Vehicle control method and device, vehicle and storage medium

Abstract

The invention discloses a vehicle control method and device, a vehicle and a storage medium, and belongs to the technical field of automobiles, the method comprises the steps that the wheel speeds of two wheels on a first driving shaft of the vehicle are obtained, the first driving shaft is any driving shaft of the vehicle, and the output torque of a first motor corresponding to the first driving shaft is first torque; under the condition that the first difference value of the two wheels on the first driving shaft is larger than a first safety threshold value, based on the slip rate of the two wheels on the first driving shaft, the output torque of the first motor is controlled to be changed from the first torque to the second torque, so that the first difference value of the two wheels on the first driving shaft is not larger than a second safety threshold value, the first difference value is a wheel speed difference or a slip rate difference, the first safety threshold value is a corresponding safety threshold value under the condition that the output torque of the first motor is the first torque, and the second safety threshold value is a corresponding safety threshold value under the condition that the output torque of the first motor is the second torque.

Description

Vehicle control method, device, vehicle and storage medium Technical Field

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

[0002] The vehicle's differential delivers different torques to the left and right drive axles, allowing the two wheels on the same driveshaft to rotate at different speeds. The differential allows the vehicle to maintain different wheel speeds on the same driveshaft during cornering. In situations where one wheel slips, such as high-speed cornering and off-roading, the differential between the two wheels on the same driveshaft can easily become excessive, potentially damaging the differential.

[0003] To address this situation, a limited slip differential (LSD) has been developed. The LSD includes an electronically controlled actuator and a clutch. When controlling the vehicle, the electronically controlled actuator controls the clutch state, which in turn controls the degree of engagement of the left and right drive axles connected to the clutch, thereby limiting the first difference between the two wheels on the same drive shaft.

[0004] Since LSD requires an electronically controlled actuator and its clutch is subject to significant wear and tear during operation and has a short lifespan, the cost of using LSD for differential control is high.

[0005] Summary of the Invention

[0006] The present application provides a vehicle control method, device, vehicle and storage medium, which enable the vehicle to solve the problem of excessively large first difference by using an ordinary differential, thereby saving costs.

[0007] In a first aspect, the present application provides a vehicle control method, the method comprising: obtaining the wheel speeds of two wheels on a first drive shaft of the vehicle, the output torque of a first motor corresponding to the first drive shaft being a first torque; when a first difference between the two wheels on the first drive shaft of the vehicle is greater than a first safety threshold, based on the slip rate of the two wheels on the first drive shaft, controlling the output torque of the first motor to change from the first torque to a second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0008] The first drive shaft may be any drive shaft of the vehicle. For example, the first drive shaft may be the front drive shaft of the vehicle, and the method is applied to the front drive shaft so that the first difference between the two wheels on the front drive shaft is controlled within a safety threshold. For another example, the first drive shaft may be the rear drive shaft of the vehicle, and the method is applied to the rear drive shaft so that the first difference between the two wheels on the rear drive shaft is controlled within a safety threshold. For another example, the first drive shaft may be either the front drive shaft or the rear drive shaft of the vehicle, and the method is applied to both the front drive shaft and the rear drive shaft so that the first difference between the two wheels on the rear drive shaft is controlled within a safety threshold.

[0009] For example, the drive shaft and motor to which the method is applied can be determined based on the configuration of the motor and the clutch. For example, the method can be applied to a drive shaft and motor configured with an open differential.

[0010] The first difference is a wheel speed difference or a slip ratio difference. The wheel speed difference between the two wheels on the first drive shaft of the vehicle can be directly obtained by subtracting the wheel speeds of the two wheels and taking the absolute value. The slip ratio difference between the two wheels on the first drive shaft of the vehicle can be obtained by subtracting the slip ratios of the two wheels and taking the absolute value. Generally, a greater slip ratio difference indicates a greater wheel speed difference.

[0011] The safety thresholds are different depending on the output torque of the first motor corresponding to the first drive shaft. The first safety threshold is the safety threshold corresponding to the output torque of the first motor being a first torque, and the second safety threshold is the safety threshold corresponding to the output torque of the first motor being a second torque.

[0012] For a vehicle, a large first differential between the two wheels on the first drive shaft typically occurs during high-speed cornering (drifting) or off-road escape scenarios. In such situations, adjusting the output torque of the first motor can change the first differential and the safety threshold, ensuring that the first differential between the two wheels on the first drive shaft does not exceed the safety threshold. This vehicle control solution allows the vehicle to resolve the problem of excessive differential speed using only a standard differential. Furthermore, this solution can extend the life of the differential and control costs.

[0013] Optionally, the method may further include: determining a first safety threshold, wherein the safety threshold refers to a wheel speed difference (or slip ratio) range that can ensure safe operation of the differential under the output torque of the first motor.

[0014] Since the motor output torque is negatively correlated with the threshold, determining the first safety threshold includes:

[0015] Obtain a correspondence between the motor output torque and the threshold; and obtain a first safety threshold corresponding to the case where the output torque of the first motor is the first torque from the correspondence between the motor output torque and the threshold.

[0016] In this way, the safety threshold corresponding to the first torque of the current vehicle can be obtained in real time, providing a basis for controlling the output torque of the motor, preventing the first difference from exceeding the safety threshold, and ensuring safety.

[0017] The motor output torque and threshold can be obtained through a vehicle bench endurance test. For example, under a certain output torque, the wheel speed difference or slip difference between the two wheels is controlled to vary from small to large, and the critical value between an undamaged differential and a damaged differential is determined. This critical value is used as the threshold corresponding to the output torque. Alternatively, under a certain wheel speed difference or slip difference, the output torque is controlled to vary from small to large, and the critical value between an undamaged differential and a damaged differential is determined. This critical value is used as the output torque, and the wheel speed difference or slip difference is used as the corresponding threshold. In this way, the threshold corresponding to each output torque is determined, forming a corresponding relationship.

[0018] Among them, controlling the wheel speed difference or slip rate difference between the two wheels to change from small to large can be achieved by applying different braking forces to the two wheels, or adding different loads to the two wheels.

[0019] Accordingly, the method for determining the second safety threshold is the same as the method for determining the first safety threshold, that is, obtaining the second safety threshold corresponding to the output torque of the first motor after dynamic control from the correspondence between the motor output torque and the threshold.

[0020] For a vehicle, the current scenario of the vehicle can be identified through the slip rates of the two wheels on the first drive shaft.

[0021] In the implementation of the present application, the current scene of the vehicle can be identified based on the relationship between the slip rate of the wheel with the smaller wheel speed among the two wheels on the first drive shaft and the slip rate range, and then the output torque of the first motor can be controlled based on the current scene of the vehicle.

[0022] The slip ratio range can be obtained through tire characteristic tests. Tire adhesion and slip ratio have a quadratic function relationship. Within this slip ratio range, the wheel has optimal adhesion. The slip ratio range can be 10% to 25%.

[0023] For example, the slip rate of the wheel with the slower speed among the two wheels on the first drive shaft is lower than the lower limit of the slip rate range, and one wheel of the first drive shaft has no slip at all, so it is determined that the vehicle is in an escape scenario where one wheel has good adhesion, such as an off-road escape scenario.

[0024] For another example, the slip rate of the wheel with the slower speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, and both wheels of the first drive shaft have slipped, so it is determined that the vehicle is in a drifting scenario where the wheels on both sides have lost adhesion, such as a high-speed cornering (drifting) scenario.

[0025] When the vehicle is in different scenarios, the output torque of the motor is controlled differently so that a first difference between the two wheels on the first drive shaft is no greater than a second safety threshold.

[0026] Exemplarily, the second torque is greater than the first torque;

[0027] Based on the slip ratios of the two wheels on the first drive shaft, controlling the output torque of the first motor to change from the first torque to the second torque so that a first difference between the two wheels on the first drive shaft is not greater than a second safety threshold includes:

[0028] When the slip rate of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is lower than the lower limit of the slip rate range, the wheel with the larger wheel speed or slip rate among the two wheels on the first drive shaft is braked; and the output torque of the first motor is controlled to increase from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0029] When the vehicle is in an escape scenario, it is necessary to increase the output torque of the first motor so that the vehicle can obtain greater kinetic energy to escape. However, since the output torque of the motor and the safety threshold are negatively correlated, increasing the output torque of the first motor will lower the safety threshold. At the same time, increasing the output torque will also cause the first difference to increase. Therefore, only increasing the output torque cannot ensure that the first difference between the two wheels is not greater than the second safety threshold while meeting the kinetic energy requirements. To this end, the implementation method of the present application first reduces the first difference by braking the wheel with the larger wheel speed or slip rate among the two wheels, and then increases the output torque on this basis to ensure that while increasing the output torque, the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0030] In this scenario, the combination of braking and increasing the output torque can not only ensure the kinetic energy requirements of the vehicle in the scenario, but also ensure that the wheel speed difference is below the safety threshold, thereby ensuring the safety of the differential.

[0031] Braking the wheel with a larger wheel speed or slip ratio among the two wheels on the first drive shaft; and controlling the output torque of the first motor to increase from a first torque to a second torque so that a first difference between the two wheels on the first drive shaft is no greater than a second safety threshold may include:

[0032] A target difference after braking is determined, where the target difference after braking is less than a first safety threshold, for example, less than the first safety threshold by a certain value or more, such as less than 20% or more of the first safety threshold; a braking force is provided according to the target difference, and the wheel with a larger wheel speed or slip ratio among the two wheels is braked; after braking causes the first difference between the two wheels to reach the target difference, the output torque of the first motor is controlled to increase from the first torque to the second torque, so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0033] In one embodiment, the first motor can be controlled to increase the output torque in a step-by-step manner until the first difference between the two wheels on the first drive shaft is equal to the second safety threshold, or until the first difference between the two wheels on the first drive shaft is less than the second safety threshold, and the difference between the two is small, such as 1 to 5%.

[0034] In another approach, controlling the first motor to increase the output torque can first determine a second torque corresponding to the first difference between the two wheels, where the safety threshold corresponding to the second torque is greater than the first difference between the two wheels. Since the first difference between the two wheels increases as the torque increases, a margin can be reserved when determining the second torque. For example, the maximum safe output torque can be determined based on the first difference after braking, and then reduced by a certain amount or percentage (such as 10%) as the second torque to ensure that after the output torque is increased, the first difference still does not exceed the safety threshold.

[0035] Exemplarily, the second torque is less than the first torque;

[0036] Based on the slip ratios of the two wheels on the first drive shaft, controlling the output torque of the first motor to change from the first torque to the second torque so that a first difference between the two wheels on the first drive shaft is not greater than a second safety threshold includes:

[0037] The first method: when the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, the output torque of the first motor is controlled to be reduced from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0038] The second method: when the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, the wheel with the larger speed or slip rate among the two wheels on the first drive shaft is braked; the output torque of the first motor is controlled to be reduced from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0039] When the vehicle is cornering (drifting) at high speed, since the output torque of the motor and the safety threshold are negatively correlated, reducing the output torque of the first motor increases the safety threshold. Simultaneously, reducing the output torque also causes the first difference to decrease. Therefore, by reducing the output torque of the first motor, the first difference between the two wheels on the first drive shaft can be reduced to no greater than the second safety threshold. In addition to reducing the output torque alone to reduce the first difference between the two wheels on the first drive shaft to no greater than the second safety threshold, it is also possible to combine reducing the output torque with braking to reduce the first difference between the two wheels on the first drive shaft to no greater than the second safety threshold.

[0040] In this scenario, the vehicle's drift can be reduced by controlling the output torque of the motor, and the wheel speed difference can be kept below the safety threshold to ensure the safety of the differential by reducing the output torque or a combination of reducing the output torque and braking.

[0041] In the first method described above, the method for reducing the motor output torque can be a step-by-step method. The method for reducing the motor output torque can also be to first determine a second torque corresponding to the first difference between the two wheels, the second torque being a safe output torque, and use the second torque to control the motor. The safety threshold corresponding to the second torque can be greater than or equal to the first difference between the two wheels, ensuring that the first difference is less than the safety threshold; the safety threshold corresponding to the second torque can also be less than the first difference between the two wheels. Since the first difference between the two wheels decreases as the torque decreases, the safety threshold is slightly smaller than the first difference between the two wheels (for example, 5%), which can also ensure that the first difference is less than the safety threshold.

[0042] In the second method mentioned above, the target difference after braking can be determined first; braking force is provided according to the first difference, and the wheel with a larger wheel speed or slip ratio among the two wheels is braked; after braking makes the first difference between the two wheels reach the target difference, the output torque of the first motor is controlled to be reduced from the first torque to the second torque, so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0043] In one approach, if the target difference after braking is less than the first safety threshold, then further reduction in output torque will ensure that the first difference between the two wheels does not exceed the second safety threshold. In another approach, the target difference after braking can also be no less than the first safety threshold, or even no less than the subsequent second safety threshold. By further reduction in output torque, a combination of these two approaches can ensure that the first difference between the two wheels does not exceed the second safety threshold.

[0044] In the implementation of the present application, the output torque of the first motor can be controlled through control instructions.

[0045] Exemplarily, controlling the output torque of the first motor to change from the first torque to the second torque so that a first difference between two wheels on the first drive shaft is no greater than a second safety threshold includes:

[0046] Determine a second torque based on a first difference between two wheels on the first drive shaft; output a control instruction based on the second torque; and use the control instruction to control the output torque of the first motor so that the first difference between the two wheels on the first drive shaft is no greater than a second safety threshold.

[0047] The first difference value used here to determine the second torque is, if braking is not performed, the first difference value between the two wheels that have not been braked; if braking is performed, the first difference value between the two wheels that have been braked.

[0048] In the case of increasing the output torque, the maximum safe output torque is determined according to the first difference after braking, and then reduced by a certain amount or percentage (such as 10%) as the second torque.

[0049] When the output torque is reduced, the safety threshold corresponding to the second torque can be greater than or equal to the first difference between the two wheels; the safety threshold corresponding to the second torque can also be less than the first difference between the two wheels, such as the safety threshold is slightly smaller than the first difference between the two wheels (for example, 5%).

[0050] For a front-wheel drive or rear-wheel drive vehicle, it is sufficient to control the motor of only the first drive shaft.

[0051] For a four-wheel drive vehicle, when controlling the first drive shaft, the second drive shaft can also be controlled. For example:

[0052] When the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, and the slip rate of the wheel with the smaller speed among the two wheels on the second drive shaft of the vehicle is not higher than the upper limit of the slip rate range, the output torque of the second motor corresponding to the second drive shaft of the vehicle is controlled to increase from the third torque to the fourth torque, and the first difference between the two wheels on the second drive shaft is not greater than the third safety threshold, which is the safety threshold corresponding to the case where the output torque of the second motor is the fourth torque.

[0053] For a four-wheel drive vehicle, when the slip ratio of the wheel with a slower wheel speed on the other drive shaft does not exceed the upper limit, torque transfer can be performed to ensure the overall driving force of the vehicle.

[0054] The output torque control of the second motor can be performed in a step-by-step manner or by determining a safe output torque corresponding to the first difference between the two wheels on the second drive shaft and then performing control. The detailed process can be referred to the control of the first motor described above.

[0055] When the slip rate of the wheel with the slower speed among the two wheels on the second drive shaft of the vehicle is higher than the upper limit of the slip rate range, the second motor corresponding to the second drive shaft is controlled to reduce the output torque. The detailed process can refer to the aforementioned control of the first motor.

[0056] In the implementation of this application, slip ratio is the proportion of slip in wheel motion, and slip ratio is the ratio of the difference between vehicle speed and wheel speed to vehicle speed. The vehicle speed and wheel speed may be average vehicle speed and average wheel speed, for example, the average vehicle speed and average wheel speed over a period of time.

[0057] In some possible implementations of the present application, the slip ratios of the two wheels on the first drive shaft are obtained according to the wheel speeds of the two wheels and the rotational speed of the first motor.

[0058] Wheel speeds are typically measured by wheel speed sensors and reported by the brake control unit. If a wheel speed sensor fails, the wheel speeds are inaccurate, making it impossible to correctly calculate the slip ratio. Therefore, determining the slip ratios of the two wheels on the first drive shaft involves:

[0059] The rotational speed of the first motor is obtained; based on the rotational speed of the first motor and the wheel speeds of the two wheels on the first drive shaft, the wheel speeds are determined to be accurate; if the wheel speeds of the two wheels on the first drive shaft are accurate, the slip ratios of the two wheels on the first drive shaft are determined based on the wheel speeds of the two wheels on the first drive shaft and the rotational speed of the first motor. If the wheel speeds of the two wheels on the first drive shaft are inaccurate, a fault indication is output, indicating that the wheel speed sensor needs to be inspected or replaced.

[0060] In this implementation, after the wheel speed is accurately determined, the slip ratio of the wheel is calculated, thereby ensuring the accuracy of the calculated slip ratio.

[0061] Among them, based on the wheel speeds of the two wheels on the first drive shaft and the rotational speed of the first motor, it can be determined whether the wheel speeds of the two wheels on the first drive shaft are accurate. For example, by comparing the rotational speed of the motor with the average of the wheel speeds of the two wheels, if the difference is greater than the set difference, the wheel speed is considered to be inaccurate, otherwise the wheel speed is considered to be accurate.

[0062] When calculating the slip ratio based on the wheel speeds of the two wheels and the rotation speed of the first motor, the vehicle speed may be first calculated based on the rotation speed of the first motor, and then the slip ratios of the two wheels may be calculated based on the vehicle speed and the wheel speeds of the two wheels.

[0063] In other possible implementations, the vehicle speed may also be additionally acquired, and the slip rates of the two wheels may be calculated based on the vehicle speed and the wheel speeds of the two wheels.

[0064] In other possible implementations, the vehicle acceleration may be additionally obtained, the vehicle acceleration may be integrated to determine the vehicle speed, and the slip rates of the two wheels may be calculated based on the vehicle speed and the wheel speeds of the two wheels.

[0065] In some possible implementations of the present application, the method is executed by a vehicle control unit. For example, the vehicle control unit controls the output torque of the first motor, or controls the single-wheel brake and the output torque of the first motor.

[0066] When the vehicle control unit executes the method, obtaining the wheel speeds of the two wheels on the first drive shaft includes: obtaining the wheel speeds of the two wheels on the first drive shaft output by the vehicle's brake control unit. Obtaining the rotational speed of the first motor includes: obtaining the rotational speed of the first motor output by the vehicle's motor controller.

[0067] In some possible implementations of the present application, the method is executed by a motor controller. For example, a vehicle control unit controls the output torque of the first motor, or controls the single-wheel brake and the output torque of the first motor.

[0068] When the motor controller executes the method, obtaining the wheel speeds of the two wheels on the first drive shaft includes: obtaining the wheel speeds of the two wheels on the first drive shaft output by the vehicle's brake control unit. Obtaining the rotational speed of the first motor includes: obtaining the rotational speed detected by a sensor in the first motor.

[0069] In this implementation, either the vehicle control unit or the motor controller can be used as the execution body. Any controller can be used for control according to actual conditions to implement the differential protection solution, which is conducive to integrated control and layout of practical applications.

[0070] In a second aspect, the present application provides a vehicle control device, the device comprising:

[0071] an acquisition unit, configured to acquire wheel speeds of two wheels on a first drive shaft of the vehicle, where the first drive shaft is any drive shaft of the vehicle, and the output torque of a first motor corresponding to the first drive shaft is a first torque;

[0072] A control unit is used to control the output torque of the first motor to change from a first torque to a second torque based on the slip rate of the two wheels on the first drive shaft when a first difference between the two wheels on the first drive shaft is greater than a first safety threshold, so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold, the first difference is a wheel speed difference or a slip rate difference, the first safety threshold is a safety threshold corresponding to the case where the output torque of the first motor is the first torque, and the second safety threshold is a safety threshold corresponding to the case where the output torque of the first motor is the second torque.

[0073] Optionally, the second torque is greater than the first torque;

[0074] A control unit is used to brake the wheel with the larger wheel speed or slip ratio among the two wheels on the first drive shaft when the slip ratio of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is lower than the lower limit of the slip ratio range; and control the output torque of the first motor to increase from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0075] Optionally, the second torque is less than the first torque;

[0076] A control unit is used to control the output torque of the first motor to decrease from a first torque to a second torque when the slip rate of the wheel with a smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

[0077] Optionally, the second torque is less than the first torque;

[0078] A control unit is used to brake the wheel with the larger wheel speed or slip ratio among the two wheels on the first drive shaft when the slip ratio of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is higher than the upper limit of the slip ratio range; and control the output torque of the first motor to be reduced from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0079] Optionally, the control unit is used to determine the second torque based on the first difference between the two wheels on the first drive shaft; output a control instruction based on the second torque; and use the control instruction to control the output torque of the first motor so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

[0080] Optionally, the control unit is also used to control the output torque of the second motor corresponding to the second drive shaft of the vehicle to increase from the third torque to the fourth torque, and to make the first difference between the two wheels on the second drive shaft not greater than a third safety threshold, when the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range and the slip rate of the wheel with the smaller speed among the two wheels on the second drive shaft of the vehicle is not higher than the upper limit of the slip rate range. The third safety threshold is the safety threshold corresponding to the case where the output torque of the second motor is the fourth torque.

[0081] Optionally, the acquiring unit is further configured to acquire the rotational speed of the first motor;

[0082] The device also includes: a determination unit for determining whether the wheel speed is accurate based on the rotational speed of the first motor and the wheel speed of the two wheels on the first drive shaft; when the wheel speed of the two wheels on the first drive shaft is accurate, determining the slip rate of the two wheels on the first drive shaft based on the wheel speed of the two wheels on the first drive shaft and the rotational speed of the first motor.

[0083] Optionally, the device includes a vehicle control unit, or the device includes a motor controller.

[0084] Optionally, the acquisition unit is also used to obtain the correspondence between the motor output torque and the threshold, and the motor output torque and the threshold are negatively correlated; and obtain the first safety threshold corresponding to the case where the output torque of the first motor is the first torque from the correspondence between the motor output torque and the threshold.

[0085] In a third aspect, the present application provides a vehicle, comprising the vehicle control device and a motor as described in the second aspect, wherein the vehicle control device is connected to the motor.

[0086] In a fourth aspect, the present application provides a vehicle control device, which includes a processor and a memory; the memory is used to store software programs and modules, and the processor enables the vehicle control device to implement the method in any possible implementation of the above-mentioned first aspect by running or executing the software programs and / or modules stored in the memory.

[0087] Optionally, there are one or more processors and one or more memories.

[0088] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0089] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips. The embodiments of the present application do not limit the type of memory and the setting method of the memory and the processor.

[0090] In a fifth aspect, the present application provides a computer program (product), which includes: computer program code, which, when executed by a computer, enables the computer to execute a method in any possible implementation of the first aspect.

[0091] In a sixth aspect, the present application provides a computer-readable storage medium, which is used to store program codes executed by a processor, wherein the program codes include a method for implementing any possible implementation of the first aspect.

[0092] In a seventh aspect, a chip is provided, comprising a processor, the processor being configured to call and execute instructions stored in a memory from the memory, so that a communication device equipped with the chip executes a method in any possible implementation of the first aspect above.

[0093] In the eighth aspect, another chip is provided, comprising: an input interface, an output interface, a processor and a memory, wherein the input interface, the output interface, the processor and the memory are connected via an internal connection path, and the processor is used to execute the code in the memory. When the code is executed, the processor is used to execute the method in any possible implementation of the above-mentioned first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] FIG1 is a schematic diagram of the architecture of a vehicle provided in an embodiment of the present application;

[0095] FIG2 is a flow chart of a vehicle control method provided by an embodiment of the present application;

[0096] FIG3 is a flow chart of a vehicle control method according to an embodiment of the present application;

[0097] FIG4 is a schematic diagram showing the relationship between a threshold value and output torque provided in an embodiment of the present application;

[0098] FIG5 is a flow chart of a vehicle control method provided by an embodiment of the present application;

[0099] FIG6 is a block diagram of a vehicle control device provided in an embodiment of the present application;

[0100] FIG7 is a schematic structural diagram of a vehicle control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0101] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0102] To facilitate understanding of the technical solutions provided in the embodiments of this application, let's first introduce the system architecture of this application. The system architecture of this application is a vehicle. Figure 1 is a schematic diagram of the architecture of a vehicle provided in the embodiments of this application. Referring to Figure 1, the vehicle includes a motor control circuit and a brake control circuit.

[0103] The motor control circuit primarily includes a vehicle control unit (VCU) 1, a front motor controller 2, a rear motor controller 3, a front motor 4, and a rear motor 5. The VCU 1 is the vehicle's main control unit, receiving motor speed and torque signals from the motor controllers and controlling their torque requirements. The front motor controller 2 and the rear motor controller 3 control the torque requirements of the front motor 4 and rear motor 5, respectively, based on the torque request / command from the VCU 1. They also detect the actual speed and torque signals of the front and rear motors and feed them back to the VCU 1.

[0104] The brake control circuit includes a vehicle control unit 1, a brake control unit 7, a right front wheel speed sensor 7, a right rear wheel speed sensor 8, a left front wheel speed sensor 9, a left rear wheel speed sensor 10, a right front wheel brake 11, a right rear wheel brake 12, a left front wheel brake 13, and a left rear wheel brake 14. The vehicle control unit 1 receives wheel speed and brake pressure signals from the brake control unit and controls the pressure buildup in the brake circuit. The brake control unit 6 primarily controls the pressure buildup, pressure maintenance, and pressure reduction in the brake circuit, thereby achieving precise control of wheel-side brake pressure and implementing the differential control function.

[0105] Of course, FIG1 is only an example. In other implementations, there may be only one set of the front motor and the front motor controller, and the rear motor and the rear motor controller in FIG1 .

[0106] FIG2 is a flow chart of a vehicle control method provided by an embodiment of the present application. The method can be executed by a vehicle control unit or a motor controller of the vehicle. As shown in FIG2 , the method includes the following steps:

[0107] 101: Obtain wheel speeds of two wheels on a first drive shaft of a vehicle, where the output torque of a first motor corresponding to the first drive shaft is a first torque.

[0108] The first drive shaft may be any drive shaft of the vehicle. For example, the first drive shaft may be the front drive shaft of the vehicle, and the method is applied to the front drive shaft so that the first difference between the two wheels on the front drive shaft is controlled within a safety threshold. For another example, the first drive shaft may be the rear drive shaft of the vehicle, and the method is applied to the rear drive shaft so that the first difference between the two wheels on the rear drive shaft is controlled within a safety threshold. For another example, the first drive shaft may be either the front drive shaft or the rear drive shaft of the vehicle, and the method is applied to both the front drive shaft and the rear drive shaft so that the first difference between the two wheels on the rear drive shaft is controlled within a safety threshold.

[0109] For example, the drive shaft and motor to which the method is applied can be determined based on the configuration of the motor and the clutch. For example, the method can be applied to a drive shaft and motor configured with an open differential.

[0110] 102: When a first difference between two wheels on a first drive shaft of a vehicle is greater than a first safety threshold, based on the slip rate of the two wheels on the first drive shaft, the output torque of the first motor is controlled to change from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

[0111] The first difference is a wheel speed difference or a slip ratio difference. The wheel speed difference between the two wheels on the first drive shaft of the vehicle can be directly obtained by subtracting the wheel speeds of the two wheels and taking the absolute value. The slip ratio difference between the two wheels on the first drive shaft of the vehicle can be obtained by subtracting the slip ratios of the two wheels and taking the absolute value. Generally, a greater slip ratio difference indicates a greater wheel speed difference.

[0112] The safety thresholds are different depending on the output torque of the first motor corresponding to the first drive shaft. The first safety threshold is the safety threshold corresponding to the output torque of the first motor being a first torque, and the second safety threshold is the safety threshold corresponding to the output torque of the first motor being a second torque.

[0113] For a vehicle, a large first differential between the two wheels on the first drive shaft typically occurs during high-speed cornering (drifting) or off-road escape scenarios. In such situations, adjusting the output torque of the first motor can change the first differential and the safety threshold, ensuring that the first differential between the two wheels on the first drive shaft does not exceed the safety threshold. This vehicle control solution allows the vehicle to resolve the problem of excessive differential speed using only a standard differential. Furthermore, this solution can extend the life of the differential and control costs.

[0114] FIG3 is a flow chart of a vehicle control method provided by an embodiment of the present application. The method can be executed by a vehicle control unit or a motor controller. Taking the vehicle control unit as an example, when the vehicle control unit performs control, the motor controller and the brake control unit coordinate control, as shown in FIG3 , the method includes the following steps:

[0115] 201: Obtain wheel speeds of two wheels on a first drive shaft and a rotational speed of a first motor. The output torque of the first motor corresponding to the first drive shaft is a first torque.

[0116] The vehicle control unit obtains the wheel speeds of the two wheels on the first drive shaft output by the vehicle's brake control unit, and the vehicle control unit obtains the rotational speed of the first motor output by the vehicle's motor controller.

[0117] Optionally, the method may further include: acquiring the braking force of each wheel, for example, monitoring the braking force of each wheel through a brake pressure sensor, to provide a basis for subsequent single-wheel braking of the wheel.

[0118] 202: Determine whether the wheel speeds of the two wheels on the first drive shaft are accurate based on the wheel speeds of the two wheels on the first drive shaft and the rotational speed of the first motor. If the wheel speeds of the two wheels on the first drive shaft are accurate, proceed to step 204; otherwise, proceed to step 203.

[0119] Wheel speeds are typically measured by wheel speed sensors (or differential speed sensors), such as the four shown in Figure 1. These sensors are then reported to the vehicle control unit via the brake control unit. If a wheel speed sensor (or differential speed sensor) fails, wheel speeds may be inaccurate.

[0120] For example, the motor speed is compared with the average of the two wheel speeds. If the difference is greater than the set difference, it is considered inaccurate, otherwise it is considered accurate.

[0121] 203: Output fault prompt, indicating that the wheel speed sensor needs to be repaired or replaced.

[0122] Step 203 is an optional step.

[0123] 204 : Determine the slip ratios of the two wheels on the first drive shaft based on the wheel speeds of the two wheels on the first drive shaft and the rotation speed of the first motor.

[0124] The slip ratio is the proportion of slip in wheel motion. The slip ratio is the ratio of the difference between the vehicle speed and the wheel speed to the vehicle speed. The vehicle speed and wheel speed can be average vehicle speed and average wheel speed, for example, the average vehicle speed and average wheel speed over a period of time.

[0125] In some possible implementations of the present application, the slip ratios of the two wheels on the first drive shaft are obtained based on the wheel speeds of the two wheels and the rotational speed of the first motor. When calculating the slip ratio based on the wheel speeds of the two wheels and the rotational speed of the first motor, the vehicle speed can be first calculated based on the rotational speed of the first motor, and then the slip ratios of the two wheels can be calculated based on the vehicle speed and the wheel speeds of the two wheels.

[0126] In this case, there is no need to use the vehicle's actual speed, which reduces the acquisition of parameters and reduces complexity.

[0127] In other possible implementations, the vehicle speed may also be additionally acquired, and the slip rates of the two wheels may be calculated based on the vehicle speed and the wheel speeds of the two wheels.

[0128] In other possible implementations, the vehicle acceleration may be additionally obtained, the vehicle acceleration may be integrated to determine the vehicle speed, and the slip rates of the two wheels may be calculated based on the vehicle speed and the wheel speeds of the two wheels.

[0129] 205 : Obtaining a first safety threshold corresponding to a case where the output torque of the first motor is the first torque from a correspondence between the motor output torque and the threshold.

[0130] In this step, the vehicle control unit first obtains the output torque of the first motor. This output torque of the first motor is transmitted to the vehicle control unit by the motor controller connected to the first motor. For example, the front motor controller in Figure 1 can transmit the output torque of the front motor to the vehicle control unit. The vehicle control unit then obtains a first safety threshold corresponding to the output torque of the first motor when it is at the first torque based on the corresponding relationship between the motor output torque and the threshold. The motor output torque and the threshold are negatively correlated. This corresponding relationship can be stored in the vehicle control unit or other storage device in the vehicle.

[0131] The motor output torque and threshold can be obtained through a vehicle bench endurance test. For example, under a certain output torque, the wheel speed difference or slip difference between the two wheels is controlled to vary from small to large, and the critical value between an undamaged differential and a damaged differential is determined. This critical value is used as the threshold corresponding to the output torque. Alternatively, under a certain wheel speed difference or slip difference, the output torque is controlled to vary from small to large, and the critical value between an undamaged differential and a damaged differential is determined. This critical value is used as the output torque, and the wheel speed difference or slip difference is used as the corresponding threshold. In this way, the threshold corresponding to each output torque is determined, forming a corresponding relationship.

[0132] Among them, controlling the wheel speed difference or slip rate difference between the two wheels to change from small to large can be achieved by applying different braking forces to the two wheels, or adding different loads to the two wheels.

[0133] 206 : Determine whether a first difference between two wheels on a first drive shaft of the vehicle is greater than a first safety threshold. If the first difference between two wheels on the first drive shaft is greater than the first safety threshold, execute step 207 .

[0134] For example, to determine whether the wheel speed difference between two wheels on a first drive shaft of the vehicle is greater than a first safety threshold, the vehicle control unit, after receiving the wheel speeds of each wheel, subtracts the wheel speeds of the two wheels on the same drive shaft to obtain the wheel speed difference between the two wheels on the first drive shaft.

[0135] For another example, it is determined whether the slip ratio difference between two wheels on a first drive shaft of the vehicle is greater than a first safety threshold, and the safety threshold corresponding to the wheel speed difference is different from the safety threshold corresponding to the slip ratio difference.

[0136] Otherwise, the subsequent steps may not be performed and the output torque of the first motor may be maintained.

[0137] 207: Braking the wheel with the larger wheel speed or slip ratio among the two wheels on the first drive shaft.

[0138] The determined braking force should be greater than the braking force monitored from the wheel with a larger current wheel speed or slip ratio.

[0139] Braking the wheels refers to performing wheel-side hydraulic braking on the wheels, for example, providing braking pressure to a wheel brake device (such as a brake pump) in a brake circuit to achieve braking.

[0140] In one possible implementation, the vehicle control unit determines a target difference after braking, where the target difference after braking is less than a first safety threshold, for example, less than the first safety threshold by a certain value, such as less than 20% of the first safety threshold; braking force is provided according to the target difference, and the wheel with the larger wheel speed or slip ratio among the two wheels is braked.

[0141] For the two wheels on the first drive shaft, the first wheel has the lower speed, while the second wheel has the higher speed. During braking, the target speed of the second wheel is first determined based on the speed of the first wheel. This target speed ensures that the speed difference between the first and second wheels reaches the target difference. The required speed reduction for braking is then determined based on the target speed and current speed of the second wheel, and the corresponding braking force is then determined based on the required speed reduction.

[0142] There is a mapping relationship between the braking force and the reduced wheel speed, which can be obtained through vehicle bench testing and will not be elaborated here.

[0143] After the wheels are braked so that the first difference between the two wheels is no greater than the first safety threshold, braking of the wheel with the larger wheel speed or slip ratio among the two wheels on the first drive shaft is stopped.

[0144] In another possible implementation, the vehicle control unit determines a target difference after braking, which is greater than the first safety threshold, but the difference between the target difference and the first safety threshold is smaller than the difference between the first difference and the first safety threshold.

[0145] After braking the wheels for a period of time, stop braking the wheel with the larger wheel speed or slip rate among the two wheels on the first drive shaft. When braking stops, the first difference between the two wheels is still greater than the first safety threshold, but the gap between the first difference and the first safety threshold becomes smaller.

[0146] Optionally, step 207 may also be performed after step 208 and step 210 .

[0147] 208: Determine whether the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is greater than the lower limit of the slip ratio range. If the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is less than the lower limit of the slip ratio range, proceed to step 209. Otherwise, proceed to step 210.

[0148] Here, when determining whether the slip ratio of the wheel with the slower speed of the two wheels is higher than the lower limit of the slip ratio range, it is possible to determine whether the slip ratio is higher than the lower limit of the slip ratio range before braking or after braking. Since step 207 brakes the wheel with the faster speed, and the slip ratio of the wheel with the slower speed is not significantly affected by the braking, the slip ratio of the wheel with the slower speed of the two wheels before braking and after braking do not change or change only slightly.

[0149] Based on the relationship between the slip rate of the wheel with a smaller wheel speed among the two wheels on the first drive shaft and the slip rate range, the current scene of the vehicle is identified, and then based on the current scene of the vehicle, the output torque of the first motor is controlled.

[0150] The slip ratio range can be obtained through tire characteristic tests. Tire adhesion and slip ratio have a quadratic function relationship. Within this slip ratio range, the wheel has optimal adhesion. The slip ratio range can be 10% to 25%.

[0151] When the slip ratio of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is lower than the lower limit of the slip ratio range, it is determined that the vehicle is in an escape scenario where one wheel has good adhesion, such as an off-road escape scenario.

[0152] 209: Control the output torque of the first motor to increase from the first torque to the second torque, so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0153] The second safety threshold is a safety threshold corresponding to a case where the output torque of the first motor is the second torque.

[0154] After braking causes the first difference between the two wheels to reach the target difference, the output torque of the first motor is controlled to increase from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is no greater than the second safety threshold.

[0155] In one embodiment, the first motor can be controlled to increase the output torque in a step-by-step manner until the first difference between the two wheels on the first drive shaft is equal to the second safety threshold, or until the first difference between the two wheels on the first drive shaft is less than the second safety threshold, and the difference between the two is small, such as 1 to 5%.

[0156] During step control, the output torque is increased by one unit each time based on the previous output torque. After control is completed, the first difference between the two wheels is determined to be greater than the second safety threshold. This process is repeated until the first difference between the two wheels is no greater than the second safety threshold. The unit of each increase is determined by the control accuracy of the motor.

[0157] In another approach, controlling the first motor to increase the output torque can first determine a second torque corresponding to the first difference between the two wheels, where the safety threshold corresponding to the second torque is greater than the first difference between the two wheels. Since the first difference between the two wheels increases as the torque increases, a margin can be reserved when determining the second torque. For example, the maximum safe output torque can be determined based on the first difference after braking, and then reduced by a certain amount or percentage (such as 10%) as the second torque to ensure that after the output torque is increased, the first difference still does not exceed the safety threshold.

[0158] Figure 4 illustrates the relationship between torque and threshold values, which are negatively correlated. As shown in Figure 4, before step 208, the output torque of the first motor is a, corresponding to the first safety threshold value A. After braking, the wheel speed difference between the two wheels of the first drive shaft decreases to C. At this point, the torque value cannot be directly selected as the output torque c corresponding to C as the threshold value. Instead, an output torque b smaller than c must be selected to ensure that, after the output torque increases to b, the first difference does not exceed the second safety threshold value B corresponding to b.

[0159] That is, the second torque is determined according to the first difference between the two wheels on the first drive shaft; a first control instruction is output based on the second torque; and the first control instruction is used to control the output torque of the first motor to increase from the first torque to the second torque.

[0160] When the vehicle is in an escape scenario, it is necessary to increase the output torque of the first motor so that the vehicle can obtain greater kinetic energy to escape. However, since the output torque of the motor and the safety threshold are negatively correlated, increasing the output torque of the first motor will lower the safety threshold. At the same time, increasing the output torque will also cause the first difference to increase. Therefore, only increasing the output torque cannot ensure that the first difference between the two wheels is not greater than the second safety threshold while meeting the kinetic energy requirements. To this end, the implementation method of the present application first reduces the first difference by braking the wheel with the larger wheel speed or slip rate among the two wheels, and then increases the output torque on this basis to ensure that while increasing the output torque, the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0161] In this scenario, the combination of braking and increasing the output torque can not only ensure the kinetic energy requirements of the vehicle in the scenario, but also ensure that the wheel speed difference is below the safety threshold, thereby ensuring the safety of the differential.

[0162] The torque increment created by the increased torque is used to compensate for power loss caused by unilateral braking. Besides being limited by the first difference, this increment can also be positively correlated with the brake pressure of a single wheel. In other words, while ensuring that the first difference does not exceed the safety threshold, a higher torque increment can be selected as the brake pressure of a single wheel increases.

[0163] 210: Determine whether the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is greater than the upper limit of the slip ratio range. If the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is greater than the upper limit of the slip ratio range, execute step 211. Otherwise, maintain the output torque of the first motor.

[0164] Here, when judging whether the slip rate of the wheel with the smaller speed among the two wheels is higher than the upper limit of the slip rate range, it can be judged whether the slip rate before braking is higher than the upper limit of the slip rate range, or whether the slip rate after braking is higher than the upper limit of the slip rate range.

[0165] When the slip rate of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, it is determined that the vehicle is in a drifting scenario where wheels on both sides lose adhesion, such as a high-speed cornering (drifting) scenario.

[0166] 211: Control the output torque of the first motor to decrease from the first torque to the second torque, so that a first difference between two wheels on the first drive shaft is not greater than a second safety threshold.

[0167] After braking causes the first difference between the two wheels to reach the target difference, the output torque of the first motor is controlled to decrease from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is no greater than the second safety threshold.

[0168] A second torque is determined according to a first difference between two wheels on the first drive shaft; a second control instruction is output based on the second torque; and the second control instruction is used to control the first motor to increase or decrease the torque.

[0169] In one approach, if the target difference after braking is less than the first safety threshold, then further reduction in output torque will ensure that the first difference between the two wheels does not exceed the second safety threshold. In another approach, the target difference after braking can also be no less than the first safety threshold, or even no less than the subsequent second safety threshold. By further reduction in output torque, a combination of these two approaches can ensure that the first difference between the two wheels does not exceed the second safety threshold.

[0170] When the slip rate of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is within the slip rate range, it is considered that the vehicle is in a transitional operating scenario, and the differential protection strategy does not perform torque control on the first motor.

[0171] For a four-wheel drive vehicle, when the first drive shaft is controlled, the second drive shaft may also be controlled. For example, the method may further include:

[0172] When the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, and the slip rate of the wheel with the smaller speed among the two wheels on the second drive shaft of the vehicle is not higher than the upper limit of the slip rate range, the output torque of the second motor corresponding to the second drive shaft of the vehicle is controlled to increase from the third torque to the fourth torque, and the first difference between the two wheels on the second drive shaft is not greater than the third safety threshold, which is the safety threshold corresponding to the case where the output torque of the second motor is the fourth torque.

[0173] For a four-wheel drive vehicle, when the slip ratio of the wheel with a slower wheel speed on the other drive shaft does not exceed the upper limit, torque transfer can be performed to ensure the overall driving force of the vehicle.

[0174] The output torque control of the second motor can be performed in a step-by-step manner or by determining a safe output torque corresponding to the first difference between the two wheels on the second drive shaft and then performing control. The detailed process can be referred to the control of the first motor described above.

[0175] When the slip rate of the wheel with the slower speed among the two wheels on the second drive shaft of the vehicle is higher than the upper limit of the slip rate range, the second motor corresponding to the second drive shaft is controlled to reduce the output torque. The detailed process can refer to the aforementioned control of the first motor.

[0176] In addition, the solution for controlling wheel speed difference provided in the embodiment of the present application intervenes earlier than the traction control system, thereby avoiding power problems caused by the intervention of the traction control system during vehicle operation and ensuring sports performance.

[0177] FIG5 is a flow chart of a vehicle control method provided by an embodiment of the present application. The method can be executed by a vehicle control unit or a motor controller. Below, the motor controller is used as an example. When the motor controller performs control, the brake control unit performs coordinated control. As shown in FIG5 , the method includes the following steps:

[0178] 301: Obtain wheel speeds of two wheels on a first drive shaft and a rotational speed of a first motor. The output torque of the first motor corresponding to the first drive shaft is a first torque.

[0179] The motor controller obtains the wheel speeds of the two wheels on the first drive shaft output by the vehicle's brake control unit through the vehicle control unit, and the motor controller obtains the rotational speed detected by the sensor in the first motor.

[0180] 302: Determine whether the wheel speeds of the two wheels on the first drive shaft are accurate based on the wheel speeds of the two wheels on the first drive shaft and the rotational speed of the first motor. If the wheel speeds of the two wheels on the first drive shaft are accurate, proceed to step 304; otherwise, proceed to step 303.

[0181] The detailed process of step 302 is shown in step 202 and will not be repeated here.

[0182] 303: Output fault prompt, indicating that the wheel speed sensor needs to be inspected or replaced.

[0183] Step 303 is an optional step.

[0184] 304 : Determine the slip ratios of the two wheels on the first drive shaft based on the wheel speeds of the two wheels on the first drive shaft and the rotation speed of the first motor.

[0185] The detailed process of step 304 is as described in step 204 and will not be repeated here.

[0186] 305 : Obtaining a first safety threshold corresponding to a case where the output torque of the first motor is the first torque from a correspondence between the motor output torque and the threshold.

[0187] The detailed process of step 305 is as described in step 205 and will not be repeated here.

[0188] 306 : Determine whether the first difference between the two wheels on the first drive shaft of the vehicle is greater than a first safety threshold. If the first difference between the two wheels on the first drive shaft is greater than the first safety threshold, execute step 307 .

[0189] Otherwise, the subsequent steps may not be performed and the output torque of the first motor may be maintained.

[0190] The detailed process of step 306 is shown in step 206 and will not be repeated here.

[0191] 307: Determine whether the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is greater than the lower limit of the slip ratio range. If the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is less than the lower limit of the slip ratio range, execute step 308. Otherwise, execute step 310.

[0192] The detailed process of step 307 is shown in step 208 and will not be repeated here.

[0193] 308: Braking the wheel with the larger wheel speed or slip ratio among the two wheels on the first drive shaft.

[0194] The detailed process of step 308 is described in step 207 and will not be repeated here.

[0195] 309 : Control the output torque of the first motor to increase from the first torque to the second torque, so that a first difference between two wheels on the first drive shaft is no greater than a second safety threshold.

[0196] The detailed process of step 309 refers to step 209 and will not be repeated here.

[0197] 310: Determine whether the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is greater than the upper limit of the slip ratio range. If the slip ratio of the wheel with the slower speed of the two wheels on the first drive shaft is greater than the upper limit of the slip ratio range, execute step 311. Otherwise, maintain the output torque of the motor.

[0198] The detailed process of step 310 refers to step 210 and will not be repeated here.

[0199] 311 : Control the output torque of the first motor to decrease from the first torque to the second torque, so that a first difference between two wheels on the first drive shaft is no greater than a second safety threshold.

[0200] The detailed process of step 311 refers to step 211 and will not be repeated here.

[0201] Compared with the method provided in FIG. 2 , the method shown in FIG. 5 differs from the method provided in FIG. 2 in that, in addition to the difference in the executing entities, braking is only performed in the escape scenario, and no braking is performed in the high-speed cornering (drifting) scenario.

[0202] Figure 6 is a block diagram of a vehicle control device provided by an embodiment of the present application. The vehicle control device can be implemented as all or part of a vehicle control unit or motor controller through software, hardware, or a combination of both. The vehicle control device may include: an acquisition unit 401 and a control unit 402.

[0203] The acquisition unit 401 is configured to acquire the wheel speeds of two wheels on a first drive shaft of the vehicle, where the first drive shaft is any drive shaft of the vehicle, and the output torque of the first motor corresponding to the first drive shaft is the first torque;

[0204] The control unit 402 is used to control the output torque of the first motor to change from a first torque to a second torque based on the slip rate of the two wheels on the first drive shaft when the first difference between the two wheels on the first drive shaft is greater than a first safety threshold, so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold, the first difference is the wheel speed difference or the slip rate difference, the first safety threshold is the safety threshold corresponding to the case where the output torque of the first motor is the first torque, and the second safety threshold is the safety threshold corresponding to the case where the output torque of the first motor is the second torque.

[0205] Optionally, the second torque is greater than the first torque;

[0206] The control unit 402 is used to brake the wheel with the larger wheel speed or slip ratio among the two wheels on the first drive shaft when the slip ratio of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is lower than the lower limit of the slip ratio range; and control the output torque of the first motor to increase from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0207] Optionally, the second torque is less than the first torque;

[0208] The control unit 402 is used to control the output torque of the first motor to be reduced from the first torque to the second torque when the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0209] Optionally, the second torque is less than the first torque;

[0210] The control unit 402 is used to brake the wheel with the larger wheel speed or slip ratio among the two wheels on the first drive shaft when the slip ratio of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is higher than the upper limit of the slip ratio range; and control the output torque of the first motor to be reduced from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

[0211] Optionally, the control unit 402 is used to determine the second torque based on the first difference between the two wheels on the first drive shaft; output a control instruction based on the second torque; and use the control instruction to control the output torque of the first motor so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

[0212] Optionally, the control unit 402 is also used to control the output torque of the second motor corresponding to the second drive shaft of the vehicle to increase from the third torque to the fourth torque, and to make the first difference between the two wheels on the second drive shaft not greater than a third safety threshold when the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range and the slip rate of the wheel with the smaller speed among the two wheels on the second drive shaft of the vehicle is not higher than the upper limit of the slip rate range, and to make the first difference between the two wheels on the second drive shaft not greater than a third safety threshold. The third safety threshold is the safety threshold corresponding to the case where the output torque of the second motor is the fourth torque.

[0213] Optionally, the acquiring unit 401 is further configured to acquire the rotational speed of the first motor;

[0214] The device also includes: a determination unit 403, which is used to determine whether the wheel speed is accurate based on the rotational speed of the first motor and the wheel speed of the two wheels on the first drive shaft; when the wheel speed of the two wheels on the first drive shaft is accurate, the slip rate of the two wheels on the first drive shaft is determined based on the wheel speed of the two wheels on the first drive shaft and the rotational speed of the first motor.

[0215] Optionally, the device includes a vehicle control unit, or the device includes a motor controller.

[0216] Optionally, the acquisition unit 401 is also used to obtain the correspondence between the motor output torque and the threshold, and the motor output torque and the threshold are negatively correlated; and the first safety threshold corresponding to the case where the output torque of the first motor is the first torque is obtained from the correspondence between the motor output torque and the threshold.

[0217] The vehicle control device provided in the above embodiment is illustrated by the division of the aforementioned functional units during operation. In actual applications, the aforementioned functions can be assigned to different functional units as needed, i.e., the internal structure of the device can be divided into different functional units to perform all or part of the functions described above. Furthermore, the vehicle control device provided in the above embodiment and the vehicle control method embodiment are based on the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0218] The descriptions of the processes corresponding to the above figures have different focuses. For parts that are not described in detail in a certain process, please refer to the relevant descriptions of other processes.

[0219] The embodiment of the present application further provides a vehicle, which includes a vehicle control device and a motor as shown in FIG6 , wherein the vehicle control device is connected to the motor.

[0220] FIG7 illustrates a schematic diagram of the structure of a vehicle control device 900 provided by an exemplary embodiment of the present application. The vehicle control device 900 shown in FIG7 is configured to perform the operations involved in the vehicle control methods shown in FIG2 , FIG3 , or FIG5 . The vehicle control device 900 may include the aforementioned vehicle control unit or motor controller. The vehicle control device 900 may be implemented using a general bus architecture.

[0221] As shown in FIG. 7 , the vehicle control device 900 includes at least one processor 901 , a memory 903 , and at least one communication interface 904 .

[0222] The processor 901 is, for example, a general-purpose central processing unit (CPU), a digital signal processor (DSP), a network processor (NP), a graphics processing unit (GPU), a neural-network processing unit (NPU), a data processing unit (DPU), a microprocessor, or one or more integrated circuits for implementing the solution of the present application. For example, the processor 901 includes an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or other programmable logic devices, a transistor logic device, a hardware component, or any combination thereof. The PLD is, for example, a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. It can implement or execute the various logic blocks, modules, and circuits described in conjunction with the disclosure of the embodiments of the present invention. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like.

[0223] Optionally, the vehicle control device 900 also includes a bus. The bus is used to transmit information between the various components of the vehicle control device 900. The bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, for example. Buses can be divided into address buses, data buses, control buses, etc. For ease of illustration, FIG7 shows only one thick line, but this does not mean that there is only one bus or only one type of bus.

[0224] The memory 903 is, for example, a read-only memory (ROM) or other type of static storage device that can store static information and instructions, or a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 903 is, for example, independent and connected to the processor 901 via a bus. The memory 903 can also be integrated with the processor 901.

[0225] The communication interface 904 uses any transceiver-like device for communicating with other devices or a communication network, such as Ethernet, a radio access network (RAN), or a Bluetooth network. The communication interface 904 may include a wired communication interface or a wireless communication interface. In the embodiment of the present application, the communication interface 904 may be used for the vehicle control device 900 to communicate with other devices.

[0226] In a specific implementation, as an embodiment, the processor 901 may include one or more CPUs, such as CPU0 and CPU1 shown in FIG7 . Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0227] In a specific implementation, as an example, the vehicle control device 900 may include multiple processors, such as processor 901 and processor 905 shown in FIG7 . Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). A processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0228] In a specific implementation, as an embodiment, the vehicle control device 900 may further include an output device and an input device. The output device communicates with the processor 901 and can display information in a variety of ways. For example, the output device can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device communicates with the processor 901 and can receive user input in a variety of ways. For example, the input device can be a touch screen device or a sensor device.

[0229] In some embodiments, the memory 903 is used to store program code 910 for executing the solution of the present application, and the processor 901 can execute the program code 910 stored in the memory 903. That is, the vehicle control device 900 can implement the vehicle control method provided by the method embodiment through the processor 901 and the program code 910 in the memory 903. The program code 910 may include one or more software modules. Optionally, the processor 901 itself may also store program code or instructions for executing the solution of the present application.

[0230] In a specific embodiment, the vehicle control device 900 of the embodiment of the present application may correspond to the motor control module or motor controller in the above-mentioned method embodiments. The processor 901 in the vehicle control device 900 reads the instructions in the memory 903, so that the vehicle control device 900 shown in Figure 7 can execute all or part of the operations performed by the motor control module or motor controller.

[0231] Specifically, the processor 901 is used to obtain the wheel speeds of two wheels on the first drive shaft of the vehicle, where the first drive shaft is any drive shaft of the vehicle, and the output torque of the first motor corresponding to the first drive shaft is the first torque; when the first difference between the two wheels on the first drive shaft is greater than the first safety threshold, based on the slip rate of the two wheels on the first drive shaft, the output torque of the first motor is controlled to change from the first torque to the second torque, so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold, the first difference is the wheel speed difference or the slip rate difference, the first safety threshold is the safety threshold corresponding to the case where the output torque of the first motor is the first torque, and the second safety threshold is the safety threshold corresponding to the case where the output torque of the first motor is the second torque.

[0232] For the sake of brevity, other optional implementations are not described here in detail.

[0233] The vehicle control device 900 may also correspond to the vehicle control apparatus shown in FIG6 , wherein each functional module in the vehicle control apparatus is implemented using the software of the vehicle control device 900 . In other words, the functional modules included in the vehicle control apparatus are generated by the processor 901 of the vehicle control device 900 reading the program code 910 stored in the memory 903 .

[0234] Among them, each step of the vehicle control method shown in Figure 2, Figure 3 or Figure 5 is completed by the hardware integrated logic circuit or software instructions in the processor of the vehicle control device 900. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a mature storage medium in the art such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0235] An embodiment of the present application also provides a chip, including: an input interface, an output interface, a processor and a memory, wherein the input interface, the output interface, the processor and the memory are connected through an internal connection path, and the processor is used to execute the code in the memory. When the code is executed, the processor is used to execute any of the above-mentioned vehicle control methods.

[0236] It should be understood that the processor may be a CPU, or other general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. It is worth noting that the processor may be a processor supporting the ARM architecture.

[0237] Furthermore, in an optional embodiment, there are one or more processors and one or more memories. Alternatively, the memories may be integrated with the processors, or provided separately from the processors. The memories may include read-only memory and random access memory, and provide instructions and data to the processors. The memories may also include non-volatile random access memory. For example, the memories may also store reference blocks and target blocks.

[0238] The memory may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be ROM, PROM, EPROM, EEPROM, or flash memory. The volatile memory may be RAM, which serves as an external cache. By way of example and not limitation, many forms of RAM are available, including, for example, SRAM, DRAM, SDRAM, DDR SDRAM, ESDRAM, SLDRAM, and DR RAM.

[0239] In an embodiment of the present application, a computer-readable storage medium is also provided, which stores computer instructions. When the computer instructions stored in the computer-readable storage medium are executed by a vehicle control device, the vehicle control device executes the vehicle control method provided above.

[0240] In an embodiment of the present application, a computer program product containing instructions is also provided, which, when executed on a vehicle control device, enables the vehicle control device to execute the vehicle control method provided above.

[0241] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described herein are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive).

[0242] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or by a program to instruct the relevant hardware, and the program may be stored in a computer-readable storage medium, which may be a read-only memory, a disk, or an optical disk, etc.

[0243] The above are merely optional embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A vehicle control method, characterized in that: The method comprises: Obtaining wheel speeds of two wheels on a first drive shaft of a vehicle, where the first drive shaft is any drive shaft of the vehicle, and an output torque of a first motor corresponding to the first drive shaft is a first torque; When a first difference between two wheels on the first drive shaft is greater than a first safety threshold, based on the slip rate of the two wheels on the first drive shaft, the output torque of the first motor is controlled to be changed from the first torque to the second torque, so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold, the first difference is a wheel speed difference or a slip rate difference, the first safety threshold is a safety threshold corresponding to the case where the output torque of the first motor is the first torque, and the second safety threshold is a safety threshold corresponding to the case where the output torque of the first motor is the second torque.

2. The method according to claim 1, characterized in that The second torque is greater than the first torque; The controlling the output torque of the first motor to change from the first torque to the second torque based on the slip rate of the two wheels on the first drive shaft so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold comprises: When the slip ratio of the wheel with a smaller wheel speed among the two wheels on the first drive shaft is lower than the lower limit of the slip ratio range, braking the wheel with a larger wheel speed or slip ratio among the two wheels on the first drive shaft; The output torque of the first motor is controlled to increase from the first torque to the second torque so that a first difference between two wheels on the first drive shaft is not greater than a second safety threshold.

3. The method according to claim 1, characterized in that: The second torque is less than the first torque; The controlling the output torque of the first motor to change from the first torque to the second torque based on the slip rate of the two wheels on the first drive shaft so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold comprises: When the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, the output torque of the first motor is controlled to be reduced from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

4. The method according to claim 1, characterized in that: The second torque is less than the first torque; The controlling the output torque of the first motor to change from the first torque to the second torque based on the slip rate of the two wheels on the first drive shaft so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold comprises: When the slip ratio of the wheel with a smaller wheel speed among the two wheels on the first drive shaft is higher than the upper limit of the slip ratio range, braking the wheel with a larger wheel speed or slip ratio among the two wheels on the first drive shaft; The output torque of the first motor is controlled to be reduced from the first torque to the second torque so that a first difference between two wheels on the first drive shaft is not greater than a second safety threshold.

5. The method according to any one of claims 1 to 4, characterized in that: The controlling the output torque of the first motor to change from the first torque to the second torque so that a first difference between two wheels on the first drive shaft is not greater than a second safety threshold includes: Determine the second torque according to the first difference between the two wheels on the first drive shaft; output a control instruction based on the second torque; use the control instruction to control the output torque of the first motor so that the first drive shaft The first difference between the two wheels is not greater than the second safety threshold.

6. The method according to any one of claims 1 to 5, characterized in that: The method further comprises: When the slip rate of the wheel with the smaller wheel speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, and the slip rate of the wheel with the smaller wheel speed among the two wheels on the second drive shaft of the vehicle is not higher than the upper limit of the slip rate range, the output torque of the second motor corresponding to the second drive shaft of the vehicle is controlled to increase from the third torque to the fourth torque, and the first difference between the two wheels on the second drive shaft is made not greater than a third safety threshold, and the third safety threshold is a safety threshold corresponding to the case where the output torque of the second motor is the fourth torque.

7. The method according to any one of claims 1 to 6, characterized in that: The method further comprises: Acquiring the rotation speed of the first motor; Determine whether the wheel speed is accurate based on the rotational speed of the first motor and the wheel speed of the two wheels on the first drive shaft; when the wheel speed of the two wheels on the first drive shaft is accurate, determine the slip rate of the two wheels on the first drive shaft based on the wheel speed of the two wheels on the first drive shaft and the rotational speed of the first motor.

8. The method according to any one of claims 1 to 7, characterized in that: The method is executed by a vehicle control unit, or the method is executed by a motor controller.

9. The method according to any one of claims 1 to 8, characterized in that: The method further comprises: Acquire a corresponding relationship between a motor output torque and a threshold value, wherein the motor output torque and the threshold value are negatively correlated; The first safety threshold corresponding to the output torque of the first motor before dynamic control is obtained from the correspondence between the motor output torque and the threshold.

10. A vehicle control device, characterized in that: The device comprises: an acquisition unit, configured to acquire wheel speeds of two wheels on a first drive shaft of a vehicle, wherein the first drive shaft is any drive shaft of the vehicle, and an output torque of a first motor corresponding to the first drive shaft is a first torque; A control unit, for controlling the output torque of the first motor to change from the first torque to a second torque based on the slip rate of the two wheels on the first drive shaft when a first difference between the two wheels on the first drive shaft is greater than a first safety threshold, so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold, the first difference being a wheel speed difference or a slip rate difference, the first safety threshold being a safety threshold corresponding to the case where the output torque of the first motor is the first torque, and the second safety threshold being a safety threshold corresponding to the case where the output torque of the first motor is the second torque.

11. The device according to claim 10, characterized in that The second torque is greater than the first torque; The control unit is used to brake the wheel with a larger wheel speed or slip rate among the two wheels on the first drive shaft when the slip rate of the wheel with a smaller wheel speed among the two wheels on the first drive shaft is lower than the lower limit of the slip rate range; and control the output torque of the first motor to increase from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

12. The device according to claim 10, characterized in that The second torque is less than the first torque; The control unit is used to control the output torque of the first motor to be reduced from the first torque to the second torque when the slip rate of the wheel with a smaller wheel speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range, so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

13. The device according to claim 10, characterized in that The second torque is less than the first torque; The control unit is used to brake the wheel with a larger wheel speed or slip ratio among the two wheels on the first drive shaft when the slip ratio of the wheel with a smaller wheel speed among the two wheels on the first drive shaft is higher than the upper limit of the slip ratio range. control the output torque of the first motor to be reduced from the first torque to the second torque so that the first difference between the two wheels on the first drive shaft is not greater than the second safety threshold.

14. The device according to any one of claims 10 to 13, characterized in that The control unit is used to determine the second torque based on a first difference between two wheels on the first drive shaft; output a control instruction based on the second torque; and use the control instruction to control the output torque of the first motor so that the first difference between the two wheels on the first drive shaft is not greater than a second safety threshold.

15. The device according to any one of claims 10 to 14, characterized in that The control unit is also used to control the output torque of the second motor corresponding to the second drive shaft of the vehicle to increase from the third torque to the fourth torque, and to make the first difference between the two wheels on the second drive shaft not greater than a third safety threshold when the slip rate of the wheel with the smaller speed among the two wheels on the first drive shaft is higher than the upper limit of the slip rate range and the slip rate of the wheel with the smaller speed among the two wheels on the second drive shaft of the vehicle is not higher than the upper limit of the slip rate range, and to make the first difference between the two wheels on the second drive shaft not greater than a third safety threshold, wherein the third safety threshold is a safety threshold corresponding to the case where the output torque of the second motor is the fourth torque.

16. The device according to any one of claims 10 to 15, characterized in that The acquisition unit is further used to acquire the rotation speed of the first motor; The device also includes: A determination unit is used to determine whether the wheel speed is accurate based on the rotational speed of the first motor and the wheel speed of the two wheels on the first drive shaft; when the wheel speed of the two wheels on the first drive shaft is accurate, the slip rate of the two wheels on the first drive shaft is determined based on the wheel speed of the two wheels on the first drive shaft and the rotational speed of the first motor.

17. The device according to any one of claims 10 to 16, characterized in that The device includes a vehicle control unit, or the device includes a motor controller.

18. The device according to any one of claims 10 to 17, characterized in that The acquisition unit is also used to acquire the correspondence between the motor output torque and the threshold, and the motor output torque is negatively correlated with the threshold; and to acquire the first safety threshold corresponding to the output torque of the first motor before dynamic control from the correspondence between the motor output torque and the threshold.

19. A vehicle, characterized in that: The vehicle comprises the vehicle control device according to any one of claims 10 to 18 and a motor, wherein the vehicle control device is connected to the motor.

20. A vehicle control device, characterized in that: The vehicle control device comprises a processor and a memory, wherein the memory is used to store a software program, and the processor runs or executes the software program stored in the memory so that the vehicle control device implements the method according to any one of claims 1 to 9.

21. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes executed by a processor, wherein the program codes include instructions for implementing the method according to any one of claims 1 to 9.

22. A computer program, characterized in that The computer program comprises: computer program codes, which, when executed by a computer, enable the computer to execute instructions of the method according to any one of claims 1 to 9.

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