Differential protection methods, devices, vehicles, media, and procedures

Abstract

This application relates to the field of vehicle technology, and in particular to a method, device, vehicle, medium, and program for protecting a differential. The method includes: identifying the speed difference between the left and right wheels of the drive motor and the permissible peak torque of the electric axle under differential-free operating conditions; when the speed difference between the left and right wheels of the drive motor is within a preset differential range, activating the active differential protection function and / or traction control function of the differential, and obtaining the maximum permissible output torque under differential protection; and controlling the output torque of the drive motor to decrease to the maximum permissible output torque under differential protection. This solves the problems in related technologies where failure of the TCS function can easily lead to electric differential failure, causing vehicle malfunctions, reduced vehicle lifespan, and impacting user safety.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method, device, vehicle, medium, and procedure for protecting a differential. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the quality of electric drive systems has become a key concern for consumers. Meanwhile, the development of electric drive systems has diversified, with the mainstream being the three-in-one system, comprising a motor, electronic control unit, and reducer. This system serves as a simple and reliable power unit for the entire vehicle, requiring no additional vehicle functions. The differential, as a differential transmission mechanism, allows the left and right drive wheels to rotate at different speeds, ensuring power transmission to the drive wheels in different driving modes.

[0003] In related technologies, when a vehicle sideslips, the speed difference between the inner and outer wheels increases, and the speed of the inner wheel is relatively small compared to the speed of the outer wheel. In extreme conditions such as climbing hills on opposite sides of the road, the TCS (Traction Control System) needs to intervene to prevent wheel slippage. If the TCS function fails or is not activated, the speed difference between the left and right wheels will exist for a long time, causing the differential to wear beyond the differential's design limit. This can easily lead to the failure of the electric drive differential and cause vehicle malfunction, reducing vehicle life and affecting personal safety. Summary of the Invention

[0004] This application provides a method, device, vehicle, medium, and program for protecting a differential, in order to solve the problems in the related art where the failure of the TCS function can easily lead to the failure of the electric drive differential, resulting in vehicle malfunction, reduced vehicle life, and impact on user safety.

[0005] The first aspect of this application provides a method for protecting a differential, comprising the following steps: identifying the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the bridge under differential-free operating conditions; when the speed difference between the left and right wheels of the drive motor is within a preset differential range, activating the active differential protection function and / or traction control function of the differential, and obtaining the maximum allowable output torque under differential protection; controlling the output torque of the drive motor to decrease to the maximum allowable output torque under differential protection.

[0006] Optionally, in one embodiment of this application, obtaining the maximum allowable output torque under differential protection includes: obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference; and calculating the maximum allowable output torque under differential protection based on the allowable peak torque of the bridge, the torque limiting coefficient, and the time coefficient.

[0007] Optionally, in one embodiment of this application, obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference includes: querying a first preset table with the current speed difference to obtain the corresponding torque coefficient; and querying a second preset table with the duration of the speed difference to obtain the corresponding time coefficient, wherein the first preset table is a correspondence table between the current speed difference and the torque coefficient, and the second preset table is a correspondence table between the duration of the speed difference and the time coefficient.

[0008] Optionally, in one embodiment of this application, the preset differential range includes a first differential range and a second differential range, wherein, in the first differential range, the execution priority of the traction control function is higher than the execution priority of the active differential protection function, and in the second differential range, the execution priority of the active differential protection function is higher than the execution priority of the traction control function, and the minimum value of the second differential range is greater than the maximum value of the first differential range.

[0009] Optionally, in one embodiment of this application, activating the active differential protection function and / or traction control function of the differential includes: if the traction control function fails to activate and the speed difference between the left and right wheels of the drive motor reaches the second differential range, then the traction control function is reactivated, and the active protection function of the differential is activated at the same time; if the active protection function of the differential is identified as failing, then an alarm message is issued.

[0010] Optionally, in one embodiment of this application, before identifying the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under the condition of no differential speed, the method includes: obtaining multiple experimental differential speed results of the current model differential; generating a corresponding differential speed protection boundary curve based on the multiple experimental differential speed results; and selecting a preset differential speed range that meets preset conditions based on the differential speed protection boundary curve.

[0011] Optionally, in one embodiment of this application, before obtaining the multiple experimental differential results of the current model differential, the method includes: testing the usage boundaries of the current model differential under different operating conditions; and generating multiple experimental differential results based on the usage boundaries.

[0012] A second aspect of this application provides a protection device for a differential, comprising: an identification module for identifying the speed difference between the left and right wheels of a drive motor and the allowable peak torque of the electric bridge under differential-free operating conditions; an activation module for activating the active differential protection function and / or traction control function of the differential when the speed difference between the left and right wheels of the drive motor is within a preset differential range, and obtaining the maximum allowable output torque under differential protection; and a control module for controlling the output torque of the drive motor to decrease to the maximum allowable output torque under differential protection.

[0013] A third aspect of this application provides a vehicle including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to perform a differential protection method as described in the above embodiments.

[0014] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to perform the differential protection method as described in the above embodiments.

[0015] A fifth aspect of this application provides a computer program product, including a computer program or instructions, characterized in that, when the computer program or instructions are executed, they implement the differential protection method as described in the above embodiments.

[0016] Therefore, this application has at least the following beneficial effects:

[0017] This application embodiment can actively activate the differential protection function when the speed difference between the left and right wheels is too large. It can also be linked with the TCS system to perform differential protection on the differential. At the same time, it controls the output torque of the drive motor to reduce to the maximum torque allowed under differential protection. This avoids damage to the differential caused by the failure to perform differential protection when the speed difference and torque are too large. It also greatly reduces the wear and tear on the electric drive differential, improves the service life of electric vehicles, reduces the failure rate, and enhances the user's driving experience.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0020] Figure 1 This is a flowchart of a differential protection method provided according to an embodiment of this application;

[0021] Figure 2 This is a flowchart of a differential active protection method provided according to an embodiment of this application;

[0022] Figure 3 The differential protection boundary curve provided according to the embodiments of this application;

[0023] Figure 4 This is a schematic diagram of a protection device for a differential provided according to an embodiment of this application;

[0024] Figure 5This is a structural schematic diagram of a vehicle provided according to an embodiment of this application. Detailed Implementation

[0025] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0026] The following description, with reference to the accompanying drawings, outlines a differential protection method, apparatus, electronic device, and storage medium according to embodiments of this application. Addressing the issue mentioned in the background section where the TCS function is not activated or malfunctions, leading to electric differential failure and vehicle malfunction, reduced vehicle lifespan, and compromised user safety, this application provides a differential protection method. In this method, when the speed difference between the left and right wheels is excessive, the differential protection function is actively activated and can be linked with the TCS system to provide differential protection. Simultaneously, the output torque of the drive motor is controlled to decrease to the maximum allowable torque under differential protection, preventing differential damage caused by excessive speed and torque without differential protection. This also significantly reduces wear on the electric drive differential, extending the lifespan of the electric vehicle, reducing the failure rate, and improving the user's driving experience. Therefore, this method solves the problems in the related technologies where the TCS function is not activated or malfunctions, leading to electric differential failure, vehicle malfunction, reduced vehicle lifespan, and compromised user safety.

[0027] Specifically, Figure 1 This is a flowchart illustrating a differential protection method provided in an embodiment of this application.

[0028] like Figure 1 As shown, the protection method for this differential includes the following steps:

[0029] In step S101, the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under the condition of no differential speed are identified.

[0030] It is understood that the embodiments of this application can identify the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under differential-free operating conditions, so as to activate the active differential protection function and / or traction control function of the differential according to the speed difference between the left and right wheels of the drive motor.

[0031] It should be noted that the solutions in this application are all applied to the electric drive device of a vehicle. The wheel speeds of the left and right wheels connected to the output half-shaft of the electric vehicle drive motor are actively acquired by means of wheel speed sensors and the difference between the left and right wheel speeds of the drive motor is calculated. The peak torque allowed by the electric axle under the condition of no differential is usually determined through the design and testing process of the electric drive axle. This application is the maximum torque value that the electric axle can safely output under ideal conditions (i.e., when the vehicle is traveling in a straight line and there is no lateral force or differential requirement).

[0032] In one embodiment of this application, before identifying the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under the condition of no differential speed, the process includes: obtaining multiple experimental differential speed results of the current model differential; generating a corresponding differential protection boundary curve based on the multiple experimental differential speed results; and selecting a preset differential speed range that meets preset conditions based on the differential protection boundary curve.

[0033] The preset conditions can be conditions where the speed difference between the left and right wheels of the drive motor reaches the point where the vehicle slips. The preset differential range can be selected based on the range of the speed difference between the left and right wheels of the drive motor in the differential protection boundary curve. It can be set according to actual needs and is not specifically limited.

[0034] It is understood that the embodiments of this application can obtain multiple experimental differential results of the current model differential; generate a corresponding differential protection boundary curve based on the multiple experimental differential results, and select a preset differential range that meets the preset conditions based on the differential protection boundary curve, which can provide an accurate preset differential range for differentials of different vehicle models and improve the safety performance of the vehicle.

[0035] In one embodiment of this application, before obtaining multiple experimental differential results for the current model differential, the method includes: testing the usage boundaries of the current model differential under different operating conditions; and generating multiple experimental differential results based on the usage boundaries.

[0036] It is understood that the embodiments of this application can test the usage boundaries of the current model differential under different operating conditions; generate multiple experimental differential results based on the usage boundaries, and generate corresponding experimental results by combining different operating conditions and the specific situation of the differential, thereby improving the accuracy of differential data.

[0037] In step S102, when the speed difference between the left and right wheels of the drive motor is within the preset differential range, the active differential protection function and / or traction control function of the differential are activated, and the maximum allowable output torque under differential protection is obtained.

[0038] The preset differential range includes a first differential range and a second differential range. In the first differential range, the execution priority of the traction control function is higher than that of the active differential protection function. In the second differential range, the execution priority of the active differential protection function is higher than that of the traction control function. The minimum value of the second differential range is greater than the maximum value of the first differential range.

[0039] It is understood that, in the embodiments of this application, when the speed difference between the left and right wheels of the drive motor is within a preset differential range, the active differential protection function and / or traction control function of the differential are activated to protect the differential, so as to avoid damage to the differential caused by excessive speed difference between the left and right half shafts without torque protection. It can also greatly reduce the wear and tear on the electric drive differential of electric vehicles, improve the life of electric vehicles, reduce the failure rate, and improve the user's driving experience.

[0040] In one embodiment of this application, activating the active differential protection function and / or traction control function of the differential includes: if the traction control function fails to activate and the speed difference between the left and right wheels of the drive motor reaches the second differential range, then the traction control function is reactivated, and the active protection function of the differential is activated at the same time; if the active protection function of the differential is identified as failing, then an alarm message is issued.

[0041] It is understood that in the embodiments of this application, if the traction control function fails to activate and the speed difference between the left and right wheels of the drive motor reaches the second differential range, the traction control function will be reactivated, and the active protection function of the differential will be activated at the same time; if the active protection function of the differential is detected to be ineffective, an alarm message will be issued to improve the safety performance of the vehicle.

[0042] It should be noted that the warning information may include messages such as "Active protection of the differential has failed, please reduce speed" displayed on the vehicle's display screen or instrument panel, in order to alert the driver to the malfunction and improve driving safety.

[0043] In one embodiment of this application, obtaining the maximum allowable output torque under differential protection includes: obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference, and calculating the maximum allowable output torque under differential protection based on the bridge's allowable peak torque, torque limiting coefficient, and time coefficient.

[0044] It is understood that the embodiments of this application can obtain the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference. Based on the allowable peak torque of the electric bridge, the torque limiting coefficient and the time coefficient, the maximum allowable output torque under differential protection is calculated so that the output torque of the drive motor can be reduced to the maximum allowable output torque under differential protection. This avoids damage to the differential caused by excessive speed difference between the left and right half shafts without torque protection. It can also greatly reduce the wear and tear on the electric drive differential of electric vehicles, improve the lifespan of electric vehicles, reduce the failure rate, and improve the user's driving experience.

[0045] It should be noted that the maximum allowable output torque under differential protection = the peak allowable torque of the electric bridge under non-differential operating conditions × torque limiting coefficient × time coefficient.

[0046] In one embodiment of this application, obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference includes: querying a first preset table to obtain the corresponding torque coefficient based on the current speed difference; and querying a second preset table to obtain the corresponding time coefficient based on the duration of the speed difference, wherein the first preset table is a correspondence table between the current speed difference and the torque coefficient, and the second preset table is a correspondence table between the duration of the speed difference and the time coefficient.

[0047] It is understood that in this application embodiment, the corresponding torque coefficient is obtained by querying the first preset table with the current speed difference; and the corresponding time coefficient is obtained by querying the second preset table with the duration of the speed difference. By pre-calibrating, it is convenient to quickly control the vehicle to reduce to the target torque when the speed difference is greater than the preset differential range, which greatly reduces the wear of electric drive differential of electric vehicle and improves the user driving experience.

[0048] For example, the first preset table can be as shown in Table 1 below, which is a table showing the correspondence between the current speed difference and the torque coefficient.

[0049] Speed ​​difference Torque limit coefficient 50 1 55 0.85 200 0.77 500 0.5 1000 0.16 1351 0.04 1500 0.04

[0050] The second preset table can be shown in Table 2 below. Table 2 is a table showing the correspondence between the duration of the speed difference and the time coefficient.

[0051] time Time coefficient t≤3 1 3<t≤4 0.8 4<t≤6 0.5 6<t≤8 0.18 8<t≤10 0.05 t>10 0

[0052] It should be noted that the above tables can be calibrated according to actual needs, without any specific limitations.

[0053] In step S103, the output torque of the control drive motor is reduced to the maximum torque allowed to be output under differential protection.

[0054] It is understood that the embodiments of this application can control the output torque of the drive motor to be reduced to the maximum torque allowed to be output under differential protection, so as to avoid damage to the differential caused by excessive differential between the left and right half shafts without torque protection. It can also greatly reduce the wear and tear on the electric drive differential of electric vehicles, improve the life of electric vehicles, reduce the failure rate, and improve the user's driving experience.

[0055] According to the differential protection method proposed in the embodiments of this application, when the speed difference between the left and right wheels of the drive motor is large, the differential active protection function is activated and linked with TCS to protect the differential. This avoids damage to the differential caused by excessive speed difference between the left and right half shafts without torque protection. It can also greatly reduce the wear and tear on the electric drive differential of electric vehicles, improve the lifespan of electric vehicles, reduce the failure rate, and enhance the user's driving experience.

[0056] The following will combine Figure 2 and Figure 3 The active protection method for differentials is described, and the specific steps are as follows:

[0057] Step 1: Conduct experimental testing to assess the differential capability of the electric drive differential.

[0058] Differential tests were conducted based on the developed differential, with near-failure of the differential as the evaluation criterion, and the ultimate capability of the differential was determined as the boundary of its use.

[0059] Step 2: Formulate protection strategies based on the wheel speed signal and the principle of zoning.

[0060] (1) Obtain the left and right wheel speed signals and torque request signals of the drive motor;

[0061] (2) When the speed difference between the left and right wheels of the drive motor is within the first preset speed range: the differential active protection strategy is not implemented, the TCS function is activated, the output torque requested by the drive motor is reduced, thereby reducing the speed difference between the left and right half shafts of the drive motor differential until it is reduced to the safe speed range.

[0062] If the gravity control system is not activated within the first preset speed range, the output torque capability of the drive motor is not limited, and the speed difference between the left and right wheels of the drive motor differential continues to rise to the second preset speed range, then the differential protection function is activated.

[0063] (3) When the speed difference between the left and right wheels of the drive motor is within the second preset speed range, which is within the differential active protection strategy area, the output torque of the drive motor is actively reduced to reduce the speed difference between the left and right wheels of the drive motor to the safe speed range. At this time, the motor reduces the available torque (calibrated) and reports the protection information.

[0064] It should be noted that within the first differential speed range, the execution priority of the TCS is higher than that of the active differential protection function. However, within the second speed range, the execution priority of the active differential function is higher than that of the TCS. The minimum value in the second speed range is greater than the maximum value of the first speed device.

[0065] Step 3: The differential active protection function and TCS function are linked to minimize the impact on integrated power performance.

[0066] (1) When the TCS function is normal, in the first differential range, the TCS is activated and the requested torque of the drive motor is reduced to reduce the speed difference between the left and right sides of the drive motor differential to the safe speed range. When the TCS is not activated, the speed difference between the left and right sides of the drive motor differential reaches the second preset speed range and activates the TCS and differential active protection functions. The differential takes priority and the TCS is forcibly activated.

[0067] (2) TCS malfunction, wheel speed signal valid: differential active protection function is effective.

[0068] (3) TCS abnormal, wheel speed signal failure: the differential active protection function fails and an alarm message is issued.

[0069] Next, the protective device for the differential proposed according to the embodiments of this application is described with reference to the accompanying drawings.

[0070] Figure 4 This is a block diagram of the protection device for the differential in an embodiment of this application.

[0071] like Figure 4 As shown, the differential protection device 10 includes: an identification module 100, an activation module 200, and a control module 300.

[0072] The identification module 100 is used to identify the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under differential conditions; the activation module 200 is used to activate the active differential protection function and / or traction control function of the differential when the speed difference between the left and right wheels of the drive motor is within a preset differential range, and to obtain the maximum allowable output torque under differential protection; the control module 300 is used to control the output torque of the drive motor to decrease to the maximum allowable output torque under differential protection.

[0073] In this embodiment of the application, the activation module 200 is further configured to: if the traction control function fails to activate and the speed difference between the left and right wheels of the drive motor reaches the second preset protection range, then reactivate the traction control function and activate the active protection function of the differential at the same time; if the active protection function of the differential is identified as failing, then issue an alarm action.

[0074] In this embodiment, the activation module 200 is further configured to: obtain the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference; and calculate the maximum allowable output torque under the differential protection based on the allowable peak torque of the bridge, the torque limiting coefficient, and the time coefficient.

[0075] In this embodiment of the application, the activation module 200 is further configured to: query a first preset table to obtain the corresponding torque coefficient based on the current speed difference; and query a second preset table to obtain the corresponding time coefficient based on the duration of the speed difference, wherein the first preset table is a table showing the correspondence between the current speed difference and the torque coefficient, and the second preset table is a table showing the correspondence between the duration of the speed difference and the time coefficient.

[0076] In this embodiment of the application, the preset differential range includes a first differential range and a second differential range. In the first differential range, the execution priority of the traction control function is higher than the execution priority of the active differential protection function. In the second differential range, the execution priority of the active differential protection function is higher than the execution priority of the traction control function. The minimum value of the second differential range is greater than the maximum value of the first speed range.

[0077] In this embodiment of the application, it further includes: a selection module, used to obtain multiple experimental differential results of the current model differential; generate a corresponding differential protection boundary curve based on the multiple experimental differential results, and select a preset differential range that meets preset conditions based on the differential protection boundary curve.

[0078] In this embodiment of the application, it also includes: a testing module, used to test the usage boundaries of the current model differential under different operating conditions; and to generate multiple experimental differential results based on the usage boundaries.

[0079] It should be noted that the foregoing explanation of the differential protection method embodiment also applies to the differential protection device of this embodiment, and will not be repeated here.

[0080] According to the differential protection device proposed in the embodiments of this application, when the speed difference between the left and right wheels of the drive motor is large, the differential active protection function is activated and linked with the TCS to protect the differential. This avoids damage to the differential caused by excessive speed difference between the left and right half shafts without torque protection. It can also greatly reduce the wear and tear on the electric drive differential of electric vehicles, improve the lifespan of electric vehicles, reduce the failure rate, and enhance the user's driving experience.

[0081] Figure 5 A schematic diagram of the structure of a vehicle provided in an embodiment of this application. The vehicle may include:

[0082] The memory 501, the processor 502, and the computer program stored on the memory 501 and capable of running on the processor 502.

[0083] When processor 502 executes the program, it implements the differential protection method provided in the above embodiments.

[0084] Furthermore, the vehicle also includes:

[0085] Communication interface 503 is used for communication between memory 501 and processor 502.

[0086] The memory 501 is used to store computer programs that can run on the processor 502.

[0087] The memory 501 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0088] If the memory 501, processor 502, and communication interface 503 are implemented independently, then the communication interface 503, memory 501, and processor 502 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0089] Optionally, in a specific implementation, if the memory 501, processor 502, and communication interface 503 are integrated on a single chip, then the memory 501, processor 502, and communication interface 503 can communicate with each other through an internal interface.

[0090] Processor 502 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0091] This application also provides a computer-readable storage medium storing a computer program or instructions thereon, which, when executed by a processor, implements the differential protection method described above.

[0092] This application also provides a computer program product, including a computer program or instructions, characterized in that, when the computer program or instructions are executed, they implement the above-described differential protection method.

[0093] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0094] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0095] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0096] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0097] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

Claims

1. A method for protecting a differential, characterized in that, Includes the following steps: Identify the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under differential-free operating conditions; When the speed difference between the left and right wheels of the drive motor is within a preset differential range, the active differential protection function and / or traction control function of the differential are activated, and the maximum allowable output torque under differential protection is obtained. The preset differential range includes a first differential range and a second differential range. In the first differential range, the execution priority of the traction control function is higher than the execution priority of the active differential protection function. In the second differential range, the execution priority of the active differential protection function is higher than the execution priority of the traction control function. The minimum value of the second differential range is greater than the maximum value of the first differential range. The active differential protection function and / or traction control function of the activated differential include: If the traction control function fails to activate and the speed difference between the left and right wheels of the drive motor reaches the second differential range, the traction control function will be activated again, and the active protection function of the differential will also be activated. If the active protection function of the differential is found to be ineffective, an alarm message will be issued. The step of obtaining the maximum allowable output torque under differential protection includes: obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference; and calculating the maximum allowable output torque under differential protection based on the allowable peak torque of the bridge, the torque limiting coefficient, and the time coefficient. The step of obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference includes: querying a first preset table to obtain the corresponding torque coefficient based on the current speed difference; and querying a second preset table to obtain the corresponding time coefficient based on the duration of the speed difference. The first preset table is a table showing the correspondence between the current speed difference and the torque coefficient, and the second preset table is a table showing the correspondence between the duration of the speed difference and the time coefficient. The output torque of the drive motor is controlled to be reduced to the maximum torque allowed to be output under the differential protection.

2. The differential protection method according to claim 1, characterized in that, Before identifying the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under differential-free operating conditions, the following is included: Test the operating limits of the current model differential under different working conditions; Based on the aforementioned usage boundaries, multiple experimental differential speed results are generated; Based on the results of the multiple differential speed experiments, a corresponding differential speed protection boundary curve is generated, and a preset differential speed range that meets the preset conditions is selected based on the differential speed protection boundary curve.

3. A protection device for a differential, characterized in that, include: The identification module is used to identify the speed difference between the left and right wheels of the drive motor and the allowable peak torque of the electric bridge under differential conditions. An activation module is used to activate the active differential protection function and / or traction control function of the differential when the speed difference between the left and right wheels of the drive motor is within a preset differential range, and to obtain the maximum allowable output torque under differential protection. The preset differential range includes a first differential range and a second differential range. Within the first differential range, the execution priority of the traction control function is higher than the execution priority of the active differential protection function. Within the second differential range, the execution priority of the active differential protection function is higher than the execution priority of the traction control function. The minimum value of the second differential range is greater than the maximum value of the first differential range. The active differential protection function and / or traction control function of the activated differential include: If the traction control function fails to activate and the speed difference between the left and right wheels of the drive motor reaches the second differential range, the traction control function will be activated again, and the active protection function of the differential will also be activated. If the active protection function of the differential is found to be ineffective, an alarm message will be issued. The step of obtaining the maximum allowable output torque under differential protection includes: obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference; and calculating the maximum allowable output torque under differential protection based on the allowable peak torque of the bridge, the torque limiting coefficient, and the time coefficient. The step of obtaining the torque limiting coefficient corresponding to the current speed difference of the differential and the time coefficient corresponding to the duration of the speed difference includes: querying a first preset table to obtain the corresponding torque coefficient based on the current speed difference; and querying a second preset table to obtain the corresponding time coefficient based on the duration of the speed difference. The first preset table is a table showing the correspondence between the current speed difference and the torque coefficient, and the second preset table is a table showing the correspondence between the duration of the speed difference and the time coefficient. The control module is used to control the output torque of the drive motor to decrease to the maximum torque allowed to be output under the differential protection.

4. A vehicle, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the differential protection method as described in any one of claims 1-2.

5. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by the processor, they are used to implement the differential protection method as described in any one of claims 1-2.

6. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed, they implement the differential protection method as described in any one of claims 1-2.

Images