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

Abstract

The application 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 following steps: acquiring the vehicle type, a vehicle body attachment point and a vehicle body longitudinal beam of a preset vehicle body; performing attachment point dynamic stiffness testing according to the vehicle body attachment point to obtain an attachment point dynamic stiffness testing result; performing modal testing according to the vehicle body longitudinal beam to obtain a vibration mode description; constructing attachment point dynamic stiffness historical data and preset vehicle body modal historical data according to at least two of the vehicle type, the attachment point dynamic stiffness testing result and the vibration mode description; and predicting the vehicle body modal of a to-be-tested vehicle type according to the attachment point dynamic stiffness historical data and the preset vehicle body modal historical data. Through the technical means of combining attachment point dynamic stiffness testing and modal testing, the vehicle body modal of the to-be-tested vehicle type is accurately predicted.

Description

TECHNICAL FIELD

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

[0002] In the design and performance optimization of an automobile structure, accurate prediction of the modal characteristics of a vehicle body plays a key role in the comfort, durability and vibration noise control of the vehicle. The existing technology usually relies on actual testing of the modal characteristics of the vehicle body, and obtains modal parameters such as vibration modes and natural frequencies through modal testing of a body-in-white. However, the actual testing process is time-consuming and costly, and needs to be repeated for the development of a new vehicle model, resulting in a long development cycle. In addition, the existing method is insufficient in data accumulation and model prediction, and cannot efficiently predict the modal characteristics of a new vehicle model through historical data and measured dynamic stiffness information, lacking support for the design stage.

[0003] The above content is only used to assist in understanding the technical solutions of the present application and does not represent the acknowledgement of the above content as prior art. SUMMARY

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

[0005] To achieve the above-mentioned purpose, the present application provides a vehicle body modal prediction method, which comprises the following steps:

[0006] obtaining a vehicle model, body attachment points and body side members of a preset vehicle body;

[0007] performing attachment point dynamic stiffness testing according to the body attachment points to obtain attachment point dynamic stiffness testing results;

[0008] performing modal testing according to the body side members to obtain a vibration mode description;

[0009] constructing attachment point dynamic stiffness historical data and preset vehicle body modal historical data according to at least two of the vehicle model, the attachment point dynamic stiffness testing results and the vibration mode description;

[0010] predicting the modal characteristics of a vehicle body of a to-be-tested vehicle model according to the attachment point dynamic stiffness historical data and the preset vehicle body modal historical data.

[0011] In an embodiment, the step of performing attachment point dynamic stiffness testing according to the body attachment points to obtain attachment point dynamic stiffness testing results comprises the following steps:

[0012] acquiring a preset response bandwidth, a preset test number, and an attachment point position of an attachment point of a vehicle body;

[0013] performing an attachment point dynamic stiffness test at the attachment point position for the preset test number 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, obtaining an attachment point dynamic stiffness test result according to the test result.

[0015] In an embodiment, the step of obtaining a mode shape description according to the vehicle body longitudinal beam includes:

[0016] obtaining an excitation point according to the vehicle body longitudinal beam, exciting at the position of the excitation point to obtain a wideband white noise signal;

[0017] when the wideband white noise signal meets a preset signal-to-noise ratio, obtaining a response point according to a vehicle model of the preset vehicle body;

[0018] determining whether the excitation force and a response signal of the excitation force meet a preset standard;

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

[0020] calculating a dynamic stiffness according to the vehicle body response signal, and obtaining a mode shape description according to the dynamic stiffness.

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

[0022] acquiring a preset vehicle body stiffness, a preset vehicle body damping, an excitation force size, and an excitation frequency;

[0023] calculating a vehicle body displacement according to the preset vehicle body stiffness, the preset vehicle body damping, the excitation force size, and the vehicle body response signal;

[0024] calculating a dynamic stiffness according to the vehicle body displacement and the vehicle body response signal.

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

[0026] acquiring a self-power spectrum of the excitation force, and analyzing a frequency distribution of the excitation force according to the self-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 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 linearly related, the positions of the excitation point and the response point are exchanged, the response signal is measured according to the exchanged positions, and it is detected whether the response signals are consistent;

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

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

[0031] In an embodiment, the step of constructing the attachment point dynamic stiffness historical data and the preset vehicle body modal historical data according to at least two of the vehicle type, the attachment point dynamic stiffness test result, and the mode shape description comprises:

[0032] The attachment point dynamic stiffness test result is analyzed to obtain dynamic stiffness data;

[0033] The trough frequency is obtained according to the dynamic stiffness data;

[0034] The attachment point dynamic stiffness historical data is constructed according to the vehicle type, the dynamic stiffness data, and the trough frequency;

[0035] The preset vehicle body modal historical data is constructed according to the vehicle type, the trough frequency, and the mode shape description.

[0036] In an embodiment, the step of predicting the vehicle body modal of the to-be-tested vehicle type according to the attachment point dynamic stiffness historical data and the preset vehicle body modal historical data comprises:

[0037] The resonance frequency of the to-be-tested vehicle type is obtained according to the to-be-tested vehicle type and the attachment point dynamic stiffness historical data;

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

[0039] In addition, to achieve the above object, the application further provides a vehicle body modal prediction device, which comprises an acquisition module configured to acquire a vehicle type of a preset vehicle body, vehicle body attachment points, and vehicle body longitudinal beams;

[0040] A test module is configured to perform attachment point dynamic stiffness test according to the vehicle body attachment points to obtain attachment point dynamic stiffness test results;

[0041] The test module is further configured to perform modal test according to the vehicle body longitudinal beams to obtain mode shape descriptions;

[0042] The constructing module is configured to construct attachment point dynamic stiffness historical data and preset body modal historical data according to at least two of the vehicle type, the attachment point dynamic stiffness test result and the mode shape description;

[0043] The predicting module is configured to predict a body modal of the vehicle type to be tested according to the attachment point dynamic stiffness historical data and the preset body modal historical data.

[0044] In addition, to achieve the above-mentioned purpose, the application further provides a body modal prediction device, which comprises a memory, a processor and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the body modal prediction method as described above.

[0045] In addition, to achieve the above-mentioned purpose, the application further provides a storage medium, which is a computer readable storage medium, and the storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the body modal prediction method as described above.

[0046] In addition, to achieve the above-mentioned purpose, the application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the body modal prediction method as described above.

[0047] The one or more technical solutions provided by the application have at least the following technical effects:

[0048] The present application provides a body modal prediction method, which comprises the following steps: acquiring a vehicle type to be tested; acquiring an attachment point dynamic stiffness test result of the vehicle type to be tested; acquiring a mode shape description of the vehicle type to be tested; constructing attachment point dynamic stiffness historical data and preset body modal historical data according to at least two of the vehicle type, the attachment point dynamic stiffness test result and the mode shape description; and predicting a body modal of the vehicle type to be tested according to the attachment point dynamic stiffness historical data and the preset body modal historical data. BRIEF DESCRIPTION OF DRAWINGS

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

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced as follows. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0051] Figure 1A flowchart provided by the embodiment one of the body modal prediction method of the application;

[0052] Figure 2 A schematic diagram of the attachment point clamp provided by the embodiment one of the body modal prediction method of the application;

[0053] Figure 3 A dynamic stiffness frequency response curve schematic diagram provided by the embodiment one of the body modal prediction method of the application;

[0054] Figure 4 A flowchart provided by the embodiment two of the body modal prediction method of the application;

[0055] Figure 5 A response point distribution schematic diagram provided by the embodiment two of the body modal prediction method of the application;

[0056] Figure 6 A flowchart provided by the embodiment three of the body modal prediction method of the application;

[0057] Figure 7 A brief flowchart of the body modal prediction method provided by the embodiment three of the application;

[0058] Figure 8 A module structure schematic diagram of the embodiment of the body modal prediction device of the application;

[0059] Figure 9 A device structure schematic diagram of the hardware running environment involved in the body modal prediction method in the embodiment of the application.

[0060] The purpose of the application, the functional characteristics and the advantages will be further described with reference to the embodiments and 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 application, and are not used to limit the application.

[0062] In order to better understand the technical solutions of the application, the following will be described in detail in combination with the drawings and specific embodiments of the specification.

[0063] The main solution of the embodiment of the application is to obtain the vehicle type, the body attachment point and the body longitudinal beam of the preset vehicle body;

[0064] According to the body attachment point, the attachment point dynamic stiffness test is performed to obtain the attachment point dynamic stiffness test result;

[0065] According to the body longitudinal beam, the modal test is performed to obtain the mode shape description;

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

[0067] predicting a body modal of a to-be-tested vehicle type according to the attachment point dynamic stiffness historical data and the preset body modal historical data.

[0068] In the embodiment, for convenience of description, the following describes an identification body modal prediction device as an execution subject.

[0069] Since the prior art relies on actual test for body modal prediction, the body modal cannot be predicted by using historical dynamic stiffness data and modal data, which leads to a long development cycle. The present application provides a solution, which establishes a body attachment point dynamic stiffness historical data and modal historical database by combining the technical means of attachment point dynamic stiffness test and modal test, and performs modal prediction based on the database, thereby solving the problem in the prior art that the body modal prediction relies on actual test. By the data-driven prediction mode, the body modal of the to-be-tested vehicle type can be efficiently predicted in the design stage, the development cycle is significantly shortened and the test cost is reduced, and the efficiency and accuracy of new vehicle type development are improved.

[0070] It should be noted that the execution subject of the embodiment can 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, a body modal prediction device, etc. that can realize the above functions. The following describes the embodiment and each of the following embodiments by taking the body modal prediction device as an example.

[0071] Based on this, the embodiment of the present application provides a body modal prediction method, which refers to Figure 1 , Figure 1 The flowchart of the first embodiment of the body modal prediction method of the present application is shown in FIG. 1.

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

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

[0074] It should be noted that the above-mentioned vehicle models can refer to specific body-in-white types for which dynamic stiffness and modal testing are planned. The body-in-white design varies for each vehicle type, such as sedans, sport utility vehicles (SUVs), and multi-purpose vehicles (MPVs). Therefore, pre-setting is necessary based on the actual vehicle model to ensure the test meets the specific requirements of the body structure. Attachment points refer to critical locations on the vehicle body that connect to other structures, such as subframes, suspensions, and mounting systems. These attachment points directly affect the vibration transmission path; therefore, selecting attachment points for dynamic stiffness testing in vibration testing can reflect the vibration resistance of the body at that location. Longitudinal beams are the main load-bearing components in the body structure, typically located at the bottom of the body and extending along the longitudinal direction of the vehicle. The design and arrangement of longitudinal beams directly affect the overall rigidity and torsional strength of the vehicle; therefore, they are often used as installation locations for vibration exciters in modal testing.

[0075] Understandably, for locations where vehicle body attachment points are difficult to excite or where signals are difficult to pick up, special fixtures can be made for testing.

[0076] Reference Figure 2 , Figure 2 This is a schematic diagram of the attachment point fixture in the first embodiment of the vehicle body modal prediction method of this application.

[0077] like Figure 2 As shown, the clamp is a metal rod-shaped structure that securely fixes the sensor to a point near the vehicle body. The clamp's function is to ensure the sensor does not move during testing, thus enabling accurate vibration signal pickup. The sensor, with a small device connected to a cable, is fixed to the vehicle body by the clamp. During dynamic stiffness testing, the clamp helps ensure the testing equipment can effectively acquire vibration data, preventing data accuracy issues caused by sensor loosening or position changes.

[0078] Step S20: Perform dynamic stiffness test on the attachment point based on the vehicle body attachment point to obtain the dynamic stiffness test result of the attachment point.

[0079] It should be noted that the purpose of the aforementioned dynamic stiffness test at the attachment points is to measure the stiffness of each attachment point at different frequencies, i.e., its resistance to vibration. The dynamic stiffness value at the attachment point is a parameter reflecting the vehicle body's resistance to vibration at the attachment point. Specifically, it represents the relationship between the displacement and force generated at the attachment point when a vibration force is applied. High dynamic stiffness indicates that the vehicle body has a strong resistance to vibration at that attachment point, and the vibration is less transmitted to the vehicle body. Low dynamic stiffness indicates that the vehicle body is more prone to large displacement at that attachment point, and the vibration is more easily transmitted to the vehicle body.

[0080] It can be understood that the dynamic stiffness test result includes the dynamic stiffness value of each attachment point at different frequencies, and the dynamic stiffness frequency response curve can be further obtained according to the dynamic stiffness value. Through these data, it can be observed that the dynamic stiffness value at some frequencies decreases significantly, which usually indicates that the body is weak in resisting vibration at this frequency, i.e. the resonance frequency.

[0081] In addition, it should be noted that in the dynamic stiffness test, an acceleration sensor can be used to measure the vibration response of the body at a specific attachment point or excitation point. The acceleration sensor is installed at the attachment point or response point of the 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 body at different frequencies. The attachment point dynamic stiffness test can be performed by conducting a hammer test near the acceleration sensor. The hammer test, also known as the knock test, is a way of applying a transient force in the test. This impact force will produce an excitation in a wide frequency range in a short time, covering multiple frequencies. In this way, one knock can cause the body to vibrate at multiple frequencies at the same time. The vibration signal is usually a time-domain signal representing the vibration response in a certain period of time. In order to analyze the dynamic stiffness of each frequency, it is necessary to convert the time-domain signal to the frequency-domain signal, which requires the use of Fourier transform. Fourier transform can decompose the vibration signal in time into different frequency components, 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 transform, the test data will show the response at each frequency. Combined with the applied excitation force and the measured vibration displacement, the dynamic stiffness value at different frequencies can be calculated.

[0082] For example, the attachment point dynamic stiffness test can be performed by connecting a vibration noise test system. After debugging the vibration noise test system, an acceleration sensor is used to adhere to each test position. After being fixed firmly, a hammer test is performed next to the sensor. After testing one point, the acceleration sensor and the knock point are moved to the next test position, which includes but is not limited to the subframe body mounting point, the suspension body mounting point, and the suspension body mounting point. The process is repeated until the test of all preselected points is completed.

[0083] In a possible implementation, the step S20 can include steps S21-S23:

[0084] The step S21 acquires a preset response bandwidth, a preset test number, and an attachment point position of the 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, and ensures that the test can collect vibration data in the specified frequency range. The preset test number refers to the number of tests required to be repeated at each attachment point position in the attachment point dynamic stiffness test in order to obtain stable dynamic stiffness data. The average value of multiple tests can reduce accidental errors and ensure the accuracy of the data. In the embodiment, the preset response bandwidth can be 1000 Hz, and the preset test number can be 5 times.

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

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

[0088] Step S22, performing attachment point dynamic stiffness tests at the attachment point positions for a preset number of tests 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 result includes the dynamic stiffness value under the test response bandwidth.

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

[0091] It can be understood that the test response bandwidth and the preset response bandwidth are compared to ensure that the frequency range actually measured in the test is greater than or equal to the preset frequency range. If the test response bandwidth is less than the preset response bandwidth, the test may need to be retested or the system configuration may need to be adjusted to ensure that the frequency range is wide enough.

[0092] In addition, it can be understood that after confirming that the bandwidth meets the requirements, the average value of the multiple test results in step S22 is obtained to obtain the dynamic stiffness value of each frequency point.

[0093] Step S30, performing a modal test according to the vehicle body longitudinal beam to obtain a mode shape 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 a shaker to apply a vibration force to the vehicle body to cause resonance, thereby capturing the natural vibration characteristics of the vehicle body. Mode shape description refers to the vibration mode of the vehicle body at a specific frequency, which can be visualized through modal test data. Mode shape description includes the motion form of the vehicle body at a specific frequency, such as torsion, bending, etc., which shows the vibration response of the vehicle body at that frequency.

[0095] It can be understood that the excitation points on the vehicle body longitudinal beam are distributed as 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 a vibration force to the longitudinal beam, i.e. starting modal testing, can excite 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 historical data and preset vehicle body modal historical data according to at least two of the vehicle model, the attachment point dynamic stiffness test result and the mode shape description;

[0097] It should be noted that the attachment point dynamic stiffness historical data can refer to the cumulative results of the dynamic stiffness data of different vehicle models at each attachment point position. When constructing the historical data, the dynamic stiffness results of multiple vehicle models are archived to form a database that accumulates the dynamic stiffness characteristics of a certain vehicle body under different conditions, so that future comparison and analysis of the dynamic stiffness of new vehicle models can be quickly performed based on the existing data. The preset vehicle body modal historical data is the vehicle body modal data accumulated based on the mode shape description, including the natural frequency and mode shape characteristics of different vehicle models, such as torsion and bending modes.

[0098] It can be understood that according to the data sources of different vehicle 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 attachment point dynamic stiffness historical data and the vehicle body modal historical data, 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 repeated testing requirements in the development process of new vehicle models, improves data utilization, and shortens the development cycle.

[0099] In a possible implementation, step S40 can include steps S41-S44:

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

[0101] It should be noted that the dynamic stiffness data contains dynamic stiffness values at different frequencies, which is a quantitative description of the stiffness performance of the attachment point when vibrating. The dynamic stiffness data can be in the form of a chart generated by the data, which can more clearly show the frequencies and corresponding dynamic stiffnesses at which resonance is likely to occur.

[0102] It can be understood that the dynamic stiffness frequency response curve can be obtained according to the attachment point dynamic stiffness test results, showing the dynamic stiffness values 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] Referring to Figure 3 , Figure 3 is a schematic diagram of the dynamic stiffness frequency response curve of the first embodiment of the vehicle body modal prediction method.

[0104] As Figure 3 indicated, the abscissa represents the frequency of vibration, with units of hertz (Hz). Frequency indicates the speed of vibration, with higher values indicating faster vibration. From left to right in the figure, the frequency increases from low to high, showing the response of the attachment point at different frequencies. The ordinate represents the dynamic stiffness of the attachment point, with units of Newton per meter (N / m), and the dynamic stiffness values are shown on the graph using a logarithmic scale (Log). At some frequencies, the dynamic stiffness values will decrease significantly, i.e., there will be a trough. These frequencies are usually the resonance frequencies of the vehicle body, indicating that the vehicle body is most likely to resonate at these frequencies. For example, 44.8 Hz, 51.6 Hz, etc. These frequency points indicate that the vehicle body is more likely to resonate at these specific frequencies. By observing these data, optimization can be performed in vehicle body design to avoid or reduce resonance phenomena.

[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 at which the dynamic stiffness value on the dynamic stiffness frequency response curve decreases significantly, which usually corresponds to the resonance frequency of the vehicle body. At these frequencies, the vehicle body has the weakest resistance to vibration forces. If the dynamic stiffness of the front suspension mounting point decreases significantly at 60 Hz, then 60 Hz 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 historical data according to the vehicle model, the dynamic stiffness data, and the trough frequency;

[0108] It can be understood that the analyzed dynamic stiffness data and trough frequency are classified by vehicle model and stored in the attachment point dynamic stiffness historical database, forming structured data and accumulating the dynamic stiffness performance of different vehicle models at different attachment points, facilitating subsequent queries and model matching.

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

[0110] It can be understood that, in combination with the aforementioned valley frequency and mode shape description, such as first-order torsional mode, second-order bending mode, etc., recorded in the body modal history database, help to analyze the structural characteristics of the new vehicle model. The preset body modal history data can be Table 1 below:

[0111] Table 1

[0112]

[0113]

[0114] It should be noted that the overall first-order torsion refers to the overall torsional mode of the vehicle body at a lower frequency. In this mode, the vehicle body is twisted along the longitudinal axis (usually the centerline of the vehicle body), i.e. 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 may rotate to the right, forming a shape similar to a "twisted doughnut". This deformation usually reflects the overall rigidity of the vehicle body, and 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 vertically 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 "bent 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, and if the mode frequency is low, the vehicle body is prone to unnecessary vertical oscillation on a bumpy road, affecting the ride comfort.

[0116] The front end 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 may bend up and down, while the rest of the vehicle body may remain relatively stable. This mode is related to the rigidity of the front suspension and the front structure, and if the front end is not rigid enough, it may cause front shaking and instability during driving.

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

[0118] The combined bending and torsion deformation refers to a composite mode in which the vehicle body simultaneously undergoes bending and torsion at a specific frequency, i.e., a part of the vehicle body undergoes bending and another part undergoes torsion. For example, the front end of the vehicle body can undergo vertical bending, while the middle and rear end can undergo torsion. Such a composite deformation can cause insufficient local rigidity of the vehicle body, increase the shaking and instability during driving, and affect the handling and comfort of the vehicle.

[0119] The floor bending deformation refers to the bending deformation of the floor (the area under the vehicle) in the vertical direction. The floor area can bend upward or downward, while the upper structure of the vehicle body remains relatively unchanged. The floor bending affects the stability of the passenger compartment and can cause unnecessary vibration of the floor area when the vehicle passes through a bumpy road or makes a sharp turn, thereby reducing the riding comfort.

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

[0121] In step S50, the body mode of the vehicle to be tested is predicted according to the attachment point dynamic stiffness historical data and the preset body mode historical data.

[0122] It should be noted that the vehicle to be tested is a vehicle type for which a body structure model needs to be obtained. After the above data accumulation, the body mode corresponding to the vehicle type can be obtained according to the vehicle type and the accumulated data. Specifically, by matching the attachment point dynamic stiffness value with the vibration mode characteristics, the natural frequency and vibration mode of the body corresponding to the vehicle type can be estimated, and according to the data accumulation of the previous steps, even without actual modal test data, an accurate body mode prediction result can be obtained.

[0123] The embodiment provides a body mode prediction method, which solves the technical problems of insufficient data accumulation and low test efficiency in traditional body mode prediction by combining the technical means of attachment point dynamic stiffness testing and body mode testing, and achieves the beneficial effects of improving data utilization rate in the development process of new vehicle types, shortening the development cycle, and accurately predicting the body mode.

[0124] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as the above embodiment one can refer to the above introduction, and the following will not be repeated. On this basis, please refer to Figure 4 , the step S30 of the body mode prediction method comprises steps S31-S35:

[0125] In step S31, an excitation point is obtained according to the vehicle body longitudinal beam, excitation is performed at the position of the excitation point, and a wideband white noise signal is obtained;

[0126] It should be noted that the excitation point refers to a specific position selected on the body longitudinal beam for applying an external excitation force. When selecting the position of the excitation point, the position that can excite the overall vibration response of the vehicle body is usually preferred in order to comprehensively capture the dynamic characteristics of the vehicle body. Excitation refers to applying a vibration force at the excitation point position by a device such as a shaker or an impact hammer, so that the vehicle body generates a vibration response. 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. Wideband white noise is a random signal with a wide frequency coverage range, and the signal contains vibration components of multiple frequencies, so it can excite vibration modes at multiple frequencies simultaneously in modal testing.

[0127] Referring to Figure 5 , Figure 5 is a schematic diagram of the response point distribution of the second embodiment of the vehicle body modal prediction method.

[0128] As Figure 5 shown, the small red squares in the figure represent response points arranged at various parts of the vehicle body, which are distributed at different positions of the vehicle body. By arranging response points at key positions of the vehicle body, the vibration responses of these positions can be measured, and the vibration modes of the vehicle body at different frequencies can be understood. The selection of the positions of these response points is usually based on the shape characteristics of the vehicle body structure, to ensure that the dynamic characteristics of the overall vehicle body and local areas can be captured.

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

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

[0131] For example, using double exciter to excite the body side member can make the broadband white noise signal clear and achieve a high enough signal-to-noise ratio to excite the modal of the body. The double exciter excites the body side member by using two exciters working simultaneously and installed at different positions of the body side member. This method is called double exciter excitation. The reason for using double exciter 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 double exciter 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 strength of the signal to the strength of the noise. In modal testing, the signal is the vibration response of the vehicle body, and the noise is the environmental interference or electrical noise that cannot be avoided during the test. By using double exciter, the applied vibration force can be enhanced, so that the vibration response signal of the vehicle body is much larger than the background noise, so that clearer vibration data can be obtained. A higher signal-to-noise ratio means that the measured 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 a specific position on the vehicle body for measuring the vibration response. It is usually distributed at key positions of the vehicle body, such as the roof, doors, chassis, etc., to ensure that the vibration characteristics of the vehicle body can be captured comprehensively.

[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 a judgment standard set before the test to ensure the quality of the excitation and response signals. These standards usually include signal-to-noise ratio, linearity and reciprocity, etc. to ensure that the excitation force and the response signal have high accuracy and consistency.

[0135] In a possible implementation, step S33 can include steps S331-S335:

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

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

[0138] It can be understood that in the modal test, the excitation force needs to be uniformly distributed in the target frequency range, ensuring that the vehicle body can be effectively excited at different frequencies. Through the analysis of the self-power spectrum, it is confirmed whether the distribution of the excitation force in the set frequency range is uniform. If the excitation force is not uniformly distributed in the frequency distribution, it may affect the accuracy of the subsequent test.

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

[0140] It should be noted that the linearity detection is used to judge the proportional relationship between the excitation force and the response signal. Ideally, the excitation force and the response signal should be in a linear relationship, that is, when the excitation force increases, the response signal should also increase accordingly.

[0141] It can be understood that the linear relationship indicates that the response behavior of the system is predictable when it is subjected to external excitation, which is crucial for the repeatability of data. Under the condition that the excitation force is uniformly distributed, excitation forces of different intensities are applied, and the corresponding response signals are measured to confirm whether the changes of the two are linear.

[0142] In step S333, when the excitation force and the response signal are in a linear relationship, the positions of the excitation point and the response point are exchanged, the response signal is measured according to the exchanged positions, and whether the response signal is consistent is detected;

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

[0144] In step S334, when the response signal is consistent, whether the excitation force and the response signal are related is analyzed;

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

[0146] In step S335, when the excitation force and the response signal are related, it is determined that the excitation force and the response signal of the excitation force meet the preset standard.

[0147] It can be understood that, after the uniform distribution, the linear relationship, the reciprocity and the correlation of the signal all meet the standard, it is considered that the excitation force and the response signal meet the preset standard, and the accuracy and the reliability of the signal data are ensured.

[0148] It should be noted that, the case of not meeting the standard is that: the self-power spectrum of the excitation force is obtained, and the frequency distribution of the excitation force is analyzed according to the self-power spectrum, if the excitation force is not uniformly distributed at the frequency, it is determined that the excitation force and the response signal of the excitation force do not meet the preset standard; when the excitation force is uniformly distributed at the frequency, the linearity of the excitation force and the response signal of the excitation force is detected, if the excitation force and the response signal are not in a linear relationship, it is determined that the excitation force and the response signal of the excitation force do not meet the preset standard; when the excitation force and the response signal are in a linear relationship, the positions of the excitation point and the response point are exchanged, the response signal is measured according to the exchanged positions, if the response signal is not consistent, it is determined that the excitation force and the response signal of the excitation force do not meet the preset standard; when the response signal is consistent, whether the excitation force and the response signal are correlated is analyzed, if the excitation force and the response signal are not correlated, it is determined that the excitation force and the response signal of the excitation force do not meet the preset standard.

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

[0150] It can be understood that, after the quality of the signal meets the standard, the formal excitation test can be continued at the response point, and the data is ensured to be effective. When the excitation force is applied, the exciter applies the preset excitation on the response points one by one to obtain the vibration signal at the position. This operation ensures that each response point is excited, and the vibration characteristics of different parts are recorded. The excitation force is usually applied in the form of wideband white noise to cover a wide frequency range, and to ensure that the modal characteristics of the vehicle body are excited, and the application mode of the excitation force is not limited in the embodiment.

[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 vehicle body under the action of the excitation force, and contains the modal characteristics such as the natural frequency and the mode shape of the vehicle body.

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

[0153] It should be noted that the mode shape is the vibration mode of the vehicle body at the resonance frequency. By analyzing the dynamic stiffness frequency response curve, the mode shape at different frequencies can be identified. The mode shape description usually includes the shape change 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 drawn. The dynamic stiffness frequency response curve shows a significant trough at 50 Hz, indicating that this frequency is one of the resonance frequencies of the vehicle body. Combined with the mode shape description analysis, the car occurs first-order bending mode at 50 Hz, which is manifested as a mode in which the front and rear parts of the vehicle body vibrate in opposite directions.

[0155] In a possible implementation, step S35 can include steps S351-S353:

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

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

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

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

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

[0161]

[0162] In the formula, m is the mass of the vehicle body, k is the preset vehicle body stiffness, c is the preset vehicle body damping, f is the excitation force size, and x is the displacement of the vehicle body under the action of the force f, i.e. the vehicle body response signal.

[0163] Solving the above formula 1 can obtain the following formula 2:

[0164]

[0165] In the formula, m is the vehicle mass, k is the preset vehicle stiffness, c is the preset vehicle damping, f is the magnitude of the excitation force, x is the displacement of the vehicle under the action of force f, i.e., the vehicle response signal, and j is the imaginary unit, used for complex number representation.

[0166] Step S353: Calculate the dynamic stiffness based on the vehicle body displacement and the vehicle body response signal.

[0167] Understandably, the formula for calculating dynamic stiffness is as follows: Equation 3:

[0168]

[0169] In the formula, m is the vehicle mass, k is the preset vehicle stiffness, c is the preset vehicle damping, f is the magnitude of the excitation force, x is the displacement of the vehicle under the action of force f, i.e., the vehicle response signal, and j is the imaginary unit, used for complex number representation.

[0170] Furthermore, it's understandable that Equation 3 above shows that dynamic stiffness is related to the vehicle's mass *m*, static stiffness *k*, and damping *c*, with the stiffness value changing with frequency. In the resonant frequency range, the amplitude is *wc*, and the dynamic stiffness value decreases significantly, mainly controlled by damping; at this frequency, the structure's resistance to deformation is minimal. This can be verified by observing the measuring points. Figure 3 The origin dynamic stiffness curve shows that the troughs of the curve correspond to the vehicle body modal frequencies. This is because dynamic stiffness can be calculated from the frequency response function, and the troughs of the dynamic stiffness curve are the peaks of the frequency response function, which is the fundamental data used to calculate modal parameters. From the theoretical derivation of the dynamic stiffness at the vehicle body attachment points above, it can be seen that the frequency response function at the origin, i.e., the origin dynamic stiffness, includes the entire structural response, including all local, semi-global, and global components, up to the origin. Therefore, the origin dynamic stiffness is related to the physical structural characteristics of the entire vehicle body.

[0171] This embodiment provides a vehicle body modal prediction method. By applying broadband white noise signals to excitation points on the longitudinal beams of the vehicle body and arranging response points at key parts of the vehicle body, it solves the technical problems in traditional modal testing, such as unstable excitation force and response signal quality, low signal-to-noise ratio, poor linearity and reciprocity. It achieves 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 this application, in the third embodiment of this application, the content that is the same as or similar to that in the first embodiment described above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 6 The vehicle body modal prediction method includes steps S51 to S52 in step S50:

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

[0174] It should be noted that the resonance frequency refers to a frequency point at which the vehicle body vibrates most strongly at a specific frequency. The resonance frequency reflects the inherent characteristics of the vehicle and is a key parameter in vehicle modal analysis. At the resonance frequency, the dynamic stiffness of the vehicle body is the smallest and the vibration amplitude is the largest. Determining the resonance frequency helps to identify the weak areas of the vehicle at a specific frequency, so as to improve the structure.

[0175] For example, according to the to-be-tested vehicle model, find a measured vehicle model with similar structure and characteristics in the attachment point dynamic stiffness historical database. Extract the attachment point dynamic stiffness data of the similar vehicle model and observe its dynamic stiffness frequency response curve. The trough position in the frequency response curve usually corresponds to the resonance frequency. By comparing with the historical data, the resonance frequency of the to-be-tested vehicle model at the similar attachment point position is inferred. If the historical data shows that there is a resonance in a certain frequency range, the to-be-tested vehicle model may also have resonance characteristics at the same frequency.

[0176] Step S52, predicting the body modal of the to-be-tested vehicle model according to the to-be-tested vehicle model, the resonance frequency and the preset body modal historical data.

[0177] For example, according to the design parameters of the to-be-tested vehicle model and the resonance frequency, find similar vehicle models and modal characteristics at similar frequencies from the preset body modal historical database. By referring to the modal characteristics of similar vehicle models in the historical data, analyze the modal pattern of the to-be-tested vehicle model at the similar resonance frequency. The vibration mode description usually includes the vibration form of the vehicle body, such as first-order torsion or second-order bending, etc. According to the analysis result, predict the vibration mode of the to-be-tested vehicle model at different resonance frequencies. For example, if the historical data shows that a similar vehicle model has a significant torsion modal at a certain frequency, it can be inferred that the to-be-tested vehicle model may also have a similar torsion modal at that frequency. For example, assuming that in the modal historical data of a certain SUV vehicle model, the front suspension position shows a first-order bending modal at 60Hz, and the vibration mode description shows that the modal is mainly manifested as vertical vibration of the front and rear ends of the vehicle body. When predicting a to-be-tested SUV vehicle model, if the resonance frequency of the front suspension position of the to-be-tested vehicle model is also 60Hz, it can be predicted that the to-be-tested vehicle model will also produce a similar first-order bending modal at this frequency.

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

[0179] Exemplarily, in order to facilitate the understanding of the implementation process of the body modal prediction method obtained by combining the above-mentioned embodiment one, please refer to Figure 7 , Figure 7 A brief flowchart of a body modal prediction method is provided, and specifically:

[0180] The body-in-white modal data includes the body modal data of different types of vehicles (such as SUV, Sedan, and MPV). According to the vehicle type (SUV, Sedan, and MPV), the dynamic stiffness data of the subframe mounting point and the dynamic stiffness data of the suspension mounting point of the vehicle are found in the database. The dynamic stiffness data of these mounting points describes the dynamic characteristics of the body at different mounting points, and is an important basis for modal analysis. The matched data is applied to the new vehicle to be tested to predict the modal of each order of the vehicle. Finally, the modal characteristics of the new vehicle are derived through these data, which provides basic data for structural optimization and dynamic performance improvement.

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

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

[0183] The acquisition module 10 is configured to acquire the vehicle type, the body attachment point, and the body longitudinal beam of the preset body.

[0184] The test module 20 is configured to perform attachment point dynamic stiffness testing according to the body attachment point to obtain an attachment point dynamic stiffness test result.

[0185] The test module 20 is further configured to perform a modal test on the vehicle body longitudinal beam to obtain a mode shape description.

[0186] The construction module 30 is configured to construct attachment point dynamic stiffness historical data and preset vehicle body modal historical data according to at least two of the vehicle type, the attachment point dynamic stiffness test result and the mode shape description.

[0187] The prediction module 40 is configured to predict a vehicle body modal of the vehicle type to be tested according to the attachment point dynamic stiffness historical data and the preset vehicle body modal historical data.

[0188] The vehicle body modal prediction device provided in the present application adopts the vehicle body modal prediction method in the above embodiments, and can solve the technical problem that the vehicle body modal prediction relies on actual test and cannot utilize 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 vehicle body modal prediction device provided in the present application has the same beneficial effects as the vehicle body modal prediction method provided in the above embodiments, and other technical features in the vehicle body modal prediction device are the same as the features disclosed in the above embodiments, which will not be described here.

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

[0190] In an embodiment, the test module 20 is further configured to obtain an excitation point from the vehicle body longitudinal beam, excite at the excitation point to obtain a wideband white noise signal, obtain a response point from a preset vehicle body when the wideband white noise signal meets a preset signal-to-noise ratio, determine whether an excitation force and a response signal of the excitation force meet a preset standard, excite at the response point to obtain a vehicle body response signal when the excitation force and the response signal meet the preset standard, calculate a dynamic stiffness according to the vehicle body response signal, and obtain a mode shape description according to the dynamic stiffness.

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

[0192] In an embodiment, the test module 20 is further configured to acquire a self-power spectrum of the excitation force, analyze a frequency distribution of the excitation force according to the self-power spectrum, and determine whether the excitation force is uniformly distributed at the frequency; when the excitation force is uniformly distributed at the frequency, detect linearity of the excitation force and a response signal of the excitation force, determine 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 the linear relationship, exchange positions of an excitation point and a response point, measure a response signal according to the exchanged positions, and detect whether the response signal is consistent; when the response signal is consistent, analyze whether the excitation force and the response signal are correlated; and 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 an embodiment, the construction module 30 is further configured to analyze the attachment point dynamic stiffness test result to obtain dynamic stiffness data, obtain a valley frequency according to the dynamic stiffness data, construct attachment point dynamic stiffness historical data according to the vehicle type, the dynamic stiffness data, and the valley frequency, and construct preset vehicle body mode historical data according to the vehicle type, the valley frequency, and the vibration mode description.

[0194] In an embodiment, the prediction module 40 is further configured to obtain a resonance frequency of a to-be-tested vehicle type according to the to-be-tested vehicle type and the attachment point dynamic stiffness historical data, and predict a vehicle body mode of the to-be-tested vehicle type according to the to-be-tested vehicle type, the resonance frequency, and the preset vehicle body mode historical data.

[0195] The present application provides a vehicle body mode prediction device, which comprises at least one processor and a memory in communication connection with 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 to enable the at least one processor to perform the vehicle body mode prediction method in Embodiment I.

[0196] Reference will now be made to the following description Figure 9 which shows a structural schematic diagram of a vehicle body mode prediction device suitable for implementing embodiments of the present application. The vehicle body mode prediction device in embodiments of the present application can include, but is not limited to, mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (for example, vehicle-mounted navigation terminals), and the like, and fixed terminals such as digital TVs, desktop computers, and the like. Figure 9The illustrated vehicle body mode prediction device is merely an example and should not impose any limitations on the functions and the range of use of the embodiments of the present application.

[0197] As shown in Figure 9 The vehicle body mode prediction device can include a processing device 1001 (e.g., a central processing unit, a graphics processing unit, etc.) that can perform various appropriate actions and processes in accordance with a program stored in a read only memory (ROM) 1002 or a program loaded from a storage device 1003 into a random access memory (RAM) 1004. Various programs and data required for the operation of the vehicle body mode prediction device are also stored in the RAM 1004. 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), a speaker, a vibrator, etc.; the 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 mode prediction device to communicate wirelessly or by wire with other devices to exchange data. Although the vehicle body mode prediction device having various systems is illustrated in the figure, it should be understood that all of the illustrated systems are not required to be implemented or provided. More or fewer systems can be alternatively implemented or provided.

[0198] In particular, the processes described above with reference to the flowcharts can be implemented as a computer software program according to the embodiments disclosed herein. For example, the embodiments disclosed herein include a computer program product comprising a computer program carried on a computer readable medium, the computer program containing program code for performing the methods illustrated by the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network by the communication device, or installed from the storage device 1003, or installed from the ROM 1002. When the computer program is executed by the processing device 1001, the above-described functions defined in the methods of the embodiments disclosed herein are performed.

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

[0200] It should be understood that various parts of the present application can be realized 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 merely specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

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

[0203] The computer readable storage medium provided in the application may, for example, be a U disk, but is not limited to an electric, magnetic, optical, electromagnetic, infrared, or semiconductor system, system, or device, or any combination of the above. More specific examples of the computer readable storage medium may include, but are not limited to, an electric connection with one or more conductive 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 the 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 can be transmitted by any suitable medium, including but not limited to an electric wire, an optical cable, an RF (Radio Frequency), and the like, or any suitable combination of the above.

[0204] The above computer readable storage medium may be contained in the vehicle body modal prediction device, or may exist separately without being assembled into the vehicle body modal prediction device.

[0205] The above 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 is caused to: acquire a vehicle type, a vehicle body attachment point, and a vehicle body longitudinal beam of a preset vehicle body; perform an attachment point dynamic stiffness test according to the vehicle body attachment point to obtain an attachment point dynamic stiffness test result; perform a modal test according to the vehicle body longitudinal beam to obtain a mode shape description; construct attachment point dynamic stiffness history data and preset vehicle body modal history data according to at least two of the vehicle type, the attachment point dynamic stiffness test result, and the mode shape description; and predict a vehicle body modal of a to-be-tested vehicle type according to the attachment point dynamic stiffness history data and the preset vehicle body modal history data.

[0206] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can 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 the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0207] The flow diagrams and the block diagrams in the drawings are illustrations of architectures, functionalities, and operations of possible implementations of systems, methods, and computer program products according to various embodiments of present application. In this regard, each block in the flow diagrams or block diagrams can represent a module, a segment, or a portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flow diagrams, and combinations thereof, can be implemented by special purpose hardware-based systems that perform the specified functions or operations, or combinations of special purpose hardware and computer instructions.

[0208] The modules involved in the embodiments of the present application can be implemented in software or hardware. In some cases, the names of the modules do not constitute a limitation on the modules themselves.

[0209] The readable storage medium provided by the present application is a computer readable storage medium, which stores computer readable program instructions (i.e. computer programs) for executing the vehicle body modal prediction method described above, and can solve the technical problem that the vehicle body modal prediction relies on actual testing and cannot utilize 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 computer readable storage medium provided by the present application has the same beneficial effects as the vehicle body modal prediction method provided by the above-mentioned embodiments, and will not be described here.

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

[0211] The computer program product provided by the application can solve the technical problem that the vehicle body modal prediction relies on actual testing and cannot utilize 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 application are the same as those of the vehicle body modal prediction method provided by the above-described embodiments, and are not described here.

[0212] The above only describes some embodiments of the application, and does not limit the patent scope of the application. Any equivalent structural transformation made by using the content of the specification and drawings, or direct / indirect application in other related technical fields under the technical concept of the application is included in the patent protection scope of the application.

Claims

1. A method of body mode prediction, characterized in that, The method comprises: acquiring a vehicle model of a preset vehicle body, a vehicle body attachment point, and a vehicle body longitudinal beam; performing an attachment point dynamic stiffness test according to the vehicle body attachment point to obtain an attachment point dynamic stiffness test result; performing a modal test according to the vehicle body longitudinal beam to obtain a mode shape description; constructing attachment point dynamic stiffness historical data and preset vehicle body modal historical data according to at least two of the vehicle model, the attachment point dynamic stiffness test result, and the mode shape description; predicting a vehicle body mode of a to-be-tested vehicle model according to the attachment point dynamic stiffness historical data and the preset vehicle body modal historical data; the step of constructing the attachment point dynamic stiffness historical data and the preset vehicle body modal historical data according to at least two of the vehicle model, the attachment point dynamic stiffness test result, and the mode shape description comprises: analyzing the attachment point dynamic stiffness test result to obtain dynamic stiffness data; obtaining a valley frequency according to the dynamic stiffness data; constructing the attachment point dynamic stiffness historical data according to the vehicle model, the dynamic stiffness data, and the valley frequency; constructing the preset vehicle body modal historical data according to the vehicle model, the valley frequency, and the mode shape description.

2. The method of claim 1, wherein, the step of performing the attachment point dynamic stiffness test according to the vehicle body attachment point to obtain the attachment point dynamic stiffness test result comprises: acquiring a preset response bandwidth, a preset test number, and an attachment point position of the vehicle body attachment point; performing the attachment point dynamic stiffness test for the preset test number 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, obtaining the attachment point dynamic stiffness test result according to the test result.

3. The method of claim 1, wherein, the step of performing the modal test according to the vehicle body longitudinal beam to obtain the mode shape description comprises: obtaining an excitation point according to the vehicle body longitudinal beam, exciting at the position of the excitation point to obtain a wideband white noise signal; when the wideband white noise signal meets a preset signal-to-noise ratio, obtaining a response point according to the vehicle model of the preset vehicle body; determining whether the excitation force and a response signal of the excitation force meet a preset standard; when the excitation force and the response signal meet the preset standard, exciting at the position of the response point to obtain a vehicle body response signal; calculating a dynamic stiffness according to the vehicle body response signal, and obtaining the mode shape description according to the dynamic stiffness.

4. The method of claim 3, wherein, the step of calculating the dynamic stiffness according to the vehicle body response signal comprises: acquiring a preset vehicle body stiffness, a preset vehicle body damping, an excitation force size, and an excitation frequency; calculating a vehicle body displacement according to the preset vehicle body stiffness, the preset vehicle body damping, the excitation force size, and the vehicle body response signal; calculating the dynamic stiffness according to the vehicle body displacement and the vehicle body response signal.

5. The method of claim 3, wherein, the step of determining whether the excitation force and a response signal of the excitation force meet a preset standard comprises: acquiring a self-power spectrum of the excitation force, and analyzing a frequency distribution of the excitation force according to the self-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 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, the positions of the excitation point and the response point are exchanged, the response signal is measured according to the exchanged positions, and it is detected whether the response signals are consistent; When the response signals are consistent, it is analyzed whether the excitation force and the response signal are correlated; 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 preset standards.

6. The method of claim 1, wherein, The step of predicting the body mode of the to-be-tested vehicle model according to the attachment point dynamic stiffness historical data and the preset body mode historical data comprises: obtaining a resonance frequency of the to-be-tested vehicle model according to the to-be-tested vehicle model and the attachment point dynamic stiffness historical data; predicting the body mode of the to-be-tested vehicle model according to the to-be-tested vehicle model, the resonance frequency and the preset body mode historical data.

7. A vehicle body mode predicting apparatus characterized by comprising: The device comprises: an acquisition module configured to acquire a vehicle model of a preset body, body attachment points and body side members; a test module configured to perform attachment point dynamic stiffness tests according to the body attachment points to obtain attachment point dynamic stiffness test results; the test module is further configured to perform modal tests according to the body side members to obtain mode shapes; a construction module configured to construct attachment point dynamic stiffness historical data and preset body mode historical data according to at least two of the vehicle model, the attachment point dynamic stiffness test results and the mode shape descriptions; a prediction module configured to predict the body mode of a to-be-tested vehicle model according to the attachment point dynamic stiffness historical data and the preset body mode historical data; the construction module is further configured to analyze the attachment point dynamic stiffness test results to obtain dynamic stiffness data, obtain a valley frequency according to the dynamic stiffness data, construct attachment point dynamic stiffness historical data according to the vehicle model, the dynamic stiffness data and the valley frequency, and construct preset body mode historical data according to the vehicle model, the valley frequency and the mode shape descriptions.

8. A vehicle body mode prediction device characterized by comprising: The device comprises a memory, a processor and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the body mode prediction method according to any one of claims 1 to 6.

9. A storage medium, characterized by The storage medium is a computer readable storage medium, and the storage medium stores a computer program, and the computer program is executed by the processor to implement the steps of the body mode prediction method according to any one of claims 1 to 6.

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