CN116861556A - Method, device, equipment and medium for identifying cause of large residual vibration of vehicle - Google Patents

Method, device, equipment and medium for identifying cause of large residual vibration of vehicle Download PDF

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Publication number
CN116861556A
CN116861556A CN202310824213.5A CN202310824213A CN116861556A CN 116861556 A CN116861556 A CN 116861556A CN 202310824213 A CN202310824213 A CN 202310824213A CN 116861556 A CN116861556 A CN 116861556A
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vehicle
vehicle body
finite element
body assembly
frequency
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刘侃
邓晓姣
翟润国
涂龙飞
张炫
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Lantu Automobile Technology Co Ltd
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Lantu Automobile Technology Co Ltd
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    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/15—Vehicle, aircraft or watercraft design
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces

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  • Automation & Control Theory (AREA)
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Abstract

The application discloses a method, a device, equipment and a medium for identifying the cause of a large-amplitude aftershock of a vehicle, which are characterized in that corresponding parts in a pre-established whole vehicle multi-body dynamics model are replaced by flexible bodies according to flexible body files of generated vehicle body assemblies and chassis parts; setting a vehicle body assembly in the whole vehicle multi-body dynamics model as a rigid body from a flexible body, and performing a smoothness simulation test to judge whether the vehicle body assembly causes a large residual vibration of a vehicle body; if the vehicle body assembly is determined to cause the vehicle to largely vibrate, the vibration mode frequency of the vehicle body to largely vibrate is determined based on the response signals in the ride comfort simulation test and the mode frequency of the vehicle body assembly, so that the component modes of the vehicle to largely vibrate are accurately identified, and an accurate and effective optimization basis is provided for improving the ride comfort of the vehicle.

Description

Method, device, equipment and medium for identifying cause of large residual vibration of vehicle
Technical Field
The application relates to the technical field of automobile state optimization, in particular to a method, a device, equipment and a medium for identifying the cause of a large-amplitude aftershock of a vehicle.
Background
Vehicle ride comfort, which is vibration and impact generated by a vehicle during running, is mainly evaluated according to the comfort level of an occupant, and is also referred to as riding comfort. When the smoothness of the vehicle is poor, the driver and passengers feel uncomfortable, even the human health is damaged, and for the freight vehicle, the transported goods can be damaged if the smoothness is poor. With the development of vehicle performance, the riding experience of the vehicle becomes more and more a concern, and the vehicle aftershock is an important parameter for determining the smoothness of the vehicle, and the vehicle aftershock waveform is shown in fig. 1, and the vehicle aftershock is caused by abnormal aftershock generated by a vehicle body part.
Therefore, how to accurately identify the cause of the substantial aftershock of the vehicle affecting the driving experience is a technical problem to be solved.
Disclosure of Invention
The application mainly aims to provide a method, a device, equipment and a medium for identifying the cause of the vehicle residual vibration greatly, which aim to solve the technical problem of accurately identifying the cause of the vehicle residual vibration greatly.
In a first aspect, the present application provides a method for identifying a cause of a substantial residual vibration of a vehicle, the method comprising the steps of:
According to the generated flexible body file of the vehicle body assembly and the chassis part, replacing the corresponding part in the whole vehicle multi-body dynamics model which is built in advance with a flexible body;
setting a vehicle body assembly in the whole vehicle multi-body dynamics model as a rigid body from a flexible body, and performing a smoothness simulation test to judge whether the vehicle body assembly causes a large residual vibration of a vehicle body;
if the vehicle body assembly is determined to cause the vehicle to have a large residual vibration, the residual vibration mode frequency which causes the vehicle to have the large residual vibration is determined based on the response signal in the ride comfort simulation test and the mode frequency of the vehicle body assembly.
In a second aspect, the present application also provides a device for identifying a cause of a substantial residual vibration of a vehicle, the device comprising:
the replacing module is used for replacing corresponding parts in the pre-established whole vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and the chassis parts;
the simulation module is used for setting a vehicle body assembly in the whole vehicle multi-body dynamics model into a rigid body from a flexible body, performing a smoothness simulation test and judging whether the vehicle body assembly causes a large residual vibration of the vehicle body or not;
and the determining module is used for determining the aftervibration modal frequency which causes the vehicle body to largely aftervibration based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly if the vehicle body assembly is determined to cause the vehicle to largely aftervibration.
In a third aspect, the present application also provides a computer device comprising a processor, a memory, and a computer program stored on the memory and executable by the processor, wherein the computer program when executed by the processor implements the steps of the method for identifying the cause of substantial vehicle aftershock as described above.
In a fourth aspect, the present application also provides a computer readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method as described above.
The application provides a method, a device, equipment and a medium for identifying the cause of a large residual vibration of a vehicle, which are characterized in that corresponding parts in a pre-established whole vehicle multi-body dynamics model are replaced by flexible bodies according to generated flexible body files of a vehicle body assembly and chassis parts; setting a vehicle body assembly in the whole vehicle multi-body dynamics model as a rigid body from a flexible body, and performing a smoothness simulation test to judge whether the vehicle body assembly causes a large residual vibration of a vehicle body; if the vehicle body assembly is determined to cause the vehicle to largely vibrate, the vibration mode frequency of the vehicle body to largely vibrate is determined based on the response signals in the ride comfort simulation test and the mode frequency of the vehicle body assembly, so that the component modes of the vehicle to largely vibrate are accurately identified, and an accurate and effective optimization basis is provided for improving the ride comfort of the vehicle.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of residual vibration waveforms;
fig. 2 is a schematic flow chart of a method for identifying the cause of a large residual vibration of a vehicle according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a first acceleration signal time domain plot;
FIG. 4 is a schematic diagram of comparing a second acceleration signal time domain curve with a first acceleration signal time domain curve;
FIG. 5 is a schematic diagram of an amplitude-frequency characteristic of an acceleration signal;
FIG. 6 is a graph showing a comparison of time-domain curves of the acceleration signal and the first acceleration signal in modes below 7.5hz and below 7.8 hz;
FIG. 7 is a schematic block diagram of a device for identifying the cause of a large residual vibration of a vehicle according to an embodiment of the present application;
fig. 8 is a schematic block diagram of a computer device according to an embodiment of the present application.
The achievement of the objects, functional features and advantages of the present application will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
The flow diagrams depicted in the figures are merely illustrative and not necessarily all of the elements and operations/steps are included or performed in the order described. For example, some operations/steps may be further divided, combined, or partially combined, so that the order of actual execution may be changed according to actual situations.
The embodiment of the application provides a method, a device, equipment and a medium for identifying the cause of a large-amplitude aftershock of a vehicle. The method for identifying the cause of the large residual vibration of the vehicle can be applied to computer equipment, and the computer equipment can be electronic equipment such as a notebook computer, a desktop computer and the like.
Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.
Referring to fig. 2, fig. 2 is a flow chart of a method for identifying a cause of a large residual vibration of a vehicle according to an embodiment of the application.
As shown in fig. 2, the method includes steps S1 to S3.
And S1, replacing corresponding parts in the pre-established whole vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and the chassis parts.
It should be noted that, the body assembly flexible body file in this embodiment is generated according to the body assembly finite element model, and the chassis component flexible body file is generated according to the chassis component finite element model. Before a flexible body file of the vehicle body assembly and a flexible body file of a chassis part are generated, a part list needing to be subjected to flexible body modeling is determined, a finite element model is built according to corresponding parts, and then the flexible body file is generated according to the finite element model, so that a flexible body is built.
The components required to create the flexible body in this embodiment include, by way of example, three types, a body component, a chassis component, and a mass point component, respectively. The vehicle body parts comprise a white vehicle body assembly (with a windshield, a metal instrument panel tubular beam and a battery pack), a rear door (bilateral symmetry), a front hatch cover assembly, a rear hatch cover assembly, a front door (bilateral symmetry), a plastic instrument panel and a secondary instrument desk. The chassis component comprises a front knuckle, a rear knuckle, a front subframe, a rear subframe and a bar system. The mass point components comprise articles such as a front bumper, a rear bumper, an inner carpet, an inner top cover inner decoration plate, a vehicle door inner decoration plate (front and rear), a cabin cover inner decoration plate (front and rear), a cabin storage battery, a spare tire and the like. Body components and chassis components. After determining the parts needing to build the flexible body, building finite element models for the body parts and the chassis parts according to the real vehicle parts.
In some embodiments, when building the body assembly finite element model and the chassis component finite element model, further comprising: performing free modal analysis on the finite element models of all the vehicle body parts forming the vehicle body assembly respectively to obtain modal frequencies of the finite element models of all the vehicle body parts so as to determine the establishment accuracy of the finite element models of the vehicle body parts; the vehicle body part finite element model is assembled in a total mode to form the vehicle body assembly finite element model, free mode analysis is conducted on the vehicle body assembly finite element model, and mode frequencies of the vehicle body assembly finite element model are obtained to determine the accuracy of building of the vehicle body assembly finite element model; and carrying out free modal analysis on the finite element models of all the chassis parts to obtain modal frequencies of the finite element models of all the chassis parts so as to determine the accuracy of establishing the finite element models of all the chassis parts.
In the embodiment, the free mode analysis is performed on the finite element models of the vehicle body parts, the accuracy of the finite element models of the single vehicle body part is confirmed, and the condition that the connection inside the finite element models of the single vehicle body part is inconsistent with the entity parts is eliminated. And then, the body part finite element model is assembled to form the body assembly finite element model, and free mode analysis is performed again, so that the accuracy of building the body assembly finite element model is ensured, and the structure which is not in line with the actual body assembly is ensured not to appear. If there is a structure that does not conform to the reality, the model needs to be adapted to conform to the reality, thereby ensuring the quality of the process of generating the flexible body. Similarly, the free mode analysis is performed on the chassis part finite element models respectively to confirm the accuracy of the single chassis part finite element model.
The flexible body to be produced in the present embodiment includes a vehicle body assembly flexible body and each chassis member flexible body. Therefore, the finite element model of the vehicle body part is required to be assembled into the finite element model of the vehicle body assembly, only the modal analysis is carried out, and the chassis part is carried out by a single chassis part when the flexible body is generated, so that the modal analysis can be carried out on the single chassis part finite element model. After it is reduced to a mass point for the mass point component, no finite element model needs to be built.
Further, the resulting flexible body file for the body assembly and chassis components includes: determining whether the number of units of a pre-established body assembly finite element model and a chassis part finite element model exceeds a preset unit number threshold value or not respectively; if the number of units of the vehicle body assembly finite element model exceeds the threshold value of the number of units, generating a vehicle body assembly flexible body file through an automatic multi-layer substructure modal solving algorithm ASMES based on the vehicle body assembly finite element model, otherwise, generating the vehicle body assembly flexible body file through a Lanczos algorithm; and if the number of the units of the chassis part finite element model exceeds the threshold value of the number of the units, generating a chassis part flexible body file through an automatic multi-layer substructure modal solving algorithm ASMES based on the chassis part finite element model, otherwise, generating the chassis part flexible body file through an Lanczos algorithm.
As a preferable real-time mode, if the number of units of the finite element model of the vehicle body assembly exceeds the threshold value of the number of units, judging that the weight connection unit duty ratio in the units of the finite element model of the vehicle body assembly exceeds the threshold value of the preset proportion, if so, generating the flexible body file of the vehicle body assembly according to Langerhans algorithm Lanczos based on the finite element model of the vehicle body assembly, otherwise, generating the flexible body file of the vehicle body assembly by an automatic multi-layer substructure modal solving algorithm ASMES. If the number of the units of the chassis part finite element model exceeds the threshold value of the number of the units, judging that the weight connection unit duty ratio in the units of the chassis part finite element model exceeds the threshold value of the preset proportion, if yes, generating the chassis part flexible body file according to Lanczos algorithm based on the chassis part finite element model, otherwise, generating the chassis part flexible body file through automatic multi-layer substructure modal solving algorithm ASMES. The unit number threshold in this embodiment may be set according to actual calculation requirements. The ratio threshold in this embodiment is 1/3.
For example, the body assembly finite element model and the individual chassis component finite element models may be divided into two scales, size and dimension, depending on whether the number of units exceeds the number of units threshold. For a large-scale finite element model, determining whether RBE3 weight connection units in the structure exceed 1/3 of the total unit number, if so, generating a corresponding flexible body file by adopting Lanczos algorithm Lanczos, and if not, carrying out flexible body calculation by adopting an amps method. For a 700 ten thousand-unit vehicle body assembly finite element model, the Lanczos algorithm is adopted for about 4 days, and the ASMES method is adopted for calculation, so that the calculation time of the flexible body file can be reduced to 4 hours, and the time for generating the flexible body file by the large-scale finite element model is effectively improved.
The RBE3 unit is a common unit for welding joint connection between vehicle bodies and a common connection unit for mass balance weight in the finite element model. Lanczos is a modal solver, and is an algorithm for solving eigenvalues and eigenvectors of a large sparse matrix. The ASMES method is an automatic multi-layer substructure modal solution method and is also a calculation modal method, and the ASMES method can calculate the finite elements with more units faster to obtain the flexible body file.
It is worth to say that, when the flexible body file is obtained through calculation, a wire frame display unit can be created based on the PLOTEL unit to display the whole structure instead, so that the excessive calculation process file is avoided. When the flexible body file is generated, a response point needs to be reserved, wherein the position of the response point can correspond to the position of the response point on the real vehicle, and the response point in the embodiment is the pedal point of a second-row passenger in the carriage.
Further, according to the generated flexible body file of the vehicle body assembly and the chassis component, replacing the corresponding component in the pre-established whole vehicle multi-body dynamics model with a flexible body, including: replacing the vehicle body assembly in the whole vehicle multi-body dynamics model with a flexible body according to the vehicle body assembly flexible body file; and replacing each chassis part in the whole vehicle multi-body dynamics model with a flexible body according to the chassis part flexible body file.
Preferably, after replacing the corresponding component in the pre-established whole vehicle multi-body dynamics model with the flexible body according to the generated flexible body file of the vehicle body assembly and the chassis component, the method further comprises: determining whether the quality information of each flexible body in the whole vehicle multi-body dynamics model is the same as the quality of a corresponding vehicle body assembly finite element model or chassis part finite element model; performing modal analysis on each flexible body in the whole-vehicle multi-body dynamics model, and determining 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 part finite element model; setting a simulation acceleration sensor at a preset response point in the whole vehicle dynamics multi-body model, and carrying out a smoothness simulation test based on the whole vehicle dynamics multi-body model to obtain a first acceleration signal output by the simulation acceleration sensor; and if the mass of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding vehicle body assembly finite element model or the corresponding chassis part 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 vehicle body assembly finite element model or the corresponding chassis part finite element model, the trend of the time domain curve of the measured acceleration signal of the same response point is the same when the first acceleration signal and the ride comfort real vehicle are tested, and the difference value 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 smaller than a preset first difference value threshold, determining that the whole vehicle dynamics multi-body model is established to be qualified.
Exemplary, based on the flexible body file obtained by calculation, the vehicle body assembly and the chassis part in the pre-established vehicle multi-body dynamics model are replaced by flexible bodies, and the vehicle multi-body dynamics model with the vehicle body assembly and the chassis part being flexible bodies is obtained. After the replacement is finished, whether the quality information of the flexible body in the whole vehicle multi-body dynamics model is different from the quality of the corresponding finite element model or not is confirmed again, so that the quality information of the flexible body in the multi-body model is accurate. Carrying out modal analysis on a flexible body in the whole vehicle multi-body dynamics model, and confirming that the modal frequency values of the flexible body in the whole vehicle multi-body dynamics model and the corresponding finite element model are consistent in free modal analysis, so that accuracy of the flexible body model is confirmed, and the modes participating in calculation in the flexible body mode are confirmed to not comprise 1-6-order rigid body modes. According to the reserved response points, a simulated acceleration signal sensor focused on the residual vibration problem is created and used for outputting a simulated acceleration sensor signal, then a road model is built according to a road of a real vehicle ride test to carry out a real ride test, a first acceleration signal is obtained at the response points through the simulated acceleration sensor, a time domain curve of the obtained first acceleration signal is shown in fig. 3, the first acceleration time domain curve is a curve of the change of acceleration of the response points along with time, and the time domain curve of the acceleration signal can reflect the residual vibration condition of the response points. The trend of the first acceleration signal time domain curve is the same as that of the actually measured acceleration signal time domain curve, and the residual vibration peak value errors of the two time domain curves, particularly the maximum peak value error in the residual vibration peak value is within 10%, represent that the whole vehicle dynamics multi-body model is standard-matched with the real vehicle after being replaced by the flexible body, so that the building is qualified. The simulation acceleration signal is an acceleration signal of the simulation sensor in the Z direction.
And S2, setting a vehicle body assembly in the whole vehicle multi-body dynamics model as a rigid body from a flexible body, and performing a smoothness simulation test to judge whether the vehicle body assembly causes a large residual vibration of the vehicle body.
Specifically, the method for setting the vehicle body assembly in the whole vehicle multi-body dynamics model as a rigid body by a flexible body, and performing a smoothness simulation test to judge whether the vehicle body assembly causes a large residual vibration of the vehicle body comprises the following steps: when the vehicle body assembly in the whole vehicle multi-body dynamics model is set to be a rigid body by a flexible body and a ride comfort simulation test is carried out, if the difference value 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 larger than a preset second difference value threshold, determining that the vehicle body assembly causes the vehicle body to have a large residual vibration.
The vehicle body assembly in the whole vehicle multi-body dynamics model after the replacement of the vehicle body assembly and the chassis component with the flexible body is set to be a rigid body again, the chassis component is still a flexible body at the moment, and the second acceleration signal is obtained according to the whole vehicle multi-body dynamics model in a simulation mode again. The second acceleration signal time domain curve is compared with the first acceleration signal time domain curve when the body is flexible. The body assembly is provided with the rigid body, is of a structure with infinite rigid body strength, is of an ideal structure with infinite flexible body assembly, can be used for calculating and comparing the final form of the body after the body is supposed to be reinforced, and is used for confirming the effect of the body after the body is reinforced. As shown in fig. 4, it can be seen that the vehicle body assembly is configured as a rigid body, that is, after the structure is reinforced, the magnitude of the residual vibration peak value of the second acceleration signal at the floor obtained by simulation is obviously reduced, which means that the residual vibration is obviously reduced. The method has the advantages that the vehicle body assembly which is arranged as the rigid body is obviously improved on the aftervibration, and the reason of a certain mode in the vehicle body assembly can be determined to cause the larger aftervibration. In this embodiment, the second difference threshold is 50%.
And step S3, if the vehicle body assembly is determined to cause the vehicle to have a large residual vibration, determining the residual vibration mode frequency which causes the vehicle to have the large residual vibration based on the response signal in the ride comfort simulation test and the mode frequency of the vehicle body assembly.
Specifically, determining a residual vibration modal frequency that causes a substantial residual vibration of the vehicle body based on a response signal in a ride comfort simulation test and the modal frequency of the vehicle body assembly includes: performing fast Fourier change on the first acceleration signal to obtain an acceleration signal amplitude-frequency characteristic curve with frequency as an abscissa and amplitude as an ordinate; and circularly dividing a frequency interval preset on the amplitude-frequency characteristic curve of the acceleration signal into two frequency subintervals, sequentially suppressing modes corresponding to the mode frequencies of all the vehicle body assembly finite element models contained in the two frequency subintervals, and performing a smoothness simulation test to obtain a corresponding suppressed acceleration signal, wherein the frequency interval contains the maximum amplitude on the amplitude-frequency characteristic curve of the acceleration signal. Dividing the frequency subinterval corresponding to the restrained acceleration signal with larger residual vibration peak value difference of the first acceleration signal again, sequentially restraining all modes in the frequency subinterval divided again, and then respectively carrying out a smoothness simulation test until the divided frequency subinterval only comprises one mode frequency of the vehicle body assembly finite element model, and determining the mode frequency as the residual vibration mode frequency.
For example, after determining that the vehicle body assembly is the main cause of the problem of the large residual vibration, it is also necessary to identify which modal frequency of the vehicle body assembly causes the large residual vibration. After the establishment of the whole vehicle dynamics multi-body model with the vehicle body assembly and the chassis part replaced by the flexible body is confirmed to be qualified, FFT fast Fourier analysis is carried out according to a first acceleration signal of simulation response of the established qualified whole vehicle dynamics multi-body model. The input signal of the fast fourier analysis is a first acceleration signal, the fast fourier analysis is performed on the first acceleration signal, and the output is an acceleration signal amplitude-frequency characteristic curve with the frequency as an abscissa and the amplitude as an ordinate as shown in fig. 5. In order to identify which specific modal frequency in a specific vehicle body assembly causes a larger problem of residual vibration, a dichotomy method is adopted to confirm the detailed modal frequency.
It should be noted that, the frequency interval must be set to include the maximum amplitude on the amplitude-frequency characteristic curve of the acceleration signal, as shown in fig. 5, in this embodiment, the larger area of the amplitude is concentrated within 1-10Hz, so the frequency interval must include 1-10Hz. The frequency interval is set to 0-100Hz in this embodiment.
And carrying out specific detailed modal contribution identification by adopting a dichotomy, and dividing the frequency interval into two frequency subintervals of 0-50Hz and 50-100Hz according to the dichotomy. Firstly, suppressing modes corresponding to the mode frequencies of all the finite element models of the vehicle body parts contained in 0-50hz, and then performing a smoothness simulation test to obtain a corresponding third acceleration signal; and then canceling the inhibition of the modes in 0-50Hz, inhibiting the modes corresponding to the mode frequencies of all the finite element models of the vehicle body parts contained in 50-100Hz, and then performing a ride comfort simulation test to obtain a corresponding fourth acceleration signal, wherein the third acceleration signal and the fourth acceleration signal are inhibition acceleration signals. If the difference between the third acceleration signal and the first acceleration signal is relatively large, the mode causing the residual vibration can be determined to be between 0 and 50Hz, otherwise, the mode causing the residual vibration is between 50 and 100Hz, wherein the difference is mainly the difference value of residual vibration peaks corresponding to the acceleration signals. In this embodiment, the difference between the third acceleration signal and the first acceleration signal is relatively large, so that it can be determined that the mode causing the problem of residual vibration is within 0-50 Hz. Dividing 0-50Hz into 0-25Hz and 25-50Hz, inhibiting the modes corresponding to the mode frequencies of all the finite element models of the vehicle body parts contained in the finite element models again, carrying out a smoothness simulation test to obtain corresponding acceleration signals, dividing the frequency subinterval corresponding to the acceleration signals with larger difference between the first acceleration signals again until only one mode frequency of the finite element models of the vehicle body parts is contained in the frequency interval, and determining the mode frequency as the residual vibration mode frequency which causes the large residual vibration of the vehicle body.
Alternatively, the amplitude-frequency characteristic curve of the acceleration signal shown in fig. 5 can be seen to concentrate in the range of about 1-10Hz in a region of larger amplitude, and the maximum is located in a comparative concentration of 7.8 Hz. In combination with the foregoing free mode analysis performed on the vehicle body assembly, the mode frequencies of the finite element models of the respective vehicle body parts are obtained, and in this embodiment, a plurality of vehicle body mode frequencies included in 1-10Hz, 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, may be determined by suppressing these modes one by one in the vehicle multi-body dynamics model, and then performing a smoothness simulation, so that the suppressed mode frequency in which the difference between the responsive acceleration signal and the first acceleration signal is the largest is the aftervibration mode frequency that causes the vehicle body to largely aftervibration. The method and the dichotomy can determine the residual vibration mode frequency which causes the substantial residual vibration of the vehicle body, and the method and the dichotomy can be used singly or in combination for mutual verification.
In this embodiment, the difference between the acceleration signal and the first acceleration signal, which are responsive when the mode corresponding to 7.5Hz or less and the mode corresponding to 7.8Hz or less is suppressed, is shown in fig. 6, and only one mode of 7.7Hz is included between 7.5Hz and 7.8 Hz. It was confirmed that the identified 7.7Hz mode was responsible for the large residual vibration. In the embodiment, the vehicle body mode of 7.7Hz of the vehicle body is identified as the residual vibration reason, and the mode has larger contribution to the Z-direction acceleration residual vibration of the response point. The vehicle body mode of 7.7Hz can be optimized, the structure corresponding to the vehicle body mode is optimized, after the upper and lower vibration modes of the vehicle body are restrained, after the optimized structure is used for producing a flexible body and is subjected to simulation again, the residual vibration peak value of the corresponding acceleration signal is obviously reduced relative to the first acceleration response signal.
In some embodiments, if it is determined that the body assembly is not responsible for vehicle after-vibration, the chassis components may be optimized, such as for suspension bushing stiffness or shock absorber damping. The method is mainly aimed at optimizing residual vibration, and parameters such as the rigidity of a suspension bushing, the damping of a shock absorber and the like are closely related to other performances such as stable operation parameters. Other properties need to be optimized as boundary constraints. The embodiment mainly aims at identifying the reason of the residual vibration caused by the vehicle body problem, so that the residual vibration caused by the chassis part is optimized without repeated description.
The embodiment of the application provides a method for identifying the cause of a large-amplitude residual vibration of a vehicle, which ensures the accuracy of the establishment of each finite element model by carrying out self-modal analysis on a finite element model of a vehicle body part, a finite element model of a vehicle body assembly and a finite element model of a chassis part, thereby ensuring the accuracy of a generated flexible body file. And different flexible body generation algorithms are selected according to the number of units of the finite element model, so that the generation efficiency of flexible body files can be effectively improved, and the generation time is shortened. After the vehicle body assembly and the chassis part in the whole vehicle multi-body dynamics model are replaced by flexible bodies, the quality verification, the modal verification and the response acceleration signal verification are carried out on the flexible bodies, the accuracy of the established whole vehicle multi-body dynamics model is ensured, and a foundation is laid for the follow-up accurate residual vibration cause identification. The vehicle body assembly in the whole vehicle multi-body dynamics model is set to be a rigid body, whether the vehicle body assembly causes the vehicle to have a large residual vibration or not is judged, after the vehicle body assembly is judged to have the large residual vibration, the residual vibration mode frequency which causes the vehicle residual vibration is determined according to the simulation test result and the mode frequency of each part in the vehicle body assembly, the accurate identification of the part modes which cause the vehicle residual vibration is realized, and an accurate and effective optimization basis is provided for improving the vehicle smoothness.
Referring to fig. 7, fig. 7 is a schematic block diagram of a device for identifying a cause of a substantial residual vibration of a vehicle according to an embodiment of the present application.
As shown in fig. 7, the apparatus includes:
the replacing module is used for replacing corresponding parts in the pre-established whole vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and the chassis parts;
the simulation module is used for setting a vehicle body assembly in the whole vehicle multi-body dynamics model into a rigid body from a flexible body, performing a smoothness simulation test and judging whether the vehicle body assembly causes a large residual vibration of the vehicle body or not;
and the determining module is used for determining the aftervibration modal frequency which causes the vehicle body to largely aftervibration based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly if the vehicle body assembly is determined to cause the vehicle to largely aftervibration.
Wherein the device is also used for:
determining whether the number of units of a pre-established body assembly finite element model and a chassis part finite element model exceeds a preset unit number threshold value or not respectively;
if the number of units of the vehicle body assembly finite element model exceeds the threshold value of the number of units, generating a vehicle body assembly flexible body file through an automatic multi-layer substructure modal solving algorithm ASMES based on the vehicle body assembly finite element model, otherwise, generating the vehicle body assembly flexible body file through a Lanczos algorithm;
And if the number of the units of the chassis part finite element model exceeds the threshold value of the number of the units, generating a chassis part flexible body file through an automatic multi-layer substructure modal solving algorithm ASMES based on the chassis part finite element model, otherwise, generating the chassis part flexible body file through an Lanczos algorithm.
Wherein the device is also used for:
performing free modal analysis on the finite element models of all the vehicle body parts forming the vehicle body assembly respectively to obtain modal frequencies of the finite element models of all the vehicle body parts so as to determine the establishment accuracy of the finite element models of the vehicle body parts;
the vehicle body part finite element model is assembled in a total mode to form the vehicle body assembly finite element model, free mode analysis is conducted on the vehicle body assembly finite element model, and mode frequencies of the vehicle body assembly finite element model are obtained to determine the accuracy of building of the vehicle body assembly finite element model;
and carrying out free modal analysis on the finite element models of all the chassis parts to obtain modal frequencies of the finite element models of all the chassis parts so as to determine the accuracy of establishing the finite element models of all the chassis parts.
Wherein the replacement module is further configured to:
Replacing the vehicle body assembly in the whole vehicle multi-body dynamics model with a flexible body according to the vehicle body assembly flexible body file;
and replacing each chassis part in the whole vehicle multi-body dynamics model with a flexible body according to the chassis part flexible body file.
Wherein the device is also used for:
determining whether the quality information of each flexible body in the whole vehicle multi-body dynamics model is the same as the quality of a corresponding vehicle body assembly finite element model or chassis part finite element model;
performing modal analysis on each flexible body in the whole-vehicle multi-body dynamics model, and determining 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 part finite element model;
setting a simulation acceleration sensor at a preset response point in the whole vehicle dynamics multi-body model, and carrying out a smoothness simulation test based on the whole vehicle dynamics multi-body model to obtain a first acceleration signal output by the simulation acceleration sensor;
and if the mass of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding vehicle body assembly finite element model or the corresponding chassis part 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 vehicle body assembly finite element model or the corresponding chassis part finite element model, the trend of the time domain curve of the measured acceleration signal of the same response point is the same when the first acceleration signal and the ride comfort real vehicle are tested, and the difference value 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 smaller than a preset first difference value threshold, determining that the whole vehicle dynamics multi-body model is established to be qualified.
Wherein, the emulation module is further used for:
when the vehicle body assembly in the whole vehicle multi-body dynamics model is set to be a rigid body by a flexible body and a ride comfort simulation test is carried out, if the difference value 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 larger than a preset second difference value threshold, determining that the vehicle body assembly causes the vehicle body to have a large residual vibration.
Wherein the determining module is further configured to:
performing fast Fourier change on the first acceleration signal to obtain an acceleration signal amplitude-frequency characteristic curve with frequency as an abscissa and amplitude as an ordinate;
circularly dividing a frequency interval preset on the amplitude-frequency characteristic curve of the acceleration signal into two frequency subintervals, sequentially suppressing modes corresponding to the mode frequencies of all the vehicle body assembly finite element models contained in the two frequency subintervals, and performing a smoothness simulation test to obtain a corresponding suppressed acceleration signal, wherein the frequency interval contains the maximum amplitude value on the amplitude-frequency characteristic curve of the acceleration signal;
dividing the frequency subinterval corresponding to the restrained acceleration signal with larger residual vibration peak value difference of the first acceleration signal again, sequentially restraining all modes in the frequency subinterval divided again, and then respectively carrying out a smoothness simulation test until the divided frequency subinterval only comprises one mode frequency of the vehicle body assembly finite element model, and determining the mode frequency as the residual vibration mode frequency.
It should be noted that, for convenience and brevity of description, specific working procedures of the above-described apparatus and each module and unit may refer to corresponding procedures in the foregoing embodiments, and are not repeated herein.
The apparatus provided by the above embodiments may be implemented in the form of a computer program which may be run on a computer device as shown in fig. 8.
Referring to fig. 8, fig. 8 is a schematic block diagram of a computer device according to an embodiment of the present application. The computer device may be a terminal.
As shown in fig. 8, the computer device includes a processor, a memory, and a network interface connected by a system bus, wherein the memory may include a non-volatile storage medium and an internal memory.
The non-volatile storage medium may store an operating system and a computer program. The computer program comprises program instructions which, when executed, cause the processor to perform any one of a number of methods for identifying the cause of substantial vehicle vibration.
The processor is used to provide computing and control capabilities to support the operation of the entire computer device.
The internal memory provides an environment for the execution of a computer program in a non-volatile storage medium that, when executed by a processor, causes the processor to perform any one of a number of methods for identifying the cause of substantial vehicle vibration.
The network interface is used for network communication such as transmitting assigned tasks and the like. It will be appreciated by those skilled in the art that the structure shown in FIG. 8 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the computer device to which the present inventive arrangements may be applied, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.
It should be appreciated that the processor may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field-programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. Wherein the general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
Embodiments of the present application also provide a computer readable storage medium having a computer program stored thereon, the computer program including program instructions that, when executed, implement methods that can be referred to in various embodiments of the present application.
The computer readable storage medium may be an internal storage unit of the computer device according to the foregoing embodiment, for example, a hard disk or a 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 Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), or the like, which are provided on the computer device.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The foregoing embodiment numbers of the present application are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments. While the application has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (10)

1. The method for identifying the cause of the large aftershock of the vehicle is characterized by comprising the following steps:
according to the generated flexible body file of the vehicle body assembly and the chassis part, replacing the corresponding part in the whole vehicle multi-body dynamics model which is built in advance with a flexible body;
setting a vehicle body assembly in the whole vehicle multi-body dynamics model as a rigid body from a flexible body, and performing a smoothness simulation test to judge whether the vehicle body assembly causes a large residual vibration of a vehicle body;
if the vehicle body assembly is determined to cause the vehicle to have a large residual vibration, the residual vibration mode frequency which causes the vehicle to have the large residual vibration is determined based on the response signal in the ride comfort simulation test and the mode frequency of the vehicle body assembly.
2. The method for identifying causes of substantial aftershock in a vehicle according to claim 1, wherein the generated flexible body file of the body assembly and chassis components includes:
determining whether the number of units of a pre-established body assembly finite element model and a chassis part finite element model exceeds a preset unit number threshold value or not respectively;
if the number of units of the vehicle body assembly finite element model exceeds the threshold value of the number of units, generating a vehicle body assembly flexible body file through an automatic multi-layer substructure modal solving algorithm ASMES based on the vehicle body assembly finite element model, otherwise, generating the vehicle body assembly flexible body file through a Lanczos algorithm;
And if the number of the units of the chassis part finite element model exceeds the threshold value of the number of the units, generating a chassis part flexible body file through an automatic multi-layer substructure modal solving algorithm ASMES based on the chassis part finite element model, otherwise, generating the chassis part flexible body file through an Lanczos algorithm.
3. The method for identifying causes of substantial vehicle aftershock according to claim 2, further comprising, when establishing the body assembly finite element model and the chassis component finite element model:
performing free modal analysis on the finite element models of all the vehicle body parts forming the vehicle body assembly respectively to obtain modal frequencies of the finite element models of all the vehicle body parts so as to determine the establishment accuracy of the finite element models of the vehicle body parts;
the vehicle body part finite element model is assembled in a total mode to form the vehicle body assembly finite element model, free mode analysis is conducted on the vehicle body assembly finite element model, and mode frequencies of the vehicle body assembly finite element model are obtained to determine the accuracy of building of the vehicle body assembly finite element model;
and carrying out free modal analysis on the finite element models of all the chassis parts to obtain modal frequencies of the finite element models of all the chassis parts so as to determine the accuracy of establishing the finite element models of all the chassis parts.
4. The method for identifying the cause of the substantial residual vibration of the vehicle according to claim 3, wherein the replacing the corresponding component in the pre-established whole vehicle multi-body dynamics model with the flexible body according to the generated flexible body file of the vehicle body assembly and the chassis component comprises the following steps:
replacing the vehicle body assembly in the whole vehicle multi-body dynamics model with a flexible body according to the vehicle body assembly flexible body file;
and replacing each chassis part in the whole vehicle multi-body dynamics model with a flexible body according to the chassis part flexible body file.
5. The method for identifying causes of substantial vehicle aftershock according to claim 3, further comprising, after replacing corresponding parts in a pre-established whole vehicle multi-body dynamics model with flexible bodies according to the generated flexible body file of the vehicle body assembly and chassis parts:
determining whether the quality information of each flexible body in the whole vehicle multi-body dynamics model is the same as the quality of a corresponding vehicle body assembly finite element model or chassis part finite element model;
performing modal analysis on each flexible body in the whole-vehicle multi-body dynamics model, and determining 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 part finite element model;
Setting a simulation acceleration sensor at a preset response point in the whole vehicle dynamics multi-body model, and carrying out a smoothness simulation test based on the whole vehicle dynamics multi-body model to obtain a first acceleration signal output by the simulation acceleration sensor;
and if the mass of each flexible body in the whole vehicle multi-body dynamics model is the same as that of the corresponding vehicle body assembly finite element model or the corresponding chassis part 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 vehicle body assembly finite element model or the corresponding chassis part finite element model, the trend of the time domain curve of the measured acceleration signal of the same response point is the same when the first acceleration signal and the ride comfort real vehicle are tested, and the difference value 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 smaller than a preset first difference value threshold, determining that the whole vehicle dynamics multi-body model is established to be qualified.
6. The method for identifying a cause of a substantial residual vibration of a vehicle according to claim 5, wherein the step of setting a vehicle body assembly in the whole-vehicle multi-body dynamics model from a flexible body to a rigid body and performing a ride comfort simulation test to determine whether the vehicle body assembly causes the substantial residual vibration of the vehicle body, includes:
When the vehicle body assembly in the whole vehicle multi-body dynamics model is set to be a rigid body by a flexible body and a ride comfort simulation test is carried out, if the difference value 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 larger than a preset second difference value threshold, determining that the vehicle body assembly causes the vehicle body to have a large residual vibration.
7. The method for identifying a cause of substantial vehicle aftervibration according to claim 6, characterized in that determining an aftervibration modal frequency that causes substantial vehicle aftervibration based on a response signal in a ride comfort simulation test and the modal frequency of the vehicle body assembly includes:
performing fast Fourier change on the first acceleration signal to obtain an acceleration signal amplitude-frequency characteristic curve with frequency as an abscissa and amplitude as an ordinate;
circularly dividing a frequency interval preset on the amplitude-frequency characteristic curve of the acceleration signal into two frequency subintervals, sequentially suppressing modes corresponding to the mode frequencies of all the vehicle body assembly finite element models contained in the two frequency subintervals, and performing a smoothness simulation test to obtain a corresponding suppressed acceleration signal, wherein the frequency interval contains the maximum amplitude value on the amplitude-frequency characteristic curve of the acceleration signal;
Dividing the frequency subinterval corresponding to the restrained acceleration signal with larger residual vibration peak value difference of the first acceleration signal again, sequentially restraining all modes in the frequency subinterval divided again, and then respectively carrying out a smoothness simulation test until the divided frequency subinterval only comprises one mode frequency of the vehicle body assembly finite element model, and determining the mode frequency as the residual vibration mode frequency.
8. A cause identifying device for a large residual vibration of a vehicle, comprising:
the replacing module is used for replacing corresponding parts in the pre-established whole vehicle multi-body dynamics model with flexible bodies according to the generated flexible body files of the vehicle body assembly and the chassis parts;
the simulation module is used for setting a vehicle body assembly in the whole vehicle multi-body dynamics model into a rigid body from a flexible body, performing a smoothness simulation test and judging whether the vehicle body assembly causes a large residual vibration of the vehicle body or not;
and the determining module is used for determining the aftervibration modal frequency which causes the vehicle body to largely aftervibration based on the response signal in the ride comfort simulation test and the modal frequency of the vehicle body assembly if the vehicle body assembly is determined to cause the vehicle to largely aftervibration.
9. A computer device, characterized in that it comprises a processor, a memory, and a computer program stored on the memory and executable by the processor, wherein the computer program, when executed by the processor, realizes the steps of the method for identifying the cause of a substantial aftershock in a vehicle according to any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a computer program, wherein the computer program, when executed by a processor, implements the steps of the method for identifying the cause of a substantial aftershock in a vehicle according to any one of claims 1 to 7.
CN202310824213.5A 2023-07-05 2023-07-05 Method, device, equipment and medium for identifying cause of large residual vibration of vehicle Pending CN116861556A (en)

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CN202310824213.5A CN116861556A (en) 2023-07-05 2023-07-05 Method, device, equipment and medium for identifying cause of large residual vibration of vehicle

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CN202310824213.5A CN116861556A (en) 2023-07-05 2023-07-05 Method, device, equipment and medium for identifying cause of large residual vibration of vehicle

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