Vehicle control method, storage medium and vehicle

Abstract

The present application provides a vehicle control method, a storage medium and a vehicle, and belongs to the field of vehicle technology. By acquiring vehicle status information when the vehicle is in a low-speed four-wheel drive state, the vehicle can be controlled to switch from the current drive mode to the low-speed direct drive mode when the vehicle status information meets the mode switching conditions, and the vehicle can be controlled to travel in the low-speed direct drive mode; wherein, in the low-speed direct drive mode, the clutch of the vehicle is in a slipping state, and the engine is in a driving state. By developing a low-speed direct drive mode, the embodiment of the present application enables the engine to drive the vehicle in a low-speed scenario, on the one hand, effectively solving the problem of excessive power consumption of the vehicle in winter, thereby improving the vehicle's power conservation ability; on the other hand, the vehicle can always be maintained in a four-wheel drive state at a low speed, effectively avoiding the vehicle from skidding and drifting in snowy weather, thereby ensuring the vehicle's driving safety.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a vehicle control method, a storage medium and a vehicle. Background Art

[0002] In order to adapt to different road conditions and driving requirements, new energy vehicles usually have multiple driving modes including series mode, pure electric four-wheel drive mode and direct drive mode.

[0003] In the related art, since the engine is prone to flameout when the vehicle is driving at low speed in direct drive mode, in order to ensure the safety of the vehicle driving at low speed in snowy weather, new energy vehicles usually switch to pure electric four-wheel drive mode. However, since new energy vehicles consume energy faster in winter, when the high-voltage battery power is low, the vehicle will not be able to support four-wheel drive and will switch to series mode to drive in two-wheel drive state. At this time, the vehicle is prone to skidding or tail swinging. Summary of the invention

[0004] The present application provides a vehicle control method, a storage medium and a vehicle to solve the problem that the current vehicle driving mode cannot effectively meet the low-speed driving demand of the vehicle on snowy days.

[0005] In order to solve the above problems, this application adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a vehicle control method, the method comprising:

[0007] When the vehicle is in low-speed four-wheel drive state, obtain vehicle status information;

[0008] When the vehicle status information satisfies the mode switching conditions, the vehicle is controlled to switch from the current driving mode to the low-speed direct drive mode, and the vehicle is controlled to travel in the low-speed direct drive mode; wherein, in the low-speed direct drive mode, the clutch of the vehicle is in a slipping state, and the engine is in a driving state.

[0009] In one embodiment of the present application, the vehicle state information includes clutch state information, and any one of first state information and second state information; wherein the first state information includes current ambient temperature and current road conditions; and the second state information includes current driving mode;

[0010] The method further comprises:

[0011] In the case where the clutch state information satisfies the slipping driving condition, the current ambient temperature is less than the temperature threshold, and the current road condition is a slippery road condition, determining that the vehicle state information satisfies the mode switching condition; or,

[0012] In a case where the clutch state information satisfies the slipping drive condition and the current driving mode is the target driving mode, it is determined that the vehicle state information satisfies the mode switching condition.

[0013] In an embodiment of the present application, the clutch state information includes an overheating signal and a hardware fault signal; the method further includes:

[0014] When the overheat signal indicates that the clutch is not overheated and the hardware fault signal indicates that the clutch has no hardware fault, it is determined that the clutch state information satisfies the slipping drive condition.

[0015] In one embodiment of the present application, the step of controlling the vehicle to switch from the current driving mode to the low-speed direct drive mode includes:

[0016] Determining a target clutch pressure based on the current engine torque of the engine and a preset mapping relationship; the mapping relationship represents a comparison relationship between the engine torque and the clutch pressure under a clutch slip state;

[0017] Based on the target clutch pressure, the clutch is controlled to switch to the slipping state so that the vehicle switches from the current driving mode to the low-speed direct drive mode.

[0018] In an embodiment of the present application, the step of controlling the clutch to switch to the slipping state based on the target clutch pressure includes:

[0019] When the current driving mode is the idle electric four-wheel drive mode, controlling the current clutch pressure of the clutch to increase to the target clutch pressure, so that the clutch is switched from the open state to the slipping state;

[0020] When the current driving mode is the direct driving mode, the current clutch pressure of the clutch is controlled to be reduced to the target clutch pressure so that the clutch is switched from the closed state to the slipping state.

[0021] In an embodiment of the present application, the step of controlling the current clutch pressure of the clutch to increase to the target clutch pressure includes:

[0022] According to a preset first pressure change gradient, controlling the current clutch pressure of the clutch to gradually increase to the target clutch pressure;

[0023] The step of controlling the current clutch pressure of the clutch to decrease to the target clutch pressure comprises:

[0024] According to a preset second pressure change gradient, the current clutch pressure of the clutch is controlled to be gradually reduced to the target clutch pressure.

[0025] In one embodiment of the present application, the step of controlling the vehicle to travel in the low-speed direct drive mode includes:

[0026] determining an engine torque intervention value when a speed difference between two ends of the clutch exceeds a preset speed range;

[0027] Based on the engine torque intervention value, torque regulation is performed on the engine.

[0028] In one embodiment of the present application, the step of determining the engine torque intervention value includes:

[0029] The engine torque intervention value is determined based on the current engine torque of the engine and the speed difference across the clutch.

[0030] In a second aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle control device, the device comprising:

[0031] An information acquisition module, used to acquire vehicle status information when the vehicle is in a low-speed four-wheel drive state;

[0032] A mode switching module is used to control the vehicle to switch from the current driving mode to the low-speed direct drive mode and control the vehicle to travel in the low-speed direct drive mode when the vehicle status information meets the mode switching conditions; wherein, in the low-speed direct drive mode, the clutch of the vehicle is in a slipping state and the engine is in a driving state.

[0033] In one embodiment of the present application, the vehicle state information includes clutch state information, and any one of first state information and second state information; wherein the first state information includes current ambient temperature and current road conditions; the second state information includes current driving mode; the vehicle control device includes:

[0034] A first condition determination module, configured to determine that the vehicle state information satisfies the mode switching condition when the clutch state information satisfies the slipping drive condition, the current ambient temperature is less than a temperature threshold, and the current road condition is a slippery road condition;

[0035] The second condition determination module is used to determine that the vehicle state information satisfies the mode switching condition when the clutch state information satisfies the slipping drive condition and the current driving mode is the target driving mode.

[0036] In one embodiment of the present application, the clutch state information includes an overheating signal and a hardware fault signal; the vehicle control device includes:

[0037] The second condition determination module is used to determine that the clutch state information satisfies the slipping drive condition when the overheating signal indicates that the clutch is not overheated and the hardware fault signal indicates that the clutch has no hardware fault.

[0038] In one embodiment of the present application, the mode switching module includes:

[0039] a pressure determination submodule, for determining a target clutch pressure based on a current engine torque of the engine and a preset mapping relationship; the mapping relationship represents a comparison relationship between the engine torque and the clutch pressure under a clutch slip state;

[0040] The mode switching submodule is used to control the clutch to switch to the slipping state based on the target clutch pressure, so that the vehicle switches from the current driving mode to the low-speed direct drive mode.

[0041] In an embodiment of the present application, the mode switching submodule includes:

[0042] A first state switching unit, configured to control the current clutch pressure of the clutch to increase to the target clutch pressure when the current driving mode is the idle electric four-wheel drive mode, so as to switch the clutch from the open state to the slipping state;

[0043] The second state switching unit is used for controlling the current clutch pressure of the clutch to decrease to the target clutch pressure when the current driving mode is the direct drive mode, so as to switch the clutch from the closed state to the slipping state.

[0044] In one embodiment of the present application, the first state switching unit is specifically used to control the current clutch pressure of the clutch to gradually increase to the target clutch pressure according to a preset first pressure change gradient; the second state switching unit is specifically used to control the current clutch pressure of the clutch to gradually decrease to the target clutch pressure according to a preset second pressure change gradient.

[0045] In an embodiment of the present application, the mode switching module further includes:

[0046] an intervention value determination submodule, configured to determine an engine torque intervention value when a speed difference between two ends of the clutch exceeds a preset speed range;

[0047] The torque regulation submodule is used to regulate the torque of the engine based on the engine torque intervention value.

[0048] In an embodiment of the present application, the intervention value determination submodule is specifically used to determine the engine torque intervention value based on the current engine torque of the engine and the speed difference between the two ends of the clutch.

[0049] In the third aspect, based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium on which an executable program is stored, and when the executable program is executed by a processor, the vehicle control method proposed in the first aspect of the present application is implemented.

[0050] In a fourth aspect, based on the same inventive concept, an embodiment of the present application provides a vehicle, including:

[0051] A memory for storing an executable program;

[0052] processor;

[0053] When the executable program is executed by the processor, the vehicle control method proposed in the first aspect of the present application is implemented.

[0054] Compared with the prior art, this application has the following advantages:

[0055] A vehicle control method provided in an embodiment of the present application can obtain vehicle status information when the vehicle is in a low-speed four-wheel drive state, and can control the vehicle to switch from the current drive mode to the low-speed direct drive mode when the vehicle status information meets the mode switching conditions, and control the vehicle to travel in the low-speed direct drive mode; wherein, in the low-speed direct drive mode, the clutch of the vehicle is in a slipping state, and the engine is in a driving state. By developing a low-speed direct drive mode, on the one hand, the embodiment of the present application enables the engine to drive the vehicle in a low-speed scenario, effectively solving the problem of excessive power consumption of the vehicle in winter, thereby improving the vehicle's power conservation ability; on the other hand, it enables the vehicle to always maintain a four-wheel drive state at a low speed, effectively avoiding the vehicle from skidding and drifting in snowy weather, thereby ensuring the vehicle's driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0057] Figure 1 is a flowchart of a vehicle control method in one embodiment of the present application;

[0058] Figure 2 is a functional module diagram of a vehicle control device in one embodiment of the present application;

[0059] Figure 3 It is a structural schematic diagram of a vehicle in one embodiment of the present application. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] It should be noted that in direct drive mode, the engine is in a driving state, the clutch is in a closed state, the rear axle motor is in a driving state, and the front axle motor is usually in a driving state. The power of the engine directly drives the vehicle through the clutch and the front axle transmission in turn. Since in direct drive mode, the engine and the front axle motor can jointly drive the front axle of the vehicle, the driving force of the whole vehicle in direct drive mode is usually greater than the driving force of the whole vehicle in other modes. However, since in direct drive mode, the engine is directly connected to the wheel end, the engine speed has a certain speed ratio with the vehicle speed. When the vehicle is driving at a low speed, it is easy for the engine speed to be too low and the flameout to occur.

[0062] Therefore, when the vehicle is driving at a low speed on snowy days, it usually switches to pure electric four-wheel drive mode. However, when using the car in winter, in addition to the normal driving energy consumption, new energy vehicles also have many energy consumptions such as passenger compartment heating, seat heating, defrosting and defogger. Therefore, the energy consumption required by new energy vehicles in winter is higher than that in other seasons. Since new energy vehicles consume energy faster in winter, when the high-voltage battery is low, the vehicle will not be able to support four-wheel drive driving and will switch to series mode. In series mode, the engine drives the front axle motor to generate electricity, and the generated electricity is used to charge the battery or provide it to the rear axle motor to drive the vehicle. Although the battery can be charged in series mode to prevent the battery power from further decreasing, it will cause the vehicle to drive in a two-wheel drive state. At this time, the vehicle is prone to slipping or tail swinging.

[0063] In view of the problem that the current vehicle driving mode cannot effectively meet the low-speed driving needs of the vehicle in snowy weather, the present application aims to provide a vehicle control method, which can obtain vehicle status information when the vehicle is in a low-speed four-wheel drive state, and can control the vehicle to switch from the current driving mode to the low-speed direct drive mode when the vehicle status information meets the mode switching conditions, and control the vehicle to travel in the low-speed direct drive mode; wherein, in the low-speed direct drive mode, the clutch of the vehicle is in a slipping state, and the engine is in a driving state. By developing a low-speed direct drive mode, the embodiment of the present application, on the one hand, enables the engine to drive the vehicle in a low-speed scenario, effectively solving the problem of excessive power consumption of the vehicle in winter driving, thereby improving the vehicle's power conservation ability; on the other hand, enables the vehicle to always maintain a four-wheel drive state at a low speed, effectively avoiding the vehicle from slipping and drifting in snowy weather, thereby ensuring the driving safety of the vehicle.

[0064] Reference Figure 1 , showing a vehicle control method of the present application, the method may include the following steps:

[0065] S101: When the vehicle is in a low-speed four-wheel drive state, obtain vehicle state information.

[0066] It should be noted that the execution subject of this embodiment can be a computing service device with data processing, network communication and program running functions, or an electronic device with the above functions such as a driving computer, a car computer, etc., such as an ECU (Electronic Control Unit), an HCU (Hybrid Control Unit), a TCU (Transmission Control Unit), etc. This implementation does not impose specific restrictions on the type of execution subject. In order to shorten the signal transmission link and improve control efficiency, the following description will take TCU as the execution subject.

[0067] In this embodiment, if the TCU detects that the vehicle is in the four-wheel drive state and the current vehicle speed is less than the vehicle speed threshold, it determines that the vehicle is in the low-speed four-wheel drive state.

[0068] In a specific implementation, the TCU can determine whether the vehicle is in a four-wheel drive state by detecting the current driving mode of the vehicle. For example, when the TCU detects that the current driving mode is a pure electric four-wheel drive mode or a direct drive mode, it determines that the vehicle is in a four-wheel drive state; or, the TCU can also obtain the front axle torque and the rear axle torque, and when it detects that the front axle torque and the rear axle torque are both greater than the torque threshold, it determines that the vehicle is in a four-wheel drive state.

[0069] In this embodiment, if it is detected that the vehicle is in a low-speed four-wheel drive state, it means that the vehicle may be driving at a low speed on a slippery road in winter snowy weather. At this time, traditional four-wheel drive modes such as pure electric four-wheel drive mode or direct drive mode will not be able to effectively meet the vehicle's driving needs. Therefore, the TCU will obtain the vehicle status information and, based on the vehicle status information, determine whether it is necessary to control the vehicle to switch modes.

[0070] S102: When the vehicle state information satisfies the mode switching condition, the vehicle is controlled to switch from the current driving mode to the low-speed direct drive mode, and the vehicle is controlled to travel in the low-speed direct drive mode.

[0071] In this embodiment, the mode switching condition is used to determine whether the vehicle is in a state of high energy consumption and a strong four-wheel drive demand. That is, if the TCU determines that the vehicle is in a state of high energy consumption and a strong four-wheel drive demand based on the vehicle state information, it determines that the vehicle state information meets the mode switching condition. Among them, high energy consumption means that the power demand of the whole vehicle is greater than the power threshold.

[0072] In a specific implementation, the vehicle status information includes first status information, which may include the current ambient temperature and the current road condition. When the TCU determines that the current ambient temperature is less than the temperature threshold and the current road condition is a slippery road condition, it determines that the vehicle status information meets the mode switching condition. It should be noted that when the current ambient temperature is less than the temperature threshold, the user usually enables the heating system, thereby causing the vehicle to enter a high energy consumption state; when the current road condition is a slippery road condition, the vehicle needs to be in a four-wheel drive state to avoid the vehicle from slipping and improve the vehicle's driving performance.

[0073] In this embodiment, it is possible to determine whether the current road condition is a slippery road condition based on the weather type and / or the road surface image. Specifically, the TCU can determine that the current road condition is a slippery road condition when it detects that the weather type is a rainy type, a snowy type, or a hail type; and / or input the road surface image into a preset road condition recognition model and output a road condition recognition result, which is used to indicate whether the vehicle is in a slippery road condition.

[0074] In a specific implementation, the vehicle state information includes second state information, and the second state information may include the current driving mode. If the TCU detects that the current driving mode is the target driving mode, it determines that the vehicle state information meets the mode switching condition. In the target driving mode, the vehicle will be in a state of high energy consumption and strong four-wheel drive demand.

[0075] Exemplarily, the target driving mode may include a snow driving mode. Since when the vehicle is in the snow driving mode, there is a strong demand for four-wheel drive and the heating system needs to be activated, the TCU can quickly determine whether the vehicle state information meets the mode switching condition by detecting whether the vehicle is in the snow driving mode, without having to determine the first state information.

[0076] In this embodiment, the user can manually control the vehicle to enter the target driving mode, for example, by triggering a mode switching command through a preset physical button, a virtual button, or by voice. At this time, the TCU will switch the vehicle to the target driving mode in response to the mode switching command triggered by the user. The TCU can also automatically switch to the target driving mode when it detects that the vehicle meets the switching conditions for switching to the target driving mode. Specifically, the TCU can determine that the vehicle meets the switching conditions for switching to the target driving mode when it detects that the current ambient temperature is less than the temperature threshold and the current road condition is a slippery road condition.

[0077] In this embodiment, if the TCU detects that the vehicle status information meets the mode switching conditions, it means that the battery energy consumption of the vehicle is high and needs to be in the four-wheel drive state. At this time, in order to meet the user's power demand and driving safety requirements at the same time, the TCU will control the vehicle to switch from the current drive mode to the low-speed direct drive mode. In the low-speed direct drive mode, the current speed of the vehicle is less than the speed threshold, the clutch of the vehicle is in a slipping state, and the engine is in a driving state; at the same time, the rear axle motor is in a driving state, and the front axle motor is in a power generation state or a driving state.

[0078] It should be noted that the slipping state is an intermediate state between the closed state and the open state. When the clutch is in the slipping state, the clutch is not fully engaged and there is relative sliding at both ends of the clutch. In this state, the friction material of the clutch is rotating but the engine torque is not fully transmitted.

[0079] In this embodiment, since the clutch is in a slipping state, the engine and the wheel end are not in a hard-connected state. At this time, the engine can not only transmit the engine torque to the wheel end through the clutch and the front axle gearbox, but also run at a higher speed when the vehicle is driving at a low speed, thereby effectively avoiding the phenomenon of the engine being stalled due to being dragged too low.

[0080] In this embodiment, by developing a low-speed direct drive mode, on the one hand, the engine can drive the vehicle in low-speed scenarios, effectively solving the problem of excessive power consumption of the vehicle in winter, thereby improving the vehicle's power conservation ability; on the other hand, the vehicle can always maintain a four-wheel drive state at low speeds, effectively preventing the vehicle from skidding and drifting in snowy weather, thereby ensuring the vehicle's driving safety.

[0081] In a feasible implementation manner, the vehicle state information includes clutch state information and a current driving mode; the vehicle control method may further include the following steps:

[0082] S201: When the clutch state information satisfies the slipping drive condition, the current ambient temperature is less than the temperature threshold, and the current road condition is a slippery road condition, determining that the vehicle state information satisfies the mode switching condition.

[0083] S202: When the clutch state information satisfies the sliding friction driving condition and the current driving mode is the target driving mode, determining that the vehicle state information satisfies the mode switching condition.

[0084] In this embodiment, considering that the vehicle needs to rely on the clutch to transfer the engine torque to the gearbox in the low-speed direct drive mode, in order to ensure the safe use of the clutch, the TCU will also obtain the clutch status information and determine whether the clutch meets the slipping drive conditions based on the clutch status information.

[0085] In a specific implementation, the clutch state information includes an overheat signal and a hardware fault signal. When the overheat signal indicates that the clutch is not overheated and the hardware fault signal indicates that the clutch has no hardware fault, the TCU determines that the clutch state information meets the slipping drive condition.

[0086] In this embodiment, by comprehensively considering the clutch state information on the basis of the first state information and the second state information, it is possible to ensure that the clutch can effectively transmit torque after the vehicle switches to the low-speed direct drive mode, thereby ensuring the safety of clutch use and vehicle driving safety.

[0087] In this embodiment, after the TCU detects that the vehicle status information meets the mode switching condition, it can also send a mode switching signal to the HCU. After receiving the mode switching signal, the HCU will reduce the effective vehicle speed of the direct drive mode from the direct drive enable value to the target value, for example, reducing the effective vehicle speed from 25km / h to 0km / h. Among them, the direct drive enable value represents the minimum speed at which the vehicle can enter the direct drive mode. In other words, in the direct drive mode, the vehicle's speed can only be reduced to the direct drive enable value at the lowest. If the vehicle speed is less than the direct drive enable value, there is a risk of burning out the engine. At this time, the vehicle may be controlled to switch to other modes. Therefore, by reducing the effective vehicle speed of the direct drive mode from the direct drive enable value to the target value, the logical conflict between the low-speed direct drive mode and the vehicle's existing direct drive mode can be effectively avoided, so that the vehicle can run smoothly in the low-speed direct drive mode. After the vehicle exits the low-speed direct drive mode, the HCU will restore the effective vehicle speed to the direct drive enable value to ensure the normal operation of the vehicle in the direct drive mode.

[0088] In a feasible implementation manner, the step of controlling the vehicle to switch from the current driving mode to the low-speed direct drive mode in S102 may specifically include the following sub-steps:

[0089] S102-1: Determine a target clutch pressure based on the current engine torque of the engine and a preset mapping relationship.

[0090] In this embodiment, the mapping relationship represents the comparison between the engine torque and the clutch pressure in the clutch slip state. It should be noted that, unlike when the clutch is in a fully closed state, the transmission torque corresponding to the clutch pressure is greater than or equal to the engine torque. In the above mapping relationship, the transmission torque corresponding to the clutch pressure will be less than the engine torque so that the clutch can be in a slip state. Among them, the transmission torque is the torque transmitted to the engine through the clutch to the input shaft of the gearbox.

[0091] In this embodiment, the mapping relationship can be obtained through experimental calibration. Specifically, the engine can be controlled to output according to a preset engine torque, and then the clutch pressure can be controlled to change according to a certain gradient, for example, the clutch pressure can be controlled to gradually increase or decrease according to a certain pressure change gradient, so that the clutch can reach a stable slip state, and when the clutch is in a stable slip state, the corresponding clutch pressure is recorded to obtain a set of corresponding relationships between the engine torque and the clutch pressure. By repeating the above calibration steps under different engine torques, multiple groups of test data can be obtained, and then by fitting the multiple groups of data, the above mapping relationship can be finally obtained.

[0092] S102-2: Based on the target clutch pressure, control the clutch to switch to the slipping state so that the vehicle switches from the current driving mode to the low-speed direct drive mode.

[0093] In this embodiment, the TCU will adjust the clutch pressure according to the preset pressure change gradient so that the clutch gradually switches to the slipping state. In this way, it can effectively avoid large fluctuations in torque and improve the smoothness of mode switching. The pressure change gradient represents the change in clutch pressure per unit time.

[0094] In a specific implementation, S102-2 may include the following sub-steps:

[0095] S102-2-1: When the current driving mode is the idle electric four-wheel drive mode, the current clutch pressure of the clutch is controlled to increase to the target clutch pressure so that the clutch is switched from the open state to the slipping state.

[0096] It should be noted that in the idle electric four-wheel drive mode, the front axle motor and the rear axle motor of the vehicle are in the driving state, the engine is in the idling state, and the clutch is in the disengaged state. In this mode, the front axle motor and the rear axle motor drive the vehicle forward, and the engine is in the idling state but does not output torque. Compared with the traditional pure electric four-wheel drive mode, the engine needs to be kept in the off state, and the engine will remain in the idling state in the idle electric four-wheel drive mode. On the one hand, when the vehicle needs to switch from the idle electric four-wheel drive mode to the direct drive mode, the steps of starting the engine can be reduced, thereby improving the mode switching speed and the dynamic response performance of the vehicle; on the other hand, since the front axle motor and the rear axle motor are both in the driving state, they can improve the ground adhesion better and effectively help the vehicle get out of trouble. After the vehicle is out of trouble, it can quickly switch back to the series mode, thereby avoiding repeated start and stop of the engine, and effectively improving the driving performance of the vehicle on low-attachment roads. Therefore, when the remaining power of the high-voltage battery is sufficient, the HCU will control the vehicle to drive in the idle electric four-wheel drive mode.

[0097] In this embodiment, considering that the current driving mode of the vehicle is the idle electric four-wheel drive mode, the engine is in an idle state and the clutch is in an open state. Therefore, it is only necessary to control the clutch to switch from the open state to the slipping state to achieve the switch from the idle electric four-wheel drive mode to the low-speed direct drive mode.

[0098] In a specific implementation, the TCU will control the current clutch pressure of the clutch to gradually increase to the target clutch pressure according to a preset first pressure change gradient, so that the clutch gradually switches from an open state to a slipping state.

[0099] S102-2-2: When the current driving mode is the direct drive mode, the current clutch pressure of the clutch is controlled to be reduced to the target clutch pressure so that the clutch is switched from the closed state to the slipping state.

[0100] In this embodiment, considering that the current driving mode of the vehicle is the direct drive mode, the engine is in a driving state and the clutch is in a closed state. Therefore, it is only necessary to control the clutch to switch from the closed state to the slipping state to achieve the switch from the direct drive mode to the low-speed direct drive mode.

[0101] In a specific implementation, the TCU will control the current clutch pressure of the clutch to gradually decrease to the target clutch pressure according to the preset second pressure change gradient, so that the clutch gradually switches from the closed state to the slipping state. The second pressure change gradient and the first pressure change gradient may be the same or different.

[0102] In this embodiment, by gradually increasing or decreasing the clutch pressure according to a certain pressure change gradient, the clutch can be switched to the slipping state more smoothly, avoiding a large torque fluctuation caused by a large sudden change in the clutch pressure, thereby effectively ensuring the driver's driving experience during the mode switching process.

[0103] In this embodiment, to ensure that the clutch can output torque stably, the TCU will detect the speed difference between the two ends of the clutch while adjusting the clutch pressure, and trigger the timing for the stable time when the speed difference is detected to be within the preset speed range, and determine that the clutch is in a slip state when the stable time reaches the time threshold. By detecting the speed difference between the two ends of the clutch, it can be ensured that the clutch is in a stable slip state when the mode switching is completed, thereby avoiding torque fluctuations.

[0104] In a feasible implementation manner, the step of controlling the vehicle to travel in the low-speed direct drive mode in S102 may specifically include the following sub-steps:

[0105] S102-3: When the speed difference between the two ends of the clutch exceeds a preset speed range, determine the engine torque intervention value.

[0106] In the present embodiment, the speed difference across the clutch represents the speed difference between the engine speed and the transmission input shaft speed.

[0107] In this embodiment, after the vehicle switches to the low-speed direct drive mode, the clutch pressure will still be adjusted in real time according to the mapping relationship and the current engine torque. Considering that when the vehicle is accelerating or decelerating suddenly, the clutch pressure may not be adjusted in time, causing the speed difference at both ends of the clutch to fluctuate greatly. Therefore, in order to avoid the engine speed being too low or the phenomenon of overrunning, the TCU will intervene and adjust the engine torque when it detects that the speed difference at both ends of the clutch exceeds the preset speed range to maintain the engine speed stable.

[0108] It should be noted that the preset speed range is a closed interval consisting of a lower speed limit and an upper speed limit. When the speed difference at both ends of the clutch is always within the preset speed range, it means that the speed difference fluctuates within a reasonable range; when the speed difference is less than the lower speed limit, it means that the engine speed is too low; when the speed difference is greater than the upper speed limit, it means that the engine speed is too high.

[0109] In this embodiment, in order to match the appropriate engine torque intervention value, the TCU will comprehensively consider the current engine torque of the engine and the speed difference between the two ends of the clutch to determine the engine torque intervention value.

[0110] In the specific implementation, the TCU stores a preset torque intervention comparison table, which represents the comparison relationship between the engine torque and speed difference and the engine torque intervention value; after obtaining the current engine torque and speed difference, the TCU can quickly determine the appropriate engine torque intervention value by querying the torque intervention comparison table.

[0111] S102-4: Based on the engine torque intervention value, adjust the engine torque.

[0112] In a specific implementation, after determining the engine torque intervention value, the TCU will send the engine torque intervention value to the engine controller, so that the engine controller can determine the target engine torque based on the engine torque intervention value and the current engine torque, and adjust the engine torque according to the target engine torque as the control target.

[0113] In this embodiment, after the vehicle switches to the low-speed direct drive mode, the TCU can not only control the clutch to effectively transmit the engine torque to the wheel end by adjusting the clutch pressure and intervening in the engine torque, but also can accurately calculate the engine torque intervention value after the speed fluctuation occurs at both ends of the clutch, and timely control the engine torque increase or decrease, thereby maintaining the engine speed stable. In this way, the driving safety of the vehicle in the low-speed direct drive mode can be effectively guaranteed, and the user's driving experience can be improved.

[0114] In the second aspect, based on the same inventive concept, refer to Figure 2 , the embodiment of the present application provides a vehicle control device, the vehicle control device 200 includes:

[0115] The information acquisition module 201 is used to acquire vehicle status information when the vehicle is in a low-speed four-wheel drive state;

[0116] The mode switching module 202 is used to control the vehicle to switch from the current driving mode to the low-speed direct drive mode and control the vehicle to travel in the low-speed direct drive mode when the vehicle status information meets the mode switching conditions; wherein, in the low-speed direct drive mode, the vehicle's clutch is in a slipping state and the engine is in a driving state.

[0117] In one embodiment of the present application, the vehicle state information includes clutch state information, and any one of first state information and second state information; wherein the first state information includes the current ambient temperature and the current road condition; the second state information includes the current driving mode; the vehicle control device 200 includes:

[0118] A first condition determination module is used to determine that the vehicle state information meets the mode switching condition when the clutch state information meets the slipping drive condition, the current ambient temperature is less than the temperature threshold, and the current road condition is a slippery road condition;

[0119] The second condition determination module is used to determine that the vehicle state information meets the mode switching condition when the clutch state information meets the sliding friction driving condition and the current driving mode is the target driving mode.

[0120] In one embodiment of the present application, the clutch state information includes an overheating signal and a hardware fault signal; the vehicle control device 200 includes:

[0121] The second condition determination module is used to determine that the clutch state information meets the slipping drive condition when the overheating signal indicates that the clutch is not overheated and the hardware fault signal indicates that the clutch has no hardware fault.

[0122] In one embodiment of the present application, the mode switching module 202 includes:

[0123] A pressure determination submodule, for determining a target clutch pressure based on a current engine torque of the engine and a preset mapping relationship; the mapping relationship represents a comparison relationship between the engine torque and the clutch pressure under a clutch slip state;

[0124] The mode switching submodule is used to control the clutch to switch to a slipping state based on a target clutch pressure, so that the vehicle switches from the current driving mode to a low-speed direct drive mode.

[0125] In one embodiment of the present application, the mode switching submodule includes:

[0126] A first state switching unit is used to control the current clutch pressure of the clutch to increase to the target clutch pressure when the current driving mode is the idle electric four-wheel drive mode, so as to switch the clutch from the open state to the slipping state;

[0127] The second state switching unit is used to control the current clutch pressure of the clutch to decrease to the target clutch pressure when the current driving mode is the direct drive mode, so as to switch the clutch from the closed state to the slipping state.

[0128] In one embodiment of the present application, the first state switching unit is specifically used to control the current clutch pressure of the clutch to gradually increase to the target clutch pressure according to a preset first pressure change gradient; the second state switching unit is specifically used to control the current clutch pressure of the clutch to gradually decrease to the target clutch pressure according to a preset second pressure change gradient.

[0129] In an embodiment of the present application, the mode switching module 202 further includes:

[0130] An intervention value determination submodule, used for determining an engine torque intervention value when a speed difference between two ends of the clutch exceeds a preset speed range;

[0131] The torque regulation submodule is used to regulate the engine torque based on the engine torque intervention value.

[0132] In one embodiment of the present application, the intervention value determination submodule is specifically used to determine the engine torque intervention value based on the current engine torque of the engine and the speed difference between the two ends of the clutch.

[0133] It should be noted that the specific implementation of the vehicle control device 200 in the embodiment of the present application refers to the specific implementation of the vehicle control method proposed in the first aspect of the embodiment of the present application, and will not be repeated here.

[0134] On the third aspect, based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium on which an executable program is stored. When the executable program is executed by a processor, the vehicle control method proposed in the first aspect of the present application is implemented.

[0135] It should be noted that the specific implementation of the computer-readable storage medium of the embodiment of the present application refers to the specific implementation of the vehicle control method proposed in the first aspect of the embodiment of the present application, and will not be repeated here.

[0136] Fourthly, refer to Figure 3 Based on the same inventive concept, the embodiment of the present application provides a vehicle 300, including:

[0137] Memory 301, used for storing executable programs;

[0138] Processor 302;

[0139] When the executable program is executed by the processor 302, the vehicle control method proposed in the first aspect of the present application is implemented.

[0140] It should be noted that the specific implementation of the vehicle 300 in the embodiment of the present application refers to the specific implementation of the vehicle control method proposed in the first aspect of the embodiment of the present application, and will not be repeated here.

[0141] It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the embodiments of the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0142] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0143] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0144] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0145] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0146] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0147] The vehicle control method, storage medium and vehicle provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A vehicle control method, characterized in that: The method comprises: When the vehicle is in low-speed four-wheel drive state, obtain vehicle status information; When the vehicle state information satisfies the mode switching condition, the vehicle is controlled to switch from the current driving mode to the low-speed direct driving mode, and the vehicle is controlled to travel in the low-speed direct driving mode; wherein, in the low-speed direct driving mode, the clutch of the vehicle is in a slipping state, and the engine is in a driving state; The vehicle state information includes clutch state information, and any one of first state information and second state information; wherein the first state information includes current ambient temperature and current road conditions; and the second state information includes current driving mode; The method further comprises: In the case where the clutch state information satisfies the slipping driving condition, the current ambient temperature is less than the temperature threshold, and the current road condition is a slippery road condition, determining that the vehicle state information satisfies the mode switching condition; or, When the clutch state information satisfies the sliding friction driving condition and the current driving mode is the target driving mode, it is determined that the vehicle state information satisfies the mode switching condition; and the target driving mode is the snow driving mode.

2. The vehicle control method according to claim 1, characterized in that: The clutch state information includes an overheating signal and a hardware fault signal; the method further includes: When the overheat signal indicates that the clutch is not overheated and the hardware fault signal indicates that the clutch has no hardware fault, it is determined that the clutch state information satisfies the slipping drive condition.

3. The vehicle control method according to claim 1, characterized in that: The step of controlling the vehicle to switch from the current driving mode to the low-speed direct drive mode comprises: Determining a target clutch pressure based on the current engine torque of the engine and a preset mapping relationship; the mapping relationship represents a comparison relationship between the engine torque and the clutch pressure under a clutch slip state; Based on the target clutch pressure, the clutch is controlled to switch to the slipping state so that the vehicle switches from the current driving mode to the low-speed direct drive mode.

4. The vehicle control method according to claim 3, characterized in that: The step of controlling the clutch to switch to the slipping state based on the target clutch pressure comprises: When the current driving mode is the idle electric four-wheel drive mode, controlling the current clutch pressure of the clutch to increase to the target clutch pressure, so that the clutch is switched from the open state to the slipping state; When the current driving mode is the direct driving mode, the current clutch pressure of the clutch is controlled to be reduced to the target clutch pressure so that the clutch is switched from the closed state to the slipping state.

5. The vehicle control method according to claim 4, characterized in that: The step of controlling the current clutch pressure of the clutch to increase to the target clutch pressure comprises: According to a preset first pressure change gradient, controlling the current clutch pressure of the clutch to gradually increase to the target clutch pressure; The step of controlling the current clutch pressure of the clutch to decrease to the target clutch pressure comprises: According to a preset second pressure change gradient, the current clutch pressure of the clutch is controlled to be gradually reduced to the target clutch pressure.

6. The vehicle control method according to claim 1, characterized in that: The step of controlling the vehicle to travel in the low-speed direct drive mode comprises: determining an engine torque intervention value when a speed difference between two ends of the clutch exceeds a preset speed range; Based on the engine torque intervention value, torque regulation is performed on the engine.

7. The vehicle control method according to claim 6, characterized in that: The step of determining the engine torque intervention value comprises: The engine torque intervention value is determined based on the current engine torque of the engine and the speed difference across the clutch.

8. A computer-readable storage medium having an executable program stored thereon, characterized in that: When the executable program is executed by a processor, the vehicle control method according to any one of claims 1 to 7 is implemented.

9. A vehicle, characterized in that: include: A memory for storing an executable program; processor; When the executable program is executed by the processor, the vehicle control method according to any one of claims 1 to 7 is implemented.

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