A method of bench brake noise simulation

Abstract

The application discloses a kind of test rig brake noise simulation methods, by collecting the objective data of whole vehicle brake noise as brake condition and brake noise condition;The percentage of brake noise condition and brake condition is used as the reference value of test rig simulation;In the test process, the condition of brake noise of test rig is extracted to obtain the actual brake noise condition, and the actual brake condition consistent with the actual brake noise condition in the whole test process is extracted to obtain the actual brake noise ratio;The actual brake noise ratio of the whole vehicle obtained by test is compared with the reference value of test rig simulation to evaluate, realize the simulation of test rig brake noise, the method of test rig brake noise simulation of the application can realize the correlation of whole vehicle and test rig, and the simulation result of test rig brake noise is close to the result of whole vehicle.

Description

Technical Field

[0001] This invention belongs to the field of automotive engineering technology and relates to a method for simulating braking noise on a test bench. Background Technology

[0002] The design and braking processes of vehicles require testing the functionality of prototype vehicles to prevent malfunctions and potential hazards after delivery. Research indicates that braking noise is closely related to braking conditions, such as initial braking speed, braking pressure, humidity, and temperature. Existing braking friction noise testing devices simply simulate actual braking conditions using the planar contact of two blocks. Therefore, in current technology, technicians often place the prototype vehicle on a test bench after setting it up and then test its various performance characteristics.

[0003] However, brake noise has long been a hot topic in after-sales service for OEMs, and existing vehicle and bench testing methods cannot effectively correlate them. The results of brake noise bench verification often differ significantly from those of the whole vehicle. At present, it is necessary to utilize the capabilities of bench testing to verify the braking road spectrum of the whole vehicle on the bench, and to conduct multiple verification iterations to make the bench verification results as close as possible to the whole vehicle results. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a method for simulating test bench braking noise, which realizes the simulation of test bench braking noise. The test bench braking noise simulation method of the present invention can link the whole vehicle and the test bench, and the test bench braking noise simulation results are close to the results of the whole vehicle.

[0005] This invention is achieved through the following technical solution:

[0006] A method for simulating bench braking noise includes,

[0007] S1, collect objective data on the braking noise of the whole vehicle as the braking condition, among which, objective data that can emit noise are used as the braking noise condition.

[0008] S2, the percentage of braking noise condition to braking condition is used as a reference value for bench simulation;

[0009] S3. During the test, the actual braking noise conditions of the vehicle are extracted to obtain the actual braking noise conditions. Then, the actual braking conditions that are consistent with the actual braking noise conditions during the entire test are extracted to obtain the actual braking noise ratio.

[0010] S4 compares and evaluates the actual braking noise ratio of the whole vehicle obtained from the test with the reference value of the bench simulation, thereby realizing the simulation of bench braking noise.

[0011] Preferably, the braking conditions include friction pad temperature, braking deceleration, initial braking speed, final braking speed, brake pipe pressure, ambient temperature, and ambient humidity.

[0012] Preferably, the test bench is operated according to the braking conditions. If the actual braking noise ratio obtained is close to the reference value simulated by the test bench, it indicates that the test bench braking noise simulation is effective.

[0013] Preferably, the extraction of the operating conditions in which braking noise occurs includes the extraction of noise spectrum and braking spectrum, wherein the noise spectrum is the number of times noise occurs on the test bench during the test, and the braking spectrum is the number of times the test bench brakes during the test.

[0014] Preferably, the method for simulating bench braking noise is adapted to high-frequency braking noise with a frequency greater than 3000Hz.

[0015] Preferably, the noise decibel value and noise frequency are used as the basis for judging noise, and a noise occurrence is recorded as a record of a decibel value ≥ 50dB.

[0016] Preferably, the specific process of extracting the actual braking noise condition is as follows: During the test, the braking condition, noise decibel value, and noise frequency are used as the basis for judging the noise. Based on the braking noise condition generated on the test bench, various parameters after the braking noise occurs in one cycle are extracted. These parameters are used as a reference point, and the parameters of the entire cycle are extracted again to obtain the actual braking noise condition.

[0017] Preferably, the cyclical operating conditions include mountain road conditions, urban conditions, suburban road conditions, highway conditions, reversing and parking conditions, and forward parking conditions.

[0018] Preferably, the calculated result of the number of noise occurrences / number of braking occurrences is compared with the reference value of the bench simulation. If the similarity is ≥70%, the verification is considered valid.

[0019] Preferably, the reference value for bench simulation is in the range of 22% to 26%.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] This invention discloses a method for simulating brake noise on a test bench. It collects objective data on the braking noise of the entire vehicle as braking conditions and braking noise conditions; uses the percentage of braking noise conditions to braking conditions as a reference value for the test bench simulation; during the test, the conditions where braking noise occurs on the test bench are extracted to obtain the actual braking noise conditions; then, the actual braking conditions consistent with the actual braking noise conditions throughout the entire test are extracted to obtain the actual braking noise ratio; the actual braking noise ratio of the entire vehicle obtained from the test is compared and evaluated with the reference value of the test bench simulation to achieve test bench braking noise simulation. This method of simulating brake noise on a test bench can link the entire vehicle and the test bench, and the results of the test bench braking noise simulation are close to the results of the entire vehicle.

[0022] Furthermore, the method for simulating brake noise on a test bench according to the present invention does not involve mold opening and other costs, and the implementation cost is relatively low. In particular, it can quickly reproduce brake noise on a test bench, especially for after-sales issues and brake noise rectification. The operation is simple and convenient.

[0023] Furthermore, the method for simulating braking noise of the present invention is adapted to high-frequency braking noise with a braking noise frequency of 3000Hz or higher. Attached Figure Description

[0024] Figure 1 A flowchart for simulating braking noise on a test bench;

[0025] Figure 2 The diagram shows the initial velocity distribution in the embodiment; Figure (a) shows the initial velocity of cycle condition 1, and Figure (b) shows the initial velocity of cycle condition 2. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] A method for simulating bench braking noise, characterized by comprising,

[0029] S1, collect objective data on the braking noise of the whole vehicle as the braking condition, among which, objective data that can emit noise are used as the braking noise condition.

[0030] S2, the percentage of braking noise condition to braking condition is used as a reference value for bench simulation;

[0031] S3. During the test, the actual braking noise conditions of the vehicle are extracted to obtain the actual braking noise conditions. Then, the actual braking conditions that are consistent with the actual braking noise conditions during the entire test are extracted to obtain the actual braking noise ratio.

[0032] S4 compares and evaluates the actual braking noise ratio of the whole vehicle obtained from the test with the reference value of the bench simulation, thereby realizing the simulation of bench braking noise.

[0033] The braking conditions include friction pad temperature, braking deceleration, initial braking speed, final braking speed, brake line pressure, ambient temperature, and ambient humidity.

[0034] If the actual braking noise obtained is close to the reference value simulated by the test bench, it indicates that the test bench braking noise simulation is effective.

[0035] Extracting the operating conditions where braking noise occurs includes noise spectrum extraction and braking spectrum extraction. The noise spectrum is the number of times noise occurs on the test bench during the test, and the braking spectrum is the number of times the test bench brakes during the test.

[0036] The method for simulating braking noise on a test bench is applicable to high-frequency braking noise with a frequency greater than 3000Hz; this patent defines noise above 3000Hz as high-frequency noise and noise below 3000Hz as low-frequency noise.

[0037] The noise decibel value and noise frequency are used as the basis for judging noise. A noise event is recorded as a record when the decibel value is ≥50dB.

[0038] The specific process of extracting the actual braking noise condition is as follows: During the test, the braking condition, noise decibel value and noise frequency are used as the basis for judging the noise. Based on the braking noise condition generated on the test bench, the parameters after the braking noise occurs in one cycle are extracted. The parameters are used as the reference point, and the parameters of the entire cycle are extracted again to obtain the actual braking noise condition.

[0039] The cycle conditions include mountain road conditions, urban conditions, suburban road conditions, highway conditions, reversing and parking conditions, and forward parking conditions.

[0040] The calculated number of noise occurrences / number of braking occurrences is compared with the reference value of bench simulation. If the similarity is ≥70%, the verification is considered valid.

[0041] The reference values ​​obtained from bench simulation experiments ranged from 22% to 26%.

[0042] Objective data on vehicle braking noise are collected, including: friction pad temperature, braking deceleration, initial braking speed, final braking speed, brake line pressure, ambient temperature, and ambient humidity. This data serves as the braking condition, and the conditions where noise occurs are designated as the braking noise condition. The braking noise condition is extracted, and then the braking condition consistent with the braking noise condition throughout the entire test process is extracted. The percentage of these two conditions (braking noise condition / braking condition) serves as a reference value for bench simulation. If the braking noise ratio is close to the reference value when the bench operates under the braking conditions, the benchmarking is effective. This condition can serve as the basis for bench simulation and as a verification method after addressing braking noise issues.

[0043] Figure 1 This is a schematic diagram illustrating the principle of the bench braking noise simulation method according to the present invention. Figure 1 The system shown includes: noise spectrum extraction, which extracts the number of noise occurrences; and braking spectrum extraction, which extracts the number of braking operations corresponding to the noise spectrum extraction. It can extract data for one or more cycles of operation throughout the entire test process. Data analysis shows that the braking conditions are basically consistent across cycles. The proportions described above are calculated as reference values. The cycle conditions include mountain roads, urban roads, suburban roads, highways, reversing and parking maneuvers, and forward parking maneuvers. The cycle path is 200 kilometers.

[0044] Extraction principles: 1. Weather: Including rainy, sunny, and foggy weather conditions; 2. Mileage: Initial, middle, and final stages; 3. Drivers: 3 drivers; 4. Subjective evaluation: Conditions with low driver subjective scores and frequent noise occurrences. For example... Figure 2 As shown in Figure (a), the initial velocity of cycle condition 1 is shown, and the initial velocity of cycle condition 2 is shown in Figure (b). The initial velocities of the two cycle conditions show a similar trend. Similarly, by selecting braking parameters, the noise spectrum can be confirmed, as shown in Table 1. After extracting the noise spectrum and braking spectrum, the ratio between the two can be calculated, i.e., the number of noise occurrences / the number of braking operations, as shown in Table 2. The reference values ​​in Table 2 are between 22% and 26%. Comparing the three cycle conditions, cycle b has a wider coverage in terms of ambient temperature and humidity, and the reference values ​​for the three cycles are relatively close. Therefore, 22% was ultimately selected as the reference value.

[0045] Table 1 shows the extraction parameters for the noise path spectrum.

[0046]

[0047]

[0048] Table 2 shows the calculated ratio of noise occurrences to braking frequency.

[0049] Loop count Noise count Total number of times percentage a 23 105 22％ b 15 67 22％ c 15 57 26％

[0050] This invention discloses a method for simulating brake noise on a test bench. This invention does not involve mold making or other costs, resulting in relatively low implementation costs. It simply adds a method, especially useful for after-sales issues and brake noise rectification, allowing for quick reproduction of brake noise on a test bench. Based on a reference value of 22%, the closer the test results are to 22%, the closer they are to the actual vehicle operating conditions. A contrast ratio of ≥70% indicates that the comparison is effective.

[0051] Preferred embodiment 1:

[0052] Note: The road test method for brake noise refers to the industry standard brake noise test method "Road Test Method and Evaluation of Brake Noise and Vibration of Passenger Cars" T / CAAMTB 17—2019

[0053] According to standard requirements, data collection was conducted using a brake noise road test device. The data collected included: braking deceleration (g), braking pressure (bar), braking speed (km / h), friction pad temperature (°C), ambient temperature (°C), and ambient humidity (%). Noise decibel (dB) and noise frequency (Hz) were used only as criteria for noise assessment; according to internal standards, a record of a decibel value ≥ 50 (dB) did not constitute one instance of noise.

[0054] Noise Road Test Process Description: Subjective and objective tests of braking noise were conducted on the mountain roads of Huangshan. At the start of the test, the noise acquisition equipment needed to be properly configured, and data was recorded throughout the test. Approximately 1000 braking cycles were performed on each mountain road, including mountain road, urban driving conditions, suburban road conditions, highway driving conditions, and reversing / forward parking maneuvers. The number of test cycles conformed to industry and company standards, and will not be elaborated upon in this patent.

[0055] Explanation of Table 1: The parameters in Table 1 represent the operating conditions under which braking noise occurs, primarily characterized by low speed and low deceleration, with the friction pad temperature at room temperature. The two sets of data in Table 1 represent noise occurring twice. The method for extracting braking noise mainly focuses on the noise decibel value and noise frequency. This process can be repeated to extract various parameters after one cycle of braking noise. Using these parameters as a baseline, similar parameters for the entire cycle are extracted again. Note 1: Due to the large number of braking operations, each parameter is provided within a range, for example: braking speed 8–10 km / h, deceleration 0.12–0.15g. Note 2: The extracted parameters are only those similar to the braking noise occurrence conditions. For example, if a noise occurs at a speed of 10 km / h, but no noise occurs at the next 10 km / h speed, the 10 km / h speed represents the total number of occurrences in Table 2. Other parameters can be extracted similarly to represent the total number of occurrences and the number of noise occurrences in Table 2. Therefore, this working condition can be used as a test bench to simulate braking noise conditions, and can be braked 1000 or 2000 times depending on the actual situation.

[0056] The result of the number of noise occurrences / number of braking occurrences is compared with 22%. If the similarity is ≥70%, the verification is considered valid.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A method for simulating braking noise on a test bench, characterized in that, include, S1, collect objective data on the braking noise of the whole vehicle as the braking condition, among which, objective data that can emit noise are used as the braking noise condition. S2, the percentage of braking noise condition to braking condition is used as a reference value for bench simulation; S3. During the test, the actual braking noise conditions of the vehicle are extracted to obtain the actual braking noise conditions. Then, the actual braking conditions that are consistent with the actual braking noise conditions during the entire test are extracted to obtain the actual braking noise ratio. S4 compares and evaluates the actual braking noise ratio of the whole vehicle obtained from the test with the reference value of the bench simulation, thereby realizing the simulation of bench braking noise.

2. The method for simulating bench braking noise according to claim 1, characterized in that, The braking conditions include friction pad temperature, braking deceleration, initial braking speed, final braking speed, brake line pressure, ambient temperature, and ambient humidity.

3. The method for simulating bench braking noise according to claim 1, characterized in that, If the actual braking noise obtained is close to the reference value simulated by the test bench, it indicates that the test bench braking noise simulation is effective.

4. The method for simulating bench braking noise according to claim 1, characterized in that, Extracting the operating conditions where braking noise occurs includes extracting the noise spectrum and the braking spectrum. The noise spectrum is the number of times noise occurs on the test bench during the test, and the braking spectrum is the number of times the test bench brakes during the test.

5. The method for simulating bench braking noise according to claim 1, characterized in that, The method for simulating braking noise on a test bench is suitable for high-frequency braking noise with a frequency greater than 3000Hz.

6. The method for simulating bench braking noise according to claim 1, characterized in that, The noise decibel value and noise frequency are used as the basis for judging noise. A noise event is recorded as a record when the decibel value is ≥50dB.

7. The method for simulating bench braking noise according to claim 1, characterized in that, The specific process for extracting the actual braking noise condition is as follows: During the test, the braking condition, noise decibel value, and noise frequency are used as the basis for judging the noise. Based on the braking noise condition generated on the test bench, various parameters after the braking noise occurs in one cycle are extracted. These parameters are used as a reference point, and the parameters of the entire cycle are extracted again to obtain the actual braking noise condition.

8. The method for simulating bench braking noise according to claim 7, characterized in that, The cyclical operating conditions include mountain road conditions, urban conditions, suburban conditions, highway conditions, reversing and parking conditions, and forward parking conditions.

9. The method for simulating bench braking noise according to claim 7, characterized in that, The calculated number of noise occurrences / number of braking occurrences is compared with the reference value of bench simulation. If the similarity is ≥70%, the verification is considered valid.

10. The method for simulating bench braking noise according to claim 1, characterized in that, The reference values ​​for bench simulation range from 22% to 26%.

Images