Brake system leakage monitoring method

Abstract

Disclosed in the present invention is a brake system leakage monitoring method. In the method, an electronic booster (Ebooster) controller in an Ebooster is used to monitor brake fluid pressures at different positions in a brake system and wheel speeds, a set determination rule and process is used to identify whether the brake system has a leakage risk, and a specific brake fluid leakage position is found when the brake system has a leakage risk.

Description

A method for monitoring brake system leakage

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The embodiments of this application are based on and claim the priority of Chinese patent application with application number 202310907267.8 and application date July 21, 2023. The entire contents of the Chinese patent application are hereby introduced into the embodiments of this application as a reference. Technical Field

[0003] The present invention relates to the technical field of brake system monitoring, and in particular to a brake system leakage monitoring method. Background Art

[0004] This patent is mainly aimed at vehicles with electric drive systems, including hybrid and pure electric vehicles; it involves a method for active monitoring and alarm of brake fluid leakage in the braking system.

[0005] In recent years, with the rapid development of electric, intelligent, and connected vehicles, the proportion of electronic components in automotive parts has continued to increase. As a key automotive subsystem, the brake system has gradually been replaced by electronic power-assisted braking solutions, replacing traditional vacuum-assisted solutions. Unlike vacuum-assisted systems, the electronic brake-assisting device (Ebooster) integrates signals such as brake pedal travel and assist current, providing greater potential for the creation of new features. Furthermore, the increasing intelligence of vehicles has also placed higher demands on vehicle safety. Current mainstream brake systems use hydraulic transmission to drive the caliper piston. Over time, such systems can experience brake fluid leakage, or after damage to the piping caused by collisions, leading to a gradual loss of braking force in the basic braking system. Current systems can only rely on level sensors in the brake reservoir to monitor and alert drivers when the leak is severe. This is unpredictable for ordinary drivers, posing a serious safety hazard.

[0006] Prior art 1 discloses a solution that places a fluid level sensor in the brake fluid reservoir and connects it to the controller via a rigid cable. When the sensor detects a critically low fluid level, it automatically triggers an alarm. However, this solution's disadvantage is that it only triggers an alarm when a leak is severe, when the fluid level falls below a minimum threshold. This lack of early warning presents a significant safety hazard. Furthermore, this solution only monitors the brake fluid level in the reservoir and cannot determine the specific location of the leak.

[0007] Prior art 2 discloses a solution that primarily involves placing a level closure switch and other sensors, such as temperature and water detectors, in a brake fluid reservoir. This solution generates an alarm when abnormalities in the brake fluid in the reservoir occur. However, this solution's disadvantages are that it primarily monitors the amount of brake fluid in the reservoir and cannot directly detect brake fluid leaks. Therefore, it cannot effectively detect slow leaks. Furthermore, the cost of multiple sensors combined for monitoring is high.

[0008] Summary of the Invention

[0009] The object of the present invention is to provide a brake system leakage monitoring method to achieve timely and accurate identification of the leakage location in the brake system.

[0010] To solve the above technical problems, the present invention provides a technical solution: a brake system leakage monitoring method, which is applicable to the brake system of an EBbooster electronic power booster, in which a brake master cylinder is connected to a first pipeline, and a second pipeline is connected to a brake hydraulic control unit. The pipeline between the brake master cylinder and the brake hydraulic control unit constitutes a primary brake circuit, and the pipelines between the brake hydraulic control unit and the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder constitute a secondary brake circuit.

[0011] The method includes:

[0012] Real-time collection of brake fluid pressures from the master cylinder, first pipeline, and second pipeline; and determination of whether to proceed with the subsequent brake fluid leakage location determination process based on the brake fluid pressures from the master cylinder, first pipeline, second pipeline, and pedal travel;

[0013] Determine whether the brake fluid leak is located in the primary brake circuit or the secondary brake circuit based on the brake fluid pressures of the brake master cylinder, the first pipeline, the second pipeline, and the pedal stroke;

[0014] When it is determined that the brake fluid leakage location is located in the primary brake circuit, the brake fluid leakage location is determined to be in the brake master cylinder, the first pipeline, the second pipeline, and the pedal stroke; when it is determined that the brake fluid leakage location is the secondary brake circuit and the current driving road surface is a homogeneous road surface, the brake fluid leakage location is determined to be in the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, or the right rear wheel caliper wheel cylinder based on the left front wheel speed, the right front wheel speed, the left rear wheel speed, and the right rear wheel speed.

[0015] As a second aspect, the present invention further provides a brake system with a leakage monitoring function for implementing the above-mentioned brake system leakage monitoring method, comprising a brake pedal, an EBbooster electronic booster, a brake master cylinder, a brake hydraulic control unit, a left front wheel caliper wheel cylinder, a right front wheel caliper wheel cylinder, a left rear wheel caliper wheel cylinder, a right rear wheel caliper wheel cylinder, a first brake pressure sensor, a second brake pressure sensor, a third brake pressure sensor, and wheel speed sensors provided on four wheels;

[0016] The EBbooster electronic booster includes an input push rod, a travel sensor, an EBbooster controller, and a boost motor; the brake pedal is transmission-connected to the input push rod, the travel sensor is arranged on the input push rod and is electrically connected to the EBbooster controller, and the boost motor is electrically connected to the EBbooster controller;

[0017] The power-assisting motor is connected to the piston of the brake master cylinder through a driving mechanism. The brake master cylinder is connected to the brake hydraulic control unit through a first pipeline and a second pipeline. The brake hydraulic control unit is connected to the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder through pipelines. The pipeline between the brake master cylinder and the brake hydraulic control unit constitutes a primary brake circuit, and the pipelines between the brake hydraulic control unit and the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder constitute a secondary brake circuit.

[0018] The first brake pressure sensor is arranged in the brake master cylinder, the second brake pressure sensor is arranged in the first pipeline, and the third brake pressure sensor is arranged in the second pipeline; the first, second and third brake pressure sensors are all electrically connected to the EBbooster electronic booster;

[0019] The wheel speed sensor is electrically connected to the EBbooster electronic power booster;

[0020] The first brake pressure sensor, the second brake pressure sensor, and the third brake pressure sensor are used to collect the brake hydraulic pressure PS1, PS2, and PS3 of the brake master cylinder, the first pipeline, and the second pipeline respectively;

[0021] The wheel speed sensor is used to collect the left front wheel speed ω FL , right front wheel speedω FR 、Left rear wheel speedω RL 、Right rear wheel speedω RR ;

[0022] The EBbooster controller obtains the target brake fluid pressure PS through the pedal travel signal of the travel sensor. tar , and combined with PS1, PS2, PS3, ω FL 、ω FR、ω RL 、ω RR Determine whether there is a brake fluid leak and the specific location of the brake fluid leak.

[0023] As a third aspect, the present invention further provides a computer comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-described brake system leakage monitoring method when executing the computer program.

[0024] As a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the brake system leakage monitoring method described above.

[0025] As a fifth aspect, the present invention further provides an automobile having the above-mentioned braking system with leakage monitoring function.

[0026] The present invention has the beneficial effect of monitoring the brake fluid pressure and wheel speed at different locations in the brake system to determine whether a vehicle is at risk of brake fluid leakage and the specific location of the leak. Compared with existing technologies, this method is more timely and accurate in determining brake fluid leaks and can help vehicle owners or maintenance personnel quickly identify the fault location. The sensors required by this method are all built-in sensors in the vehicle, and the calculation and control are implemented by the EBbooster controller, without adding additional hardware costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic diagram of a brake system with a leakage monitoring function according to an embodiment of the present invention;

[0028] FIG. 2 is a diagram showing a corresponding relationship between a pedal stroke signal and a target brake hydraulic pressure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0030] A brake system leakage monitoring method is implemented based on a brake system using an EBbooster electronic booster. In the brake system, a brake master cylinder is connected to a first pipeline, and a second pipeline is connected to a brake hydraulic control unit. The pipeline between the brake master cylinder and the brake hydraulic control unit constitutes a primary brake circuit, and the pipelines between the brake hydraulic control unit and the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder constitute a secondary brake circuit.

[0031] The method comprises the following steps:

[0032] S1, real-time collection of brake hydraulic pressure PS1, PS2, PS3 of the brake master cylinder, the first pipeline, and the second pipeline;

[0033] S2, during braking, the EBbooster controller in the EBbooster electronic booster obtains the target brake hydraulic pressure PS according to the pedal travel signal. tar ; Calculate the mean of PS1, PS2, and PS3 And calculate PS tar and The difference ΔPS;

[0034] When ΔPS ≥ 0, the subsequent brake fluid leakage position determination process is activated; otherwise, the process returns to S1;

[0035] S3, if ΔPS≤MAX{1bar,1%×PS tra If the primary brake circuit is normal, execute S5; otherwise, execute S4;

[0036] S4. Calculate PS respectively tra The differences with PS1, PS2, and PS3 are ΔPS1, ΔPS2, and ΔPS3;

[0037] If ΔPS1>MAX{1bar,1%×PS tra} ΔPS2>MAX{1bar,1%×PS tra ΔPS3>MAX{1bar,1%×PS tra}

[0038] The leakage location is determined to be the brake master cylinder;

[0039] If ΔPS1 is satisfied at the same time <MAX{1bar,1%×PS tra} ΔPS2>MAX{1bar,1%×PS tra} ΔPS3 <MAX{1bar,1%×PS tra}

[0040] Then the leakage location is determined to be the first pipeline;

[0041] If ΔPS1 is satisfied at the same time <MAX{1bar,1%×PS tra} ΔPS2 <MAX{1bar,1%×PS tra ΔPS3>MAX{1bar,1%×PS tra}

[0042] Then it is determined that the leakage location is the second pipeline;

[0043] S5. If the current braking condition is a normal braking condition (and the vehicle's stability control functions such as ABS or AYC are not triggered, and the braking condition is obtained by the EBbooster controller through the electronic power assist mode in its program), and the current driving road surface is a homogeneous road surface, then proceed to the subsequent steps; the current driving road surface determination is specifically:

[0044] Collect the left front wheel speed ω FL , right front wheel speedω FR 、Left rear wheel speedω RL 、Right rear wheel speedω RR , calculate the left front wheel deceleration Right front wheel deceleration Left rear wheel deceleration Right rear wheel deceleration Get the average of the two front wheel decelerations and the average of the two rear wheel decelerations

[0045] If both are satisfied,

[0046] It is judged that the current driving road surface is a homogeneous road surface;

[0047] S6. Select three braking actions with target brake fluid pressure within the range of (25 bar, 50 bar) under normal braking conditions and on homogeneous road conditions. Take the average of the four-wheel deceleration corresponding to the three selected braking actions for the left front wheel, right front wheel, left rear wheel, and right rear wheel, and obtain Then there is,

[0048] If both meet

[0049] The leak is determined to be at the left front wheel caliper cylinder.

[0050] If both meet

[0051] The leak is determined to be at the right front wheel caliper cylinder.

[0052] If both meet

[0053] The leak is determined to be at the left rear wheel caliper cylinder.

[0054] If both meet

[0055] The leakage location is determined to be the right rear wheel caliper wheel cylinder.

[0056] Referring to FIG1 , a brake system with a leakage monitoring function for implementing the brake system leakage monitoring method described above includes a brake pedal, an EBbooster electronic booster, a brake master cylinder, a brake hydraulic control unit, a left front wheel caliper wheel cylinder, a right front wheel caliper wheel cylinder, a left rear wheel caliper wheel cylinder, a right rear wheel caliper wheel cylinder, a first brake pressure sensor, a second brake pressure sensor, a third brake pressure sensor, and wheel speed sensors provided on four wheels;

[0057] The EBbooster electronic booster includes an input push rod, a travel sensor, an EBbooster controller, and a boost motor; the brake pedal is transmission-connected to the input push rod, the travel sensor is arranged on the input push rod and is electrically connected to the EBbooster controller, and the boost motor is electrically connected to the EBbooster controller;

[0058] The power-assisting motor is connected to the piston of the brake master cylinder through a driving mechanism. The brake master cylinder is connected to the brake hydraulic control unit through a first pipeline and a second pipeline. The brake hydraulic control unit is connected to the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder through pipelines. The pipeline between the brake master cylinder and the brake hydraulic control unit constitutes a primary brake circuit, and the pipelines between the brake hydraulic control unit and the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder constitute a secondary brake circuit.

[0059] The first brake pressure sensor is arranged in the brake master cylinder, the second brake pressure sensor is arranged in the first pipeline, and the third brake pressure sensor is arranged in the second pipeline; the first, second and third brake pressure sensors are all electrically connected to the EBbooster electronic booster;

[0060] The wheel speed sensor is electrically connected to the EBbooster electronic power booster;

[0061] The first brake pressure sensor, the second brake pressure sensor, and the third brake pressure sensor are used to collect the brake hydraulic pressure PS1, PS2, and PS3 of the brake master cylinder, the first pipeline, and the second pipeline respectively;

[0062] The wheel speed sensor is used to collect the left front wheel speed ω FL , right front wheel speedω FR 、Left rear wheel speedω RL 、Right rear wheel speedω RR ;

[0063] The EBbooster controller obtains the target brake fluid pressure PS through the pedal travel signal of the travel sensor. tra , and combined with PS1, PS2, PS3, ω FL 、ω FR 、ω RL 、ω RR Determine whether there is a brake fluid leak and the specific location of the brake fluid leak.

[0064] A computer comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned brake system leakage monitoring method when executing the computer program.

[0065] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the brake system leakage monitoring method described above.

[0066] A car is provided with the above-mentioned braking system with leakage monitoring function.

[0067] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A brake system leakage monitoring method, characterized in that: The method is applicable to the braking system of an EBbooster electronic booster, in which a brake master cylinder is connected to a first pipeline and a second pipeline is connected to a brake hydraulic control unit, the pipeline between the brake master cylinder and the brake hydraulic control unit constitutes a primary braking circuit, and the pipelines between the brake hydraulic control unit and a left front wheel caliper wheel cylinder, a right front wheel caliper wheel cylinder, a left rear wheel caliper wheel cylinder, and a right rear wheel caliper wheel cylinder constitute a secondary braking circuit; The method includes: Collect the brake fluid pressure of the master cylinder, the first pipeline, and the second pipeline in real time; and determine whether to perform the subsequent brake fluid leakage position determination process according to the brake fluid pressure of the master cylinder, the first pipeline, the second pipeline, and the pedal stroke; According to the brake fluid pressures of the brake master cylinder, the first pipeline, the second pipeline, and the pedal stroke, it is determined that the brake fluid leakage position is located in the primary brake circuit or the secondary brake circuit; When it is determined that the brake fluid leakage location is located in the primary brake circuit, the brake fluid leakage location is determined to be in the brake master cylinder, the first pipeline, the second pipeline, and the pedal stroke; when it is determined that the brake fluid leakage location is the secondary brake circuit and the current driving road surface is a homogeneous road surface, the brake fluid leakage location is determined to be in the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, or the right rear wheel caliper wheel cylinder according to the left front wheel speed, the right front wheel speed, the left rear wheel speed, and the right rear wheel speed.

2. The brake system leakage monitoring method according to claim 1, characterized in that: The specific process of determining whether to proceed with the subsequent brake fluid leakage position determination process according to the brake fluid pressure of the brake master cylinder, the first pipeline, the second pipeline, and the pedal stroke is as follows: During braking, the EBbooster controller in the EBbooster electronic booster obtains the target brake hydraulic pressure PS according to the pedal travel signal. tar ; The brake hydraulic pressures of the brake master cylinder, the first pipeline, and the second pipeline are PS1, PS2, and PS3 respectively. Calculate the average of PS1, PS2, and PS3 And calculate PS tar and The difference ΔPS; When ΔPS ≥ 0, the subsequent brake fluid leakage position determination process is enabled, otherwise the brake fluid pressures of the brake master cylinder, the first pipeline, and the second pipeline are continuously collected and ΔPS is calculated.

3. The brake system leakage monitoring method according to claim 2, characterized in that: The initial determination process of the brake fluid leakage location is as follows: If ΔPS≤MAX{αbar,β%×PS tar }, it is judged that the brake fluid leakage position is located in the secondary brake circuit, otherwise it is judged that the brake fluid leakage position is located in the primary brake circuit; wherein α is the preset pressure value, and β is the preset percentage value.

4. The brake system leakage monitoring method according to claim 3, characterized in that: When it is determined that the brake fluid leakage position is located in the primary brake circuit, the specific judgment process of the brake fluid leakage position is as follows: Calculate PS respectively tar The differences with PS1, PS2, PS3 are ΔPS1, ΔPS2, ΔPS3; If both meet ΔPS1>MAX{αbar,β%×PS tar } ΔPS2>MAX{αbar,β%×PS tar } ΔPS3>MAX{αbar,β%×PS tar } Then the leakage location is judged to be the brake master cylinder; If both meet ΔPS1<MAX{αbar,β%×PS tar } ΔPS2>MAX{αbar,β%×PS tar } ΔPS3<MAX{αbar,β%×PS tar } Then it is determined that the leakage location is the first pipeline; If both meet ΔPS1<MAX{αbar,β%×PS tar } ΔPS2 <MAX{αbar,β%×PS tar } ΔPS3>MAX{αbar,β%×PS tar } It is determined that the leakage location is the second pipeline.

5. The brake system leakage monitoring method according to claim 3, characterized in that: The specific method for judging the mean road surface is as follows: When it is determined that the brake fluid leakage position is located in the second-level brake circuit, the specific judgment process of the brake fluid leakage position is as follows: Collect the left front wheel speed ω FL , right front wheel speedω FR 、Left rear wheel speedω RL 、Right rear wheel speedω RR , calculate the left front wheel deceleration Right front wheel deceleration Left rear wheel deceleration Right rear wheel deceleration Get the average of the two front wheel decelerations and the average of the two rear wheel decelerations If both are satisfied, The current driving road surface is judged to be a homogeneous road surface; wherein γ is a preset percentage value.

6. The brake system leakage monitoring method according to claim 3, characterized in that: When it is determined that the brake fluid leakage position is located in the secondary brake circuit and the current driving road surface is a homogeneous road surface, the specific judgment process of the brake fluid leakage position is as follows: Select several braking actions with target brake fluid pressure within a certain threshold under normal braking conditions and driving on homogeneous road conditions, and take the average of the four-wheel deceleration corresponding to the selected several braking actions according to the left front wheel, right front wheel, left rear wheel, and right rear wheel, and get Then there is, If both meet The leaking location is determined to be the left front wheel caliper wheel cylinder; If both meet The leak location is determined to be the right front wheel caliper wheel cylinder; If both meet The leak location is determined to be the left rear wheel caliper wheel cylinder; If both meet The leak location is determined to be the right rear wheel caliper wheel cylinder; Where ε and μ are preset percentage values.

7. A brake system with leakage monitoring function for implementing the brake system leakage monitoring method according to any one of claims 1 to 6, characterized in that: It includes a brake pedal, an EBbooster electronic booster, a brake master cylinder, a brake hydraulic control unit, a left front wheel caliper wheel cylinder, a right front wheel caliper wheel cylinder, a left rear wheel caliper wheel cylinder, a right rear wheel caliper wheel cylinder, a first brake pressure sensor, a second brake pressure sensor, a third brake pressure sensor, and wheel speed sensors arranged on four wheels; The EBbooster electronic booster includes an input push rod, a travel sensor, an EBbooster controller and a boost motor; the brake pedal is transmission-connected to the input push rod, the travel sensor is arranged on the input push rod and is electrically connected to the EBbooster controller, and the boost motor is electrically connected to the EBbooster controller; The booster motor is connected to the piston of the brake master cylinder through a first pipeline and a second pipeline, and the brake hydraulic control unit is connected to the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder through pipelines. The pipeline between the brake master cylinder and the brake hydraulic control unit constitutes a primary brake circuit. The brake hydraulic control unit is connected to the left front wheel caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder through pipelines. The pipelines between the caliper wheel cylinder, the right front wheel caliper wheel cylinder, the left rear wheel caliper wheel cylinder, and the right rear wheel caliper wheel cylinder constitute a secondary brake circuit; The first brake pressure sensor is arranged in the brake master cylinder, the second brake pressure sensor is arranged in the first pipeline, and the third brake pressure sensor is arranged in the second pipeline; the first, second and third brake pressure sensors are all electrically connected to the EBbooster electronic booster; The wheel speed sensor is electrically connected to the EBbooster electronic booster; The first brake pressure sensor, the second brake pressure sensor, and the third brake pressure sensor are used to collect the brake hydraulic pressure PS1, PS2, and PS3 of the brake master cylinder, the first pipeline, and the second pipeline, respectively; The wheel speed sensor is used to collect the left front wheel speed ω FL , right front wheel speedω FR 、Left rear wheel speedω RL 、Right rear wheel speedω RR ; The EBbooster controller obtains the target brake fluid pressure PS through the pedal travel signal of the travel sensor. tar , and combined with PS1, PS2, PS3, ω FL ,ω FR ,ω RL ,ω RR Determine whether there is a brake fluid leak and the specific location of the brake fluid leak.

8. A computer comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the brake system leakage monitoring method according to any one of claims 1-6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the brake system leakage monitoring method according to any one of claims 1 to 6 are implemented.

10. An automobile, characterized in that: It has the brake system with leakage monitoring function as claimed in claim 7.

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