A method of controlling a vehicle, a vehicle and a storage medium

Abstract

The application provides a method for controlling a vehicle, a vehicle and a storage medium, the method applied to the technical field of vehicles, and the method comprises the following steps: in the case that the vehicle is in a power drop mode, judging whether the vehicle meets a first preset condition of switching to a power maintenance mode; in the case that it is determined that the vehicle meets the first preset condition, switching the vehicle from the power drop mode to the power maintenance mode; in the case that the vehicle is in the power maintenance mode, judging whether the vehicle meets a second preset condition of switching to an engine forced start mode; in the case that it is determined that the vehicle meets the second preset condition, switching the vehicle from the power maintenance mode to the engine forced start mode. The method can avoid serious power battery power loss, improve the power performance of the vehicle, and improve the driving experience of the user.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more specifically, to a method for controlling a vehicle, a vehicle, and a storage medium in the field of vehicles. Background Technology

[0002] In recent years, with the continuous development of society and the improvement of people's living standards, the demand for automobiles has been increasing. Due to the increasingly serious energy shortage and environmental pollution problems caused by traditional fuel vehicles, hybrid vehicles have gradually become the mainstream choice in the market due to their advantages in reducing energy consumption and environmental pollution.

[0003] In existing technologies, to optimize the performance of the power battery in hybrid vehicles, multiple operating modes are designed based on the battery's charge level, and the vehicle is controlled to switch between these modes with the aim of achieving a longer pure electric driving range. While this method of switching operating modes can improve the vehicle's fuel economy, it can easily lead to the risk of the power battery running out of power, affecting the vehicle's power performance and the user's driving experience. Summary of the Invention

[0004] This application provides a method for controlling a vehicle, a vehicle, and a storage medium. This method can prevent severe battery depletion, improve vehicle power performance, and enhance the user's driving experience.

[0005] Firstly, a method for controlling a vehicle is provided, the method comprising: when the vehicle is in a battery depletion mode, determining whether the vehicle meets a first preset condition for switching to a battery maintenance mode; wherein, in the battery depletion mode, the vehicle starts the engine based on torque demand, and in the battery maintenance mode, the vehicle starts the engine based on power demand; if the vehicle meets the first preset condition, switching the vehicle from the battery depletion mode to the battery maintenance mode; when the vehicle is in the battery maintenance mode, determining whether the vehicle meets a second preset condition for switching to an engine forced start mode; wherein, in the engine forced start mode, the vehicle forcibly starts the engine; if the vehicle meets the second preset condition, switching the vehicle from the battery maintenance mode to the engine forced start mode.

[0006] In the above technical solution, a logic is set to switch from a battery depletion mode to a battery maintenance mode. When the vehicle is in battery depletion mode and meets the first preset condition for switching to battery maintenance mode, the vehicle switches from battery depletion mode to battery maintenance mode. In battery maintenance mode, the engine can start based on power demand, which is easier than starting the engine based on torque demand in battery depletion mode. This provides a certain degree of battery preservation capability and improves the vehicle's power performance. Switching directly from battery depletion mode to battery maintenance mode effectively utilizes the battery maintenance capability to keep the power battery charge within a certain range, avoiding insufficient power due to low battery charge. When the vehicle is in battery maintenance mode and meets the second preset condition for switching to engine forced start mode, the vehicle switches from battery maintenance mode to engine forced start mode. In engine forced start mode, the vehicle forcibly starts the engine, further ensuring sufficient power output while preventing long-term over-discharge of the power battery. Through the intelligent switching between these modes, the power battery charge can be effectively managed, ensuring it is always maintained within a suitable range. This avoids insufficient power or battery damage caused by over-discharge, reduces unnecessary energy waste, improves vehicle power performance, and enhances the user's driving experience.

[0007] In conjunction with the first aspect, in some possible implementations, when the vehicle is in a power depletion mode, determining whether the vehicle meets the first preset condition for switching to a power maintenance mode includes: when the vehicle is in a power depletion mode, obtaining the current first actual power level of the vehicle's power battery; determining the exit threshold of the power depletion mode based on the vehicle's current first driving mode and first ambient temperature; and determining whether the vehicle meets the first preset condition based on the first actual power level and the exit threshold of the power depletion mode.

[0008] In the above technical solution, the impact of driving mode and ambient temperature on the power battery's charge management strategy is considered. The exit threshold for the charge reduction mode is determined based on the current first driving mode and the first ambient temperature. This exit threshold can be dynamically adjusted according to different driving conditions (such as driving mode and ambient temperature) to ensure optimal decision-making under various circumstances, improve the accuracy of mode switching, and more precisely control battery charge usage. For example, in low-temperature environments, battery performance may decline; appropriately increasing the exit threshold can prevent over-discharge and ensure battery health.

[0009] In combination with the first aspect and the above implementation methods, in some possible implementation methods, determining whether the vehicle meets the first preset condition based on the first actual battery level and the exit threshold of the battery level reduction mode includes: determining the first target battery level of the power battery based on the first driving mode, the first ambient temperature and the current first vehicle speed; subtracting the first target battery level from the first actual battery level to obtain the first battery level difference; and determining that the vehicle meets the first preset condition if the first battery level difference is less than the exit threshold of the battery level reduction mode.

[0010] In the above technical solution, a first target battery level is determined based on driving mode, ambient temperature, and vehicle speed. The difference between the first actual battery level and the first target battery level (i.e., the first battery level difference) is used to determine whether to exit the battery depletion mode. This allows the system to make more accurate judgments based on the current actual state of the vehicle (including factors such as driving mode, ambient temperature, and vehicle speed), further improving the accuracy of mode switching.

[0011] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, when the vehicle is in the battery maintenance mode, determining whether the vehicle meets the second preset condition for switching to the engine forced start mode includes: when the vehicle is in the battery maintenance mode, obtaining the current second actual charge of the vehicle's power battery; determining the exit threshold of the battery maintenance mode based on the vehicle's current second driving mode and second ambient temperature; and determining whether the vehicle meets the second preset condition based on the second actual charge and the exit threshold of the battery maintenance mode.

[0012] In combination with the first aspect and the above implementation methods, in some possible implementation methods, based on the second actual battery level and the exit threshold of the battery maintenance mode, it is determined whether the vehicle meets the second preset condition, including: determining the second target battery level based on the second driving mode, the second ambient temperature and the current second vehicle speed; subtracting the second target battery level from the second actual battery level to obtain the second battery level difference; and determining that the vehicle meets the second preset condition if the second battery level difference is less than the exit threshold of the battery maintenance mode.

[0013] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the method further includes: when the vehicle is in the engine forced start mode, determining the entry threshold of the battery maintenance mode based on the vehicle's current third driving mode and third ambient temperature; based on the entry threshold of the battery maintenance mode, determining whether the vehicle meets the third preset condition for switching to the battery maintenance mode; and if it is determined that the vehicle meets the third preset condition, switching the vehicle from the engine forced start mode to the battery maintenance mode.

[0014] In the above technical solution, a logic is set to switch the engine forced start mode to the battery maintenance mode, ensuring that the vehicle can switch back to the battery maintenance mode in a timely manner, reducing fuel consumption and improving the vehicle's economic performance.

[0015] Combining the first aspect and the above implementation methods, in some possible implementation methods, when the vehicle is in the battery maintenance mode, the entry threshold for the battery depletion mode is determined based on the vehicle's current fourth driving mode and fourth ambient temperature; based on the entry threshold for the battery depletion mode, it is determined whether the vehicle meets the fourth preset condition for switching to the battery depletion mode; if it is determined that the vehicle meets the fourth preset condition, the vehicle is switched from the battery maintenance mode to the battery depletion mode.

[0016] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the method further includes: charging the power battery based on a target charging power when the vehicle is in the engine forced start mode, wherein the target charging power is greater than a preset charging power threshold.

[0017] In the above technical solution, when the vehicle is in the engine forced start mode, the remaining power of the vehicle's power battery is usually low. At this time, charging the power battery with a larger charging power can ensure that the power battery can obtain more power replenishment in a short time, quickly restore the power battery's power, and prevent the power battery from being deeply discharged.

[0018] In combination with the first aspect and the above implementation methods, in some possible implementation methods, before determining whether the vehicle meets the first preset condition for switching to the battery maintenance mode when the vehicle is in the battery depletion mode, the method further includes: determining that the vehicle's target battery adjustment function is inactive, wherein when the target battery adjustment function is activated, the vehicle adjusts the target battery charge based on the user's charging habits; or, determining that the vehicle's driving mode is a mode other than the economy mode.

[0019] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the method further includes: when the vehicle's target battery level adjustment function is activated and the vehicle's driving mode is economy mode, if the vehicle is currently in a battery level depletion mode, then determining whether the vehicle meets the fifth preset condition for switching to the engine forced start mode; wherein, when the target battery level adjustment function is activated, the vehicle adjusts the target battery level based on the user's charging habits; and if it is determined that the vehicle meets the fifth preset condition, the vehicle is switched from the battery level depletion mode to the engine forced start mode.

[0020] The above technical solution, by switching between the activation status of the target battery adjustment function and the driving mode, can further improve the flexibility of vehicle energy management. This ensures that the vehicle can prioritize pure electric operation even under special circumstances (e.g., when the target battery adjustment function is activated and the driving mode is in economy mode), increasing the pure electric range, meeting user driving needs, and improving the user's driving experience.

[0021] In summary, this application establishes a logic for cyclical switching of operating modes through four switching thresholds: switching from battery depletion mode to battery maintenance mode, switching from battery maintenance mode to engine forced start mode, switching from engine forced start mode to battery maintenance mode, and switching from battery maintenance mode back to battery depletion mode. This logic facilitates earlier engine start, improving vehicle power performance, and effectively utilizes the battery maintenance mode's power reserve capability to maintain the battery's charge within a certain range, preventing insufficient power due to low battery charge. When the vehicle is in engine forced start mode, a higher charging power is used to charge the battery, ensuring it receives more power replenishment in a shorter time, rapidly restoring its charge and preventing deep discharge. The four switching thresholds can be dynamically adjusted based on different driving conditions (such as driving mode and ambient temperature), ensuring optimal decision-making under various circumstances, improving the accuracy of mode switching, and enabling more precise control over battery power usage.

[0022] Secondly, a vehicle control device is provided, comprising: a first determining module, configured to determine whether the vehicle meets a first preset condition for switching to a battery maintenance mode when the vehicle is in a battery depletion mode; wherein, in the battery depletion mode, the vehicle starts the engine based on torque demand, and in the battery maintenance mode, the vehicle starts the engine based on power demand; a first switching module, configured to switch the vehicle from the battery depletion mode to the battery maintenance mode when the first preset condition is met; a second determining module, configured to determine whether the vehicle meets a second preset condition for switching to an engine forced start mode when the vehicle is in the battery maintenance mode; wherein, in the engine forced start mode, the vehicle forcibly starts the engine; and a second switching module, configured to switch the vehicle from the battery maintenance mode to the engine forced start mode when the second preset condition is met.

[0023] Thirdly, a vehicle is provided, including a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, causing the vehicle to perform the methods described in the first aspect or any possible implementation thereof.

[0024] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof.

[0025] Fifthly, a computer-readable storage medium is provided that stores computer program code, which, when executed on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of a method for controlling a vehicle provided in an embodiment of this application.

[0027] Figure 2 This is a schematic diagram of a mode switching provided in an embodiment of this application.

[0028] Figure 3 This is another schematic diagram of mode switching provided in the embodiments of this application.

[0029] Figure 4 This is a schematic diagram of a device for controlling a vehicle provided in an embodiment of this application.

[0030] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0031] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0032] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0033] In existing technologies, to optimize the performance of the power battery in hybrid vehicles, multiple operating modes are designed based on the battery's charge level, and the vehicle is controlled to switch between these modes with the aim of achieving a longer pure electric driving range. While this method of switching operating modes can improve the vehicle's fuel economy, it can easily lead to the risk of the power battery running out of power, affecting the vehicle's power performance and the user's driving experience.

[0034] Based on this, this application proposes a method for controlling a vehicle to avoid severe battery depletion, improve vehicle power performance, and enhance the user's driving experience.

[0035] Figure 1 This is a schematic flowchart illustrating a method for controlling a vehicle according to an embodiment of this application. The method is applied to hybrid vehicles.

[0036] For example, such as Figure 1 As shown, the method 100 includes:

[0037] Step 101: When the vehicle is in the power depletion mode, determine whether the vehicle meets the first preset condition for switching to the power maintenance mode.

[0038] In the low battery mode, the vehicle starts the engine based on torque demand, while in the battery maintenance mode, the vehicle starts the engine based on power demand.

[0039] Step 102: If the vehicle meets the first preset condition, switch the vehicle from the battery depletion mode to the battery maintenance mode.

[0040] Step 103: When the vehicle is in battery maintenance mode, determine whether the vehicle meets the second preset condition for switching to engine forced start mode.

[0041] Among them, the engine forced start mode forces the vehicle to start the engine.

[0042] Step 104: If the vehicle meets the second preset condition, switch the vehicle from the battery maintenance mode to the engine forced start mode.

[0043] exist Figure 1In the illustrated embodiment, logic is set for switching from a battery depletion mode to a battery maintenance mode. When the vehicle is in battery depletion mode and meets the first preset condition for switching to battery maintenance mode, the vehicle switches from battery depletion mode to battery maintenance mode. In battery maintenance mode, the engine can start based on power demand, which is easier than starting the engine based on torque demand in battery depletion mode. This provides a certain degree of battery retention and improves the vehicle's power performance. Switching directly from battery depletion mode to battery maintenance mode effectively utilizes the battery maintenance mode's battery retention capability, keeping the power battery's charge within a certain range and preventing insufficient power due to low battery charge. When the vehicle is in battery maintenance mode and meets the second preset condition for switching to engine forced start mode, the vehicle switches from battery maintenance mode to engine forced start mode. In engine forced start mode, the vehicle forcibly starts the engine, further ensuring sufficient power output while preventing prolonged over-discharge of the power battery. Through the intelligent switching between these modes, the power battery's charge can be effectively managed, ensuring it is always maintained within a suitable range. This avoids insufficient power or battery damage caused by over-discharge, reduces unnecessary energy waste, improves vehicle power performance, and enhances the user's driving experience.

[0044] The following is about Figure 1 The specific implementation methods of each step in the illustrated embodiments are explained in detail below:

[0045] In step 101, the vehicle is a hybrid vehicle, which includes an engine, a drive motor, and a power battery. The power battery provides electrical energy to the drive motor to drive the vehicle, and the engine drives the vehicle by burning fuel.

[0046] Charge Depleting (CD) mode, also known simply as CD mode, prioritizes electric power and avoids starting the engine as much as possible, typically only starting it when torque demand is required. In other words, in Charge Depleting mode, the vehicle will primarily use the charge from the battery to drive the electric motors, minimizing engine starts and operation to extend the pure electric driving range. The engine will only be started in Charge Depleting mode when the vehicle's required torque exceeds the preset torque, allowing the engine to provide some torque to meet the vehicle's torque needs.

[0047] The preset torque can be the maximum torque that the power battery can provide. When the torque required by the vehicle is greater than the maximum torque that the power battery can provide, it is determined that the power battery cannot meet the torque requirements of the vehicle. At this time, the engine needs to be started to provide part of the torque.

[0048] Understandably, vehicles typically enter a battery depletion mode when the battery is near full charge or exceeds a preset charge level (e.g., 90%). In other words, in battery depletion mode, the battery has sufficient charge to power the vehicle, and therefore, the vehicle will prioritize using the battery's charge to drive the aforementioned drive motors.

[0049] The vehicle offers multiple operating modes, including series mode, parallel mode, power split mode, pure electric four-wheel drive mode, idle pure electric four-wheel drive mode, and pure electric two-wheel drive mode. When the vehicle is in a low battery mode, it can be controlled to operate in one of these modes depending on the actual situation.

[0050] In some embodiments, the vehicle also includes three power modes: forced pure electric mode, pure electric priority mode, and intelligent hybrid mode. In forced pure electric mode, the vehicle relies entirely on the power battery for operation, suitable for urban commuting, low-speed driving, or areas with strict emission requirements. In pure electric priority mode, the vehicle prioritizes the use of the power battery's electrical energy, with the engine only intervening in special circumstances, suitable for daily commuting and situations where fuel consumption and emissions reduction are desired. In intelligent hybrid mode, the vehicle's energy management system intelligently determines when to use the power battery and when to start the engine based on real-time data (such as battery level, driving conditions, road conditions, etc.) to achieve optimal energy utilization efficiency, suitable for long-distance travel, complex road conditions, or variable driving conditions.

[0051] The default power mode for most vehicles is pure electric priority mode, but users can choose whether to change it. If the user chooses to change the default power mode, they can select any of the above power modes as the new default, and can also choose whether to remember the selected power mode. When the user chooses to remember the selected power mode, the vehicle's default power mode will change to the user-selected power mode.

[0052] In forced pure electric mode, the vehicle relies solely on the battery's charge, therefore there is no switching between battery depletion mode and battery maintenance mode. In pure electric priority mode and intelligent hybrid mode, different energy management strategies are employed for the battery; therefore, the vehicle's operating mode may differ when it is in battery depletion mode in these two modes.

[0053] The vehicle also includes multiple driving modes such as Eco, Standard, Sport, Light Snow, Snow, Mud, Sand, High-Speed ​​4WD, and Low-Speed ​​4WD. In different driving modes, the vehicle also has different energy management strategies for the power battery. Therefore, when the vehicle is in a battery depletion mode, the operating mode for controlling the vehicle may be different.

[0054] The following section provides a further explanation of the battery depletion mode in conjunction with the power mode and driving mode.

[0055] When the vehicle's power mode is set to pure electric priority mode, and the current driving mode is any one of the driving modes that does not force engine start (e.g., Eco, Standard, Sport, Light Snow), the vehicle will maintain pure electric priority mode when the battery is depleted. This means the operating mode is either pure electric four-wheel drive or pure electric two-wheel drive, and the engine remains off. During driving, the vehicle will monitor its acceleration in real time and determine whether the required torque exceeds the preset torque. If the acceleration exceeds the preset acceleration, it indicates that the vehicle needs rapid acceleration, meaning the required torque is greater than the preset torque. In this case, the engine will start, and the control mode will switch to parallel mode or power split mode, with the engine providing some torque.

[0056] When the vehicle's power mode is in pure electric priority mode, and the current driving mode is any of the forced engine start driving modes such as snow mode, mud mode, sand mode, high-speed four-wheel drive mode, and low-speed four-wheel drive mode, the vehicle's operating mode will switch to idle pure electric four-wheel drive mode when the battery is depleted. In this mode, the engine remains idle and does not participate in torque output, relying on the power battery for power. For driving modes such as snow mode, mud mode, sand mode, and high-speed four-wheel drive mode, the vehicle will monitor its speed in real time during driving and determine whether the required torque exceeds the preset torque. If the speed exceeds the first preset speed, and the required torque exceeds the preset torque, the vehicle's operating mode will switch from idle pure electric four-wheel drive mode to parallel mode, with the engine providing some torque. If the speed exceeds the second preset speed, the vehicle will switch from parallel mode to power split mode, with the engine providing some torque while simultaneously driving the drive motor to generate electricity.

[0057] The first preset vehicle speed is lower than the second preset vehicle speed. For example, the first preset vehicle speed could be 25 kilometers per hour (kph), and the second preset vehicle speed could be 85 kph. In the low-speed four-wheel drive mode, the vehicle maintains an idle speed pure electric four-wheel drive mode when the battery is low.

[0058] Understandably, the low-speed four-wheel drive mode is primarily used for extreme off-road conditions, such as climbing steep slopes or traversing deep ditches. In such situations, the vehicle typically travels at a very low speed, generally well below the first preset speed of 25 kph. Therefore, during the battery depletion mode in low-speed four-wheel drive, the vehicle usually maintains an idling pure electric four-wheel drive mode.

[0059] In some embodiments, for driving modes such as snow mode, mud mode, sand mode, and high-speed four-wheel drive mode, the gears engaged in the vehicle's transmission are typically slightly higher than those engaged in low-speed four-wheel drive mode. For example, in driving modes such as snow mode, mud mode, sand mode, and high-speed four-wheel drive mode, the gear is engaged in 2nd gear in idle pure electric four-wheel drive mode, parallel mode, and power split mode, while in low-speed four-wheel drive mode, the gear is engaged in 1st gear in idle pure electric four-wheel drive mode.

[0060] Understandably, snow, mud, sand, and high-speed four-wheel drive modes typically require a smooth and controllable power output over a wide speed range. Low-speed four-wheel drive mode is mainly used for extreme off-road conditions, where the vehicle usually travels at very low speeds and does not require a wide speed range. Therefore, the gears engaged in snow, mud, sand, and high-speed four-wheel drive modes are slightly higher than those engaged in low-speed four-wheel drive mode.

[0061] When the vehicle's power mode is intelligent hybrid mode, and the current driving mode is any one of the driving modes that does not force engine start (e.g., Eco, Standard, Sport, Light Snow, etc.), the vehicle will maintain a pure electric priority power mode when the battery is depleted. This means the operating mode is either pure electric four-wheel drive or pure electric two-wheel drive, and the engine remains off. The engine will only start during rapid acceleration. Unlike the pure electric priority power mode, the vehicle also monitors the battery level. When the battery level falls below a preset level (e.g., 90%), the vehicle will switch to a dual-power depletion mode, using electricity as much as possible in urban scenarios and starting the engine at medium to high speeds. For example, it can determine if the vehicle is at a medium to high speed when the speed exceeds 60 km / h (kph).

[0062] The "dual reduction in fuel economy and battery power" mode refers to a mode that maximizes both fuel economy and battery power utilization. In this mode, the vehicle may take measures to simultaneously reduce fuel consumption and battery power usage.

[0063] Understandably, the core objective of the pure electric priority mode is to utilize the battery as much as possible to drive the vehicle, reducing engine start frequency, thereby lowering fuel consumption and improving the driving experience. Therefore, in the pure electric priority mode's battery depletion mode, the system will only start the engine and switch to parallel or power-split mode during rapid acceleration (acceleration exceeding a preset value). The pure electric priority mode does not actively monitor whether the battery level is below a certain high threshold; instead, it tries to maintain pure electric drive until rapid acceleration or other special circumstances trigger engine start. The core objective of the intelligent hybrid mode is to comprehensively optimize fuel economy and battery level management, achieving optimal energy utilization efficiency under different driving conditions by dynamically adjusting the operating states of the engine and drive motor. Therefore, the intelligent hybrid mode's battery depletion mode monitors the battery level in real time. When the battery level drops below a certain high threshold (e.g., 90%), the system enters a "dual-mode" (electric and gasoline depletion). In urban scenarios (e.g., at speeds below 60 kph), the system will try to use the drive motor to save fuel. In medium-to-high speed scenarios (such as vehicle speeds greater than 60 kph), the system will start the engine and operate within its high-efficiency range, while simultaneously charging the battery or directly driving the wheels, ensuring optimal energy utilization efficiency under various driving conditions.

[0064] When the vehicle's power mode is intelligent hybrid mode, and the vehicle's current driving mode is any one of the driving modes that force engine start, such as snow mode, mud mode, sand mode, high-speed four-wheel drive mode, and low-speed four-wheel drive mode, the control method of the operating mode is the same as the control method of the driving mode that forces engine start when the power mode is pure electric priority mode, and will not be repeated here.

[0065] The power maintenance mode in this embodiment is (Charge Sustaining-High Efficiency, CS-H), or simply CS-H mode. This mode is used to maintain the battery's charge at a relatively high level, typically operating within its high-efficiency range. In CS-H mode, the engine is started more frequently based on power demand to ensure the battery charge does not become too low.

[0066] It is understandable that the conversion formula between power and torque is as shown in the following formula (1):

[0067] P=(T*ω) / 9550 (1)

[0068] In formula (1), P is power, in kilowatts (kW); T is torque, in Newton-meters (Nm); and ω is angular velocity, in revolutions per minute (rpm). The constant 9550 is a coefficient that converts the units from Nm and rpm to kW.

[0069] Based on formula (1), power is the product of torque and speed. Power demand depends not only on torque but also on vehicle speed (i.e., speed). For example, at high speeds, although the vehicle's torque demand may not be high, the power demand is still high due to the high vehicle speed (high speed). In other words, starting the engine based on power demand covers various operating conditions, including high torque demand and high vehicle speed. In contrast, starting the engine based on torque demand is mainly concentrated in specific situations such as acceleration and hill climbing. Therefore, the strategy of starting the engine based on power demand will be triggered under more driving conditions, thereby increasing the frequency of engine starting.

[0070] Specifically, in battery maintenance mode, the vehicle will start the engine when the current power demand exceeds the preset power, in order to balance the consumption of battery power and replenish the battery power.

[0071] The preset power can be the maximum power that the power battery can provide under the current charge level. When the power demand is greater than the maximum power that the power battery can provide, the power battery cannot meet the current power demand of the vehicle. At this time, the vehicle starts the engine and the engine provides part of the power.

[0072] Understandably, vehicles typically enter a battery maintenance mode when the battery's charge is depleted to a certain level. In other words, in battery maintenance mode, the battery's charge is insufficient to meet high-power demands, thus requiring more frequent engine starts to assist vehicle operation.

[0073] The logic for switching from a power depletion mode to a power maintenance mode is pre-set in the vehicle, along with the first preset condition that must be met during the switch. When it is determined that the vehicle is currently in a power depletion mode, the system can monitor in real time whether the vehicle meets the first preset condition.

[0074] In one possible implementation, when the vehicle is in a power depletion mode, determining whether the vehicle meets the first preset condition for switching to a power maintenance mode includes: when the vehicle is in a power depletion mode, obtaining the current first actual power level of the vehicle's power battery; determining the exit threshold of the power depletion mode based on the vehicle's current first driving mode and first ambient temperature; and determining whether the vehicle meets the first preset condition based on the first actual power level and the exit threshold of the power depletion mode.

[0075] Vehicles typically have a Battery Management System (BMS) to monitor the remaining charge of the battery in real time. When the vehicle is in a depleted charge mode, the remaining charge of the battery, as monitored in real time by the BMS, can be obtained to determine the initial actual charge level.

[0076] The vehicle can have a pre-set correspondence between two parameters—driving mode and ambient temperature—and the exit threshold for the battery depletion mode. When the vehicle is determined to be in battery depletion mode, the current driving mode and ambient temperature can be obtained to obtain the aforementioned first driving mode and first ambient temperature. Then, based on the first driving mode and first ambient temperature, the exit threshold for the battery depletion mode corresponding to the first driving mode and first ambient temperature is determined within the aforementioned first correspondence.

[0077] It is understandable that the power battery employs different energy management strategies under different driving modes, and different ambient temperatures also affect these strategies. Therefore, a preliminary correlation can be established between the driving mode and ambient temperature parameters and the exit threshold for the battery depletion mode. This preliminary correlation can be shown in Table 1 below:

[0078] Table 1

[0079] y\x A B C D E F G H I -15 A11 B11 C11 D11 E11 F11 G11 H11 I11 0 A12 B12 C12 D12 E12 F12 G12 H12 I12 15 A13 B13 C13 D13 E13 F13 G13 H13 I13 20 A14 B14 C14 D14 E14 F14 G14 H14 I14 ... ... ... ... ... ... ... ... ... ...

[0080] In Table 1, y represents temperature (°C), and x represents driving mode. Specifically, A is Standard mode, B is Sport mode, C is Snow mode, D is Mud mode, E is Sand mode, F is Eco mode, G is High-speed 4WD mode, H is Low-speed 4WD mode, and I is Light Snow mode. As shown in Table 1, different battery depletion mode exit thresholds are calibrated at different temperatures for the same driving mode. For example, for Standard mode A, the battery depletion mode exit threshold A11 is calibrated at -15°C, A12 at 0°C, A13 at 15°C, and A14 at 20°C, etc. For Sport Mode B, the exit threshold B11 for the battery depletion mode is calibrated at -15℃, B12 at 0℃, B13 at 15℃, and B14 at 20℃, and so on. The corresponding exit threshold for the battery depletion mode is calibrated for different driving modes at different temperatures.

[0081] The exit threshold for the battery depletion mode can be a threshold based on the remaining charge of the power battery. The calibration rule for this threshold can be as follows: For the same driving mode (e.g., snow mode), the calibrated exit threshold increases as the ambient temperature decreases, i.e., B11 is greater than B14. For the same ambient temperature (e.g., -15℃), a smaller exit threshold can be set for snow mode, mud mode, sand mode, high-speed four-wheel drive mode, and low-speed four-wheel drive mode, such as 25%. For light snow mode, a threshold slightly higher than the exit thresholds for snow mode, mud mode, sand mode, high-speed four-wheel drive mode, and low-speed four-wheel drive mode can be set, such as 40%. For the remaining driving modes, a threshold slightly higher than the exit threshold for light snow mode can be set, such as 45%.

[0082] Understandably, the primary goals of Snow Mode, Mud Mode, Sand Mode, High-Speed ​​4WD Mode, and Low-Speed ​​4WD Mode are to provide optimal traction and vehicle stability in complex terrain or special road conditions. Compared to the engine, the drive motor offers higher efficiency and smoother operation, providing more stable power output. Therefore, in these modes, the vehicle tends to rely more on the drive motor and reduce engine intervention. Consequently, the battery depletion thresholds for these modes are relatively low, expanding the range of battery depletion modes and extending the pure electric driving range.

[0083] The light snow mode is suitable for light snow or icy roads. Its main goal is to ensure that the vehicle has good traction and stability under these conditions. The road conditions in light snow mode are relatively better than those in snow mode, so the reliance on the drive motor can be relaxed to a certain extent. The exit threshold of the battery depletion mode is slightly increased, and the range of the battery depletion mode is narrowed, so that the vehicle can start the engine earlier, thereby improving fuel economy.

[0084] The remaining driving modes are suitable for normal road conditions and are designed to meet various daily driving needs, including fuel economy, acceleration performance, and comfort. In other words, these modes must consider both fuel economy and the driver's different power requirements. A higher battery depletion mode exit threshold can be set to ensure that, in most situations, the vehicle can operate economically in battery depletion mode while simultaneously starting the engine early to maintain acceleration performance and replenishing the battery charge in a timely manner, preventing the driving experience from being negatively impacted by low battery levels.

[0085] When the exit threshold for the power battery depletion mode is the threshold of the remaining power battery capacity, the current first actual power battery capacity can be compared with the exit threshold of the power battery depletion mode. If it is determined that the first actual power battery capacity is less than the exit threshold of the power battery depletion mode, the vehicle is determined to meet the first preset condition.

[0086] For example, when the vehicle is in a battery depletion mode, the current actual charge level of the vehicle's power battery is 20%; the current driving mode is Sand Mode, and the ambient temperature is -15°C. Based on the Sand Mode and the -15°C ambient temperature, referring to Table 1 above, the exit threshold for the battery depletion mode is found to be E11. Assuming E11 is 25%, and the actual charge level of 20% is less than the exit threshold of 25%, it can be determined that the vehicle meets the first preset condition.

[0087] The above method considers the impact of driving mode and ambient temperature on the power battery's charge management strategy. It determines the exit threshold for the charge reduction mode based on the current first driving mode and the first ambient temperature. This exit threshold can be dynamically adjusted according to different driving conditions (such as driving mode and ambient temperature) to ensure optimal decision-making under various circumstances, improve the accuracy of mode switching, and more precisely control battery charge usage. For example, in low-temperature environments, battery performance may decline; appropriately increasing the exit threshold can prevent over-discharge and ensure battery health.

[0088] In some embodiments, the exit threshold for the power depletion mode can also be a threshold for the power difference. The following embodiments will describe this situation in detail:

[0089] In one possible implementation, determining whether the vehicle meets the first preset condition based on the first actual battery level and the exit threshold of the battery level reduction mode includes: determining the first target battery level of the power battery based on the first driving mode, the first ambient temperature, and the vehicle's current first speed; subtracting the first target battery level from the first actual battery level to obtain a first battery level difference; and determining that the vehicle meets the first preset condition if the first battery level difference is less than the exit threshold of the battery level reduction mode.

[0090] A power battery has a target charge level that needs to be maintained, usually expressed as a percentage, such as 30% to 70%. This target charge level is used to keep the power battery's charge within a reasonable range, avoiding overcharging or over-discharging, thereby extending battery life. The target charge level is affected by driving mode, ambient temperature, and vehicle speed. When the vehicle is in a battery depletion mode, the current driving mode (first driving mode), the current ambient temperature (first ambient temperature), and the current vehicle speed (first vehicle speed) are obtained. Then, based on the first driving mode, the first ambient temperature, and the first vehicle speed, the current target charge level of the power battery is determined, resulting in the aforementioned first target charge level.

[0091] Specifically, the vehicle's driving modes can be divided into two main categories, and different relationships between ambient temperature and vehicle speed and the target battery level can be assigned to these two categories. The first category of driving modes can include: Standard Mode, Sport Mode, and Eco Mode. The correspondence between the first category of driving modes is denoted as MAP-0, as shown in Table 2 below.

[0092] Table 2

[0093] y\z 5 10 20 40 60 80 100 120 130 -15 K11 K21 K31 K41 K51 K61 K71 K81 K91 0 K12 K22 K32 K42 K52 K62 K72 K82 K92 15 K13 K23 K33 K43 K53 K63 K73 K83 K93 20 K14 K24 K34 K44 K54 K64 K74 K84 K94 ... ... ... ... ... ... ... ... ... ...

[0094] In Table 2, y represents temperature (°C) and z represents vehicle speed (kph). As shown in Table 2, different target charges are calibrated for the same temperature at different vehicle speeds. For example, for a temperature of 0°C, the target charge K12 is calibrated at a vehicle speed of 5 kph, K22 at 10 kph, K32 at 20 kph, and K42 at 40 kph, and so on, calibrating the target charge corresponding to each vehicle speed at the same temperature. Similarly, different target charges are calibrated for the same vehicle speed at different temperatures. For example, for a vehicle speed of 20 kph, the target charge K31 is calibrated at -15°C, K32 at 0°C, K33 at 15°C, and K34 at 20°C, and so on, calibrating the target charge corresponding to each temperature at the same vehicle speed.

[0095] In some embodiments, Table 2 shows that when calibrating the target battery capacity at the same vehicle speed under different temperatures, the target battery capacity increases as the temperature decreases; when calibrating the target battery capacity at the same temperature under different vehicle speeds, the target battery capacity increases as the vehicle speed increases.

[0096] The second category of driving modes can include: Snow Mode, Mud Mode, Sand Mode, High-Speed ​​4WD Mode, Low-Speed ​​4WD Mode, and Light Snow Mode. The correspondence between these second category of driving modes is denoted as MAP-1, as shown in Table 3 below.

[0097] Table 3

[0098] y\z 5 10 20 40 60 80 100 120 130 -15 L11 L21 L31 L41 L51 L61 L71 L81 L91 0 L12 L22 L32 L42 L52 L62 L72 L82 L92 15 L13 L23 L33 L43 L53 L63 L73 L83 L93 20 L14 L24 L34 L44 L54 L64 L74 L84 L94 ... ... ... ... ... ... ... ... ... ...

[0099] In Table 3, y represents temperature (°C) and z represents vehicle speed (kph). The target energy level specified in Table 3 is represented by L. Similar to Table 2, Table 3 specifies different target energy levels for the same temperature at different vehicle speeds, and different target energy levels for the same vehicle speed at different temperatures. For the same temperature and vehicle speed, the target energy level L specified in Table 3 may be different from or the same as the target energy level K specified in Table 2.

[0100] In some embodiments, the calibration rules in Table 3 can be similar to those in Table 2. When calibrating the target battery capacity at the same vehicle speed under different temperatures, the target battery capacity tends to increase as the temperature decreases. When calibrating the target battery capacity at the same temperature under different vehicle speeds, the target battery capacity tends to increase as the vehicle speed increases.

[0101] For example, if the first driving mode is determined to be Sand Mode, which belongs to the second category, then MAP-1 needs to be looked up, i.e., Table 3 above. Assuming the first ambient temperature is -15℃ and the first vehicle speed is 60kph, then looking up Table 3 can determine that the first target battery level is L51.

[0102] The exit threshold for the battery depletion mode can specifically be a threshold value representing the difference between the current battery charge and the target battery charge. When the exit threshold for the battery depletion mode is the aforementioned battery charge difference threshold, the first battery charge difference can be obtained by subtracting the first target battery charge determined based on the current first driving mode, first ambient temperature, and first vehicle speed from the current actual battery charge. This first battery charge difference is then compared with the exit threshold for the battery depletion mode to determine whether the vehicle meets the first preset condition. Specifically, if the first battery charge difference is less than the exit threshold for the battery depletion mode, the vehicle is deemed to meet the first preset condition.

[0103] It is understandable that when the exit threshold for the battery depletion mode is the threshold of the battery difference, the first actual battery level threshold for exiting the battery depletion mode is the target battery level plus the exit threshold of the battery depletion mode. The first battery difference is the difference between the first actual battery level and the first target battery level. When the first battery difference is less than the exit threshold of the battery depletion mode, it can be said that the first actual battery level of the power battery is less than the first actual battery level threshold, that is, at this time it can be determined that the vehicle meets the first preset condition.

[0104] For example, the exit threshold for the battery depletion mode is -1%, the first target battery level L51 is 30%, and the first actual battery level is 28%. By calculation, the first battery level difference = first actual battery level - first target battery level = 28% - 30% = -2%. The first battery level difference -2% < the exit threshold for the battery depletion mode -1%, at which point it is determined that the vehicle meets the first preset condition.

[0105] In the above method, a first target battery level is determined based on driving mode, ambient temperature, and vehicle speed. The difference between the first actual battery level and the first target battery level (i.e., the first battery level difference) is used to determine whether to exit the battery depletion mode. This allows the system to make more accurate judgments based on the current actual state of the vehicle (including factors such as driving mode, ambient temperature, and vehicle speed), further improving the accuracy of mode switching.

[0106] In step 102, after determining that the vehicle meets the first preset condition for switching to the battery maintenance mode, the vehicle will exit the battery depletion mode and enter the battery maintenance mode, thereby switching from the battery depletion mode to the battery maintenance mode.

[0107] Figure 2 This is a schematic diagram of a mode switching provided in an embodiment of this application.

[0108] For example, such as Figure 2 As shown, the y-axis represents the battery difference, and the x-axis represents the operating mode. Figure 2 The CD-OFF threshold, or the exit threshold for the battery depletion mode, is -1%. When the current mode is battery depletion mode and the first battery difference is greater than CD-OFF, the vehicle remains in battery depletion mode. As the vehicle's battery is consumed during driving, when the first battery difference falls below CD-OFF, the vehicle exits battery depletion mode and enters battery sustain mode.

[0109] As described in the above embodiments, the vehicle includes multiple operating modes such as series mode, parallel mode, power split mode, pure electric four-wheel drive mode, idle pure electric four-wheel drive mode, and pure electric two-wheel drive mode. When the vehicle is in battery maintenance mode, it can be controlled to operate in one of the above-mentioned operating modes according to the actual situation.

[0110] As described in the above embodiments, the vehicle also includes multiple power modes and driving modes, resulting in different energy management strategies. Since the power mode has a relatively small impact on the energy management strategy in the battery maintenance mode, only the impact of the driving mode on the vehicle's operating mode needs to be considered in the battery maintenance mode.

[0111] The following section provides a further explanation of the battery maintenance mode in conjunction with driving modes.

[0112] For driving modes that do not force engine start, such as Eco, Standard, and Sport modes, when the vehicle is in battery maintenance mode, the vehicle typically keeps the battery charge near the target level. Under low power demand, the vehicle operates in pure electric four-wheel drive or pure electric two-wheel drive mode to enable pure electric drive. Under high power demand, when the engine is started, if the vehicle speed is below a third preset speed after engine start, the operating mode switches to series mode or power split mode; if the vehicle speed is above the third preset speed, the operating mode switches to parallel mode.

[0113] The third preset vehicle speed could be, for example, 70 kph. The target battery level is the level that the power battery needs to maintain while the hybrid vehicle is in operation.

[0114] Specifically, when the vehicle is in battery maintenance mode, for Eco mode, if the vehicle speed is below the third preset speed after engine start, the operating mode switches to series mode; if the vehicle speed is above the third preset speed, the operating mode switches to parallel mode. For Standard mode, if the vehicle speed is below the third preset speed after engine start, the operating mode switches to either series mode or power-split mode; if the vehicle speed is above the third preset speed, the operating mode switches to parallel mode. For Sport mode, if the vehicle speed is below the third preset speed after engine start, the operating mode switches to power-split mode; if the vehicle speed is above the third preset speed, the operating mode switches to parallel mode.

[0115] Understandably, the economy mode prioritizes fuel efficiency. Therefore, when the vehicle speed is below the third preset speed of 70 kph after engine start, the relatively low speed allows switching to series mode. This enables the engine to generate electricity solely for powering the drive motor, which then directly drives the wheels, improving fuel economy. When the speed exceeds 70 kph, the vehicle enters high-speed driving mode, increasing power demand. Switching to parallel mode at this point allows both the engine and drive motor to work together, providing higher power output while maintaining good fuel economy.

[0116] In standard mode, aiming to balance fuel economy and driving experience, when the vehicle speed is below the third preset speed, either series mode or power-split mode can be selected based on real-time power demand and driving conditions. Series mode is suitable for relatively smooth low-speed driving, while power-split mode provides more flexibility, delivering higher power output when needed. When the vehicle speed is above the third preset speed, parallel mode is selected to ensure sufficient power support and maintain vehicle stability at high speeds.

[0117] The goal of Sport mode is to provide optimal power response and driving experience, typically sacrificing some fuel economy. Therefore, when the vehicle speed is below the third preset speed, power split mode is prioritized to ensure a consistently high power output to meet the driver's acceleration needs. When the vehicle speed is above the third preset speed, parallel mode is selected to guarantee maximum power output, ensuring vehicle stability and responsiveness at high speeds.

[0118] In the light snow mode, when the vehicle is in the battery maintenance mode, the engine will be forcibly started directly. When the vehicle speed is lower than the third preset speed, the operation mode will be switched to power split mode, and when the vehicle speed is higher than the third preset speed, the operation mode will be switched to parallel mode.

[0119] Understandably, the Light Snow mode aims to optimize vehicle performance on lightly icy and snowy roads, focusing on preventing wheel slippage while maintaining a certain level of power output and stability. The Light Snow mode's operating logic prioritizes engine start-up and power distribution flexibility to ensure vehicle safety and controllability on icy and snowy roads. Therefore, when the vehicle is in battery maintenance mode under Light Snow mode, the engine will be forcibly started.

[0120] For driving modes that force engine start, such as snow mode, mud mode, sand mode, and high-speed four-wheel drive mode, when the vehicle is in battery maintenance mode, the vehicle will control the operation mode to power split mode. When the vehicle speed is lower than the fourth preset speed and the vehicle is currently accelerating with heavy throttle, the control operation mode will switch to parallel mode. When the vehicle speed is higher than the fifth preset speed, the control operation mode will switch back to power split mode.

[0121] The fourth preset speed is less than the fifth preset speed. For example, the fourth preset speed is 60 kph and the fifth preset speed is 85 kph. This can determine that the vehicle is currently in a high-throttle acceleration state when the accelerator pedal opening is greater than the preset opening (e.g., 60%).

[0122] Understandably, snow, mud, sand, and high-speed four-wheel drive modes demand high power performance and operate on complex road conditions. Therefore, when in battery maintenance mode, switching to power-split mode at lower speeds in snow, mud, sand, and high-speed four-wheel drive modes better adapts to these changing road conditions, ensuring the vehicle maintains good passability and stability. When the vehicle is traveling at low speeds and the driver needs to accelerate with heavy throttle, it indicates that the current road conditions or driving demands require higher power output. For example, greater torque is needed to overcome resistance in mud, or stronger power is needed to prevent slippage on snow. In this situation, parallel mode can provide stronger power support through the coordinated work of the engine and drive motor, ensuring the vehicle can smoothly traverse complex terrain or complete acceleration maneuvers. When the vehicle speed exceeds 85 kph, the vehicle enters high-speed driving mode. While the power demand remains high, stability and fuel economy are prioritized. Power-split mode can optimize the operation of the engine and drive motor through a more efficient energy management strategy at high speeds, ensuring vehicle stability and responsiveness while improving fuel economy.

[0123] In low-speed four-wheel drive mode, when the vehicle is in battery maintenance mode, the vehicle will switch the control mode to power split mode and keep the control mode in power split mode.

[0124] Understandably, in low-speed four-wheel drive mode, the vehicle usually travels at extremely low speeds, typically not exceeding the fourth preset speed, so the vehicle's operating mode remains in power split mode.

[0125] In some embodiments, when the operating mode is power-split mode or parallel mode, the vehicle still needs to engage gears. The gear engaged in power-split mode or parallel mode in low-speed four-wheel drive mode is designated as the first gear; the gear engaged in power-split mode or parallel mode in driving modes such as snow mode, mud mode, sand mode, and high-speed four-wheel drive mode is designated as the second gear; and the gear engaged in power-split mode or parallel mode in other remaining driving modes is designated as the third gear. The third gear is typically higher than the second gear, and the second gear is typically higher than the first gear. For example, the first gear could be 1st gear, the second gear could be 2nd gear, and the third gear could be 3rd gear.

[0126] Understandably, in low-speed four-wheel drive mode, the vehicle typically travels at extremely low speeds and requires a large torque output; therefore, in low-speed four-wheel drive mode, the vehicle is usually engaged in the lowest gear, first gear. Snow mode, mud mode, sand mode, and high-speed four-wheel drive mode present complex road conditions, and the vehicle's speed is usually not very high, but it will be higher than the speed in low-speed four-wheel drive mode. Furthermore, snow mode, mud mode, sand mode, and high-speed four-wheel drive mode do not require as much torque as low-speed four-wheel drive mode; therefore, the gear is usually slightly higher, i.e., second gear is higher than first gear. The remaining driving modes are normal modes, and the driving speed is usually higher than the aforementioned driving modes for complex road conditions; therefore, the third gear is usually higher than the second gear.

[0127] In step 103, under the forced engine start mode, the vehicle will forcibly start the engine to provide power or assist the drive motor. The vehicle no longer relies solely on the power battery for power output, which can effectively protect the power battery and avoid over-discharge. The forced engine start mode in this embodiment is (Charge Sustaining-Low Efficiency, CS-L), abbreviated as CS-L mode. CS-L mode focuses more on energy management under inefficient operating conditions.

[0128] The logic for switching from battery maintenance mode to engine forced start mode is pre-set in the vehicle, along with a second preset condition that needs to be met during the switch. When it is determined that the vehicle is currently in battery maintenance mode, the second preset condition can be monitored in real time.

[0129] In one possible implementation, when the vehicle is in battery maintenance mode, determining whether the vehicle meets the second preset condition for switching to engine forced start mode includes: when the vehicle is in battery maintenance mode, obtaining the current second actual charge of the vehicle's power battery; determining the exit threshold of battery maintenance mode based on the vehicle's current second driving mode and second ambient temperature; and determining whether the vehicle meets the second preset condition based on the second actual charge and the exit threshold of battery maintenance mode.

[0130] As described in the above embodiment, the vehicle is equipped with a battery management system. When the vehicle is in power maintenance mode, the remaining power of the power battery, which is monitored in real time by the battery management system, can be obtained to obtain a second actual power level. The second actual power level is usually less than the first actual power level.

[0131] A second mapping relationship can be pre-set in the vehicle between two parameters: driving mode and ambient temperature, and the exit threshold for battery maintenance mode. When it is determined that the vehicle is in battery maintenance mode, the current driving mode and ambient temperature can also be obtained to obtain the aforementioned second driving mode and second ambient temperature.

[0132] It is understandable that the region or time of day when the vehicle is in battery sustain mode may differ from the region or time of day when the vehicle is in battery depletion mode, and the vehicle may also be in a different driving mode. Furthermore, the ambient temperature may vary depending on the region or time of day. Therefore, the second driving mode and second ambient temperature obtained in battery sustain mode may differ from the first driving mode and first ambient temperature obtained in battery depletion mode.

[0133] As mentioned earlier, the power battery employs different energy management strategies under different driving modes, and varying ambient temperatures also affect these strategies. Therefore, a second correspondence can be pre-defined between these two parameters—driving mode and ambient temperature—and the exit threshold for the battery maintenance mode. This second correspondence is shown in Table 4 below.

[0134] Table 4

[0135] y\x A B C D E F G H I -15 A21 B21 C21 D21 E21 F21 G21 H21 I21 0 A22 B22 C22 D22 E22 F22 G22 H22 I22 15 A23 B23 C23 D23 E23 F23 G23 H23 I23 20 A24 B24 C24 D24 E24 F24 G24 H24 I24 ... ... ... ... ... ... ... ... ... ...

[0136] In Table 4, y represents temperature (°C), and x represents driving mode. Specifically, A is Standard mode, B is Sport mode, C is Snow mode, D is Mud mode, E is Sand mode, F is Eco mode, G is High-speed 4WD mode, H is Low-speed 4WD mode, and I is Light Snow mode. As shown in Table 4, different battery maintenance mode exit thresholds are calibrated for the same driving mode at different temperatures. For example, for Standard mode A, the battery maintenance mode exit threshold A21 is calibrated at -15°C, A22 at 0°C, A23 at 15°C, and A24 at 20°C, etc. For Sport Mode B, the exit threshold B21 for the battery maintenance mode is calibrated at -15℃, the exit threshold B22 at 0℃, the exit threshold B23 at 15℃, the exit threshold B24 at 20℃, and so on. The corresponding exit threshold for the battery maintenance mode is calibrated for different driving modes at different temperatures.

[0137] The exit threshold for the battery maintenance mode can also be a threshold based on the remaining charge of the power battery. The calibration rule for this threshold can be as follows: For the same driving mode (e.g., snow mode), the calibrated exit threshold increases as the ambient temperature decreases, i.e., B21 is greater than B24. For the same ambient temperature (e.g., -15℃), a smaller exit threshold can be set for snow mode, mud mode, sand mode, high-speed four-wheel drive mode, and low-speed four-wheel drive mode, such as 12%. For light snow mode, a threshold slightly higher than the exit thresholds for snow mode, mud mode, sand mode, high-speed four-wheel drive mode, and low-speed four-wheel drive mode can be set, such as 22%. For the remaining driving modes, a threshold slightly higher than the exit threshold for light snow mode can be set, such as 42%.

[0138] For the same driving mode and the same ambient temperature, the exit threshold for the battery maintenance mode is lower than the exit threshold for the battery depletion mode. In other words, the thresholds in the second correspondence are all lower than the thresholds in the first correspondence.

[0139] When the exit threshold of the battery maintenance mode is the threshold of the remaining battery level, the second actual battery level can be compared with the exit threshold of the battery maintenance mode. If it is determined that the second actual battery level is less than the exit threshold of the battery maintenance mode, the vehicle is determined to meet the second preset condition.

[0140] For example, when the vehicle is in battery maintenance mode, the current actual charge level of the vehicle's power battery is obtained as 10%; the current second driving mode is standard mode and the second ambient temperature is -15°C. Based on the second driving mode (standard mode) and the second ambient temperature (-15°C), referring to Table 2 above, the exit threshold for battery maintenance mode is obtained as A21. Assuming A21 is 42%, and the second actual charge level of 10% is less than the exit threshold of 42% for battery maintenance mode, it can be determined that the vehicle meets the second preset condition.

[0141] In some embodiments, the exit threshold for the power maintenance mode can also be a threshold for the power difference. The following embodiments will describe this situation in detail:

[0142] In one possible implementation, determining whether the vehicle meets the second preset condition based on the second actual battery level and the exit threshold of the battery maintenance mode includes: determining the second target battery level based on the second driving mode, the second ambient temperature, and the vehicle's current second speed; subtracting the second target battery level from the second actual battery level to obtain the second battery level difference; and determining that the vehicle meets the second preset condition if the second battery level difference is less than the exit threshold of the battery maintenance mode.

[0143] As mentioned earlier, the power battery has a target charge level that needs to be maintained. This target charge level is affected by the driving mode, ambient temperature, and vehicle speed. Given that the vehicle is in charge maintenance mode, the current driving mode can be obtained to obtain a second driving mode; the current ambient temperature can be obtained to obtain a second ambient temperature; and the current vehicle speed can be obtained to obtain a second vehicle speed. Then, based on the second driving mode, the second ambient temperature, and the second vehicle speed, the current target charge level of the power battery is determined, resulting in the aforementioned second target charge level.

[0144] Since the second driving mode, second ambient temperature, and second vehicle speed may differ from the first driving mode, first ambient temperature, and first vehicle speed, the determined second target battery level may also differ from the first target battery level.

[0145] As in the above embodiments, two MAPs are pre-calibrated for the two major driving modes, namely Table 2 and Table 3 above. The target MAP to be searched can be determined based on the second driving mode, and the target MAP can be searched based on the second ambient temperature and the second vehicle speed to obtain the second target battery level.

[0146] For example, if the second driving mode is standard mode, which belongs to the first category, then the target MAP can be determined as MAP-0, as shown in Table 2 above. Assuming the second ambient temperature is -15℃ and the second vehicle speed is 40kph, referring to Table 2, the second target battery level can be determined as K41.

[0147] The exit threshold for the battery maintenance mode can specifically be a threshold value representing the difference between the current battery charge and the target battery charge. When the exit threshold for the battery maintenance mode is the aforementioned battery charge difference threshold, the second battery charge difference can be obtained by subtracting the second target battery charge determined based on the current second driving mode, second ambient temperature, and second vehicle speed from the current actual battery charge. This second battery charge difference is then compared with the exit threshold for the battery maintenance mode to determine whether the vehicle meets the second preset condition. Specifically, if the second battery charge difference is less than the exit threshold for the battery maintenance mode, the vehicle is deemed to meet the second preset condition.

[0148] It is understandable that when the exit threshold for the battery maintenance mode is the threshold of the battery difference, the second actual battery level threshold for exiting the battery maintenance mode is the target battery level plus the exit threshold of the battery maintenance mode. The second battery difference is the difference between the second actual battery level and the second target battery level. When the second battery difference is less than the exit threshold of the battery maintenance mode, it can be said that the second actual battery level of the power battery is less than the second actual battery level threshold, that is, at this time it can be determined that the vehicle meets the second preset condition.

[0149] For example, the exit threshold for the battery maintenance mode is -2%, the second target battery level K41 is 25%, and the first actual battery level is 22%. By calculation, the second battery level difference = second actual battery level - second target battery level = 22% - 25% = -3%. The second battery level difference -3% < the exit threshold for the battery maintenance mode -2%, at which point it is determined that the vehicle meets the second preset condition.

[0150] In step 104, after determining that the vehicle meets the second preset condition for switching to the engine forced start mode, the vehicle will exit the battery maintenance mode and enter the engine forced start mode, thereby switching from the battery maintenance mode to the engine forced start mode.

[0151] like Figure 2 As shown, Figure 2 The CS-H-OFF threshold, which is the exit threshold for the battery maintenance mode, is -2%. When the current mode is battery maintenance mode and the second battery difference is greater than CS-H-OFF, the vehicle remains in battery maintenance mode. As the battery is consumed during driving, when the second battery difference falls below CS-H-OFF, the vehicle switches from battery maintenance mode to engine start-up mode.

[0152] As described in the above embodiments, the vehicle includes multiple operating modes such as series mode, parallel mode, power split mode, pure electric four-wheel drive mode, idle pure electric four-wheel drive mode, and pure electric two-wheel drive mode. When the vehicle is in the engine forced start mode, it can be controlled to operate in one of the above-mentioned series mode, parallel mode, or power split mode according to the actual situation, that is, the vehicle is no longer controlled to be in pure electric mode.

[0153] Similar to the battery maintenance mode, the power mode has a smaller impact on the energy management strategy in the engine forced start mode. Therefore, in the engine forced start mode, only the impact of the driving mode on the vehicle's operating mode can be considered.

[0154] The following section provides a further explanation of the battery maintenance mode in conjunction with driving modes.

[0155] For driving modes that do not force engine start, such as Eco, Standard, Sport, and Light Snow modes, when the vehicle is in engine-forced start mode, the vehicle controls the engine to start forcibly. If the vehicle speed is below the sixth preset speed, the operating mode switches to series mode or power-split mode. If the vehicle speed is above the sixth preset speed, the operating mode switches to parallel mode. The sixth preset speed could be, for example, 70 kph.

[0156] Specifically, as mentioned earlier, the target performance achieved by the vehicle differs in Eco mode, Standard mode, Sport mode, and Light Snow mode. When the vehicle is in engine forced start mode, for Eco mode, if the vehicle speed is below the sixth preset speed after engine start, the operating mode switches to series mode; if the vehicle speed is above the sixth preset speed, the operating mode switches to parallel mode. For Standard mode, if the vehicle speed is below the sixth preset speed after engine start, the operating mode switches to series mode or power split mode; if the vehicle speed is above the sixth preset speed, the operating mode switches to parallel mode. For Sport mode and Light Snow mode, if the vehicle speed is below the sixth preset speed after engine start, the operating mode switches to power split mode; if the vehicle speed is above the sixth preset speed, the operating mode switches to parallel mode.

[0157] For driving modes that force engine start, such as Snow Mode, Mud Mode, Sand Mode, High-Speed ​​4WD Mode, and Low-Speed ​​4WD Mode, the vehicle is typically driven on complex terrains, such as snow, mud, sand, or off-road conditions requiring high traction. Power Split Mode allows the engine and drive motor to flexibly distribute power according to real-time needs. The engine can directly drive the wheels, or the generator can convert the engine's energy into electricity to power the drive motor. This flexibility enables the vehicle to better handle traction demands under different road conditions, ensuring stability and passability. Therefore, the vehicle can be controlled to operate in Power Split Mode.

[0158] Similarly, the first gear engaged in low-speed four-wheel drive mode is usually lower than the second gear engaged in snow mode, mud mode, sand mode, and high-speed four-wheel drive mode. The second gear engaged in snow mode, mud mode, sand mode, and high-speed four-wheel drive mode is lower than the third gear engaged in economy mode, standard mode, sport mode, and light snow mode.

[0159] In one possible implementation, the method further includes: charging the power battery based on a target charging power when the vehicle is in engine forced start mode, wherein the target charging power is greater than a preset charging power threshold.

[0160] The vehicle can pre-set multiple charging modes for the power battery, such as: efficiency charging mode, enhanced charging mode, and forced charging mode.

[0161] In the efficiency charging mode, the vehicle charges the battery in the most energy-efficient way, typically by utilizing excess kinetic energy or a portion of the engine's power while the engine is running normally. This mode has a lower charging power but minimal impact on fuel economy.

[0162] Enhanced charging mode is a charging strategy between forced charging mode and efficiency charging mode. In enhanced charging mode, the engine is started and generates electricity to charge the battery. To replenish the battery faster than efficiency charging mode, enhanced charging mode typically sacrifices some fuel economy, and its charging power is higher than that of efficiency charging mode.

[0163] In forced charging mode, the engine is forcibly started, and the electric motor charges the battery. Forced charging mode provides the highest charging power to the battery via the electric motor. Forced charging mode is typically activated when the battery has very low remaining charge, such as less than 9%, to quickly restore battery power and ensure the vehicle can continue to operate efficiently.

[0164] The aforementioned preset charging power threshold can be the charging power corresponding to the efficiency charging mode, or slightly greater than the charging power corresponding to the efficiency charging mode. In this embodiment, when the vehicle is in the engine forced start mode, the enhanced charging mode of the power battery will be activated, a target charging power greater than the preset charging power threshold will be determined, and the power battery will be charged based on the target power. At this time, the vehicle will sacrifice some fuel economy, but the power battery can be charged relatively quickly.

[0165] In the above method, when the vehicle is in the engine forced start mode, the remaining charge of the vehicle's power battery is usually low. At this time, charging the power battery with a larger charging power can ensure that the power battery can obtain more charge in a shorter time, quickly restore the power battery's charge, and prevent the power battery from being deeply discharged.

[0166] In one possible implementation, the method further includes: when the vehicle is in engine forced start mode, determining an entry threshold for battery maintenance mode based on the vehicle's current third driving mode and third ambient temperature; determining whether the vehicle meets the third preset condition for switching to battery maintenance mode based on the entry threshold for battery maintenance mode; and switching the vehicle from engine forced start mode to battery maintenance mode if the vehicle meets the third preset condition.

[0167] The vehicle can also be configured with an entry threshold for the battery maintenance mode. This entry threshold can differ from the exit threshold to prevent the vehicle from switching back and forth between entering and exiting the battery maintenance mode. Typically, the entry threshold for the battery maintenance mode can be set to be higher than the exit threshold.

[0168] The entry threshold for the battery maintenance mode is also related to the driving mode and ambient temperature. The correspondence between these two parameters and the entry threshold for the battery maintenance mode can be called the third correspondence. When the vehicle is determined to be in engine forced start mode, the current driving mode and ambient temperature can also be obtained to obtain the aforementioned third driving mode and third ambient temperature. Then, based on the third driving mode and third ambient temperature, the aforementioned third correspondence is used to determine the entry threshold for the battery maintenance mode corresponding to the third driving mode and third ambient temperature.

[0169] It is understandable that the region or time of day when the vehicle is in engine start-up mode may differ from the region or time of day when the vehicle is in battery maintenance mode, and the vehicle may be in different driving modes, with varying ambient temperatures in different regions or at different times. Therefore, the third driving mode and third ambient temperature obtained in engine start-up mode may differ from the second driving mode and second ambient temperature obtained in battery maintenance mode. Similarly, the third driving mode and third ambient temperature may also differ from the first driving mode and first ambient temperature obtained in battery depletion mode.

[0170] As mentioned earlier, the power battery employs different energy management strategies under different driving modes, and different ambient temperatures also affect these strategies. Therefore, a third correspondence can be pre-defined between the driving mode and ambient temperature parameters and the entry threshold for the battery maintenance mode. This third correspondence is shown in Table 5 below:

[0171] Table 5

[0172] y\x A B C D E F G H I -15 A31 B31 C31 D31 E31 F31 G31 H31 I31 0 A32 B32 C32 D32 E32 F32 G32 H32 I32 15 A33 B33 C33 D33 E33 F33 G33 H33 I33 20 A34 B34 C34 D34 E34 F34 G34 H34 I34 ... ... ... ... ... ... ... ... ... ...

[0173] In Table 5, y represents temperature (°C), and x represents driving mode. Specifically, A is Standard mode, B is Sport mode, C is Snow mode, D is Mud mode, E is Sand mode, F is Eco mode, G is High-speed 4WD mode, H is Low-speed 4WD mode, and I is Light Snow mode. As shown in Table 5, different entry thresholds for the battery maintenance mode are calibrated at different temperatures for the same driving mode. For example, for Standard mode A, the entry threshold A31 for the battery maintenance mode is calibrated at -15°C, A32 at 0°C, A33 at 15°C, and A34 at 20°C, etc. For Sport Mode B, the entry threshold B31 for the battery maintenance mode is calibrated at -15℃, the entry threshold B32 for the battery maintenance mode is calibrated at 0℃, the entry threshold B33 for the battery maintenance mode is calibrated at 15℃, the entry threshold B34 for the battery maintenance mode is calibrated at 20℃, and so on. The corresponding entry threshold for the battery maintenance mode is calibrated for different driving modes at different temperatures.

[0174] The entry threshold for the battery maintenance mode can also be the threshold of the remaining battery charge. The calibration rules for the entry threshold of the battery maintenance mode are similar to those for the exit threshold, and will not be repeated here. The difference is that, for the same driving mode and the same ambient temperature, the entry threshold for the battery maintenance mode is greater than the exit threshold. In other words, the threshold in the third correspondence is uniformly greater than the threshold in the second correspondence.

[0175] When the entry threshold for the power maintenance mode is the threshold of the remaining power, the current actual power of the power battery can be obtained to obtain the third actual power. The third actual power is compared with the entry threshold of the power maintenance mode. If it is determined that the third actual power is greater than the entry threshold of the power maintenance mode, the vehicle is determined to meet the third preset condition.

[0176] As mentioned earlier, the power battery has a target charge level that needs to be maintained. The threshold for entering the charge maintenance mode can also be the threshold of the difference between the current actual charge level of the power battery and the target charge level. At this time, the charge difference between the third actual charge level and the target charge level can be calculated and compared with the threshold for entering the charge maintenance mode to determine whether the vehicle meets the third preset condition.

[0177] The target battery level is affected by driving mode, ambient temperature, and vehicle speed. Even when the vehicle is in engine-forced start mode, these factors may change. Therefore, a third target battery level needs to be determined based on the current third driving mode, third ambient temperature, and third vehicle speed. The third target battery level is then subtracted from the third actual battery level to obtain the third battery level difference. This third battery level difference is compared to the entry threshold for battery maintenance mode. If the third battery level difference is greater than the entry threshold, the vehicle meets the third preset condition. In this case, the vehicle exits engine-forced start mode and enters battery maintenance mode. The specific process for determining whether the vehicle meets the third preset condition is similar to the process for determining whether the vehicle meets the first and second preset conditions, and will not be elaborated here.

[0178] like Figure 2 As shown, the entry threshold CS-H-ON for the battery maintenance mode is -1.5%. When the vehicle is in engine start-stop mode, if the third battery level difference is less than -1.5%, the vehicle remains in engine start-stop mode. If the third battery level difference is greater than -1.5%, the vehicle switches from engine start-stop mode to battery maintenance mode.

[0179] The above method includes setting logic to switch the engine forced start mode to the battery maintenance mode, ensuring that the vehicle can switch back to the battery maintenance mode in a timely manner, reducing fuel consumption and improving the vehicle's economic performance.

[0180] In one possible implementation, when the vehicle is in battery maintenance mode, an entry threshold for battery depletion mode is determined based on the vehicle's current fourth driving mode and fourth ambient temperature; based on the entry threshold for battery depletion mode, it is determined whether the vehicle meets the fourth preset condition for switching to battery depletion mode; if it is determined that the vehicle meets the fourth preset condition, the vehicle is switched from battery maintenance mode to battery depletion mode.

[0181] The vehicle can also be configured with an entry threshold for the battery depletion mode. This entry threshold can differ from the exit threshold to prevent the vehicle from switching back and forth between entering and exiting the battery depletion mode. Typically, the entry threshold for the battery depletion mode can be set to be higher than the exit threshold.

[0182] The entry threshold for the battery depletion mode is also related to the driving mode and ambient temperature. The correspondence between these two parameters and the entry threshold for the battery depletion mode can be called the fourth correspondence. When the vehicle is determined to be in battery maintenance mode, the current driving mode and ambient temperature can also be obtained to obtain the aforementioned fourth driving mode and fourth ambient temperature. Then, based on the fourth driving mode and fourth ambient temperature, the fourth correspondence is looked up to determine the entry threshold for the battery depletion mode corresponding to the fourth driving mode and fourth ambient temperature.

[0183] It is understandable that the region or time of day when the vehicle is in battery maintenance mode may differ from the region or time of day when the vehicle is in engine start-up mode, and the vehicle may be in different driving modes, with varying ambient temperatures in different regions or at different times. Therefore, the fourth driving mode and fourth ambient temperature obtained in battery maintenance mode may differ from the third driving mode and third ambient temperature obtained in engine start-up mode.

[0184] As mentioned earlier, the power battery employs different energy management strategies under different driving modes, and different ambient temperatures also affect these strategies. Therefore, a fourth correspondence can be pre-defined between the driving mode and ambient temperature parameters and the threshold for entering the battery depletion mode. This fourth correspondence is shown in Table 6 below:

[0185] Table 6

[0186] y\x A B C D E F G H I -15 A41 B41 C41 D41 E41 F41 G41 H41 I41 0 A42 B42 C42 D42 E42 F42 G42 H42 I42 15 A43 B43 C43 D43 E43 F43 G43 H43 I43 20 A44 B44 C44 D44 E44 F44 G44 H44 I44 ... ... ... ... ... ... ... ... ... ...

[0187] In Table 6, y represents temperature (°C), and x represents driving mode. Specifically, A is Standard mode, B is Sport mode, C is Snow mode, D is Mud mode, E is Sand mode, F is Eco mode, G is High-speed 4WD mode, H is Low-speed 4WD mode, and I is Light Snow mode. As shown in Table 6, different battery depletion mode entry thresholds are calibrated at different temperatures for the same driving mode. For example, for Standard mode A, the battery depletion mode entry threshold A41 is calibrated at -15°C, A42 at 0°C, A43 at 15°C, and A44 at 20°C, etc. For Sport Mode B, the entry threshold B41 for the battery depletion mode is calibrated at -15℃, B42 at 0℃, B43 at 15℃, B44 at 20℃, and so on. The corresponding entry threshold for the battery depletion mode is calibrated for different driving modes at different temperatures.

[0188] The entry threshold for the battery depletion mode can also be the threshold of the remaining battery charge. The calibration rules for the entry threshold of the battery depletion mode are similar to those for the exit threshold, and will not be repeated here. The difference is that, for the same driving mode and the same ambient temperature, the corresponding entry threshold for the battery depletion mode is greater than the exit threshold. In other words, the thresholds in the fourth correspondence are uniformly greater than the thresholds in the first correspondence.

[0189] When the entry threshold for the power battery depletion mode is the threshold of the remaining power battery, the current actual power battery level can be obtained to obtain the fourth actual power battery level. The fourth actual power battery level is compared with the entry threshold for the power battery depletion mode. If it is determined that the fourth actual power battery level is greater than the entry threshold for the power battery depletion mode, the vehicle is determined to meet the fourth preset condition.

[0190] As mentioned earlier, the power battery has a target charge level that needs to be maintained. The threshold for entering the charge reduction mode can also be the threshold of the difference between the current actual charge level of the power battery and the target charge level. At this point, the charge difference between the fourth actual charge level and the target charge level can be calculated and compared with the threshold for entering the charge reduction mode to determine whether the vehicle meets the fourth preset condition.

[0191] The target battery level is affected by driving mode, ambient temperature, and vehicle speed. Even when the vehicle is in battery maintenance mode, the current driving mode, ambient temperature, and vehicle speed may change. In this case, the target battery level needs to be determined based on the current fourth driving mode, fourth ambient temperature, and fourth vehicle speed to obtain the fourth target battery level. Subtracting the fourth target battery level from the fourth actual battery level yields the fourth battery level difference. Comparing this fourth battery level difference with the entry threshold for battery depletion mode, if the fourth battery level difference is greater than the entry threshold for battery maintenance mode, the vehicle is determined to meet the fourth preset condition. At this point, the vehicle exits battery maintenance mode and enters battery depletion mode. The specific process for determining whether the vehicle meets the fourth preset condition is similar to the process for determining whether the vehicle meets the first and second preset conditions, and will not be elaborated here.

[0192] like Figure 2 As shown, the entry threshold CD-ON for the battery depletion mode is 3.5%. When the vehicle is in battery maintenance mode, if the fourth battery difference is less than 3.5%, the vehicle remains in battery maintenance mode. If the fourth battery difference is greater than 3.5%, the vehicle switches from battery maintenance mode to battery depletion mode.

[0193] In one possible implementation, before determining whether the vehicle meets the first preset condition for switching to the battery maintenance mode when the vehicle is in a battery depletion mode, the method further includes: determining that the vehicle's target battery adjustment function is inactive, wherein when the target battery adjustment function is active, the vehicle adjusts the target battery charge based on the user's charging habits; or, determining that the vehicle's driving mode is a mode other than the economy mode.

[0194] The target charge adjustment function refers to a feature that adjusts the target charge level of the power battery based on the user's usual charging habits. Only when the target charge adjustment function is activated will the vehicle adjust the target charge level of the power battery based on the user's typical charging habits.

[0195] The vehicle can adjust the default target battery level based on the user's usual charging habits. Typically, the vehicle's default target battery level is relatively high, and pure electric driving consumes less energy. Therefore, when the target battery level adjustment function is activated, it usually lowers the target battery level based on the user's usual charging habits to extend the pure electric driving range and save energy. For example, when the target battery level adjustment function is active, if the vehicle determines that the user's charging frequency is high, it will proactively lower the target battery level.

[0196] Therefore, if the target battery level adjustment function is active, it is determined that the vehicle's target battery level needs to be lowered to extend the pure electric driving range. In this case, switching from battery depletion mode to battery maintenance mode is unlikely to meet this requirement. Therefore, when the vehicle is in battery depletion mode, it is necessary to determine whether the vehicle meets the first preset condition for switching to battery maintenance mode before confirming that the target battery level adjustment function is inactive.

[0197] As mentioned earlier, the vehicle includes multiple driving modes, such as Eco, Standard, Sport, Light Snow, Snow, Mud, Sand, High-Speed ​​4WD, and Low-Speed ​​4WD. Different driving modes employ different energy management strategies for the battery. Only Eco mode prioritizes fuel economy, while the other modes prioritize power. Pure electric driving is more economical, while engine engagement better meets power performance requirements. Switching from the battery depletion mode to the battery maintenance mode allows the engine to engage earlier, improving vehicle power performance. Therefore, before determining whether the vehicle meets the first preset condition for switching to the battery maintenance mode while in battery depletion mode, it's necessary to ensure the driving mode is other than Eco.

[0198] The vehicle may include two mode switching methods, one of which is Figure 2 The method shown is a cyclical switching method that switches from battery depletion mode to battery maintenance mode, from battery maintenance mode to engine forced start mode, from engine forced start mode to battery maintenance mode, and from battery maintenance mode back to battery depletion mode. The switching process relies on four thresholds: CD-OFF, CD-ON, CS-H-OFF, and CS-H-ON. This is referred to as the first switching method.

[0199] Understandably, in the first switching method, the vehicle switches from the battery depletion mode to the battery maintenance mode. The battery maintenance mode has a higher switching threshold, and the vehicle is in a smaller range of battery depletion mode. This allows the vehicle to start the engine to participate in power output when the battery is high, thereby improving the vehicle's power performance.

[0200] Figure 3 This is another schematic diagram of mode switching provided in the embodiments of this application.

[0201] Another one is Figure 3 The method shown is a cyclical switching method that switches from battery depletion mode to engine forced start mode, from engine forced start mode to battery maintenance mode, and from battery maintenance mode back to battery depletion mode. The switching process relies on three thresholds: CD-OFF, CD-ON, and CS-H-ON, and is referred to as the second switching method.

[0202] like Figure 3As shown, when switching between the three thresholds CD-OFF, CD-ON, and CS-H-ON, the threshold value for CD-OFF, which is the smallest (-2%), is less than the threshold value for the vehicle to switch directly from the battery depletion mode to the engine forced start mode. Figure 2 The value of CD-OFF, that is... Figure 3 The range of the medium-power decrease mode is relatively large.

[0203] Understandably, in the second switching method, the vehicle directly switches from the battery depletion mode to the engine forced start mode. The switching threshold for the engine forced start mode is relatively small, and the vehicle is in a larger range of battery depletion mode. At this time, the vehicle relies on the power battery and tries to avoid starting the engine, resulting in higher vehicle fuel economy.

[0204] In some embodiments, the various driving modes included in the vehicle can be calibrated in advance, and the calibration results are shown in Table 7:

[0205] Table 7

[0206] A B C D E F G H I 0 0 0 0 0 1 0 0 0

[0207] In Table 7, A represents Standard mode, B represents Sport mode, C represents Snow mode, D represents Mud mode, E represents Sand mode, F represents Economy mode, G represents High-speed 4WD mode, H represents Low-speed 4WD mode, and I represents Light Snow mode. Table 7 assigns a value of 1 to Economy mode and 0 to the other driving modes.

[0208] When the vehicle queries Table 7 based on the current driving mode and the result is 0, or when it is determined that the target battery adjustment function is not activated, the vehicle uses the first switching method to switch between the three operating modes.

[0209] In some embodiments, when the vehicle queries Table 7 based on the current driving mode and the result is 1, and the target battery adjustment function is active, the vehicle uses the second switching method to switch between the three operating modes. The following embodiments provide a detailed explanation of this situation:

[0210] In one possible implementation, the method further includes: when the vehicle's target battery level adjustment function is activated and the vehicle's driving mode is economy mode, if the vehicle is currently in a battery level depletion mode, determining whether the vehicle meets the fifth preset condition for switching to the engine forced start mode; wherein, when the target battery level adjustment function is activated, the vehicle adjusts the target battery level based on the user's charging habits; and if it is determined that the vehicle meets the fifth preset condition, the vehicle is switched from the battery level depletion mode to the engine forced start mode.

[0211] As mentioned earlier, the second switching method allows the vehicle to rely more on the power battery, prioritizing pure electric power. When the target battery level adjustment function is active, the vehicle needs to prioritize pure electric power, and the vehicle also needs to prioritize pure electric power in economy mode. Therefore, when the target battery level adjustment function is active and the driving mode is economy mode, the vehicle will use the aforementioned second switching method to switch between operating modes to achieve pure electric power priority.

[0212] Specifically, the vehicle can also pre-set a fifth correspondence between the driving mode and ambient temperature parameters and the exit threshold of the battery depletion mode. The fifth correspondence is similar to the first correspondence, but the difference is that, under the same driving mode and ambient temperature, the exit threshold of the battery depletion mode in the fifth correspondence is lower than the exit threshold of the battery depletion mode in the first correspondence.

[0213] It is understandable that the exit threshold for the battery depletion mode in the fifth correspondence is lower than the exit threshold for the battery depletion mode in the first correspondence, which can increase the range in which the vehicle is in the battery depletion mode, thereby increasing the pure electric driving range of the vehicle.

[0214] When it is determined that the vehicle is using the second switching method to switch between operating modes and the vehicle is in a battery depletion mode, the vehicle's current fifth driving mode and fifth ambient temperature can also be obtained. Then, based on the fifth driving mode and fifth ambient temperature, the exit threshold for the battery depletion mode corresponding to the fifth driving mode and fifth ambient temperature is determined in the aforementioned fifth correspondence relationship. To distinguish this from the battery depletion mode exit threshold mentioned earlier, the battery depletion mode exit threshold determined based on the fifth correspondence relationship can be denoted as the second exit threshold for the battery depletion mode.

[0215] The second exit threshold of the power maintenance mode can also be the threshold of the remaining power. In this case, the current actual power of the power battery can be obtained to get the fifth actual power. The fifth actual power is compared with the second exit threshold of the power maintenance mode. If it is determined that the fifth actual power is less than the second exit threshold of the power maintenance mode, the vehicle is determined to meet the fifth preset condition.

[0216] As mentioned earlier, the power battery has a target charge level that needs to be maintained. The second exit threshold for the charge maintenance mode can also be a threshold representing the difference between the battery's current actual charge level and the target charge level. At this point, a fifth charge difference between the actual charge level and the target charge level can be calculated. This fifth charge difference is then compared with the second exit threshold of the charge maintenance mode to determine whether the vehicle meets the fifth preset condition. The target charge level can be determined based on the fifth driving mode, the fifth ambient temperature, and the vehicle's current fifth speed. Specifically, the vehicle is considered to meet the fifth preset condition when the fifth charge difference is less than the second exit threshold of the charge maintenance mode.

[0217] Understandably, when the target battery level adjustment function is active, the vehicle prioritizes pure electric driving, typically lowering the target battery level based on the user's driving and charging habits. With the remaining battery charge remaining constant, lowering the target battery level increases the difference between the remaining battery charge and the target charge. Therefore, after lowering the target battery level, the difference will only fall below the exit threshold for the battery level reduction mode when the remaining battery charge is even lower. At this point, the vehicle will switch from battery level reduction mode to engine forced start mode, further extending the range the vehicle remains in battery level reduction mode and increasing the pure electric driving range.

[0218] For example, such as Figure 3 The exit threshold CD-OFF for the battery depletion mode is -2%. Assuming the initial target battery level is 30%, if the difference between the remaining battery level and the initial target battery level is less than -2% when the initial target battery level is not lowered, the vehicle switches from battery depletion mode to engine forced start mode. Based on the formula "remaining battery level - initial target battery level 30% < -2%", it can be calculated that the vehicle switches from battery depletion mode to engine forced start mode when the remaining battery level is less than 28%. Assuming the user's charging frequency is determined to be higher than a preset frequency based on their charging habits, the initial target battery level is lowered from 30% to 20%, resulting in the current target battery level. At this point, if the remaining battery level - current target battery level 20% < -2%, the vehicle switches from battery depletion mode to engine forced start mode. This can be calculated that the vehicle switches from battery depletion mode to engine forced start mode when the remaining battery level is less than 18%. In summary, by lowering the target battery level, the vehicle will only switch from battery depletion mode to engine forced start mode when the remaining battery level is even lower, further extending the range of the vehicle in battery depletion mode and increasing the pure electric driving range.

[0219] like Figure 2 , Figure 3 As shown, in the second switching method, after the vehicle is in the engine forced start mode, the process of switching from the engine forced start mode to the battery maintenance mode and from the battery maintenance mode to the battery depletion mode is similar to the first switching method, and will not be described again here.

[0220] The above method, which flexibly switches between the target battery level adjustment function and the driving mode to select the operating mode, can further improve the flexibility of vehicle energy management. This ensures that the vehicle can prioritize pure electric driving even in special circumstances (e.g., when the target battery level adjustment function is active and the driving mode is in economy mode), increasing the pure electric range, meeting user driving needs, and improving the user's driving experience.

[0221] In summary, this application establishes a logic for cyclical switching of operating modes through four switching thresholds: switching from battery depletion mode to battery maintenance mode, switching from battery maintenance mode to engine forced start mode, switching from engine forced start mode to battery maintenance mode, and switching from battery maintenance mode back to battery depletion mode. This logic facilitates earlier engine start, improving vehicle power performance, and effectively utilizes the battery maintenance mode's power reserve capability to maintain the battery's charge within a certain range, preventing insufficient power due to low battery charge. When the vehicle is in engine forced start mode, a higher charging power is used to charge the battery, ensuring it receives more power replenishment in a shorter time, rapidly restoring its charge and preventing deep discharge. The four switching thresholds can be dynamically adjusted based on different driving conditions (such as driving mode and ambient temperature), ensuring optimal decision-making under various circumstances, improving the accuracy of mode switching, and enabling more precise control over battery power usage.

[0222] Figure 4 This is a schematic diagram of a device for controlling a vehicle provided in an embodiment of this application.

[0223] For example, such as Figure 4 As shown, the device 400 includes:

[0224] The first judgment module 401 is used to determine whether the vehicle meets the first preset condition for switching to the battery maintenance mode when the vehicle is in the battery depletion mode; wherein, in the battery depletion mode, the vehicle starts the engine based on torque demand, and in the battery maintenance mode, the vehicle starts the engine based on power demand.

[0225] The first switching module 402 is used to switch the vehicle from the power depletion mode to the power maintenance mode when it is determined that the vehicle meets the first preset conditions.

[0226] The second judgment module 403 is used to determine whether the vehicle meets the second preset condition for switching to the engine forced start mode when the vehicle is in the battery maintenance mode; wherein, in the engine forced start mode, the vehicle forcibly starts the engine.

[0227] The second switching module 404 is used to switch the vehicle from the battery maintenance mode to the engine forced start mode when it is determined that the vehicle meets the second preset conditions.

[0228] In one possible implementation, the first judgment module 401 is specifically used to: when the vehicle is in a power depletion mode, obtain the current first actual power level of the vehicle's power battery; determine the exit threshold of the power depletion mode based on the current first driving mode and the first ambient temperature of the vehicle; and determine whether the vehicle meets the first preset condition based on the first actual power level and the exit threshold of the power depletion mode.

[0229] In one possible implementation, the first judgment module 401 is specifically used to: determine the first target charge of the power battery based on the first driving mode, the first ambient temperature and the vehicle's current first speed; subtract the first target charge from the first actual charge to obtain a first charge difference; and determine that the vehicle meets the first preset condition if the first charge difference is less than the exit threshold of the charge reduction mode.

[0230] In one possible implementation, the second judgment module 403 is specifically used to determine whether the vehicle meets the second preset condition for switching to the engine forced start mode when the vehicle is in the battery maintenance mode. This includes: obtaining the current second actual charge of the vehicle's power battery when the vehicle is in the battery maintenance mode; determining the exit threshold of the battery maintenance mode based on the current second driving mode and second ambient temperature of the vehicle; and determining whether the vehicle meets the second preset condition based on the second actual charge and the exit threshold of the battery maintenance mode.

[0231] In one possible implementation, the second judgment module 403 is specifically used to: determine the second target battery level based on the second driving mode, the second ambient temperature, and the vehicle's current second speed; subtract the second target battery level from the second actual battery level to obtain the second battery level difference; and determine that the vehicle meets the second preset condition if the second battery level difference is less than the exit threshold of the battery maintenance mode.

[0232] In one possible implementation, the device 400 further includes: a third switching module, configured to determine an entry threshold for the battery maintenance mode based on the vehicle's current third driving mode and third ambient temperature when the vehicle is in the engine forced start mode; determine whether the vehicle meets the third preset condition for switching to the battery maintenance mode based on the entry threshold for the battery maintenance mode; and switch the vehicle from the engine forced start mode to the battery maintenance mode if the vehicle meets the third preset condition.

[0233] In one possible implementation, the device 400 further includes: a fourth switching module, configured to determine an entry threshold for a battery depletion mode based on the vehicle's current fourth driving mode and fourth ambient temperature when the vehicle is in a battery maintenance mode; determine whether the vehicle meets the fourth preset condition for switching to the battery depletion mode based on the entry threshold for the battery depletion mode; and switch the vehicle from the battery maintenance mode to the battery depletion mode if the vehicle meets the fourth preset condition.

[0234] In one possible implementation, the device 400 further includes a charging module for charging the power battery based on a target charging power greater than a preset charging power threshold when the vehicle is in engine forced start mode.

[0235] In one possible implementation, the device 400 further includes: a determining module, configured to determine that the vehicle's target charge adjustment function is inactive before determining whether the vehicle meets the first preset condition for switching to the charge maintenance mode when the vehicle is in a charge depletion mode, wherein when the target charge adjustment function is activated, the vehicle adjusts the target charge of the power battery based on the user's charging habits; or, determine that the vehicle's driving mode is a mode other than the economy mode.

[0236] In one possible implementation, the device further includes: a fifth switching module, used to determine whether the vehicle meets the fifth preset condition for switching to the engine forced start mode if the vehicle is currently in a battery depletion mode when the vehicle's target battery adjustment function is activated and the vehicle's driving mode is economy mode; wherein, when the target battery adjustment function is activated, the vehicle adjusts the target battery charge based on the user's charging habits; and when it is determined that the vehicle meets the fifth preset condition, the vehicle is switched from the battery depletion mode to the engine forced start mode.

[0237] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0238] For example, such as Figure 5 As shown, the vehicle 500 includes a memory 501 and a processor 502. The memory 501 stores executable program code 5011, and the processor 502 is used to call and execute the executable program code 5011 to perform a method for controlling the vehicle.

[0239] Furthermore, embodiments of this application also protect an apparatus that may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a method for controlling a vehicle provided in embodiments of this application.

[0240] This embodiment can divide the device into functional modules based on the above method example. For example, each module can correspond to a separate function, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0241] When each functional module is divided according to its corresponding function, the device may further include a first judgment module, a first switching module, a second judgment module, and a second switching module. It should be noted that all relevant content regarding the steps involved in the above method embodiments can be referenced from the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0242] It should be understood that the device provided in this embodiment is used to execute the above-described method for controlling a vehicle, and therefore can achieve the same effect as the above-described implementation method.

[0243] When using an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module can be used to control and manage the vehicle's movements. The storage module can be used to support the vehicle in executing relevant program code.

[0244] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits shown in conjunction with the disclosure of this application. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0245] In addition, the device provided in the embodiments of this application may specifically be a chip, component or module. The chip may include a connected processor and a memory. The memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute a method for controlling a vehicle provided in the above embodiments.

[0246] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement a method for controlling a vehicle provided in the above embodiment.

[0247] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement a method for controlling a vehicle provided in the above embodiment.

[0248] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0249] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0250] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0251] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for controlling a vehicle, characterized in that, The method includes: When the vehicle is in a battery depletion mode, it is determined whether the vehicle meets the first preset condition for switching to a battery maintenance mode; wherein, in the battery depletion mode, the vehicle starts the engine based on torque demand, and in the battery maintenance mode, the vehicle starts the engine based on power demand. If the vehicle meets the first preset condition, the vehicle will be switched from the battery depletion mode to the battery maintenance mode. When the vehicle is in battery maintenance mode, it is determined whether the vehicle meets the second preset condition for switching to engine forced start mode; wherein, in engine forced start mode, the vehicle forcibly starts the engine; If the vehicle meets the second preset condition, the vehicle is switched from the battery maintenance mode to the engine forced start mode.

2. The method according to claim 1, characterized in that, When the vehicle is in a battery depletion mode, determining whether the vehicle meets the first preset condition for switching to a battery sustainment mode includes: When the vehicle is in a power depletion mode, obtain the first actual power level of the vehicle's power battery. Based on the vehicle's current first driving mode and first ambient temperature, determine the exit threshold for the battery depletion mode; Based on the first actual battery level and the exit threshold of the battery depletion mode, it is determined whether the vehicle meets the first preset condition.

3. The method according to claim 2, characterized in that, The step of determining whether the vehicle meets the first preset condition based on the first actual battery level and the exit threshold of the battery depletion mode includes: Based on the first driving mode, the first ambient temperature, and the vehicle's current first speed, the first target charge of the power battery is determined; Subtract the first target power from the first actual power to obtain the first power difference; If the first battery difference is less than the exit threshold of the battery depletion mode, the vehicle is determined to meet the first preset condition.

4. The method according to any one of claims 1 to 3, characterized in that, When the vehicle is in battery maintenance mode, determining whether the vehicle meets the second preset condition for switching to engine forced start mode includes: When the vehicle is in power maintenance mode, obtain the current second actual power level of the vehicle's power battery; Based on the vehicle's current second driving mode and second ambient temperature, determine the exit threshold for the battery maintenance mode; Based on the second actual battery level and the exit threshold of the battery maintenance mode, it is determined whether the vehicle meets the second preset condition.

5. The method according to claim 4, characterized in that, The step of determining whether the vehicle meets the second preset condition based on the second actual battery level and the exit threshold of the battery maintenance mode includes: The second target battery level is determined based on the second driving mode, the second ambient temperature, and the vehicle's current second speed; Subtract the second target power from the second actual power to obtain the second power difference; If the second battery difference is less than the exit threshold of the battery maintenance mode, it is determined that the vehicle meets the second preset condition.

6. The method according to claim 1, characterized in that, The method further includes: When the vehicle is in engine forced start mode, the entry threshold for the battery maintenance mode is determined based on the vehicle's current third driving mode and third ambient temperature. Based on the entry threshold of the battery maintenance mode, it is determined whether the vehicle meets the third preset condition for switching to the battery maintenance mode. If the vehicle meets the third preset condition, the vehicle is switched from the engine forced start mode to the battery maintenance mode.

7. The method according to claim 1 or 6, characterized in that, The method further includes: When the vehicle is in battery maintenance mode, the threshold for entering the battery depletion mode is determined based on the vehicle's current fourth driving mode and fourth ambient temperature. Based on the entry threshold of the battery depletion mode, determine whether the vehicle meets the fourth preset condition for switching to the battery depletion mode; If the vehicle meets the fourth preset condition, the vehicle is switched from the battery maintenance mode to the battery depletion mode.

8. The method according to any one of claims 1 to 3, characterized in that, The method further includes: When the vehicle is in engine forced start mode, the power battery is charged based on a target charging power, which is greater than a preset charging power threshold.

9. The method according to any one of claims 1 to 3, characterized in that, Before determining whether the vehicle meets the first preset condition for switching to the battery maintenance mode when the vehicle is in a battery depletion mode, the method further includes: The vehicle's target battery level adjustment function is determined to be inactive. When the target battery level adjustment function is active, the vehicle adjusts the target battery level based on the user's charging habits; or... The driving mode of the vehicle is determined to be a mode other than the economy mode.

10. The method according to any one of claims 1 to 3, characterized in that, The method further includes: When the target battery level adjustment function of the vehicle is activated and the driving mode of the vehicle is economy mode, if the vehicle is currently in battery depletion mode, it is determined whether the vehicle meets the fifth preset condition for switching to engine forced start mode; wherein, when the target battery level adjustment function is activated, the vehicle adjusts the target battery level of the power battery based on the user's charging habits. If the vehicle meets the fifth preset condition, the vehicle is switched from the battery depletion mode to the engine forced start mode.

11. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1 to 10.

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