A high-frequency broadband sound power identification method

Abstract

The present invention provides a high-frequency broadband sound power identification method, including establishing a source-path-receiver model for high-frequency acoustic transmission problems, testing the acoustic transfer function from each sound source to each receiver respectively, testing the high-frequency broadband response function of the receiver when multiple sound sources are emitting sound simultaneously, and calculating the high-frequency broadband sound power curve of each sound source based on the data measured in S1, S2, and S3. High frequency means that the sound power frequency required is above 400 Hz, and broadband refers to a wide frequency band, that is, a continuous frequency range within a certain range, usually expressed in the form of an octave. The beneficial effects of the present invention are as follows: the sound power curves of each sound source can be obtained without disassembling parts and isolating sound sources, and the method has the characteristics of high efficiency, low cost, and high precision. It can provide guidance for the sound power testing and acoustic performance development of each sound source of automobiles, rail vehicles, engineering machinery, and other mechanical products.

Description

Technical Field

[0001] The invention belongs to the field of acoustic performance development of mechanical products, and in particular relates to a high-frequency broadband sound power identification method. Background Art

[0002] Sound power is the main indicator to characterize the characteristics of a sound source, reflecting the size and frequency distribution of the sound radiation of the sound source. Obtaining the sound power of each sound source is an important part of developing the acoustic performance of mechanical products. The sound power of a sound source can be obtained based on experimental testing. Place the sound source, such as an engine or cooling fan, in a semi-anechoic chamber, control its speed, load and other operating parameters, arrange a certain number of microphones around it, and calculate the sound power based on the sound pressure level curve obtained from the test. Experimental testing of the sound power of a sound source has the following disadvantages: the sound source needs to be disassembled independently for testing; professional fixtures are required to fix the sound source; professional equipment is required to accurately control the working conditions of the sound source; and a lot of time and cost are required for testing. The above disadvantages are destined to make the sound power test time-consuming and costly.

[0003] Compared with experimental testing methods, load identification is a very low-cost method. However, current load identification is performed at a narrowband frequency, and there is no high-frequency, broadband load identification method. Summary of the Invention

[0004] In view of this, the present invention aims to propose a high-frequency broadband sound power identification method to solve the problems that experimental testing methods require a lot of time and cost, and that load identification methods all perform identification at narrowband frequencies.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A high-frequency broadband sound power identification method comprises the following steps:

[0007] S1: Establish a source-path-receiver model for high-frequency acoustic transmission problems;

[0008] S2: Test the acoustic transfer function from each sound source to each receiver respectively;

[0009] S3: Test the high-frequency broadband response of the receiver under the condition of multiple sound sources sounding simultaneously;

[0010] S4: Calculate the high-frequency broadband sound power curve of each sound source based on the data measured in S2 and S3;

[0011] The high frequency means that the frequency of the sound power to be sought is above 400 Hz, and the broadband refers to a wide frequency band, that is, a continuous frequency range within a certain range, usually expressed in the form of an octave.

[0012] Furthermore, in the source-path-receiver model in step S1, the source represents a sound source, and there are multiple sound sources;

[0013] The receiver represents a response point. There are multiple response points for sound testing, and the number of response points needs to be greater than 1.5 times the number of sound sources.

[0014] The transmission of sound from a sound source to a receiver represents a path. For a source-path-receiver model with M sound sources and N receivers, there are M*N paths in total.

[0015] According to the above content, a mathematical relationship is established:

[0016] p0 2 M f ·M w =M p

[0017] In the above formula, p0=2×10 -5 Pa, M f is the transfer function matrix, M w is the sound power matrix of the sound source under ideal conditions, M p is the high-frequency broadband response function matrix of the receptor.

[0018] Furthermore, the process of testing the acoustic transfer function in step S2 is:

[0019] S21: Place the volume sound source at the position to be measured;

[0020] S22: placing the receiver at a position where the sound is to be received;

[0021] S23: Turn on the volume sound source and adjust the volume velocity of the sound emitted by the volume sound source to 1m^3 / s;

[0022] S24: The sound pressure level obtained from the receiver test at this time is the acoustic transfer function from the volume sound source to the receiver.

[0023] Furthermore, in step S3, multiple sound sources emit sound simultaneously, and the sound pressure level collected by the receiver is the high-frequency broadband response of the receiver.

[0024] Furthermore, the calculation method for calculating the high-frequency broadband sound power curve of each sound source in step S4 is:

[0025]

[0026] In the above formula, M w,test This is the sound source power matrix calculated by this method, σ i is the transfer function matrix M f The i-th singular value of i、v i M f The left and right singular column vectors of M p,test is the receiver sound pressure level matrix when multiple sound sources sound simultaneously, w(σ i ) is the regularization function, p0=2×10 -5 Pa.

[0027] Furthermore, the sound source sound power matrix is ​​calculated as follows:

[0028]

[0029] In the above formula, L w,i represents the sound power level of the i-th sound source.

[0030] Furthermore, the transfer function matrix is ​​calculated as follows:

[0031]

[0032] In the above formula, L f,ij represents the acoustic transfer function from the i-th sound source to the j-th receiver.

[0033] Furthermore, the receptor sound pressure level matrix is ​​calculated as follows:

[0034] M p =[p1 2 p2 2 L p n 2 ] T

[0035] In the above formula, p j represents the sound pressure of the jth receiver.

[0036] Furthermore, when the test level is constant, the transfer function matrix M f The singular value σ i It will amplify the test error and cause serious deviation in the sound power calculation results. i ) can avoid this situation, and w(σ i ) has a value range of:

[0037]

[0038] Furthermore, the φ is a regularization parameter, and the curve is drawn on a logarithmic scale with ||M p,test -p0 2 M f ·M w || is the horizontal axis, ||M w,test|| is the vertical axis. This curve will show a clear L shape, and the φ value corresponding to the inflection point of the L curve is the optimal regularization parameter value.

[0039] Compared with the prior art, the high-frequency broadband sound power identification method described in the present invention has the following beneficial effects:

[0040] The high-frequency broadband sound power identification method described in the present invention can obtain the sound power curve of each sound source without disassembling components and isolating the sound sources. It has the characteristics of high efficiency, low cost and high accuracy, and can provide guidance for the sound power testing and acoustic performance development of various sound sources in automobiles, rail vehicles, construction machinery and other mechanical products. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0042] Figure 1 A schematic flow chart of a high-frequency broadband sound power identification method according to an embodiment of the present invention;

[0043] Figure 2 Schematic diagram of the acoustic transfer function according to an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the high-frequency broadband response of a receptor according to an embodiment of the present invention;

[0045] Figure 4 Schematic diagram of the sound power of the sound source according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0047] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0048] like Figure 1 A method for identifying high-frequency broadband sound power is shown, comprising the following steps:

[0049] S1: Establish a source-path-receiver model for high-frequency acoustic transmission problems;

[0050] S2: Test the acoustic transfer function from each sound source to each receiver respectively;

[0051] S3: Test the high-frequency broadband response of the receiver under the condition of multiple sound sources sounding simultaneously;

[0052] S4: Calculate the high-frequency broadband sound power curve of each sound source based on the data measured in S2 and S3;

[0053] The high frequency means that the frequency of the sound power to be sought is above 400 Hz, and the broadband refers to a wide frequency band, that is, a continuous frequency range within a certain range, usually expressed in the form of an octave.

[0054] The invention realizes a method for obtaining the sound power curve of each sound source without disassembling components and isolating the sound sources, and at the same time makes up for the deficiency of the prior art in high-frequency broadband power.

[0055] In the source-path-receiver model of S1, the source represents the sound source, of which there are multiple sound sources, and the receptor represents the response point. There are multiple response points for sound testing, and the number of response points needs to be greater than 1.5 times the number of sound sources. The transmission of sound from a sound source to a receptor represents a path. For a source-path-receiver model with M sound sources and N receptors, there are M*N paths in total. Based on the above content, the mathematical relationship is established: p0 2 M f ·M w =M p In the above formula, p0=2×10 -5 Pa, M f is the transfer function matrix, M w is the sound power matrix of the sound source under ideal conditions, M p is the high-frequency broadband response function matrix of the receptor.

[0056] The source-path-receiver model is used to determine which sound sources and receivers are involved in the problem. A two-dimensional table is listed based on the number of paths in the source-path-receiver model. Through subsequent testing steps, a two-dimensional graph of the acoustic transfer function and a two-dimensional graph of the high-frequency broadband response are obtained. The high-frequency broadband sound power curve is calculated using the two two-dimensional graphs.

[0057] like Figure 1 、 Figure 2 As shown: The process of testing the acoustic transfer function in S2 is:

[0058] S21: Place the volume sound source at the position to be measured;

[0059] S22: placing the receiver at a position where the sound is to be received;

[0060] S23: Turn on the volume sound source and adjust the volume velocity of the sound emitted by the volume sound source to 1m^3 / s;

[0061] S24: The sound pressure level obtained from the receiver test at this time is the acoustic transfer function from the volume sound source to the receiver.

[0062] Taking a car as an example, to test the acoustic transfer function from the engine to the driver's position, place a volume sound source at the engine position, adjust the volume velocity of the sound emitted by the volume sound source to 1m^3 / s, and place a microphone at the driver's position. The sound pressure level obtained by the microphone test at this time is the acoustic transfer function from the engine to the driver's position.

[0063] like Figure 1 、 Figure 3 As shown in Figure 3: In S3, multiple sound sources emit sound simultaneously, and the sound pressure level collected by the receiver is the high-frequency broadband response of the receiver.

[0064] Taking the idling condition of a car as an example, keep the car idling. At this time, the engine, air conditioner, intake system, and exhaust system are all sound sources. Several sound sources make sounds at the same time. Place the microphone at the position of the receiver to be tested, such as the driver, co-driver, and rear left passenger. The noise sound pressure level collected by the microphone is the high-frequency broadband response of the receiver.

[0065] like Figure 1 、 Figure 4 As shown: The calculation method for calculating the high-frequency broadband sound power curve of each sound source in S4 is:

[0066]

[0067] In the above formula, M w,test This is the sound source power matrix calculated by this method, σ i is the transfer function matrix M f The i-th singular value of i 、v i M f The left and right singular column vectors of M p,test is the receiver sound pressure level matrix when multiple sound sources sound simultaneously, w(σ i ) is the regularization function, p0=2×10 -5 Pa.

[0068] The sound power matrix of the sound source is calculated as:

[0069]

[0070] In the above formula, L w,i represents the sound power level of the i-th sound source.

[0071] The transfer function matrix is ​​calculated as:

[0072]

[0073] In the above formula, L f,ij represents the acoustic transfer function from the i-th sound source to the j-th receiver.

[0074] The receptor sound pressure level matrix is ​​calculated as:

[0075] M p =[p1 2 p2 2 L p n 2 ] T

[0076] In the above formula, p j represents the sound pressure of the jth receiver.

[0077] When the test level is constant, the transfer function matrix M f The singular value σ i It will amplify the test error and cause serious deviation in the sound power calculation results. i ) can avoid this situation, and w(σ i ) has a value range of:

[0078]

[0079] φ is the regularization parameter, and the curve is drawn on a logarithmic scale with ||M p,test -p0 2 M f ·M w || is the horizontal axis, ||M w,test || is the vertical axis. This curve will show a clear L shape, and the φ value corresponding to the inflection point of the L curve is the optimal regularization parameter value.

[0080] The above formula can be used to calculate the high-frequency broadband sound power curve of each sound source. The high-frequency broadband sound power curve can provide guidance for the sound power testing and acoustic performance development of various sound sources in automobiles, rail vehicles, construction machinery and other mechanical products.

[0081] Those skilled in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0082] In the several embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of the units described above is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment of the present invention.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-frequency broadband sound power identification method, characterized by: The steps include: S1: Establish a source-path-receiver model for high-frequency acoustic transmission problems; S2: Test the acoustic transfer function from each sound source to each receiver respectively; S3: Test the high-frequency broadband response function of the receiver under the condition of multiple sound sources sounding simultaneously; S4: Calculate the high-frequency broadband sound power curve of each sound source based on the acoustic transfer function in S2 and the high-frequency broadband response function in S3; The high frequency means that the frequency of the sound power to be sought is above 400 Hz, and the broadband refers to a wide frequency band, that is, a continuous frequency range within a certain range, usually expressed in the form of an octave; In the source-path-receiver model in step S1, the source represents a sound source, and there are multiple sound sources; The receiver represents a response point. There are multiple response points for sound testing, and the number of response points needs to be greater than 1.5 times the number of sound sources. The transmission of sound from a sound source to a receiver represents a path. For a source-path-receiver model with M sound sources and N receivers, there are M*N paths in total. According to the above content, a mathematical relationship is established: p0 2 M f ·M nf =M p In the above formula, , is the transfer function matrix, M nf is the sound power matrix of the sound source under ideal conditions, M p is the high-frequency broadband response function matrix of the receptor; The process of testing the acoustic transfer function in step S2 is: S21: Place the volume sound source at the position to be measured; S22: placing the receiver at a position where the sound is to be received; S23: Turn on the volume sound source and adjust the volume velocity of the sound emitted by the volume sound source to 1m^3 / s; S24: The sound pressure level obtained from the receiver test at this time is the acoustic transfer function from the volume sound source to the receiver; In step S3, multiple sound sources emit sound simultaneously, and the sound pressure level collected by the receiver is the high-frequency broadband response function of the receiver; The calculation method for calculating the high-frequency broadband sound power curve of each sound source in step S4 is: In the above formula, This is the sound source sound power matrix obtained by calculation, is the transfer function matrix No. singular values, 、 They are The left and right singular column vectors of , is the receiver sound pressure level matrix when multiple sound sources sound simultaneously, is the regularization function, .

2. The high-frequency broadband sound power identification method according to claim 1, characterized in that: The sound source sound power matrix is ​​calculated as follows: In the above formula, Indicates the The sound power level of a sound source, where is 1, 2…m.

3. The high-frequency broadband sound power identification method according to claim 1, characterized in that: The transfer function matrix is ​​calculated as follows: In the above formula, Indicates the The sound source to the The acoustic transfer function of a receiver is is 1, 2…n.

4. The high-frequency broadband sound power identification method according to claim 3, characterized in that: The receptor sound pressure level matrix is ​​calculated as follows: In the above formula, Indicates the The sound pressure of a receiver.

5. The high-frequency broadband sound power identification method according to claim 3, characterized in that: When the test level is constant, the transfer function matrix The singular values ​​of It will amplify the test error and cause serious deviation in the sound power calculation results. The introduction of can avoid this situation, and The value range is: ； in, is the regularization parameter.

6. The high-frequency broadband sound power identification method according to claim 5, characterized in that: Plot the curve on a logarithmic scale. is the horizontal axis, As the vertical coordinate, this curve will show an obvious L shape, and the φ value corresponding to the inflection point of the L curve is the optimal regularization parameter value.

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