Differential protection method and vehicle

Abstract

This application provides a differential protection method and a vehicle; the method includes: determining the instantaneous heat dissipation power of the left and right drive wheels of the differential based on the current temperature of the differential and the ambient temperature where the differential is located, and determining the instantaneous heat generation power of the differential based on the user-input torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. Thus, the current heat load can be determined based on the instantaneous heat dissipation power and the instantaneous heat generation power. Then, based on the current heat load, it is detected whether the operating state of the differential of the target vehicle meets the preset limit conditions. If the operating state of the differential of the target vehicle meets the preset limit conditions, the differential of the target vehicle is protected and controlled according to the protection torque coefficient corresponding to the current heat load.

Description

Technical Field

[0001] This application relates to vehicle control technology, and more particularly to a differential protection method and a vehicle. Background Technology

[0002] When a car is running, the differential outputs torque to keep it moving. Normally, for proper steering, a wheel receives more torque when the resistance it experiences is less than that of another wheel. However, under certain conditions, when a car is driving on a split-plane road with a large drive torque output, the wheels may slip, potentially causing loss of steering control. Simultaneously, due to the significant difference in traction between the left and right tires, the tire on the side with lower traction may spin at high speed. Prolonged high-speed spinning can easily cause the differential at the drive axle to burn out and become damaged.

[0003] In related technologies, the torque limiting coefficient is usually obtained by "direct mapping of multiple parameters (speed difference, oil temperature, etc.) to a table", and the wheels are braked based on the torque limiting coefficient to alleviate the wheel slippage problem.

[0004] However, the methods in the relevant technologies are designed to protect the differential from wheel spin rather than the wheel spin. In some cases, the wheel spin problem is solved, but the differential overheating problem is not solved. Therefore, there is an urgent need for a method that can protect the differential from overheating. Summary of the Invention

[0005] This application provides a differential protection method and a vehicle that can provide protection for the differential.

[0006] The technical solution of this application embodiment is implemented as follows: In a first aspect, embodiments of this application provide a differential protection method, the method comprising: Determine the instantaneous heat dissipation power of the left and right drive wheels of the differential based on the current temperature of the differential and the ambient temperature of the differential. The instantaneous heating power of the differential is determined based on the user's input torque demand for the target vehicle and the speed difference between the left and right drive wheels of the differential. Determine the current heat load based on the instantaneous heat dissipation power and instantaneous heat generation power; Based on the current heat load, check whether the operating status of the differential of the target vehicle meets the preset limits; If the operating state of the differential of the target vehicle meets the preset limit conditions, the differential of the target vehicle is protected and controlled according to the protection torque coefficient corresponding to the current heat load.

[0007] Secondly, embodiments of this application provide a differential protection device, comprising: The heat dissipation power determination module is used to determine the instantaneous heat dissipation power of the left and right drive wheels of the differential based on the current temperature of the differential and the ambient temperature where the differential is located. The heat generation power determination module is used to determine the instantaneous heat generation power of the differential based on the user-input required torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. The heat load determination module is used to determine the current heat load based on the instantaneous heat dissipation power and the instantaneous heat generation power; The detection module is used to detect whether the operating status of the differential of the target vehicle meets the preset limits based on the current heat load. The protection module is used to protect the differential of the target vehicle if the operating state of the differential meets the preset limit conditions, based on the protection torque coefficient corresponding to the current thermal load.

[0008] Thirdly, embodiments of this application provide a vehicle, which includes a memory and a vehicle processor, wherein the memory is used to store computer-executable instructions or computer programs; and the vehicle processor is used to implement the method provided in embodiments of this application when executing the computer-executable instructions or computer programs stored in the memory.

[0009] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program or computer-executable instructions for implementing the method provided in embodiments of this application when executed by a processor.

[0010] Fifthly, embodiments of this application provide a computer program product, including a computer program or computer-executable instructions, wherein when the computer program or computer-executable instructions are executed by a processor, the multi-device control method provided in embodiments of this application is implemented.

[0011] This application provides a differential protection scheme, specifically including a differential protection method and a vehicle. The method includes: determining the instantaneous heat dissipation power of the left and right drive wheels of the differential based on the current temperature of the differential and the ambient temperature of the differential; and determining the instantaneous heat generation power of the differential based on the user-input torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. Thus, the current heat load can be determined based on the instantaneous heat dissipation power and the instantaneous heat generation power. Then, based on the current heat load, it is detected whether the operating state of the differential of the target vehicle meets preset limit conditions. If the operating state of the differential of the target vehicle meets the preset limit conditions, the differential of the target vehicle is protected and controlled according to the protection torque coefficient corresponding to the current heat load.

[0012] In the above embodiments, the instantaneous heat dissipation power of the left and right drive wheels of the differential is determined by the current temperature of the differential and the ambient temperature of the differential. The instantaneous heat generation power of the differential is determined based on the user-input torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. Based on this, the current internal heat energy state of the differential is accurately determined. Whether the differential's operating state meets preset limits based on the current heat load is identified, thus more accurately determining whether the differential has an overheating risk. If so, the corresponding protection torque coefficient is determined based on the current heat load of the differential. On the one hand, compared to the method of determining the torque limiting coefficient by looking up a table in related technologies, the technical solution provided in this application determines the protection torque limiting coefficient based on the differential's heat load, making the determination process more targeted and improving the accuracy and real-time performance of differential protection. On the other hand, this application provides a calculation process for the current heat load. By calculating the instantaneous heat dissipation power and the instantaneous heat generation power, the current heat load data reflecting the current thermal energy state of the differential can be accurately calculated, providing accurate data for subsequent judgment on whether to perform overheat protection for the differential. Attached Figure Description

[0013] Figure 1 A schematic diagram of the implementation process of a differential protection method provided in this application embodiment. Figure 1 ; Figure 2 A schematic diagram of the implementation process of a differential protection method provided in this application embodiment. Figure 2 ; Figure 3 A schematic diagram of the implementation process of a differential protection method provided in this application embodiment. Figure 3 ; Figure 4 This is a schematic diagram of the composition structure of a differential protection device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the hardware entity of a vehicle provided in an embodiment of this application.

[0014] It should be noted that the terms "first" and "second" mentioned above are only used to distinguish between different options and do not represent the degree of superiority or inferiority of the options or their priority in the implementation process. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application are further described in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] In the following description, references to "some embodiments" refer to a subset of all possible embodiments. It is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. The terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application.

[0018] In electric or hybrid vehicles, the electric drive system consists of a drive motor, a reducer, and a differential. When the vehicle is traveling on surfaces with one wheel off the ground, low traction surfaces, or with one wheel suspended in the air, the drive wheel on the side with low traction is prone to slippage and spinning, resulting in a significant speed difference between the output shafts on both sides of the differential. This sustained large speed difference causes the gears, bearings, and other components inside the differential to generate a large amount of frictional heat due to high-speed relative motion. If heat dissipation is insufficient, the differential temperature will rise sharply, leading to a decrease in lubricating oil performance, tooth surface seizing, and ultimately damage to the differential, seriously affecting driving safety.

[0019] In related technologies, the control logic for differentials is relatively mechanical. It typically involves monitoring parameters such as the differential's speed difference and oil temperature, and combining these with preset thresholds to limit the motor's output torque in order to prevent the differential from overheating and being damaged.

[0020] However, such methods rely on fixed control logic and lookup table strategies, failing to make dynamic adjustments based on the actual thermal state of the differential, and thus cannot provide accurate and timely protection for the differential.

[0021] In view of this, this application provides a differential protection scheme, specifically including a differential protection method and a vehicle. The method includes: determining the instantaneous heat dissipation power of the left and right drive wheels of the differential based on the current temperature of the differential and the ambient temperature of the differential; and determining the instantaneous heat generation power of the differential based on the user-input torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. Thus, the current heat load can be determined based on the instantaneous heat dissipation power and the instantaneous heat generation power. Then, based on the current heat load, it is detected whether the operating state of the differential of the target vehicle meets the preset limit conditions. If the operating state of the differential of the target vehicle meets the preset limit conditions, the differential of the target vehicle is protected and controlled according to the protection torque coefficient corresponding to the current heat load.

[0022] In the above embodiments, the instantaneous heat dissipation power of the left and right drive wheels of the differential is determined by the current temperature of the differential and the ambient temperature of the differential. The instantaneous heat generation power of the differential is determined based on the user-input torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. Based on this, the current internal heat energy state of the differential is accurately determined. Whether the differential's operating state meets preset limits based on the current heat load is identified, thus more accurately determining whether the differential has an overheating risk. If so, the corresponding protection torque coefficient is determined based on the current heat load of the differential. On the one hand, compared to the method of determining the torque limiting coefficient by looking up a table in related technologies, the technical solution provided in this application determines the protection torque limiting coefficient based on the differential's heat load, making the determination process more targeted and improving the accuracy and real-time performance of differential protection. On the other hand, this application provides a calculation process for the current heat load. By calculating the instantaneous heat dissipation power and the instantaneous heat generation power, the current heat load data reflecting the current thermal energy state of the differential can be accurately calculated, providing accurate data for subsequent judgment on whether to perform overheat protection for the differential.

[0023] This application provides a differential protection method, which can be applied to a vehicle and executed by the vehicle's processor. The vehicle can be an intelligent vehicle with data processing capabilities, including but not limited to: sedans, sports cars, SUVs, commercial vehicles, engineering vehicles, etc.

[0024] Figure 1 A schematic diagram of the implementation process of a differential protection method provided in this application embodiment. Figure 1 ,like Figure 1 As shown, the method includes the following steps S101 to S105: Step S101: Determine the instantaneous heat dissipation power of the left and right drive wheels of the differential based on the current temperature of the differential and the ambient temperature where the differential is located.

[0025] Here, the current temperature can refer to the temperature value inside the differential or on the surface of the housing. In some embodiments, the current temperature of the differential can be detected by a temperature sensor deployed inside or on the surface of the differential, thereby obtaining the current temperature of the differential.

[0026] Here, ambient temperature can refer to the operating environment temperature of the differential, such as the temperature of the space where the differential is located, which can be detected by a specific temperature sensor.

[0027] In this embodiment of the application, in order to determine whether there is a risk of overheating in the thermal state of the differential, it is necessary to determine whether the power of its heat dissipation and the power of its heat generation are balanced. Based on this, it is necessary to calculate the current instantaneous heat dissipation power of the differential. Here, the instantaneous heat dissipation power can refer to the rate at which the differential dissipates heat to the surrounding environment through heat conduction, convection and other means at the current moment.

[0028] In some embodiments, the instantaneous heat dissipation power can be determined based on the current temperature of the differential and the ambient temperature.

[0029] In one possible implementation, the current temperature and ambient temperature can be substituted into a preset instantaneous heat dissipation power calculation formula to calculate the instantaneous heat dissipation power of the differential.

[0030] For the calculation formula of instantaneous heat dissipation power, please refer to Formula 1 below: P_diss = C * (T_diff - T_amb) Formula 1 Wherein, P_diss can refer to the instantaneous heat dissipation power of the left and right drive wheels of the differential, C is the comprehensive heat dissipation coefficient, which takes into account the heat dissipation of the differential housing, oil convection heat dissipation, etc. It can be calibrated by test and can be dynamically corrected in relation to vehicle speed, that is, the higher the vehicle speed, the larger C is; T_diff is the current temperature of the differential; T_amb is the ambient temperature of the differential.

[0031] Step S102: Determine the instantaneous heating power of the differential based on the user-inputted torque of the target vehicle and the speed difference between the left and right drive wheels of the differential.

[0032] Here, the required torque is the torque at the input end of the differential that the user inputs based on the current road conditions. In this embodiment, when the user inputs the required torque through an interactive device, such as an accelerator pedal or a vehicle controller, the relevant data of the required torque can be obtained.

[0033] Here, the speed difference between the left and right drive wheels of the differential can refer to the difference in angular velocity between the left and right half-shafts of the differential, which is usually calculated by wheel speed sensors.

[0034] It is understandable that the heat generated by the differential mainly comes from two parts: one part is the load heat generated by the gear meshing when transmitting torque, and the other part is the internal friction heat generated by the speed difference between the left and right wheels. Based on this, the instantaneous heat generation power can be calculated and determined based on the required torque and the speed difference between the left and right drive wheels of the differential.

[0035] Here, instantaneous heat generation power can refer to the heat generated by the differential per unit time due to mechanical friction and gear meshing losses under the conditions of required torque and speed difference.

[0036] In one possible implementation, the required torque and speed difference can be substituted into a preset instantaneous heat generation power calculation formula to calculate the instantaneous heat generation power of the differential.

[0037] For the calculation formula of instantaneous heating power, please refer to Formula 2 below: P_fric = k * |T_input| * |Δω| Formula 2 Wherein, P_fric is the instantaneous heating power, k is the equivalent friction coefficient, which can be directly obtained and is an experimental calibration value, related to the structure and lubrication conditions of the differential; T_input is the required torque at the input end of the differential, which can be approximated as the motor output torque in this embodiment; Δω can refer to the speed difference between the two ends of the differential.

[0038] The calculation process for Δω can be referred to the following formula 3: Δω = 2π * (|n1 - n2|) / 6 Formula 3 Wherein, n1 and n2 refer to the wheel speeds of the drive wheels at the left and right ends of the differential, respectively. In this embodiment, n1 and n2 can be obtained by wheel speed sensors deployed on the drive wheels.

[0039] Step S103: Determine the current heat load based on the instantaneous heat dissipation power and the instantaneous heat generation power.

[0040] Here, heat load can refer to, but is not limited to, a virtual value based on the fitting of instantaneous heat generation power and instantaneous heat dissipation power, which can be used to reflect the current heat reserve status of the differential.

[0041] In one possible implementation, there is a mapping relationship between instantaneous heat dissipation power, instantaneous heat generation power, and heat load. This mapping relationship can be calculated based on the instantaneous heat dissipation power and instantaneous heat generation power, and the current heat load can be determined based on this mapping relationship.

[0042] In another possible implementation, the instantaneous heat dissipation power and instantaneous heat generation power can be substituted into a preset formula for calculating the current heat load to determine the current heat load.

[0043] In some embodiments, the formula for calculating the current heat load can refer to the following formula 4: Q_acc(t) = Q_acc(t-Δt) + (P_fric - P_diss) * Δt Formula 4 Here, Q_acc(t) refers to the heat load calculated at time t, and Δt refers to the time interval since the last heat load calculation.

[0044] In the embodiments of this application, the initial value of Q_acc can be set to 0 or initialized based on the oil temperature.

[0045] In this way, the current thermal load of the differential can be determined through the above process.

[0046] Step S104: Based on the current heat load, detect whether the operating status of the differential of the target vehicle meets the preset limit conditions.

[0047] Here, the operating status of the differential may refer to, but is not limited to, the current working condition of the differential, including but not limited to status parameters such as thermal load and temperature.

[0048] Here, the preset limiting condition may, but is not limited to, a criterion for judging whether the operating state of the differential is at risk of overheating. In this way, when the operating state of the differential meets the preset limiting condition, it can be determined that the differential is facing the risk of overheating and needs to be protected against overheating.

[0049] In one possible implementation, the temperature of the differential can be monitored in real time, and a safe temperature threshold can be set as a preset limit. When the temperature of the differential exceeds the safe temperature threshold, it is determined whether the operating state of the differential meets the preset limit.

[0050] In another possible implementation, the process of "identifying whether the operating state of the target vehicle's differential meets preset constraints" may include the following steps: Step S1041: Obtain the current thermal load of the differential, the speed difference between the two ends, and the thermal load growth rate.

[0051] Step S1042: When the current heat load is greater than the first load threshold, detect whether the time when the speed difference between the two ends is greater than the speed difference threshold is greater than the time threshold, and / or whether the heat load growth rate of the differential of the target vehicle reaches the growth rate threshold.

[0052] Step S1043: If the current heat load is greater than the first load threshold, and the time for the speed difference between the two ends to be greater than the speed difference threshold is greater than the time threshold, and / or the heat load growth rate is greater than the growth rate threshold, determine that the operating state of the differential of the target vehicle meets the preset restriction conditions.

[0053] Here, heat load can refer to, but is not limited to, a virtual value based on the fitting of instantaneous heat generation power and instantaneous heat dissipation power, which can be used to reflect the current heat reserve state of the differential; the speed difference between the two ends, that is, the speed difference between the left and right drive wheels of the differential, can refer to the difference in angular velocity between the left and right half-shafts of the differential, which is usually calculated by wheel speed sensors; the heat load growth rate can characterize the positive change of heat load per unit time, which can reflect the drastic degree of change in the internal thermal energy state of the differential.

[0054] In this embodiment, the operating state of the differential of the target vehicle can be determined by obtaining the current heat load, the speed difference between the two ends of the differential, and the rate of increase of the heat load. Regarding the process of obtaining the current heat load, in one possible implementation, the current heat load of the differential can be archived in a database in real time, and the vehicle can obtain it directly from the database.

[0055] In another possible implementation, the required parameters can be collected by sensors, and the current thermal load of the differential can be calculated using a preset thermal load calculation model.

[0056] The specific calculation process can be referred to Formulas 1 to 4 above. Here, the calculation process for the current heat load will not be repeated. It can be understood that in the process of calculating the current heat load, the speed difference between the two ends and the heat load growth rate can also be obtained.

[0057] Understandably, when the current heat load reaches a certain threshold, it can be determined that the differential's heat load has entered a warning level and is about to face the risk of overheating. At this time, measures need to be taken to prevent the differential's current heat load from reaching a dangerous value and facing the risk of ablation.

[0058] In this embodiment, a first load threshold is set, which can be used to distinguish the boundary between the differential in normal operation and operation under risk. In this embodiment, the first load threshold is a test calibration value, but it can be adjusted according to the actual condition of the differential.

[0059] In some embodiments, in order to avoid false triggering caused by a brief increase in heat load, a secondary detection is set up. When the current heat load is detected to be greater than the first load threshold, the detection is set to check whether the time for the speed difference to be greater than the speed difference threshold is greater than the time threshold, and / or whether the heat load growth rate of the differential of the target vehicle reaches the growth rate threshold.

[0060] It is understandable that the speed difference threshold can be the maximum speed difference limit allowed by the differential. When the speed difference between the two ends is greater than the speed difference threshold, it indicates that the operation of the differential has exceeded the design boundary of the conventional power distribution. This may be a normal dynamic response of the vehicle under extreme driving conditions, or it may be an abnormal signal of fault or failure of the differential body or transmission system. When the current speed difference is greater than the speed difference threshold for a preset time threshold, it can be determined that the vehicle is in an abnormal state.

[0061] The heat load growth rate threshold can be used to determine whether the heat load of the differential will rise sharply beyond the safety line in a short period of time. By judging whether the heat load growth rate exceeds the growth rate threshold, it is possible to predict whether the differential is about to face the risk of overheating.

[0062] Based on this, when the current heat load is detected to reach the first load threshold, if the duration of the speed difference exceeding the speed difference threshold exceeds the preset time threshold, and / or the heat load growth rate exceeds the growth rate threshold, it can be determined that the operating state of the differential of the target vehicle meets the preset limit conditions, and overheat protection is required at this time.

[0063] In the above embodiments, the differential's operating status is determined based on thermal load and multi-parameter linkage to determine whether it meets the set limiting conditions. This allows for the rapid and accurate identification of potential thermal risk states under complex operating conditions. Subsequently, reasonable protective measures are taken based on the identified potential thermal risk states, ensuring the safety of the differential.

[0064] Step S105: If the operating state of the differential of the target vehicle meets the preset limit conditions, the differential of the target vehicle is protected and controlled according to the protection torque coefficient corresponding to the current heat load.

[0065] In some embodiments, when the operating state of the differential of the target vehicle is found to meet the preset limiting conditions, subsequent protection measures for the differential can be executed. In this embodiment, the corresponding protection torque coefficient can be determined according to the current thermal load of the differential.

[0066] Here, the protection torque coefficient can be, but is not limited to, a dynamically adjusted proportional factor used to limit the torque demanded by the driver, thereby reducing the mechanical load on the differential and preventing it from overheating and being damaged. For example, when driving on low-friction surfaces, if the speed difference between the wheels on both sides of the differential remains large and the thermal load gradually rises to near the design critical value, a lower protection torque coefficient can be determined based on the current thermal load to limit the motor output torque, thereby reducing frictional heat generation inside the differential.

[0067] In one possible implementation, there is a mapping relationship between the protection torque coefficient and different current heat loads, and the protection torque coefficient can be determined based on the current heat load mapping.

[0068] In another possible implementation, the protection torque coefficient can be determined by substituting the current heat load into the formula below, referring to the calculation formula 5.

[0069] Formula 5 Where η(t) is the protection torque coefficient corresponding to the current thermal load, Q_warning is the first load threshold, and Q_critical is the safety threshold. It can be understood that if the current thermal load exceeds the safety threshold, it can be determined that the differential is facing the risk of overheating. At this time, the protection torque coefficient is directly set to 0, that is, the input torque is set to 0, and the power is cut off protectively. f(Q_acc(t)) can be a monotonically decreasing function, which can be in the form of piecewise linear or S-curve.

[0070] In some embodiments, after determining the protection torque coefficient, the user-inputted torque can be limited based on the protection torque coefficient to reduce the torque input to the differential, thereby achieving the desired protection of the differential.

[0071] Regarding the process of calculating the torque based on the protection torque coefficient, please refer to the following formula 6: T_diff_prot = T_driver_demand * η(t) Formula 6 Where T_driver_demand is the user-inputted required torque, and T_diff_prot is the protection torque used to control the differential after being limited by the protection torque coefficient.

[0072] In the above embodiments, the instantaneous heat dissipation power of the left and right drive wheels of the differential is determined by the current temperature of the differential and the ambient temperature of the differential. The instantaneous heat generation power of the differential is determined based on the user-input torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. Based on this, the current internal heat energy state of the differential is accurately determined. Whether the differential's operating state meets preset limits based on the current heat load is identified, thus more accurately determining whether the differential has an overheating risk. If so, the corresponding protection torque coefficient is determined based on the current heat load of the differential. On the one hand, compared to the method of determining the torque limiting coefficient by looking up a table in related technologies, the technical solution provided in this application determines the protection torque limiting coefficient based on the differential's heat load, making the determination process more targeted and improving the accuracy and real-time performance of differential protection. On the other hand, this application provides a calculation process for the current heat load. By calculating the instantaneous heat dissipation power and the instantaneous heat generation power, the current heat load data reflecting the current thermal energy state of the differential can be accurately calculated, providing accurate data for subsequent judgment on whether to perform overheat protection for the differential.

[0073] In some embodiments, the differential protection method provided in this application may further include the following steps: Step S106: Detect whether the traction control module of the target vehicle is in an active state.

[0074] Here, the traction control module is a functional module commonly used in vehicles to prevent drive wheel slippage, usually called the traction control system (TCS).

[0075] Understandably, in some scenarios, such as when the target vehicle is driving on a low-friction surface, the vehicle slips. At this time, the traction control module is activated and outputs a control torque to limit the operation of the differential to optimize traction performance and thus prevent the drive wheels from slipping. However, in this scenario, vehicle slippage will cause a difference in the rotational speeds at both ends of the differential, and the thermal load of the differential will increase. When the current thermal load of the differential exceeds the first load threshold, the operation state of the target vehicle's differential meets the preset limit conditions, and the traction control system is activated. Both of these events will simultaneously limit the torque of the differential.

[0076] Therefore, in order to avoid conflicts in the control logic, it is necessary to detect whether the traction control module of the target vehicle is active.

[0077] In some embodiments, the activation status of the traction control module can be determined based on the corresponding status identifier of the traction control module.

[0078] Step S107: With the traction control module in an active state, acquire the control torque output by the traction control module.

[0079] In some embodiments, when the traction control module is in an active state, it is necessary to balance the control torque output by the traction control module with the protection torque coefficient determined by this application after determining that the operating state of the differential of the target vehicle meets the preset limiting conditions, so as to avoid conflict between the two protection mechanisms.

[0080] Here, the control torque output by the traction control module can refer to a torque value actively output by the traction control module when it is active, based on the current road conditions and degree of slippage, to control the operation of the differential. For example, on a wet and slippery surface, the traction control module may output a lower control torque to prevent the drive wheels from slipping further; while on a drier surface, the traction control module may allow a higher control torque output to improve the ability to get out of trouble.

[0081] In this embodiment of the application, the value corresponding to the control torque output by the traction control module can be obtained directly by communicating with the traction control module.

[0082] Based on the above, in some embodiments, if the operating state of the differential of the target vehicle meets the preset limiting conditions, the above step S105 "to perform protective control on the differential of the target vehicle according to the protection torque coefficient corresponding to the current heat load" includes: performing protective control on the differential of the target vehicle according to the protection torque coefficient and the control torque.

[0083] In some embodiments, when the operating state of the differential of the target vehicle meets the preset limiting conditions, the determined protection torque coefficient will limit the required torque input by the user to obtain the protection torque used to control the operation of the differential. If at the same time, the traction control module is in an active state, it will also control the differential based on the control torque output by the traction control module.

[0084] At this point, the protection torque and control torque need to be arbitrated and merged to determine the final torque used to control the operation of the differential.

[0085] In one possible implementation, the torque of the subsequent protection control differential can be selected from the protection torque and the control torque, depending on the current road conditions.

[0086] In another possible implementation, the protection torque and control torque can be weighted to determine the final torque used to control the operation of the differential.

[0087] Regarding the weights of the protective torque and the control torque, in some embodiments, they can be determined based on the current road conditions; in other embodiments, they can be preset based on empirical values.

[0088] In some embodiments, if the operating state of the differential of the target vehicle is found to meet preset restrictions, but the traction control system is not activated, the differential can be directly controlled according to the protection torque.

[0089] In the above embodiments, a traction control module for detecting the differential is introduced to determine whether it is activated. When activated, the module works with the traction control module to determine the final control torque used for differential protection, thereby avoiding control conflicts, improving the overall vehicle driving safety and stability, and achieving deep integration and optimization of differential protection and the target vehicle traction control module.

[0090] Figure 2 A schematic diagram of the implementation process of a differential protection method provided in this application embodiment. Figure 2 ,like Figure 3 As shown, "protective control of the differential of the target vehicle based on the protection torque coefficient and control torque" may include the following steps: Step S201: Determine the protection torque based on the protection torque coefficient and the required torque input by the user of the target vehicle.

[0091] Here, the required torque can refer to, but is not limited to, the desired output torque value input by the driver via the accelerator pedal or other control devices. The required torque reflects the driver's demand for vehicle power performance. The protective torque, on the other hand, is a limiting torque value determined by applying a protective torque coefficient to the required torque, used to prevent overheating or damage to the vehicle's differential. The calculation of the protective torque combines the protective torque coefficient and the required torque to achieve dynamic protection of the drive system.

[0092] In this embodiment, the calculation process for the protective torque can refer to the aforementioned formula 6.

[0093] Step S202: Arbitrate the protection torque and control torque to determine the execution torque.

[0094] Step S203: Protective control of the differential of the target vehicle is performed by applying torque.

[0095] In this embodiment, both the protection torque and the control torque limit the differential. To avoid this conflict, the protection torque and the control torque need to be arbitrated to determine the final execution torque used to control the operation of the differential.

[0096] Regarding the arbitration process, it's understandable that it typically involves comparing the protective torque with the control torque, and determining the final torque value to be executed through a pre-defined arbitration fusion strategy. This arbitration fusion strategy can employ methods such as weighted averaging, minimum value selection, or dynamic adjustment based on current operating conditions. For example, when the target vehicle's differential is under high thermal load, the arbitration mechanism may favor the protective torque in order to prioritize the safety of the target vehicle's differential.

[0097] In one possible implementation, the process of determining the execution torque may include: obtaining the road surface adhesion coefficient through the traction control module; calculating the arbitration coefficient based on the road surface adhesion coefficient and the current thermal load; and determining the execution torque by weighting the protection torque and the control torque using the arbitration coefficient.

[0098] Here, the coefficient of friction (COP) refers to the magnitude of the friction between the tire and the road surface, reflecting the tire's ability to effectively transmit driving or braking forces. For example, the COP is lower on icy or snowy roads, while it is higher on dry asphalt roads. The COP is crucial for determining whether a vehicle is in a slippery condition.

[0099] Understandably, the traction control module typically detects whether the drive wheels are slipping and outputs control torque to control them. It can monitor and control the adhesion state between the vehicle's drive wheels and the ground. The traction control module can collect road surface information (such as tire slip rate, wheel speed difference, etc.) through sensors to estimate the road surface adhesion coefficient of the current driving section. Therefore, the road surface adhesion coefficient can be obtained directly through the traction control module.

[0100] In this embodiment, the arbitration coefficient can be calculated based on the road surface adhesion coefficient and the current thermal load. Here, the arbitration coefficient is a dynamic weighting factor. In the process of integrating the control torque and the protection torque, the arbitration coefficient is used as a weighting coefficient for the control and protection torque. The calculation of the arbitration coefficient depends on two key variables: the current thermal load state and the road surface adhesion coefficient.

[0101] The calculation process for the arbitration coefficient can be referred to the following formula 7: λ = g(Q_acc(t), μ) Formula 7 Where μ is the road surface adhesion coefficient and λ is the arbitration coefficient, the function gkeyi1 dynamically determines the priority of the two controls based on the current heat load and road surface adhesion xishu1. For example, when Q_acc is extremely high or μ is extremely low, λ tends to protect the torque (λ is larger); when the heat load is moderate and the road surface needs to be extricated, λ tends to control the torque (λ is smaller).

[0102] The process of weighting the protection torque and control torque using arbitration coefficients can be referenced in Formula 8 below: T_final = λ * T_diff_prot + (1 - λ) * T_TCS Formula 8 Among them, T_diff_prot is the protection torque, T_TCS is the control torque, and T_final is the execution torque.

[0103] In this way, the road adhesion coefficient can be easily obtained through the traction control module, and the protection torque and control torque in the module are weighted and arbitrated in combination with the current thermal load state, so as to obtain the final execution torque used to control the differential, so that the vehicle can still maintain good driving stability and safety under complex working conditions.

[0104] In another possible implementation, the process of determining the execution torque may include: acquiring current operating condition information through an information acquisition device, the current operating condition information including at least the current thermal load and the road surface adhesion coefficient; and selecting a target torque from the protection torque and the control torque as the execution torque corresponding to the current moment based on the current operating condition information.

[0105] Here, information acquisition equipment refers to sensors or measuring devices used to collect data related to the differential's thermal state and driving environment during vehicle operation. Information acquisition equipment may include, but is not limited to, wheel speed sensors, temperature sensors, oil temperature sensors, yaw rate sensors, etc. Through information acquisition equipment, key parameters such as differential input torque, output shaft speed difference, lubricating oil temperature, ambient temperature, and road surface adhesion coefficient can be obtained in real time.

[0106] In this embodiment of the application, current operating condition information can be collected by an information collection device, including at least the current heat load and the road surface adhesion coefficient. The current operating condition information can be used to determine whether the current condition is a high-risk condition that may cause the differential to overheat or slip.

[0107] In some embodiments, based on the current operating condition information, the final execution torque can be determined by dynamic interpolation between min(T_diff_prot,T_TCS) and max(T_diff_prot,T_TCS).

[0108] For example, when the differential is overheated, the max(T_diff_prot,T_TCS) formula can be used to select a larger torque as the final execution torque; when the heat load is not high and the road surface adhesion coefficient is low, the min(T_diff_prot,T_TCS) formula can be used to select a smaller torque as the final execution torque.

[0109] In this way, information acquisition equipment is introduced to obtain current operating condition information in real time, and dynamic arbitration is performed on the protection torque and control torque based on the current operating condition information to realize intelligent coordination between differential protection and vehicle traction control, thereby improving vehicle safety and handling.

[0110] By obtaining the final execution torque through the above embodiments and applying the execution torque to the differential of the target vehicle, the speed difference between the two sides of the differential of the target vehicle can be effectively controlled, thereby reducing the risk of friction and heat generation caused by slippage.

[0111] Figure 3 A schematic diagram of the implementation process of a differential protection method provided in this application embodiment. Figure 4 ,like Figure 4 As shown, the process of "determining the protection torque coefficient corresponding to the current thermal load of the differential" may include the following steps: Step S301: If the current heat load is greater than or equal to the first load threshold and less than the second load threshold, determine the protection torque coefficient corresponding to the current moment based on the current heat load.

[0112] Among them, the first load threshold is less than the second load threshold, and the protection torque coefficient is not less than the minimum torque limit coefficient.

[0113] Step S302: If the current heat load is greater than or equal to the second load threshold, determine the protection torque coefficient as the first target value.

[0114] Among them, the first target value is less than the minimum torque coefficient.

[0115] Here, the second load threshold is the aforementioned safety threshold. If the current heat load reaches the second load threshold, it can be determined that the differential has reached an extremely dangerous level.

[0116] Therefore, when the current heat load is detected to be greater than or equal to the first load threshold and less than the second load threshold, protective limiting measures are required.

[0117] The calculation process for the protection torque coefficient can be referred to Formula 5 mentioned above.

[0118] Here, the minimum torque limit coefficient is a preset lower limit value, which is the minimum value that the protection torque coefficient can reach when the current thermal load is between the first load threshold and the second load threshold. By limiting the minimum torque limit coefficient, the differential can be prevented from being cut off due to false triggering. Therefore, the protection torque coefficient calculated in the end is not less than the minimum torque limit coefficient.

[0119] Understandably, when the current thermal load of the differential rises further and exceeds the second load threshold, it indicates that the internal temperature of the differential is approaching its design limit, and more stringent protective measures must be taken immediately. Therefore, when the current thermal load of the differential exceeds the second load threshold, the protection torque coefficient can be fixed to a first target value lower than the minimum torque limit coefficient, thereby minimizing heat accumulation.

[0120] In some embodiments, the first target value can be determined by experimental data and safety boundaries. The goal of this target value is to ensure that the differential does not suffer irreversible damage due to overheating. In one possible implementation, the first target value can be 0. In this way, when the current thermal load of the differential exceeds the second load threshold, the power to the differential can be directly cut off to prevent the thermal load from rising further.

[0121] In the above embodiments, by setting tiered heat load ranges and dynamically adjusting them in conjunction with the current heat load and the first target value, the thermal risk status of the differential can be assessed more accurately, thereby achieving a reasonable allocation of the protection torque coefficient. Through this method, an appropriate level of protection can be provided under different operating conditions, thus avoiding performance loss or safety hazards caused by excessive or insufficient restriction.

[0122] In some embodiments, as the thermal load of the differential gradually decreases, the protection torque coefficient also needs to gradually return to normal. This process may include: determining a safe time period when the current thermal load is less than a third load threshold and the speed difference between the two ends of the differential of the target vehicle is less than a safe speed difference threshold, wherein the third load threshold is less than a first load threshold; and after the safe time period has elapsed, restoring the protection torque coefficient to a second target value, wherein the second target value is greater than the protection torque coefficient.

[0123] Here, the third load threshold is a limit value that is less than the first load threshold. When the current thermal load of the differential is consistently less than the third load threshold, it can be determined that the internal thermal load of the differential remains within a safe range.

[0124] Understandably, in order to avoid misjudgment caused by environmental factors, it is also necessary to check whether the speed difference between the two ends of the differential has also decreased to below the safe speed difference threshold.

[0125] In some embodiments, if the differential maintains a current thermal load less than a third load threshold and the speed difference between its two ends is lower than a safe speed difference threshold, monitoring can begin to determine whether the duration for which the differential maintains this state has reached a safe duration.

[0126] Here, the safe duration can be set according to preset rules. When the differential continuously maintains a front heat load less than the third load threshold and the speed difference between the two ends is lower than the safe speed difference threshold for a safe duration, it can be determined that the differential has returned to normal operation. At this time, the protection torque coefficient needs to be gradually restored to the normal value, i.e., the second target value. In some embodiments, the second target value is 1.

[0127] In one possible implementation, the recovery process can be gradual to prevent sudden torque changes from causing a discontinuous driving experience. For example, the protection torque coefficient can be set to gradually increase according to a linear function or an S-curve, and the recovery rate can be adjusted based on the decreasing trend of the current heat load. Alternatively, the recovery rate can be correlated with the difference between the current heat load and a first compliance threshold. In this way, dynamically adjusting the recovery rate can achieve a more intelligent and smooth exit process.

[0128] In the above embodiments, by setting a safe duration when the differential of the target vehicle has a low thermal load and a small speed difference, and restoring the protection torque coefficient according to the set safe duration, the actual thermal state of the differential of the target vehicle can be reflected more accurately, thereby avoiding secondary risks caused by premature restoration.

[0129] The process of "restoring the protection torque coefficient to the second target value" may include: determining the rate of decrease of thermal load based on the thermal load of the differential of the target vehicle at different times; determining the recovery rate based on the rate of decrease of thermal load; and restoring the protection torque coefficient to the second target value based on the recovery rate.

[0130] Here, the rate of decrease in heat load can be used to represent the rate of change of heat load over time, i.e., d(Q_acc(t)) / dt. In some embodiments, the rate of decrease in heat load reflects the rate at which the internal temperature of the differential is cooling, and is an important basis for determining whether it is safe to exit the protection state.

[0131] The rate of decrease in heat load can be determined based on the heat load of the differential at different times.

[0132] In this embodiment of the application, the recovery rate of the protection torque coefficient can be determined based on the rate of decrease in heat load. Here, the recovery rate refers to the speed at which the protection torque coefficient η(t) recovers to the normal second target value.

[0133] Understandably, when the rate of decrease in heat load is large, it indicates that the thermal state of the differential is recovering rapidly, and the recovery speed of the protection torque coefficient can be accelerated. Conversely, if the rate of decrease in heat load is slow, the recovery speed should be slowed down to avoid secondary risks caused by premature release of protection.

[0134] Once the recovery rate is determined, the protection torque coefficient can be gradually increased according to the set recovery rate. For example, the protection torque coefficient can be smoothly transitioned from a current lower value (e.g., 0.2) to a second target value (1.0). The process of gradually increasing the protection torque coefficient according to the set recovery rate usually lasts from several seconds to tens of seconds, depending on the rate of heat load decrease and the minimum / maximum recovery rate limits set by the system.

[0135] For example, if the initial protection torque coefficient is 0.2, the target recovery value is 1.0, and the recovery rate is 0.05 / s, the control system will complete the recovery after 16 seconds. This gradual recovery method effectively prevents driving shock caused by sudden torque changes, improving ride comfort.

[0136] In the above embodiments, by dynamically adjusting the recovery rate according to the rate of decrease in differential thermal load, and thereby achieving a gradual recovery of the protection torque coefficient, the risk of damage caused by premature exit of protection can be avoided, thereby improving the overall reliability of the system and the driving experience.

[0137] The following describes the application of the embodiments of this application in a real-world scenario.

[0138] In electric or hybrid vehicles, the electric drive system consists of a drive motor, a reducer, and a differential. When the vehicle is traveling on surfaces with one wheel off the ground, low traction surfaces, or with one wheel suspended in the air, the drive wheel on the side with low traction is prone to slippage and spinning, resulting in a significant speed difference between the output shafts on both sides of the differential. This sustained large speed difference causes the gears, bearings, and other components inside the differential to generate a large amount of frictional heat due to high-speed relative motion. If heat dissipation is insufficient, the differential temperature will rise sharply, leading to a decrease in lubricating oil performance, tooth surface seizing, and ultimately damage to the differential, seriously affecting driving safety.

[0139] To address this issue, existing technologies primarily limit motor torque by monitoring parameters such as speed difference and oil temperature. However, this approach has the following drawbacks: The control logic is rather mechanical: it mainly relies on looking up discrete parameters in a table to obtain the torque limiting coefficient, and fails to perform continuous, dynamic, and precise control based on the physical nature of differential thermal balance.

[0140] The protection triggering and deactivation are not intelligent enough: the triggering conditions rely on a fixed combination of thresholds, and the deactivation conditions are simple. They fail to fully reflect the real-time heat accumulation and heat dissipation status of the differential, which may lead to delayed protection intervention or abrupt recovery.

[0141] Limited inter-system coordination: The lack of deep integration and intelligent coordination with the vehicle's traction control system (TCS) at the information and control levels may lead to control conflicts or efficiency losses.

[0142] Therefore, there is a need for a differential protection method that can accurately estimate the differential thermal load in real time, perform adaptive and smooth torque control based on thermal conditions, and can intelligently coordinate with TCS.

[0143] The core concept of this application is to construct a real-time thermal load estimation model for the differential based on physical principles, using this model as the core to drive the entire process control of differential protection. By continuously calculating the heat generation and heat dissipation power of the differential, a "virtual thermal load value" reflecting its thermal state is obtained in real time. This thermal load value is not only used to accurately trigger protection, but also serves as a key input to dynamically adjust the torque limiting coefficient and guide the smooth deactivation of the protection function. Simultaneously, a two-way information sharing and intelligent collaborative arbitration mechanism with the TCS system is designed to achieve coordinated optimization of differential thermal protection and vehicle traction control.

[0144] Compared with existing technologies, this application differs fundamentally in its technical approach: Existing technology: The torque limiting coefficient is obtained by "direct mapping lookup of multiple parameters (speed difference, oil temperature, etc.)," ​​which is a rule-based discrete control.

[0145] This application employs "continuous estimation of heat load model + model-based state feedback control", which is a continuous dynamic control based on physical processes.

[0146] This model-based approach can more accurately and fundamentally reflect the thermal state of the differential, thereby enabling more forward-looking, smoother, and smarter protection control.

[0147] The technical solution of this application is as follows: 1. System Composition Core controller: Vehicle Controller Unit (VCU), responsible for executing this method.

[0148] Sensor input: a) Left and right drive wheel speed sensors (n1, n2).

[0149] b) Motor output torque sensor or estimated value (T_m).

[0150] c) Differential lubricating oil temperature sensor (optional, for model calibration).

[0151] d) Ambient temperature sensor (T_amb).

[0152] e) (Optional) Vehicle yaw rate and steering wheel angle signal.

[0153] Communication and interaction: a) The VCU communicates with the motor controller (MCU) to send torque requests.

[0154] b) The VCU communicates with the traction control system (TCS) controller to achieve information sharing and collaboration.

[0155] 2. Real-time heat load estimation model for differential The model is based on the first law of thermodynamics and calculates the differential's "virtual heat load value" Q_acc (unit: joules) in real time, which reflects the current accumulated thermal energy state of the differential.

[0156] The calculation process for heat load: (1) The calculation process for instantaneous frictional heating power can be referred to the following formula 9: P_fric = k * |T_input| * |Δω| Formula 9 Where T_input is the differential input torque (which can be approximated by the motor output torque T_m); Δω is the angular velocity difference between the left and right output ends of the differential, Δω = 2π * (|n1 - n2|) / 60 (unit: rad / s); k is the equivalent friction coefficient, which is calibrated through bench testing and is related to the differential structure and lubrication conditions.

[0157] (2) The instantaneous heat dissipation power calculation process can refer to the following formula 10: P_diss = C * (T_diff - T_amb) (Formula 10) Where T_diff is the estimated current temperature of the differential, which can be calculated based on Q_acc, differential heat capacity and initial temperature; T_amb is the ambient temperature; C is the comprehensive heat dissipation coefficient, which takes into account the heat dissipation of the differential housing, oil convection heat dissipation, etc., and can be calibrated by test and can be dynamically corrected in relation to vehicle speed (the higher the vehicle speed, the larger C is).

[0158] (3) Update of heat load status: The process of updating the heat load value for each control cycle (e.g., 10ms) can be referenced by the following formula 11: Q_acc(t) = Q_acc(t-Δt) + (P_fric - P_diss) * Δt Formula 11 The initial value of Q_acc can be set to 0 or initialized based on the oil temperature. When Q_acc exceeds the preset thermal load critical threshold (Q_critical, corresponding to the differential design limit temperature), it indicates that the differential is at risk of burning.

[0159] 3. Layered protection control logic based on heat load Step S1: Data acquisition and basic calculations.

[0160] The VCU collects signals such as n1, n2, T_m, T_amb in real time, calculates Δn = |n1 - n2| and Δω. According to the above heat load model, Q_acc(t) is calculated in real time.

[0161] Step S2: Protection trigger judgment.

[0162] Design a more intelligent trigger condition, comprehensively considering the heat load status and continuous risk: Main trigger condition: When Q_acc(t) ≥ the first preset heat load threshold (Q_warning, less than Q_critical), it indicates that the differential heat load has reached the warning level, and enters the protection ready state.

[0163] Auxiliary confirmation condition: On the premise that the main trigger condition is satisfied, if any of the following conditions is met, the protection is officially triggered and the torque limit control is executed: a) Δn ≥ the preset rotational speed difference threshold Δn_th, and the continuous duration reaches the preset time threshold Δt_th.

[0164] b) The heat load growth rate (dQ_acc / dt) exceeds the preset growth rate threshold.

[0165] This "heat load priority + continuous risk confirmation" mechanism can not only respond to heat risks in a timely manner, but also avoid false triggers caused by short-term normal slips.

[0166] Step S3: Determination of the dynamic torque limit coefficient and torque limitation.

[0167] Once the protection is triggered, the VCU determines a dynamic torque limit coefficient η(t) according to the current Q_acc(t).

[0168] η(t) = f(Q_acc(t)): The function f is a monotonically decreasing function. For example, a piecewise linear or S-curve form can be adopted: When Q_acc(t) < Q_warning, η(t) = 1.0 (no torque limit).

[0169] When Q_warning ≤ Q_acc(t) < Q_critical, η(t) linearly / curvely decreases from 1.0 to the minimum torque limit coefficient η_min (such as 0.2).

[0170] When Q_acc(t) ≥ Q_critical, η(t) = 0 (the requested torque is 0, and the power is cut off protectively).

[0171] Initial torque limit calculation: T_diff_prot = T_driver_demand * η(t), where T_driver_demand is the driver's demanded torque.

[0172] Final torque determination: See “Intelligent Collaboration with TCS” below.

[0173] Step S4: Intelligent collaborative arbitration mechanism with TCS.

[0174] To resolve the potential conflict when differential protection and TCS function are activated simultaneously, the following coordination strategy is designed: (1) Two-way information sharing: The VCU sends the real-time thermal load status of the differential (Q_acc value and corresponding temperature level) to the TCS controller.

[0175] The TCS controller sends its current activation state, target torque T_TCS, and identified road adhesion coefficient (μ) to the VCU.

[0176] (2) Collaborative Arbitration Logic: If only differential protection is activated, then the torque T_final = T_diff_prot is executed.

[0177] If only TCS is activated, then the torque T_final = T_TCS is executed.

[0178] If both are activated simultaneously, the system enters intelligent arbitration mode: Arbitration factor λ calculation: λ=g(Q_acc,μ), where function g dynamically determines the priority of control based on the current heat load and road surface adhesion. For example, when Q_acc is extremely high or μ is extremely low, λ tends to protect the differential (λ is larger); when the heat load is moderate and traction is required, λ tends to control TCS (λ is smaller).

[0179] Weighted fusion or minimum value selection: adopt a fusion strategy, T_final=λ*T_diff_prot+(1-λ)*T_TCS, or use dynamic interpolation between min(T_diff_prot,T_TCS) and max(T_diff_prot,T_TCS) according to the working conditions.

[0180] Torque change rate limit: Regardless of the arbitration strategy used, the rate of change (dT_final / dt) of the final torque T_final is clamped to prevent sudden torque changes from causing vehicle impact.

[0181] Step S5: Model-based smooth exit mechanism.

[0182] Once protection is triggered, Q_acc(t) is continuously monitored. The exit conditions are more rigorous and model-based. Exit Check: The exit procedure will begin when all of the following conditions are met: Q_acc(t) < The second preset heat load threshold Q_release (Q_release < Q_warning, with a hysteresis characteristic to prevent oscillation).

[0183] Δn < The safe speed difference threshold Δn_safe and remains below it for a safety confirmation time t_safe (such as 3 seconds).

[0184] Progressive torque recovery: During the exit process, the torque limit coefficient η(t) does not immediately jump back to 1.0 but recovers gradually based on the heat load decrease rate. For example: The recovery rate is positively correlated with (ΔQ / Δt) or (Q_warning - Q_acc). The faster the heat load decreases or the lower the remaining heat load, the faster the recovery can be.

[0185] Adopt a linear or S - curve to smoothly and asymptotically recover η(t) from the current value to 1.0, and the minimum / maximum rate limits can be set during the recovery process. Thus, a true "thermal state recovery" is achieved to ensure driving smoothness.

[0186] Step S6: Road condition adaptive parameter adjustment (optional optimization).

[0187] The VCU can identify the current road condition (such as an oncoming traffic road surface, a low - adhesion ice - snow road surface) based on wheel speed characteristics, vehicle status, etc. For different road conditions, dynamically adjust the model parameters or control thresholds. For example: Oncoming traffic road surface: Appropriately increase Q_warning and Δt_th, and adopt a milder initial change rate of η(t) to balance脱困 and protection.

[0188] Low - adhesion ice - snow road surface: Adopt stricter Q_warning and η_min to ensure the safety of the differential first.

[0189] The technical solutions provided by this application have the following technical effects: 1. More precise control and more in line with physical essence: Abandon the mechanical method based on discrete parameter look - up tables in the prior art, and innovatively introduce a continuous heat load estimation model based on thermodynamics principles. The protection decision is directly based on the core physical quantity of the continuous "heat load value", realizing real - time and precise perception and control of the differential thermal state, and the control is more accurate and scientific.

[0190] 2. Smarter and smoother triggering and exit: The protection trigger adopts a dual mechanism of "heat load priority + continuous risk confirmation", which is both forward - looking and prevents false triggering. The exit condition is strictly based on the "virtual heat load value" dropping to a safe level and stabilizing, and a dynamic progressive recovery mechanism associated with the heat load decrease rate is designed instead of a simple linear recovery, greatly improving driving smoothness and comfort.

[0191] 3. Achieved deep intelligent collaboration with the TCS system: Beyond the simple "minimum torque" logic of existing technologies, a two-way information sharing and intelligent arbitration factor adjustment strategy based on thermal load and road surface adhesion were designed. This enabled dynamic and collaborative optimization between differential thermal protection and vehicle traction control, resolved control conflicts between systems, and improved the overall performance and safety of the vehicle.

[0192] 4. Strong System Robustness and Adaptability: The core is based on a physical model, exhibiting robustness to sensor noise and parameter variations. Optional road condition adaptive functionality allows the system to automatically optimize protection strategies in different scenarios, broadening its application range.

[0193] Based on the foregoing embodiments, this application provides a differential protection device, which includes various units and modules included in each unit. It can be implemented by a vehicle processor in the vehicle; of course, it can also be implemented by specific logic circuits. In the implementation process, the processor can be a central processing unit (CPU), a microprocessor unit (MPU), a digital signal processor (DSP), or a field programmable gate array (FPGA), etc.

[0194] Figure 5 This is a schematic diagram of the composition structure of a differential protection device provided in an embodiment of this application, as shown below. Figure 5 As shown, the differential protection device 400 includes: a coefficient determination module 401, a detection module 402, an acquisition module 403, and a protection module 404, wherein: The heat dissipation determination module 401 is used to determine the instantaneous heat dissipation power of the left and right drive wheels of the differential based on the current temperature of the differential and the ambient temperature where the differential is located. The heat generation determination module 402 is used to determine the instantaneous heat generation power of the differential based on the user-input required torque of the target vehicle and the speed difference between the left and right drive wheels of the differential. The heat load determination module 403 is used to determine the current heat load based on the instantaneous heat dissipation power and the instantaneous heat generation power; The detection module 404 is used to detect whether the operating status of the differential of the target vehicle meets the preset limit conditions based on the current heat load. The protection module 405 is used to protect the differential of the target vehicle if the operating state of the differential of the target vehicle meets the preset limit conditions, based on the protection torque coefficient corresponding to the current heat load.

[0195] In some embodiments, the differential protection device 400 further includes: The activation detection module is used to detect whether the traction control module of the target vehicle is in an active state. The acquisition module is used to acquire the control torque output by the traction control module when the traction control module is in an active state. The aforementioned protection module 405 is specifically used to perform protection control on the differential of the target vehicle based on the protection torque coefficient and the control torque.

[0196] In some embodiments, the protection module 405 includes: The protection torque determination unit is used to determine the protection torque based on the protection torque coefficient and the required torque input by the user of the target vehicle. The arbitration unit is used to arbitrate the protection torque and the control torque to determine the execution torque; The control unit is used to provide protective control over the differential of the target vehicle by applying torque.

[0197] In some embodiments, the arbitration unit is specifically used to perform: The road surface adhesion coefficient is obtained through the traction control module; The arbitration coefficient is calculated based on the road surface adhesion coefficient and the current heat load. The execution torque is determined by weighting the protection torque and control torque using arbitration coefficients.

[0198] In some embodiments, the arbitration unit is specifically used to perform: The current operating condition information is obtained through information acquisition equipment. The current operating condition information includes at least the current heat load and the road surface adhesion coefficient. Based on the current operating condition information, the target torque is selected from the protection torque and control torque as the execution torque corresponding to the current moment.

[0199] In some embodiments, the coefficient determination module 401 includes: The first determining unit is used to determine the protection torque coefficient corresponding to the current moment based on the current heat load when the current heat load is greater than or equal to the first load threshold and less than the second load threshold. The first load threshold is less than the second load threshold, and the protection torque coefficient is not less than the minimum torque limit coefficient. The second determining unit is used to determine the protection torque coefficient as a first target value when the current heat load is greater than or equal to the second load threshold, and the first target value is less than the minimum torque limit coefficient.

[0200] In some embodiments, the coefficient determination module 401 further includes: The third determining unit determines the safe duration when the current heat load is less than the third load threshold and the speed difference between the two ends of the differential of the target vehicle is less than the safe speed difference threshold. The third load threshold is less than the first load threshold. The recovery unit is used to restore the protection torque coefficient to a second target value after a safe period of time, the second target value being greater than the protection torque coefficient.

[0201] In some embodiments, the recovery unit is specifically used to perform: Determine the rate of decrease in heat load based on the heat load of the target vehicle's differential at different times; The recovery rate is determined based on the rate of decrease in heat load. The protection torque coefficient is restored to the second target value based on the recovery rate.

[0202] In some embodiments, the apparatus further includes: The identification module is used to acquire the current thermal load of the differential, the speed difference between its two ends, and the thermal load growth rate; when the current thermal load is greater than a first load threshold, it detects whether the time for the speed difference between its two ends to be greater than the speed difference threshold is greater than a time threshold, and / or whether the thermal load growth rate of the differential of the target vehicle reaches the growth rate threshold; if the current thermal load is greater than the first load threshold, and the time for the speed difference between its two ends to be greater than the speed difference threshold is greater than the time threshold, and / or the thermal load growth rate is greater than the growth rate threshold, it determines that the operating state of the differential of the target vehicle meets the preset restriction conditions.

[0203] It should be noted that, in the embodiments of this application, if the above-mentioned differential protection method is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, or the part that contributes to the related technology, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause the vehicle to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), magnetic disks, or optical disks. Thus, the embodiments of this application are not limited to any specific hardware, software, or firmware, or any combination of hardware, software, and firmware.

[0204] This application provides a vehicle in which the processor executes some or all of the steps in the above method when executing the program.

[0205] This application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements some or all of the steps in the above-described method. The computer-readable storage medium can be transient or non-transient.

[0206] This application provides a computer program including computer-readable code, wherein when the computer-readable code is run in a vehicle, a vehicle processor in the vehicle executes some or all of the steps in the above-described method.

[0207] This application provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program. When the computer program is read and executed by a computer, it implements some or all of the steps in the above-described method. This computer program product can be implemented specifically through hardware, software, or a combination thereof. In some embodiments, the computer program product is specifically embodied as a computer storage medium; in other embodiments, the computer program product is specifically embodied as a software product, such as a software development kit (SDK), etc.

[0208] It should be noted that the descriptions of the various embodiments above tend to emphasize the differences between them, while their similarities or commonalities can be referenced interchangeably. The descriptions of the vehicle, storage medium, computer program, and computer program product embodiments above are similar to the descriptions of the method embodiments above, and have similar beneficial effects. For technical details not disclosed in the vehicle, storage medium, computer program, and computer program product embodiments of this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0209] ​ This is a schematic diagram of the hardware entity of a vehicle provided in an embodiment of this application, such as... ​ As shown, the hardware entity of the vehicle 500 includes: a vehicle processor 501, a communication interface 502, and a memory 503, wherein: When the vehicle processor 501 executes the program, it implements the steps of any of the above-mentioned differential protection methods. The processor 501 typically controls the overall operation of the vehicle 500.

[0210] Communication interface 502 enables the vehicle to communicate with other terminals or servers via a network.

[0211] The memory 503 is configured to store instructions and applications executable by the vehicle processor 501, and can also cache data to be processed or already processed by the processor 501 and various modules in the vehicle 500 (e.g., image data, audio data, voice communication data, and video communication data). It can be implemented using flash memory or random access memory (RAM). Data transfer between the vehicle processor 501, the communication interface 502, and the memory 503 can be performed via bus 504.

[0212] This application provides a computer storage medium storing one or more programs that can be executed by one or more processors to implement the steps of the differential protection method as described in any of the above embodiments.

[0213] It should be noted that the descriptions of the storage medium and device embodiments above are similar to the descriptions of the method embodiments above, and have similar beneficial effects. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0214] The aforementioned vehicle processor can be at least one of the following: Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), Central Processing Unit (CPU), controller, microcontroller, and microprocessor. It is understood that other electronic devices can also implement the functions of the aforementioned processor, and this application does not specifically limit the specific implementation.

[0215] The aforementioned computer storage media / memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM), etc.; or it can be various terminals that include one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc.

[0216] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A differential protection method, characterized in that, The method includes: Based on the current temperature of the differential and the ambient temperature of the differential, determine the instantaneous heat dissipation power of the left and right drive wheels of the differential; The instantaneous heating power of the differential is determined based on the user-input torque demand of the target vehicle and the speed difference between the left and right drive wheels of the differential. The current heat load is determined based on the instantaneous heat dissipation power and the instantaneous heat generation power. Based on the current heat load, detect whether the operating status of the differential of the target vehicle meets the preset restrictions; If the operating state of the differential of the target vehicle meets the preset restriction conditions, the differential of the target vehicle is protected and controlled according to the protection torque coefficient corresponding to the current thermal load.

2. The method according to claim 1, characterized in that, Before performing protective control on the differential of the target vehicle based on the protection torque coefficient corresponding to the current thermal load, the method further includes: Detect whether the traction control module of the target vehicle is active; When the traction control module is in the activated state, the control torque output by the traction control module is obtained; The step of protecting and controlling the differential of the target vehicle based on the protection torque coefficient corresponding to the current heat load includes: The differential of the target vehicle is protected and controlled according to the protection torque coefficient and the control torque.

3. The method according to claim 2, characterized in that, The step of protecting and controlling the differential of the target vehicle based on the protection torque coefficient and the control torque includes: The protection torque is determined based on the protection torque coefficient and the required torque input by the user of the target vehicle. Arbitration is performed on the protection torque and the control torque to determine the execution torque; The differential of the target vehicle is protected by the torque applied.

4. The method according to claim 3, characterized in that, The arbitration process for the protection torque and the control torque to determine the execution torque includes: The road surface adhesion coefficient is obtained through the traction control module; The arbitration coefficient is calculated based on the road surface adhesion coefficient and the current heat load. The execution torque is determined by weighting the protection torque and the control torque using the arbitration coefficient.

5. The method according to claim 2, characterized in that, The arbitration process for the protection torque and the control torque to determine the execution torque includes: The current operating condition information is obtained through information acquisition equipment, and the current operating condition information includes at least the current heat load and the road surface adhesion coefficient. Based on the current operating condition information, a target torque is selected from the protection torque and the control torque as the execution torque corresponding to the current moment.

6. The method according to any one of claims 1 to 5, characterized in that, Determining the protection torque coefficient corresponding to the current thermal load of the differential includes: When the current heat load is greater than or equal to a first load threshold and less than a second load threshold, the protection torque coefficient corresponding to the current moment is determined based on the current heat load, wherein the first load threshold is less than the second load threshold and the protection torque coefficient is not less than the minimum torque limit coefficient; When the current heat load is greater than or equal to the second load threshold, the protection torque coefficient is determined to be a first target value, which is less than the minimum torque limit coefficient.

7. The method according to claim 6, characterized in that, The method further includes: When the current heat load is less than the third load threshold and the speed difference between the two ends of the differential of the target vehicle is less than the safe speed difference threshold, a safe duration is determined, wherein the third load threshold is less than the first load threshold. After the specified safe duration, the protection torque coefficient is restored to a second target value, which is greater than the protection torque coefficient.

8. The method according to claim 7, characterized in that, Restoring the protection torque coefficient to the second target value includes: Determine the rate of decrease in heat load based on the heat load of the differential of the target vehicle at different times; The recovery rate is determined based on the rate of decrease in heat load. The protection torque coefficient is restored to the second target value according to the recovery rate.

9. The method according to any one of claims 1 to 5, characterized in that, The step of detecting whether the operating state of the differential of the target vehicle meets preset restrictions includes: Obtain the current thermal load, the speed difference between the two ends, and the rate of increase of the thermal load of the differential; When the current heat load is greater than the first load threshold, it is detected whether the time when the speed difference between the two ends is greater than the speed difference threshold is greater than the time threshold, and / or whether the heat load growth rate of the differential of the target vehicle reaches the growth rate threshold. If the current heat load is greater than the first load threshold, and the time during which the speed difference between the two ends is greater than the speed difference threshold is greater than the time threshold, and / or the heat load growth rate is greater than the growth rate threshold, it is determined that the operating state of the differential of the target vehicle meets the preset restriction conditions.

10. A vehicle, comprising a memory and a vehicle processor, the memory storing a computer program executable on the processor, characterized in that, When the vehicle processor executes the program, it implements the steps of the method according to any one of claims 1 to 9.

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