A method for compiling a multi-channel load spectrum

Abstract

The present application relates to a kind of multi-channel load spectrum's compilation method, compilation equipment and computer readable storage medium.The multi-channel load spectrum's compilation method includes S1, input multi-channel's load spectrum, set up pseudo-damage retention proportion target and time length screening threshold Tt, and set up the load spectrum of each channel Small load threshold Ta;S2, traverse load spectrum, according to time length screening threshold Tt and small load threshold Ta find all load time period, calculate the intersection of multi-channel's load time period;S3, judge whether it meets pseudo-damage retention proportion target, if there is a channel, turn into step S4;If all channels do not meet, modify small load threshold Ta, turn into step S2;S4, output multi-channel's acceleration spectrum.The present application proposes a kind of multi-channel load spectrum's compilation method, compilation equipment and computer readable storage medium, can realize the efficient compilation of load spectrum, analysis difficulty is less and easy for engineering application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle road simulation test, in particular to a multi-channel load spectrum compilation method. BACKGROUND

[0002] There are two mainstream technologies in the field of vehicle road simulation test, including the mature time-domain damage editing method and the new road simulation test random load spectrum editing method based on short-time Fourier transform and wavelet transform.

[0003] I. Time-domain damage editing method

[0004] By calculating the damage-time distribution characteristics of the local detail strain / force load spectrum of the structure, the time history information of the load spectrum with less damage is identified and obtained, and the time length of the load spectrum is shortened by deleting the time history of the load spectrum with less damage, thereby realizing the compilation of the test load spectrum.

[0005] When using the time-domain damage editing method to compile the test load spectrum, the researchers must have the strain / force load spectrum of the local details of the test structure. In many practical engineering applications, the test personnel only have the external excitation load spectrum (such as force, displacement, and acceleration, etc.) of the test structure, which leads to insufficient engineering applicability of this method. In addition, to obtain the strain / force load spectrum of the local details of the structure, it can be obtained by establishing a finite element model and virtually simulating, but this method is limited by the accuracy of the finite element model. Or by sticking strain gauges on the fatigue dangerous parts of the test structure to measure the actual road, this method is restricted by the number of sampling resources, manpower and material resources, and it is difficult to measure the strain / force spectrum of the most dangerous part of the structure.

[0006] II. Random load spectrum editing method

[0007] (1) Short-time Fourier transform analysis method, by analyzing the time-energy (cumulative power spectral density) distribution characteristics of the load spectrum, locating the time segments of the load spectrum with energy lower than the set threshold, and deleting them, thereby realizing the reduction of the time length of the load spectrum.

[0008] The short-time Fourier transform analysis method analyzes the time-frequency characteristics of the load spectrum, involving many parameters, such as the number of discrete Fourier transform points, the overlap ratio between time windows, and the window function type, etc. These parameters have a certain influence on the analysis and calculation results of the load spectrum, and the analysis is difficult.

[0009] (2) Wavelet transform analysis method, the load spectrum is decomposed into multiple wavelet coefficients, by studying the characteristics of the wavelet coefficients under multi-resolution (such as cumulative power spectral density and amplitude variation trend, etc.), identifying and deleting the time history corresponding to the low amplitude load, thereby realizing the reduction of the time length of the load spectrum.

[0010] The algorithm for preparing the test load spectrum based on the wavelet transform analysis method is relatively complex, and the wavelet function type, the wavelet decomposition layer number and the definition of the small load characteristics all have certain influences on the load spectrum preparation result, and the analysis difficulty is relatively large. SUMMARY

[0011] In view of the above problems of the prior art, the application provides a method for preparing a multi-channel load spectrum, which realizes efficient preparation of the load spectrum, has relatively small analysis difficulty and is convenient for engineering application.

[0012] Specifically, the application provides a method for preparing a multi-channel load spectrum, comprising the following steps:

[0013] S1, inputting the load spectrum of multiple channels, setting a pseudo-damage retention proportion target and a time length screening threshold Tt, and setting a small load threshold Ta of the load spectrum of each channel;

[0014] S2, traversing the load spectrum, finding all load time periods according to the time length screening threshold Tt and the small load threshold Ta, calculating the intersection of the load time periods of the multiple channels, deleting the time periods corresponding to the intersection on the load spectrum, connecting and reconstructing the remaining time periods of the load spectrum to generate an accelerated spectrum of the multiple channels;

[0015] S3, calculating and comparing the rain flow cycles of the load spectrum and the accelerated spectrum of each channel, judging whether the pseudo-damage retention proportion target is met, if one channel meets the target, turning to step S4; if all channels do not meet the target, modifying the small load threshold Ta, and turning to step S2;

[0016] S4, outputting the accelerated spectrum of the multiple channels.

[0017] According to an embodiment of the application, in step S2, finding all load time periods comprises:

[0018] S21, finding the load time periods meeting the small load threshold Ta on the load spectrum, and calculating the time length Δt of each load time period;

[0019] S22, if the time length Δt of the load time period is greater than the time length screening threshold Tt, the load time period is the finding target.

[0020] According to an embodiment of the application, in step S1, the threshold upper limit T of the small load threshold Ta of each channel is set as T = M + (M-A)·na, and the threshold lower limit T of the small load threshold Ta is set as T = M-(M-A)·na. a,up max th a,down min th ;​​​​​

[0021] wherein M is the mean value of the load channels of the load spectrum, A max is the maximum value of the load channels of the load spectrum, A min is the minimum value of the load channels of the load spectrum, parameter a th is a threshold growth coefficient, which is set as a constant, and parameter n is a natural number.

[0022] According to an embodiment of the present application, in step S1, parameter a th = 0.01, and the initial value of parameter n is 1.

[0023] According to an embodiment of the present application, in step S3, modifying the small load threshold Ta means modifying parameter a th and / or parameter n to recalculate the small load threshold Ta.

[0024] According to an embodiment of the present application, in step S2, the operation of connecting and reconstructing the time periods of the remaining multi-channel load spectrum to generate a multi-channel acceleration spectrum comprises connecting the time periods of the remaining load spectrum by using a signal smoothing technique.

[0025] According to an embodiment of the present application, in step S2, a transition signal of a suitable length is added to both ends of the reconstructed signal of the load spectrum.

[0026] The present application also provides a multi-channel load spectrum compiling device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the compiling method according to any one of the preceding embodiments when executing the computer program.

[0027] The present application also provides a computer readable storage medium, which stores a computer program, wherein the computer program is executable on a processor to implement the steps of the compiling method according to any one of the preceding embodiments.

[0028] The present application provides a multi-channel load spectrum compiling method, which can realize efficient compilation of a load spectrum, has less analysis difficulty, and is convenient for engineering application, in combination with a pseudo-damage retention criterion.

[0029] It should be understood that the above general description and the following detailed description of the present application are exemplary and illustrative, and are intended to provide further explanation of the present application as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings are included to provide further explanation of the present application, which are incorporated and constitute a part of the present application, and show embodiments of the present application, and together with the present specification, serve to explain the principles of the present application. In the drawings:

[0031] Figure 1 A flow chart showing the method of compiling a multi-channel load spectrum of an embodiment of the present application.

[0032] Figure 2 A load spectrum not processed by the compiling method of the present application.

[0033] Figure 3 Figure 2 An acceleration spectrum processed by the compiling method of the present application.

[0034] Figure 4A A load spectrum showing the vertical displacement of the left front wheel of a whole vehicle.

[0035] Figure 4B A load spectrum showing the vertical displacement of the right front wheel of a whole vehicle.

[0036] Figure 5 A graph showing the variation trend of the proportion of pseudo-damage retention of each channel with the parameter a of the small load threshold Ta th

[0037] Figure 6A Figure 4A A schematic diagram of the identification of the small load threshold Ta under the condition that the target proportion of pseudo-damage retention is 90%.

[0038] Figure 6B Figure 4B A schematic diagram of the identification of the small load threshold Ta under the condition that the target proportion of pseudo-damage retention is 90%.

[0039] Figure 7A Figure 4A A load spectrum with the intersection of load time periods corresponding to small loads marked.

[0040] Figure 7B Figure 4B A load spectrum with the intersection of load time periods corresponding to small loads marked.

[0041] Figure 8 Figure 4B An acceleration spectrum under the condition that the target proportion of pseudo-damage retention is 90%.

[0042] Figure 9A A comparison graph of the cumulative cycle count of the acceleration spectrum and the load spectrum of the left front wheel of a whole vehicle.

[0043] Figure 9B A comparison graph of the cumulative cycle count of the acceleration spectrum and the load spectrum of the right front wheel of a whole vehicle.

[0044] Figure 10A A PSD analysis comparison graph of the acceleration spectrum and the load spectrum of the left front wheel of a whole vehicle.

[0045] ​​​​​​​Figure 10B A PSD analysis comparison chart of the acceleration spectrum and load spectrum of the right front wheel of the whole vehicle is shown. DETAILED DESCRIPTION

[0046] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict if possible.

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0048] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0049] Unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in the various embodiments described herein are not limiting. It should be understood that the various parts shown in the drawings are not necessarily drawn to scale in proportion. The techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the specification when appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0050] In the description of the present application, it needs to be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship is generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element indicated must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0051] In addition, it needs to be pointed out that the use of "first", "second" and the like to limit the parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, therefore, it cannot be understood as a limitation on the scope of protection of the present application. In addition, although the terms used in the present application are selected from the commonly known and used terms, some terms mentioned in the specification of the present application may be selected by the applicant according to his or her judgment, and the detailed meaning of each term is explained in the relevant part of the description. In addition, the present application is required to be understood not only by the actual terms used, but also by the meaning implied by each term.

[0052] Figure 1 The flow chart of the method for compiling a multi-channel load spectrum is shown. As shown in the figure, the method for compiling a multi-channel load spectrum provided by the present application comprises the following steps:

[0053] S1, input the load spectrum of each channel in the multi-channel, set the pseudo-damage retention ratio target and the time length screening threshold Tt. Set the small load threshold Ta of the load spectrum of each channel.

[0054] S2, traverse the load spectrum, find all the load time periods meeting the conditions according to the time length screening threshold Tt and the small load threshold Ta. Calculate the intersection of the load time periods of the multi-channel, delete the time periods corresponding to the intersection on the load spectrum of each channel. Connect and reconstruct the remaining time periods of the load spectrum to generate the acceleration spectrum on each channel.

[0055] S3, calculate and compare the rain flow cycles of the load spectrum and the acceleration spectrum of each channel, and judge whether the pseudo-damage retention ratio target is met. If any channel meets the pseudo-damage retention ratio target, go to step S4; if none of the channels meets the pseudo-damage retention ratio target, modify the small load threshold Ta, and go to step S2;

[0056] S4, output the acceleration spectrum of the multi-channel, which is the result obtained by the compiling method.

[0057] Preferably, in step S2, finding all the load time periods comprises:

[0058] S21, finding a load time period meeting the small load threshold Ta on the load spectrum, calculating the time length At of each load time period;

[0059] S22, if the time length At of the load time period is greater than the time length screening threshold Tt, the load time period is the target to be found.

[0060] Preferably, in step S1, the threshold upper limit T a,up a of the small load threshold Ta of each channel is set as M+(A max -M)·na th , and the threshold lower limit T a,down a of the small load threshold Ta is set as M-(M-A min )·na th . Since the small load identification threshold Ta is related to the definition of invalid load, there is no uniform standard for small load deletion in the load spectrum at present, and it is difficult to accurately obtain the small load threshold Ta. Therefore, in the present application, the pseudo-damage retention ratio target is used to determine the small load identification threshold Ta. In other words, if the pseudo-damage retention ratio target is not met, the value of the small load identification threshold Ta needs to be adjusted repeatedly.

[0061] In the above threshold expression, M is the mean value of the load channels of the load spectrum, A max is the maximum value of the load channels of the load spectrum, A min is the minimum value of the load channels of the load spectrum, the parameter a th is a threshold growth coefficient, which is set as a constant, and the parameter n is a natural number. More preferably, the parameter a th is set as 0.01, and the initial value of the parameter n is 1, in the iteration process, n=n+1, and a th is increased by 0.01 each time. As an example but not limitation, the parameter a th may also be set as 0.001, 0.1 or other values that meet the setting requirements; and the initial value of the parameter n can also be other natural numbers.

[0062] Preferably, in step S3, modifying the small load threshold Ta means modifying the parameter a th and / or the parameter n to recalculate the threshold range of the small load threshold Ta. Conventionally, only the parameter n is adjusted, and the value of the parameter n is updated by multiple iterations with a step size of 1, the load time period is calculated in step S2, and the pseudo-damage retention ratio target is met in step S3.

[0063] Preferably, in step S2, the operation of connecting and reconstructing the time periods of the remaining multi-channel load spectrum to generate a multi-channel acceleration spectrum includes connecting the time periods of the remaining load spectrum by using a signal smoothing technique.

[0064] Preferably, in step S2, a transition signal of suitable length is added to both ends of the reconstructed load spectrum signal. In order to avoid the impact on the actuator of the device caused by the acceleration spectrum obtained by the compiling method of the present application in the subsequent bench test, a transition signal of suitable length is added to both ends of the reconstructed load spectrum signal to form the acceleration spectrum.

[0065] Figure 2 A load spectrum not processed by the compiling method of the present application is shown. Figure 3 Figure 2 An acceleration spectrum processed by the compiling method of the present application. Referring to Figure 2 , the figure shows a single-channel load spectrum, with the horizontal axis representing time and the vertical axis representing load. The sawtooth line 201 represents a random load history varying with time, and the two parallel dashed lines 202, 203 above and below represent the upper threshold of the small load identification threshold Ta and the lower threshold of the small load identification threshold Ta, respectively. The beginning and end data (time) points of the load spectrum are represented by capital letters A and N, and capital letters B, C, D, E, F, G, H, I, J, K, L, M represent the time points corresponding to the intersection of the sawtooth line and the two threshold dashed lines in the load spectrum. As can be easily understood, for example, from time point A to B, time point C to D, the load time periods AB, CD conforming to the small load identification threshold Ta are formed, i.e. the load time periods AB, CD fall between the upper threshold and the lower threshold of the small load identification threshold Ta. Similarly, the load time periods EF, GH, IJ, KL and MN are all load time periods conforming to the small load identification threshold Ta. According to the time length screening threshold Tt set in step S1, the time length Δt (the time length of each load time period from the beginning to the end) of each load time period AB, CD, EF, GH, IJ, KL and MN is calculated, and it is determined whether the time length Δt of the small load segment is greater than the time length screening threshold Tt. If the time length Δt of the found load time period is greater than the time length screening threshold Tt, then the load time period is the target to be found, marked as O; if the time length Δt of the found load time period is not greater than the time length screening threshold Tt, then the load time period is not the target to be found, i.e. it is determined to be a useful load segment to be retained, marked as R. Suppose that the time lengths Δt of the load time periods AB, CD, IJ and MN are greater than the time length screening threshold Tt, and are determined to be load time periods conforming to the target to be found. The time lengths of the load time periods EF, GH and KL are not greater than the time length screening threshold Tt, and are retained.

[0066] ​Then, the intersection of the load time periods of the multiple channels is calculated. For example, if there is another channel load spectrum processed by the above steps, and the time length of the load time periods C'D' and I'J' is greater than the time length screening threshold Tt, then the two load time periods are the target to be found. Assuming that the time span of the load time period CD is 15-18s, the time span of the load time period IJ is 24-26s, the time span of the load time period C'D' is 16-19s, and the time span of the load time period I'J' is 25-27s, then the intersection of the load time periods of the two channels is the load time period C'D and the load time period I'J, and the time span of the load time period C'D is 16-18s and the time span of the load time period I'J is 25-26s. In the subsequent steps, the time periods of the above intersection need to be deleted from the load spectrum of the two channels, that is, the load time period C'D and the load time period I'J are deleted.

[0067] For the convenience of understanding, still taking the load spectrum of a single channel in Figure 2 as an example, it is assumed that the load time periods AB, CD, IJ and MN are all intersections. As shown in Figure 3 , after the load time periods AB, CD, IJ and MN which are useless in Figure 2 are deleted, the remaining load signals are connected and reconstructed by using the signal smoothing connection technology, and appropriate length of transition signals 301 are added at both ends of the reconstructed signal, and finally the acceleration spectrum as shown in Figure 3 is obtained. The acceleration spectrum retains the amplitudes and orders of the large amplitude load signals 302, deletes part of the load time periods of small loads, and retains the time periods of small loads under high average.

[0068] The following describes a method for compiling a multi-channel load spectrum provided by the application in detail with reference to the front wheel and rear wheel pull rod displacement spectra collected by a certain automobile test field and representing the vertical jumping of the wheels, and in combination with the accompanying drawings.

[0069] Figure 4A Fig. 1 shows the load spectrum of the vertical displacement of the left front wheel of the whole vehicle. Figure 4B Fig. 2 shows the load spectrum of the vertical displacement of the right front wheel of the whole vehicle. Figure 4A Fig. 3 is the load spectrum of the vertical displacement of the left front wheel obtained by the displacement sensor arranged on the front wheel pull rod. Figure 4B Fig. 4 is the load spectrum of the vertical displacement of the right front wheel obtained by the displacement sensor arranged on the front wheel pull rod. The horizontal axis is time, and the vertical axis is displacement.

[0070] Figure 5 Fig. 6 shows the change trend graph of the proportion of the pseudo-damage reserved in each channel with the parameter a of the small load threshold Ta. th Fig. 7 shows the change trend graph of the proportion of the pseudo-damage reserved in each channel with the parameter a of the small load threshold Ta. th Fig. 8 shows the change trend graph of the proportion of the pseudo-damage reserved in each channel with the parameter a of the small load threshold Ta. The small load threshold Ta is set as a parameter a = 0.01, and the initial value of the parameter n is 1. As shown in the figure, the horizontal axis represents the parameter ath , the vertical axis represents the pseudo-damage retention ratio. As the threshold range of the small load threshold Ta expands, the pseudo-damage retention ratio of each load channel, including the left front wheel load spectrum 501 and the right front wheel load spectrum 502, gradually decreases. The right front wheel load spectrum 502 has a faster decrease rate than the left front wheel load spectrum 501. Therefore, the pseudo-damage retention ratio of the right front wheel load spectrum 502 will first meet the preset pseudo-damage retention ratio target.

[0071] Figure 6A is Figure 4A An identification diagram of the small load threshold Ta under the condition that the pseudo-damage retention ratio is 90%. Figure 6B is Figure 4B An identification diagram of the small load threshold Ta under the condition that the pseudo-damage retention ratio target is 90%. In Figure 6A and Figure 6B , the threshold range of the small load threshold Ta is marked.

[0072] Figure 7A is Figure 4A The load spectrum in which the intersection of the load time periods under the corresponding small load is marked. Figure 7B is Figure 4B The load spectrum in which the intersection of the load time periods under the corresponding small load is marked. In Figure 7A and Figure 7B , the intersection of all load time periods within the threshold range of the small load threshold Ta is marked.

[0073] Figure 8 is Figure 4B The acceleration spectrum under the condition that the pseudo-damage retention ratio is 90%. It is equivalent to Figure 7B , deleting all load time period intersections, using signal smoothing technology to connect the time periods of the load spectrum remaining after deletion, and adding appropriate length transition signals at both ends of the signal of the reconnected load spectrum.

[0074] In summary, using the multi-channel load spectrum compilation method of the present application, the load spectrum of Figure 4B is processed until the acceleration spectrum of Figure 8 is obtained. The acceleration spectrum time length is shortened to 26s, which is 45% of the corresponding load spectrum time length, and the acceleration spectrum perfectly retains the time fluctuation history of the damage dominant load.

[0075] Figure 9A shows the cumulative cycle count comparison diagram of the acceleration spectrum and the load spectrum of the left front wheel of the whole vehicle. Figure 9B shows the cumulative cycle count comparison diagram of the acceleration spectrum and the load spectrum of the right front wheel of the whole vehicle. As Figure 9A and 9BAs shown, the horizontal axis is the cumulative cycle count, the vertical axis is the load range, and the point line graphs 901 and 902 in each graph represent the original load spectrum and the accelerated spectrum, respectively. The rain flow cycles of the load spectrum and the accelerated spectrum of the two channels of the left front wheel and the right front wheel are calculated and compared. It can be seen that the cumulative cycle count distribution of the accelerated spectrum is basically consistent with that of the original load spectrum for large and medium load ranges, and the large and medium load ranges that play a leading role in damage are well preserved.

[0076] Figure 10A A PSD analysis comparison graph of the accelerated spectrum and the load spectrum of the left front wheel of the whole vehicle is shown. Figure 10B A PSD analysis comparison graph of the accelerated spectrum and the load spectrum of the right front wheel of the whole vehicle is shown. In the two graphs, the horizontal axis represents the frequency, and the vertical axis represents the power spectrum density. The point line graphs 1001 and 1002 in each graph represent the original load spectrum and the accelerated spectrum, respectively. As can be easily understood, the PSD analysis of the accelerated spectrum and the original load spectrum shows that the load frequency range is concentrated within 30 Hz. The PSD distribution trend of the accelerated spectrum is very consistent with that of the original load spectrum, and the PSD distribution curves have the same shape. In some frequency ranges, the energy of the accelerated spectrum is slightly higher than that of the original load spectrum, which is due to the deletion of a large number of small load time histories, which causes the average vibration energy of the load spectrum to increase. Overall, the accelerated spectrum well preserves the frequency domain characteristics of the original load spectrum.

[0077] The application further provides a multi-channel load spectrum compiling device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of any one of the above-mentioned compiling methods when executing the computer program.

[0078] The application further provides a computer readable storage medium, which stores a computer program, and the computer program implements the steps of any one of the above-mentioned compiling methods when executed by a processor.

[0079] The specific implementation modes and technical effects of the multi-channel load spectrum compiling device and the computer readable storage medium can be referred to the above-mentioned embodiments of the compiling method provided by the application, and will not be repeated here.

[0080] The application further provides a multi-channel load spectrum compiling method, a compiling device and a computer readable storage medium, and the compiling method combines the pseudo-damage reservation principle and the multi-channel load spectrum. The original load spectrum and the acceleration spectrum obtained by the compiling method are compared and analyzed from the amplitude domain and the frequency domain. The comparison result shows that the acceleration spectrum has consistency with the load distribution characteristics of the original load spectrum, and the large-range and medium-range loads which play a leading role in damage are well reserved. The obtained acceleration spectrum well reserves the frequency domain characteristics of the original load spectrum, and can replace the original load spectrum to perform the road simulation test. From the perspective of the four-column road simulation test of the whole vehicle, the acceleration spectrum well reproduces the time domain waveform and frequency vibration characteristics of the original load spectrum, and achieves a good multi-channel load spectrum simulation effect. From the perspective of the whole vehicle durability test on the test bench, the fatigue failure position exposed on the test bench is consistent with that of the whole vehicle durability test on the test field, and the effectiveness and feasibility of the multi-channel load spectrum compiling method are verified again.

[0081] Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

[0082] The various illustrative logical blocks, and circuits described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0083] The steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In the alternative, the processor and the storage medium can reside as discrete components in a user terminal.

[0084] In one or more exemplary embodiments, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0085] As will be apparent to those of ordinary skill in the art, various modifications and variations can be made to the above-described exemplary implementations of the present application without departing from the spirit or scope of the present application. Thus, it is intended that the present application cover the modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

Claims

1. A method for compiling a multi-channel load spectrum, comprising the following steps: S1, Input the load spectrum of the multi-channel array, set the target for the pseudo-damage retention ratio and the duration filtering threshold Tt, and set the upper limit T of the small load threshold Ta of the load spectrum of each channel. a,up =M+(A max -M)·n·a th Set the lower limit T of the small load threshold Ta. a,down =M-(MA) min )·n·a th ; in, M is the mean value of the load channels in the load spectrum, A max A is the maximum value of the load channel of the load spectrum. min The minimum value of the load channel of the load spectrum, parameter α th The threshold growth coefficient is set to a constant, and the parameter n is a natural number. S2, traverse the load spectrum, find all load time periods according to the duration filtering threshold Tt and the small load threshold Ta, calculate the intersection of the load time periods of the multi-channel, delete the time periods on the load spectrum corresponding to the intersection, connect and reconstruct the remaining time periods of the load spectrum to generate a multi-channel acceleration spectrum. S3, calculate and compare the rainflow cycle of the load spectrum and acceleration spectrum of each channel to determine whether it meets the pseudo-damage retention ratio target. If one channel meets the target, proceed to step S4; if none of the channels meet the target, modify the small load threshold Ta and proceed to step S2. S4, outputs the multi-channel acceleration spectrum; In step S2, finding all load time periods includes: S21, find the load time period that meets the small load threshold Ta on the load spectrum, and calculate the time length Δt of each load time period; S22, if the duration Δt of the load time period is greater than the duration filtering threshold Tt, then the load time period is the target to be searched.

2. The compilation method as described in claim 1, characterized in that, In step S1, parameter α is set. th =0.01, and the initial value of parameter n is 1.

3. The compilation method as described in claim 1, characterized in that, In step S3, modifying the small load threshold Ta refers to modifying the parameter α. th And / or parameter n to recalculate the small load threshold Ta.

4. The compilation method as described in claim 1, characterized in that, In step S2, the operation of connecting and reconstructing the remaining time periods of the load spectrum in the multi-channel to generate the multi-channel acceleration spectrum includes connecting the remaining time periods of the load spectrum using signal smoothing techniques.

5. The compilation method as described in claim 4, characterized in that, In step S2, a transition signal of a set length is added to both ends of the reconstructed load spectrum signal to make the two ends of the reconstructed signal transition smoothly.

6. A device for compiling multi-channel load spectra, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the compilation method as described in any one of claims 1-5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the compilation method as described in any one of claims 1-5.

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