Method, controller and program product for determining fatigue damage of electrically driven axle

Abstract

The invention relates to a method, a controller and a computer program product for determining fatigue damage of an electrically driven axle. The method includes acquiring a detection quantity at a detection position of the electrically driven bridge, and determining a target position of the electrically driven bridge. The method further includes determining a target stress at the target location based on the detected quantity and the target transitive relationship. The target transfer relationship indicates a transfer relationship between the detection amount at the detection position and the target stress at the target position. The method further includes determining a fatigue damage at the target location based on the target stress. In this way, under the condition that a small number of sensors are arranged, fatigue damage of all the positions prone to fatigue can be determined in time, so that the health state of the electric drive axle is provided for a user, and fatigue failure of the electric drive axle during driving is avoided.

Description

Technical Field

[0001] The present disclosure relates to the field of vehicle testing, and more particularly, to a method, controller, and computer program product for determining fatigue damage of an electric drive axle. Background Art

[0002] As a major load-bearing component in a vehicle, the drive axle has a direct impact on its handling and ride comfort. As electric vehicles become increasingly popular, the reliability requirements for electric drive axle assemblies used in pure electric and hybrid vehicles, which replace traditional engine-based powertrains, are becoming increasingly stringent.

[0003] Similar to non-electric powertrains, the electric drive axle assembly is the connecting bridge between the frame and the wheels. In addition to bearing the weight of the vehicle body, it also needs to bear the vertical load between the ground and the frame, braking force, lateral force, and the torque caused by the lateral force. Summary of the Invention

[0004] The embodiments of the present disclosure propose a solution for monitoring fatigue damage of a concerned position of an electric drive axle using a virtual sensor technology.

[0005] In a first aspect of the present disclosure, a method for determining fatigue damage of an electric drive axle is provided. The method further includes obtaining a detection quantity at a detection position of the electric drive axle. The method further includes determining a target position of the electric drive axle. The method further includes determining a target stress at the target position based on the detection quantity and a target transfer relationship. Here, the target transfer relationship indicates a transfer relationship between the detection quantity at the detection position and the target stress at the target position. The method further includes determining fatigue damage at the target position based on the target stress.

[0006] In a second aspect of the present disclosure, a device for determining fatigue damage of an electric drive bridge is provided. The device includes a detection quantity acquisition module, which is configured to acquire a detection quantity at a detection position of the electric drive bridge. The device also includes a target position determination module, which is configured to determine the target position of the electric drive bridge. The device also includes a stress determination module, which is configured to determine a target stress at the target position based on the detection quantity and a target transfer relationship. Here, the target transfer relationship indicates a transfer relationship between the detection quantity at the detection position and the stress at the target position. The device also includes a fatigue damage determination module, which is configured to determine the fatigue damage at the target position based on the target stress.

[0007] In a third aspect of the present disclosure, a controller is provided, comprising: at least one processor; and a memory coupled to the at least one processor and having instructions stored therein, which, when executed by the at least one processor, cause an electronic device to perform the method according to the first aspect of the present disclosure.

[0008] In a fourth aspect of the present disclosure, an electric drive axle system is provided. The electric drive axle system includes an electric drive axle body including an axle housing; an acceleration sensor disposed on the axle housing and configured to detect acceleration; and a controller according to the third aspect of the present disclosure, configured to receive acceleration as a detected quantity from the acceleration sensor.

[0009] In a fifth aspect of the present disclosure, a computer program product is provided, which includes computer-executable instructions, wherein the computer-executable instructions are executed by a processor to implement the method provided according to the first aspect of the present disclosure.

[0010] In a sixth aspect of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer-executable instructions, wherein the computer-executable instructions are executed by a processor to implement the method provided according to the first aspect of the present disclosure.

[0011] It should be understood that the contents described in the Summary of the Invention section are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0013] Figure 1A A schematic diagram illustrating an example electric drive axle system in which various embodiments of the present disclosure may be implemented is shown;

[0014] Figures 1B-1J A schematic diagram illustrating different components of an example electric drive axle according to some embodiments of the present disclosure;

[0015] Figure 2 A flowchart illustrating an example method for determining fatigue damage of an electric drive axle according to some embodiments of the present disclosure is shown;

[0016] Figure 3 A schematic diagram illustrating an example method for calculating fatigue damage of an electric drive axle according to some embodiments of the present disclosure is shown;

[0017] Figure 4 A schematic diagram illustrating an example process for calculating fatigue damage of an electric drive axle according to some embodiments of the present disclosure is shown;

[0018] Figure 5A block diagram illustrating an example apparatus for determining fatigue damage of an electric drive axle according to some embodiments of the present disclosure; and

[0019] Figure 6 A block diagram of a device in which various embodiments of the present disclosure may be implemented is shown. DETAILED DESCRIPTION

[0020] The following describes embodiments of the present disclosure in more detail with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure.

[0021] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to." The term "based on" should be understood as "based at least in part on." The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment." The terms "first," "second," etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0022] It should be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, no intervening elements may be present. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0023] An electric drive axle assembly typically includes components such as a drive motor, a speed reducer, a differential, axle housing, and axle shafts. These components constitute unsprung mass. Therefore, during vehicle operation, vibrations from these components cannot be mitigated by the vehicle's damping springs. In conventional electric drive axle structures, the motor is placed inside the axle via gears connected to both sides of the axle tube. Due to the unstable operation of the motor, vibrations generated by the motor are transmitted to the axle housing through the connection, causing damage to the axle housing. Furthermore, since the electric drive assembly is suspended on one side of the axle, its own weight can also damage the axle housing during unstable driving. Furthermore, due to lightweight design considerations, axle housings are being designed to be increasingly thin, increasing the risk of damage from motor vibration. Therefore, the operating status of the electric drive axle is extremely important to driving safety. If an electric drive axle malfunctions during operation, it can cause a serious accident. Therefore, it is necessary to monitor the operating status of the electric drive axle, especially the fatigue damage of its components.

[0024] In the related art, electric axle fatigue damage testing is typically performed only upon customer request. Since vehicles are typically not equipped with fatigue damage detection devices, testing typically requires the installation of new detection devices, such as strain gauges, at the locations to be tested. In the case of additional strain gauges, the surfaces at the test locations must be treated to suit the installation and testing requirements of the added strain gauges. Therefore, electric axle fatigue damage testing cannot be performed in real time and requires additional installation.

[0025] In light of this, embodiments of the present disclosure provide a solution for monitoring fatigue damage using virtual sensors. In this solution, sensing devices for detecting physical quantities are installed at appropriate locations on the electric drive axle. After acquiring a measured quantity, such as acceleration, the measured quantity is converted into a target stress at the target location of interest based on a transfer relationship. Finally, the resulting stress can be used to determine fatigue damage at the target location.

[0026] According to the embodiments of the present disclosure, through a specially installed fatigue detection device, the user can detect fatigue damage of the electric drive axle at a desired time point, so as to timely understand the usage status of the electric drive axle to avoid accidents caused by failure of the electric drive axle during driving.

[0027] The following will be combined Figures 1A to 6 The scheme and principle of the embodiments of the present disclosure are introduced in detail. Figure 1AA schematic diagram of an example electric drive axle system 100 in which various embodiments of the present disclosure may be implemented is shown. As shown in FIG1 , the electric drive axle system 100 includes an electric drive axle 102. The electric drive axle 102 includes an axle housing 104 for accommodating components such as half shafts, a motor housing 106 for accommodating an electric motor, and a gearbox housing 108 for accommodating a speed reducer or differential.

[0028] At a position of the electric drive bridge 102 suitable for setting a sensing device, a sensor for sensing the detection amount is provided. In some embodiments, the sensor for detecting the amount may be, for example, an acceleration sensor. The acceleration sensor can be used to measure the frequency and amplitude of vibration. In the embodiment shown in Figure 1, sensors 110-1, 110-2, and 110-3 (individually or collectively referred to as sensors 110) for detecting the amount are provided on the electric drive bridge 102. For example, sensor 110-1 is installed at the right wheel end of the electric drive bridge 102, that is, the position where the leaf spring of the right wheel of the vehicle is installed is connected to the electric drive bridge 102. Correspondingly, sensor 110-3 is installed at the left wheel end of the electric drive bridge 102, that is, the position where the leaf spring of the left wheel of the vehicle is installed is connected to the electric drive bridge 102. In addition, sensor 110-2 is installed at the middle part of the electric drive bridge 102, that is, the position where the thrust rod of the electric drive bridge 102 connected to the body of the vehicle is connected.

[0029] The location for installing the sensor shown in Figure 1 is the connection interface between the electric drive bridge 102 as a whole and other vehicle components. At such a connection interface, the vibration transmitted from other vehicle components has the greatest impact on the electric drive bridge. Therefore, the detection quantity detected at such a location (for example, the detected acceleration) contains less interference and is therefore more accurate. In some embodiments, the installation location of the sensor can be a location with a larger vibration amplitude obtained based on the stress simulation of the electric drive bridge. It should be understood that the listed installation locations of the sensor 110 are only exemplary, and in other electric drive bridge installation configurations, the sensor can also be set at other locations. In addition, the number of sensors 110 shown in Figure 1 is only exemplary. The electric drive bridge system 100 can also have only one sensor 110. In such an embodiment, only one sensor 110 can be set at any of the first contact position of the electric drive axle coupled to the first wheel (for example, the leaf spring connection position coupled to the left wheel), the second contact position of the electric drive axle coupled to the second wheel (for example, the leaf spring connection position coupled to the right wheel), or the third connection position of the electric drive axle coupled to the vehicle body (for example, the thrust rod connection position).

[0030] like Figure 1AAs shown, the electric drive axle system 100 also includes a controller 120. The controller 120 can be, for example, any computing device in the vehicle that communicates with the sensor 110 and has computing capabilities. In some embodiments, the controller 120 can be a microcontroller (MCU) of the vehicle. In the case where the sensor 110 is an acceleration sensor, after the sensor 110 collects the acceleration 112, the sensor 110 can send the collected acceleration 112 to the controller 120 via wired or wireless communication. The controller 120 can convert the received acceleration 112 into stress. The controller 120 includes a fatigue damage determination module 122. The fatigue damage determination module 122 can receive the calculated stress from the sensor 110 and determine the converted target stress at a target location of interest (the location most susceptible to fatigue) on the electric drive axle 102 based on the received stress. Finally, the fatigue damage determination module 122 can determine fatigue damage 114 at the target location based on the target stress.

[0031] Furthermore, in some embodiments, after the fatigue damage determination module 122 of the controller 120 calculates the current fatigue damage of the electric drive axle, the fatigue damage determination module 122 may provide driving advice based on whether the fatigue damage of the electric drive axle exceeds a predetermined fatigue damage threshold. For example, in some embodiments, if the fatigue damage estimated by the fatigue damage determination module 122 based on the current stress exceeds the predetermined fatigue damage threshold, the fatigue damage determination module 122 may generate a warning signal to prompt the driver to inspect the target position of the electric drive axle. Conversely, if the estimated fatigue damage does not exceed the predetermined fatigue damage threshold, the fatigue damage determination module 122 may store the current fatigue damage for subsequent reference.

[0032] like Figure 1A As shown, in some embodiments, the electric axle system 100 may further include a cloud-based server 130. After the fatigue damage determination module 122 estimates fatigue damage, it may report the fatigue damage to the server 130. Furthermore, the fatigue damage determination module 122 may also report any intermediate data to the server 130. Furthermore, the electric axle system 100 may further include a user terminal 140. The user terminal 140 may communicate with the server 130 and receive fatigue damage data from the server 130.

[0033] In some embodiments, the target location of interest may be one or more components of the electric drive axle that are mechanically susceptible to damage, or individual locations of these components. In such an embodiment, the target location may be determined based on a fatigue analysis of the electric drive axle as a whole. For example, the fatigue analysis may be performed during the design phase of the electric drive axle. Figures 1B-1J Let's introduce the target location.

[0034] Figure 1BFIG. 1 shows a schematic diagram of a first portion 108A of a gearbox housing 108 of an example electric drive axle 102 according to some embodiments of the present disclosure, viewed from one perspective. Figure 1B As shown, location 152 within first portion 108A is the connection point between two structures of different shapes. Furthermore, there is a bend at this location. Therefore, location 152 may be subject to stress in different directions, making it susceptible to fatigue. In other words, location 152 is a target location of interest.

[0035] Figure 1C A schematic diagram of the first portion 108A of the gearbox housing 108 of the example electric drive axle 102 according to some embodiments of the present disclosure is shown in another perspective. Figure 1B From another opposite perspective, Figure 1C Schematic diagram of the other side of the first portion 108A is shown. Figure 1C As shown, the interior of the first portion 108A has a long straight portion. However, the straight portion has a small thickness, so the position 154 located in the portion is easily fatigued and is a target position of concern.

[0036] Figure 1D FIG. 1 shows a schematic diagram of a second portion 108B of the gearbox housing 108 of an example electric drive axle 102 according to some embodiments of the present disclosure, viewed from one perspective. Figure 1D As shown, positions 156 and 158 in the interior of the second portion 108B are connecting walls of the protruding portion. The geometric transition between positions 156 and 158 is sharp and not smooth, so they are target positions that are prone to fatigue.

[0037] Figure 1E A schematic diagram of the second portion 108B of the gearbox housing 108 of the example electric drive axle 102 according to some embodiments of the present disclosure is shown in another perspective. Figure 1D From another opposite perspective, Figure 1E FIG. 1 shows a schematic diagram of the other side of the second portion 108B. Figure 1E As shown, the position 160 outside the second portion 108B is also a connecting wall of the protruding portion. The geometric transition of the position 160 is sharp and not smooth, so it is a target position that is easily fatigued.

[0038] Figure 1F FIG. 1 is a schematic diagram of a third portion 108C of the gearbox housing 108 of an example electric drive axle 102 according to some embodiments of the present disclosure, viewed from one perspective. Figure 1F As shown, the position 162 inside the third portion 108C is a reinforcing rib, which is subjected to greater stress and is therefore prone to fatigue and is a target location of concern. It should be understood that for the purpose of simplicity and without loss of generality, Figure 1FOnly the target position including two stiffeners is indicated. The target position 162 should include all stiffeners of the same configuration.

[0039] Figure 1G A schematic diagram of the third portion 108C of the gearbox housing 108 of the example electric drive axle 102 according to some embodiments of the present disclosure is shown in another perspective. Figure 1F From another opposite perspective, Figure 1E FIG. 1 shows a schematic diagram of the other side of the third portion 108C. Figure 1G As shown, the location 164 outside the third portion 108C is the connecting wall of the protruding portion. The geometric transition of location 164 is sharp and not smooth enough, so it is a target location that is easily fatigued.

[0040] Figure 1H FIG. 1 shows a schematic diagram of a motor housing 106 of an example electric drive bridge 102 according to some embodiments of the present disclosure from one perspective. Figure 1H As shown, location 166 inside the motor housing 106 is a reinforcing rib that is subject to greater stress and is therefore susceptible to fatigue and is a target location of concern. It should be understood that for the purpose of simplicity and without loss of generality, Figure 1H Only the target position including 5 ribs is indicated. The target position 166 should include all ribs of the same configuration.

[0041] Figure 1I A schematic diagram of the motor housing 106 of an example electric drive bridge 102 according to some embodiments of the present disclosure is shown in another perspective. Figure 1H From another opposite perspective, Figure 1I Schematic diagram of the other side of the motor housing 106 is shown. Figure 1I As shown, the position 168 outside the motor housing 106 is also a reinforcing rib, which is subjected to greater stress and is therefore prone to fatigue and is a target location of concern. It should be understood that for the purpose of simplicity and without loss of generality, Figure 1I Only the target position including 4 ribs is indicated. The target position 166 should include all ribs of the same configuration.

[0042] Figure 1J 1 shows a schematic diagram of the bridge tube 116 of an example electric drive bridge 102 according to some embodiments of the present disclosure. Figure 1J As shown, axle tube 116 includes a left half-shaft 118 for supporting the left wheel and a right half-shaft 117 for supporting the right wheel. Location 170 of right half-shaft 117, where the shaft connects to the flange, is subject to significant alternating strain and is therefore susceptible to fatigue, making it a target location of concern. Similarly, location 172 of left half-shaft 118, where the shaft connects to the flange, is also subject to significant alternating strain and is therefore susceptible to fatigue, making it a target location of concern.

[0043] As discussed above, the target locations of interest are mainly distributed in locations with complex structures that are subject to various stresses and locations with small thickness. Figures 1B to 1J As can be seen in the figure, most target locations are not suitable for sensor installation. Therefore, in related technologies, maintenance personnel need to install dedicated sensors and even establish a dedicated testing environment to collect sufficient usable data to estimate fatigue damage of the electric drive axle. In contrast, according to the solution of the embodiment of the present disclosure, only sensors need to be installed at the detection position of the electric drive axle to understand the fatigue status of the target location of interest.

[0044] The target positions are distributed at different locations of different components of the electric drive bridge, such as the inside and outside of the bridge tube, housing, gearbox and other components. In contrast, the detection position is relatively fixed. In addition, the detection quantity detected at one detection position can be used as input to match the transfer relationship of all target positions. When modeling or simulating the electric drive bridge system to study the transfer relationship of the detection position relative to each target position, the simulation model needs to be calibrated. Here, calibration can include modifying the parameters of the model, such as the stiffness value of the connection relationship, the connection method, the damping, etc.

[0045] Figure 2 FIG2 is a flow chart showing an example method 200 for determining fatigue damage of an electric drive axle according to some embodiments of the present disclosure. Figures 1A to 1J The method 200 can be described as follows. Figure 1A The controller 120 is shown executing.

[0046] like Figure 2 As shown, at 202, method 200 includes obtaining a detection quantity at a detection position of the electric drive bridge. Figures 1A to 1J In the illustrated embodiment, the controller 120 may obtain a detection quantity 112 detected at a detection position of the electric drive axle from a sensor 110 disposed at the detection position.

[0047] In some embodiments, the detection amount may be detected in real time using an acceleration sensor disposed at the detection position. In some embodiments, the controller 120 may receive detection amounts for different detection positions from a plurality of different sensors.

[0048] At 204, method 200 includes determining a target position of the electric drive axle. Figures 1A to 1JIn the illustrated embodiment, the controller 120 may determine one or more target positions of the electric drive axle 102. In some embodiments, the target position may include a local position on the outside of the gearbox housing of the electric drive axle. The target position may include a local position on the inside of the gearbox housing of the electric drive axle. The target position may include a reinforcing rib within the gearbox housing of the electric drive axle. The target position may include a reinforcing rib within the motor housing of the electric drive axle. The target position may include a reinforcing rib within the motor end cover of the electric drive axle. The target position may include a bridge tube of the electric drive axle. It should be understood that the target positions listed here are merely exemplary. The target positions may also include other fatigue-critical positions specific to different electric drive axles. The present disclosure is not intended to be limiting in this regard.

[0049] like Figures 1B to 1J As discussed in [ ], the electric drive axle 102 can include target locations located internally or externally that are susceptible to stress fatigue. The controller 120 can select the target locations. In some embodiments, the user can select the target locations for fatigue damage they wish to inspect based on their driving experience. The controller 120 can then determine the target locations based on the user's selection. This improves the targeted nature of the inspection and reduces unnecessary computational overhead.

[0050] At 206, method 200 includes determining a target stress at a target location based on the detected quantity and the target transfer relationship. The target transfer relationship indicates a transfer relationship of stress between the detected location and the corresponding target location. Figures 1A to 1J In the illustrated embodiment, the controller 120 may determine a target stress at a target location based on the detected quantity and the target transfer relationship.

[0051] In an embodiment where multiple sensors are arranged at different locations, the controller 120 can determine a target stress for each pair of a detection position and a target position based on the transfer relationship between each of the multiple detection positions and each of the multiple target positions. In such an embodiment, for a single target position, the controller 120 can calculate multiple target stresses based on the different detection positions and their corresponding transfer relationships. To this end, the controller 120 can calculate a weighted sum of the multiple target stresses based on the degree of influence of each detection position on the target position as the final target stress.

[0052] In some embodiments, the target stress may include an equivalent stress power spectrum density at the target location associated with fatigue damage. The controller 120 may convert the time-domain detection quantity into a power spectrum density (PSD) in the frequency domain. The controller 120 then determines a target stress response PSD at the target location based on the detection quantity response PSD and the target transfer relationship.

[0053] In some embodiments, after controller 120 obtains multiple target stresses, it can verify whether each of the multiple target stresses is credible. For example, controller 120 can determine whether the obtained multiple target stresses are within a predetermined range, or whether the difference between the multiple target stresses is less than a predetermined tolerance threshold. In this way, the accuracy of the target stresses can be improved.

[0054] In some embodiments, the transfer relationship can be a transfer function obtained through experiments and simulations during the design phase of the electric drive bridge. In such embodiments, the electric drive bridge can be modeled as a linear, time-invariant model. In some alternative embodiments, the transfer relationship can be a mapping table, a frequency-domain curve function, etc.

[0055] At 208, method 200 includes determining fatigue damage at a target location based on the target stress. Figures 1A to 1J In the illustrated embodiment, the controller 120 may determine fatigue damage at a target location based on the target stress and estimate fatigue damage corresponding to the detected detection variable based on the correlation between stress and fatigue damage.

[0056] exist Figure 2 In the illustrated embodiment, the controller 120 can determine fatigue damage to the electric axle based on the detected quantity detected at the detection position and the transmission relationship between the detection position and the target position. In this way, fatigue damage, particularly at multiple fatigue-prone locations, can be promptly determined with only a small number of sensors, thereby providing the user with timely information on the health status of the electric axle and preventing stress failure of the electric axle during driving.

[0057] Figure 3 A schematic diagram of an example method 300 for determining fatigue damage of an electric drive axle according to other embodiments of the present disclosure is shown. Figures 1A to 1J The method 200 can be described as follows. Figures 1A to 1J The controller 120 shown is executed. The vehicle is always in a vibration environment during driving, and structural fatigue damage caused by long-term vibration is the main form of vehicle structural failure and damage. Fatigue damage calculation methods can be divided into two methods: time domain and frequency domain. The time domain method can, for example, use the rain flow cycle counting method to obtain the stress response information of the dangerous parts of the structure under the vibration environment. The frequency of stress at various amplitude and mean levels of the structure. However, the time domain method requires vibration stress in a longer time domain. In view of this, some embodiments of the present disclosure use a frequency calculation method.

[0058] like Figure 3As shown, at 302, the controller 120 estimates the number of stress cycles at the target location based on the target stress response PSD and the stress cycle probability model. After obtaining the target stress response PSD, the controller 120 can determine spectral parameters corresponding to the stress cycle probability model that can well represent the statistical information of the random process. The spectral parameters may include, for example, a spectral width coefficient and a spectral irregularity factor.

[0059] At 304, controller 120 obtains a stress-life curve associated with the material at the target location. After estimating the current number of cycles based on the selected stress cycle probability model, controller 120 selects a stress-life curve (SN curve) corresponding to the material at the target location. The stress-life curve represents the relationship between fatigue strength and fatigue life of a standard specimen under certain cycling characteristics.

[0060] At 306, controller 120 determines fatigue damage based on the number of stress cycles and the stress-life curve. Fatigue damage indicates the ratio of incurred fatigue damage to the total lifespan. For example, controller 120 may find a fatigue damage representation corresponding to the number of stress cycles in the stress-life curve. In this way, by utilizing a frequency calculation method, the amount of data processing can be reduced, and corresponding fatigue damage can be determined using the stress of the vehicle when traveling under any desired road conditions.

[0061] Figure 4 FIG. 4 is a schematic diagram illustrating an example process 400 for determining fatigue damage of an electric drive axle according to other embodiments of the present disclosure. Figure 4 As shown, in process 400, a vehicle 401 is traveling on a road 402 with specific operating conditions. At this point, the driver, for example, issues a test command to initiate a fatigue damage test for the electric drive axle. After the test mechanism is activated, the accelerometers mounted on the electric drive axle begin collecting vibration data at their locations. After vehicle 401 travels over road 402, the accelerometers transmit the collected vibration data 404 to the MCU of vehicle 401. After receiving the time-domain vibration data 404 from the accelerometers, the data conversion module 406 of the MCU's power spectral density (PSD) conversion module 405 converts the time-domain vibration data 404 into a frequency-domain power spectral density (PSD) 407. Simultaneously, the model parameter module 408 of the PSD conversion module 405 determines a transfer function 409 corresponding to the detected target location. PSD 407 is then calculated with transfer function 409 to obtain a stress response (PSD) 410 at the target location. In some embodiments, stress response PSD 410 may be input into a server as intermediate data.

[0062] The PSD conversion module 405 transmits the obtained stress response PSD 410 to the damage determination module 411 of the MCU. The damage determination module 411 processes the stress response PSD 410 to obtain four PSD spectral moments 412. The damage determination module 411 processes the PSD spectral moments 412 based on the Dirlik model to obtain a probability density function 413 and a number of stress cycles occurring per unit time 414. The number of stress cycles 415 can be calculated based on the probability density function 413 and the number of stress cycles occurring per unit time 414. The damage determination module 411 determines the SN curve 416 corresponding to the material at the target location based on the material. The damage determination module 411 can determine fatigue damage 417 based on the number of stress cycles 415 and the SN curve 416. Fatigue damage 417 indicates the ratio of the damage already received to the total life.

[0063] It should be understood that Figure 4 The Dirlik model in the embodiment shown is only exemplary, and the damage determination module 411 can also perform calculations based on other feasible models, such as the Steinberg model or the Lalanne model. The present disclosure is not intended to be limited to this. Figure 4 The SN curve in the illustrated embodiment may be a standard, modified, or initial curve. In some embodiments, the stress-life curve may include a first segment before a predetermined number of cycles and a second segment after the predetermined number of cycles. The slope of the first segment is less than the slope of the second segment.

[0064] Figure 5 FIG. 5 is a block diagram illustrating an example apparatus 500 for determining fatigue damage of an electric drive axle according to some embodiments of the present disclosure. Figure 5 As shown, the apparatus 500 includes a detection quantity acquisition module 502, which is configured to acquire a detection quantity at a detection position of the electric drive axle. The apparatus 500 also includes a target position determination module 504, which is configured to determine the target position of the electric drive axle. The apparatus 500 also includes a stress determination module 506, which is configured to determine a target stress at the target position based on the detection quantity and a target transfer relationship. Here, the target transfer relationship indicates the transfer relationship between the stress at the detection position and the corresponding target position. The apparatus 500 also includes a fatigue damage determination module 508, which is configured to determine fatigue damage at the target position based on the target stress.

[0065] In some embodiments, the stress determination module 506 includes: a PSD conversion unit configured to convert the detected quantity from the time domain into a stress response power spectrum density PSD in the frequency domain; and a PSD determination unit configured to determine the target stress response PSD at the target position based on the detected quantity response PSD and the target transfer relationship.

[0066] In some embodiments, the fatigue damage determination module 508 includes: a cycle number estimation unit, configured to estimate the number of stress cycles at the target location based on the target stress response PSD and according to a stress cycle probability model; a stress-life curve acquisition unit, configured to acquire a stress-life curve associated with the material at the target location; and a fatigue damage determination unit, configured to determine fatigue damage based on the stress cycle number and the stress-life curve, where the fatigue damage indicates a ratio of fatigue damage to the total life.

[0067] In some embodiments, the stress-life curve includes a first segment before a predetermined number of cycles and a second segment after the predetermined number of cycles, and a slope of the first segment is smaller than a slope of the second segment.

[0068] In some embodiments, acceleration as a detection quantity is detected in real time using an acceleration sensor provided at a detection position.

[0069] In some embodiments, the detection position is one of: a first contact position of the electric drive axle coupled to the first wheel; a second contact position of the electric drive axle coupled to the second wheel; or a third connection position of the electric drive axle coupled to the vehicle body.

[0070] In some embodiments, the target location is at least one of: the outside of the gearbox housing of the electric drive axle; the inside of the gearbox housing of the electric drive axle; the reinforcing ribs inside the gearbox housing of the electric drive axle; the reinforcing ribs inside the motor housing of the electric drive axle; the reinforcing ribs inside the motor end cover of the electric drive axle; or the bridge tube of the electric drive axle.

[0071] In some embodiments, the transfer relationship is a transfer function between the detection quantity at the detection position and the target stress at the target position, which is obtained in advance through experiments and / or simulations.

[0072] In some embodiments, the apparatus 500 further includes: a fatigue damage sending device configured to send the fatigue damage in real time to a computing device located outside the vehicle including the electric drive axle, so that the computing device monitors the target position.

[0073] It can be understood that by utilizing the apparatus 500 of the present disclosure, at least one of the advantages that can be achieved by the method or process described above can be achieved.

[0074] Figure 6 1 shows a schematic block diagram of an example device 600 that can be used to implement an embodiment of the present disclosure. The example device 600 can be, for example, Figure 1AController 120 in. As shown in the figure, device 600 includes a computing unit 601, which can perform various appropriate actions and processes according to computer program instructions stored in read-only memory (ROM) 602 or computer program instructions loaded from storage unit 608 into random access memory (RAM) 603. Various programs and data required for the operation of device 600 can also be stored in RAM 603. Computing unit 601, ROM 602 and RAM 603 are connected to each other via bus 604. Input / output (I / O) interface 605 is also connected to bus 604.

[0075] The various processes and procedures described above, such as method 200 and method 300, may be executed by processor 601. For example, in some embodiments, method 200 and method 300 may be implemented as a computer software program tangibly embodied on a machine-readable medium. In some embodiments, part or all of the computer program may be loaded and / or installed onto device 600 via ROM 602. When the computer program is loaded into RAM 603 and executed by processor 601, one or more actions of methods 200, 300, and 400 described above may be performed.

[0076] The present disclosure may be a method, an apparatus, a system and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing various aspects of the present disclosure.

[0077] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), and any suitable combination thereof. The computer-readable storage medium used herein is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagated through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0078] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in the computer-readable storage medium in each computing / processing device.

[0079] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional procedural programming languages ​​such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., utilizing an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions. The electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0080] Various aspects of the present disclosure are described herein with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0081] These computer-readable program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine such that when these instructions are executed by the processing unit of the computer or other programmable data processing device, a device is generated that implements the functions / actions specified in one or more blocks in the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium, where these instructions cause the computer, programmable data processing device, and / or other device to operate in a specific manner. Thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing various aspects of the functions / actions specified in one or more blocks in the flowchart and / or block diagram.

[0082] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operational steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more blocks in the flowchart and / or block diagram.

[0083] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and the part of the module, program segment or instruction contains one or more executable instructions for realizing the prescribed logical function. In some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the prescribed function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0084] While various embodiments of the present disclosure have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technical improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method (200) for determining fatigue damage of an electric drive axle (102), comprising: Acquiring (202) a detection quantity at a detection position of the electric drive bridge (102); determining (204) a target position of the electric drive bridge (110); determining (206) a target stress at the target location based on the detected quantity and a target transfer relationship, wherein the target transfer relationship indicates a transfer relationship between the detected quantity at the detected location and the target stress at the target location; as well as Based on the target stress, fatigue damage at the target location is determined (208).

2. The method (200) of claim 1, wherein determining the target stress comprises: Converting the detected quantity in the time domain into a detected stress response power spectrum density PSD in the frequency domain; as well as Based on the detected stress response PSD and the target transfer relationship, a target stress response PSD at the target position is determined, where the target stress includes the target stress response PSD.

3. The method (200) of claim 2, wherein determining the fatigue damage comprises: estimating the number of stress cycles at the target location based on the target stress response PSD and a stress cycle probability distribution model; obtaining a stress-life curve associated with the material at the target location; as well as Based on the number of stress cycles and the stress-life curve, the fatigue damage is determined, the fatigue damage indicating a ratio of fatigue damage that has occurred to the total life.

4. The method (200) according to claim 3, wherein the stress-life curve includes a first section located before a predetermined number of cycles and a second section located after the predetermined number of cycles, and the slope of the first section is smaller than the slope of the second section.

5. The method (200) according to claim 1, wherein the acceleration as the detection quantity is detected in real time using an acceleration sensor provided at the detection position.

6. The method (200) of claim 1, wherein the detection location is one of: a first contact position of the electric drive axle coupled to the first wheel; A second contact position of the electric drive axle coupled to a second wheel; or The electric drive axle has a third connection point coupled to the vehicle body.

7. The method (200) of claim 1, wherein the target location is at least one of: the outer side of the gearbox housing of the electric drive axle; the inner side of the gearbox housing of the electric drive axle; Reinforcement ribs in the gearbox housing of the electric drive axle; Reinforcing ribs in the motor housing of the electric drive axle; The reinforcing ribs in the motor end cover of the electric drive axle; or The bridge tube of the electric drive bridge.

8. The method (200) according to claim 1, wherein the transfer relationship is a transfer function between the detection quantity at the detection position and the stress at the target position, which is obtained in advance through experiments and / or simulations.

9. The method (200) of claim 1, further comprising: The fatigue damage is transmitted in real time to a computing device located outside the vehicle including the electric drive axle, so that the computing device monitors the target position.

10. A controller comprising: at least one processor; as well as A memory is coupled to the at least one processor and has instructions stored thereon, which, when executed by the at least one processor, cause the controller to perform the method according to any one of claims 1 to 9.

11. An electric drive axle system, comprising: The main body of the electric drive axle, including the axle housing; an acceleration sensor disposed on the axle housing and configured to detect acceleration; as well as The controller according to claim 10, further comprising: a controller configured to receive the acceleration as a detection amount from the acceleration sensor.

12. A computer program product comprising computer executable instructions, wherein the computer executable instructions are executed by a processor to implement the method according to any one of claims 1 to 9.

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