Differential protection control method, device and electronic equipment

Abstract

The application provides a differential protection control method and device and electronic equipment to solve the problem of differential sintering or wear caused by vehicle driving under the current differential working condition. The method comprises: obtaining the cumulative slip energy of the differential based on the differential between the left and right wheel ends of the vehicle in the running time and the current motor output torque; determining the maximum torque output by the motor based on the cumulative slip energy of the differential; and controlling the output torque of the motor based on the maximum torque. The application monitors the speed difference between the left and right wheels during the running time of the vehicle, and obtains the friction energy accumulated by the differential in a period of time under the current working condition according to the speed difference between the left and right wheels and the transmission torque borne by the differential, and dynamically limits the torque according to the energy value, which can effectively enhance the robustness of the single slip speed difference protection and protect the differential structure under the abuse working condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of differential, and in particular to a differential protection control method and device and electronic equipment. BACKGROUND

[0002] The differential is the main component of the automobile drive axle, and the automobile differential can enable the left and right (or front and rear) drive wheels to rotate at different speeds.

[0003] When the torque loading rate of the automobile is accelerated and the torque output is increased, it will cause a severe differential working condition of large speed difference and large impact load between the two ends of the wheel. If the user drives the vehicle in such a working condition, the sticking wear between the cross shaft and the planetary gear in the severe two-wheel differential working condition is much more than the daily driving wear. The high temperature generated by internal friction reduces the oil viscosity in the differential cavity, the lubricating oil film between the planetary gear and the cross shaft is damaged, dry friction occurs, which will cause the differential to sinter or wear out.

[0004] Therefore, it is urgent to propose a differential protection control scheme that can protect the differential in the differential working condition while ensuring the stable driving of the vehicle. SUMMARY

[0005] In view of the above problems, the present application provides a differential protection control method, device and electronic equipment to solve the problem of differential sintering or wear caused by vehicle driving in the differential working condition.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme:

[0007] The present application provides a differential protection control method, comprising:

[0008] Based on the differential between the wheels at each stage and the current motor output torque during the running time of the vehicle, the cumulative slip energy of the differential is obtained;

[0009] Based on the cumulative slip energy of the differential, the maximum torque output by the motor is determined;

[0010] Based on the maximum torque, the output torque of the motor is controlled.

[0011] In one embodiment, the maximum torque output by the motor based on the cumulative slip energy of the differential comprises:

[0012] Based on the cumulative slip energy of the differential and the energy dissipation coefficient, the residual slip energy of the differential is obtained;

[0013] Based on the residual slip energy of the differential, the maximum torque output by the motor is determined.

[0014] In an embodiment, before obtaining the differential cumulative slip energy, further comprising:

[0015] If there is a differential stage between the wheel ends of the vehicle within the running time that is less than the differential threshold, the differential stage less than the differential threshold is eliminated to obtain an eliminated differential stage;

[0016] The differential cumulative slip energy is obtained, comprising:

[0017] Based on the eliminated differential stage and the current motor output torque, the differential cumulative slip energy is obtained.

[0018] In an embodiment, the maximum torque of the motor output is determined based on the differential residual slip energy, comprising:

[0019] The differential residual slip energy at the current time is obtained based on the differential residual slip energy at the previous time;

[0020] The maximum torque of the motor output is determined based on the differential residual slip energy at the current time.

[0021] In an embodiment, the differential cumulative slip energy satisfies the following formula:

[0022] E accum = K * ∫T * Ratio * ΔSpd * dt

[0023] In the formula, E accum represents the differential cumulative slip energy, K represents the differential coefficient, T represents the current motor output torque, Ratio represents the ratio, ΔSpd represents the differential stage between the wheel ends at the corresponding time, and t represents the running time.

[0024] In an embodiment, the differential residual slip energy satisfies the following formula:

[0025]

[0026] In the formula, E represents the differential residual slip energy, E accum represents the differential cumulative slip energy, H represents the energy dissipation coefficient, and t represents the running time.

[0027] In an embodiment, before determining the maximum torque of the motor output based on the differential cumulative slip energy, further comprising:

[0028] Detecting whether the active hydraulic function of the vehicle is activated, if so, jumping out of the step of determining the maximum torque of the motor output based on the differential cumulative slip energy, and controlling the braking state of the vehicle based on the active hydraulic function.

[0029] In an embodiment, after determining the maximum torque of the motor output based on the cumulative slip energy of the differential, further comprising:

[0030] sending a prompt message to the instrument based on the communication bus, so that the instrument displays the prompt message, and the prompt message is used to prompt the maximum torque of the motor output.

[0031] According to another aspect of the present application, a differential protection control device is provided, comprising:

[0032] The acquisition module is configured to acquire the cumulative slip energy of the differential based on the differential of each stage between the wheel ends of the vehicle in the running time and the current motor output torque;

[0033] The determination module is configured to determine the maximum torque of the motor output based on the cumulative slip energy of the differential;

[0034] The transmission module is configured to control the output torque of the motor based on the maximum torque.

[0035] According to still another aspect of the present application, an electronic device is provided, comprising a memory and a processor;

[0036] The memory stores computer execution instructions;

[0037] The processor executes the computer execution instructions stored in the memory, so that the electronic device performs the differential protection control method.

[0038] According to the differential protection control method, device and electronic device provided by the present application, the cumulative slip energy of the differential is acquired based on the differential of each stage between the wheel ends of the vehicle in the running time and the current motor output torque; the maximum torque of the motor output is determined based on the cumulative slip energy of the differential; and the output torque of the motor is controlled based on the maximum torque. Through the above method, the wheel speed difference between the left and right wheels in the running time of the vehicle is monitored, and the friction energy accumulated by the differential in the current working condition for a period of time is acquired according to the wheel speed difference between the left and right wheels and the transmission torque borne by the differential, and dynamic torque limitation is performed according to the energy value, which can effectively enhance the robustness of the single slip wheel speed difference protection and protect the differential structure under abuse working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0039] The drawings herein are incorporated into the specification and form part of the specification, show embodiments consistent with the present application, and together with the specification serve to explain the principles of the present application.

[0040] Figure 1a A possible system structure diagram provided by the embodiment of the present application;

[0041] Figure 1b A structural schematic diagram of a vehicle provided for an embodiment of the present application is provided.

[0042] Figure 2 A flowchart of a differential protection control method provided for an embodiment of the present application is provided.

[0043] Figure 3 A flowchart of another differential protection control method provided for an embodiment of the present application is provided.

[0044] Figure 4 A flowchart of still another differential protection control method provided for an embodiment of the present application is provided.

[0045] Figure 5 A structural schematic diagram of a differential protection control device provided for an embodiment of the present application is provided.

[0046] Figure 6 A structural schematic diagram of an electronic device provided for an embodiment of the present application is provided.

[0047] Through the above-mentioned drawings, the specific embodiments of the present application have been shown, and will be described in more detail hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0048] With the rise of the electric vehicle market, electric drive systems are also being applied more and more widely. The differential is a main component of the automobile drive axle. With the increasing integration of the electric drive assembly, the differential is usually integrated inside the three-in-one electric drive assembly. The function of the differential is to transmit power to the two half shafts while allowing the two half shafts to rotate at different speeds, so as to enable the two sides of the vehicle to travel at different distances in the form of rolling as much as possible.

[0049] Compared with traditional fuel vehicles, electric vehicles have fast torque loading rate and large torque output, which have strong impact load on the transmission components. Usually, the mechanical durability design index of the differential of an electric vehicle is verified by the standard “Q / JLYJ7111261B-2020 Differential Reliability Test Conditions”, but there are still severe differential conditions of large speed difference and large impact load at both ends of the wheel speed for the torque output characteristics of electric vehicles. If the user abuses the vehicle under such conditions, the sticking wear between the spider and the planetary gear under the severe two-wheel differential condition is much larger than the wear in daily driving. Due to the high temperature generated by internal friction, the oil viscosity in the differential cavity is reduced, the lubricating oil film between the planetary gear and the spider is damaged, dry friction is generated, which can cause the differential to sinter or wear and damage.

[0050] For the above-mentioned differential abuse working condition of the electric vehicle, in the related technology, the differential slip working condition of the two sides of the wheel is monitored by software, and when the working condition is detected, the hydraulic brake system is activated to reduce the speed difference of the two sides of the wheel. There is also related technology that reduces the motor torque by detecting that the speed difference of the two wheels is greater than a certain threshold. The above-mentioned solutions can protect the differential transmission system to some extent. But the following problems are easy to occur:

[0051] 1) The scheme based on hydraulic active braking to reduce the speed difference of the two sides of the wheel is similar to the dynamic stability system ESP equipped on the vehicle, which usually provides a button for the user to turn off the active intervention. If the user chooses to turn off the function, it cannot well cope with the severe differential working condition;

[0052] 2) The above-mentioned related technology belongs to single limitation of severe differential working condition, for example, long uphill low adhesion road surface, split road surface, desert and other unconventional road surface driving. If there is a continuous differential abuse working condition, although the differential protection function can be single, the repeated activation and exit still exist the risk of sintering of the differential transmission components in the short time accumulated heat energy;

[0053] 3) The continuity of the torque limitation of the differential working condition is poor. Based on the scheme that limits the torque when the speed difference of the wheel exceeds a certain threshold, the scheme is triggered frequently, the torque can be quickly reduced, but at the same time the speed difference of the wheel is also reduced, and the torque output will exist intermittence. If the power is lost instantaneously in the turning working condition, it will cause safety problems of the vehicle, and the escape working condition is easy to appear unable to escape smoothly.

[0054] 4) The motor torque control system and the hydraulic active braking system are not matched, resulting in conflict between driving force and braking force.

[0055] In view of the above technical problems, the embodiment of the present application provides a differential protection control method, device and electronic equipment. The differential cumulative slip energy is obtained based on the differential of each stage between the wheels of the vehicle in the running time and the current motor output torque, and the maximum torque of the motor output is determined based on the differential cumulative slip energy. Then the output torque of the motor is controlled based on the maximum torque. This process is a protection for the residual slip energy in the differential, which is a time dimension consideration method, which can enhance the robustness of the single slip speed difference protection and protect the differential structure under abuse working condition, and comprehensively consider the independence of the vehicle stability system, while effectively avoiding the incoordination caused by the independent control of each system to the torque.

[0056] For the purpose, technical solutions and advantages of the present application to be clearer, the technical solutions in the embodiments of the present application will be described in more details below with reference to the drawings in the embodiments of the present application. The same or similar notations represent the same or similar components or components with the same or similar functions throughout the drawings. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0057] Figure 1a A possible system structure diagram provided by the embodiments of the present application is shown in FIG. 1, which comprises a vehicle stability control system (Electronic Stability Program, ESP) 110, a motor control system 120 and an instrument system 130, wherein the vehicle stability control system 110, the motor control system 120 and the instrument system 130 and other systems in the network can be electrically connected through a communication bus, and vehicle data is transmitted by using the communication bus.

[0058] The vehicle body stability control system is a braking system for preventing vehicle skidding under emergency driving conditions, and its main feature is its initiative. Compared with the Antilock Brake System (ABS), the ESP can take preventive measures based on its initiative. When emergency conditions such as emergency turning, emergency acceleration and emergency braking occur, the vehicle can quickly perceive and take corresponding braking measures, such as individually controlling each tire and reducing engine output to maintain the stability of the vehicle body. In the embodiments, the differential cumulative slip energy is obtained by using the motor control system, and the maximum torque of the motor output is determined according to the differential cumulative slip energy to achieve the protection of the differential, and the main function of the motor control system is to control the motor output torque to make the vehicle travel, and the entire electronic control system is equivalent to the engine and engine controller of the fuel vehicle; the vehicle body stability control system can obtain more vehicle posture information, and in some extreme slip conditions, the vehicle stability system can activate the active hydraulic control to reduce the speed difference between the wheels on both sides; the instrument system, i.e., the instrument, is an important interface for the driver to exchange information with the vehicle. With the development of automobile electronic technology, the amount of information of the vehicle driving conditions and various mechanisms and parts has increased significantly. The driver must know more and more timely whether the various parameters of the vehicle and engine are normal when driving the vehicle, so as to take timely measures to prevent accidents.

[0059] For the purpose of understanding the embodiments of the present application, combined with Figure 1b , as shown in FIG. 1, Figure 1bA schematic view of a structure of a vehicle, including a left wheel 1, a left wheel speed sensor 2, a driving motor 3, a speed reduction mechanism 4, a differential 5, a right wheel speed sensor 6, a right wheel 7, a right hydraulic brake execution unit 8, and a left hydraulic brake execution unit.

[0060] The driving motor 3 amplifies the motor torque through the speed reduction mechanism 4 and inputs the motor torque to an input shaft of the differential 5. The driving motor 3 is electrically connected to the motor control system 120. In this embodiment, the differential is an open type without the function of limiting slip and locking. The half shaft gears in the differential 5 are rigidly connected to the left wheel 1 and the right wheel 7 through half shafts. The vehicle stability control system 110 senses the wheel speed change by collecting the left wheel speed sensor 2 and the right wheel speed sensor 6, processes the original signals of the sensors into wheel speeds, and sends the wheel speeds to the communication bus. The controllers on the communication bus, such as the motor control system 120, can obtain the wheel speed information. The two hydraulic brake units can be controlled by the vehicle stability control system. In some working conditions, the ESP can actively activate the hydraulic brake units to control the braking force of each wheel.

[0061] The network architecture of the application is briefly described above. The motor control system 110 applied to FIG. 1 is taken as an example to describe the differential protection control method provided by the embodiment of the application in detail.

[0062] Please refer to Figure 2 , Figure 2 A flowchart of a differential protection control method provided by the embodiment of the application is shown. The method includes steps S201-S203.

[0063] In step S201, the differential cumulative slip energy is obtained based on the differential of each stage between the wheel ends of the vehicle in the running time and the current motor output torque.

[0064] In this embodiment, the differential cumulative slip energy is the cumulative friction energy of the differential working condition of the two wheel ends. The running time is the running time in the working state of the vehicle. The running time can be all running time in the working state or a certain running time. The running time can be adaptively adjusted according to the actual application requirement. The differential of each stage is the differential of each stage corresponding to each time in the running time. Each time can be information corresponding to one time or multiple times. This embodiment takes one time as an example for description.

[0065] It can be understood that the accumulated slip energy in the embodiment is the residual slip energy of the differential in a certain time period, and the motor output torque is determined based on the residual slip energy, which can largely avoid the wear and tear caused by the continuous use of the differential. In some cases, the differential may not immediately appear wear and tear and the like for single or short period of use, but based on the accumulated state of continuous use, it will cause the differential wear and tear. The embodiment uses the differential stages between the wheel ends and the current motor output torque to obtain the accumulated slip energy of the differential, which can well solve the above problems.

[0066] In step S202, the maximum torque of the motor output is determined based on the accumulated slip energy of the differential.

[0067] In an embodiment, the differential tolerance energy Eprotet is set. In order to avoid the residual slip energy accumulation value exceeding the differential tolerance energy Eprotet, the motor controller can dynamically limit the maximum available torque of the motor according to the size of the differential accumulated slip energy.

[0068] It can be understood that Eprotet in the embodiment is a reference energy protection threshold value. The value can be designed according to the input shaft speed, the bearing torque, the cycle number, the high-speed low-torque, the low-speed high-torque, and the differential reliability durability test under different slip rates. The maximum energy protection value observed in the test is set as Eprotet. Further, the differential receiving energy value Emax can be 1.2 times the maximum energy protection value Eprotet. In an implementation, if it is monitored that the differential accumulated slip energy E(t) exceeds Eprotet, and there is no active hydraulic activation, the motor controller linearly limits the maximum available torque of the motor in the interval [Eprotet, Emax]. When E(t)>Emax, the current maximum available torque of the motor is reduced to 30% of the un-limited torque.

[0069] In step S203, the output torque of the motor is controlled based on the maximum torque.

[0070] Compared with the protection of the differential in the related art by instant and single limitation, the motor control system in the embodiment monitors the speed difference between the left and right wheels in real time during the vehicle operation time, estimates the friction power generated by the differential under the current working condition according to the speed difference between the left and right wheels and the transmission torque borne by the differential, calculates the accumulated friction energy in a period of time, and dynamically limits the torque according to the energy value. It is a protection based on the residual slip energy in the differential, which is a time dimension consideration method, and can effectively enhance the robustness of the single slip speed difference protection and the protection of the differential structure under abuse working conditions.

[0071] Please refer to Figure 3 ,Figure 3 The flowchart of another differential protection control method provided by the embodiment of the present application is shown in the figure. Based on the above embodiment, the embodiment considers that, with the passage of time, the energy dissipates. In order to improve the accuracy of the obtained differential residual slip energy value, the embodiment introduces an energy dissipation coefficient when obtaining the differential residual slip energy, and obtains the final differential residual slip energy after energy dissipation according to the differential cumulative slip energy and the energy dissipation coefficient. The maximum torque of the motor output is determined based on the differential cumulative slip energy (step S202), which includes step S2021 and step S2022.

[0072] Step S2021, obtaining the differential residual slip energy based on the differential cumulative slip energy and the energy dissipation coefficient.

[0073] It should be noted that the energy dissipation coefficient can be determined by the person skilled in the art in combination with the actual application and the prior art. The greater the energy dissipation coefficient, the faster the energy dissipation.

[0074] In a preferred embodiment, the differential residual slip energy satisfies the following formula:

[0075]

[0076] In the formula, E represents the differential residual slip energy, E accum represents the differential cumulative slip energy, H represents the energy dissipation coefficient, and t represents the running time.

[0077] In the embodiment, it is assumed that E accum is constant. With the passage of time, the equivalent friction heat energy (i.e. residual slip energy) remaining in the differential gradually decreases. In the present example, according to the material and structural characteristics of the differential, H is 0.012.

[0078] Step S2022, determining the maximum torque of the motor output based on the differential residual slip energy.

[0079] Compared with the above embodiment, the present embodiment considers the energy dissipation process of the friction heat energy. The differential residual slip energy after energy dissipation is obtained based on the differential cumulative slip energy, so that the differential energy value used to determine the maximum torque of the motor output is more accurate, and the technical effect of further balancing the protection of the differential and the stability of the vehicle is achieved.

[0080] In a preferred embodiment, in order to enhance the robustness of differential energy accumulation, the wheel end speed difference is segmented, and based on the size of the wheel end speed difference, it is determined whether to perform the calculation of the differential internal participating energy accumulation. Specifically, before the differential cumulative slip energy is obtained (step S201), the method further comprises the following steps:

[0081] If there is a differential stage between the wheel ends of the vehicle within the running time, which is less than the differential threshold, the differential stage less than the differential threshold is removed to obtain the removed differential stages.

[0082] The differential cumulative slip energy is obtained (step S201), specifically: based on the removed differential stages and the current motor output torque, the differential cumulative slip energy is obtained.

[0083] In this embodiment, the motor control system obtains the left wheel end speed WhlSpdLeft and the right wheel end speed WhlSpdRight through the communication bus at a period of not less than 200ms, and calculates the absolute value of the differential speed difference between the two ends of the differential in real time:

[0084] ΔSpd = |WhlSpdLeft-WhlSpdRight|

[0085] In one implementation, for the speed difference ΔSpd between the wheel ends within the running time, E accum No accumulation calculation is performed when the speed difference ΔSpd is greater than or equal to 100rpm, E accum The energy accumulation calculation is started. Wherein, 100rpm is the differential threshold set in this embodiment, in other implementations, other differential thresholds can also be set, and this embodiment does not make special limitations.

[0086] In a preferred embodiment, the differential cumulative slip energy satisfies the following formula:

[0087] E accum = K * ∫T * Ratio * ΔSpd * dt

[0088] Wherein, E accum represents the differential cumulative slip energy, K represents the differential coefficient, T represents the current motor output torque, Ratio represents the proportion, ΔSpd represents the stage differential between the wheel ends at the corresponding time, and t represents the running time.

[0089] The derivation process of the above formula is to calculate the friction energy accumulation of the differential in the differential working condition of the two wheel ends:

[0090] E accum = ∫P * dt = ∫F * vspli *dt

[0091] F = a * T * Ratio

[0092] P is the differential slip power;

[0093] F is the differential planetary gear friction surface pressure;

[0094] v spli is the planetary gear mesh surface linear velocity.

[0095] Further, depending on the configuration of the differential, the gear mesh surface pressure F and the differential input torque (i.e. motor torque T * reducer ratio Ratio), the internal center hole pitch, and the mesh surface friction coefficient are related, and for engineering applications, the planetary gear friction surface pressure can be expressed as F = a * T * Ratio, where a is the influence coefficient after the above-mentioned influencing factors are fuzzified;

[0096] Further, the mesh surface linear velocity v spli is related to the current two-wheel end speed difference and the internal gear radius, and for engineering applications, v spli = b * ΔSpd, where b is the influence coefficient after the above-mentioned influencing factors are fuzzified;

[0097] The above-mentioned a, b coefficients are determined by the differential structure and material and can be considered as a constant value K, and in the present example, the coefficient K takes the value 1.

[0098] Therefore, after the equivalent conversion of the above-mentioned formula, the cumulative friction energy remaining in the differential under the differential condition of the two-wheel end can be equivalently expressed as an expression related to the current motor output torque T and the wheel end speed difference value ΔSpd:

[0099] E accum = K * ∫T * RatioO ΔSpd * dt

[0100] In one embodiment, in addition to calculating the differential residual slip energy based on the above-mentioned formula, the differential residual slip energy at the current time can also be obtained based on the differential residual slip energy at the last time in incremental form, specifically, the maximum torque output by the motor is determined based on the differential residual slip energy, comprising:

[0101] obtaining the differential residual slip energy at the current time based on the differential residual slip energy at the last time;

[0102] determining the maximum torque output by the motor based on the differential residual slip energy at the current time.

[0103] In an implementation, the energy calculation is performed in an operation period t, as follows, E(t-1) is the differential residual slip energy at the last period, ΔE is the energy change in the operation period t, and the differential residual slip energy E(t) calculated in the current operation period is expressed as

[0104] E(t) = E(t-1) + ΔE

[0105] Please refer to Figure 4 , Figure 4 The flowchart of another differential protection control method provided by the embodiment of the present application is shown in FIG. 4. Based on the above embodiment, the vehicle stability system can obtain more vehicle posture information in this embodiment, and in some extreme slip conditions, the vehicle stability system activates the active hydraulic control to reduce the wheel speed difference between the two sides. To ensure the consistency of the vehicle torque coordination, the torque limiting unit is closed when the active hydraulic function of the vehicle stability system is detected to be activated, and the motor torque is not actively reduced. Specifically, before the maximum torque of the motor output is determined based on the differential cumulative slip energy (step S202), steps S401 and S402 are further included.

[0106] Step S401, detecting whether the active hydraulic function of the vehicle is activated, if yes, the step of determining the maximum torque of the motor output based on the differential cumulative slip energy is skipped, and step S402 is executed; otherwise, step S201 is executed.

[0107] It should be noted that step S401 of the embodiment is arranged after step S201 and before step S202. In some embodiments, step S401 can also be arranged before step S201, or both steps are synchronized. The embodiment only illustrates one sequence, and the sequence is not specifically limited.

[0108] It can be understood that the active hydraulic function is the brake function of the hydraulic braking system. In the embodiment, the vehicle stability system can obtain more vehicle posture information, and in extreme conditions, the vehicle uses the active hydraulic function. Even if the differential cumulative slip energy value exceeds the motor controller, the energy accumulation monitoring will be stopped, and the maximum torque of the motor output will not be intervened. Compared with the related art, the independence of the vehicle stability system is considered comprehensively, and the incoordination caused by the individual control of each system on the torque is avoided.

[0109] Step S402, controlling the brake state of the vehicle based on the active hydraulic function.

[0110] In an implementation, after the maximum torque of the motor output is determined based on the differential cumulative slip energy (step S202), the following steps are further included.

[0111] sending a prompt message to the instrument based on a communication bus, so that the instrument displays the prompt message, the prompt message being used to prompt the maximum torque output by the motor.

[0112] In this embodiment, in order to improve user experience, when the available torque of the motor is limited due to the residual slip energy of the differential, the controller performance limitation information is sent to the instrument through the communication bus to remind the user.

[0113] According to another aspect of the embodiments of the present application, a differential protection control device is also provided, as shown in the figure, comprising: Figure 5

[0114] The acquisition module 51 is configured to acquire the differential cumulative slip energy based on the differential of each stage between the wheel ends of the vehicle within the running time and the current motor output torque.

[0115] The determination module 52 is configured to determine the maximum torque output by the motor based on the differential cumulative slip energy.

[0116] The transmission module 53 is configured to control the output torque of the motor based on the maximum torque.

[0117] In an embodiment, the determination module 52 comprises:

[0118] The acquisition unit is configured to acquire the differential residual slip energy based on the differential cumulative slip energy and the energy dissipation coefficient.

[0119] The determination unit is configured to determine the maximum torque output by the motor based on the differential residual slip energy.

[0120] In an embodiment, the device further comprises:

[0121] The stage identification module is configured to, when there is a differential stage less than the differential threshold in the differential of each stage between the wheel ends of the vehicle within the running time, eliminate the differential stage less than the differential threshold to obtain the eliminated differential of each stage.

[0122] The acquisition module is specifically configured to acquire the differential cumulative slip energy based on the eliminated differential of each stage and the current motor output torque.

[0123] In an embodiment, the determination unit is specifically configured to acquire the differential residual slip energy at the current time based on the differential residual slip energy at the last time, and determine the maximum torque output by the motor based on the differential residual slip energy at the current time.

[0124] In an embodiment, the differential cumulative slip energy is obtained by satisfying the following formula: ​

[0125] E accum = K * ∫T * Ratio * ΔSpd * dt

[0126] wherein, E accum represents the cumulative differential slip energy of the differential, K represents the differential coefficient, T represents the current motor output torque, Ratio represents the ratio, ΔSpd represents the stage differential between the wheels at the corresponding moment, and t represents the running time.

[0127] In an embodiment, the differential residual slip energy satisfies the following formula:

[0128]

[0129] wherein, E represents the differential residual slip energy, E accum represents the cumulative differential slip energy of the differential, and H represents the energy dissipation coefficient, and t represents the running time.

[0130] In an embodiment, the device further comprises:

[0131] a detection module configured to detect whether the active hydraulic function of the vehicle is activated, and if so, the determination module determines the maximum torque output by the motor based on the cumulative differential slip energy of the differential, and controls the braking state of the vehicle based on the active hydraulic function.

[0132] In an embodiment, the device further comprises:

[0133] a prompt module configured to send a prompt message to the instrument based on the communication bus, so that the instrument displays the prompt message, and the prompt message is used to prompt the maximum torque output by the motor.

[0134] According to another aspect of the embodiments of the present application, an electronic device is also provided, as shown in the figure, comprising a memory 61 and a processor 62. Figure 6

[0135] The memory 61 stores computer execution instructions.

[0136] The processor 62 executes the computer execution instructions stored in the memory, so that the electronic device executes the differential protection control method.

[0137] ​Those of ordinary skill in the art will realize and understand that all or some of the steps in the methods disclosed above and the functional modules / units in the systems and devices can be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component can have multiple functions, or one function or step can be performed by several physical components in cooperation. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transitory media).

[0138] As is well known to those of ordinary skill in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by a computer.

[0139] In addition, it is well known to those of ordinary skill in the art that communication media typically includes computer readable instructions, data structures, program modules or other data in modulated data signals such as carrier waves or other transport mechanisms, and can include any information delivery medium.

[0140] In the description of embodiments of the present application, the term "and / or" only represents an association relationship of describing associated objects, and represents that there can be three relationships, for example, A and / or B, which can represent three cases of A alone, A and B together, and B alone. In addition, the term "at least one" represents any combination of one or at least two of the plurality, for example, including at least one of A, B, and C, which can represent any one or more elements selected from the set of A, B, and C.

[0141] In the description of the embodiments of the present application, the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the term "a plurality of" means two or more, unless otherwise specifically specified.

[0142] In the description of the embodiments of the present application, the terms "first", "second", "third", "fourth" and the like (if present) are used to distinguish similar objects, and do not necessarily have to describe a particular order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0143] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A differential protection control method, characterized in that, include: Based on the differential speed between the wheel ends at each stage during the vehicle's operation time and the current motor output torque, the cumulative slip energy of the differential is obtained; The residual slip energy of the differential is obtained based on the cumulative slip energy and energy dissipation coefficient of the differential. The maximum torque output by the motor is determined based on the residual slip energy of the differential. The output torque of the motor is controlled based on the maximum torque. The residual slip energy of the differential is obtained by the following formula: In the formula, This represents the residual slip energy of the differential. This indicates the cumulative slip energy of the differential. Indicates the energy dissipation coefficient. Indicates the runtime.

2. The method according to claim 1, characterized in that, Before acquiring the cumulative slip energy of the differential, the following is also included: If there is a differential speed stage with a speed difference less than the differential speed threshold among the differential speeds between the wheel ends of the vehicle during the running time, then the differential speed stage with a speed difference less than the differential speed threshold is removed to obtain the differential speeds of each stage after removal. The acquisition of the differential's cumulative differential energy includes: Based on the eliminated differential speeds at each stage and the current motor output torque, the cumulative slip energy of the differential is obtained.

3. The method according to any one of claims 1, characterized in that, The determination of the maximum output torque of the motor based on the residual slip energy of the differential includes: The residual slip energy of the differential at the current moment is obtained based on the residual slip energy of the differential at the previous moment. The maximum torque output by the motor is determined based on the residual slip energy of the differential at the current moment.

4. The method according to claim 1, characterized in that, The cumulative slip energy of the differential is obtained by the following formula: In the formula, This represents the cumulative slip energy of the differential, where K represents the differential coefficient. This indicates the current output torque of the motor. Indicates proportion, This represents the stage differential speed between the wheel ends at corresponding moments, where t represents the running time.

5. The method according to claim 1, characterized in that, Before determining the maximum output torque of the motor based on the cumulative slip energy of the differential, the following steps are also included: If the active hydraulic function of the vehicle is activated, the process skips the step of determining the maximum torque output of the motor based on the cumulative slip energy of the differential, and controls the braking state of the vehicle based on the active hydraulic function.

6. The method according to claim 1, characterized in that, After determining the maximum output torque of the motor based on the cumulative slip energy of the differential, the following is also included: A prompt message is sent to the instrument via the communication bus so that the instrument displays the prompt message, which is used to indicate the maximum torque output by the motor.

7. A differential protection control device, characterized in that, include: The acquisition module is configured to acquire the cumulative slip energy of the differential based on the differential speed between the wheel ends at each stage during the vehicle's operation time and the current motor output torque. The determination module is configured to obtain the residual slip energy of the differential based on the cumulative slip energy and energy dissipation coefficient of the differential; The maximum torque output by the motor is determined based on the residual slip energy of the differential. The transmission module is configured to control the output torque of the motor based on the maximum torque. The residual slip energy of the differential is obtained by the following formula: In the formula, This represents the residual slip energy of the differential. This indicates the cumulative slip energy of the differential. Indicates the energy dissipation coefficient. Indicates the runtime.

8. An electronic device, characterized in that, include: Memory and processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the electronic device to perform the differential protection control method according to any one of claims 1-6.

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