Method and electronic device for testing gear strength of electric drive axle of vehicle

Abstract

The present disclosure relates to a method and an electronic device for testing gear strength of an electric drive axle of a vehicle. The method comprises: setting a plurality of target strengths based on a desired strength of the gear, the plurality of target strengths being arranged in ascending order of strength, the desired strength of the gear indicating a theoretical damage that a gear with the desired strength can resist under a desired torque for a desired number of cycles; constructing a corresponding plurality of load spectra for the plurality of target strengths in the arranged order, each load spectrum comprising at least one test condition; testing the gear based on the plurality of load spectra in the arranged order, wherein a sum of damages that the gear suffers under a currently tested load spectrum and a tested load spectrum is equal to a theoretical damage that a gear with a target strength corresponding to the currently tested load spectrum can resist; and in response to the gear failing under a target load spectrum among the plurality of load spectra, determining the strength of the gear based on the target load spectrum and a previous load spectrum of the target load spectrum.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle electric drive system technology, and more specifically, to a method for testing the strength of vehicle electric drive axle gears, electronic equipment, computer-readable storage medium, and computer program product. Background Technology

[0002] As a core component of the integrated electric drive system of a vehicle, the fatigue reliability of the gear transmission system of the electric drive axle directly affects the service life and safety of the entire vehicle. Gear fatigue bench testing is an important means of assessing the fatigue reliability of gear transmission systems. By simulating the fatigue damage process of gears under real vehicle operating conditions through reasonable load design, it can determine the fatigue life of the gears and verify the rationality of the gear design. Summary of the Invention

[0003] A brief overview of this disclosure is given below to provide a basic understanding of some aspects of it. However, it should be understood that this overview is not an exhaustive summary of this disclosure. It is not intended to identify key or essential parts of this disclosure, nor is it intended to limit the scope of this disclosure. Its purpose is merely to present certain concepts of this disclosure in a simplified form as a prelude to the more detailed description that follows.

[0004] According to a first aspect of this disclosure, a method for testing the strength of a vehicle electric drive axle gear is provided, comprising: setting multiple target strengths based on the desired strength of the gear, the multiple target strengths being arranged in ascending order of strength, the desired strength of the gear indicating that a gear with the desired strength can resist theoretical damage generated by cyclically performing a desired number of cycles under a desired torque; constructing multiple load spectra corresponding to the multiple target strengths in an ordered manner, each load spectrum including at least one test condition, each of the at least one test condition having a torque, a torque coefficient, and a number of cycles; testing the gear based on the multiple load spectra in an ordered manner, wherein the sum of the damage suffered by the gear under the currently tested load spectrum and the previously tested load spectra is equal to the theoretical damage that a gear with the target strength corresponding to the currently tested load spectrum can resist; and determining the strength of the gear based on the target load spectrum and the previous load spectrum of the target load spectrum in response to the gear failing under a target load spectrum among the multiple load spectra.

[0005] In some embodiments, the torque coefficient for each test condition is determined based on bench test standards for vehicle electric drive axles, and the torque for each test condition is determined based on a corresponding torque and the torque coefficient for that test condition, wherein the corresponding torque is the torque indicated by the target strength corresponding to the load spectrum to which the test condition belongs.

[0006] In some embodiments, constructing multiple load spectra corresponding to multiple target strengths in an ordered manner includes: constructing a first load spectrum for a first target strength among the multiple target strengths, wherein the number of cycles for each test condition in the first load spectrum is determined according to bench test standards for vehicle electric drive axles; and constructing at least one corresponding load spectrum for the second to the last target strength among the multiple target strengths in an ordered manner, wherein when constructing the current load spectrum for the current target strength, the number of cycles for each test condition in the current load spectrum is determined based on the cumulative damage suffered by the gear under load spectra prior to the current load spectrum and the theoretical damage that the gear with the current target strength can resist.

[0007] In some embodiments, each load spectrum in the corresponding at least one load spectrum includes a single test condition, the torque coefficient of the single test condition being 100%, and constructing the corresponding at least one load spectrum includes: taking each target strength from the second target strength to the last target strength as the current target strength in order of arrangement; performing a first operation for the current target strength to construct the current load spectrum, the first operation including: determining the number of cycles for the single test condition based on the difference between the cumulative damage suffered by the gear under load spectra prior to the current load spectrum and the theoretical damage that the gear with the current target strength can resist, the torque of the determined single test condition, the slope of the fatigue life curve of the gear, and the material constant of the gear, wherein the theoretical damage that the gear with the current target strength can resist is determined based on the torque indicated by the current target strength and the number of cycles, as well as the slope of the fatigue life curve of the gear and the material constant of the gear.

[0008] In some embodiments, each load spectrum in the corresponding at least one load spectrum includes multiple test conditions with different torque coefficients, and the method further includes: for each target strength from the second target strength to the last target strength, obtaining multiple theoretical test conditions for the target strength, wherein each theoretical test condition in the multiple theoretical test conditions has torque, torque coefficient, and number of cycles, the torque of each theoretical test condition in the multiple theoretical test conditions is determined based on the torque indicated by the target strength and the torque coefficient of the theoretical test condition, and the number of cycles and torque coefficient of each theoretical test condition in the multiple theoretical test conditions are determined based on bench test standards for vehicle electric drive axles, wherein constructing the corresponding at least one load spectrum includes: taking each target strength from the second target strength to the last target strength as the current target strength in an ordered manner; A second operation is performed to construct the current load spectrum for the current target strength. The second operation includes: for each test condition in the current load spectrum, determining the number of cycles for the test condition based on the difference between the cumulative damage borne by the gear under the corresponding test condition in the load spectrum prior to the current load spectrum and the theoretical damage that the gear with the current target strength can resist under the corresponding theoretical test condition for the current target strength, the determined torque of the test condition, the slope of the gear's fatigue life curve, and the material constant of the gear. The corresponding test condition and the corresponding theoretical test condition have the same torque coefficient as the test condition. The theoretical damage that the gear with the current target strength can resist under the corresponding theoretical test condition for the current target strength is determined based on the torque and number of cycles of the corresponding theoretical test condition, as well as the slope of the gear's fatigue life curve and the material constant of the gear.

[0009] In some embodiments, determining the gear strength based on the target load spectrum and the previous load spectrum of the target load spectrum includes: determining that the gear strength is greater than the second target strength and less than the first target strength based on the first target strength corresponding to the target load spectrum and the second target strength corresponding to the previous load spectrum of the target load spectrum.

[0010] In some embodiments, the plurality of target intensities includes a first target intensity that is lower than the desired intensity, a second target intensity that is equal to the desired intensity, and a third target intensity that is higher than the desired intensity.

[0011] In some embodiments, each load spectrum also includes the number of test conditions and the type of each test condition determined based on bench test standards for electric drive axles for vehicles, the types of test conditions including forward drive test conditions and reverse drive test conditions.

[0012] In some embodiments, the desired number of cycles is determined based on bench test standards for vehicle electric drive axles.

[0013] In some embodiments, the desired strength of the gear is determined based on the desired torque, the desired number of cycles, and the slope of the gear's fatigue life curve.

[0014] According to a second aspect of this disclosure, an electronic device is provided, comprising: a processor; and a memory storing computer-executable instructions, which, when executed by the processor, cause the processor to perform the method described in any embodiment of the first aspect of this disclosure.

[0015] According to a third aspect of this disclosure, a computer-readable storage medium is provided having computer-executable instructions stored thereon, which, when executed by a processor, cause the processor to perform the method described according to any embodiment of the first aspect of this disclosure.

[0016] According to a fourth aspect of this disclosure, a computer program product is provided, the computer program product including instructions that, when executed by a processor, implement the method described according to any embodiment of the first aspect of this disclosure. Attached Figure Description

[0017] The foregoing and other features and advantages of this disclosure will become clear from the following description of embodiments illustrated in conjunction with the accompanying drawings. The drawings, incorporated herein and forming a part of the specification, are further used to explain the principles of this disclosure and to enable those skilled in the art to make and use it. Wherein: Figure 1 This is a flowchart illustrating a method for testing the strength of electric drive axle gears in a vehicle according to some embodiments of the present disclosure; Figure 2 This is a schematic block diagram illustrating an electronic device according to some embodiments of the present disclosure; Figure 3 This is a schematic block diagram illustrating a computer system on which embodiments of the present disclosure may be implemented.

[0018] Note that in the embodiments described below, the same reference numerals are sometimes used across different figures to denote the same parts or parts with the same function, and repeated descriptions are omitted. In some cases, similar reference numerals and letters are used to denote similar items, so once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0019] For ease of understanding, the positions, dimensions, and extents of the structures shown in the accompanying drawings and other materials may not represent actual positions, dimensions, and extents. Therefore, this disclosure is not limited to the positions, dimensions, and extents disclosed in the accompanying drawings and other materials. Detailed Implementation

[0020] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0021] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this disclosure or its application or use. That is, the structures and methods herein are shown in an exemplary manner to illustrate different embodiments of the structures and methods in this disclosure. However, those skilled in the art will understand that they merely illustrate exemplary ways that can be used to implement this disclosure, and not exhaustive ways. Furthermore, the drawings are not necessarily drawn to scale, and some features may be enlarged to show details of specific components.

[0022] In addition, techniques, methods and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods and equipment should be considered part of the specification.

[0023] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0024] The load spectrum of a bench test is a statistical representation used in mechanical engineering to describe the changes in load experienced by a load-bearing structure during operation. The load spectrum reflects the law of load variation over time. Gear strength refers to the theoretical damage a gear of that strength can resist under a specific torque and a specific number of cycles, and can be used to evaluate the fatigue reliability of gears. In related technologies, gear fatigue bench testing methods typically use a single target strength to set the load spectrum. That is, gear fatigue bench testing methods in related technologies set a set of test conditions based on the target strength required by the vehicle design. These test conditions include a fixed torque and a fixed number of cycles, and the sample is then evaluated in one go based on the load spectrum including this set of test conditions.

[0025] If the gear test piece fails at the target strength, we can only conclude that the strength of the gear test piece is less than the target strength, without obtaining more detailed information about the strength itself. This results in the loss of initial investment in sample costs, test bench time, and manual debugging costs, and requires a new round of resource investment, further lengthening the testing cycle. Furthermore, tests targeting a single target strength can only obtain a binary result of "pass" or "failure," failing to systematically acquire information on the damage accumulation patterns and fatigue limits of gears under different load levels, thus limiting its guiding value for optimizing the design of vehicle gear transmission systems.

[0026] Therefore, this disclosure provides a method for testing the strength of electric drive axle gears in vehicles. This method sets multiple target strengths around the desired strength of the gear. Based on Miner's theory, the test to determine whether the gear can reach the desired strength is divided into multiple tests corresponding to the multiple target strengths. By progressively accumulating the damage to the gear through multiple tests, the damage pattern of the gear under different load levels can be obtained. Furthermore, the strength range and fatigue limit information of the gear can be obtained more accurately, which is beneficial for guiding the optimized design of the vehicle's gear transmission system. Miner's theory is a linear cumulative damage method used to predict the fatigue life of materials or structures under cyclic loading. Its core assumption is that damage under different stress levels can be linearly superimposed.

[0027] The method for testing the strength of electric drive axle gears of a vehicle according to the present disclosure will now be described in detail with reference to the accompanying drawings. It should be understood that the actual method for testing the strength of electric drive axle gears of a vehicle may include other steps, but in order to avoid obscuring the essential points of the present disclosure, these other steps will not be discussed herein and are not shown in the accompanying drawings.

[0028] Figure 1 This is a flowchart illustrating a method 100 (hereinafter referred to as "method 100") for testing the strength of electric drive axle gears of a vehicle according to some embodiments of the present disclosure. Figure 1 As shown, method 100 may include steps S102 to S108.

[0029] In step S102, multiple target strengths are set based on the desired strength of the gear, and the multiple target strengths are arranged in ascending order of strength. Here, the desired strength of the gear indicates that the gear with the desired strength can resist the theoretical damage generated by cyclically performing a desired number of cycles under the desired torque.

[0030] In this disclosure, for ease of description, "a gear with desired strength can resist theoretical damage generated by cycling a desired number of times under desired torque" can be simplified to "theoretical damage that a gear with desired strength can resist" or "theoretical damage indicated by desired strength".

[0031] In some embodiments, the desired strength of the gear is determined based on the desired torque, the desired number of cycles, and the slope of the gear's fatigue life curve.

[0032] In some examples, the expected intensity is assumed. The indicated desired torque is And the expected number of iterations is It can be determined The indicated theoretical damage D0 is Where p is the slope of the SN curve of the gear, and C is the material constant of the gear to indicate the fatigue capacity of the material. Reaching point C indicates that the material has reached its fatigue limit. Here, the SN curve is the fatigue life curve, used to describe the fatigue performance of a material under cyclic stress. The SN curve plots stress on the ordinate and the logarithm of fatigue life on the abscissa, reflecting the relationship between the stress level and the number of cycles leading to material fracture. Therefore, it can be determined that... .

[0033] In this disclosure, the same or similar characters may be used to represent the same or similar variables. Therefore, once a variable is defined in one embodiment, it does not need to be described again in subsequent embodiments.

[0034] In some embodiments, the desired number of cycles can be determined based on bench test standards for vehicle electric drive axles.

[0035] In some examples, designers can specify the desired torque of the vehicle's electric drive axle based on design requirements and determine the desired number of cycles by referring to the number of cycles required in the gear fatigue life test condition table recorded in the bench test standard for vehicle electric drive axles, thereby determining the corresponding desired strength.

[0036] As a non-limiting example, the bench test standard for electric drive axles in vehicles can be found in T / CAAMTB174-2023 "Technical Requirements and Bench Test Methods for Centrally Integrated Commercial Vehicle Electric Drive Axle Assemblies". Table 1 below shows the gear fatigue life test conditions described in the bench test standard for electric drive axles in vehicles.

[0037] Table 1

[0038] Expected strength Indicated desired torque The peak torque of the motor can be determined, therefore the input torque for stage 1 shown in Table 1 can be determined as follows: Meanwhile, the total number of loops at the output of stage 1 is 15. 10 4 It can be determined as the expected intensity The expected number of cycles indicated .

[0039] In some embodiments, the multiple target strengths may include a first target strength lower than the expected strength, a second target strength equal to the expected strength, and a third target strength higher than the expected strength. Thus, the first target strength lower than the expected strength ensures a high probability of the gear passing the test and verifies its reliability; the second target strength equal to the expected strength determines whether the gear meets design requirements and verifies its practicality; and the third target strength higher than the expected strength explores the gear's fatigue limit and determines its load-bearing limit.

[0040] In step S104, multiple load spectra are constructed for each of the multiple target intensities according to the arrangement order. Here, each load spectrum includes at least one test condition, and each test condition in the at least one test condition has torque, torque coefficient, and number of cycles.

[0041] In step S106, the gear is tested based on multiple load spectra in the order of arrangement.

[0042] As a non-limiting example, according to the first target strength Second target intensity Third target intensity The order can be used to target different aspects. Constructing the first load spectrum, targeting Constructing the second load spectrum, targeting Construct the third load spectrum.

[0043] By refining the desired strength into multiple target strengths in a stepped manner and constructing multiple load spectra for these target strengths, gears can be tested based on these constructed load spectra. Detailed fatigue information of the gears can be obtained through load spectra of different target strengths, which further facilitates the optimization of gear and vehicle electric drive axle design. Compared to a single target strength, gear problems can be detected earlier and more accurately, avoiding ineffective testing.

[0044] For example, if a gear fails under a low-intensity load spectrum, it indicates a fundamental flaw in the overall gear design, requiring a complete redesign and halting further testing. If the gear fails under a load spectrum approaching but not yet reaching the target strength, the overall design is feasible but requires localized optimization (such as material upgrades or improved heat treatment) to enhance its strength. If the gear fails under a load spectrum exceeding the target strength, it indicates excessive strength, allowing for further design optimization to reduce cost or expand application scenarios while maintaining the desired strength.

[0045] The sum of the damage a gear suffers under the current load spectrum and the load spectra already tested is equal to the theoretical damage that a gear with the target strength corresponding to the current load spectrum can resist.

[0046] Taking the first load spectrum and the second load spectrum as examples, since this disclosure uses the same gear to conduct tests continuously under multiple load spectra in an arranged order, after the gear is tested under the first load spectrum, the gear has already suffered first damage under the first load spectrum (for example, the gear may experience microcracks, residual stress redistribution, changes in the microstructure of the hardened layer on the tooth surface, etc.). Therefore, when the gear is tested under the second load spectrum, the gear is loaded from the first damage to the theoretical damage indicated by the second target strength, rather than starting from 0 and loading the second load spectrum to the theoretical damage indicated by the second target strength.

[0047] Therefore, when constructing subsequent load spectra of the first load spectrum, for the currently constructed load spectrum (i.e., the current load spectrum), it is necessary to take into account the cumulative damage caused to the gear by load spectra prior to the current load spectrum, so that the cumulative damage to the gear from the first load spectrum to the current load spectrum is equal to the theoretical damage indicated by the target intensity corresponding to the current load spectrum. The following will describe in detail how to construct multiple load spectra with specific embodiments.

[0048] In some embodiments, the torque coefficient for each test condition is determined based on bench test standards for vehicle electric drive axles, and the torque for each test condition is determined based on a corresponding torque and the torque coefficient for that test condition, wherein the corresponding torque is the torque indicated by the target strength corresponding to the load spectrum to which the test condition belongs.

[0049] For example, for each test condition in the first load spectrum, the torque of each test condition can be based on the product of the torque indicated by the first target strength corresponding to the first load spectrum and the torque coefficient of that test condition.

[0050] In some embodiments, each load spectrum may further include the number of test conditions and the type of each test condition, determined based on bench testing standards for vehicle electric drive axles. The types of test conditions may include forward drive test conditions and reverse drive test conditions. For example, each load spectrum may include two forward drive test conditions and one reverse drive test condition.

[0051] Continuing with the previous example of non-restrictive description, assume that... Indicated torque It is 300 Nm. Indicated torque It is 400 Nm. Indicated torque The torque is 500 Nm. Since Table 1 specifies the number and type of test conditions and the torque coefficient for each test condition, the first load spectrum, the second load spectrum, and the third load spectrum shown in Tables 2, 3, and 4 can be obtained by combining Table 1.

[0052] Table 2

[0053] As shown in Table 2, the first load spectrum includes two test conditions of type forward rotation and forward drive (i.e., the first test condition and the third test condition) and one test condition of type forward rotation and reverse drive. Specifically, the torque coefficient of the first test condition is 100% and has a torque of 300 Nm, the torque coefficient of the second test condition is 75% and has a torque of 225 Nm, and the torque coefficient of the third test condition is 60% and has a torque of 180 Nm.

[0054] Table 3

[0055] As shown in Table 3, the second load spectrum includes two test conditions of type forward rotation and forward drive (i.e., the first test condition and the third test condition) and one test condition of type forward rotation and reverse drive. Specifically, the torque coefficient of the first test condition is 100% and has a torque of 400 Nm, the torque coefficient of the second test condition is 75% and has a torque of 300 Nm, and the torque coefficient of the third test condition is 60% and has a torque of 240 Nm.

[0056] Table 4

[0057] As shown in Table 4, the third load spectrum includes two test conditions of type forward rotation and forward drive (i.e., the first test condition and the third test condition) and one test condition of type forward rotation and reverse drive. Specifically, the torque coefficient of the first test condition is 100% and has a torque of 500 Nm, the torque coefficient of the second test condition is 75% and has a torque of 375 Nm, and the torque coefficient of the third test condition is 60% and has a torque of 300 Nm.

[0058] In some embodiments, constructing multiple load spectra corresponding to multiple target intensities in an ordered manner may include: constructing a first load spectrum for the first target intensity among the multiple target intensities, wherein the number of cycles for each test condition in the first load spectrum is determined according to the bench test standard for vehicle electric drive axles.

[0059] Continuing with the aforementioned non-limiting example, since Table 1 also specifies the number of cycles for each test condition, combining Table 1 and Table 2 yields the first load spectrum as shown in the updated Table 2 below.

[0060] Updated Table 2

[0061] As shown in the updated Table 2, for the first load spectrum, the torque coefficient of the first test condition is 100% and has a torque of 300 Nm and 15 10 4 The number of cycles, the torque coefficient of the second test condition is 75% and has a torque of 225 Nm and 3 10 4 The number of cycles, the torque coefficient of the third test condition is 60% and has a torque of 180 Nm and 45 10 4 The number of loops.

[0062] In some embodiments, constructing multiple load spectra corresponding to multiple target intensities in an ordered manner may further include: constructing at least one corresponding load spectrum for the second to the last target intensities in an ordered manner, wherein when constructing the current load spectrum for the current target intensity, the number of cycles for each test condition in the current load spectrum is determined based on the cumulative damage borne by the gear under load spectra prior to the current load spectrum and the theoretical damage that the gear with the current target intensity can resist.

[0063] In some embodiments, each load spectrum in the corresponding at least one load spectrum includes a single test condition with a torque coefficient of 100%. That is, in this embodiment, the torque of the single test condition in each load spectrum is the torque indicated by the target strength corresponding to that load spectrum.

[0064] In this embodiment, constructing at least one corresponding load spectrum includes: taking each target intensity from the second target intensity to the last target intensity as the current target intensity in the order of arrangement; and performing a first operation on the current target intensity to construct the current load spectrum.

[0065] Here, the first operation includes: determining the first theoretical damage based on the difference between the cumulative damage the gear suffers under the load spectrum prior to the current load spectrum and the theoretical damage that the gear with the current target strength can resist (hereinafter referred to as "first theoretical damage" for ease of description and to distinguish it from the theoretical damage indicated by the desired strength), the torque of the determined single test condition, the slope of the gear's fatigue life curve, and the material constant of the gear, wherein the first theoretical damage is determined based on the torque and number of cycles indicated by the current target strength, the slope of the gear's fatigue life curve, and the material constant of the gear.

[0066] In some examples, it is assumed that the current target strength is... For the k-th target intensity (k is an integer greater than 1) among all target intensities, the corresponding current load spectrum is the k-th load spectrum. The indicated torque is and the number of cycles is It can be determined Indicated first theoretical damage .

[0067] In this example, the gear is The previous target strength is the target strength. to The corresponding load spectra are the first load spectra to the (k-1)th load spectra. The cumulative damage experienced by the gear under all load spectra prior to the kth load spectra. Where i represents the i-th load spectrum, j represents the j-th test condition, and m represents the number of test conditions for the i-th load spectrum. This represents the number of cycles for the j-th test condition in the i-th load spectrum. This represents the torque of the j-th test condition in the i-th load spectrum. This represents the sum of damage suffered by the gear under all test conditions in the i-th load spectrum, that is, the damage suffered by the gear under the i-th load spectrum.

[0068] Damage that the gear should withstand under the k-th load spectrum for and The difference, i.e. Thus, the number of cycles for a single test condition of the k-th load spectrum. .

[0069] Under the same target strength, when the gear passes through a high-torque test condition, it demonstrates that it can generally also pass test conditions with low torque (such as 75% or 60% of the motor's peak torque), even if the types of test conditions may differ. Therefore, by constructing subsequent load spectra of the first load spectrum to include only a single test condition with a torque of 100% of the motor's peak torque, the number of test conditions in subsequent load spectra of the first load spectrum can be reduced, thus lowering test costs and improving test efficiency.

[0070] In some embodiments, each load spectrum in the corresponding at least one load spectrum includes multiple test conditions with different torque coefficients, and method 100 may further include: for each target strength from a second target strength to a last target strength, obtaining multiple theoretical test conditions for the target strength, wherein each of the multiple theoretical test conditions has a torque, a torque coefficient, and a number of cycles, the torque of each of the multiple theoretical test conditions is determined based on the torque indicated by the target strength and the torque coefficient of the theoretical test condition, and the number of cycles and the torque coefficient of each of the multiple theoretical test conditions are determined based on bench test standards for vehicle electric drive axles.

[0071] For example, taking Table 3 above as an example, the second load spectrum shown in Table 3 includes three test conditions. The torque coefficient of the first test condition is 100%, the torque coefficient of the second test condition is 75%, and the torque coefficient of the third test condition is 60%.

[0072] For the second load spectrum (i.e., the intensity of the second target), assuming Indicated torque The torque is 400 Nm. Based on the bench test standards for vehicle electric drive axles shown in Table 1, the following table (Table 5) can be used to obtain the torque. Three theoretical test conditions.

[0073] Table 5

[0074] As shown in Table 5, for The first theoretical test condition included a torque coefficient of 100%, a torque of 400 Nm, and 15 cycles. 10 4 Since the torque coefficient of the first theoretical test condition is the same as that of the first test condition in the second load spectrum, it can be considered that the first theoretical test condition corresponds to the first test condition in the second load spectrum; the torque coefficient of the second theoretical test condition is 75%, the torque is 300 Nm, and the number of cycles is 3. 10 4 Since the torque coefficient of the second theoretical test condition is the same as that of the second test condition in the second load spectrum, it can be considered that the second theoretical test condition corresponds to the second test condition in the second load spectrum; corresponding to the third test condition in the second load spectrum, the torque coefficient of the third theoretical test condition is 60%, the torque is 240 Nm, and the number of cycles is 45. 10 4 Since the torque coefficient of the third theoretical test condition is the same as that of the third test condition of the second load spectrum, it can be considered that the third theoretical test condition corresponds to the third test condition of the second load spectrum.

[0075] Furthermore, by referring to Tables 2 (or the updated Table 2), 3, and 4, it can be understood that the first test condition of the first load spectrum, the first test condition of the second load spectrum, and the first test condition of the third load spectrum correspond to each other; the second test condition of the first load spectrum, the second test condition of the second load spectrum, and the second test condition of the third load spectrum correspond to each other; and the third test condition of the first load spectrum, the third test condition of the second load spectrum, and the third test condition of the third load spectrum correspond to each other.

[0076] Thus, by using the same torque coefficient, each test condition of the current load spectrum is correlated with the test conditions of the load spectrum preceding the current load spectrum, and each test condition of the current load spectrum is also associated with the theoretical test condition for the current target strength.

[0077] In this embodiment, constructing at least one corresponding load spectrum includes: taking each target strength from the second to the last target strength in order of arrangement as the current target strength; performing a second operation for the current target strength to construct the current load spectrum, the second operation including: for each test condition in the current load spectrum, determining the number of cycles for the test condition based on the difference between the cumulative damage borne by the gear under the corresponding test condition in the load spectrum prior to the current load spectrum and the theoretical damage that the gear with the current target strength can resist under the corresponding theoretical test condition for the current target strength (hereinafter, for ease of description and to distinguish it from the theoretical damage indicated by the desired strength and the first theoretical damage, it can be referred to as "second theoretical damage"), the determined torque of the test condition, the slope of the gear's fatigue life curve, and the material constant of the gear. Here, the corresponding test condition and the corresponding theoretical test condition have the same torque coefficient as the test condition, and the second theoretical damage is determined based on the torque and number of cycles of the corresponding theoretical test condition, as well as the slope of the gear's fatigue life curve and the material constant of the gear.

[0078] For example, suppose the current target strength is The current load spectrum is the third load spectrum. For the first test condition in the third load spectrum, the torque coefficient is 100%. Therefore, the cumulative damage suffered by the gear under the corresponding test conditions in the load spectra before the current load spectrum is the sum of the damage suffered by the gear under the first test condition in the first load spectrum and the damage suffered by the gear under the first test condition in the second load spectrum. The second theoretical damage is the damage suffered by the gear when used in... The theoretical damage that can be resisted under the first theoretical test condition.

[0079] In some examples, it is assumed that the current target strength is... For the k-th target intensity out of all target intensities, the corresponding current load spectrum is the k-th load spectrum. The indicated torque is , obtain for The q theoretical test conditions can determine the characteristics The second theoretical damage of the gear under the z-th theoretical test condition ,in, Indicates used for The number of cycles for the z-th theoretical test condition. Indicates used for The torque of the z-th theoretical test condition and ,in, Let z be the torque coefficient for the z-th theoretical test condition. Here, z is a given constant when determining the number of cycles for a test condition in the current load spectrum. For example, z is 1 when determining the number of cycles for the first test condition in the second load spectrum.

[0080] In this example, the gear is The previous target strength is the target strength. to The corresponding load spectra are the first load spectra to the (k-1)th load spectra. For the z-th test condition of the k-th load spectra, the cumulative damage experienced by the gear under the z-th test condition in all load spectra prior to the k-th load spectra is... ,in, This represents the number of cycles for the z-th test condition in the i-th load spectrum. This represents the torque of the z-th test condition in the i-th load spectrum. This represents the damage the gear experiences under the z-th test condition of the i-th load spectrum.

[0081] The damage that the gear should withstand under the z-th test condition of the k-th load spectrum. for and The difference, i.e. Therefore, the number of cycles for the z-th test condition of the k-th load spectrum is... This allows us to obtain the number of cycles for each test condition in each load spectrum, starting from the second load spectrum.

[0082] Therefore, by linking and classifying the number of undetermined cycles under different test conditions according to the torque coefficient, a more detailed load spectrum can be constructed, the process steps of gear bench testing can be refined, and more detailed damage evolution data of gears from the safe zone to the failure zone can be obtained.

[0083] At step S108, in response to the gear failing under the target load spectrum among multiple load spectra, the strength of the gear is determined based on the target load spectrum and the previous load spectrum of the target load spectrum.

[0084] In some embodiments, determining the gear strength based on the target load spectrum and the previous load spectrum of the target load spectrum includes: determining that the gear strength is greater than the second target strength and less than the first target strength based on the first target strength of the gear corresponding to the target load spectrum and the second target strength corresponding to the previous load spectrum of the target load spectrum.

[0085] Therefore, by setting multiple target intensities in a stepped manner, the intensity range of the gear can be determined. It can be understood that the more refined the target intensities are set (i.e., the smaller the difference between adjacent target intensities and the greater the number of target intensities), the more accurate the determined intensity range of the gear will be, and it can even approach a specific intensity value.

[0086] This disclosure also provides an electronic device. (See reference...) Figure 2 This is a schematic block diagram illustrating an electronic device 200 according to some embodiments of the present disclosure. Figure 2 As shown, electronic device 200 includes a processor 202 and a memory 204 storing computer-executable instructions that, when executed by processor 202, cause processor 202 to perform the method 100 according to any of the foregoing embodiments. Processor 202 may be, for example, a central processing unit (CPU) of electronic device 200. Processor 202 may be any type of general-purpose processor, or it may be a processor specifically designed for testing the strength of electric drive axle gears in a vehicle, such as an application-specific integrated circuit (“ASIC”). Memory 204 may be coupled to processor 202 and may include various computer-readable media accessible by processor 202. In various embodiments, memory 204 described herein may include volatile and non-volatile media, removable and non-removable media. For example, memory 204 may include any combination of: random access memory (“RAM”), dynamic RAM (“DRAM”), static RAM (“SRAM”), read-only memory (“ROM”), flash memory, cache memory, and / or any other type of non-transient computer-readable media. The memory 204 may store instructions that, when executed by the processor 202, cause the processor 202 to execute the method 100 according to any of the foregoing embodiments of the present disclosure.

[0087] The electronic device 200 is configured to perform the method 100 described in any of the foregoing embodiments, and therefore reference can be made to the description of the various embodiments of method 100 above, which will not be repeated here.

[0088] This disclosure also provides a computer-readable storage medium having computer-executable instructions stored thereon, which, when executed by a processor, cause the processor to perform the method 100 according to any of the foregoing embodiments of this disclosure.

[0089] This disclosure also provides a computer program product that may include instructions that, when executed by a processor, implement the method 100 according to any of the foregoing embodiments of this disclosure. The instructions may be any set of instructions that will be executed directly by one or more processors, such as machine code, or any set of instructions that will be executed indirectly, such as a script. The instructions may be stored in an object code format for direct processing by one or more processors, or stored in any other computer language, including scripts or sets of independent source code modules that are interpreted on demand or compiled in advance.

[0090] Figure 3This is a schematic block diagram illustrating a computer system 300 on which embodiments of the present disclosure may be implemented. The computer system 300 includes a bus 302 or other communication mechanism for transmitting information, and a processing device 304 coupled to the bus 302 for processing information. The computer system 300 also includes a memory coupled to the bus 302 for storing instructions to be executed by the processing device 304; the memory may be random access memory 306 or other dynamic storage device. The memory may also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processing device 304. The computer system 300 also includes a read-only memory 308 or other static storage device coupled to the bus 302 for storing static information and instructions for the processing device 304. A storage device 310, such as a magnetic disk or optical disk, is provided and coupled to the bus 302 for storing information and instructions. The computer system 300 may be coupled via the bus 302 to an output device 312 for providing output to a user, such as, but not limited to, a display (such as a cathode ray tube (CRT) or liquid crystal display (LCD)), a speaker, etc. Input devices 314, such as a keyboard, mouse, and microphone, are coupled to bus 302 for transmitting information and command selections to processing device 304. Computer system 300 can execute embodiments of this disclosure. Consistent with certain implementations of this disclosure, computer system 300 provides results in response to processing device 304 executing one or more sequences of one or more instructions contained in memory. Such instructions may be read into memory from another computer-readable medium, such as storage device 310. Execution of the sequence of instructions contained in memory causes processing device 304 to perform the methods described herein. Alternatively, hard-wired circuitry may be used in place of or in combination with software instructions to implement the teachings. Therefore, implementations of this disclosure are not limited to any particular combination of hardware circuitry and software. In various embodiments, computer system 300 may be connected across a network via network interface 316 to one or more other computer systems, such as computer system 300, to form a networked system. This network may include a private network or a public network such as the Internet. In a networked system, one or more computer systems may store data and supply data to other computer systems. As used herein, the term "computer-readable medium" refers to any medium that participates in providing instructions to the processing device 304 for execution. Such media can take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical discs or magnetic disks such as storage device 310. Volatile media include dynamic memory such as memory. Transmission media include coaxial cables, copper wires, and optical fibers, including wiring that includes bus 302.Common forms of computer-readable media or computer program products include, for example, floppy disks, flexible disks, hard disks, magnetic tapes, or any other magnetic media, CD-ROMs, digital video discs (DVDs), Blu-ray discs, any other optical media, thumb drives, memory cards, RAM, PROMs and EPROMs, fast EPROMs, any other memory chips or cartridges, or any other tangible media from which a computer can read. Various forms of computer-readable media may be involved when carrying one or more sequences of one or more instructions to processing device 304 for execution. For example, instructions may initially be carried on a disk of a remote computer. The remote computer may load the instructions into its dynamic memory and transmit the instructions over a telephone line using a modem. A modem local to computer system 300 may receive data over a telephone line and convert the data into an infrared signal using an infrared transmitter. An infrared detector coupled to bus 302 may receive the data carried in the infrared signal and place the data on bus 302. Bus 302 carries the data to memory, and processing device 304 retrieves the instructions from memory and executes the instructions. Optionally, instructions received from the memory may be stored on the storage device 310 before or after execution by the processing device 304.

[0091] According to various embodiments, instructions configured to be executed by a processing device to perform a method are stored on a computer-readable medium. The computer-readable medium may be a device for storing digital information. For example, a computer-readable medium includes a compact disc read-only memory (CD-ROM) as known in the art for storing software. The computer-readable medium is accessed by a processor adapted to execute the instructions configured to be executed.

[0092] The foregoing has described one or more exemplary embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0093] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. A typical implementation device is a server system. Of course, this disclosure does not exclude the possibility that, with the future development of computer technology, the computer implementing the functions of the above embodiments can be, for example, a personal computer, a laptop computer, an in-vehicle human-machine interaction device, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0094] While one or more embodiments of this disclosure provide the method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-inventive means. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only execution order. In actual device or terminal product execution, the methods shown in the embodiments or drawings can be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed data processing environment).

[0095] The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitation, the presence of other identical or equivalent elements in the process, method, product, or apparatus that includes said elements is not excluded. For example, the use of terms such as "first" or "second" to denote names does not indicate any particular order.

[0096] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, when implementing one or more embodiments of this disclosure, the functions of each module can be implemented in one or more software and / or hardware, or a module that performs the same function can be implemented by a combination of multiple sub-modules or sub-units. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0097] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0098] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more blocks of a block diagram.

[0099] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more blocks of a block diagram.

[0100] Those skilled in the art will understand that one or more embodiments of this disclosure may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, one or more embodiments of this disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0101] One or more embodiments of this disclosure can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a particular task or implement a particular abstract data type. One or more embodiments of this disclosure can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In a distributed computing environment, program modules can reside in local and remote computer storage media, including storage devices.

[0102] The same or similar parts between the various embodiments of this disclosure can be referred to mutually, and each embodiment focuses on describing the differences from other embodiments. In particular, for the apparatus embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and relevant parts can be referred to the description of the method embodiments. In the description of this disclosure, the descriptions of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., mean that the specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of this disclosure. In this disclosure, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this disclosure and the features of the different embodiments or examples.

[0103] Additionally, when used in this disclosure, the terms “here,” “above,” “below,” “below,” “in the following,” “overall,” and similar terms should refer to the entirety of this disclosure and not any particular part thereof. Furthermore, unless expressly stated otherwise or otherwise understood in the context in which they are used, conditional language used herein, such as “may,” “possibly,” “for example,” “like,” etc., is generally intended to express that certain embodiments include, while other embodiments do not, certain features, elements, and / or states. Therefore, such conditional language is not generally intended to imply that one or more embodiments require features, elements, and / or states in any way, or whether such features, elements, and / or states are included or performed in any particular embodiment.

[0104] The above description is merely an embodiment of one or more embodiments of this disclosure and is not intended to limit the scope of the one or more embodiments of this disclosure. Various modifications and variations can be made to the one or more embodiments of this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of the claims.

Claims

1. A method for testing the strength of electric drive axle gears in a vehicle, comprising: Multiple target strengths are set based on the expected strength of the gear, and the multiple target strengths are arranged in ascending order of strength. The expected strength of the gear indicates that the gear with the expected strength can resist the theoretical damage generated by cycling a expected number of times under the expected torque. Multiple load spectra are constructed for the multiple target intensities according to the arrangement order. Each load spectrum includes at least one test condition. Each test condition in the at least one test condition has torque, torque coefficient and number of cycles. According to the arrangement order, the gear is tested based on the multiple load spectra, wherein the sum of the damage suffered by the gear under the currently tested load spectrum and the previously tested load spectra is equal to the theoretical damage that the gear with the target strength corresponding to the currently tested load spectrum can resist. In response to the gear failing under a target load spectrum among the plurality of load spectra, the strength of the gear is determined based on the target load spectrum and a previous load spectrum of the target load spectrum.

2. The method according to claim 1, wherein, The torque coefficient for each test condition is determined based on bench test standards for vehicle electric drive axles. The torque for each test condition is determined based on the corresponding torque and the torque coefficient for that test condition, wherein the corresponding torque is the torque indicated by the target strength corresponding to the load spectrum to which the test condition belongs.

3. The method according to claim 1, wherein, Multiple load spectra are constructed for the multiple target intensities according to the arrangement order, including: A first load spectrum is constructed for the first target strength among the plurality of target strengths, wherein the number of cycles for each test condition in the first load spectrum is determined according to bench test standards for vehicle electric drive axles; and At least one load spectrum is constructed for each of the plurality of target intensities from the second to the last target intensity according to the arrangement order. When constructing the current load spectrum for the current target intensity, the number of cycles for each test condition in the current load spectrum is determined based on the cumulative damage suffered by the gear under load spectra prior to the current load spectrum and the theoretical damage that the gear with the current target intensity can resist.

4. The method according to claim 3, wherein, Each load spectrum in the at least one corresponding load spectrum includes a single test condition, wherein the torque coefficient of the single test condition is 100%, and constructing the at least one corresponding load spectrum includes: Each of the target intensities from the second target intensity to the last target intensity is taken as the current target intensity according to the stated arrangement order; Perform a first operation on the current target intensity to construct the current load spectrum, the first operation including: The number of cycles for a single test condition is determined based on the difference between the cumulative damage the gear experiences under load spectra prior to the current load spectrum and the theoretical damage the gear with the current target strength can resist, the torque of the determined single test condition, the slope of the gear's fatigue life curve, and the material constant of the gear. The theoretical damage that the gear with the current target strength can resist is determined based on the torque and number of cycles indicated by the current target strength, the slope of the fatigue life curve of the gear, and the material constant of the gear.

5. The method according to claim 3, wherein, Each load spectrum in the at least one corresponding load spectrum includes multiple test conditions with different torque coefficients, and the method further includes: For each target strength from the second to the last target strength, multiple theoretical test conditions are obtained for that target strength. Each of the multiple theoretical test conditions has torque, torque coefficient, and number of cycles. The torque of each of the multiple theoretical test conditions is determined based on the torque indicated by the target strength and the torque coefficient of the theoretical test condition. The number of cycles and the torque coefficient of each of the multiple theoretical test conditions are determined based on the bench test standard for the vehicle electric drive axle. Constructing at least one corresponding load spectrum includes: Each target intensity from the second target intensity to the last target intensity is taken as the current target intensity according to the stated arrangement order; Perform a second operation on the current target intensity to construct the current load spectrum, the second operation including: For each test condition in the current load spectrum, the number of cycles for that test condition is determined based on the difference between the cumulative damage borne by the gear under the corresponding test condition in the load spectrum prior to the current load spectrum and the theoretical damage that the gear with the current target strength can resist under the corresponding theoretical test condition for the current target strength, the determined torque of that test condition, the slope of the fatigue life curve of the gear, and the material constant of the gear. The corresponding test condition and the corresponding theoretical test condition have the same torque coefficient as the test condition. The theoretical damage that the gear with the current target strength can resist under the corresponding theoretical test conditions for the current target strength is determined based on the torque and number of cycles of the corresponding theoretical test conditions, the slope of the fatigue life curve of the gear, and the material constant of the gear.

6. The method according to claim 1, wherein, Determining the strength of the gear based on the target load spectrum and the previous load spectrum of the target load spectrum includes: Based on the first target strength corresponding to the target load spectrum and the second target strength corresponding to the previous load spectrum of the target load spectrum, it is determined that the strength of the gear is greater than the second target strength and less than the first target strength.

7. The method according to claim 1, wherein, The plurality of target intensities includes a first target intensity lower than the expected intensity, a second target intensity equal to the expected intensity, and a third target intensity higher than the expected intensity.

8. The method according to claim 1, wherein, Each load spectrum also includes the number of test conditions and the type of each test condition determined based on the bench test standard for electric drive axles for vehicles. The types of test conditions include forward drive test conditions and reverse drive test conditions.

9. The method according to claim 1, wherein, The desired number of cycles is determined based on the bench test standard for vehicle electric drive axles.

10. The method according to claim 1, wherein, The desired strength of the gear is determined based on the desired torque, the desired number of cycles, and the slope of the gear's fatigue life curve.

11. An electronic device, comprising: processor; as well as A memory storing computer-executable instructions, which, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 10.

12. A computer-readable storage medium having computer-executable instructions stored thereon, the computer-executable instructions causing a processor to perform the method according to any one of claims 1 to 10 when executed by a processor.

13. A computer program product comprising instructions that, when executed by a processor, implement the method according to any one of claims 1 to 10.

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