A method, device, equipment and medium for identifying the cause of large residual vibration of a vehicle

Abstract

The present application discloses a method, device, equipment and medium for identifying the cause of large vehicle residual vibration. The method replaces the corresponding components in a pre-established multi-body dynamics model of a whole vehicle with flexible bodies according to the generated flexible body files of the body assembly and chassis components; the body assembly in the multi-body dynamics model of the whole vehicle is set from a flexible body to a rigid body, and a smoothness simulation test is performed to determine whether the body assembly causes the large vehicle residual vibration; if it is determined that the body assembly causes the large vehicle residual vibration, the residual vibration modal frequency that causes the large vehicle residual vibration is determined based on the response signal in the smoothness simulation test and the modal frequency of the body assembly, thereby achieving accurate identification of the component mode that causes the vehicle residual vibration, and providing an accurate and effective optimization basis for improving the vehicle smoothness.

Description

Technical Field

[0001] The present application relates to the technical field of automobile state optimization, and in particular to a method, device, equipment and medium for identifying the cause of significant residual vibration of a vehicle. Background Art

[0002] Vehicle ride comfort refers to the vibration and impact generated by the vehicle during driving. It is mainly evaluated based on the comfort level of the passengers, so it is also called ride comfort. When the vehicle ride comfort is poor, it will make the driver and passengers feel uncomfortable and even cause damage to human health. For freight vehicles, poor ride comfort may cause damage to the transported goods. With the development of vehicle performance, the driving experience of vehicles has become an issue of concern to people. Vehicle residual vibration is an important parameter that determines the quality of vehicle ride comfort. The waveform of vehicle residual vibration is as follows: Figure 1 As shown, vehicle residual vibration is mostly caused by abnormal residual vibration of vehicle body parts.

[0003] Therefore, how to accurately identify the cause of the vehicle's large residual vibration that affects the driving experience is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The main purpose of the present application is to provide a method, device, equipment and medium for identifying the cause of vehicle residual vibration, aiming to solve the technical problem of how to accurately identify the cause of the large vehicle residual vibration.

[0005] In a first aspect, the present application provides a method for identifying the cause of a large residual vibration of a vehicle, the method comprising the following steps:

[0006] According to the generated flexible body files of the vehicle body assembly and chassis components, the corresponding components in the pre-established vehicle multi-body dynamics model are replaced with flexible bodies;

[0007] The body assembly in the vehicle multi-body dynamics model is set from a flexible body to a rigid body, and a ride comfort simulation test is performed to determine whether the body assembly causes a large residual vibration of the vehicle body;

[0008] If it is determined that the vehicle body assembly causes significant residual vibration of the vehicle, the residual vibration modal frequency causing the significant residual vibration of the vehicle body is determined based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly.

[0009] In a second aspect, the present application further provides a device for identifying the cause of a large residual vibration of a vehicle, the device comprising:

[0010] A replacement module, which is used to replace the corresponding components in the pre-established vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and chassis components;

[0011] A simulation module, which is used to set the body assembly in the whole vehicle multi-body dynamics model from a flexible body to a rigid body, and perform a smoothness simulation test to determine whether the body assembly causes a large residual vibration of the body;

[0012] A determination module is used to determine the residual vibration modal frequency causing the large residual vibration of the vehicle body based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly if it is determined that the vehicle body assembly causes large residual vibration of the vehicle.

[0013] In a third aspect, the present application also provides a computer device, comprising a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, the steps of the method for identifying the cause of significant vehicle residual vibration as described above are implemented.

[0014] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored, wherein when the computer program is executed by a processor, the steps of the above method are implemented.

[0015] The present application provides a method, device, equipment and medium for identifying the cause of large vehicle residual vibrations. The method replaces the corresponding components in a pre-established whole vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the body assembly and chassis components; the body assembly in the whole vehicle multi-body dynamics model is set from a flexible body to a rigid body, and a smoothness simulation test is performed to determine whether the body assembly causes the large vehicle body residual vibrations; if it is determined that the body assembly causes the large vehicle residual vibrations, the residual vibration modal frequency that causes the large vehicle body residual vibrations is determined based on the response signal in the smoothness simulation test and the modal frequency of the body assembly, thereby achieving accurate identification of the component modes that cause the vehicle residual vibrations, and providing an accurate and effective optimization basis for improving the vehicle smoothness. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the residual vibration waveform;

[0018] Figure 2 A flowchart of a method for identifying the cause of a significant aftershock of a vehicle provided in an embodiment of the present application;

[0019] Figure 3 is a schematic diagram of a time domain curve of a first acceleration signal;

[0020] Figure 4 is a schematic diagram comparing the time domain curve of the second acceleration signal with the time domain curve of the first acceleration signal;

[0021] Figure 5 It is a schematic diagram of the amplitude-frequency characteristic curve of the acceleration signal;

[0022] Figure 6 A schematic diagram showing a time domain curve comparison between the acceleration signal and the first acceleration signal when suppressing modes below 7.5 Hz and 7.8 Hz;

[0023] Figure 7 A schematic block diagram of a device for identifying the cause of a significant aftershock of a vehicle provided in an embodiment of the present application;

[0024] Figure 8 The present invention is a block diagram showing the structure of a computer device according to an embodiment of the present application.

[0025] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] The flowcharts shown in the accompanying drawings are only examples and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may also be decomposed, combined or partially merged, so the actual execution order may change according to actual conditions.

[0028] The embodiment of the present application provides a method, device, equipment and medium for identifying the cause of a large vehicle residual vibration. The method for identifying the cause of a large vehicle residual vibration can be applied to a computer device, which can be an electronic device such as a laptop computer or a desktop computer.

[0029] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0030] Please refer to Figure 2 , Figure 2 A flowchart of a method for identifying the cause of a significant aftershock of a vehicle is provided in an embodiment of the present application.

[0031] like Figure 2 As shown, the method includes steps S1 to S3.

[0032] Step S1: According to the generated flexible body files of the vehicle body assembly and chassis components, the corresponding components in the pre-established vehicle multi-body dynamics model are replaced with flexible bodies.

[0033] It is worth noting that the vehicle body assembly flexible body file in this embodiment is generated based on the vehicle body assembly finite element model, and the chassis component flexible body file is generated based on the chassis component finite element model. Before generating the vehicle body assembly flexible body file and the chassis component flexible body file, determine the list of components that need to be modeled as flexible bodies, establish a finite element model based on the corresponding components, and then generate a flexible body file based on the finite element model to establish a flexible body.

[0034] Exemplarily, in this embodiment, the parts that need to establish flexible bodies include three categories, namely body parts, chassis parts and mass point parts. Among them, the body parts include the body-in-white assembly (with windshield, metal instrument panel tube beam, battery pack), rear door (left-right symmetrical), front hood assembly, rear hood assembly, front door (left-right symmetrical), plastic instrument panel and auxiliary instrument panel. The chassis parts include the front steering knuckle, rear steering knuckle, front subframe, rear subframe and rod system. The mass point parts include the front bumper, rear bumper, inner carpet, inner top cover interior panel, door interior panel (front and rear), hood interior panel (front and rear) and cabin battery, spare tire and other items. Body parts and chassis parts. After determining the parts that need to establish flexible bodies, establish finite element models for each body part and chassis part according to the actual vehicle parts.

[0035] In some embodiments, when establishing the body assembly finite element model and the chassis component finite element model, it also includes: performing free modal analysis on the finite element models of each body component constituting the body assembly, and obtaining the modal frequency of the finite element model of each body component, so as to determine the accuracy of establishing the finite element model of the body component; assembling the finite element models of the body components as a whole to form the body assembly finite element model, and performing free modal analysis on the finite element model of the body assembly, and obtaining the modal frequency of the finite element model of the body assembly, so as to determine the accuracy of establishing the finite element model of the body assembly; performing free modal analysis on the finite element models of each chassis component, and obtaining the modal frequency of the finite element model of each chassis component, so as to determine the accuracy of establishing the finite element model of the chassis component.

[0036] It is worth noting that, in this embodiment, free modal analysis is first performed on the finite element models of the body parts respectively, and the accuracy of the finite element models of the individual body parts is first confirmed to eliminate the inconsistency between the internal connections of the finite element models of the individual body parts and the physical parts. Then, the finite element models of the body parts are assembled as a whole to form the finite element model of the body assembly, and free modal analysis is performed again to ensure the accuracy of the establishment of the finite element model of the body assembly and to ensure that there are no structures that are inconsistent with the actual body assembly. If there are structures that are inconsistent with the actual situation, the model needs to be debugged to make it consistent with the actual situation, so as to ensure the quality of the flexible body generation process. Similarly, free modal analysis is performed on the finite element models of the chassis parts respectively to confirm the accuracy of the finite element models of the individual chassis parts.

[0037] It should be noted that the flexible bodies to be generated in this embodiment include the flexible bodies of the vehicle body assembly and the flexible bodies of the chassis components. Therefore, the finite element models of the vehicle body components need to be assembled into the finite element model of the vehicle body assembly for modal analysis only, while the chassis components are generated as a single chassis component when generating the flexible body, so the modal analysis of the finite element model of the single chassis component is sufficient. For the mass point components, after being simplified to mass points, there is no need to establish a finite element model.

[0038] Furthermore, the generated flexible body files of the body assembly and chassis components include: respectively determining whether the number of units of the pre-established body assembly finite element model and the chassis component finite element model exceeds a preset unit number threshold; if the number of units of the body assembly finite element model exceeds the unit number threshold, then based on the body assembly finite element model, the body assembly flexible body file is generated by the automatic multi-layer substructure modal solution algorithm ASMES, otherwise, the body assembly flexible body file is generated by the Lanczos algorithm Lanczos; if the number of units of the chassis component finite element model exceeds the unit number threshold, then based on the chassis component finite element model, the chassis component flexible body file is generated by the automatic multi-layer substructure modal solution algorithm ASMES, otherwise, the chassis component flexible body file is generated by the Lanczos algorithm Lanczos.

[0039] As a preferred real-time method, if the number of units in the body assembly finite element model exceeds the unit number threshold, it is determined whether the proportion of weighted connection units in the units of the body assembly finite element model exceeds the preset proportion threshold. If so, the body assembly flexible body file is generated based on the body assembly finite element model according to the Lanczos algorithm. Otherwise, the body assembly flexible body file is generated by the automatic multi-layer substructure modal solution algorithm ASMES. If the number of units in the chassis component finite element model exceeds the unit number threshold, it is determined whether the proportion of weighted connection units in the units of the chassis component finite element model exceeds the preset proportion threshold. If so, the chassis component flexible body file is generated based on the chassis component finite element model according to the Lanczos algorithm. Otherwise, the chassis component flexible body file is generated by the automatic multi-layer substructure modal solution algorithm ASMES. Among them, the unit number threshold in this embodiment can be set according to actual calculation requirements. The proportion threshold in this embodiment is 1 / 3.

[0040] Exemplarily, the body assembly finite element model and each chassis component finite element model can be divided into two sizes according to whether the number of units exceeds the unit number threshold. For large-scale finite element models, determine whether the RBE3 weighted connection units in its structure exceed 1 / 3 of the total number of units. If it exceeds 1 / 3, the Lanczos algorithm is still used to generate the corresponding flexible body file. If it does not exceed 1 / 3, the ASMES method is used for flexible body calculation. For a body assembly finite element model with 7 million units, it takes about 4 days to use the Lanczos algorithm, while the ASMES method can reduce the calculation time of the flexible body file to 4 hours, effectively improving the time for generating flexible body files for large-scale finite element models.

[0041] Among them, the RBE3 unit is a commonly used unit for welding point connection between car bodies and a commonly used connection unit for mass counterweight in the finite element model. Lanczos is a modal solver, an algorithm for solving eigenvalues ​​and eigenvectors of large sparse matrices. The ASMES method is an automatic multi-layer substructure modal solver, which is also a method for calculating modalities. It can calculate finite elements with a large number of units more quickly to obtain flexible body files.

[0042] It is worth noting that when the flexible body file is calculated, a wireframe display unit can be created based on the PLOTEL unit to display the entire structure, so as to avoid the calculation process file being too large. And when generating the flexible body file, a response point needs to be reserved, where the position of the response point can correspond to the position of the response point on the actual vehicle. In this embodiment, the response point is the footrest point of the second row of passengers in the car.

[0043] Furthermore, according to the generated flexible body files of the body assembly and chassis components, corresponding components in the pre-established multi-body dynamics model of the whole vehicle are replaced with flexible bodies, including: replacing the body assembly in the multi-body dynamics model of the whole vehicle with a flexible body according to the body assembly flexible body file; replacing each chassis component in the multi-body dynamics model of the whole vehicle with a flexible body according to the chassis component flexible body file.

[0044] Preferably, after replacing the corresponding components in the pre-established vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and chassis components, the method further includes: determining whether the mass information of each flexible body in the vehicle multi-body dynamics model is the same as the mass of the corresponding vehicle body assembly finite element model or chassis component finite element model; performing modal analysis on each flexible body in the vehicle multi-body dynamics model to determine whether the modal frequency of each flexible body is the same as the modal frequency of the corresponding vehicle body assembly finite element model or chassis component finite element model; setting a simulated acceleration sensor at a preset response point in the vehicle multi-body dynamics model, and performing smoothness analysis based on the vehicle multi-body dynamics model. A simulation test is performed to obtain a first acceleration signal output by the simulation acceleration sensor; if the mass of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding body assembly finite element model or chassis component finite element model, the modal frequency of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding body assembly finite element model or chassis component finite element model, and the first acceleration signal has the same trend as the time domain curve of the measured acceleration signal of the same response point during the smoothness actual vehicle test, and the difference between the residual vibration peak value of the time domain curve of the first acceleration signal and the residual vibration peak value of the time domain curve of the measured acceleration signal is less than a preset first difference threshold, then it is determined that the whole vehicle dynamics multi-body model is qualified.

[0045] Demonstratively, based on the calculated flexible body file, the body assembly and chassis components in the pre-established vehicle multi-body dynamics model are replaced with flexible bodies to obtain a vehicle multi-body dynamics model in which both the body assembly and the chassis components are flexible bodies. After the replacement is completed, it is confirmed again whether there is a difference between the mass information of the flexible body in the vehicle multi-body dynamics model and the mass of the corresponding finite element model to ensure that the mass information of the flexible body in the multi-body model is accurate. Modal analysis is performed on the flexible body in the vehicle multi-body dynamics model to confirm that the modal frequency value of the flexible body modal in the vehicle multi-body dynamics model and its corresponding finite element model during free modal analysis is consistent, thereby confirming its accuracy and confirming that the modal involved in the calculation of the flexible body modal does not include 1st-6th order rigid body modes. According to the reserved response point, a simulated acceleration signal sensor of concern in this residual vibration problem is created to output the simulated acceleration sensor signal, and then a road model is established according to the road of the smoothness actual vehicle test to perform a smoothness simulation test, and a first acceleration signal is obtained at the response point through the simulated acceleration sensor. The time domain curve of the obtained first acceleration signal is shown as follows. Figure 3 As shown, the first acceleration time domain curve is a curve of the acceleration of the response point changing with time, and the acceleration signal time domain curve can reflect the residual vibration of the response point. The first acceleration signal time domain curve has the same trend as the measured acceleration signal time domain curve, and the residual vibration peak error of the two time domain curves, especially the maximum peak error in the residual vibration peak value, is within 10%, indicating that the vehicle dynamics multi-body model is benchmarked with the actual vehicle after replacing the flexible body, so it is qualified. Among them, the simulated acceleration signal is the acceleration signal of the simulated sensor in the Z direction.

[0046] Step S2: The body assembly in the whole vehicle multi-body dynamics model is set from a flexible body to a rigid body, and a smoothness simulation test is performed to determine whether the body assembly causes a large residual vibration of the body.

[0047] Specifically, the body assembly in the multi-body dynamics model of the whole vehicle is set from a flexible body to a rigid body, and a smoothness simulation test is performed to determine whether the body assembly causes substantial residual vibration of the body, including: setting the body assembly in the multi-body dynamics model of the whole vehicle from a flexible body to a rigid body, and performing a smoothness simulation test, if the difference between the residual vibration peak value of the second acceleration signal time domain curve corresponding to the response point and the residual vibration peak value of the first acceleration signal time domain curve is greater than a preset second difference threshold, it is determined that the body assembly causes substantial residual vibration of the body.

[0048] As an example, after the body assembly and chassis components are replaced with flexible bodies, the body assembly in the multi-body dynamics model of the whole vehicle is set as a rigid body again. At this time, the chassis components are still flexible bodies. The second acceleration signal is simulated again according to the multi-body dynamics model of the whole vehicle. The time domain curve of the second acceleration signal is compared with the time domain curve of the first acceleration signal when it is a flexible body. Since the body assembly is set as a rigid body, it is an infinitely strong rigid body structure, which is an ideal structure after the flexible body assembly is infinitely strengthened. It can be used as the final form of the assumed body after strengthening for calculation and comparison, and is used to confirm the effect of the body strengthening. Figure 4 As shown, it can be seen that the body assembly is set as a rigid body, that is, after the structure is strengthened, the residual vibration peak value of the second acceleration signal at the floor obtained by simulation is significantly reduced, indicating that the residual vibration is significantly reduced. This shows that the body assembly set as a rigid body has a significant improvement on the residual vibration, that is, it can be determined that a certain mode in the body assembly causes a large residual vibration. In this embodiment, the second difference threshold is 50%.

[0049] Step S3: If it is determined that the vehicle body assembly causes significant residual vibration of the vehicle, the residual vibration modal frequency causing the significant residual vibration of the vehicle body is determined based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly.

[0050] Specifically, the residual vibration modal frequency that causes the large residual vibration of the vehicle body is determined based on the response signal in the smoothness simulation test and the modal frequency of the vehicle body assembly, including: performing a fast Fourier transform on the first acceleration signal to obtain an acceleration signal amplitude-frequency characteristic curve with frequency as the horizontal coordinate and amplitude as the vertical coordinate; cyclically dividing the preset frequency interval on the acceleration signal amplitude-frequency characteristic curve into two frequency sub-intervals, sequentially suppressing the modes corresponding to the modal frequencies of all the vehicle body assembly finite element models contained in the two frequency sub-intervals, and performing a smoothness simulation test to obtain a corresponding suppressed acceleration signal, wherein the frequency interval contains the maximum amplitude on the acceleration signal amplitude-frequency characteristic curve. The frequency sub-interval corresponding to the suppressed acceleration signal having a large difference from the residual vibration peak value of the first acceleration signal is divided again, and all the modes in the re-divided frequency sub-intervals are sequentially suppressed and then the smoothness simulation test is performed respectively, until the divided frequency sub-interval includes only one modal frequency of the vehicle body assembly finite element model, and the modal frequency is determined to be the residual vibration modal frequency.

[0051] For example, after determining that the body assembly is the main cause of the large residual vibration problem, it is also necessary to identify which modal frequency of the body assembly causes the large residual vibration. After determining that the whole vehicle dynamics multi-body model in which the body assembly and chassis components are replaced with flexible bodies is qualified, perform FFT fast Fourier analysis on the first acceleration signal of the simulation response of the qualified whole vehicle dynamics multi-body model. The input signal of the fast Fourier analysis is the first acceleration signal, and the first acceleration signal is subjected to fast Fourier analysis, and the output is as follows: Figure 5 The acceleration signal amplitude-frequency characteristic curve is shown with frequency as the horizontal axis and amplitude as the vertical axis. In order to identify which modal frequency in a specific body assembly causes a large residual vibration problem, a dichotomy method is used to confirm the detailed modal frequency.

[0052] It is worth noting that the frequency range must include the maximum value on the amplitude-frequency characteristic curve of the acceleration signal when setting it. Figure 5 As shown, in this embodiment, the region with larger amplitude is concentrated in 1-10 Hz, so the frequency interval must include 1-10 Hz. In this embodiment, the frequency interval is set to 0-100 Hz.

[0053] The dichotomy method is used to identify the specific and detailed modal contribution, and the frequency interval is divided into two frequency sub-intervals of 0-50Hz and 50-100Hz according to the dichotomy method. First, the modes corresponding to the modal frequencies of the finite element models of all body parts contained in 0-50hz are suppressed, and then a smoothness simulation test is performed to obtain the corresponding third acceleration signal; then the suppression of the modes in 0-50Hz is canceled, and the modes corresponding to the modal frequencies of the finite element models of all body parts contained in 50-100Hz are suppressed, and then a smoothness simulation test is performed to obtain the corresponding fourth acceleration signal, wherein the third acceleration signal and the fourth acceleration signal are the suppressed acceleration signals. If the difference between the third acceleration signal and the first acceleration signal is relatively large, it can be determined that the mode causing the residual vibration is between 0-50Hz, otherwise, it is between 50-100Hz, and the difference is mainly the difference in the residual vibration peak value corresponding to the acceleration signal. In this embodiment, the difference between the third acceleration signal and the first acceleration signal is relatively large, and it can be determined that the mode causing the residual vibration problem is in 0-50Hz. 0-50Hz is divided into 0-25Hz and 25-50Hz, and the modes corresponding to the modal frequencies of the finite element models of all body components contained therein are suppressed again. A smoothness simulation test is performed to obtain the corresponding acceleration signal, and the frequency sub-interval corresponding to the acceleration signal that is significantly different from the first acceleration signal is divided again until the frequency interval contains only one modal frequency of the finite element model of the body component, and the modal frequency is determined to be the residual vibration modal frequency that causes substantial residual vibration of the body.

[0054] Or, according to Figure 5The acceleration signal amplitude-frequency characteristic curve shown can be seen to be concentrated in the 1-10Hz range in the area with larger amplitude, and the maximum is relatively concentrated at 7.8Hz. Combined with the free modal analysis of the body assembly above, the modal frequencies of the finite element models of each body component are obtained. In this embodiment, 1-10Hz contains multiple body modal frequencies, including 5.4Hz, 5.9Hz, 6.0Hz, 6.4Hz, 6.6Hz, 7.2Hz, 7.7Hz, 7.94Hz, 8.5Hz, 9.0Hz, 9.2Hz, 9.8Hz and 10.4Hz. These modes can be suppressed one by one in the multi-body dynamics model of the whole vehicle, and then a smoothness simulation is performed to determine that the suppressed modal frequency in which the response acceleration signal differs the most from the first acceleration signal is the residual vibration modal frequency that causes large residual vibration of the body. This method and the above-mentioned dichotomy can both determine the residual vibration modal frequency that causes large residual vibration of the body, and the two can be used alone or in combination to verify each other.

[0055] In this embodiment, the difference between the acceleration signal corresponding to the mode below 7.5 Hz and the mode below 7.8 Hz and the first acceleration signal is as follows: Figure 6 As shown, there is only one 7.7Hz mode between 7.5Hz and 7.8Hz. It can be confirmed that the identified 7.7Hz mode is the cause of the large residual vibration. In this embodiment, the 7.7Hz body mode of the vehicle body is identified as the cause of the residual vibration, and this mode contributes greatly to the Z-direction acceleration residual vibration of the response point. The 7.7Hz body mode can be optimized, and the structure corresponding to this mode of the vehicle body can be optimized. After suppressing its up and down vibration modes, the optimized structure is produced into a flexible body and re-simulated. The residual vibration peak value of the corresponding acceleration signal is significantly reduced relative to the first acceleration response signal.

[0056] In some embodiments, if it is determined that the body assembly is not the cause of the vehicle's residual vibration, the chassis components can be optimized, such as the suspension bushing stiffness or shock absorber damping. The main focus here is on the optimization of residual vibration, because the suspension bushing stiffness, shock absorber damping, and other parameters are closely related to other performance, such as stable operating parameters. Therefore, other performance needs to be optimized as boundary constraints. This embodiment mainly identifies the cause of residual vibration caused by body problems, so the optimization of chassis components that cause residual vibration will not be repeated.

[0057] The embodiment of the present application provides a method for identifying the cause of a large residual vibration of a vehicle. By performing self-modal analysis on the finite element model of the body component, the finite element model of the body assembly and the finite element model of the chassis component, the accuracy of the establishment of each finite element model is ensured, thereby ensuring the accuracy of the generated flexible body file. And by selecting different flexible body generation algorithms according to the number of units of the finite element model, the generation efficiency of the flexible body file can be effectively improved and the generation time can be shortened. After the body assembly and chassis components in the multi-body dynamics model of the whole vehicle are replaced with flexible bodies, quality verification, modal verification and response acceleration signal verification are performed on them to ensure the accuracy of the established multi-body dynamics model of the whole vehicle, laying the foundation for the subsequent accurate identification of the cause of residual vibration. By setting the body assembly in the multi-body dynamics model of the whole vehicle from a flexible body to a rigid body, it is determined whether the body assembly causes the large residual vibration of the vehicle, and after the judgment is yes, the residual vibration modal frequency that causes the vehicle residual vibration is determined according to the simulation test results and the modal frequencies of each component in the body assembly, so as to achieve accurate identification of the component modality that causes the vehicle residual vibration, and provide an accurate and effective optimization basis for improving the vehicle's smoothness.

[0058] Please refer to Figure 7 , Figure 7 A schematic block diagram of a device for identifying the cause of a significant aftershock of a vehicle provided in an embodiment of the present application.

[0059] like Figure 7 As shown, the device comprises:

[0060] A replacement module, which is used to replace the corresponding components in the pre-established vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and chassis components;

[0061] A simulation module, which is used to set the body assembly in the whole vehicle multi-body dynamics model from a flexible body to a rigid body, and perform a smoothness simulation test to determine whether the body assembly causes a large residual vibration of the body;

[0062] The determination module is used to determine the residual vibration modal frequency causing the large residual vibration of the vehicle body based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly if it is determined that the vehicle body assembly causes large residual vibration of the vehicle.

[0063] The device is also used for:

[0064] respectively determining whether the number of units of the pre-established vehicle body assembly finite element model and the chassis component finite element model exceeds a preset unit number threshold;

[0065] If the number of units of the body assembly finite element model exceeds the unit number threshold, based on the body assembly finite element model, the body assembly flexible body file is generated by an automatic multi-layer substructure modal solution algorithm ASMES; otherwise, the body assembly flexible body file is generated by a Lanczos algorithm Lanczos;

[0066] If the number of units of the chassis component finite element model exceeds the unit number threshold, the chassis component flexible body file is generated based on the chassis component finite element model by the automatic multi-layer substructure modal solution algorithm ASMES; otherwise, the chassis component flexible body file is generated by the Lanczos algorithm Lanczos.

[0067] The device is also used for:

[0068] Performing free modal analysis on the finite element models of the various body parts constituting the body assembly to obtain the modal frequencies of the finite element models of the various body parts to determine the accuracy of the finite element models of the body parts;

[0069] Assembling the finite element models of the vehicle body components as a whole to form the finite element model of the vehicle body assembly, and performing free modal analysis on the finite element model of the vehicle body assembly to obtain the modal frequency of the finite element model of the vehicle body assembly to determine the accuracy of establishing the finite element model of the vehicle body assembly;

[0070] Free modal analysis is performed on the finite element model of each chassis component to obtain the modal frequency of the finite element model of each chassis component, so as to determine the accuracy of the establishment of the finite element model of the chassis component.

[0071] Wherein, the replacement module is also used for:

[0072] Replacing the body assembly in the vehicle multi-body dynamics model with a flexible body according to the body assembly flexible body file;

[0073] Each chassis component in the whole vehicle multi-body dynamics model is replaced with a flexible body according to the chassis component flexible body file.

[0074] The device is also used for:

[0075] Determining whether the mass information of each flexible body in the whole vehicle multi-body dynamics model is the same as the mass of the corresponding body assembly finite element model or chassis component finite element model;

[0076] Performing modal analysis on each flexible body in the vehicle multi-body dynamics model to determine whether the modal frequency of each flexible body is the same as the modal frequency of the corresponding vehicle body assembly finite element model or chassis component finite element model;

[0077] Setting a simulated acceleration sensor at a preset response point in the whole vehicle dynamics multi-body model, and performing a ride comfort simulation test based on the whole vehicle multi-body dynamics model to obtain a first acceleration signal output by the simulated acceleration sensor;

[0078] If the mass of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding body assembly finite element model or chassis component finite element model, the modal frequency of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding body assembly finite element model or chassis component finite element model, and the trend of the time domain curve of the first acceleration signal and the measured acceleration signal of the same response point during the smoothness actual vehicle test is the same, and the difference between the residual vibration peak value of the time domain curve of the first acceleration signal and the residual vibration peak value of the time domain curve of the measured acceleration signal is less than a preset first difference threshold, then it is determined that the whole vehicle dynamics multi-body model is established qualified.

[0079] Wherein, the simulation module is also used for:

[0080] The body assembly in the whole vehicle multi-body dynamics model is set from a flexible body to a rigid body. When a smoothness simulation test is performed, if the difference between the aftershock peak value of the second acceleration signal time domain curve corresponding to the response point and the aftershock peak value of the first acceleration signal time domain curve is greater than a preset second difference threshold, it is determined that the body assembly causes substantial aftershock of the body.

[0081] Wherein, the determining module is also used for:

[0082] Performing a fast Fourier transform on the first acceleration signal to obtain an acceleration signal amplitude-frequency characteristic curve with frequency as the abscissa and amplitude as the ordinate;

[0083] cyclically dividing a preset frequency interval on the acceleration signal amplitude-frequency characteristic curve into two frequency sub-intervals, sequentially suppressing the modes corresponding to the modal frequencies of all the vehicle body assembly finite element models contained in the two frequency sub-intervals, and performing a smoothness simulation test to obtain a corresponding suppressed acceleration signal, wherein the frequency interval contains the maximum amplitude on the acceleration signal amplitude-frequency characteristic curve;

[0084] The frequency sub-interval corresponding to the suppressed acceleration signal which has a large difference from the aftervibration peak value of the first acceleration signal is divided again, and all modes in the re-divided frequency sub-intervals are suppressed in turn and then smoothness simulation tests are performed respectively until the divided frequency sub-interval includes only one modal frequency of the finite element model of the vehicle body assembly, and the modal frequency is determined to be the aftervibration modal frequency.

[0085] It should be noted that those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and modules and units can refer to the corresponding processes in the aforementioned embodiments and will not be repeated here.

[0086] The apparatus provided in the above embodiment may be implemented in the form of a computer program. The computer program may be Figure 8 Runs on the computer device shown.

[0087] See also Figure 8 , Figure 8 A schematic block diagram of the structure of a computer device provided in an embodiment of the present application. The computer device may be a terminal.

[0088] like Figure 8 As shown, the computer device includes a processor, a memory, and a network interface connected via a system bus, wherein the memory may include a non-volatile storage medium and an internal memory.

[0089] The non-volatile storage medium can store an operating system and a computer program. The computer program includes program instructions, and when the program instructions are executed, the processor can execute any one of the methods for identifying the cause of the significant residual vibration of the vehicle.

[0090] The processor is used to provide computing and control capabilities and support the operation of the entire computer equipment.

[0091] The internal memory provides an environment for the operation of the computer program in the non-volatile storage medium. When the computer program is executed by the processor, the processor can execute any method for identifying the cause of the significant residual vibration of the vehicle.

[0092] The network interface is used for network communication, such as sending assigned tasks, etc. Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0093] It should be understood that the processor may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0094] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. The computer program includes program instructions. The method implemented when the program instructions are executed can refer to the various embodiments of the present application.

[0095] The computer-readable storage medium may be an internal storage unit of the computer device described in the foregoing embodiment, such as a hard disk or memory of the computer device. The computer-readable storage medium may also be an external storage device of the computer device, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc., equipped on the computer device.

[0096] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0097] The serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments. The above description is only a specific implementation mode of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for identifying the cause of a large residual vibration of a vehicle, characterized in that: include: According to the generated flexible body files of the vehicle body assembly and chassis components, the corresponding components in the pre-established vehicle multi-body dynamics model are replaced with flexible bodies; The body assembly in the vehicle multi-body dynamics model is set from a flexible body to a rigid body, and a ride comfort simulation test is performed to determine whether the body assembly causes a large residual vibration of the vehicle body; If it is determined that the vehicle body assembly causes significant residual vibration of the vehicle, determining the residual vibration modal frequency causing the significant residual vibration of the vehicle body based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly; The generated flexible body files of the body assembly and chassis components include: respectively determining whether the number of units of the pre-established vehicle body assembly finite element model and the chassis component finite element model exceeds a preset unit number threshold; If the number of units of the body assembly finite element model exceeds the unit number threshold, based on the body assembly finite element model, the body assembly flexible body file is generated by an automatic multi-layer substructure modal solution algorithm ASMES; otherwise, the body assembly flexible body file is generated by a Lanczos algorithm Lanczos; If the number of units of the chassis component finite element model exceeds the unit number threshold, the chassis component flexible body file is generated based on the chassis component finite element model by the automatic multi-layer substructure modal solution algorithm ASMES; otherwise, the chassis component flexible body file is generated by the Lanczos algorithm Lanczos.

2. The method for identifying the cause of a large aftershock of a vehicle according to claim 1, characterized in that: When establishing the vehicle body assembly finite element model and the chassis component finite element model, it also includes: Performing free modal analysis on the finite element models of the various body parts constituting the body assembly to obtain the modal frequencies of the finite element models of the various body parts to determine the accuracy of the finite element models of the body parts; Assembling the finite element models of the vehicle body components as a whole to form the finite element model of the vehicle body assembly, and performing free modal analysis on the finite element model of the vehicle body assembly to obtain the modal frequency of the finite element model of the vehicle body assembly to determine the accuracy of establishing the finite element model of the vehicle body assembly; Free modal analysis is performed on the finite element model of each chassis component to obtain the modal frequency of the finite element model of each chassis component, so as to determine the accuracy of the establishment of the finite element model of the chassis component.

3. The method for identifying the cause of a large aftershock of a vehicle according to claim 2, characterized in that: The step of replacing the corresponding components in the pre-established vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and chassis components includes: Replacing the body assembly in the vehicle multi-body dynamics model with a flexible body according to the body assembly flexible body file; Each chassis component in the whole vehicle multi-body dynamics model is replaced with a flexible body according to the chassis component flexible body file.

4. The method for identifying the cause of a large aftershock of a vehicle according to claim 2, characterized in that: After replacing the corresponding parts in the pre-established vehicle multibody dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and chassis components, the following also includes: Determining whether the mass information of each flexible body in the whole vehicle multi-body dynamics model is the same as the mass of the corresponding body assembly finite element model or chassis component finite element model; Performing modal analysis on each flexible body in the vehicle multi-body dynamics model to determine whether the modal frequency of each flexible body is the same as the modal frequency of the corresponding vehicle body assembly finite element model or chassis component finite element model; Setting a simulated acceleration sensor at a preset response point in the whole vehicle multi-body dynamics model, and performing a ride comfort simulation test based on the whole vehicle multi-body dynamics model to obtain a first acceleration signal output by the simulated acceleration sensor; If the mass of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding body assembly finite element model or chassis component finite element model, the modal frequency of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding body assembly finite element model or chassis component finite element model, and the trend of the time domain curve of the first acceleration signal and the measured acceleration signal of the same response point during the smoothness actual vehicle test is the same, and the difference between the residual vibration peak value of the time domain curve of the first acceleration signal and the residual vibration peak value of the time domain curve of the measured acceleration signal is less than a preset first difference threshold, then it is determined that the whole vehicle multi-body dynamics model is established qualified.

5. The method for identifying the cause of a large aftershock of a vehicle according to claim 4, characterized in that: The step of setting the body assembly in the vehicle multi-body dynamics model from a flexible body to a rigid body and performing a ride comfort simulation test to determine whether the body assembly causes a large residual vibration of the vehicle body includes: The body assembly in the whole vehicle multi-body dynamics model is set from a flexible body to a rigid body. When a smoothness simulation test is performed, if the difference between the aftershock peak value of the second acceleration signal time domain curve corresponding to the response point and the aftershock peak value of the first acceleration signal time domain curve is greater than a preset second difference threshold, it is determined that the body assembly causes substantial aftershock of the body.

6. The method for identifying the cause of a large aftershock of a vehicle according to claim 5, characterized in that: Determining the residual vibration modal frequency causing the substantial residual vibration of the vehicle body based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly includes: Performing a fast Fourier transform on the first acceleration signal to obtain an acceleration signal amplitude-frequency characteristic curve with frequency as the abscissa and amplitude as the ordinate; cyclically dividing a preset frequency interval on the acceleration signal amplitude-frequency characteristic curve into two frequency sub-intervals, sequentially suppressing the modes corresponding to the modal frequencies of all the vehicle body assembly finite element models contained in the two frequency sub-intervals, and performing a smoothness simulation test to obtain a corresponding suppressed acceleration signal, wherein the frequency interval contains the maximum amplitude on the acceleration signal amplitude-frequency characteristic curve; The frequency sub-interval corresponding to the suppressed acceleration signal which has a large difference from the aftervibration peak value of the first acceleration signal is divided again, and all modes in the re-divided frequency sub-intervals are suppressed in turn and then smoothness simulation tests are performed respectively until the divided frequency sub-interval includes only one modal frequency of the finite element model of the vehicle body assembly, and the modal frequency is determined to be the aftervibration modal frequency.

7. A device for identifying the cause of a large residual vibration of a vehicle, characterized in that: include: A replacement module, which is used to replace the corresponding components in the pre-established vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and chassis components; A simulation module, which is used to set the body assembly in the whole vehicle multi-body dynamics model from a flexible body to a rigid body, and perform a smoothness simulation test to determine whether the body assembly causes a large residual vibration of the body; a determination module, configured to determine the residual vibration modal frequency causing the large residual vibration of the vehicle body based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly if it is determined that the vehicle body assembly causes large residual vibration of the vehicle; The device is also used for: respectively determining whether the number of units of the pre-established vehicle body assembly finite element model and the chassis component finite element model exceeds a preset unit number threshold; If the number of units of the body assembly finite element model exceeds the unit number threshold, based on the body assembly finite element model, the body assembly flexible body file is generated by an automatic multi-layer substructure modal solution algorithm ASMES; otherwise, the body assembly flexible body file is generated by a Lanczos algorithm Lanczos; If the number of units of the chassis component finite element model exceeds the unit number threshold, the chassis component flexible body file is generated based on the chassis component finite element model by the automatic multi-layer substructure modal solution algorithm ASMES; otherwise, the chassis component flexible body file is generated by the Lanczos algorithm Lanczos.

8. A computer device, characterized in that: The computer device includes a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, the steps of the method for identifying the cause of a significant aftershock of a vehicle as described in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, the steps of the method for identifying the cause of a significant aftershock of a vehicle as claimed in any one of claims 1 to 6 are implemented.

Images