CN113901580A - Method and system for predicting abnormal sound of vehicle shock absorber - Google Patents
Method and system for predicting abnormal sound of vehicle shock absorber Download PDFInfo
- Publication number
- CN113901580A CN113901580A CN202111167867.2A CN202111167867A CN113901580A CN 113901580 A CN113901580 A CN 113901580A CN 202111167867 A CN202111167867 A CN 202111167867A CN 113901580 A CN113901580 A CN 113901580A
- Authority
- CN
- China
- Prior art keywords
- shock absorber
- tested
- vehicle
- noise
- piston rod
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- 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
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H1/00—Measuring characteristics of vibrations in solids by using direct conduction to the detector
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M17/00—Testing of vehicles
- G01M17/007—Wheeled or endless-tracked vehicles
- G01M17/04—Suspension or damping
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/02—Vibration-testing by means of a shake table
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/17—Mechanical parametric or variational 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
- G06F2119/10—Noise analysis or noise optimisation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Abstract
The application relates to a method and a system for predicting abnormal sound of a vehicle shock absorber, which relate to the technical field of vehicle design, and the method for predicting the abnormal sound of the vehicle shock absorber comprises the following steps: testing to obtain the vibration acceleration of the upper end of a piston rod of a damper to be tested of a target vehicle; simulating to obtain the upper support dynamic stiffness of the shock absorber to be tested; simulating to obtain a noise transfer function of the shock absorber to be tested; and calculating to obtain the abnormal sound noise volume corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient. This application obtains piston rod upper end vibration acceleration, the last dynamic stiffness of supporting and noise transfer function of surveying the bumper shock absorber through the test to this is basis, through the abnormal sound noise volume that the prediction awaits measuring bumper shock absorber corresponds, thereby predicts bumper shock absorber noise level, provides the data basis for later stage design optimization.
Description
Technical Field
The application relates to the technical field of vehicle design, in particular to a method and a system for predicting abnormal sound of a vehicle shock absorber.
Background
The abnormal sound development is one of the key development investments of various manufacturers as the important work content for improving the quality of the whole vehicle. The chassis abnormal sound occupies a larger proportion in the whole vehicle abnormal sound development work, wherein the problem of the abnormal sound of the shock absorber is particularly prominent. The abnormal sound problem of the shock absorber is greatly influenced by the road surface and has important correlation with the ambient temperature, and impact vibration can be generated in the reversing process of the pulling-up and compression of the shock absorber, so that the vehicle body is excited to generate noise, abnormal noise can be generated in serious conditions, and the comfort in the vehicle is influenced.
At present, the abnormal sound of the shock absorber is mainly identified according to a vehicle road test, but the method can only be carried out after a sample vehicle is produced and manufactured, so that the shock absorber is short in development period, high in risk after problems occur, and high in improvement difficulty. In addition, related researchers can also identify abnormal sound risks according to a bench test, but cannot consider the influence of matching with the whole vehicle.
Aiming at the defects of the prior art, a novel vehicle shock absorber abnormal sound prediction technology is provided to meet the requirements.
Disclosure of Invention
The application provides a vehicle shock absorber abnormal sound prediction method and system, vibration acceleration, upper support dynamic stiffness and a noise transfer function of the upper end of a piston rod of a shock absorber are obtained through testing, and on the basis, abnormal sound noise volume corresponding to the shock absorber to be tested is predicted through calculation, so that the noise level of the shock absorber is predicted, and data basis is provided for later-stage design optimization.
In a first aspect, the present application provides a method for predicting vehicle shock absorber abnormal sound, the method comprising the steps of:
testing to obtain the vibration acceleration of the upper end of a piston rod of a damper to be tested of a target vehicle;
simulating to obtain the upper support dynamic stiffness of the shock absorber to be tested;
simulating to obtain a noise transfer function of the shock absorber to be tested;
and calculating to obtain the abnormal noise volume corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the upper support dynamic stiffness, the noise transfer function and a preset first correction coefficient.
This application obtains piston rod upper end vibration acceleration, the last dynamic stiffness of supporting and noise transfer function of surveying the bumper shock absorber through the test to this is basis, through the abnormal sound noise volume that the prediction awaits measuring bumper shock absorber corresponds, thereby predicts bumper shock absorber noise level, provides the data basis for later stage design optimization.
In addition, the level of the noise of the shock absorber is predicted on the basis of the displacement output of the shock absorber, the rubber dynamic stiffness of the shock absorber and the vehicle body noise transfer function, the frequency exceeding the target value is subjected to targeted optimization, and by means of the scheme, the abnormal sound risk of the carrying working condition of the whole vehicle can be comprehensively considered in the shock absorber development stage, development work is advanced, and the development period is shortened.
Specifically, the test method for obtaining the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested of the target vehicle comprises the following steps:
mounting the shock absorber to be tested on a preset shock absorber abnormal sound rack;
the lower end of the to-be-tested shock absorber is connected with a vibration exciter, and the upper end of the to-be-tested shock absorber is provided with a vibration sensor;
testing a vibration response level of the shock absorber at different excitation inputs based on the vibration exciter and the vibration sensor;
and obtaining the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested based on the vibration response levels of the shock absorber under different excitation inputs.
Specifically, the step of obtaining the upper support dynamic stiffness of the shock absorber to be tested through simulation includes the following steps:
and simulating based on the vehicle body parameters of the target vehicle and the performance parameters of a piston rod connected with the shock absorber to obtain the upper support dynamic stiffness of the shock absorber to be tested.
Specifically, the step of obtaining the noise transfer function of the shock absorber to be tested through simulation includes:
establishing a complete vehicle finite element structure model and a cavity model of the target vehicle;
and processing to obtain the noise transfer function of the shock absorber to be tested at the corresponding mounting point.
Specifically, the method for calculating and obtaining the volume of the abnormal noise corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient comprises the following steps:
carrying out Fourier transform on the vibration acceleration of the upper end of the piston rod to obtain the vibration acceleration of the upper end of the piston rod in a frequency spectrum form;
carrying out high-pass filtering on the vibration acceleration of the upper end of the piston rod in the form of frequency spectrum, and carrying out secondary integration on the result after the high-pass filtering to obtain a corresponding displacement parameter under a frequency domain;
and calculating to obtain the volume of the abnormal noise corresponding to the shock absorber to be tested based on the displacement parameter under the frequency domain, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient.
Specifically, the magnitude of the abnormal sound in the vehicle can be analyzed by using a calculation formula of the abnormal sound in the vehicle below:
S＝20lg((∫∫a(ω))Kd(ω))+NTF(ω)+K(ω)；
in the above formula, a (ω) is the vibration acceleration of the upper end of the piston rod of the shock absorber;
Kd(omega) is the upper support dynamic stiffness of the shock absorber;
NTF (omega) is a noise transfer function from a mounting point corresponding to the shock absorber to the interior of the vehicle;
k (omega) is a first correction coefficient, and data errors can be corrected through empirical data accumulation;
in each symbol, ω represents a frequency domain.
Further, after the abnormal noise volume corresponding to the shock absorber to be tested is calculated and obtained based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient, the method further comprises the following steps:
comparing the abnormal noise volume corresponding to the shock absorber to be tested with a preset abnormal noise volume threshold value;
and generating a structural optimization early warning when the volume of the abnormal noise is greater than the threshold of the volume of the abnormal noise.
In a second aspect, the present application provides a vehicle shock absorber abnormal sound prediction system, the system comprising:
the first testing device is used for testing and obtaining the vibration acceleration of the upper end of the piston rod of the damper to be tested of the target vehicle;
the second testing device is used for simulating and obtaining the upper support dynamic stiffness of the shock absorber to be tested;
the third testing device is used for simulating and obtaining a noise transfer function of the shock absorber to be tested;
and the noise calculation device is used for calculating and obtaining the volume of the abnormal noise corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient.
Specifically, the first test apparatus includes:
the shock absorber abnormal sound rack is used for mounting the shock absorber to be tested;
the vibration exciter is used for being connected with the lower end of the shock absorber to be tested;
and the vibration sensor is used for being connected with the upper end of the shock absorber to be tested.
Specifically, the second testing device is used for simulating based on the body parameters of the target vehicle and the performance parameters of a piston rod connected with the damper to obtain the upper support dynamic stiffness of the damper to be tested.
Specifically, the third testing device is used for establishing a complete vehicle finite element structure model and a cavity model of the target vehicle and is also used for processing and obtaining the noise transfer function of the shock absorber to be tested at the corresponding mounting point.
Specifically, the magnitude of the abnormal sound in the vehicle can be analyzed by using a calculation formula of the abnormal sound in the vehicle below:
S＝20lg((∫∫a(ω))Kd(ω))+NTF(ω)+K(ω)；
in the above formula, a (ω) is the vibration acceleration of the upper end of the piston rod of the shock absorber;
Kd(omega) is the upper support dynamic stiffness of the shock absorber;
NTF (omega) is a noise transfer function from a mounting point corresponding to the shock absorber to the interior of the vehicle;
k (omega) is a first correction coefficient, and data errors can be corrected through empirical data accumulation;
in each symbol, ω represents a frequency domain.
The beneficial effect that technical scheme that this application provided brought includes:
this application obtains piston rod upper end vibration acceleration, the last dynamic stiffness of supporting and noise transfer function of surveying the bumper shock absorber through the test to this is basis, through the abnormal sound noise volume that the prediction awaits measuring bumper shock absorber corresponds, thereby predicts bumper shock absorber noise level, provides the data basis for later stage design optimization.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a flow chart illustrating steps of a method for predicting vehicle shock absorber abnormal sound provided in an embodiment of the present application;
FIG. 2 is a schematic frequency domain diagram of vibration acceleration of a shock absorber in a method for predicting abnormal sound of a vehicle shock absorber provided in an embodiment of the present application;
FIG. 3 is a schematic frequency domain diagram of the vibration damper displacement in the method for predicting the abnormal sound of the vibration damper of the vehicle according to the embodiment of the present application;
FIG. 4 is a diagram illustrating a noise transfer function NTF in a method for predicting abnormal sound of a vehicle shock absorber provided in an embodiment of the present application;
FIG. 5 is a schematic diagram illustrating an in-vehicle noise in a method for predicting abnormal sound of a vehicle shock absorber provided in an embodiment of the present application;
fig. 6 is a block diagram showing a structure of a vehicle shock absorber abnormal sound prediction system provided in the embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
The embodiment of the application provides a method and a system for predicting abnormal sound of a vehicle shock absorber.
In order to achieve the technical effects, the general idea of the application is as follows:
a method for predicting vehicle shock absorber abnormal sound, the method comprising the steps of:
s1, testing to obtain the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested of the target vehicle;
s2, simulating to obtain the upper support dynamic stiffness of the shock absorber to be tested;
s3, simulating to obtain a noise transfer function of the shock absorber to be tested;
and S4, calculating and obtaining the abnormal noise volume corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the upper support dynamic stiffness, the noise transfer function and a preset first correction coefficient.
Embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
In a first aspect, referring to fig. 1 to 5, an embodiment of the present application provides a method for predicting abnormal sound of a vehicle shock absorber, including the following steps:
s1, testing to obtain the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested of the target vehicle;
s2, simulating to obtain the upper support dynamic stiffness of the shock absorber to be tested;
s3, simulating to obtain a noise transfer function of the shock absorber to be tested;
and S4, calculating and obtaining the abnormal noise volume corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the upper support dynamic stiffness, the noise transfer function and a preset first correction coefficient.
In this application embodiment, piston rod upper end vibration acceleration, the last support dynamic stiffness and the noise transfer function of survey bumper shock absorber are obtained through the test to this is the basis, and the abnormal sound noise volume that corresponds through the calculation prediction bumper shock absorber that awaits measuring to the prediction bumper shock absorber noise level provides the data basis for later stage design optimization.
Specifically, in the daily running process of the vehicle, when the shock absorber is excited by an uneven road surface, the shock absorber can continuously stretch and compress, and in the process, the upper end of the shock absorber vibrates through the upper support to impact the structure of the vehicle body to vibrate and send out abnormal sound;
the abnormal frequency of the damper generally varies by several hundred Hz, so that the upper limit frequency can be set to 1000Hz at the time of prediction.
The size of the abnormal sound in the vehicle can be analyzed by using a calculation formula of the abnormal sound in the vehicle below:
S＝20lg((∫∫a(ω))Kd(ω))+NTF(ω)+K(ω)；
in the above formula, a (ω) is the vibration acceleration of the upper end of the piston rod of the shock absorber;
Kd(omega) is the upper support dynamic stiffness of the shock absorber;
NTF (omega) is a noise transfer function from a mounting point corresponding to the shock absorber to the interior of the vehicle;
k (omega) is a first correction coefficient, and data errors can be corrected through empirical data accumulation;
in each symbol, ω represents a frequency domain.
Specifically, in the step S1, the step of obtaining the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested of the target vehicle includes the following steps:
mounting the shock absorber to be tested on a preset shock absorber abnormal sound rack;
the lower end of the to-be-tested shock absorber is connected with a vibration exciter, and the upper end of the to-be-tested shock absorber is provided with a vibration sensor;
testing a vibration response level of the shock absorber at different excitation inputs based on the vibration exciter and the vibration sensor;
and obtaining the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested based on the vibration response levels of the shock absorber under different excitation inputs.
Specifically, in the step S2, the step of obtaining the upper support dynamic stiffness of the shock absorber to be tested through simulation includes the following steps:
and simulating based on the vehicle body parameters of the target vehicle and the performance parameters of a piston rod connected with the shock absorber to obtain the upper support dynamic stiffness of the shock absorber to be tested.
Specifically, in step S3, the step of obtaining the noise transfer function of the shock absorber to be tested through simulation includes the following steps:
establishing a complete vehicle finite element structure model and a cavity model of the target vehicle;
and processing to obtain the noise transfer function of the shock absorber to be tested at the corresponding mounting point.
Specifically, the processing to obtain the noise transfer function of the shock absorber to be tested at the corresponding mounting point may be obtained through CAE (Computer Aided Engineering) calculation or experiment.
Specifically, in step S4, the method for calculating and obtaining the abnormal noise volume corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the upper support dynamic stiffness, the noise transfer function, and the preset first correction coefficient includes the following steps:
carrying out Fourier transform on the vibration acceleration of the upper end of the piston rod to obtain the vibration acceleration of the upper end of the piston rod in a frequency spectrum form;
carrying out high-pass filtering on the vibration acceleration of the upper end of the piston rod in the form of frequency spectrum, and carrying out secondary integration on the result after the high-pass filtering to obtain a corresponding displacement parameter under a frequency domain;
and calculating to obtain the volume of the abnormal noise corresponding to the shock absorber to be tested based on the displacement parameter under the frequency domain, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient.
Specifically, after step S4, that is, after the abnormal noise volume corresponding to the shock absorber to be tested is calculated and obtained based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function, and a preset first correction coefficient, the method further includes the following steps:
comparing the abnormal noise volume corresponding to the shock absorber to be tested with a preset abnormal noise volume threshold value;
and generating a structural optimization early warning when the volume of the abnormal noise is greater than the threshold of the volume of the abnormal noise.
In addition, according to the method, the level of the noise of the shock absorber is predicted on the basis of the displacement output of the shock absorber, the rubber dynamic stiffness of the shock absorber and the vehicle body noise transfer function, and the frequency exceeding the target value is optimized in a targeted mode.
Based on the technical scheme of the embodiment of the application, a specific implementation operation flow is provided, and the specific conditions are as follows:
firstly, testing the vibration acceleration a of the upper end of a piston rod of the vibration absorber;
the vibration absorber is arranged on a vibration absorber abnormal sound rack, the lower end of the vibration absorber is connected with a vibration exciter, and the upper end of a piston rod is provided with a vibration sensor;
testing and recording the vibration response level of the vibration absorber under different excitation inputs; wherein the content of the first and second substances,
when the bench test is carried out, the analysis frequency f is ensured to be above 1000Hz, and a long enough time is recorded for subsequent analysis;
the excitation of the bench test can collect vibration under the actual road and then load the vibration, and can also be artificially set to have excitation with different frequencies and amplitude characteristics;
by combining development requirements, bench tests at different temperatures can be carried out by adding an auxiliary device, and the working difference of the shock absorber at extreme temperatures can be verified.
Secondly, processing acceleration a data;
fourier transformation is carried out on the acceleration a in the first step to obtain a frequency spectrum form a (omega), and abnormal sound of the shock absorber mainly occurs in the stretching and reversing processes of the shock absorber, so that time domain data of the acceleration can be split into two sections, wherein one section is from stretching to compressing, and the other section is from compressing to stretching, so that the working state of the shock absorber when the abnormal sound occurs can be identified; wherein the content of the first and second substances,
windowing is needed during signal post-processing, leakage is reduced, a time period with a fixed length is selected for processing, and the analysis frequency is over 1000Hz, preferably 1024 Hz.
Thirdly, integrating the acceleration a (omega) to obtain displacement;
in the second step, after the frequency acceleration a (ω) is obtained, high-pass filtering is performed on the acceleration a (ω), and secondary integration is performed on the result to obtain the displacement ([ integral ] a (ω)) in the frequency domain; wherein the content of the first and second substances,
the purpose of the high-pass filtering is mainly to remove constant terms in the acceleration and reduce errors after integration.
Fourthly, calculating the upper support dynamic stiffness K of the shock absorberd(ω)；
The upper support of the shock absorber is mainly connected with a piston rod and a vehicle body and comprises an aluminum alloy frame and internal vulcanized rubber, and the rigidity value in the analysis frequency f can be obtained through experiments or simulation.
Fifthly, calculating a noise transfer function NTF of the shock absorber;
specifically, a finished automobile finite element structure model and a cavity model are established, the supporting mounting points on the vibration absorbers are used as excitation points, Noise Transfer Function (NTF) data from the excitation points to human ears in the automobile are calculated, and the frequency of the NTF data is consistent with the analysis frequency f.
Sixthly, predicting the noise in the vehicle;
based on the data in the first step to the fifth step and by combining the in-vehicle abnormal sound calculation formula, the in-vehicle noise data when the shock absorber passes through the impact road surface is calculated, and K is passedd(ω) the result is corrected.
It should be noted that the in-vehicle noise may be the result of a single damper or the sum of noises generated by a plurality of dampers.
Based on the technical scheme of the embodiment of the application, risk judgment and improvement can be performed;
and according to the noise at the ears of the back row of people obtained in the sixth step, comparing the noise with the abnormal sound noise volume threshold value, and judging the abnormal sound risk.
The noise at the ears of the back row of people obviously exceeds the volume threshold of the abnormal noise near 550Hz, and the main reason is that the vibration output of the piston rod of the shock absorber is obviously large, the vibration isolation rate of the upper support near the frequency is insufficient, and the NTF has an obvious peak value at the position, so that the problem is caused together;
therefore, the peak value component of 550Hz can be reduced by optimizing the structure of the valve system of the shock absorber body, and the noise in the vehicle can be reduced to be lower than the volume threshold of the abnormal noise by optimizing the vibration isolation rate of the upper support and the peak value of NTF.
In a second aspect, referring to fig. 6, an embodiment of the present application provides a vehicle shock absorber abnormal sound prediction system based on the vehicle shock absorber abnormal sound prediction method of the first aspect, the system including:
the first testing device is used for testing and obtaining the vibration acceleration of the upper end of the piston rod of the damper to be tested of the target vehicle;
the second testing device is used for simulating and obtaining the upper support dynamic stiffness of the shock absorber to be tested;
the third testing device is used for simulating and obtaining a noise transfer function of the shock absorber to be tested;
and the noise calculation device is used for calculating and obtaining the volume of the abnormal noise corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient.
In this application embodiment, piston rod upper end vibration acceleration, the last support dynamic stiffness and the noise transfer function of survey bumper shock absorber are obtained through the test to this is the basis, and the abnormal sound noise volume that corresponds through the calculation prediction bumper shock absorber that awaits measuring to the prediction bumper shock absorber noise level provides the data basis for later stage design optimization.
Specifically, in the daily running process of the vehicle, when the shock absorber is excited by an uneven road surface, the shock absorber can continuously stretch and compress, and in the process, the upper end of the shock absorber vibrates through the upper support to impact the structure of the vehicle body to vibrate and send out abnormal sound;
the abnormal frequency of the damper generally varies by several hundred Hz, so that the upper limit frequency can be set to 1000Hz at the time of prediction.
The size of the abnormal sound in the vehicle can be analyzed by using a calculation formula of the abnormal sound in the vehicle below:
S＝20lg((∫∫a(ω))Kd(ω))+NTF(ω)+K(ω)；
in the above formula, a (ω) is the vibration acceleration of the upper end of the piston rod of the shock absorber;
Kd(omega) is the upper support dynamic stiffness of the shock absorber;
NTF (omega) is a noise transfer function from a mounting point corresponding to the shock absorber to the interior of the vehicle;
k (omega) is a first correction coefficient, and data errors can be corrected through empirical data accumulation;
in each symbol, ω represents a frequency domain.
Specifically, the first test apparatus includes:
the shock absorber abnormal sound rack is used for mounting the shock absorber to be tested;
the vibration exciter is used for being connected with the lower end of the shock absorber to be tested;
and the vibration sensor is used for being connected with the upper end of the shock absorber to be tested.
Specifically, the second testing device is used for simulating based on the body parameters of the target vehicle and the performance parameters of a piston rod connected with the damper to obtain the upper support dynamic stiffness of the damper to be tested.
Specifically, the third testing device is used for establishing a complete vehicle finite element structure model and a cavity model of the target vehicle and is also used for processing and obtaining the noise transfer function of the shock absorber to be tested at the corresponding mounting point.
Specifically, the processing to obtain the noise transfer function of the shock absorber to be tested at the corresponding mounting point may be obtained through CAE (Computer Aided Engineering) calculation or experiment.
Specifically, the noise calculation device includes the following calculation procedures when calculating and obtaining the abnormal noise volume corresponding to the damper to be measured based on the vibration acceleration of the upper end of the piston rod, the upper support dynamic stiffness, the noise transfer function and a preset first correction coefficient:
carrying out Fourier transform on the vibration acceleration of the upper end of the piston rod to obtain the vibration acceleration of the upper end of the piston rod in a frequency spectrum form;
carrying out high-pass filtering on the vibration acceleration of the upper end of the piston rod in the form of frequency spectrum, and carrying out secondary integration on the result after the high-pass filtering to obtain a corresponding displacement parameter under a frequency domain;
and calculating to obtain the volume of the abnormal noise corresponding to the shock absorber to be tested based on the displacement parameter under the frequency domain, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient.
Specifically, the vehicle shock absorber abnormal sound prediction system further comprises a noise early warning device, which is used for:
comparing the abnormal noise volume corresponding to the shock absorber to be tested with a preset abnormal noise volume threshold value;
and generating a structural optimization early warning when the volume of the abnormal noise is greater than the threshold of the volume of the abnormal noise.
In addition, according to the vibration absorber noise level prediction system, the level of vibration absorber noise is predicted on the basis of testing the displacement output of the vibration absorber, the rubber dynamic stiffness of the vibration absorber and a vehicle body noise transfer function, the frequency exceeding a target value is subjected to targeted optimization, and by means of the vibration absorber noise level prediction system, the abnormal sound risk of the carrying working condition of the whole vehicle can be comprehensively considered in the vibration absorber development stage, development work is advanced, and the development period is shortened.
Based on the technical scheme of the embodiment of the application, a specific implementation operation flow is given by depending on the vehicle shock absorber abnormal sound prediction system, and the specific conditions are as follows:
firstly, testing the vibration acceleration a of the upper end of a piston rod of the vibration absorber;
the vibration absorber is arranged on a vibration absorber abnormal sound rack, the lower end of the vibration absorber is connected with a vibration exciter, and the upper end of a piston rod is provided with a vibration sensor;
testing and recording the vibration response level of the vibration absorber under different excitation inputs; wherein the content of the first and second substances,
when the bench test is carried out, the analysis frequency f is ensured to be above 1000Hz, and a long enough time is recorded for subsequent analysis;
the excitation of the bench test can collect vibration under the actual road and then load the vibration, and can also be artificially set to have excitation with different frequencies and amplitude characteristics;
by combining development requirements, bench tests at different temperatures can be carried out by adding an auxiliary device, and the working difference of the shock absorber at extreme temperatures can be verified.
Secondly, processing acceleration a data;
fourier transformation is carried out on the acceleration a in the first step to obtain a frequency spectrum form a (omega), and abnormal sound of the shock absorber mainly occurs in the stretching and reversing processes of the shock absorber, so that time domain data of the acceleration can be split into two sections, wherein one section is from stretching to compressing, and the other section is from compressing to stretching, so that the working state of the shock absorber when the abnormal sound occurs can be identified; wherein the content of the first and second substances,
windowing is needed during signal post-processing, leakage is reduced, a time period with a fixed length is selected for processing, and the analysis frequency is over 1000Hz, preferably 1024 Hz.
Thirdly, integrating the acceleration a (omega) to obtain displacement;
in the second step, after the frequency acceleration a (ω) is obtained, high-pass filtering is performed on the acceleration a (ω), and secondary integration is performed on the result to obtain the displacement ([ integral ] a (ω)) in the frequency domain; wherein the content of the first and second substances,
the purpose of the high-pass filtering is mainly to remove constant terms in the acceleration and reduce errors after integration.
Fourthly, calculating the upper support dynamic stiffness K of the shock absorberd(ω)；
The upper support of the shock absorber is mainly connected with a piston rod and a vehicle body and comprises an aluminum alloy frame and internal vulcanized rubber, and the rigidity value in the analysis frequency f can be obtained through experiments or simulation.
Fifthly, calculating a noise transfer function NTF of the shock absorber;
specifically, a finished automobile finite element structure model and a cavity model are established, the supporting mounting points on the vibration absorbers are used as excitation points, Noise Transfer Function (NTF) data from the excitation points to human ears in the automobile are calculated, and the frequency of the NTF data is consistent with the analysis frequency f.
Sixthly, predicting the noise in the vehicle;
based on the data in the first step to the fifth step and by combining the in-vehicle abnormal sound calculation formula, the in-vehicle noise data when the shock absorber passes through the impact road surface is calculated, and K is passedd(ω) the result is corrected.
It should be noted that the in-vehicle noise may be the result of a single damper or the sum of noises generated by a plurality of dampers.
Based on the technical scheme of the embodiment of the application, risk judgment and improvement can be performed;
and according to the noise at the ears of the back row of people obtained in the sixth step, comparing the noise with the abnormal sound noise volume threshold value, and judging the abnormal sound risk.
The noise at the ears of the back row of people obviously exceeds the volume threshold of the abnormal noise near 550Hz, and the main reason is that the vibration output of the piston rod of the shock absorber is obviously large, the vibration isolation rate of the upper support near the frequency is insufficient, and the NTF has an obvious peak value at the position, so that the problem is caused together;
therefore, the peak value component of 550Hz can be reduced by optimizing the structure of the valve system of the shock absorber body, and the noise in the vehicle can be reduced to be lower than the volume threshold of the abnormal noise by optimizing the vibration isolation rate of the upper support and the peak value of NTF.
It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus 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 apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The foregoing are merely exemplary embodiments of the present application and are presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A method for predicting vehicle shock absorber abnormal sound, said method comprising the steps of:
testing to obtain the vibration acceleration of the upper end of a piston rod of a damper to be tested of a target vehicle;
simulating to obtain the upper support dynamic stiffness of the shock absorber to be tested;
simulating to obtain a noise transfer function of the shock absorber to be tested;
and calculating to obtain the abnormal noise volume corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the upper support dynamic stiffness, the noise transfer function and a preset first correction coefficient.
2. The method for predicting abnormal sound of a shock absorber of a vehicle according to claim 1, wherein the test for obtaining the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested of the target vehicle comprises the steps of:
mounting the shock absorber to be tested on a preset shock absorber abnormal sound rack;
the lower end of the to-be-tested shock absorber is connected with a vibration exciter, and the upper end of the to-be-tested shock absorber is provided with a vibration sensor;
testing a vibration response level of the shock absorber at different excitation inputs based on the vibration exciter and the vibration sensor;
and obtaining the vibration acceleration of the upper end of the piston rod of the shock absorber to be tested based on the vibration response levels of the shock absorber under different excitation inputs.
3. The method for predicting the abnormal sound of the vehicle shock absorber according to claim 1, wherein the step of simulating the upper support dynamic stiffness of the shock absorber to be tested comprises the following steps:
and simulating based on the vehicle body parameters of the target vehicle and the performance parameters of a piston rod connected with the shock absorber to obtain the upper support dynamic stiffness of the shock absorber to be tested.
4. The method for predicting abnormal sound of a shock absorber of a vehicle according to claim 1, wherein the step of obtaining the noise transfer function of the shock absorber under test by simulation comprises the steps of:
establishing a complete vehicle finite element structure model and a cavity model of the target vehicle;
and processing to obtain the noise transfer function of the shock absorber to be tested at the corresponding mounting point.
5. The method for predicting the abnormal noise of the vehicle shock absorber according to claim 1, wherein the step of calculating and obtaining the abnormal noise volume corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient comprises the following steps:
carrying out Fourier transform on the vibration acceleration of the upper end of the piston rod to obtain the vibration acceleration of the upper end of the piston rod in a frequency spectrum form;
carrying out high-pass filtering on the vibration acceleration of the upper end of the piston rod in the form of frequency spectrum, and carrying out secondary integration on the result after the high-pass filtering to obtain a corresponding displacement parameter under a frequency domain;
and calculating to obtain the volume of the abnormal noise corresponding to the shock absorber to be tested based on the displacement parameter under the frequency domain, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient.
6. The method for predicting abnormal noise of a vehicle shock absorber according to claim 1, wherein after the abnormal noise volume corresponding to the shock absorber to be tested is calculated and obtained based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient, the method further comprises the following steps:
comparing the abnormal noise volume corresponding to the shock absorber to be tested with a preset abnormal noise volume threshold value;
and generating a structural optimization early warning when the volume of the abnormal noise is greater than the threshold of the volume of the abnormal noise.
7. A vehicle shock absorber abnormal sound prediction system, said system comprising:
the first testing device is used for testing and obtaining the vibration acceleration of the upper end of the piston rod of the damper to be tested of the target vehicle;
the second testing device is used for simulating and obtaining the upper support dynamic stiffness of the shock absorber to be tested;
the third testing device is used for simulating and obtaining a noise transfer function of the shock absorber to be tested;
and the noise calculation device is used for calculating and obtaining the volume of the abnormal noise corresponding to the shock absorber to be tested based on the vibration acceleration of the upper end of the piston rod, the dynamic stiffness of the upper support, the noise transfer function and a preset first correction coefficient.
8. The vehicle shock absorber abnormal sound prediction system according to claim 7, wherein said first test device includes:
the shock absorber abnormal sound rack is used for mounting the shock absorber to be tested;
the vibration exciter is used for being connected with the lower end of the shock absorber to be tested;
and the vibration sensor is used for being connected with the upper end of the shock absorber to be tested.
9. The vehicle shock absorber abnormal sound prediction system according to claim 7, wherein:
and the second testing device is used for simulating based on the body parameters of the target vehicle and the performance parameters of a piston rod connected with the damper to obtain the upper support dynamic stiffness of the damper to be tested.
10. The vehicle shock absorber abnormal sound prediction system according to claim 7, wherein:
the third testing device is used for establishing a complete vehicle finite element structure model and a cavity model of the target vehicle and is also used for processing and obtaining the noise transfer function of the shock absorber to be tested at the corresponding mounting point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111167867.2A CN113901580A (en) | 2021-09-28 | 2021-09-28 | Method and system for predicting abnormal sound of vehicle shock absorber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111167867.2A CN113901580A (en) | 2021-09-28 | 2021-09-28 | Method and system for predicting abnormal sound of vehicle shock absorber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113901580A true CN113901580A (en) | 2022-01-07 |
Family
ID=79190237
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111167867.2A Pending CN113901580A (en) | 2021-09-28 | 2021-09-28 | Method and system for predicting abnormal sound of vehicle shock absorber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113901580A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114462276A (en) * | 2022-01-25 | 2022-05-10 | 岚图汽车科技有限公司 | Performance conversion verification method and system for air inlet corrugated pipe |
| CN115659694A (en) * | 2022-11-10 | 2023-01-31 | 昆山适途模型科技有限公司 | Method and system for evaluating and optimizing damping effect of whole vehicle |
| CN117599942A (en) * | 2024-01-24 | 2024-02-27 | 山东山矿机械有限公司 | Method for monitoring running state of ore crusher equipment |
-
2021
- 2021-09-28 CN CN202111167867.2A patent/CN113901580A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114462276A (en) * | 2022-01-25 | 2022-05-10 | 岚图汽车科技有限公司 | Performance conversion verification method and system for air inlet corrugated pipe |
| CN115659694A (en) * | 2022-11-10 | 2023-01-31 | 昆山适途模型科技有限公司 | Method and system for evaluating and optimizing damping effect of whole vehicle |
| CN115659694B (en) * | 2022-11-10 | 2023-08-22 | 昆山适途模型科技有限公司 | Evaluation optimization method and system for damping effect of whole vehicle |
| CN117599942A (en) * | 2024-01-24 | 2024-02-27 | 山东山矿机械有限公司 | Method for monitoring running state of ore crusher equipment |
| CN117599942B (en) * | 2024-01-24 | 2024-04-09 | 山东山矿机械有限公司 | Method for monitoring running state of ore crusher equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113901580A (en) | Method and system for predicting abnormal sound of vehicle shock absorber | |
| Borowiec et al. | Vibrations of a vehicle excited by real road profiles | |
| Ye et al. | Transfer path analysis and its application in low-frequency vibration reduction of steering wheel of a passenger vehicle | |
| CN112597595A (en) | Method for diagnosing and optimizing structure noise in automobile | |
| Szymański et al. | Application of time–frequency analysis to the evaluation of the condition of car suspension | |
| CN111595590A (en) | Idle noise optimization method, device, equipment and storage medium | |
| Kim et al. | Optimization of the lower arm of a vehicle suspension system for road noise reduction by sensitivity analysis | |
| CN108801451B (en) | method for checking vibration of waist of vehicle seat | |
| CN107144435B (en) | A kind of dynamic vibration absorber frequency test method | |
| Park et al. | Operational spindle load estimation methodology for road NVH applications | |
| Lee | Identification of a vibration transmission path in a vehicle by measuring vibrational power flow | |
| Klapka et al. | Twilight of the EUSAMA diagnostic methodology | |
| Van der Linden et al. | Experimental determination of low frequency noise contributions of interior vehicle body panels in normal operation | |
| Ryu | A study on obtaining excitation load of virtual test lab using virtual iteration method | |
| Weisch et al. | The creation of a car interior noise quality index for the evaluation of rattle phenomena | |
| Deleener et al. | Extraction of static car body stiffness from dynamic measurements | |
| Fukazawa et al. | The method to predict the vibration transfer function of hydraulic engine mount on a vehicle | |
| Chanpong et al. | A study of tire cavity resonance and its mitigation using modal analysis method | |
| Gehringer | Application of experimental transfer path analysis and hybrid FRF-based substructuring model to SUV axle noise | |
| Kang et al. | Virtual road profile modeling using equivalent damage method for VPG simulation | |
| Lu et al. | Investigating structure-borne noise propagation through powertrain mounts using operational transfer path analysis | |
| CN113139270B (en) | Magneto-rheological vibration reduction system dynamics modeling device and method | |
| Mohamed et al. | Assessment of vibration and transmissibility behaviour of a rubber engine mount considering vibration tuned modification | |
| CN117760709A (en) | Method and device for acquiring loading spectrum of durability test of rubber shock absorber | |
| JPH11264784A (en) | Method and device for inspecting installed shock absorber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |