A whole vehicle vibration noise transfer function testing device and testing method

Abstract

The application discloses a kind of whole vehicle vibration noise transfer function testing device and testing method.The testing device includes: exciter, for exciting wheel tread;Receiver, for picking up vehicle vibration data and sound data;Control acquisition system, electrically connected with exciter, receiver.Control acquisition system controls exciter to input periodic random signal to tread, and synchronously acquires the input signal of exciter and the response signal of receiver;Control acquisition system processes and obtains the cross power spectrum of input signal and response signal and the self-power spectrum of response signal, calculates transfer function.The testing method includes: input periodic random signal to tread, pick up the vibration / noise response signal in vehicle;Synchronously acquire input signal and the response signal of receiver, process and obtain the cross power spectrum of input signal and response signal and the self-power spectrum of response signal, calculate transfer function.The application can excite tire tread, and obtain transfer function, and test result is accurate and reliable.

Description

Technical Field

[0001] This invention relates to the field of automotive noise, vibration, and comfort (NVH) testing technology, specifically to a whole vehicle vibration noise transfer function testing device and testing method. Background Technology

[0002] During vehicle operation, the excitation forces from the road surface cause the wheel centers to vibrate, which are then transmitted to the body and steering wheel through the suspension and steering systems. Simultaneously, this vibration also excites the body, generating structural noise. These vibrations and noises can cause discomfort to the occupants. With advancements in automotive technology and rising consumer standards, NVH performance (noise, vibration, and harshness) is increasingly valued by consumers and plays a crucial role in vehicle development. The vehicle noise / vibration transfer function (VFD) is the acoustic / vibration response of a vehicle to external stimuli and is a key indicator for evaluating NVH performance; therefore, accurate testing of the VFD is essential.

[0003] In existing technologies, tests typically only excite the wheel center (usually near the wheel center bore) to measure the transfer function between the wheel center and the suspension mounting point to evaluate the suspension's transmission characteristics, or excite the suspension mounting point to measure the transfer function between the mounting point and the listener's ear to evaluate the vehicle's transmission characteristics. These tests fail to account for the tire's contribution, only assessing the transmission characteristics of the suspension or vehicle body, and cannot comprehensively evaluate the impact of the wheel system on the overall vehicle transmission characteristics. Furthermore, as a major contributor to road noise, the tire's vibration characteristics have a significant impact on overall vehicle road noise.

[0004] Chinese patent CN115200885A discloses a method and apparatus for testing the road noise characteristics of a vehicle. The method involves disassembling each tire individually in a semi-anechoic chamber environment, measuring the vibration transfer function from the wheel hub to the vehicle interior at each tire removal point, as well as the dynamic stiffness at the wheel hub center. It also measures the vibration transfer function from the tire's contact point to the wheel center and the dynamic stiffness at the wheel center center, and then calculates the overall vehicle vibration transfer function. However, this method does not consider the influence of the front and rear suspension constraint boundaries on tire vibration characteristics, and therefore cannot reflect the actual vibration characteristics of the tires in the vehicle's prepared state. Furthermore, the method uses an elastic rope to suspend the entire vehicle, which does not match the actual suspension preload, resulting in discrepancies between the test results and the actual situation.

[0005] Chinese patent CN116609095A discloses a device and method for simulating the contribution of road noise to automobiles. It uses a vibrator to excite the wheel to simulate and adjust the impact of vibration on road noise. However, this method is mainly used to decompose the contribution of each excitation direction of the tire to road noise, and has little to do with how to excite the tire tread under the condition of the whole vehicle landing and test the transfer function from the tire tread to the ear of the person inside the vehicle.

[0006] In summary, the existing technologies have the following problems:

[0007] Tire vibration characteristics obtained by disassembling and testing tires do not take into account the influence of the front and rear suspension constraint boundaries, and therefore cannot reflect the actual vibration characteristics of the tires in the vehicle's prepared state.

[0008] Using elastic ropes to suspend the entire vehicle does not match the actual suspension preload. Therefore, the test results will differ somewhat from the actual situation.

[0009] Unable to excite the tire tread and test the tread-to-ear transfer function under conditions where the vehicle is on the ground, the overall vehicle's transmission characteristics are evaluated.

[0010] The vehicle constraint methods and boundary conditions used in the test did not match the actual conditions.

[0011] Therefore, a new testing device and method are needed to solve the above problems. Summary of the Invention

[0012] The purpose of this invention is to provide a vehicle vibration and noise transfer function testing device and method, which can excite the tire tread under vehicle conditions and test the transfer function from the tire tread to the ear of a person inside the vehicle to evaluate the vehicle's transmission characteristics. This solves the problem that it is impossible to excite the tire tread and test the tire tread-to-ear transfer function under vehicle-landing conditions to evaluate the vehicle's transmission characteristics, as well as the problem that the vehicle constraint method and boundary conditions during testing do not match reality and are inconsistent with the actual vehicle assembly.

[0013] To achieve the above objectives, in a first aspect, the present invention provides a vehicle vibration noise transfer function testing device, comprising:

[0014] Vibration exciter, used to excite the tire tread of a vehicle;

[0015] Receiver, used to pick up vehicle vibration and sound data;

[0016] The control and acquisition system is electrically connected to the exciter and receiver.

[0017] The control and acquisition system controls the exciter to input a periodic random signal to the tire tread and simultaneously acquires the input signal of the exciter and the response signal of the receiver; the control and acquisition system processes the input signal and the response signal to obtain the cross power spectrum of the response signal and the autopower spectrum of the response signal, and calculates the transfer function.

[0018] In some optional embodiments of the present invention, the testing apparatus further includes a support device for supporting the wheels of the vehicle to achieve transfer function measurement in the vehicle state.

[0019] Preferably, the support device includes:

[0020] The ramp for vehicle entry is designed to facilitate the entry and exit of the entire vehicle.

[0021] The support frame body is used to support the entire vehicle;

[0022] An excitation groove is provided on the support frame body to allow the exciter top rod to pass through and excite the tire tread.

[0023] The exciter placement area is used to place the exciter.

[0024] In a further preferred embodiment, the centerline of the tire tread coincides with the centerline of the excitation groove.

[0025] In some optional embodiments of the present invention, the excitation direction of the vibrator is adjustable to achieve excitation of the tire tread in the X, Y, and Z directions.

[0026] In some optional embodiments of the present invention, one or more exciters are provided to achieve unidirectional or multidirectional excitation according to actual needs.

[0027] In some alternative embodiments of the present invention, the testing device further includes a tooling fixture fixed to the tire tread; the vibrator excites the tire tread through the tooling fixture.

[0028] In some alternative embodiments of the present invention, the receiver is used to pick up vehicle vibration data and sound data at the human ear; wherein the receiver for picking up vehicle vibration data is placed on the floor or in the area of ​​interest of the tester, and the receiver for picking up in-vehicle sound data is installed at the height of the human ear inside the vehicle.

[0029] Secondly, the present invention provides a method for testing the vibration noise transfer function of a vehicle using the testing device described in the first aspect, comprising the following steps:

[0030] Input a periodic random signal into the tire tread and pick up the vibration / noise response signal inside the vehicle;

[0031] The input signal and the receiver response signal are acquired synchronously, and the cross power spectrum of the input signal and the response signal, as well as the auto-power spectrum of the response signal, are obtained through processing. The transfer function is then calculated.

[0032] In some optional embodiments of the present invention, the formula for calculating the transfer function is:

[0033]

[0034] Where: R is the response signal, F is the input signal, N is the number of samples, and R i and F i Let these represent the response and excitation force of the i-th sample, respectively. For R i . conjugate.

[0035] In some alternative embodiments of the invention, vehicle vibration data is picked up on the floor or in the area of ​​interest of the tester, and sound data inside the vehicle is picked up at ear height inside the vehicle.

[0036] In some optional embodiments of the present invention, vibration excitations in the X, Y, and Z directions are applied to the tire tread respectively to obtain transfer functions in different directions.

[0037] Preferably, one or more exciters are provided to achieve unidirectional or multidirectional excitation according to actual needs.

[0038] In some alternative embodiments of the invention, after the vehicle is placed, it is ensured that the vehicle is in a locked state.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] 1. The testing device of the present invention, through a specially designed support device, realizes direct excitation of the tire tread when the vehicle is on the ground, ensuring that the boundary conditions during the test are consistent with the actual driving conditions, and improving the accuracy of the test results.

[0041] 2. This invention uses a periodic random signal as the excitation input, which can effectively reduce the influence of nonlinearity and improve the test accuracy.

[0042] 3. The testing device of the present invention can excite the tire tread in the X, Y and Z directions, and can comprehensively evaluate the impact of vibration in different directions on the transmission characteristics of the whole vehicle.

[0043] 4. The testing method of the present invention can obtain the transmission characteristic data of the whole vehicle in one test, which significantly improves the testing efficiency.

[0044] 5. The support device of the present invention has a simple structure, is easy to operate, and is suitable for testing vehicles with different wheelbases. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments disclosed in this invention, the accompanying drawings of the embodiments will be briefly described below. These drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0046] Figure 1 This is a schematic diagram of a vehicle vibration noise transfer function testing device provided in an embodiment of the present invention;

[0047] Figure 2 This is a schematic diagram of the structure of a support device for a vehicle vibration and noise transfer function testing device provided in an embodiment of the present invention;

[0048] Figure 3 This is a schematic diagram of the exciter structure of a vehicle vibration noise transfer function testing device provided in an embodiment of the present invention. Detailed Implementation

[0049] The technical solutions (including preferred technical solutions) of the present invention will be further described in detail below with reference to the accompanying drawings and by way of listing some optional embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0050] Example 1

[0051] like Figure 1 As shown in the figure, this embodiment provides a basic device for testing the vibration and noise transfer function of a vehicle. The device includes:

[0052] Vibrator 4 is used to excite the tire tread of the vehicle;

[0053] Receiver 3 is used to pick up vehicle vibration data and sound data at the human ear; the receiver for picking up vehicle vibration data is placed on the floor or in the area of ​​interest of the tester, and the receiver for picking up sound data inside the vehicle is installed at the height of the human ear inside the vehicle.

[0054] The control and acquisition system is electrically connected to the exciter 4 and receiver 3.

[0055] The control and acquisition system includes a data acquisition device 5 and a computer 6. It controls the vibrator 4 to input periodic random signals to the tire tread and simultaneously acquires the input signals of the vibrator 4 and the response signals of the receiver 3. The control and acquisition system is also responsible for processing the acquired data, calculating the cross-power spectrum of the input and response signals, as well as the auto-power spectrum of the response signal, and ultimately obtaining the transfer function.

[0056] In some embodiments of the present invention, the receiver for picking up sound data at the human ear in the vehicle is a microphone.

[0057] The testing method in this embodiment includes the following steps:

[0058] Park the vehicle in the test position and ensure that the vehicle is locked;

[0059] Fix the vibrator 4 in a suitable position so that it can excite the tire tread;

[0060] Install a microphone inside the car, at ear level;

[0061] The exciter 4 is controlled by the control and acquisition system to input a periodic random signal to the tire tread.

[0062] Vehicle vibration data and sound data are picked up by receiver 3. Specifically, vehicle vibration data is picked up on the floor or in the area of ​​interest of the tester, and sound data inside the vehicle is picked up at ear height.

[0063] The control and acquisition system synchronously acquires input and response signals;

[0064] The cross-power spectrum G of the input signal and the response signal is obtained through processing. FR and the self-power spectrum G of the response signal RR ;

[0065] Calculate the transfer function.

[0066] In some embodiments of the present invention, the formula for calculating the transfer function is as follows:

[0067]

[0068] Where: R is the response signal, F is the input signal, N is the number of samples, and R i and F i Let these represent the response and excitation force of the i-th sample, respectively. For R i . conjugate.

[0069] Example 2

[0070] Based on Example 1, this example adds a support device 2. For example... Figure 1 and Figure 2 As shown, the support device 2 includes:

[0071] The vehicle entry ramp is 2.1, which facilitates the entry and exit of the entire vehicle;

[0072] The support frame body is 2.2 mm in size and is used to support the weight of the entire vehicle.

[0073] Excitation groove 2.3 is set on the support frame body 2.2 for the exciter top rod to pass through;

[0074] Exciter placement area 2.4 is used to place the exciter.

[0075] The specific design of support device 2 takes into account the following aspects:

[0076] The height of the support frame body, 2.2 meters, has been precisely calculated to ensure that the entire vehicle is in a grounded position;

[0077] The position of the excitation slot 2.3 is adjustable to accommodate vehicles with different wheelbases;

[0078] The slope of the vehicle entry ramp is 2.1, which is moderate and ensures that vehicles can enter and exit smoothly.

[0079] The entire support system adopts a modular design, which facilitates transportation and installation.

[0080] During testing, first install support device 2 into place, then:

[0081] The vehicle is slowly driven onto the support frame body 2.2 via the ramp 2.1.

[0082] Adjust the vehicle position so that the centerline of the tire tread coincides with the centerline of the excitation groove 2.3;

[0083] Place the vibrator in the vibrator placement area 2.4, so that its push rod passes through the excitation groove 2.3 and contacts the tire tread;

[0084] The test was conducted according to the steps in Example 1.

[0085] Example 3: Multi-directional excitation test system

[0086] Based on Example 2, this example adds a tooling fixture 4.1 and multiple vibrators 4 to achieve multi-directional excitation of the tire tread. For example... Figure 3 As shown:

[0087] In some embodiments of the present invention, the tooling fixture 4.1 is made of high-strength aluminum alloy, which ensures rigidity and reduces weight. It can be bonded to the tire tread by adhesive bonding. The vibrator 4 excites the tire tread through the tooling fixture 4.1.

[0088] Test plan:

[0089] a) Unidirectional test:

[0090] The transfer functions in the X, Y, and Z directions are measured sequentially.

[0091] After testing in each direction, adjust the installation angle of the vibrator.

[0092] Record and compare the test results from different directions.

[0093] b) Multi-directional synchronous testing:

[0094] Multiple exciters are simultaneously arranged, each corresponding to a different direction;

[0095] A multi-channel synchronous acquisition system is adopted;

[0096] Analyze the coupling effects of vibrations in different directions.

[0097] Example 4

[0098] 1. Preparation of the testing equipment

[0099] In the laboratory according to Figure 1Set up the test setup as shown. Place the support device 2 on a flat surface. Slowly drive the vehicle to be tested 1 onto the support device 2, ensuring that the centerline of the vehicle's tire tread is aligned with the excitation groove 2.3. Lock the vehicle to prevent it from moving during the test.

[0100] Place the vibrator 4 in the vibrator placement area 2.4, and adjust the height and position of the vibrator 4 so that its push rod can directly contact the tire tread through the excitation groove 2.3. According to the testing requirements, the excitation direction of the vibrator 4 can be adjusted to achieve excitation of the tire tread in the X, Y, and Z directions.

[0101] Install the microphone inside the vehicle at ear level to ensure that the noise signal felt by the occupants is picked up; collect vehicle vibration data on the floor or in the area of ​​interest to the tester to ensure that the vibration signal felt by the occupants is picked up.

[0102] 2. Data testing and processing

[0103] Start the data acquisition device 5 and computer 6, ensuring the system is working properly. Control the vibrator 4 via computer 6 to input a periodic random signal to the tire tread. The periodic random signal should cover the required frequency range to meet the testing requirements.

[0104] Microphone 3 picks up vibration and noise response signals at the ear of a person inside the vehicle in real time. Data acquisition device 5 synchronously acquires the input signal of the exciter and the response signal of the microphone and transmits them to computer 6.

[0105] In computer 6, the acquired data is processed to calculate the cross-power spectrum G of the input signal and the response signal. FR and the self-power spectrum G of the response signal RR .

[0106] 3. Calculation of the transfer function

[0107] Calculate the vibration / noise transfer function H from the tire tread to the vehicle interior using the following formula:

[0108]

[0109] Where: R is the response signal, F is the input signal, N is the number of samples, and R i and F i Let these represent the response and excitation force of the i-th sample, respectively. For R i . conjugate.

[0110] The calculated transfer function H can be used to assess the impact of tire tread vibration on vibration and noise at the ear level inside the vehicle, and thus evaluate the vibration and noise transmission characteristics of the entire vehicle.

[0111] In this embodiment, using a periodic random signal as the input signal can effectively reduce the influence of nonlinearity and improve test accuracy. Furthermore, a linearity check can be performed during the data testing and processing steps to further ensure the accuracy of the test results.

[0112] Example 5

[0113] Based on Example 4, in order to more comprehensively evaluate the impact of vibrations in different directions on in-vehicle noise, the excitation direction of the exciter 4 can be adjusted to achieve excitation of the tire tread in the X, Y, and Z directions.

[0114] The specific steps are as follows:

[0115] Adjust the position and orientation of the vibrator 4 so that it applies vibration excitation in the X, Y, and Z directions to the tire tread respectively.

[0116] Repeat the testing and data processing steps of Example 4 to obtain the transfer function H under different excitation directions.

[0117] By comparing the transfer functions in different directions, the contribution of vibration in each direction to in-vehicle noise can be analyzed, which helps to optimize the vehicle's NVH performance in a targeted manner.

[0118] This invention provides a vehicle transfer function testing device and method based on a vibrator, solving the problem in existing technologies that cannot excite the tire tread and test the tread-to-ear transfer function under full vehicle landing conditions. It also addresses the issue of discrepancies between vehicle constraints and boundary conditions during testing and actual conditions. This invention can more comprehensively and accurately evaluate the vehicle's transfer characteristics, providing a powerful tool for optimizing automotive NVH performance. By using a vibrator for excitation, combined with periodic random signals and linearity checks, this invention further improves testing accuracy. Furthermore, the testing device of this invention is easy to assemble and highly adaptable, meeting the testing needs of different vehicle models. In summary, this invention provides an efficient and accurate solution for evaluating and optimizing automotive NVH performance, possessing significant practical application value.

[0119] It will be readily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A device for testing the vibration and noise transfer function of a vehicle, characterized in that, include: Vibration exciter, used to excite the tire tread of a vehicle; Receiver, used to pick up vehicle vibration and sound data; The control and acquisition system is electrically connected to the exciter and receiver. The testing device also includes a support device for supporting the wheels of the vehicle to achieve transfer function measurement in the vehicle state; The support device includes: The ramp for vehicle entry is designed to facilitate the entry and exit of the entire vehicle. The support frame body is used to support the entire vehicle and ensure that the vehicle is in a grounded position. An excitation groove is provided on the support frame body to allow the exciter top rod to pass through and excite the tire tread. Exciter placement area, used to place the exciter. The control and acquisition system controls the exciter to input a periodic random signal to the tire tread and simultaneously acquires the input signal of the exciter and the response signal of the receiver; the control and acquisition system processes the input signal and the response signal to obtain the cross power spectrum of the response signal and the autopower spectrum of the response signal, and calculates the transfer function.

2. The vehicle vibration noise transfer function testing device according to claim 1, characterized in that: The excitation direction of the vibrator is adjustable to achieve excitation of the tire tread in the X, Y, and Z directions.

3. The vehicle vibration noise transfer function testing device according to claim 2, characterized in that: Set one or more exciters to achieve unidirectional or multidirectional excitation according to actual needs.

4. The vehicle vibration noise transfer function testing device according to claims 1 to 3, characterized in that: The testing device also includes a fixture fixed to the tire tread; the vibrator excites the tire tread through the fixture.

5. The vehicle vibration noise transfer function testing device according to claim 1, characterized in that: The receiver is used to pick up vehicle vibration data and sound data at the human ear; wherein the receiver for picking up vehicle vibration data is placed on the floor or in the area of ​​interest of the tester, and the receiver for picking up in-vehicle sound data is installed at the height of the human ear inside the vehicle.

6. A method for testing the vibration noise transfer function of a vehicle using a testing device, characterized in that, Includes the following steps: The vehicle is placed on the support device as described in any one of claims 1 to 5 to achieve testing of the vehicle in a landing posture; Input a periodic random signal into the tire tread and pick up the vibration / noise response signal inside the vehicle; The input signal and the receiver response signal are acquired synchronously, and the cross power spectrum of the input signal and the response signal, as well as the auto-power spectrum of the response signal, are obtained through processing. The transfer function is then calculated.

7. The method for testing the vehicle vibration noise transfer function using the testing device according to claim 6, wherein the formula for calculating the transfer function is: in: R is the response signal, F is the input signal, and N is the number of sampling points. For R i . conjugate.

8. The method for testing the whole vehicle vibration noise transfer function using the testing device according to claim 6, characterized in that: Vibration data of the vehicle was collected on the floor or in the area of ​​interest to the tester, and sound data of the vehicle was collected at ear level inside the vehicle.

9. The method for testing the whole vehicle vibration noise transfer function using the testing device according to claim 6, characterized in that: Vibration excitations in the X, Y, and Z directions are applied to the tire tread to obtain transfer functions in different directions; one or more exciters are set up to achieve unidirectional or multidirectional excitation according to actual needs.

Images