A method for diagnosing and testing road noise of a structure in a vehicle under an operating condition

Abstract

The application discloses a kind of running conditions under vehicle interior structure road noise diagnostic test method, belong to automobile structure road noise diagnostic technical field, comprising the following steps: S1, establish vehicle transmission path analysis model: define unevenness of road as excitation source, rubber bushing of vehicle chassis suspension system is vibration energy transmission path, vehicle body is as vibration receiving structure;S2, transfer function test and acquisition: obtain two core transfer functions by vehicle body noise transfer function and origin dynamic stiffness test;S3, running condition simulation and sound pressure-acceleration transmission relationship derivation: S4, based on step S3 obtains sound pressure-acceleration transfer function.The running conditions under vehicle interior structure road noise diagnostic test method can be used for the diagnosis optimization of vehicle interior structure road noise, can shorten test cycle, improve transmission path analysis accuracy simultaneously, provide new ideas for transmission path analysis, with good engineering application value.

Description

Technical Field

[0001] This invention relates to the field of automotive structural road noise diagnosis technology, and in particular to a method for diagnosing and testing in-vehicle structural road noise under operating conditions. Background Technology

[0002] After decades of development, automotive noise and vibration control technology has effectively controlled noise in traditional engine power systems. However, tire / tire noise has gradually increased its proportion and impact on overall vehicle noise. In recent years, with the promotion of electric vehicles, their ride comfort has also received attention.

[0003] Since the power system of electric vehicles contributes significantly less to in-vehicle noise compared to traditional electric vehicles, the impact of tire / road noise on in-vehicle noise is more prominent. In-vehicle noise is divided into structural noise and airborne noise based on different transmission media. The noise generated in the vehicle by vibrations caused by road excitation through the tires, suspension, chassis, and body structure is called structural road noise. Structural road noise includes issues such as "drumming sound" and "tire cavity sound," which are the focus of automotive vibration and noise control.

[0004] For structural road noise problems, the Transfer Path Analysis (TPA) method is mainly used for problem diagnosis. The traditional TPA method uses methods such as hammering to test the transfer function of each path and identify the load, which can accurately find the source of vibration noise.

[0005] However, traditional TPA testing requires the deployment of large sensors and the testing of numerous vibration transfer functions, which is time-consuming and labor-intensive. Operational Transfer Path Analysis (OTPA), on the other hand, calculates the transfer rate matrix between the response near the excitation source and the response at the target point under vehicle operating conditions to obtain the contribution of each transfer path. Compared with traditional TPA, this method significantly reduces the workload. However, OTPA suffers from significant deficiencies in analysis accuracy due to the coherence between excitations and the omission of transfer paths. Therefore, a new in-vehicle structural road noise diagnostic testing method under operating conditions is proposed to address these issues. Summary of the Invention

[0006] (a) Purpose of the invention

[0007] To address the technical problems existing in the background art, this invention proposes a diagnostic testing method for road noise in the vehicle interior under operating conditions, which solves the problem of significant deficiencies in analysis accuracy and has the advantages of balancing testing efficiency and analysis accuracy.

[0008] (II) Technical Solution

[0009] This invention provides a method for diagnosing road noise in vehicle interior structures under operating conditions, comprising the following steps:

[0010] S1. Establish a vehicle transmission path analysis model: Define road surface unevenness as the excitation source, the rubber bushings of the vehicle chassis suspension system as the vibration energy transmission path, and the vehicle body as the vibration receiving structure.

[0011] In the model:

[0012] (a) The excitation input is the excitation effect of road surface unevenness on the wheel;

[0013] (b) The transmission path is the process of vibration energy being transmitted to the vehicle body through the rubber bushing;

[0014] (c) The receiver response is the in-vehicle sound pressure response caused by vehicle body vibration;

[0015] S2. Transfer Function Testing and Acquisition: Two core transfer functions are obtained through vehicle body noise transfer function and origin dynamic stiffness test;

[0016] (a) Sound pressure-force transfer function:

[0017] For the first An excitation force Fi(ω) is applied to the rubber bushing on the side of the vehicle body along the transmission path, and the sound pressure response SPL inside the vehicle is measured simultaneously. i (ω), the transfer function between the force and the sound pressure inside the vehicle at the response point is calculated through vehicle body noise transfer function testing: NTF i (ω)= SPL i (ω) / F i (ω);

[0018] (b) Acceleration-force transfer function:

[0019] For the first An excitation force F is applied to the rubber bushing on the side of the vehicle body along the transmission path. i (ω), synchronously measure the acceleration frequency response ai(ω) at this point, and calculate the transfer function between the acceleration and force at the response point through the origin dynamic stiffness test: IPIi(ω)= ai(ω) / Fi(ω);

[0020] Where ω is the angular frequency. To transmit the path number, =1, 2, ..., n, where n is the number of transmission paths in the chassis structure;

[0021] S3. Simulation of operating conditions and derivation of the sound pressure-acceleration transmission relationship:

[0022] The wheels are driven by a silent rotating hub in a semi-anechoic chamber to simulate the actual operating conditions of a vehicle, and the following operations are performed:

[0023] (a) Vibration data acquisition under operating conditions:

[0024] Measure the first under the operating conditions The acceleration frequency response of the rubber bushing on the side of the vehicle body along the transmission path. oi (ω);

[0025] (b) Generation of the sound pressure-acceleration transfer function:

[0026] Under vehicle operating conditions, the vibration at the vehicle body response point is acquired. Based on the sound pressure-force transfer function NTFi(ω) and acceleration-force transfer function IPIi(ω) obtained in step S2, the derive of the first... The sound pressure-acceleration transmission relationship along the transmission path is expressed as: ATFi(ω)=NTFi(ω) / IPIi(ω);

[0027] Among them, ATFi(ω) characterizes the in-vehicle sound pressure response generated under unit acceleration excitation, and establishes a direct mapping relationship between vehicle body vibration and noise;

[0028] S4. Based on step S3, obtain the sound pressure-acceleration transfer function ATFi(ω) and the operating condition acceleration a. oi (ω) Calculate the transmission path sound pressure SPL corresponding to the response point on the vehicle side of each rubber bushing. oi (ω), Total In-Vehicle Sound Pressure Level (SPL) o (ω) and the sound pressure contribution Ci(ω) of each transmission path.

[0029] Preferably, in step S1, the chassis rubber bushings include a front bushing for the front lower control arm, a rear bushing for the front lower control arm, an upper bushing for the front shock absorber, a front bushing for the rear control arm, a rear bushing for the rear control arm, a side bushing for the rear tie rod, and an upper bushing for the rear shock absorber. The chassis structure is symmetrical from left to right, and each type of bushing is distributed in pairs, totaling 14 rubber bushings.

[0030] Preferably, the vibration of each rubber bushing is transmitted independently along the three orthogonal directions X, Y, and Z, and the total number of transmission paths is 42.

[0031] Preferably, in step S2, when performing the vehicle body noise transfer function test, the sound pressure level near the driver's right ear is used as the response point.

[0032] Preferably, the path sound pressure calculation in step S4 is as follows:

[0033] For the first SPL is used to calculate the contribution of vibration at the side response point of the rubber bushing to the in-vehicle sound pressure level. oi (ω)=ATFi(ω)⋅a oi (ω);

[0034] Among them, SPL oi (ω) represents only the first The sound pressure inside the vehicle generated by the vibration energy transmitted along the path.

[0035] Preferably, in step S4, the in-vehicle sound pressure level is synthesized as follows:

[0036] The total sound pressure level inside the vehicle is obtained by complex superposition of the sound pressure contributions from all transmission paths in the frequency domain:

[0037] ;

[0038] Preferably, the sound pressure contribution of each transmission path in step S4 is:

[0039] Calculate the first The contribution of each transmission path to the total sound pressure level inside the vehicle:

[0040] ;

[0041] Where β is SPL oi (ω) and SPL o The angle between (ω) and Ci(ω) is the proportion of frequency domain sound pressure energy, which is used to diagnose key noise transmission paths.

[0042] Compared with the prior art, the above-mentioned technical solution of the present invention has the following beneficial technical effects:

[0043] This in-vehicle structural road noise diagnosis and testing method under operating conditions can be used for the diagnosis and optimization of in-vehicle structural road noise. It can shorten the testing cycle and improve the accuracy of transmission path analysis, providing a new approach to transmission path analysis and has good engineering application value. Attached Figure Description

[0044] Figure 1 This is a flowchart of the in-vehicle structural road noise diagnosis and testing method under the operating conditions of the present invention;

[0045] Figure 2 This is a schematic diagram showing the location of the chassis rubber bushing of the present invention;

[0046] Figure 3 The sound pressure-force transfer function spectrum curve from the side of the rubber bushing to the driver's right ear;

[0047] Figure 4 The acceleration-force transfer function spectrum curve of the rubber bushing on the vehicle body side;

[0048] Figure 5 The acceleration spectrum curve of the rubber bushing on the vehicle body side;

[0049] Figure 6The sound pressure-acceleration transfer function spectrum curve from the side of the rubber bushing to the driver's right ear;

[0050] Figure 7 The contribution of sound pressure along each transmission path to the sound pressure inside the vehicle. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0052] In the description of the invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, such as welding, riveting, or bonding; it can also be a detachable connection, such as threaded connection, keyed connection, or pin connection; or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] like Figure 1-6 As shown, the present invention proposes a method for diagnosing road noise in the vehicle interior under operating conditions, comprising the following steps:

[0055] S1. Establish a vehicle transmission path analysis model: Define road surface unevenness as the excitation source, the rubber bushings of the vehicle chassis suspension system as the vibration energy transmission path, and the vehicle body as the vibration receiving structure.

[0056] In the model:

[0057] (a) The excitation input is the excitation effect of road surface unevenness on the wheel;

[0058] (b) The transmission path is the process of vibration energy being transmitted to the vehicle body through the rubber bushing;

[0059] (c) The receiver response is the in-vehicle sound pressure response caused by vehicle body vibration;

[0060] The chassis rubber bushings include the front lower control arm bushing, the rear lower control arm bushing, the upper bushing of the front shock absorber, the front control arm bushing, the rear control arm bushing, the rear tie rod side bushing, and the upper bushing of the rear shock absorber. The chassis structure is symmetrical, with each type of bushing distributed in pairs, totaling 14 rubber bushings. The vibration of each rubber bushing is transmitted independently along the three orthogonal directions (X, Y, and Z), and the total number of transmission paths is 42 (the bushing distribution is as follows). Figure 2 (as shown)

[0061] S2. Transfer Function Testing and Acquisition: Two core transfer functions are obtained through vehicle body noise transfer function and origin dynamic stiffness test;

[0062] (a) Sound pressure-force transfer function:

[0063] For the first An excitation force Fi(ω) is applied to the rubber bushing on the side of the vehicle body along the transmission path, and the sound pressure response SPL inside the vehicle is measured simultaneously. i (ω), the transfer function between the force and the sound pressure inside the vehicle at the response point is calculated through vehicle body noise transfer function testing: NTF i (ω)= SPL i (ω) / F i (ω);

[0064] Figure 3 The spectral curve of the sound pressure-force transfer function NTFi(ω) from the side of the rubber bushing to the driver's right ear;

[0065] (b) Acceleration-force transfer function at the body side response point of the rubber bushing:

[0066] For the first An excitation force F is applied to the rubber bushing on the side of the vehicle body along the transmission path. i (ω), synchronously measure the acceleration frequency response ai(ω) at this point, and calculate the transfer function between the acceleration and force at the response point through the origin dynamic stiffness test: IPIi(ω)= ai(ω) / Fi(ω);

[0067] Figure 4 The acceleration-force transfer function IPIi(ω) spectrum curve of the rubber bushing on the vehicle body side.

[0068] Where ω is the angular frequency. To transmit the path number, =1, 2, ..., n, where n is the number of transmission paths in the chassis structure;

[0069] When conducting tests on the vehicle body noise transfer function and origin dynamic stiffness, an acceleration sensor is placed on the side of the rubber bushing on the vehicle body, a sound pressure sensor is placed next to the driver's right ear inside the vehicle, and a force sensor (such as...) is placed on the force hammer. Figure 2 (as shown)

[0070] S3. Simulation of operating conditions and derivation of the sound pressure-acceleration transmission relationship:

[0071] The wheels are driven by a silent rotating hub in a semi-anechoic chamber to simulate the actual operating conditions of a vehicle, and the following operations are performed:

[0072] (a) Vibration data acquisition under operating conditions:

[0073] Measurement under operating conditions The acceleration frequency response of the rubber bushing on the side of the vehicle body along the transmission path. oi (ω);

[0074] Figure 5 The acceleration spectrum curve of the rubber bushing on the vehicle body side;

[0075] (b) Generation of the sound pressure-acceleration transfer function:

[0076] Under vehicle operating conditions, the vibration at the vehicle body response point is acquired. Based on the sound pressure-force transfer function NTFi(ω) and acceleration-force transfer function IPIi(ω) obtained in step S2, the derive of the first... The sound pressure-acceleration transmission relationship along the transmission path is expressed as follows:

[0077] ;

[0078] Among them, ATFi(ω) characterizes the in-vehicle sound pressure response generated under unit acceleration excitation, and establishes a direct mapping relationship between vehicle body vibration and noise;

[0079] Figure 6 The ATFi(ω) spectrum curve of the sound pressure-acceleration transfer function from the side of the rubber bushing to the driver's right ear;

[0080] S4. Based on step S3, obtain the sound pressure-acceleration transfer function ATFi(ω) and the operating condition acceleration a. oi (ω) Calculate the transmission path sound pressure SPL corresponding to the response point on the vehicle side of each rubber bushing. oi (ω), Total sound pressure level inside the car (SPL) o (ω) and the sound pressure contribution Ci(ω) of each transmission path;

[0081] Based on the acceleration frequency response at the body side response point of the rubber bushing under operating conditions, a oiThe sound pressure-acceleration transmission relationship ATFi(ω) is used to calculate the transmission path sound pressure SPL corresponding to the response point on the side of the rubber bushing body. oi (ω):

[0082] ;

[0083] The total in-vehicle sound pressure level (SPL) is obtained by complex superposition of the sound pressure contributions from all transmission paths in the frequency domain. o (ω):

[0084] ;

[0085] Calculate the first The contribution of each transmission path to the total sound pressure level inside the vehicle:

[0086] Calculate the sound pressure level (SPL) inside the car oi The amplitude of (ω)|SPL oi (ω)| and phase α;

[0087] set up:

[0088]

[0089]

[0090] Then the sound pressure level inside the car (SPL) oi The amplitude of (ω)|SPL oi (ω)| is:

[0091]

[0092] Then the sound pressure level inside the car (SPL) oi The phase α of (ω) is:

[0093] ;

[0094] The above acceleration response a oi (ω) and sound pressure response SPL oi (ω) are all complex numbers, containing amplitude and phase information, and they are all calculated according to the rules of complex number operations;

[0095] Based on the transmission path sound pressure SPL corresponding to the response point on the side of the rubber bushing body oi (ω) and total sound pressure level SPL inside the car o (ω), calculate the sound pressure contribution C of each transmission path. i (ω):

[0096]

[0097] Where β is SPL oi (ω) and SPLo The angle between (ω);

[0098] Figure 7 The contribution of sound pressure along each transmission path to the sound pressure inside the vehicle.

[0099] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for diagnosing road noise in vehicle interior under operating conditions, characterized in that, Includes the following steps: S1. Establish a vehicle transmission path analysis model: Define road surface unevenness as the excitation source, the rubber bushings of the vehicle chassis suspension system as the vibration energy transmission path, and the vehicle body as the vibration receiving structure. In the model: (a) The excitation input is the excitation effect of road surface unevenness on the wheel; (b) The transmission path is the process of vibration energy being transmitted to the vehicle body through the rubber bushing; (c) The receiver response is the in-vehicle sound pressure response caused by vehicle body vibration; S2. Transfer Function Testing and Acquisition: Two core transfer functions are obtained through vehicle body noise transfer function and origin dynamic stiffness test; (a) Sound pressure-force transfer function: For the Excitation force is applied to the rubber bushing on the side of the vehicle body along the transmission path. Simultaneous measurement of sound pressure response inside the vehicle By testing the vehicle body noise transfer function, the transfer function between the force at the response point and the sound pressure inside the vehicle was calculated. ; (b) Acceleration-force transfer function: For the Excitation force is applied to the rubber bushing on the side of the vehicle body along the transmission path. Simultaneously measure the acceleration frequency response at this point. By performing a dynamic stiffness test at the origin, the transfer function between the acceleration and force at the response point was calculated: ; in, It is the angular frequency. To transmit the path number, Number of transmission paths for the chassis structure; S3. Simulation of operating conditions and derivation of the sound pressure-acceleration transmission relationship: The wheels are driven by a silent rotating hub in a semi-anechoic chamber to simulate the actual operating conditions of a vehicle, and the following operations are performed: (a) Vibration data acquisition under operating conditions: Measure the first under the operating conditions Acceleration frequency response of the rubber bushing on the side of the vehicle body along the transmission path ; (b) Generation of the sound pressure-acceleration transfer function: Under vehicle operating conditions, the vibration at the vehicle body response point is acquired, based on the sound pressure-force transfer function obtained in step S2. and acceleration-force transfer function Derivation of the first The sound pressure-acceleration transmission relationship along the transmission path is expressed as follows: ; in, The in-vehicle sound pressure response generated under unit acceleration excitation is characterized, and a direct mapping relationship between vehicle body vibration and noise is established. S4. Obtain the sound pressure-acceleration transfer function based on step S3. and the acceleration frequency response under operating conditions Calculate the sound pressure along the transmission path corresponding to the response point on the vehicle body side of each of the rubber bushings. Total sound pressure level inside the vehicle and the sound pressure contribution of each transmission path .

2. The method for diagnosing road noise in vehicle interior under operating conditions according to claim 1, characterized in that, In step S1, the chassis rubber bushings include the front lower control arm bushing, the rear lower control arm bushing, the upper front shock absorber bushing, the front rear control arm bushing, the rear rear control arm bushing, the rear tie rod body side bushing, and the upper rear shock absorber bushing. The chassis structure is symmetrical from left to right, and each type of bushing is distributed in pairs, totaling 14 rubber bushings.

3. The method for diagnosing road noise in vehicle interior under operating conditions according to claim 2, characterized in that, The vibration of each rubber bushing is transmitted independently along the three orthogonal directions X, Y, and Z, and there are a total of 42 transmission paths.

4. The method for diagnosing road noise in vehicle interior under operating conditions according to claim 1, characterized in that, In step S2, when performing the vehicle body noise transfer function test, the sound pressure near the driver's right ear is used as the response point.

5. The method for diagnosing road noise in vehicle interior under operating conditions according to claim 1, characterized in that, The path sound pressure calculation in step S4: For the first The transmission path is calculated to determine the contribution of the in-vehicle sound pressure caused by vibration at the body-side response point of the rubber bushing: ; in, The characterization is only by the first The sound pressure inside the vehicle generated by the vibration energy transmitted along the path.

6. The method for diagnosing road noise in vehicle interior under operating conditions according to claim 1, characterized in that, In step S4, the sound pressure synthesis inside the vehicle is performed as follows: The total sound pressure level inside the vehicle is obtained by complex superposition of the sound pressure contributions from all transmission paths in the frequency domain: 。 7. The method for diagnosing road noise in vehicle interior under operating conditions according to claim 1, characterized in that, The sound pressure contribution of each transmission path in step S4: Calculate the first The contribution of each transmission path to the total sound pressure level inside the vehicle: ； in, for and The angle between them This represents the proportion of sound pressure energy in the frequency domain, used to diagnose key noise transmission paths.

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