CN115139805B

CN115139805B - Brake control method, brake control device, brake control medium, and electronic apparatus

Info

Publication number: CN115139805B
Application number: CN202110351936.9A
Authority: CN
Inventors: 陆国祥; 杨冬生; 朱晓军; 李守泽
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2023-02-10
Anticipated expiration: 2041-03-31
Also published as: CN115139805A

Abstract

The disclosure relates to a brake control method, a brake control device, a brake control medium and electronic equipment, belongs to the field of vehicles, can achieve real-time maximum energy recovery, and is suitable for any multi-motor system. A brake control method comprising: obtaining braking control parameters, includingMaximum braking torque F of shaft motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} Ground stable braking margin k x T _road And total required braking torque F _b (ii) a At F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1‑β _I ) Not simultaneously satisfy, if satisfy k T _road ≥F _b Determining a target braking force distribution coefficient beta and a target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h (ii) a At F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1‑β _I ) If not, k x T _road ≥F _b Determining beta according to the requirement of maximizing the braking stability and determining F according to the requirement of maximizing the motor braking _{m_f} 、F _{m_r} And F _h (ii) a Wherein, F _b ＝F _{m_f} +F _{m_r} +F _h 。

Description

Brake control method, brake control device, brake control medium, and electronic apparatus

Technical Field

The present disclosure relates to the field of vehicles, and in particular, to a brake control method, apparatus, medium, and electronic device.

Background

CN201210385428.3 discloses a control method of a regenerative braking system of a four-wheel independent drive electric vehicle driven by a hub motor, which includes the following steps: a. the vehicle control unit receives various data parameters and calculates the currently required braking strength and the total braking force; b. when the whole vehicle enters a braking state, simultaneously carrying out the steps c and d; c. calculating the braking force required by the front axle and the rear axle according to the ideal braking force distribution; d. judging whether regenerative braking can be carried out or not; e. distributing respective motor braking force and mechanical braking force of the front axle and the rear axle according to the required braking force of the front axle and the rear axle and the running state of the vehicle; f. and the motor controller controls the motor to recover energy according to the requirement.

The disadvantage of this solution is that, in order to meet the ideal braking force distribution requirement, the braking capabilities of the front and rear motors cannot be fully utilized, so that the maximization of energy recovery cannot be guaranteed. Meanwhile, the method has a limited application range because not all systems can realize the ideal braking force distribution method, and the method needs four hub motors with higher power to meet the ideal braking force distribution requirement under various braking strengths; or it requires the braking system to have four-wheel independent braking capability. This clearly limits the scope of application of the method, increasing costs.

Disclosure of Invention

The purpose of the present disclosure is to provide a brake control method, device, medium, and electronic apparatus, which can achieve a real-time maximum energy recovery, reduce algorithm complexity, and are applicable to any multi-motor system.

According to a first embodiment of the present disclosure, there is provided a brake control method including: obtaining brake control parameters, wherein the brake control parameters comprise the maximum braking torque F of the front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} Ground stable braking margin and total required braking torque F _b (ii) a Determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I If the ground stable braking margin is greater than or equal to the total required braking torque F _b Determining the target braking torque F of the front axle motor according to the maximum requirement of the motor brake _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h (ii) a Determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I If the ground stability braking margin is not satisfied, the total required braking torque F is greater than or equal to _b Determining the target braking force distribution coefficient beta according to the requirement of maximizing the braking stability, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h (ii) a Wherein the total required braking torque F _b Equal to the target braking torque F of the front axle motor _{m_f} The rear axle motor target braking torque F _{m_r} With said hydraulic braking torque F _h And (4) summing.

According to a second embodiment of the present disclosure, there is provided a brake control apparatus including:

an obtaining module for obtaining a braking control parameter, wherein the braking control parameter comprises a maximum braking torque F of the front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} Ground stable braking margin and total required braking torque F _b (ii) a And

a control module to:

determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I If the ground stable braking margin is greater than or equal to the total required braking torque F _b Determining the target braking torque F of the front axle motor according to the maximum requirement of the motor brake _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h ；

Determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I If the ground stability braking margin is not satisfied, the total required braking torque F is greater than or equal to _b Determining the target braking force distribution coefficient beta according to the requirement of maximizing the braking stability, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h ；

Wherein the total required braking torque F _b Equal to the target braking torque F of the front axle motor _{m_f} The rear axle motor target braking torque F _{m_r} With said hydraulic braking torque F _h And (4) summing.

According to a third embodiment of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to the first embodiment of the present disclosure.

According to a fourth embodiment of the present disclosure, there is provided an electronic apparatus including: a memory having a computer program stored thereon; a processor for executing the computer program in the memory to carry out the steps of the method according to the first embodiment of the disclosure.

By adopting the technical scheme, the braking power can be dynamically distributed by comprehensively considering the requirements of the braking energy recovery rate and the braking stability, the optimal distribution of the braking force can be realized only by an algebraic operation method through the distribution algorithm design under different working conditions, the maximum energy recovery is realized, and a complex online or offline optimization algorithm is not required, so that the calculation is simple, the calculation amount is small, and the real-time operation and control requirements can be met. In addition, the brake control method can cover the conventional brake working condition with high road adhesion margin and the emergency brake working condition with small road adhesion margin, and has strong adaptability. In addition, the brake control method according to the embodiment of the present disclosure is applicable to a front and rear two-motor system, a front and rear three-motor system, a distributed front and rear four-motor system, other multi-motor systems, and the like.

Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

fig. 1 is a flowchart of a brake control method according to an embodiment of the present disclosure.

FIG. 2 shows a schematic diagram of a distributed drive vehicle composition.

Fig. 3 is a graphical representation of the braking force distribution coefficient range required by the ECE R13 regulation.

FIG. 4 is a graphical representation of the brake force distribution coefficient range under all operating conditions.

FIG. 5 is yet another flow chart of a braking control method according to an embodiment of the present disclosure.

FIG. 6 shows yet another flow chart, in formulaic form, of a braking control method according to an embodiment of the present disclosure.

FIG. 7 is a schematic block diagram of a brake control apparatus according to an embodiment of the present disclosure.

FIG. 8 is a block diagram of an electronic device shown in accordance with an example embodiment.

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

Fig. 1 is a flowchart of a braking control method according to an embodiment of the present disclosure. As shown in fig. 1, the method includes the following steps S101 to S103.

In step S101, brake control parameters are obtained, wherein the brake control parameters include a maximum brakeable torque F of the front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} Ground stability braking margin and total demand braking torque.

Maximum braking torque F of front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} The braking capability of the motor is embodied.

In some embodiments, where the vehicle has at least one front motor and at least one rear motor, the front axle motor maximum brakeable torque is the sum of the motor maximum brakeable torques of all the front motors and the rear axle motor maximum brakeable torque is the sum of the motor maximum brakeable torques of all the rear motors. Therefore, the brake control method according to the embodiment of the present disclosure is applicable to various types of vehicles having multiple motor drives, for example, a vehicle in which front and rear single motors are driven separately, a vehicle in which front and rear double motors are driven, a vehicle in which front and rear single motors are driven, a vehicle in which front and rear double motors are driven, and the like. For example, for a front and rear single-motor drive system, the maximum brakeable torque of the front axle motor is the maximum brakeable torque of the front motor, and the maximum brakeable torque of the rear axle motor is the maximum brakeable torque of the rear motor; for a distributed four-motor system, the maximum brakeable torque of the front-shaft motor is the sum of the maximum brakeable torques of the two front motors, the maximum brakeable torque of the rear-shaft motor is the sum of the maximum brakeable torques of the two rear motors, and taking the maximum brakeable torque of the front-shaft motor as an example, the maximum brakeable torque of the front-shaft motor and the maximum brakeable torque of the front-shaft motor can be calculated firstly, and then the maximum brakeable torque of the front-shaft motor and the maximum brakeable torque of the front-shaft motor can be summed, so that the maximum brakeable torque of the front-shaft motor can be obtained. Fig. 2 shows a schematic diagram of a distributed drive vehicle composition, in which reference numeral 1 denotes a vehicle body, reference numeral 2 denotes a right front wheel, reference numeral 3 denotes a left front wheel, reference numeral 4 denotes a right rear wheel, reference numeral 5 denotes a left rear wheel, reference numeral 6 denotes a right front brake, reference numeral 7 denotes a left front brake, reference numeral 8 denotes a right rear brake, reference numeral 9 denotes a left rear brake, reference numeral 10 denotes a left front drive motor and its controller, reference numeral 11 denotes a regenerative brake controller, reference numeral 12 denotes a left rear drive motor and its controller, reference numeral 13 denotes a right front drive motor and its controller, and reference numeral 14 denotes a right rear drive motor and its controller, which are connected to the respective wheel brakes and motor controllers through signal lines to control the respective motors and brakes.

The maximum motor braking torque of the front motor or the rear motor can be obtained in such a way that the maximum motor braking torque is the smaller value of the external characteristic torque of the motor and the maximum motor limiting torque calculated according to the charging limiting power of the battery.

The external characteristic torque of the motor is related to the current rotating speed of the motor, and belongs to the common knowledge.

The maximum limit torque of the motor calculated from the charging limit power of the battery can then be determined by the following formula:

wherein, T _{max_bat} Representing the maximum limit torque of the motor calculated according to the charging limit power of the battery; p _{max_charge} Representing a battery charge limit power; eta _{e_motor} Representing the power generation efficiency of the motor; n is _m Representing the equivalent motor speed calculated from the vehicle speed.

In some embodiments, ground stability braking margin = k × T _road ，T _road ＝μ _road ·M·g·r ₀ . Wherein, T _road The maximum braking torque can be provided for the ground; mu.s _road Is the road surface adhesion coefficient; m is the mass of the whole vehicle; g is the acceleration of gravity; r is ₀ Is the effective rolling radius of the tire; k is a ground stability braking margin coefficient, and may generally take on 0.8 or other values.

The total demanded braking torque may be obtained from a vehicle controller of the vehicle. That is, the vehicle controller may calculate the total required Braking torque comprehensively based on the Braking demand information input by the brake pedal depth, the accelerator depth, the current vehicle speed or vehicle distance, or other Automatic driving functions (such as Adaptive Cruise Control (ACC), automatic Emergency Braking (AEB)).

In step S102, it is determined that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system is not satisfied based on the braking control parameter _I If the ground stable braking margin is greater than or equal to the total required braking torque F _b Determining the target braking torque F of the front axle motor according to the maximum requirement of the motor brake _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h ；。

In step S103, it is determined that the target braking force distribution coefficient beta is not satisfied when braking is performed using only the motor brake system based on the braking control parameter, and the ideal braking force distribution coefficient beta is _I If the ground stability braking margin is not satisfied, the ground stability braking margin is not less than or equal toTotal required braking torque F _b Determining the target braking force distribution coefficient beta according to the requirement of maximizing the braking stability, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h 。

Since the braking energy recovery can be realized through the motor braking, the energy recovery maximization can be realized as long as the motor braking is maximized (namely, the sum of the target braking torque of the front axle motor and the target braking torque of the rear axle motor is maximized).

By adopting the technical scheme, the braking power can be dynamically distributed by comprehensively considering the requirements of the braking energy recovery rate and the braking stability, the optimal distribution of the braking force can be realized only by an algebraic operation method through the distribution algorithm design under different working conditions, the maximum energy recovery is realized, and a complex online or offline optimization algorithm is not required, so that the calculation is simple, the calculation amount is small, and the real-time operation and control requirements can be met. In addition, the brake control method can cover the conventional brake working condition with high road adhesion margin and the emergency brake working condition with small road adhesion margin, and has strong adaptability. Moreover, the brake control method according to the embodiment of the present disclosure is applicable to a front and rear two-motor system, a front and rear three-motor system, a distributed front and rear four-motor system, other multi-motor systems, and the like.

Next, a description will be given of a braking force distribution coefficient to be referred to hereinafter.

FIG. 3 is a graphical illustration of a braking force distribution coefficient range required by the ECE R13 code. It is clear that the reasonable range of the braking force distribution coefficient beta value of the braking strength z (which is the multiple of the gravity acceleration g) is within the range of 0.1-z-0.61, and the mapping relationship between the braking strength and the gravity acceleration exists, for example, if z =0.5, the gravity accelerationIs 0.5g, where g may be a fixed value of 9.8m/s ² And can also be measured according to the position. That is, when the braking intensity z is within 0.1 dynamic intensity, for example, 1, the maximum value of the braking force distribution coefficient β cannot exceed the upper boundary, and the minimum value cannot exceed the lower boundary. The braking force distribution coefficient beta is a known parameter, and is generally referred to as the sum of braking torques F of the front axle _f For total demanded braking torque F _b Is calculated by the following formula.

For z<0.1 and z>In the case of 0.61, the ECE R13 regulation has no specific requirement, namely that the maximum possible value of the braking force distribution coefficient β is 1. Meanwhile, the stability of braking is considered, the situation that the rear wheel is locked first is prevented, and the minimum value of the braking force distribution coefficient is taken as a value corresponding to an ideal braking force distribution curve. Therefore, all working conditions can be obtained, namely the static value range of the braking force distribution coefficient beta and the corresponding upper boundary value beta under different braking strengths within the range of the braking strength z = 0-1 (or more than 1) _H And a lower boundary value beta _L As shown in the brake force distribution coefficient range diagram under the full operating condition of fig. 4. That is, the lower bound β _L The upper oblique straight line of (b) is the ideal braking force distribution curve (beta) _I -z curve), β _I ≥β _L 。

FIG. 5 is yet another flow chart of a braking control method according to one embodiment of the present disclosure. Fig. 6 shows a further flow chart of a braking control method according to an embodiment of the disclosure in the form of a formula, fig. 6 corresponding to the steps in fig. 5.

In step S1, brake control parameters are obtained, including the maximum brakeable torque F of the front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} Ground stable braking margin and total required braking torque F _b . The specific obtaining manner has been described in the foregoing, and is not described herein again.

In step S2, the braking torque F is adjusted according to the total demand _b Maximum braking torque F of front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} And ideal braking force distribution coefficient beta _I Judging whether the ideal braking can be satisfied by only using the motor feedback brakingForce distribution requirements.

In some embodiments, one way to implement the determination of step S2 is to determine whether the following two conditions are satisfied at the same time: (1) F _{m_f_max} ≥F _b ·β _I ；(2)F _{m_r_max} ≥F _b ·(1-β _I ). Wherein, F _{m_f_max} Representing the maximum braking torque of the front axle motor; f _{m_r_max} The maximum braking torque of the rear axle motor is represented; f _b Representing the total demand braking torque; beta is a _I Representing the corresponding ideal brake force distribution coefficient at the current brake intensity.

Wherein the ideal braking force distribution coefficient beta _I Means that the target braking force distribution coefficient beta = beta _I The front axle and the rear axle can be locked simultaneously, and under the condition, the stability of the vehicle is highest, and the direction is prevented from being out of control or drifting. Ideal braking force distribution coefficient beta _I According to the braking intensity z (or the current total required braking torque F) _b ) And (4) determining.

If the two conditions are met simultaneously, the situation that the ideal braking force distribution requirement can be met only by using the motor feedback braking is shown, and the step is switched to the step S3; otherwise, if the two conditions are not satisfied at the same time, which indicates that the ideal braking force distribution requirement cannot be satisfied only by using the motor regenerative braking, the process goes to step S4.

In step S3, only the motor is required to participate in braking, since the ideal braking force distribution requirement can be satisfied only by using motor regenerative braking. In this step, the ideal brake force distribution coefficient is used to distribute the brake force between the front and rear axle motors, that is, the front axle motor target brake torque F _{m_f} ＝F _b ·β _I Rear axle motor target braking torque F _{m_r} ＝F _b ·(1-β _I ). The braking energy recovery efficiency under the working condition is highest because hydraulic pressure is not needed to participate in braking.

In step S4, since it is determined in step S2 that the ideal braking force distribution requirement cannot be satisfied using only the motor regenerative braking, that is, F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) At least one ofOne is not satisfied, and therefore, in this step S4, the total required braking torque F is continuously judged _b And (4) judging whether the braking is smaller than the stable braking margin on the ground or not, namely judging whether the braking has no instability risk or not. If so, the stability of the brake can be better guaranteed, so that the maximum regenerative braking efficiency can be considered first, and the step goes to step S5, and if not, the stability of the brake is at risk, so that the stability of the brake needs to be guaranteed first, and the step goes to step S16.

In step S5, since it is determined in step S4 that the stability of the braking can be better ensured, the maximum braking torque F of the front axle motor continues to be used in step S5 _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} And total required braking torque F _b Judging whether the pure electric brake can meet the braking requirement, namely judging the total braking torque F of the motor _{m_f_max} +F _{m_r_max} Whether or not it is greater than total required braking torque F _b . If yes, go to step S6, if no, go to step S11. The main purpose of step S5 is to distribute the braking force in a manner that prioritizes maximizing energy recovery on the premise that the purely electric braking cannot meet the ideal braking force distribution demand.

In step S6, since it has been determined in the previous step that the stability of the braking can be better ensured, and only the motor regenerative braking energy satisfies the braking requirement, it may be considered that the regenerative braking efficiency is maximized (i.e. β does not need to satisfy the ideal braking force distribution curve), so it is further determined in step S6 whether only the motor regenerative braking can satisfy the distribution requirement, i.e. whether the target braking force distribution coefficient can fall within the static value range. If yes, go to step S7, and if not, go to step S8.

In some embodiments, one way of determining step S6 is according to F _{m_f_max} 、F _{m_r_max} 、F _b And the static value range beta of the target braking force distribution coefficient _L ～β _H Judging whether the target braking force distribution coefficient can fall into a static value range or not if the pure motor is braked, namely judging whether the target braking force distribution coefficient can fall into the static value range or notF _{m_f_max} ≥F _b ·β _L (the condition represents the minimum requirement on the braking force of the front axle motor when the target braking force distribution coefficient is in the lower limit of the static value range, namely, whether the braking capacity of the front axle motor can meet the braking capacity required by the static value range is judged), and F _{m_r_max} ≥F _b -min(F _{m_f_max} ,F _b ·β _H ) (the formula is used for expressing the minimum requirement on the braking force of the rear axle motor when the target braking force distribution coefficient is in the upper limit of the static value range, namely judging whether the braking capability of the rear axle motor can meet the braking capability required by the static value range). In some embodiments of the present disclosure, the static value range of the target braking force distribution coefficient is determined according to the regulatory requirement, specifically, β _L ～β _H (ii) a In other embodiments of the present disclosure, the static value range of the target braking force distribution coefficient may be determined according to other limiting conditions.

In step S7, if the condition in step S6 is satisfied, it means that only the motor is required to perform feedback, and hydraulic braking is not required. Then, the stability of the braking needs to be further considered on the premise of satisfying the maximum energy recovery. Under the condition, the target braking force distribution coefficient beta takes the minimum value (namely the target braking torque F of the front axle motor) _{m_f} Minimum value), the smaller the beta, the closer the beta is to the ideal braking force distribution coefficient beta _I The better the stability. At this time, the following braking force distribution is performed, that is:

front axle motor target braking torque F _{m_f} ＝max(F _b ·β _L ,F _b -F _{m_r_max} )；

Rear axle motor target braking torque F _{m_r} ＝F _b -F _{m_f} ；

Hydraulic braking torque of F _h ＝0。

By adopting the braking force distribution scheme, the maximum energy recovery can be realized, and meanwhile, the braking stability can be maximized because the target braking force distribution coefficient beta is the minimum value, and the smaller the beta is, the closer the beta is to the ideal braking force distribution, the better the stability is.

In step S8, if the condition of step S6 is not satisfied, it indicates that the regenerative braking of the motor alone cannot satisfy the braking force distribution requirement, and the braking process requires hydraulic braking to participate, that is, requires the motor to perform hydraulic braking together.

At this time, first, upper and lower limits β of the target braking force distribution coefficient β required for the pure electric braking are set _max 、β _min And (6) performing calculation. The calculation method is as follows: beta is a _max ＝F _{m_f_max} /F _b ；β _min ＝(F _b -F _{m_r_max} )/F _b Obviously, [ beta ] since motor regenerative braking alone cannot meet the distribution demand _min ,β _max ]Does not fall within the upper bound of the static range of values beta _H And a lower boundary beta _L Within the range of (1).

Then, the lower limit β of the braking force distribution coefficient is determined _min Whether or not it is less than the lower boundary value beta of the static value range _L Or an upper limit beta of the braking force distribution coefficient _max Whether or not it is less than the lower boundary value beta of the static value range _L . If yes, go to step S9; if not, then beta is indicated _min Upper boundary value beta greater than static value range _H At this time, the target braking force distribution coefficient β needs to take the upper bound β _H And goes to step S10. The value of beta can maximize the braking of the motor.

The essence of the step S8 is that the value lower limit beta of the target braking force distribution coefficient under the pure electric braking condition is adopted _min With the lower boundary value beta of the static value range _L The comparison of the two values to judge the regulation object of the motor brake, namely, the front axle motor outputs the maximum brake torque and regulates the output torque of the rear axle motor, or the rear axle motor outputs the maximum brake torque and regulates the output torque of the front axle motor.

In step S9, the lower limit of the braking force distribution coefficient beta is determined in step S8 _min Lower boundary value beta smaller than static value range _L Therefore, the target braking force distribution coefficient is increased to beta by supplementing the front axle motor to output the maximum braking torque, adjusting the rear axle motor to output the torque and performing hydraulic braking _L . Therefore, in step S9, the target braking force distribution coefficient beta is made to be staticLower boundary value beta of the value range _L I.e. the target brake force distribution coefficient β = β _L And performs the following braking force distribution:

front axle motor target braking torque F _{m_f} ＝F _{m_f_max} ；

Rear axle motor target braking torque F _{m_r} ＝[(β _h -β _L )·F _b +(1-β _h )·F _{m_f_max} ]/β _h ；

Hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

By so distributing the braking force, it is possible to maximize both the energy recovery and the braking stability.

In step S10, the lower limit of the braking force distribution coefficient beta is determined in step S8 _min Not less than the lower boundary value beta of the static value range _L That is, the target brake force distribution coefficient under pure electric braking is larger than the upper boundary value beta of the static value range _H Therefore, the target braking force distribution coefficient is reduced to beta by making the rear axle motor output the maximum braking torque, adjusting the front axle motor output torque and supplementing the hydraulic braking _H . Therefore, in step S10, the upper boundary value β of the static value range of the target braking force distribution coefficient is determined _H And performs the following braking force distribution:

front axle motor target braking torque F _{m_f} ＝[(β _H -β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h )；

Rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} ；

Hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

By so distributing, both energy recovery maximization and braking stability maximization can be achieved.

In step S11, the total braking torque F of the motor is determined in step S5 _{m_f_max} +F _{m_r_max} Less than total required braking torque F _b It is obvious thatIn this case, if both the front and rear axle motors can be operated at the maximum possible braking torque, the maximum regenerative braking efficiency can be obtained, and the braking force distribution coefficient at this time is recorded as β _m And determining beta _m Whether the dynamic range of the target braking force distribution coefficient beta is included. It should be noted that the dynamic value range of the target braking force distribution coefficient beta depends on the total required braking torque F _b And static value range determination. That is, the essence of step S11 is to determine whether or not the front and rear motors can be fully braked, based on the braking force distribution coefficient β m and the dynamic range a to b of braking force when the front and rear motors are fully braked.

In some embodiments, the dynamic range of the target braking force distribution coefficient β is calculated as follows:

from the formula of beta, F _{m_f} Smaller, F _{m_r} Larger, smaller beta, thus taking F _{m_f} ＝0、F _{m_r} ＝F _{m_r_max} When beta is the minimum value a ₁ ＝β _h -β _h ·F _{m_r_max} /F _b ；F _{m_f} The larger, F _{m_r} The smaller, the larger beta, thus taking F _{m_f} ＝F _{m_f_max} 、F _{m_r} When =0, β is the maximum value b ₁ ＝β _h +(1-β _h )·F _{m_f_max} /F _b . Thus, the dynamic range [ a, b ] of the target braking force distribution coefficient β]Comprises the following steps: a = max (a) ₁ ,β _L )，b＝min(b ₁ ,β _H )。

β＝(F _{m_f} +F _{h_f} )/F _b ＝(F _{m_f} +β _h ·F _h )/F _b

＝[F _{m_f} +β _h ·(F _b -F _{m_f} -F _{m_r} )]/F _b

＝β _h +[(1-β _h )·F _{m_f} -β _h ·F _{m_r} ]/F _b

It should be noted that when the hydraulic brake is applied, braking forces are applied to both the front axle and the rear axle, wherein the total hydraulic braking torque is F _h Front axle hydraulic braking torqueIs F _{h_f} Rear axle hydraulic braking torque of F _{h_r} Defining the braking force distribution coefficient of the hydraulic brake as beta _h ＝F _{h_f} /F _h＝ F _{h_f} /(F _{h_f} +F _{h_f} ) The value is generally set at the beginning according to the specific vehicle design.

After determining the dynamic value range [ a, b]Then, whether a is less than or equal to beta can be continuously judged _m B, since the braking force distribution coefficient must fall within [ a ] ₁ ,b ₁ ]Therefore, the determination method here may be a method of directly determining whether or not β is satisfied _L ≤β _m ≤β _H . If yes, the front and rear axle motors can work with the maximum braking torque, the step S12 is switched to, if not, the step S13 is switched to further judge beta _m Whether greater than b or less than a.

In step S12, it is determined in step S11 that the braking force distribution coefficient when the front and rear motors perform maximum regenerative braking respectively satisfies a ≦ β _m B is less than or equal to b, so in the condition, the front motor and the rear motor can carry out maximum feedback braking, but the hydraulic braking is required to supplement the maximum feedback braking. Therefore, in step S12, the following braking force distribution is performed:

front axle motor target braking torque F _{m_f} ＝F _{m_f_max} ；

Rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} ；

Hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

By adopting the distribution scheme, the energy recovery maximization and the braking stability maximization can be realized.

In step S13, the braking force distribution coefficient when the front and rear motors are respectively subjected to maximum regenerative braking is determined not to satisfy a ≦ β in step S11 _m B is less than or equal to b, so that the target braking force distribution coefficient can not be beta _m At this time, the target braking force distribution coefficient β needs to be newly determined based on the principle of maximizing the regenerative braking efficiency. Specifically, it is necessary to further judge β _m Whether it is less than a. If less than, go to stepIn step S14, the target braking force distribution coefficient beta is set to a, and if not, beta is explained _m If b is larger, the process proceeds to step S15 to set the target braking force distribution coefficient β to b. The value of the beta can maximize the braking of the motor.

That is, the essence of step S13 lies in that the braking force distribution coefficient β under the front-rear motor full-force braking condition is determined according to _m And comparing the value with the lower limit a of the dynamic range to judge the regulating object of the motor brake, namely enabling the front axle motor to output the maximum brake torque and regulate the output torque of the rear axle motor, and enabling the rear axle motor to output the maximum brake torque and regulate the output torque of the front axle motor.

In step S14, since β is determined in step S13 _m <a holds, so in step S14, the target brake force distribution coefficient β = a, and in this case, the front axle motor is braked with the maximum brake torque, thereby maximizing the energy recovery. The corresponding brake force distribution is then as follows:

front axle motor target braking torque F _{m_f} ＝F _{m_f_max} ；

Rear axle motor target braking torque F _{m_r} ＝[(β _h -a)·F _b +(1-β _h )·F _{m_f_max} ]/β _h ；

Hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

That is, in step S14, the front axle motor outputs the maximum braking torque, the rear axle motor output torque is adjusted, and the hydraulic brake is supplemented to increase the target braking force distribution coefficient to the value lower limit a, so as to achieve the purposes of maximizing energy recovery and maximizing braking stability.

In step S15, since β is determined in step S13 _m <a is not established, so the target braking force distribution coefficient β = b is set in step S15, and in this case, the rear axle motor is braked at the maximum braking torque, thereby maximizing the energy recovery. That is, the following braking force distribution can be performed:

front axle motor target braking torque F _{m_f} ＝[(b-β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h )；

Rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} ；

Hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

That is, in step S15, the rear axle motor outputs the maximum braking torque, the front axle motor output torque is adjusted, and the hydraulic braking is supplemented to reduce the target braking force distribution coefficient to the upper limit b, so as to achieve the purposes of maximizing the energy recovery and maximizing the braking stability.

In step S16, since it has been determined in step S2 that the purely electric brake cannot meet the demand for ideal brake force distribution, hydraulic brake cooperation is required to approach the ideal distribution as much as possible, and it has been determined in step S4 that there is a risk in stability of the brake, it is necessary to ensure the brake stability first, and at this time, the target brake force distribution coefficient β takes the minimum value (based on different value ranges), and the smaller β is, the closer β is to the ideal brake force distribution coefficient β _I The better the stability. In order to ensure the braking stability and the closest possible ideal distribution, it is then necessary in step S16 to continue to use the maximum braking torque F of the front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} And total required braking torque F _b Judging whether the pure electric brake can meet the braking requirement, namely judging the total braking torque F of the motor _{m_f_max} +F _{m_r_max} Whether or not it is greater than total required braking torque F _b . If so, step S17 is executed, and if not, step S20 is executed.

In step S17, the total braking torque F of the motor is determined in step S16 _{m_f_max} +F _{m_r_max} Greater than total required braking torque F _b This means that the braking capacity of the electric machine has a large margin, and under these conditions, in order to ensure the stability of the braking, an ideal braking force distribution method can be used, i.e. the target braking force distribution coefficient β = β is achieved by supplementing the hydraulic braking _I That is, electric regenerative braking and hydraulic braking are simultaneously engaged, that is, such that:

β＝F _f /F _b ＝(F _{m_f} +F _{h_f} )/F _b ＝(F _{m_f} +β _h ·F _h )/F _b ＝β _I

therefore, in step S17, the front axle required braking torque F can be distributed according to the ideal distribution _b ·β _I Maximum feedback torque F with front axle _{m_f_max} The different distribution modes are determined to realize the target braking force distribution coefficient beta = beta _I . The specific judgment conditions are as follows: f _{m_f_max} ＜F _b ·β _I . If so, step S18 is executed, and if not, step S19 is executed, so that the motor brake adjustment target can be determined from the comparison result, compared to the pure electric brake and the ideal brake force distribution. That is, it is to make the front axle motor output the maximum braking torque and adjust the rear axle motor output torque, or to make the rear axle motor output the maximum braking torque and adjust the front axle motor output torque.

In step S18, if it is judged in step S17 that F is present _{m_f_max} ＜F _b ·β _I The front axle motor is braked with the maximum braking torque, and the rear axle motor and the hydraulic brake are calculated through a distribution relation, so that the front axle motor and the rear axle motor participate in braking as much as possible, and the regenerative braking efficiency is maximized. At this time, the braking force is distributed as follows:

front axle motor target braking torque F _{m_f} ＝F _{m_f_max} ；

Rear axle motor feedback braking torque F _{m_r} ＝F _b -F _{m_f} -F _h ；

Hydraulic braking torque F _h ＝(F _b ·β _I -F _{m_f_max} )/β _h 。

That is, in step S18, since the distribution coefficient under pure motor braking is smaller than the ideal distribution, the target braking force distribution coefficient is increased to β by supplementing the front axle motor to output the maximum braking torque, the rear axle motor to output the torque, and the hydraulic braking _I . It can be shown that under such conditions, when the front axle motor is braked with a maximum brakable torque, the total motor braking torque isMaximum, thereby enabling maximization of energy recovery and maximization of stability.

In step S19, if it is determined in step S17 that F is not satisfied _{m_f_max} ＜F _b ·β _I Then obviously satisfy F _{m_r_max} ＜F _b ·(1-β _I ) So that the rear axle motor can be braked with maximum torque F _{m_r_max} And braking, wherein the front motor and the hydraulic braking are calculated through a distribution relation so that the front and rear shaft motors participate in electric braking as much as possible. That is, the following braking force distribution is performed:

rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} ；

Front axle motor target braking torque F _{m_f} ＝F _b -F _{m_r} -F _h ；

Hydraulic braking torque F _h ＝[F _b ·(1-β _I )-F _{m_r_max} ]/(1-β _h )。

That is, in step S19, since the distribution coefficient under pure motor braking is larger than the ideal distribution, the target braking force distribution coefficient is decreased to β by supplementing the rear axle motor with the maximum braking torque, the front axle motor output torque, and the hydraulic braking _I . It can be shown that in this condition, the total motor braking torque is at a maximum when the rear axle motor is braked with a maximum brakable torque, so that not only is the braking stability maximized, but also the energy recovery is maximized.

In step S20, since it is determined in step S16 that the pure motor brake cannot satisfy the braking request, that is, the total motor regenerative torque F is determined _{m_f_max} +F _{m_r_max} Less than total required braking torque F _b This means that the motor braking capacity is insufficient and, in addition, since the total required braking torque F is also determined in step S4 _b Exceeds the ground stable braking margin, and therefore, the target braking force distribution coefficient β = β cannot be achieved even by the supplementary hydraulic braking under the conditions of step S4 and step S16 _I Therefore, in step S20, in order to achieve maximum braking stability, the front axle motor target braking torque F is calculated _{m_f} Equal to the maximum braking torque F of the front axle motor _{m_f_max} And rear axle motor target braking torque F _{m_r} Equal to the maximum braking torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m And a lower limit value a of the dynamic value range, wherein a satisfies: a = max (a) ₁ ,β _L ) And a is a ₁ ＝β _h -β _h ·F _{m_r_max} /F _b (ii) a And determining beta _m Whether or not less than a, i.e. according to beta _m And a comparing result judges the motor brake adjusting object compared with the full-force brake condition of the front and rear motors, namely, the front axle motor outputs the maximum brake torque and adjusts the rear axle motor output torque, or the rear axle motor outputs the maximum brake torque and adjusts the front axle motor output torque, thereby realizing the maximization of the regenerative brake efficiency. If so, step S21 is executed, otherwise, step S22 is executed.

In step S21, since it is determined in step S20 that β is satisfied _m Less than a indicates the braking force distribution coefficient beta when the regenerative braking efficiency is maximized (the front and rear motors are both subjected to maximum regenerative braking) _m Still less than the target value a, so that the front axle motor is fed back at the maximum braking torque and the rear axle motor is fed back at the normal braking torque, the target braking force distribution coefficient β can be increased to the target value a, thereby maximizing the regenerative braking. The braking force distribution in this case is as follows:

front axle motor target braking torque F _{m_f} ＝F _{m_f_max} ；

Hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

In step S22, since it is determined in step S20 that β is not satisfied _m Less than a indicates the braking force distribution coefficient beta when the regenerative braking efficiency is maximized (the front and rear motors are both subjected to maximum regenerative braking) _m Still greater than the target value a, so that the rear axle motor can feed back with maximum braking torque and the front axle motor can feed back with normal braking forceThe torque feedback may reduce the target brake force distribution coefficient β to the target value a, thereby maximizing regenerative braking. That is, the following braking force distribution is performed:

front axle motor target braking torque F _{m_f} ＝[(a-β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h )；

Rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} ；

Hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

Therefore, the main concept of the present disclosure is to increase the ratio of motor braking as much as possible on the premise that the target braking force distribution coefficient β is within a hard range (including a static value range or a dynamic value range), so as to increase the efficiency of regenerative braking, and finally make the target braking force distribution coefficient β approach an ideal braking force distribution curve as much as possible, that is, first ensure the maximum efficiency of regenerative braking, and then increase the braking stability as much as possible.

Specifically, the core concept is as follows:

(1) Whether it is possible to satisfy both the energy recovery maximization (motor braking only) and the braking stability maximization (β = β) at the same time _I ) (ii) a If yes, only the motor is braked, and the condition that beta = beta is taken _I (ii) a If not, executing the step (2);

(2) Whether the braking has instability risk (namely whether the total required braking torque is smaller than the ground stable braking margin) or not; if yes, executing (3), if not, executing (4);

(3) In the regulation requirement (or called static value range), the energy recovery is maximized as much as possible (namely, the motor braking ratio is maximized);

(4) First, beta is determined based on maximizing braking stability (making beta as close to beta as possible) _I Specifically, the value of beta is the minimum value in the dynamic value range), and then the energy recovery is maximized as much as possible (namely, the motor braking ratio is maximized) on the basis.

By adopting the technical scheme, the braking force can be dynamically distributed by comprehensively considering the braking energy recovery rate and the braking stability requirement, the optimal distribution of the braking force can be realized only by an algebraic operation method through distribution algorithm design under different working conditions, the maximum energy recovery is realized, and a complex online or offline optimization algorithm is not required, so that the calculation is simple, the calculation amount is small, and the real-time operation and control requirements can be met. In addition, the brake control method according to the embodiment of the disclosure can cover a conventional brake condition with high road adhesion margin and an emergency brake condition with small road adhesion margin, and has strong adaptability, that is, considering the relationship between road adhesion and required brake strength, the maximization of energy recovery under the condition of high road adhesion margin, the maximization of brake stability under the condition of small road adhesion margin, and the maximization of energy recovery under the condition of maximized brake stability can be realized. In addition, the brake control method according to the embodiment of the present disclosure is applicable to a front and rear two-motor system, a front and rear three-motor system, a distributed front and rear four-motor system, other multi-motor systems, and the like.

FIG. 7 is a schematic block diagram of a brake control apparatus according to an embodiment of the present disclosure. As shown in fig. 7, the apparatus includes:

an obtaining module 81 for obtaining braking control parameters, wherein the braking control parameters comprise a maximum brakeable torque F of the front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} Ground stable braking margin and total required braking torque F _b (ii) a And

a control module 82 for:

determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I If the ground stable braking margin is not less than the total required braking torque F _b Determining the target braking torque F of the front axle motor according to the maximum requirement of the motor brake _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h ；

The determination that braking is to be performed using only the motor braking system based on the braking control parameter is not satisfiedThe target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta _I If the ground stability braking margin is not satisfied, the total required braking torque F is greater than or equal to _b Determining the target braking force distribution coefficient beta according to the requirement of maximizing the braking stability, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h ；

Wherein the total required braking torque F _b Equal to the target braking torque F of the front axle motor _{m_f} The rear axle motor target braking torque F _{m_r} With said hydraulic braking torque F _h And (4) the sum.

By adopting the technical scheme, the braking force can be dynamically distributed by comprehensively considering the braking energy recovery rate and the braking stability requirement, the optimal distribution of the braking force can be realized only by an algebraic operation method through distribution algorithm design under different working conditions, the maximum energy recovery is realized, and a complex online or offline optimization algorithm is not required, so that the calculation is simple, the calculation amount is small, and the real-time operation and control requirements can be met. In addition, the brake control method can cover the conventional brake working condition with high road adhesion margin and the emergency brake working condition with small road adhesion margin, and has strong adaptability. In addition, the brake control method according to the embodiment of the present disclosure is applicable to a front and rear two-motor system, a front and rear three-motor system, a distributed front and rear four-motor system, other multi-motor systems, and the like.

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy the target brake force distribution coefficient β being equal to the ideal brake force distribution coefficient β _I If the ground stable braking margin is greater than or equal to the total required braking torque F _b Determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h The method comprises the following steps:

determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the braking force distribution coefficient when only the motor braking system is used for braking meets the requirement of a static value range, determining that the hydraulic braking torque is equal to 0, and determining the target braking torque F of the front axle motor according to the requirement of the motor braking maximization _{m_f} And the target braking torque F of the rear axle motor _{m_r} (ii) a Or

Determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b And if the braking force distribution coefficient of braking only by using the motor braking system does not meet the requirement of the static value range, determining the target braking force distribution coefficient beta according to the static value range, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h (ii) a Or alternatively

Determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m If the requirement of the dynamic value range is met, determining the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} The rear axle motor target braking torque F _{m_r} Equal to the maximum braking force F of the rear axle motor _{m_r_max} And braking torque F according to said total demand _b The front axle motor target braking torque F _{m_f} And the target braking torque F of the rear axle motor _{m_r} Determining the hydraulic braking torque F _h (ii) a Or alternatively

Determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m If the requirement of the dynamic value range is not met, the target braking force distribution coefficient beta is determined according to the dynamic value range, and the target braking torque F of the front axle motor is determined according to the requirement of the motor brake maximization _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h 。

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I If the ground stability braking margin is not satisfied, the total required braking torque F is greater than or equal to _b Determining the target braking force distribution coefficient beta according to the requirement of maximizing the braking stability, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I And the braking torque F does not meet the requirement that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b Then it is determined that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I And determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h (ii) a Or

Determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I And the brake torque F does not meet the condition that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b Then get according to the dynamicThe value range determines the target braking force distribution coefficient beta, and determines the front axle motor target braking torque F according to the motor braking maximization requirement _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h 。

Optionally, the maximum brakeable torque F of the front axle motor _{m_f_max} And maximum braking torque F of the rear axle motor _{m_r_max} The lower value of the corresponding external characteristic torque of the motor and the maximum limiting torque of the motor calculated according to the charging limiting power of the battery is obtained; the maximum limit torque of the motor calculated according to the charging limit power of the battery is determined by the following formula:

wherein, T _{max_bat} Representing the maximum limit torque of the motor calculated according to the charging limit power of the battery; p _{max_charge} Representing a battery charge limit power; eta _{e_motor} Representing the generating efficiency of the motor; n is a radical of an alkyl radical _m Representing the equivalent motor speed.

Optionally, the method further comprises: determining that braking using only the motor brake system based on the brake control parameter can satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I In the case where the target braking force distribution coefficient beta is determined to be equal to the ideal braking force distribution coefficient beta _I The front axle motor target braking torque F _{m_f} Target braking torque F of rear axle motor _{m_r} The sum of which is equal to the total required braking torque F _b Said hydraulic braking torque F _h Equal to 0.

Alternatively, if F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) If the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta, the motor braking system is determined to be used for braking energy meeting the target braking force distribution coefficient beta only _I (ii) a If F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Is not satisfied, it is determined that the target braking force distribution coefficient beta is not satisfied by braking only using the motor brake system, and the ideal braking force distribution coefficient beta is equal to the target braking force distribution coefficient beta _I 。

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the braking force distribution coefficient when only the motor braking system is used for braking meets the requirement of a static value range, determining that the hydraulic braking torque is equal to 0, and determining the target braking torque F of the front axle motor according to the requirement of the maximum motor braking _{m_f} And the target braking torque F of the rear axle motor _{m_r} The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy and satisfies that the ground stability braking margin is greater than or equal to the total required braking torque F _b If F is satisfied _{m_f_max} +F _{m_r_max} ≥F _b And if F _{m_f_max} ≥F _b ·β _L And F _{m_r_max} ≥F _b -min(F _{m_f_max} ,F _b ·β _H ) If the two conditions are met, the hydraulic braking torque F is determined _h Equal to 0 and the target braking torque F of the front axle motor _{m_f} ＝max(F _b ·β _L ,F _b -F _{m_r_max} ) The rear axle motor target braking torque F _{m_r} ＝F _b -F _{m_f} ；

Wherein, beta _L Is the lower boundary value, beta, of the static value range _H The upper boundary value of the static value range.

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the braking force distribution coefficient of braking only by using the motor braking system does not meet the requirement of the static value range, determining the target braking force distribution coefficient beta according to the static value range, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy and satisfies that the ground stability braking margin is greater than or equal to the total required braking torque F _b If F is satisfied _{m_f_max} +F _{m_r_max} ≥F _b And if F _{m_f_max} ≥F _b ·β _L And F _{m_r_max} ≥F _b -min(F _{m_f_max} ,F _b ·β _H ) When at least one of the braking force distribution coefficients is not satisfied, a maximum braking force distribution coefficient beta when braking is performed using only the motor braking system is calculated _max Or a minimum braking force distribution coefficient beta when only the motor braking system is used for braking _min Wherein, β _max ＝F _{m_f_max} /F _b ，β _min ＝(F _b -F _{m_r_max} )/F _b ；

If beta is satisfied _max <β _L Or satisfy beta _min <β _L Then the target braking force distribution coefficient beta is taken as the static valueLower boundary value of the range beta _L And make the front axle motor target brake torque F _{m_f} ＝F _{m_f_max} Target braking torque F of the rear axle motor _{m_r} ＝[(β _h -β _L )·F _b +(1-β _h )·F _{m_f_max} ]/β _h Said hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

If not beta _max <β _L Or does not satisfy beta _min <β _L Then the target braking force distribution coefficient beta is taken as the upper boundary value beta of the static value range _H And make the front axle motor target brake torque F _{m_f} ＝[(β _H -β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h ) The target braking torque F of the rear axle motor _{m_r} ＝F _{m_r_max} The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

Wherein, beta _h The braking force distribution coefficient of the hydraulic braking system.

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m If the requirement of the dynamic value range is met, determining the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} The rear axle motor targetBraking torque F _{m_r} Equal to the maximum braking force F of the rear axle motor _{m_r_max} And braking torque F according to said total demand _b The front axle motor target braking torque F _{m_f} And the target braking torque F of the rear axle motor _{m_r} Determining the hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy and satisfies that the ground stability braking margin is greater than or equal to the total required braking torque F _b If F is not satisfied in the case of (1) _{m_f_max} +F _{m_r_max} ≥F _b Then calculating the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m The lower limit value a of the dynamic value range and the upper limit value b of the dynamic value range, wherein a satisfies: a = max (a) ₁ ,β _L ) And a is a ₁ ＝β _h -β _h ·F _{m_r_max} /F _b B satisfies b = min (b) ₁ ,β _H ) And b is ₁ ＝β _h +(1-β _h )·F _{m_f_max} /F _b ；

If a is less than or equal to beta _m B is less than or equal to b, the target braking torque F of the front axle motor is enabled _{m_f} ＝F _{m_f_max} The rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} 。

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} And the rear shaft motorMaximum brakable torque F _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m If the requirement of the dynamic value range is not met, the target braking force distribution coefficient beta is determined according to the dynamic value range, and the target braking torque F of the front axle motor is determined according to the requirement of the motor braking maximization _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) If at least one of the braking torque values does not satisfy and the ground stable braking margin is equal to or greater than the total required braking torque, F _{m_f_max} +F _{m_r_max} ≥F _b Then calculating the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m The lower limit value a of the dynamic value range and the upper limit value b of the dynamic value range, wherein a satisfies: a = max (a) ₁ ,β _L ) And a is a ₁ ＝β _h -β _h ·F _{m_r_max} /F _b B satisfies b = min (b) ₁ ,β _H ) And b is ₁ ＝β _h +(1-β _h )·F _{m_f_max} /F _b ；

If a is not more than beta _m B is less than or equal to b, then beta is satisfied _m If the target brake force distribution coefficient is smaller than a, the target brake force distribution coefficient is set to be beta = a, and the front axle motor target brake torque is set to be F _{m_f} ＝F _{m_f_max} The rear axle motor target braking torque F _{m_r} ＝[(β _h -a)·F _b +(1-β _h )·F _{m_f_max} ]/β _h The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

If a is not more than beta _m B is less than or equal to b, then beta is not satisfied _m If the target braking force distribution coefficient is smaller than a, the target braking force distribution coefficient is set to be beta = b, and the front axle motor target braking torque is set to be F _{m_f} ＝[(b-β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h ) The rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the braking torque F does not meet the requirement that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b Then it is determined that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta _I And determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy, and does not satisfy the ground stability braking margin is equal to or greater than the total required braking torque F _b If F is satisfied _{m_f_max} +F _{m_r_max} ≥F _b Judging whether F is satisfied _{m_f_max} ＜F _b ·β _I ；

If F is satisfied _{m_f_max} ＜F _b ·β _I Make the front axle motor target brake torque F _{m_f} ＝F _{m_f_max} The rear axle motor target braking torque F _{m_r} ＝F _b -F _{m_f} -F _h The hydraulic braking torque F _h ＝(F _b ·β _I -F _{m_f_max} )/β _h ；

If not satisfying F _{m_f_max} ＜F _b ·β _I Make the rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} The front axle motor target braking torque F _{m_f} ＝F _b -F _{m_r} -F _h The hydraulic braking torque F _h ＝[F _b ·(1-β _I )-F _{m_r_max} ]/(1-β _h )；

Optionally, the determination that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the braking torque F does not meet the requirement that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b Determining the target braking force distribution coefficient beta according to the dynamic value range, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) If at least one of the braking torque values does not satisfy and the ground stability braking margin is not satisfied, and the total required braking torque is not larger than or equal to the total required braking torque, F _{m_f_max} +F _{m_r_max} ≥F _b Then calculating the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m And a lower limit value a of the dynamic value range, wherein a satisfies: a = max (a) ₁ ,β _L ) And a is ₁ ＝β _h -β _h ·F _{m_r_max} /F _b ；

If beta is satisfied _m Less than a, the target braking torque F of the front axle motor _{m_f} ＝F _{m_f_max} The target braking torque F of the rear axle motor _{m_r} ＝[(β _h -a)·F _b +(1-β _h )·F _{m_f_max} ]/β _h The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

If beta is not satisfied _m Less than a, the target braking torque F of the front axle motor _{m_f} ＝[(a-β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h ) The rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

Optionally, the ground stability braking margin is k · T _road Wherein T is _road ＝μ _road ·M·g·r ₀ ，

Wherein, T _road The maximum braking torque which can be provided for the ground; mu.s _road Is the road adhesion coefficient; m is the mass of the whole vehicle; g is the acceleration of gravity; r is ₀ Is the effective rolling radius of the tire; and k is a ground stable braking margin coefficient.

With regard to the apparatus in the above embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be described in detail here.

Fig. 8 is a block diagram illustrating an electronic device 700 in accordance with an example embodiment. As shown in fig. 8, the electronic device 700 may include: a processor 701 and a memory 702. The electronic device 700 may also include one or more of a multimedia component 703, an input/output (I/O) interface 704, and a communication component 705.

The processor 701 is configured to control the overall operation of the electronic device 700, so as to complete all or part of the steps in the braking control method. The memory 702 is used to store various types of data to support operation at the electronic device 700, such as instructions for any application or method operating on the electronic device 700 and application-related data, such as contact data, transmitted and received messages, pictures, audio, video, and so forth. The Memory 702 may be implemented by any type or combination of volatile and non-volatile Memory devices, such as Static Random Access Memory (SRAM), electrically Erasable Programmable Read-Only Memory (EEPROM), erasable Programmable Read-Only Memory (EPROM), programmable Read-Only Memory (PROM), read-Only Memory (ROM), magnetic Memory, flash Memory, magnetic or optical disk. The multimedia components 703 may include screen and audio components. Wherein the screen may be, for example, a touch screen and the audio component is used for outputting and/or inputting audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signal may further be stored in the memory 702 or transmitted through the communication component 705. The audio assembly also includes at least one speaker for outputting audio signals. The I/O interface 704 provides an interface between the processor 701 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual buttons or physical buttons. The communication component 705 is used for wired or wireless communication between the electronic device 700 and other devices. Wireless Communication, such as Wi-Fi, bluetooth, near Field Communication (NFC), 2G, 3G, or 4G, or a combination of one or more of them, so that the corresponding Communication component 705 may include: wi-Fi module, bluetooth module, NFC module.

In an exemplary embodiment, the electronic Device 700 may be implemented by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components for performing the above-described braking control method.

In another exemplary embodiment, a computer readable storage medium comprising program instructions which, when executed by a processor, implement the steps of the braking control method described above is also provided. For example, the computer readable storage medium may be the above-described memory 702 including program instructions that are executable by the processor 701 of the electronic device 700 to perform the above-described braking control method.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. A brake control method for controlling a motor brake system and a hydraulic brake system of a vehicle, characterized by comprising:

obtaining brake control parameters, wherein the brake control parameters comprise the maximum braking torque F of the front axle motor _{m_f_max} Maximum braking torque F of rear axle motor _{m_r_max} Ground stable braking margin and total required braking torque F _b ；

2. The method of claim 1, wherein the determining that braking with the motor brake system alone based on the braking control parameter does not satisfy a target brake force distribution coefficient β equal to an ideal brake force distribution coefficient β _I If the ground is satisfiedThe stable braking margin is more than or equal to the total required braking torque F _b Determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h The method comprises the following steps:

determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b And if the braking force distribution coefficient when only the motor braking system is used for braking meets the requirement of a static value range, determining that the hydraulic braking torque is equal to 0, and determining the target braking torque F of the front axle motor according to the requirement of the motor braking maximization _{m_f} And the target braking torque F of the rear axle motor _{m_r} (ii) a Or

Based on the systemDetermining that braking using only the motor brake system does not satisfy the target brake force distribution coefficient beta being equal to the ideal brake force distribution coefficient beta _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m If the requirement of the dynamic value range is met, determining the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} The rear axle motor target braking torque F _{m_r} Equal to the maximum braking force F of the rear axle motor _{m_r_max} And braking torque F according to said total demand _b The front axle motor target braking torque F _{m_f} And the target braking torque F of the rear axle motor _{m_r} Determining the hydraulic braking torque F _h (ii) a Or

Determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m Not satisfying the movementDetermining the target braking force distribution coefficient beta according to the dynamic value range and determining the target braking torque F of the front axle motor according to the maximum requirement of the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h 。

3. The method of claim 1, wherein the determining that braking with only the electric machine braking system based on the braking control parameter fails to satisfy the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I If the ground stability braking margin is not satisfied, the total required braking torque F is greater than or equal to _b Determining the target braking force distribution coefficient beta according to the requirement of maximizing the braking stability, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I And the brake torque F does not meet the condition that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b Then it is determined that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta _I And determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h (ii) a Or

Determining that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient when it is determined based on the brake control parameter that braking using only the motor brake system cannot be satisfiedNumber beta _I And the braking torque F does not meet the requirement that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b Determining the target braking force distribution coefficient beta according to the dynamic value range, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h 。

4. Method according to claim 1, characterized in that the maximum brakeable torque F of the front axle motor is _{m_f_max} And maximum braking torque F of the rear axle motor _{m_r_max} The lower value of the corresponding external characteristic torque of the motor and the maximum limit torque of the motor calculated according to the charging limit power of the battery is obtained;

the maximum limiting torque of the motor calculated according to the charging limiting power of the battery is determined by the following formula:

wherein, T _{max_bat} Representing the maximum limit torque of the motor calculated according to the charging limit power of the battery; p _{max_charge} Representing a battery charge limit power; eta _{e_motor} Representing the power generation efficiency of the motor; n is _m Representing the equivalent motor speed.

5. The method of claim 1, further comprising: determining that braking using only the motor brake system based on the brake control parameter can satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I In the case where the target braking force distribution coefficient beta is determined to be equal to the ideal braking force distributionCoefficient beta _I The front axle motor target braking torque F _{m_f} Target braking torque F of rear axle motor _{m_r} The sum of which is equal to the total required braking torque F _b Said hydraulic braking torque F _h Equal to 0.

6. The method of claim 5,

if F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) If the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta, the motor braking system is determined to be used for braking energy meeting the target braking force distribution coefficient beta only _I ；

If F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Is not satisfied, it is determined that the target brake force distribution coefficient beta is not satisfied by braking only using the motor brake system, and the ideal brake force distribution coefficient beta is not satisfied _I 。

7. The method of claim 2, wherein the determining that braking with only the electric machine braking system based on the braking control parameter fails to satisfy the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b And if the braking force distribution coefficient when only the motor braking system is used for braking meets the requirement of a static value range, determining that the hydraulic braking torque is equal to 0, and determining the target braking torque F of the front axle motor according to the requirement of the motor braking maximization _{m_f} And the target braking torque F of the rear axle motor _{m_r} The method comprises the following steps:

Wherein beta is _L Is the lower boundary value, beta, of the static value range _H Is the upper boundary value of the static value range.

8. The method of claim 2, wherein the determining that braking with only the electric machine braking system based on the braking control parameter fails to satisfy the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the braking force distribution coefficient of braking only by using the motor braking system does not meet the requirement of the static value range, determining the target braking force distribution coefficient beta according to the static value range, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy and satisfies that the ground stability braking margin is greater than or equal to the total required braking torque F _b If F is satisfied _{m_f_max} +F _{m_r_max} ≥F _b And if F _{m_f_max} ≥F _b ·β _L And F _{m_r_max} ≥F _b -min(F _{m_f_max} ,F _b ·β _H ) When at least one of the braking force distribution coefficients is not satisfied, the maximum braking force distribution coefficient beta when braking is performed using only the motor braking system is calculated _max Or a minimum braking force distribution coefficient beta when only the motor braking system is used for braking _min Wherein, β _max ＝F _{m_f_max} /F _b ，β _min ＝(F _b -F _{m_r_max} )/F _b ；

If beta is satisfied _max <β _L Or satisfy beta _min <β _L Then the target braking force distribution coefficient beta is taken as the lower boundary value beta of the static value range _L And make the front axle motor target brake torque F _{m_f} ＝F _{m_f_max} Target braking torque F of the rear axle motor _{m_r} ＝[(β _h -β _L )·F _b +(1-β _h )·F _{m_f_max} ]/β _h Said hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

9. According toThe method of claim 2, wherein the determining that braking with only the electric machine braking system based on the braking control parameter does not satisfy the target braking force distribution coefficient β is equal to the ideal braking force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m If the requirement of the dynamic value range is met, determining the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} The rear axle motor target braking torque F _{m_r} Equal to the maximum braking force F of the rear axle motor _{m_r_max} And braking torque F according to said total demand _b The front axle motor target braking torque F _{m_f} And the target braking torque F of the rear axle motor _{m_r} Determining the hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy and satisfies that the ground stability braking margin is greater than or equal to the total required braking torque F _b If F is not satisfied _{m_f_max} +F _{m_r_max} ≥F _b Then calculating the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m The lower limit value a of the dynamic value range and the upper limit value b of the dynamic value range, wherein a satisfies:a＝max(a ₁ ,β _L ) And a is ₁ ＝β _h -β _h ·F _{m_r_max} /F _b B satisfies b = min (b) ₁ ,β _H ) And b is ₁ ＝β _h +(1-β _h )·F _{m_f_max} /F _b ；

10. The method of claim 2, wherein the determining that braking with only the electric machine braking system based on the braking control parameter fails to satisfy the target brake force distribution coefficient β is equal to the ideal brake force distribution coefficient β _I And the requirement that the ground stable braking margin is more than or equal to the total required braking torque F is met _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b And if the front axle motor target braking torque F _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m If the requirement of the dynamic value range is not met, the target braking force distribution coefficient beta is determined according to the dynamic value range, and the target braking torque F of the front axle motor is determined according to the requirement of the motor braking maximization _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy and satisfies the ground stability braking margin is greater than or equal to the total demandIf the braking torque does not satisfy F _{m_f_max} +F _{m_r_max} ≥F _b Then calculating the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m The lower limit value a of the dynamic value range and the upper limit value b of the dynamic value range, wherein a satisfies: a = max (a) ₁ ,β _L ) And a is ₁ ＝β _h -β _h ·F _{m_r_max} /F _b B satisfies b = min (b) ₁ ,β _H ) And b is ₁ ＝β _h +(1-β _h )·F _{m_f_max} /F _b ；

If a is not more than beta _m B is less than or equal to b, then beta is not satisfied _m If the target braking force distribution coefficient is smaller than a, the target braking force distribution coefficient is set to be beta = b, and the front axle motor target braking torque is set to be F _{m_f} ＝[(b-β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h ) The target braking torque F of the rear axle motor _{m_r} ＝F _{m_r_max} The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

11. The method of claim 3, wherein the determining based on the braking control parameter to brake only using the motor braking systemThe target braking force distribution coefficient beta is not satisfied to be equal to the ideal braking force distribution coefficient beta _I And the braking torque F does not meet the requirement that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total braking torque F and the total braking torque F _b Then it is determined that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta _I And determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The rear axle motor target braking torque F _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) Does not satisfy and does not satisfy the ground stability braking margin is greater than or equal to the total required braking torque F _b If F is satisfied _{m_f_max} +F _{m_r_max} ≥F _b Judging whether F is satisfied _{m_f_max} ＜F _b ·β _I ；

If F is satisfied _{m_f_max} ＜F _b ·β _I Make the front axle motor target braking torque F _{m_f} ＝F _{m_f_max} The rear axle motor target braking torque F _{m_r} ＝F _b -F _{m_f} -F _h Said hydraulic braking torque F _h ＝(F _b ·β _I -F _{m_f_max} )/β _h ；

12. The method of claim 3, wherein the determining based on the braking control parameter that braking using only the electric motor brake system does not satisfy the target brake force distribution coefficient β being equal to the ideal brake force distribution coefficient β _I And the brake torque F does not meet the condition that the ground stable braking margin is more than or equal to the total required braking torque F _b If the maximum braking torque F of the front axle motor is not satisfied _{m_f_max} Maximum braking torque F of the rear axle motor _{m_r_max} The sum of the total required braking torque F is more than or equal to the total required braking torque F _b Determining the target braking force distribution coefficient beta according to the dynamic value range, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h The method comprises the following steps:

at F _{m_f_max} ≥F _b ·β _I And F _{m_r_max} ≥F _b ·(1-β _I ) If at least one of the braking torque values does not satisfy the condition that the ground stability braking margin is not satisfied and is more than or equal to the total required braking torque, if F is not satisfied _{m_f_max} +F _{m_r_max} ≥F _b Then calculating the target braking torque F of the front axle motor _{m_f} Equal to the maximum brakeable torque F of the front axle motor _{m_f_max} And the target braking torque F of the rear axle motor _{m_r} Equal to the maximum brakeable torque F of the rear axle motor _{m_r_max} Time of braking force distribution coefficient beta _m And a lower limit a of the dynamic value range, wherein a satisfies: a = max (a) ₁ ,β _L ) And a is ₁ ＝β _h -β _h ·F _{m_r_max} /F _b ；

If beta is satisfied _m Less than a, the target braking torque F of the front axle motor _{m_f} ＝F _{m_f_max} The rear axle motor target braking torque F _{m_r} ＝[(β _h -a)·F _b +(1-β _h )·F _{m_f_max} ]/β _h The hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

If not beta _m Less than a, the target braking torque F of the front axle motor _{m_f} ＝[(a-β _h )·F _b +β _h ·F _{m_r_max} ]/(1-β _h ) The rear axle motor target braking torque F _{m_r} ＝F _{m_r_max} Said hydraulic braking torque F _h ＝F _b -F _{m_f} -F _{m_r} ；

13. The method of claim 1,

the stable braking margin on the ground is k.T _road Wherein T is _road ＝μ _road ·M·g·r ₀ ，

Wherein, T _road The maximum braking torque can be provided for the ground; mu.s _road Is the road surface adhesion coefficient; m is the mass of the whole vehicle; g is gravity acceleration; r is ₀ Is the effective rolling radius of the tire; and k is a ground stable braking margin coefficient.

14. A brake control apparatus, characterized by comprising:

a control module to:

determining that braking using only the motor brake system based on the brake control parameter does not satisfy that the target brake force distribution coefficient beta is equal to the ideal brake force distribution coefficient beta _I If the ground stable braking margin is greater than or equal to the total required braking torque F _b Determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} Rear axle motor target braking torque F _{m_r} And a hydraulic braking torque F _h ；

Determining that the target braking force distribution coefficient beta is equal to the ideal braking force distribution coefficient beta when it is determined that braking using only the motor brake system based on the brake control parameter cannot be satisfied _I If the ground stability braking margin is not satisfied, the total required braking torque F is greater than or equal to _b Determining the target braking force distribution coefficient beta according to the requirement of maximizing the braking stability, and determining the target braking torque F of the front axle motor according to the requirement of maximizing the motor braking _{m_f} The target braking torque F of the rear axle motor _{m_r} And said hydraulic braking torque F _h ；

Wherein the total required braking torque F _b Equal to the target braking torque F of the front axle motor _{m_f} The target braking torque F of the rear axle motor _{m_r} With said hydraulic braking torque F _h And (4) the sum.

15. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 13.

16. An electronic device, comprising:

a memory having a computer program stored thereon;

a processor for executing the computer program in the memory to carry out the steps of the method of any one of claims 1 to 13.