A method and system for determining the vehicle curb body noise transfer function

Abstract

The present invention provides a method and a system for determining the noise transfer function of a vehicle's kerb body. The method includes: obtaining the first modal frequency and the first modal damping corresponding to each set structural modal order in the structural modal test of the vehicle's kerb body, determining the final structural modal frequency and the final structural modal damping based on the first modal frequency and the first modal damping, and obtaining the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order in the acoustic cavity modal test of the vehicle, determining the final acoustic cavity modal frequency and the final acoustic cavity modal damping based on the second modal frequency and the second modal damping; calculating the noise transfer function of the vehicle's kerb body based on the final structural modal frequency, the final structural modal damping, the final acoustic cavity modal frequency, and the final acoustic cavity modal damping. The present invention provides a reliable method for obtaining damping, greatly improving the reliability of the NTF calculation result and enhancing the road noise efficiency of the whole vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of calculating the noise of a prepared body, and particularly to a method and a system for determining the noise transfer function of a vehicle's prepared body. Background Art

[0002] In recent years, automotive technology has become increasingly mature. In addition to the requirements for vehicle drivability, consumers increasingly value the NVH (Noise, Vibration, Harshness) performance of automobiles. The development of automotive NVH performance is a complex discipline, and subsystems such as the powertrain, chassis, body, and electrical appliances can all be noise sources or transmission paths that cause NVH problems. The main task of NVH engineers is to reduce noise sources, control transmission paths, and improve vehicle comfort.

[0003] Whether the NTF (Noise Transfer Function) of the prepared body is reasonable is an important evaluation criterion for body NVH development. Currently, empirical parameters are used more frequently for the damping ratio parameter in NTF simulation analysis, and it is difficult to accurately obtain the damping, while the damping model has a great influence on the error of calculating NTF by finite element simulation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and a system for determining the noise transfer function of a vehicle's prepared body, so as to solve the defect in the prior art that empirical parameters are used for the damping parameter in NTF simulation analysis, and it is difficult to accurately obtain the damping, resulting in a large error in NTF calculation.

[0005] The first aspect of the present invention provides a method for determining the noise transfer function of a vehicle's prepared body, including:

[0006] Obtaining the first modal frequency and the first modal damping corresponding to each set structural modal order in the structural modal test of the vehicle's prepared body, determining the final structural modal frequency and the final structural modal damping corresponding to each set structural modal order in the structural modal test of the prepared body according to the first modal frequency and the first modal damping corresponding to each set structural modal order, and obtaining the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order in the acoustic cavity modal test of the vehicle, and determining the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order in the acoustic cavity modal test of the prepared body according to the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order;

[0007] The vehicle's curb body noise transfer function is calculated based on the final structural modal frequencies and final structural modal damping corresponding to each set structural modal order, and the final acoustic cavity modal frequencies and final acoustic cavity modal damping corresponding to each set acoustic cavity modal order.

[0008] In a specific embodiment, the obtaining of the first modal frequency and the first modal damping corresponding to each set structural modal order in the vehicle's curb body structural modal test specifically includes:

[0009] Obtain the structural modal frequency response matrix collected in the curb body structural modal test and the set structural modal order.

[0010] Use the least squares complex exponential method to identify the structural modal frequency response matrix, and obtain the first modal frequency and the first modal damping corresponding to each set structural modal order.

[0011] In a specific embodiment, the determining of the final structural modal frequencies and final structural modal damping corresponding to each set structural modal order in the curb body structural modal test according to the first modal frequency and the first modal damping corresponding to each set structural modal order specifically includes:

[0012] Determine the structural modal comprehensive frequency response curve of any first response source to any first excitation source in the curb body structural modal test system according to the first modal frequency and the first modal damping corresponding to each set structural modal order.

[0013] Calculate the first correlation value and the first error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve.

[0014] Judge whether the first correlation value is less than the first correlation set value and judge whether the first error value is less than the first error set value. If the first correlation value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve is greater than the first correlation set value and the first error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve is less than the first error set value, then determine the first modal frequency corresponding to the set structural modal order as the final structural modal frequency corresponding to the set structural modal order, and determine the first modal damping corresponding to the set structural modal order as the final structural modal damping corresponding to the set structural modal order.

[0015] In a specific embodiment, determining the final structural modal frequency and the final structural modal damping corresponding to each set structural modal order in the as-prepared body structural modal test according to the first modal frequency and the first modal damping corresponding to each set structural modal order specifically includes:

[0016] Revise the first modal frequency and the first modal damping corresponding to each set structural modal order respectively, and correspondingly obtain the revised structural modal frequency and the revised structural modal damping corresponding to each set structural modal order;

[0017] Determine the structural modal comprehensive frequency response curve of any first response source to any first excitation source in the as-prepared body structural modal test system according to the revised structural modal frequency and the revised structural modal damping corresponding to each set structural modal order;

[0018] Calculate the second correlation value and the second error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve;

[0019] Judge whether the second correlation value is greater than the second correlation set value and judge whether the second error value is less than the second error set value. If the second correlation value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve is greater than the second correlation set value and the second error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve is less than the second error set value, then determine the revised structural modal frequency corresponding to the set structural modal order as the final structural modal frequency corresponding to the set structural modal order, and determine the revised structural modal damping corresponding to the set structural modal order as the final structural modal damping corresponding to the set structural modal order.

[0020] In a specific embodiment, obtaining the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order in the vehicle acoustic cavity modal test specifically includes:

[0021] Obtain the acoustic cavity modal frequency response matrix collected in the vehicle acoustic cavity modal test and the set acoustic cavity modal order;

[0022] Use the least squares complex exponential method to identify the acoustic cavity modal frequency response matrix, and obtain the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order.

[0023] In a specific embodiment, determining the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order of the prepared vehicle body acoustic cavity modal test according to the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order specifically includes:

[0024] Determine the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source in the prepared vehicle body acoustic cavity modal test system according to the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order;

[0025] Calculate the third correlation value and the third error value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source in the acoustic cavity modal test system and the corresponding measured acoustic cavity modal frequency response curve;

[0026] Judge whether the third correlation value is greater than the third correlation set value and judge whether the third error value is less than the third error set value. If the third correlation value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured acoustic cavity modal frequency response curve is greater than the third correlation set value and the third error value between the acoustic cavity modal comprehensive frequency response curve of any second response source and any second excitation source and the corresponding measured acoustic cavity modal frequency response curve is less than the third error set value, then determine the second modal frequency corresponding to the set acoustic cavity modal order as the final acoustic cavity modal frequency corresponding to the set acoustic cavity modal order, and determine the second modal damping corresponding to the set acoustic cavity modal order as the final acoustic cavity modal damping corresponding to the set acoustic cavity modal order.

[0027] In a specific embodiment, determining the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order of the prepared vehicle body acoustic cavity modal test according to the second modal frequency and the second modal damping corresponding to each modal acoustic cavity order specifically includes:

[0028] Respectively correct the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order, and correspondingly obtain the corrected acoustic cavity modal frequency and the corrected acoustic cavity modal damping corresponding to each set acoustic cavity modal order;

[0029] Determine the acoustic cavity modal comprehensive frequency response curve between any second excitation source and the second response source in the prepared vehicle body acoustic cavity modal test system according to the corrected acoustic cavity modal frequency and the corrected acoustic cavity modal damping corresponding to each set acoustic cavity modal order;

[0030] Calculate the fourth correlation value and the fourth error value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured acoustic cavity modal frequency response curve;

[0031] Determine whether the fourth correlation value is greater than the fourth correlation setting value and determine whether the fourth error value is less than the fourth error setting value. If the fourth correlation value between the integrated frequency response curve of the acoustic cavity mode between any second response source and the second excitation source and the corresponding measured acoustic cavity mode frequency response curve is greater than the fourth correlation setting value and the fourth error value between the integrated frequency response curve of the acoustic cavity mode between any second response source and any second excitation source and the corresponding measured acoustic cavity mode frequency response curve is less than the fourth error setting value, then determine the corrected acoustic cavity mode frequency corresponding to the set acoustic cavity mode order as the final acoustic cavity mode frequency corresponding to the set acoustic cavity mode order, and determine the corrected acoustic cavity mode damping corresponding to the set acoustic cavity mode order as the final acoustic cavity mode damping corresponding to the set acoustic cavity mode order.

[0032] In a specific embodiment, the first correlation setting value is 95%, the first error setting value is 5%, the second correlation setting value is 95%, the second error setting value is 5%, the third correlation setting value is 98%, the third error setting value is 2%, the fourth correlation setting value is 98%, and the fourth error setting value is 2%.

[0033] In a specific embodiment, the calculating the noise transfer function of the prepared vehicle body according to the final structural mode frequency and the final structural mode damping corresponding to each set structural mode order and the final acoustic cavity mode frequency and the final acoustic cavity mode damping corresponding to each set acoustic cavity mode order specifically includes:

[0034] Form coordinate points with the final structural mode frequency and the final structural mode damping corresponding to each set structural mode order, perform interpolation on the coordinate points obtained in the structural mode test to generate a structural damping ratio curve, and form coordinate points with the final acoustic cavity mode frequency and the final acoustic cavity mode damping corresponding to each set acoustic cavity mode order, perform interpolation on the coordinate points obtained in the acoustic cavity mode test to generate an acoustic cavity damping curve;

[0035] Calculate the noise transfer function of the prepared vehicle body according to the structural damping curve and the acoustic cavity damping curve.

[0036] A second aspect of the present invention provides a system for determining the noise transfer function of a vehicle's prepared body, including:

[0037] A first mode frequency and first mode damping acquisition unit, configured to acquire the first mode frequency and the first mode damping corresponding to each set structural mode order in the structural mode test of the vehicle's prepared body;

[0038] A final structural modal frequency and final structural modal damping determination unit, configured to determine the final structural modal frequency and final structural modal damping corresponding to each set structural modal order in the as-prepared body structural modal test according to the first modal frequency and the first modal damping;

[0039] A second modal frequency and second modal damping acquisition unit, configured to acquire the second modal frequency and second modal damping corresponding to each set acoustic cavity modal order in the vehicle acoustic cavity modal test;

[0040] A final acoustic cavity modal frequency and final acoustic cavity modal damping determination unit, configured to determine the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each set acoustic cavity modal order in the as-prepared body acoustic cavity test according to the second modal frequency and the second modal damping;

[0041] A noise transfer function determination unit, configured to calculate and obtain the as-prepared body noise transfer function according to the final structural modal frequency and final structural modal damping corresponding to each set structural modal order and the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each set acoustic cavity modal order

[0042] The beneficial effects of the embodiments of the present invention are as follows: The present invention respectively obtains the first modal frequency, first modal damping corresponding to the set structural modal order, and the measured structural modal frequency response curve to determine the final structural modal frequency and final structural modal damping corresponding to each structural modal order, and obtains the second modal frequency, second modal damping corresponding to the set acoustic cavity modal order, and the measured acoustic cavity modal frequency response curve to determine the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each acoustic cavity modal order, and determines the NTF value according to the final structural modal frequency and damping and the final acoustic cavity modal frequency and damping. This method provides a relatively reliable method for obtaining damping parameters, greatly improves the reliability of the NTF calculation result, improves the efficiency of NTF optimization in the vehicle model development process and the efficiency of vehicle NVH tuning in the tuning stage, reduces the number of vehicle tuning rounds, improves the road noise and acceleration R & D accuracy and efficiency of the vehicle, and reduces the R & D cost. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0044] Figure 1 is a flowchart of a method for determining the noise transfer function of an as-prepared vehicle body according to an embodiment of the present invention;

[0045] Figure 2 This is the corresponding diagram of the second modal frequency, the second modal damping, their corrected frequencies, and their corrected dampings in a method for determining the noise transfer function of a vehicle's curb body according to an embodiment of the present invention. Detailed implementation manners

[0046] The descriptions of the following embodiments refer to the accompanying drawings to exemplify specific embodiments in which the present invention can be implemented.

[0047] The following refers to Figure 1 As shown, Embodiment 1 of the present invention provides a method for determining the noise transfer function of a vehicle's curb body, including the following steps:

[0048] S1. Obtain the first modal frequency and the first modal damping corresponding to each set structural modal order in the structural modal test of the vehicle's curb body, determine the final structural modal frequency and the final structural modal damping corresponding to each set structural modal order in the structural modal test of the curb body according to the first modal frequency and the first modal damping corresponding to each set structural modal order, and obtain the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order in the acoustic cavity modal test of the vehicle, and determine the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order in the acoustic cavity modal test of the curb body according to the second modal frequency and the second modal damping corresponding to each modal acoustic cavity order.

[0049] In order to calculate the NTF value of the vehicle, it is necessary to perform a structural modal test of the curb body and an acoustic cavity test of the curb body respectively.

[0050] Specifically, prepare the curb body and test equipment and materials according to the vehicle state required for the vehicle's curb body. Before the test, arrange a set number of first excitation sources and a set number of first response sources in the structural modal test system according to the test requirements. The first excitation source is a sound source, and the first response source can be a speaker. After the arrangement is completed, collect the structural modal frequency response matrix data of the structural modal test of the curb body, that is, obtain the measured structural modal response of any first response source to any first excitation source. Obtain the set structural modal order, and use the least squares complex exponential method to identify the modal parameters of the measured structural modal frequency response matrix of the test curb body to obtain the first modal frequency and the first modal damping corresponding to each structural modal order. Since the structural modal density of the curb body is relatively large, as many modes of the curb body as possible should be estimated to ensure that the test structural modes of the curb body are not lost. In a specific implementation manner, the estimated frequencies of the structural modes of the curb body are 80 orders from 20 Hz to 200 Hz, that is, the structural modal order can be set to 80 orders. The first modal frequency and the first modal damping corresponding to each structural modal order are obtained by using the least squares complex exponential method.

[0051] After obtaining the first modal frequency and the first modal damping corresponding to each structural modal order, the structural modal comprehensive frequency response curve of each first response source to each first excitation source in the kerb weight body structural modal test system can be calculated by using the first modal frequency and the first modal damping corresponding to each structural modal order. Calculate the first correlation value and the first error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve, and judge whether the first correlation value is greater than the first correlation value setting and whether the first error value is less than the first error setting. If the first correlation value between the structural modal comprehensive frequency response curve of any first response source to a first excitation source and the corresponding measured structural modal frequency response curve is greater than the first correlation value setting and the first error value between the structural modal comprehensive frequency response curve of any first response source to a first excitation source and the corresponding measured structural modal frequency response curve is less than the first error setting, then determine the first modal frequency corresponding to the set structural modal order as the final structural modal frequency corresponding to the set structural modal order, and determine the first modal damping corresponding to the set structural modal order as the final structural modal damping corresponding to the set structural modal order.

[0052] For example, assume that in the kerb weight body structural modal test system, a total of 4 first excitation sources are arranged, namely A / B / C / D, and 4 response sources are set, namely E / F / G / H. Then, the structural modal comprehensive frequency response curve of any first response source E / F / G / H to any first excitation source A / B / C / D can be calculated by using the first modal frequency and the first modal damping corresponding to each set structural modal order. Specifically, the structural modal comprehensive frequency response curve of the first response source E to the first excitation source A is denoted as EA. Assume that the measured structural modal comprehensive frequency response curve of the first response source E to the first excitation source A is denoted as E1A1. Calculate the first correlation value and the first error value between the curve EA and the curve E1A1, and judge whether the first correlation value is greater than the first correlation value setting and whether the first error value is less than the first error setting. If so, continue to calculate the structural modal comprehensive frequency response curve of the first response source E to the first excitation source B according to the above method until the structural modal comprehensive frequency response curve of the first response source H to the first excitation source D is calculated. If the first correlation value between the structural modal comprehensive frequency response curves of all response sources to all excitation sources and the corresponding measured structural modal frequency response curves is greater than the first correlation value setting and the first error value is less than the first error setting, then determine the first modal frequency corresponding to the set structural modal order as the final structural modal frequency corresponding to the set structural modal order, and determine the first modal damping corresponding to the set structural modal order as the final structural modal damping corresponding to the set structural modal order.

[0053] Form coordinate points with the final structural modal frequencies and final structural modal damping corresponding to each set structural modal order number, then a total number of coordinate points equal to the set structural modal order number can be obtained, and interpolate the said coordinate points to obtain a structural modal damping curve.

[0054] In a specific embodiment, the first correlation setting value is 95%, and the first error setting value is 5%.

[0055] Specifically, conduct a sound cavity modal test on the vehicle, perform point-by-point tests in the entire sound field space, arrange a set number of second excitation sources and a set number of second response sources in the entire sound field space. The second excitation source is a sound source, and the second response source can be a speaker. Collect the sound cavity modal frequency response matrix, that is, the measured sound cavity modal response of each second response source to each second excitation source. Obtain the sound cavity modal order number, use the LSCE method to identify the sound cavity modal parameters for the sound cavity modal response matrix, and obtain the second modal frequency and second modal damping corresponding to each sound cavity modal order number. Determine the sound cavity modal comprehensive frequency response curve of any second response source to any second excitation source in the sound cavity modal test system of the unloaded body according to the second modal frequency and the second modal damping corresponding to each set sound cavity modal order number, and calculate the third correlation value and the third error value between the sound cavity modal comprehensive frequency response curve of any second response source to the second excitation source and the corresponding measured sound cavity modal frequency response curve; judge whether the third correlation value is greater than the third correlation setting value and judge whether the third error value is less than the third error setting value. If the third correlation value between the sound cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured sound cavity modal frequency response curve is greater than the third correlation setting value and the third error value between the sound cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured sound cavity modal frequency response curve is less than the third error setting value, then determine the second modal frequency corresponding to the set sound cavity modal order number as the final sound cavity modal frequency corresponding to the set sound cavity modal order number, and determine the second modal damping corresponding to the set sound cavity modal order number as the final sound cavity modal damping corresponding to the set sound cavity modal order number.

[0056] Specifically, in a specific embodiment, count the modal orders within 200HZ for the sound cavity mode of a certain vehicle model, and determine that the sound cavity modal order number is 11. Therefore, the set sound cavity modal order number is determined to be 11.

[0057] For example, assume that in the test system for the acoustic cavity mode of a prepared vehicle body, a total of 4 excitation sources are arranged, namely A2 / B2 / C2 / D2, and 4 response sources are set, namely E2 / F2 / G2 / H2. Then, the comprehensive frequency response curve of the acoustic cavity mode of any second response source E2 / F2 / G2 / H2 to any second excitation source A2 / B2 / C2 / D2 can be calculated through the second mode frequency and the second mode damping corresponding to each set acoustic cavity mode order. Specifically, the comprehensive frequency response curve of the acoustic cavity mode of the second response source E2 to the second excitation source A2 is denoted as E2A2. Assume that the measured comprehensive frequency response curve of the acoustic cavity mode of the second response source E2 to the second excitation source A2 is denoted as E3A3. Calculate the second correlation value and the second error value between the curve E2A2 and the curve E3A3, and determine whether the second correlation value is greater than the second correlation set value, and whether the second error value is less than the second error set value. If so, continue to calculate the comprehensive frequency response curve of the acoustic cavity mode of the second response source E2 to the second excitation source B2 according to the above method until the comprehensive frequency response curve of the acoustic cavity mode of the second response source H2 to the second excitation source D2 is calculated. If the second correlation value between the comprehensive frequency response curve of the acoustic cavity mode of some second response sources to all second excitation sources and the measured acoustic cavity mode frequency response curve is greater than the second correlation set value, and the second error value is less than the second error set value, then the second mode frequency corresponding to the set acoustic cavity mode order is determined as the final acoustic cavity mode frequency corresponding to the set acoustic cavity mode order, and the second mode damping corresponding to the set acoustic cavity mode order is determined as the final acoustic cavity mode damping corresponding to the set acoustic cavity mode order. Form coordinate points with the final acoustic cavity mode frequency and the final acoustic cavity mode damping corresponding to each set acoustic cavity mode order, then a total number of coordinate points equal to the number of set acoustic cavity mode orders can be obtained. Perform interpolation on the coordinate points to obtain the acoustic cavity mode damping curve.

[0058] In a specific embodiment, the third correlation set value is 98%, and the first error set value is 2%.

[0059] S2. Calculate the noise transfer function of the prepared vehicle body according to the final structural mode frequency and the final structural mode damping corresponding to each set structural mode order, and the final acoustic cavity mode frequency and the final acoustic cavity mode damping corresponding to each set acoustic cavity mode order.

[0060] Specifically, input the structural mode damping curve and the acoustic cavity mode damping curve into the TABDMP card in the NASTRAN calculation software, and perform the NTF calculation of the prepared vehicle body to obtain the NTF value.

[0061] The method for determining the noise transfer function of a vehicle's curb body in the first embodiment of the present invention determines the final structural modal frequency and final structural modal damping corresponding to each structural modal order by respectively obtaining the first modal frequency, the first modal damping corresponding to the set structural modal order, and the measured structural modal frequency response curve, and determines the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each acoustic cavity modal order by obtaining the second modal frequency, the second modal damping corresponding to the set acoustic cavity modal order, and the measured acoustic cavity modal frequency response curve, and determines the NTF value based on the final structural modal frequency and damping and the final acoustic cavity modal frequency and damping. This method provides a relatively reliable method for obtaining damping parameters, greatly improves the reliability of the NTF calculation result, enhances the efficiency of NTF optimization in the vehicle model R & D process and the efficiency of vehicle NVH tuning in the tuning stage, reduces the number of vehicle tuning rounds, improves the accuracy and efficiency of vehicle road noise and acceleration R & D, and reduces the R & D cost.

[0062] Based on the first embodiment of the present invention, the second embodiment of the present invention provides a method for determining the noise transfer function of a vehicle's curb body, including the following steps:

[0063] S1. Obtain the first modal frequency and the first modal damping corresponding to each set structural modal order in the structural modal test of the vehicle's curb body, determine the final structural modal frequency and final structural modal damping corresponding to each set structural modal order in the structural modal test of the curb body according to the first modal frequency and the first modal damping corresponding to each set structural modal order, and obtain the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order in the acoustic cavity modal test of the vehicle, and determine the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each set acoustic cavity modal order in the acoustic cavity modal test of the curb body according to the second modal frequency and the second modal damping corresponding to each acoustic cavity modal order.

[0064] Specifically, in step S1 of this embodiment, obtaining the first modal frequency and the first modal damping corresponding to each set structural modal order and obtaining the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order are the same as those in the first embodiment, and thus will not be elaborated herein.

[0065] In this embodiment, after obtaining the first modal frequency and the first modal damping corresponding to each set structural modal order, the first modal frequency and the first modal damping corresponding to each set structural modal order are respectively corrected to correspondingly obtain the corrected structural modal frequency and the corrected structural modal damping corresponding to each set structural modal order. Specifically, the maximum likelihood estimation algorithm can be used to correct the first modal frequency and the first modal damping. The structural modal comprehensive frequency response curve of any first response source to the first excitation source in the prepared body structure modal test system is determined according to the corrected structural modal frequency and the corrected structural modal damping corresponding to each set structural modal order, and the second correlation value and the second error value between the structural modal comprehensive frequency response curve of any first response source to the first excitation source and the measured structural modal frequency response curve of the corresponding any first response source to the first excitation source are calculated. It is judged whether the second correlation value is greater than the second correlation set value and whether the second error value is less than the second error set value. If the second correlation value between the structural modal comprehensive frequency response curve of any first response source to the first excitation source and the corresponding measured structural modal frequency response curve is greater than the second correlation set value and the second error value between the structural modal comprehensive frequency response curve of any first response source to the first excitation source and the corresponding measured structural modal frequency response curve is less than the second error set value, then the corrected structural modal frequency corresponding to the set structural modal order is determined as the final structural modal frequency corresponding to the set structural modal order, and the corrected structural modal damping corresponding to the set structural modal order is determined as the final structural modal damping corresponding to the set structural modal order. The final structural modal frequency and the final structural modal damping corresponding to each set structural modal order form coordinate points, then a total number of coordinate points of the set structural modal order can be obtained, and the coordinate points are differentiated to obtain the structural modal damping curve.

[0066] In this embodiment, after obtaining the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order, the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order are respectively corrected to obtain the corrected acoustic cavity modal frequency and the corrected acoustic cavity modal damping corresponding to each set acoustic cavity modal order. Specifically, the maximum likelihood estimation algorithm can be used to correct the second modal frequency and the second modal damping. According to the corrected acoustic cavity modal frequency and the corrected acoustic cavity modal damping corresponding to each set acoustic cavity modal order, the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source in the prepared vehicle body acoustic cavity modal test system is determined, and the fourth correlation value and the fourth error value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured acoustic cavity modal frequency response curve are calculated. It is judged whether the fourth correlation value is greater than the fourth correlation value setting and whether the fourth error value is less than the fourth error setting. If the fourth correlation value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured acoustic cavity modal frequency response curve is greater than the fourth correlation value setting and the fourth error value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured acoustic cavity modal frequency response curve is less than the fourth error setting, then the corrected acoustic cavity modal frequency corresponding to the set acoustic cavity modal order is determined as the final acoustic cavity modal frequency corresponding to the set acoustic cavity modal order, and the corrected acoustic cavity modal damping corresponding to the set acoustic cavity modal order is determined as the final acoustic cavity modal damping corresponding to the set acoustic cavity modal order.

[0067] Specifically, as Figure 2 The modal frequency and modal damping table of the acoustic cavity modal test is given. In this table, the acoustic cavity modal order is set to 11 orders, and the corresponding second modal frequency, second modal damping, and the corrected modal frequency and modal damping are shown in the table.

[0068] Taking the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order as coordinate points, the total number of coordinate points corresponding to the set acoustic cavity modal order can be obtained, and the acoustic cavity modal damping curve is obtained by taking the difference of the coordinate points.

[0069] S2. Calculate and obtain the vehicle prepared body noise transfer function according to the final structural modal frequency and the final structural modal damping corresponding to each set structural modal order and the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order.

[0070] The specific implementation of this step is the same as that of step S2 in Embodiment 1, so it will not be elaborated here.

[0071] The method for determining the vehicle's as-built body noise transfer function according to the embodiments of the present invention corrects the first modal frequency and the first modal damping corresponding to each structural modal order obtained by using the maximum likelihood estimation method, and determines the final structural modal frequency and the final modal damping corresponding to each structural modal order through the corrected structural modal frequency and the structural modal damping. In addition, the second modal frequency and the second modal damping corresponding to each cavity modal order obtained are corrected by using the maximum likelihood estimation method, and the final cavity modal frequency and the final modal damping corresponding to each cavity modal order are determined through the corrected cavity modal frequency and the cavity modal damping, which further improves the accuracy of the NTF calculation.

[0072] Based on the first embodiment of the present invention, the third embodiment of the present invention provides a system for determining the vehicle's as-built body noise transfer function, including a first modal frequency and a first modal damping acquisition unit, a final structural modal frequency and a final modal damping determination unit, a second modal frequency and a second modal damping acquisition unit, a final cavity modal frequency and a final modal damping determination unit, and a noise transfer function determination unit. Among them, the first modal frequency and the first modal damping acquisition unit is used to acquire the first modal frequency and the first modal damping corresponding to each set structural modal order of the vehicle's as-built body structural modal test. The final structural modal frequency and the final modal damping determination unit is used to determine the final structural modal frequency and the final modal damping corresponding to each set structural modal order of the as-built body structural modal test according to the first modal frequency and the first modal damping. The second modal frequency and the second modal damping acquisition unit is used to acquire the second modal frequency and the second modal damping corresponding to each set cavity modal order of the vehicle's cavity modal test. The final cavity modal frequency and the final modal damping determination unit is used to determine the final cavity modal frequency and the final modal damping corresponding to each set cavity modal order of the as-built body cavity test according to the second modal frequency and the second modal damping. The noise transfer function determination unit is used to calculate and obtain the as-built body noise transfer function according to the final structural modal frequency and the final modal damping corresponding to each set structural modal order and the final cavity modal frequency and the final modal damping corresponding to each set cavity modal order.

[0073] For the working principle and the beneficial effects of this embodiment, please refer to the description of the first embodiment of the present invention, which will not be repeated here.

[0074] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A method for determining the vehicle curb body noise transfer function, characterized in that Including: Obtaining a first modal frequency and a first modal damping corresponding to each set structural modal order in the vehicle's as-built body structure modal test, determining a final structural modal frequency and a final modal damping corresponding to each set structural modal order of the as-built body structure modal test according to the first modal frequency and the first modal damping corresponding to each set structural modal order, and obtaining a second modal frequency and a second modal damping corresponding to each set acoustic cavity modal order in the as-built body acoustic cavity modal test, determining a final acoustic cavity modal frequency and a final modal damping corresponding to each set acoustic cavity modal order of the as-built body acoustic cavity modal test according to the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order; Calculating and obtaining the vehicle's as-built body noise transfer function according to the final structural modal frequency and the final modal damping corresponding to each set structural modal order and the final acoustic cavity modal frequency and the final modal damping corresponding to each set acoustic cavity modal order; Specifically including: Forming coordinate points with the final structural modal frequency and the final modal damping corresponding to each set structural modal order, interpolating the coordinate points obtained in the structural modal test to generate a structural damping curve, and forming coordinate points with the final acoustic cavity modal frequency and the final modal damping corresponding to each set acoustic cavity modal order, interpolating the coordinate points obtained in the acoustic cavity modal test to generate an acoustic cavity damping curve; Calculating and obtaining the as-built body noise transfer function according to the structural damping curve and the acoustic cavity damping curve.

2. The method according to claim 1, wherein The specific process of obtaining the first modal frequency and the first modal damping corresponding to each set structural modal order in the vehicle's as-built body structure modal test includes: Obtaining the structural modal frequency response matrix collected in the as-built body structure modal test and the set structural modal order; Using the least squares complex exponential method to identify the structural modal frequency response matrix, and obtaining the first modal frequency and the first modal damping corresponding to each set structural modal order.

3. The method according to claim 2, wherein The specific process of determining the final structural modal frequency and the final modal damping corresponding to each set structural modal order in the as-built body structure modal test according to the first modal frequency and the first modal damping corresponding to each set structural modal order includes: Determining the structural modal comprehensive frequency response curve of any first response source to any first excitation source in the as-built body structure modal test system according to the first modal frequency and the first modal damping corresponding to each set structural modal order; Calculating a first correlation value and a first error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve; Judge whether the first correlation value is less than the first correlation set value and whether the first error value is less than the first error set value. If the first correlation value between the structural modal comprehensive frequency response curve of any first response source to any of the first excitation sources and the corresponding measured structural modal frequency response curve is greater than the first correlation set value and the first error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve is less than the first error set value, then determine the first modal frequency corresponding to the set structural modal order as the final structural modal frequency corresponding to the set structural modal order, and determine the first modal damping corresponding to the set structural modal order as the final structural modal damping corresponding to the set structural modal order.

4. The method according to claim 2, wherein The specific process of determining the final structural modal frequency and final structural modal damping corresponding to each set structural modal order in the prepared body structural modal test according to the first modal frequency and the first modal damping corresponding to each set structural modal order includes: Respectively correct the first modal frequency and the first modal damping corresponding to each set structural modal order, and correspondingly obtain the corrected structural modal frequency and corrected structural modal damping corresponding to each set structural modal order; Determine the structural modal comprehensive frequency response curve of any first response source to any first excitation source in the prepared body structural modal test system according to the corrected structural modal frequency and corrected structural modal damping corresponding to each set structural modal order; Calculate the second correlation value and the second error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve; Judge whether the second correlation value is greater than the second correlation set value and whether the second error value is less than the second error set value. If the second correlation value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve is greater than the second correlation set value and the second error value between the structural modal comprehensive frequency response curve of any first response source to any first excitation source and the corresponding measured structural modal frequency response curve is less than the second error set value, then determine the corrected structural modal frequency corresponding to the set structural modal order as the final structural modal frequency corresponding to the set structural modal order, and determine the corrected structural modal damping corresponding to the set structural modal order as the final structural modal damping corresponding to the set structural modal order.

5. The method according to claim 3 or 4, characterized in that, The specific process of obtaining the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order in the prepared body acoustic cavity modal test includes: Obtain the acoustic cavity modal frequency response matrix collected in the vehicle acoustic cavity modal test and the set acoustic cavity modal order; Use the least squares complex exponential method to identify the acoustic cavity modal frequency response matrix, and obtain the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order.

6. The method according to claim 5, wherein Determining the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order of the prepared vehicle body acoustic cavity modal test based on the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order specifically includes: Determining the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source in the prepared vehicle body acoustic cavity modal test system based on the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order; Calculating the third correlation value and the third error value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source in the acoustic cavity modal test system and the corresponding measured acoustic cavity modal frequency response curve; Judging whether the third correlation value is greater than the third correlation set value and judging whether the third error value is less than the third error set value. If the third correlation value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured acoustic cavity modal frequency response curve is greater than the third correlation set value and the third error value between the acoustic cavity modal comprehensive frequency response curve of any second response source and any second excitation source and the corresponding measured acoustic cavity modal frequency response curve is less than the third error set value, then determining the second modal frequency corresponding to the set acoustic cavity modal order as the final acoustic cavity modal frequency corresponding to the set acoustic cavity modal order, and determining the second modal damping corresponding to the set acoustic cavity modal order as the final acoustic cavity modal damping corresponding to the set acoustic cavity modal order.

7. The method according to claim 6, wherein Determining the final acoustic cavity modal frequency and the final acoustic cavity modal damping corresponding to each set acoustic cavity modal order of the prepared vehicle body acoustic cavity modal test based on the second modal frequency and the second modal damping corresponding to each modal acoustic cavity order specifically includes: Respectively correcting the second modal frequency and the second modal damping corresponding to each set acoustic cavity modal order, and correspondingly obtaining the corrected acoustic cavity modal frequency and the corrected acoustic cavity modal damping corresponding to each set acoustic cavity modal order; Determining the acoustic cavity modal comprehensive frequency response curve between any second excitation source and the second response source in the prepared vehicle body acoustic cavity modal test system based on the corrected acoustic cavity modal frequency and the corrected acoustic cavity modal damping corresponding to each set acoustic cavity modal order; Calculating the fourth correlation value and the fourth error value between the acoustic cavity modal comprehensive frequency response curve of any second response source to any second excitation source and the corresponding measured acoustic cavity modal frequency response curve; Determine whether the fourth correlation value is greater than the fourth correlation set value and whether the fourth error value is less than the fourth error set value. If the fourth correlation value between the synthesized frequency response curve of the acoustic cavity mode between any second response source and the second excitation source and the corresponding measured acoustic cavity mode frequency response curve is greater than the fourth correlation set value and the fourth error value between the synthesized frequency response curve of the acoustic cavity mode of any second response source to any second excitation source and the corresponding measured acoustic cavity mode frequency response curve is less than the fourth error set value, then determine the corrected acoustic cavity mode frequency corresponding to the set acoustic cavity mode order as the final acoustic cavity mode frequency corresponding to the set acoustic cavity mode order, and determine the corrected acoustic cavity mode damping corresponding to the set acoustic cavity mode order as the final acoustic cavity mode damping corresponding to the set acoustic cavity mode order.

8. The method according to claim 7, wherein: The first correlation set value is 95%, the first error set value is 5%, the second correlation set value is 95%, the second error set value is 5%, the third correlation set value is 98%, the third error set value is 2%, the fourth correlation set value is 98%, and the fourth error set value is 2%.

9. A system for determining the vehicle's curb body noise transfer function, characterized in that, Comprising: A first modal frequency and first modal damping acquisition unit, configured to acquire the first modal frequency and first modal damping corresponding to each set structural modal order in the vehicle's curb body structure modal test; A final structural modal frequency and final structural modal damping determination unit, configured to determine the final structural modal frequency and final structural modal damping corresponding to each set structural modal order in the curb body structure modal test according to the first modal frequency and the first modal damping; A second modal frequency and second modal damping acquisition unit, configured to acquire the second modal frequency and second modal damping corresponding to each set acoustic cavity modal order in the curb body acoustic cavity modal test; A final acoustic cavity modal frequency and final acoustic cavity modal damping determination unit, configured to determine the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each set acoustic cavity modal order in the curb body acoustic cavity modal test according to the second modal frequency and the second modal damping; A noise transfer function determination unit, configured to calculate and obtain the curb body noise transfer function according to the final structural modal frequency and final structural modal damping corresponding to each set structural modal order and the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each set acoustic cavity modal order; The noise transfer function determination unit is specifically configured to form coordinate points with the final structural modal frequency and final structural modal damping corresponding to each set structural modal order, perform interpolation on the coordinate points obtained in the structural modal test to generate a structural damping curve, and form coordinate points with the final acoustic cavity modal frequency and final acoustic cavity modal damping corresponding to each set acoustic cavity modal order, perform interpolation on the coordinate points obtained in the acoustic cavity modal test to generate an acoustic cavity damping curve; calculate and obtain the curb body noise transfer function according to the structural damping curve and the acoustic cavity damping curve.

Images