteristic degradation factor.

[0050]

[0051] in, Indicates the thermal property degradation factor; This represents the real-time temperature curve data during the braking process; This indicates the heating phase (from time...) arrive The actual heating rate is obtained by differentiating the temperature curve, integrating, and averaging. This represents the standard heating rate matched from the standard thermal response model under the same operating conditions. This indicates the cooling phase (from time...) arrive The actual cooling rate is obtained by differentiating the temperature curve, integrating, and averaging. This indicates the standard cooling rate matched under the same operating conditions.

[0052] The temperature data and the dynamic measurement data of the equivalent capacitance are aligned on the time axis. Then, for each time point, the corresponding (temperature, capacitance) value is found on the aligned data. The dielectric constant of the healthy disk at the corresponding temperature is found, and the theoretical capacitance value is obtained by substituting it into the disk thickness after wear. The deviation between the two is calculated. The deviation at all time points during the entire heating process is integrated to quantify the overall deviation of the actual capacitance-temperature curve from the standard reference curve, which is used as the electrical characteristic degradation factor.

[0053]

[0054] in, Indicates the degradation factor of electrical properties; This indicates that the deviation over the entire heating process is integrated; Indicates at time The actual measured dynamic measurement data of the equivalent capacitance; Represents the theoretical capacitance value; This represents the dielectric constant of the healthy disk at that temperature, obtained from the capacitor temperature drift characteristic reference based on the real-time temperature T(t). This represents the effective plate area of ​​the equivalent capacitor, which is a constant. This means that the current worn disk thickness is obtained by subtracting the calculated actual wear amount from the initial disk thickness.

[0055]

[0056] thermal property degradation factor With electrical property degradation factor A weighted summation is performed (considering that thermal characteristics are directly related to braking performance, while electrical characteristics serve more as a sensitive indicator of changes in internal structure, the weighting coefficients can be taken as follows). =0.6、 = 0.4) to obtain the comprehensive health index of materials .

[0057] Then, the material comprehensive health index is used to match the adaptive specific heat capacity of the current disk state in a preset lookup table that stores the correspondence between health index and specific heat capacity. Then, the dynamic temperature difference compensation value that characterizes the temperature difference between the surface and the interior is calculated based on the thermal characteristic degradation factor.

[0058]

[0059] in, This represents the final calculated dynamic temperature difference compensation value; It represents an experimentally calibrated geometric and thermal resistance coefficient that is related to the geometry of the disk (such as thickness) and the thermal conductivity of the material; This represents the average braking pressure, obtained from multidimensional braking data, that indicates the current braking intensity. This represents the average relative slip velocity during braking; This represents the increment of the thermal property degradation factor relative to the initial healthy state (value 1).

[0060] By incorporating dynamic temperature difference compensation values ​​to correct real-time temperature curve data, the directly measured surface temperature is converted into an effective average temperature rise of the friction zone, which better represents the overall energy storage state of the friction zone. Based on thermodynamic formulas, the effective average temperature rise of the friction zone, the adaptive specific heat capacity, and a preset constant representing the mass of the effective friction zone of this brake disc model are multiplied. The product is the total heat energy absorbed by the brake disc during this braking event, i.e., the total heat energy of a single braking event.

[0061]

[0062] in, This represents the total heat energy generated during a single braking operation. For the effective friction zone quality; For adaptive specific heat capacity; The peak surface temperature rise is extracted from the real-time temperature profile; This is the dynamic temperature difference compensation value.

[0063] Total heat of a single braking operation Divisible by standard loss energy Furthermore, to more realistically simulate the accelerated wear and tear effect of high load on lifespan, the calculation results will be subjected to a power-law calculation based on the damage aggravation index obtained through extensive experimental calibration. (2.2 can be taken as an example) to finally obtain the equivalent wear amount of this braking event. .

[0064] S4: Iteratively update the full-cycle benchmark model by combining real-time state parameters and equivalent consumption. The process of iteratively updating the full-cycle benchmark model involves creating a real-time working copy of the full-cycle benchmark model after its establishment. After a braking event occurs, the parameters of the real-time working copy are updated using real-time status parameters. The equivalent consumption is subtracted from the remaining equivalent consumption of the real-time working copy to obtain the latest remaining equivalent consumption, thus completing the iterative update of the real-time working copy.

[0065] Once the initial calibration process is completed and the full-cycle benchmark model containing various zero-point reference values ​​and the initial total lifespan is stored, a complete copy of the model is then made in the vehicle's readable and writable storage area (such as RAM or flash memory) as a real-time working copy.

[0066] After the braking event ends, the latest calculated real-time status parameters reflecting the current physical and material state (e.g., the latest "actual wear" and "material overall health index") are used to directly overwrite and replace the corresponding old parameters previously recorded in the real-time working copy. The latest remaining equivalent consumption total is obtained by subtracting the equivalent consumption from the remaining equivalent consumption total recorded in the real-time working copy.

[0067] S5: Analyze the updated model to perform a comprehensive diagnosis of the current health status of the brake disc, and output a diagnostic report when the health status is poor. A comprehensive diagnosis of the current health status of the brake disc is performed, and the cumulative performance deviation is calculated by comparing the real-time status parameters with the baseline values ​​of the status parameters. If the cumulative performance deviation exceeds the preset performance warning threshold, the current status of the brake disc is diagnosed as significantly deteriorated. If the remaining equivalent total consumption is lower than the preset wear warning threshold, the current state of the brake disc will be marked as wear approaching the limit. The diagnostic report specifically includes: recommendations to replace brake discs, potential risk parameters that lead to poor brake condition, and potential braking risks that these parameters may cause.

[0068] Each time the real-time working copy data is updated, a diagnostic analysis is performed on the data.

[0069] First, the real-time state parameters are compared with the initial baseline values ​​stored in the full-cycle baseline model. The ratio is then compared with a performance warning threshold set based on a large amount of experimental data, which represents the critical point at which the material properties deteriorate to the point where they can significantly affect braking stability and thermal fade performance. If the cumulative performance deviation exceeds this threshold, the current state of the brake disc will be diagnosed as significantly deteriorated.

[0070] The remaining equivalent total wear is divided by the initial equivalent total wear, and the result is compared with a preset wear warning threshold (e.g., 10%). If the wear is below this threshold, the brake disc is considered to be approaching its limit.

[0071] If either of the two diagnostic tests is triggered, the brake discs are considered to be in poor health, and a diagnostic report is immediately generated and output. A clear warning is then issued to the user via the vehicle's central control display, instrument panel warning lights, or a companion mobile application.

[0072] When brake discs are worn close to their limit, they can cause brake disc failure during braking, prompting a recommendation to replace them. However, the causes of failure differ in these two situations. To ensure users better understand the advice, the relevant parameters will be included in the report, along with an explanation of the reasons for the failure: Significant performance degradation can lead to a severe decrease in the material’s thermal conductivity and heat dissipation capacity. During continuous downhill driving or high-intensity driving, the braking system may experience sudden thermal fade due to overheating, resulting in a significant increase in braking distance or even temporary failure.

[0073] Wear approaching its limit indicates that the disc thickness is close to the safety limit. At this stage, the mechanical strength of the disc is insufficient, and there is a risk of cracking or breaking under extreme braking loads, which may lead to the complete failure of the braking system.

[0074] In one embodiment of the present invention, the metal brake pad backplates on both sides of the brake caliper are used as the two plates of a capacitor. The silicon carbide brake disc in the middle and the micro-gap between the disc surface and the brake pad together constitute a composite dielectric. In order to prevent short circuits between the plates due to the conductivity of the carbon fiber network that may be generated at high temperatures, the system uses the ceramic-based friction material layer on the surface of the brake pad as a natural high-insulation dielectric layer. Therefore, the electrical model is actually a series capacitor structure composed of "left backplate - insulating friction layer - brake disc core - insulating friction layer - right backplate".

[0075] Example 2 Reference Figure 2 and Figure 4 These are two embodiments of the present invention. This embodiment provides a real-time prediction system for the remaining service life of a silicon carbide brake disc. This system is typically deployed on a high-performance computing server to execute the steps described in Embodiment 1.

[0076] The system's software architecture consists of a set of highly collaborative functional modules, specifically including: Model Management Module: Retains the full-cycle baseline model, creates a real-time working copy based on the full-cycle baseline model, and updates the real-time working copy after the braking event ends; Time synchronization module: Receives multi-dimensional data streams transmitted from sensors and assigns a unified timestamp to the multi-dimensional data streams; Wear calculation module: Calculates preliminary mechanical wear and preliminary electrical wear through multi-dimensional data streams, and extrapolates the actual wear of the brake disc; Materials evaluation module: Calculates thermal property degradation factors and electrical property degradation factors through multi-dimensional data streams, and deduces the comprehensive material health index of the brake disc; Equivalent Consumption Quantification Module: Receives the comprehensive material health index from the material evaluation module and converts the losses from braking events into equivalent consumption. Health status diagnosis module: compares the real-time working copy with the full-cycle benchmark model and preset warning thresholds to make independent diagnostic judgments on the performance degradation and physical wear status of the brake disc. Report generation module: Receives the poor health status judgment result from the health status diagnosis module, generates the corresponding diagnostic report and sends it to the vehicle display device.

[0077] After the vehicle completes maintenance and performs initial calibration, the model management module saves the full-cycle baseline model and then establishes a real-time working copy that is updated in real time according to braking events.

[0078] During normal vehicle operation, once a braking event is triggered, the time synchronization module gathers the raw data stream from various sensors and the vehicle bus in real time, and applies a unified timestamp to it internally using a high-precision clock. This ultimately generates a synchronized data stream containing all multi-dimensional braking data, which is then distributed in parallel to the physical wear calculation module and the material performance evaluation module.

[0079] After receiving the data packet, the physical wear calculation module calculates the actual wear amount, which characterizes physical wear, by differentially subtracting the piston stroke data and resistance data in the data packet and combining the calibration correction of the capacitance data.

[0080] The material performance evaluation module calculates the thermal property degradation factor and electrical property degradation factor based on temperature curve data and capacitance dynamic data, through comparative analysis with the benchmark model, and generates a comprehensive material health index based on the thermal property degradation factor and electrical property degradation factor.

[0081] The materials performance evaluation module sends the comprehensive material health index and thermal property degradation factor to the equivalent consumption quantification module. Combined with temperature data obtained from the synchronous data stream, and based on the principles of energy conservation and nonlinear damage, the equivalent consumption of this braking event is calculated.

[0082] Actual wear and tear, overall material health index, and equivalent consumption are all submitted to the model management module. Based on these latest calculation results, the model management module updates the corresponding status parameters in the real-time working copy and deducts the current consumption from the remaining lifespan.

[0083] Afterwards, the model management module sends an update completion trigger signal to the health status diagnosis module. Upon receiving the signal, the health status diagnosis module compares the real-time working copy with the full-cycle baseline model and preset thresholds to determine if there is significant performance degradation or wear approaching its limit. If any warning state is diagnosed, a diagnostic signal containing specific diagnostic conclusions is generated and sent to the report generation and output module.

[0084] Furthermore, considering the semiconductor characteristics that silicon carbide materials may exhibit under high-temperature conditions (i.e., a decrease in internal equivalent parallel resistance), the capacitance measurement circuit does not employ the traditional DC charge-discharge measurement method. Instead, it uses a high-frequency AC excitation method for measurement. This is because as the temperature increases, the thermal vibration of the silicon carbide lattice intensifies, and the polarization state of the microcrack interfaces within the material changes, leading to a regular shift in its relative permittivity. The permittivity of a damaged silicon carbide disk will change; by monitoring whether the capacitance value has abnormally drifted, the condition of the disk can be inferred.

[0085] Finally, after receiving the diagnostic signal, the report generation module organizes and generates the corresponding risk explanation text and action suggestions according to the type of conclusion in the signal, and finally presents the complete diagnostic report to the driver in the form of a warning pop-up or a dedicated interface.

[0086] In summary, this invention accurately separates and quantifies the physical wear of the brake disc by combining mechanical displacement differential calculation with capacitive sensing calibration; by analyzing thermal response characteristics and capacitive temperature drift, it incorporates the degradation of material microstructure into the evaluation system. This achieves a multi-dimensional and comprehensive diagnosis of brake disc physical wear and performance degradation, resulting in more accurate and comprehensive predictions. By calculating and accumulating the total energy dissipated in each braking event, all non-standard and complex driving behaviors are scientifically and fairly converted into a unified unit of lifespan consumption. This allows lifespan prediction to truly adapt to and reflect the driving habits of different users, achieving personalized and high-precision lifespan management. An equivalent consumption quantification model based on energy dissipation is constructed, enabling scientific assessment of lifespan loss under different driving conditions. When issuing a warning, this invention can clearly distinguish and point out the root cause of the warning and clearly explain the specific potential risks that the cause may cause, providing a penetrating diagnostic report from root cause to risk, improving the guidance and safety of warning information.

[0087] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for real-time prediction of the remaining service life of a silicon carbide brake disc, characterized in that, Performed by computer equipment, Includes the following steps: S1: After vehicle maintenance, perform brake disc initialization calibration to establish a full-cycle benchmark model that includes state parameter benchmark values ​​and initial equivalent total consumption. S2: During its service life, the brake disc responds to braking events and collects multi-dimensional braking data associated with the braking events in real time. S3: Based on the dynamic multidimensional braking data, calculate the real-time state parameters used to characterize the physical wear and material properties of the brake disc, and calculate the equivalent consumption of the braking event loss. S4: Iteratively update the full-cycle benchmark model by combining the real-time state parameters and the equivalent consumption; S5: Analyze the updated model to perform a comprehensive diagnosis of the current health status of the brake disc, and output a diagnostic report if the health status is poor.

2. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 1, characterized in that, The process of establishing the full-cycle benchmark model in step S1 specifically includes: The zero-point position reference value of the caliper piston used to calculate the total wear stroke, the initial resistance reference value of the brake pad wear sensor used to calculate the independent wear amount of the brake pad, and the equivalent capacitance reference value used to calibrate the real-time effective thickness of the disc body are measured and stored as state parameter reference values. The preset standard thermal response model describing the standard heating and cooling rate of the new disc under different braking conditions, and the capacitance temperature drift characteristic benchmark describing the law of capacitance value change with temperature of the new disc, are loaded together into the full-cycle benchmark model. The initial equivalent total consumption is the total number of design braking cycles of the brake disc, converted into a dimensionless initial lifespan based on the standard aging test environment.

3. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 2, characterized in that, The multidimensional braking data in step S2 includes: Real-time caliper piston stroke data collected by a high-precision displacement sensor is used to calculate the total wear, including wear on the brake disc and brake pads. Real-time resistance data collected by the brake pad wear sensor to calculate the current wear amount of the brake pad; The dynamic measurement data of equivalent capacitance collected by the capacitance measurement circuit, the rate of change of data during the approach of the brake pad is used to sense the gap closing process, and the drift after brake contact can help evaluate the temperature-induced changes of the disc material. The real-time temperature curve data of the braking process collected by the temperature sensor is used as the temperature reference for comparison with the standard thermal response model, and helps to analyze the degree of thermal property degradation of the disc material. Braking pressure data, obtained from the vehicle bus, is used to characterize braking intensity, and current vehicle speed data is used to define the initial braking state, serving as braking condition data.

4. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 3, characterized in that, The process of calculating the physical wear of the brake disc in step S3 specifically includes: calculating the difference between the real-time caliper piston stroke data and the zero-point position reference value as the total wear stroke; calculating the difference between the real-time resistance data solution and the initial resistance reference value to calculate the independent wear amount of the brake pad; and subtracting the independent wear amount from the total wear stroke to obtain the preliminary mechanical wear amount of the brake disc. Under non-braking steady-state conditions, the thickness of the air medium in the equivalent capacitance reference value is increased according to the independent wear amount to obtain a reference equivalent capacitance characterizing the independent wear amount. The difference between the reference equivalent capacitance and the dynamic measurement data of the equivalent capacitance is calculated. The preliminary electrical wear amount is calculated based on the difference between the pre-stored brake disc and the air dielectric constant. The actual wear of the brake disc is obtained by comprehensively evaluating the preliminary mechanical wear and the preliminary electrical wear.

5. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 3, characterized in that, The process of calculating the real-time state parameters of the material properties of the brake disc in step S3 specifically includes: extracting temperature data within the braking time period from the real-time temperature curve data of the braking process, calculating the time slope to obtain the actual heating rate and the actual cooling rate; retrieving and matching the standard heating rate and the standard cooling rate under the corresponding working condition in the standard thermal response model; and obtaining the thermal characteristic degradation factor characterizing the deterioration of the disc's thermal conductivity and heat dissipation capacity by comprehensively evaluating the ratio of the actual heating rate to the standard heating rate and the ratio of the actual cooling rate to the standard cooling rate. The time frame of the temperature data and the equivalent capacitance dynamic measurement data is unified. The temperature data is substituted into the capacitance temperature drift characteristic reference to obtain the theoretical capacitance dynamic measurement data. The deviation between the equivalent capacitance dynamic measurement data and the theoretical capacitance dynamic measurement data is calculated. The electrical property degradation factor characterizing the change of internal electrical properties of the material is obtained by integration. By comprehensively evaluating the thermal property degradation factor and the electrical property degradation factor, a comprehensive material health index is obtained.

6. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 5, characterized in that, The process of calculating the equivalent consumption of the braking event loss in step S3 specifically includes: Based on the comprehensive material health index, an adaptive specific heat capacity matching the current disc condition is looked up in a preset lookup table containing the comprehensive material health index and corresponding specific heat capacity values. A dynamic temperature difference compensation value is calculated based on the thermal characteristic degradation factor. This dynamic temperature difference compensation value characterizes the difference between the surface temperature and the average temperature of the effective friction zone. The average temperature rise of the effective friction zone is calculated by combining the real-time temperature curve data and the dynamic temperature difference compensation value. The total heat energy absorbed by the brake event during a single braking event is calculated by combining the adaptive specific heat capacity, the average temperature rise of the effective friction zone, and a preset constant representing the mass of the effective friction zone of the brake disc. The total heat energy absorbed by the single braking event is divided by the standard energy loss under standard test conditions, and then exponentially calculated using a damage aggravation index used to characterize the nonlinear cumulative effect of damage. Finally, the equivalent energy consumption of this braking event is calculated.

7. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 1, characterized in that, The iterative update process of the full-cycle benchmark model in step S4 specifically includes: After the full-cycle benchmark model is established, a real-time working copy of the full-cycle benchmark model is created. After a braking event occurs, the parameters of the real-time working copy are updated using the real-time status parameters. The equivalent consumption is subtracted from the remaining equivalent consumption of the real-time working copy to obtain the latest remaining equivalent consumption, thus completing the iterative update of the real-time working copy.

8. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 7, characterized in that, The process of comprehensively diagnosing the current health status of the brake disc in step S5 specifically includes: The cumulative performance deviation is calculated by comparing the real-time status parameters with the baseline value of the status parameters; if the cumulative performance deviation exceeds the preset performance warning threshold, the current state of the brake disc is diagnosed as significantly deteriorated. If the remaining equivalent total consumption is lower than the preset wear warning threshold, the current state of the brake disc is marked as wear approaching the limit.

9. The method for real-time prediction of the remaining service life of a silicon carbide brake disc according to claim 1, characterized in that, The diagnostic report in step S5 specifically includes: brake disc replacement recommendations, potential risk parameters that lead to poor health, and potential braking risks that the potential risk parameters may cause.

10. A real-time prediction system for the remaining service life of a silicon carbide brake disc, characterized in that, The system is used to perform the method according to any one of claims 1 to 9, specifically including: Model management module: retains the full-cycle baseline model, creates a real-time working copy based on the full-cycle baseline model, and updates the real-time working copy after the braking event ends; Time synchronization module: Receives multi-dimensional data streams transmitted from sensors and assigns a unified timestamp to the multi-dimensional data streams; Wear calculation module: Calculates the preliminary mechanical wear and preliminary electrical wear through the multi-dimensional data stream, and extrapolates the actual wear of the brake disc; Material evaluation module: Calculates the thermal property degradation factor and electrical property degradation factor through the multi-dimensional data stream, and deduces the comprehensive material health index of the brake disc; Equivalent Consumption Quantification Module: Receives the material comprehensive health index from the material evaluation module and converts the losses from braking events into equivalent consumption. Health status diagnosis module: compares the real-time working copy with the full-cycle benchmark model and the preset warning threshold to make independent diagnostic judgments on the performance degradation and physical wear status of the brake disc. Report generation module: Receives the health status determination result of poor health status from the health status diagnosis module, generates the corresponding diagnostic report and sends it to the vehicle display device.

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