A passenger car brake noise test device and method with suspension support and road surface feedback

Abstract

The present application relates to the technical field of passenger car brake noise testing, and more specifically, to a passenger car brake noise testing device and method with suspension support and road surface feedback. The device includes a suspension support structure, a road surface feedback structure, a brake inertia platform, a microphone, and a test unit. The present application installs the brake disc and the brake caliper to be tested through the suspension support structure to provide support force for the wheel. The road surface simulation device is in contact with the tire to simulate the actual road surface, provide friction force for the tire and support the wheel; the brake inertia platform is connected to the tire to provide rotational inertia for the tire. The microphone is located around the wheel to collect noise during braking; the test unit is used to obtain test results based on the noise collected by the microphone. The present application achieves the simulation of the actual driving state of the vehicle and the testing of the brake noise of the passenger car.

Description

Technical Field

[0001] The present application relates to the technical field of passenger car brake noise testing, and in particular to a passenger car brake noise testing device and method with suspension support and road surface feedback. Background Art

[0002] With the development of the automobile industry and the improvement of living standards, the ride comfort of vehicles has received more and more attention, and brake noise is an important factor affecting comfort. At the same time, large brake noise is often accompanied by the occurrence of brake system failures, so the existence of brake noise also poses a great hidden danger to the safe operation of the car.

[0003] Currently, bench testing and verification are common means of brake noise matching testing. For bench noise testing, the test tooling must be sufficiently close to the actual vehicle state so that the installation of each component is consistent with the actual vehicle. However, the brake noise test device in the prior art cannot reflect the actual vehicle state and road feedback, resulting in inaccurate brake noise testing.

[0004] In view of this, this application is hereby filed. Summary of the invention

[0005] The purpose of the present application is to provide a passenger car brake noise testing device and method with suspension support and road surface feedback, in which the actual vehicle state and road surface feedback are taken into consideration during the brake noise testing process to improve the accuracy of the test.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a passenger car brake noise test device with suspension support and road surface feedback, comprising: a suspension support structure, a road surface feedback structure, a brake inertia platform, a microphone and a test unit;

[0008] The suspension support structure includes a wheel, a tire and a suspension component, and is used to install a brake disc and a brake caliper to be tested, and provide support force for the wheel;

[0009] The road surface feedback structure includes a rotating hub and a road surface simulation device mounted on the rotating hub, wherein the road surface simulation device is in contact with the tire and is used to simulate the actual road surface, provide friction for the tire and support the wheel; the road surface simulation device includes a plurality of materials with different road surface adhesion coefficients;

[0010] The brake inertia platform is connected to the tire and is used to provide rotational inertia for the tire;

[0011] The microphone is located around the wheel and is used to collect noise during braking;

[0012] The testing unit is used to obtain a testing result according to the noise collected by the microphone.

[0013] In a second aspect, the present application provides a method for testing brake noise of a passenger car with suspension support and road surface feedback, comprising:

[0014] Install the brake disc and brake caliper to be tested on the suspension support structure;

[0015] The road surface simulation device is mounted on the rotating hub;

[0016] adjusting a position of a road surface feedback structure so that the road surface feedback structure contacts the wheel;

[0017] The testing unit tests the braking noise according to the noise collected by the microphone, the road adhesion coefficient of the road simulation device, the vehicle load and the rotation speed change of the wheel.

[0018] Compared with the prior art, the beneficial effects of this application are:

[0019] The passenger car brake noise test device with suspension support and road feedback provided in the embodiment of the present application can simulate the passenger car noise test in the real road environment, simulate the actual vehicle state through the suspension support structure, and simulate the road state through the road feedback structure. At the same time, the test method in the present application also provides a test process and method basis for carrying out passenger car noise testing, taking into account different road adhesion coefficients and different wheel speed changes, and accurately testing the brake noise close to the actual driving environment.

[0020] The suspension support structure provided in the present application is close to the real vehicle at the suspension end, and the road surface feedback structure simulates the real road surface. The two together make the brake noise bench test conditions closer to the real vehicle state and reproduce more realistic brake noise.

[0021] This application can be applied to the bench test research of wear particle emission of passenger car tires and brake systems, and can also be adjusted to meet the tests under different load conditions and different tire models. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a structural schematic diagram of a passenger car brake noise testing device with suspension support and road surface feedback provided in an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of a suspension support structure provided in an embodiment of the present application;

[0025] Figure 3 is a schematic diagram of a road surface feedback structure provided in an embodiment of the present application;

[0026] Figure 4 It is a flow chart of a passenger car brake noise testing method with suspension support and road surface feedback provided in an embodiment of the present application;

[0027] Among them, 1-suspension support structure, 2-road surface feedback structure, 3-brake inertia platform, 4-microphone, 5-test unit, 11-wheel, 12-tire, 13-shock absorber, 14-stabilizer bar, 15-H-type flange, 16-fixed end, 21-rotating hub, 22-road surface simulation device, 23-height adjustment device, 24-lateral adjustment device, 25-longitudinal adjustment device, 26-baffle, 27-bearing, 28-base, 29-fixed bottom plate, 291-adjusting rod, 292-fixed rod, 31-rotating end. DETAILED DESCRIPTION

[0028] The following is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0029] Figure 1 : is a schematic diagram of the structure of a passenger car brake noise test device with suspension support and road feedback provided by an embodiment of the present application. This embodiment is suitable for performing brake noise bench testing on a brake disc and a brake caliper under test. Figure 1 The device provided in this embodiment includes a suspension support structure 1, a road surface feedback structure 2, a brake inertia platform 3, a microphone 4 and a test unit 5. The structure and function of each component are specifically introduced below.

[0030] The positions of the various parts of the suspension support structure 1 are consistent with the actual vehicle state in order to simulate the braking conditions under the actual vehicle state. Figure 2 The suspension support structure 1 includes a wheel 11, a tire 12 and a suspension component, which is used to install the brake disc and the brake caliper to be tested, and provide support for the wheel 11. Optionally, the suspension component includes a stabilizer bar 14 and a shock absorber 13. In addition, it can also include the following components consistent with the actual vehicle: a steering tie rod fixing and adjusting device, a steering knuckle fixing device, a lower swing arm supporting device, and a stabilizer bar fixing and adjusting device. The suspension support structure 1 is installed at the fixed end 16.

[0031] The knuckle fixing device is used to fix the knuckle that matches the brake disc and the brake caliper to be tested, and can adjust the knuckle. One side of the knuckle is connected to the wheel 11 through the H-shaped flange 15, and the other side of the knuckle is connected to the steering tie rod, the lower swing arm and the stabilizer bar 14.

[0032] The steering tie rod fixing and adjusting device is used to fix and adjust the steering tie rod to adapt to different loads. The stabilizer bar fixing and adjusting device is used to fix and adjust the stabilizer bar 14 to adapt to different loads. The lower swing arm support device is used to support the lower swing arm. The shock absorber fixing and adjusting device is used to fix the shock absorber 13 and adjust the compression amount of the shock absorber 13 to simulate different load conditions.

[0033] The suspension support structure 1 in this embodiment is designed as a structure with adjustable suspension height, and can meet different load conditions (empty, half-loaded, fully loaded) by adjusting the compression of the shock absorber 13, the steering rod, and the stabilizer bar 14.

[0034] See also Figure 3 The road surface feedback structure 2 is installed below the suspension support structure 1, and includes a rotating hub 21 and a road surface simulation device 22 mounted on the rotating hub 21. The road surface simulation device 22 is in contact with the tire 12, and is used to simulate the actual road surface, provide friction for the tire 12 and support the wheel 11; the road surface simulation device 22 includes a variety of materials with different road surface adhesion coefficients, and provides friction through a replaceable covering surface such as sandpaper, and is used to simulate the actual road state.

[0035] Optionally, the road surface feedback structure 2 includes a multi-degree-of-freedom adjustment device for adjusting the spatial position of the hub 21; the multi-degree-of-freedom adjustment device includes a height adjustment device 23, a lateral adjustment device 24 and a longitudinal adjustment device 25, so as to realize the hub 21 being height adjustable, lateral adjustable and longitudinal adjustable to adapt to tires 12 of different sizes, vehicle models and different load conditions.

[0036] The road surface feedback structure 2 also includes: a base 28, a fixed bottom plate 29, an adjustment rod 291 and a baffle 26. In order to achieve the effect of rotation, the rotating hub 21 is connected to the baffle 26 through a bearing 27, and the baffle 26 is a frame-shaped structure sleeved around the rotating hub 21. The base 28 is used to support the road surface feedback structure 2. The fixed bottom plate 29 is used to fix the wheel hub and the multi-degree-of-freedom adjustment device. The adjustment rod 291 is used to provide an up and down movement channel for the height adjustment device 23.

[0037] Optionally, the brake inertia platform 3 is connected to the tire 12 to provide rotational inertia for the tire 12. The brake inertia platform 3 includes a control system, a drive inertia system, a brake disc test spindle device, a brake force application system and a brake disc temperature measuring device to reproduce the braking behavior under different working conditions.

[0038] The control system is used to send control instructions to the brake force application system and the driving inertia system, specifically sending a driving control instruction to the driving inertia system and sending a braking control instruction to the brake force application system.

[0039] An inertia disc is provided on the brake disc test spindle device, and the driving inertia system responds to the control instruction to drive the inertia disc to rotate through the brake disc test spindle device; the brake force application system is arranged on one side of the brake disc test spindle device, and brakes the inertia disc in response to the control instruction; the brake disc temperature measuring device is arranged on one side of the brake disc test spindle device, and is used to detect the temperature change of the brake disc being tested.

[0040] See also Figure 1 The tire 12 of the suspension support structure 1 is connected to the rotating end 31 of the brake inertia platform 3 through the H-shaped flange 15.

[0041] Optionally, the hub 21 moves with the wheel 11, that is, it rotates with the wheel 11 under the friction of the road simulation device 22. The bearing 27 can also be connected to a power source (such as a hydraulic power source or a motor output shaft), and the hub 21 is driven to rotate under the action of the power source to achieve relative movement of the ground relative to the wheel 11 to model different working conditions.

[0042] The control system issues different control instructions through a set program to make the brake inertia platform work according to the set speed, set acceleration, set deceleration, set torque or set pressure (for the brake insert).

[0043] The microphone 4 is located around the wheel 11 and is used to collect noise during the braking process; the number of microphones 4 can be one or more, and multiple microphones 4 can capture braking noise from multiple angles to improve the accuracy of the test.

[0044] The test unit 5 is electrically connected to the microphone 4, and is used to collect the noise of the microphone 4 and obtain the test result according to the noise. The test unit 5 includes a memory and a processor, and the memory stores computer instructions, and the processor is used to execute the computer instructions to implement the passenger car brake noise test method with suspension support and road feedback provided in this application.

[0045] A passenger car brake noise test device with suspension support and road surface feedback provided in an embodiment of the present application can simulate the passenger car noise test in a real road environment, simulating the actual vehicle state through the suspension support structure 1, and simulating the road state through the road surface feedback structure 2. The suspension support structure 1 provided in the present application is close to the real vehicle at the suspension end, and the road surface feedback structure 2 simulates the real road surface. The two together make the brake noise bench test conditions closer to the real vehicle state and reproduce more realistic brake noise. The present application can be applied to the bench test research of wear particle emission of passenger car wheels and brake systems, and can also be adjusted to meet the test under different load conditions and different tire models.

[0046] like Figure 4 As shown, this embodiment provides a passenger car brake noise test method with suspension support and road surface feedback, using the passenger car brake noise test device with suspension support and road surface feedback provided by the above embodiment, including the following steps:

[0047] S110. Install the brake disc and brake caliper to be tested on the suspension support structure.

[0048] The brake disc and brake caliper to be tested are fixed on the steering knuckle and connected to the wheel 11 through the H flange. The other side of the steering knuckle is connected to the steering tie rod, lower swing arm, stabilizer bar 14 and other structures.

[0049] S120, sleeve the road surface simulation device on the rotating hub.

[0050] The road simulation device 22 is covered on the rotating hub 21. The road simulation device 22 has covering surfaces with different friction coefficients according to different test requirements. The road simulation device 22 is made into a size that can completely fit on the rotating hub 21 and is fixed on the rotating hub 21 by an adhesive.

[0051] S130: Adjust the position of the road surface feedback structure so that the road surface feedback structure contacts the wheel.

[0052] Specifically, the vertical position of the rotating hub 21 is adjusted by adjusting the height adjustment device 23 so that the road surface feedback structure 2 on the rotating hub 21 contacts the wheel 11. The height adjustment device 23 is located in the middle of the adjustment rod 291 and can be adjusted by means of a screw. The lateral position and longitudinal position of the rotating hub 21 are adjusted by means of a lateral adjustment device 24 and a longitudinal adjustment device 25 so that the line connecting the center of the rotating hub 21 and the center of the wheel 11 is perpendicular to the ground. An adjustment rod 291 is installed on one side of the fixed base plate 29, which is adjusted by means of a screw in order to ensure the stability of the rotating hub 21. A fixing rod 292 is installed on the opposite side of the adjustment rod 291 to fix the rotating hub 21.

[0053] S140, the testing unit tests the braking noise according to the noise collected by the microphone, the road adhesion coefficient of the road simulation device, the vehicle load and the rotation speed change of the wheel.

[0054] The test method in this application also provides a test process and method basis for conducting passenger car noise testing. Taking into account different road adhesion coefficients and different wheel 11 speed changes, the brake noise is accurately tested in a noise environment close to the actual driving environment.

[0055] Optionally, before installing the brake disc and the brake caliper to be tested on the suspension support structure 1 , the following steps may be performed: adjusting the compression of the shock absorber 13 , adjusting the steering rod, and adjusting the stabilizer bar 14 according to the test requirements to simulate different load conditions. The vehicle load is input into the test unit 5 .

[0056] Optionally, during the test, the power source is used to control the rotation of the rotating hub 21 to simulate the relative movement between the ground and the wheel 11. The linear speed of the rotating hub 21 is sent to the test unit 5.

[0057] S140 specifically includes the following operations:

[0058] S141. The testing unit obtains audio features according to the noise collected by the microphone.

[0059] The audio data collected by multiple microphones 4 at the same time are averaged to extract the audio features, or the audio features are extracted from the audio data collected by one microphone 4. The audio features include but are not limited to time domain features and frequency domain features.

[0060] S142. The test unit collects in advance audio feature benchmark values ​​of multiple passenger cars under different road adhesion coefficients, different loads, different initial wheel speeds, and different decelerations within a set time period.

[0061] The set time length can be 3 minutes, 5 minutes, etc., which are defined according to needs. The default braking noise has the same audio characteristics within the set time length, which is the smallest unit for braking noise testing. The initial wheel speed is the wheel speed of the wheel 11 at the beginning of the set time length. The deceleration is the deceleration of the vehicle within the set time length. Calculate multiple audio feature reference values ​​of multiple vehicles under the same road adhesion coefficient, the same load, the same initial wheel speed and the same deceleration within the set time length, and average them to obtain the audio feature reference value corresponding to the road adhesion coefficient, load, initial wheel speed and deceleration, which reflects the average braking noise level of the vehicle under the above conditions. The audio feature reference value is related to the road adhesion coefficient, load, initial wheel speed and deceleration.

[0062] S143, fitting the road adhesion coefficient, load, initial wheel speed and deceleration within a set time period to obtain an audio feature reference value and obtain a fitting equation.

[0063] In order to accurately describe the corresponding relationship between the audio feature benchmark value and each condition (road adhesion coefficient, load, initial wheel speed and deceleration), and to reduce the number of tests, a linear fitting method is used to obtain the fitting equation. The independent variables are road adhesion coefficient, load, initial wheel speed and deceleration, and the dependent variable is the audio feature benchmark value, thereby obtaining the audio feature benchmark value under any conditions.

[0064] The fitting equation is stored in the database for subsequent brake noise testing.

[0065] S144: Input the road adhesion coefficient, load, initial wheel speed and deceleration within a set time period in the current test into the fitting equation to obtain a current audio feature reference value.

[0066] During this test, the road adhesion coefficient, load, initial wheel speed and deceleration within the set time, as well as the audio features within the set time are collected. The road adhesion coefficient, load, initial wheel speed and deceleration within the set time in the current test are input into the fitting equation to obtain the current audio feature benchmark value.

[0067] S145: If the audio feature does not exceed the current audio feature reference value, the brake noise test passes.

[0068] Assuming that the current audio feature reference value is the average loudness within the set time length, if the average loudness does not exceed the current audio feature reference value under the same conditions, the brake noise test passes. If the average loudness exceeds the current audio feature reference value under the same conditions, the brake noise test fails, that is, the tested brake disc and the tested brake caliper do not reach the industry average level.

[0069] In the actual test process, different loads may be applied to the wheel 11 , the road simulation device 22 may be wrapped with different materials, and different initial wheel speeds may be applied to the wheel 11 through the brake inertia platform 3 to achieve testing under different conditions.

[0070] Optionally, the road adhesion coefficient is not only related to the material and structure of the tire 12 and the road surface, but also affected by the vehicle speed, load, tire 12 air pressure and road surface conditions (such as dry, wet, waterlogged, ice and snow, etc.). During vehicle driving, the adhesion coefficient is a dynamically changing value, which changes with the increase in vehicle speed, the degree of sliding of the wheel 11 on the road surface and the change in road surface conditions. After research, it was found that during the braking process, the tire 12 both slides and rolls relative to the road surface. When the slip rate reaches a certain range (such as 15% to 20%), the braking force reaches the maximum value. At this time, the ratio of the tangential force to the normal reaction force on the tire 12 is the adhesion coefficient of the test road surface. This maximum value is usually called the peak adhesion coefficient.

[0071] Based on this, in order to conduct noise testing more accurately, this embodiment controls the rotation of the road feedback structure 2 through a power source to simulate different vehicle speeds. If the road feedback structure 2 and the wheel 11 have relative motion, the road adhesion coefficient changes. Before inputting the road adhesion coefficient, load, initial speed and deceleration within the set time length in the current test into the fitting equation, refer to the following formula to calculate the vehicle's slip rate S based on the linear speed of the hub 21 and the linear speed of the tire 12 within the set time length in the current test; determine the road adhesion coefficient based on the slip rate.

[0072] S = [linear speed of the hub 21 - linear speed of the tire 12) / linear speed of the hub 21] × 100%;

[0073] Among them, the linear speed of the hub 21 can be considered as the vehicle speed. When the road simulation device 22 on the drum moves with the tire 12, the linear speed of the tire 12 is equal to the linear speed of the hub 21, which is also equal to the vehicle speed; when the road simulation device 22 on the hub 21 and the tire 12 produce relative motion, the vehicle speed is different from the linear speed of the tire 12, resulting in slip. A positive slip rate indicates that the tire 12 is sliding, and a negative slip rate indicates that the tire 12 is pulling. The road adhesion coefficient (especially the longitudinal adhesion coefficient) shows a trend of first increasing and then decreasing with the increase of the slip rate. Generally, the maximum longitudinal adhesion coefficient is around 15% to 20%. When the wheel 11 is locked, the longitudinal adhesion coefficient is reduced, but it can still provide a large braking force. Therefore, this embodiment calculates the slip rate of the vehicle according to the linear speed of the hub 21 and the linear speed of the tire 12 within a set time, and then calculates the road adhesion coefficient according to the slip rate, which can improve the accuracy of the calculation of the road adhesion coefficient.

[0074] Optionally, during the test, the temperature of the brake disc being tested is collected by a brake disc temperature measuring device, and the temperature is sent to a control system; if the temperature exceeds a safety threshold, the control system brakes the inertia disc through a brake force system to brake the tire 12 and end the test.

[0075] The test method in this application also provides a test process and method basis for conducting passenger car noise testing, taking into account different road adhesion coefficients and different wheel 11 speed changes, and accurately testing the brake noise close to the actual driving environment. Furthermore, by simulating the vehicle speed through the rotation of the hub 21, the calculation of the road adhesion coefficient is optimized, making the noise test more accurate.

[0076] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0077] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A passenger car brake noise test device with suspension support and road feedback, characterized in that: include: Suspension support structure, road surface feedback structure, brake inertia table, microphone and test unit; The suspension support structure includes a wheel, a tire and a suspension component, and is used to install a brake disc and a brake caliper to be tested, and provide support force for the wheel; The road surface feedback structure includes a rotating hub and a road surface simulation device mounted on the rotating hub, wherein the road surface simulation device is in contact with the tire and is used to simulate the actual road surface, provide friction for the tire and support the wheel; the road surface simulation device includes a plurality of materials with different road surface adhesion coefficients; The brake inertia platform is connected to the tire and is used to provide rotational inertia for the tire; The microphone is located around the wheel and is used to collect noise during braking; The testing unit is used to obtain a testing result according to the noise collected by the microphone.

2. The device according to claim 1, characterized in that The suspension components include stabilizer bars and shock absorbers; Different loading conditions are simulated by adjusting the compression of the shock absorber.

3. The device according to claim 1, characterized in that The road surface feedback structure further includes a multi-degree-of-freedom adjustment device for adjusting the spatial position of the rotating hub; The multi-degree-of-freedom adjustment device includes a height adjustment device, a lateral adjustment device and a longitudinal adjustment device; The rotating hub is connected to the baffle plate through a bearing, and the baffle plate is a frame-shaped structure sleeved around the rotating hub; The bearing is connected to a power source, and drives the rotating hub to rotate under the action of the power source; or the rotating hub moves with the wheel.

4. The device according to claim 1, characterized in that The brake inertia platform includes a control system, a drive inertia system, a brake disc test spindle device, a brake force application system and a brake disc temperature measuring device; The control system is used to send control instructions to the brake force application system and the driving inertia system; An inertia disk is provided on the brake disc test spindle device, and the driving inertia system drives the inertia disk to rotate through the brake disc test spindle device in response to the control instruction; The brake force application system is arranged on one side of the brake disc test spindle device, and brakes the inertia disc in response to the control command; The brake disc temperature measuring device is arranged on one side of the brake disc test spindle device, and is used to detect the temperature change of the brake disc being tested.

5. The device according to claim 4, characterized in that The control system issues different control instructions through a set program, so that the brake inertia platform works according to a set speed, a set acceleration, a set deceleration, a set torque or a set pressure.

6. A method for testing brake noise of a passenger car with suspension support and road surface feedback, applicable to the device according to any one of claims 1 to 5, characterized in that: include: Install the brake disc and brake caliper to be tested on the suspension support structure; The road surface simulation device is mounted on the rotating hub; adjusting a position of a road surface feedback structure so that the road surface feedback structure contacts the wheel; The testing unit tests the braking noise according to the noise collected by the microphone, the road adhesion coefficient of the road simulation device, the vehicle load and the rotation speed change of the wheel.

7. The method according to claim 6, characterized in that Before installing the brake disc and brake caliper under test on the suspension support structure, it also includes: According to the test requirements, the compression of the shock absorber is adjusted to simulate different load conditions.

8. The method according to claim 7, characterized in that Also includes: During the test, the rotating hub is controlled to rotate by a power source to simulate the relative movement between the ground and the wheel.

9. The method according to any one of claims 6 to 8, characterized in that: The test unit tests the brake noise according to the noise collected by the microphone, the road adhesion coefficient of the road simulation device, the vehicle load and the rotation speed change of the wheel, including: The test unit obtains audio features based on the noise collected by the microphone; The test unit collects audio feature benchmark values ​​of multiple passenger cars under different road adhesion coefficients, different loads, different initial wheel speeds, and different decelerations within a set time. The road adhesion coefficient, load, initial wheel speed and deceleration within a set time are fitted to obtain the audio feature reference value and obtain the fitting equation; Inputting the road adhesion coefficient, load, initial wheel speed and deceleration within a set time in the current test into the fitting equation to obtain a current audio feature reference value; If the audio characteristic does not exceed the current audio characteristic baseline value, the brake noise test passes.

10. The method according to claim 9, characterized in that Before inputting the road adhesion coefficient, load, initial rotation speed and deceleration within the set time in the current test into the fitting equation, it also includes: The vehicle slip rate is calculated based on the linear speed of the rotating hub and the linear speed of the tire within the set time in the current test; The road adhesion coefficient is determined according to the slip ratio.

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