Vehicle body modal prediction method and device, equipment and storage medium

Abstract

The invention discloses a vehicle body modal prediction method, device and equipment and a storage medium, relates to the technical field of vehicle vibration analysis and modal testing, and discloses a vehicle body modal prediction method which comprises the steps that the vehicle type, vehicle body attachment points and vehicle body longitudinal beams of a preset vehicle body are obtained; carrying out an attachment point dynamic stiffness test according to the vehicle body attachment point to obtain an attachment point dynamic stiffness test result; performing modal test according to the vehicle body longitudinal beam to obtain vibration mode description; according to at least two items in the vehicle type, the connection point dynamic stiffness test result and the vibration mode description, connection point dynamic stiffness historical data and preset vehicle body modal historical data are constructed; and according to the historical data of the dynamic stiffness of the attachment point and the historical data of the preset vehicle body mode, predicting the vehicle body mode of the to-be-detected vehicle model. Through the technical means of combining the dynamic stiffness test and the modal test of the attachment point, accurate prediction of the vehicle body modal of the to-be-tested vehicle model is realized.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle vibration analysis and modal testing, and in particular to a vehicle body modal prediction method, device, equipment and storage medium. Background Art

[0002] In the design and performance optimization of automobile structures, accurate prediction of the modal characteristics of the vehicle body plays a key role in the comfort, durability, and vibration and noise control of the vehicle. Existing technologies usually rely on actual testing of the vehicle body modal, and obtain modal parameters such as vibration mode and natural frequency through modal tests of the body-in-white. However, the actual testing process is time-consuming and costly, and the development of new models needs to be repeated, resulting in a long development cycle. In addition, the existing methods are insufficient in data accumulation and model prediction. It is impossible to efficiently predict the modal of new models through historical data and measured dynamic stiffness information, and lack support for the design stage.

[0003] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The main purpose of this application is to provide a vehicle body modal prediction, device, equipment and storage medium, aiming to solve the technical problem that vehicle body modal prediction relies on actual testing and cannot use historical dynamic stiffness data and modal data to predict vehicle body modal, resulting in a long development cycle.

[0005] To achieve the above objectives, the present application proposes a vehicle body modal prediction method, the method comprising:

[0006] Get the model, body attachment points and body longitudinal beams of the preset body;

[0007] Performing a dynamic stiffness test on the attachment point according to the vehicle body attachment point to obtain a dynamic stiffness test result of the attachment point;

[0008] Performing modal testing on the vehicle body longitudinal beam to obtain a vibration mode description;

[0009] constructing attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result and at least two of the mode shape description;

[0010] The body mode of the vehicle model to be tested is predicted according to the attachment point dynamic stiffness historical data and the preset body mode historical data.

[0011] In one embodiment, the step of performing an attachment point dynamic stiffness test according to the vehicle body attachment point to obtain the attachment point dynamic stiffness test result comprises:

[0012] Obtaining a preset response bandwidth, a preset number of tests, and an attachment point location of a vehicle body attachment point;

[0013] Performing a preset number of test times of the attachment point dynamic stiffness test at the attachment point position to obtain a test response bandwidth and a test result;

[0014] When the test response bandwidth is greater than or equal to the preset response bandwidth, the attachment point dynamic stiffness test result is obtained according to the test result.

[0015] In one embodiment, the step of performing a modal test on the vehicle body longitudinal beam to obtain a vibration mode description comprises:

[0016] An excitation point is obtained according to the longitudinal beam of the vehicle body, and excitation is performed at the position of the excitation point to obtain a broadband white noise signal;

[0017] When the broadband white noise signal meets a preset signal-to-noise ratio, a response point is obtained according to a preset vehicle body type;

[0018] Determining whether the excitation force and the response signal of the excitation force meet the preset standards;

[0019] When the excitation force and the response signal meet the preset standard, excitation is performed at the position of the response point to obtain a vehicle body response signal;

[0020] The dynamic stiffness is calculated according to the vehicle body response signal, and a vibration mode description is obtained according to the dynamic stiffness.

[0021] In one embodiment, the step of calculating the dynamic stiffness according to the vehicle body response signal comprises:

[0022] Obtaining preset vehicle body stiffness, preset vehicle body damping, excitation force magnitude, and excitation frequency;

[0023] Calculating the vehicle body displacement according to the preset vehicle body stiffness, the preset vehicle body damping, the magnitude of the excitation force and the vehicle body response signal;

[0024] The dynamic stiffness is calculated according to the vehicle body displacement and the vehicle body response signal.

[0025] In one embodiment, the step of determining whether the excitation force and the response signal of the excitation force meet a preset standard comprises:

[0026] Obtaining an auto-power spectrum of the excitation force, and analyzing the frequency distribution of the excitation force according to the auto-power spectrum to confirm whether the excitation force is uniformly distributed at the frequency;

[0027] When the excitation force is uniformly distributed at the frequency, detecting the linearity of the excitation force and the response signal of the excitation force, and confirming whether the excitation force and the response signal are in a linear relationship according to the linearity;

[0028] When the excitation force and the response signal are in a linear relationship, exchanging the positions of the excitation point and the response point, measuring the response signal according to the exchanged positions, and detecting whether the response signals are consistent;

[0029] When the response signals are consistent, analyzing whether the excitation force and the response signal are related;

[0030] When the excitation force and the response signal are correlated, it is determined that the excitation force and the response signal of the excitation force meet a preset standard.

[0031] In one embodiment, the step of constructing the attachment point dynamic stiffness history data and the preset vehicle body modal history data according to at least two of the vehicle model, the attachment point dynamic stiffness test result, and the vibration mode description comprises:

[0032] Analyzing the dynamic stiffness test results of the attachment points to obtain dynamic stiffness data;

[0033] Obtaining a trough frequency according to the dynamic stiffness data;

[0034] constructing attachment point dynamic stiffness history data according to the vehicle type, the dynamic stiffness data, and the trough frequency;

[0035] Preset vehicle body modal history data is constructed according to the vehicle model, the trough frequency and the vibration shape description.

[0036] In one embodiment, the step of predicting the body mode of the vehicle to be tested according to the attachment point dynamic stiffness history data and the preset body mode history data comprises:

[0037] Obtaining the resonance frequency of the vehicle to be tested according to the vehicle to be tested and the historical data of the dynamic stiffness of the attachment point;

[0038] The body mode of the vehicle type to be tested is predicted according to the vehicle type to be tested, the resonance frequency and preset vehicle body mode historical data.

[0039] In addition, to achieve the above-mentioned purpose, the present application also proposes a vehicle body modal prediction device, the vehicle body modal prediction device comprising: an acquisition module, used to acquire a vehicle model, a vehicle body attachment point, and a vehicle body longitudinal beam of a preset vehicle body;

[0040] A testing module, used for performing an attachment point dynamic stiffness test according to the vehicle body attachment point to obtain an attachment point dynamic stiffness test result;

[0041] The test module is further used to perform a modal test on the vehicle body longitudinal beam to obtain a vibration shape description;

[0042] A construction module, configured to construct attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result, and at least two of the vibration mode descriptions;

[0043] A prediction module is used to predict the body mode of the vehicle model to be tested based on the historical data of the dynamic stiffness of the attachment point and the historical data of the preset body mode.

[0044] In addition, to achieve the above-mentioned purpose, the present application also proposes a vehicle body modal prediction device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the vehicle body modal prediction method as described above.

[0045] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the vehicle body modal prediction method described above are implemented.

[0046] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, the steps of the vehicle body modal prediction method as described above are implemented.

[0047] One or more technical solutions proposed in this application have at least the following technical effects:

[0048] This solution combines the technical means of attachment point dynamic stiffness test and modal test to establish the historical data of body attachment point dynamic stiffness and modal history database, and uses this as the basis for modal prediction, thus solving the problem of body modal prediction relying on actual testing in the existing technology. Through this data-driven prediction method, the body modal of the vehicle model to be tested can be efficiently predicted during the design stage, significantly shortening the development cycle and reducing testing costs, improving the efficiency and accuracy of new vehicle model development. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0051] Figure 1A schematic diagram of a process flow provided for the first embodiment of the vehicle body modal prediction method of the present application;

[0052] Figure 2 A schematic diagram of an attachment point fixture provided in the first embodiment of the vehicle body modal prediction method of the present application;

[0053] Figure 3 A schematic diagram of a dynamic stiffness frequency response curve provided for the first embodiment of the vehicle body modal prediction method of the present application;

[0054] Figure 4 A schematic diagram of a flow chart provided for the second embodiment of the vehicle body modal prediction method of the present application;

[0055] Figure 5 A schematic diagram of response point distribution provided for the second embodiment of the vehicle body modal prediction method of the present application;

[0056] Figure 6 A schematic diagram of a flow chart of a vehicle body modal prediction method according to a third embodiment of the present application;

[0057] Figure 7 A schematic diagram of a brief flow chart of a vehicle body modal prediction method provided in Embodiment 3 of the present application;

[0058] Figure 8 This is a schematic diagram of the module structure of the vehicle body modal prediction device according to an embodiment of the present application;

[0059] Fig. 9 Schematic diagram of the device structure of the hardware operating environment involved in the vehicle body modal prediction method in the embodiment of the present application.

[0060] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0061] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0062] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0063] The main solution of the embodiment of the present application is: obtaining the model of the preset vehicle body, the vehicle body attachment point and the vehicle body longitudinal beam;

[0064] Performing a dynamic stiffness test on the attachment point according to the vehicle body attachment point to obtain a dynamic stiffness test result of the attachment point;

[0065] Performing modal testing on the vehicle body longitudinal beam to obtain a vibration mode description;

[0066] constructing attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result and at least two of the mode shape description;

[0067] The body mode of the vehicle model to be tested is predicted according to the attachment point dynamic stiffness historical data and the preset body mode historical data.

[0068] In this embodiment, for the convenience of description, the following description is made by taking the identification of the vehicle body modal prediction device as the execution subject.

[0069] Since the existing technology relies on actual testing for the prediction of body modal, it is impossible to use historical dynamic stiffness data and modal data to predict the body modal, resulting in a long development cycle. This application provides a solution. By combining the technical means of attachment point dynamic stiffness test and modal test, a body attachment point dynamic stiffness historical data and modal history database are established, and modal prediction is performed based on this, thereby solving the problem of the existing technology that the body modal prediction relies on actual testing. Through this data-driven prediction method, the body modal of the vehicle model to be tested can be efficiently predicted in the design stage, significantly shortening the development cycle and reducing testing costs, and improving the efficiency and accuracy of new vehicle model development.

[0070] It should be noted that the execution subject of this embodiment may be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a vehicle body modal prediction device, etc. The following takes the vehicle body modal prediction device as an example to illustrate this embodiment and the following embodiments.

[0071] Based on this, the embodiment of the present application provides a vehicle body modal prediction method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the vehicle body modal prediction method of the present application.

[0072] In this embodiment, the vehicle body modal prediction method includes steps S10 to S50:

[0073] Step S10, obtaining a preset vehicle body model, a vehicle body attachment point, and a vehicle body longitudinal beam;

[0074] It should be noted that the above-mentioned vehicle models can be specific types of white bodies planned for dynamic stiffness and modal tests. The white body design of each vehicle model, such as sedans, sport utility vehicles (SUVs), multi-purpose vehicles (MPVs), etc., will be different, so it is necessary to preset according to the actual vehicle model to ensure that the test is targeted at the specific needs of the body structure. Attachment points refer to the key locations where the body is connected to other structures, such as subframes, suspensions, and suspension systems. These attachment points directly affect the transmission path of vibration, so selecting attachment points for dynamic stiffness testing in vibration testing can reflect the vibration resistance of the body in this area. The longitudinal beam is the main load-bearing component in the body structure, usually located at the bottom of the body and extending along the front and rear directions of the vehicle. The design and layout of the longitudinal beam will directly affect the overall rigidity and torsional strength of the vehicle, so it is usually used as the installation location of the exciter in modal testing.

[0075] It is understandable that for locations where it is difficult to excite or pick up signals at the vehicle body attachment point, a special fixture can be made to conduct the test.

[0076] Reference Figure 2 , Figure 2 Schematic diagram of an attachment point fixture of the first embodiment of the vehicle body modal prediction method of the present application.

[0077] like Figure 2 As shown in the figure, the fixture is a metal rod-like structure that firmly fixes the sensor near an attachment point on the body of the car. The purpose of the fixture is to ensure that the sensor does not move during the test so that the vibration signal can be accurately picked up. In the figure, you can see the sensor, and the small device with a cable connection above is fixed to the body of the car through the fixture, so that when performing dynamic stiffness tests, the fixture will help ensure that the test equipment can effectively obtain vibration data and avoid affecting the accuracy of the data due to loose sensors or changes in position during the test.

[0078] Step S20, performing a dynamic stiffness test of the attachment point according to the vehicle body attachment point to obtain a dynamic stiffness test result of the attachment point;

[0079] It should be noted that the purpose of the above-mentioned attachment point dynamic stiffness test can be to measure the stiffness of each attachment point at different frequencies, that is, the resistance to vibration force. The attachment point dynamic stiffness value refers to a parameter that reflects the resistance of the vehicle body to vibration at the attachment point of the vehicle body. Specifically, it represents the relationship between the displacement and force generated at the attachment point when a vibration force is applied to the attachment point. High dynamic stiffness means that the vehicle body has a strong resistance to vibration force at the attachment point, and the degree of vibration transmission to the vehicle body is small. Low dynamic stiffness means that the vehicle body is more likely to produce a larger displacement at the attachment point, and the vibration is easily transmitted to the vehicle body.

[0080] It is understood that the dynamic stiffness test results include the dynamic stiffness values ​​of each attachment point at different frequencies, and the dynamic stiffness frequency response curve can be further obtained based on the dynamic stiffness values. Through these data, it can be observed that the dynamic stiffness value drops significantly at certain frequencies, which usually indicates that the body is less resistant to vibration at this frequency, that is, the resonant frequency.

[0081] In addition, it should be noted that in the dynamic stiffness test, an accelerometer can be used to measure the vibration response of the vehicle body at a specific attachment point or excitation point. The accelerometer is installed at the attachment point or response point of the vehicle body to capture the vibration response of these positions under the action of the excitation force. The response is usually recorded in the form of acceleration, reflecting the vibration intensity of the vehicle body at different frequencies. The dynamic stiffness test of the attachment point can be performed by performing a hammer test near the accelerometer. The hammer test, also known as the knock test, is a way of applying an instantaneous force in the test. This impact force will produce a wide frequency range of excitation in a short time, covering multiple frequencies. In this way, a single knock can cause the vehicle body to produce vibration responses at multiple frequencies at the same time. The vibration signal is usually a time domain signal, which represents the vibration response within a certain period of time. In order to analyze the dynamic stiffness of each frequency, the time domain signal needs to be converted into a frequency domain signal, which requires the use of Fourier transform. Fourier transform can decompose the vibration signal in time into components of different frequencies, thereby obtaining the vibration response intensity at each frequency. This is equivalent to splitting a complex time waveform into a series of simplified vibration frequencies. After Fourier transformation, the test data will show the response at each frequency. Combining the applied excitation force and the measured vibration displacement, the dynamic stiffness value at different frequencies can be calculated.

[0082] For example, the dynamic stiffness test of the attachment point can be performed by connecting the vibration and noise test system. After debugging the vibration and noise test system, an acceleration sensor is used to bond at each test position. After it is firmly fixed, a hammer test is performed next to the sensor. After testing one point, the acceleration sensor and the knocking point are moved to the next test position. The test positions include but are not limited to the subframe body mounting point, the suspension body mounting point, and the suspension body mounting point. Repeat until the test work of all pre-selected points is completed.

[0083] In a feasible implementation, step S20 may include steps S21 to S23:

[0084] Step S21: obtaining a preset response bandwidth, a preset number of tests, and a location of an attachment point of a vehicle body attachment point;

[0085] It should be noted that the preset response bandwidth refers to the frequency range required to be measured in the test, which indicates the frequency coverage of the vibration response signal, ensuring that the test can collect vibration data within the specified frequency range. The preset number of tests refers to the number of tests that need to be repeated at each attachment point in order to obtain stable dynamic stiffness data in the attachment point dynamic stiffness test. The average value of multiple tests can reduce accidental errors and ensure the accuracy of the data. In this embodiment, the preset response bandwidth can be 1000 Hz, and the preset number of tests can be 5 times.

[0086] It is understood that the attachment point location refers to the specific part of the vehicle body used to test the dynamic stiffness, which is the key location for connecting with other vehicle body parts. Determining the attachment point location can help install the sensor and exciter in the correct position for testing, ensuring that the dynamic stiffness data obtained can represent the actual dynamic characteristics of the vehicle body at that part.

[0087] For example, in a certain SUV model, the attachment point positions of the body attachment points may include front suspension mounting points and rear suspension mounting points, etc. The dynamic stiffness data of these positions can be used to analyze the response characteristics of the body to external vibrations.

[0088] Step S22, performing a preset number of test times of the attachment point dynamic stiffness test at the attachment point position to obtain a test response bandwidth and a test result;

[0089] It should be noted that the test response bandwidth refers to the frequency range actually measured in the test. The test results include the dynamic stiffness value within the test response bandwidth.

[0090] Step S23, when the test response bandwidth is greater than or equal to the preset response bandwidth, obtaining the attachment point dynamic stiffness test result according to the test result.

[0091] It is understood that the test response bandwidth is compared with the preset response bandwidth to ensure that the frequency range actually measured by the test is greater than or equal to the preset frequency band. If the test response bandwidth is less than the preset response bandwidth, it may be necessary to retest or adjust the system configuration to ensure that the frequency range is wide enough.

[0092] In addition, it is understandable that after confirming that the bandwidth meets the requirements, the multiple test results in step S22 are averaged to obtain the dynamic stiffness value of each frequency point.

[0093] Step S30, performing a modal test on the vehicle body longitudinal beam to obtain a vibration mode description;

[0094] It should be noted that the purpose of modal testing is to determine the vibration characteristics of the vehicle body at different frequencies, especially the natural frequency, mode shape and damping characteristics. Modal testing uses an exciter to apply vibration force to make the vehicle body resonate, thereby capturing the natural vibration characteristics of the vehicle body. The mode shape description refers to the vibration mode of the vehicle body at a specific frequency, which can be visualized through modal test data. The mode shape description includes the movement form of the vehicle body at a specific frequency, such as torsion, bending, etc., which shows the vibration response of the vehicle body at this frequency.

[0095] It is understandable that the longitudinal beams of the vehicle body are used as excitation points for modal testing. The longitudinal beam is the main load-bearing component of the vehicle body structure and runs through the bottom of the vehicle body. Therefore, applying vibration force on the longitudinal beam, that is, starting the modal test, can stimulate the overall vibration of the vehicle body and help measure the global modal characteristics of the vehicle body.

[0096] Step S40, constructing attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result and at least two of the vibration mode descriptions;

[0097] It should be noted that the historical data of the dynamic stiffness of the attachment point may refer to the accumulated results of the dynamic stiffness data of different vehicle models at each attachment point. When constructing historical data, the dynamic stiffness results of the attachment points of multiple vehicle models are archived to form a database, which accumulates the dynamic stiffness characteristics of the body of a certain vehicle model under different conditions, so that in the future, the dynamic stiffness of the attachment point of new models can be quickly compared and analyzed through existing data. The preset body modal historical data is the body modal data accumulated based on the vibration type description, including the natural frequency and vibration type characteristics of different vehicle models, such as torsion and bending modes.

[0098] It is understandable that, according to the data sources of different models, the attachment point dynamic stiffness and modal characteristics are classified and stored according to the attachment point position and modal frequency for subsequent query and use. By constructing the historical data of the attachment point dynamic stiffness and the historical data of the body modal, a large amount of vehicle model data can be accumulated in the database to form a data-driven design tool. This step effectively reduces the need for repeated testing during the development of new models, improves data utilization, and shortens the development cycle.

[0099] In a feasible implementation, step S40 may include steps S41 to S44:

[0100] Step S41, analyzing the dynamic stiffness test result of the attachment point to obtain dynamic stiffness data;

[0101] It should be noted that the dynamic stiffness data includes dynamic stiffness values ​​at different frequencies, which is a quantitative description of the stiffness performance of the attachment point during vibration. The dynamic stiffness data can be expressed in a chart generated from the data, and the chart can more clearly show the frequencies that are prone to resonance and the corresponding dynamic stiffness.

[0102] It is understandable that the frequency response curve of dynamic stiffness can be obtained based on the test results of the dynamic stiffness of the attachment point, showing the dynamic stiffness value at each frequency. By analyzing the curve, the vibration response characteristics of the attachment point at different frequencies can be understood, and key information such as the resonance frequency can be identified.

[0103] Reference Figure 3 , Figure 3 It is a schematic diagram of a dynamic stiffness frequency response curve of the first embodiment of the vehicle body modal prediction method of the present application.

[0104] like Figure 3 As shown, the horizontal axis represents the frequency of vibration, in Hertz (Hz). The frequency indicates the speed of vibration. The higher the value, the faster the frequency of vibration. From left to right in the figure, the frequency is from low to high, showing the response of the attachment point at different frequencies. The vertical axis represents the dynamic stiffness of the attachment point, in Newton per meter (N / m), and the dynamic stiffness value is displayed on a logarithmic scale (Log). At some frequencies, the dynamic stiffness value will show a significant decrease, that is, the trough. These frequencies are usually the resonant frequencies of the car body, indicating that the car body is most likely to resonate at these frequencies. For example, 44.8Hz, 51.6Hz, etc. in the figure. These frequency points indicate that the car body is more likely to resonate at these specific frequencies. By observing these data, it can help to optimize the car body design and avoid or reduce resonance.

[0105] Step S42, obtaining the trough frequency according to the dynamic stiffness data;

[0106] It should be noted that the trough frequency refers to the frequency point where the dynamic stiffness value on the dynamic stiffness frequency response curve drops significantly, which usually corresponds to the resonant frequency of the vehicle body. At these frequencies, the vehicle body's resistance to vibration forces is the weakest. If the dynamic stiffness of the front suspension mounting point drops significantly at 60Hz, then 60Hz is the trough frequency of the attachment point, indicating that the vehicle body is prone to resonance at this frequency.

[0107] Step S43, constructing attachment point dynamic stiffness history data according to the vehicle type, the dynamic stiffness data and the trough frequency;

[0108] It can be understood that the dynamic stiffness data and trough frequency obtained by analysis are classified by vehicle type and stored in the attachment point dynamic stiffness history database to form structured data and accumulate the dynamic stiffness performance of different vehicle types at different attachment points, which is convenient for subsequent query and model matching.

[0109] Step S44, constructing preset vehicle body modal history data according to the vehicle model, the trough frequency and the vibration mode description.

[0110] It is understandable that the above-mentioned trough frequency and vibration mode description, such as the first-order torsional mode, the second-order bending mode, etc., are recorded in the body modal history database to help analyze the structural characteristics of the new model. The preset body modal history data can be the following Table 1:

[0111] Table 1

[0112]

[0113]

[0114] It should be noted that the overall first-order torsion refers to the overall torsion mode of the vehicle body at a lower frequency. In this mode, the vehicle body undergoes torsional deformation along the longitudinal axis (usually the centerline of the vehicle body), that is, the front and rear ends of the vehicle body rotate in opposite directions. For example, the front of the vehicle may rotate to the left, while the rear of the vehicle rotates to the right, forming a deformation similar to a "twisted knot". This deformation usually reflects the overall rigidity of the vehicle body. If the rigidity is insufficient, it may affect the handling stability.

[0115] The overall first-order vertical bending refers to the mode in which the vehicle body bends in the vertical direction as a whole. In this mode, the front and rear ends of the vehicle body vibrate up and down, forming a shape similar to a "bow". In this mode, the middle of the vehicle body bends downward, and the front and rear ends lift upward, or vice versa. This mode reflects the longitudinal rigidity of the vehicle body. If the frequency of this mode is low, the vehicle body is prone to unnecessary vertical swing on bumpy roads, affecting driving comfort.

[0116] Front module bending refers to the local bending deformation of the front end of the vehicle body (such as the engine compartment and front suspension area) in the vertical direction. For example, the front end will bend up and down, while the rest of the body may remain relatively stable. This mode is related to the stiffness of the front suspension and front structure. If the front end is not rigid enough, it may cause front shaking and instability during driving.

[0117] Global torsional deformation is similar to global first-order torsion, and refers to the global torsion of the vehicle body over a larger range. Global torsional deformation is similar to global first-order torsion, but may refer to a higher-order torsion mode, or to the global torsion of the vehicle body over a larger range. The various parts of the vehicle body undergo a large angle of rotational deformation along the centerline of the vehicle body, and the front and rear ends rotate in opposite directions.

[0118] Combined bending and torsion deformation refers to a composite mode in which the vehicle body bends and twists at a specific frequency, that is, one part of the vehicle body bends and the other part twists. For example, the front end of the vehicle body may bend vertically, while the middle and rear ends may twist. This composite deformation may lead to insufficient rigidity of the local body, increase shaking and instability during driving, and affect the handling and comfort of the vehicle.

[0119] Floor bending deformation refers to the bending deformation of the vehicle body floor (underbody area) in the vertical direction. The floor area may bend upward or downward, while the upper structure of the body remains relatively unchanged. Floor bending affects the stability of the passenger compartment and may cause unnecessary vibrations in the floor area when the vehicle passes through bumpy roads or sharp turns, reducing ride comfort.

[0120] Specifically, this embodiment does not limit the specific type of vibration mode description.

[0121] Step S50 , predicting the body mode of the vehicle model to be tested according to the historical data of the attachment point dynamic stiffness and the historical data of the preset body mode.

[0122] It should be noted that the vehicle model to be tested is the vehicle model that needs to obtain the body structure model. After the above data accumulation, the body mode corresponding to this vehicle model can be obtained based on the vehicle model and the accumulated data. Specifically, by matching the dynamic stiffness value and vibration mode characteristics of the vehicle model, the natural frequency and vibration mode of the body corresponding to the vehicle model can be estimated. According to the data accumulation in the previous step, even without actual modal test data, accurate body modal prediction results can be obtained.

[0123] This embodiment provides a vehicle body modal prediction method, which solves the technical problems of insufficient data accumulation and low testing efficiency in traditional vehicle body modal prediction by combining the technical means of attachment point dynamic stiffness test and vehicle body modal test, thereby achieving the beneficial effects of improving data utilization and shortening the development cycle in the process of new vehicle model development, and being able to accurately predict the vehicle body modal.

[0124] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 4 The step S30 of the vehicle body modal prediction method includes steps S31 to S35:

[0125] Step S31, obtaining an excitation point according to the longitudinal beam of the vehicle body, and performing excitation at the position of the excitation point to obtain a broadband white noise signal;

[0126] It should be noted that the excitation point refers to a specific position selected on the longitudinal beam of the vehicle body for applying an external excitation force. When selecting the position of the excitation point, priority is usually given to the position that can excite the overall vibration response of the vehicle body in order to fully capture the dynamic characteristics of the vehicle body. Excitation refers to the application of vibration force at the excitation point position through equipment such as an exciter or an impact hammer to cause the vehicle body to vibrate. The purpose of excitation is to excite the natural modes of the vehicle body so that subsequent tests can record the vibration characteristics of the vehicle body at different frequencies. Broadband white noise is a random signal with a wide frequency coverage range. The signal contains vibration components of multiple frequencies, so vibration modes at multiple frequencies can be excited simultaneously in modal testing.

[0127] Reference Figure 5 , Figure 5 This is a schematic diagram of the response point distribution of the second embodiment of the vehicle body modal prediction method of the present application.

[0128] like Figure 5 As shown in the figure, the small red squares represent the response points arranged in various parts of the car body. These points are distributed in different positions of the car body. By arranging response points in various key parts of the car body, the vibration response of these positions can be measured to understand the vibration mode of the car body at different frequencies. The location of these response points is usually selected based on the shape characteristics of the car body structure to ensure that the dynamic characteristics of the whole car body and local areas can be captured.

[0129] Step S32, when the broadband white noise signal meets the preset signal-to-noise ratio, obtaining a response point according to a preset vehicle body type;

[0130] It should be noted that the preset signal-to-noise ratio is the minimum signal-to-noise ratio standard set before the test to ensure that the measured signal quality is high enough. If the signal-to-noise ratio of the broadband white noise signal reaches or exceeds the preset value, it means that the data of the test system is valid and clear.

[0131] For example, dual exciters are used to excite the longitudinal beam of the vehicle body, so that the broadband white noise signal is clear and a sufficiently high signal-to-noise ratio is achieved, so that the frequency modes of the white body can be excited. The dual exciter excitation of the longitudinal beam of the vehicle body uses two exciters to work simultaneously, which are installed at different positions of the longitudinal beam of the vehicle body. This method is called dual exciter excitation. The reason for using dual exciters is that it can produce more uniform and stable vibration excitation on the vehicle body, making the test data more comprehensive and accurate. The use of dual exciters helps to excite more modes, so that more vibration characteristics and data can be captured in the test. The signal-to-noise ratio (SNR) refers to the ratio of the intensity of the signal to the intensity of the noise. In modal testing, the signal is the vibration response of the vehicle body, and the noise is the inevitable environmental interference or electrical noise during the test. By using dual exciters, the applied vibration force can be enhanced, thereby increasing the vibration response signal of the vehicle body, making it much greater than the background noise, so that clearer vibration data can be obtained. A higher signal-to-noise ratio means that the measurement data is more reliable and accurate, which helps to more accurately analyze the modal characteristics of the vehicle body.

[0132] In addition, it should be noted that the response point refers to the specific location on the vehicle body used to measure the vibration response. It is usually distributed in key parts of the vehicle body, such as the roof, door, chassis, etc., to ensure that the vibration characteristics of the vehicle body can be fully captured.

[0133] Step S33, determining whether the excitation force and the response signal of the excitation force meet the preset standard;

[0134] It should be noted that the response signal refers to the vibration response measured at each response point after the excitation force acts on the vehicle body. These signals are usually recorded in the form of displacement, velocity or acceleration, reflecting the dynamic characteristics of the vehicle body. The preset standard is the judgment standard set before the test to ensure the quality of the excitation and response signals. These standards usually include parameters such as signal-to-noise ratio, linearity and reciprocity to ensure that the excitation force and response signals have high accuracy and consistency.

[0135] In a feasible implementation, step S33 may include steps S331 to S335:

[0136] Step S331, obtaining an auto-power spectrum of the excitation force, and analyzing the frequency distribution of the excitation force according to the auto-power spectrum to confirm whether the excitation force is uniformly distributed at the frequency;

[0137] It should be noted that the autopower spectrum is used to analyze the energy distribution of the excitation force signal in the frequency domain. The autopower spectrum can show the intensity of the excitation force at each frequency.

[0138] It is understandable that in modal testing, the excitation force needs to be evenly distributed within the target frequency range to ensure that the vehicle body can be effectively excited at different frequencies. The autopower spectrum analysis is used to confirm whether the excitation force is evenly distributed within the set frequency range. If the excitation force is not evenly distributed in frequency, it may affect the accuracy of subsequent tests.

[0139] Step S332, when the excitation force is uniformly distributed at the frequency, detecting the linearity of the excitation force and the response signal of the excitation force, and confirming whether the excitation force and the response signal are in a linear relationship according to the linearity;

[0140] It should be noted that the linearity test is used to determine the proportional relationship between the excitation force and the response signal. Ideally, the excitation force and the response signal should be linearly related, that is, when the excitation force increases, the response signal should also increase accordingly.

[0141] It is understandable that the linear relationship indicates that the system's response behavior is predictable when it is stimulated by external factors, which is crucial for data repeatability. Under the condition of uniform distribution of the excitation force, different intensities of excitation force are applied, and the corresponding response signals are measured to confirm whether the changes of the two are linear.

[0142] Step S333, when the excitation force and the response signal are in a linear relationship, exchanging the positions of the excitation point and the response point, measuring the response signal according to the exchanged positions, and detecting whether the response signals are consistent;

[0143] As can be understood, swapping the positions of the excitation and response points is used to verify the reciprocity of the system. Ideally, the same response signal should be generated after the excitation and response points are swapped. Reciprocity ensures that the system's response to the excitation is consistent, indicating that the system characteristics do not change with the change of the measurement position. On the basis of satisfying the linear relationship, the excitation point and the response point are swapped, the same excitation force is applied again, and the new response signal is measured to ensure that it is consistent with the original response.

[0144] Step S334, when the response signals are consistent, analyzing whether the excitation force and the response signal are related;

[0145] It should be noted that correlation analysis is used to confirm the causal relationship between the excitation force and the response signal, that is, whether the change in the excitation force directly causes the change in the response signal. The correlation function between the excitation force and the response signal is calculated to observe the correlation between the two. If the two are highly correlated, it means that the response signal is directly caused by the excitation force.

[0146] Step S335 : when the excitation force and the response signal are correlated, determining whether the excitation force and the response signal of the excitation force meet a preset standard.

[0147] It can be understood that when the uniform distribution, linear relationship, reciprocity and correlation of the signal meet the standards, the excitation force and the response signal can be considered to meet the preset standards, ensuring the accuracy and reliability of the signal data.

[0148] It should be noted that the situations that do not meet the standards are as follows: obtaining the autopower spectrum of the excitation force, and analyzing the frequency distribution of the excitation force based on the autopower spectrum; if the excitation force is not uniformly distributed at the frequency, determining that the excitation force and the response signal of the excitation force do not meet the preset standards; when the excitation force is uniformly distributed at the frequency, detecting the linearity of the excitation force and the response signal of the excitation force; if the excitation force and the response signal are not in a linear relationship, determining that the excitation force and the response signal of the excitation force do not meet the preset standards; when the excitation force and the response signal are in a linear relationship, exchanging the positions of the excitation point and the response point, measuring the response signal based on the exchanged positions, if the response signals are inconsistent, determining that the excitation force and the response signal of the excitation force do not meet the preset standards; when the response signals are consistent, analyzing whether the excitation force and the response signal are correlated; if the excitation force and the response signal are not correlated, determining that the excitation force and the response signal of the excitation force do not meet the preset standards.

[0149] Step S34, when the excitation force and the response signal meet the preset standard, excitation is performed at the position of the response point to obtain a vehicle body response signal;

[0150] It is understandable that only after the signal quality meets the standard can the formal excitation test be continued at the response point to ensure the validity of the data. When applying the excitation force, the exciter will apply the preset excitation to these response points one by one to obtain the vibration signal at that position. This operation ensures that each response point is excited, which is convenient for recording the vibration characteristics of different parts. The excitation force is usually applied in the form of broadband white noise to cover a wide frequency range and ensure the excitation of multiple modal characteristics of the vehicle body. In this embodiment, the method of applying the excitation force is not limited.

[0151] It should be noted that the body response signal refers to the vibration data measured at the response point, including displacement, velocity or acceleration at different frequencies. The body response signal reflects the dynamic behavior of the body under the action of the excitation force, including the modal characteristics of the body such as the natural frequency and vibration mode.

[0152] Step S35, calculating the dynamic stiffness according to the vehicle body response signal, and obtaining a vibration mode description according to the dynamic stiffness.

[0153] It should be noted that the vibration mode is the vibration mode of the vehicle body at the resonant frequency. By analyzing the dynamic stiffness frequency response curve, the vibration mode at different frequencies can be identified. The vibration mode description usually includes the morphological changes of the vehicle body at a certain frequency, such as first-order bending, second-order torsion, etc. These modal characteristics provide a full picture of the dynamic behavior of the vehicle body.

[0154] For example, the excitation force and response signal are measured at the front suspension attachment point of the car, the dynamic stiffness value at each frequency is calculated, and the dynamic stiffness frequency response curve is plotted. The dynamic stiffness frequency response curve shows a significant trough at 50Hz, indicating that this frequency is one of the resonant frequencies of the car body. Combined with the vibration mode description analysis, the car has a first-order bending mode at 50Hz, which is manifested as a mode in which the front and rear parts of the car body vibrate in opposite directions.

[0155] In a feasible implementation, step S35 may include steps S351 to S353:

[0156] Step S351, obtaining a preset vehicle body stiffness, a preset vehicle body damping, an excitation force magnitude, and an excitation frequency;

[0157] It should be noted that the preset body stiffness refers to the structural stiffness of the body under static or low-frequency excitation, and is an important parameter for measuring the body's ability to resist deformation. The higher the stiffness, the stronger the body's ability to resist external forces. The preset body damping refers to the body structure's ability to attenuate vibrations. The greater the damping, the faster the vibration energy decays, which helps to reduce the vibration amplitude of the body and improve comfort. The excitation force refers to the amount of vibration force applied in dynamic stiffness and modal tests to induce the vibration response of the body. Different excitation force magnitudes will induce different vibration response intensities. The excitation frequency refers to the frequency of the vibration force applied to the body.

[0158] Step S352, calculating the body displacement according to the preset body stiffness, the preset body damping, the excitation force magnitude and the body response signal;

[0159] It should be noted that the vehicle body displacement refers to the displacement of the vehicle body caused by the excitation force.

[0160] It can be understood that the vibration equation of the single degree of freedom system can be obtained according to the preset body stiffness, the preset body damping, the magnitude of the excitation force and the body response signal. The vibration equation of the single degree of freedom system is as follows:

[0161]

[0162] Where m is the vehicle body mass, k is the preset vehicle body stiffness, c is the preset vehicle body damping, f is the magnitude of the excitation force, and x is the displacement of the vehicle body under the action of force f, that is, the vehicle body response signal.

[0163] Solving the above equation 1, we can get the following equation 2:

[0164]

[0165] Where m is the vehicle body mass, k is the preset vehicle body stiffness, c is the preset vehicle body damping, f is the magnitude of the excitation force, x is the displacement of the vehicle body under the action of force f, that is, the vehicle body response signal, and j is an imaginary unit used for complex form representation.

[0166] Step S353: calculating the dynamic stiffness according to the vehicle body displacement and the vehicle body response signal.

[0167] It can be understood that the calculation formula of dynamic stiffness is as follows:

[0168]

[0169] Where m is the vehicle body mass, k is the preset vehicle body stiffness, c is the preset vehicle body damping, f is the magnitude of the excitation force, x is the displacement of the vehicle body under the action of force f, that is, the vehicle body response signal, and j is an imaginary unit used for complex form representation.

[0170] In addition, it can be understood that the dynamic stiffness is related to the mass m, static stiffness k, and damping c of the vehicle body through the above formula 3, and the stiffness value changes with the frequency. In the resonant frequency range, the amplitude is wc, and the dynamic stiffness value decreases significantly, which is mainly controlled by damping. At this frequency, the ability of the structure to resist deformation is the smallest. By observing the measuring point Figure 3 The dynamic stiffness curve of the origin, the frequency corresponding to the trough of the dynamic stiffness curve is the modal frequency of the vehicle body, mainly because the dynamic stiffness can be calculated by the frequency response function, and the trough of the dynamic stiffness is the peak position of the frequency response function, and the frequency response function is the basic data used to calculate the modal parameters. From the theoretical derivation of the dynamic stiffness of the vehicle body attachment point above, it can be found that the frequency response function of the origin, that is, the dynamic stiffness of the origin, includes all local, semi-global, and global structural responses including the origin. Therefore, the dynamic stiffness of the origin is related to the physical structural characteristics of the entire vehicle body.

[0171] This embodiment provides a vehicle body modal prediction method, which solves the technical problems of unstable quality of excitation force and response signal, low signal-to-noise ratio, poor linearity and reciprocity in traditional modal testing by selecting excitation points on the vehicle body longitudinal beam to apply a broadband white noise signal and arranging response points at key parts of the vehicle body, thereby achieving the beneficial effects of improving the accuracy of vehicle body modal prediction and ensuring the reliability and consistency of test data.

[0172] Based on the first embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 6 The step S50 of the vehicle body modal prediction method includes steps S51 to S52:

[0173] Step S51, obtaining the resonance frequency of the vehicle type to be tested according to the vehicle type to be tested and the historical data of the dynamic stiffness of the attachment point;

[0174] It should be noted that the resonant frequency refers to the frequency point where the vibration response of the vehicle body is the strongest at a specific frequency. The resonant frequency reflects the inherent characteristics of the vehicle and is a key parameter in vehicle modal analysis. At the resonant frequency, the dynamic stiffness of the vehicle body is the smallest and the vibration amplitude is the largest. Determining the resonant frequency helps identify weak areas of the vehicle at a specific frequency so that structural improvements can be made.

[0175] Exemplarily, according to the vehicle model to be tested, the historical database of dynamic stiffness at the attachment point is searched for tested vehicle models with similar structures and characteristics. The dynamic stiffness data of the attachment points of similar vehicles are extracted, and their dynamic stiffness frequency response curves are observed. The trough position in the frequency response curve usually corresponds to the resonant frequency. By comparing with the historical data, the resonant frequency of the vehicle model to be tested at a similar attachment point position is inferred. If the historical data shows that there is resonance within a certain frequency range, the vehicle model to be tested may also have resonant characteristics at the same frequency.

[0176] Step S52: predicting the body mode of the vehicle type to be tested according to the vehicle type to be tested, the resonance frequency and preset body mode historical data.

[0177] Exemplarily, according to the design parameters and resonant frequency of the vehicle model to be tested, similar vehicle models and modal characteristics at similar frequencies are searched from a preset vehicle body modal history database. By referring to the modal characteristics of similar vehicle models in historical data, the modal mode of the vehicle model to be tested at similar resonant frequencies is analyzed. The vibration mode description usually includes the vibration form of the vehicle body, such as first-order torsion or second-order bending. According to the analysis results, the vibration mode of the vehicle model to be tested at different resonant frequencies is predicted. For example, if the historical data shows that similar vehicle models have obvious torsion modes at a certain frequency, it can be inferred that the vehicle model to be tested may also have similar torsion modes at this frequency. For example, suppose that in the modal history data of a certain SUV model, the front suspension position shows a first-order bending mode at 60Hz, and the vibration mode description shows that the mode is mainly manifested as vertical vibration at the front and rear ends of the vehicle body. When predicting an SUV model to be tested, if the resonant frequency of its front suspension position is also 60Hz, it can be predicted that the model will also produce a similar first-order bending mode at this frequency.

[0178] Through the big data analysis of the early body-in-white modal database and the dynamic stiffness database, this embodiment provides a body modal prediction method. By using the technical means of the historical data of the dynamic stiffness of the attachment point and the preset historical data of the body modal, the dynamic response characteristics of each order of the body can be derived through the dynamic stiffness. In this way, the modal and dynamic stiffness tests can be completed using a body-in-white dynamic stiffness test, shortening the development cycle and reducing the development cost. At the same time, the big data analysis of dynamic stiffness can predict the design deficiencies of the structural dynamic characteristics at an early stage, and the structure can be modified in the early stage of development, reducing the difficulty of design in the later stage. By analyzing the dynamic stiffness of key points, the transmission path of vibration noise can be found, and the impact of vibration noise in the car can be cut off or reduced from the transmission path, thereby improving the quietness of the body. The technical problem of requiring a large number of real vehicle tests to determine the body modal in the development process of new models is solved, achieving the beneficial effects of reducing real vehicle tests, shortening the development cycle and improving prediction accuracy.

[0179] For example, to help understand the implementation process of the vehicle body modal prediction method obtained by combining this embodiment with the above-mentioned embodiment 1, please refer to Figure 7 , Figure 7 A brief flow chart of a vehicle body modal prediction method is provided, specifically:

[0180] The body-in-white modal data includes the body modal data of different types of vehicle models (such as SUV, Sedan, MPV). According to the vehicle type (SUV, Sedan, MPV), the subframe mounting point dynamic stiffness data and suspension mounting point dynamic stiffness data of the vehicle model are searched in the database. The dynamic stiffness data of these mounting points describe the dynamic characteristics of the vehicle body at different mounting points and are an important basis for modal analysis. The matched data is applied to the new vehicle model to be tested to predict the various modes of the vehicle model. Finally, the modal characteristics of the new vehicle model are derived from these data, providing basic data for structural optimization and dynamic performance improvement.

[0181] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the vehicle body modal prediction method of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0182] This application also provides a vehicle body modal prediction device, please refer to Figure 8 , the vehicle body modal prediction device comprises:

[0183] An acquisition module 10 is used to acquire a preset vehicle body model, a vehicle body attachment point, and a vehicle body longitudinal beam;

[0184] A testing module 20, configured to perform a dynamic stiffness test of the attachment point according to the vehicle body attachment point to obtain a dynamic stiffness test result of the attachment point;

[0185] The test module 20 is further used to perform a modal test on the vehicle body longitudinal beam to obtain a vibration shape description;

[0186] A construction module 30, for constructing attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result and at least two of the vibration mode description;

[0187] The prediction module 40 is used to predict the body mode of the vehicle model to be tested according to the historical data of the dynamic stiffness of the attachment point and the historical data of the preset body mode.

[0188] The vehicle body modal prediction device provided by the present application adopts the vehicle body modal prediction method in the above-mentioned embodiment, which can solve the technical problem that the vehicle body modal prediction relies on actual testing and cannot use historical dynamic stiffness data and modal data to predict the vehicle body modal, resulting in a long development cycle. Compared with the prior art, the beneficial effects of the vehicle body modal prediction device provided by the present application are the same as the beneficial effects of the vehicle body modal prediction method provided by the above-mentioned embodiment, and the other technical features in the vehicle body modal prediction device are the same as the features disclosed in the above-mentioned embodiment method, which will not be repeated here.

[0189] In one embodiment, the test module 20 is further used to obtain a preset response bandwidth, a preset number of tests, and an attachment point position of the vehicle body attachment point; perform a preset number of test times of the attachment point dynamic stiffness test at the attachment point position to obtain a test response bandwidth and a test result; and when the test response bandwidth is greater than or equal to the preset response bandwidth, obtain an attachment point dynamic stiffness test result based on the test result.

[0190] In one embodiment, the test module 20 is further used to obtain an excitation point based on the vehicle body longitudinal beam, perform excitation at the position of the excitation point to obtain a broadband white noise signal; when the broadband white noise signal meets a preset signal-to-noise ratio, obtain a response point according to a preset vehicle body model; determine whether the excitation force and the response signal of the excitation force meet a preset standard; when the excitation force and the response signal meet the preset standard, perform excitation at the position of the response point to obtain a vehicle body response signal; calculate the dynamic stiffness based on the vehicle body response signal, and obtain a vibration mode description based on the dynamic stiffness.

[0191] In one embodiment, the test module 20 is further used to obtain a preset vehicle body stiffness, a preset vehicle body damping, an excitation force magnitude, and an excitation frequency; calculate a vehicle body displacement according to the preset vehicle body stiffness, the preset vehicle body damping, the excitation force magnitude, and the vehicle body response signal; and calculate dynamic stiffness according to the vehicle body displacement and the vehicle body response signal.

[0192] In one embodiment, the test module 20 is further used to obtain the autopower spectrum of the excitation force, and analyze the frequency distribution of the excitation force based on the autopower spectrum to confirm whether the excitation force is uniformly distributed at the frequency; when the excitation force is uniformly distributed at the frequency, detect the linearity of the excitation force and the response signal of the excitation force, and confirm whether the excitation force and the response signal are in a linear relationship based on the linearity; when the excitation force and the response signal are in a linear relationship, exchange the positions of the excitation point and the response point, measure the response signal based on the exchanged positions, and detect whether the response signals are consistent; when the response signals are consistent, analyze whether the excitation force and the response signal are correlated; when the excitation force and the response signal are correlated, determine that the excitation force and the response signal of the excitation force meet a preset standard.

[0193] In one embodiment, the construction module 30 is further used to analyze the dynamic stiffness test results of the attachment point to obtain dynamic stiffness data; obtain the trough frequency based on the dynamic stiffness data; construct the dynamic stiffness history data of the attachment point based on the vehicle model, the dynamic stiffness data and the trough frequency; and construct the preset vehicle body modal history data based on the vehicle model, the trough frequency and the vibration mode description.

[0194] In one embodiment, the prediction module 40 is further used to obtain the resonance frequency of the vehicle type to be tested based on the vehicle type to be tested and the historical data of the dynamic stiffness of the attachment point; and predict the body mode of the vehicle type to be tested based on the vehicle type to be tested, the resonance frequency and preset body modal historical data.

[0195] The present application provides a vehicle body modal prediction device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the vehicle body modal prediction method in the above-mentioned embodiment one.

[0196] Reference below Fig. 9 , which shows a schematic diagram of the structure of a vehicle body modal prediction device suitable for implementing the embodiment of the present application. The vehicle body modal prediction device in the embodiment of the present application may include but is not limited to mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Fig. 9The vehicle body modal prediction device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0197] like Fig. 9 As shown, the vehicle body modal prediction device may include a processing device 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In the RAM 1004, various programs and data required for the operation of the vehicle body modal prediction device are also stored. The processing device 1001, the ROM 1002, and the RAM 1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the vehicle body modal prediction device to communicate with other devices wirelessly or by wire to exchange data. Although the figure shows a vehicle body modal prediction device with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented or have alternatively.

[0198] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0199] The vehicle body modal prediction device provided by the present application adopts the vehicle body modal prediction method in the above embodiment, which can solve the technical problem that the vehicle body modal prediction relies on actual testing and cannot use historical dynamic stiffness data and modal data to predict the vehicle body modal, resulting in a long development cycle. Compared with the prior art, the beneficial effects of the vehicle body modal prediction device provided by the present application are the same as the beneficial effects of the vehicle body modal prediction method provided by the above embodiment, and the other technical features in the vehicle body modal prediction device are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0200] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0201] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0202] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, and the computer-readable program instructions are used to execute the vehicle body modal prediction method in the above-mentioned embodiment.

[0203] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0204] The computer-readable storage medium may be included in the vehicle body modal prediction device; or may exist independently without being assembled into the vehicle body modal prediction device.

[0205] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by the vehicle body modal prediction device, the vehicle body modal prediction device: obtains a vehicle model, a vehicle body attachment point, and a vehicle body longitudinal beam of a preset vehicle body; performs an attachment point dynamic stiffness test according to the vehicle body attachment point to obtain an attachment point dynamic stiffness test result; performs a modal test according to the vehicle body longitudinal beam to obtain a vibration mode description; constructs attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result, and at least two of the vibration mode description; and predicts the vehicle body mode of the vehicle model to be tested according to the attachment point dynamic stiffness history data and the preset vehicle body modal history data.

[0206] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0207] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0208] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0209] The readable storage medium provided in the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned vehicle body modal prediction method, and can solve the technical problem that vehicle body modal prediction relies on actual testing and cannot use historical dynamic stiffness data and modal data to predict vehicle body modal, resulting in a long development cycle. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in the present application are the same as the beneficial effects of the vehicle body modal prediction method provided in the above-mentioned embodiment, and will not be repeated here.

[0210] The present application also provides a computer program product, including a computer program, which implements the steps of the above-mentioned vehicle body modal prediction method when executed by a processor.

[0211] The computer program product provided by the present application can solve the technical problem that the vehicle body modal prediction relies on actual testing and cannot use historical dynamic stiffness data and modal data to predict the vehicle body modal, resulting in a long development cycle. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as the beneficial effects of the vehicle body modal prediction method provided by the above embodiment, and will not be repeated here.

[0212] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A vehicle body modal prediction method, characterized in that: The method comprises: Get the model, body attachment points and body longitudinal beams of the preset body; Performing a dynamic stiffness test on the attachment point according to the vehicle body attachment point to obtain a dynamic stiffness test result of the attachment point; Performing modal testing on the vehicle body longitudinal beam to obtain a vibration mode description; constructing attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result and at least two of the mode shape description; The body mode of the vehicle model to be tested is predicted according to the attachment point dynamic stiffness historical data and the preset body mode historical data.

2. The method according to claim 1, characterized in that The step of performing a dynamic stiffness test on the attachment point according to the vehicle body attachment point to obtain a dynamic stiffness test result of the attachment point comprises: Obtaining a preset response bandwidth, a preset number of tests, and an attachment point location of a vehicle body attachment point; Performing a preset number of test times of the attachment point dynamic stiffness test at the attachment point position to obtain a test response bandwidth and a test result; When the test response bandwidth is greater than or equal to the preset response bandwidth, the attachment point dynamic stiffness test result is obtained according to the test result.

3. The method according to claim 1, characterized in that The step of performing modal testing on the vehicle body longitudinal beam to obtain a vibration mode description comprises: An excitation point is obtained according to the longitudinal beam of the vehicle body, and excitation is performed at the position of the excitation point to obtain a broadband white noise signal; When the broadband white noise signal meets a preset signal-to-noise ratio, a response point is obtained according to a preset vehicle body type; Determining whether the excitation force and the response signal of the excitation force meet the preset standards; When the excitation force and the response signal meet the preset standard, excitation is performed at the position of the response point to obtain a vehicle body response signal; The dynamic stiffness is calculated according to the vehicle body response signal, and a vibration mode description is obtained according to the dynamic stiffness.

4. The method according to claim 3, characterized in that The step of calculating the dynamic stiffness according to the vehicle body response signal comprises: Obtaining preset vehicle body stiffness, preset vehicle body damping, excitation force magnitude, and excitation frequency; Calculating the vehicle body displacement according to the preset vehicle body stiffness, the preset vehicle body damping, the magnitude of the excitation force and the vehicle body response signal; The dynamic stiffness is calculated according to the vehicle body displacement and the vehicle body response signal.

5. The method according to claim 3, characterized in that The step of determining whether the excitation force and the response signal of the excitation force meet the preset standard comprises: Obtaining an auto-power spectrum of the excitation force, and analyzing the frequency distribution of the excitation force according to the auto-power spectrum to confirm whether the excitation force is uniformly distributed at the frequency; When the excitation force is uniformly distributed at the frequency, detecting the linearity of the excitation force and the response signal of the excitation force, and confirming whether the excitation force and the response signal are in a linear relationship according to the linearity; When the excitation force and the response signal are in a linear relationship, exchanging the positions of the excitation point and the response point, measuring the response signal according to the exchanged positions, and detecting whether the response signals are consistent; When the response signals are consistent, analyzing whether the excitation force and the response signal are related; When the excitation force and the response signal are correlated, it is determined that the excitation force and the response signal of the excitation force meet a preset standard.

6. The method according to claim 1, characterized in that The step of constructing the attachment point dynamic stiffness history data and the preset vehicle body modal history data according to at least two of the vehicle model, the attachment point dynamic stiffness test result and the vibration mode description comprises: Analyzing the dynamic stiffness test results of the attachment points to obtain dynamic stiffness data; Obtaining a trough frequency according to the dynamic stiffness data; constructing attachment point dynamic stiffness history data according to the vehicle type, the dynamic stiffness data, and the trough frequency; Preset vehicle body modal history data is constructed according to the vehicle model, the trough frequency and the vibration shape description.

7. The method according to claim 1, characterized in that The step of predicting the body mode of the vehicle to be tested according to the attachment point dynamic stiffness historical data and the preset body mode historical data comprises: Obtaining the resonance frequency of the vehicle to be tested according to the vehicle to be tested and the historical data of the dynamic stiffness of the attachment point; The body mode of the vehicle type to be tested is predicted according to the vehicle type to be tested, the resonance frequency and preset vehicle body mode historical data.

8. A vehicle body modal prediction device, characterized in that: The device comprises: An acquisition module, used for acquiring a vehicle model, a vehicle body attachment point, and a vehicle body longitudinal beam of a preset vehicle body; A testing module, used for performing an attachment point dynamic stiffness test according to the vehicle body attachment point to obtain an attachment point dynamic stiffness test result; The test module is further used to perform a modal test on the vehicle body longitudinal beam to obtain a vibration shape description; A construction module, configured to construct attachment point dynamic stiffness history data and preset vehicle body modal history data according to the vehicle model, the attachment point dynamic stiffness test result, and at least two of the vibration mode descriptions; A prediction module is used to predict the body mode of the vehicle model to be tested based on the historical data of the dynamic stiffness of the attachment point and the historical data of the preset body mode.

9. A vehicle body modal prediction device, characterized in that: The device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the vehicle body modal prediction method according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the vehicle body modal prediction method according to any one of claims 1 to 7 are implemented.

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