Out-of-machine radiation noise prediction and index decomposition method and device

Abstract

The invention provides an off-machine radiation noise prediction and index decomposition method and device, and relates to the technical field of engineering vehicles. The method comprises the following steps: setting an external radiation noise target; dividing a sound source of radiation noise outside the machine; acquiring a numerical value or a frequency spectrum curve of the sound source; acquiring a transfer function of the sound source; according to the numerical value and the transfer function, or the frequency spectrum curve and the transfer function, performing off-machine radiation noise prediction to obtain a prediction result; and judging whether the prediction result meets a set external radiation noise target, if so, outputting the prediction result, and if not, carrying out sound source and transfer function index decomposition. According to the method, the off-machine radiation noise and the contribution of each sound source can be predicted, and the off-machine radiation noise target is decomposed into each system component.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering vehicles, and in particular to a method and a device for predicting and decomposing external radiated noise of a machine. Background Art

[0002] The "Law of the People's Republic of China on the Prevention and Control of Noise Pollution", "Construction Law of the People's Republic of China", "Environmental Protection Law of the People's Republic of China", "Management Specifications for Labor Protection Articles of Employers" and other laws clearly put forward noise limit standards as effective measures; in order to implement the above laws and regulations, the Ministry of Industry and Information Technology, the Ministry of Ecology and Environment, the Ministry of Housing and Urban-Rural Development, and the State Administration for Market Regulation have determined the "Guidelines for Low-Noise Construction Equipment (First Batch)" to promote the application of low-noise construction equipment and help prevent and control noise pollution; in November 2023, the European Parliament and the European Council issued a document to revise the 2000 / 14 / EC Noise Directive, the National Technical Committee for Standardization of Earthmoving Machinery established a standard revision group, and the new version of GB16710 will be released soon. The requirements of standards and regulations on noise levels are becoming increasingly stringent. Different market demands have brought about differentiated product configurations and diversified models, and customized design performance has become more and more prominent. It is urgent to predict the external radiated noise and decompose indicators during the product design stage.

[0003] The main noise sources of engineering vehicles include engine noise, transmission system noise, hydraulic system noise, cooling fan noise, etc. At present, the noise performance development work that should have been carried out in the product design and trial production stages is placed in the noise problem improvement stage of mass-produced products, which greatly increases the iterative improvement cycle of noise problems and makes it difficult to meet the needs of rapid market response and customization of products. At present, in the product design stage, the relationship between the noise of each component and the external radiation noise cannot be determined, and the component noise control requirements cannot be effectively proposed, making it difficult to predict and control the external radiation noise. In order to meet the different requirements of customers in different markets for the noise performance of engineering machinery products, it has become a very urgent issue to predict and decompose the external radiation noise of engineering vehicles.

[0004] The general process of the current engineering vehicle noise design method is: prototype offline - external radiated noise test and noise source identification - main noise source noise reduction design and improvement - whether the improved external radiated noise test meets the requirements. If the improved prototype noise test meets the requirements, the rectification is completed. If the improved prototype noise test does not meet the requirements, the above process is repeated until the external radiated noise meets the requirements.

[0005] Acoustic simulation software can be used to simulate and design the noise of components such as mufflers and fans. However, when simulating vehicle-level noise, due to the large number of sound sources and the different frequency characteristics of different sound sources, it is necessary to use a combination of simulation methods such as finite element method and statistical energy method. Modeling and calculation take a long time and it is difficult to adapt to the product development cycle. In addition, the simulation requires many parameters, some of which are difficult to obtain. Therefore, vehicle-level noise simulation has not been widely used in the engineering vehicle industry.

[0006] CN202310518674.X proposes a method for testing the external noise of a loader. It only needs to set up the test points once at the high-altitude test points, and the vehicle only needs to turn around when the test on one side is finished.

[0007] CN201711105388.1 proposes a low-noise forward design method, which performs a whole vehicle noise simulation analysis based on the optimal parameters of each component.

[0008] CN201811086231.3 discloses a method and system for quickly predicting the exterior noise of a high-speed train, which simplifies the sound sources in different areas into compact point sound sources, calculates the radiation sound pressure level of each compact point sound source, and establishes an energy superposition model of the radiation sound pressure levels of multiple compact point sound sources.

[0009] CN201610669592.5 discloses an ultra-low noise explosion-proof hydraulic excavator. The explosion-proof air-conditioning system is driven by an auxiliary hydraulic motor and can achieve the functions of refrigeration and temperature regulation.

[0010] CN202011560561.9 discloses a method for predicting and reducing exterior vehicle noise, and details how to model and perform simulation analysis.

[0011] CN202311473240.9 discloses a method for predicting exterior vehicle noise based on machine learning, which predicts exterior vehicle noise through the noise of each sound source.

[0012] CN202311538489.3 discloses a key system target confirmation method for passing noise based on a neural network, which predicts passing noise through key structural parameters of the vehicle and noise data of key subsystems of the vehicle. Summary of the invention

[0013] In order to solve the technical problems that the prior art cannot determine the relationship between the noise of each component and the external radiation noise, lacks a method for calculating and predicting the external radiation noise, cannot obtain the noise distribution, cannot effectively know the contribution of each noise source, cannot propose component noise control requirements, cannot control the external radiation noise from the design stage, and often requires several rounds of rectification after the prototype is offline to make the noise meet the requirements, which not only prolongs the product development cycle, but also wastes human and material resources and increases the product development cost, the embodiment of the present invention provides a method and device for predicting and decomposing the external radiation noise. The technical solution is as follows:

[0014] On the one hand, a method for predicting external radiated noise and index decomposition is provided, which is implemented by an external radiated noise prediction and index decomposition device, and includes:

[0015] S1. Set the external radiated noise target.

[0016] S2. Classify the sources of external radiated noise.

[0017] S3. Obtain the numerical value or spectrum curve of the sound source.

[0018] S4. Obtain the transfer function of the sound source.

[0019] S5. Predict the external radiated noise according to the numerical value and the transfer function, or the spectrum curve and the transfer function, and obtain a prediction result.

[0020] S6. Determine whether the prediction result meets the set external radiated noise target. If so, output the prediction result. If not, perform sound source and transfer function index decomposition.

[0021] Optionally, the sound sources in S2 include: engine noise, cooling system noise, exhaust noise, intake noise, hydraulic component noise and transmission component noise.

[0022] Optionally, the transfer function in S4 includes: an exhaust transfer function, an intake transfer function, a cooling system transfer function, an engine transfer function, a transmission component transfer function and a hydraulic component transfer function.

[0023] Among them, the exhaust transfer function is the exhaust correction value S in the entire frequency band e Or the exhaust transfer function TF in the 1 / 3 octave band of the center frequency f ef .

[0024] Among them, the exhaust correction amount S in the entire frequency band e As shown in the following equation (1), the exhaust gas transfer function TF in the 1 / 3 octave band of the center frequency f is ef As shown in the following formula (2):

[0025]

[0026]

[0027] Where r is the radius of the hemispherical surface for the test of the external radiated sound power level, x1, x2, x3, x4, x5, x6 are the distances from the exhaust port to the six measuring points specified in the standard, and TF is ief Represents the sound pressure level of the noise value at the i-th measuring point.

[0028] The intake transfer function is the intake correction value S in the entire frequency band. a Or the air transfer function TF in the 1 / 3 octave band of the center frequency f af .

[0029] Among them, the intake correction amount S in the entire frequency band a As shown in the following equation (3), the transfer function TF of the intake air in the 1 / 3 octave band of the center frequency f is af As shown in the following formula (4):

[0030]

[0031]

[0032] Where y1, y2, y3, y4, y5, and y6 represent the distances of the six measuring points specified in the air inlet distance standard, and TF iaf Represents the sound pressure level of the noise value at the i-th measuring point.

[0033] The cooling system transfer function is the sound insulation of the hood to the cooling system in the entire frequency band N f Or the cooling system transfer function TF in the 1 / 3 octave band of the center frequency f ff .

[0034] Among them, the sound insulation of the cooling system by the hood in the entire frequency band is N f As shown in equation (5), the transfer function TF of the cooling system in the 1 / 3 octave band of the center frequency f is ff As shown in the following formula (6):

[0035]

[0036]

[0037] Where, L f It indicates the sound power level of the cooling system under a certain working condition. L indicates the sound power level of the external radiation of the whole machine under the corresponding working condition in the fixed state. L0 indicates the sound power level of the whole machine under the corresponding working condition in the fixed state with the fan removed. TF iff Represents the sound pressure level of the noise value at the i-th measuring point.

[0038] The engine transfer function is the sound insulation of the hood to the engine in the entire frequency band N m Or the engine transfer function TF in the 1 / 3 octave band of the center frequency f mf .

[0039] Among them, the sound insulation of the hood to the engine in the entire frequency band is N m As shown in the following equation (7), the engine transfer function TF in the 1 / 3 octave band of the center frequency f is mf As shown in the following formula (8):

[0040]

[0041]

[0042] Where, L m Indicates the sound power level of the engine under a certain working condition, P e Indicates the sound pressure level at 0.5 meters at the exhaust port under the corresponding working conditions, P a Indicates that the sound pressure level at 0.5 meters under the corresponding working conditions of the air outlet is, TF ijmf Represents the sound pressure level of the noise value at the i-th measuring point on the j-th surface.

[0043] The transmission component transfer function is the sound insulation of the hood to the transmission component in the entire frequency band N c Or the transmission component transfer function TF in the 1 / 3 octave band of the center frequency f cf .

[0044] Among them, the sound insulation of the hood to the transmission parts in the entire frequency band is N c As shown in the following equation (9), the transfer function TF of the transmission component in the 1 / 3 octave band of the center frequency f is cf As shown in the following formula (10):

[0045]

[0046]

[0047] Where, L c It indicates the sound power level of the transmission component under a certain working condition. L1 indicates the external radiated sound power level of the whole machine under the corresponding working condition in the stationary state. L2 indicates the sound power level of the whole machine under the corresponding working condition in the stationary state. TF ijcf Represents the sound pressure level of the noise value at the i-th measuring point on the j-th surface.

[0048] The transfer function of the hydraulic components is the sound insulation of the hood to the hydraulic components in the entire frequency band N y Or the transfer function TF of the hydraulic component in the 1 / 3 octave band of the center frequency f yf .

[0049] Among them, the sound insulation of the hood to the hydraulic components in the entire frequency band is N y As shown in the following equation (11), the transfer function TF of the hydraulic component in the 1 / 3 octave band of the center frequency f is yf As shown in the following formula (12):

[0050]

[0051]

[0052] Where, L y It indicates the sound power level of the hydraulic components under a certain working condition, L3 indicates the sound power level of the whole machine under the corresponding working condition in the stationary state, TF ijyf Represents the sound pressure level of the noise value at the i-th measuring point on the j-th surface.

[0053] Optionally, in S5, predicting the external radiated noise according to the numerical value and the transfer function, or the spectrum curve and the transfer function, to obtain the prediction result includes:

[0054] S51. Calculate the external radiated noise and the contribution energy ratio of each sound source to the external radiated noise in the entire frequency band according to the numerical value and the transfer function.

[0055] S52. According to the frequency spectrum curve and the transfer function, the sound power level of the external radiated noise of the machine in a 1 / 3 octave band with a center frequency of f and the energy contribution ratio of each sound source to the external radiated noise of the machine in a 1 / 3 octave band with a center frequency of f are calculated.

[0056] Optionally, the external radiation noise in S51 is as shown in the following equation (13):

[0057]

[0058] Where, L W Indicates the sound power level of external radiated noise in the entire frequency band, SWL m Indicates the sound power level of the engine in the entire frequency band, N m Indicates the sound insulation of the hood to the engine in the entire frequency band, SWL f Indicates the sound power level of the cooling system in the entire frequency band, N f Indicates the sound insulation of the hood to the cooling system in the entire frequency band, SWL c Indicates the sound power level of the transmission component in the entire frequency band, N c Indicates the sound insulation of the hood to the transmission parts in the entire frequency band, SWL y Indicates the sound power level of hydraulic components in the entire frequency band, N y Indicates the sound insulation of the hood to the hydraulic components in the entire frequency band, SWL e It represents the exhaust sound power level in the whole frequency band, S eIndicates the exhaust correction amount in the entire frequency band, SWL a Indicates the sound power level of intake air in the entire frequency band, S a Indicates the amount of intake correction over the entire frequency band.

[0059] The energy ratio of each sound source to the external radiated noise in the entire frequency band is shown in the following formula (14):

[0060]

[0061] In the formula, k i Indicates the energy ratio of each sound source to the external radiated noise in the entire frequency band, SWL i Indicates the sound power level of a sound source in the entire frequency band, TF i It indicates the sound insulation amount of the hood to a certain sound source in the entire frequency band or the correction amount of a certain sound source in the entire frequency band.

[0062] Optionally, the sound power level of the external radiated noise in S52 in a band with a center frequency of 1 / 3 octave f is as shown in the following formula (15):

[0063]

[0064] Where, L Wf It indicates the sound power level of the external radiated noise in the 1 / 3 octave band of the center frequency f, SWL mf It indicates the sound power level of the engine in the 1 / 3 octave band of the center frequency f, TF mf It represents the transfer function of the generator in the 1 / 3 octave band of the center frequency f, SWL ff It represents the sound power level of the cooling system in the 1 / 3 octave band of the center frequency f, TF ff It represents the transfer function of the cooling system in the 1 / 3 octave band of the center frequency f, SWL cf It indicates the sound power level of the transmission component in the 1 / 3 octave band of the center frequency f, TF cf It represents the transfer function of the transmission component in the 1 / 3 octave band of the center frequency f, SWL yf It indicates the sound power level of hydraulic components in the 1 / 3 octave band with the center frequency f, TF yf It represents the transfer function of the hydraulic component in the 1 / 3 octave band of the center frequency f, SWL ef It indicates the sound power level of the exhaust in the 1 / 3 octave band with the center frequency f, TF ef It represents the exhaust gas transfer function in the 1 / 3 octave band of the center frequency f, SWL af Indicates the sound power level of the intake air in the 1 / 3 octave band with the center frequency f, TF af It represents the transfer function of the intake air in the 1 / 3 octave band of the center frequency f, S iIt represents the predicted area of ​​the sphere with radius i, and S0 represents the reference surface area.

[0065] The energy ratio of each sound source to the external radiated noise in the 1 / 3 octave band of the center frequency f is shown in the following formula (16):

[0066]

[0067] In the formula, k if It indicates the contribution energy ratio of a sound source in the 1 / 3 octave band of the center frequency f. if It indicates the sound power level of a sound source in a 1 / 3 octave band with a center frequency of f, TF if It represents the transfer function of a sound source in a 1 / 3 octave band with a center frequency of f.

[0068] Optionally, the index decomposition in S6 is as shown in the following equations (17) and (18):

[0069]

[0070]

[0071] Where SWL i Indicates the sound power level of a sound source in the entire frequency band, TF i It indicates the sound insulation of the hood to a certain sound source in the whole frequency band or the correction amount of a certain sound source in the whole frequency band. Indicates the contribution, L Wb Indicates the external radiated noise index requirements in the entire frequency band, SWL if It indicates the sound power level of a sound source in a 1 / 3 octave band with a center frequency of f, TF if It represents the transfer function of a sound source in a 1 / 3 octave band with a center frequency of f, S i represents the predicted area of ​​the sphere with radius i, S0 represents the reference surface area, L Wfb It indicates the index requirement of the external radiated noise within the 1 / 3 frequency band of the center frequency f.

[0072] On the other hand, a device for predicting and decomposing external radiated noise is provided, and the device is applied to a method for predicting and decomposing external radiated noise, and the device comprises:

[0073] The setting module is used to set the external radiated noise target.

[0074] The division module is used to divide the sound sources of the external radiated noise.

[0075] The first acquisition module is used to acquire the value or frequency spectrum curve of the sound source.

[0076] The second acquisition module is used to acquire the transfer function of the sound source.

[0077] The prediction module is used to predict the external radiated noise according to the numerical value and the transfer function, or the spectrum curve and the transfer function, and obtain the prediction result.

[0078] The output module is used to determine whether the prediction results meet the set external radiated noise target. If so, the prediction results are output; if not, the sound source and transfer function index decomposition is performed.

[0079] On the other hand, a device for predicting external radiation noise and decomposing an index is provided, and the device comprises: a processor; a memory, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, any one of the above-mentioned methods for predicting external radiation noise and decomposing an index is implemented.

[0080] On the other hand, a computer-readable storage medium is provided, wherein at least one instruction is stored in the storage medium, and the at least one instruction is loaded and executed by a processor to implement any one of the above-mentioned external radiation noise prediction and index decomposition methods.

[0081] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0082] In the embodiment of the present invention, the indicators of various components can be decomposed according to the external radiation noise indicators in the new product design stage, the noise control of the components can be achieved in the design stage, and the contribution of each sound source can be accurately obtained in the prototype debugging stage.

[0083] The present invention can avoid completely relying on the test of the physical prototype during the product development process, avoid the test rectification and retesting work after the prototype is offline, and save product development costs.

[0084] The present invention does not completely rely on simulation, but is based on a data calculation method, so as to obtain the passing noise result more quickly and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0086] Figure 1 This is a flow chart of a method for predicting external radiated noise and decomposing an index provided by an embodiment of the present invention;

[0087] Figure 2 This is a sound source division diagram without a hood provided by an embodiment of the present invention;

[0088] Figure 3 is a diagram of an earthmoving machine with a hood provided by an embodiment of the present invention;

[0089] Figure 4 It is a measuring point diagram of earth-moving machinery provided by an embodiment of the present invention;

[0090] Figure 5 is a diagram of the arrangement of intake and exhaust measurement points provided by an embodiment of the present invention;

[0091] Figure 6 It is a block diagram of an external radiation noise prediction and index decomposition device provided by an embodiment of the present invention;

[0092] Figure 7 It is a structural schematic diagram of an off-machine radiation noise prediction and index decomposition device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0093] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0094] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0095] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same.

[0096] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0097] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0098] The embodiment of the present invention provides a method for predicting external radiation noise and index decomposition, which can be implemented by an external radiation noise prediction and index decomposition device, which can be a terminal or a server. Figure 1The flowchart of the method for predicting and decomposing the external radiated noise of the machine is shown in FIG. 1 . The processing flow of the method may include the following steps:

[0099] S1. Set the external radiated noise target.

[0100] In a feasible implementation, the external radiated sound power level of the whole machine of the new model is determined within the entire frequency band or within a certain 1 / 3 frequency band according to relevant standard requirements, customer requirements or design requirements.

[0101] S2. Classify the sources of external radiated noise.

[0102] In a feasible implementation manner, the external radiated noise is formed by the superposition of noises of various components, such as Figure 2 , Figure 3 As shown, the contribution of each component noise to the measuring point is calculated, and then the noise contribution of each component is added up to predict the external radiated noise level. The external radiated noise is decomposed into the main noise sources such as engine noise, cooling system noise, exhaust noise, intake noise, hydraulic component noise, transmission component noise, etc.

[0103] S3. Obtain the numerical value or spectrum curve of the sound source.

[0104] Specifically, 1) engine sound power level SWL m or SWL mf It can be obtained from the engine supplier, and provides the engine body radiated sound power level value SWL according to GB / T1859 "Engineering method and simplified method for measuring air noise radiated by reciprocating internal combustion engines" m Or spectrum curve SWL mf If the data provided does not match the required speed condition, based on the existing test data statistics, a correction can be made based on the noise increasing by 1dB(A) for every 100rpm increase in engine speed.

[0105] 2) Cooling system sound power level SWL f or SWL ff It can be obtained from the cooling system supplier. According to the design speed ratio of the engine and cooling system, refer to the measurement point arrangement of GB / T 25612 "Fixed test conditions for determination of sound power level of earth-moving machinery", and test the sound power level value SWL of the cooling system noise at the corresponding speed. f Or spectrum curve SWL ff The cooling system needs to be tested for the radiated sound power level of the fan and radiator. If the radiator cannot provide the test, the correction value needs to be increased based on the noise data of the cooling fan alone. If the fan blades are curved, it is recommended to increase by 6dB(A) after matching the radiator. If the fan blades are linear, it is recommended to increase by 3dB(A) after matching the radiator.

[0106] 3) Exhaust sound power level SWL e or SWL ef . Exhaust Sound Power Level SWL e or SWL ef The noise sound pressure level SPL at 0.5 meters from the exhaust port e or SPL ef The noise value at 0.5 meters from the exhaust port can be obtained from the exhaust supplier, or from the data accumulated in the previous vehicle test, such as Figure 4 The exhaust noise is simplified to a point sound source centered at the center of the exhaust port. If the directivity of the exhaust noise is not considered, then according to the point sound source spherical radiation calculation method, the exhaust sound power level SWL e or SWL ef And the noise sound pressure level SPL at 0.5 meters from the exhaust port e or SPL ef The relationship within the entire frequency band or a 1 / 3 octave band is as follows:

[0107] SWL e =SPL e +10*lg(4π*0.5 2 )=SPL e +5 (1)

[0108] SWL ef =SPL ef +10*lg(4π*0.5 2 )=SPL ef +5 (2)

[0109] However, the directionality of exhaust noise is quite obvious. The sound pressure value at the same distance between the front and back of the exhaust port differs by about 4dB(A). Through the directivity test of the actual vehicle and the point sound source simulation test, after considering the directionality of the exhaust noise, the exhaust sound power level SWL e or SWL ef And the noise sound pressure level SPL at 0.5 meters from the exhaust port e or SPL ef The relationship over the entire frequency band or within a 1 / 3 octave band can be defined as:

[0110] SWL e =SPL e +2 (3)

[0111] SWL ef =SPL ef +2 (4)

[0112] 4) Intake sound power level SWL a or SWL af . Intake Sound Power Level SWLa or SWL af The noise sound pressure level SPL at 0.5 meters from the air inlet a or SPL af The noise value at 0.5 meters from the air inlet can be obtained from the air inlet supplier, or from the data accumulated in the previous vehicle test, such as Figure 4 The intake noise is simplified to a point sound source centered at the center of the air inlet. According to the sound source spherical radiation calculation method, the intake sound power level SWL a or SWL af And the noise sound pressure level SPL at 0.5 meters from the air inlet a or SPL af The relationship within the entire frequency band or a 1 / 3 octave band is as follows:

[0113] SWL a =SPL a +10*lg(4π*0.5 2 )=SPL a +5 (5)

[0114] SWL af =SPL af +10*lg(4π*0.5 2 )=SPL af +5 (6)

[0115] 5) Transmission parts sound power level SWL c or SWL cf It can be obtained from the transmission component supplier. According to the design speed ratio of the engine and transmission components, refer to the measurement point arrangement of GB / T 25612 "Fixed test conditions for determination of sound power level of earth-moving machinery", and test the transmission component noise sound power level value SWL at the corresponding speed. c Or spectrum curve SWL cf .

[0116] 6) Hydraulic components sound power level SWL y or SWL yf It can be obtained from the hydraulic component supplier. According to the design speed ratio of the engine and transmission components, refer to the measurement point arrangement of GB / T 25612 "Fixed test conditions for determination of sound power level of earth-moving machinery", and test the sound power level value SWL of the hydraulic component noise at the corresponding speed. y Or spectrum curve SWL yf .

[0117] S4. Obtain the transfer function of the sound source.

[0118] Optionally, the transfer function in S4 may include: an exhaust transfer function, an intake transfer function, a cooling system transfer function, an engine transfer function, a transmission component transfer function, and a hydraulic component transfer function.

[0119] 1) Exhaust transfer function S e or TF ef :S e Here, the exhaust correction is used to represent the test hemispherical radius of the external radiated sound power level. The distances from the exhaust port to the six test points specified in the standard are x1, x2, x3, x4, x5, and x6, respectively. Figure 5 As shown, according to the noise radiation law of point sound source, the noise correction amount S caused by the exhaust port deviating from the center of the whole machine is e It can be calculated by the following formula:

[0120]

[0121] TF ef The sound pressure level of the noise value in each 1 / 3 octave band at six measurement points outside the machine is measured by a microphone. ef It can be calculated by the following formula:

[0122]

[0123] Where: TF ief It represents the noise value sound pressure level at the i-th measuring point, in decibels (dB).

[0124] 2) Intake transfer function S a or TF af :S a Here, the air intake correction is used to represent the noise. Assuming that the radius of the hemispherical surface for the external radiated sound power level test is r, and the distances between the air intake and the six measuring points specified in the standard are y1, y2, y3, y4, y5, and y6, the noise correction S4 caused by the air intake deviating from the center of the whole machine can be calculated by the following formula according to the noise radiation law of the point sound source:

[0125]

[0126] TF af The sound pressure level of the noise value in each 1 / 3 octave band at six measurement points outside the machine is measured by a microphone. af It can be calculated by the following formula:

[0127]

[0128] Where: TFiaf It represents the noise value sound pressure level at the i-th measuring point, in decibels (dB).

[0129] 3) Cooling system transfer function N f or TF ff :N f Here, the sound insulation of the cooling system is expressed by the hood, which can be obtained through physical testing of similar models of the previous generation. The test method is as follows: It is known that the sound power level of the cooling system under a certain working condition is L f , the sound power level of the external radiation of the whole machine under the working condition of the whole machine in the fixed state is L, and the sound power level of the whole machine in the fixed state with the fan removed is L0, so the contribution of the fan to the sound power level of the whole machine is 10*lg(10 0.1*L -10 0.1*L0 ). Then the noise insulation of the hood to the cooling system noise is N f for:

[0130]

[0131] TF ff The sound pressure level of the noise value in each 1 / 3 octave band at six measurement points outside the machine is measured by a microphone. ff It can be calculated by the following formula:

[0132]

[0133] Where: TF iff It represents the noise value sound pressure level at the i-th measuring point, in decibels (dB).

[0134] 4) Engine transfer function N m or TF mf :N m Here, the engine hood is used to represent the sound insulation of the engine, which can be obtained through physical testing of similar models of the previous generation. The test method is as follows: It is known that the sound power level of the engine under a certain working condition is L m The sound power level of the external radiation of the whole machine under the working condition of the whole machine stationary state (without starting the transmission components and hydraulic components) is L, the sound power level of the whole machine stationary state (without starting the transmission components and hydraulic components) with the fan removed is L0, and the sound pressure level at 0.5 meters at the exhaust port under the working condition is P e , the sound pressure level at 0.5 meters at the air inlet under the corresponding working conditions is P a Without starting the transmission and hydraulic components, the engine contributes 10*lg(10 0.1*L0 -10 0.1*(Pe+2+Se) -10 0.1*(Pa+5+Sa) ), then the noise insulation of the hood to the engine noise is N m for:

[0135]

[0136] TF mf The sound pressure level of the six external sound power points in each 1 / 3 octave band is measured by using a microphone. The volume sound source is placed at the center of the six engine surfaces 100 mm away from the surface, and a sound source with a sound power of 1 W is applied. The sound pressure level of the six external sound power points in each 1 / 3 octave band is obtained. TF ff It can be calculated by the following formula:

[0137]

[0138] Where: TF ijmf It represents the noise sound pressure level at the i-th measuring point on the j-th surface, in decibels (dB).

[0139] 5) Transmission component transfer function N c or TF cf :N c Here, the sound insulation of the transmission components by the hood is expressed, which can be obtained through the actual test of the previous generation of similar models. The test method is as follows: It is known that the sound power level of the transmission component under a certain working condition is L c , the sound power level of the external radiation of the whole machine under the working condition of the stationary state is L1, and the sound power level of the whole machine under the stationary state (without turning on the transmission components) is L2. The contribution of the transmission components to the sound power level of the whole machine is 10*lg(10 0.1*L1 -10 0.1*L2 ). Then the noise insulation of the hood to the transmission parts is N c for:

[0140]

[0141] TF cf The sound pressure level of the noise value in each 1 / 3 octave band at six measurement points outside the machine is measured by a microphone. cf It can be calculated by the following formula:

[0142]

[0143] Where: TF ijcf It represents the noise sound pressure level at the i-th measuring point on the j-th surface, in decibels (dB).

[0144] 6) Hydraulic component transfer function N y or TF yf :N yHere, the sound insulation of the hydraulic components by the hood is expressed, which can be obtained through the actual test of the previous generation of similar models. The test method is as follows: It is known that the sound power level of the hydraulic component under a certain working condition is L y , the sound power level of the external radiation of the whole machine under the working condition of the whole machine in the fixed state is L1, and the sound power level of the whole machine in the fixed state (without opening the hydraulic components) is L3. The contribution of the hydraulic components to the sound power level of the whole machine is 10*lg(10 0.1*L1 -10 0.1*L3 ). Then the noise insulation of the hood to the noise of hydraulic components is N y for:

[0145]

[0146] TF yf The sound pressure level of the six external sound power measurement points in each 1 / 3 octave band is measured by using a microphone. yf It can be calculated by the following formula:

[0147]

[0148] Where: TF ijyf It represents the noise sound pressure level at the i-th measuring point on the j-th surface, in decibels (dB).

[0149] S5. Predict the external radiated noise according to the numerical value and the transfer function, or the spectrum curve and the transfer function, and obtain a prediction result.

[0150] Optionally, the above step S5 may include the following steps S51-S52:

[0151] S51. Calculate the external radiated noise and the contribution energy ratio of each sound source to the external radiated noise in the entire frequency band according to the numerical value and the transfer function.

[0152] In a feasible implementation, when only a single value of each sound source characteristic and the transfer function in the entire frequency band can be obtained, a synthetic calculation method based on an empirical formula is proposed.

[0153] External radiated sound power level L W It can be calculated by the following formula:

[0154]

[0155] Where, L W It indicates the sound power level of the external radiated noise in the whole frequency band, in decibels (dB), SWL m It indicates the sound power level of the engine in the entire frequency band, in decibels (dB), Nm It indicates the sound insulation of the hood to the engine in the whole frequency band, in decibels (dB), SWL f It indicates the sound power level of the cooling system in the whole frequency band, in decibels (dB), N f It indicates the sound insulation of the hood to the cooling system in the entire frequency band, in decibels (dB), SWL c It indicates the sound power level of the transmission component in the entire frequency band, in decibels (dB), N c It indicates the sound insulation of the hood to the transmission parts in the whole frequency band, in decibels (dB), SWL y It indicates the sound power level of hydraulic components in the whole frequency band, in decibels (dB), N y It indicates the sound insulation of the hood to the hydraulic components in the entire frequency band, in decibels (dB), SWL e It indicates the sound power level of exhaust in the whole frequency band, in decibels (dB), S e Indicates the amount of exhaust correction in the entire frequency band, in decibels (dB), SWL a It indicates the sound power level of the intake air in the whole frequency band, in decibels (dB), S a Indicates the amount of intake correction in the entire frequency band, in decibels (dB).

[0156] The energy ratio of each sound source to the external radiated noise in the entire frequency band is shown in the following formula (20):

[0157]

[0158] In the formula, k i It indicates the energy ratio of each sound source to the external radiated noise in the whole frequency band, in %, SWL i Indicates the sound power level of a sound source in the entire frequency band, TF i It indicates the sound insulation of the hood to a certain sound source in the entire frequency band or the correction amount of a certain sound source in the entire frequency band, in decibels (dB).

[0159] S52. According to the frequency spectrum curve and the transfer function, the sound power level of the external radiated noise of the machine in a 1 / 3 octave band with a center frequency of f and the energy contribution ratio of each sound source to the external radiated noise of the machine in a 1 / 3 octave band with a center frequency of f are calculated.

[0160] In a feasible implementation, when the characteristics of each sound source and the transfer function curve values ​​in the 1 / 3 octave band are available, a one-dimensional calculation method based on spectrum data is proposed.

[0161] The contribution of each sound source to the external radiated noise in each 1 / 3 octave band is:

[0162] SPL ii =SWLii +TF ii -120 (21)

[0163] Among them: SPL ii It is the sound pressure level of the external radiated noise measurement point in a certain 1 / 3 octave band, in decibels (dB); SWL ii It is the sound power level of a sound source in a 1 / 3 octave band, measured in decibels (dB); TF ii It is the transfer function of a sound source in a 1 / 3 octave band when the incident sound power is 1W, and the unit is decibel (dB).

[0164] The noise value of the external radiated noise in each 1 / 3 octave band is calculated according to formula (22):

[0165]

[0166] Where, L Wf It indicates the sound power level of the external radiated noise in the 1 / 3 octave band of the center frequency f, in decibels (dB). mf It indicates the sound power level of the engine in the 1 / 3 octave band of the center frequency f, in decibels (dB), TF mf It represents the transfer function of the generator in the 1 / 3 octave band of the center frequency f, in decibels (dB), SWL ff It indicates the sound power level of the cooling system in the 1 / 3 octave band of the center frequency f, in decibels (dB), TF ff It represents the transfer function of the cooling system in the 1 / 3 octave band of the center frequency f, in decibels (dB), SWL cf It indicates the sound power level of the transmission component in the 1 / 3 octave band of the center frequency f, in decibels (dB), TF cf It indicates the transfer function of the transmission component in the 1 / 3 octave band of the center frequency f, in decibels (dB), SWL yf It indicates the sound power level of hydraulic components in the 1 / 3 octave band of the center frequency f, in decibels (dB), TF yf It represents the transfer function of the hydraulic component in the 1 / 3 octave band of the center frequency f, in decibels (dB), SWL ef It indicates the sound power level of the exhaust in the 1 / 3 octave band of the center frequency f, in decibels (dB), TF ef It represents the exhaust gas transfer function in the 1 / 3 octave band of the center frequency f, in decibels (dB), SWL af It indicates the sound power level of the intake air in the 1 / 3 octave band with the center frequency f, in decibels (dB), TF af It represents the transfer function of the intake air in the 1 / 3 octave band of the center frequency f, in decibels (dB), Si Indicates the predicted area of ​​the sphere with radius i, in square meters (m 2 ), S0 represents the reference surface area, which is 1m 2 .

[0167] The energy ratio of each sound source to the external radiated noise in the 1 / 3 octave band of the center frequency f is shown in the following formula (23):

[0168]

[0169] In the formula, k if It indicates the contribution energy ratio of a sound source in the 1 / 3 octave band of the center frequency f, in %, SWL if It indicates the sound power level of a sound source in a 1 / 3 octave band with a center frequency of f, in decibels (dB). if It represents the transfer function of a sound source in a 1 / 3 octave band with a center frequency of f, in decibels (dB).

[0170] The external radiated noise is calculated according to formula (24):

[0171]

[0172] Where: L W It indicates the noise value of the external radiated noise in the whole frequency band, in decibel (dB), L Wi It indicates the noise value of the external radiated noise in the 1 / 3 octave band of the center frequency i, in decibels (dB).

[0173] S6. Determine whether the prediction result meets the set external radiated noise target. If so, output the prediction result. If not, perform sound source and transfer function index decomposition.

[0174] In a feasible implementation, if the predicted external radiated noise meets the noise target of step S1, there is no need to perform the following decomposition of the sound sources and transfer functions. If not, the sound sources and transfer function indicators should be reset to reduce the excitation of each sound source, optimize each transfer function, and find a balance between performance and cost in each sound source and transfer function. The external radiated noise is optimized by taking the external radiated noise as the optimization target, the immutable sound sources and transfer functions as constraints, and the mutable sound sources and transfer functions as variables. The indicator decomposition can be performed according to the following formula, so that the contribution of a certain sound source does not exceed the external radiated noise indicator. times.

[0175]

[0176]

[0177] Where SWL i It indicates the sound power level of a sound source in the entire frequency band, in decibels (dB). i It indicates the sound insulation of the hood to a certain sound source in the entire frequency band or the correction amount of a certain sound source in the entire frequency band, in decibels (dB). Indicates contribution, in percentage (%), L Wb It indicates the external radiated noise index requirement in the entire frequency band, in decibels (dB), SWL if It indicates the sound power level of a sound source in a 1 / 3 octave band with a center frequency of f, in decibels (dB). if It represents the transfer function of a sound source in a 1 / 3 octave band with a center frequency of f, in decibels (dB). Wfb It indicates the external radiated noise requirement within the 1 / 3 octave band of the center frequency f, in decibels (dB).

[0178] Further, the sound power level index of each sound source is evaluated: the sound power level of each sound source can be determined according to national standards, industry standards, enterprise standards, benchmark products or contribution. Select each sound source that meets the target requirements from the database. If there is none, select each sound source closest to the index, and adjust the transfer function index accordingly, and return to the prediction part to ensure that the calculated external radiated sound power level meets S1.

[0179] Furthermore, the transfer function index of each sound source is evaluated: the transfer function of each sound source is judged. If it is less than the preset target, the hood needs to be redesigned for sound absorption and insulation, or the intake and exhaust positions need to be adjusted, and the prediction part is returned to ensure that the calculated external radiated sound power level meets step S1.

[0180] In the embodiment of the present invention, the indicators of various components can be decomposed according to the external radiation noise indicators in the new product design stage, the noise control of the components can be achieved in the design stage, and the contribution of each sound source can be accurately obtained in the prototype debugging stage.

[0181] The present invention can avoid completely relying on the test of the physical prototype during the product development process, avoid the test rectification and retesting work after the prototype is offline, and save product development costs.

[0182] The present invention does not completely rely on simulation, but is based on a data calculation method, so as to obtain the passing noise result more quickly and accurately.

[0183] Figure 6 The block diagram of a device for predicting external radiation noise and decomposing an index according to an exemplary embodiment is shown. The device is used in a method for predicting external radiation noise and decomposing an index. Figure 6The device includes a setting module 310, a division module 320, a first acquisition module 330, a second acquisition module 340, a prediction module 350 and an output module 360. Among them:

[0184] The setting module 310 is used to set the external radiated noise target.

[0185] The division module 320 is used to divide the sound sources of the external radiated noise.

[0186] The first acquisition module 330 is used to acquire the value or frequency spectrum curve of the sound source.

[0187] The second acquisition module 340 is used to acquire the transfer function of the sound source.

[0188] The prediction module 350 is used to predict the external radiated noise according to the numerical value and the transfer function, or the spectrum curve and the transfer function, to obtain a prediction result.

[0189] The output module 360 ​​is used to determine whether the prediction result meets the set external radiated noise target. If so, the prediction result is output; if not, the sound source and transfer function index decomposition is performed.

[0190] In the embodiment of the present invention, the indicators of various components can be decomposed according to the external radiation noise indicators in the new product design stage, the noise control of the components can be achieved in the design stage, and the contribution of each sound source can be accurately obtained in the prototype debugging stage.

[0191] The present invention can avoid completely relying on the test of the physical prototype during the product development process, avoid the test rectification and retesting work after the prototype is offline, and save product development costs.

[0192] The present invention does not completely rely on simulation, but is based on a data calculation method, so as to obtain the passing noise result more quickly and accurately.

[0193] Figure 7 is a schematic diagram of the structure of an off-machine radiation noise prediction and index decomposition device provided by an embodiment of the present invention, such as Figure 7 As shown, the external radiation noise prediction and index decomposition equipment may include the above Figure 6 Optionally, the device 410 for predicting and decomposing external radiated noise may include a first processor 2001 .

[0194] Optionally, the external radiation noise prediction and index decomposition device 410 may further include a memory 2002 and a transceiver 2003 .

[0195] The first processor 2001, the memory 2002 and the transceiver 2003 may be connected via a communication bus.

[0196] Combine the following Figure 7 The components of the external radiation noise prediction and index decomposition device 410 are specifically introduced:

[0197] The first processor 2001 is the control center of the external radiation noise prediction and index decomposition device 410, which can be a processor or a general term for multiple processing elements. For example, the first processor 2001 is one or more central processing units (CPUs), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiment of the present invention, such as one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (field programmable gate arrays, FPGAs).

[0198] Optionally, the first processor 2001 may perform various functions of the external radiation noise prediction and index decomposition device 410 by running or executing a software program stored in the memory 2002 and calling data stored in the memory 2002 .

[0199] In a specific implementation, as an embodiment, the first processor 2001 may include one or more CPUs, such as Figure 7 CPU0 and CPU1 are shown in FIG.

[0200] In a specific implementation, as an embodiment, the external radiation noise prediction and index decomposition device 410 may also include multiple processors, such as Figure 7 The first processor 2001 and the second processor 2004 are shown in FIG. Each of these processors can be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor here can refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0201] The memory 2002 is used to store the software program for executing the solution of the present invention, and is controlled to be executed by the first processor 2001. The specific implementation method can refer to the above method embodiment, which will not be repeated here.

[0202] Optionally, the memory 2002 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 2002 may be integrated with the first processor 2001, or may exist independently, and may be accessed through the interface circuit ( Figure 7 (not shown) is coupled to the first processor 2001, which is not specifically limited in this embodiment of the present invention.

[0203] The transceiver 2003 is used to communicate with a network device or a terminal device.

[0204] Optionally, the transceiver 2003 may include a receiver and a transmitter ( Figure 7 The receiver is used to implement a receiving function, and the transmitter is used to implement a sending function.

[0205] Optionally, the transceiver 2003 may be integrated with the first processor 2001, or may exist independently, and may be connected to the first processor 2001 through the interface circuit ( Figure 7 (not shown) is coupled to the first processor 2001, which is not specifically limited in this embodiment of the present invention.

[0206] It should be noted that Figure 7 The structure of the external radiation noise prediction and index decomposition device 410 shown in the figure does not constitute a limitation on the router. The actual knowledge structure identification device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0207] In addition, the technical effects of the external radiation noise prediction and index decomposition device 410 can refer to the technical effects of the external radiation noise prediction and index decomposition method described in the above method embodiment, which will not be repeated here.

[0208] It should be understood that the first processor 2001 in the embodiment of the present invention may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0209] It should also be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0210] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0211] It should be understood that the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding.

[0212] In the present invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0213] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0214] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. 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.

[0215] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0216] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0217] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0218] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0219] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0220] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for predicting external radiated noise and decomposing indicators, characterized in that: The method comprises: S1. Set the external radiated noise target; S2. Classify the sources of external radiated noise; S3, obtaining the value or frequency spectrum curve of the sound source; S4, obtaining a transfer function of the sound source; S5. Predicting the external radiated noise according to the numerical value and the transfer function, or the spectrum curve and the transfer function, to obtain a prediction result; S6. Determine whether the prediction result meets the set external radiated noise target. If so, output the prediction result. If not, perform sound source and transfer function index decomposition.

2. The method for predicting and decomposing external radiated noise according to claim 1, characterized in that: The sound sources in S2 include: engine noise, cooling system noise, exhaust noise, intake noise, hydraulic component noise and transmission component noise.

3. The method for predicting and decomposing external radiated noise according to claim 1, characterized in that: The transfer functions in S4 include: an exhaust transfer function, an intake transfer function, a cooling system transfer function, an engine transfer function, a transmission component transfer function, and a hydraulic component transfer function; The exhaust transfer function is the exhaust correction value S in the entire frequency band. P Or the exhaust transfer function TF in the 1 / 3 octave band of the center frequency f ef ; Among them, the exhaust correction amount S in the entire frequency band P As shown in the following equation (1), the exhaust gas transfer function TF in the 1 / 3 octave band of the center frequency f is ef As shown in the following formula (2): Where r is the radius of the hemispherical surface for the test of the external radiated sound power level, x1, x2, x3, x4, x5, x6 are the distances from the exhaust port to the six measuring points specified in the standard, and TF is ief Represents the sound pressure level of the noise value at the i-th measuring point; The intake transfer function is the intake correction value S in the entire frequency band. a Or the air transfer function TF in the 1 / 3 octave band of the center frequency f af ; Among them, the intake correction amount S in the entire frequency band a As shown in the following equation (3), the transfer function TF of the intake air in the 1 / 3 octave band of the center frequency f is af As shown in the following formula (4): Where y1, y2, y3, y4, y5, and y6 represent the distances of the six measuring points specified in the air inlet distance standard, and TF iaf Represents the sound pressure level of the noise value at the i-th measuring point; The cooling system transfer function is the sound insulation N of the hood to the cooling system in the entire frequency band. f Or the cooling system transfer function TF in the 1 / 3 octave band of the center frequency f ff ; Among them, the sound insulation of the cooling system by the hood in the entire frequency band is N f As shown in equation (5), the transfer function TF of the cooling system in the 1 / 3 octave band of the center frequency f is ff As shown in the following formula (6): Where, L f It indicates the sound power level of the cooling system under a certain working condition. L indicates the sound power level of the external radiation of the whole machine under the corresponding working condition in the fixed state. L0 indicates the sound power level of the whole machine under the corresponding working condition in the fixed state with the fan removed. TF iff Represents the sound pressure level of the noise value at the i-th measuring point; The engine transfer function is the sound insulation N of the hood to the engine in the entire frequency band. m Or the engine transfer function TF in the 1 / 3 octave band of the center frequency f mf ; Among them, the sound insulation of the hood to the engine in the entire frequency band is N m As shown in the following equation (7), the engine transfer function TF in the 1 / 3 octave band of the center frequency f is mf As shown in the following formula (8): Where, L m Indicates the sound power level of the engine under a certain working condition, P e Indicates the sound pressure level at 0.5 meters at the exhaust port under the corresponding working conditions, P a Indicates that the sound pressure level at 0.5 meters under the corresponding working conditions of the air outlet is, TF ijmf Indicates the sound pressure level of the noise value at the i-th measuring point on the j-th surface; The transmission component transfer function is the sound insulation N of the hood to the transmission component in the entire frequency band. c Or the transmission component transfer function TF in the 1 / 3 octave band of the center frequency f cf ; Among them, the sound insulation of the hood to the transmission parts in the entire frequency band is N c As shown in the following equation (9), the transfer function TF of the transmission component in the 1 / 3 octave band of the center frequency f is cf As shown in the following formula (10): Where, L c It indicates the sound power level of the transmission component under a certain working condition. L1 indicates the external radiated sound power level of the whole machine under the corresponding working condition in the stationary state. L2 indicates the sound power level of the whole machine under the corresponding working condition in the stationary state. TF ijcf Indicates the sound pressure level of the noise value at the i-th measuring point on the j-th surface; The hydraulic component transfer function is the sound insulation N of the hood to the hydraulic component in the entire frequency band. y Or the transfer function TF of the hydraulic component in the 1 / 3 octave band of the center frequency f yf ; Among them, the sound insulation of the hood to the hydraulic components in the entire frequency band is N y As shown in the following equation (11), the transfer function TF of the hydraulic component in the 1 / 3 octave band of the center frequency f is yf As shown in the following formula (12): Where, L y It indicates the sound power level of the hydraulic components under a certain working condition, L3 indicates the sound power level of the whole machine under the corresponding working condition in the stationary state, TF ijyf Represents the sound pressure level of the noise value at the i-th measuring point on the j-th surface.

4. The method for predicting and decomposing external radiated noise according to claim 1, characterized in that: The step of performing external radiated noise prediction according to the numerical value and the transfer function, or the spectrum curve and the transfer function, to obtain a prediction result in S5 includes: S51, calculating the external radiated noise and the contribution energy ratio of each sound source to the external radiated noise in the entire frequency band according to the numerical value and the transfer function; S52. According to the frequency spectrum curve and the transfer function, the sound power level of the external radiated noise in the 1 / 3 octave band of the center frequency f and the energy contribution ratio of each sound source to the external radiated noise in the 1 / 3 octave band of the center frequency f are calculated.

5. The method for predicting and decomposing external radiated noise according to claim 4, characterized in that: The external radiation noise in S51 is as shown in the following equation (13): Where, L W Indicates the sound power level of external radiated noise in the entire frequency band, SWL m Indicates the sound power level of the engine in the entire frequency band, N m Indicates the sound insulation of the hood to the engine in the entire frequency band, SWL f Indicates the sound power level of the cooling system in the entire frequency band, N f Indicates the sound insulation of the hood to the cooling system in the entire frequency band, SWL c It indicates the sound power level of the transmission parts in the whole frequency band, Nc indicates the sound insulation of the hood to the transmission parts in the whole frequency band, SWL y Indicates the sound power level of hydraulic components in the entire frequency band, N y Indicates the sound insulation of the hood to the hydraulic components in the entire frequency band, SWL e It represents the exhaust sound power level in the whole frequency band, S e Indicates the exhaust correction amount in the entire frequency band, SWL a Indicates the sound power level of intake air in the entire frequency band, S a Indicates the amount of intake correction in the entire frequency band; The energy ratio of each sound source to the external radiated noise in the entire frequency band is as shown in the following formula (14): In the formula, k i Indicates the energy ratio of each sound source to the external radiated noise in the entire frequency band, SWL i Indicates the sound power level of a sound source in the entire frequency band, TF i It indicates the sound insulation amount of the hood to a certain sound source in the entire frequency band or the correction amount of a certain sound source in the entire frequency band.

6. The method for predicting and decomposing external radiated noise according to claim 4, characterized in that: The sound power level of the external radiated noise in S52 in a band with a center frequency of 1 / 3 octave f is as shown in the following formula (15): Where, L Wf It indicates the sound power level of the external radiated noise in the 1 / 3 octave band of the center frequency f, SWL mf It indicates the sound power level of the engine in the 1 / 3 octave band of the center frequency f, TF mf It represents the transfer function of the generator in the 1 / 3 octave band of the center frequency f, SWL ff It represents the sound power level of the cooling system in the 1 / 3 octave band of the center frequency f, TF ff It represents the transfer function of the cooling system in the 1 / 3 octave band of the center frequency f, SWL cf It indicates the sound power level of the transmission component in the 1 / 3 octave band of the center frequency f, TF cf It represents the transfer function of the transmission component in the 1 / 3 octave band of the center frequency f, SWL yf It indicates the sound power level of hydraulic components in the 1 / 3 octave band with the center frequency f, TF yf It represents the transfer function of the hydraulic component in the 1 / 3 octave band of the center frequency f, SWL ef It indicates the sound power level of the exhaust in the 1 / 3 octave band with the center frequency f, TF ef It represents the exhaust gas transfer function in the 1 / 3 octave band of the center frequency f, SWL af Indicates the sound power level of the intake air in the 1 / 3 octave band with the center frequency f, TF af It represents the transfer function of the intake air in the 1 / 3 octave band of the center frequency f, S i represents the predicted area of ​​the sphere with radius i, and S0 represents the reference surface area; The energy ratio of each sound source to the external radiated noise in the 1 / 3 octave band of the center frequency f is as shown in the following formula (16): In the formula, k if It indicates the contribution energy ratio of a sound source in the 1 / 3 octave band of the center frequency f. if It indicates the sound power level of a sound source in a 1 / 3 octave band with a center frequency of f, TF if It represents the transfer function of a sound source in a 1 / 3 octave band with a center frequency of f.

7. The method for predicting and decomposing external radiated noise according to claim 1, characterized in that: The index decomposition in S6 is shown in the following equations (17) and (18): Where SWL i Indicates the sound power level of a sound source in the entire frequency band, TF i It indicates the sound insulation of the hood to a certain sound source in the whole frequency band or the correction amount of a certain sound source in the whole frequency band. Indicates the contribution, L Wb Indicates the external radiated noise index requirements in the entire frequency band, SWL if It indicates the sound power level of a sound source in a 1 / 3 octave band with a center frequency of f, TF if It represents the transfer function of a sound source in a 1 / 3 octave band with a center frequency of f, S i represents the predicted area of ​​the sphere with radius i, S0 represents the reference surface area, L Wfb It indicates the index requirement of the external radiated noise within the 1 / 3 frequency band of the center frequency f.

8. An external radiation noise prediction and index decomposition device, the external radiation noise prediction and index decomposition device is used to implement the external radiation noise prediction and index decomposition method according to any one of claims 1 to 7, characterized in that: The device comprises: A setting module is used to set the external radiated noise target; A division module is used to divide the sound sources of external radiated noise; A first acquisition module, used to acquire the value or frequency spectrum curve of the sound source; A second acquisition module, used to acquire the transfer function of the sound source; A prediction module, used to predict the external radiated noise according to the numerical value and the transfer function, or the spectrum curve and the transfer function, to obtain a prediction result; The output module is used to determine whether the prediction result meets the set external radiated noise target. If so, the prediction result is output; if not, the sound source and transfer function index decomposition is performed.

9. An external radiated noise prediction and index decomposition device, characterized in that: The external radiated noise prediction and index decomposition equipment includes: processor; A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program codes, which can be called by a processor to execute the method according to any one of claims 1 to 7.

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