Braking squeal evaluation method and braking squeal evaluation device
Through the automated braking and howling evaluation method, the noise evaluation index is calculated using vibration signals and noise signal data, which solves the problem of relying on professional equipment and personnel on brake and howling testing is carried out, and costs and efficiency improvements are achieved.
Patent Information
- Application Number
- CN202411277958.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-12
- Publication Date
- 2025-01-07
AI Technical Summary
Automobile brake whistling tests and evaluations require multiple tests under multiple operating conditions, relying on the participation of professional testing equipment and professional personnel, resulting in excessive labor and material cost for testing and evaluation.
Provide a braking howling evaluation method, by obtaining the vibration signal data, noise signal data and braking stroke information of the vehicle, performing energy detection and effectiveness judgment, and calculate the antonal protrusion ratio of the noise signal and the braking howling generation of the braking. The number of times is to calculate the noise evaluation index of the vehicle, and use the acquisition module, calculation module and evaluation module to achieve automated evaluation.
It reduces the testing cost and reduces manpower and material investment. The evaluation of braking can be completed through data calculation and analysis, which is more cost-effective than traditional testing methods.
Smart Images
Figure CN119268832A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of automobile noise analysis, and in particular to a brake squeal evaluation method and a brake squeal evaluation device. Background Art
[0002] The high-frequency friction squeal of automobile brakes has always been a hot and difficult issue in the automotive industry and academia. It not only has a serious impact on the comfort and environmental performance of the car, but also seriously damages the market reputation of the product, often resulting in huge losses. Therefore, the control level of friction squeal of brakes has become an important indicator of the design and development level of automobile brakes, and has been highly valued by the industry. The noise of the braking system can be divided into low-frequency noise and medium-high frequency noise. Usually, noise below 1,000 Hz is called low-frequency noise, and noise above 1,000 Hz is called medium-high frequency noise, often called squeal noise. Squeal noise mainly occurs when the brake pedal is lightly pressed at low speed, and is greatly affected by the environment, and is often complained by customers. The mechanism of squeal noise generation is complex, mainly involving stick-slip mechanism, self-locking-sliding theory, modal coupling theory, hammering theory and unified theory, etc. It is often improved and optimized by modifying the structure of the brake pad and adding silencers. However, noise testing is required before improving and optimizing the braking system.
[0003] In the related technology, brake noise test is divided into bench test and vehicle test. The bench test adopts the internationally accepted SAEJ2521 standard for bench noise test. The vehicle test is generally carried out on urban and mountain roads to subjectively and objectively evaluate the overall brake noise level of the car. Brake noise test requires not only professional test equipment but also professional personnel. However, due to the large number of working conditions and the large number of tests, the recorded data is huge, resulting in high test equipment investment and labor costs. Summary of the invention
[0004] Regarding the related technologies, the automobile brake squeal test and evaluation requires multiple tests under various working conditions, and the brake squeal test and evaluation test rely on professional testing equipment and the participation of professionals, resulting in the problem of excessively high manpower and material costs for the test and evaluation.
[0005] In a first aspect, an embodiment of the present application provides a brake squeal evaluation method, the brake squeal evaluation method comprising:
[0006] Obtaining vibration signal data, noise signal data and braking stroke information of the vehicle;
[0007] Perform energy detection on the vibration signal data and the noise signal data, and obtain the number of times the brake squeal occurs according to the energy detection result and the braking stroke information;
[0008] The abnormal sound prominence ratio of the noise signal data is calculated, and the noise evaluation index of the vehicle is calculated based on the abnormal sound prominence ratio and the number of times brake squeal occurs.
[0009] In combination with the first aspect, in one implementation, after obtaining the vibration signal data and the noise signal data of the vehicle, the method further includes:
[0010] The validity of the vibration signal data and the noise signal data is judged to obtain first valid vibration signal data and first valid noise signal data.
[0011] In combination with the first aspect, in one implementation, the performing validity judgment on the vibration signal data and the noise signal data to obtain first valid vibration signal data and first valid noise signal data includes:
[0012] The signal data of vibration and noise are subjected to high-pass filtering to obtain first effective vibration signal data and first effective noise signal data that meet a preset frequency threshold.
[0013] In combination with the first aspect, in one implementation, the performing energy detection on the vibration signal data and the noise signal data includes:
[0014] Normalizing the first vibration signal data and the first noise signal data to obtain second vibration signal data and second noise signal data;
[0015] Dividing the second vibration signal data and the second noise signal data into a plurality of short frames of equal length respectively;
[0016] The short-time energy of each frame of the second vibration signal data and the second noise signal data is calculated.
[0017] In combination with the first aspect, in one implementation, obtaining the braking travel information of the vehicle includes:
[0018] According to the vehicle braking system parameters, the total number of active braking times and the corresponding times during the vehicle's driving process are recorded.
[0019] In combination with the first aspect, in one implementation, obtaining the number of times brake squeal occurs according to the energy detection result and the brake stroke information includes:
[0020] Set the vibration signal threshold and noise signal threshold;
[0021] The short-time energy data of each frame is screened according to the vibration signal threshold, noise signal threshold and braking stroke information;
[0022] When the short-time energy of the second vibration signal data and the second noise signal data in the frame is respectively greater than the vibration signal threshold and the noise signal threshold, and the braking stroke information at the corresponding moment of the short frame shows that there is an active braking action, the short frame is recorded as a brake squeal.
[0023] In combination with the first aspect, in one implementation, calculating the unusual sound prominence ratio of the noise signal data includes: calculating the unusual sound prominence ratio of the second noise signal data in each short frame.
[0024] In combination with the first aspect, in one implementation, the calculating of the vehicle noise evaluation index according to the abnormal sound prominence ratio and the number of brake squeals comprises:
[0025] The noise evaluation index s(I) is calculated according to the formula:
[0026]
[0027] Where N j is the number of times brake squeal occurs, N B is the total number of vehicle braking times in the braking stroke information, s i (PR) is the noise prominence ratio of each frame of noise signal.
[0028] In combination with the first aspect, in one implementation, the obtaining of the vibration and noise signal data and the braking stroke information of the vehicle further includes:
[0029] A vibration sensor is provided on the vehicle brake, and microphones are arranged in the near field of the vehicle brake disc and / or at the ear points of the driver and passengers in the vehicle;
[0030] Perform vehicle or bench tests on the vehicle and collect vibration signal data, noise signal data, and brake travel information.
[0031] In a second aspect, an embodiment of the present application provides a brake squeal evaluation device, which includes:
[0032] An acquisition module, which is used to obtain vibration and noise signal data and braking stroke information of the vehicle;
[0033] A calculation module, which is used to perform energy detection on the vibration signal data and the noise signal data, and obtain the number of times the brake squeal occurs according to the energy detection result and the braking stroke information;
[0034] The evaluation module is used to calculate the noise prominence ratio of the noise signal data, and calculate the vehicle noise evaluation index according to the noise prominence ratio and the number of brake squeals.
[0035] The beneficial effects brought by the technical solution provided by the embodiments of the present application include:
[0036] By collecting vibration signal data, noise signal data and brake stroke information on the vehicle, the number of brake squeals generated during the vehicle test is automatically calculated and analyzed, and the evaluation index for evaluating brake squeals is obtained based on the noise data's abnormal sound prominence ratio and the number of brake squeals generated. This application does not rely on professional equipment and professional personnel, and the evaluation of brake squeals can be completed only through data calculation and analysis. Compared with traditional testing methods, it is less costly and requires less manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Figure 1 This is a flow chart of the first embodiment of the brake squeal evaluation method of the present application;
[0038] Figure 2 This is a schematic diagram of the hardware structure of the brake squeal evaluation device involved in the embodiment of the present application. DETAILED DESCRIPTION
[0039] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0040] Regarding the related technologies, the automobile brake squeal test and evaluation requires multiple tests under various working conditions, and the brake squeal test and evaluation test rely on professional testing equipment and the participation of professionals, resulting in the problem of excessively high manpower and material costs for the test and evaluation.
[0041] In a first aspect, the present application provides a brake squeal evaluation method, the brake squeal evaluation method comprising:
[0042] Step S1, obtaining vibration signal data, noise signal data and braking stroke information of the vehicle.
[0043] In some specific implementations, the above step S1 includes:
[0044] Step S1a: a vibration sensor is provided on the vehicle brake, and microphones are arranged in the near field of the vehicle brake disc and / or at the ear points of the driver and passengers in the vehicle.
[0045] It is understandable that in the bench or vehicle brake noise test, a vibration sensor is attached to the brake. For bench testing, a microphone can be arranged in the near field of the brake disc, and for vehicle testing, a microphone can be arranged at the ear point of the driver and passenger in the vehicle.
[0046] Step S1b: perform a vehicle or bench test on the vehicle and collect vibration signal data, noise signal data and braking travel information.
[0047] Specifically, a brake noise test is performed according to the test requirements, and the vibration sensor data a1 and the microphone noise data s1 are recorded during the entire test process.
[0048] Furthermore, according to the vehicle braking system parameters, the total number of active braking times and the corresponding time during the vehicle driving process are recorded. The specific recording process includes: recording the braking stroke information B1 of the brake pedal during the test to determine whether braking is performed. B1 can be used to determine whether braking is performed based on the relevant parameters of the braking system, which can be parameters such as the brake light switch signal, brake oil pressure, and brake pedal stroke. In this example, the brake light switch signal is used for analysis, which can be simply recorded as:
[0049]
[0050] The total number of braking times N can be obtained based on the braking stroke information B1. B , and the travel time node corresponding to each active braking.
[0051] Step S1c: judging the validity of the vibration signal data and the noise signal data to obtain first valid vibration signal data and first valid noise signal data.
[0052] Specifically, the validity judgment process includes: performing high-pass filtering on the vibration and noise signal data to obtain first valid vibration signal data and first valid noise signal data that meet a preset frequency threshold.
[0053] Optionally, the process of high-pass filtering the signal data of vibration and noise includes: filtering through a high-pass filter H(f) to obtain second vibration signal data a2 and second noise signal data s2, and the specific calculation formula includes:
[0054]
[0055] Among them, f c is the cutoff frequency of the high-pass filter, and f is the frequency of the signal.
[0056] It is worth noting that during the brake noise test, the brake disc DVT jump or road impact has a great impact on the signal, so the above signal needs to be screened during the test calculation. The main frequency component of brake noise is generally above 1,000 Hz, so high-pass filtering can be used to effectively screen it.
[0057] Step S2: Perform energy detection on the vibration signal data and the noise signal data.
[0058] In some specific implementation manners, the vibration signal data and the noise signal data are processed in the same manner in the above step S2. The vibration signal processing process in step S2 of the present application includes:
[0059] Step S2a, normalizing the first vibration signal data and the first noise signal data to obtain second vibration signal data and second noise signal data.
[0060] Specifically, in order to simplify the subsequent calculation and analysis process, the amplitude of the second vibration signal data a2 is normalized to the interval [-1, 1] to obtain the processed data a(n).
[0061]
[0062] In the formula, n is the amount of signal data, mean[a2] is the average value of the signal absolute value, and max|a2| is the maximum value of the signal absolute value.
[0063] Step S2b, dividing the second vibration signal data and the second noise signal data into a plurality of short frames of equal length respectively.
[0064] Specifically, the data a(n) is divided into several short frames (10-30ms) of equal length, and the data length of each frame is N, which is recorded as
[0065] a i (m) = a[(i-1)M+N]
[0066] Where i is the number of frames and M is the overlap ratio, which can generally be taken as 50%.
[0067] Step S2c, calculating the short-time energy of each frame of the second vibration signal data and the second noise signal data.
[0068] Specifically, the short-time energy calculation process includes: calculating the short-time energy of each frame of data after framing according to the following formula:
[0069]
[0070] Similarly, the short-time energy E of the noise can be obtained si .
[0071] Step S3: Obtain the number of times brake squeal occurs according to the energy detection result and the brake stroke information.
[0072] Step S3a, setting the vibration signal threshold E a0 and noise signal threshold E s0 .
[0073] Step S3b: screening the short-time energy data of each frame according to the vibration signal threshold, the noise signal threshold and the braking stroke information.
[0074] Specifically, the brake squeal judgment screening process includes: when the short-time energy E of the second vibration signal data in a short frame is ai and the short-time energy E of the second noise signal data si Respectively greater than the vibration signal threshold E a0 , noise signal threshold E s0 , and the braking stroke information at the corresponding moment of the short frame shows that there is an active braking action, then the short frame is recorded as a braking howl. ai ≥E a0 And E si ≥E s0 At the same time, B1=1 at the corresponding moment, that is, when active braking occurs, it is determined that there is brake squeal at this time. Record each brake squeal, and then analyze the data to obtain the number of brake squeals N. j .
[0075] It is worth noting that the present application obtains the time node of each brake squeal through data analysis, so that the number of squeals generated can be automatically obtained during the test, which is convenient for squeal evaluation.
[0076] Step S4, calculating the abnormal sound prominence ratio of the noise signal data, and calculating the noise evaluation index of the vehicle according to the abnormal sound prominence ratio and the number of times the brake squeal occurs.
[0077] The above step S4 comprises:
[0078] Step S4a, calculating the abnormal sound prominence ratio of the second noise signal data in each short frame divided in the above step S2b.
[0079] Specifically, brake noise is the most direct way for drivers and passengers to feel vibration and noise during braking, so the evaluation is mainly conducted on the noise signal. The PR (Prominence Ratio) value of each frame of the noise signal is calculated according to the following formula.
[0080]
[0081] Where B is the energy of the middle bandwidth, A and C are the energies of the left bandwidth and the right bandwidth respectively. For related calculations, see the international standard ECMA-74.
[0082] Step S4b, calculate the noise evaluation index s(I) according to the formula:
[0083]
[0084] Where N j is the number of times brake squeal occurs, N B is the total number of vehicle braking times in the braking stroke information, s i(PR) is the noise prominence ratio of each frame of noise signal.
[0085] It should be noted that brake squeal can be evaluated according to the noise evaluation index.
[0086] It is worth noting that the above steps S1-S4 are an embodiment provided by the present application. When used in practice, the order of some steps may be changed as needed.
[0087] In a second aspect, the embodiment of the present application further provides a brake squeal evaluation device, which includes: a collection module, a calculation module and an evaluation module; wherein:
[0088] An acquisition module is used to obtain the vibration and noise signal data and braking stroke information of the vehicle; a calculation module is used to perform energy detection on the vibration signal data and the noise signal data, and obtain the number of brake squeals based on the energy detection results and the braking stroke information; an evaluation module is used to calculate the abnormal sound prominence ratio of the noise signal data, and calculate the noise evaluation index of the vehicle based on the abnormal sound prominence ratio and the number of brake squeals.
[0089] In conjunction with the second aspect, in some optional implementation modes, the acquisition process of the acquisition module includes:
[0090] Step A1: a vibration sensor is provided on the vehicle brake, and microphones are arranged in the near field of the vehicle brake disc and / or at the ear points of the driver and passengers in the vehicle.
[0091] It is understandable that in the bench or vehicle brake noise test, a vibration sensor is attached to the brake. For bench testing, a microphone can be arranged in the near field of the brake disc, and for vehicle testing, a microphone can be arranged at the ear point of the driver and passenger in the vehicle.
[0092] Step A2: Perform a vehicle or bench test on the vehicle and collect vibration signal data, noise signal data, and braking travel information.
[0093] Specifically, a brake noise test is performed according to the test requirements, and the vibration sensor data a1 and the microphone noise data s1 are recorded during the entire test process.
[0094] Furthermore, according to the vehicle braking system parameters, the total number of active braking times and the corresponding time during the vehicle driving process are recorded. The specific recording process includes: recording the braking stroke information B1 of the brake pedal during the test to determine whether braking is performed. B1 can be used to determine whether braking is performed based on the relevant parameters of the braking system, which can be parameters such as the brake light switch signal, brake oil pressure, and brake pedal stroke. In this example, the brake light switch signal is used for analysis, which can be simply recorded as:
[0095]
[0096] The total number of braking times N can be obtained based on the braking stroke information B1. B , and the travel time node corresponding to each active braking.
[0097] Step A3: judge the validity of the vibration signal data and the noise signal data to obtain first valid vibration signal data and first valid noise signal data.
[0098] Specifically, the validity judgment process includes: performing high-pass filtering on the vibration and noise signal data to obtain first valid vibration signal data and first valid noise signal data that meet a preset frequency threshold.
[0099] Optionally, the process of high-pass filtering the signal data of vibration and noise includes: filtering through a high-pass filter H(f) to obtain second vibration signal data a2 and second noise signal data s2, and the specific calculation formula includes:
[0100]
[0101] Among them, f c is the cutoff frequency of the high-pass filter, and f is the frequency of the signal.
[0102] It is worth noting that during the brake noise test, the brake disc DVT jump or road impact has a greater impact on the signal, so the above signal needs to be screened during the test calculation. The main frequency component of brake noise is generally above 1,000 Hz, so high-pass filtering can effectively screen it.
[0103] Furthermore, the calculation process of the calculation module includes:
[0104] Step B1, normalize the first vibration signal data and the first noise signal data to obtain second vibration signal data and second noise signal data.
[0105] Specifically, in order to simplify the subsequent calculation and analysis process, the amplitude of the second vibration signal data a2 is normalized to the interval [-1, 1] to obtain the processed data a(n).
[0106]
[0107] In the formula, n is the amount of signal data, mean[a2] is the average value of the signal absolute value, and max|a2| is the maximum value of the signal absolute value.
[0108] Step B2: Divide the second vibration signal data and the second noise signal data into a plurality of short frames of equal length respectively.
[0109] Specifically, the data a(n) is divided into several short frames (10-30ms) of equal length, and the data length of each frame is N, which is recorded as
[0110] a i (m) = a[(i-1)M+N]
[0111] Where i is the number of frames and M is the overlap ratio, which can generally be taken as 50%.
[0112] Step B3: Calculate the short-time energy of each frame of the second vibration signal data and the second noise signal data.
[0113] Specifically, the short-time energy calculation process includes: calculating the short-time energy of each frame of data after framing according to the following formula:
[0114]
[0115] Similarly, the short-time energy E of the noise can be obtained si .
[0116] Step B4: Setting the vibration signal threshold E a0 and noise signal threshold E s0 .
[0117] Step B5: screening the short-time energy data of each frame according to the vibration signal threshold, the noise signal threshold and the braking stroke information.
[0118] Specifically, the brake squeal judgment screening process includes: when the short-time energy E of the second vibration signal data in a short frame is ai and the short-time energy E of the second noise signal data si Respectively greater than the vibration signal threshold E a0 , noise signal threshold E s0 , and the braking stroke information at the corresponding moment of the short frame shows that there is an active braking action, then the short frame is recorded as a braking squeal. ai ≥E a0 And E si ≥E s0 At the same time, B1=1 at the corresponding moment, that is, when active braking occurs, it is determined that there is brake squeal at this time. Record each brake squeal, and then analyze the data to obtain the number of brake squeals N j .
[0119] It is worth noting that the present application obtains the time node of each brake squeal through data analysis, so that the number of squeals generated can be automatically obtained during the test, which is convenient for squeal evaluation.
[0120] Furthermore, the evaluation process of the evaluation module includes:
[0121] Step C1, calculating the abnormal sound prominence ratio of the second noise signal data in each short frame divided in the above step S2b.
[0122] Specifically, brake noise is the most direct way for drivers and passengers to feel vibration and noise during braking, so the evaluation is mainly conducted on the noise signal. The PR (Prominence Ratio) value of each frame of the noise signal is calculated according to the following formula.
[0123]
[0124] Where B is the energy of the middle bandwidth, A and C are the energies of the left bandwidth and the right bandwidth respectively. For related calculations, see the international standard ECMA-74.
[0125] Step C2: Calculate the noise evaluation index s(I) according to the formula:
[0126]
[0127] Where N j is the number of times brake squeal occurs, N B is the total number of vehicle braking times in the braking stroke information, s i (PR) is the noise prominence ratio of each frame of noise signal.
[0128] Among them, the functional implementation of each module in the above-mentioned brake squeal evaluation device corresponds to the various steps in the above-mentioned brake squeal evaluation method embodiment, and its functions and implementation processes are no longer repeated here.
[0129] In a third aspect, an embodiment of the present application provides a brake squeal evaluation device, which may be a device with data processing function, such as a personal computer (PC), a laptop computer, or a server.
[0130] Reference Figure 2 , Figure 2 Schematic diagram of the hardware structure of the brake squeal evaluation device involved in the embodiment of the present application. In the embodiment of the present application, the brake squeal evaluation device may include a processor, a memory, a communication interface and a communication bus.
[0131] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.
[0132] The communication interface includes input / output (I / O) interface, physical interface and logical interface, etc., which are used to realize the interconnection of devices inside the AAAA device, and the interface used to realize the interconnection between the AAAA device and other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, a fiber optic interface, an ATM interface, etc.; the user device can be a display (Display), a keyboard (Keyboard), etc.
[0133] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.
[0134] The processor may be a general-purpose processor, and the general-purpose processor may call the AAAA program stored in the memory and execute the AAAA method provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the AAAA program is called may refer to the various embodiments of the AAAA method of the present application, and will not be repeated here.
[0135] Those skilled in the art will understand that Figure 2 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.
[0136] In summary, this application collects vibration signal data, noise signal data and brake stroke information on the vehicle to automatically calculate and analyze the number of times brake squeal occurs during vehicle testing, and obtains an evaluation index for evaluating brake squeal based on the noise data's abnormal sound prominence ratio and the number of times brake squeal occurs. This application does not rely on professional equipment and professional personnel, and can complete the evaluation of brake squeal only through data calculation and analysis. Compared with traditional testing methods, it has lower costs and less investment in manpower and material resources.
[0137] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.
[0138] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.
[0139] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.
[0140] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.
[0141] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.
[0142] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.
[0143] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A brake squeal evaluation method, characterized in that: The brake squeal evaluation method comprises: Obtaining vibration signal data, noise signal data and braking stroke information of the vehicle; Perform energy detection on the vibration signal data and the noise signal data, and obtain the number of times the brake squeal occurs according to the energy detection result and the braking stroke information; The abnormal sound prominence ratio of the noise signal data is calculated, and the noise evaluation index of the vehicle is calculated based on the abnormal sound prominence ratio and the number of times brake squeal occurs.
2. The brake squeal evaluation method according to claim 1, characterized in that: After the vibration signal data and noise signal data of the vehicle are obtained, the method further includes: The validity of the vibration signal data and the noise signal data is judged to obtain first valid vibration signal data and first valid noise signal data.
3. The brake squeal evaluation method according to claim 2, characterized in that: The step of performing validity judgment on the vibration signal data and the noise signal data to obtain first valid vibration signal data and first valid noise signal data includes: The signal data of vibration and noise are subjected to high-pass filtering to obtain first effective vibration signal data and first effective noise signal data that meet a preset frequency threshold.
4. The brake squeal evaluation method according to claim 2, characterized in that: The energy detection of the vibration signal data and the noise signal data comprises: Normalizing the first vibration signal data and the first noise signal data to obtain second vibration signal data and second noise signal data; Dividing the second vibration signal data and the second noise signal data into a plurality of short frames of equal length respectively; The short-time energy of each frame of the second vibration signal data and the second noise signal data is calculated.
5. The brake squeal evaluation method according to claim 4, characterized in that: The obtaining of the braking travel information of the vehicle includes: According to the vehicle braking system parameters, the total number of active braking times and the corresponding times during the vehicle's driving process are recorded.
6. The brake squeal evaluation method according to claim 5, characterized in that: The obtaining the number of times the brake squeal occurs according to the energy detection result and the brake stroke information includes: Set the vibration signal threshold and noise signal threshold; The short-time energy data of each frame is screened according to the vibration signal threshold, noise signal threshold and braking stroke information; When the short-time energy of the second vibration signal data and the second noise signal data in the frame is respectively greater than the vibration signal threshold and the noise signal threshold, and the braking stroke information at the corresponding moment of the short frame shows that there is an active braking action, the short frame is recorded as a brake squeal.
7. The brake squeal evaluation method according to claim 4, characterized in that: The calculating of the unusual sound prominence ratio of the noise signal data includes: calculating the unusual sound prominence ratio of the second noise signal data in each short frame.
8. The brake squeal evaluation method according to claim 1, characterized in that: The calculation of the vehicle noise evaluation index according to the abnormal sound prominence ratio and the number of brake squeals comprises: The noise evaluation index s(I) is calculated according to the formula: Where N j is the number of times brake squeal occurs, N B is the total number of vehicle braking times in the braking stroke information, s i (PR) is the noise prominence ratio of each frame of noise signal.
9. The brake squeal evaluation method according to claim 1, characterized in that: The step of obtaining the vibration and noise signal data and the braking stroke information of the vehicle further includes: A vibration sensor is provided on the vehicle brake, and microphones are arranged in the near field of the vehicle brake disc and / or at the ear points of the driver and passengers in the vehicle; Perform vehicle or bench tests on the vehicle and collect vibration signal data, noise signal data, and brake travel information.
10. A brake squeal evaluation device, characterized in that: include: An acquisition module, which is used to obtain vibration and noise signal data and braking stroke information of the vehicle; A calculation module, which is used to perform energy detection on the vibration signal data and the noise signal data, and obtain the number of times the brake squeal occurs according to the energy detection result and the braking stroke information; The evaluation module is used to calculate the abnormal sound prominence ratio of the noise signal data, and calculate the noise evaluation index of the vehicle according to the abnormal sound prominence ratio and the number of times the brake squeal occurs.