Vehicle braking noise testing method and system

Abstract

The invention provides a vehicle braking noise testing method and system, and relates to the technical field of noise testing, the braking noise testing method can automatically detect the braking noise, is suitable for a large number of limit working conditions, is comprehensive in scene, enriches the testing working conditions of the vehicle braking noise, and improves the precision of a testing result. And on the other hand, a unified evaluation standard is set for the noise test and is used for accurately measuring whether the braking performance is qualified or not, so that the pertinence and the accuracy of the braking noise test are further ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of noise testing, and particularly to a vehicle braking noise testing method and system. Background Art

[0003] Braking noise is closely related to people's daily use of vehicles, and different braking noises under various working conditions have attracted much attention. Braking noise is a very crucial performance among automotive noises. During driving, the braking noise generated during braking has a direct impact on the passengers inside the vehicle. The testing and evaluation of braking noise are of crucial engineering significance for optimizing braking noise.

[0004] In the existing technology, the only available testing and evaluation standards generally only target the test bench and do not involve the whole vehicle. As a result, on the one hand, the pertinence and accuracy of the evaluation of the whole vehicle cannot be guaranteed; on the other hand, it is not comprehensive enough and cannot cover all the working conditions of users, being too one-sided; thus, the accuracy of the results obtained by the braking noise testing scheme of the existing technology is insufficient. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide a vehicle braking noise testing method and system, which are used to solve the technical problem of insufficient accuracy of the results obtained by the braking noise testing scheme in the existing technology.

[0006] On the one hand, the present invention provides a vehicle braking noise testing method, including:

[0007] Obtaining the vehicle driving mileage to obtain the noise score according to a preset mileage interval, and respectively obtaining the test data of the drag torque test and the detection data of the brake disc end face runout according to multiple preset mileage values;

[0008] Judging whether the noise score is lower than a preset decibel value;

[0009] If not, respectively judging whether both the test data and the detection data are qualified;

[0010] If both the test data and the detection data are qualified, the current braking scheme meets the review standard and the braking system matching is completed;

[0011] If there is any unqualified in the test data and the detection data, the current braking scheme does not meet the review standard and the braking system needs to be rectified again.

[0012] The above vehicle braking noise test method can automatically detect braking noise by setting a braking noise test method. It is applicable to a large number of extreme working conditions with a comprehensive scenario, enriching the test working conditions of vehicle braking noise and improving the accuracy of test results. On the other hand, there is a unified evaluation standard for noise testing to accurately measure whether the braking performance is qualified, further ensuring the pertinence and accuracy of braking noise testing.

[0013] In addition, according to the above vehicle braking noise test method of the present invention, the following additional technical features may also be included:

[0014] Further, before the step of respectively determining whether the test data and the detection data are both qualified, it further includes:

[0015] Judging whether the noise score, the test data, and the detection data meet the standards through a centralized formula;

[0016] If the standards are met, then respectively determine whether the test data and the detection data are both qualified.

[0017] Further, in the step of obtaining the vehicle driving mileage to obtain the noise score according to the preset mileage interval, the noise score includes a cold-state noise score and a high-temperature noise score;

[0018] Among them, the noise score calculation formula is:

[0019]

[0020] In the formula, G represents the noise score; G l represents the evaluation score of the low-temperature noise that appears for the i-th time; G h represents the evaluation score of the high-temperature noise that appears for the h-th time; Z j represents the noise weighting value corresponding to the j-th type of noise; N 1 represents the total number of brakings for the evaluation.

[0021] Further, the step of obtaining the vehicle driving mileage to obtain the noise score according to the preset mileage interval includes:

[0022] The vehicle conducts 8 evaluations on the braking noise every 200 km of travel to obtain the noise score.

[0023] Further, the vehicle braking noise incidence rate calculation formula is:

[0024]

[0025] In the formula, P is the braking noise incidence rate; A x represents the number of times of generating braking noise greater than 30 dB in the x-th trip; Z yRepresent the noise weighting values corresponding to noises greater than 30 dB, 40 dB, and 50 dB; N 2 Represent the total number of brakes.

[0026] Further, in the step of respectively obtaining the test data of the drag torque test and the detection data of the brake disc end face runout according to multiple sets of mileage preset values, the method includes: The vehicle conducts the drag torque test twice every 1600 km, and the brake disc end face runout is detected once at the beginning and once at the end.

[0027] Further, the evaluation criteria include: When the full load mass of all vehicles < 3500 Kg, the incidence rate P of brake noise < 0.1%, where all vehicles include passenger cars, buses, trucks, and freight trucks;

[0028] When the full load mass of a single-tire vehicle ≥ 3500 Kg, the incidence rate P of brake noise < 1%;

[0029] When the full load mass of a double-tire vehicle ≥ 3500 Kg, the incidence rate P of brake noise < 1.5%;

[0030] The brake disc end face runout ≤ 18 μm;

[0031] The starting torque in the drag torque ≤ 6 N·m, and the rotational torque ≤ 4 N·m;

[0032] The comprehensive noise score G shall not be lower than 8 points.

[0033] On the other hand, the present invention provides a vehicle brake noise test system, and the system includes:

[0034] An acquisition module, configured to acquire the vehicle driving mileage to obtain a noise score according to a preset mileage interval, and respectively acquire the test data of the drag torque test and the detection data of the brake disc end face runout according to multiple sets of mileage preset values;

[0035] A judgment module, configured to judge whether the noise score is lower than a preset decibel value;

[0036] A first execution module, configured to respectively judge whether the test data and the detection data are both qualified when the noise score is not lower than the preset decibel value;

[0037] A second execution module, configured to when the test data and the detection data are both qualified, it means that the current brake scheme meets the evaluation criteria and the brake system matching is completed;

[0038] A third execution module, configured to when the test data and the detection data are unqualified, it means that the current brake scheme does not meet the evaluation criteria and the brake system needs to be rectified again. Description of the Drawings

[0039] Figure 1 It is a flowchart of the vehicle braking noise test method in the embodiment of the present invention;

[0040] Figure 2 It is a schematic structural diagram of a new type of tooling for end face runout detection in the embodiment of the present invention;

[0041] Description of compliance of main structural components:

[0042] Calipers 1 Fastening bolt 2 Movable connecting piece 3 Steel cable 4 Positioning rod 5 Capacitance probe mounting fixture 6 Capacitance probe mounting through-hole 7

[0043] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0044] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0046] In order to solve the technical problem of insufficient accuracy of the results obtained by the existing braking noise test scheme. The present application provides a vehicle braking noise test method. By setting a braking noise test method, automatic detection of braking noise can be performed, which is applicable to a large number of extreme working conditions, with a comprehensive scenario, enriching the test working conditions of vehicle braking noise and improving the accuracy of test results; on the other hand, there is a unified evaluation standard for noise testing to accurately measure whether the braking performance is qualified, further ensuring the pertinence and accuracy of the braking noise test.

[0047] To facilitate the understanding of the present invention, several embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0048] Embodiment 1

[0049] Please refer to Figure 1 , which shows the vehicle braking noise test method in the first embodiment of the present invention. The method includes steps S101 to S105:

[0050] S101. Obtain the vehicle driving mileage to obtain the noise score according to the preset mileage interval, and according to multiple sets of preset mileage values, respectively obtain the test data of the drag torque test and the detection data of the brake disc runout detection.

[0051] In this embodiment, the noise score includes a cold-state noise score and a high-temperature noise score. The vehicle evaluates the braking noise 8 times every 200 km of travel to obtain the noise score. The vehicle conducts two drag torque tests every 1600 km, and performs a brake disc runout detection at the beginning and end respectively.

[0052] As a specific example, the environmental temperature of the test site needs to be between 15°C and 25°C, the environmental humidity is not less than 80%, the mountainous area altitude is not less than 1200 m, and the entire test process involves mountain roads, suburban roads, and highways. Specifically, an acoustic microphone (frequency range: 6.3 Hz to 20 kHz) is arranged outside the main driver's ear; four single-axis acceleration sensors (frequency range: 0 kHz to 12 kHz) are respectively arranged on the vehicle calipers to monitor the caliper vibration; a deceleration sensor (range: ±1.0 g) and a temperature and humidity sensor (range: 0 rh-100% rh & -40°C to 60°C) are arranged on the vehicle to detect the environment and driving conditions; four thermocouples are respectively installed on the vehicle friction material to monitor the braking temperature. Prepare two brake pressure sensors (range: 0 MPa-20.684 MPa) to monitor the brake fluid pressure.

[0053] Further, set the trigger event parameters: First, it is necessary to understand the braking pressure when the vehicle braking system starts to work. Taking the initial braking pressure as the standard, when the braking pressure of any wheel is greater than the initial braking pressure, start recording data, and stop recording when the braking pressure drops to "initial braking pressure - 0.5 bar". Set that when there is any wheel vibration in the vehicle braking and the interior noise is coupled at the same frequency and the generated noise amplitude is higher than 30 dB, the system automatically captures this noise.

[0054] In this embodiment, the entire test route includes suburban roads, highways, and mountain roads. The braking temperature section during the driving process should include from the ambient temperature to 300°C, and the number of braking times is 450 - 500 times. The driving mileage of suburban roads, highways, and mountain roads respectively accounts for 20%, 20%, and 60%. The total driving mileage of the entire process is 8000 km, and 40 test trips are carried out. Specifically, the formula for calculating the vehicle braking noise incidence rate is:

[0055]

[0056] In the formula, P is the braking noise incidence rate; A x represents the number of times of generating braking noise greater than 30 dB in the x-th trip; Z yIndicates the noise weighting values corresponding to noises greater than 30 dB, 40 dB, and 50 dB; N 2 Indicates the total number of brakings.

[0057] The vehicle is parked outdoors throughout the whole journey. In the morning when the vehicle has not been braked, a cold-state noise assessment is first carried out. The first 10 - 48 brakings need to be evaluated separately to distinguish and highlight the early morning cold noise. Then the Groan noise is evaluated on slopes of 18% and 12%. After completion, a daily assessment is carried out. The forward, reverse, left front, right front, left rear, and right rear brakings are each carried out twice and scored. The scoring criteria are shown in Table 1. The entire test route is 200 km, and a daily assessment is carried out every about 40 km. The two evaluation points on the mountainous winding road need to be evaluated twice, namely the high-temperature braking assessment and the low-temperature assessment below 100 °C. The noise scoring calculation formula is:

[0058]

[0059] In the formula, G represents the noise score; G l represents the evaluation score of the low-temperature noise that appears for the i-th time; G h represents the evaluation score of the high-temperature noise that appears for the h-th time; Z j represents the noise weighting value corresponding to the j-th type of noise; N 1 represents the total number of brakings for the evaluation.

[0060] Table 1: Scoring criteria table

[0061]

[0062]

[0063] The brake disc end face runout test is carried out at 0 km and 8000 km of mileage. After that, the drag torque tests are carried out at 0 km, 400 km, 1600 km, 2000 km, 3200 km, 3600 km, 4800 km, 5200 km, 6400 km, 6800 km, and 8000 km respectively. The new tooling is used for the end face runout detection. As Figure 2 shown, the new tooling includes a caliper 1, a fastening bolt 2, a movable connecting piece 3, a steel cable 4, a positioning rod 5, a capacitance probe mounting fixture 6, and a capacitance probe mounting through hole 7. The tooling can be installed at any position through the caliper 1. By tightening the fastening bolt 2 to tighten the steel cable 4, the movable connecting piece 3 can be fixed. The capacitance probe mounting inner and outer fixtures 6 are installed at the end of the positioning rod 5. There are two capacitance probe mounting through holes 7 on the capacitance probe mounting fixture 6 for installing capacitance probes. When detecting the end face runout, the capacitance probe mounting fixture 6 can be rotated to detect the DTV (Dimensional Technical Variance, hereinafter referred to as DTV) at three positions of the inner, middle, and outer of the brake disc.

[0064] S102. Determine whether the noise score is lower than the preset decibel value.

[0065] If the noise score is not lower than the preset decibel value, then step S103 is executed; if the noise score is lower than the preset decibel value, then step S105 is executed; specifically, as a specific example, the preset decibel value is 7 dB. When the braking noise with a score lower than 7 dB appears, the braking system needs to be rectified again. If there is no braking noise lower than 7 dB, it is necessary to respectively determine whether the test data and the detection data are both qualified.

[0066] S103. Respectively determine whether the test data and the detection data are both qualified.

[0067] In this embodiment, before the step of respectively determining whether the test data and the detection data are both qualified, it also includes: judging whether the noise score, the test data and the detection data meet the standards through the centralized formula; if they meet the standards, then respectively determine whether the test data and the detection data are both qualified; if they do not meet the standards, then rectify the braking system again.

[0068] If the test data and the detection data are both qualified, then step S104 is executed;

[0069] If there are unqualified test data and detection data, then step S105 is executed;

[0070] S104. The current braking scheme reaches the review standard, and the braking system matching is completed.

[0071] S105. The current braking scheme does not reach the review standard, and the braking system is rectified again.

[0072] In this embodiment, the review standards include: when the full load mass of all vehicles < 3500 Kg, the incidence rate P of braking noise < 0.1%, where all vehicles include passenger cars, buses, trucks and freight trucks; when the full load mass of single-tire vehicles ≥ 3500 Kg, the incidence rate P of braking noise < 1%; when the full load mass of double-tire vehicles ≥ 3500 Kg, the incidence rate P of braking noise < 1.5%; the end face runout of the brake disc ≤ 18 μm; the starting torque in the drag torque ≤ 6 N·m, and the rotational torque ≤ 4 N·m; the comprehensive noise score G shall not be lower than 8 points.

[0073] In summary, for the vehicle braking noise test method in the above embodiments of the present invention, by setting a braking noise test method, it can automatically detect the braking noise, is applicable to a large number of extreme working conditions, has a comprehensive scenario, enriches the test working conditions of vehicle braking noise, and improves the accuracy of the test results; on the other hand, there is a unified evaluation standard for the noise test, which is used to accurately measure whether the braking performance is qualified, and further ensures the pertinence and accuracy of the braking noise test.

[0074] Embodiment 2

[0075] The second embodiment of the present invention provides a vehicle braking noise test system, including:

[0076] An acquisition module, configured to acquire the vehicle driving mileage to obtain a noise score according to a preset mileage interval, and respectively acquire test data of the drag torque test and detection data of the brake disc end face runout according to multiple sets of preset mileage values;

[0077] A judgment module, configured to judge whether the noise score is lower than a preset decibel value;

[0078] A first execution module, configured to respectively judge whether the test data and the detection data are both qualified when the noise score is not lower than the preset decibel value;

[0079] A second execution module, configured to indicate that the current braking scheme meets the review standard and the braking system matching is completed when the test data and the detection data are both qualified;

[0080] A third execution module, configured to indicate that the current braking scheme does not meet the review standard and the braking system needs to be rectified again when the test data and the detection data are unqualified.

[0081] In summary, the vehicle braking noise test system in the above embodiments of the present invention can automatically detect braking noise by setting a braking noise test method, is applicable to a large number of extreme working conditions, has a comprehensive scenario, enriches the test working conditions of vehicle braking noise, and improves the accuracy of test results; on the other hand, there is a unified evaluation standard for noise testing to accurately measure whether the braking performance is qualified, further ensuring the pertinence and accuracy of the braking noise test.

[0082] The logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device.

[0083] It should be understood that each part of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one of the following techniques known in the art or a combination thereof can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0085] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A vehicle braking noise testing method, characterized in that: include: Obtaining the vehicle mileage to obtain a noise score according to a preset mileage interval, and obtaining test data of a drag torque test and test data of a brake disc end face runout test according to multiple sets of mileage preset values; Determining whether the noise score is lower than a preset decibel value; If not, determining whether the test data and the detection data are both qualified; If the test data and the detection data are both qualified, the current braking scheme meets the review criteria and the braking system matching is completed; If the test data and the detection data are unqualified, the current braking scheme does not meet the review standards and the braking system is rectified.

2. The vehicle brake noise testing method according to claim 1, characterized in that: Before the step of respectively judging whether the test data and the detection data are both qualified, the step further includes: Determining whether the noise score, the test data, and the detection data meet the standard by a centralized formula; If the standard is met, it is determined whether the test data and the detection data are both qualified.

3. The vehicle brake noise testing method according to claim 1, characterized in that: In the step of obtaining the vehicle mileage to obtain a noise score according to a preset mileage interval, the noise score includes a cold state noise score and a high temperature noise score; The noise score calculation formula is: Where G represents the noise score; G l represents the evaluation score of the low-temperature noise that occurs for the i-th time; G h represents the evaluation score of the high temperature noise that occurs for the hth time; Z j represents the noise weighted value corresponding to the jth noise; N1 represents the total number of brakes evaluated.

4. The vehicle brake noise testing method according to claim 3, characterized in that: The steps of obtaining vehicle mileage to obtain noise scores based on preset mileage intervals include: The brake noise was evaluated eight times every 200 km of vehicle travel to obtain the noise score.

5. The vehicle brake noise testing method according to claim 4, characterized in that: The calculation formula for the occurrence rate of vehicle brake noise is: Where, P is the occurrence rate of brake noise; A x Indicates the number of times a braking noise greater than 30dB is generated in the xth stroke; Z y It represents the noise weighted value corresponding to noise greater than 30dB, 40dB and 50dB; N2 represents the total braking number.

6. The vehicle brake noise testing method according to claim 1, characterized in that: In the steps of respectively obtaining test data of the drag torque test and the brake disc end face runout detection according to multiple sets of mileage preset values, the method includes: performing two drag torque tests on the vehicle every 1600 km, and performing a brake disc end face runout detection once at the beginning and end respectively.

7. The vehicle brake noise testing method according to claim 5, characterized in that: The evaluation criteria include: when the fully loaded mass of all vehicles is less than 3500Kg, the occurrence rate of brake noise is less than 0.1%, among which all vehicles include passenger cars, buses, trucks and vans; When the fully loaded mass of a single-tire vehicle is ≥3500Kg, the occurrence rate of brake noise P is less than 1%; When the full load mass of a dual-tire vehicle is ≥3500Kg, the occurrence rate of brake noise P is less than 1.5%; Brake disc end face runout ≤18μm; The initial torque of the drag torque is ≤6N·m, and the rotation torque is ≤4N·m; The comprehensive noise score G shall not be less than 8 points.

8. A vehicle brake noise testing system, characterized in that: The system comprises: An acquisition module, used to acquire the vehicle mileage to acquire the noise score according to a preset mileage interval, and to acquire the test data of the drag torque test and the test data of the brake disc end face runout test according to multiple sets of mileage preset values; A judgment module, used to judge whether the noise score is lower than a preset decibel value; A first execution module, configured to determine whether the test data and the detection data are both qualified when the noise score is not lower than a preset decibel value; A second execution module is used for, when the test data and the detection data are both qualified, the current braking scheme meets the review standard and the braking system matching is completed; The third execution module is used to correct the braking system when the test data and the detection data are unqualified and the current braking scheme does not meet the review standard.

Images