Vehicle control method, vehicle, and computer-readable storage medium

Abstract

The present application relates to the field of vehicle control, and provides a vehicle control method, a vehicle, and a computer-readable storage medium. The method comprises: when it is determined that a vehicle slides downward due to gravity during uphill driving, if receiving brake pedal travel, on the basis of the brake pedal travel, obtaining a first braking force to be allocated to wheels; when the first braking force is greater than a wheel braking force limit, reducing the first braking force to below the wheel braking force limit so as to obtain a second braking force; controlling a service braking system to apply a braking force to each wheel on the basis of the second braking force; acquiring a slip ratio of the wheel; and when the slip ratio of the wheel is less than the minimum value of a threshold interval, controlling a power system and / or a parking braking system to perform braking force compensation on the wheel, so that the slip ratio of the wheel is within the threshold interval. The present application can avoid vehicle instability when the vehicle experiences rollback or downhill sliding, thereby being conducive to improving the stability and safety of the vehicle in an off-road scenario.

Description

Vehicle control methods, vehicles, and computer-readable storage media

[0001] This application claims priority to Chinese Patent Application No. 2025100769093, filed on January 17, 2025, entitled "Vehicle Control Method, Vehicle and Computer-Readable Storage Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of vehicle control, and more particularly to a vehicle control method, a vehicle, and a computer-readable storage medium in the field of vehicle control. Background Technology

[0003] With the increasing popularity of off-road vehicles, more and more drivers prefer to drive in complex terrain conditions, especially in mountainous areas, deserts, or muddy roads. However, in these extreme environments, especially when climbing steep slopes, vehicles are prone to backsliding or rolling backwards. During this process, the vehicle is susceptible to instability, posing safety hazards to the driver and passengers. Summary of the Invention

[0004] This application provides a vehicle control method, a vehicle, and a computer-readable storage medium. This application can prevent vehicle instability when the vehicle is on a slope or slipping, which helps to improve the stability and safety of the vehicle in off-road scenarios.

[0005] In a first aspect, a vehicle control method is provided, comprising: when it is determined that a preset phenomenon occurs during vehicle climbing, if a first brake pedal travel is received, for each wheel, obtaining a first target braking torque allocated to the wheel based on the first brake pedal travel; wherein the preset phenomenon is the phenomenon of the vehicle sliding downhill on the slope due to gravity; if the first target braking torque is greater than the wheel braking torque extreme value, reducing the first target braking torque to obtain a second target braking torque corresponding to the wheel; wherein the second target braking torque is less than the wheel braking extreme value; controlling the service braking system to apply braking torque to the wheel based on the second target braking torque; obtaining the actual slip ratio of the wheel; if the actual slip ratio is less than the minimum value of the slip ratio threshold range, controlling the power system and / or parking braking system to perform braking torque compensation on the wheel so that the actual slip ratio is within the slip ratio threshold range.

[0006] In one possible implementation, when the actual slip ratio is less than the minimum value of the slip ratio threshold range, controlling the power system and / or parking brake system to compensate for the braking torque of the wheel includes: when the actual slip ratio is less than the minimum value of the slip ratio threshold range, obtaining the second brake pedal travel and the actual braking torque applied to the wheel by the service brake system; if the second brake pedal travel is greater than the first brake pedal travel and the actual braking torque is less than the extreme value of the wheel braking torque, controlling the power system and / or parking brake system to compensate for the braking torque of the wheel.

[0007] In one possible implementation, the control of the powertrain and / or parking brake system to compensate for the braking torque of the wheels includes at least one of the following: controlling the target drive motor in the powertrain to output a first stall torque, using the first stall torque as a compensating braking torque, and applying it to the wheels; controlling the parking brake system to output a first parking braking torque, using the first parking braking torque as a compensating braking torque, and applying it to the wheels; controlling the target drive motor in the powertrain to output a second stall torque, using the sum of the second stall torque and the second parking braking torque as a compensating braking torque, and applying it to the wheels; wherein, the target drive motor is the drive motor that drives the wheels, the first stall torque and the second stall torque are both in the opposite direction to the drive torque output by the target drive motor, and the compensating braking torque is the difference between the extreme value of the wheel braking torque and the actual braking torque.

[0008] In one possible implementation, the vehicle control method further includes: when the target drive motor meets a first condition, executing the step of controlling the target drive motor in the power system to output a first stall torque; wherein the first condition includes the ambient temperature being less than a first temperature threshold, the motor temperature being less than a second temperature threshold, the battery temperature of the power battery being less than a third temperature threshold, the remaining charge of the power battery being greater than a charge threshold, and the motor output power being greater than a power threshold.

[0009] In one possible implementation, controlling the target drive motor in the power system to output a first stall torque includes: controlling the target drive motor to output a first stall torque according to a time-torque curve with a first slope; controlling the parking brake system to output a first parking braking torque includes: controlling the parking brake system to output a first parking braking torque according to a time-torque curve with a second slope.

[0010] In one possible implementation, the vehicle control method further includes: determining the first wheel vertical load based on the change in suspension height corresponding to the wheel and the actual slope of the road where the vehicle is located; and obtaining the extreme value of the wheel braking torque based on the product of the first wheel vertical load and the actual slip ratio.

[0011] In one possible implementation, obtaining the actual slip ratio of the wheel includes: acquiring a road image of the road where the vehicle is located; determining the matching degree between the road image and a preset road image; and determining the actual slip ratio of the wheel based on the matching degree.

[0012] In one possible implementation, determining the actual slip ratio of the wheel based on the matching degree includes: if the matching degree is greater than the matching degree threshold, obtaining the actual vehicle speed and the linear velocity of the wheel; and determining the actual slip ratio of the wheel based on the actual vehicle speed and the linear velocity.

[0013] In one possible implementation, determining the actual slip ratio of the wheel based on the matching degree includes: if the matching degree is less than or equal to a matching degree threshold, determining the second wheel vertical load based on the suspension parameters of the vehicle suspension; wherein the suspension parameters include at least one of suspension deformation, suspension stiffness, and damping coefficient; determining the wheel longitudinal load based on a first target braking torque and a target torque emitted by the power system; wherein the target torque is a driving torque or a recovery torque; determining the road adhesion coefficient based on the ratio of the wheel longitudinal load to the second wheel vertical load; wherein the road adhesion coefficient includes multiple adhesion coefficient values; determining the derivative of the road adhesion coefficient with respect to the slip ratio during wheel slippage, obtaining multiple derivative values; and determining the adhesion coefficient value corresponding to the target derivative value as the actual slip ratio of the wheel; wherein the target derivative value is the derivative value among the multiple derivative values ​​whose difference from 0 is less than a preset difference.

[0014] In one possible implementation, determining the second wheel vertical load based on the suspension parameters of the vehicle suspension includes: determining the load transfer amount of the wheel based on the suspension deformation, suspension stiffness, and damping coefficient; determining the unsprung mass transfer amount based on the load transfer amount; obtaining the sprung load based on the suspension deformation; and obtaining the second wheel vertical load based on the unsprung mass, the unsprung mass transfer amount, and the sprung load.

[0015] In one possible implementation, after the powertrain and / or parking brake system compensates for the braking torque applied to the wheels, the vehicle control method further includes: in response to a brake pedal reset signal, controlling the powertrain and / or parking brake system to reduce the compensated braking torque applied to the wheels according to a gradient descent strategy.

[0016] In one possible implementation, after obtaining the actual slip ratio of the wheels, the vehicle control method further includes: prohibiting the control power system and parking brake system from performing braking torque compensation on the wheels when the actual slip ratio of the wheels is greater than the maximum value of the slip ratio threshold range.

[0017] In one possible implementation, after the vehicle braking system applies a braking torque to the wheels based on a second target braking torque, the vehicle control method further includes: restricting steering wheel rotation when a second condition is met; wherein the second condition includes at least one of the following: the vehicle's longitudinal acceleration is less than an acceleration threshold, the yaw angle is less than an angle threshold, the steering wheel rotation speed is greater than a rotation speed threshold, and there are no obstacles in the environment behind the vehicle.

[0018] In one possible implementation, the vehicle control method further includes: upon receiving an activation command for the vehicle's off-road assist function, obtaining the actual slope of the road where the vehicle is located; if the actual slope is greater than a slope threshold and the vehicle's driving direction is the same as the slope direction of the road, determining whether a preset phenomenon occurs during the vehicle's ascent.

[0019] In one possible implementation, obtaining the actual slope of the road where the vehicle is located includes: determining a first slope of the road based on the vehicle's longitudinal acceleration; obtaining a second slope of the road identified by the vehicle's intelligent driving system; if the deviation between the first slope and the second slope is less than or equal to a deviation threshold, determining the first slope or the second slope as the actual slope; if the deviation is greater than the deviation threshold, continuously obtaining multiple longitudinal accelerations within a preset time period; determining multiple third slopes of the road based on the multiple longitudinal accelerations, and determining the average of the multiple third slopes as the actual slope.

[0020] Secondly, a vehicle control device is provided, the vehicle control device comprising:

[0021] The first acquisition module is used to, when it is determined that a preset phenomenon occurs during the vehicle's ascent, if a first brake pedal travel is received, acquire a first target braking torque allocated to each wheel based on the first brake pedal travel; wherein, the preset phenomenon is the phenomenon of the vehicle sliding downhill on the slope due to gravity.

[0022] The torque adjustment module is used to reduce the first target braking torque when the first target braking torque is greater than the wheel braking torque limit, so as to obtain the second target braking torque corresponding to the wheel; wherein the second target braking torque is less than the wheel braking limit.

[0023] The braking control module is used to control the service braking system to apply braking torque to the wheels based on a second target braking torque;

[0024] The second acquisition module is used to acquire the actual slip ratio of the wheel;

[0025] The braking compensation module is used to control the power system and / or parking brake system to compensate the braking torque of the wheels when the actual slip ratio is less than the minimum value of the slip ratio threshold range, so that the actual slip ratio is within the slip ratio threshold range.

[0026] 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 vehicle control method of the first aspect or any possible implementation thereof.

[0027] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to execute the vehicle control method in the first aspect or any possible implementation thereof.

[0028] 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 vehicle control method of the first aspect or any possible implementation thereof. Attached Figure Description

[0029] Figure 1 shows a schematic flowchart of a vehicle control method provided in an embodiment of this application;

[0030] Figure 2 shows a schematic diagram of a vehicle slipping on a hill during its ascent;

[0031] Figure 3 shows a schematic diagram of the torque curve;

[0032] Figure 4 shows a schematic diagram of a vehicle control device provided in an embodiment of this application;

[0033] Figure 5 shows a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] With the increasing popularity of off-road vehicles, more and more drivers enjoy driving in complex terrain conditions, especially in mountainous areas, deserts, or muddy roads. However, in these extreme environments, particularly when climbing steep slopes, vehicles are prone to rolling backwards or sliding. For example, during a vehicle's backward or sliding motion, the normal pressure on the front axle tires is greatly reduced due to axle load transfer, making the front axle very susceptible to brake lock-up. Furthermore, due to the vehicle's direction of travel (facing downhill), the front axle effectively becomes the rear axle. If the front axle locks up, the vehicle will simultaneously lose steering ability and may fishtail, meaning the vehicle is prone to instability during backward or sliding motion, posing a safety hazard to the driver and passengers.

[0037] To address the aforementioned issues, this application provides a vehicle control method, a vehicle, and a computer-readable storage medium. This application utilizes intelligent control of braking torque to dynamically adjust the braking torque of each wheel when the vehicle experiences slippage during hill climbing. This ensures the wheels do not lock up and maintains an appropriate slip ratio. This strategy not only improves the vehicle's stability and safety on slopes but also optimizes braking force distribution, ensuring smooth deceleration. By monitoring and compensating for the actual wheel slip ratio in real time, braking performance can be further enhanced, ensuring vehicle safety and driving experience. Specifically, it prevents vehicle instability when the vehicle is rolling backwards or slipping, thus improving stability and safety in off-road scenarios.

[0038] The following is an embodiment of a vehicle control method provided in this application specification.

[0039] Figure 1 shows a schematic flowchart of a vehicle control method provided in an embodiment of this application. As shown in Figure 1, the vehicle control method provided in this embodiment is applied to the central control unit of a vehicle. The vehicle includes an intelligent driving system, a suspension system, a steering system, a braking system, a power system, etc. The intelligent driving system includes a radar system, a vision system, etc. The braking system includes a service braking system and a parking braking system. The power system includes an engine and a drive motor for driving the wheels. If there are two drive motors, one drive motor drives the front wheels and the other drive the rear wheels; if there are four drive motors, each drive motor drives one wheel. The parking braking system and the drive motors in the power system can both serve as backups for the parking braking system. Wheel braking control can also be achieved through the parking braking system and the drive motors. Controlling the parking calipers in the parking braking system to clamp can achieve wheel braking, and controlling the drive motor to output torque in the opposite direction to the driving torque can achieve wheel braking.

[0040] The above-mentioned vehicle control methods include the following schemes:

[0041] S110: When it is determined that the vehicle has a preset phenomenon during the uphill climb, if the first brake pedal travel is received, for each wheel, the first target braking torque to be allocated to the wheel is obtained according to the first brake pedal travel.

[0042] In an exemplary embodiment, the preset phenomenon is the phenomenon of a vehicle sliding down a slope due to gravity. For example, the preset phenomenon is specifically reverse slope or rollback. As shown in Figure 2, Figure 2 shows a schematic diagram of a vehicle rolling back down a slope during climbing. P represents the slope, C represents the vehicle, T represents the front of the vehicle, B represents the rear of the vehicle, and the arrow indicates the direction of the vehicle's rollback (which is also the opposite direction of the vehicle's travel direction, i.e., the direction of sliding downhill).

[0043] During vehicle climbing, if a preset phenomenon is detected and a brake pedal signal is received, it indicates that the driver has controlled the vehicle to brake. The first brake pedal travel is obtained from the brake pedal signal. For each wheel Wi, the preset braking torque corresponding to the first brake pedal travel is obtained to obtain the first target braking torque allocated to wheel Wi.

[0044] S120: When the first target braking torque is greater than the extreme value of the wheel braking torque, reduce the first target braking torque to obtain the second target braking torque corresponding to the wheel.

[0045] As the vehicle is uphill on a slope and begins to roll downhill, its center of gravity shifts significantly, resulting in uneven load distribution between the front and rear axles. Due to the component of gravity along the slope, the center of gravity shifts forward, reducing the vertical load on the front axle. This means less friction between the front wheels and the road surface, and consequently, a lower braking limit for the front axle. Conversely, the vertical load on the rear axle increases as more weight is transferred there, increasing friction between the rear wheels and the road surface, and resulting in a relatively higher braking limit for the rear axle.

[0046] The extreme value of wheel braking torque can also be understood as the maximum braking torque that a wheel can withstand. One way to determine the extreme value of wheel braking torque is: when the parameters of the suspension system can be obtained normally (the suspension system is in a normal state), it is calculated using parameters such as the change in suspension height corresponding to the wheel during vehicle operation and the actual slope of the road where the vehicle is located. Another way to determine the extreme value of wheel braking torque is: when the parameters of the suspension system cannot be obtained (the suspension system is in an abnormal state), the extreme value of wheel braking torque is the braking distance applied to the wheel when the wheel slip ratio is greater than the maximum value of the slip ratio threshold range. This can also be understood as the extreme value of wheel braking torque when the vehicle loses stability after braking control of the wheel.

[0047] After obtaining the first target braking torque allocated to wheel Wi, if it is determined that the first target braking torque allocated to wheel Wi is greater than the extreme value of the wheel braking torque corresponding to wheel Wi, it means that the first target braking torque allocated to wheel Wi exceeds the actual friction limit of wheel Wi, which may cause wheel Wi to lock up. To avoid this situation, the central control unit will reduce the first target braking torque allocated to wheel Wi to a safe range, ensuring that it does not exceed the extreme value of the wheel braking torque corresponding to wheel Wi. This can prevent wheel Wi from locking up, maintain the stability and controllability of the vehicle, and ensure that the vehicle can decelerate safely.

[0048] For the front wheels, the first target braking torque allocated to the front wheels is reduced to obtain the second target braking torque corresponding to the front wheels. The second target braking torque corresponding to the front wheels is less than the wheel braking extreme value corresponding to the front wheels. For the rear wheels, the reduced portion of the first target braking torque allocated to the front wheels is transferred to the rear wheels. The sum of the reduced portion and the wheel braking extreme value corresponding to the rear wheels is taken as the new wheel braking extreme value corresponding to the rear wheels. Then, based on the new wheel braking extreme value corresponding to the rear wheels, the first target braking torque allocated to the rear wheels is reduced to obtain the second target braking torque corresponding to the rear wheels. The second target braking torque corresponding to the rear wheels is less than the new wheel braking extreme value corresponding to the rear wheels. In this way, the second target braking torque corresponding to wheel Wi can be obtained.

[0049] S130: Control the service braking system to apply braking torque to the wheels based on the second target braking torque.

[0050] After obtaining the second target braking torque corresponding to wheel Wi, the vehicle braking system applies braking torque to wheel Wi based on this second target braking torque to control wheel Wi's deceleration, thereby controlling the overall vehicle deceleration. Since the second target braking torque corresponding to wheel Wi is less than the extreme value of the wheel braking torque corresponding to wheel Wi, applying braking torque to wheel Wi based on this second target braking torque ensures that wheel Wi will not lock up during the braking process controlled by the vehicle braking system.

[0051] S140: Obtain the actual slip ratio of the wheel.

[0052] After the vehicle braking system applies a braking torque to wheel Wi based on the second target braking torque corresponding to wheel Wi, the actual slip ratio of wheel Wi is obtained. The slip ratio refers to the difference between the actual linear velocity of the wheel and its theoretical rolling speed, reflecting the degree of wheel slippage relative to the road surface.

[0053] S150: When the actual slip ratio is less than the minimum value of the slip ratio threshold range, control the power system and / or parking brake system to compensate the braking torque of the wheels so that the actual slip ratio is within the slip ratio threshold range.

[0054] The slip ratio threshold range is determined based on the tire's friction characteristic curve. For example, the slip ratio threshold range is [10%, 20%]. Within this range, the tire provides maximum friction, ensuring vehicle stability and optimal braking performance. If the actual slip ratio of wheel Wi is less than the minimum value of the slip ratio threshold range, it indicates that the slip ratio of wheel Wi is too low, suggesting insufficient braking torque applied to wheel Wi by the service braking system, which may lead to poor vehicle deceleration. In this case, the powertrain and / or parking brake system are introduced to compensate for the braking torque of wheel Wi, restoring the actual slip ratio of wheel Wi to within the slip ratio threshold range.

[0055] This application embodiment employs a technical solution that, when a vehicle is determined to be sliding downhill due to gravity during hill climbing, if a first brake pedal travel is received, a first target braking torque is obtained for each wheel based on the first brake pedal travel. If the first target braking torque allocated to each wheel is greater than the wheel's maximum braking torque value, the first target braking torque allocated to each wheel is reduced to obtain a second target braking torque corresponding to each wheel. If the second target braking torque corresponding to each wheel is less than the wheel's maximum braking torque value, the service braking system is controlled to apply braking torque to each wheel based on the second target braking torque corresponding to each wheel, and the actual slip ratio of each wheel is obtained. If the actual slip ratio of each wheel is less than the minimum value of the slip ratio threshold range, the power system and / or parking brake system are controlled to perform braking torque compensation on each wheel, so that the actual slip ratio of each wheel is within the slip ratio threshold range. This technical solution can prevent vehicle instability when the vehicle is sliding downhill or rolling backwards, and is beneficial to improving the stability and safety of the vehicle in off-road scenarios. By reducing the target braking torque allocated to the wheels to below their maximum braking torque value, it ensures that the wheels do not exceed their friction limit and lock up. This not only improves vehicle stability but also avoids the risk of loss of control due to wheel lockup. By monitoring the actual wheel slip ratio in real time and compensating with braking force through the powertrain and / or parking brake system when the slip ratio is too low, it ensures that the wheel slip ratio remains within the slip ratio threshold range. This not only improves braking performance but also ensures vehicle stability and controllability.

[0056] In one possible implementation, when the actual slip ratio is less than the minimum value of the slip ratio threshold range, controlling the power system and / or parking brake system to compensate for the braking torque of the wheels includes the following steps:

[0057] When the actual slip ratio is less than the minimum value of the slip ratio threshold range, the second brake pedal travel and the actual braking torque applied to the wheels by the service brake system are obtained.

[0058] If the travel of the second brake pedal is greater than that of the first brake pedal and the actual braking torque is less than the extreme value of the wheel braking torque, the control power system and / or parking brake system shall compensate the wheel for the braking torque.

[0059] If the actual slip ratio of wheel Wi is less than the minimum value of the slip ratio threshold range, the brake pedal signal continues to be acquired. The second brake pedal travel is obtained from the acquired brake pedal signal. If the second brake pedal travel is greater than the first brake pedal travel, it indicates that the driver has found the vehicle's deceleration effect unsatisfactory and has continued to depress the brake pedal to increase braking force, meaning the driver intends to further control the vehicle and apply the brakes. Then, it is determined whether the actual braking torque applied by the service braking system to wheel Wi is less than the maximum braking torque that wheel Wi can withstand. If the actual braking torque applied by the service braking system to wheel Wi is less than the maximum braking torque that wheel Wi can withstand... The maximum braking torque indicates that the service braking system's ability to continuously increase pressure is insufficient, and there is still room for improvement in the braking torque applied to wheel Wi without causing wheel Wi to lock up. Simply applying braking torque to wheel Wi through the service braking system cannot keep the actual slip ratio of wheel Wi within the slip ratio threshold range. Therefore, the control power system and / or parking brake system provide additional braking torque compensation to wheel Wi. This can increase the braking torque of wheel Wi, restore the actual slip ratio of wheel Wi to within the slip ratio threshold range, compensate for the insufficient braking torque of the service braking system, and ensure that the vehicle can effectively decelerate and remain stable.

[0060] In one possible implementation, the aforementioned control power system and / or parking brake system compensates for the braking torque of the wheels, including at least one of the following:

[0061] The target drive motor in the control power system outputs a first stall torque, which is then used as a compensating braking torque and applied to the wheels.

[0062] The parking brake system outputs a first parking braking torque, which is then used as a compensating braking torque and applied to the wheels.

[0063] The target drive motor in the control power system outputs a second stall torque, and the sum of the second stall torque and the second parking braking torque is used as a compensating braking torque and applied to the wheels.

[0064] The target drive motor is the drive motor that drives the wheel Wi in the power system. The first stall torque and the second stall torque are both in the opposite direction to the drive torque output by the target drive motor. The compensation braking torque is the difference between the extreme value of the wheel braking torque of the wheel Wi and the actual braking torque of the wheel Wi, that is, the compensation braking torque = extreme value of the wheel braking torque - actual braking torque.

[0065] For the braking torque compensation of the wheel Wi only through the power system, the compensation braking torque is used as the target value of the torque output by the target drive motor, and the stall torque output by the target drive motor is controlled to gradually reach the compensation braking torque.

[0066] For wheel Wi braking torque compensation only through the parking brake system, the compensated braking torque is used as the target value of the parking brake system output parking brake torque, and the parking brake system output parking brake torque is controlled to gradually reach the compensated braking torque.

[0067] For the braking torque compensation of wheel Wi through the power system and parking brake system, the compensation braking torque is divided into two parts: the first part is the second stall torque, and the second part is the second parking braking torque. The second stall torque and the second parking braking torque can be the same or different. The second stall torque is used as the target value of the torque output by the target drive motor, and the stall torque output by the target drive motor is controlled to gradually reach the second stall torque. The second parking braking torque is used as the target value of the parking braking torque output by the parking brake system, and the parking braking torque output by the parking brake system is controlled to gradually reach the second parking braking torque.

[0068] In one possible implementation, the vehicle control method described above further includes the following steps:

[0069] If the target drive motor meets the first condition, the step of controlling the target drive motor in the power system to output the first stall torque is executed; wherein, the first condition includes the ambient temperature being less than a first temperature threshold, the motor temperature being less than a second temperature threshold, the battery temperature of the power battery being less than a third temperature threshold, the remaining charge of the power battery being greater than a charge threshold, and the motor output power being greater than a power threshold.

[0070] An ambient temperature below the first temperature threshold indicates that the external ambient temperature will not be too high, preventing the target drive motor and power battery from operating in high-temperature environments and preventing overheating risks. A motor temperature below the second temperature threshold indicates that the target drive motor's temperature is within a safe range, allowing it to output torque normally. A power battery temperature below the third temperature threshold indicates that the power battery's temperature is within a safe range, preventing the power battery from supplying power to the target drive motor at high temperatures, which could lead to safety accidents. A remaining power battery charge greater than the charge threshold indicates that the power battery has sufficient remaining charge to supply power to the target drive motor, ensuring the target drive motor can continuously output stall torque. A motor output power greater than the power threshold indicates that the stall torque output by the target drive motor can fully reach the first stall torque value.

[0071] Determining that the target drive motor meets the first condition indicates that the power system can operate normally, and that it is safe to compensate for the braking torque of the wheels Wi through the power system. Alternatively, the power system can completely compensate for the insufficient braking torque of the service braking system. Therefore, when the target drive motor meets the first condition, executing the step of controlling the target drive motor in the power system to output the first stall torque not only improves the safety of the target drive motor outputting the first stall torque, but also improves the reliability of the target drive motor outputting the first stall torque.

[0072] Before or during the braking torque compensation of wheel Wi, if the target drive motor does not meet any of the first conditions, the power system will not be used to compensate for the braking torque of wheel Wi. If the target drive motor does not meet the first condition that the remaining charge of the power battery is greater than the charge threshold, the engine will be started to charge the power battery. After the power battery is charged, if the first condition that the remaining charge of the power battery is still not greater than the charge threshold is not met, the power system will not be used to compensate for the braking torque of wheel Wi, and the parking brake system will be used to compensate for the braking torque of wheel Wi.

[0073] In one possible implementation, the output of the first stall torque by the target drive motor in the above-mentioned control power system includes the following steps:

[0074] The control target drive motor outputs the first stall torque according to the time-torque curve with the first slope.

[0075] As shown in Figure 3, which illustrates the torque curve, Q1 represents the time-torque curve with the first slope k1, T represents time, and F1 represents the stall torque. During the process of compensating for the braking torque of the wheels Wi using the power system, by controlling the target drive motor to gradually increase the stall torque output according to Q1 until the first stall torque is reached, it is possible to avoid the target drive motor suddenly outputting excessive stall torque, which helps reduce the impact on the vehicle and ensures vehicle stability.

[0076] The above-mentioned control of the parking brake system to output the first parking braking torque includes the following steps:

[0077] The parking brake system is controlled to output the first parking braking torque according to the time-torque curve with the second slope.

[0078] As shown in Figure 3, Q2 represents the time-torque curve with the second slope k2, and F2 represents the parking braking torque. During the process of using the parking braking system to compensate for the braking torque of wheel Wi, by controlling the parking braking system to gradually increase the output parking braking torque according to Q2 until the first parking braking torque is reached, it is possible to avoid the parking braking system suddenly outputting excessive parking braking torque, which helps to reduce the impact on the vehicle and ensure vehicle stability. k1 and k2 can be the same or different.

[0079] In one possible implementation, the vehicle control method described above further includes the following steps:

[0080] The calculation process for the maximum braking torque that wheel Wi can withstand includes:

[0081] The first vertical load of wheel Wi is determined based on the change in suspension height corresponding to wheel Wi and the actual slope of the road where the vehicle is located.

[0082] The maximum braking torque that wheel Wi can withstand is obtained by multiplying the vertical load of the first wheel by the actual slip ratio.

[0083] After obtaining the suspension height change corresponding to wheel Wi and the actual slope of the road where the vehicle is located, the preset wheel vertical load corresponding to the suspension height change corresponding to wheel Wi and the actual slope of the road where the vehicle is located is obtained, and the first wheel vertical load of wheel Wi is obtained. Then, the maximum braking torque that wheel Wi can withstand is obtained by using the first wheel vertical load of wheel Wi and the actual slip ratio of wheel Wi. That is, the maximum braking torque that wheel Wi can withstand = the first wheel vertical load of wheel Wi × the actual slip ratio of wheel Wi.

[0084] In one possible implementation, obtaining the actual slip ratio of the wheel includes the following steps:

[0085] Acquire a road image of the road where the vehicle is located;

[0086] Determine the matching degree between the road image and the preset road image;

[0087] The actual slip ratio of the wheel is determined based on the matching degree.

[0088] The system controls a vision system to capture road images of the road where the vehicle is located. It calculates the similarity between road surface features in the road images and those in preset road images. This similarity represents the matching degree between the road images and the preset road images. The matching degree is then compared with a matching threshold. A target strategy for calculating the actual slip ratio of wheel Wi is determined from a first calculation strategy and a second calculation strategy. The actual slip ratio of wheel Wi is then calculated using the target strategy. Specifically, the first calculation strategy calculates the slip ratio based on vehicle speed and wheel linear velocity, and the second calculation strategy calculates the slip ratio based on suspension parameters of the suspension system.

[0089] In one possible implementation, determining the actual slip ratio of the wheel based on the matching degree includes the following steps:

[0090] If the matching degree is greater than the matching degree threshold, obtain the vehicle's actual speed and the linear velocity of the wheels;

[0091] The actual slip ratio of the wheels is determined based on the actual vehicle speed and linear velocity.

[0092] If the matching degree is determined to be greater than the matching degree threshold, it indicates that the road surface of the slope where the vehicle is located is a smooth road surface with good road uniformity. The first calculation strategy is then determined as the target strategy, and the actual slip ratio of wheel Wi is calculated using the first calculation strategy, i.e.:

[0093] Actual slip ratio = [(actual vehicle speed - wheel linear velocity) / actual vehicle speed] × 100%.

[0094] In one possible implementation, determining the actual slip ratio of the wheel based on the matching degree includes the following steps:

[0095] If the matching degree is less than or equal to the matching degree threshold, the second wheel vertical load of the wheel is determined according to the suspension parameters of the vehicle suspension.

[0096] Based on the first target braking torque and the target torque emitted by the power system, the longitudinal load of the wheel is determined; where the target torque is either the driving torque or the recovery torque.

[0097] The road surface adhesion coefficient is determined based on the ratio of the longitudinal load of the first wheel to the vertical load of the second wheel; the road surface adhesion coefficient includes multiple adhesion coefficient values.

[0098] The derivative of the road surface adhesion coefficient with respect to the slip ratio during wheel slippage was determined, and multiple derivative values ​​were obtained;

[0099] The adhesion coefficient value corresponding to the target derivative value is determined as the actual slip ratio of the wheel.

[0100] Suspension parameters include at least one of suspension deformation, suspension stiffness, and damping coefficient. If the matching degree is determined to be less than or equal to the matching degree threshold, it indicates that the road surface of the slope where the vehicle is located is uneven and has poor road surface uniformity, making it impossible to calculate the actual slip ratio of wheel Wi based on the first calculation strategy. In this case, the second calculation strategy is determined as the target strategy, and the actual slip ratio of wheel Wi is estimated using the second calculation strategy.

[0101] The second calculation strategy for estimating the actual slip ratio of wheel Wi includes: calculating the second wheel vertical load corresponding to wheel Wi using the suspension parameters corresponding to wheel Wi; then calculating the wheel longitudinal load of wheel Wi using the first target braking torque corresponding to wheel Wi, the target torque generated by the powertrain (target torque generated by the powertrain), and the slope information of the road where the vehicle is located; and finally obtaining the road adhesion coefficient μ using the second wheel vertical load and the wheel longitudinal load corresponding to wheel Wi.

[0102] Road surface adhesion coefficient μ = longitudinal load of wheel / vertical load of second wheel.

[0103] Since the vehicle is in a sliding motion, the calculated road surface adhesion coefficient μ includes multiple adhesion coefficient values. Then, the derivative of the road surface adhesion coefficient μ with respect to the slip ratio s, i.e., dμ / ds, is calculated for the wheel Wi during the sliding process, resulting in multiple derivative values, each corresponding to an adhesion coefficient value. A target derivative value is obtained from these multiple derivative values. The target derivative value is the derivative value whose difference from 0 is less than a preset difference, and is also the derivative value closest to 0. The adhesion coefficient value corresponding to the target derivative value is determined as the actual slip ratio of the wheel Wi, thus realizing the estimation of the actual slip ratio of the wheel Wi.

[0104] By matching the road image with the preset road image, the wheel slip ratio can be calculated for both smooth and uneven road surfaces, which improves the flexibility of wheel slip ratio calculation.

[0105] In one possible implementation, determining the second wheel vertical load based on the suspension parameters of the vehicle suspension includes the following steps:

[0106] The load transfer amount of the wheel is determined based on the suspension deformation, suspension stiffness, and damping coefficient.

[0107] Determine the unsprung mass transfer amount based on the load transfer amount;

[0108] The sprung load is obtained from the suspension deformation.

[0109] The vertical load of the second wheel is obtained based on the unsprung mass, the amount of unsprung mass transferred, and the sprung load.

[0110] The load transfer amounts corresponding to the suspension deformation, suspension stiffness, and damping coefficient are obtained to calculate the load transfer amount of wheel Wi. The unsprung mass transfer amount is then estimated using the load transfer amount of wheel Wi. In practical applications, the transfer amounts of sprung mass and unsprung mass are not exactly the same. To simplify calculations, it can be roughly assumed that the percentage of sprung mass transfer is the same as the percentage of unsprung mass transfer. That is, assuming that a certain proportion of sprung mass is transferred, the same proportion of unsprung mass is transferred. This approximation method is reasonable in most cases, especially when the vehicle structure is relatively symmetrical.

[0111] Obtain the preset load corresponding to the suspension deformation to get the sprung load. Based on the unsprung mass, unsprung mass transfer amount and sprung load, obtain the second wheel vertical load of wheel Wi, that is, the second wheel vertical load = unsprung mass + sprung load + unsprung mass transfer amount.

[0112] In one possible implementation, after the aforementioned control power system and / or parking brake system compensate for the braking torque of the wheels, the vehicle control method further includes the following steps:

[0113] In response to the brake pedal reset signal, the power system and / or parking brake system are controlled according to a gradient descent strategy to reduce the compensating braking torque applied to the wheels.

[0114] If a brake pedal reset signal is detected, it indicates that the driver has released the brake pedal, meaning the driver is no longer controlling the vehicle's braking. This also suggests that the driver may believe the vehicle is about to reverse onto a level surface, hence the release of the brake pedal. To prevent the compensating braking torque from being withdrawn too quickly, which could cause the vehicle to reverse too rapidly, a gradient descent strategy is used to control the power system and / or parking brake system to reduce the compensating braking torque applied to the wheels. This means gradually reducing the compensating braking torque applied to the wheels by the power system and / or parking brake system according to a certain gradient descent value until the compensating braking torque is reduced to 0. This ensures the stability of the vehicle during the withdrawal of the compensating braking torque, allowing the vehicle to smoothly transition after the brake pedal is released, thus improving driving safety.

[0115] In one possible implementation, after obtaining the actual slip ratio of the wheel, the vehicle control method further includes the following steps:

[0116] When the actual slip ratio of the wheels is greater than the maximum value of the slip ratio threshold range, it is prohibited to control the power system and parking brake system to compensate for the braking torque of the wheels.

[0117] If the actual slip ratio of wheel Wi is greater than the maximum value of the slip ratio threshold range, it indicates that the slip ratio of wheel Wi is too high. It is assumed that the braking torque applied to wheel Wi by the service braking system is sufficient, and controlling wheel Wi solely through the service braking system can keep the actual slip ratio of wheel Wi within the slip ratio threshold range. If braking torque compensation for wheel Wi is applied through the powertrain and / or parking brake systems, it will exacerbate the vehicle's slippage. Therefore, braking torque compensation for wheel Wi is not necessary; that is, braking torque compensation for wheel Wi is not applied through the powertrain and parking brake systems.

[0118] In one possible implementation, after the above-mentioned vehicle braking system applies a braking torque to the wheels based on a second target braking torque, the vehicle control method further includes the following steps:

[0119] If the second condition is met, the steering wheel rotation is restricted;

[0120] The second condition includes at least one of the following: the vehicle's longitudinal acceleration is less than an acceleration threshold, the yaw angle is less than an angle threshold, the steering wheel rotation speed is greater than a rotation speed threshold, and there are no obstacles in the environment behind the vehicle.

[0121] If the vehicle's longitudinal acceleration is less than the acceleration threshold, it means the vehicle is stationary or sliding at low speed. If the yaw angle is less than the angle threshold, it means the vehicle has almost no lateral movement. If the steering wheel rotation speed is greater than the rotation speed threshold, it means the steering wheel is turning a large range, and the driver may be panicked. If there are no obstacles in the environment behind the vehicle, it means the reversing path is safe.

[0122] If the vehicle meets the second condition, steering wheel rotation is restricted to prevent the vehicle from overturning due to driver panic and erratic steering while reversing or rolling downhill. Specifically, restricting steering wheel rotation involves controlling the power steering motor to output a damping force that inhibits steering wheel movement, thus minimizing the driver's attempts to turn the steering wheel. After restricting steering wheel rotation, the driver is reminded not to turn the steering wheel to prevent accidental malfunctions that could jeopardize the vehicle's operation.

[0123] In one possible implementation, the vehicle control method described above further includes the following steps:

[0124] Upon receiving the activation command for the vehicle's off-road assist function, obtain the actual slope of the road where the vehicle is located;

[0125] If the actual slope is greater than the slope threshold, and the vehicle's driving direction is the same as the slope direction of the road, determine whether the vehicle exhibits a preset phenomenon during the uphill climb.

[0126] The vehicle has an off-road assist function, which can be activated via a function switch. Once the function switch is triggered, an activation command for the off-road assist function is issued. Upon receiving the activation command, the off-road assist function is not activated immediately. Instead, it is determined whether the actual slope of the road where the vehicle is located exceeds a slope threshold. If the actual slope exceeds the slope threshold and the vehicle's direction of travel is the same as the slope direction, it is assumed that the vehicle is climbing the slope, and the off-road assist function is activated. Then, it is determined whether a preset phenomenon occurs during the climb. If the preset phenomenon occurs during the climb, the off-road assist control operation is executed, i.e., S110-S150 is executed.

[0127] In one possible implementation, obtaining the actual slope of the road where the vehicle is located includes the following steps:

[0128] The first gradient of the road is determined based on the longitudinal acceleration of the vehicle;

[0129] The vehicle's intelligent driving system identifies the second slope of the road.

[0130] If the deviation between the first slope and the second slope is less than or equal to the deviation threshold, the first slope or the second slope is determined as the actual slope.

[0131] If the deviation value is greater than the deviation threshold, multiple longitudinal accelerations are continuously acquired within a preset time period;

[0132] Multiple third slopes of the road are determined based on multiple longitudinal accelerations, and the average value of the multiple third slopes is determined as the actual slope.

[0133] There are two ways to calculate the actual slope of the road where the vehicle is located. The first method is to calculate the first slope of the road using the vehicle's longitudinal acceleration, and simultaneously identify the second slope using the radar system in the intelligent driving system. Then, it is determined whether the deviation between the first and second slopes is less than or equal to a deviation threshold. If so, it means that the first and second slopes are the same or close, and the first or second slope is determined as the actual slope. If not, the second method is used to calculate the actual slope, which involves continuously acquiring multiple longitudinal accelerations within a preset time period, such as 20 longitudinal accelerations. A third slope is calculated from each of the 20 longitudinal accelerations, resulting in 20 third slopes. The average of these 20 third slopes is then calculated to obtain the actual slope.

[0134] To ensure that the vehicle's various systems and power battery can function effectively when stability risks arise, it is necessary to monitor the status information of these systems and power battery to determine whether off-road assist functions can be activated.

[0135] The following situations allow the activation of off-road assist functions:

[0136] 1. If the service braking system can brake, all drive motors in the power system cannot participate in braking torque compensation, but the parking braking system can participate in braking torque compensation, then the off-road assist function can be activated, and braking torque compensation will only be performed through the parking braking system. The following factors will prevent all drive motors in the power system from participating in braking torque compensation: the battery temperature of the power battery being greater than or equal to a third temperature threshold, the remaining charge of the power battery being less than or equal to a charge threshold, and the output power of all drive motors being less than or equal to a power threshold.

[0137] 2. If the service braking system can brake and all drive motors in the power system can participate in braking torque compensation, but the parking brake system cannot participate in braking torque compensation, then the off-road assist function can be activated, and braking torque compensation will only be performed through the power system.

[0138] 3. The service braking system can brake. Some of the drive motors in the power system can participate in braking torque compensation, while others cannot. This allows the activation of the off-road assist function. Braking torque compensation is performed by the drive motors in the power system that can participate in braking torque compensation, and the parking brake system replaces the drive motors in the power system that cannot participate in braking torque compensation for braking torque compensation.

[0139] 4. The service braking system can brake. Some parking calipers in the parking braking system can participate in braking torque compensation, while others cannot. This allows activation of the off-road assist function. Braking torque compensation is performed by the parking calipers that can participate in compensation, and the drive motor corresponding to the non-compensating parking calipers in the power system compensates for the non-compensating calipers. For example, if the parking caliper on the right rear wheel cannot compensate for braking torque, the drive motor on the right rear wheel will compensate for braking torque in place of the parking caliper on the right rear wheel.

[0140] 5. The tire pressure and brake disc temperature are normal, so the off-road assist function can be activated; the temperature of the power steering motor in the steering system is normal and the response performance of the steering system is normal, so the off-road assist function can be activated; the suspension system is in normal condition, so the off-road assist function can be activated.

[0141] Off-road assist functions should not be activated in the following situations:

[0142] 1. If the vehicle's braking system is unable to brake, the off-road assist function must not be activated.

[0143] 2. If the tire pressure or brake disc temperature is abnormal, do not activate the off-road assist function.

[0144] 3. If the temperature of the power steering motor in the steering system is abnormal or the response performance of the steering system is abnormal, the off-road assist function must not be activated.

[0145] 4. The suspension system is in an abnormal state; off-road assist function must not be activated.

[0146] When the off-road assist function is disabled, a reminder message will be output to remind the driver to stop driving the vehicle for off-road operations.

[0147] In one possible implementation, if a suspension system malfunction occurs when the actual slip ratio of wheel Wi needs to be calculated using the second calculation strategy based on the matching degree, resulting in the inability to obtain suspension parameters or accurate suspension parameters, meaning the actual slip ratio of wheel Wi calculated based on the second calculation strategy is meaningless, then the actual slip ratio of wheel Wi calculated using the first calculation strategy is used. After the vehicle braking system is controlled to apply braking torque to the wheel based on the second target braking torque, if it is determined that the actual slip ratio of wheel Wi is less than the minimum value of the slip ratio threshold range, then the target drive motor is controlled according to a time-torque curve with a first slope. The system outputs a compensating braking torque, or controls the parking brake system to output a compensating braking torque according to a time-torque curve with a second slope, or controls the target drive motor to output a third stall torque according to a time-torque curve with a first slope, and controls the parking brake system to output a third parking braking torque according to a time-torque curve with a second slope. The sum of the third stall torque and the third parking braking torque is the compensating braking torque, until the actual slip ratio of wheel Wi is within the slip ratio threshold range. This allows for braking compensation of wheel Wi even when suspension parameters cannot be accurately obtained, which helps improve the reliability of braking compensation of wheel Wi.

[0148] It is worth noting that the above description refers to vehicle braking control during a downhill or rolling slope when the vehicle is facing upwards. Similarly, the vehicle control method provided in this application embodiment is also applicable to vehicle braking control during a downhill slope when the vehicle is facing downwards. Whether it is a downhill or rolling slope scenario when the vehicle is facing upwards, or a downhill scenario when the vehicle is facing downwards, the vehicle control method provided in this application embodiment can ensure the stability of the vehicle on the slope and improve the safety of the vehicle in off-road scenarios.

[0149] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0150] Figure 4 shows a schematic diagram of a vehicle control device provided in an embodiment of this application. As shown in Figure 4, the vehicle control device 400 includes:

[0151] The first acquisition module 410 is used to, when it is determined that a preset phenomenon occurs during the vehicle's ascent, if a first brake pedal travel is received, acquire a first target braking torque allocated to each wheel based on the first brake pedal travel; wherein, the preset phenomenon is the phenomenon of the vehicle sliding downhill on the slope due to gravity.

[0152] The torque adjustment module 420 is used to reduce the first target braking torque when the first target braking torque is greater than the extreme value of the wheel braking torque, so as to obtain the second target braking torque corresponding to the wheel; wherein, the second target braking torque is less than the extreme value of the wheel braking torque.

[0153] Braking control module 430 is used to control the service braking system to apply braking torque to the wheels based on a second target braking torque;

[0154] The second acquisition module 440 is used to acquire the actual slip ratio of the wheel;

[0155] The braking compensation module 450 is used to control the power system and / or parking brake system to compensate the braking torque of the wheels when the actual slip ratio is less than the minimum value of the slip ratio threshold range, so that the actual slip ratio is within the slip ratio threshold range.

[0156] In one possible implementation, the braking compensation module 450 includes:

[0157] The acquisition unit is used to acquire the second brake pedal travel and the actual braking torque applied to the wheels by the service braking system when the actual slip ratio is less than the minimum value of the slip ratio threshold range.

[0158] The compensation unit is used to control the power system and / or parking brake system to compensate for the braking torque of the wheels if the travel of the second brake pedal is greater than the travel of the first brake pedal and the actual braking torque is less than the extreme value of the wheel braking torque.

[0159] In one possible implementation, the compensation unit includes:

[0160] The first compensation subunit is used to control the target drive motor in the power system to output the first stall torque, and to use the first stall torque as a compensation braking torque and apply it to the wheels.

[0161] The second compensation subunit is used to control the parking brake system to output the first parking braking torque, use the first parking braking torque as the compensation braking torque, and apply it to the wheels.

[0162] The third compensation subunit is used to control the target drive motor in the power system to output the second stall torque, and to use the sum of the second stall torque and the second parking braking torque as the compensation braking torque and apply it to the wheels.

[0163] The target drive motor is the drive motor that drives the wheels. The first stall torque and the second stall torque are both in the opposite direction to the drive torque output by the target drive motor. The compensation braking torque is the difference between the extreme value of the wheel braking torque and the actual braking torque.

[0164] In one possible implementation, the first compensation subunit is used to control the target drive motor in the power system to output a first stall torque when the target drive motor meets a first condition.

[0165] The first condition includes: ambient temperature being less than a first temperature threshold, motor temperature being less than a second temperature threshold, battery temperature being less than a third temperature threshold, remaining charge of the power battery being greater than a charge threshold, and motor output power being greater than a power threshold.

[0166] In one possible implementation, a first compensation subunit is used to control the target drive motor to output a first stall torque according to a time-torque curve with a first slope.

[0167] The second compensation subunit is used to control the parking brake system to output the first parking braking torque according to the time-torque curve with the second slope.

[0168] In one possible implementation, the vehicle control device 400 further includes:

[0169] The first calculation unit is used to determine the first wheel vertical load based on the change in suspension height corresponding to the wheel and the actual slope of the road where the vehicle is located; and to obtain the extreme value of the wheel braking torque based on the product of the first wheel vertical load and the actual slip ratio.

[0170] In one possible implementation, the second acquisition module 440 includes:

[0171] The image acquisition unit is used to acquire road images of the road where the vehicle is located.

[0172] The second calculation unit is used to determine the matching degree between the road image and the preset road image;

[0173] The third calculation unit is used to determine the actual slip ratio of the wheel based on the matching degree.

[0174] In one possible implementation, the third computing unit includes:

[0175] The first calculation subunit is used to obtain the actual vehicle speed and the linear velocity of the wheels if the matching degree is greater than the matching degree threshold; and to determine the actual slip ratio of the wheels based on the actual vehicle speed and the linear velocity.

[0176] In one possible implementation, the third computing unit includes:

[0177] The second calculation subunit is used to determine the second wheel vertical load of the wheel based on the suspension parameters of the vehicle suspension if the matching degree is less than or equal to the matching degree threshold; wherein the suspension parameters include at least one of suspension deformation, suspension stiffness, and damping coefficient; determine the wheel longitudinal load based on the first target braking torque and the target torque emitted by the power system; wherein the target torque is the driving torque or recovery torque; determine the road adhesion coefficient based on the ratio of the wheel longitudinal load to the second wheel vertical load; wherein the road adhesion coefficient includes multiple adhesion coefficient values; determine the derivative of the road adhesion coefficient with respect to the slip ratio during wheel slippage, and obtain multiple derivative values; determine the adhesion coefficient value corresponding to the target derivative value as the actual slip ratio of the wheel; wherein the target derivative value is the derivative value among the multiple derivative values ​​whose difference from 0 is less than a preset difference.

[0178] In one possible implementation, the second calculation subunit, in determining the second wheel vertical load based on the suspension parameters of the vehicle suspension, specifically determines the load transfer amount of the wheel based on the suspension deformation, suspension stiffness, and damping coefficient; determines the unsprung mass transfer amount based on the load transfer amount; obtains the sprung load based on the suspension deformation; and obtains the second wheel vertical load based on the unsprung mass, the unsprung mass transfer amount, and the sprung load.

[0179] In one possible implementation, the vehicle control device further includes:

[0180] The torque reduction unit is used to control the power system and / or parking brake system to reduce the compensating braking torque applied to the wheels in response to the brake pedal reset signal, according to a gradient descent strategy.

[0181] In one possible implementation, the vehicle control device 400 further includes:

[0182] The system disable unit is used to prevent the control system and parking brake system from performing braking torque compensation on the wheels when the actual slip ratio of the wheels is greater than the maximum value of the slip ratio threshold range.

[0183] In one possible implementation, the vehicle control device 400 further includes:

[0184] A steering wheel limiting unit is used to limit steering wheel rotation when a second condition is met.

[0185] The second condition includes at least one of the following: the vehicle's longitudinal acceleration is less than an acceleration threshold, the yaw angle is less than an angle threshold, the steering wheel rotation speed is greater than a rotation speed threshold, and there are no obstacles in the environment behind the vehicle.

[0186] In one possible implementation, the vehicle control device 400 further includes:

[0187] The fourth calculation unit is used to obtain the actual slope of the road where the vehicle is located when it receives the activation command of the vehicle's off-road assist function;

[0188] The judgment unit is used to determine whether a preset phenomenon occurs during the uphill climb if the actual slope is greater than the slope threshold and the vehicle's driving direction is the same as the slope direction of the road.

[0189] In one possible implementation, the fourth calculation unit is specifically used to determine the first slope of the road based on the longitudinal acceleration of the vehicle; acquire the second slope of the road identified by the vehicle's intelligent driving system; if the deviation between the first slope and the second slope is less than or equal to a deviation threshold, determine the first slope or the second slope as the actual slope; if the deviation is greater than the deviation threshold, acquire multiple longitudinal accelerations continuously within a preset time period; determine multiple third slopes of the road based on the multiple longitudinal accelerations, and determine the average value of the multiple third slopes as the actual slope.

[0190] It should be noted that the vehicle control device provided in the above embodiments is only illustrated by the division of the above functional modules when executing the vehicle control method. In practical 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. In addition, the vehicle control device and the vehicle control method embodiments provided in the above embodiments belong to the same concept. Therefore, for details not disclosed in the device embodiments of this application, please refer to the embodiments of the vehicle control method of this application, which will not be repeated here.

[0191] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0192] Figure 5 shows a schematic diagram of the structure of a vehicle provided in an embodiment of this application. As shown in Figure 5, 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 vehicle control method.

[0193] This embodiment can divide the vehicle into functional modules according to the above method example. For example, each function can be assigned to a separate module, 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.

[0194] When each functional module is divided according to its corresponding function, the vehicle may include: a first acquisition module, a torque adjustment module, a braking control module, a second acquisition module, a braking compensation module, etc. It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0195] The vehicle provided in this embodiment is used to execute the vehicle control method described above, and therefore can achieve the same effect as the above implementation method.

[0196] When using integrated units, the vehicle may include a processing module and a storage module. The processing module is used to control and manage the vehicle's movements. The storage module is used to support the vehicle in executing relevant program code and data.

[0197] The processing module may be a processor or a controller, which can implement or execute the various exemplary logic blocks, modules, and circuits described 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.

[0198] 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 vehicle control method in the above embodiment.

[0199] 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 vehicle control method as described in the above embodiment.

[0200] In addition, the vehicle provided in the embodiments of this application may specifically be a chip, component or module. The vehicle may include a connected processor and a memory. The memory is used to store instructions. When the vehicle is running, the processor may call and execute the instructions to make the chip execute a vehicle control method in the above embodiments.

[0201] In this embodiment, the vehicle, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding vehicle control method provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects in the corresponding vehicle control method provided above, and will not be repeated here.

[0202] 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.

[0203] 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.

[0204] 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 vehicle control method, wherein, The vehicle control method includes: When it is determined that the vehicle has encountered a preset phenomenon during the uphill climb, if the first brake pedal travel is received, for each wheel, a first target braking torque is obtained based on the first brake pedal travel; wherein, the preset phenomenon is the phenomenon that the vehicle slides downhill on the slope due to gravity. When the first target braking torque is greater than the extreme value of the wheel braking torque, the first target braking torque is reduced to obtain the second target braking torque corresponding to the wheel; wherein, the second target braking torque is less than the extreme value of the wheel braking torque; The vehicle braking system is controlled to apply braking torque to the wheels based on the second target braking torque; Obtain the actual slip ratio of the wheel; If the actual slip ratio is less than the minimum value of the slip ratio threshold range, the control system and / or parking brake system shall compensate the braking torque of the wheel so that the actual slip ratio is within the slip ratio threshold range.

2. The vehicle control method according to claim 1, wherein, When the actual slip ratio is less than the minimum value of the slip ratio threshold range, the method of controlling the power system and / or parking brake system to compensate the braking torque of the wheels includes: When the actual slip ratio is less than the minimum value of the slip ratio threshold range, the second brake pedal travel and the actual braking torque applied to the wheel by the service braking system are obtained. If the travel of the second brake pedal is greater than the travel of the first brake pedal and the actual braking torque is less than the extreme value of the wheel braking torque, the power system and / or the parking brake system are controlled to compensate the wheel for braking torque.

3. The vehicle control method according to claim 2, wherein, The method of controlling the power system and / or the parking brake system to compensate the braking torque of the wheels includes at least one of the following: The target drive motor in the power system is controlled to output a first stall torque, which is then used as a compensating braking torque and applied to the wheel. The parking brake system is controlled to output a first parking braking torque, which is then used as the compensating braking torque and applied to the wheels. The target drive motor in the power system is controlled to output a second stall torque. The sum of the second stall torque and the second parking braking torque is used as the compensation braking torque and applied to the wheel. Wherein, the target drive motor is the drive motor that drives the wheel, the first stall torque and the second stall torque are both in the opposite direction to the drive torque output by the target drive motor, and the compensation braking torque is the difference between the extreme value of the wheel braking torque and the actual braking torque.

4. The vehicle control method according to claim 3, wherein, The vehicle control method further includes: When the target drive motor meets the first condition, the step of controlling the target drive motor in the power system to output the first stall torque is executed; The first condition includes an ambient temperature lower than a first temperature threshold, a motor temperature lower than a second temperature threshold, a power battery temperature lower than a third temperature threshold, a remaining power charge of the power battery greater than a power charge threshold, and a motor output power greater than a power output threshold.

5. The vehicle control method according to claim 4, wherein, The vehicle control method further includes: If the target drive motor does not meet the first condition that the remaining power of the power battery is greater than the power threshold, the engine is started to charge the power battery. After the power battery is charged, if the first condition that the remaining power of the power battery is still not greater than the power threshold is not met, the power system is not used to compensate for the braking torque of the wheels, and the parking brake system is used to compensate for the braking torque of the wheels.

6. The vehicle control method according to claim 4, wherein, The control of the target drive motor outputting the first stall torque in the power system includes: The target drive motor is controlled to output the first stall torque according to a time-torque curve with a first slope; The control of the parking brake system to output the first parking braking torque includes: The parking brake system is controlled to output the first parking braking torque according to a time-torque curve with a second slope.

7. The vehicle control method according to claim 2, wherein, The vehicle control method further includes: The first vertical load of the wheel is determined based on the change in suspension height corresponding to the wheel and the actual slope of the road where the vehicle is located; The extreme value of the wheel braking torque is obtained by multiplying the vertical load of the first wheel by the actual slip ratio.

8. The vehicle control method according to claim 2, wherein, The process of obtaining the actual slip ratio of the wheel includes: Obtain a road image of the road where the vehicle is located; Determine the matching degree between the road image and the preset road image; The actual slip ratio of the wheel is determined based on the matching degree.

9. The vehicle control method according to claim 8, wherein, Determining the actual slip ratio of the wheel based on the matching degree includes: If the matching degree is greater than the matching degree threshold, obtain the actual vehicle speed and the linear velocity of the wheels; The actual slip ratio of the wheel is determined based on the actual vehicle speed and the linear velocity.

10. The vehicle control method according to claim 8, wherein, Determining the actual slip ratio of the wheel based on the matching degree includes: If the matching degree is less than or equal to the matching degree threshold, the second wheel vertical load of the wheel is determined according to the suspension parameters of the vehicle suspension; wherein, the suspension parameters include at least one of suspension deformation, suspension stiffness and damping coefficient; The longitudinal load on the wheel is determined based on the first target braking torque and the target torque emitted by the power system; wherein the target torque is the driving torque or the recovery torque. The road surface adhesion coefficient is determined based on the ratio of the longitudinal load of the first wheel to the vertical load of the second wheel; wherein the road surface adhesion coefficient includes multiple adhesion coefficient values. The derivative of the road surface adhesion coefficient with respect to the slip ratio during the wheel slippage process is determined, and multiple derivative values ​​are obtained; The adhesion coefficient value corresponding to the target derivative value is determined as the actual slip ratio of the wheel; wherein, the target derivative value is the derivative value among the plurality of derivative values ​​whose difference from 0 is less than a preset difference.

11. The vehicle control method according to claim 10, wherein, The step of determining the second wheel vertical load of the wheel based on the suspension parameters of the vehicle suspension includes: The load transfer amount of the wheel is determined based on the suspension deformation, the suspension stiffness, and the damping coefficient; The unsprung mass transfer amount is determined based on the load transfer amount; The sprung load is obtained based on the suspension deformation. The vertical load of the second wheel is obtained based on the unsprung mass, the amount of unsprung mass transfer, and the sprung load.

12. The vehicle control method according to claim 8, wherein, Determining the actual slip ratio of the wheel based on the matching degree includes: If the matching degree is less than or equal to the matching degree threshold and the suspension system malfunctions, obtain the actual vehicle speed and the linear velocity of the wheels; The actual slip ratio of the wheel is determined based on the actual vehicle speed and the linear velocity.

13. The vehicle control method according to claim 12, wherein, The vehicle control method further includes: When the actual slip ratio is less than the minimum value of the slip ratio threshold range, the target drive motor is controlled to output a compensating braking torque according to a time-torque curve with a first slope, or the parking brake system is controlled to output the compensating braking torque according to a time-torque curve with a second slope, or the target drive motor is controlled to output a third stall torque according to a time-torque curve with a first slope and the parking brake system is controlled to output a third parking braking torque according to a time-torque curve with a second slope, until the actual slip ratio of the wheel is within the slip ratio threshold range; Wherein, the target drive motor is the drive motor that drives the wheels, and the sum of the third stall torque and the third parking braking torque is the compensation braking torque.

14. The vehicle control method according to claim 3, wherein, After the control power system and / or parking brake system compensate for the braking torque of the wheels, the vehicle control method further includes: In response to the brake pedal reset signal, the power system and / or the parking brake system are controlled according to a gradient descent strategy to reduce the compensating braking torque applied to the wheels.

15. The vehicle control method according to claim 1, wherein, After obtaining the actual slip ratio of the wheel, the vehicle control method further includes: If the actual slip ratio of the wheels is greater than the maximum value of the slip ratio threshold range, the power system and the parking brake system shall be prohibited from compensating for the braking torque of the wheels.

16. The vehicle control method according to claim 1, wherein, After the vehicle braking system applies a braking torque to the wheels based on the second target braking torque, the vehicle control method further includes: If the second condition is met, the steering wheel rotation is restricted; The second condition includes at least one of the following: the vehicle's longitudinal acceleration is less than an acceleration threshold, the yaw angle is less than an angle threshold, the steering wheel rotation speed is greater than a rotation speed threshold, and there are no obstacles in the environment behind the vehicle.

17. The vehicle control method according to claim 1, wherein, The vehicle control method further includes: Upon receiving the activation command for the off-road assist function of the vehicle, the actual slope of the road where the vehicle is located is obtained; If the actual slope is greater than the slope threshold, and the vehicle's driving direction is the same as the slope direction of the road, determine whether the vehicle exhibits the preset phenomenon during the uphill climb.

18. The vehicle control method according to claim 17, wherein, The process of obtaining the actual slope of the road where the vehicle is located includes: The first gradient of the road is determined based on the longitudinal acceleration of the vehicle; Obtain the second slope of the road as identified by the vehicle's intelligent driving system; If the deviation between the first slope and the second slope is less than or equal to the deviation threshold, the first slope or the second slope is determined as the actual slope. If the deviation value is greater than the deviation threshold, multiple longitudinal accelerations are continuously acquired within a preset time period; Multiple third slopes of the road are determined based on the multiple longitudinal accelerations, and the average value of the multiple third slopes is determined as the actual slope.

19. A vehicle, wherein, The vehicles include: Memory, used to store executable program code; A processor is configured to call and run the executable program code from the memory, causing the vehicle to perform the vehicle control method as described in any one of claims 1 to 18.

20. A computer-readable storage medium, wherein, The computer-readable storage medium stores a computer program that, when executed, implements the vehicle control method as described in any one of claims 1 to 18.

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