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 being applied to the technical field of vehicles and comprising the following steps: activating a rescue mode of the vehicle when preset activation conditions are met, and determining a type of the rescue mode; determining whether a speed control mode of a motor of the vehicle is activated when the rescue mode is in an activated state and the type of the rescue mode is a motor speed control type; determining a target speed of the motor when the speed control mode of the motor is in the activated state, and controlling a torque of the motor based on the target speed; determining an anti-skid torque value based on current motor operating parameters during the control of the torque of the motor based on the target speed, and limiting the torque of the motor based on the anti-skid torque value. The method can effectively prevent the vehicle from skidding in the rescue mode, ensure that the vehicle outputs as large a torque as possible to perform rescue, and improve the reliability of the rescue mode.

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] During driving, a vehicle may malfunction or encounter an accident. In such cases, the vehicle needs to seek assistance, such as calling a tow truck when it breaks down or needing to be tractioned to get out of trouble when it is stuck.

[0003] During the rescue operation, rescue vehicles may encounter problems such as slippage or insufficient power, which increases the difficulty of the rescue and may even affect the safety of the rescue vehicle. Summary of the Invention

[0004] This application provides a method for controlling a vehicle, a vehicle, and a storage medium. The method can reduce vehicle slippage in rescue mode while ensuring that the vehicle outputs the maximum torque possible for rescue, thereby improving the reliability of the rescue mode.

[0005] In a first aspect, a method for controlling a vehicle is provided, the method comprising: activating a rescue mode of the vehicle when a preset activation condition is met, and determining the type of the rescue mode; when the rescue mode is activated and the type of the rescue mode is motor speed control, determining whether to activate the motor speed control mode of the vehicle; when the motor speed control mode is activated, determining the target speed of the motor, and controlling the torque of the motor based on the target speed; during the process of controlling the torque of the motor based on the target speed, determining an anti-slip torque value based on the current motor operating parameters, and limiting the torque of the motor based on the anti-slip torque value.

[0006] In the above technical solution, under the condition of activating the rescue mode, activating the rescue mode facilitates the vehicle to begin rescue operations, enabling the vehicle to assist other vehicles in getting out of trouble while in rescue mode. When the vehicle's rescue mode is activated and it is of the motor speed control type, by activating the motor speed control mode and controlling the motor torque based on the target speed, it can be ensured that the motor output torque in rescue mode can provide sufficient traction, guaranteeing rescue efficiency. During the process of controlling the motor torque based on the target speed, determining the anti-slip torque value based on the current motor operating parameters and limiting the motor torque based on this value can effectively reduce the risk of vehicle slippage, ensuring the safety of the rescue process and avoiding secondary accidents caused by wheel slippage during rescue. Limiting the motor torque based on the anti-slip torque value also ensures that after the vehicle activates the rescue mode, it can output as much torque as possible without slippage, guaranteeing the reliability of the rescue mode.

[0007] In conjunction with the first aspect, in some possible implementations, determining the anti-slip torque value based on the current motor operating parameters includes: obtaining the target road surface adhesion level of the road surface where the vehicle is currently located; determining the correspondence between the target road surface adhesion level and the anti-slip torque value; the correspondence is used to describe the correspondence between the motor operating parameters and the anti-slip torque value under the target road surface adhesion level; and determining the anti-slip torque value corresponding to the current motor operating parameters based on the correspondence.

[0008] Combining the first aspect and the above implementation methods, in some possible implementation methods, obtaining the target road surface adhesion level of the road surface where the vehicle is currently located includes: obtaining the current state parameters of the vehicle and determining whether the current state parameters meet the entry conditions for road surface adhesion level self-learning; if the entry conditions for road surface adhesion level self-learning are met, road surface adhesion level self-learning is performed based on the current speed of the motor and the maximum speed of the motor within a preset historical time period to determine the target road surface adhesion level of the road surface where the vehicle is located.

[0009] In the above technical solution, by setting a road surface adhesion level self-learning function, under the condition that the entry conditions for road surface adhesion level self-learning are met, the road surface adhesion level can be obtained by self-learning based on the current speed of the motor and the maximum speed within a preset historical time period. This simplifies the method of determining the road surface adhesion level. Even if the vehicle cannot estimate the road surface adhesion coefficient, the target road surface adhesion level can be determined through the above self-learning method, which improves the efficiency of determining the road surface adhesion level. It does not rely on multiple sensor data to calculate the adhesion coefficient, thus reducing costs.

[0010] Combining the first aspect and the above implementation methods, in some possible implementation methods, road surface adhesion level self-learning is performed based on the current motor speed to determine the target road surface adhesion level of the road where the vehicle is located. This includes: determining the initial road surface adhesion level before performing this road surface adhesion level self-learning; wherein, when the rescue mode is activated and road surface adhesion level self-learning is not performed, the initial road surface adhesion level is the default level; adjusting the initial road surface adhesion level based on the current motor speed and the maximum motor speed within a preset historical time period to obtain the corrected road surface adhesion level after this road surface adhesion level self-learning; after obtaining the corrected road surface adhesion level, if the entry conditions for road surface adhesion level self-learning are still met, the corrected road surface adhesion level is used as the initial road surface adhesion level before the next road surface adhesion level self-learning, and the initial road surface adhesion level is adjusted based on the current motor speed and the maximum motor speed within a preset historical time period to obtain the corrected road surface adhesion level after the next road surface adhesion level self-learning, until the exit conditions for road surface adhesion level self-learning are met; and determining the corrected road surface adhesion level after the last road surface adhesion level self-learning as the target road surface adhesion level of the road where the vehicle is located.

[0011] In the above technical solution, the initial road surface adhesion level is adjusted by the current speed of the motor and the maximum speed within a preset historical time. The above steps are repeated to achieve self-learning, which can quickly determine the target road surface adhesion level. Moreover, the motor speed can intuitively reflect the vehicle's slippage, thus improving the accuracy of determining the road surface adhesion level.

[0012] Combining the first aspect and the above implementation methods, in some possible implementation methods, the current state parameters include: dragging state, throttle opening, and motor torque. Determining whether the current state parameters meet the entry conditions for road adhesion level self-learning includes: determining that the vehicle meets the entry conditions for road adhesion level self-learning when the dragging state is active, the throttle opening is greater than the first preset opening, and the absolute value of the motor torque is greater than the target torque; wherein, the dragging state is activated when the rescue mode is active, the rescue mode type is motor speed control type, and the absolute value of the motor torque is greater than the first preset torque.

[0013] Combining the first aspect and the above implementation methods, in some possible implementation methods, obtaining the target road surface adhesion level of the road surface where the vehicle is currently located includes: obtaining the current state parameters of the vehicle, and determining whether the current state parameters meet the activation conditions for self-learning for a preset road surface, wherein the preset road surface is a road surface with an adhesion coefficient less than a preset coefficient; if the activation conditions for self-learning for a preset road surface are met, determining the target road surface adhesion level as the preset road surface level.

[0014] In the above technical solution, considering the special characteristics of the adhesion level of the preset road surface with an adhesion coefficient less than the preset coefficient, a special self-learning function for the preset road surface is set up. When the current state parameters of the vehicle meet the activation conditions for the self-learning function for the preset road surface, the self-learning function for the preset road surface is activated. Through the self-learning function for the preset road surface, the adhesion level of the target road surface can be quickly determined to be the preset road surface level, which helps the vehicle to adopt a control strategy suitable for driving on the preset road surface in a targeted manner, effectively improving the success rate of preventing vehicle skidding and ensuring the smooth progress of the rescue process.

[0015] Combining the first aspect and the above implementation methods, in some possible implementation methods, the current state parameters include: throttle opening, current motor speed and current torque, and current road surface adhesion level. It is determined whether the current state parameters meet the activation conditions for self-learning for the preset road surface, including: if the throttle opening is greater than the second preset opening, the current speed is greater than the first preset speed, the current torque is within the preset torque range, and the current road surface adhesion level is less than the preset level, then it is determined that the activation conditions for self-learning for the preset road surface are met.

[0016] Combining the first aspect and the above implementation methods, in some possible implementation methods, determining whether to activate the vehicle's motor speed control mode includes: obtaining the vehicle's gear lever position, brake pedal travel, drive mode, transmission gear, current motor torque, and current speed; activating the motor speed control mode when the gear lever position is any one of D, R, or M, the brake pedal travel is less than a preset travel, the drive mode is pure electric drive mode, the transmission gear is a preset gear, the absolute value of the current torque is less than a second preset torque, and the current speed is less than a second preset speed.

[0017] In the above technical solution, the vehicle's gear lever position, brake pedal travel, drive mode, transmission gear position, current motor torque, and current speed are used to determine whether the vehicle meets the conditions for activating the motor speed control mode. If the conditions for activating the motor speed control mode are met, the motor speed control mode is activated. This achieves comprehensive judgment of multiple vehicle operating parameters when activating the speed control mode, ensuring that no conflict occurs when activating the motor speed control mode, and improving the vehicle's driving experience and safety.

[0018] Combining the first aspect and the above implementation methods, in some possible implementation methods, determining the target speed of the motor includes: obtaining the throttle opening of the vehicle; determining the target vehicle speed based on the throttle opening; and calculating the target speed based on the target vehicle speed, the vehicle's tire radius, and a preset speed ratio.

[0019] In the above technical solution, the throttle opening directly reflects the driver's needs. The throttle opening determines the driver's desired target vehicle speed in rescue mode, and based on this target speed, the target motor speed is determined to control the motor. This allows the vehicle to dynamically control the motor according to the driver's needs, ensuring the vehicle reaches the desired target speed and accurately reflects the driver's operational intentions. Through this design, in rescue mode, the driver only needs to press the accelerator pedal to control the vehicle speed, eliminating the need for manual adjustment of other parameters, simplifying the operation process and improving the efficiency of rescue mode.

[0020] In conjunction with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the anti-slip torque value includes a maximum anti-slip torque value or a minimum anti-slip torque value. Limiting the motor torque based on the anti-slip torque value includes: determining a maximum torque limit or a minimum torque limit for the motor; determining the minimum value between the maximum torque limit and the maximum anti-slip torque value as a first torque limit value; or determining the maximum value between the minimum anti-slip torque value and the minimum torque limit as a second torque limit value; and limiting the motor torque based on the first torque limit value or the second torque limit value.

[0021] In the above technical solution, the output torque of the motor is limited by taking the smaller of the maximum anti-slip torque value and the maximum torque limit of the motor itself; or, the output torque of the motor is limited by taking the larger of the minimum torque limit and the minimum anti-slip torque value of the motor itself. This achieves the limitation of the motor's own performance parameters on the motor's output torque when limiting the motor's output torque, ensuring that the output torque of the motor can reduce vehicle slippage while ensuring the safety of motor operation.

[0022] In combination with the first aspect and the above implementation methods, in some possible implementation methods, determining the maximum torque limit or minimum torque limit of the motor includes: determining the discharge current limit of the motor based on the peak discharge power, maximum discharge current, motor voltage, high-voltage accessory current consumption, and reserved discharge current of the battery management system, and determining the maximum torque limit based on the discharge current limit; or, determining the charging current limit of the motor based on the peak charging power, maximum charging current, motor voltage, high-voltage accessory current consumption, and reserved charging current of the battery management system, and determining the minimum torque limit based on the charging current limit.

[0023] Combining the first aspect and the above implementation methods, in some possible implementation methods, the type of rescue mode is determined by: obtaining the availability status of the vehicle's rescue mode and the battery level; if the availability status is available and the battery level is greater than the preset level, the type of rescue mode is determined to be motor speed control type.

[0024] In the above technical solution, when the availability status of the rescue mode is available and the battery power is greater than the preset power, it can be determined that the vehicle's battery power can guarantee sufficient range. At this time, the rescue mode type is determined to be motor speed control type. Under the motor speed control type, rescue operations in the rescue mode can be realized through precise control of the motor, ensuring the vehicle's range while improving the accuracy of rescue operations in the rescue mode.

[0025] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, the availability state of the rescue mode includes: an available state, an inaccessible state, and an exitable state; before determining the type of the rescue mode as motor speed control type when the availability state is available and the battery charge is greater than a preset charge, the method further includes: when the availability state of the rescue mode is inaccessible, if the vehicle meets a first preset condition, setting the availability state of the rescue mode from inaccessible to available; wherein, in the inaccessible state, the vehicle's power system does not have a preset fault; when the availability state of the rescue mode is exitable, if the vehicle meets a second preset condition, setting the availability state of the rescue mode from exitable to available; wherein, in the exitable state, the vehicle's rescue mode is active and the vehicle speed is greater than a preset speed, or, in the exitable state, the vehicle's rescue mode is active and the vehicle's throttle opening is greater than a third preset opening.

[0026] In the above technical solution, by setting multiple availability states for the rescue mode, the accuracy and security of the rescue mode activation control are improved. For example, setting a non-exit state ensures that if an accidental operation causes the rescue mode to exit, thus interrupting the rescue operation, the problem will be prevented. Furthermore, the switching between multiple availability states improves the flexibility of activating and exiting the rescue mode.

[0027] Combining the first aspect and the above implementation methods, in some possible implementation methods, the first preset condition includes: the vehicle's driving mode is 4L mode, and the vehicle speed is less than the preset speed; the second preset condition includes: the vehicle speed is less than the preset speed and the vehicle's throttle opening is less than the fourth preset opening; wherein, the third preset opening is greater than the fourth preset opening.

[0028] In summary, this application sets multiple availability states for the rescue mode, improving the accuracy, safety, and flexibility of rescue mode activation control. When the rescue mode's availability state is "available" and the battery charge is greater than the preset charge level, the rescue mode type is determined to be motor speed control, ensuring vehicle range while improving the accuracy of rescue operations in rescue mode. After the rescue mode is activated, by activating the motor speed control mode and controlling the motor torque based on the target speed, it can be ensured that the motor output torque in rescue mode provides sufficient traction, guaranteeing rescue efficiency. By setting a road adhesion level self-learning function, the road adhesion level can be obtained by self-learning based on the motor's current speed and the maximum speed within a preset historical time period, simplifying the determination method of road adhesion level, improving the efficiency of road adhesion level determination, and reducing costs by not relying on the road adhesion coefficient. Considering the special nature of the preset road adhesion level, a dedicated self-learning function for the preset road is set. When the vehicle's current state parameters meet the activation conditions for the self-learning function for the preset road, the self-learning function for the preset road is activated, determining the target road adhesion level as the preset road level, further improving the efficiency of road adhesion level determination. By determining the anti-skid torque value based on the road surface adhesion level and limiting the motor torque based on this value, the risk of vehicle skidding can be effectively reduced, ensuring the safety of the rescue process.

[0029] Secondly, a device for controlling a vehicle is provided, the device comprising:

[0030] The first activation module is used to activate the vehicle's rescue mode and determine the type of rescue mode when preset activation conditions are met.

[0031] The second activation module is used to determine whether to activate the vehicle's motor speed control mode when the rescue mode is active and the rescue mode type is motor speed control.

[0032] The first control module is used to determine the target speed of the motor when the motor speed control mode is active, and to control the torque of the motor based on the target speed.

[0033] The second control module is used to determine the anti-slip torque value based on the current motor operating parameters during the process of controlling the motor torque based on the target speed, and to limit the motor torque based on the anti-slip torque value.

[0034] 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 of the first aspect or any possible implementation thereof.

[0035] 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.

[0036] 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

[0037] Figure 1 This is a schematic flowchart of a method for controlling a vehicle provided in an embodiment of this application.

[0038] Figure 2 This is a schematic diagram of a rescue mode pop-up provided in an embodiment of this application.

[0039] Figure 3 This is a schematic diagram of an availability state transition provided in an embodiment of this application.

[0040] Figure 4 This is a schematic diagram of a device for controlling a vehicle provided in an embodiment of this application.

[0041] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] During driving, a vehicle may malfunction or encounter an accident. In such cases, the vehicle needs to seek assistance, such as calling a tow truck when it breaks down or needing to be tractioned to get out of trouble when it is stuck.

[0045] During the rescue operation, rescue vehicles may experience slippage or insufficient power, which increases the difficulty of the rescue and may even affect the safety of the rescue vehicle.

[0046] Based on this, this application provides a method for controlling a vehicle, which can prevent the vehicle from slipping while outputting greater power, thereby improving the safety of the rescue vehicle.

[0047] Figure 1 This is a schematic flowchart illustrating a method for controlling a vehicle according to an embodiment of this application. It is applied to a vehicle, specifically to the vehicle control unit (VCU).

[0048] For example, such as Figure 1 As shown, the method 100 includes:

[0049] Step 101: If the preset activation conditions are met, activate the vehicle's rescue mode and determine the type of rescue mode;

[0050] Step 102: If the rescue mode is active and the rescue mode type is motor speed control, determine whether to activate the vehicle's motor speed control mode.

[0051] Step 103: When the motor speed control mode is active, determine the target speed of the motor and control the motor torque based on the target speed.

[0052] Step 104: In the process of controlling the motor torque based on the target speed, the anti-slip torque value is determined based on the current motor operating parameters, and the motor torque is limited based on the anti-slip torque value.

[0053] exist Figure 1 In the illustrated embodiment, under the condition of activating the rescue mode, the rescue mode is activated, facilitating the vehicle to begin rescue operations and enabling the vehicle to assist other vehicles in getting out of trouble. When the vehicle's rescue mode is activated and it is of the motor speed control type, by activating the motor speed control mode and controlling the motor torque based on the target speed, it can be ensured that the torque output by the motor in the rescue mode provides sufficient traction, guaranteeing rescue efficiency. During the process of controlling the motor torque based on the target speed, an anti-slip torque value is determined based on the current motor operating parameters, and the motor torque is limited based on this value. This effectively reduces the risk of vehicle slippage, ensures the safety of the rescue process, and avoids secondary accidents caused by wheel slippage during the rescue. Limiting the motor torque based on the anti-slip torque value also ensures that after the vehicle activates the rescue mode, it can output as much torque as possible without slippage, guaranteeing the reliability of the rescue mode.

[0054] The following is about Figure 1 The specific implementation methods of each step in the illustrated embodiments are described in detail below:

[0055] In step 101, the vehicle architecture can specifically be a non-decoupled four-wheel drive architecture, which includes: an engine, a drive motor, a clutch, a torque converter, and a transmission. The engine is connected to the drive motor via the clutch, and the drive motor is connected to the transmission via the torque converter. The power from the drive motor and / or the engine is output to the front and rear wheels via a driveshaft. "Non-decoupled" means that there is a relatively tight mechanical connection or power transmission relationship between the various drive wheels in the four-wheel drive system, and the vehicle cannot achieve completely independent control of the power output to each wheel. For example, the power from the drive motor cannot be independently output to the front or rear wheels of the vehicle.

[0056] The aforementioned vehicles with non-decoupled four-wheel drive architecture include multiple drive modes such as pure electric drive mode and hybrid mode.

[0057] Driving mode refers to the operating mode and collaborative logic of various subsystems in a vehicle under different operating conditions. Driving mode is typically selected automatically by the vehicle's control unit (such as the power management system and energy management system) based on current driving conditions and vehicle status to ensure optimal vehicle operating efficiency and safety. Driving mode focuses more on the coordinated operation of the vehicle's internal systems.

[0058] In pure electric drive mode, the clutch is open, the torque converter is locked, and the drive motor is running, supplying power to the front and rear wheels of the vehicle via the transmission. Pure electric drive mode specifically includes idle pure electric drive mode and non-idle pure electric drive mode. In idle pure electric drive mode, the engine maintains idle speed; in non-idle pure electric drive mode, the engine is shut down.

[0059] In hybrid mode, the clutch is engaged, the engine is running, the torque converter is engaged, and the drive motor is running. The drive motor and the engine work together to output power to the front and rear wheels of the vehicle through the transmission.

[0060] Activating rescue mode typically requires meeting certain preset activation conditions. When these conditions are met, the vehicle activates rescue mode. These preset conditions indicate whether the vehicle has rescue capabilities and whether there is a current need for rescue. If the vehicle currently has rescue capabilities and there is a current need for rescue, then the preset activation conditions for rescue mode are met. If the vehicle currently does not have rescue capabilities or there is no current need for rescue, then the preset activation conditions for rescue mode are not met.

[0061] The preset activation conditions may specifically include: the vehicle receiving a request to activate the rescue mode function, and the current availability status of the vehicle's rescue mode being available.

[0062] As one implementation, the vehicle includes an in-vehicle entertainment multimedia host (HUT). When the driver determines that he needs to help other vehicles get out of trouble or that his own vehicle is stuck and needs to get out of trouble, he sends a request to the vehicle to activate the rescue mode function through the HUT interface.

[0063] Specifically, the HUT interface may include buttons related to the rescue mode function. When the user clicks a button related to the rescue mode function, a pop-up window will be displayed on the interface to confirm whether to activate the rescue mode.

[0064] Figure 2 This is a schematic diagram of a rescue mode pop-up provided in an embodiment of this application.

[0065] For example, such as Figure 2 As shown, the HUT interface 200 displays a pop-up window 201, which includes a prompt message asking "Activate rescue mode?", as well as a confirmation button 2011 and a cancel button 2012. When the HUT detects that the driver clicks the confirmation button 2011, the HUT sends a rescue mode activation request to the vehicle's VCU, and the vehicle receives the request. When the HUT detects that the driver clicks the cancel button 2012, it determines that rescue mode does not need to be activated at present and exits the rescue mode activation process.

[0066] The availability status of the rescue mode indicates the current availability of the vehicle's rescue mode. An availability status of "available" means that the rescue mode for this vehicle can be activated and used. When a rescue mode activation request is received, and the availability status of the rescue mode is determined to be "available," the vehicle's rescue mode is activated.

[0067] In some embodiments, the preset activation condition also includes: the ignition switch being in the "on" state, i.e., the vehicle is powered on. Typically, the HUT can detect when the driver's operation is performed, indicating that the vehicle is powered on, i.e., the ignition switch is in the "on" state.

[0068] In the aforementioned preset activation conditions, an availability status of "available" and an ignition switch status of "on" indicate that the vehicle currently possesses rescue capabilities. Receiving an activation request for rescue mode indicates that the vehicle currently has a rescue need. When it is determined that the vehicle possesses rescue capabilities and has a rescue need, the vehicle's rescue mode can be activated.

[0069] When the vehicle is a non-decoupled four-wheel drive vehicle as described above, the vehicle's rescue mode includes multiple types. After determining that the rescue mode is activated, it is also necessary to determine the type of the activated rescue mode.

[0070] In one possible implementation, determining the type of rescue mode includes: obtaining the availability status of the vehicle's rescue mode and the battery level; if the availability status is available and the battery level is greater than a preset level, determining the type of rescue mode as motor speed control type.

[0071] The vehicle also includes a power battery that supplies electrical energy to the drive motor, enabling the drive motor to operate and output power. The battery's charge level typically affects the vehicle's driving mode. For example, when the battery charge is high, the vehicle can operate in pure electric mode; when the battery charge is low, pure electric mode may not meet the range requirements, and the vehicle usually needs to operate in hybrid mode.

[0072] When a vehicle activates its emergency rescue mode and operates in different driving modes, the control mechanisms under those emergency rescue modes differ. Therefore, the type of emergency rescue mode can be pre-defined based on the battery level. For example, the emergency rescue mode when the battery level is greater than a preset level can be designated as type 1. In some embodiments, the preset level is designated as the first preset level, and the emergency rescue mode when the battery level is less than the second preset level is designated as type 2. The purpose of designating the second preset level as less than the first preset level is to establish a hysteresis interval and avoid frequent switching between emergency rescue mode types.

[0073] The first and second preset power values ​​can be pre-calibrated based on the ambient temperature. The calibration rules could be, for example, that the higher the ambient temperature, the lower the values ​​of the first and second preset power values; conversely, the lower the ambient temperature, the higher the values ​​of the first and second preset power values; and that the second preset power value is less than the first preset power value at the same ambient temperature.

[0074] When the first and second preset power supplies are calibrated in advance based on the ambient temperature, the current ambient temperature can be obtained to determine the corresponding first and second preset power supplies. For example, if the current ambient temperature is 25℃, the first preset power supply calibrated for 25℃ could be 15%, and the second preset power supply calibrated for 25℃ could be 12%.

[0075] It is understandable that when the battery level is higher than the preset level, the vehicle can operate in pure electric drive mode. In this mode, the component driving the vehicle is the drive motor. Therefore, the control in rescue mode type 1 is usually based on the control of the drive motor torque according to the motor speed. In some embodiments, type 1 may also be referred to as motor speed control type.

[0076] When the battery level is lower than the second preset battery level, the vehicle needs to operate in hybrid mode. Therefore, the control in rescue mode type 2 is usually based on the control of engine torque according to vehicle speed. In some embodiments, type 2 can also be referred to as vehicle speed closed-loop control type.

[0077] The availability of rescue mode also affects the rescue mode type. Understandably, a vehicle can only activate rescue mode if it is available; therefore, the rescue mode type only needs to be determined when rescue mode is available.

[0078] Therefore, while activating the rescue mode, the availability status of the rescue mode and the remaining battery power can be obtained. Based on the availability status and battery power, it can be determined whether the rescue mode type is motor speed control. Specifically, if the availability status is available and the battery power is greater than the preset power level, the rescue mode type is determined to be motor speed control.

[0079] In some embodiments, after the rescue mode is activated, if the vehicle's current gear lever is in a forward gear, the VCU needs to correct the transmission's target gear to a calibrable gear. The calibrable gear is typically a low gear in the rear axle transmission; for example, if the transmission includes 1st, 2nd, 3rd, and 4th gears, the calibrable gear could be 1st or 2nd to ensure the vehicle outputs maximum torque. The gear correction is canceled after the rescue mode is exited. After the rescue mode is activated, the VCU also disables pedal torque; this is canceled after the rescue mode is exited and the accelerator is released. Pedal torque refers to the logic for determining the vehicle's target output torque based on pedal opening during normal driving without the rescue mode activated.

[0080] Understandably, in rescue scenarios, a calibrable gear in the transmission typically provides the maximum torque output, facilitating towing and dragging operations at low speeds and under high resistance, thus aiding rescue efforts. Therefore, the transmission's target gear can be adjusted to a calibrable gear to facilitate rescue work. Furthermore, since the vehicle itself has existing gear selection logic, adjusting the transmission's target gear to a calibrable gear avoids switching the target gear based on existing selection logic, which could result in a different target gear and compromise the high torque output required for rescue operations.

[0081] Under normal vehicle operation (when rescue mode is not activated), there is a clear correspondence between throttle opening and output torque, as described above in the pedal torque logic. The degree to which the driver depresses the accelerator pedal (i.e., throttle opening) determines the magnitude of the engine's output torque. Generally, the deeper the accelerator pedal is pressed, the greater the throttle opening, the greater the engine's output torque, and the stronger the vehicle's power, resulting in faster acceleration; conversely, the shallower the accelerator pedal is pressed, the smaller the throttle opening, the smaller the output torque, and the slower the vehicle's speed change. However, when rescue mode is activated, the vehicle may be in a specific rescue scenario. To ensure the safety and smooth progress of the rescue operation, special control of the vehicle's power output is required. In this case, the normal correspondence between throttle pedal opening and output torque can be disabled to prevent the driver from accidentally pressing the accelerator pedal during the rescue process, causing the vehicle to suddenly gain power and affecting the rescue process. In this situation, the vehicle's power output is no longer directly controlled based on the currently used correspondence between throttle opening and output torque, but is determined by a specific control strategy under rescue mode.

[0082] The aforementioned forward gears specifically include D and M. D stands for Drive, and is the forward gear in an automatic transmission. M stands for Manual, and is a mode that allows the driver to manually control gear shifting. In some vehicles equipped with automatic transmissions, the driver can manually select the desired gear in M ​​mode using paddle shifters, a gear lever, or other methods.

[0083] The gear lever positions of the aforementioned non-decoupled four-wheel drive architecture vehicles include: D, R, M, P, N, etc., where D is the forward gear, R is the reverse gear, M is another forward gear, P is the parking gear, and N is the neutral gear.

[0084] When the rescue mode is activated, the rescue mode type is Type 1, and the gear lever is in any of the following positions: D, R, or M, the vehicle's drive mode must be switched to pure electric drive mode. In pure electric drive mode, the engine is idling or stopped, the clutch is open, and the torque converter is locked. After (rescue mode is deactivated, or the rescue mode type is not Type 1, or the gear lever is in P or N) and the rescue mode availability status is available, switch the vehicle's drive mode from idle pure electric drive mode to hybrid mode. In hybrid mode, the torque converter is open, and the clutch is closed.

[0085] In some embodiments, when the vehicle is equipped with a crawl function, the VCU will also prohibit the vehicle from crawling after the rescue mode is activated; and will cancel the crawl prohibition after the rescue mode is exited and the accelerator is released. When the vehicle is equipped with an ejection function, the VCU will prohibit the ejection function from being activated; and will cancel the ejection function prohibition after the rescue mode is exited and the accelerator is released.

[0086] Crawl function refers to the ability of a vehicle to move forward or backward at a very low speed without the driver pressing the accelerator pedal. If crawl function is activated while the vehicle's rescue mode is active, the vehicle may move uncontrollably and slowly, potentially hindering rescue efforts. Therefore, when rescue mode is active, the vehicle's VCU can disable crawl function to ensure smooth rescue operations. Specifically, during crawling, the crawl module calculates a crawl torque and outputs it to allow the vehicle to move slowly. However, when rescue mode is active, torque output is controlled according to the torque control strategy corresponding to that mode. Therefore, to prevent crawl torque from interfering with the torque control strategy in rescue mode, crawling is disabled when rescue mode is active.

[0087] Launch control refers to a feature that allows a vehicle to gain significant acceleration in a short period of time. If launch control is active while the vehicle's emergency rescue mode is in effect, the sudden, extremely rapid acceleration could pose a significant safety hazard. Therefore, when emergency rescue mode is active, the vehicle's VCU (Vehicle Control Unit) can disable launch control to ensure vehicle safety. Understandably, when launch control is activated, it calculates and outputs the corresponding launch torque to initiate a launch. However, in emergency rescue mode, torque output is controlled according to the torque control strategy specific to that mode. Therefore, to prevent launch torque from interfering with the torque control strategy in emergency rescue mode, launch control is disabled when emergency rescue mode is active.

[0088] In the above method, when the availability status of the rescue mode is available and the battery power is greater than the preset power, it can be determined that the vehicle's battery power can guarantee sufficient range. At this time, the rescue mode type is determined to be motor speed control type. Under the motor speed control type, rescue operations in the rescue mode can be realized through precise control of the motor, ensuring the vehicle's range while improving the accuracy of rescue operations in the rescue mode.

[0089] In one possible implementation, the availability states of the rescue mode include: an available state, an inaccessible state, and an exitable state. Before determining the rescue mode type as motor speed control type when the availability state is available and the battery charge is greater than a preset charge, the method further includes: when the availability state of the rescue mode is inaccessible, setting the availability state of the rescue mode from inaccessible to available if the vehicle meets a first preset condition; wherein, in the inaccessible state, the vehicle's power system does not have a preset fault; when the availability state of the rescue mode is exitable, setting the availability state of the rescue mode from exitable to available if the vehicle meets a second preset condition; wherein, in the exitable state, the vehicle's rescue mode is active and the vehicle speed is greater than a preset speed, or, in the exitable state, the vehicle's rescue mode is active and the vehicle's throttle opening is greater than a third preset opening.

[0090] The availability status of rescue mode includes several states such as available, inaccessible, and non-exit.

[0091] The available status indicates that the rescue mode of the vehicle can be activated and used. Activation means that if the preset activation conditions are met, the rescue mode will be activated while the vehicle is in the available status.

[0092] The "Unaccessible" status indicates that the vehicle's rescue mode is currently restricted and cannot be activated. These restrictions can be lifted by prompting the user to perform specific actions, such as reducing vehicle speed and switching the driving mode to 4L.

[0093] The "cannot be exited" state indicates that the vehicle's rescue mode is currently activated but cannot be exited. "Cannot be exited" means that exiting is not allowed. In the "cannot be exited" state, even if the battery charge is low, the vehicle speed is high, or the throttle opening is large, the rescue mode will not be easily exited.

[0094] Specifically, the vehicle's powertrain in the inaccessible state does not have any pre-existing faults. These pre-existing faults are specifically those where the powertrain's performance is insufficient to support the high torque required for rescue operations, such as a battery malfunction. Assuming that all of these pre-existing faults related to insufficient powertrain performance to support high torque for rescue operations are classified as level two or higher, it can be determined that the vehicle's powertrain in the inaccessible state does not have any faults of level two or higher.

[0095] As the vehicle's status changes, the availability of the rescue mode can switch from an inaccessible state to an available state. Specifically, when the vehicle's rescue mode is in an inaccessible state, after detecting a change in the vehicle's status to meet a first preset condition, the availability of the rescue mode is changed from an inaccessible state to an available state.

[0096] The first preset condition includes: the vehicle's driving mode is low-speed four-wheel drive mode, and the vehicle's speed is less than the preset speed.

[0097] Driving modes refer to the ways in which a vehicle adjusts the operation of its engine, transmission, suspension system, steering system, and other components based on the driver's preferences and road conditions to provide different driving experiences and performance characteristics. The main purpose of driving modes is to optimize the vehicle's dynamic response and meet the driver's needs.

[0098] The vehicle's driving modes may include: Eco mode, Sport mode, Snow mode, Mud mode, Sand mode, Low-speed four-wheel drive mode (also known as 4L mode), etc.

[0099] Understandably, when a vehicle receives an activation request for the rescue mode function and obtains that the current availability status of the rescue mode is inaccessible, the vehicle can proactively prompt the driver to switch the driving mode to 4L mode and reduce the vehicle speed to below the preset speed, so that the vehicle's status changes to meet the first preset condition, thereby triggering the rescue mode availability status to change from inaccessible to available, so as to ensure that the vehicle can activate the rescue mode in the future.

[0100] If the vehicle's rescue mode is active and the vehicle speed is greater than a preset speed, or if the vehicle's rescue mode is active and the throttle opening is greater than a third preset opening, this indicates that the vehicle is currently undergoing rescue operations. To prevent accidental exit from rescue mode during the rescue process, which could interrupt the current rescue, the availability status of the rescue mode is set to non-exitable.

[0101] As the vehicle's status changes, the availability of the rescue mode can switch from a non-exit state to an available state. Specifically, when the vehicle's rescue mode is in a non-exit state, after detecting a change in the vehicle's status to meet a second preset condition, the availability of the rescue mode is changed from a non-exit state to an available state.

[0102] The second preset condition includes: the vehicle speed is less than the preset speed and the throttle opening is less than the fourth preset opening; wherein the third preset opening is greater than the fourth preset opening.

[0103] The purpose of setting the fourth preset opening degree to be less than the third preset opening degree is to set a hysteresis interval to avoid frequent switching of the availability state of the rescue mode when the throttle opening degree fluctuates around the third preset opening degree.

[0104] Understandably, when the availability status of the rescue mode is in an unexitable state, the vehicle is usually performing a rescue operation. After the vehicle completes the current rescue operation, the driver releases the accelerator, reducing the accelerator opening to less than the fourth preset opening, and the vehicle speed to less than the preset speed. Once the vehicle's status changes to meet the second preset condition, the availability status of the rescue mode changes from an unexitable state to an available state.

[0105] In some embodiments, the availability state of the rescue mode also includes an unavailable state, which indicates that the rescue mode of the vehicle cannot be activated and used at present. In the unavailable state, the preset activation conditions will not be met. The aforementioned available state, non-exit state, and non-entry state can all be converted to the unavailable state under certain conditions.

[0106] Figure 3 This is a schematic diagram illustrating an availability state transition provided in an embodiment of this application. The following is in conjunction with... Figure 3 Further explanation of the transitions between driving mode availability states:

[0107] For example, such as Figure 3 As shown, the unavailable state can be transformed into the inaccessible state; the inaccessible state can be transformed into the available state; the available state can be transformed into the exitable state; the exitable state can also be transformed into the inaccessible state or the unavailable state; the available state can also be transformed into the unavailable state.

[0108] Specifically, such as Figure 3 As shown, if the power system has no level 2 or higher faults, and the availability status of the rescue mode is unavailable, the availability status of the rescue mode can be switched from unavailable to inaccessible if the power system is free of level 2 or higher faults.

[0109] If the power system has a level 2 or higher fault, and the rescue mode is in an inaccessible state, the rescue mode can be switched from an inaccessible state to an unavailable state.

[0110] If the power system has a level 2 or higher fault while the rescue mode is in an available state, the rescue mode can be switched from an available state to an unavailable state.

[0111] If the power system has a level 2 or higher fault, and the rescue mode is in an unaccessible state, the rescue mode can be switched from an inaccessible state to an unavailable state.

[0112] For example, the fault levels of a vehicle's powertrain system can be divided into three levels: Level 1 fault, Level 2 fault, and Level 3 fault.

[0113] Level 1 faults refer to minor faults that do not temporarily have a serious impact on the basic functions of the power system or the vehicle's operation.

[0114] Level 2 faults are of moderate severity and may affect some performance aspects of the powertrain. If a Level 2 fault exists in the powertrain, although the vehicle can still be driven, it will no longer meet normal driving requirements and needs to be repaired as soon as possible.

[0115] Level 3 faults are the most serious level of faults, which can severely damage or even completely disable the basic functions of the power system. If there is a Level 3 fault in the power system, the vehicle will not be able to drive normally.

[0116] Generally, if the powertrain has a level 2 or higher fault (i.e., a level 2 or 3 fault), it indicates that the powertrain performance is insufficient to support the high torque required for rescue operations. In this case, the rescue mode cannot be used, and its availability status should be set to unavailable. Conversely, if the powertrain does not have a level 2 or higher fault, it means the vehicle currently meets normal driving needs. In this case, the rescue mode can be activated under certain conditions, and its availability status should be set to inaccessible.

[0117] If the rescue mode is inaccessible, and the vehicle's driving mode is 4L, the current speed is less than the preset speed, and the preset mode is not activated, the rescue mode can be switched from inaccessible to accessible.

[0118] Conversely, if the availability status of the rescue mode is available, and any of the following conditions are met: the vehicle's driving mode is not 4L mode, the rescue mode is inactive and the current vehicle speed is greater than the preset vehicle speed, or the preset mode is active (or pending activation), then the availability status of the rescue mode can be switched from available to inaccessible.

[0119] Additionally, if the rescue mode is in an unexitable state, and any of the following conditions are met: the vehicle's driving mode is not 4L mode, and the preset mode is active (or pending activation), then the rescue mode's availability can be switched from an unexitable state to an inaccessible state.

[0120] It is understandable that the 4L mode mentioned above refers to the low-speed four-wheel drive mode in the vehicle. In this mode, the engine power will be transmitted to the four wheels at a larger transmission ratio, which will greatly amplify the torque of the vehicle. This means that the vehicle can obtain stronger traction when driving at low speeds, so as to carry out rescue operations.

[0121] If the vehicle's driving mode is 4L, it means that the vehicle can output a large amount of torque at low speeds, which can generate sufficient traction to facilitate rescue operations. In other words, when the vehicle's driving mode is 4L, it is suitable to use the rescue mode.

[0122] For example, the preset vehicle speed can be set according to actual needs, such as 1 kilometer per hour (kph).

[0123] If the vehicle's current speed is lower than the preset speed, it means that the vehicle is in a relatively low-speed state. Activating the rescue mode in this low-speed state will be safer and more stable, avoiding the risk of loss of vehicle control that may occur when switching modes at high speeds.

[0124] The aforementioned preset modes refer to modes that conflict with the rescue mode and have higher priority when activated, such as the low-speed off-road cruise mode (Cruise Control Off-road, CCO).

[0125] If the preset mode in the vehicle is active or inactive, it means that the preset mode should be used first, and the availability status of the rescue mode can be controlled to be inaccessible; if the preset mode in the vehicle is inactive, it means that there is no conflict with other modes at present, and the rescue mode is suitable to be used, and the availability status of the rescue mode can be controlled to be available.

[0126] In summary, when the vehicle's driving mode is 4L, the vehicle's current speed is lower than the preset speed, and the preset mode is not activated, the rescue mode can be used, which means that the availability status of the rescue mode can be set to available.

[0127] Furthermore, under certain conditions, the availability status of the rescue mode can be switched from the available state to the non-exit state.

[0128] For example, if the rescue mode is in an available state and the rescue mode is active and the current vehicle speed is greater than or equal to the preset vehicle speed (or the throttle opening is greater than the third preset opening), the availability state of the rescue mode can be switched from the available state to the non-exit state.

[0129] Conversely, if the availability status of the rescue mode is in an unexitable state, and the vehicle's current speed is less than the preset speed and the throttle opening is less than the fourth preset opening, the availability status of the rescue mode can be switched from the unexitable state to the available state.

[0130] For example, the preset vehicle speed can be set according to actual needs, such as 1 kilometer per hour (kph or km / h).

[0131] The third and fourth preset openings can be set according to actual needs. Usually, the third preset opening can be set to be larger than the fourth preset opening. For example, the first preset opening can be set to 50% and the third preset opening can be set to 10%.

[0132] Understandably, when the rescue mode is active, if the vehicle's current speed is greater than or equal to the preset speed or the throttle opening is greater than the third preset opening, it means that the vehicle is currently traveling at a relatively high speed or the driver has a greater demand for the vehicle's power. This will ensure that the vehicle maintains the current rescue mode and prevent the vehicle from losing control due to an unexpected exit from the rescue mode. In other words, the availability of the rescue mode can be switched from an available state to an unexitable state.

[0133] If the vehicle's current speed decreases to below the preset speed and the throttle opening is less than the fourth preset opening, it indicates that the vehicle's current driving speed is low and the throttle opening is small. The vehicle's current driving state is relatively stable, and the availability of the rescue mode can be switched from the non-exit state to the available state.

[0134] If the rescue mode is active, the user can control the rescue mode to exit the active state by initiating a request to exit the rescue mode function.

[0135] The above method improves the accuracy and security of rescue mode activation control by setting multiple availability states for the rescue mode. For example, setting a non-exit state ensures that if an accidental operation causes the rescue mode to exit, the rescue operation will be interrupted. Furthermore, the ability to switch between multiple availability states enhances the flexibility of rescue mode activation and deactivation.

[0136] In step 102, when the rescue mode is available and the battery power is greater than the preset power, the rescue mode type is determined to be motor speed control type.

[0137] The rescue mode is active, meaning the current rescue mode is activated. In the motor speed control type rescue mode, the motor needs to be controlled to enter speed control mode, and the motor torque is controlled based on the motor speed. The motor is the drive motor in the above embodiment. Therefore, after determining that the rescue mode is active and the rescue mode type is motor speed control, it is necessary to determine whether to activate the motor speed control mode.

[0138] In one possible implementation, determining whether to activate the vehicle's motor speed control mode includes: acquiring the vehicle's gear lever position, brake pedal travel, drive mode, transmission gear, current motor torque, and current speed; activating the motor speed control mode when the gear lever position is any one of D, R, or M, the brake pedal travel is less than a preset travel, the drive mode is pure electric drive mode, the transmission gear is a preset gear, the absolute value of the current torque is less than a second preset torque, and the current speed is less than a second preset speed.

[0139] When the rescue mode is active and the rescue mode type is Type 1 "Motor Speed ​​Control Type", activating the motor speed control mode requires the vehicle to meet certain conditions. Before activating the motor speed control mode, the vehicle's operating parameters can be obtained, and based on these parameters, it can be determined whether the vehicle meets the conditions for activating the motor speed control mode. If the conditions for activating the motor speed control mode are met, then the motor speed control mode is activated.

[0140] The operating parameters may include: gear lever position, brake pedal travel, drive mode, transmission gear, current motor torque, and current motor speed.

[0141] The conditions for activating the motor speed control mode include: the gear lever is in any one of D, R, or M gear; the brake pedal travel is less than the preset travel; the drive mode is pure electric drive mode; the gearbox is in the preset gear; and the absolute value of the current torque of the motor is less than the second preset torque and the current speed is less than the second preset speed.

[0142] Specifically, when the gear lever is in D or M mode, the preset gear of the transmission is 1st gear; when the gear lever is in R mode, the preset gear of the transmission is R mode.

[0143] Understandably, D, R, and M are all gears used for vehicle movement. D and M are for forward driving, and R is for reverse driving. This means that the vehicle only needs to move when it's in D, R, or M gear, and only then does the vehicle's motor require speed control to provide appropriate traction. Therefore, activating the motor's speed control mode requires the gear lever to be in one of D, R, or M gear.

[0144] Before activating the motor's speed control mode, it's necessary to confirm that the vehicle's drive mode has switched to pure electric drive mode, meaning the vehicle is currently outputting power based on the drive motor. For vehicles with the aforementioned non-decoupled four-wheel drive architecture, the drive mode can be determined by acquiring the engine status, clutch status, and torque converter status. Pure electric drive mode includes idle pure electric drive mode and non-idle pure electric drive mode. When the engine is running, the clutch is engaged, and the torque converter is locked, the vehicle's drive mode is determined to be idle pure electric drive mode; when the engine is stopped, the clutch is engaged, and the torque converter is locked, the vehicle's drive mode is determined to be non-idle pure electric drive mode.

[0145] The preset travel distance could be, for example, 2%, the second preset torque could be, for example, 2 Nm, and the second preset speed could be, for example, 100 rpm. If the brake pedal travel is less than 2% of the preset travel distance, the absolute value of the current motor torque is less than the second preset torque of 2 Nm, and the current speed is less than the second preset speed of 100 rpm, it indicates that the vehicle is currently stationary or in a relatively stable state. After the motor speed control mode is activated, the vehicle needs to control the motor torque based on the motor speed. Before activating the motor speed control mode, it is necessary to ensure that the above conditions are met to reduce conflicts when activating the motor speed control mode.

[0146] When the vehicle's operating parameters meet the above conditions, the VCU corrects the motor speed control mode to an active state and controls the motor to enter speed control mode. In speed control mode, the vehicle controls the motor's torque to control the motor's rotation based on the target speed.

[0147] In some embodiments, when the rescue mode is inactive, the absolute value of the current torque of the motor is less than the second preset torque, and the current speed is less than the third preset speed, the speed control mode of the motor is not activated.

[0148] Alternatively, if the rescue mode type is not type 1 "motor speed control type", and the absolute value of the current torque of the motor is less than the second preset torque and the current speed is less than the third preset speed, the motor speed control mode will not be activated.

[0149] Alternatively, if the shift lever is in P or N position, and the absolute value of the motor's current torque is less than the second preset torque and the current speed is less than the third preset speed, the motor's speed control mode will not be activated.

[0150] The third preset speed can be different from the second preset speed; for example, the third preset speed can be 1000 rpm.

[0151] The above method determines whether the vehicle meets the conditions for activating the motor speed control mode by checking the vehicle's gear lever position, brake pedal travel, drive mode, transmission gear position, current motor torque, and current speed. If the conditions for activating the motor speed control mode are met, the motor speed control mode is activated. This method achieves comprehensive judgment of multiple vehicle operating parameters when activating the speed control mode, ensuring that no conflict occurs when activating the motor speed control mode, and improving the vehicle's driving experience and safety.

[0152] In step 103, the motor's speed control mode is activated, meaning the motor has entered speed control mode. The target speed is the speed that the motor needs to reach in rescue mode to ensure that the vehicle can output sufficient traction for rescue operations.

[0153] The process of controlling motor torque based on a target speed includes: obtaining the current motor speed; subtracting the current speed from the target speed to obtain the speed difference; calculating the required torque adjustment based on the speed difference; and adjusting the motor torque according to the calculated torque adjustment to make the motor's current speed approach the target speed. A PID controller or other control algorithms can be used to calculate the required torque adjustment based on the speed difference.

[0154] In one possible implementation, determining the target speed of the motor includes: acquiring the throttle opening of the vehicle; determining the target vehicle speed based on the throttle opening; and calculating the target speed based on the target vehicle speed, the vehicle's tire radius, and a preset speed ratio.

[0155] The driver needs to press the accelerator pedal to drive the vehicle and perform the rescue operation. The accelerator pedal position reflects the driver's driving needs. After activating the rescue mode, the current accelerator pedal position can be obtained, and the driver's desired vehicle speed can be determined based on the accelerator pedal position.

[0156] In some embodiments, before obtaining the accelerator pedal opening, in addition to determining that the rescue mode is active, it is also necessary to determine that the current gear lever position is any one of D, M, or R, and to determine that the vehicle currently has a driving need.

[0157] As one implementation method, the vehicle stores a mapping table representing the correspondence between throttle opening and target vehicle speed in rescue mode. After obtaining the throttle opening, the target vehicle speed corresponding to the throttle opening can be obtained by looking up the mapping table based on the throttle opening. The mapping table representing the correspondence between throttle opening and target vehicle speed is shown in Table 1:

[0158] Table 1

[0159] Throttle opening (%) Target speed (kph or km / h) 0 1.2 20 2.1 40 4.5 60 7.8 80 12.1 100 14.8

[0160] In Table 1, the target vehicle speed corresponding to 0% throttle opening is 1.2 kph; the target vehicle speed corresponding to 20% throttle opening is 2.1 kph; the target vehicle speed corresponding to 40% throttle opening is 4.5 kph; the target vehicle speed corresponding to 60% throttle opening is 7.8 kph; the target vehicle speed corresponding to 80% throttle opening is 12.1 kph; and the target vehicle speed corresponding to 100% throttle opening is 14.8 kph.

[0161] It is understandable that the throttle opening and corresponding target vehicle speed in Table 1 are just examples, and the actual mapping table may include the target vehicle speed corresponding to all throttle openings.

[0162] In some embodiments, different mapping tables can be pre-stored for different gear positions. For example, a first mapping table can be stored for D and M gears, and a second mapping table can be stored for R gear. The first and second mapping tables are similar to Table 1 above, except that the target vehicle speed corresponding to the same throttle opening is different in the first and second mapping tables. Generally, for the same throttle opening, the target vehicle speed corresponding to the first mapping table is greater than the target vehicle speed corresponding to the second mapping table.

[0163] The second mapping table stored in the vehicle for the reverse gear can be shown in Table 2 below:

[0164] Table 2

[0165] Throttle opening (%) Target speed (kph) 0 1.0 36 2.5 49 5.1 63 7.62 86 10.8 100 12.5

[0166] Understandably, when driving in D and M gears, the driver can observe the road conditions ahead more promptly and comprehensively, resulting in lower risks. Therefore, the target speed corresponding to the same throttle opening can be higher in D and M gears to meet driving needs. Conversely, when driving in R gear, the driver cannot observe the road conditions behind the vehicle promptly and comprehensively, resulting in higher risks. Therefore, the target speed corresponding to the same throttle opening can be lower to ensure safe driving.

[0167] When different mapping tables are stored in advance for different gear positions, after obtaining the throttle opening, it is necessary to determine the target mapping table corresponding to the current gear position from the pre-stored mapping tables, and then find the target mapping table based on the throttle opening to obtain the target vehicle speed.

[0168] Once the target vehicle speed is obtained, the target motor speed can be calculated based on that speed. Specifically, the vehicle's tire radius and preset speed ratio can be acquired. The target motor speed is then calculated based on the target vehicle speed, tire radius, and preset speed ratio.

[0169] The preset speed ratio is the speed ratio between the motor speed and the wheel speed, representing the conversion relationship between the motor speed and the wheel speed.

[0170] Specifically, the formula for converting vehicle speed v from km / h (kilometers per hour) to m / s (meters per second) is shown in the following formula (1):

[0171] v m / s =v km / h / 3.6 (1)

[0172] Based on the vehicle speed v and the tire radius r, the formula for calculating the wheel's angular velocity ω (rad / s) is shown in the following formula (2):

[0173] ω=v m / s / r=v km / h / (3.6*r) (2)

[0174] Based on the wheel angular velocity ω (rad / s, radians per second), the formula for calculating the wheel rotation speed n1 is shown in the following formula (3):

[0175] n1=ω*60 / 2π=v km / h *60 / (2π*3.6*r) (3)

[0176] Based on the wheel speed n1 and the preset speed ratio i, the formula for calculating the target speed n2 of the motor is shown in the following formula (4):

[0177] n2 = n1 * i = v km / h *60*i / (2π*3.6*r) (4)

[0178] Simplifying formula (4) yields a formula for calculating the target speed of the motor based on the target vehicle speed v, the preset speed ratio i, and the tire radius r, as shown in formula (5):

[0179] n2 = v km / h *i / (0.377*r) (5)

[0180] For example, if the target vehicle speed is 12km / h, the preset speed ratio i is 8, and the tire radius r is 0.3m, then by substituting the target vehicle speed of 12km / h, the preset speed ratio of 8, and the tire radius of 0.3m into formula (5), the target speed of the motor n2 can be calculated as n2 = 12*8 / (0.377*0.3) ≈ 848.84rpm (revolutions per minute).

[0181] In some embodiments, after determining the target speed of the motor, a filtering gradient can be determined based on the throttle opening and the current speed; then, the current speed of the motor is transitioned to the target speed according to the determined filtering gradient.

[0182] Understandably, when the difference between the current speed of the target motor and the calculated target speed is large, directly switching the motor from the current speed to the target speed may cause a sudden change in the motor's output torque, resulting in vehicle vibration or shaking. By determining a filtering gradient based on the throttle opening and the current speed, and then gradually transitioning from the current speed to the target speed based on this gradient, sudden changes in the target motor's output torque can be effectively avoided, reducing vehicle vibration or shaking and ensuring the smooth operation of the target motor.

[0183] In the above method, the throttle opening directly reflects the driver's needs. The throttle opening determines the driver's desired target vehicle speed in rescue mode, and based on this target speed, the target motor speed is determined to control the motor. This allows the vehicle to dynamically control the motor according to the driver's needs, ensuring the vehicle reaches the desired target speed and accurately reflects the driver's intentions. Through this design, in rescue mode, the driver only needs to press the accelerator pedal to control the vehicle speed, eliminating the need for manual adjustment of other parameters, simplifying the operation process and improving the efficiency of rescue mode.

[0184] In step 104, the anti-slip torque value is the boundary value of the torque that the motor can output to prevent vehicle wheels from slipping. Since the torque output by the motor can be positive or negative, the boundary value of the torque to prevent vehicle wheels from slipping includes a positive boundary and a negative boundary. Therefore, the anti-slip torque value can include the maximum anti-slip torque value (i.e., the aforementioned positive boundary) or the minimum anti-slip torque value (i.e., the aforementioned negative boundary).

[0185] The motor torque is limited based on the anti-slip torque value. That is, when the motor output torque is positive, the motor output torque is limited to be less than or equal to the maximum anti-slip torque value; when the motor output torque is negative, the motor output torque is limited to be greater than or equal to the minimum anti-slip torque value.

[0186] It is understandable that during the process of controlling the motor torque to achieve the target speed, excessive output torque may cause wheel slippage. Therefore, in the above control process, the current motor operating parameters can be acquired in real time, an anti-slip torque value can be determined based on these parameters, and the motor torque can be limited based on this anti-slip torque value.

[0187] In one possible implementation, determining the anti-slip torque value based on the current motor operating parameters includes: obtaining the target road surface adhesion level of the road surface where the vehicle is currently located; determining the correspondence between the target road surface adhesion level and the anti-slip torque value; the correspondence is used to describe the correspondence between the motor operating parameters and the anti-slip torque value under the target road surface adhesion level; and determining the anti-slip torque value corresponding to the current motor operating parameters based on the correspondence.

[0188] The anti-slip torque value of a motor is related to the coefficient of friction of the road surface on which the vehicle is currently located. A higher coefficient of friction indicates greater friction between the wheels and the road surface, and thus a higher allowable anti-slip torque value from the motor. Conversely, a lower coefficient of friction indicates less friction between the wheels and the road surface, and thus a lower allowable anti-slip torque value from the motor.

[0189] As one implementation method, the adhesion coefficient can be pre-defined into ranges, and road surfaces with adhesion coefficients falling into different ranges can be classified into different grades, resulting in multiple road surface adhesion grades. The rule for grading is: the higher the adhesion coefficient, the lower the grade. The specific road surface adhesion grades are shown in Table 3 below:

[0190] Table 3

[0191] Adhesion coefficient range (0.8,0.9] (0.6,0.8] (0.4,0.6] (0.2,0.4] (0.1,0.2] (0.05,0.1] Road surface adhesion level 1 2 3 4 5 6

[0192] As shown in Table 3, the adhesion coefficient is divided into six ranges: (0.8, 0.9], (0.6, 0.8], (0.4, 0.6], (0.2, 0.4], (0.1, 0.2], and (0.05, 0.1]. The road surface adhesion level is set as follows: (0.8, 0.9] for road surfaces with an adhesion coefficient of (0.6, 0.8], (0.4, 0.6) for road surfaces with an adhesion coefficient of (0.2, 0.4) for road surfaces with an adhesion coefficient of (0.1, 0.2) for road surfaces with an adhesion coefficient of (0.05, 0.1) for road surfaces with an adhesion coefficient of (0.05, 0.1) for road surfaces with an adhesion coefficient of (0.1, 0.2) for road surfaces with an adhesion coefficient of (0.05, 0.1) for road surfaces with an adhesion coefficient of (0.05, 0.1) for road surfaces with an adhesion coefficient of (0.8, 0.9] for road surfaces with an adhesion coefficient of (0.6, 0.8) for road surfaces with an adhesion coefficient of (0.6, 0.4) for road surfaces with an adhesion coefficient of (0.4, 0.6) for road surfaces with an adhesion coefficient of (0.2, 0.4) for road surfaces with an adhesion coefficient of (0.2, 0.4) for road surfaces with an adhesion coefficient of (0.1, 0.2) for road surfaces with an adhesion coefficient of (0.05, 0.1 ...

[0193] In the process of controlling the motor torque based on the target speed, the road adhesion coefficient of the road surface where the vehicle is currently located can be obtained. Based on the range of the road adhesion coefficient, the target road adhesion level can be determined. For example, if the road adhesion coefficient of the road surface where the vehicle is currently located is 0.3, which is within the range (0.2, 0.4], according to Table 2, the road adhesion level corresponding to the range (0.2, 0.4) is level 4. Therefore, the target road adhesion level of the road surface where the vehicle is currently located can be determined to be level 4.

[0194] As one implementation method, the slippage of vehicle wheels and vehicle dynamics can be monitored in real time by using acceleration sensors, wheel speed sensors, and other sensors installed in the vehicle, and the road adhesion coefficient can be estimated through the vehicle's dynamic parameters.

[0195] Under a fixed road surface adhesion level, the motor operating parameters also affect the motor's anti-slip torque value. The correspondence between different motor operating parameters and anti-slip torque under a fixed road surface adhesion level can be determined in advance and stored in the vehicle according to the corresponding road surface adhesion level. Specifically, the motor operating parameters include motor speed and the rate of change of motor speed.

[0196] Understandably, the higher the motor speed, the higher the wheel speed; the greater the rate of change of motor speed, the greater the rate of change of wheel speed. Under the same road surface adhesion coefficient, when the wheel speed is higher, the vehicle is more likely to approach the slippage threshold, and the range of the anti-slip torque limit will be smaller. When the wheel speed is lower, the vehicle is farther from the slippage threshold, which may allow the motor to output greater torque. Correspondingly, the range of the anti-slip torque limit will be larger.

[0197] Similarly, under the same road surface adhesion coefficient, if the rate of change of motor speed (i.e., acceleration or deceleration) is large, it means the vehicle is accelerating or decelerating rapidly. In this case, to maintain vehicle traction and stability, the torque output needs to be adjusted more sensitively to avoid sudden slippage, and the range of the anti-slip torque limit will be smaller. When the rate of change of motor speed is small, the vehicle can adjust torque more smoothly, and the range of the anti-slip torque limit will be larger.

[0198] For example, as shown in Table 3, the road surface adhesion level is divided into 6 levels according to the road surface adhesion coefficient, including: Level 1, Level 2, Level 3, Level 4, Level 5 and Level 6; wherein, the higher the road surface adhesion level, the lower the road surface adhesion coefficient.

[0199] For the six levels mentioned above, different anti-slip torques can be determined based on the motor speed and the rate of change of motor speed. Specifically, when the rescue mode and the motor speed control mode are both active, this anti-slip torque value is used to limit the torque output by the motor to achieve the purpose of preventing the entire vehicle from slipping.

[0200] For example: when the road surface adhesion level is level 1: the torque corresponding to the lowest speed and the lowest speed change rate is the peak torque of the motor, and the torque corresponding to the highest speed and the highest speed change rate is reduced to the maximum torque at which the slippage state can be exited on a high-adhesion road surface level 1.

[0201] When the road surface adhesion level is level 2: the torque corresponding to the lowest speed and the lowest speed change rate is the slip boundary torque of high adhesion road surface 1 + 20 Nm, and the torque corresponding to the highest speed and the highest speed change rate is reduced to the maximum torque at which high adhesion road surface 1 can exit the slip state.

[0202] Level 3: The torque corresponding to the lowest speed and the lowest speed change rate is the slip boundary torque of the high-adhesion surface 2 + 20 Nm, and the torque at the highest speed and the highest speed change rate is reduced to the maximum torque at the high-adhesion surface 2 to exit the slip state.

[0203] Level 4: The torque corresponding to the lowest speed and the lowest speed change rate is the slip boundary torque of the high-adhesion surface 3 + 20 Nm, and the torque at the highest speed and the highest speed change rate is reduced to the maximum torque at the high-adhesion surface 3 to exit the slip state.

[0204] Level 5: The torque corresponding to the lowest speed and the lowest speed change rate is the slip boundary torque of the low-adhesion surface 1 + 20 Nm, and the torque at the highest speed and the highest speed change rate is reduced to the maximum torque at the low-adhesion surface 1 to exit the slip state.

[0205] Level 6: The torque corresponding to the lowest speed and the lowest speed change rate is the slip boundary torque of the low-adhesion surface 2 + 20 Nm, and the torque at the highest speed and the highest speed change rate is reduced to the maximum torque at the low-adhesion surface 2 to exit the slip state.

[0206] Among them, the road adhesion coefficient corresponding to the high-adhesion road surface 1 is higher than that corresponding to the high-adhesion road surface 2; the road adhesion coefficient corresponding to the high-adhesion road surface 2 is higher than that corresponding to the high-adhesion road surface 3; the road adhesion coefficient corresponding to the high-adhesion road surface 3 is higher than that corresponding to the low-adhesion road surface 1; and the road adhesion coefficient corresponding to the low-adhesion road surface 1 is higher than that corresponding to the low-adhesion road surface 2.

[0207] Understandably, with a road surface adhesion level of 1, the minimum engine speed and the minimum rate of change of engine speed indicate that the vehicle is on a surface with the highest coefficient of adhesion and is either starting or traveling at its lowest speed. In this situation, the vehicle needs to overcome significant static friction and its own inertia to begin moving. Therefore, the maximum torque that the motor can output is its peak torque to ensure that the vehicle has sufficient power to overcome these resistances and start smoothly.

[0208] When a vehicle travels on a high-friction surface at its maximum speed and maximum speed change rate, the motor rotates very fast. If the torque output by the motor is too high at this time, the rotational force of the wheels can easily exceed the adhesion of the road surface, causing the wheels to slip. Once slipping occurs, the vehicle's handling and stability will drop sharply, and it may even lead to danger. Reducing the torque output by the motor to the maximum torque corresponding to the high-friction surface 1 that can extricate the vehicle from slipping ensures that the wheels can maintain good adhesion to the road surface even when rotating at high speed, thus preventing slipping.

[0209] The slip boundary torque of the high-adhesion road surface 1 mentioned above refers to the torque value when the vehicle is about to slip under the conditions of the high-adhesion road surface 1.

[0210] With a road surface adhesion level of 2, the minimum engine speed and the minimum rate of change of engine speed indicate that the vehicle is starting on a surface with a high coefficient of adhesion or is traveling at its lowest speed. The slippage boundary torque on the high-adhesion surface 1 mentioned above refers to the torque value at which the vehicle is about to slip under high-adhesion surface 1 conditions. Adding 20 Nm to this value provides a relatively large and conservative torque value when the vehicle is at its lowest engine speed and the minimum rate of change of engine speed. This ensures that even at low motor speeds, especially in special situations such as when the vehicle needs to climb hills, has a heavy load, or the road surface has a certain gradient, there is sufficient power to overcome resistance and ensure that the vehicle can drive normally, while preventing slippage easily on high-adhesion surface 1 due to excessive torque.

[0211] Reducing the torque corresponding to the maximum speed and the maximum rate of change of speed to the maximum torque required to exit the slippage state on the high-friction surface 1 is to ensure that the wheels maintain good adhesion to the high-friction surface 1 when the motor is running at high speed, thus preventing wheel slippage. When the speed is high, the linear velocity of the wheels also increases accordingly. If the torque is too large, the driving force on the wheels can easily exceed the adhesion of the road surface, leading to slippage. Reducing the torque to the maximum torque that allows the vehicle to exit the slippage state on the high-friction surface 1 satisfies the vehicle's power requirements while ensuring driving safety and stability.

[0212] The method for determining the minimum speed and the torque corresponding to the minimum speed change rate under levels 3, 4, 5, and 6 is similar to the method for determining the minimum speed and the torque corresponding to the minimum speed change rate under level 2. Specifically, the torque is determined as: the slippage boundary torque corresponding to the current level + 20 Nm. The purpose is to ensure that there is sufficient power to overcome resistance when the motor speed is low, ensuring that the vehicle can drive normally, while preventing slippage on the current road surface due to excessive torque.

[0213] Similarly, the method for determining the torque corresponding to the highest speed and the rate of change of the highest speed at levels 3, 4, 5, and 6 is similar to the method for determining the torque corresponding to the highest speed and the rate of change of the highest speed at level 2. Specifically, the torque is determined as the maximum torque required to exit a slippery state on the road surface corresponding to the current level. The purpose is to ensure that the wheels maintain good adhesion to the current road surface when the motor is running at high speed, preventing wheel slippage. This satisfies the vehicle's power requirements while ensuring driving safety and stability.

[0214] For example, the target correspondence for road surface adhesion level 3 can be shown in Table 4 below:

[0215] Table 4

[0216] y\x 0 1000 2000 3000 4000 5000 6000 12000 100 420 420 420 420 420 420 420 370 200 420 395 345 320 320 320 320 270 300 400 360 340 320 300 280 200 150 400 390 360 340 320 300 280 200 150

[0217] In Table 4, y represents the motor speed (rpm), and x represents the rate of change of motor speed (rpm / s). As shown in Table 4, when the motor speed is constant, the anti-slip torque value decreases as the rate of change of motor speed increases; conversely, when the rate of change of motor speed is constant, the anti-slip torque value decreases as the motor speed increases. The motor speed, rate of change of motor speed, and anti-slip torque value in Table 4 are only examples.

[0218] It is understandable that motor speed can be positive or negative. The motor speeds in Table 4 above can be absolute values, as can the rate of change of motor speed in Table 4. The corresponding anti-slip torque values ​​are also absolute values. When the motor speed is negative, the corresponding anti-slip torque value is also negative; when the motor speed is positive, the corresponding anti-slip torque value is also positive.

[0219] Since a higher road surface adhesion level corresponds to a lower road surface adhesion coefficient, the vehicle is more prone to slipping, and the absolute value of the torque that the motor can output is smaller, the anti-slip torque value corresponding to the same motor operating parameters decreases as the road surface adhesion level increases.

[0220] As in the above embodiment, six road surface adhesion levels are defined, and the vehicle stores the corresponding relationships for each of the six road surface adhesion levels. After determining the target road surface adhesion level, the target correspondence for the target road surface adhesion level can be determined from the six correspondences, and based on the target correspondence, the anti-slip torque value corresponding to the motor operating parameters can be determined.

[0221] For example, if the road surface adhesion level of the vehicle is currently known to be level 3, then the target correspondence corresponding to level 3 can be obtained, as shown in Table 4 above. If the motor speed is known to be 100 rpm and the absolute value of the motor speed change rate is 1000 rpm / s, then by referring to Table 4 above, the anti-slip torque value of the motor can be determined to be 420 Nm.

[0222] In one possible implementation, obtaining the target road surface adhesion level of the road surface where the vehicle is currently located includes: obtaining the current state parameters of the vehicle and determining whether the current state parameters meet the entry conditions for road surface adhesion level self-learning; if the entry conditions for road surface adhesion level self-learning are met, road surface adhesion level self-learning is performed based on the current speed of the motor and the maximum speed of the motor within a preset historical time period to determine the target road surface adhesion level of the road surface where the vehicle is located.

[0223] The vehicle can be equipped with a road surface adhesion level self-learning function, which is used to automatically learn based on the motor speed and determine the target road surface adhesion level of the current road surface. Even if the vehicle cannot estimate the road surface adhesion coefficient, the target road surface adhesion level can be determined through the above self-learning method.

[0224] The road surface adhesion level self-learning has certain entry conditions. When the rescue mode is activated, the vehicle's current state parameters can be obtained. Based on the vehicle's current state parameters, it is determined whether the vehicle meets the entry conditions for road surface adhesion level self-learning. If the vehicle meets the entry conditions, road surface adhesion level self-learning begins based on motor speed to determine the target road surface adhesion level. The motor speed includes the motor's current speed and its maximum speed within a preset historical time period.

[0225] In the above method, by setting a road surface adhesion level self-learning function, under the condition that the entry conditions for road surface adhesion level self-learning are met, the road surface adhesion level can be obtained by self-learning based on the current speed of the motor and the maximum speed within a preset historical time period. This simplifies the method of determining the road surface adhesion level. Even if the vehicle cannot estimate the road surface adhesion coefficient, the target road surface adhesion level can be determined through the above self-learning method, which improves the efficiency of determining the road surface adhesion level. It does not rely on multiple sensor data to calculate the adhesion coefficient, thus reducing costs.

[0226] In one possible implementation, the current state parameters include: towing state, gear lever position, throttle opening, and motor torque. Determining whether the current state parameters meet the entry conditions for road surface adhesion level self-learning includes: determining that the vehicle meets the entry conditions for road surface adhesion level self-learning when the towing state is active, the throttle opening is greater than a first preset opening, and the absolute value of the motor torque is greater than a target torque; wherein the towing state is activated when the rescue mode is active, the rescue mode type is motor speed control, and the absolute value of the motor torque is greater than a first preset torque.

[0227] The vehicle's current status parameters may include: towing status, throttle opening, and motor torque.

[0228] The "drag state" refers to the state activated when a vehicle is towing another vehicle in rescue mode.

[0229] For example, if the rescue mode is active and the rescue mode type is motor speed control, and the absolute value of the motor torque is greater than the first preset torque and the duration for which the absolute value of the motor torque is greater than the first preset torque is greater than the first preset duration, then the above-mentioned dragging state is activated.

[0230] For example, the first preset torque can be set according to actual needs, such as 100 Nm, and the first preset duration can also be set according to actual needs, such as 1 second (s).

[0231] The vehicle's VCU can monitor relevant parameters of the rescue mode in real time. When the rescue mode is active and the rescue mode type is motor speed control, it further monitors the vehicle's motor torque. Specifically, the VCU can measure the motor torque in real time through the torque sensor installed in the vehicle and compare the real-time measured motor torque with a first preset torque. If the motor torque is greater than the first preset torque for a duration greater than a first preset duration, the vehicle's towing state is activated. Specifically, the VCU sets the towing state activation status to "activated state" at this time; otherwise, the towing state is in "inactive state".

[0232] The throttle opening is usually obtained through the throttle pedal position sensor. Specifically, the percentage of throttle opening can be calculated based on the position signal of the throttle pedal position sensor. The motor torque is obtained through the torque sensor in the vehicle.

[0233] Understandably, when towing is active, it indicates the vehicle is in a rescue scenario and has begun outputting significant torque to tow other vehicles, posing a risk of skidding. Therefore, the vehicle can be controlled to perform road surface adhesion level self-learning to determine the target road surface adhesion level. Based on this target level, the anti-skid torque value can be determined to limit the motor's torque, preventing the vehicle from skidding.

[0234] When the throttle opening exceeds a first preset opening, it indicates that the driver has a certain power demand on the vehicle, and the engine or electric motor needs to output a certain amount of power to drive the vehicle. The throttle opening directly affects the vehicle's power output; exceeding the preset opening means the vehicle has sufficient power to move, and under this power output condition, the interaction between the vehicle and the road surface is more pronounced, which is beneficial for analyzing road surface adhesion by observing the vehicle's driving state. Therefore, when the throttle opening exceeds the first preset opening, it can provide important basis for determining the target road surface adhesion level, making it suitable for road surface adhesion level self-learning.

[0235] When the absolute value of the motor torque exceeds the target torque, it indicates that the vehicle's drive system is outputting a larger torque to overcome resistance and propel the vehicle forward or backward. In this situation, it is easier to observe the differences in vehicle performance under different road surface adhesion conditions, thus providing more accurate data for road surface adhesion level self-learning. Therefore, when the absolute value of the motor torque exceeds the target torque, it provides more accurate data for road surface adhesion level self-learning, making it suitable for such applications.

[0236] In some embodiments, the vehicle's current state parameters may also include the gear position, and the entry conditions for road surface adhesion level self-learning may also include: the gear position is any one of D, R, or M.

[0237] Understandably, the gear position is typically determined by a position sensor in the vehicle's transmission. When the gear lever is in drive (D, M) or reverse (R), it indicates the vehicle is in a position with power output and capable of movement. In drive or reverse, the vehicle's drive system can output power according to the driver's input, enabling the vehicle to move and allowing information about road surface adhesion to be obtained from its movement. However, if the gear lever is in neutral or park, the vehicle's powertrain is disconnected or the vehicle is stationary, making it impossible to effectively acquire road surface adhesion data during movement. Therefore, when the gear lever is in drive or reverse, it provides road surface adhesion data for the vehicle to perform self-learning of its road surface adhesion level, making it suitable for this purpose.

[0238] In summary, when all four conditions are met simultaneously—namely, the towing state is activated, the gear lever is in forward (D or M) or reverse (R), the throttle opening is greater than the first preset opening, and the total wheel-end drive torque is greater than the first preset torque—it is determined that the vehicle meets the entry conditions for road adhesion level self-learning.

[0239] For example, the first preset opening can be set according to actual needs, such as 50%. The target torque can also be set according to actual needs, specifically according to the current gear position, such as 170Nm in forward gear (D or M) and 100Nm in reverse gear (R).

[0240] Furthermore, if it is determined that the vehicle meets the entry conditions for road surface adhesion level self-learning, the vehicle can be controlled to start road surface adhesion level self-learning to obtain the target road surface adhesion level.

[0241] In one possible implementation, road surface adhesion level self-learning is performed based on the current motor speed to determine the target road surface adhesion level of the road where the vehicle is located. This includes: determining the initial road surface adhesion level before this road surface adhesion level self-learning; wherein, when the rescue mode is activated and road surface adhesion level self-learning is not performed, the initial road surface adhesion level is the default level; adjusting the initial road surface adhesion level based on the current motor speed and the maximum motor speed within a preset historical time period to obtain the corrected road surface adhesion level after this road surface adhesion level self-learning; after obtaining the corrected road surface adhesion level, if the entry conditions for road surface adhesion level self-learning are still met, the corrected road surface adhesion level is used as the initial road surface adhesion level before the next road surface adhesion level self-learning, and the initial road surface adhesion level is adjusted based on the current motor speed and the maximum motor speed within a preset historical time period to obtain the corrected road surface adhesion level after the next road surface adhesion level self-learning, until the exit conditions for road surface adhesion level self-learning are met; and determining the corrected road surface adhesion level after the last road surface adhesion level self-learning as the target road surface adhesion level of the road where the vehicle is located.

[0242] It is understandable that the aforementioned initial road surface adhesion level refers to the road surface adhesion level before the start of this road surface adhesion level self-learning process.

[0243] If road surface adhesion level self-learning has not been performed before, the default level will be set as the initial road surface adhesion level. For example, under normal circumstances, after the rescue mode is activated, the default road surface adhesion level is level 2, so level 2 can be used as the initial road surface adhesion level.

[0244] Furthermore, as mentioned earlier, when the rescue mode is of the motor speed control type, the vehicle's drive mode needs to be switched to pure electric drive mode. In pure electric drive mode, the torque converter is locked, and the power transmission between the vehicle's motor and transmission is rigidly connected, with no slippage. The motor speed can accurately reflect the vehicle's current driving state, and the acquisition of the motor speed in the current vehicle is more precise and real-time. Therefore, with the torque converter locked, the current driving state of the vehicle can be more directly reflected by acquiring the motor speed, providing a more accurate basis for judging the road surface adhesion level.

[0245] The maximum speed of the motor within a preset historical time period can often reveal the upper limit of the motor's driving capability within a certain time. Furthermore, the maximum speed the motor can achieve varies under different road surface adhesion conditions. Therefore, obtaining the maximum speed within a preset historical time period helps to more comprehensively understand the vehicle's driving performance under current road surface conditions, thus providing more information for determining the road surface adhesion level.

[0246] In summary, based on the motor's current speed and its maximum speed within a preset historical time period, the current driving state of the vehicle can be understood more accurately, making it easier to infer the road surface adhesion characteristics. This allows for adjustments to the initial road surface adhesion level, resulting in a corrected road surface adhesion level after self-learning.

[0247] In some embodiments, if the initial road surface adhesion level is greater than a preset lower level, and the product of the current rotational speed and the target direction correction factor is less than the first target rotational speed, and the duration for which the product of the current rotational speed and the target direction correction factor is less than the first target rotational speed is greater than the calibrable duration of 1, then the initial road surface adhesion level can be downgraded. Specifically, downgrading the initial road surface adhesion level can be done by subtracting 1 level from the initial road surface adhesion level to obtain the corrected road surface adhesion level after self-learning. The product of the current rotational speed and the target direction correction factor can also be referred to as the absolute value of the current rotational speed.

[0248] The target direction correction factor can be determined based on the vehicle's gear position. For example, the target direction correction factor can be set to 1 when the gear is in drive (D or M) and -1 when the gear is in reverse (R).

[0249] The aforementioned first target speed is a decorrelated speed threshold determined based on the initial road surface adhesion level. This decorrelated speed threshold characterizes the minimum speed at which the motor operates when the vehicle is traveling on a road surface of that level. When the motor speed is lower than this decorrelated speed threshold, it indicates that the actual road surface adhesion level of the vehicle is currently on is lower than the initial road surface adhesion level, and the initial road surface adhesion level needs to be downgraded. Assuming the initial road surface adhesion level is level 2, and the decorrelated speed threshold for level 2 is 50 rpm, then the first target speed can be determined to be 50 rpm.

[0250] The aforementioned preset low level can be set according to actual needs. For example, it can be set to the lowest level among the previously established road surface adhesion levels, i.e., level 1. By determining that the initial road surface adhesion level is greater than the preset low level, it can be determined that there is still room for downgrading the current initial road surface adhesion level.

[0251] For example, the preset low level is level 1, the initial road surface adhesion level is level 2, the relevant subtraction speed threshold corresponding to level 2 is 50 rpm, that is, the first target speed is 50 rpm, and the calibrable duration 1 corresponding to level 2 is 5s. At this time, the current speed of the motor is obtained as 30 rpm, the current gear lever position is D, and the target direction correction factor 1 can be determined. The absolute value of the current speed obtained by multiplying the current speed by the target direction correction factor is 30 rpm. 30 rpm is less than the first target speed of 50 rpm, and the initial road surface adhesion level is level 2 which is greater than the preset low level (level 1). Furthermore, the duration for which the absolute value of the current motor speed is continuously detected to be less than 50 rpm is greater than the calibrable duration 1 (5s). At this time, the initial road surface adhesion level (level 2) is reduced by 1 level, and the corrected road surface adhesion level after self-learning is level 1.

[0252] The calibrable duration 1 is the time interval for downgrade adjustment corresponding to the initial road surface adhesion level. This is used to exclude situations where the absolute value of the motor's current speed is briefly lower than the first target speed due to other reasons, thus avoiding erroneous adjustments to the initial road surface adhesion level. Assuming the initial road surface adhesion level is level 2, the corresponding calibrable duration 1 could be, for example, 5 seconds.

[0253] In other embodiments, if the initial road surface adhesion level is lower than a preset higher level, and the maximum speed of the motor within a preset historical time period is greater than a second target speed, and the duration for which the maximum speed is greater than the second target speed is greater than the calibrable time period of 2, then the initial road surface adhesion level can be upgraded. Specifically, upgrading the initial road surface adhesion level can involve adding one level to the initial road surface adhesion level to obtain the corrected road surface adhesion level after self-learning.

[0254] The aforementioned second target speed is an additively correlated speed threshold determined based on the initial road surface adhesion level. This threshold characterizes the maximum speed at which the motor operates when the vehicle is traveling on a road surface of that level. When the motor speed exceeds this threshold, it indicates that the actual road surface adhesion level is higher than the initial level, requiring an upgrade to the initial road surface adhesion level. Assuming the initial road surface adhesion level is level 2, and the corresponding additively correlated speed threshold is 1000 rpm, then the second target speed can be determined to be 1000 rpm.

[0255] The aforementioned preset high level can be set according to actual needs. For example, it can be set to the highest level among the previously established road surface adhesion levels, namely level 6. By determining that the initial road surface adhesion level is lower than the preset high level, it can be determined that there is room for upgrading and adjusting the current initial road surface adhesion level.

[0256] The calibrable duration 2 is the time interval for upgrading the initial road surface adhesion level. It is used to exclude situations where the maximum motor speed briefly exceeds the first target speed due to other reasons, thus avoiding erroneous adjustments to the initial road surface adhesion level. The calibrable duration 2 can be less than or equal to the calibrable duration 1. For example, if the initial road surface adhesion level is level 2, the corresponding calibrable duration 2 could be 3 seconds.

[0257] For example, the preset historical duration is 500 milliseconds (ms), the preset high-level is level 6, the initial road surface adhesion level is level 2, the relevant speed threshold corresponding to level 2 is 1000 rpm, that is, the second target speed is 1000 rpm, and the calibrable duration 2 corresponding to level 2 is 3 seconds. The maximum speed of the motor within 500 ms before the current moment is 1200 rpm. 1200 rpm is greater than the second target speed of 1000 rpm, and the initial road surface adhesion level of level 2 is less than the preset high-level (level 6), and the duration of continuous detection of the maximum speed greater than the second target speed of 1000 rpm is greater than the calibrable duration 2 (3 seconds), at this time, the initial road surface adhesion level (level 2) is increased by 1 level, and the corrected road surface adhesion level after self-learning is level 3.

[0258] Furthermore, after upgrading or downgrading the initial pavement adhesion level, a corrected pavement adhesion level after self-learning can be obtained. If the conditions for entering pavement adhesion level self-learning are still met after obtaining this corrected pavement adhesion level, it indicates that the corrected pavement adhesion level after self-learning needs to be adjusted again.

[0259] The corrected road surface adhesion level can be used as the initial road surface adhesion level before the next road surface adhesion level self-learning. Similarly, based on the current speed of the motor and the maximum speed of the motor within the preset historical time, the initial road surface adhesion level is adjusted to obtain the corrected road surface adhesion level after the next road surface adhesion level self-learning.

[0260] Through the continuous iteration of the above process, the road adhesion level can be adjusted each time using new parameter information (i.e., the current speed and the maximum speed of the motor within the preset historical time period from the current moment) until the vehicle meets the exit conditions for road adhesion level self-learning.

[0261] The exit conditions mentioned above may be reaching a certain number of learning cycles, or any of the following conditions: during a downgrade operation, the initial road surface adhesion level is equal to the preset low level; during an upgrade operation, the initial road surface adhesion level is equal to the preset high level; the current speed of the motor is greater than the first target speed and the maximum speed within the preset historical time period is less than the second target speed; the vehicle does not meet the entry conditions for road surface adhesion level self-learning.

[0262] For example, the corrected road adhesion level after this self-learning is level 3. After this self-learning, the vehicle meets the entry conditions for road adhesion level self-learning, and level 3 is used as the initial road adhesion level. The first target speed is obtained by subtracting the relevant speed threshold corresponding to the initial road adhesion level, and the second target speed is obtained by adding the relevant speed threshold corresponding to the initial road adhesion level. If the initial road adhesion level is level 3, which is greater than the preset lower level (level 1), then if the current motor speed is less than the first target speed, the initial road adhesion level (i.e., level 3) is subtracted by 1 level, resulting in a corrected road adhesion level of level 2. If the initial road adhesion level is level 3, which is less than the preset higher level (level 6), then if the current motor speed is greater than the second target speed, the initial road adhesion level is added by 1 level, resulting in a corrected road adhesion level of level 4.

[0263] If the exit conditions for road surface adhesion level self-learning are met, the corrected road surface adhesion level after the last self-learning can be determined as the final target road surface adhesion level. For example, if the vehicle no longer meets the entry conditions for road surface adhesion level self-learning after obtaining a corrected road surface adhesion level of 4, then the vehicle is determined to currently meet the exit conditions for road surface adhesion level self-learning. In this case, the corrected road surface adhesion level obtained from the last self-learning (i.e., level 4) is taken as the target road surface adhesion level.

[0264] In the above method, the initial road surface adhesion level is adjusted by the current speed of the motor and the maximum speed within a preset historical time. The above steps are repeated to achieve self-learning, which can quickly determine the target road surface adhesion level. Moreover, the motor speed can intuitively reflect the vehicle's slippage, thus improving the accuracy of determining the road surface adhesion level.

[0265] In some embodiments, because the road surface adhesion coefficient corresponding to preset road surfaces such as ice and snow is very low, it may not be possible to accurately determine whether the current road surface is an ice or snow surface during the aforementioned road surface adhesion level self-learning process. Therefore, a separate preset road surface level can be set, which can be obtained through self-learning for the preset road surface.

[0266] In one possible implementation, obtaining the target road surface adhesion level of the road surface where the vehicle is currently located includes: obtaining the current state parameters of the vehicle, and determining whether the current state parameters meet the activation conditions for self-learning for a preset road surface, wherein the preset road surface is a road surface with an adhesion coefficient less than a preset coefficient; if the activation conditions for self-learning for the preset road surface are met, determining the target road surface adhesion level as the preset road surface level.

[0267] The preset coefficient can be a small adhesion coefficient set in advance, such as the lower boundary of the highest level (i.e., level 6) in Table 1 above, which is 0.05. If the adhesion coefficient of the preset road surface is less than the preset coefficient, it means that the adhesion coefficient of the preset road surface is small, and the preset road surface is ice, snow, or other similar surfaces, and the road surface adhesion level cannot be determined through road surface adhesion level self-learning.

[0268] It is understood that the preset road surface level is any level other than the six levels in Table 1 above, and the target road surface adhesion level being the preset road surface level means that the road surface the vehicle is currently on is a low-adhesion preset road surface such as ice or snow. In some embodiments, the self-learning for the preset road surface can also be referred to as ice surface self-learning.

[0269] When determining whether the activation conditions for self-learning on a preset road surface are met, the current state parameters of the vehicle can include the gear position, throttle opening, road slope, current motor speed and torque, and current road surface adhesion level. Based on these current state parameters, it is determined whether the activation conditions for self-learning on the preset road surface are met.

[0270] When the activation conditions for self-learning for a preset road surface are met, the VCU activates the vehicle's self-learning state for the preset road surface, that is, sets the self-learning state for the preset road surface to active. When the self-learning state for the preset road surface is active, it can be determined that the vehicle is currently on a preset road surface with low adhesion, such as ice or snow, that is, the road surface adhesion level at this time is determined to be the preset road surface level.

[0271] In the above method, considering the special nature of the adhesion level of the preset road surface, a special self-learning function for the preset road surface is set up. When the current state parameters of the vehicle meet the activation conditions for the self-learning function for the preset road surface, the self-learning function for the preset road surface is activated. Through the self-learning function for the preset road surface, the adhesion level of the target road surface can be quickly determined to be the preset road surface level. This helps the vehicle to adopt a control strategy suitable for driving on the preset road surface, effectively improving the success rate of preventing vehicle skidding and ensuring the smooth progress of the rescue process.

[0272] In one possible implementation, the current state parameters include: throttle opening, current motor speed and current torque, and current road surface adhesion level. It is determined whether the current state parameters meet the activation conditions for self-learning for the preset road surface, including: if the throttle opening is greater than a second preset opening, the current speed is greater than a first preset speed, the current torque is within a preset torque range, and the current road surface adhesion level is less than a preset level, then it is determined that the activation conditions for self-learning for the preset road surface are met.

[0273] The purpose of self-learning for the preset road surface is to determine whether the adhesion level of the road surface the vehicle is currently on is the preset road surface level, so as to determine the anti-skid torque value based on the preset road surface level, limit the motor torque, and prevent the vehicle from skidding.

[0274] It is understandable that the second preset opening degree can be the same as the first preset opening degree, for example, both being 50%. When the throttle opening degree is greater than the second preset opening degree by 50%, it can be determined that the vehicle currently has a demand for high torque output. At this time, it is necessary to determine the anti-slip torque value to limit the torque of the motor. That is, it is determined that when the throttle opening degree is greater than the second preset opening degree, self-learning for the preset road surface is required.

[0275] The first preset speed is a relatively high speed, for example, 2000 rpm. When the current motor speed is higher than the first preset speed, it can be determined that the current motor speed is too high. The preset torque range is a relatively small torque range, for example, 50 Nm to 170 Nm. When the current motor torque is within the preset torque range, it can be determined that the current motor torque is low. If the motor speed is still high when the torque is low, it can be determined that the motor is currently experiencing severe slippage, and self-learning for the preset road surface is required.

[0276] The preset adhesion level is usually a lower level, for example, it can be slightly higher than the default level. Assuming the default level is 2, the preset level can be 3 or 4. When the vehicle is currently on a low-adhesion surface such as ice, the vehicle cannot learn the rules for self-learning the road adhesion level, and the road adhesion level will remain at the default level.

[0277] If the current road surface adhesion level is lower than the preset level, it can be determined that the adhesion coefficient of the road surface the vehicle is currently on is relatively high. If the road surface adhesion coefficient obtained by the self-learning of the road surface adhesion level is still relatively high when the motor speed is too high and the torque is too low, it can be determined that the vehicle cannot currently perform self-learning of the road surface adhesion level and needs to perform self-learning for the preset road surface.

[0278] Furthermore, if the activation conditions for self-learning of the preset road surface are met, and the duration of the activation conditions for self-learning of the preset road surface is greater than or equal to a second preset duration, then the self-learning state for the preset road surface is activated. The second preset duration is a pre-set calibration value, for example, 6 seconds.

[0279] In some embodiments, the current state parameters may further include: the gear position and the slope of the road surface where the vehicle is currently located. The activation conditions for self-learning for the preset road surface also include: the gear position is any one of D, R, or M and the slope is less than the preset slope.

[0280] Similar to the previously discussed "determining whether the entry conditions for road surface adhesion level self-learning are met," if the gear lever is in a forward gear (including D and M) or reverse gear (R), it indicates that the vehicle is in a gear with power output and capable of driving. The vehicle will only experience slippage in forward or reverse gears, requiring self-learning for the preset road surface.

[0281] The preset slope, for example, can be 5%, used to determine whether the road surface the vehicle is currently on is relatively flat. If the road surface slope is less than the preset slope, it is determined that the vehicle is currently driving on a relatively flat road surface. At this time, the vehicle is prone to slipping due to the influence of the road surface adhesion coefficient, especially on icy surfaces. In this case, it is determined that self-learning for the preset road surface is required.

[0282] Understandably, if the road slope is too steep, the vehicle's driving status will be greatly affected by gravity, making it difficult to accurately judge the vehicle's driving characteristics on low-adhesion road surfaces such as ice and snow. Therefore, self-learning for the preset road surface when the slope is relatively small can eliminate the interference of the slope on the vehicle's power and driving status.

[0283] In some embodiments, when the rescue mode is active, the self-learning state for the preset road surface is typically inactive by default. Road surface adhesion level self-learning is prioritized, and self-learning for the preset road surface is performed after the road surface adhesion level self-learning is completed.

[0284] In some embodiments, the self-learning state for a preset road surface is set to an inactive state if any of the following conditions are met: the rescue mode is not active; the gear lever is not in drive or reverse (i.e., in park or neutral), and the duration exceeds the calibrated duration (e.g., 6 seconds).

[0285] Furthermore, when the self-learning state for the preset road surface is set to the active state, it can be determined that the road surface where the vehicle is currently located is a preset road surface with low adhesion, such as ice, that is, the target road surface adhesion level is determined to be the preset road surface level.

[0286] It is understandable that when a vehicle includes the aforementioned road surface adhesion self-learning function and a self-learning function for a preset road surface, the road surface adhesion level can specifically include the six levels shown in Table 3 and a preset road surface level. For the seven levels of level 1, level 2, level 4, level 5, level 6 and preset road surface level, the vehicle stores different correspondences between motor operating parameters and anti-slip torque values.

[0287] In one possible implementation, the anti-slip torque value includes a maximum anti-slip torque value or a minimum anti-slip torque value. Limiting the motor torque based on the anti-slip torque value includes: determining a maximum torque limit or a minimum torque limit for the motor; determining the minimum of the maximum torque limit and the maximum anti-slip torque value as a first torque limit value; or, determining the maximum of the minimum anti-slip torque value and the minimum torque limit as a second torque limit value; and limiting the motor torque based on the first torque limit value or the second torque limit value.

[0288] As in the above embodiment, when the motor speed is positive, the determined anti-slip torque value is also positive, and at this time, the anti-slip torque value is the maximum anti-slip torque value. When the motor speed is negative, the determined anti-slip torque value is also negative, and at this time, the anti-slip torque value is the minimum anti-slip torque value.

[0289] The maximum torque limit of a motor is the maximum positive torque value that the motor can output, influenced by its performance. The minimum torque limit of a motor is the minimum negative torque value that the motor can output, also influenced by its performance. Once the anti-slip torque value is obtained, the maximum torque limit or minimum torque limit of the motor can be determined based on its relevant performance characteristics.

[0290] Specifically, when the anti-slip torque value is the maximum anti-slip torque value, the maximum torque limit of the motor is determined based on the relevant performance characteristics of the motor. When the anti-slip torque value is the minimum anti-slip torque value, the minimum torque limit of the motor is determined based on the relevant performance characteristics of the motor.

[0291] Once the maximum torque limit is determined, the smaller of the maximum anti-slip torque value and the maximum torque limit is taken to obtain the first torque limit value, which restricts the motor torque to be less than or equal to the first torque limit value. Once the minimum torque limit is determined, the larger of the minimum anti-slip torque value and the minimum torque limit is taken to obtain the second torque limit value, which restricts the motor torque to be greater than or equal to the second torque limit value.

[0292] For example, when the motor speed is positive, the motor output torque is also positive, and the corresponding anti-slip torque value is the maximum anti-slip torque value. Assuming the maximum anti-slip torque value is 360 Nm, the maximum torque limit of the motor is determined to be 350 Nm based on its relevant performance characteristics. If the maximum torque limit is less than the maximum anti-slip torque value, then the maximum torque limit is determined as the first torque limit value, i.e., the first torque limit value is 350 Nm. Afterwards, the motor output torque is limited to be less than the first torque limit value of 350 Nm.

[0293] For example, when the motor speed is negative, the motor output torque is also negative, and the corresponding anti-slip torque value is the minimum slip torque value. Assuming the minimum anti-slip torque value is -360 Nm, the minimum torque limit for the motor is determined to be -350 Nm based on its performance characteristics. Since the minimum torque limit is greater than the minimum anti-slip torque value, this minimum torque limit is defined as the second torque limit value, i.e., -350 Nm. Subsequently, the motor output torque is limited to be greater than this second torque limit value of -350 Nm.

[0294] When limiting the motor torque based on a first torque limit value or a second torque limit value, the torque limit value needs to be corrected. The specific steps of the correction include: resetting the torque limit value to the motor's current output torque, and correcting the torque limit value from the motor's current output torque to the first torque limit value or the second torque limit value based on a certain gradient.

[0295] Specifically, when either the first or second torque limit value is greater than the motor's current output torque, an upward gradient can be determined based on the motor's current speed and the target road surface adhesion level, and then the torque limit value is corrected to the first or second torque limit value based on this upward gradient. When either the first or second torque limit value is less than the motor's current output torque, a downward gradient can be determined based on the motor's current speed and the target road surface adhesion level, and then the torque limit value is corrected to the first or second torque limit value based on this downward gradient.

[0296] The vehicle can store a first correspondence between motor speed, road surface adhesion level and upward gradient, and a second correspondence between motor speed, road surface adhesion level and downward gradient. The first or second correspondence can be found based on the current motor speed and the target road surface adhesion level to determine the upward or downward gradient.

[0297] In some embodiments, a first correspondence and a second correspondence can be calibrated for D and M gears, and a different first correspondence and a second correspondence can be calibrated for R gear. The two types of first and second correspondences are stored according to the gear position of the gear lever. Before looking up the correspondence, the target correspondence needs to be determined based on the gear position of the gear lever, and then the ascending or descending gradient needs to be determined based on the target correspondence.

[0298] Understandably, a vehicle's acceleration, deceleration, and torque requirements differ when in D, M, and R gears. For example, D and M are drive gears, typically requiring faster response and higher torque output. R is reverse gear, typically requiring slower response and lower torque output. Therefore, the upward or downward gradient between M and D gears is usually larger, while the upward or downward gradient between R gears is smaller.

[0299] In some embodiments, when the motor is in speed control mode, if any one of the following conditions 1 to 5 is detected to be met, the torque limit value is reset to the current torque of the motor, and then the torque limit value is corrected from the current torque of the motor to 0 according to a gradient related to the motor speed and the road surface adhesion level.

[0300] Condition 1: Rescue mode is exited; Condition 2: The rescue mode type is not type 1 "Motor speed control type"; Condition 3: The gear lever is in P or N position; Condition 4: The gear lever is in any one of D, M, or R position, and (the brake pedal travel is greater than the preset reference travel (e.g., 20%), or the Electronic Parking Brake (EPB) is off, or the Automatic Vehicle Hold (AVH) is active); Condition 5: The ignition switch is switched to the off position.

[0301] In some embodiments, once it is determined that the motor has exited the speed control mode, the vehicle will no longer perform the aforementioned torque limit value correction operation.

[0302] In some embodiments, the anti-slip torque value may include both a maximum anti-slip torque value and a minimum anti-slip torque value. For example, a positive value of the found anti-slip torque may be used as the maximum anti-slip torque value, and a negative value of the found anti-slip torque may be used as the minimum anti-slip torque value. Based on the relevant performance of the motor, both a maximum torque limit and a minimum torque limit are determined. Then, the minimum of the maximum torque limit and the maximum anti-slip torque value is determined as a first torque limit value; and the maximum of the minimum anti-slip torque value and the minimum torque limit is determined as a second torque limit value; thus, the motor torque is limited to the range determined by the first and second torque limit values.

[0303] In some embodiments, when the motor speed control mode is activated as described above, the motor speed control correction state of the rescue mode can also be activated. Before performing the following steps: "determine the minimum value between the maximum torque limit and the maximum anti-slip torque value as the first torque limit value; or determine the maximum value between the minimum anti-slip torque value and the minimum torque limit value as the second torque limit value", it is also necessary to determine that the motor speed control correction state of the rescue mode is activated.

[0304] In some embodiments, when the motor speed control correction state in the rescue mode is inactive, the operation of taking the smaller of the maximum torque limit and the maximum anti-slip torque value will be canceled, and the operation of taking the larger of the minimum anti-slip torque value and the minimum torque limit will also be canceled. In this case, the output torque of the motor is not limited.

[0305] In the above method, the output torque of the motor is limited by taking the smaller of the maximum anti-slip torque value and the maximum torque limit of the motor itself; or, the output torque of the motor is limited by taking the larger of the minimum torque limit and the minimum anti-slip torque value of the motor itself. This achieves the limitation of the motor's own performance parameters on the motor's output torque when limiting the motor's output torque, ensuring that the output torque of the motor can reduce vehicle slippage while ensuring the safety of motor operation.

[0306] In one possible implementation, determining the maximum or minimum torque limit of the motor includes: determining the discharge current limit of the motor based on the peak discharge power, maximum discharge current, motor voltage, high-voltage accessory current consumption, and reserved discharge current of the battery management system, and determining the maximum torque limit based on the discharge current limit; or, determining the charging current limit of the motor based on the peak charging power, maximum charging current, motor voltage, high-voltage accessory current consumption, and reserved charging current of the battery management system, and determining the minimum torque limit based on the charging current limit.

[0307] The peak discharge power of a Battery Management System (BMS) refers to the maximum power that the battery can provide over a short period of time. The maximum discharge current refers to the maximum allowable discharge current of the high-voltage battery. Different high-voltage battery models typically correspond to different peak discharge powers and different maximum discharge currents. By obtaining the high-voltage battery model in the current vehicle, the peak discharge power and maximum discharge current of the BMS can be determined based on the high-voltage battery model.

[0308] Motor voltage refers to the operating voltage of a motor. Usually, the corresponding operating parameters of the motor are calibrated in advance, and the operating voltage of the motor can be determined based on the calibrated operating parameters.

[0309] The high-voltage accessory current consumption refers to the current consumed by the high-voltage accessories currently operating in the vehicle's high-voltage system. These high-voltage accessories can include components such as air conditioners and heaters. To determine the high-voltage accessory current consumption, it is necessary to identify the currently operating high-voltage accessories in the vehicle. The sum of the current consumption of each operating high-voltage accessory will yield the total high-voltage accessory current consumption.

[0310] Reserved discharge current refers to a portion of current reserved to ensure vehicle safety and stability. It is usually a calibration value set in advance based on the vehicle's performance, and the reserved discharge current can be obtained by directly acquiring this calibration value stored in the vehicle.

[0311] After obtaining the aforementioned high-voltage battery discharge parameters, the discharge current limit of the motor can be determined based on these parameters. The motor's discharge current limit refers to the maximum current that the motor can safely and effectively obtain from the battery under given conditions. This limit is specifically affected by discharge-related parameters such as the peak discharge power of the battery management system, the maximum discharge current, the motor voltage, the current consumed by high-voltage accessories, and the reserved discharge current.

[0312] When the motor speed is positive, the high-voltage battery discharges to provide electrical energy to the motor. At this time, the aforementioned discharge-related parameters can be obtained. Based on these parameters, the motor's discharge current limit is determined, and based on this discharge current limit, the maximum torque limit is determined.

[0313] The peak discharge power of a battery management system is typically measured in kilowatts (kW). Based on discharge-related parameters, the process for determining the discharge current limit can be illustrated by the following formula:

[0314] Motor discharge current limit = max[min(BMS peak discharge power * 1000 / motor voltage, BMS discharge current constraint) - accessory current consumption - reserve, 0].

[0315] In the above formula, the peak discharge power of the battery management system is first multiplied by 1000 to convert it to watts (W); then the peak discharge power of the battery management system after conversion is divided by the motor voltage to obtain the preliminary maximum discharge current; then the minimum value between the preliminary maximum discharge current and the maximum discharge current of the battery calibrated by the battery management system is determined as the reference maximum discharge current; the current consumed by the high-voltage accessories and the reserved discharge current are subtracted from the reference maximum discharge current to obtain the candidate maximum discharge current; finally, the maximum value between the candidate maximum discharge current and 0 is used as the discharge current limit of the motor.

[0316] The process of determining the maximum torque limit based on the discharge current limit may include: determining the torque constant of the motor; usually a constant calibrated in advance for the motor; multiplying the discharge current limit by the torque constant of the motor to obtain the maximum torque limit.

[0317] For example, if the calculated discharge current limit is 136.67A and the motor torque constant is 0.1Nm / A, then the maximum torque limit = discharge current limit * torque constant = 13.67Nm.

[0318] The peak charging power of a battery management system (BMS) refers to the maximum power the battery can accept over a short period of time. The maximum charging current refers to the maximum allowable charging current for the high-voltage battery. Different high-voltage battery models typically correspond to different peak charging powers and different maximum charging currents. By obtaining the high-voltage battery model in the current vehicle, the peak charging power and maximum charging current of the BMS can be determined based on the high-voltage battery model.

[0319] The motor voltage and current consumption of high-voltage accessories are as described in the above embodiments and will not be repeated here. Reserved charging current refers to a portion of the charging current reserved to ensure vehicle safety and stability. It is usually a calibration value pre-set based on the vehicle's performance; this calibration value stored in the vehicle can be directly obtained to determine the reserved charging current.

[0320] After obtaining the aforementioned high-voltage battery charging parameters, the charging current limit of the motor can be determined based on these parameters. The motor's charging current limit refers to the maximum current that the motor can safely and effectively obtain from the battery under given conditions. This limit is specifically affected by charging-related parameters such as the peak charging power of the battery management system, the maximum charging current, the motor voltage, the current consumed by high-voltage accessories, and the reserved charging current.

[0321] When the motor speed is negative, the motor generates electricity and supplies power to the high-voltage battery to charge it. At this time, the aforementioned charging-related parameters can be obtained. Based on these parameters, the motor's charging current limit can be determined, and based on this charging current limit, the minimum torque limit can be determined.

[0322] The peak charging power of a battery management system is typically measured in kilowatts (kW), and the charging current is usually negative. The process of calculating the charging current limit can include: first, multiplying the peak charging power of the battery management system by 1000 to convert it to watts (W); then, dividing the converted peak charging power of the battery management system by the motor voltage and taking the negative value to obtain the initial minimum charging current; then, determining the maximum value between the initial minimum charging current and the minimum charging current of the battery calibrated by the battery management system as the reference minimum charging current; subtracting the current consumed by high-voltage accessories and the reserved charging current from the reference minimum charging current to obtain the candidate minimum charging current; finally, taking the minimum value between the candidate minimum charging current and 0 as the charging current limit of the motor.

[0323] The specific calculation process for the motor charging current limit can be exemplified as follows: Motor charging current limit = min[max(BMS peak charging power * 1000 / motor voltage * -1, BMS charging current constraint) - accessory current consumption - reserve, 0].

[0324] The process of determining the minimum torque limit based on the charging current limit may include: determining the torque constant of the motor; multiplying the charging current limit by the torque constant of the motor to obtain the minimum torque limit.

[0325] For example, if the calculated charging current limit is -136.67A and the motor torque constant is 0.1Nm / A, then the minimum torque limit = charging current limit * torque constant = -13.67Nm.

[0326] In some embodiments, after obtaining the target road surface adhesion level, the speed limit corresponding to the target road surface adhesion level can also be determined. The maximum value of the target speed should be limited by a speed limit related to a front axle road surface adhesion level (different calibration values ​​are provided for when the preset road surface self-learning state is active or inactive).

[0327] In some embodiments, when the rescue mode is active, the motor is in a non-stalled state, and the towing state is active, the vehicle's hydraulic brake compensation enable flag can also be set to an active state. Setting the hydraulic brake compensation enable flag to an active state indicates that compensation for the vehicle's hydraulic braking torque can currently be performed.

[0328] In some embodiments, it is also necessary to determine that the self-learning for the preset road surface is inactive before activating the hydraulic brake compensation enable flag.

[0329] With the hydraulic brake compensation enable flag set to active, the current motor speed and the vehicle's current reference speed can be obtained. Based on the current speed and reference speed, a hydraulic compensation torque value is determined to compensate for the hydraulic brake torque. The reference speed is the vehicle's speed relative to the ground. The preset history duration can be, for example, 500ms prior to the current moment.

[0330] The process of determining a hydraulic compensation torque value based on the current speed and the reference vehicle speed includes: determining the reference speed of the motor based on the reference vehicle speed, subtracting the reference speed from the current speed of the motor to obtain the speed difference, determining a hydraulic compensation torque value based on the current speed of the motor and the speed difference, and adjusting the hydraulic braking torque intervention value to the determined hydraulic compensation torque value.

[0331] As can be understood, the reference speed is the vehicle's speed relative to the ground, i.e., the vehicle's actual speed. The reference motor speed, determined based on this reference speed, is the speed the motor should maintain when the vehicle is traveling at the reference speed. The difference between the motor's current speed and the reference speed characterizes the difference between the motor's current speed and the actual speed to be maintained. This speed difference is usually caused by vehicle slippage, therefore, the speed difference can intuitively represent the vehicle's current slippage state.

[0332] The current motor speed and speed difference can jointly reflect the degree of slippage. The hydraulic compensation torque value determined based on the current motor speed and speed difference can reduce vehicle slippage. Through hydraulic braking and torque limiting, the success rate of slippage control can be effectively improved.

[0333] In summary, this application sets multiple availability states for the rescue mode, improving the accuracy, safety, and flexibility of rescue mode activation control. When the rescue mode's availability state is "available" and the battery charge is greater than the preset charge level, the rescue mode type is determined to be motor speed control, ensuring vehicle range while improving the accuracy of rescue operations in rescue mode. After the rescue mode is activated, by activating the motor speed control mode and controlling the motor torque based on the target speed, it can be ensured that the motor output torque in rescue mode provides sufficient traction, guaranteeing rescue efficiency. By setting a road adhesion level self-learning function, the road adhesion level can be obtained by self-learning based on the motor's current speed and the maximum speed within a preset historical time period, simplifying the determination method of road adhesion level, improving the efficiency of road adhesion level determination, and reducing costs by not relying on the road adhesion coefficient. Considering the special nature of the preset road adhesion level, a dedicated self-learning function for the preset road is set. When the vehicle's current state parameters meet the activation conditions for the self-learning function for the preset road, the self-learning function for the preset road is activated, determining the target road adhesion level as the preset road level, further improving the efficiency of road adhesion level determination. Determining the anti-skid torque value based on the road surface adhesion level and limiting the motor torque based on this value can effectively reduce the risk of vehicle skidding and ensure the safety of the rescue process.

[0334] Figure 4 This is a schematic diagram of a device for controlling a vehicle provided in an embodiment of this application.

[0335] For example, such as Figure 4 As shown, the device 400 includes:

[0336] The first activation module 401 is used to activate the vehicle's rescue mode and determine the type of rescue mode when the preset activation conditions are met.

[0337] The second activation module 402 is used to determine whether to activate the motor speed control mode of the vehicle when the rescue mode is active and the rescue mode type is motor speed control.

[0338] The first control module 403 is used to determine the target speed of the motor when the motor speed control mode is activated, and to control the torque of the motor based on the target speed.

[0339] The second control module 404 is used to determine the anti-slip torque value based on the current motor operating parameters during the process of controlling the motor torque based on the target speed, and to limit the motor torque based on the anti-slip torque value.

[0340] It is not difficult to see that the embodiments of this application are device embodiments corresponding to the method embodiments described above, and the embodiments of this application can be implemented in conjunction with the method embodiments described above. The relevant technical details and technical effects mentioned in the method embodiments described above are still effective in the embodiments of this application, and will not be repeated here to reduce repetition.

[0341] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0342] 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.

[0343] 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.

[0344] 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.

[0345] When each functional module is divided according to its corresponding function, the device may further include a first activation module, a second activation module, a first control module, and a second control 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.

[0346] 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.

[0347] 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.

[0348] 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.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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: If the preset activation conditions are met, the vehicle's rescue mode is activated, and the type of the rescue mode is determined. If the rescue mode is active and the rescue mode type is motor speed control, determine whether to activate the motor speed control mode of the vehicle. When the motor's speed control mode is active, the target speed of the motor is determined, and the torque of the motor is controlled based on the target speed. In the process of controlling the motor torque based on the target speed, an anti-slip torque value is determined based on the current motor operating parameters, and the motor torque is limited based on the anti-slip torque value.

2. The method according to claim 1, characterized in that, The process of determining the anti-slip torque value based on the current motor operating parameters includes: Obtain the target road surface adhesion level of the road surface where the vehicle is currently located; Determine the correspondence between the target road surface adhesion level and the target road surface adhesion level; the correspondence is used to describe the relationship between the motor operating parameters and the anti-slip torque value under the target road surface adhesion level. Based on the correspondence, the anti-slip torque value corresponding to the current motor operating parameters is determined.

3. The method according to claim 2, characterized in that, The step of obtaining the target road surface adhesion level of the road surface where the vehicle is currently located includes: Obtain the current state parameters of the vehicle and determine whether the current state parameters meet the entry conditions for road surface adhesion level self-learning. If the conditions for self-learning of the road surface adhesion level are met, the road surface adhesion level is self-learned based on the current speed of the motor and the maximum speed of the motor within a preset historical time period to determine the target road surface adhesion level of the road where the vehicle is located.

4. The method according to claim 3, characterized in that, The method of performing road surface adhesion level self-learning based on the current speed of the motor and the maximum speed of the motor within a preset historical time period to determine the target road surface adhesion level of the road surface where the vehicle is located includes: The initial road surface adhesion level is determined before the road surface adhesion level self-learning is performed; wherein, when the rescue mode is activated and the road surface adhesion level self-learning is not performed, the initial road surface adhesion level is the default level; Based on the current speed of the motor and the maximum speed of the motor within a preset historical time period, the initial road surface adhesion level is adjusted to obtain the corrected road surface adhesion level after self-learning. After obtaining the corrected road surface adhesion level, if the entry conditions for the road surface adhesion level self-learning are still met, the corrected road surface adhesion level is used as the initial road surface adhesion level before the next road surface adhesion level self-learning. The initial road surface adhesion level is adjusted based on the current speed of the motor and the maximum speed within the preset historical time period to obtain the corrected road surface adhesion level after the next road surface adhesion level self-learning, until the exit conditions for the road surface adhesion level self-learning are met. The corrected road surface adhesion level after the last self-learning of the road surface adhesion level is determined as the target road surface adhesion level for the vehicle.

5. The method according to claim 3, characterized in that, The current state parameters include: dragging state, throttle opening, and motor torque. Determining whether the current state parameters meet the entry conditions for road surface adhesion level self-learning includes: When the towing state is active, the throttle opening is greater than a first preset opening, and the absolute value of the motor torque is greater than the target torque, it is determined that the vehicle meets the entry conditions for the road surface adhesion level self-learning; wherein, the towing state is activated when the rescue mode is active, the rescue mode type is motor speed control type, and the absolute value of the motor torque is greater than the first preset torque.

6. The method according to claim 2, characterized in that, The step of obtaining the target road surface adhesion level of the road surface where the vehicle is currently located includes: The current state parameters of the vehicle are obtained, and it is determined whether the current state parameters meet the activation conditions for self-learning for a preset road surface, wherein the preset road surface is a road surface with an adhesion coefficient less than a preset coefficient. If the activation conditions for self-learning for the preset road surface are met, the target road surface adhesion level is determined to be the preset road surface level.

7. The method according to claim 6, characterized in that, The current state parameters include: throttle opening, current motor speed and torque, and current road surface adhesion level. Determining whether the current state parameters meet the activation conditions for self-learning on a preset road surface includes: When the throttle opening is greater than the second preset opening, the current speed is greater than the first preset speed, the current torque is within the preset torque range, and the current road surface adhesion level is less than the preset level, it is determined that the activation conditions for self-learning for the preset road surface are met.

8. The method according to any one of claims 1 to 7, characterized in that, The determination of whether to activate the motor speed control mode of the vehicle includes: The vehicle's gear position, brake pedal travel, drive mode, transmission gear, and the current torque and speed of the motor are obtained. When the gear lever is in any one of D, R, or M gear, the brake pedal travel is less than a preset travel, the drive mode is pure electric drive mode, the transmission gear is a preset gear, the absolute value of the current torque is less than a second preset torque, and the current speed is less than a second preset speed, the motor speed control mode is activated.

9. The method according to any one of claims 1 to 7, characterized in that, Determining the target speed of the motor includes: Obtain the throttle opening of the vehicle; The target vehicle speed is determined based on the throttle opening. The target rotational speed is calculated based on the target vehicle speed, the vehicle's tire radius, and the preset speed ratio.

10. The method according to any one of claims 1 to 7, characterized in that, The anti-slip torque value includes a maximum anti-slip torque value or a minimum anti-slip torque value, and limiting the motor torque based on the anti-slip torque value includes: Determine the maximum torque limit or minimum torque limit of the motor; The minimum value between the maximum torque limit and the maximum anti-slip torque value is determined as the first torque limit value; or, the maximum value between the minimum anti-slip torque value and the minimum torque limit is determined as the second torque limit value. The torque of the motor is limited based on either the first torque limit value or the second torque limit value.

11. The method according to claim 10, characterized in that, Determining the maximum torque limit or minimum torque limit of the motor includes: Based on the peak discharge power, maximum discharge current, motor voltage, high-voltage accessory current consumption, and reserved discharge current of the battery management system, the discharge current limit of the motor is determined, and based on the discharge current limit, the maximum torque limit is determined; or, Based on the peak charging power, maximum charging current, motor voltage, high-voltage accessory current consumption, and reserved charging current of the battery management system, the charging current limit of the motor is determined, and based on the charging current limit, the minimum torque limit is determined.

12. The method according to any one of claims 1 to 7, characterized in that, Determining the type of the rescue mode includes: Obtain the availability status of the vehicle's rescue mode and battery level; If the availability status is available and the battery charge is greater than the preset charge, the rescue mode type is determined to be the motor speed control type.

13. 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 12.

14. 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 12.

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