Automobile brake friction plate wear monitoring method and automobile

Abstract

The application discloses a kind of automobile brake friction plate wear monitoring method and automobile.The method comprises: after the first mileage period of automobile driving, the real-time liquid level height of brake fluid storage tank is obtained when automobile is under preset stationary condition;Real-time wear thickness of brake friction plate corresponding to the first mileage period is determined according to real-time liquid level height;Determine wear monitoring result according to real-time wear thickness.The application for the automobile that has assembled brake fluid storage tank liquid level sensor, without additional increase hardware in brake, will not bring the increase of component cost and weight, can realize the real-time monitoring of the wear degree of brake friction plate, and then let driver can understand the wear state of brake friction plate in real time, timely alarm to prompt driver to replace brake friction plate.The application can improve the safety performance of automobile, meet the intelligent demand of automobile.

Description

Technical Field

[0001] This invention relates to the field of automotive brake pad wear technology, and more particularly to a method for monitoring automotive brake pad wear and an automotive vehicle. Background Technology

[0002] Brake pads are crucial components related to automotive safety. They generate braking torque through friction with the brake disc, thus achieving braking. However, brake pads are also wear-prone parts, requiring replacement once they reach a certain wear level. Severe wear of the brake pads leads to a decrease in braking torque, an increase in braking distance, and in extreme cases, brake failure, seriously affecting driving safety. Current technology employs the following brake pad wear alarm method: when the brake pads wear to their limit, an audible alarm is generated through sliding friction between a mechanical alarm pad and the brake disc. The shortcomings of this solution are: the mechanical alarm pad increases hardware costs, and it cannot monitor the brake pad thickness in real time; it only alarms when the brake pads reach their wear limit, failing to assess the overall wear condition of the brake pads. Another existing technology for brake friction pad wear alarm involves adding a displacement sensor or resistor to the brake to monitor and alarm the thickness of the brake friction pad in real time. The drawback of this solution is that it requires placing the displacement sensor on the brake piston or the resistor on the brake friction pad. Due to the compact space of the brake, the space for placing the displacement sensor is very limited, which will lead to a shortage of space. At the same time, this solution will also increase the weight of the brake and significantly increase the cost, making it impractical. Summary of the Invention

[0003] This invention provides a method for monitoring the wear of automotive brake pads and an automotive vehicle, thereby solving the problem that existing technologies require adding hardware to the brake system when monitoring the wear state of automotive brake pads.

[0004] This invention provides a method for monitoring wear of automotive brake pads, comprising:

[0005] After the first mileage cycle of the vehicle, the real-time liquid level of the brake fluid reservoir is obtained when the vehicle is under preset stationary conditions; the real-time liquid level is measured in real time by a liquid level sensor installed inside the brake fluid reservoir.

[0006] The real-time wear thickness of the brake friction pads corresponding to the first mileage cycle is determined based on the real-time liquid level height.

[0007] The wear monitoring results are determined based on the real-time wear thickness.

[0008] This invention provides an automobile, including a brake fluid reservoir and a controller. The brake fluid reservoir is equipped with a level sensor for measuring the real-time fluid level of the brake fluid reservoir. The controller is connected to the level sensor and is used to execute the automobile brake pad wear monitoring method.

[0009] Compared with the prior art, the embodiments of the present invention have the following advantages: In the automotive brake pad wear monitoring method provided by the embodiments of the present invention, after the first mileage cycle of the vehicle, the real-time liquid level of the brake fluid reservoir is obtained when the vehicle is under preset stationary conditions; the real-time wear thickness of the brake pad corresponding to the first mileage cycle is determined based on the real-time liquid level; and the wear monitoring result is determined based on the real-time wear thickness. In the present invention, the real-time liquid level measured in real time by the liquid level sensor installed in the brake fluid reservoir can determine the real-time wear thickness of the brake pad, and thus determine the wear monitoring result. For vehicles equipped with a liquid level sensor in the brake fluid reservoir, the present invention eliminates the need to add additional hardware to the brake, thus avoiding an increase in component cost and weight. Real-time monitoring of the wear degree (i.e., real-time wear thickness) of the brake pad can be achieved. Based on the wear monitoring result obtained from the above-mentioned wear thickness measurement, the driver can understand the wear state of the brake pad in real time, and when the brake pad reaches the wear limit, an alarm is triggered to remind the driver to replace the brake pad. The present invention can improve the safety performance of automobiles and meet the intelligent needs of automobiles. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. 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.

[0011] Figure 1 This is a flowchart of a method for monitoring wear of automotive brake pads according to an embodiment of the present invention.

[0012] Figure 2 This is a flowchart of step S300 of the method for monitoring wear of automotive brake friction pads provided in an embodiment of the present invention.

[0013] Figure 3 This is a partial structural schematic diagram of an automobile brake provided in an embodiment of the present invention.

[0014] Figure 4 This is a schematic diagram of the structure of a brake fluid reservoir provided in an embodiment of the present invention.

[0015] Figure 5 This is a schematic diagram of the structure of an automobile brake provided in another embodiment of the present invention.

[0016] The reference numerals in the accompanying drawings are as follows:

[0017] 1. Brake fluid reservoir; 11. Liquid level sensor; 12. Hydraulic chamber; 13. First liquid level line; 14. Second liquid level line; 15. Third liquid level line; 2. Brake; 21. Brake friction pad; 22. Piston; 23. Brake caliper; 24. Sealing ring; 25. Piston chamber; 26. Brake disc; 3. EPB motor. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, the wear monitoring method for automotive brake friction pads 21 in this embodiment of the invention specifically includes the following steps:

[0020] S100: After the first mileage cycle of the vehicle, the real-time fluid level of the brake fluid reservoir 1 is obtained when the vehicle is under preset stationary conditions. The real-time fluid level is measured in real time by the fluid level sensor 11 installed in the brake fluid reservoir 1. In this embodiment, the first mileage cycle can be set according to requirements, such as setting it to 500 kilometers (or other mileage) as the first mileage cycle, or driving for one month or other duration (i.e., setting the first mileage cycle based on the vehicle's driving time). The preset stationary conditions refer to the condition that the vehicle is stationary on a level road surface and there is no braking operation. Understandably, in this invention, whether the vehicle is stationary can be determined based on the vehicle speed signal or gear signal, and whether the vehicle is braking can be determined based on the brake switch signal. In this invention, the real-time level of the brake fluid can only be monitored stably if the vehicle is under a preset stationary condition and the level of the brake fluid in the brake fluid reservoir 1 is stable. In this invention, the real-time level refers to the stable level measured in the brake fluid reservoir 1 within a certain period of time after the vehicle is under the preset stationary condition (the real-time level is considered stable if it does not change within the aforementioned certain period of time).

[0021] like Figure 3As shown, the automotive brake 2 has a self-adjusting function for the clearance of the brake friction pad 21 after wear. Specifically, this is achieved through the relative movement between the piston 22 and the sealing ring 24. That is, after the brake friction pad 21 is worn, the thickness of the brake friction pad 21 decreases. Figure 3 The piston 22 will automatically move to the right relative to the brake caliper 23, thereby increasing the volume of the piston chamber 25 between the piston 22 and the brake caliper 23. Figure 4 The brake fluid reservoir 1 shown will automatically replenish brake fluid into the piston chamber 25, thereby causing the brake fluid level in the brake fluid reservoir 1 to decrease accordingly. Understandably, to ensure functional safety requirements, the brake fluid reservoir 1 in this invention is equipped with a level sensor 11. Furthermore, the level sensor 11 of the brake fluid reservoir 1 can be a Hall effect level sensor 11 with excellent safety and reliability, employing a normally closed design to achieve real-time monitoring of the level signal.

[0022] In this invention, utilizing Figure 4 The liquid level sensor 11 in the system can monitor the real-time liquid level of the brake fluid reservoir 1 of the vehicle when it is under preset static conditions; the specific implementation process is as follows:

[0023] like Figure 4 In the brake fluid reservoir 1, the real-time fluid level is monitored by a fluid level sensor 11. The real-time fluid level range will be within the maximum fluid level line ( Figure 4 The first liquid level line 13 and its preset range above and below are considered to be at the highest liquid level line. The preset range can be set according to requirements, such as 5mm above and below. The lowest liquid level line (…) Figure 4 The second liquid level line 14 and its preset range above and below are considered to vary between the lowest liquid level line. The highest and lowest liquid level lines can be set according to the specific capacity of the brake fluid reservoir 1; for example, they can be set to... Figure 4 The first liquid level line 13 is the highest liquid level line, and the second liquid level line 14, which is lower than the first liquid level line 13, is the lowest liquid level line. The highest liquid level line is the initial real-time liquid level height corresponding to the new brake friction pad 21 that has not been worn (at this time, the real-time wear thickness of the brake friction pad 21 is 0). The lowest liquid level line is the lowest real-time liquid level height corresponding to the minimum brake friction pad 21 thickness that can ensure safe driving (at this point, if the real-time wear thickness of the brake friction pad 21 continues to increase, safe driving cannot be guaranteed). Furthermore, in the brake fluid reservoir 1, an alarm liquid level line is also provided between the highest liquid level line and the lowest liquid level line. Figure 4The third liquid level line 15 and its preset range above and below are considered to be at the alarm liquid level line. The height of the alarm liquid level line can also be set according to the requirements. The alarm liquid level line refers to the real-time liquid level height when the brake friction pad 21 currently in use is worn to the limit position (at this time, the real-time wear thickness of the brake friction pad 21 is the limit wear thickness).

[0024] S200: Determine the real-time wear thickness of the brake friction pad 21 corresponding to the first mileage cycle based on the real-time fluid level height; that is, based on the real-time fluid level height, the real-time wear thickness of the brake friction pad 21, the mileage traveled, and the mileage to be replaced can be calculated. Specifically, there is a preset correlation between the real-time fluid level height of the brake fluid reservoir 1 and the real-time wear thickness of the brake friction pad 21, and the preset correlation can be determined based on the following mathematical model:

[0025] Wf=k×h×A / (3.14×(Df²+ Dr²))

[0026] Wr = h × A / (3.14 × (Df² + Dr²))

[0027] in:

[0028] Wf: Real-time wear thickness of front brake friction pad 21;

[0029] Wr: Real-time wear thickness of rear brake friction pad 21;

[0030] Df: Front wheel cylinder diameter;

[0031] Dr: Rear wheel cylinder diameter;

[0032] k: The ratio of the real-time wear thickness of the front brake friction pad 21 to that of the rear brake friction pad 21;

[0033] h: Real-time brake fluid level in brake fluid reservoir 1.

[0034] Therefore, in this embodiment, the real-time wear thickness of the brake friction pad 21 can be calculated based on the real-time liquid level height using the above correspondence.

[0035] Meanwhile, in this invention, there is a preset correspondence between the real-time wear thickness of the brake friction pad 21, the vehicle's mileage, and the mileage to be replaced. The preset correspondence can be stored in the vehicle's ECU (Electronic Control Unit). When it is necessary to determine the preset correspondence, it can be determined by querying the ECU, as shown in Table 1 (the preset correspondence can be determined according to the actual structure and material of the brake friction pad 21 and the brake fluid reservoir 1, etc. Table 1 is only an example and does not represent the actual preset correspondence).

[0036] Table 1 Preset Correspondence Table

[0037]

[0038] S300: Determine the wear monitoring result based on the real-time wear thickness. The wear monitoring result can indicate whether the brake friction pad 21 has reached its wear limit, whether replacement or other measures are needed, etc. In one embodiment, such as... Figure 2 As shown, in step S30, determining the wear monitoring result based on the real-time wear thickness includes:

[0039] S301, obtain the historical wear thickness of the brake friction pad 21 corresponding to the historical mileage cycle, and determine the wear correction coefficient based on the historical wear thickness and the preset wear thickness; the historical mileage cycle refers to the previous mileage cycle before the first mileage cycle; in this embodiment, the historical mileage cycle refers to the previous mileage cycle before the first mileage cycle, and the historical mileage cycle can be determined in the same or different way as the first mileage cycle. It can also be set as a mileage cycle corresponding to a certain number of kilometers driven, or a mileage cycle corresponding to a certain preset driving time. For example, the historical mileage cycle and the first mileage cycle can both be a mileage cycle of 500 kilometers driven or both be a mileage cycle of two weeks driven; but it can also be the following situation: the historical mileage cycle is a mileage cycle of 500 kilometers driven, but the first mileage cycle is a mileage cycle of two weeks driven (or vice versa).

[0040] Due to differences in vehicle operating environments and driving styles among drivers, the actual correlation between the real-time wear thickness of the brake friction pads 21 and the mileage to be replaced may deviate from the preset correlation. Therefore, by analyzing various signals collected in real time, the vehicle's operating environment and driver's driving style can be analyzed, and then the preset correlation between the real-time wear thickness of the brake friction pads 21 and the mileage to be replaced can be corrected through self-learning, thus obtaining the corrected mileage to be replaced. Specifically, the following should be calculated first: the historical mileage of the vehicle in the previous historical mileage cycle (i.e., the actual mileage in the previous historical mileage cycle), the historical fluid level drop height (i.e., the actual fluid level drop height in the previous historical mileage cycle), or the historical wear thickness (i.e., the actual wear thickness in the previous historical mileage cycle, which can be the real-time wear thickness after final correction according to the wear detection method of the vehicle brake friction pad 21 in the previous historical mileage cycle); and the preset mileage (e.g., the mileage corresponding to the historical real-time fluid level in Table 1), preset fluid level drop height (e.g., the fluid level drop height corresponding to the historical real-time fluid level in the previous historical mileage cycle), or preset wear thickness (e.g., the real-time wear thickness corresponding to the historical real-time fluid level in Table 1) determined based on the historical real-time fluid level height in the previous historical mileage cycle and the preset correspondence (e.g., the preset correspondence in Table 1). Then, the wear correction coefficient should be determined based on the above data.

[0041] In one embodiment, the wear correction coefficient can be determined directly in the following mathematical model based on the above-mentioned historical wear thickness and the preset wear thickness;

[0042] δ=△WT / △WP

[0043] δ: Wear correction factor

[0044] △WT: Historical wear thickness;

[0045] △Wp: Preset wear thickness.

[0046] In another embodiment, the wear correction coefficient δ can be determined using the following mathematical model: δ = a△WT / △WP; where △WT is the historical liquid level drop height, △WP is the preset liquid level drop height, and a is the first correction constant coefficient. The wear correction coefficient δ can also be determined in this embodiment.

[0047] In another embodiment, the wear correction coefficient δ can be determined using the following mathematical model: δ = b△WT / △WP; where △WT is the historical mileage, △WP is the preset mileage, and b is the second correction constant coefficient. The wear correction coefficient δ can also be determined in this embodiment.

[0048] In the above embodiments of the present invention, the wear correction coefficient can reflect the driver's driving habits and the wear state of the brake friction pad 21 in the previous historical mileage cycle. In the embodiments of the present invention, the following settings can be made according to the actual situation:

[0049] When the wear correction factor δ is greater than or equal to the second calibration factor and less than the third calibration factor (the third calibration factor is greater than the second calibration factor and less than the first calibration factor, for example, the first calibration factor is 6, the second calibration factor is 0.5, and the third calibration factor is 2), the car is in a normal use environment and the driver's driving style.

[0050] When the wear correction factor δ is greater than or equal to the third calibration factor and less than the first calibration factor, the driving style is more aggressive or there are more driving conditions on mountain roads.

[0051] When the wear correction coefficient δ is greater than or equal to the first calibration coefficient, it indicates that there is a brake fluid leak in the brake line system. Further, in step S301, after determining the wear correction coefficient based on the historical wear thickness and the preset wear thickness, the method includes: when the wear correction coefficient is greater than or equal to the first calibration coefficient, indicating a leak in the brake line system via a preset warning device, and that the brake pad 21 wear monitoring has failed. That is, when the wear correction coefficient is greater than or equal to the first calibration coefficient, it indicates a brake fluid leak in the brake line system. Since the preset warning device may include a preset display screen on the instrument panel, relevant warning data can be displayed on the instrument panel to indicate a leak in the brake line system, thereby informing the vehicle user of the brake pad 21 wear status and maintenance mileage monitoring system failure. In other words, the current brake pad 21 wear monitoring has failed, and the wear monitoring result indicates that the wear limit has been reached, requiring maintenance. In this invention, other preset warning devices (such as audible warning devices or light warning devices) can also be used to indicate a leak in the brake line system.

[0052] S302, determine the wear monitoring result based on the real-time wear thickness and the wear correction coefficient. That is, in this embodiment, different comparisons can be made based on the wear correction coefficient and the real-time wear thickness to obtain different wear monitoring results. Further, in step S302, determining the wear monitoring result based on the real-time wear thickness and the wear correction coefficient includes:

[0053] When the wear correction coefficient is less than the first calibration coefficient, the replacement mileage is determined based on the real-time wear thickness, and the corrected replacement mileage is determined based on the replacement mileage and the wear correction coefficient. As mentioned above, a wear correction coefficient less than the first calibration coefficient can be categorized into two cases: the wear correction coefficient δ is greater than or equal to the second calibration coefficient and less than the third calibration coefficient, indicating the vehicle is in a normal operating environment and driving style; the wear correction coefficient δ is greater than or equal to the third calibration coefficient and less than the first calibration coefficient, indicating a more aggressive driving style or frequent driving on mountain roads. However, in both cases, if the current thickness of the brake friction pad 21 is greater than a preset thickness value, the brake friction pad 21 has not reached its wear limit. Therefore, only the replacement mileage needs to be corrected according to the aforementioned wear correction coefficient to obtain the corrected replacement mileage. The wear monitoring results can then be further determined based on the corrected replacement mileage and the real-time wear thickness. Specifically, determining the corrected replacement mileage based on the replacement mileage and the wear correction coefficient requires the following mathematical model:

[0054] S = Sp / δ

[0055] in:

[0056] S refers to the corrected replacement mileage (i.e., the replacement mileage that needs to be displayed, suggested, and prompted on the preset display screen).

[0057] Sp represents the mileage to be replaced;

[0058] δ is the wear correction factor.

[0059] The wear monitoring result is determined based on the corrected replacement mileage and the real-time wear thickness. That is, the wear monitoring result can be determined based on the corrected replacement mileage and the real-time wear thickness. After determining the wear monitoring result, the corrected replacement mileage and the real-time wear thickness of the brake friction pad 21 need to be sent to a preset display screen on an instrument panel or similar device for display, to inform the vehicle's personnel of the current wear status.

[0060] Further, determining the wear monitoring result based on the corrected replacement mileage and the real-time wear thickness includes:

[0061] The current thickness of the brake friction pad 21 is determined based on the real-time wear thickness. That is, in this embodiment, after determining the replacement mileage and the real-time wear thickness, since the wear monitoring result is also related to the current thickness of the brake friction pad 21, this embodiment does not directly obtain a definite wear monitoring result, but rather needs to first determine the current thickness of the brake friction pad 21 based on the real-time wear thickness. Understandably, in each previous historical mileage cycle, the real-time wear thickness corresponding to each historical mileage cycle is already known. Therefore, as long as the preset initial thickness of the brake friction pad 21 is obtained, the current thickness can be obtained by subtracting the real-time wear thickness corresponding to all historical mileage cycles and the first mileage cycle from the preset initial thickness.

[0062] When the current thickness is greater than a preset thickness value, the wear monitoring result is determined to be that the wear limit has not been reached, and the current thickness and the corrected replacement mileage are displayed on a preset display screen. That is, when the current thickness is greater than the preset thickness value (the preset thickness value can be set according to needs, for example, 2mm, and the preset thickness value is the minimum critical value for whether the brake friction pad 21 needs to be replaced), it means that the brake friction pad 21 does not need to be replaced at present. At this time, it can be determined that the wear monitoring result has not reached the wear limit. Therefore, after determining the wear monitoring result, the corrected replacement mileage, the current thickness, and the real-time wear thickness of the brake friction pad 21 need to be sent to the preset display screen of the instrument panel, etc., for display to inform the vehicle driver and other personnel of the current wear status.

[0063] Furthermore, after determining the current thickness of the brake friction pad 21 based on the real-time wear thickness, the method further includes:

[0064] When the current thickness is less than or equal to the preset minimum thickness value, the wear monitoring result is determined to have reached the wear limit, and a preset warning device is used to prompt the replacement of the brake friction pad 21. That is, when the current thickness is less than or equal to the preset thickness value, it indicates that the brake friction pad 21 needs to be replaced. At this time, the wear monitoring result can be determined to have reached the wear limit. Therefore, after determining that the wear monitoring result has reached the wear limit, the wear monitoring result can be sent to a preset warning device (such as an instrument), and then displayed on a preset display screen of the preset warning device to prompt the replacement of the brake friction pad 21. Furthermore, in this invention, other preset warning devices (such as audible warning devices or visual warning devices) can also be used to prompt the replacement of the brake friction pad 21.

[0065] In this invention, the real-time wear thickness of the brake friction pad 21 can be determined by measuring the real-time fluid level height using a fluid level sensor 11 installed in the brake fluid reservoir 1, thereby determining the wear monitoring result. In this embodiment, no additional hardware needs to be added to the brake 2 to achieve real-time monitoring of the wear degree (i.e., real-time wear thickness) of the brake friction pad 21. Based on the wear monitoring result obtained from the aforementioned wear thickness measurement, the driver can understand the wear state of the brake friction pad 21 in real time. Furthermore, when the brake friction pad 21 reaches its wear limit, an alarm is triggered to prompt the driver to replace the brake friction pad 21. This invention can improve the safety performance of automobiles and meet the intelligent needs of automobiles.

[0066] In one embodiment, step S300, determining the wear monitoring result based on the real-time wear thickness, includes:

[0067] After the second mileage cycle of the vehicle, the mechanical calibration wear thickness corresponding to the second mileage cycle is obtained; the second mileage cycle is greater than the first mileage cycle; wherein, in this embodiment, the second mileage cycle can be set according to needs, for example, it can be set as 2000 kilometers (or other mileage) as the second mileage cycle of the vehicle, or three months or other durations (i.e., the second mileage cycle is set based on the vehicle's driving time). Understandably, when the mileage cycle is calculated in the same way, the second mileage cycle should be greater than the first mileage cycle.

[0068] In this invention, to further ensure the accuracy of the preset correspondence between the real-time wear thickness of the brake friction pad 21 and the real-time liquid level of the brake fluid reservoir 1, the real-time wear thickness of the brake friction pad 21 can be periodically calibrated by calculating the mechanical calibration wear thickness. Further, obtaining the mechanical calibration wear thickness corresponding to the second mileage cycle includes:

[0069] When the vehicle is under a preset stationary condition, the real-time travel distance of the brake friction pad 21 driven by the vehicle's EPB motor 3 is obtained. This real-time travel distance refers to the distance between the preset position where the EPB motor 3 reverses to fully release the parking brake force after the vehicle has traveled for a second mileage cycle, and the real-time clamping position where the EPB motor 3 clamps the brake disc 26. The preset stationary condition refers to the vehicle being stationary on a level road surface without any braking operation (i.e., the vehicle is stationary or in a parking state). Understandably, in this invention, whether the vehicle is stationary can be determined based on a vehicle speed signal or gear signal, and whether the vehicle is braking can be determined based on a brake switch signal. In this invention, the measurement result of the real-time travel distance can only be stable when the vehicle is under the preset stationary condition. Figure 5 The EPB motor 3 shown clamps the brake disc 26. After releasing the parking brake power to the extreme position (which is the preset position) by reversing the EPB motor 3 on one side, it rotates forward again to clamp the brake disc 26 (at this time, it is in the real-time clamping position). Then, based on the extreme position and different real-time clamping positions, the moving distance of the piston 22 at different real-time wear thicknesses of the brake friction pad 21 is calculated. The moving distance of the piston 22 is the real-time moving stroke X2.

[0070] The initial travel distance of the brake friction pad 21 is obtained. This initial travel distance refers to the distance between the EPB motor 3 reversing to a preset position where the parking brake force is fully released, and the initial clamping position where the EPB motor 3 clamps the brake disc 26, before the brake friction pad 21 is worn. In other words, when the brake friction pad 21 is not worn and the vehicle meets preset conditions and is stationary or parked,... Figure 5 The EPB motor 3 shown clamps the brake disc 26. After releasing the parking brake power to the extreme position (which can be named the preset position) by reversing the EPB motor 3 on one side, it rotates forward again to clamp the brake disc 26 (at this time, it is in the initial clamping position). Then, based on the extreme position and the initial clamping position, the moving distance of the piston 22 during the movement process is calculated. The moving distance of the piston 22 is the initial moving stroke X1.

[0071] The difference between the real-time travel distance and the initial travel distance is recorded as the mechanical calibration wear thickness. That is, in this embodiment, Figure 5 The difference between the real-time travel distance X2 and the initial travel distance X1 shown is the mechanical calibration wear thickness.

[0072] In another embodiment, the number of braking events can be counted based on the brake switch signal, and the braking deceleration signal can be obtained at the same time. The braking intensity and driving slope can be determined based on the number of braking events and the braking deceleration signal (the braking deceleration signal can be used to determine whether the car is on a level road, the braking intensity and slope, and whether it is driving on a mountain road). Then, the ambient temperature is monitored by an ambient temperature sensor, and the mechanical calibration wear thickness is obtained based on the ambient temperature, braking intensity and driving slope.

[0073] The ratio between the mechanical calibration wear thickness and the real-time wear thickness is obtained. This ratio indicates whether there is a leak in the current brake piping system, thereby determining the wear condition of the brake pads 21 and whether the maintenance mileage monitoring system has failed and requires repair. When the ratio is less than a preset ratio (which can be set as needed, for example, to 10%), the real-time wear thickness is corrected based on the mechanical calibration wear thickness, and the wear monitoring result is determined based on the corrected real-time wear thickness. Specifically, when the ratio is less than the preset ratio, it indicates that there is no leak in the current brake piping system; therefore, only the real-time wear thickness needs to be corrected based on the mechanical calibration wear thickness to make the final wear monitoring result more accurate. Specifically, correcting the real-time wear thickness based on the mechanical calibration wear thickness includes: obtaining the average value of the mechanical calibration wear thickness and the real-time wear thickness, and recording the average value as the corrected real-time wear thickness. That is, the specific correction method is to use the average value of the mechanical calibration wear thickness and the real-time wear thickness as the corrected real-time wear thickness.

[0074] Furthermore, after obtaining the ratio between the mechanical calibration wear thickness and the real-time wear thickness, the method further includes:

[0075] When the ratio is greater than or equal to the preset ratio, a preset warning device indicates a leak in the brake piping system and that the brake pad 21 wear monitoring system has failed. That is, when the ratio is greater than or equal to the preset ratio, it proves that there is a brake fluid leak in the brake piping system, thus confirming that the brake pad 21 wear condition and maintenance mileage monitoring system have failed and require repair. Therefore, at this time, a warning can be issued on a preset display screen of a preset warning device (such as an instrument panel) indicating a leak in the brake piping system and that the brake pad 21 wear monitoring system has failed and requires repair; furthermore, in this invention, other preset warning devices (such as audible or visual warning devices) can also be used to issue a warning indicating a leak in the brake piping system and that the brake pad 21 wear monitoring system has failed and requires repair.

[0076] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0077] In one embodiment, the present invention also discloses an automobile, including a brake fluid reservoir 1 and a controller. The brake fluid reservoir 1 is equipped with a level sensor 11 for real-time measurement of the real-time fluid level. The controller is connected to the level sensor 11 and is used to execute the automobile brake pad 21 wear monitoring method. Understandably, the automobile may also include various modules actually used and installed on the automobile in the above-described automobile brake pad 21 wear monitoring method, such as the EPB motor 3 and the brake 1, which will not be elaborated further here.

[0078] The process by which the controller in this embodiment implements its function can be specifically referred to in the description of the aforementioned method for monitoring the wear of brake pads 21, and will not be repeated here. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the vehicle's controller can be divided into different functional units or modules to complete all or part of the functions described above.

[0079] The above-described 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, and should all be included within the protection scope of the present invention.

Claims

1. A method for monitoring wear of automotive brake pads, characterized in that, include: After the first mileage cycle of the vehicle, the real-time liquid level of the brake fluid reservoir is obtained when the vehicle is under preset stationary conditions; The real-time liquid level height is measured in real time by a liquid level height sensor installed in the brake fluid reservoir. The real-time wear thickness of the brake friction pads corresponding to the first mileage cycle is determined based on the real-time liquid level height. The wear monitoring results are determined based on the real-time wear thickness. The step of determining the wear monitoring result based on the real-time wear thickness includes: The historical wear thickness of the brake friction pads corresponding to a historical mileage cycle is obtained, and a wear correction coefficient is determined based on the historical wear thickness and a preset wear thickness; the historical mileage cycle refers to the previous mileage cycle preceding the first mileage cycle. The wear monitoring results are determined based on the real-time wear thickness and the wear correction coefficient.

2. The method for monitoring wear of automotive brake pads as described in claim 1, characterized in that, The step of determining the wear monitoring result based on the real-time wear thickness and the wear correction coefficient includes: When the wear correction coefficient is less than the first calibration coefficient, the replacement mileage is determined based on the real-time wear thickness, and the corrected replacement mileage is determined based on the replacement mileage and the wear correction coefficient. The wear monitoring results are determined based on the corrected replacement mileage and the real-time wear thickness.

3. The method for monitoring wear of automotive brake pads as described in claim 2, characterized in that, The determination of wear monitoring results based on the corrected replacement mileage and the real-time wear thickness includes: The current thickness of the brake friction pad is determined based on the real-time wear thickness. When the current thickness is greater than the preset thickness value, the wear monitoring result is determined to be that the wear limit has not been reached, and the current thickness and the correction replacement mileage are displayed on the preset display screen.

4. The method for monitoring wear of automotive brake pads as described in claim 3, characterized in that, After determining the current thickness of the brake friction pad based on the real-time wear thickness, the method further includes: When the current thickness is less than or equal to the preset thickness value, the wear monitoring result is determined to be the wear limit, and the brake friction pad is prompted to be replaced through a preset warning device.

5. The method for monitoring wear of automotive brake pads as described in claim 2, characterized in that, After determining the wear correction coefficient based on the historical wear thickness and the preset wear thickness, the process includes: When the wear correction coefficient is greater than or equal to the first calibration coefficient, a preset warning device will indicate that there is a leak in the brake pipeline system and that the brake friction pad wear monitoring has failed.

6. The method for monitoring wear of automotive brake pads as described in claim 1, characterized in that, The step of determining the wear monitoring result based on the real-time wear thickness includes: After the second mileage cycle of the vehicle, the mechanical calibration wear thickness corresponding to the second mileage cycle is obtained; the second mileage cycle is longer than the first mileage cycle. Obtain the ratio between the mechanical calibration wear thickness and the real-time wear thickness; When the ratio is less than a preset ratio, the real-time wear thickness is corrected according to the mechanical calibration wear thickness, and the wear monitoring result is determined according to the corrected real-time wear thickness.

7. The method for monitoring wear of automotive brake pads as described in claim 6, characterized in that, After obtaining the ratio between the mechanical calibration wear thickness and the real-time wear thickness, the method further includes: When the ratio is greater than or equal to the preset ratio, a preset warning device will indicate that there is a leak in the brake pipeline system and that the brake friction pad wear monitoring has failed.

8. The method for monitoring wear of automotive brake pads as described in claim 6, characterized in that, The step of obtaining the mechanical calibration wear thickness corresponding to the second mileage cycle includes: When the vehicle is in a preset stationary condition, the real-time movement distance of the brake friction pads driven by the vehicle's EPB motor is obtained; the real-time movement distance refers to the distance between the preset position where the EPB motor reverses to fully release the parking brake force and the real-time clamping position where the EPB motor clamps the brake disc after the vehicle has traveled for the second mileage cycle. The initial travel distance of the brake friction pad is obtained. The initial travel distance refers to the distance between the preset position where the EPB motor reverses to fully release the parking brake force and the initial clamping position where the EPB motor clamps the brake disc when the brake friction pad has not yet been worn. The difference between the real-time travel distance and the initial travel distance is recorded as the mechanical calibration wear thickness.

9. A car, characterized in that, The method includes a brake fluid reservoir and a controller. The brake fluid reservoir is equipped with a level sensor for measuring the real-time level of the brake fluid reservoir. The controller is connected to the level sensor and is used to execute the method for monitoring wear of automotive brake pads as described in any one of claims 1 to 8.

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