Vehicle braking control method and device, vehicle and computer readable storage medium

Abstract

The invention discloses a vehicle braking control method and device, a vehicle and a computer readable storage medium, and the method comprises the steps: distributing the total demand braking torque of the vehicle to a first motor, a second motor and a third motor when determining that the vehicle has a braking demand, when at least one of the second demand braking torque of the second motor and the third demand braking torque of the third motor is larger than the maximum braking torque capable of being output of the corresponding motor, a first difference value between the maximum braking torque capable of being output of the second motor and the maximum braking torque capable of being output of the third motor is obtained; and the first motor is controlled to output the first required braking torque, and the output braking torque of the second motor and the third motor is controlled based on the first difference value so as to brake the vehicle, so that when the vehicle is braked, the output braking torque of each motor can be accurately controlled, and the stable and efficient braking effect is achieved. And the problem of deviation of the vehicle during braking in a complex environment is prevented, so that the stability of the vehicle is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a vehicle braking control method, device, vehicle, and computer-readable storage medium. Background Technology

[0002] In existing technologies, when a vehicle brakes on a road surface, road recognition technology is typically used to assess the road surface's coefficient of friction. This is done by reducing the braking force on the side with the high coefficient of friction and increasing the braking force on the side with the low coefficient of friction, thereby narrowing the difference in ground braking force between the two wheels and reducing yaw moment. However, in complex environments, factors such as wind direction and slope may cause a difference in ground braking force between the two wheels, leading to an increase in yaw moment and causing braking deviation, which in turn affects the vehicle's stability. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0004] Therefore, one objective of this invention is to provide a vehicle braking control method that can precisely control the output braking torque of each motor when the vehicle is braking, thereby achieving a stable and efficient braking effect, preventing the vehicle from veering off course when braking in complex environments, and thus improving the vehicle's stability.

[0005] Therefore, a second objective of the present invention is to provide a vehicle braking control device.

[0006] Therefore, a third objective of the present invention is to provide a vehicle.

[0007] Therefore, a fourth object of the present invention is to provide a computer-readable storage medium.

[0008] To achieve the above objectives, a first aspect of the present invention provides a vehicle braking control method. The vehicle includes a first motor, a second motor, and a third motor. The first motor is connected to a first drive shaft, and the second and third motors are connected to a second drive shaft. The vehicle braking control method includes: when it is determined that the vehicle has a braking demand, obtaining the total required braking torque of the vehicle and the maximum output braking torque corresponding to each of the first, second, and third motors; distributing the total required braking torque to the first, second, and third motors to obtain a first required braking torque of the first motor, a second required braking torque of the second motor, and a third required braking torque of the third motor; when at least one of the second and third required braking torques is greater than the maximum output braking torque of its corresponding motor, obtaining a first difference between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor; controlling the first motor to output the first required braking torque, and controlling the output braking torque of the second and third motors based on the first difference to brake the vehicle.

[0009] According to the vehicle braking control method of the present invention, when the vehicle is braking, the total required braking torque can be distributed to a first motor, a second motor, and a third motor. Furthermore, if at least one of the required braking torques of the second motor and the third motor is greater than the maximum output braking torque of its corresponding motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between the maximum output braking torques of the second and third motors, thereby achieving a stable and efficient braking effect. This prevents the vehicle from veering off course when braking in complex environments and improves vehicle stability.

[0010] In addition, the vehicle braking control method according to embodiments of the present invention may also have the following additional technical features: In some examples, controlling the output braking torque of the second motor and the third motor based on the first difference includes: determining whether the first difference is less than a first preset difference threshold; if so, controlling the second motor to output its maximum output braking torque and controlling the third motor to output its maximum output braking torque; otherwise, obtaining the larger of the maximum output braking torque of the second motor and the maximum output braking torque of the third motor; and controlling the output braking torque of the second motor and the third motor according to the larger value. This ensures that the braking capabilities of the second and third motors are fully utilized while maintaining vehicle balance and reducing the risk of veering.

[0011] In some examples, controlling the output braking torque of the second and third motors based on the larger value includes: when the maximum output braking torque of the second motor is the larger value, controlling the maximum output braking torque of the second motor to decrease until the first difference is less than the first preset difference threshold, then controlling the second motor to output the reduced maximum output braking torque; when the maximum output braking torque of the third motor is the larger value, controlling the maximum output braking torque of the third motor to decrease until the first difference is less than the first preset difference threshold, then controlling the third motor to output the reduced maximum output braking torque. This ensures that the braking capabilities of the second and third motors are close, preventing the vehicle from veering off course.

[0012] In some examples, after controlling the output braking torque of the second motor and the third motor based on the first difference, the method further includes: obtaining a first slip ratio of the wheel corresponding to the second motor and a second slip ratio of the wheel corresponding to the third motor; and adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio. This can prevent wheel lock-up caused by vehicle slippage and improve vehicle braking stability.

[0013] In some examples, adjusting the output braking torque of the second motor and the third motor based on the first slip ratio and the second slip ratio includes: if both the first slip ratio and the second slip ratio are less than a first preset slip ratio threshold, then controlling the output braking torque of the second motor and the third motor to remain unchanged. This avoids unnecessary adjustments to the output braking torque of the second motor and the third motor, which could disrupt the current braking balance and cause changes in wheel slip ratio or a decrease in vehicle braking performance.

[0014] In some examples, adjusting the output braking torque of the second motor and the third motor based on the first slip ratio and the second slip ratio includes: if both the first slip ratio and the second slip ratio are greater than a first preset slip ratio threshold, then controlling the output braking torque of the second motor and the third motor to decrease, thereby reducing the first slip ratio and the second slip ratio, until both the first slip ratio and the second slip ratio are less than the first preset slip ratio threshold, and a second difference between the reduced output braking torque of the second motor and the reduced output braking torque of the third motor is less than the first preset difference threshold, then adjusting the output braking torque of the second motor to the reduced output braking torque of the second motor, and adjusting the output braking torque of the third motor to the reduced output braking torque of the third motor. This ensures that the vehicle achieves both anti-skid and anti-vehicle deviation effects.

[0015] In some examples, adjusting the output braking torque of the second motor and the third motor based on the first slip ratio and the second slip ratio includes: if either the first slip ratio or the second slip ratio is greater than a first preset slip ratio threshold, then controlling the output braking torque of the motor corresponding to the wheel with a slip ratio greater than the first preset slip ratio threshold to decrease until the slip ratio of the wheel corresponding to that motor is less than the first preset slip ratio threshold, and a third difference between the reduced output braking torque of that motor and the output braking torque of the other motor is less than the first preset difference threshold, then adjusting the output braking torque of that motor to the reduced output braking torque. This ensures that the vehicle achieves both anti-skid and anti-vehicle deviation effects.

[0016] In some examples, after allocating the total required braking torque to the first motor to obtain the first required braking torque of the first motor, the method further includes: determining whether the first required braking torque is less than the maximum output braking torque of the first motor; if so, controlling the first motor to output the first required braking torque; otherwise, controlling the first motor to output the maximum output braking torque of the first motor. This ensures that the braking capacity of the first motor is maximized without damage.

[0017] In some examples, after controlling the first motor to output the first required braking torque or the maximum output braking torque of the first motor, the method further includes: obtaining the slip ratio of the wheels on both sides of the first motor; and adjusting the output braking torque of the first motor according to the slip ratio of the wheels on both sides. This can prevent wheel lock-up caused by vehicle slippage and improve vehicle braking stability.

[0018] In some examples, adjusting the output braking torque of the first motor based on the slip ratio of the two wheels includes: determining whether the slip ratio of both wheels is less than a first preset slip ratio threshold; if so, controlling the output braking torque of the first motor to remain unchanged; otherwise, controlling the output braking torque of the first motor to decrease to adjust the slip ratio of the two wheels until the slip ratio of both wheels is less than the first preset slip ratio threshold, then controlling the output braking torque of the first motor to be adjusted to the decreased output braking torque of the first motor. This can prevent wheel lock-up caused by vehicle slippage and improve vehicle braking stability.

[0019] In some examples, when controlling the output braking torque of the second and third motors based on the first difference, the method further includes: determining whether the vehicle is in a straight-line state; if not, controlling the output braking torque of the second and third motors to remain unchanged; if so, obtaining the yaw rate of the vehicle; and adjusting the output braking torque of the second and third motors according to the yaw rate. This avoids the problem of vehicle deviation caused by yaw and improves the braking stability of the vehicle.

[0020] In some examples, adjusting the output braking torque of the second and third motors based on the yaw rate includes: determining whether the absolute value of the yaw rate is less than a preset yaw rate threshold; if so, controlling the output braking torque of the second and third motors to remain unchanged; otherwise, determining the vehicle's offset direction and offset coefficient; and adjusting the output braking torque of the second and third motors based on the offset direction and offset coefficient. This eliminates abnormal yaw phenomena, thereby preventing the vehicle from veering off course due to excessive yaw, and thus improving the vehicle's braking stability.

[0021] In some examples, determining the vehicle's offset direction includes: determining that the vehicle is offset to the left when the yaw rate is positive; and determining that the vehicle is offset to the right when the yaw rate is negative. Therefore, the output braking torque of the corresponding motor can be precisely adjusted based on the offset direction, preventing the vehicle from veering off course and improving the vehicle's braking stability.

[0022] In some examples, determining the vehicle's offset coefficient includes: determining the vehicle's yaw torque based on the yaw rate; and determining the offset coefficient based on the yaw torque, wherein the offset coefficient includes a left offset coefficient and a right offset coefficient, and the offset coefficient is less than a preset offset coefficient threshold. Therefore, the output braking torque of the corresponding motor can be precisely adjusted based on the offset coefficient, preventing the vehicle from veering off course and improving the vehicle's braking stability.

[0023] In some examples, adjusting the output braking torque of the second and third motors based on the offset direction and the offset coefficient includes: adjusting the output braking torque of the second motor according to the left offset coefficient when the vehicle is determined to be offset to the left based on the offset direction; and adjusting the output braking torque of the third motor according to the right offset coefficient when the vehicle is determined to be offset to the right based on the offset direction. This can precisely eliminate abnormal yaw phenomena, prevent the vehicle from veering off course due to excessive yaw, and improve the vehicle's braking stability.

[0024] In some examples, obtaining the total required braking torque of the vehicle includes: obtaining the braking intensity of the vehicle; and determining the total required braking torque based on the braking intensity. This allows for accurate determination of the total required braking torque of the vehicle, ensuring vehicle stability during braking.

[0025] In some examples, distributing the total required braking torque to the first motor, the second motor, and the third motor includes: distributing the total required braking torque to the first motor, the second motor, and the third motor based on a preset braking torque distribution strategy. The preset braking torque distribution strategy is pre-calibrated based on ECE regulations and I-curves, and includes at least a torque distribution ratio for the first motor, the second motor, and the third motor. This allows for full utilization of ground adhesion, ensuring vehicle braking stability.

[0026] To achieve the above objectives, a second aspect of the present invention provides a vehicle braking control device. The vehicle includes a first motor, a second motor, and a third motor. The first motor is connected to a first drive shaft, and the second and third motors are connected to a second drive shaft. The vehicle braking control device includes: a first acquisition module, configured to acquire the total required braking torque of the vehicle and the maximum output braking torque of each of the first, second, and third motors when a braking demand is determined to exist; an allocation module, configured to allocate the total required braking torque to the first, second, and third motors to obtain a first required braking torque of the first motor, a second required braking torque of the second motor, and a third required braking torque of the third motor; a second acquisition module, configured to acquire a first difference between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor when at least one of the second and third required braking torques is greater than the maximum output braking torque of its corresponding motor; and a control module, configured to control the first motor to output the first required braking torque and control the output braking torque of the second and third motors based on the first difference to brake the vehicle.

[0027] According to the vehicle braking control device of the present invention, when the vehicle is braking, the total required braking torque can be distributed to the first motor, the second motor, and the third motor. Furthermore, if at least one of the required braking torques of the second motor and the third motor is greater than the maximum output braking torque of its corresponding motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between the maximum output braking torques of the second and third motors, thereby achieving a stable and efficient braking effect. This prevents the vehicle from veering off course when braking in complex environments and improves vehicle stability.

[0028] To achieve the above objectives, a third aspect of the present invention discloses a vehicle, the vehicle comprising: the vehicle braking control device described in the second aspect of the present invention; or, at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores vehicle braking control instructions executable by the at least one processor, and when the vehicle braking control instructions are executed by the at least one processor, the at least one processor performs the vehicle braking control method described in the first aspect of the present invention.

[0029] According to an embodiment of the present invention, when the vehicle brakes, the total required braking torque can be distributed to a first motor, a second motor, and a third motor. Furthermore, if at least one of the required braking torques of the second motor and the third motor is greater than the maximum output braking torque of its corresponding motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between the maximum output braking torques of the second and third motors, thereby achieving a stable and efficient braking effect. This prevents the vehicle from veering off course when braking in complex environments and improves vehicle stability.

[0030] To achieve the above objectives, a fourth aspect of the present invention discloses a computer-readable storage medium storing a vehicle braking control program, which, when executed by a processor, implements the vehicle braking control method as described in the first aspect of the present invention.

[0031] According to an embodiment of the present invention, when a vehicle braking control program stored thereon is executed by a processor, the total required braking torque can be allocated to a first motor, a second motor, and a third motor. Furthermore, if at least one of the required braking torques of the second motor and the third motor is greater than the maximum output braking torque of its corresponding motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between the maximum output braking torques of the second and third motors, thereby achieving a stable and efficient braking effect. This prevents the vehicle from veering off course when braking in complex environments and improves vehicle stability.

[0032] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a vehicle braking control device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a vehicle braking control device according to another embodiment of the present invention; Figure 3 This is a schematic flowchart of a vehicle braking control method according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a vehicle braking control device according to another embodiment of the present invention.

[0034] Figure label: Vehicle braking control device-100; first acquisition module-110; distribution module-120; second acquisition module-130; control module-140. Detailed Implementation

[0035] To provide a more detailed understanding of the features and technical content of the embodiments of the present invention, the implementation of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of the present invention. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be shown in a simplified manner to simplify the drawings.

[0036] The following is for reference. Figures 1-4 A vehicle braking control method and apparatus according to an embodiment of the present invention are described.

[0037] Combination Figure 1 and Figure 2 As shown, the vehicle includes a sensor signal acquisition module, a vehicle controller, a first motor, a second motor, and a third motor, as well as a motor controller for each motor. The sensor signal acquisition module can collect and transmit vehicle status information, including but not limited to vehicle speed, wheel speed, brake pedal displacement, brake pedal force, steering wheel angle, yaw rate, and accelerator pedal travel. The vehicle controller can receive the vehicle status information from the sensor acquisition module and determine the braking intensity based on this information, thereby determining the total braking torque required by the vehicle. The first motor is connected to a first driveshaft, and the second and third motors are connected to a second driveshaft. The first and second driveshafts are not limited to being the front or rear driveshafts of the vehicle; that is, the first motor can be located on either the front or rear driveshaft, and the second and third motors can also be located on either the front or rear driveshaft. Furthermore, the first and second driveshafts are respectively connected to the corresponding wheels. The output braking torque of the first motor can be transmitted to the wheels through the first driveshaft and the reducer and differential connected to the wheels. The output braking torque of the second and third motors can be transmitted to the wheels through the second driveshaft and the reducer connected to the wheels.

[0038] Figure 3 This is a schematic flowchart of a vehicle braking control method according to an embodiment of the present invention, as shown below. Figure 3 As shown, the method includes the following steps: Step S1: When it is determined that the vehicle has a braking demand, obtain the total braking torque required by the vehicle and the maximum output braking torque of the first motor, the second motor and the third motor respectively.

[0039] Specifically, during vehicle operation, the vehicle controller can determine whether the driver intends to brake by collecting vehicle status information from signal sensors. This vehicle status information includes, but is not limited to, changes in brake pedal travel, brake pedal force, vehicle speed, and wheel speed. Furthermore, when the vehicle status information determines that there is a braking demand, i.e., the driver intends to decelerate or stop the vehicle, the total required braking torque can be obtained, i.e., the braking torque required for safe braking. Simultaneously, the maximum output braking torque of each of the first, second, and third motors can be obtained.

[0040] Step S2: Distribute the total required braking torque to the first motor, the second motor and the third motor to obtain the first required braking torque of the first motor, the second required braking torque of the second motor and the third required braking torque of the third motor.

[0041] Specifically, after obtaining the total required braking torque, the total required braking torque can be allocated to the first motor, the second motor, and the third motor according to a pre-set allocation strategy, so that the total required braking torque is optimally allocated among the three motors, thereby obtaining the first required braking torque of the first motor, the second required braking torque of the second motor, and the third required braking torque of the third motor.

[0042] Step S3: When at least one of the second required braking torque and the third required braking torque is greater than the maximum output braking torque of its corresponding motor, obtain the first difference between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor.

[0043] Specifically, when at least one of the second and third required braking torques is greater than the maximum output braking torque of its corresponding motor, it indicates that at least one of the second or third motors is over-limited. In this case, to ensure the stability and safety of the braking process, a first difference between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor can be obtained, which is a value reflecting the difference in the maximum output braking torque of the second and third motors respectively.

[0044] Step S4: Control the first motor to output the first required braking torque, and control the output braking torque of the second and third motors based on the first difference to brake the vehicle.

[0045] Specifically, after distributing the total required braking torque to the first motor, the second motor, and the third motor, the first motor can be controlled to output the first required braking torque. If at least one of the second and third required braking torques is greater than the maximum output braking torque of its corresponding motor, the output braking torques of the second and third motors are controlled based on the first difference. This ensures that the output braking torque of the second and third motors does not exceed their corresponding maximum output braking torque, and also meets the total required braking torque distributed to the second and third motors. This enables the vehicle to achieve a stable and efficient braking effect, thereby preventing the vehicle from veering off course when braking in complex environments and improving vehicle stability.

[0046] Therefore, the above-described vehicle braking control method can distribute the total required braking torque to the first motor, the second motor, and the third motor when the vehicle is braking. Furthermore, if at least one of the required braking torques of the second motor and the third motor is greater than the maximum output braking torque of their respective motors, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between their respective maximum output braking torques. This achieves a stable and efficient braking effect, thereby preventing vehicle deviation problems when braking in complex environments and improving vehicle stability.

[0047] In one embodiment of the present invention, controlling the output braking torque of the second motor and the third motor based on a first difference includes: determining whether the first difference is less than a first preset difference threshold. If so, control the second motor to output the maximum output braking torque of the second motor, and control the third motor to output the maximum output braking torque of the third motor; otherwise, obtain the larger value between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor; control the output braking torque of the second motor and the third motor according to the larger value.

[0048] Specifically, when controlling the output braking torque of the second and third motors based on the first difference, if the first difference is less than the first preset difference threshold, it means that the maximum output braking torque of the second and third motors is similar and the difference is small. At this time, controlling the second motor to output the maximum output braking torque of the second motor and controlling the third motor to output the maximum output braking torque of the third motor can ensure that the braking capabilities of the second and third motors are fully utilized while keeping the vehicle in a balanced state and reducing the risk of deviation.

[0049] Furthermore, if the first difference is not less than the first preset difference threshold, it indicates that the maximum output braking torque of the second motor and the third motor differs significantly. Directly causing both the second and third motors to output their respective maximum output braking torques would lead to an imbalance in braking torque, increasing the risk of vehicle deviation. In this case, the motor with stronger braking capability would be operating at its limit, which might result in uneven braking or vehicle instability. Therefore, the larger of the maximum output braking torque of the second motor and the maximum output braking torque of the third motor can be obtained. The output braking torque of the second and third motors can be controlled based on the larger value to keep their output braking torques close to each other, thus avoiding vehicle deviation caused by excessive differences in the output braking torques of the second and third motors.

[0050] In a specific embodiment, the first preset difference threshold can be set according to the actual situation and experimental theory.

[0051] In one embodiment of the present invention, controlling the output braking torque of the second motor and the third motor according to a larger value includes: when the maximum output braking torque of the second motor is a larger value, controlling the maximum output braking torque of the second motor to decrease until a first difference is less than a first preset difference threshold, and then controlling the second motor to output the reduced maximum output braking torque of the second motor. When the maximum output braking torque of the third motor is a large value, the maximum output braking torque of the third motor is reduced until the first difference is less than the first preset difference threshold, and then the third motor outputs the reduced maximum output braking torque.

[0052] Specifically, when controlling the output braking torque of the second and third motors based on the larger value, if the maximum output braking torque of the second motor is the larger value, the maximum output braking torque of the second motor can be gradually reduced, while simultaneously monitoring the change of the first difference (i.e., the difference between the reduced maximum output braking torque of the second motor and the maximum output braking torque of the third motor) until the first difference is less than the first preset difference threshold, indicating that the braking capabilities of the second and third motors are close and the phenomenon of vehicle deviation can be avoided. At this time, the output of the second motor can be controlled to the reduced maximum output braking torque of the second motor.

[0053] Similarly, if the maximum output braking torque of the third motor is a large value, the maximum output braking torque of the third motor can be gradually reduced, while monitoring the change of the first difference (i.e., the difference between the reduced maximum output braking torque of the third motor and the maximum output braking torque of the second motor) until the first difference is less than the first preset difference threshold. This indicates that the braking capabilities of the second motor and the third motor are close, which can prevent the vehicle from veering off course. At this time, the output of the reduced maximum output braking torque of the third motor can be controlled.

[0054] In one embodiment of the present invention, after controlling the output braking torque of the second motor and the third motor based on the first difference, the method further includes: obtaining the first slip ratio of the wheel corresponding to the second motor and the second slip ratio of the wheel corresponding to the third motor; and adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio.

[0055] Specifically, after controlling the output braking torque of the second and third motors based on the first difference, the first slip ratio of the wheel corresponding to the second motor and the second slip ratio of the wheel corresponding to the third motor can be obtained to determine the slippage of the wheels corresponding to the second and third motors. That is, the first and second slip ratios reflect the friction state between the wheels corresponding to the second and third motors and the ground during braking. When the slip ratio is too high, the wheels may slip excessively. For example, if both the first and second slip ratios are 100%, it means that the wheels corresponding to the second and third motors are currently completely stationary and locked up. This may lead to reduced braking effect, increased tire wear, and loss of steering ability and stability. Therefore, the output braking torque of the second and third motors can be adjusted according to different first and second slip ratios to avoid wheel lockup caused by vehicle slippage and improve vehicle braking stability.

[0056] In one embodiment of the present invention, adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio includes: if both the first slip ratio and the second slip ratio are less than a first preset slip ratio threshold, then controlling the output braking torque of the second motor and the third motor to remain unchanged.

[0057] Specifically, when adjusting the output braking torque of the second and third motors based on the first and second slip ratios, if both the first and second slip ratios are less than the first preset slip ratio threshold, it indicates that the braking state of the wheels corresponding to the second and third motors is stable, meaning that there is no slippage on either wheel. In this case, unnecessary adjustments to the output braking torque of the second and third motors may disrupt the current braking balance, causing changes in the wheel slip ratio or a decrease in the vehicle's braking effect. Therefore, it is not necessary to adjust the output braking torque of the second and third motors, i.e., the output braking torque of the second and third motors should remain unchanged.

[0058] In a specific embodiment, the first preset slip ratio threshold can be set according to the actual situation and experimental theory.

[0059] In one embodiment of the present invention, adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio includes: if both the first slip ratio and the second slip ratio are greater than a first preset slip ratio threshold, then controlling the output braking torque of the second motor and the third motor to decrease, so as to reduce the first slip ratio and the second slip ratio, until both the first slip ratio and the second slip ratio are less than the first preset slip ratio threshold, and the second difference between the reduced output braking torque of the second motor and the reduced output braking torque of the third motor is less than the first preset difference threshold, then adjusting the output braking torque of the second motor to the reduced output braking torque of the second motor, and adjusting the output braking torque of the third motor to the reduced output braking torque of the third motor.

[0060] Specifically, when adjusting the output braking torque of the second and third motors based on the first and second slip ratios, if both the first and second slip ratios are greater than the first preset slip ratio threshold, it indicates that the first and second slip ratios are too high under the current conditions, which will cause the wheels corresponding to the second motor and the wheels corresponding to the third motor to slip. At this time, the output braking torque of the second and third motors can be reduced to decrease the braking force of the second and third motors, thereby reducing the first and second slip ratios until both the first and second slip ratios are reduced to below the first preset difference threshold. At the same time, the change of the second difference (i.e., the difference between the reduced output braking torque of the second motor and the reduced output braking torque of the third motor) can be monitored in real time until the second difference is less than the first preset difference threshold, indicating that the braking capabilities of the second and third motors are close, which can prevent the vehicle from veering off course. At this time, the output braking torque of the second motor can be adjusted to the reduced output braking torque of the second motor, and the output braking torque of the third motor can be adjusted to the reduced output braking torque of the third motor to ensure that the vehicle achieves both anti-slip and anti-vehicle veering effects.

[0061] In one embodiment of the present invention, adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio includes: if one of the first slip ratio and the second slip ratio is greater than a first preset slip ratio threshold, then controlling the output braking torque of the motor corresponding to the wheel whose slip ratio is greater than the first preset slip ratio threshold to be reduced, until the slip ratio of the wheel corresponding to the motor is less than the first preset slip ratio threshold, and a third difference between the reduced output braking torque of the motor and the output braking torque of the other motor is less than the first preset difference threshold, then adjusting the output braking torque of the motor to the reduced output braking torque.

[0062] Specifically, when adjusting the output braking torque of the second and third motors based on the first and second slip ratios, if either the first or second slip ratio is greater than a first preset slip ratio threshold (i.e., the first slip ratio is greater than the first preset slip ratio threshold, or the second slip ratio is greater than the first preset slip ratio threshold), it indicates that the first or second slip ratio is too high under the current condition. This will cause slippage in the wheel corresponding to either the second or third motor. In this case, the output braking torque of the motor corresponding to the wheel with a slip ratio greater than the first preset slip ratio threshold can be reduced to minimize the impact on that motor. The braking force is applied to reduce the slip ratio exceeding the first preset slip ratio threshold until the slip ratio of the wheel corresponding to the motor is reduced to below the first preset slip ratio threshold. At the same time, the change of the third difference (i.e., the difference between the output braking torque of the motor after reduction and the output braking torque of the other motor) can be monitored in real time. When the third difference is less than the first preset difference threshold, it indicates that the braking capacity of the motor and the other motor are close, which can prevent the vehicle from veering off course. At this time, the output braking torque of the motor can be adjusted to the reduced output braking torque to ensure that the vehicle achieves both anti-slip and anti-vehicle veering effects.

[0063] In one embodiment of the present invention, after allocating the total required braking torque to the first motor to obtain the first required braking torque of the first motor, the method further includes: determining whether the first required braking torque is less than the maximum output braking torque of the first motor; if so, controlling the first motor to output the first required braking torque; otherwise, controlling the first motor to output the maximum output braking torque of the first motor.

[0064] Specifically, after determining the first required braking torque of the first motor, it can be determined whether the first required braking torque exceeds the maximum output braking torque of the first motor, that is, whether it exceeds the maximum braking torque that the first motor can safely and continuously provide. For example, if the first required braking torque exceeds the maximum output braking torque of the first motor, it means that the current output capacity of the first motor cannot meet the first required braking torque. In this case, to protect the first motor from damage and to provide braking force to the maximum extent, the output of the first motor can be controlled to its maximum output braking torque. If the first required braking torque does not exceed the maximum output braking torque of the first motor, it means that the current output capacity of the first motor can meet the first required braking torque. In this case, to avoid excessive braking force causing the vehicle to veer off course, the output of the first required braking torque can be controlled to the maximum output braking torque.

[0065] In one embodiment of the present invention, after controlling the first motor to output a first required braking torque or the maximum output braking torque of the first motor, the method further includes: obtaining the slip ratio of the wheels on both sides of the first motor; and adjusting the output braking torque of the first motor according to the slip ratio of the wheels on both sides.

[0066] Specifically, after controlling the first motor to output the required braking torque or the maximum output braking torque of the first motor, the slip ratio of the wheels on both sides of the first motor can be obtained to determine the slippage of the wheels. That is, the slip ratio of the wheels reflects the friction state between the wheels and the ground during braking. Understandably, when the slip ratio of the wheels is too high, the wheels may slip excessively. For example, if the slip ratio of the wheels is 100%, it means that the wheels are currently completely stationary and locked up, which may lead to reduced braking effect, increased tire wear, and loss of steering ability and stability. Therefore, the output braking torque of the first motor can be adjusted according to the slip ratio of the wheels to avoid wheel lockup caused by slippage, thereby improving the vehicle's braking stability.

[0067] In one embodiment of the present invention, adjusting the output braking torque of the first motor according to the slip ratio of the two wheels includes: determining whether the slip ratio of both wheels is less than a first preset slip ratio threshold; if so, controlling the output braking torque of the first motor to remain unchanged; otherwise, controlling the output braking torque of the first motor to decrease in order to adjust the slip ratio of the two wheels, until the slip ratio of both wheels is less than the first preset slip ratio threshold, and then controlling the output braking torque of the first motor to be adjusted to the reduced output braking torque of the first motor.

[0068] Specifically, when adjusting the output braking torque of the first motor according to the slip ratio of the wheels on both sides, if the slip ratio of both wheels is less than the first preset slip ratio threshold, it means that the braking state of both wheels is stable, that is, there is no slippage of the wheels on both sides. At this time, unnecessary adjustment of the output braking torque of the first motor may break the current braking balance state, causing the slip ratio of both wheels to change, thereby reducing the braking effect of the vehicle. Therefore, it is not necessary to adjust the output braking torque of the first motor, that is, to keep the output braking torque of the first motor unchanged.

[0069] Furthermore, if the slip ratio of both wheels exceeds the first preset slip ratio threshold, it indicates that the slip ratio of at least one wheel on both sides is too high, which may cause the corresponding wheel to slip. In this case, the output braking torque of the first motor can be reduced to adjust the slip ratio of both wheels until the slip ratio of both wheels is reduced to below the first preset slip ratio threshold. Then, the output braking torque of the first motor is adjusted to the reduced output braking torque of the first motor to avoid wheel lock-up caused by vehicle slippage and improve vehicle braking stability.

[0070] In one embodiment of the present invention, when controlling the output braking torque of the second motor and the third motor based on the first difference, the method further includes: determining whether the vehicle is in a straight-moving state; if not, controlling the output braking torque of the second motor and the third motor to remain unchanged; if so, obtaining the yaw rate of the vehicle; and adjusting the output braking torque of the second motor and the third motor according to the yaw rate.

[0071] Specifically, in the process of controlling the output braking torque of the second and third motors based on the first difference, it is possible to further determine whether the vehicle is in a straight-line state. Based on the determination result, the output braking torque of the second and third motors can be controlled. For example, if the vehicle is not in a straight-line state (e.g., turning), the output braking torque of the second and third motors can be kept unchanged to avoid unnecessary interference with the vehicle's steering operation. If the vehicle is in a straight-line state, the yaw rate of the vehicle can be obtained through the corresponding sensors, and the output braking torque of the second and third motors can be adjusted according to the yaw rate.

[0072] Furthermore, when determining whether a vehicle is traveling straight, the steering wheel angle can be obtained. The steering wheel angle is used to determine whether the vehicle is traveling straight. For example, when the steering wheel angle is greater than or equal to a preset steering wheel angle threshold, it can be determined that the vehicle is not traveling straight. When the steering wheel angle is less than the preset steering wheel angle threshold, it can be determined that the vehicle is traveling straight.

[0073] In one embodiment of the present invention, adjusting the output braking torque of the second motor and the third motor according to the yaw rate includes: determining whether the absolute value of the yaw rate is less than a preset yaw rate threshold; if so, controlling the output braking torque of the second motor and the third motor to remain unchanged; otherwise, determining the vehicle's offset direction and offset coefficient; and adjusting the output braking torque of the second motor and the third motor according to the offset direction and offset coefficient.

[0074] Specifically, during the process of adjusting the output braking torque of the second and third motors based on the yaw rate, if the absolute value of the yaw rate is less than the preset yaw rate threshold, it indicates that the vehicle's yaw phenomenon is within a safe range and there is no significant yaw. In this case, the output braking torque of the second and third motors can be kept constant. If the absolute value of the yaw rate is greater than or equal to the preset yaw rate threshold, it indicates that the vehicle may be experiencing abnormal yaw, i.e., the vehicle is losing stability. In this case, the vehicle's offset direction and offset coefficient can be obtained, and the output braking torque of the second and third motors can be adjusted according to the offset direction and offset coefficient to eliminate the abnormal yaw phenomenon, thereby avoiding the problem of the vehicle veering due to excessive yaw and improving the vehicle's braking stability.

[0075] In a specific embodiment, the preset yaw rate threshold can be set according to the actual situation and experimental theory.

[0076] In one embodiment of the present invention, determining the vehicle's offset direction includes: when the yaw rate is positive, determining that the vehicle is offset to the left; when the yaw rate is negative, determining that the vehicle is offset to the right.

[0077] Specifically, since yaw rate is the angular velocity of a vehicle rotating around its vertical axis (i.e., the Z-axis, which is perpendicular to the ground and passes through the vehicle's center of gravity), it can reflect the vehicle's rotational motion in the horizontal plane. Therefore, in determining the vehicle's offset direction, if the yaw rate is positive, it means that the vehicle is rotating clockwise around its vertical axis (viewed from the top of the vehicle), that is, the vehicle is offset to the left. If the yaw rate is negative, it means that the vehicle is rotating counterclockwise around its vertical axis (viewed from the top of the vehicle), that is, the vehicle is offset to the right.

[0078] In one embodiment of the present invention, determining the vehicle's offset coefficient includes: determining the vehicle's yaw torque based on the yaw rate; and determining the offset coefficient based on the yaw torque, wherein the offset coefficient includes a left offset coefficient and a right offset coefficient, and the offset coefficient is less than a preset offset coefficient threshold.

[0079] Specifically, in determining the vehicle's offset coefficient, the yaw torque can first be determined based on the yaw rate, including but not limited to the formula... To determine, among which This indicates the vehicle's yaw torque. This represents the moment of inertia of the vehicle about its vertical axis (Z-axis). This represents the yaw rate.

[0080] Furthermore, the offset coefficient can be determined based on the yaw torque, where the offset coefficient includes a left offset coefficient and a right offset coefficient. Specifically, the following formula can be used to calculate the right offset coefficient: ,in, Indicates the right offset coefficient. This indicates the distance between the wheels corresponding to the second and third motors, respectively. as well as This indicates the braking force of the wheels corresponding to the second and third motors, where the second motor is the drive motor for the left wheel of the vehicle and the third motor is the drive motor for the right wheel of the vehicle. The braking force of the vehicle's left wheel is calculated using the following formula: ,in, For the braking force of the vehicle's left wheel, This is the output braking torque of the second motor. This is the speed ratio of the second motor. Indicates the rolling radius of the wheel; The specific formula for calculating the braking force of the right wheel of a vehicle is as follows: ,in, The braking force for the right wheel of the vehicle. This is the output braking torque of the third motor. This is the speed ratio of the third motor. Similarly, the following formula can be used to calculate the left offset coefficient: ,in, This represents the left offset coefficient.

[0081] Furthermore, when the offset coefficient is less than the preset offset coefficient threshold, wheel slippage can be avoided during the process of correcting vehicle deviation during braking, thereby ensuring vehicle braking stability. The preset offset coefficient threshold can be set according to experimental theory, including but not limited to 1.

[0082] In one embodiment of the present invention, adjusting the output braking torque of the second motor and the third motor according to the offset direction and the offset coefficient includes: when it is determined that the vehicle is offset to the left based on the offset direction, adjusting the output braking torque of the second motor according to the left offset coefficient; when it is determined that the vehicle is offset to the right based on the offset direction, adjusting the output braking torque of the third motor according to the right offset coefficient.

[0083] Specifically, during the process of adjusting the output braking torque of the second and third motors according to the offset direction and offset coefficient, if the yaw rate is positive, it indicates that the vehicle is offset to the left. At this time, the output braking torque of the second motor can be adjusted according to the left offset coefficient, that is, the braking state of the left wheel of the vehicle can be controlled to make the vehicle return to the center. Similarly, if the yaw rate is negative, it indicates that the vehicle is offset to the right. At this time, the output braking torque of the third motor can be adjusted according to the right offset coefficient, that is, the braking state of the right wheel of the vehicle can be controlled to make the vehicle return to the center.

[0084] In one embodiment of the present invention, obtaining the total required braking torque of a vehicle includes: obtaining the braking intensity of the vehicle; and determining the total required braking torque based on the braking intensity.

[0085] Specifically, in obtaining the total required braking torque for a vehicle, the braking intensity can be derived by querying a pre-set table based on vehicle status information collected by sensor modules. This pre-set table can be derived from extensive experimental data and experience, including but not limited to information such as vehicle speed, wheel speed, brake pedal travel displacement, brake pedal force, and steering wheel angle. Furthermore, the braking intensity can be substituted into a pre-set algorithm to determine the total required braking torque.

[0086] In one embodiment of the present invention, the total required braking torque is distributed to the first motor, the second motor and the third motor, comprising: distributing the total required braking torque to the first motor, the second motor and the third motor based on a preset braking torque distribution strategy, wherein the preset braking torque distribution strategy is obtained by pre-calibration based on ECE regulations and I curves, and the preset braking torque distribution strategy includes at least the torque distribution ratio for the first motor, the second motor and the third motor.

[0087] Specifically, after obtaining the total required braking torque of the vehicle, the total required braking torque can be distributed to the first, second, and third motors according to a preset braking torque distribution strategy. This preset braking torque distribution strategy refers to rules pre-set according to ECE regulations and the I-curve, used to distribute the total required braking torque to each motor according to the torque distribution ratio, thereby fully utilizing ground adhesion and ensuring vehicle braking stability. It is understood that ECE regulations are a series of automotive safety standards established by the Economic Commission for Europe, which include specific requirements for vehicle braking performance, including limitations on braking distance, braking deceleration, and braking force distribution. The I-curve is the ideal braking force distribution curve, used to show how braking force is distributed between the front and rear axles of the vehicle to achieve optimal braking effect.

[0088] In summary, according to the vehicle braking control method of the present invention, when the vehicle is braking, the total required braking torque can be distributed to the first motor, the second motor, and the third motor. Furthermore, if at least one of the required braking torques of the second motor and the third motor exceeds the maximum output braking torque of its respective motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between their respective maximum output braking torques. This achieves a stable and efficient braking effect, preventing vehicle deviation during braking in complex environments and improving vehicle stability. Further, during braking, when the slip ratio of each wheel exceeds a set slip ratio threshold, the output braking torques of the corresponding first, second, and third motors can be adjusted to prevent wheel lock-up due to slippage, thus improving vehicle braking stability. Moreover, when the vehicle is traveling straight, the output braking torques of the second and third motors can be adjusted according to the yaw rate to eliminate abnormal yaw, preventing vehicle deviation due to excessive yaw and further improving vehicle braking stability.

[0089] A further embodiment of the present invention provides a vehicle braking control device 100. The vehicle includes a first motor, a second motor, and a third motor. The first motor is connected to a first drive shaft, and the second and third motors are connected to a second drive shaft, as shown below. Figure 4 As shown, the device includes: a first acquisition module 110, an allocation module 120, a second acquisition module 130, and a control module 140.

[0090] The first acquisition module 110 is used to acquire the total required braking torque of the vehicle and the maximum output braking torque of the first motor, the second motor and the third motor when the vehicle has a braking demand.

[0091] The distribution module 120 is used to distribute the total required braking torque to the first motor, the second motor and the third motor to obtain the first required braking torque of the first motor, the second required braking torque of the second motor and the third required braking torque of the third motor.

[0092] The second acquisition module 130 is used to acquire a first difference between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor when at least one of the second required braking torque and the third required braking torque is greater than the maximum output braking torque of the corresponding motor.

[0093] The control module 140 is used to control the first motor to output the first required braking torque, and to control the output braking torque of the second motor and the third motor based on the first difference, so as to brake the vehicle.

[0094] In some embodiments, when controlling the output braking torque of the second motor and the third motor based on the first difference, the control module 140 is specifically configured to: determine whether the first difference is less than a first preset difference threshold; if so, control the second motor to output the maximum output braking torque of the second motor, and control the third motor to output the maximum output braking torque of the third motor; otherwise, obtain the larger value between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor; and control the output braking torque of the second motor and the third motor according to the larger value.

[0095] In some embodiments, when controlling the output braking torque of the second motor and the third motor according to the larger value, the control module 140 is specifically configured to: when the maximum output braking torque of the second motor is a larger value, control the maximum output braking torque of the second motor to decrease until the first difference is less than the first preset difference threshold, and then control the second motor to output the reduced maximum output braking torque of the second motor; when the maximum output braking torque of the third motor is a larger value, control the maximum output braking torque of the third motor to decrease until the first difference is less than the first preset difference threshold, and then control the third motor to output the reduced maximum output braking torque of the third motor.

[0096] In some embodiments, after controlling the output braking torque of the second motor and the third motor based on the first difference, the control module 140 is further configured to: obtain the first slip ratio of the wheel corresponding to the second motor and the second slip ratio of the wheel corresponding to the third motor; and adjust the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio.

[0097] In some embodiments, when adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio, the control module 140 is specifically configured to: if both the first slip ratio and the second slip ratio are less than the first preset slip ratio threshold, control the output braking torque of the second motor and the third motor to remain unchanged.

[0098] In some embodiments, when adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio, the control module 140 is specifically configured to: if both the first slip ratio and the second slip ratio are greater than the first preset slip ratio threshold, control the output braking torque of the second motor and the third motor to decrease, so as to decrease the first slip ratio and the second slip ratio, until both the first slip ratio and the second slip ratio are less than the first preset slip ratio threshold, and the second difference between the reduced output braking torque of the second motor and the reduced output braking torque of the third motor is less than the first preset difference threshold, adjust the output braking torque of the second motor to the reduced output braking torque of the second motor, and adjust the output braking torque of the third motor to the reduced output braking torque of the third motor.

[0099] In some embodiments, when adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio, the control module 140 is specifically configured to: if one of the first slip ratio and the second slip ratio is greater than a first preset slip ratio threshold, control the output braking torque of the motor corresponding to the wheel whose slip ratio is greater than the first preset slip ratio threshold to be reduced until the slip ratio of the wheel corresponding to the motor is less than the first preset slip ratio threshold, and the third difference between the reduced output braking torque of the motor and the output braking torque of the other motor is less than the first preset difference threshold, then adjust the output braking torque of the motor to the reduced output braking torque.

[0100] In some embodiments, after allocating the total required braking torque to the first motor to obtain the first required braking torque of the first motor, the control module 140 is further configured to: determine whether the first required braking torque is less than the maximum output braking torque of the first motor; if so, control the first motor to output the first required braking torque; otherwise, control the first motor to output the maximum output braking torque of the first motor.

[0101] In some embodiments, after controlling the first motor to output a first required braking torque or the maximum output braking torque of the first motor, the control module 140 is further configured to: obtain the slip ratio of the wheels on both sides of the first motor; and adjust the output braking torque of the first motor according to the slip ratio of the wheels on both sides.

[0102] In some embodiments, when adjusting the output braking torque of the first motor according to the slip ratio of the two wheels, the control module 140 is specifically configured to: determine whether the slip ratio of both wheels is less than a first preset slip ratio threshold; if so, control the output braking torque of the first motor to remain unchanged; otherwise, control the output braking torque of the first motor to decrease in order to adjust the slip ratio of the two wheels until the slip ratio of both wheels is less than the first preset slip ratio threshold, and then control the output braking torque of the first motor to be adjusted to the reduced output braking torque of the first motor.

[0103] In some embodiments, when controlling the output braking torque of the second motor and the third motor based on the first difference, the control module 140 is further configured to: determine whether the vehicle is in a straight-line state; if not, control the output braking torque of the second motor and the third motor to remain unchanged; if so, obtain the yaw rate of the vehicle; and adjust the output braking torque of the second motor and the third motor according to the yaw rate.

[0104] In some embodiments, the output braking torque of the second motor and the third motor is adjusted according to the yaw rate. Specifically, the control module 140 is used to: determine whether the absolute value of the yaw rate is less than a preset yaw rate threshold; if so, control the output braking torque of the second motor and the third motor to remain unchanged; otherwise, determine the vehicle's offset direction and offset coefficient; and adjust the output braking torque of the second motor and the third motor according to the offset direction and offset coefficient.

[0105] In some embodiments, when determining the vehicle's offset direction, the control module 140 is specifically configured to: determine that the vehicle is offset to the left when the yaw rate is positive; and determine that the vehicle is offset to the right when the yaw rate is negative.

[0106] In some embodiments, when determining the vehicle's offset coefficient, the control module 140 is specifically used to: determine the vehicle's yaw torque based on the yaw rate; and determine the offset coefficient based on the yaw torque, wherein the offset coefficient includes a left offset coefficient and a right offset coefficient, and the offset coefficient is less than a preset offset coefficient threshold.

[0107] In some embodiments, when adjusting the output braking torque of the second motor and the third motor according to the offset direction and the offset coefficient, the control module 140 is specifically used to: when it is determined that the vehicle is deviating to the left based on the offset direction, adjust the output braking torque of the second motor according to the left offset coefficient; when it is determined that the vehicle is deviating to the right based on the offset direction, adjust the output braking torque of the third motor according to the right offset coefficient.

[0108] In some embodiments, when obtaining the total required braking torque of the vehicle, the first obtaining module 110 is specifically used to: obtain the braking intensity of the vehicle; and determine the total required braking torque based on the braking intensity.

[0109] In some embodiments, when distributing the total required braking torque to the first motor, the second motor, and the third motor, the distribution module 120 is specifically used to: distribute the total required braking torque to the first motor, the second motor, and the third motor based on a preset braking torque distribution strategy, wherein the preset braking torque distribution strategy is obtained by pre-calibration based on ECE regulations and I curves, and the preset braking torque distribution strategy includes at least the torque distribution ratio for the first motor, the second motor, and the third motor.

[0110] According to the vehicle braking control device 100 of the present invention, when the vehicle is braking, the total required braking torque can be distributed to the first motor, the second motor, and the third motor. If at least one of the required braking torques of the second motor and the third motor exceeds the maximum output braking torque of its corresponding motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between their respective maximum output braking torques. This achieves a stable and efficient braking effect, preventing vehicle deviation during braking in complex environments and improving vehicle stability. Furthermore, during braking, when the slip ratio of each wheel exceeds a set slip ratio threshold, the output braking torques of the corresponding first, second, and third motors can be adjusted to prevent wheel lock-up due to slippage, thus improving vehicle braking stability. Furthermore, when the vehicle is traveling straight, the output braking torques of the second and third motors can be adjusted according to the yaw rate to eliminate abnormal yaw, preventing vehicle deviation due to excessive yaw and further improving vehicle braking stability.

[0111] To achieve the above objectives, a third aspect of the present invention discloses a vehicle, the vehicle comprising: the vehicle braking control device described in the second aspect of the present invention; or, at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores vehicle braking control instructions executable by the at least one processor, and when the vehicle braking control instructions are executed by the at least one processor, the at least one processor performs the vehicle braking control method described in the first aspect of the present invention.

[0112] According to embodiments of the present invention, when the vehicle brakes, the total required braking torque can be distributed to a first motor, a second motor, and a third motor. If at least one of the required braking torques of the second motor and the third motor exceeds the maximum output braking torque of its respective motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between their respective maximum output braking torques. This achieves a stable and efficient braking effect, preventing vehicle deviation during braking in complex environments and improving vehicle stability. Furthermore, during braking, if the slip ratio of each wheel exceeds a set slip ratio threshold, the output braking torques of the corresponding first, second, and third motors can be adjusted to prevent wheel lock-up due to slippage, further improving braking stability. Moreover, when the vehicle is traveling straight, the output braking torques of the second and third motors can be adjusted based on the yaw rate to eliminate abnormal yaw, preventing vehicle deviation due to excessive yaw and further improving braking stability.

[0113] To achieve the above objectives, a fourth aspect of the present invention discloses a computer-readable storage medium storing a vehicle braking control program, which, when executed by a processor, implements the vehicle braking control method as described in the first aspect of the present invention.

[0114] According to an embodiment of the present invention, when a vehicle braking control program stored thereon is executed by a processor, during vehicle braking, the total required braking torque can be distributed to a first motor, a second motor, and a third motor. Furthermore, if at least one of the required braking torques of the second motor and the third motor exceeds the maximum output braking torque of its respective motor, the output braking torques of the second and third motors can be dynamically adjusted based on the difference between their respective maximum output braking torques. This achieves a stable and efficient braking effect, preventing vehicle deviation during braking in complex environments and improving vehicle stability. Further, during vehicle braking, if the slip ratio of each wheel exceeds a set slip ratio threshold, the output braking torques of the corresponding first, second, and third motors can be adjusted to prevent wheel lock-up due to slippage, thus improving vehicle braking stability. Furthermore, when the vehicle is traveling straight, the output braking torque of the second and third motors can be adjusted according to the yaw rate to eliminate abnormal yaw, thereby preventing the vehicle from veering off course due to excessive yaw and improving the vehicle's braking stability.

[0115] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0116] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A vehicle brake control method characterized by, The vehicle comprises a first motor, a second motor and a third motor, the first motor is connected with a first transmission shaft, the second motor and the third motor are connected with a second transmission shaft, the vehicle brake control method comprises: When it is determined that the vehicle has a braking demand, obtaining a total required braking torque of the vehicle and a maximum output braking torque corresponding to each of the first motor, the second motor and the third motor; The total required braking torque is distributed to the first motor, the second motor and the third motor to obtain a first required braking torque of the first motor, a second required braking torque of the second motor and a third required braking torque of the third motor; When at least one of the second required braking torque and the third required braking torque is greater than the maximum output braking torque of the corresponding motor, obtaining a first difference value between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor; Controlling the first motor to output the first required braking torque, and controlling the output braking torque of the second motor and the third motor based on the first difference value to brake the vehicle.

2. The vehicle brake control method according to claim 1, characterized by, The controlling the output braking torque of the second motor and the third motor based on the first difference value comprises: Determining whether the first difference value is less than a first preset difference threshold value; If yes, controlling the second motor to output the maximum output braking torque of the second motor, and controlling the third motor to output the maximum output braking torque of the third motor; Otherwise, obtaining a larger value between the maximum output braking torque of the second motor and the maximum output braking torque of the third motor; Controlling the output braking torque of the second motor and the third motor according to the larger value.

3. The vehicle brake control method according to claim 2, characterized by, The controlling the output braking torque of the second motor and the third motor according to the larger value comprises: When the maximum output braking torque of the second motor is the larger value, controlling the maximum output braking torque of the second motor to be reduced until the first difference value is less than the first preset difference threshold value, and then controlling the second motor to output the reduced maximum output braking torque of the second motor; When the maximum output braking torque of the third motor is the larger value, controlling the maximum output braking torque of the third motor to be reduced until the first difference value is less than the first preset difference threshold value, and then controlling the third motor to output the reduced maximum output braking torque of the third motor.

4. The vehicle brake control method according to claim 2, characterized by After the controlling the output braking torque of the second motor and the third motor based on the first difference value, further comprising: Obtaining a first slip ratio of a wheel corresponding to the second motor and a second slip ratio of a wheel corresponding to the third motor; Adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio.

5. The vehicle brake control method according to claim 4, characterized by The adjusting the output braking torque of the second motor and the third motor according to the first slip ratio and the second slip ratio comprises: If the first slip ratio and the second slip ratio are both less than a first preset slip ratio threshold, the output brake torque of the second motor and the third motor is controlled to remain unchanged.

6. The vehicle brake control method according to claim 4, characterized by The adjusting the output brake torque of the second motor and the third motor according to the first slip ratio and the second slip ratio comprises: If the first slip ratio and the second slip ratio are both greater than the first preset slip ratio threshold, the output brake torque of the second motor and the third motor is controlled to be reduced to reduce the first slip ratio and the second slip ratio, until the first slip ratio and the second slip ratio are both less than the first preset slip ratio threshold, and a second difference between the reduced output brake torque of the second motor and the reduced output brake torque of the third motor is less than the first preset difference threshold, the output brake torque of the second motor is adjusted to the reduced output brake torque of the second motor, and the output brake torque of the third motor is adjusted to the reduced output brake torque of the third motor.

7. The vehicle brake control method according to claim 4, characterized by The adjusting the output brake torque of the second motor and the third motor according to the first slip ratio and the second slip ratio comprises: If one of the first slip ratio and the second slip ratio is greater than the first preset slip ratio threshold, the output brake torque of the motor corresponding to the wheel with the slip ratio greater than the first preset slip ratio threshold is controlled to be reduced until the slip ratio of the wheel corresponding to the motor is less than the first preset slip ratio threshold, and a third difference between the reduced output brake torque of the motor and the output brake torque of the other motor is less than the first preset difference threshold, the output brake torque of the motor is adjusted to the reduced output brake torque of the motor.

8. The vehicle brake control method according to claim 1, characterized by After the total demand brake torque is allocated to the first motor to obtain a first demand brake torque of the first motor, the method further comprises: determining whether the first demand brake torque is less than a maximum output brake torque of the first motor; if yes, controlling the first motor to output the first demand brake torque, otherwise, controlling the first motor to output the maximum output brake torque of the first motor.

9. The vehicle brake control method according to claim 8, characterized by, After the first motor outputs the first demand brake torque or the maximum output brake torque of the first motor, the method further comprises: obtaining the slip ratio of the wheels on both sides of the first motor; adjusting the output brake torque of the first motor according to the slip ratio of the wheels on both sides of the first motor.

10. The vehicle brake control method according to claim 9, characterized by The adjusting the output brake torque of the first motor according to the slip ratio of the wheels on both sides of the first motor comprises: determining whether the slip ratio of the wheels on both sides of the first motor are both less than a first preset slip ratio threshold; if yes, controlling the output brake torque of the first motor to remain unchanged, otherwise, controlling the output brake torque of the first motor to be reduced to adjust the slip ratio of the wheels on both sides of the first motor until the slip ratio of the wheels on both sides of the first motor are both less than the first preset slip ratio threshold, and the output brake torque of the first motor is adjusted to the reduced output brake torque of the first motor.

11. The vehicle brake control method according to claim 1, characterized by In the control of the second motor and the third motor based on the first difference value, the method further comprises: determining whether the vehicle is in a straight driving state; if not, the output brake torque of the second motor and the third motor remains unchanged; if yes, the yaw rate of the vehicle is obtained; the output brake torque of the second motor and the third motor is adjusted according to the yaw rate.

12. The vehicle brake control method according to claim 11, characterized by The adjustment of the output brake torque of the second motor and the third motor according to the yaw rate comprises: determining whether the absolute value of the yaw rate is less than a preset yaw rate threshold value; if yes, the output brake torque of the second motor and the third motor remains unchanged; otherwise, the offset direction and the offset coefficient of the vehicle are determined; the output brake torque of the second motor and the third motor is adjusted according to the offset direction and the offset coefficient.

13. The vehicle brake control method according to claim 12, characterized by The determination of the offset direction of the vehicle comprises: when the yaw rate is positive, it is determined that the vehicle is offset to the left; when the yaw rate is negative, it is determined that the vehicle is offset to the right.

14. The vehicle brake control method according to claim 12, characterized by The determination of the offset coefficient of the vehicle comprises: the yaw torque of the vehicle is determined according to the yaw rate; the offset coefficient is determined based on the yaw torque, wherein the offset coefficient comprises a left offset coefficient and a right offset coefficient, and the offset coefficient is less than a preset offset coefficient threshold value.

15. The vehicle brake control method according to claim 12, characterized by The adjustment of the output brake torque of the second motor and the third motor according to the offset direction and the offset coefficient comprises: when it is determined that the vehicle is offset to the left based on the offset direction, the output brake torque of the second motor is adjusted according to the left offset coefficient; when it is determined that the vehicle is offset to the right based on the offset direction, the output brake torque of the third motor is adjusted according to the right offset coefficient.

16. The vehicle brake control method according to claim 1, characterized by The obtaining of the total demand brake torque of the vehicle comprises: the brake intensity of the vehicle is obtained; the total demand brake torque is determined based on the brake intensity.

17. The vehicle brake control method according to claim 1, characterized by, The distribution of the total demand brake torque to the first motor, the second motor and the third motor comprises: the total demand brake torque is distributed to the first motor, the second motor and the third motor based on a preset brake torque distribution strategy, wherein the preset brake torque distribution strategy is obtained by pre-calibration based on ECE regulation and I curve, and the preset brake torque distribution strategy at least comprises a torque distribution ratio for the first motor, the second motor and the third motor.

18. A vehicle brake control device, the vehicle comprising a first motor, a second motor and a third motor, the first motor being connected with a first transmission shaft, the second motor and the third motor being connected with a second transmission shaft, the vehicle brake control device comprising: a first obtaining module, configured to, when the vehicle has a brake demand, obtain a total demand brake torque of the vehicle and a maximum brake torque that can be output by the first motor, the second motor and the third motor respectively; a distribution module configured to distribute the total required braking torque to the first electric machine, the second electric machine and the third electric machine to obtain a first required braking torque of the first electric machine, a second required braking torque of the second electric machine and a third required braking torque of the third electric machine; a second obtaining module configured to obtain a first difference between a maximum braking torque outputtable by the second electric machine and a maximum braking torque outputtable by the third electric machine when at least one of the second required braking torque and the third required braking torque is greater than the maximum braking torque outputtable by the corresponding electric machine; a control module configured to control the first electric machine to output the first required braking torque, and control the second electric machine and the third electric machine to output braking torque based on the first difference, so as to brake the vehicle.

19. A vehicle characterized by comprising: comprising: the vehicle braking control device of claim 18; or, a processor, a memory, and a vehicle braking control program stored on the memory and executable on the processor, the vehicle braking control program, when executed by the processor, implements the vehicle braking control method of any one of claims 1-17.

20. A computer-readable storage medium, characterized in that, the computer readable storage medium has stored thereon a vehicle braking program, the vehicle braking program, when executed by the processor, implements the vehicle braking method of any one of claims 1-17.

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