Vehicle differential protection method and device, medium and electronic equipment

Abstract

The invention discloses a vehicle differential protection method and device, a medium and a vehicle. The method comprises the steps that the current differential power of a differential is obtained, and the current temperature of lubricating oil in the differential is obtained; according to pre-measured relational data, a first power threshold value matched with the current temperature is determined, and the relational data is a reverse relation representing the relation between the lubricating oil temperature and the power threshold value; and if the current differential power is larger than the first power threshold value, the differential mechanism is triggered to be protected. The performance of the differential mechanism is not limited.

Description

Technical Field

[0001] The present application relates to the technical field of differentials, and in particular, to a method, device, medium, and electronic device for protecting a vehicle differential. Background Art

[0002] Currently, in order to prevent the differential from failing, a fixed protection boundary is usually set for the differential. When the slip power of the differential exceeds the protection boundary, the differential protection function is activated, and a braking intervention torque is applied to the wheels to make the slip power of the differential return below the protection boundary.

[0003] However, in some application scenarios of the vehicle, the fixed protection boundary will limit the performance of the differential. Summary of the Invention

[0004] Embodiments of the present application provide a method, device, medium, and electronic device for protecting a vehicle differential, which are used to solve the technical problem that the fixed protection boundary will limit the performance of the differential when the vehicle is in some application scenarios.

[0005] Other features and advantages of the present application will become apparent through the following detailed description, or will be partially learned through the practice of the present application.

[0006] According to a first aspect of the present application, there is provided a method for protecting a vehicle differential, including:

[0007] Obtaining the current differential power of the differential and obtaining the current temperature of the lubricating oil in the differential;

[0008] Determining a first power threshold adapted to the current temperature according to pre-determined relationship data, where the relationship data is an inverse relationship characterizing the relationship between the lubricating oil temperature and the power threshold;

[0009] If the current differential power is greater than the first power threshold, trigger protecting the differential.

[0010] In some embodiments of the present application, based on the foregoing solution, the triggering of protecting the differential includes: obtaining a braking intervention torque and obtaining a power source intervention torque; if braking intervention on the target wheel is allowed, protecting the differential by applying the braking intervention torque to the target wheel, where the target wheel is the wheel with a higher wheel speed among the two wheels, and the two wheels are driven by the differential; if braking intervention on the target wheel is not allowed, protecting the differential by applying the power source intervention torque to the power source, where the power source is used to drive the differential.

[0011] In some embodiments of the present application, based on the foregoing solution, the triggering for protecting the differential includes: if braking intervention on the target wheel is allowed, determining a second power threshold adapted to the current temperature according to the relationship data, where the second power threshold is greater than the first power threshold; if the current differential power is greater than or equal to the second power threshold, protecting the differential by applying the braking intervention torque to the target wheel and applying the power source intervention torque to the power source.

[0012] In some embodiments of the present application, based on the foregoing solution, the protecting the differential by applying the braking intervention torque to the target wheel includes: obtaining the current braking torque of the target wheel, and on the basis of the current braking torque, protecting the differential by increasing the braking intervention torque to the target wheel; the protecting the differential by applying the power source intervention torque to the power source includes: obtaining the current power source torque of the power source, and on the basis of the current power source torque, protecting the differential by reducing the power source intervention torque to the power source.

[0013] In some embodiments of the present application, based on the foregoing solution, the obtaining the braking intervention torque includes: obtaining a braking torque threshold; determining the braking intervention torque according to the braking torque threshold, where the braking intervention torque is less than or equal to the braking torque threshold.

[0014] In some embodiments of the present application, based on the foregoing solution, the obtaining the power source intervention torque includes: obtaining a current torque coefficient and obtaining a first power source torque; determining the product of the current torque coefficient and the first power source torque as the first power source intervention torque.

[0015] In some embodiments of the present application, based on the foregoing solution, the obtaining the current torque coefficient includes: obtaining the current wheel speed difference acceleration of the two sides of the wheels; determining the current power ratio of the current differential power to the first power threshold; determining the current torque coefficient according to the current wheel speed difference acceleration and the current power ratio.

[0016] In some embodiments of the present application, based on the foregoing solution, the determining the current torque coefficient according to the current wheel speed difference acceleration and the current power ratio includes: obtaining the current torque coefficient from a pre-established target mapping relationship according to the current wheel speed difference acceleration and the current power ratio, where the target mapping relationship is a mapping of wheel speed difference acceleration, power ratio and torque coefficient.

[0017] In some embodiments of the present application, based on the foregoing solution, the obtaining of the torque of the first power source includes: obtaining the torque of the second power source and obtaining a preset power source torque, where the preset power source torque is greater than or equal to 0; determining the difference between the torque of the second power source and the braking intervention torque as the torque of the third power source; if the torque of the third power source is greater than 0, using the torque of the third power source as the torque of the first power source; if the torque of the third power source is less than or equal to 0, using the preset power source torque as the torque of the first power source.

[0018] In some embodiments of the present application, based on the foregoing solution, the obtaining of the torque of the second power source includes: obtaining a torque correction coefficient and obtaining the current input torque of the differential; determining the product of the torque correction coefficient and the current input torque as the torque of the second power source.

[0019] In some embodiments of the present application, based on the foregoing solution, the obtaining of the torque correction coefficient includes: obtaining the torsion ratio of the differential; determining a second difference between the torsion ratio and 1, and determining a first sum of the torsion ratio and 1; determining the quotient of the second difference and the first sum as the torque correction coefficient.

[0020] In some embodiments of the present application, based on the foregoing solution, it further includes: obtaining a power source torque threshold; determining the power source intervention torque according to the first power source intervention torque and the power source torque threshold.

[0021] In some embodiments of the present application, based on the foregoing solution, the determining of the power source intervention torque according to the first power source intervention torque and the power source torque threshold includes: obtaining a second power source intervention torque, where the second power source intervention torque is a non - negative value less than or equal to the power source torque threshold; if the first power source intervention torque is greater than the power source torque threshold, using the second power source intervention torque as the power source intervention torque; if the first power source intervention torque is less than or equal to the power source torque threshold, using the first power source intervention torque as the power source intervention torque.

[0022] In some embodiments of the present application, based on the foregoing solution, the obtaining of the power source torque threshold includes: obtaining the current input torque of the differential and obtaining a power source torque correction value, where the power source correction value is greater than 0; determining the difference between the current input torque and the power source torque correction value as the power source torque threshold.

[0023] In some embodiments of the present application, based on the foregoing solution, the obtaining of the power source torque correction value includes: obtaining the current road surface gradient, the tire rolling radius of the vehicle, and the current gravity of the vehicle; determining the product of the sine value of the current road surface gradient, the tire rolling radius, and the current gravity as the power source torque correction value.

[0024] In some embodiments of the present application, based on the foregoing solution, the obtaining of the current differential power of the differential includes: obtaining the current input torque and the torsion ratio of the differential, and obtaining the current wheel speed difference between the two wheels driven by the differential; determining the current differential power according to the current input torque, the torsion ratio, and the current wheel speed difference.

[0025] According to a second aspect of the present application, there is provided a vehicle differential protection device, including:

[0026] A first obtaining unit that obtains the current differential power of the differential and obtains the current temperature of the lubricating oil in the differential;

[0027] A first determining unit that determines a first power threshold adapted to the current temperature according to pre-determined relationship data, where the relationship data is an inverse relationship characterizing the relationship between the lubricating oil temperature and the power threshold;

[0028] A first protection unit that triggers the protection of the differential if the current differential power is greater than the first power threshold.

[0029] In some embodiments of the present application, based on the foregoing solution, the first protection unit is configured as: a second obtaining unit that obtains a braking intervention torque and obtains a power source intervention torque; a second protection unit that, if braking intervention on a target wheel is allowed, protects the differential by applying the braking intervention torque to the target wheel, where the target wheel is the wheel with a higher wheel speed among the two wheels driven by the differential; a third protection unit that, if braking intervention on the target wheel is not allowed, protects the differential by applying the power source intervention torque to the power source, where the power source is used to drive the differential.

[0030] In some embodiments of the present application, based on the foregoing solution, the first protection unit is further configured as: a second determining unit that, if braking intervention on the target wheel is allowed, determines a second power threshold adapted to the current temperature according to the relationship data, where the second power threshold is greater than the first power threshold; a fourth protection unit that, if the current differential power is greater than or equal to the second power threshold, protects the differential by applying the braking intervention torque to the target wheel and applying the power source intervention torque to the power source.

[0031] In some embodiments of the present application, based on the foregoing solution, the second protection unit is configured as follows: a fifth protection unit, which obtains the current braking torque of the target wheel, and on the basis of the current braking torque, protects the differential by adding the braking intervention torque to the target wheel; the third protection unit is configured as follows: a sixth protection unit, which obtains the current power source torque of the power source, and on the basis of the current power source torque, protects the differential by reducing the power source intervention torque from the power source.

[0032] In some embodiments of the present application, based on the foregoing solution, the second obtaining unit is configured as follows: a third obtaining unit, which obtains a braking torque threshold; a third determining unit, which determines the braking intervention torque according to the braking torque threshold, and the braking intervention torque is less than or equal to the braking torque threshold.

[0033] In some embodiments of the present application, based on the foregoing solution, the second obtaining unit is configured as follows: a fourth obtaining unit, which obtains a current torque coefficient and obtains a first power source torque; a fourth determining unit, which determines the product of the current torque coefficient and the first power source torque as the first power source intervention torque.

[0034] In some embodiments of the present application, based on the foregoing solution, the fourth obtaining unit is configured as follows: a fifth obtaining unit, which obtains the current wheel speed difference acceleration of the two wheels; a fifth determining unit, which determines the current power ratio of the current differential power to the first power threshold; a sixth determining unit, which determines the current torque coefficient according to the current wheel speed difference acceleration and the current power ratio.

[0035] In some embodiments of the present application, based on the foregoing solution, the sixth determining unit is configured as follows: a sixth obtaining unit, which obtains the current torque coefficient from a pre-established target mapping relationship according to the current wheel speed difference acceleration and the current power ratio, and the target mapping relationship is a mapping of wheel speed difference acceleration, power ratio and torque coefficient.

[0036] In some embodiments of the present application, based on the foregoing solution, the fourth obtaining unit is configured as follows: a seventh obtaining unit, which obtains a second power source torque and obtains a preset power source torque, and the preset power source torque is greater than or equal to 0; a seventh determining unit, which determines the difference between the second power source torque and the braking intervention torque as the third power source torque; a first acting unit, if the third power source torque is greater than 0, uses the third power source torque as the first power source torque; a second acting unit, if the third power source torque is less than or equal to 0, uses the preset power source torque as the first power source torque.

[0037] In some embodiments of the present application, based on the foregoing solution, the seventh acquisition unit is configured as follows: an eighth acquisition unit that acquires a torque correction coefficient and the current input torque of the differential; an eighth determination unit that determines the product of the torque correction coefficient and the current input torque as the second power source torque.

[0038] In some embodiments of the present application, based on the foregoing solution, the eighth acquisition unit is configured as follows: a ninth acquisition unit that acquires the torsion ratio of the differential; a ninth determination unit that determines the second difference between the torsion ratio and 1, and determines the first sum value of the torsion ratio and 1; a tenth determination unit that determines the quotient of the second difference and the first sum value as the torque correction coefficient.

[0039] In some embodiments of the present application, based on the foregoing solution, the device further includes: a tenth acquisition unit that acquires a power source torque threshold; an eleventh determination unit that determines the power source intervention torque according to the first power source intervention torque and the power source torque threshold.

[0040] In some embodiments of the present application, based on the foregoing solution, the eleventh determination unit is configured as follows: an eleventh acquisition unit that acquires a second power source intervention torque, where the second power source intervention torque is a non-negative value less than or equal to the power source torque threshold; a third acting unit that, if the first power source intervention torque is greater than the power source torque threshold, uses the second power source intervention torque as the power source intervention torque; a fourth acting unit that, if the first power source intervention torque is less than or equal to the power source torque threshold, uses the first power source intervention torque as the power source intervention torque.

[0041] In some embodiments of the present application, based on the foregoing solution, the tenth acquisition unit is configured as follows: a twelfth acquisition unit that acquires the current input torque of the differential and a power source torque correction value, where the power source correction value is greater than 0; a twelfth determination unit that determines the difference between the current input torque and the power source torque correction value as the power source torque threshold.

[0042] In some embodiments of the present application, based on the foregoing solution, the twelfth acquisition unit is configured as follows: a thirteenth acquisition unit that acquires the current road surface gradient, the tire rolling radius of the vehicle, and the current gravity of the vehicle; a thirteenth determination unit that determines the product of the sine value of the current road surface gradient, the tire rolling radius, and the current gravity as the power source torque correction value.

[0043] In some embodiments of the present application, based on the foregoing solution, the first acquisition unit is configured as follows: a fourteenth acquisition unit that acquires the current input torque and the torsion ratio of the differential, and acquires the current wheel speed difference between the two wheels driven by the differential; a fourteenth determination unit that determines the current differential power according to the current input torque, the torsion ratio, and the current wheel speed difference.

[0044] According to a third aspect of the present application, there is provided a computer-readable storage medium having a computer program stored thereon, the computer program including executable instructions that, when executed by a processor, implement the method according to any one of the embodiments of the first aspect of the present application.

[0045] According to a fourth aspect of the present application, there is provided a vehicle including a vehicle differential protection device according to any one of the embodiments of the second aspect of the present application.

[0046] The beneficial effects of the present application are as follows:

[0047] The first power threshold is the protection boundary of the differential, which is adapted to the current temperature rather than a fixed value. On the one hand, when the current differential power is greater than the first power threshold, the differential is protected. On the other hand, the performance of the differential is not restricted.

[0048] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. In the drawings:

[0050] Figure 1 A schematic diagram of the principle of a vehicle differential is shown;

[0051] Figure 2 A flowchart of a vehicle differential protection method in an embodiment of the present application is shown;

[0052] Figure 3 A schematic diagram of a power threshold curve in an embodiment of the present application is shown;

[0053] Figure 4 A schematic diagram of a target mapping relationship in an embodiment of the present application is shown;

[0054] Figure 5Shows a block diagram of a vehicle differential protection device in an embodiment of the present application;

[0055] Figure 6 Shows a schematic diagram of a computer-readable storage medium in an embodiment of the present application;

[0056] Figure 7 Shows a schematic structural block diagram of a vehicle in an embodiment of the present application. Detailed implementation manners

[0057] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0058] Figure 1 Shows a schematic diagram of the principle of a vehicle differential. Figure 1 In it, 1 is a controller, 2 is a power source, 3 is a transmission or a reducer, 4 is a differential, 5 and 6 are half shafts, 7 and 8 are wheel speed sensors or left and right output shaft sensors, 9 and 10 are wheels, and 11 is an oil temperature sensor. Refer to Figure 1 , and the vehicle differential will be described as follows:

[0059] The power source is controlled by the controller, and it can be a single motor or a dual motor or a multi-motor of a pure electric vehicle, or it can also be a motor and / or an engine of a hybrid vehicle. The power source drives the differential through a reducer. The differential distributes the power to the two half shafts on both sides, and the two half shafts drive the wheels to rotate. The wheel speed sensor is used to detect the wheel speed of the wheels and send the detected wheel speed data to the controller. The oil temperature sensor is used to detect the lubricating oil temperature in the differential and send the detected lubricating oil temperature to the controller. Among them, the controller does not represent the actual controller software and hardware architecture. It can be a configuration of several controllers divided according to traditional functions, or it can be a single integrated controller.

[0060] The differential includes a differential case. The differential case is connected to the driven gear of the reducer. Inside the differential case, there are planetary gears, half shaft gears, and planetary gear shafts. The planetary gears are located inside the differential case and rotate around a central point. The half shaft gears mesh with the planetary gears and are connected to the wheels through the half shafts. The planetary gear shafts are used to support the planetary gears and allow the planetary gears to rotate around their axes.

[0061] When the differential is in normal driving conditions, such as when the vehicle is going straight, it distributes power evenly to the two half shafts. The planet gears, half shaft gears, and differential housing rotate around the center of the differential simultaneously. When the differential is in differential conditions, such as when the vehicle is turning, the wheel speeds of the two sides, that is, the inner and outer wheels, are inconsistent. The planet gears rotate around the planet gear shafts, and the rotational speed of the half shaft gears around the center of the differential is inconsistent with the rotational speed of the differential housing, resulting in a wheel speed difference. The originally relatively stationary internal parts in the differential housing form multiple friction pairs, such as the planet gears and planet gear shafts, the planet gears and the differential housing (through gaskets), and the half shaft gears and the differential housing (through gaskets).

[0062] The friction boundary that the differential can withstand is limited by its physical structure, materials, coatings, lubrication, and other conditions. When an off-road vehicle encounters complex road conditions such as open roads and twisted roads, there are huge differences in the adhesion conditions on the left and right sides and the ground loads of the tires on the left and right sides. Especially when ESC / TCS is turned off, with rapid sudden changes in road surface loads, there will be a huge rotational speed difference between the left and right wheel speeds. The four-wheel drive structure with front and rear axle decoupling and the torque characteristics of electric drive in an electric off-road vehicle will cause the loads and rotational speed differences borne by the relevant friction pairs to be even greater under the above conditions, and the power of friction will be higher.

[0063] Therefore, in an electric off-road vehicle, in order to protect the differential, it is necessary to limit and actively protect the operation of the internal friction pairs of the differential to avoid exceeding its physical allowable boundary and causing the differential to fail. In the prior art, after exceeding the protection boundary, torque is intervened through the power source. The protection boundary is smaller than the allowable boundary and can be, for example, 80% of the allowable boundary.

[0064] Figure 2 The flowchart of a vehicle differential protection method in an embodiment of the present application is shown. See Figure 2 A vehicle differential protection method is provided. The vehicle differential can be the differential of an electric off-road vehicle. The method at least includes S1 to S3, which are introduced in detail as follows:

[0065] In step S1, obtain the current differential power of the differential and the current temperature of the lubricating oil in the differential. The current differential power is the differential power of the differential at the current moment, and the current temperature is the temperature of the lubricating oil in the differential at the current moment. The differential power can also be called the differential power loss or the slip power. The differential power loss can be understood as the power loss caused by factors such as internal friction, gear meshing loss, bearing loss, oil resistance, and differential design during the operation of the differential. The current temperature is the temperature at the target position in the differential housing of the differential, and the target position can be any position where there is lubricating oil, or a position where there is lubricating oil near the oil outlet of the oil pump. The oil pump pumps out the lubricating oil from the oil sump and pumps the lubricating oil into the inlet of the differential housing, and the lubricating oil enters the oil sump from the outlet of the differential housing.

[0066] In step S2, according to the pre-determined relationship data, determine the first power threshold adapted to the current temperature. The relationship data is an inverse relationship characterizing the relationship between the lubricating oil temperature and the power threshold, that is, the higher the lubricating oil temperature, the smaller the power threshold.

[0067] It should be noted that the lubricating oil in the differential forms an oil film for lubrication on the gear meshing surface, thereby reducing the friction force between the friction pairs and helping to dissipate heat, so that the differential operates within a reasonable temperature range. When the lubricating oil temperature rises, on the one hand, the lubricating oil may deteriorate, the thickness and stability of the oil film decrease, resulting in a decrease in lubrication performance, an increase in the friction force and wear between the friction pairs (such as the wear between gears and bearings), and on the other hand, the heat dissipation effect becomes worse, resulting in an increase in the internal temperature of the differential, further exacerbating the wear and damage of the friction pairs. Therefore, when the lubricating oil is at different temperatures, the influence on the friction pairs in the differential is different. When considering the protection boundary (the first power threshold) of the differential, it is necessary to fully consider the influence factor of the lubricating oil temperature, that is, different protection boundaries are set for different lubricating oil temperatures.

[0068] In some embodiments, the relationship data is a one-to-one correspondence between the lubricating oil temperature and the power threshold, that is, each lubricating oil temperature corresponds to a power threshold, and each lubricating oil temperature corresponds to a different power threshold.

[0069] Exemplarily, the relationship data is characterized by a power threshold curve. See Figure 3 , Figure 3 shows a schematic diagram of the power threshold curve in the embodiments of the present application. Figure 3In it, the horizontal axis is the lubricating oil temperature, the vertical axis is the differential power, and the curve that is entirely located below in the coordinate system is the power threshold curve. In addition, the curve that is entirely located above in the coordinate system characterizes the anti-sintering ability of the differential, that is, the corresponding relationship between the lubricating oil temperature and the anti-sintering power threshold. Each lubricating oil temperature corresponds to an anti-sintering power threshold, and each lubricating oil temperature corresponds to a different anti-sintering power threshold. For a specific temperature, when the differential power is higher than the corresponding anti-sintering power threshold, the differential will sinter. The lower the temperature, the better the anti-sintering ability.

[0070] In some embodiments, it further includes: obtaining a first power margin, where the first power margin is greater than 0; measuring the anti-sintering power threshold of the differential under different lubricating oil temperature conditions; determining the difference between the anti-sintering power threshold and the first power margin as the first power threshold; and determining the relationship data based on the first power threshold and the lubricating oil temperature. The first power threshold is less than the anti-sintering power threshold, that is, there is a safety margin of the first power margin between the two.

[0071] In some embodiments, it further includes: confirming the relationship data based on the hardware boundary of the differential, bench test data, and vehicle test data. Under different lubricating oil temperature conditions, determine the anti-sintering power threshold according to the hardware boundary of the differential, determine the first power threshold according to the sintering power threshold, and conduct bench tests and vehicle tests respectively. When the differential power of the differential is equal to the first power threshold, determine whether it simultaneously satisfies that the differential does not fail after a preset time during the bench test and the differential does not fail after the vehicle test. If so, the first power threshold is confirmed; if not, re-determine the first power threshold, that is, when the differential fails after a preset time during the bench test or the differential fails after the vehicle test, re-determine the first power threshold. The failure of the differential means that the parts inside the differential fail, and the non-failure of the differential means that the parts inside the differential do not fail.

[0072] In some embodiments, the re-determining the first power threshold includes: obtaining a threshold margin; updating the first power threshold according to the difference between the first power threshold and the threshold margin; conducting bench tests and vehicle tests respectively. When the differential power of the differential is equal to the first power threshold, determine whether it simultaneously satisfies that the differential does not fail after a preset time during the bench test and the differential does not fail after the vehicle test. If so, the first power threshold is confirmed; if not, execute the step of updating the first power threshold according to the difference between the first power threshold and the threshold margin.

[0073] In some embodiments, the relationship data is the relationship corresponding to the lubricating oil temperature range and the power threshold, that is, each lubricating oil temperature range corresponds to a power threshold, and each lubricating oil temperature range corresponds to a different power threshold. For example, when the lubricating oil temperature range is 10-20°C, the power threshold is 35KW, and when the lubricating oil temperature range is 20-30°C, the power threshold is 30KW.

[0074] In step S3, if the current differential power is greater than the first power threshold, trigger the protection of the differential. The first power threshold can be understood as the protection boundary of the differential. The first power threshold is related to the current temperature and is not a fixed value, that is, it is not a fixed boundary. At low temperatures, the first power threshold is larger, and at high temperatures, the first power threshold is smaller, so as not to limit the performance of the differential.

[0075] In some embodiments, it further includes: if the current differential power is less than or equal to the first power threshold, stop protecting the differential.

[0076] In some embodiments, when protecting the differential by applying the braking intervention torque to the target wheel, the stopping of protecting the differential includes: stopping applying the automatic intervention torque to the target wheel.

[0077] In some embodiments, when protecting the differential by applying the power source intervention torque to the power source, the stopping of protecting the differential includes: stopping applying the power source intervention torque to the power source.

[0078] In some embodiments, when protecting the differential by applying the braking intervention torque to the target wheel and applying the power source intervention torque to the power source, the stopping of protecting the differential includes: stopping applying the braking intervention torque to the target wheel and applying the power source intervention torque to the power source to protect the differential.

[0079] In some embodiments, the triggering for protecting the differential includes: obtaining a braking intervention torque and obtaining a power source intervention torque; if braking intervention on a target wheel is allowed, protecting the differential by applying the braking intervention torque to the target wheel, where the target wheel is the wheel with a higher rotational speed among the two side wheels. For example, if the rotational speed of the left wheel is 8 rad / s and the rotational speed of the right wheel is 6 rad / s, and the rotational speed of the left wheel is higher than that of the right wheel, the target wheel is the left wheel, and the two side wheels are driven by the differential; if braking intervention on the target wheel is not allowed, protecting the differential by applying the power source intervention torque to the power source, where the power source is used to drive the differential. Allowing braking intervention on the target wheel can be understood as allowing the braking system to brake the target wheel, and not allowing braking intervention on the target wheel can be understood as not allowing the braking system to brake the target wheel. For a two-wheel drive vehicle, if the vehicle is a front-wheel drive vehicle, the two side wheels are two front wheels; if the vehicle is a rear-wheel drive vehicle, the two side wheels are two rear wheels; for a four-wheel drive vehicle, if the differential is the differential of the front axle, the two side wheels are two front wheels; if the differential is the differential of the rear axle, the two side wheels are two rear wheels. The power source can be a single motor or a dual motor or multiple motors of a pure electric vehicle, or the motor and / or engine of a hybrid vehicle. Applying the braking intervention torque to the target wheel can reduce the rotational speed and rotational speed difference of the target wheel, thereby reducing the differential power of the differential, so that the differential power of the differential drops below the first power threshold, realizing the protection of the differential; applying the power source intervention torque to the power source to protect the differential can reduce the wheel end torque of the two side wheels, thereby reducing the rotational speed difference, and further reducing the differential power of the differential, so that the differential power of the differential drops below the first power threshold, realizing the protection of the differential.

[0080] In some embodiments, the triggering for protecting the differential includes: if braking intervention on the target wheel is allowed, determining a second power threshold adapted to the current temperature according to the relationship data, where the second power threshold is greater than the first power threshold; if the current differential power is greater than or equal to the second power threshold, protecting the differential by applying the braking intervention torque to the target wheel and applying the power source intervention torque to the power source. The current differential power being greater than or equal to the second power threshold can be understood as the differential operating condition of the differential being very severe and the rotational speed difference being very large. On the basis of applying the braking intervention torque to the target wheel, adding the application of the power source intervention torque to the power source, and using two methods to reduce the rotational speed difference, so that the differential power of the differential quickly returns below the first power threshold, realizing the rapid protection of the differential.

[0081] In some embodiments, it further includes: obtaining a second power margin, where the second power margin is less than the first power margin; measuring the anti-sintering power threshold of the differential at different lubricating oil temperatures; determining the difference between the anti-sintering power threshold and the second power margin as the second power threshold; and determining the relationship data based on the second power threshold and the lubricating oil temperature. The second power threshold is less than the anti-sintering power threshold, that is, there is a safety margin of the second power margin between the two.

[0082] It should be noted that when the relationship data characterizes the inverse relationship between the lubricating oil temperature and the power threshold, the power threshold can be understood as the first power threshold or the second power threshold. The higher the current temperature, the smaller the first power threshold or the second power threshold, and the first power threshold corresponding to the current temperature is less than the second power threshold.

[0083] In some embodiments, it further includes: if the current differential power is less than the second power threshold and greater than the first power threshold, protecting the differential by applying the braking intervention torque to the target wheel and not protecting the differential by applying the power source intervention torque to the power source. The current differential power being less than the second power threshold and greater than the first power threshold can be understood as the differential working condition of the differential being relatively harsh, with a large wheel speed difference. Applying the braking intervention torque to the target wheel and not superimposing the power source intervention torque applied to the power source, and using one method to reduce the wheel speed difference so that the differential power of the differential returns below the first power threshold. It should be noted that the differential working condition of the differential is characterized by the differential power of the differential.

[0084] In some embodiments, protecting the differential by applying the braking intervention torque to the target wheel includes: obtaining the current braking torque of the target wheel, and on the basis of the current braking torque, protecting the differential by increasing the braking intervention torque to the target wheel; protecting the differential by applying the power source intervention torque to the power source includes: obtaining the current power source torque of the power source, and on the basis of the current power source torque, protecting the differential by reducing the power source intervention torque to the power source.

[0085] Exemplarily, the current braking torque is 0 N·m, that is, the target wheel is not braked, the braking intervention torque is 200 N·m, and increasing the braking intervention torque to the target wheel is applying a braking torque of 200 N·m to the target wheel; the current power source torque is 300 N·m, the power source intervention torque is 50 N·m, and reducing the power source intervention torque to the power source is reducing the power source torque from 300 N·m to \(250\) N·m.

[0086] In some embodiments, obtaining the braking intervention torque includes: obtaining a braking torque threshold; determining the braking intervention torque according to the braking torque threshold, where the braking intervention torque is less than or equal to the braking torque threshold. The chassis domain controller determines the braking torque threshold based on evaluating the braking system capabilities and ensuring vehicle safety, that is, the braking torque threshold is within the braking torque range of the braking system, and when the braking system applies the braking torque threshold to the vehicle, the stability of the vehicle can be ensured.

[0087] In some embodiments, obtaining the braking intervention torque includes: obtaining a braking torque threshold; determining the power difference between the current differential power and the first power threshold, and determining the braking intervention torque according to the power difference. The greater the power difference, the greater the braking intervention torque, and the braking intervention torque is less than or equal to the braking torque threshold. The greater the power difference indicates that the differential working condition of the differential is more severe, and a greater braking intervention torque is required to perform braking intervention on the target wheel to quickly reduce the wheel speed difference, thereby achieving rapid protection of the differential.

[0088] In some embodiments, obtaining the power source intervention torque includes: obtaining the current torque coefficient and obtaining the first power source torque; determining the product of the current torque coefficient and the first power source torque as the first power source intervention torque. The current torque coefficient can also be referred to as a dynamic adjustment parameter (F dynamic ). The calculation formula for the first power source intervention torque is as follows: T g1 = F dynamic × T n1 , where T g1 is the first power source intervention torque, F dynamic is the current torque coefficient, and T n1 is the first power source torque. The current torque coefficient can be a fixed value.

[0089] In some embodiments, obtaining the current torque coefficient includes: obtaining the current wheel speed difference acceleration of the two sides of the wheels; determining the current power ratio of the current differential power to the first power threshold; and determining the current torque coefficient according to the current wheel speed difference acceleration and the current power ratio. The current wheel speed difference acceleration is the angular acceleration at the current moment.

[0090] In some embodiments, the calculation formula for the current wheel speed difference acceleration is as follows: α is the current wheel speed difference acceleration, |V 左 - V 右 |÷B is the angular velocity, V 左 is the current wheel speed of the left wheel, V 右is the current wheel speed of the right wheel, B is the wheelbase, and t is the unit time. In the above formula, it can be understood that the current wheel speed difference acceleration (angular acceleration) is obtained by performing time differentiation on the angular velocity.

[0091] Exemplarily, the wheelbase is 2m. At the 1st second, the current wheel speed of the left wheel is 8m / s, the current wheel speed of the right wheel is 6m / s, and the angular velocity is (8 - 6)÷2 = 1rad / s. At the 2nd second, the current wheel speed of the left wheel is 8m / s, the current wheel speed of the right wheel is 4m / s, and the angular velocity is (8 - 4)÷2 = 2rad / s. The current wheel speed difference acceleration is (2 - 1) / (2 - 1) = 1rad / s 2 .

[0092] In some embodiments, the determining the current torque coefficient according to the ratio of the current wheel speed difference acceleration to the current power includes: obtaining the current torque coefficient from a pre - established target mapping relationship according to the ratio of the current wheel speed difference acceleration to the current power, where the target mapping relationship is a mapping of wheel speed difference acceleration, power ratio, and torque coefficient. Obtaining the corresponding current torque coefficient from the target mapping according to the ratio of the current wheel speed difference acceleration to the current power, and the current torque coefficient corresponds to the current wheel speed difference acceleration and the current power ratio.

[0093] Figure 4 shows a schematic diagram of the target mapping relationship in an embodiment of the present application. Exemplarily, the target mapping relationship can be a target relationship table, and the target relationship table can be represented by Figure 4 a coordinate system of Figure 4 where the horizontal axis is the power ratio and the vertical axis is the wheel speed difference acceleration (unit: rad / s 2 ), and it can also be represented by Table 1. Referring to Table 1, when the wheel speed difference acceleration is 0 and the power ratio is 1.2, the current torque coefficient is 3.2.

[0094] Table 1

[0095]

[0096] In some embodiments, the obtaining the first power source torque includes: obtaining the second power source torque and obtaining a preset power source torque, where the preset power source torque is greater than or equal to 0; determining the difference between the second power source torque and the braking intervention torque as the third power source torque; if the third power source torque is greater than 0, using the third power source torque as the first power source torque; if the third power source torque is less than or equal to 0, using the preset power source torque as the first power source torque. The calculation formula for the first power source torque is as follows:

[0097] T n1 is the torque of the first power source, T n2 is the torque of the second power source, T brake is the braking intervention torque, T n2 -T brake is the torque of the third power source, T y is the preset power source torque.

[0098] In some embodiments, obtaining the torque of the second power source includes: obtaining a torque correction coefficient and obtaining the current input torque of the differential; determining the product of the torque correction coefficient and the current input torque as the torque of the second power source. The torque correction coefficient can be a fixed value.

[0099] In some embodiments, the calculation formula for the torque of the second power source is as follows: T n2 = K1 × T, where T n2 is the torque of the second power source, K1 is the torque correction coefficient, and T is the current input torque.

[0100] In some embodiments, obtaining the torque correction coefficient includes: obtaining the torque bias ratio of the differential; determining the second difference between the torque bias ratio and 1, and determining the first sum value of the torque bias ratio and 1; determining the quotient of the second difference and the first sum value as the torque correction coefficient. The calculation formula for the torque correction coefficient is as follows: where K1 is the torque correction coefficient and TBR is the torque bias ratio.

[0101] It should be noted that when there is no left - right wheel speed difference, that is, when the wheel speeds of the left and right wheels are the same, the torques of the two wheels are evenly distributed. When there is a wheel speed difference between the two wheels, the torques of the two wheels will deviate, which is defined as TBR (torque bias ratio), and TBR is a constant.

[0102] In some embodiments, it further includes: obtaining a power source torque threshold; determining the power source intervention torque according to the first power source intervention torque and the power source torque threshold. The first power source intervention torque can be understood as the calculated value of the power source intervention torque, and the power source torque threshold can be understood as the threshold of the power source intervention torque.

[0103] In some embodiments, determining the power source intervention torque according to the first power source intervention torque and the power source torque threshold includes: obtaining a second power source intervention torque, where the second power source intervention torque is a non - negative value less than or equal to the power source torque threshold; if the first power source intervention torque is greater than the power source torque threshold, using the second power source intervention torque as the power source intervention torque; if the first power source intervention torque is less than or equal to the power source torque threshold, using the first power source intervention torque as the power source intervention torque. The second power source intervention torque can be understood as the set value of the power source intervention torque. When the first power source intervention torque is greater than the power source torque threshold, that is, the calculated value of the power source intervention torque is greater than the threshold, the power source intervention torque is assigned the second power source intervention torque, that is, using the set value less than or equal to the power source torque threshold as the standard. When the first power source intervention torque is less than or equal to the power source torque threshold, the first power source intervention torque is used as the power source intervention torque, that is, using the calculated value of the power source intervention torque as the standard.

[0104] In some embodiments, obtaining the power source torque threshold includes: obtaining the current input torque of the differential and obtaining a power source torque correction value, where the power source correction value is greater than 0; determining the difference between the current input torque and the power source torque correction value as the power source torque threshold. By using the power source torque correction value to correct the current input torque, the power source torque correction value is obtained, that is, the power source correction value is less than the current input torque, and there is a margin between the two.

[0105] In some embodiments, obtaining the power source torque correction value includes: obtaining the current road surface slope, the tire rolling radius of the vehicle, and the current gravity of the vehicle; determining the product of the sine value of the current road surface slope, the tire rolling radius, and the current gravity as the power source torque correction value. When applying the power source intervention torque to the power source, it is necessary to consider the slope information of the vehicle, that is, the current road surface slope, to avoid dangerous situations such as vehicle rollback and loss of control caused by rapid torque changes, especially when the vehicle is working in harsh off - road conditions. Therefore, in this application, the power source torque correction value is obtained through the current road surface slope to correct the power source intervention torque and avoid the situation where the power source intervention torque is too large, that is, to avoid rapid torque changes in the power source.

[0106] In some embodiments, obtaining the torque correction value of the power source includes calculating the torque correction value of the power source through the following formula: T1 = m × g × r × sinα, where T1 is the torque correction value of the power source, m is the vehicle body weight, g is the acceleration due to gravity, m × g is the current gravity, r is the tire rolling radius, and α is the current road surface gradient. The vehicle body weight is the weight of the vehicle.

[0107] In some embodiments, the calculation formula for the torque threshold of the power source is: T2 = T - m × g × r × sinα, where T2 is the torque threshold of the power source, T is the current input torque, m is the vehicle body weight, g is the acceleration due to gravity, m × g is the current gravity, r is the tire rolling radius, and α is the current road surface gradient.

[0108] In some embodiments, obtaining the current differential power of the differential includes obtaining the current input torque and the torque bias ratio of the differential, and obtaining the current wheel speed difference between the two wheels driven by the differential, where the current wheel speed difference is a non - negative value; determining the current differential power according to the current input torque, the torque bias ratio, and the current wheel speed difference.

[0109] In some embodiments, obtaining the current wheel speed difference between the two wheels includes obtaining the first current wheel speed of the left wheel and the second current wheel speed of the right wheel, and determining the absolute value of the difference between the first current wheel speed and the second current wheel speed as the current wheel speed difference. The calculation formula for the current wheel speed difference is: V = |V 左 -V 右 |, where V is the current wheel speed difference, V 左 is the first current wheel speed, i.e., the current wheel speed of the left wheel, and V 右 is the second current wheel speed, i.e., the current wheel speed of the right wheel.

[0110] In some embodiments, determining the current differential power according to the current input torque, the torque bias ratio, and the current wheel speed difference includes determining a power coefficient according to the torque bias ratio; determining the product of the power coefficient, the current input torque, and the current wheel speed difference as the current differential power.

[0111] In some embodiments, determining the power coefficient according to the torque bias ratio includes determining the power coefficient according to the following formula: K2 is the power coefficient, and TBR is the torque bias ratio. Thus, the calculation formula for the current differential power is as follows: where P is the current differential power, TBR is the torque bias ratio, T is the current input torque, and Δn is the current wheel speed difference.

[0112] In this application, the first power threshold is the protection boundary of the differential, which is adapted to the current temperature rather than a fixed value. On the one hand, when the current differential power is greater than the first power threshold, the differential is protected to avoid failure problems such as sintering of the differential. On the other hand, on the basis of protecting the differential, the impact on the vehicle's power and passing performance when triggering the protection of the differential is fully considered, without restricting the performance of the differential and avoiding situations such as vehicle rollback and loss of control when triggering the protection of the differential.

[0113] Figure 5 The block diagram of a vehicle differential protection device in an embodiment of this application is shown. Refer to Figure 5 According to the second aspect of this application, a vehicle differential protection device 100 is provided, including:

[0114] A first acquisition unit 101, which acquires the current differential power of the differential and acquires the current temperature of the lubricating oil in the differential;

[0115] A first determination unit 102, which determines a first power threshold adapted to the current temperature according to pre-determined relationship data, and the relationship data is an inverse relationship representing the relationship between the lubricating oil temperature and the power threshold;

[0116] A first protection unit 103, if the current differential power is greater than the first power threshold, triggers the protection of the differential.

[0117] In some embodiments, the first protection unit is configured as: a second acquisition unit, which acquires the braking intervention torque and acquires the power source intervention torque; a second protection unit, if braking intervention on the target wheel is allowed, protects the differential by applying the braking intervention torque to the target wheel, and the target wheel is the wheel with a higher wheel speed among the two wheels, and the two wheels are driven by the differential; a third protection unit, if braking intervention on the target wheel is not allowed, protects the differential by applying the power source intervention torque to the power source, and the power source is used to drive the differential.

[0118] In some embodiments, the first protection unit is further configured as: a second determination unit, if braking intervention on the target wheel is allowed, determines a second power threshold adapted to the current temperature according to the relationship data, and the second power threshold is greater than the first power threshold; a fourth protection unit, if the current differential power is greater than or equal to the second power threshold, protects the differential by applying the braking intervention torque to the target wheel and applying the power source intervention torque to the power source.

[0119] In some embodiments, the second protection unit is configured as: a fifth protection unit, which obtains the current braking torque of the target wheel, and on the basis of the current braking torque, protects the differential by adding the braking intervention torque to the target wheel; the third protection unit is configured as: a sixth protection unit, which obtains the current power source torque of the power source, and on the basis of the current power source torque, protects the differential by reducing the power source intervention torque from the power source.

[0120] In some embodiments, the second acquisition unit is configured as: a third acquisition unit, which acquires a braking torque threshold; a third determination unit, which determines the braking intervention torque according to the braking torque threshold, and the braking intervention torque is less than or equal to the braking torque threshold.

[0121] In some embodiments, the second acquisition unit is configured as: a fourth acquisition unit, which acquires a current torque coefficient and acquires a first power source torque; a fourth determination unit, which determines the product of the current torque coefficient and the first power source torque as the first power source intervention torque.

[0122] In some embodiments, the fourth acquisition unit is configured as: a fifth acquisition unit, which acquires the current wheel speed difference acceleration of the two wheels; a fifth determination unit, which determines the current power ratio of the current differential power to the first power threshold; a sixth determination unit, which determines the current torque coefficient according to the current wheel speed difference acceleration and the current power ratio.

[0123] In some embodiments, the sixth determination unit is configured as: a sixth acquisition unit, which acquires the current torque coefficient from a pre-established target mapping relationship according to the current wheel speed difference acceleration and the current power ratio, and the target mapping relationship is a mapping of wheel speed difference acceleration, power ratio and torque coefficient.

[0124] In some embodiments, the fourth acquisition unit is configured as: a seventh acquisition unit, which acquires a second power source torque and acquires a preset power source torque, and the preset power source torque is greater than or equal to 0; a seventh determination unit, which determines the difference between the second power source torque and the braking intervention torque as the third power source torque; a first acting unit, if the third power source torque is greater than 0, uses the third power source torque as the first power source torque; a second acting unit, if the third power source torque is less than or equal to 0, uses the preset power source torque as the first power source torque.

[0125] In some embodiments, the seventh acquisition unit is configured to: an eighth acquisition unit that acquires a torque correction coefficient and acquires the current input torque of the differential; an eighth determination unit that determines the product of the torque correction coefficient and the current input torque as the second power source torque.

[0126] In some embodiments, the eighth acquisition unit is configured to: a ninth acquisition unit that acquires the torque bias ratio of the differential; a ninth determination unit that determines a second difference between the torque bias ratio and 1, and determines a first sum value of the torque bias ratio and 1; a tenth determination unit that determines the quotient of the second difference and the first sum value as the torque correction coefficient.

[0127] In some embodiments, the device further includes: a tenth acquisition unit that acquires a power source torque threshold; an eleventh determination unit that determines the power source intervention torque according to the first power source intervention torque and the power source torque threshold.

[0128] In some embodiments, the eleventh determination unit is configured to: an eleventh acquisition unit that acquires a second power source intervention torque, where the second power source intervention torque is a non-negative value less than or equal to the power source torque threshold; a third acting unit that, if the first power source intervention torque is greater than the power source torque threshold, uses the second power source intervention torque as the power source intervention torque; a fourth acting unit that, if the first power source intervention torque is less than or equal to the power source torque threshold, uses the first power source intervention torque as the power source intervention torque.

[0129] In some embodiments, the tenth acquisition unit is configured to: a twelfth acquisition unit that acquires the current input torque of the differential and a power source torque correction value, where the power source correction value is greater than 0; a twelfth determination unit that determines the difference between the current input torque and the power source torque correction value as the power source torque threshold.

[0130] In some embodiments, the twelfth acquisition unit is configured to: a thirteenth acquisition unit that acquires the current road surface slope, the tire rolling radius of the vehicle, and the current gravity of the vehicle; a thirteenth determination unit that determines the product of the sine value of the current road surface slope, the tire rolling radius, and the current gravity as the power source torque correction value.

[0131] In some embodiments, the first acquisition unit is configured to: a fourteenth acquisition unit that acquires the current input torque and torque bias ratio of the differential, and acquires the current wheel speed difference between two wheels driven by the differential; a fourteenth determination unit that determines the current differential power according to the current input torque, the torque bias ratio, and the current wheel speed difference.

[0132] Based on the same inventive concept, as a third aspect, the present application also provides a computer-readable storage medium, on which there is a program product capable of implementing the above-mentioned vehicle differential protection method in this specification. In some possible implementation manners, each aspect of the present application can also be implemented in the form of a program product, which includes program code. When the program product runs on a terminal device, the program code is used to cause the terminal device to execute the steps according to various exemplary embodiments of the present application described in the above "Exemplary Method" section of this specification.

[0133] Refer to Figure 6 As shown, a program product 200 for implementing the above method according to an embodiment of the present application is described. It can be a portable compact disc read-only memory (CD-ROM) and includes program code, and can run on a terminal device, such as a personal computer. However, the program product of the present application is not limited thereto. In this document, the readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device.

[0134] Figure 7 A schematic structural block diagram of a vehicle in an embodiment of the present application is shown. As another aspect, refer to Figure 7 , the present application also provides a vehicle 300, including a vehicle differential protection device 100 described in any embodiment of the second aspect of the present application.

[0135] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A vehicle differential protection method, characterized in that, Including: Obtaining the current differential power of the differential and obtaining the current temperature of the lubricating oil in the differential; Determining a first power threshold adapted to the current temperature according to pre-determined relationship data, where the relationship data is an inverse relationship characterizing the relationship between the lubricating oil temperature and the power threshold; If the current differential power is greater than the first power threshold, trigger to protect the differential.

2. The method according to claim 1, characterized in that, The triggering to protect the differential includes: Obtaining a braking intervention torque and obtaining a power source intervention torque; If braking intervention on the target wheel is allowed, protect the differential by applying the braking intervention torque to the target wheel, where the target wheel is the wheel with a higher wheel speed among the two side wheels, and the two side wheels are driven by the differential; If braking intervention on the target wheel is not allowed, protect the differential by applying the power source intervention torque to the power source, where the power source is used to drive the differential.

3. The method according to claim 2, wherein The triggering to protect the differential includes: If braking intervention on the target wheel is allowed, determining a second power threshold adapted to the current temperature according to the relationship data, where the second power threshold is greater than the first power threshold; If the current differential power is greater than or equal to the second power threshold, protect the differential by applying the braking intervention torque to the target wheel and applying the power source intervention torque to the power source.

4. The method according to claim 2, characterized in that, The protecting the differential by applying the braking intervention torque to the target wheel includes: Obtaining the current braking torque of the target wheel, and on the basis of the current braking torque, protecting the differential by increasing the braking intervention torque to the target wheel; The protecting the differential by applying the power source intervention torque to the power source includes: Obtaining the current power source torque of the power source, and on the basis of the current power source torque, protecting the differential by decreasing the power source intervention torque to the power source.

5. The method according to claim 2, wherein The obtaining the braking intervention torque includes: Obtaining a braking torque threshold; Determining the braking intervention torque according to the braking torque threshold, where the braking intervention torque is less than or equal to the braking torque threshold.

6. The method according to claim 2, characterized in that, The obtaining the power source intervention torque includes: Obtaining a current torque coefficient and obtaining a first power source torque; Determining the product of the current torque coefficient and the first power source torque as the first power source intervention torque.

7. The method according to claim 6, wherein The obtaining the current torque coefficient includes: Obtaining the current wheel speed difference acceleration of the two side wheels; Determining the current power ratio of the current differential power to the first power threshold; Determining the current torque coefficient according to the current wheel speed difference acceleration and the current power ratio.

8. The method according to claim 7, wherein The determining the current torque coefficient according to the current wheel speed difference acceleration and the current power ratio includes: Obtaining the current torque coefficient from a pre-established target mapping relationship according to the current wheel speed difference acceleration and the current power ratio, where the target mapping relationship is a mapping of wheel speed difference acceleration, power ratio and torque coefficient.

9. The method according to claim 6, wherein The obtaining the first power source torque includes: Obtain the torque of the second power source and obtain the preset power source torque, where the preset power source torque is greater than or equal to 0; Determine the difference between the torque of the second power source and the braking intervention torque as the torque of the third power source; If the torque of the third power source is greater than 0, use the torque of the third power source as the torque of the first power source; If the torque of the third power source is less than or equal to 0, use the preset power source torque as the torque of the first power source.

10. The method according to claim 9, wherein The obtaining of the torque of the second power source includes: Obtain the torque correction coefficient and obtain the current input torque of the differential; Determine the product of the torque correction coefficient and the current input torque as the torque of the second power source.

11. The method according to claim 10, wherein The obtaining of the torque correction coefficient includes: Obtain the torque deviation ratio of the differential; Determine the second difference between the torque deviation ratio and 1, and determine the first sum value of the torque deviation ratio and 1; Determine the quotient of the second difference and the first sum value as the torque correction coefficient.

12. The method according to claim 6, characterized in that, It further includes: Obtain the power source torque threshold; Determine the power source intervention torque according to the first power source intervention torque and the power source torque threshold.

13. The method according to claim 12, wherein The determining of the power source intervention torque according to the first power source intervention torque and the power source torque threshold includes: Obtain the second power source intervention torque, where the second power source intervention torque is a non-negative value less than or equal to the power source torque threshold; If the first power source intervention torque is greater than the power source torque threshold, use the second power source intervention torque as the power source intervention torque; If the first power source intervention torque is less than or equal to the power source torque threshold, use the first power source intervention torque as the power source intervention torque.

14. The method according to claim 12, wherein The obtaining of the power source torque threshold includes: Obtain the current input torque of the differential and obtain the power source torque correction value, where the power source correction value is greater than 0; Determine the difference between the current input torque and the power source torque correction value as the power source torque threshold.

15. The method according to claim 14, characterized in that, The obtaining of the power source torque correction value includes: Obtain the current road surface gradient, the tire rolling radius of the vehicle and the current gravity of the vehicle; Determine the product of the sine value of the current road surface gradient, the tire rolling radius and the current gravity as the power source torque correction value.

16. The method according to claim 1, characterized in that The obtaining of the current differential power of the differential includes: Obtain the current input torque and torque deviation ratio of the differential, and obtain the current wheel speed difference between the two wheels driven by the differential; Determine the current differential power according to the current input torque, the torque deviation ratio and the current wheel speed difference.

17. A vehicle differential protection device, characterized in that, It includes: The first obtaining unit, which obtains the current differential power of the differential and obtains the current temperature of the lubricating oil in the differential; The first determining unit, which determines the first power threshold adapted to the current temperature according to the pre-determined relationship data, where the relationship data is an inverse relationship characterizing the relationship between the lubricating oil temperature and the power threshold; The first protection unit, if the current differential power is greater than the first power threshold, triggers to protect the differential.

18. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program includes executable instructions that, when executed by a processor, implement the method according to any one of claims 1-16 above.

19. A vehicle, characterized in that, It includes a vehicle differential protection device according to claim 17.

Images