Brake torque control method and vehicle

Abstract

The invention provides a brake torque control method and a vehicle, belongs to the technical field of vehicles, and can limit the maximum value of the brake torque through the maximum available torque when it is determined that compensation of the brake torque needs to be carried out, so that wheel locking caused in the brake control process is avoided, and driving danger is avoided. If the braking compensation condition is met, it is indicated that braking control cannot be independently completed through electric braking, a braking system needs to participate in braking compensation, during braking compensation, needed braking torque needs to be distributed to different driving axles according to a driving mode, and the load conditions of the different driving axles are determined by determining overrun torque of the different driving axles; the phenomenon that wheels of the drive axle are locked in the brake compensation control process is avoided, the safety of the brake compensation process is ensured, brake compensation is achieved, meanwhile, wheel locking caused by brake compensation is avoided, and the safety of the brake compensation process is ensured while the speed reduction effect is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and in particular, to a method for controlling braking torque and a vehicle. Background Art

[0002] When a vehicle brakes, there are multiple sources of braking torque. Generally, electric braking is preferentially used for braking control. For example, in driving scenarios where the driver does not step on the brake pedal from medium to high speeds and needs to coast into the vehicle speed control range where the creep function is activated, or in driving scenarios where the vehicle creeps at a low speed. In both cases, the motor needs to output braking torque. However, affected by the external characteristics of the motor itself and the charging power of the power battery, the braking torque output by electric braking has an upper limit, resulting in insufficient braking force for the vehicle in some driving scenarios, unable to control the vehicle speed according to the set target, and causing safety risks. Summary of the Invention

[0003] In view of this, the purpose of the present application is to propose a method for controlling braking torque and a vehicle, which can improve the braking control effect while ensuring the safety of the vehicle driving process.

[0004] Based on the above purpose, the present application provides a method for controlling braking torque, including:

[0005] In response to the difference torque between the total required torque for recovery and the maximum motor recovery torque satisfying the compensation state condition, determine the maximum available torque according to the front axle anti-lock torque and the rear axle anti-lock torque, and determine whether the braking compensation condition is satisfied according to the maximum motor recovery torque and the maximum available torque;

[0006] In response to satisfying the braking compensation condition, determine the front axle distribution torque and the rear axle distribution torque according to the driving mode and the maximum motor recovery torque;

[0007] Determine the front axle overrun torque according to the front axle distribution torque and the front axle anti-lock torque, and determine the rear axle overrun torque according to the rear axle distribution torque and the rear axle anti-lock torque;

[0008] Perform braking compensation control according to the driving mode, the rear axle overrun torque, and the front axle overrun torque.

[0009] Optionally, the performing braking compensation control according to the driving mode, the rear axle overrun torque, and the front axle overrun torque includes:

[0010] In response to the driving mode being the four-wheel drive mode, determine the hydraulic compensation required torque according to the maximum available torque and the total required torque for recovery;

[0011] Determine the first torque compensation state of the front axle overrun torque and the second torque compensation state of the rear axle overrun torque;

[0012] In response to both the first torque compensation state and the second torque compensation state being torque remaining states, perform the braking compensation control according to the hydraulic compensation required torque, the rear axle overlimit torque, and the front axle overlimit torque;

[0013] In response to the first torque compensation state and the second torque compensation state being different, perform torque transfer control according to the rear axle overlimit torque and the front axle overlimit torque to obtain a torque transfer result, and perform the braking compensation control according to the torque transfer result and the hydraulic compensation required torque.

[0014] Optionally, the performing the braking compensation control according to the hydraulic compensation required torque, the rear axle overlimit torque, and the front axle overlimit torque includes:

[0015] Determine the sum value of the rear axle overlimit torque and the front axle overlimit torque as the available compensation torque;

[0016] In response to the available compensation torque being less than or equal to the hydraulic compensation required torque, determine the rear axle overlimit torque as the rear axle hydraulic compensation torque, and determine the front axle overlimit torque as the front axle hydraulic compensation torque;

[0017] In response to the available compensation torque being greater than the hydraulic compensation required torque, perform distribution compensation on the hydraulic compensation required torque according to the ratio of the rear axle overlimit torque to the front axle overlimit torque.

[0018] Optionally, the performing torque transfer control according to the rear axle overlimit torque and the front axle overlimit torque to obtain a torque transfer result includes:

[0019] In response to the first torque compensation state being an overlimit state and the second torque compensation state being a remaining state, determine the front axle anti-lock torque as the front axle motor request torque, and determine the sum value of the rear axle allocated torque and the absolute value of the front axle overlimit torque as the rear axle motor request torque to obtain a first torque transfer result;

[0020] In response to the first torque compensation state being a remaining state and the second torque compensation state being an overlimit state, determine the rear axle anti-lock torque as the rear axle motor request torque, and determine the sum value of the front axle allocated torque and the absolute value of the rear axle overlimit torque as the front axle motor request torque to obtain a second torque transfer result.

[0021] Optionally, the performing the braking compensation control according to the torque transfer result and the hydraulic compensation required torque includes:

[0022] Determine the sum value of the front axle overlimit torque and the rear axle overlimit torque as the available remaining torque;

[0023] In response to the torque transfer result being the first torque transfer result and the available remaining torque being less than or equal to the hydraulic compensation required torque, determine the available remaining torque as the first hydraulic request torque compensated to the rear axle;

[0024] In response to the torque transfer result being the first torque transfer result and the available remaining torque being greater than the hydraulic compensation required torque, determine the hydraulic compensation required torque as the first hydraulic request torque compensated to the rear axle;

[0025] In response to the torque transfer result being the second torque transfer result and the available remaining torque being less than or equal to the hydraulic compensation required torque, determine the available remaining torque as the second hydraulic request torque compensated to the front axle;

[0026] In response to the torque transfer result being the second torque transfer result and the available remaining torque being greater than the hydraulic compensation required torque, determine the hydraulic compensation required torque as the second hydraulic request torque compensated to the front axle.

[0027] Optionally, the determining the hydraulic compensation required torque according to the maximum available torque and the total recovery required torque includes:

[0028] In response to the maximum available torque being greater than or equal to the total recovery required torque, determine the difference between the total recovery required torque and the maximum motor recovery torque as the hydraulic compensation required torque;

[0029] In response to the maximum available torque being less than the total recovery required torque, determine the difference between the maximum available torque and the maximum motor recovery torque as the hydraulic compensation required torque.

[0030] Optionally, the determining whether the compensation status condition is satisfied according to the torque difference between the maximum motor recovery torque and the total recovery required torque includes:

[0031] In response to determining the difference torque between the maximum motor recovery torque and the total recovery required torque;

[0032] In response to the difference torque being greater than or equal to a preset first torque threshold, determine that the compensation status condition is satisfied;

[0033] In response to the difference torque being less than a preset second torque threshold, determine that the compensation status condition is not satisfied;

[0034] Wherein, the first torque threshold is greater than the second torque threshold.

[0035] Optionally, determining whether the braking compensation condition is satisfied according to the maximum motor recovery torque and the maximum available torque includes:

[0036] In response to the maximum available torque being less than or equal to the maximum motor recovery torque, it is determined that the braking compensation condition is not satisfied;

[0037] In response to the maximum available torque being greater than the maximum motor recovery torque, it is determined that the braking compensation condition is satisfied.

[0038] Optionally, the braking compensation control according to the driving mode, the over-limit torque of the rear axle, and the over-limit torque of the front axle further includes:

[0039] In response to the driving mode being the dual-drive mode, determine the active drive axle and the driven drive axle among the front drive axle and the rear drive axle, determine the target over-limit torque of the active drive axle among the over-limit torque of the rear axle and the over-limit torque of the front axle, and determine the target torque compensation state of the target over-limit torque;

[0040] In response to the target torque compensation state being the over-limit state, perform torque compensation control on the driven drive axle according to the target anti-lock torque of the active drive axle and the total recovery demand torque;

[0041] In response to the target torque compensation state being the remaining state, perform torque compensation control on the driven drive axle and / or the active drive axle according to the total recovery demand torque and the maximum motor recovery torque.

[0042] Optionally, performing torque compensation control on the driven drive axle according to the target anti-lock torque of the active drive axle and the total recovery demand torque includes:

[0043] Determine the difference between the total recovery demand torque and the anti-lock torque of the active drive axle as the dual-drive braking compensation torque;

[0044] In response to the dual-drive braking compensation torque being greater than the anti-lock torque of the driven drive axle, determine the anti-lock torque of the driven drive axle as the hydraulic request torque of the driven drive axle;

[0045] In response to the dual-drive braking compensation torque being less than or equal to the anti-lock torque of the driven drive axle, determine the dual-drive braking compensation torque as the hydraulic request torque of the driven drive axle.

[0046] Optionally, performing torque compensation control on the driven drive axle and / or the active drive axle according to the total recovery demand torque and the maximum motor recovery torque includes:

[0047] Determine the difference between the total recovery demand torque and the maximum motor recovery torque as the dual-drive braking compensation torque;

[0048] In response to the dual-drive braking compensation torque being less than or equal to the anti-lock torque of the driven drive axle, determine the dual-drive braking compensation torque as the driven hydraulic request torque;

[0049] In response to the dual-drive braking compensation torque being greater than the anti-lock torque of the driven drive axle and less than or equal to the sum of the anti-lock torque of the driven drive axle and the target over-limit torque, determine the anti-lock torque of the driven drive axle as the driven hydraulic request torque, and determine the difference between the dual-drive braking compensation torque and the anti-lock torque of the driven drive axle as the active hydraulic compensation torque;

[0050] In response to the dual-drive braking compensation torque being greater than the sum of the anti-lock torque of the driven drive axle and the target over-limit torque, determine the anti-lock torque of the driven drive axle as the driven hydraulic request torque, and determine the target over-limit torque as the active hydraulic compensation torque.

[0051] Based on the same inventive concept, the present disclosure also provides a vehicle, including an electronic device, the electronic device includes a memory, a processor, and a computer program stored on the memory and executable by the processor, and the processor implements the method as described above when executing the computer program.

[0052] As can be seen from the above, for the braking torque control method and vehicle provided by the present application, when the difference torque between the total required torque for recovery and the maximum motor recovery torque satisfies the compensation state condition, determine the maximum available torque according to the anti-lock torque of the front axle and the anti-lock torque of the rear axle, and determine whether the braking compensation condition is satisfied according to the maximum motor recovery torque and the maximum available torque; when the braking compensation condition is satisfied, determine the front axle distribution torque and the rear axle distribution torque according to the drive mode and the maximum motor recovery torque; determine the front axle over-limit torque according to the front axle distribution torque and the anti-lock torque of the front axle, and determine the rear axle over-limit torque according to the rear axle distribution torque and the anti-lock torque of the rear axle; perform braking compensation control according to the drive mode, the rear axle over-limit torque, and the front axle over-limit torque. When it is determined that braking torque compensation is required, limit the maximum value of the braking torque by the maximum available torque to avoid wheel lock-up during the braking control process and avoid driving hazards. Satisfying the braking compensation condition indicates that electric braking alone cannot complete the braking control and the braking system needs to participate in braking compensation. When performing braking compensation, the required braking torque needs to be distributed to different drive axles according to the drive mode, and the load conditions of different drive axles are determined by determining the over-limit torques of different drive axles, avoiding the phenomenon of wheel lock-up of the drive axle wheels during the braking compensation control process, ensuring the safety of the braking compensation process, achieving braking compensation while avoiding wheel lock-up caused by braking compensation, ensuring the deceleration effect while ensuring the safety of the braking compensation process. Description of the Drawings

[0053] To more clearly illustrate the technical solutions in the present application or related technologies, the following will briefly introduce the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0054] Figure 1 It is a flowchart of the control method for the braking torque in the embodiment of the present application;

[0055] Figure 2 It is a flowchart of the braking compensation control in the four-wheel drive mode in the embodiment of the present application;

[0056] Figure 3 It is a flowchart of the torque transfer control in the embodiment of the present application;

[0057] Figure 4 It is a flowchart of the braking compensation control after torque transfer in the embodiment of the present application;

[0058] Figure 5 It is a flowchart of determining whether the braking compensation condition is satisfied in the embodiment of the present application;

[0059] Figure 6 It is a flowchart of the braking compensation control in the two-wheel drive mode in the embodiment of the present application;

[0060] Figure 7 It is a schematic structural diagram of the control device for the braking torque in the embodiment of the present application;

[0061] Figure 8 It is a schematic structural diagram of the electronic device in the embodiment of the present application. Specific Embodiments

[0062] To make the objectives, technical solutions, and advantages of the present application clearer and more understandable, the following further elaborates on the present application in detail with reference to specific embodiments and the accompanying drawings.

[0063] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of this application should have the ordinary meanings understood by those of ordinary skill in the field to which this application belongs. The "first", "second" and similar terms used in the embodiments of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0064] In this article, it should be understood that any number of elements in the drawings is for illustration rather than limitation, and any naming is only for distinction and does not have any limiting meaning.

[0065] Based on the above description of the background technology, the following situations also exist in the related technology:

[0066] In the related technology, the motor system of new energy vehicles has two states, namely the driving state and the recuperation state. In the driving state, the driving torque can be released to accelerate the vehicle (corresponding to the battery discharging state), while in the recuperation state, it is similar to the braking system of the chassis to decelerate the vehicle and charge the battery at the same time. That is, in some cases, the vehicle can be decelerated through the recuperation state of the motor, and at the same time, the deceleration condition can be used to charge the battery to improve the endurance.

[0067] Based on the characteristics that the motor of new energy vehicles has two states, namely the driving state and the recuperation state, the vehicle control (Vehicle Control Unit, VCU) has added a low-speed creep function. For vehicles with a creep mode, after entering the creep mode, PI closed-loop control (Proportional Integral control, PI control) is performed based on the speed difference between the target speed and the actual speed, so that the vehicle finally reaches and stabilizes at the target speed. However, for roads with slopes, there is a risk of the vehicle slipping after entering the creep mode.

[0068] The specific control idea of the low and medium speed creep function in the VCU is as follows: First, set the target vehicle speed, and then, based on the actual vehicle speed sent by the Anti-lock Braking System (ABS), etc., perform PI control through the vehicle speed difference between the target vehicle speed and the actual vehicle speed, so that the vehicle finally reaches and stabilizes at the target vehicle speed. That is, when the actual vehicle speed > the target vehicle speed, control the vehicle to decelerate by reducing the creep torque; when the actual vehicle speed < the target vehicle speed, control the vehicle to accelerate by increasing the creep torque. Among them, it is roughly divided into two situations: starting creep (let the vehicle start from a stationary state or a low speed state without stepping on the accelerator) and coasting creep (let the vehicle decelerate from a medium and high speed state to a low speed creep state without stepping on the brake). At the same time, only the D gear and the R gear have the low speed creep function.

[0069] When the driver does not step on the brake pedal from a medium and high vehicle speed and needs to coast into the vehicle speed control range where the creep function is activated, especially after the creep function is activated, there may be creep driving scenarios of reverse in the R gear (the front of the vehicle is upward) and downhill in the D gear (the front of the vehicle is downward). Since there is no need for the driver to step on the accelerator and the brake pedal in the creep mode, it means that the vehicle's driving is completely controlled by the creep torque. The vehicle control unit needs to output the negative torque of coasting recovery and the creep negative torque to control the vehicle to coast or creep. Here, the negative torque can be understood as the motor recovery torque (making the battery enter the charging state). However, when the battery is fully charged or in a low temperature state, the battery recovery power is very small, resulting in a very small available recovery torque for the power system. During creep driving, especially in the creep driving scenarios of reverse in the R gear (the front of the vehicle is upward) and downhill in the D gear (the front of the vehicle is downward), there will be a situation of insufficient braking torque, resulting in the inability to control the vehicle speed according to the set target, leading to the phenomenon of vehicle slipping and causing safety risks.

[0070] The braking torque control method and vehicle provided in the embodiments of the present application, when the difference torque between the total required recovery torque and the maximum motor recovery torque meets the compensation state condition, determine the maximum available torque according to the front axle anti-lock torque and the rear axle anti-lock torque, and determine whether the braking compensation condition is met according to the maximum motor recovery torque and the maximum available torque; when the braking compensation condition is met, determine the front axle distribution torque and the rear axle distribution torque according to the drive mode and the maximum motor recovery torque; determine the front axle overlimit torque according to the front axle distribution torque and the front axle anti-lock torque, and determine the rear axle overlimit torque according to the rear axle distribution torque and the rear axle anti-lock torque; perform braking compensation control according to the drive mode, the rear axle overlimit torque and the front axle overlimit torque.

[0071] The difference torque between the total required torque for recovery and the maximum motor recovery torque satisfying the compensation state condition indicates that the motor alone cannot provide sufficient braking torque, and the vehicle is in a state where the braking system is required to compensate for the torque. When compensating for the braking torque, the maximum available torque is determined to avoid wheel lock-up and driving hazards. The maximum available torque limits the maximum value of the braking torque. Then, satisfying the braking compensation condition means that the braking system needs to participate in the braking compensation. When performing the braking compensation, the required braking torque needs to be distributed to different drive axles according to the driving mode, and the overload torque of different drive axles is determined to determine the load conditions of different drive axles, providing data support for the compensation of the braking torque under different driving modes, avoiding wheel lock-up of any drive axle, ensuring the safety of the braking compensation process, achieving the braking compensation while avoiding wheel lock-up caused by the braking compensation, ensuring the deceleration effect while ensuring the safety of the braking compensation process.

[0072] The following will specifically describe the braking torque control method provided by the embodiments of the present application with reference to the accompanying drawings.

[0073] In some embodiments, as Figure 1 shown, a braking torque control method includes:

[0074] Step 101: In response to the difference torque between the total required torque for recovery and the maximum motor recovery torque satisfying the compensation state condition, determine the maximum available torque according to the front axle anti-lock torque and the rear axle anti-lock torque, and determine whether the braking compensation condition is satisfied according to the maximum motor recovery torque and the maximum available torque.

[0075] Specifically, when performing braking compensation control, it is necessary to determine whether the corresponding compensation state condition is satisfied, that is, whether there is a need for braking compensation at this time. Since the braking compensation is that the braking system supplements the braking torque when the motor output torque is insufficient to achieve the corresponding control effect, there is a need for torque compensation only when the torque output by the motor cannot meet the demand.

[0076] Among them, the maximum motor recovery torque represents the maximum recovery torque value that the motor can output at the current moment, and is used to represent the total output capacity of the power battery and the motor. Because during energy recovery, it is manifested as the motor charging the power battery. Therefore, when outputting the braking torque, the maximum motor recovery torque is the minimum of the equivalent torque corresponding to the maximum recovery power of the battery and the equivalent power corresponding to the maximum power generation of the motor, that is, the maximum motor recovery torque = min(equivalent torque corresponding to the maximum recovery power of the battery, equivalent torque corresponding to the maximum power generation of the motor).

[0077] Among them, the equivalent torque corresponding to the maximum battery recovery power represents the maximum available torque value when the battery performs energy recovery, indicating the maximum torque utilization ability of the power battery; the equivalent torque corresponding to the maximum motor power generation power represents the torque value that the motor can use when operating at the maximum power generation power, indicating the maximum torque utilization ability of the traction motor.

[0078] Taking the minimum value as the maximum motor recovery torque can ensure that when using the motor for braking output, it will not damage the motor and the power battery. Generally, affected by the ambient temperature, the power battery's recovery ability will decline, which will in turn lead to a decrease in the maximum battery recovery power and a decrease in the maximum motor recovery torque. At this time, the motor alone cannot meet the braking control requirements, and the hydraulic braking torque output by the braking system needs to be used for torque compensation to achieve the braking control that meets the user's needs.

[0079] The user's demand is represented by the total recovery demand torque. The total recovery demand torque represents the minimum braking torque value required to meet the user's control requirements. If the actual output braking torque value is less than the total recovery demand torque, the user's control requirements cannot be met, and there may be a phenomenon of vehicle creep or unexpected acceleration.

[0080] By comparing the total recovery demand torque A1 and the maximum motor recovery torque A2 (in the embodiments of the present application, the interference of torque direction is not considered, and the comparison and calculation are both based on the torque value being positive), it is possible to determine whether the vehicle meets the condition for torque compensation. To simplify the comparison process, the torque difference ΔA between the total recovery demand torque A1 and the maximum motor recovery torque A2 is used to determine whether the compensation state condition is met.

[0081] If ΔA is greater than or equal to the preset torque threshold, it means that the driver controls the vehicle to be in a coasting recovery or creep activation state. The recovery capabilities of the battery and the motor will limit the recovery function, so the braking system needs to assist and use braking compensation to help the VCU control the vehicle speed; the requirement for ΔA > torque threshold is because if the difference torque is very small, such as 10 Nm, it is actually not worth having the braking system assist, and there will be no problem without braking compensation.

[0082] However, judging whether the compensation state condition is met only by a single torque threshold will cause oscillations during the braking compensation control (the New York difference fluctuates above and below the torque threshold, resulting in frequent opening and closing of the compensation control). To avoid oscillations, a hysteresis processing strategy is used to avoid their occurrence. That is, by designing two first torque thresholds and second torque thresholds with different values to judge whether the compensation state condition is met. Among them, the first torque threshold is greater than the second torque threshold, and the hysteresis interval is a torque interval with the first torque threshold as the upper boundary and the second torque threshold as the lower boundary, that is, the hysteresis interval is [the second torque threshold, the first torque threshold].

[0083] The process of using the hysteresis strategy to judge whether the compensation state condition is met is as follows:

[0084] In some embodiments, determining whether the compensation state condition is met according to the torque difference between the maximum motor recovery torque and the total recovery demand torque includes:

[0085] In response to the difference torque being greater than or equal to the preset first torque threshold, it is determined that the compensation state condition is met;

[0086] In response to the difference torque being less than the preset second torque threshold, it is determined that the compensation state condition is not met;

[0087] Among them, the first torque threshold is greater than the second torque threshold.

[0088] Since the difference torque is dynamically changing, the process of using the hysteresis strategy to judge whether the compensation state condition is met as the difference torque changes is as follows:

[0089] In response to the difference torque being less than the preset first torque threshold and greater than or equal to the preset second torque threshold, determine the change type of the difference torque;

[0090] In response to the change type being from less than the second torque threshold to greater than or equal to the second torque threshold, it is determined that the compensation state condition is not met;

[0091] In response to the change type being from greater than or equal to the first torque threshold to less than the first torque threshold, it is determined that the compensation state condition is met.

[0092] During specific implementation, if the difference torque is greater than or equal to the preset first torque threshold, it indicates that the difference torque is large and there is a large braking torque gap, and the braking system needs to participate in braking compensation, and it is determined that the compensation state condition is met.

[0093] If the difference torque is less than the preset second torque threshold, it indicates that the difference torque is small and there is a small braking torque gap, and the braking system does not need to participate in braking compensation, and it is determined that the compensation state condition is not met.

[0094] If the differential torque is less than a preset first torque threshold and greater than or equal to a preset second torque threshold, further judgment needs to be made according to the change type of the differential torque; if the change type of the differential torque is from less than the second torque threshold to greater than or equal to the second torque threshold, that is, the differential torque changes from less than the second torque threshold to greater than the second torque threshold and is within the hysteresis interval, the determination result before entering the hysteresis interval is still maintained. Since the determination result when it is less than the second torque threshold is that the compensation state condition is not satisfied, the determination result remains unchanged at this time, and it is determined that the compensation state condition is not satisfied.

[0095] Exemplarily, the first torque difference is 20 Nm and the second torque threshold is 10 Nm. If the initial value of the differential torque ΔA is 8 Nm and the corresponding initial determination result is that the compensation state condition is not satisfied, as the vehicle travels, the differential torque changes to 15 Nm. At this time, the change type of the differential torque is from less than the second torque threshold to greater than or equal to the second torque threshold, so the original determination result is maintained and it is determined that the compensation state condition is not satisfied. Only when the differential torque changes to greater than 20 Nm, the determination result is changed and it is determined that the compensation state condition is satisfied.

[0096] If the change type is from greater than or equal to the first torque threshold to less than the first torque threshold, that is, the differential torque changes from greater than the first torque threshold to less than the first torque threshold and is within the hysteresis interval, the determination result before entering the hysteresis interval is still maintained. Since the determination result when it is greater than the first torque threshold is that the compensation state condition is satisfied, the determination result remains unchanged at this time, and it is determined that the compensation state condition is satisfied.

[0097] Exemplarily, the first torque difference is 20 Nm and the second torque threshold is 10 Nm. If the initial value of the differential torque ΔA is 25 Nm and the corresponding initial determination result is that the compensation state condition is satisfied, as the vehicle travels, the differential torque changes to 15 Nm. At this time, the change type of the differential torque is from greater than or equal to the first torque threshold to less than the first torque threshold, so the original determination result is maintained and it is determined that the compensation state condition is satisfied. Only when the differential torque changes to less than 10 Nm, the determination result is changed and it is determined that the compensation state condition is not satisfied.

[0098] Judging whether the braking compensation condition is satisfied through the hysteresis strategy can effectively avoid frequent changes in the determination result, reduce the scenarios of torque control oscillation during the braking compensation control process, and improve the safety and effectiveness of the braking compensation control.

[0099] After determining that the difference torque between the total required recovery torque and the maximum motor recovery torque meets the compensation status condition, the maximum available torque is determined based on the front axle anti-lock torque and the rear axle anti-lock torque. The front axle anti-lock torque represents the maximum braking torque that can be applied before the front wheels lock, and the rear axle anti-lock torque represents the maximum braking torque that can be applied before the rear wheels lock. Among them, the maximum available torque is the sum of the front axle anti-lock torque and the rear axle anti-lock torque, representing the maximum braking torque value that can be applied before the tires lock.

[0100] Since when the wheels are subjected to braking forces (including the braking forces corresponding to the motor braking torque and the hydraulic braking torque), wheel lock may occur. To avoid the situation of wheel lock, the actually requested braking torque value needs to be less than the maximum available torque. Therefore, when the maximum available torque is less than or equal to the maximum motor recovery torque, it indicates that the output capacity of the motor exceeds the lock limit, and when performing braking control, not all of the maximum motor recovery torque can be distributed. There will be a certain remainder when distributing the maximum motor recovery torque. The maximum motor recovery torque itself already exceeds the braking capacity of the front and rear drive axles, that is, the braking torque provided by the motor is greater than the maximum required braking torque under the anti-lock limit. Then there is no need to use the braking system to compensate for the braking torque, and it is determined that the braking compensation condition is not met.

[0101] When the maximum available torque is greater than the maximum motor recovery torque, it indicates that the output capacity of the motor does not exceed the lock limit. When performing braking control, all of the maximum motor recovery torque can be distributed, and after distributing all of the maximum motor recovery torque, the braking demand still cannot be met, that is, the braking torque provided by the motor is less than the maximum required braking torque under the anti-lock limit. Then it is necessary to use the braking system to compensate for the braking torque, and it is determined that the braking compensation condition is met.

[0102] By determining whether the braking compensation condition is met, it is determined whether there is a need for the braking system to participate under the limit of the lock condition, so as to avoid ineffective braking compensation control.

[0103] Optionally, the torque compensation control is applied to the scenario where the motor braking is insufficient. To avoid control conflicts, the torque compensation control is more suitable for the scenario where the current throttle opening is less than the preset opening threshold and the electronic parking system is not activated. The throttle opening being less than the opening threshold ensures that the user has no sudden acceleration demand, avoiding conflicts between braking compensation and acceleration control. The electronic parking system not being activated can determine that the user has no parking demand and there is no interference from other braking methods.

[0104] The way to perform braking compensation is that the braking system applies additional (not provided by the motor) hydraulic braking torque to the corresponding wheel or drive axle. If the user depresses the accelerator pedal deeply, resulting in a large throttle opening, it indicates that the user has a large acceleration demand. If braking compensation is performed at this time, it will lead to an unclear acceleration effect or even acceleration failure. If the conflict between acceleration control and braking compensation control is relatively intense, there will also be a risk of vehicle out of control. Moreover, the purpose of braking compensation control is to compensate for insufficient braking torque. When there is a large acceleration demand, there is generally no need to compensate for braking torque. Therefore, to ensure the safety and rationality of braking compensation control, braking compensation needs to be performed when the user does not have a large braking demand.

[0105] The throttle opening is usually used to judge the user's acceleration demand. The opening threshold represents the maximum throttle opening value at which there will be no control conflict between the acceleration demand and braking compensation control. If the current throttle opening is greater than or equal to the opening threshold, it indicates that the user has a large acceleration demand and no braking compensation is required, and it is determined that the trigger condition for braking compensation is not met. If the current throttle opening is less than the opening threshold, it indicates that the user does not have a large acceleration demand, and there is no need to consider the control conflict between braking compensation and acceleration request, and it is determined that the trigger condition for braking compensation is met, and the vehicle is allowed to perform braking compensation control.

[0106] Furthermore, the braking torque of the vehicle can come from different systems, such as the torque output by the motor, the hydraulic torque applied by the braking system (such as ABS), and the mechanical braking torque applied by the electronic parking brake system (Electronic Park Brake, EPB). Braking compensation is that the braking system supplements the braking torque using the braking system when the motor output torque is insufficient to achieve the corresponding control effect. Therefore, during the torque compensation process, in order to avoid conflicts with the EPB parking control process, braking compensation control needs to be performed when the electronic parking brake system is not activated (or in the released state). After the electronic parking brake system is activated (or in the clamped state), the torque compensation function is stopped to ensure the safety of the parking control process.

[0107] The throttle opening being less than the opening threshold ensures that the user does not have a sudden acceleration demand, avoids the conflict between braking compensation and acceleration control, and the fact that the electronic parking brake system is not activated can determine that the user does not have a parking demand and there is no interference from other braking methods, ensuring the safety of the braking compensation control process.

[0108] Step 102: In response to meeting the braking compensation condition, determine the front axle distribution torque and the rear axle distribution torque according to the drive mode and the maximum motor regeneration torque.

[0109] During specific implementation, when the braking compensation condition is met, it indicates that there is a need for torque compensation in the braking system. At this time, the maximum motor recovery torque needs to be allocated according to the driving mode. If the driving mode is the four-wheel drive mode, it means that a part of the electric braking torque can be allocated to both the front and rear axles. If the maximum motor recovery torque is A2, A21 represents the torque allocated to the front axle, which is the braking torque required by the front drive axle from the motor, and A22 represents the torque allocated to the rear axle, which is the braking torque required by the rear drive axle from the motor. If the driving mode is the two-wheel drive mode, if it is the front-wheel two-wheel drive, the torque allocated to the front axle = A2, and the torque allocated to the rear axle = 0; if it is the rear-wheel two-wheel drive, the torque allocated to the front axle = 0, and the torque allocated to the rear axle = A2.

[0110] Since it is necessary to compensate for the shortage of the torque output by the motor during the braking compensation control, after determining the torque allocated to the front axle and the torque allocated to the rear axle, the torque compensation for the front and rear drive axles can be carried out respectively according to the anti-lock limit of each drive axle itself.

[0111] Step 103: Determine the front axle over-limit torque according to the torque allocated to the front axle and the front axle anti-lock torque, and determine the rear axle over-limit torque according to the torque allocated to the rear axle and the rear axle anti-lock torque.

[0112] During specific implementation, the difference between the front axle anti-lock torque and the torque allocated to the front axle is determined as the front axle over-limit torque, that is, the front axle over-limit torque = the front axle anti-lock torque - the torque allocated to the front axle; the difference between the rear axle anti-lock torque and the torque allocated to the rear axle is determined as the rear axle over-limit torque, that is, the rear axle over-limit torque = the rear axle anti-lock torque - the torque allocated to the rear axle.

[0113] Among them, if the front axle over-limit torque is positive, it means that the front drive axle can make full use of the torque allocated to the front axle, and there is still room for torque compensation or torque transfer. If the front axle over-limit torque is negative, it means that the front drive axle cannot make full use of the torque allocated to the front axle, there is no room for torque compensation or torque transfer, and the torque needs to be transferred out or the torque allocation ratio needs to be reduced. If the rear axle over-limit torque is positive, it means that the rear drive axle can make full use of the torque allocated to the front axle, and there is still room for torque compensation or torque transfer. If the rear axle over-limit torque is negative, it means that the rear drive axle cannot make full use of the torque allocated to the front axle, there is no room for torque compensation or torque transfer, and the torque needs to be transferred out or the torque allocation ratio needs to be reduced.

[0114] Step 104: Perform braking compensation control according to the driving mode, the rear axle over-limit torque, and the front axle over-limit torque.

[0115] During specific implementation, the four-wheel drive mode is taken as an example for illustration. Exemplarily, when the total required torque for recovery is 120 Nm and the maximum motor recovery torque is 80 Nm, the maximum value of the torque to be compensated at this time is 40 Nm, the torque distributed to the front axle is 50 Nm, and the torque distributed to the rear axle is 30 Nm. The anti-lock torque will vary dynamically due to factors such as the type of road surface and temperature. If the anti-lock torque of the front axle is 40 Nm and the anti-lock torque of the rear axle is 20 Nm at this time, the maximum available torque is 60 Nm. Since the braking compensation condition is not met and the braking system is not required to participate, the front drive axle is controlled to output at the anti-lock torque of the front axle, and the rear drive axle is controlled to output at the anti-lock torque of the rear axle. The maximum braking torque that can be provided at this time is the maximum available torque.

[0116] If the anti-lock torque of the front axle is 40 Nm and the anti-lock torque of the rear axle is 35 Nm at this time, the maximum available torque is 75 Nm. Since the braking compensation condition is not met and the braking system is not required to participate, the front drive axle is controlled to output at the anti-lock torque of the front axle, and the rear drive axle is controlled to output at the anti-lock torque of the rear axle. The maximum braking torque that can be provided at this time is the maximum available torque. Among them, 5 Nm is transferred out from the 50 Nm of the front axle distribution torque allocated to the front drive axle and transferred into the rear drive axle. After the torque transfer, in order to avoid wheel locking, the front axle distribution torque is 40 Nm and the rear axle distribution torque is 35 Nm. Still, the maximum motor recovery torque cannot be fully utilized. At this time, the braking system is still not required for torque compensation, and the front drive axle is still controlled to output at the anti-lock torque of the front axle, and the rear drive axle is controlled to output at the anti-lock torque of the rear axle. The maximum braking torque that can be provided at this time is the maximum available torque. Therefore, when the braking compensation condition is not satisfied, the anti-lock torque of the front axle is directly determined as the front axle motor request torque, and the anti-lock torque of the rear axle is determined as the rear axle motor request torque.

[0117] If the anti-lock torque of the front axle is 40 Nm and the anti-lock torque of the rear axle is 60 Nm at this time, then the maximum available torque is 100 Nm. At this time, the maximum available torque is greater than the maximum motor recovery torque, and it is determined that the braking compensation condition is satisfied and the braking system needs to be involved. However, at this time, the front axle over-limit torque = front axle anti-lock torque - front axle distributed torque = 40 - 50 = -10 Nm; the rear axle over-limit torque = rear axle anti-lock torque - rear axle distributed torque = 60 - 30 = 30 Nm. Then the front drive axle cannot fully utilize the front axle distributed torque, and the front axle over-limit torque needs to be transferred. Because the maximum available torque is greater than the maximum motor recovery torque at this time, there must be room for torque transfer in the rear drive axle. Therefore, first transfer 10 Nm to the rear drive axle. After the transfer, the front axle distributed torque is 50 Nm, and the rear axle distributed torque is 40 Nm. At this time, the rear axle over-limit torque = 60 - 40 = 20 Nm. Since the maximum available torque of 100 Nm is less than the total recovery demand torque of 120 Nm, the hydraulic compensation demand torque that the braking system can compensate at this time = 100 - 80 = 20 Nm. Then, after the torque transfer control, add 20 Nm of hydraulic braking torque to the rear drive axle for compensation.

[0118] If the anti-lock torque of the front axle is 60 Nm and the anti-lock torque of the rear axle is 70 Nm at this time, then the maximum available torque is 130 Nm. At this time, the maximum available torque is greater than the maximum motor recovery torque, and it is determined that the braking compensation condition is satisfied and the braking system needs to be involved. And at this time, the front axle over-limit torque = front axle anti-lock torque - front axle distributed torque = 60 - 50 = 10 Nm; the rear axle over-limit torque = rear axle anti-lock torque - rear axle distributed torque = 70 - 30 = 40 Nm. Then the front drive axle can fully utilize the front axle distributed torque, and there is no need to transfer the front axle over-limit torque. Also, the rear drive axle can fully utilize the front axle distributed torque, and there is no need to transfer the rear axle over-limit torque. Then there is no need to perform torque transfer control at this time, and the braking compensation control can be directly performed.

[0119] Since the maximum available torque is greater than the total recovery demand torque at this time, the hydraulic compensation demand torque that needs to be compensated = 120 - 80 = 40 Nm. And at this time, the upper limit value of the torque compensation that the front drive axle can perform is the front axle over-limit torque of 10 Nm, and the upper limit value of the torque compensation that the rear drive axle can perform is the rear axle over-limit torque of 40 Nm. Within this limit range, the braking compensation control can be performed according to the hydraulic compensation demand torque in any distribution method. Exemplarily, determine the ratio of the front axle over-limit torque to the rear axle over-limit torque, and this ratio = 1:4. Then distribute the hydraulic compensation demand torque according to the 1:4 ratio. Then compensate 8 Nm to the front drive axle and 32 Nm to the rear drive axle. Then the final braking torque applied to the front drive axle is 50 + 8 = 58 Nm, and the final braking torque applied to the rear drive axle is 30 + 32 = 62 Nm.

[0120] Optionally, one of the drive axles can be compensated to the corresponding anti-lock torque first, and then the remaining hydraulic compensation demand torque can be compensated to the other drive axle. For example, if 10 Nm of the hydraulic compensation demand torque is compensated to the front drive axle, the final braking torque applied to the front drive axle is 50 + 10 = 60 Nm. Then, if the remaining 30 Nm of the hydraulic compensation demand torque is compensated to the rear drive axle, the final braking torque applied to the rear drive axle is 30 + 30 = 60 Nm.

[0121] When performing braking compensation, it is necessary to distribute the required braking torque to different drive axles according to the driving mode, and determine the load conditions of different drive axles by determining the over-limit torque of different drive axles, so as to provide data support for the braking torque compensation under different driving modes, avoid wheel lock-up of any drive axle, ensure the safety of the braking compensation process, achieve braking compensation while avoiding wheel lock-up caused by braking compensation, ensure the deceleration effect while ensuring the safety of the braking compensation process.

[0122] In summary, for the braking torque control method provided in the embodiments of the present application, when it is determined that braking torque compensation is required, the maximum value of the braking torque is limited by the maximum available torque, avoiding wheel lock-up caused by the braking control process and avoiding driving risks. Meeting the braking compensation condition indicates that electric braking alone cannot complete the braking control, and the braking system needs to participate in braking compensation. When performing braking compensation, it is necessary to distribute the required braking torque to different drive axles according to the driving mode, and determine the load conditions of different drive axles by determining the over-limit torque of different drive axles, avoiding the phenomenon of drive axle wheel lock-up in the braking compensation control process, ensuring the safety of the braking compensation process, achieving braking compensation while avoiding wheel lock-up caused by braking compensation, ensuring the deceleration effect while ensuring the safety of the braking compensation process.

[0123] In some embodiments, such as Figure 2 shown, braking compensation control is performed according to the driving mode, rear axle over-limit torque, and front axle over-limit torque, including:

[0124] Step 201: In response to the driving mode being the four-wheel drive mode, determine the hydraulic compensation demand torque according to the maximum available torque and the total recovery demand torque.

[0125] Specifically, when implemented, if the driving mode is the four-wheel drive mode, separate braking compensation control needs to be performed on the front drive axle and the rear drive axle. Before performing the braking compensation control, it is necessary to determine the hydraulic compensation demand torque that the braking system needs to output during the compensation control process. Then, the process of determining the hydraulic compensation demand torque according to the maximum available torque and the total recovery demand torque is as follows:

[0126] In some embodiments, determining the hydraulic compensation demand torque according to the maximum available torque and the total recovery demand torque includes:

[0127] Step 2011: In response to the maximum available torque being greater than or equal to the total required torque for regeneration, determine the difference between the total required torque for regeneration and the maximum motor regeneration torque as the hydraulic compensation required torque.

[0128] In specific implementation, when the compensation state condition is met, it indicates that the maximum motor regeneration torque is less than the total required regeneration torque. If it is determined that the maximum available torque is greater than or equal to the total required torque for regeneration, then there is a situation where the maximum available torque ≥ the total required torque for regeneration > the maximum motor regeneration torque. It is determined that the motor alone cannot meet the demand of the total required torque for regeneration, and the braking system needs to compensate for the hydraulic braking torque. Since the maximum available torque is greater than or equal to the total required torque for regeneration at this time, braking compensation control based on the total required torque for regeneration will not cause wheel lock-up. Therefore, the difference between the total required torque for regeneration and the maximum motor regeneration torque is determined as the hydraulic compensation required torque, that is, the hydraulic compensation required torque = the total required torque for regeneration - the maximum motor regeneration torque. At this time, all the braking torque required for braking control can be provided, ensuring good braking control effect on the premise of avoiding wheel lock-up, avoiding the problem of insufficient braking force caused by low battery temperature or insufficient motor capacity, and improving the user's driving experience.

[0129] Step 2012: In response to the maximum available torque being less than the total required torque for regeneration, determine the difference between the maximum available torque and the maximum motor regeneration torque as the hydraulic compensation required torque.

[0130] In specific implementation, when the compensation state condition is met, it indicates that the maximum motor regeneration torque is less than the total required regeneration torque. If it is determined that the maximum available torque is less than the total required torque for regeneration, then there is a situation where the total required torque for regeneration > the maximum available torque > the maximum motor regeneration torque. It is determined that the motor alone cannot meet the demand of the total required torque for regeneration, and the braking system needs to compensate for the hydraulic braking torque. Since the maximum available torque is less than the total required torque for regeneration at this time, braking compensation control based on the total required torque for regeneration will cause wheel lock-up. Therefore, the difference between the maximum available torque and the maximum motor regeneration torque is determined as the hydraulic compensation required torque, that is, the hydraulic compensation required torque = the maximum available torque - the maximum motor regeneration torque. Due to the anti-lock limit, only part of the braking torque required for braking control can be provided at this time. On the premise of avoiding wheel lock-up, torque compensation is carried out to the greatest extent possible, ensuring torque compensation to the greatest extent possible on the premise of ensuring the safety of the braking compensation control process, ensuring braking effect while ensuring safety, and improving the user's driving experience.

[0131] Step 202: Determine the first torque compensation state of the front axle over-limit torque and the second torque compensation state of the rear axle over-limit torque.

[0132] In specific implementation, the first torque compensation state includes a torque overrun state and a torque remaining state. Among them, since the front axle overrun torque = the front axle anti-lock torque - the front axle distributed torque, if the front axle overrun torque is positive, it indicates that the front drive axle can fully utilize the front axle distributed torque and there is still room for torque compensation or torque transfer. Then, the first torque compensation state of the front axle overrun torque is the torque remaining state, and the torque remaining state represents a state with torque compensation or torque transfer space.

[0133] If the front axle overrun torque is negative, it indicates that the front drive axle cannot fully utilize the front axle distributed torque, there is no space for torque compensation or torque transfer, and it is necessary to transfer the torque out or reduce the torque distribution ratio. Then, the first torque compensation state of the front axle overrun torque is the torque overrun state, and the torque overrun state represents a state without torque compensation or torque transfer space.

[0134] Similarly, the second torque compensation state also includes a torque overrun state and a torque remaining state. Among them, since the rear axle overrun torque = the rear axle anti-lock torque - the rear axle distributed torque, if the rear axle overrun torque is positive, it indicates that the rear drive axle can fully utilize the rear axle distributed torque and there is still room for torque compensation or torque transfer. Then, the second torque compensation state of the rear axle overrun torque is the torque remaining state.

[0135] If the rear axle overrun torque is negative, it indicates that the rear drive axle cannot fully utilize the rear axle distributed torque, there is no space for torque compensation or torque transfer, and it is necessary to transfer the torque out or reduce the torque distribution ratio. Then, the second torque compensation state of the rear axle overrun torque is the torque overrun state.

[0136] By determining the first torque compensation state of the front axle overrun torque and the second torque compensation state of the rear axle overrun torque, the drive axle with torque compensation or torque transfer space is determined, providing data support for torque transfer control and braking compensation control.

[0137] Step 203: In response to both the first torque compensation state and the second torque compensation state being the torque remaining state, perform braking compensation control according to the hydraulic compensation required torque, the rear axle overrun torque, and the front axle overrun torque.

[0138] In specific implementation, if both the first torque compensation state and the second torque compensation state are the torque remaining state, it indicates that at this time, there is still room for torque compensation after the front drive axle distributes the front axle distributed torque, and there is also room for torque compensation after the rear drive axle distributes the rear axle distributed torque. At this time, there is no need to perform torque transfer control, and direct braking compensation control can be performed. The braking compensation control process at this time is as follows:

[0139] In some embodiments, performing braking compensation control according to the hydraulic compensation required torque, the rear axle overrun torque, and the front axle overrun torque includes:

[0140] Step 2031: Determine the sum value of the rear axle over-limit torque and the front axle over-limit torque as the available compensation torque.

[0141] During specific implementation, since both the first torque compensation state and the second torque compensation state are torque remaining states at this time, both the rear axle over-limit torque and the front axle over-limit torque are positive values. At this time, the rear axle over-limit torque represents the maximum value of the hydraulic torque that the rear drive axle can distribute, and the front axle over-limit torque represents the maximum value of the hydraulic torque that the front drive axle can distribute. Then, the sum value of the rear axle over-limit torque and the front axle over-limit torque is the maximum value of the total hydraulic torque that can be distributed. Therefore, determining the sum value of the rear axle over-limit torque and the front axle over-limit torque as the available compensation torque represents the maximum value of the total hydraulic torque that can be distributed.

[0142] Step 2032: In response to the available compensation torque being less than or equal to the hydraulic compensation demand torque, determine the rear axle over-limit torque as the rear axle hydraulic compensation torque, and determine the front axle over-limit torque as the front axle hydraulic compensation torque.

[0143] During specific implementation, if the available compensation torque is less than or equal to the hydraulic compensation demand torque, it indicates that all of the hydraulic compensation demand torque cannot be distributed at this time, and at this time, the hydraulic compensation demand torque = maximum available torque - maximum motor recovery torque. Then, the available compensation torque is equal to the hydraulic compensation demand torque. Directly determine the rear axle over-limit torque as the rear axle hydraulic compensation torque, and determine the front axle over-limit torque as the front axle hydraulic compensation torque. Perform braking compensation control with the maximum capabilities of the front and rear drive axles. On the premise of ensuring that the front and rear wheels do not lock, provide the maximum braking torque to ensure the braking control effect.

[0144] Exemplarily, if the front axle anti-lock torque is 60 Nm and the rear axle anti-lock torque is 40 Nm at this time, then the maximum available torque is 100 Nm. At this time, the maximum available torque is greater than the maximum motor recovery torque, it is determined that the braking compensation condition is met and the braking system needs to be involved. And at this time, the front axle over-limit torque = front axle anti-lock torque - front axle distributed torque = 60 - 50 = 10 Nm; the rear axle over-limit torque = rear axle anti-lock torque - rear axle distributed torque = 40 - 30 = 10 Nm. Then, the front drive axle can make full use of the front axle distributed torque and does not need to transfer the front axle over-limit torque, and the rear drive axle can also make full use of the front axle distributed torque and does not need to transfer the rear axle over-limit torque. Then, torque transfer control is not required at this time, and direct braking compensation control can be performed. Since the hydraulic compensation demand torque = maximum available torque - maximum motor recovery torque = 100 - 80 = 20 Nm at this time, 10 Nm of the 20 Nm is distributed to the front drive axle, and the remaining 10 Nm of the 20 Nm is distributed to the rear drive axle. Then, the rear axle hydraulic compensation torque at this time is the rear axle over-limit torque, and the front axle over-limit torque is determined as the front axle hydraulic compensation torque.

[0145] Step 2033: In response to the available compensation torque being greater than the hydraulic compensation required torque, allocate and compensate the hydraulic compensation required torque according to the ratio of the rear axle over-limit torque to the front axle over-limit torque.

[0146] During specific implementation, if the available compensation torque is greater than the hydraulic compensation required torque, it indicates that all of the hydraulic compensation required torque can be allocated. And at this time, the hydraulic compensation required torque = total recovery required torque - maximum motor recovery torque. Then, since the available compensation torque is greater than the hydraulic compensation required torque, allocate and compensate the hydraulic compensation required torque according to the ratio of the rear axle over-limit torque to the front axle over-limit torque. On the premise of ensuring that the front and rear wheels do not lock, by reasonably allocating the hydraulic compensation required torque, the possibility of wheel locking is reduced to ensure driving safety.

[0147] Exemplarily, if the front axle anti-lock torque is 60 Nm and the rear axle anti-lock torque is 70 Nm at this time, then the maximum available torque is 130 Nm. At this time, the maximum available torque is greater than the maximum motor recovery torque, it is determined that the braking compensation condition is met and the braking system needs to participate. And at this time, the front axle over-limit torque = front axle anti-lock torque - front axle allocated torque = 60 - 50 = 10 Nm; the rear axle over-limit torque = rear axle anti-lock torque - rear axle allocated torque = 70 - 30 = 40 Nm. Then the available compensation torque = 10 + 40 = 50 Nm, and the hydraulic compensation required torque = 120 - 80 = 40 Nm. Since the available compensation torque is greater than the hydraulic compensation required torque, there is no need to transfer the rear axle over-limit torque, and direct braking compensation control can be performed.

[0148] At this time, the upper limit value of torque compensation that the front drive axle can perform is the front axle over-limit torque of 10 Nm, and the upper limit value of torque compensation that the rear drive axle can perform is the rear axle over-limit torque of 40 Nm. Within this limit range, braking compensation control can be performed according to the hydraulic compensation required torque in any allocation method. Exemplarily, determine the ratio of the front axle over-limit torque to the rear axle over-limit torque, and this ratio = 1:4. Then allocate the hydraulic compensation required torque according to the 1:4 ratio, so compensate 8 Nm to the front drive axle and 32 Nm to the rear drive axle. Then the final braking torque applied to the front drive axle is 50 + 8 = 58 Nm, and the final braking torque applied to the rear drive axle is 30 + 32 = 62 Nm.

[0149] Step 204: In response to the first torque compensation state and the second torque compensation state being different, perform torque transfer control according to the rear axle over-limit torque and the front axle over-limit torque to obtain a torque transfer result, and perform braking compensation control according to the torque transfer result and the hydraulic compensation required torque.

[0150] In specific implementation, if the first torque compensation state is different from the second torque compensation state, it indicates that one of the over-limit torques of the rear axle and the front axle is positive and the other is negative, that is, there is a drive axle that needs to transfer torque out, and the other drive axle can transfer torque in. Therefore, it is necessary to first perform torque transfer control according to the over-limit torques of the rear axle and the front axle to obtain a torque transfer result, and perform braking compensation control according to the torque transfer result and the hydraulic compensation required torque.

[0151] When performing braking compensation, it is necessary to distribute the required braking torque to different drive axles according to the drive mode, and determine the load conditions of different drive axles by determining the over-limit torques of different drive axles, so as to provide data support for the compensation of braking torque under different drive modes, avoid the phenomenon of wheel lock-up on any drive axle, ensure the safety of the braking compensation process, achieve braking compensation while avoiding wheel lock-up caused by braking compensation, ensure the deceleration effect while ensuring the safety of the braking compensation process.

[0152] In some embodiments, such as Figure 3 shown, performing torque transfer control according to the over-limit torques of the rear axle and the front axle to obtain a torque transfer result, including:

[0153] Step 301: In response to the first torque compensation state being the over-limit state and the second torque compensation state being the remaining state, determine the front axle anti-lock torque as the front axle motor request torque, and determine the sum of the rear axle distributed torque and the absolute value of the front axle over-limit torque as the rear axle motor request torque to obtain the first torque transfer result.

[0154] In specific implementation, for example, if the front axle anti-lock torque is 40 Nm and the rear axle anti-lock torque is 60 Nm at this time, the maximum available torque is 100 Nm. At this time, the maximum available torque is greater than the maximum motor recovery torque, and it is determined that the braking compensation condition is satisfied and the braking system needs to participate. However, at this time, the front axle over-limit torque = front axle anti-lock torque - front axle distributed torque = 40 - 50 = -10 Nm, so the first torque compensation state is the over-limit state; the rear axle over-limit torque = rear axle anti-lock torque - rear axle distributed torque = 60 - 30 = 30 Nm, so the second torque compensation state is the remaining state. The torque transfer control is to transfer 10 Nm to the rear drive axle. After the transfer, the front axle distributed torque is 50 Nm and the rear axle distributed torque is 40 Nm. Then, determine the front axle anti-lock torque as the front axle motor request torque, and determine the sum of the rear axle distributed torque and the absolute value of the front axle over-limit torque as the rear axle motor request torque to obtain the first torque transfer result.

[0155] Step 302: In response to the first torque compensation status being the remaining status and the second torque compensation status being the over-limit status, determine the rear axle anti-lock torque as the rear axle motor requested torque, and determine the sum of the absolute values of the front axle distributed torque and the rear axle over-limit torque as the front axle motor requested torque, to obtain the second torque transfer result.

[0156] During specific implementation, for example, if the front axle anti-lock torque is 70 Nm and the rear axle anti-lock torque is 20 Nm at this time, the maximum available torque is 90 Nm. At this time, the maximum available torque is greater than the maximum motor recovery torque, and it is determined that the braking compensation condition is met and the braking system needs to participate. However, at this time, the front axle over-limit torque = front axle anti-lock torque - front axle distributed torque = 70 - 50 = 20 Nm, so the first torque compensation status is the remaining status; the rear axle over-limit torque = rear axle anti-lock torque - rear axle distributed torque = 20 - 30 = -10 Nm, so the second torque compensation status is the over-limit status. The torque transfer control is to transfer 10 Nm to the front drive axle. After the transfer, the front axle distributed torque is 60 Nm and the rear axle distributed torque is 30 Nm. Then, determine the rear axle anti-lock torque as the rear axle motor requested torque, and determine the sum of the absolute values of the front axle distributed torque and the rear axle over-limit torque as the front axle motor requested torque, to obtain the second torque transfer result.

[0157] Avoid wheel locking caused by unreasonable motor torque distribution through torque transfer, and provide a basis for the braking compensation control after torque transfer.

[0158] In some embodiments, as Figure 4 shown, perform braking compensation control according to the torque transfer result and the hydraulic compensation required torque, including:

[0159] Step 401: Determine the sum of the front axle over-limit torque and the rear axle over-limit torque as the available remaining torque.

[0160] During specific implementation, due to the different first torque compensation status and second torque compensation status, the torque sum of the front axle over-limit torque and the rear axle over-limit torque is the available remaining torque that the transferred side can additionally apply after torque transfer.

[0161] Step 402: In response to the torque transfer result being the first torque transfer result and the available remaining torque being less than or equal to the hydraulic compensation required torque, determine the available remaining torque as the first hydraulic request torque compensated to the rear axle.

[0162] In specific implementation, when the torque transfer result is the first torque transfer result, it indicates that the front drive axle can no longer perform torque compensation and only the rear drive axle can be compensated alone. If the available remaining torque is less than or equal to the hydraulic compensation demand torque, it means that the space for torque compensation at this time is not sufficient to compensate the total braking torque to the total recovery demand torque, and only the available remaining torque that the rear drive axle can apply after transfer can be used for compensation. That is, when the available remaining torque is less than or equal to the hydraulic compensation demand torque, the available remaining torque is determined as the first hydraulic request torque compensated to the rear axle, ensuring that the rear wheels will not lock up after braking compensation control and guaranteeing driving safety.

[0163] Step 403: In response to the torque transfer result being the first torque transfer result and the available remaining torque being greater than the hydraulic compensation demand torque, determine the hydraulic compensation demand torque as the first hydraulic request torque compensated to the rear axle.

[0164] In specific implementation, when the torque transfer result is the first torque transfer result, it indicates that the front drive axle can no longer perform torque compensation and only the rear drive axle can be compensated alone. If the available remaining torque is greater than the hydraulic compensation demand torque, it means that the space for torque compensation at this time can compensate the total braking torque to the total recovery demand torque. To achieve the best compensation effect, when the available remaining torque is greater than the hydraulic compensation demand torque, the hydraulic compensation demand torque is determined as the first hydraulic request torque compensated to the rear axle to meet the braking control requirements.

[0165] Step 404: In response to the torque transfer result being the second torque transfer result and the available remaining torque being less than or equal to the hydraulic compensation demand torque, determine the available remaining torque as the second hydraulic request torque compensated to the front axle.

[0166] In specific implementation, when the torque transfer result is the second torque transfer result, it indicates that the rear drive axle can no longer perform torque compensation and only the front drive axle can be compensated alone. If the available remaining torque is less than or equal to the hydraulic compensation demand torque, it means that the space for torque compensation at this time is not sufficient to compensate the total braking torque to the total recovery demand torque, and only the available remaining torque that the front drive axle can apply after transfer can be used for compensation. That is, when the available remaining torque is less than or equal to the hydraulic compensation demand torque, the available remaining torque is determined as the second hydraulic request torque compensated to the front axle, ensuring that the front wheels will not lock up after braking compensation control and guaranteeing driving safety.

[0167] Step 405: In response to the torque transfer result being the second torque transfer result and the available remaining torque being greater than the hydraulic compensation demand torque, determine the hydraulic compensation demand torque as the second hydraulic request torque compensated to the front axle.

[0168] During specific implementation, when the torque transfer result is the second torque transfer result, it indicates that the front drive axle can no longer perform torque compensation and can only be compensated separately. If the available remaining torque is greater than the hydraulic compensation required torque, it means that the space for torque compensation at this time can compensate the total braking torque to the total recovery required torque. To achieve the best compensation effect, when the available remaining torque is greater than the hydraulic compensation required torque, the hydraulic compensation required torque is determined as the first hydraulic request torque compensated to the front axle to meet the braking control requirements.

[0169] In some embodiments, as Figure 5 shown, determining whether the braking compensation condition is met according to the maximum motor recovery torque and the maximum available torque includes:

[0170] Step 501: In response to the maximum available torque being less than or equal to the maximum motor recovery torque, determine that the braking compensation condition is not met.

[0171] During specific implementation, when the maximum available torque is less than or equal to the maximum motor recovery torque, it indicates that the output capacity of the motor exceeds the anti-lock limit. When performing braking control, not all of the maximum motor recovery torque can be distributed, and there will be a certain remainder when the maximum motor recovery torque is distributed. The maximum motor recovery torque itself already exceeds the braking capacity of the front and rear drive axles, that is, the braking torque provided by the motor is greater than the maximum required braking torque under the anti-lock limit. Then, there is no need to use the braking system to compensate for the braking torque, and it is determined that the braking compensation condition is not met.

[0172] Step 502: In response to the maximum available torque being greater than the maximum motor recovery torque, determine that the braking compensation condition is met.

[0173] During specific implementation, when the maximum available torque is greater than the maximum motor recovery torque, it indicates that the output capacity of the motor does not exceed the anti-lock limit. When performing braking control, all of the maximum motor recovery torque can be distributed, and after distributing all of the maximum motor recovery torque, the braking demand still cannot be met, that is, the braking torque provided by the motor is less than the maximum required braking torque under the anti-lock limit. Then, it is necessary to use the braking system to compensate for the braking torque, and it is determined that the braking compensation condition is met.

[0174] By determining whether the braking compensation condition is met, it is determined whether there is a need for the braking system to participate under the limitation of the anti-lock condition, avoiding ineffective braking compensation control.

[0175] In one embodiment, the method for controlling the braking torque further includes:

[0176] In response to the braking compensation condition not being met, the front axle anti-lock torque is determined as the front axle motor request torque, and the rear axle anti-lock torque is determined as the rear axle motor request torque.

[0177] During specific implementation, if the braking compensation condition is not met, it indicates that the braking torque provided by the motor is greater than the maximum required braking torque under the anti-lock limit. In this case, there is no need to use the braking system to compensate for the braking torque. At this time, the front axle anti-lock torque is determined as the front axle motor request torque, and the rear axle anti-lock torque is determined as the rear axle motor request torque, so as to provide the maximum braking torque for the vehicle and improve the braking control effect as much as possible while avoiding wheel lock-up.

[0178] In some embodiments, as Figure 6 shown, the braking compensation control according to the drive mode, the rear axle over-limit torque, and the front axle over-limit torque further includes:

[0179] Step 601: In response to the drive mode being the dual-drive mode, determine the active drive axle and the driven drive axle among the front drive axle and the rear drive axle, determine the target over-limit torque of the active drive axle among the rear axle over-limit torque and the front axle over-limit torque, and determine the target torque compensation state of the target over-limit torque.

[0180] During specific implementation, the dual-drive mode includes rear-wheel dual-drive and front-wheel dual-drive. The front-wheel dual-drive is a drive mode in which the front drive axle is the active drive axle and the rear drive axle is the driven drive axle; the rear-wheel dual-drive is a drive mode in which the front drive axle is the driven drive axle and the rear drive axle is the active drive axle.

[0181] Then when it is determined that the drive mode is the dual-drive mode, it can be understood that the distributed torque of the driven drive axle is determined to be 0, and the maximum motor recovery torque is allocated to the active drive axle. Then the target over-limit torque = the front axle anti-lock torque of the active drive axle - the maximum motor recovery torque (the value in the dual-drive mode is the maximum motor recovery torque of the active drive axle), the target over-limit torque = the front axle anti-lock torque of the active drive axle - the maximum motor recovery torque, and the over-limit torque of the driven drive axle = the rear axle anti-lock torque of the driven drive axle - 0 = the rear axle anti-lock torque of the driven drive axle. If the front axle anti-lock torque of the active drive axle is greater than the maximum motor recovery torque, the target over-limit torque is positive, and the target torque compensation state is the remaining state; if the front axle anti-lock torque of the active drive axle is less than the maximum motor recovery torque, the target over-limit torque is negative, and the target torque compensation state is the over-limit state.

[0182] Step 602: In response to the target torque compensation state being the over-limit state, perform torque compensation control on the driven drive axle according to the target anti-lock torque of the active drive axle and the total recovery demand torque.

[0183] During specific implementation, performing torque compensation control on the driven drive axle according to the target anti-lock torque of the active drive axle and the total recovery demand torque includes:

[0184] Determine the difference between the total recovery demand torque and the front axle anti-lock torque of the active drive axle as the dual-drive braking compensation torque;

[0185] In response to the dual-drive braking compensation torque being greater than the anti-lock torque of the driven drive axle, determine the anti-lock torque of the driven drive axle as the driven hydraulic request torque;

[0186] In response to the dual-drive braking compensation torque being less than or equal to the anti-lock torque of the driven drive axle, determine the dual-drive braking compensation torque as the driven hydraulic request torque.

[0187] Among them, if the target torque compensation state is the over-limit state, it means that the active drive axle can only output the anti-lock torque of the active drive axle (less than the maximum motor recovery torque) before locking. Then, the dual-drive braking compensation torque that needs to be compensated = total recovery demand torque - anti-lock torque of the active drive axle. If the dual-drive braking compensation torque is greater than the anti-lock torque of the driven drive axle, it means that the driven drive axle cannot compensate all the dual-drive braking compensation torque to the driven drive axle before locking. Determine the anti-lock torque of the driven drive axle as the driven hydraulic request torque. If the dual-drive braking compensation torque is less than or equal to the anti-lock torque of the driven drive axle, it means that the driven drive axle can compensate all the dual-drive braking compensation torque to the driven drive axle before locking. Determine the dual-drive braking compensation torque as the driven hydraulic request torque.

[0188] Step 603: In response to the target torque compensation state being the remaining state, perform torque compensation control on the driven drive axle and / or the active drive axle according to the total recovery demand torque and the maximum motor recovery torque.

[0189] Specifically, when implementing, performing torque compensation control on the driven drive axle and / or the active drive axle according to the total recovery demand torque and the maximum motor recovery torque includes:

[0190] Determine the difference between the total recovery demand torque and the maximum motor recovery torque as the dual-drive braking compensation torque;

[0191] In response to the dual-drive braking compensation torque being less than or equal to the anti-lock torque of the driven drive axle, determine the dual-drive braking compensation torque as the driven hydraulic request torque;

[0192] In response to the dual-drive braking compensation torque being greater than the anti-lock torque of the driven drive axle and less than or equal to the sum of the anti-lock torque of the driven drive axle and the target over-limit torque, determine the anti-lock torque of the driven drive axle as the driven hydraulic request torque, and determine the difference between the dual-drive braking compensation torque and the anti-lock torque of the driven drive axle as the active hydraulic compensation torque;

[0193] In response to the dual-drive braking compensation torque being greater than the sum of the anti-lock torque of the driven drive axle and the target over-limit torque, determine the anti-lock torque of the driven drive axle as the driven hydraulic request torque, and determine the target over-limit torque as the active hydraulic compensation torque.

[0194] Among them, if the target torque compensation state is the remaining state, it means that the active drive axle can output all the maximum motor recovery torques before locking, and there is still a part of the compensation remaining. At this time, the dual-drive braking compensation torque to be compensated = total recovery demand torque - maximum motor recovery torque.

[0195] If the dual-drive braking compensation torque is less than or equal to the anti-lock torque of the driven drive axle, it means that the driven drive axle can compensate all the dual-drive braking compensation torques to the driven drive axle before locking, and the dual-drive braking compensation torque is determined as the driven hydraulic request torque.

[0196] If the dual-drive braking compensation torque is greater than the anti-lock torque of the driven drive axle and less than or equal to the sum of the anti-lock torque of the driven drive axle and the target overrun torque, it means that the remaining parts of the driven drive axle and the active drive axle can achieve the compensation of all the dual-drive braking compensation torques before the wheels lock. To reduce the impact on driving control, torque compensation is preferentially performed on the driven drive axle to avoid locking of the driven drive axle. The anti-lock torque of the driven drive axle is determined as the driven hydraulic request torque, and the difference between the dual-drive braking compensation torque and the anti-lock torque of the driven drive axle is determined as the active hydraulic compensation torque to achieve the distribution of the dual-drive braking compensation torque.

[0197] If the dual-drive braking compensation torque is greater than the sum of the anti-lock torque of the driven drive axle and the target overrun torque, it means that the remaining parts of the driven drive axle and the active drive axle cannot achieve the compensation of all the dual-drive braking compensation torques before the wheels lock. To avoid locking of the driven drive axle and the active drive axle, the anti-lock torque of the driven drive axle is determined as the driven hydraulic request torque, and the target overrun torque is determined as the active hydraulic compensation torque. Under the limitation of ensuring that the braking compensation control will not cause the wheels to lock, the braking torque is provided to the greatest extent possible to improve the driving experience while ensuring safety.

[0198] Furthermore, if the user deeply steps on the brake pedal for a long time during the braking compensation control process, it is considered that the user has a parking control requirement. Then, the motor output braking torque is directly stopped, and the braking system is directly controlled to output a preset parking hydraulic torque for parking brake control. If the time for the braking system to output the parking hydraulic torque is greater than the preset time threshold, it means that the parking cannot be completed only by the braking system, and the parking control is abnormal. While an alarm is given, the electronic parking system is activated for parking control.

[0199] It should be noted that the method of the embodiment of the present application can be executed by a single device, such as a computer or a server. The method of this embodiment can also be applied to a distributed scenario and completed by multiple devices cooperating with each other. In this case of a distributed scenario, one of the multiple devices can only execute one or more steps of the method of the embodiment of the present application, and these multiple devices will interact with each other to complete the described method.

[0200] It should be noted that some embodiments of the present application are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the above embodiments and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require the particular order or sequential order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0201] Based on the same inventive concept, corresponding to any of the above-described method embodiments, the present application further provides a control device for braking torque.

[0202] Referring to Figure 7 , the control device for braking torque includes:

[0203] A condition judgment module 10, configured to: in response to the difference torque between the total demand torque for recovery and the maximum motor recovery torque satisfying the compensation state condition, determine the maximum available torque according to the front axle anti-lock torque and the rear axle anti-lock torque, and determine whether the braking compensation condition is satisfied according to the maximum motor recovery torque and the maximum available torque;

[0204] A torque distribution module 20, configured to: in response to the braking compensation condition being satisfied, determine the front axle distribution torque and the rear axle distribution torque according to the driving mode and the maximum motor recovery torque;

[0205] An overlimit calculation module 30, configured to: determine the front axle overlimit torque according to the front axle distribution torque and the front axle anti-lock torque, and determine the rear axle overlimit torque according to the rear axle distribution torque and the rear axle anti-lock torque;

[0206] A torque compensation module 40, configured to perform braking compensation control according to the driving mode, the rear axle overlimit torque, and the front axle overlimit torque.

[0207] For the convenience of description, when describing the above device, it is divided into various modules according to functions and described separately. Of course, when implementing the present application, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0208] The device of the above embodiment is used to implement the corresponding braking torque control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be elaborated herein.

[0209] Based on the same inventive concept, corresponding to the method of any of the above embodiments, the present application further provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the control method of the braking torque described in any one of the above embodiments.

[0210] Figure 8 FIG. shows a more specific schematic diagram of the hardware structure of the electronic device provided in this embodiment. The device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. Among them, the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are communicatively connected to each other inside the device through the bus 1050.

[0211] The processor 1010 may be implemented in a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present specification.

[0212] The memory 1020 may be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 1020 may store an operating system and other application programs. When implementing the technical solutions provided in the embodiments of the present specification through software or firmware, the relevant program codes are stored in the memory 1020 and are called and executed by the processor 1010.

[0213] The input / output interface 1030 is used to connect to an input / output module to implement information input and output. The input / output module may be configured as a component in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Among them, the input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.

[0214] The communication interface 1040 is used to connect to a communication module (not shown in the figure) to implement communication interaction between this device and other devices. Among them, the communication module may communicate through a wired method (such as USB, network cable, etc.) or through a wireless method (such as a mobile network, WIFI, Bluetooth, etc.).

[0215] The bus 1050 includes a path for transmitting information between various components of the device, such as the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040.

[0216] It should be noted that although only the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040, and the bus 1050 are shown in the above device, in the specific implementation process, the device may further include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device may also only include the components necessary to implement the solution of the embodiments of this specification, and does not necessarily include all the components shown in the figure.

[0217] The electronic device of the above embodiment is used to implement the corresponding braking torque control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be elaborated here.

[0218] Based on the same inventive concept, corresponding to the method of any of the above embodiments, the present application also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the braking torque control method as described in any of the above embodiments.

[0219] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computing device.

[0220] The computer instructions stored in the storage medium of the above embodiment are used to cause the computer to execute the braking torque control method as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be elaborated here.

[0221] Based on the same inventive concept, corresponding to the method of any of the above embodiments, the present application further provides a vehicle, including the electronic device or the control device of the braking torque in the above embodiments, and executing the control method of the braking torque described in any of the above embodiments through the electronic device or the control device of the braking torque in the above embodiments, and having the beneficial effects of the corresponding method embodiments, which will not be elaborated herein.

[0222] It can be understood that before using the technical solutions of the various embodiments in the present disclosure, the types, usage scopes, usage scenarios, etc. of the personal information involved will be informed to the user in an appropriate manner, and the user's authorization will be obtained.

[0223] For example, when responding to a user's active request, a prompt message is sent to the user to clearly prompt the user that the operation requested by the user will require obtaining and using the user's personal information. Thus, the user can autonomously choose whether to provide personal information to software or hardware such as an electronic device, an application program, a server, or a storage medium that executes the operations of the technical solutions of the present disclosure according to the prompt message.

[0224] As an optional but non-limiting implementation manner, the manner of sending a prompt message to the user in response to receiving the user's active request may be, for example, in the form of a pop-up window, and the prompt message may be presented in text in the pop-up window. In addition, the pop-up window may also carry a selection control for the user to choose "agree" or "disagree" to provide personal information to the electronic device.

[0225] It can be understood that the above process of notifying and obtaining the user's authorization is only illustrative and does not limit the implementation manner of the present disclosure, and other manners that meet relevant laws and regulations can also be applied to the implementation manner of the present disclosure.

[0226] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present application is limited to these examples; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

[0227] In addition, for simplicity of explanation and discussion, and so as not to make the embodiments of the present application difficult to understand, well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Further, the devices may be shown in block diagram form in order to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present application are to be implemented (i.e., these details should be fully within the understanding of those skilled in the art). In cases where specific details (such as circuits) are set forth to describe exemplary embodiments of the present application, it will be apparent to those skilled in the art that the embodiments of the present application may be practiced without these specific details or with variations of these specific details. Accordingly, these descriptions should be regarded as illustrative rather than restrictive.

[0228] Although the present application has been described in connection with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description. For example, other memory architectures (such as dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0229] Embodiments of the present application are intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the claims of the present application. Accordingly, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the embodiments of the present application shall be included within the protection scope of the present application.

Claims

1. A method for controlling braking torque, characterized in that: include: In response to the difference torque between the total required recovery torque and the maximum motor recovery torque satisfying the compensation state condition, determining the maximum available torque according to the front axle anti-lock torque and the rear axle anti-lock torque, and determining whether the braking compensation condition is satisfied according to the maximum motor recovery torque and the maximum available torque; In response to satisfying the braking compensation condition, determining a front axle distribution torque and a rear axle distribution torque according to a driving mode and the maximum motor recovery torque; Determine the front axle excess torque according to the front axle distributed torque and the front axle anti-lock torque, and determine the rear axle excess torque according to the rear axle distributed torque and the rear axle anti-lock torque; Braking compensation control is performed according to the driving mode, the rear axle excess torque, and the front axle excess torque.

2. The method for controlling braking torque according to claim 1, characterized in that: The performing brake compensation control according to the driving mode, the rear axle excess torque and the front axle excess torque comprises: In response to the driving mode being the four-wheel drive mode, determining a hydraulic compensation required torque according to the maximum available torque and the total recovery required torque; Determining a first torque compensation state for the front axle excess torque and a second torque compensation state for the rear axle excess torque; In response to the first torque compensation state and the second torque compensation state being both torque surplus states, performing the brake compensation control according to the hydraulic compensation required torque, the rear axle excess torque, and the front axle excess torque; In response to the first torque compensation state and the second torque compensation state being different, torque transfer control is performed according to the rear axle excess torque and the front axle excess torque to obtain a torque transfer result, and the brake compensation control is performed according to the torque transfer result and the hydraulic compensation required torque.

3. The method for controlling braking torque according to claim 2, characterized in that: The performing the brake compensation control according to the hydraulic compensation required torque, the rear axle excess torque and the front axle excess torque comprises: determining a sum of the rear axle excess torque and the front axle excess torque as an available compensation torque; In response to the available compensation torque being less than or equal to the hydraulic compensation required torque, determining the rear axle excess torque as the rear axle hydraulic compensation torque, and determining the front axle excess torque as the front axle hydraulic compensation torque; In response to the available compensation torque being greater than the hydraulic compensation request torque, the hydraulic compensation request torque is distributed and compensated according to a ratio of the rear axle excess torque to the front axle excess torque.

4. The method for controlling braking torque according to claim 2, characterized in that: The performing torque transfer control according to the excess torque of the rear axle and the excess torque of the front axle to obtain a torque transfer result includes: In response to the first torque compensation state being an over-limit state and the second torque compensation state being a residual state, the front axle anti-lock torque is determined as the front axle motor request torque, and the sum of the rear axle distributed torque and the absolute value of the front axle over-limit torque is determined as the rear axle motor request torque, to obtain a first torque transfer result; In response to the first torque compensation state being a residual state and the second torque compensation state being an over-limit state, the rear axle anti-lock torque is determined as the rear axle motor requested torque, and the sum of the absolute values ​​of the front axle distributed torque and the rear axle over-limit torque is determined as the front axle motor requested torque, to obtain a second torque transfer result.

5. The method for controlling braking torque according to claim 2, characterized in that: The performing the braking compensation control according to the torque transfer result and the hydraulic compensation required torque includes: determining a sum of the front axle excess torque and the rear axle excess torque as the available residual torque; In response to the torque transfer result being a first torque transfer result and the available remaining torque being less than or equal to the hydraulic compensation required torque, determining the available remaining torque as a first hydraulic request torque compensated to the rear axle; In response to the torque transfer result being a first torque transfer result and the available remaining torque being greater than the hydraulic compensation required torque, determining the hydraulic compensation required torque as a first hydraulic request torque compensated to the rear axle; In response to the torque transfer result being a second torque transfer result and the available remaining torque being less than or equal to the hydraulic compensation required torque, determining the available remaining torque as a second hydraulic request torque compensated to the front axle; In response to the torque transfer result being a second torque transfer result and the available remaining torque being greater than the hydraulic compensation required torque, the hydraulic compensation required torque is determined as a second hydraulic request torque compensated to the front axle.

6. The method for controlling braking torque according to claim 2, characterized in that: The step of determining the hydraulic compensation required torque according to the maximum available torque and the total recovery required torque comprises: In response to the maximum available torque being greater than or equal to the total recovery required torque, determining a difference between the total recovery required torque and the maximum motor recovery torque as the hydraulic compensation required torque; In response to the maximum available torque being less than the total regeneration required torque, a difference between the maximum available torque and the maximum motor regeneration torque is determined as the hydraulic compensation required torque.

7. The method for controlling braking torque according to claim 1, characterized in that: Determining whether the compensation state condition is met according to the torque difference between the maximum motor recovery torque and the total recovery required torque includes: In response to determining a difference torque between the maximum motor regeneration torque and the regeneration total required torque; In response to the difference torque being greater than or equal to a preset first torque threshold, determining that the compensation state condition is satisfied; In response to the difference torque being less than a preset second torque threshold, determining that the compensation state condition is not satisfied; Wherein, the first torque threshold is greater than the second torque threshold.

8. The method for controlling braking torque according to claim 1, characterized in that: The determining whether a braking compensation condition is met according to the maximum motor recovery torque and the maximum available torque includes: In response to the maximum available torque being less than or equal to the maximum motor recovery torque, determining that the braking compensation condition is not satisfied; In response to the maximum available torque being greater than the maximum motor regeneration torque, it is determined that the braking compensation condition is satisfied.

9. The method for controlling braking torque according to claim 1, characterized in that: The performing of brake compensation control according to the driving mode, the rear axle excess torque and the front axle excess torque also includes: In response to the driving mode being the dual-drive mode, determining an active drive axle and a driven drive axle among the front drive axle and the rear drive axle, determining a target over-limit torque of the active drive axle among the rear axle over-limit torque and the front axle over-limit torque, and determining a target torque compensation state of the target over-limit torque; In response to the target torque compensation state being an over-limit state, performing torque compensation control on the driven drive axle according to the target anti-lock torque of the active drive axle and the total recovery required torque; In response to the target torque compensation state being a residual state, torque compensation control is performed on the driven drive axle and / or the active drive axle according to the total required recovery torque and the maximum motor recovery torque.

10. A vehicle comprising an electronic device, characterized in that: The electronic device comprises a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements the method according to any one of claims 1 to 9 when executing the computer program.

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