Vehicle interior structure road noise diagnosis test method under operation condition

Abstract

The invention discloses a vehicle interior structure road noise diagnosis test method under an operation condition, and belongs to the technical field of vehicle structure road noise diagnosis, and the method comprises the following steps: S1, building a vehicle transmission path analysis model: defining road surface unevenness as an excitation source, defining a rubber bushing of a vehicle chassis suspension system as a vibration energy transmission path, and building a vehicle transmission path analysis model; the vehicle body serves as a vibration receiving structure; s2, test and acquisition of transfer functions: acquiring two core transfer functions through a vehicle body noise transfer function and an original point dynamic stiffness test; s3, operation condition simulation and sound pressure-acceleration transfer relation derivation; and S4, a sound pressure-acceleration transfer function is obtained based on the step S3. The vehicle interior structure road noise diagnosis test method under the operation condition can be used for diagnosis optimization of vehicle interior structure road noise, the test period can be shortened, meanwhile, the transmission path analysis precision is improved, a new thought is provided for transmission path analysis, and good engineering application value is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile structure-borne road noise diagnosis, and in particular to a method for diagnosing and testing structure-borne road noise in a vehicle under operating conditions. Background Art

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

[0003] Since the contribution of the power system of electric vehicles to interior noise is significantly lower than that of traditional power vehicles, the impact of tire / road noise on interior noise is more prominent. Interior noise is divided into structure-borne sound and airborne sound according to different transmission media. The noise generated by the vibration caused by road excitation through the tires, suspension, chassis and body structure inside the vehicle is called structure-borne road noise. Structure-borne road noise includes problems such as "drumming" and "tire cavity noise", and is the focus of automobile vibration noise control.

[0004] To address structural road noise issues, the Transfer Path Analysis (TPA) method is primarily used for problem diagnosis. Traditional TPA methods use methods such as hammering to test the transfer functions of each path and perform load identification, which can accurately locate the source of vibration noise.

[0005] However, traditional TPA testing requires the deployment of large sensors and numerous vibration transfer function tests, which is time-consuming and labor-intensive. Operational Transfer Path Analysis (OTPA) calculates the transferability matrix between the response near the excitation source and the target point under the vehicle's operating state to obtain the contribution of each transfer path. This significantly reduces the testing workload compared to traditional TPA. However, OTPA suffers from significant limitations in analysis accuracy due to coherence between excitations and omissions of transfer paths. Therefore, a diagnostic test method for in-vehicle structural road noise under operating conditions is proposed to address these issues. Summary of the Invention

[0006] (1) Purpose of the invention

[0007] In order to solve the technical problems existing in the background technology, the present invention proposes a diagnostic test method for vehicle interior structure-based road noise under operating conditions, which solves the problem of obvious defects in analysis accuracy and has the advantages of taking into account both test efficiency and analysis accuracy.

[0008] (2) Technical solution

[0009] The present invention provides a diagnostic test method for structure-borne road noise in a vehicle under operating conditions, comprising the following steps:

[0010] S1. Establish a vehicle transfer path analysis model: define road roughness as the excitation source, the rubber bushing of the vehicle chassis suspension system as the vibration energy transfer 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 roughness on the wheel;

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

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

[0015] S2. Transfer function testing and acquisition: Two core transfer functions are obtained through vehicle body noise transfer function and origin dynamic stiffness testing;

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

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

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

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

[0020] Where ω is the circular frequency, is the transfer path number, =1, 2,…, n, where n is the number of transmission paths in the chassis structure;

[0021] S3. Operational condition simulation and derivation of the sound pressure-acceleration transmission relationship:

[0022] In a semi-anechoic chamber, the wheels are driven by silent hubs to simulate actual vehicle operating conditions, and the following operations are performed:

[0023] (a) Working condition vibration data collection:

[0024] Measure the operating conditions The acceleration frequency response ai(ω) of the response point on the body side of the rubber bushing in the transmission path;

[0025] (b) Sound pressure-acceleration transfer function generation:

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

[0027] Among them, ATFi(ω) represents the sound pressure response inside the vehicle generated by unit acceleration excitation, establishing a direct mapping relationship between vehicle body vibration and noise;

[0028] S4. Based on the sound pressure-acceleration transfer function ATFi(ω) and the operating condition acceleration ai(ω) obtained in step S3, calculate the transfer path sound pressure SPLi(ω) corresponding to each of the rubber bushing body side response points, the interior sound pressure SPL(ω) and the sound pressure contribution Ci(ω) of each transfer path.

[0029] Preferably, the chassis rubber bushings in step S1 include front end bushings of the front suspension lower arm, rear end bushings of the front suspension lower arm, upper end bushings of the front shock absorber, front end bushings of the rear suspension swing arm, rear end bushings of the rear suspension swing arm, body side bushings of the rear tie rod, and upper end bushings of the rear shock absorber. The chassis structure is bilaterally symmetrical, and each type of bushing is distributed in pairs, for a total of 14 rubber bushings.

[0030] Preferably, the vibration of each rubber bushing is independently transmitted along three orthogonal directions of 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 near the right ear of the driver in the vehicle is used as the response point.

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

[0033] For the first The contribution of the interior sound pressure caused by the vibration of the rubber bushing body side response point is calculated based on the transmission path: SPLi(ω)=ATFi(ω)⋅ai(ω);

[0034] Among them, SPLi(ω) is characterized by only The sound pressure inside the car is generated by the vibration energy transmitted through these paths.

[0035] Preferably, in step S4, the in-vehicle sound pressure synthesis is:

[0036] The sound pressure contributions of all transfer paths are complex superimposed in the frequency domain to obtain the total interior sound pressure:

[0037] .

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

[0039] Calculate the The contribution of each transfer path to the total interior sound pressure is:

[0040] ;

[0041] Where β is SPL i The angle between the sound pressure level (ω) and the SPL (ω) is shown in Figure 2. Ci(ω) is the ratio of sound pressure energy in the frequency domain and is used to diagnose key noise transfer paths.

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

[0043] The diagnostic test method for in-vehicle structure-induced road noise under this operating condition can be used for the diagnosis and optimization of in-vehicle structure-induced road noise, shorten the test cycle, and improve the accuracy of transfer path analysis. It provides a new idea for transfer path analysis and has good engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Flowchart of the diagnostic test method for structure-borne road noise in a vehicle under operating conditions of the present invention;

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

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

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

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

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

[0050] Figure 7 is the contribution of the sound pressure of each transmission path to the sound pressure inside the car. DETAILED DESCRIPTION

[0051] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present 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," "the other end," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore 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 expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, such as welding, riveting, or bonding, or a detachable connection, such as threaded connection, key connection, or pin connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium, or it may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

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

[0055] S1. Establish a vehicle transfer path analysis model: define road roughness as the excitation source, the rubber bushing of the vehicle chassis suspension system as the vibration energy transfer 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 roughness on the wheel;

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

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

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

[0061] S2. Transfer function testing and acquisition: Two core transfer functions are obtained through vehicle body noise transfer function and origin dynamic stiffness testing;

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

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

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

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

[0066] For the first The excitation force F is applied to the response point of the rubber bushing on the vehicle body side of the transmission path i (ω), synchronously measure the acceleration frequency response ai(ω) of the 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 body side

[0068] Where ω is the circular frequency, is the transfer path number, =1, 2,…, n, where n is the number of transmission paths in the chassis structure;

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

[0070] S3. Operational condition simulation and derivation of the sound pressure-acceleration transmission relationship:

[0071] In a semi-anechoic chamber, the wheels are driven by silent hubs to simulate actual vehicle operating conditions, and the following operations are performed:

[0072] (a) Working condition vibration data collection:

[0073] Measure the operating conditions The acceleration frequency response ai(ω) of the response point on the body side of the rubber bushing in the transmission path;

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

[0075] (b) Sound pressure-acceleration transfer function generation:

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

[0077] ;

[0078] Among them, ATFi(ω) represents the sound pressure response inside the vehicle generated by unit acceleration excitation, establishing a direct mapping relationship between vehicle body vibration and noise;

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

[0080] S4. Calculate the transfer path sound pressure SPLi(ω), the interior sound pressure SPL(ω), and the sound pressure contribution Ci(ω) of each transfer path corresponding to the vehicle body side response point of each rubber bushing based on the sound pressure-acceleration transfer function ATFi(ω) and the operating condition acceleration ai(ω) obtained in step S3;

[0081] According to the acceleration frequency response ai(ω) and the sound pressure-acceleration transfer relationship ATFi(ω) of the response point on the vehicle body side of the rubber bushing under operating conditions, the sound pressure SPLi(ω) of the transfer path corresponding to the response point on the vehicle body side of the rubber bushing is calculated:

[0082] ;

[0083] The sound pressure contributions of all transfer paths are complex superimposed in the frequency domain to obtain the total interior sound pressure SPL(ω):

[0084] ;

[0085] Calculate the The contribution of each transfer path to the total interior sound pressure is:

[0086] Calculate the amplitude |SPL(ω)| and phase α of the sound pressure SPL(ω) inside the vehicle;

[0087] set up:

[0088] ;

[0089] ;

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

[0091] ;

[0092] Then the phase α of the interior sound pressure SPL(ω) is:

[0093] ;

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

[0095] According to the transmission path sound pressure SPL corresponding to the response point on the vehicle body side of the rubber bushing i (ω) and the interior sound pressure SPL(ω), calculate the sound pressure contribution C of each transmission path i (ω):

[0096] ;

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

[0098] Figure 7 is the contribution of the sound pressure of each transmission path to the sound pressure inside the car.

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

Claims

1. A diagnostic test method for vehicle interior structure-borne road noise under operating conditions, characterized in that: The following steps are involved: S1. Establish a vehicle transfer path analysis model: define road roughness as the excitation source, the rubber bushing of the vehicle chassis suspension system as the vibration energy transfer path, and the vehicle body as the vibration receiving structure; In the model: (a) The excitation input is the excitation effect of road surface roughness on the wheel; (b) The transmission path is the process of vibration energy being transferred to the vehicle body through the rubber bushing; (c) The receiver response is the sound pressure response inside the vehicle caused by the vibration of the vehicle body; S2. Transfer function testing and acquisition: Two core transfer functions are obtained through vehicle body noise transfer function and origin dynamic stiffness testing; (a) Sound pressure-force transfer function: For the first The excitation force Fi(ω) is applied to the response point on the body side of the rubber bushing along the transmission path, and the sound pressure response P inside the vehicle is measured simultaneously. i (ω), and the transfer function between the force at the response point and the sound pressure inside the vehicle is calculated through the vehicle body noise transfer function test: NTFi(ω)= P i (ω) / F i (ω); (b) Acceleration-force transfer function: For the first The excitation force F is applied to the response point of the rubber bushing on the vehicle body side of the transmission path i (ω), synchronously measure the acceleration frequency response ai(ω) of the point, and calculate the transfer function between the acceleration and force of the response point through the origin dynamic stiffness test: IPIi(ω)= ai(ω) / Fi(ω); Where ω is the circular frequency, is the transfer path number, =1, 2,…, n, where n is the number of transmission paths in the chassis structure; S3. Operational condition simulation and derivation of the sound pressure-acceleration transmission relationship: In a semi-anechoic chamber, the wheels are driven by silent hubs to simulate actual vehicle operating conditions, and the following operations are performed: (a) Working condition vibration data collection: Measure the operating conditions The acceleration frequency response ai(ω) of the response point on the body side of the rubber bushing in the transmission path; (b) Sound pressure-acceleration transfer function generation: Under vehicle operation conditions, the vibration of the vehicle body response point is obtained, and based on the sound pressure-force transfer function NTFi(ω) and acceleration-force transfer function IPIi(ω) obtained in step S2, the first The sound pressure-acceleration transfer relationship of the transmission path is expressed as: ATFi(ω)=NTFi(ω) / IPIi(ω); Among them, ATFi(ω) represents the sound pressure response inside the vehicle generated by unit acceleration excitation, establishing a direct mapping relationship between vehicle body vibration and noise; S4. Based on the sound pressure-acceleration transfer function ATFi(ω) and the operating condition acceleration ai(ω) obtained in step S3, calculate the transfer path sound pressure SPLi(ω) corresponding to each of the rubber bushing body side response points, the interior sound pressure SPL(ω) and the sound pressure contribution Ci(ω) of each transfer path.

2. The diagnostic test method for vehicle interior structure-borne road noise under operating conditions according to claim 1, characterized in that: In step S1, the chassis rubber bushings include a front end bushing of the front suspension lower arm, a rear end bushing of the front suspension lower arm, an upper end bushing of the front shock absorber, a front end bushing of the rear suspension swing arm, a rear end bushing of the rear suspension swing arm, a body side bushing of the rear tie rod, and an upper end bushing of the rear shock absorber. The chassis structure is bilaterally symmetrical, and each type of bushing is distributed in pairs, for a total of 14 rubber bushings.

3. The diagnostic test method for vehicle interior structure-borne road noise under operating conditions according to claim 2, characterized in that: The vibration of each rubber bushing is transmitted independently along three orthogonal directions: X, Y, and Z, and the total number of transmission paths is 42.

4. The diagnostic test method for vehicle interior structure-borne road noise 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 in the vehicle is used as the response point.

5. The diagnostic test method for vehicle interior structure-borne road noise under operating conditions according to claim 1, characterized in that: The path sound pressure calculation in step S4 is: For the first The contribution of the interior sound pressure caused by the vibration of the rubber bushing body side response point is calculated based on the transmission path: SPLi(ω)=ATFi(ω)⋅ai(ω); Among them, SPLi(ω) is characterized by only The sound pressure inside the car is generated by the vibration energy transmitted through these paths.

6. The diagnostic test method for vehicle interior structure-borne road noise under operating conditions according to claim 1, characterized in that: In step S4, the in-vehicle sound pressure synthesis is: The sound pressure contributions of all transmission paths are complex superimposed in the frequency domain to obtain the total interior sound pressure: 。 7. The diagnostic test method for vehicle interior structure-borne road noise under operating conditions according to claim 1, characterized in that: The sound pressure contribution of each transmission path in step S4 is: Calculate the The contribution of each transfer path to the total interior sound pressure is: ; Where β is SPL i The angle between the sound pressure level (ω) and the SPL (ω) is shown in Figure 2. Ci(ω) is the ratio of sound pressure energy in the frequency domain and is used to diagnose key noise transfer paths.

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