A method and system for determining the influence of brake disc runout on travel.

Abstract

This invention provides a method and system for determining the impact of brake disc runout on travel. The method involves obtaining the brake fluid requirement at a set pressure under a set temperature and static state of the brake disc; obtaining the brake fluid requirement at a corresponding pressure under a set speed and a set temperature of the brake disc; calculating the difference between the two; and calculating the impact of brake disc runout on travel based on the difference. This invention utilizes the brake fluid requirement of the brake caliper under both dynamic and static states to determine the impact of brake disc runout.

Description

Technical Field

[0001] This invention belongs to the field of automotive engineering technology and relates to a method and system for determining the influence of brake disc runout on travel. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Brake pedal feel has become a major complaint among drivers and passengers. Insufficient braking force and soft brakes can easily cause driver panic and lead to a poor driving experience. A key indicator of a soft brake pedal is the caliper fluid requirement. Current technical specifications only require fluid requirements based on static bench tests, which often results in significant discrepancies between real-world vehicle performance and bench test results. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a method and system for determining the impact of brake disc runout on travel. This invention utilizes the fluid requirements of the brake caliper under both dynamic and static conditions to determine the impact of brake disc runout.

[0005] According to some embodiments, the present invention adopts the following technical solution:

[0006] A method for determining the effect of brake disc runout on travel includes the following steps:

[0007] Obtain the brake fluid requirement at a set pressure under a set brake disc temperature at rest.

[0008] Obtain the brake fluid requirement under the corresponding pressure when the brake disc is rotating at a set temperature and speed.

[0009] Calculate the difference between the two values, and then calculate the effect of brake disc runout on the travel based on the difference.

[0010] As an alternative implementation, the required brake fluid volume is the amount of fluid that the master cylinder needs to replenish to the brake caliper.

[0011] As an alternative implementation, the brake caliper includes two brake calipers on the front axle and two brake calipers on the rear axle.

[0012] As an alternative implementation, the data acquired is the pipeline pressure before the output hydraulic inflection point, which covers common operating conditions.

[0013] As an alternative implementation method, there are multiple set pressures;

[0014] The pressure value gradually increases, and the pressurization rate is consistent.

[0015] As an alternative implementation, the set temperature is room temperature.

[0016] As an alternative implementation method, the calculation of the difference between the two needs to be correlated with the corresponding pressure.

[0017] As an alternative implementation, the specific process of calculating the effect of brake disc runout on the stroke based on the difference includes the following: the difference is the increase in the amount of fluid supplied to the braking system by the master cylinder due to brake disc runout; the increase in fluid required is divided by the diameter of the master cylinder to obtain the increase in the master cylinder push rod stroke, which is fed back to the brake pedal as the increased pedal stroke.

[0018] A system for determining the effect of brake disc runout on travel, comprising:

[0019] The static module is configured to acquire the brake fluid requirement at a set pressure when the brake disc is at a set temperature and at rest.

[0020] The dynamic module is configured to acquire the brake fluid requirement under the corresponding pressure when the brake disc is rotating at a set temperature and a set speed.

[0021] The calculation module is configured to calculate the difference between the two, and based on the difference, calculate the effect of brake disc runout on the stroke.

[0022] As an alternative implementation, the system also includes a vehicle test bench.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention does not involve mold opening and costs, and the implementation cost is relatively low. This invention only uses existing test benches to test the dynamic fluid demand, which can obtain the fluid demand in the actual braking of the whole vehicle, and then obtain the increased pedal stroke. The calculation process is simple. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0026] Figure 1 This is a system schematic diagram of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] A method for determining the effect of brake disc runout on travel includes the following steps:

[0031] Obtain the brake fluid requirement at a set pressure under a set brake disc temperature at rest.

[0032] Obtain the brake fluid requirement under the corresponding pressure when the brake disc is rotating at a set temperature and speed.

[0033] Calculate the difference between the two values, and then calculate the effect of brake disc runout on the travel based on the difference.

[0034] As a typical implementation, bench test parameters are extracted based on a database of pedal feel from whole-vehicle tests. Since the characteristics of the vacuum booster determine the inflection point of the output hydraulic pressure during actual vehicle braking, the data extraction process only considers the pipeline pressure before the inflection point, which can cover commonly used operating conditions.

[0035] Based on the above principles: V. Static test conditions: Under normal temperature and static conditions, record the amount of fluid required by the master cylinder to supply the brake caliper under the pressure specified in Table 1, with a pressurization rate of 60 bar / s; V. Dynamic test conditions: Under normal temperature conditions, the brake disc rotates at a vehicle speed of 100 km / h, and record the amount of fluid required by the master cylinder to supply the brake caliper under the pressure specified in Table 1, with a pressurization rate of 60 bar / s. (V: Caliper fluid requirement)

[0036] Table 1

[0037]

[0038]

[0039] The test data V static and V dynamic brake caliper fluid requirements in the table are from the inertia bench test. The inertia bench system is equipped with a flow meter sensor, which can measure and record the brake fluid flow rate through the flow meter during braking, both statically and dynamically.

[0040] The difference between the dynamic fluid demand and the static fluid demand, measured by the inertia test bench at each pressure, represents the impact of brake disc vibration.

[0041] The required fluid volume of the two brake calipers on the front axle and the two brake calipers on the rear axle of the entire vehicle was tested under static and dynamic conditions on a bench.

[0042] We can conclude that:

[0043] 1: V_static (two front calipers) + V_static (two rear calipers) = the amount of fluid statically replenished to the entire braking system by the master cylinder.

[0044] 2: V-dynamic (two front calipers) + V-dynamic (two rear calipers) = the amount of fluid dynamically replenished to the entire braking system by the master cylinder.

[0045] The difference between Equation 2 and Equation 1 is the increase in the amount of fluid supplied to the braking system by the master cylinder due to the brake disc end jump. The increase in fluid required is divided by the diameter of the master cylinder to obtain the increase in the master cylinder push rod stroke, which is reflected on the brake pedal as the increased pedal stroke.

[0046] In the initial braking setup, the impact of end bounce on the actual pedal feel needs to be carefully considered. It should be noted that the above description applies only to traditional braking systems and does not apply to brake-by-wire systems.

[0047] This invention also provides:

[0048] A system for determining the effect of brake disc runout on travel, such as Figure 1 As shown, it includes:

[0049] The static module is configured to acquire the brake fluid requirement at a set pressure when the brake disc is at a set temperature and at rest.

[0050] The dynamic module is configured to acquire the brake fluid requirement under the corresponding pressure when the brake disc is rotating at a set temperature and a set speed.

[0051] The calculation module is configured to calculate the difference between the two, and based on the difference, calculate the effect of brake disc runout on the stroke.

[0052] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0053] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0054] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0055] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0057] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for determining the influence of brake disc runout on travel, characterized in that, Includes the following steps: Obtain the brake fluid requirement at a set pressure under a set brake disc temperature at rest. Obtain the brake fluid requirement under the corresponding pressure when the brake disc is rotating at a set temperature and speed. Calculate the difference between the two, and calculate the effect of brake disc runout on the stroke based on the difference; The specific process of calculating the effect of brake disc runout on the stroke based on the difference includes the following: the difference is the increase in the amount of fluid supplied to the braking system by the master cylinder due to brake disc runout; the increase in fluid required is divided by the diameter of the master cylinder to obtain the increase in the master cylinder push rod stroke, which is fed back to the brake pedal as the increased pedal stroke.

2. The method for determining the influence of brake disc runout on stroke as described in claim 1, characterized in that, The required brake fluid volume refers to the amount of fluid that the master cylinder needs to supply to the brake caliper.

3. The method for determining the influence of brake disc runout on stroke as described in claim 1, characterized in that, The brake calipers consist of two calipers on the front axle and two calipers on the rear axle.

4. The method for determining the influence of brake disc runout on stroke as described in claim 1, characterized in that, The data obtained is the pipeline pressure before the hydraulic output inflection point, and this pressure can cover common operating conditions.

5. The method for determining the influence of brake disc runout on stroke as described in claim 1, characterized in that, The set pressure is multiple; The pressure value gradually increases, and the pressurization rate is consistent.

6. The method for determining the influence of brake disc runout on stroke as described in claim 1, characterized in that, The set temperature is room temperature.

7. The method for determining the influence of brake disc runout on stroke as described in claim 1, characterized in that, In calculating the difference between the two, it is necessary to correspond to the corresponding pressure.

8. A system for determining the influence of brake disc runout on travel, employing the method for determining the influence of brake disc runout on travel as described in any one of claims 1-7, characterized in that, include: The static module is configured to acquire the brake fluid requirement at a set pressure when the brake disc is at a set temperature and at rest. The dynamic module is configured to acquire the brake fluid requirement under the corresponding pressure when the brake disc is rotating at a set temperature and a set speed. The calculation module is configured to calculate the difference between the two, and based on the difference, calculate the effect of brake disc runout on the stroke.

9. The system for determining the influence of brake disc runout on stroke as described in claim 8, characterized in that, The system also includes a vehicle test bench.

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