Vehicle frame vibration test method and system

Abstract

The invention relates to the technical field of electro-tricycle frame testing, and discloses a frame vibration testing method and system, and the method comprises the steps: collecting the dynamic displacement, strain, vibration force and other signals of two ends of a frame in real time; calculating dynamic stiffness and frequency response characteristics of the frame based on the collected data; and the resonant frequency range of the frame is determined through a method of combining a synchronous mode and an asynchronous mode. In the prior art, the regulation and control capability of a mechanism is limited in a vehicle frame vibration test process, and especially, synchronous vibration and asynchronous vibration cannot be combined to realize accurate identification of a vehicle frame resonance frequency range. Due to the combination of the synchronous mode and the asynchronous mode, the dynamic stiffness calculation and the self-adaptive dynamic regulation and control of the vibration input signal, the accurate recognition of the resonance frequency range of the frame vibration is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of electric tricycle frame testing, and in particular relates to a frame vibration testing method and system. Background Art

[0002] At present, in the field of frame vibration testing, there are still deficiencies in the accurate identification of the frame resonance frequency range. For example, the existing test system usually adopts a fixed vibration providing mechanism, lacks flexible control capabilities, and is difficult to support synchronous vibration testing and asynchronous vibration testing at the same time. In addition, during the test process, the existing technology has insufficient processing capabilities for dynamic data. For example, the calculation model of the frame dynamic stiffness, frequency response characteristics and dynamic frequency difference is not perfect, resulting in a large error in the identified resonance frequency range, which is difficult to meet the actual engineering needs. Especially when it is necessary to combine the synchronous vibration mode with the asynchronous vibration mode, the existing technology cannot effectively use the multi-mode test results to comprehensively confirm the resonance frequency point; at the same time, the existing test system is not flexible enough in input signal adjustment, and cannot adaptively control the vibration input signal according to the real-time dynamic response, thereby further reducing the accuracy and efficiency of the resonance frequency range identification. Therefore, there is an urgent need for a frame vibration test method and system that can complete the high-precision identification of the frame resonance frequency range through the coordinated testing of synchronous and asynchronous modes, combined with dynamic stiffness calculation and frequency response analysis, and by adaptively controlling the vibration input signal. Summary of the invention

[0003] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to propose a frame vibration testing method, aiming to solve the technical problem that the control ability of the mechanism provided in the frame vibration testing process in the prior art is limited, especially the inability to combine synchronous vibration and asynchronous vibration to achieve accurate identification of the frame resonance frequency range.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a frame vibration test method, The frame vibration test method comprises: Step S10: The displacement sensors, acceleration sensors and strain gauges provided on the first vibration providing mechanism and the second vibration providing mechanism at both ends of the frame are used to collect the frame vibration dynamic signal data at the time t at both ends of the frame, including: the first displacement data , the second displacement data , the first strain data , the second strain data , First vibration force data and the second vibration force data and time stamp the frame vibration dynamic signal by setting the synchronization time signal; Step S20: Calculate the fusion feature data at both ends based on the frame vibration dynamic signal data, including: dynamic displacement difference , dynamic strain difference at both ends and the average vibration force , calculate the dynamic stiffness of the frame based on the fusion feature data ; Among them, the dynamic stiffness of the frame The calculation formula is: ,in, is the time rate of change of strain, which is used to correct the contribution of local deformation to stiffness; is the dynamic correction coefficient; Step S30: First displacement data and the second displacement data Perform fast Fourier transform to extract the main vibration frequencies of the frame, including the first main vibration frequency and the second main vibration frequency , calculate the frame vibration dynamic frequency difference , ; Step S40: According to the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration Dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism, and perform synchronous mode test at both ends of the frame and asynchronous mode test at both ends of the frame to determine a set of resonance frequency points; Step S50: determining the resonance frequency range according to the resonance frequency point set and outputting the frame vibration test result.

[0005] Preferably, in step S30, , ,in, They are The frequency domain representation of is the function of the independent variable that takes the maximum value.

[0006] Preferably, in step S40, performing a synchronous mode test at both ends of the frame and an asynchronous mode test at both ends of the frame specifically includes: The first step is to conduct a synchronous mode test at both ends of the frame, dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism so that the first main vibration frequency and the second main vibration frequency Equal to , preset the first vibration frequency threshold and the second vibration frequency threshold , and gradually scan the frequency range , record the first average dynamic frequency response at both ends of the frame, set the peak point of the first average dynamic frequency response as the candidate resonance frequency point, and record the frequency value as ; The second step is to conduct asynchronous mode test at both ends of the frame, dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism to make the frame vibration dynamic frequency difference From equal Start to gradually adjust to zero and record the second average dynamic frequency response at both ends of the frame. , calculate the first derivative of the second average dynamic frequency response, and when the first derivative of the second average dynamic frequency response is greater than the preset first derivative threshold of the second average dynamic frequency response, confirm that the frequency value is recorded as The resonance frequency candidate points are the final resonance frequency points, thus forming a resonance frequency point set.

[0007] Preferably, in step S50, the frame vibration test result includes a second average dynamic frequency response , resonant frequency point set and resonant frequency range.

[0008] Preferably, in step S40, according to the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration The step of dynamically adjusting the input signals of the first vibration providing mechanism and the second vibration providing mechanism adopts a fuzzy adaptive PID control algorithm, and the formula is:

[0009] in, A unilateral input signal adjustment amount of the first vibration providing mechanism or the second vibration providing mechanism; are the proportional, integral and derivative control parameters.

[0010] Preferably, in step S20, the dynamic displacement difference = - , the dynamic strain difference at both ends = - , average vibration force = .

[0011] The present invention also provides a frame vibration testing system comprising: The dynamic data acquisition module is used to collect the frame vibration dynamic signal data at the two ends of the frame at time t through the displacement sensors, acceleration sensors and strain gauges arranged on the first vibration providing mechanism and the second vibration providing mechanism at the two ends of the frame, including: the first displacement data , the second displacement data , the first strain data , the second strain data , First vibration force data and the second vibration force data and time stamp the frame vibration dynamic signal by setting the synchronization time signal; The feature calculation module is used to calculate the fusion feature data at both ends based on the frame vibration dynamic signal data, including: dynamic displacement difference , dynamic strain difference at both ends and the average vibration force , calculate the dynamic stiffness of the frame based on the fusion feature data ; Among them, the dynamic stiffness of the frame The calculation formula is: ,in, is the time rate of change of strain, which is used to correct the contribution of local deformation to stiffness; is the dynamic correction coefficient; The resonance frequency point determination module is used to determine the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration Dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism, and perform synchronous mode test at both ends of the frame and asynchronous mode test at both ends of the frame to determine a set of resonance frequency points; Dynamic control test module, used to adjust the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration Dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism, and perform synchronous mode test at both ends of the frame and asynchronous mode test at both ends of the frame to determine a set of resonance frequency points; The test result output module is used to determine the resonance frequency range according to the resonance frequency point set and output the frame vibration test result.

[0012] The present invention also provides a computer program product, comprising a frame vibration test program, and the frame vibration test program implements the frame vibration test method when executed by a processor.

[0013] The beneficial effect of the present invention is that compared with the technical problem that the control ability of the mechanism provided during the frame vibration test in the prior art is limited, especially the inability to combine synchronous vibration and asynchronous vibration to achieve accurate identification of the frame resonance frequency range, the present application achieves accurate identification of the resonance frequency range of the frame vibration through the combination of synchronous and asynchronous modes, dynamic stiffness calculation and adaptive dynamic control of the vibration input signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 The figure is a flow chart of a first embodiment of a vehicle frame vibration testing method of the present invention.

[0016] Figure 2 The present invention is a schematic diagram of a vehicle frame vibration testing method. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1: Figure 1 FIG. 1 is a flow chart of a first embodiment of a vehicle frame vibration testing method according to the present invention, and provides a first embodiment of a vehicle frame vibration testing method according to the present invention.

[0019] In a first embodiment, the frame vibration test method includes: Step S10: The displacement sensors, acceleration sensors and strain gauges provided on the first vibration providing mechanism and the second vibration providing mechanism at both ends of the frame are used to collect the frame vibration dynamic signal data at the time t at both ends of the frame, including: the first displacement data , the second displacement data , the first strain data , the second strain data , First vibration force data and the second vibration force data and time stamp the frame vibration dynamic signal by setting the synchronization time signal; It should be understood that the purpose of collecting data is to record in real time the dynamic response of the frame during the vibration test, including its position changes, degree of deformation and stress conditions, to provide basic data for the subsequent calculation of dynamic stiffness and frequency response; the synchronous clock module is used to ensure the temporal consistency of data collected by different sensors to avoid inaccurate calculation results due to timing errors.

[0020] Step S20: Calculate the fusion feature data at both ends based on the frame vibration dynamic signal data, including: dynamic displacement difference , dynamic strain difference at both ends and the average vibration force , calculate the dynamic stiffness of the frame based on the fusion feature data ; Among them, the dynamic stiffness of the frame The calculation formula is: ,in, is the time rate of change of strain, which is used to correct the contribution of local deformation to stiffness; is the dynamic correction coefficient; It should be noted that the dynamic displacement difference = - , the dynamic strain difference at both ends = - , average vibration force = ; ,in, is the time rate of change of strain, which is used to correct the contribution of local deformation to stiffness; is the dynamic correction factor It should be understood that in order to better achieve accurate calculation of dynamic stiffness and describe the response characteristics of the frame during vibration, step S20 can fully reflect the overall dynamic characteristics of the frame and the influence of local strain correction by integrating the three parameters of dynamic displacement difference, dynamic strain difference and average vibration force.

[0021] Step S30: First displacement data and the second displacement data Perform fast Fourier transform to extract the main vibration frequencies of the frame, including the first main vibration frequency and the second main vibration frequency , calculate the frame vibration dynamic frequency difference , ; It should be understood that step S30 can realize rapid extraction of the main vibration frequencies at both ends of the frame; quantitative analysis of the distribution of the dynamic frequency difference of the frame provides important data support for subsequent identification of the resonance frequency range; Step S40: According to the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration Dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism, and perform synchronous mode test at both ends of the frame and asynchronous mode test at both ends of the frame to determine a set of resonance frequency points; It should be noted that the synchronous mode test at both ends of the frame and the asynchronous mode test at both ends of the frame specifically include: The first step is to conduct a synchronous mode test at both ends of the frame, dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism so that the first main vibration frequency and the second main vibration frequency Equal to , preset the first vibration frequency threshold and the second vibration frequency threshold , and gradually scan the frequency range , record the first average dynamic frequency response at both ends of the frame, set the peak point of the first average dynamic frequency response as the candidate resonance frequency point, and record the frequency value as ; The second step is to conduct asynchronous mode test at both ends of the frame, dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism to make the frame vibration dynamic frequency difference From equal Start to gradually adjust to zero and record the second average dynamic frequency response at both ends of the frame. , calculate the first derivative of the second average dynamic frequency response, and when the first derivative of the second average dynamic frequency response is greater than the preset first derivative threshold of the second average dynamic frequency response, confirm that the frequency value is recorded as The resonance frequency candidate points are the final resonance frequency points, thus forming a resonance frequency point set.

[0022] It should be understood that by combining the synchronous mode and the asynchronous mode, not only can the global resonant frequency be captured quickly, but the response characteristics of each frequency point can also be accurately verified through the asynchronous mode to avoid misjudgment; the dynamic stiffness fluctuation amplitude is used to adjust the input signal to ensure that the test coverage is wide enough; the regulation of the dynamic frequency difference enables the local resonance characteristics to be amplified, which helps to verify the authenticity of the candidate frequency points For example, the test parameters are as follows: Frequency range Hz, Hz; frequency sweep step Hz; initial dynamic frequency difference Hz; in synchronous mode test, the input signal frequency , gradually scan the frequency , record the dynamic frequency response , for example in and Department, A peak value appears and the candidate frequency point is recorded ; In asynchronous mode test, the input signal frequency Hz, , gradually reduce , , record the dynamic frequency response , for example when The dynamic response is significantly enhanced when is the final resonant frequency point. Finally, the resonant frequency point set is Hz, 15 Hz .

[0023] Step S50: determining the resonance frequency range according to the resonance frequency point set and outputting the frame vibration test result.

[0024] Through step S50, the resonance frequency range of the frame and related test results can be accurately output, and these data can provide a scientific basis for frame design optimization and dynamic performance analysis, while improving the practicality and test efficiency of the vibration test system.

[0025] In addition, a frame vibration test system provided by the present invention adopts a frame vibration test method in the above embodiment, which can solve a technical problem of frame vibration test. Compared with the prior art, the beneficial effects of the frame vibration test system provided by the present invention are the same as the beneficial effects of the frame vibration test method provided by the above embodiment, and other technical features of the frame vibration test system are the same as the features disclosed in the above embodiment method, which will not be described in detail here.

[0026] The present invention provides a frame vibration test device, please refer to Figure 2A frame vibration test device includes: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute a frame vibration test method in the above-mentioned embodiment 1. A frame vibration test device in the embodiment of the present invention may include but is not limited to mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. A frame vibration test device is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention. A frame vibration test device may include a processing device 1001 (such as a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM) 1004. In RAM 1004, various programs and data required for the operation of a frame vibration test device are also stored. The processing device 1001, ROM 1002, and RAM 1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow a frame vibration test device to communicate with other devices wirelessly or by wire to exchange data. Although a frame vibration test device with various systems is shown in the figure, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be implemented or have alternatively.

[0027] The present invention also provides a computer program product, including a computer program, wherein when the computer program is executed by a processor, the steps of the frame vibration test method described above are implemented. The computer program product provided by the present invention can solve the technical problem of a frame vibration test. Compared with the prior art, the beneficial effects of the computer program product provided by the present invention are the same as the beneficial effects of the frame vibration test method provided by the above embodiment, which will not be described in detail here.

[0028] In particular, according to the embodiments disclosed in the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present invention include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through a communication device, or installed from the storage device 1003, or installed from the ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present invention are executed.

[0029] It should be understood that the various parts disclosed in the present invention can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0030] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A frame vibration test method, characterized in that: Methods include: Step S10: The displacement sensors, acceleration sensors and strain gauges provided on the first vibration providing mechanism and the second vibration providing mechanism at both ends of the frame are used to collect the frame vibration dynamic signal data at the time t at both ends of the frame, including: the first displacement data , the second displacement data , the first strain data , the second strain data , First vibration force data and the second vibration force data and time stamp the frame vibration dynamic signal by setting the synchronization time signal; Step S20: Calculate the fusion feature data at both ends based on the frame vibration dynamic signal data, including: dynamic displacement difference , dynamic strain difference at both ends and the average vibration force , calculate the dynamic stiffness of the frame based on the fusion feature data ; Among them, the dynamic stiffness of the frame The calculation formula is: ,in, is the time rate of change of strain, which is used to correct the contribution of local deformation to stiffness; is the dynamic correction coefficient; Step S30: First displacement data and the second displacement data Perform fast Fourier transform to extract the main vibration frequencies of the frame, including the first main vibration frequency and the second main vibration frequency , calculate the frame vibration dynamic frequency difference , ; Step S40: According to the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration Dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism, and perform synchronous mode test at both ends of the frame and asynchronous mode test at both ends of the frame to determine a set of resonance frequency points; Step S50: determining the resonance frequency range according to the resonance frequency point set and outputting the frame vibration test result.

2. A frame vibration testing method as claimed in claim 1, characterized in that: In step S30, , ,in, They are The frequency domain representation of is the function of the independent variable that takes the maximum value.

3. A frame vibration testing method as claimed in claim 1, characterized in that: In step S40, a synchronous mode test at both ends of the frame and an asynchronous mode test at both ends of the frame are performed, specifically including: The first step is to conduct a synchronous mode test at both ends of the frame, dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism so that the first main vibration frequency and the second main vibration frequency Equal to , preset the first vibration frequency threshold and the second vibration frequency threshold , and gradually scan the frequency range , record the first average dynamic frequency response at both ends of the frame, set the peak point of the first average dynamic frequency response as the candidate resonance frequency point, and record the frequency value as ; The second step is to conduct asynchronous mode test at both ends of the frame, dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism to make the frame vibration dynamic frequency difference From equal Start to gradually adjust to zero and record the second average dynamic frequency response at both ends of the frame. , calculate the first derivative of the second average dynamic frequency response, and when the first derivative of the second average dynamic frequency response is greater than the preset first derivative threshold of the second average dynamic frequency response, confirm that the frequency value is recorded as The resonance frequency candidate points are the final resonance frequency points, thus forming a resonance frequency point set.

4. A frame vibration testing method as claimed in claim 3, characterized in that: In step S50, the frame vibration test results include a second average dynamic frequency response , resonant frequency point set and resonant frequency range.

5. A frame vibration testing method as claimed in claim 1, characterized in that: In step S40, according to the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration The step of dynamically adjusting the input signals of the first vibration providing mechanism and the second vibration providing mechanism adopts a fuzzy adaptive PID control algorithm, and the formula is: in, A unilateral input signal adjustment amount of the first vibration providing mechanism or the second vibration providing mechanism; are the proportional, integral and derivative control parameters.

6. A frame vibration testing method as claimed in claim 1, characterized in that: In step S20, the dynamic displacement difference = - , the dynamic strain difference at both ends = - , average vibration force = .

7. A frame vibration test system, characterized in that: The frame vibration test system comprises: The dynamic data acquisition module is used to collect the frame vibration dynamic signal data at the two ends of the frame at time t through the displacement sensors, acceleration sensors and strain gauges arranged on the first vibration providing mechanism and the second vibration providing mechanism at the two ends of the frame, including: the first displacement data , the second displacement data , the first strain data , the second strain data , First vibration force data and the second vibration force data and time stamp the frame vibration dynamic signal by setting the synchronization time signal; The feature calculation module is used to calculate the fusion feature data at both ends based on the frame vibration dynamic signal data, including: dynamic displacement difference , dynamic strain difference at both ends and the average vibration force , calculate the dynamic stiffness of the frame based on the fusion feature data ; Among them, the dynamic stiffness of the frame The calculation formula is: ,in, is the time rate of change of strain, which is used to correct the contribution of local deformation to stiffness; is the dynamic correction coefficient; The resonance frequency point determination module is used to determine the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration Dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism, and perform synchronous mode test at both ends of the frame and asynchronous mode test at both ends of the frame to determine a set of resonance frequency points; Dynamic control test module, used to adjust the dynamic stiffness of the frame The dynamic frequency difference between the frame vibration Dynamically adjust the input signals of the first vibration providing mechanism and the second vibration providing mechanism, and perform synchronous mode test at both ends of the frame and asynchronous mode test at both ends of the frame to determine a set of resonance frequency points; The test result output module is used to determine the resonance frequency range according to the resonance frequency point set and output the frame vibration test result.

8. A vehicle frame vibration testing device, characterized in that: The frame vibration test device comprises: a memory, a processor, and a frame vibration test program stored in the memory and executable on the processor. When the frame vibration test program is executed by the processor, the frame vibration test method according to any one of claims 1 to 6 is implemented.

9. A computer program product, characterized in that The computer program product comprises a frame vibration test program, and when the frame vibration test program is executed by a processor, the frame vibration test method according to any one of claims 1 to 6 is implemented.

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