阅读说明：本技术 一种重型汽车的辅助制动控制方法及装置 (Auxiliary braking control method and device for heavy-duty car ) 是由 田莹 陈国涛 马明霞 吴学强 赵国强 沈兆树 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种重型汽车的辅助制动控制方法及装置,可以获取与汽车制动相关的运行参数；将运行参数与进入各制动模式的条件进行对比,每个制动模式至少对应一种制动器件,汽车的制动器件包括：发动机、电机以及液力缓速器；当运行参数满足进入各制动模式中一个制动模式的条件时,则控制该制动模式对应的制动器件进行辅助制动。本发明判断在什么情况下,采用与该情况对应的一种或多种的辅助制动设备,使制动效果达到最佳。(The invention discloses an auxiliary braking control method and device for a heavy-duty car, which can obtain running parameters related to car braking; comparing the operating parameters with conditions for entering the braking modes, each braking mode corresponding to at least one braking device, the braking device of the vehicle comprising: the system comprises an engine, a motor and a hydraulic retarder; and when the operation parameters meet the condition of entering one of the braking modes, controlling the braking device corresponding to the braking mode to perform auxiliary braking. The invention judges under what condition, adopts one or more auxiliary braking devices corresponding to the condition to ensure that the braking effect is optimal.)

1. An auxiliary brake control method of a heavy-duty vehicle, comprising:

acquiring operation parameters related to automobile braking, wherein the operation parameters comprise at least one of the opening degree of a brake pedal, the state of an auxiliary brake operating handle, the braking power required by the heavy automobile, the speed of the heavy automobile, the battery capacity ratio and the acceleration of the heavy automobile, and the battery capacity ratio is the ratio of the actual residual capacity of the automobile to the total capacity;

comparing the operating parameters with conditions for entering braking modes, each braking mode corresponding to at least one braking device, the braking device of the vehicle comprising: the system comprises an engine, a motor and a hydraulic retarder;

and when the operating parameters meet the condition of entering one of the braking modes, controlling the braking device corresponding to the braking mode to perform auxiliary braking.

2. The method according to claim 1, wherein when the operating parameter satisfies a condition for entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking comprises:

when the operating parameters meet the condition of entering a motor recovery braking mode, controlling the motor to provide braking power for auxiliary braking;

wherein the condition for entering the motor recovery braking mode comprises: at least one of a first condition, a second condition, a third condition, and a fourth condition,

the first condition is: the auxiliary brake handle is opened, the opening degree of the brake pedal is smaller than a second opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the second condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is smaller than a third opening limit value, and the speed of the heavy-duty car is smaller than a first speed limit value;

the third condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is not smaller than the third opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the fourth condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is not greater than the rated power of the motor.

3. The method according to claim 1, wherein when the operating parameter satisfies a condition for entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking comprises:

when the operating parameters meet the condition of entering an engine-motor combined braking mode, controlling the engine and the motor to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined engine-motor braking mode comprises: at least one of a fifth condition, a sixth condition, and a seventh condition,

the fifth condition is: the auxiliary brake operating handle is opened, the opening degree of a brake pedal is not greater than a second limit value, and the required brake power of the heavy truck is greater than the rated power of the motor;

the sixth condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is not smaller than a third opening degree limit value, and the brake power required by the heavy-duty car is larger than the rated power of the motor;

the seventh condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than a first speed limit value, and the required brake power of the heavy-duty car is greater than the rated power of the motor.

4. The method according to claim 2, wherein when the operating parameter satisfies a condition for entering one of the braking modes, the method controls a braking device corresponding to the braking mode to perform auxiliary braking, and further comprising:

after the heavy-duty car enters the motor recovery braking mode, when the operation parameters meet the condition that the motor recovery braking mode enters the engine auxiliary braking mode, controlling the engine to provide braking power for auxiliary braking;

wherein the condition for entering the engine auxiliary braking mode from the electric machine recuperation braking mode comprises: in the eighth condition, it is preferable that,

the eighth condition is: the battery capacity ratio is greater than a first capacity limit.

5. The method according to claim 3, wherein when the operating parameter satisfies a condition for entering one of the braking modes, the method controls a braking device corresponding to the braking mode to perform auxiliary braking, and further comprising:

after the heavy-duty car enters the engine-motor combined braking mode for a preset time, when the operation parameters meet the condition of entering the engine-motor-hydraulic retarder combined braking mode from the engine-motor combined braking mode, controlling the engine, the motor and the hydraulic retarder to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined engine-motor-hydraulic retarder braking mode from the combined engine-motor braking mode comprises the following conditions: in the ninth condition, the first condition is that,

the ninth condition is: the heavy vehicle acceleration is greater than a first acceleration limit.

6. The method of claim 5, wherein when the operating parameter satisfies a condition for entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking, further comprising:

after the heavy-duty car enters the engine-motor-hydraulic retarder combined braking mode for a preset time, when the operation parameters meet the condition of opening upshift of the hydraulic retarder electromagnetic valve, controlling the opening upshift of the hydraulic retarder electromagnetic valve to provide larger braking power for auxiliary braking;

wherein, the condition that the opening of the electromagnetic valve of the hydraulic retarder shifts up comprises: under the tenth condition, the first condition is that,

the tenth condition is: the acceleration of the heavy-duty vehicle is greater than a second acceleration limit.

7. The method according to claim 1, wherein when the operating parameter satisfies a condition for entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking comprises:

when the operation parameters meet the condition of entering a combined braking mode of the engine and the hydraulic retarder, controlling the engine and the hydraulic retarder to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined engine-hydraulic retarder braking mode comprises: under the eleventh condition, the first condition is that,

the eleventh condition is: the brake pedal opening is greater than a first opening limit.

8. The method according to claim 1, wherein when the operating parameter satisfies a condition for entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking comprises:

when the operating parameters meet the condition of entering an engine auxiliary braking mode, controlling the engine to provide braking power for auxiliary braking;

wherein the condition for entering the engine auxiliary braking mode comprises: in the twelfth condition, it is assumed that,

the twelfth condition is: the auxiliary operation brake handle is opened, the opening degree of the brake pedal is not larger than a first opening degree limiting value, the opening degree of the brake pedal is larger than a second opening degree limiting value, and the first opening degree limiting value is larger than the second opening degree limiting value.

9. An auxiliary brake control apparatus for a heavy vehicle, the apparatus comprising: an acquisition unit, a comparison unit and a control unit,

the acquisition unit is used for acquiring operation parameters related to automobile braking, wherein the operation parameters comprise at least one of the opening degree of a brake pedal, the state of an auxiliary brake operating handle, the braking power required by the heavy automobile, the speed of the heavy automobile, the battery capacity ratio and the acceleration of the heavy automobile, and the battery capacity ratio is the ratio of the actual residual capacity of the automobile to the total capacity;

the comparison unit is used for comparing the operation parameters with conditions for entering various braking modes, each braking mode at least corresponds to one braking device, and the braking device of the automobile comprises: the system comprises an engine, a motor and a hydraulic retarder;

and the control unit is used for controlling a brake device corresponding to the brake mode to perform auxiliary braking when the operation parameter meets the condition of entering one of the brake modes.

10. The apparatus of claim 9,

the control unit includes: a first control sub-unit for controlling the operation of the electronic device,

the first control subunit is used for controlling the motor to provide braking power to perform auxiliary braking when the operation parameters meet the condition of entering a motor recovery braking mode;

wherein the condition for entering the motor recovery braking mode comprises: at least one of a first condition, a second condition, a third condition, and a fourth condition,

the first condition is: the auxiliary brake handle is opened, the opening degree of the brake pedal is smaller than a second opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the second condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is smaller than a third opening limit value, and the speed of the heavy-duty car is smaller than a first speed limit value;

the third condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is not smaller than the third opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the fourth condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is not greater than the rated power of the motor.

Technical Field

The invention relates to the field of automobile control, in particular to an auxiliary braking control method and device for a heavy automobile.

Background

In the daily running process of the heavy vehicle, if the heavy vehicle runs on a smooth road surface, the service brake can generally meet the braking requirement. However, under the working condition of a road surface with a long slope under full load, in order to avoid that the vehicle continuously accelerates to a dangerous speed under the action of self gravity, if the purpose of stabilizing the speed is achieved by only continuously braking the vehicle by the service brake, the temperature is too high due to the fact that the service brake works for a long time, the braking effect is rapidly reduced or even fails, and the potential safety hazard of driving exists.

At present, the auxiliary braking equipment such as an engine, a motor, a hydraulic retarder and the like can realize the effect that a heavy automobile needs less service or does not use a service brake, and the effect of keeping the speed of the automobile reduced or stable is achieved. However, the prior art does not determine which one or more braking devices are used in which case to optimize the braking effect.

Disclosure of Invention

Accordingly, the present invention is directed to a method and apparatus for controlling auxiliary braking of a heavy vehicle to determine which one or more braking devices are used to optimize braking performance under the condition.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention discloses an auxiliary braking control method of a heavy-duty car, which comprises the following steps:

acquiring operation parameters related to automobile braking, wherein the operation parameters comprise at least one of the opening degree of a brake pedal, the state of an auxiliary brake operating handle, the braking power required by the heavy automobile, the speed of the heavy automobile, the battery capacity ratio and the acceleration of the heavy automobile, and the battery capacity ratio is the ratio of the actual residual capacity of the automobile to the total capacity;

comparing the operating parameters with conditions for entering braking modes, each braking mode corresponding to at least one braking device, the braking device of the vehicle comprising: the system comprises an engine, a motor and a hydraulic retarder;

and when the operating parameters meet the condition of entering one of the braking modes, controlling the braking device corresponding to the braking mode to perform auxiliary braking.

Optionally, when the operating parameter meets a condition of entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking includes:

when the operating parameters meet the condition of entering a motor recovery braking mode, controlling the motor to provide braking power for auxiliary braking;

wherein the condition for entering the motor recovery braking mode comprises: at least one of a first condition, a second condition, a third condition, and a fourth condition,

the first condition is: the auxiliary brake handle is opened, the opening degree of the brake pedal is smaller than a second opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the second condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is smaller than a third opening limit value, and the speed of the heavy-duty car is smaller than a first speed limit value;

the third condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is not smaller than the third opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the fourth condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is not greater than the rated power of the motor.

Optionally, when the operating parameter meets a condition of entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking includes:

when the operating parameters meet the condition of entering an engine-motor combined braking mode, controlling the engine and the motor to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined engine-motor braking mode comprises: at least one of a fifth condition, a sixth condition, and a seventh condition,

the fifth condition is: the auxiliary brake operating handle is opened, the opening degree of a brake pedal is not greater than a second limit value, and the required brake power of the heavy truck is greater than the rated power of the motor;

the sixth condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is not smaller than a third opening degree limit value, and the brake power required by the heavy-duty car is larger than the rated power of the motor;

the seventh condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than a first speed limit value, and the required brake power of the heavy-duty car is greater than the rated power of the motor.

Optionally, when the operating parameter meets a condition of entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking, further includes:

after the heavy-duty car enters the motor recovery braking mode, when the operation parameters meet the condition that the motor recovery braking mode enters the engine auxiliary braking mode, controlling the engine to provide braking power for auxiliary braking;

wherein the condition for entering the engine auxiliary braking mode from the electric machine recuperation braking mode comprises: in the eighth condition, it is preferable that,

the eighth condition is: the battery capacity ratio is greater than a first capacity limit.

Optionally, when the operating parameter meets a condition of entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking, further includes:

after the heavy-duty car enters the engine-motor combined braking mode for a preset time, when the operation parameters meet the condition of entering the engine-motor-hydraulic retarder combined braking mode from the engine-motor combined braking mode, controlling the engine, the motor and the hydraulic retarder to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined engine-motor-hydraulic retarder braking mode from the combined engine-motor braking mode comprises the following conditions: in the ninth condition, the first condition is that,

the ninth condition is: the heavy vehicle acceleration is greater than a first acceleration limit.

Optionally, when the operating parameter meets a condition of entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking, further includes:

after the heavy-duty car enters the engine-motor-hydraulic retarder combined braking mode for a preset time, when the operation parameters meet the condition of opening upshift of the hydraulic retarder electromagnetic valve, controlling the opening upshift of the hydraulic retarder electromagnetic valve to provide larger braking power for auxiliary braking;

wherein, the condition that the opening of the electromagnetic valve of the hydraulic retarder shifts up comprises: under the tenth condition, the first condition is that,

the tenth condition is: the acceleration of the heavy-duty vehicle is greater than a second acceleration limit.

Optionally, when the operating parameter meets a condition of entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking includes:

when the operation parameters meet the condition of entering a combined braking mode of the engine and the hydraulic retarder, controlling the engine and the hydraulic retarder to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined engine-hydraulic retarder braking mode comprises: under the eleventh condition, the first condition is that,

the eleventh condition is: the brake pedal opening is greater than a first opening limit.

Optionally, when the operating parameter meets a condition of entering one of the braking modes, controlling a braking device corresponding to the braking mode to perform auxiliary braking includes:

when the operating parameters meet the condition of entering an engine auxiliary braking mode, controlling the engine to provide braking power for auxiliary braking;

wherein the condition for entering the engine auxiliary braking mode comprises: in the twelfth condition, it is assumed that,

the twelfth condition is: the auxiliary operation brake handle is opened, the opening degree of the brake pedal is not larger than a first opening degree limiting value, the opening degree of the brake pedal is larger than a second opening degree limiting value, and the first opening degree limiting value is larger than the second opening degree limiting value.

In a second aspect of the present invention, there is disclosed an auxiliary brake control apparatus for a heavy-duty car, the apparatus comprising: an acquisition unit, a comparison unit and a control unit,

the acquisition unit is used for acquiring operation parameters related to automobile braking, wherein the operation parameters comprise at least one of the opening degree of a brake pedal, the state of an auxiliary brake operating handle, the braking power required by the heavy automobile, the speed of the heavy automobile, the battery capacity ratio and the acceleration of the heavy automobile, and the battery capacity ratio is the ratio of the actual residual capacity of the automobile to the total capacity;

the comparison unit is used for comparing the operation parameters with conditions for entering various braking modes, each braking mode at least corresponds to one braking device, and the braking device of the automobile comprises: the system comprises an engine, a motor and a hydraulic retarder;

and the control unit is used for controlling a brake device corresponding to the brake mode to perform auxiliary braking when the operation parameter meets the condition of entering one of the brake modes.

Optionally, the control unit includes: a first control sub-unit for controlling the operation of the electronic device,

the first control subunit is used for controlling the motor to provide braking power to perform auxiliary braking when the operation parameters meet the condition of entering a motor recovery braking mode;

wherein the condition for entering the motor recovery braking mode comprises: at least one of a first condition, a second condition, a third condition, and a fourth condition,

the first condition is: the auxiliary brake handle is opened, the opening degree of the brake pedal is smaller than a second opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the second condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is smaller than a third opening limit value, and the speed of the heavy-duty car is smaller than a first speed limit value;

the third condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is not smaller than the third opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the fourth condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is not greater than the rated power of the motor.

Optionally, the control unit includes: a second control sub-unit for controlling the operation of the motor,

the second control subunit is used for controlling the engine and the motor to jointly provide braking power for auxiliary braking when the operating parameters meet the condition of entering the engine-motor combined braking mode;

wherein the condition for entering the combined engine-motor braking mode comprises: at least one of a fifth condition, a sixth condition, and a seventh condition,

the fifth condition is: the auxiliary brake operating handle is opened, the opening degree of a brake pedal is not greater than a second limit value, and the required brake power of the heavy truck is greater than the rated power of the motor;

the sixth condition is: the auxiliary brake handle is closed, the opening degree of the brake pedal is not smaller than a third opening degree limit value, and the brake power required by the heavy-duty car is larger than the rated power of the motor;

the seventh condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than a first speed limit value, and the required brake power of the heavy-duty car is greater than the rated power of the motor.

Optionally, the control unit further includes: a third control sub-unit for controlling the operation of the motor,

the third control subunit is used for controlling the engine to provide braking power for auxiliary braking when the operation parameters meet the condition that the motor recovery braking mode enters the engine auxiliary braking mode after the heavy-duty automobile enters the motor recovery braking mode;

wherein the condition for entering the engine auxiliary braking mode from the electric machine recuperation braking mode comprises: in the eighth condition, it is preferable that,

the eighth condition is: the battery capacity ratio is greater than a first capacity limit.

Optionally, the control unit further includes: a fourth control sub-unit for controlling the operation of the motor,

the fourth control subunit is used for controlling the engine, the motor and the hydraulic retarder to jointly provide braking power for auxiliary braking when the operation parameters meet the condition of entering the engine-motor-hydraulic retarder combined braking mode from the engine-motor combined braking mode after the heavy-duty automobile enters the engine-motor combined braking mode for a preset time period;

wherein the condition for entering the combined engine-motor-hydraulic retarder braking mode from the combined engine-motor braking mode comprises the following conditions: in the ninth condition, the first condition is that,

the ninth condition is: the heavy vehicle acceleration is greater than a first acceleration limit.

Optionally, the control unit further includes: a fifth control sub-unit for controlling the operation of the motor,

the fifth control subunit is used for controlling the opening upshift of the electromagnetic valve of the hydraulic retarder to provide higher braking power for auxiliary braking when the operation parameters meet the condition of opening upshift of the electromagnetic valve of the hydraulic retarder after the heavy-duty automobile enters the engine-motor-hydraulic retarder combined braking mode for a preset time period;

wherein, the condition that the opening of the electromagnetic valve of the hydraulic retarder shifts up comprises: under the tenth condition, the first condition is that,

the tenth condition is: the acceleration of the heavy-duty vehicle is greater than a second acceleration limit.

Optionally, the control unit includes: a sixth control sub-unit for controlling the operation of the motor,

the sixth control subunit is configured to, when the operating parameter meets a condition of entering a combined braking mode of the engine and the hydraulic retarder, control the engine and the hydraulic retarder to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined engine-hydraulic retarder braking mode comprises: under the eleventh condition, the first condition is that,

the eleventh condition is: the brake pedal opening is greater than a first opening limit.

Optionally, the control unit includes: a seventh control sub-unit for controlling the operation of the motor,

the seventh control subunit is configured to, when the operating parameter meets a condition for entering an engine auxiliary braking mode, control the engine to provide braking power for auxiliary braking;

wherein the condition for entering the engine auxiliary braking mode comprises: in the twelfth condition, it is assumed that,

the twelfth condition is: the auxiliary operation brake handle is opened, the opening degree of the brake pedal is not larger than a first opening degree limiting value, the opening degree of the brake pedal is larger than a second opening degree limiting value, and the first opening degree limiting value is larger than the second opening degree limiting value.

The auxiliary braking control method and the auxiliary braking control device for the heavy-duty car can acquire the running parameters related to car braking; comparing the operating parameters with conditions for entering the braking modes, each braking mode corresponding to at least one braking device, the braking device of the vehicle comprising: the system comprises an engine, a motor and a hydraulic retarder; and when the operation parameters meet the condition of entering one of the braking modes, controlling the braking device corresponding to the braking mode to perform auxiliary braking. The invention judges under what condition, adopts one or more auxiliary braking devices corresponding to the condition to ensure that the braking effect is optimal.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a schematic flow chart illustrating a method for controlling auxiliary braking of a heavy-duty vehicle according to an embodiment of the present invention;

FIG. 2 is a logic diagram illustrating the condition of the heavy-duty vehicle entering various braking modes according to an embodiment of the present invention;

FIG. 3 is a logic diagram illustrating conditional access of a heavy-duty vehicle from a motor braking recovery mode to an engine auxiliary braking mode in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating the connection between the auxiliary braking devices provided by the embodiment of the present invention;

fig. 5 is a schematic structural diagram of an auxiliary brake control device of a heavy-duty vehicle according to an embodiment of the present invention.

Detailed Description

The invention discloses an auxiliary braking control method and device for a heavy-duty car, and a person skilled in the art can appropriately improve technological parameters by referring to the content. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.

Under the working condition of a heavy vehicle on a long slope road surface under full load, in order to avoid that the vehicle continuously accelerates to dangerous speed under the action of self gravity, a service braking and/or auxiliary braking mode is adopted. The prior art cannot judge what auxiliary braking strategy should be adopted to achieve the optimal condition through a heavy-duty vehicle control system. Now, judge and judge the auxiliary brake mode, mainly judge by the driver by oneself, lead to the braking effect can't reach best or ideal state, judge by the driver moreover often only can adopt an auxiliary brake mode, and every auxiliary brake mode all has its limitation, and same service braking also has its limitation, as follows:

service braking: the friction action of the fixed part and the rotating part is adopted to generate braking torque, and when a heavy vehicle descends a long slope, the long-time frequent use of the service brake can cause the temperature of the friction plate to rise, so that the braking efficiency is declined and even fails. The water spraying device commonly used in the market can reduce the temperature of the friction plate by spraying water, effectively reduce the thermal attenuation of the brake pad, and prolong the service life of the service brake. The user installs the water drenching device additional by oneself, and is with low costs, need not extra operation, only need regularly add water can.

But the frequency of brake replacement is increased, and the use cost of the user is increased. Although the service cycle of the brake can be prolonged by additionally arranging the water drenchers, the water drenchers are easy to cause road surface icing and rollover accidents in winter, so that serious potential safety hazards are caused, and the water drenchers gradually become special treatment projects of traffic management departments at present.

Auxiliary braking of an engine: the fuel supply of the engine is stopped for the running vehicle, the vehicle keeps sliding in the gear, and the vehicle drives the crankshaft of the engine to continuously rotate through the driving wheel, the rear axle and the speed changer to consume certain kinetic energy. On the basis, a set of device is added to the engine, so that friction consumption and energy consumption in the working stroke of the engine are increased, the engine is forced to reduce the rotating speed, and the purpose of reducing the vehicle speed in a short time is achieved.

The braking power provided by the engine is limited under the conditions of high speed, heavy load and steep gradient of the vehicle, and the power required by the heavy-duty vehicle braking is still not fully provided.

Braking of the hydraulic retarder: when the vehicle needs to be braked under a long-slope working condition, the retarder shell is filled with working liquid, the vehicle drives the rotating impeller to drive the working liquid to rotate along with the rotation of the output shaft through the driving wheel, the rear axle and the speed changer, torque is applied to the fixed impeller and the shell, the fixed impeller generates reaction force on the working liquid, the reaction force is transmitted to the rotating impeller, and then the reaction force is transmitted to the driving wheel to achieve the purpose of vehicle deceleration.

The hydraulic retarder can provide enough braking power, but the working process of the hydraulic retarder converts the kinetic energy of a vehicle into heat energy, and the heat energy is dissipated through a cooling system of a heavy-duty car, so that the braking power is not suitable to be too large under the influence of a heat dissipation system, the arrangement of the heavy-duty car, the size and the weight. Meanwhile, the hydraulic retarder provides braking power, a driver still selects gears according to actual road conditions through manual operation, the required braking power is different under different speeds, weights and slopes, and the driving difficulty is increased. In addition, the hydraulic retarder generally uses the same set of cooling system with the engine, and if the heavy-duty car cooling system temperature is too high, the hydraulic retarder will not reach the anticipated braking effect.

And (3) motor recovery braking: the heavy-duty car control system looks up a table through a brake Map, negative torque required by the motor is sent out, the motor becomes a power generation mode, at the moment, the stator can generate electromagnetic torque opposite to the rotation direction of the rotor for the rotor, the motor generates brake torque for a driving wheel, at the moment, the kinetic energy of a car is converted into electric energy, and the electric energy is stored in a power battery and used for driving working conditions.

However, the motor power is limited, the motor can run for a long time under the rated power of the motor, and after the rated power of the motor is exceeded, the running time is limited, and the brake power which can be provided is limited.

Therefore, the invention provides an auxiliary braking control method and an auxiliary braking control device for a heavy-duty car, which can judge under what conditions, adopt one or more auxiliary braking devices corresponding to the conditions, and enable the braking effect to be optimal.

As shown in fig. 1, an embodiment of the present invention provides an auxiliary braking control method for a heavy-duty vehicle, including:

step S101: and acquiring operation parameters related to automobile braking.

It should be noted that the operation parameter includes at least one of a brake pedal opening, an auxiliary brake operating handle state, a braking power required by the heavy-duty vehicle, a speed of the heavy-duty vehicle, a battery charge ratio, and an acceleration of the heavy-duty vehicle.

The opening degree of the brake pedal is the stepping degree of the brake pedal, and the higher the opening degree of the brake pedal is, the higher the required braking power is represented by percentage;

the auxiliary brake operating handle is divided into an opening state and a closing state;

the braking power required by the heavy-duty car is calculated according to a formula P (FV) (F1+ F2+ F3+ ma) V, wherein P is the braking power required by the heavy-duty car, F1 is the friction resistance between the heavy-duty car and the ground, F2 is the air resistance (wind resistance) of the heavy-duty car during running, F3 is the slope resistance of the heavy-duty car during running on a slope, m is the mass of the heavy-duty car, a is the acceleration of the heavy-duty car during running, and V is the speed of the heavy-duty car during running;

the battery capacity ratio is the ratio of the actual remaining capacity of the automobile to the total capacity.

Step S102: the operating parameters are compared to the conditions for entering each braking mode.

It should be noted that each braking mode corresponds to at least one braking device, and the braking device of the automobile includes: the system comprises an engine, a motor and a hydraulic retarder.

Step S103: and when the operation parameters meet the condition of entering one of the braking modes, controlling the braking device corresponding to the braking mode to perform auxiliary braking.

Optionally, in a specific embodiment, when the operating parameter meets the condition of entering the motor recovery braking mode, the motor is controlled to provide braking power to perform auxiliary braking;

wherein the condition for entering the motor regenerative braking mode comprises: at least one of a first condition, a second condition, a third condition, and a fourth condition,

the first condition is: the auxiliary brake handle is opened, the opening degree of a brake pedal is smaller than a second opening degree limit value, and the required brake power of the heavy-duty car is not larger than the rated power of the motor;

the second condition is: the auxiliary brake handle is closed, the opening degree of a brake pedal is smaller than a third opening degree limit value, and the speed of the heavy-duty car is smaller than a first speed limit value;

the third condition is: the auxiliary brake handle is closed, the opening degree of a brake pedal is not smaller than a third opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the fourth condition is that: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is not greater than the rated power of the motor.

Optionally, after the heavy-duty vehicle enters the motor recovery braking mode, when the operation parameters meet the condition that the motor recovery braking mode enters the engine auxiliary braking mode, controlling the engine to provide braking power for auxiliary braking;

wherein the condition for entering the engine auxiliary braking mode from the electric machine recuperation braking mode comprises: in the eighth condition, it is preferable that,

the eighth condition is: the battery charge ratio is greater than a first charge limit. Optionally, in a specific embodiment, when the operating parameter meets the condition of entering the engine-motor combined braking mode, the engine and the motor are controlled to jointly provide braking power for auxiliary braking;

wherein the condition for entering the engine-motor combined braking mode comprises: at least one of a fifth condition, a sixth condition, and a seventh condition,

the fifth condition is: the auxiliary brake operating handle is opened, the opening degree of a brake pedal is not more than a second limit value, and the required brake power of the heavy-duty car is more than the rated power of the motor;

the sixth condition is: the auxiliary brake handle is closed, the opening degree of a brake pedal is not less than a third opening degree limit value, and the required brake power of the heavy-duty car is greater than the rated power of the motor;

the seventh condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is greater than the rated power of the motor.

Optionally, after the heavy-duty vehicle enters an engine-motor combined braking mode for a preset time, when the operation parameters meet the condition of entering the engine-motor-hydraulic retarder combined braking mode from the engine-motor combined braking mode, controlling the engine, the motor and the hydraulic retarder to jointly provide braking power for auxiliary braking;

the condition for entering the combined braking mode of the engine-motor-hydraulic retarder from the combined braking mode of the engine-motor comprises the following conditions: in the ninth condition, the first condition is that,

the ninth condition is: the heavy vehicle acceleration is greater than the first acceleration limit.

Optionally, after the heavy-duty vehicle enters an engine-motor-hydraulic retarder combined braking mode for a preset time, when the operation parameter meets the condition of opening upshift of the hydraulic retarder electromagnetic valve, controlling the opening upshift of the hydraulic retarder electromagnetic valve to provide larger braking power for auxiliary braking;

wherein, the condition that hydraulic retarber solenoid valve opening shifted up includes: under the tenth condition, the first condition is that,

the tenth condition is: the acceleration of the heavy-duty vehicle is greater than the second acceleration limit.

Optionally, in a specific embodiment, when the operating parameter meets the condition of entering the combined braking mode of the engine and the hydraulic retarder, the engine and the hydraulic retarder are controlled to jointly provide braking power for auxiliary braking;

wherein the condition for entering the combined braking mode of the engine-hydraulic retarder comprises the following conditions: under the eleventh condition, the first condition is that,

the eleventh condition is: the brake pedal opening is greater than a first opening limit.

Optionally, in a specific embodiment, when the operating parameter meets the condition of entering the auxiliary braking mode of the engine, the engine is controlled to provide braking power for auxiliary braking;

wherein the condition for entering the engine auxiliary braking mode comprises: in the twelfth condition, it is assumed that,

the twelfth condition is: the auxiliary operation brake handle is opened, the opening degree of a brake pedal is not larger than a first opening degree limiting value, the opening degree of the brake pedal is larger than a second opening degree limiting value, and the first opening degree limiting value is larger than the second opening degree limiting value.

Note that, the first opening degree limit > the second opening degree limit > the third opening degree limit, and the first acceleration limit > the second acceleration limit. Alternatively, in a specific embodiment, the logic for determining the conditions using each auxiliary brake device is as shown in fig. 2:

in fig. 2, a1 is a first opening limit, a2 is a second opening limit, A3 is a third opening limit, V1 is a first speed limit, B1 is a first acceleration limit, B2 is a second acceleration limit, P1 is the braking power required by the heavy-duty vehicle, and P2 is the motor rated power.

Note that, the first opening degree limit > the second opening degree limit > the third opening degree limit, and the first acceleration limit > the second acceleration limit.

Step S201: judging whether the opening degree of a brake pedal is larger than A1, wherein A1 is a larger numerical value and is close to 100%, if the opening degree of the brake pedal is larger than A1, indicating that the heavy-duty automobile meets the emergency braking condition, at the moment, even if no auxiliary handle signal exists, the engine and the hydraulic retarder are used for braking together, namely, the engine-hydraulic retarder combined braking mode is entered, meanwhile, the service braking also acts to ensure the driving safety, and if not, the step S202 is carried out.

Step S202: and judging whether the auxiliary brake operating handle is opened, if so, performing step S203, otherwise, performing step S204, wherein when the auxiliary brake operating handle is opened, the heavy-duty automobile descends a long slope.

Step S203: and judging whether the opening degree of the brake pedal is larger than A2, if so, adopting the engine to brake, namely, entering an engine auxiliary braking mode, and if not, performing step S205.

Step S204: and judging whether the opening degree of a brake pedal is less than A3 and the vehicle speed is less than V1, if the opening degree of the brake pedal is less than A3 and the vehicle speed is less than V1, indicating that the braking power required by the vehicle is small and the motor is enough to provide the braking power required by the heavy-duty vehicle, adopting motor recovery braking, namely entering a motor recovery braking mode, and if at least one of the opening degree of the brake pedal is not greater than A3, performing step S205.

Step S205: judging whether P1 is greater than P2, if so, indicating that the braking power required by the heavy-duty automobile exceeds the rated power of the motor, and simultaneously providing braking power by adopting the motor and the engine, namely entering an engine-motor combined braking mode; if not, the braking power required by the heavy-duty automobile does not exceed the rated power of the motor, and the motor is adopted to provide the braking power, namely, the motor recovery braking mode is entered.

Step S206: after the heavy-duty automobile enters an engine-motor combined braking mode for a preset time, judging whether the acceleration of the heavy-duty automobile is greater than B1, if so, indicating that the heavy-duty automobile cannot run stably, and controlling a hydraulic retarder electromagnetic valve to be opened, namely, entering the engine-motor-hydraulic retarder combined braking mode, and if not, ending the operation.

Step S207: after the heavy-duty car enters an engine-motor-hydraulic retarder combined braking mode for a preset time period, judging whether the acceleration of the heavy-duty car is smaller than B1, if not, indicating that the provided braking power still does not meet the braking power required by the heavy-duty car, controlling the opening of a solenoid valve of the hydraulic retarder to shift up at the moment, and if so, ending the operation.

As shown in fig. 3, SOC is the battery capacity ratio, and S1 is the first capacity limit, where the first capacity limit is a higher limit, which indicates that the capacity reaches the preset value and charging cannot be continued.

In the embodiment in fig. 2, the method further includes step S301: in all the modes, when the motor provides braking power, whether the battery power ratio SOC of the motor is larger than S1 is judged, if yes, the battery cannot recover more power, the part of braking power provided by the motor is provided by the engine, and if not, the motor continues to provide automatic power required to be provided.

The connection of the auxiliary brake device to the heavy-duty vehicle device is shown in fig. 4, wherein VCU represents the heavy-duty vehicle control system, ECU represents the engine controller, and MCU represents the motor controller.

The VCU directly or indirectly controls the engine, the motor and the hydraulic retarder to provide braking power, so that the speed changer is influenced, then the transmission shaft is connected, then the rear axle is connected, and finally the driving wheel is connected, and the speed change of the heavy-duty car is realized.

Alternatively, the engine-assisted braking may include exhaust braking, bleeder braking, in-cylinder braking, and the like.

Optionally, the above hydrodynamic retarder can be replaced by a retarder such as an eddy current retarder.

The auxiliary braking control method for the heavy-duty car can acquire running parameters related to car braking; comparing the operating parameters with conditions for entering the braking modes, each braking mode corresponding to at least one braking device, the braking device of the vehicle comprising: the system comprises an engine, a motor and a hydraulic retarder; and when the operation parameters meet the condition of entering one of the braking modes, controlling the braking device corresponding to the braking mode to perform auxiliary braking. The embodiment of the invention judges under what condition, adopts one or more auxiliary braking devices corresponding to the condition to ensure that the braking effect is optimal. The optimal braking effect comprises the following three aspects:

under the working condition of a long slope, the invention can recover the braking energy to the maximum extent and reduce the use frequency of the service brake on the basis of ensuring the driving safety.

According to the invention, the auxiliary brake handle is operated by a driver only once, and gear switching is not required according to working conditions such as vehicle speed and gradient, so that the driving strength is reduced, and the driving comfort is improved.

The invention fully considers the situation that the driver does not take risk avoiding measures under the condition of emergency braking, and takes reasonable and effective braking measures according to the opening degree of the brake pedal.

Based on the auxiliary braking control method of the heavy-duty car disclosed by the embodiment of the invention, the embodiment of the invention also discloses an auxiliary braking control device of the heavy-duty car as shown in fig. 5, and the device comprises: an acquisition unit 501, a comparison unit 502 and a control unit 503.

An obtaining unit 501 is configured to obtain an operation parameter related to braking of the vehicle.

It should be noted that the operation parameter includes at least one of a brake pedal opening, an auxiliary brake operating handle state, a braking power required by the heavy-duty vehicle, a speed of the heavy-duty vehicle, a battery charge ratio, and an acceleration of the heavy-duty vehicle.

The opening degree of the brake pedal is the stepping degree of the brake pedal, and the higher the opening degree of the brake pedal is, the higher the required braking power is represented by percentage;

the auxiliary brake operating handle is divided into an opening state and a closing state;

the braking power required by the heavy-duty car is calculated according to a formula P (FV) (F1+ F2+ F3+ ma) V, wherein P is the braking power required by the heavy-duty car, F1 is the friction resistance between the heavy-duty car and the ground, F2 is the air resistance (wind resistance) of the heavy-duty car during running, F3 is the slope resistance of the heavy-duty car during running on a slope, m is the mass of the heavy-duty car, a is the acceleration of the heavy-duty car during running, and V is the speed of the heavy-duty car during running;

the battery capacity ratio is the ratio of the actual remaining capacity of the automobile to the total capacity.

A comparison unit 502 for comparing the operating parameters with the conditions for entering the respective braking modes.

It should be noted that each braking mode corresponds to at least one braking device, and the braking device of the automobile includes: the system comprises an engine, a motor and a hydraulic retarder.

And the control unit 503 is configured to, when the operating parameter meets a condition for entering one of the braking modes, control the braking device corresponding to the braking mode to perform auxiliary braking.

Optionally, in a specific embodiment, the control unit includes: a first control sub-unit for controlling the operation of the electronic device,

the first control subunit is used for controlling the motor to provide braking power to perform auxiliary braking when the operation parameters meet the condition of entering the motor recovery braking mode;

wherein the condition for entering the motor regenerative braking mode comprises: at least one of a first condition, a second condition, a third condition, and a fourth condition,

the first condition is: the auxiliary brake handle is opened, the opening degree of a brake pedal is smaller than a second opening degree limit value, and the required brake power of the heavy-duty car is not larger than the rated power of the motor;

the second condition is: the auxiliary brake handle is closed, the opening degree of a brake pedal is smaller than a third opening degree limit value, and the speed of the heavy-duty car is smaller than a first speed limit value;

the third condition is: the auxiliary brake handle is closed, the opening degree of a brake pedal is not smaller than a third opening degree limit value, and the brake power required by the heavy-duty car is not larger than the rated power of the motor;

the fourth condition is that: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is not greater than the rated power of the motor.

Optionally, the control unit further includes: a third control sub-unit for controlling the operation of the motor,

the third control subunit is used for controlling the engine to provide braking power for auxiliary braking when the operation parameters meet the condition that the heavy-duty car enters the auxiliary braking mode of the engine from the motor recovery braking mode after entering the motor recovery braking mode;

wherein the condition for entering the engine auxiliary braking mode from the electric machine recuperation braking mode comprises: in the eighth condition, it is preferable that,

the eighth condition is: the battery charge ratio is greater than a first charge limit.

Optionally, in a specific embodiment, the control unit includes: a second control sub-unit for controlling the operation of the motor,

the second control subunit is used for controlling the engine and the motor to jointly provide braking power for auxiliary braking when the operation parameters meet the condition of entering the engine-motor combined braking mode;

wherein the condition for entering the engine-motor combined braking mode comprises: at least one of a fifth condition, a sixth condition, and a seventh condition,

the fifth condition is: the auxiliary brake operating handle is opened, the opening degree of a brake pedal is not more than a second limit value, and the required brake power of the heavy-duty car is more than the rated power of the motor;

the sixth condition is: the auxiliary brake handle is closed, the opening degree of a brake pedal is not less than a third opening degree limit value, and the required brake power of the heavy-duty car is greater than the rated power of the motor;

the seventh condition is: the auxiliary brake handle is closed, the speed of the heavy-duty car is not less than the first speed limit value, and the required brake power of the heavy-duty car is greater than the rated power of the motor.

Optionally, the control unit further includes: a fourth control sub-unit for controlling the operation of the motor,

the fourth control subunit is used for controlling the engine, the motor and the hydraulic retarder to jointly provide braking power for auxiliary braking when the operation parameters meet the condition of entering the engine-motor-hydraulic retarder combined braking mode from the engine-motor combined braking mode after the heavy-duty automobile enters the engine-motor combined braking mode for a preset time period;

the condition for entering the combined braking mode of the engine-motor-hydraulic retarder from the combined braking mode of the engine-motor comprises the following conditions: in the ninth condition, the first condition is that,

the ninth condition is: the heavy vehicle acceleration is greater than the first acceleration limit.

Optionally, the control unit further includes: a fifth control sub-unit for controlling the operation of the motor,

the fifth control subunit is used for controlling the opening upshift of the electromagnetic valve of the hydraulic retarder to provide larger braking power for auxiliary braking when the operation parameters meet the condition of opening upshift of the electromagnetic valve of the hydraulic retarder after the heavy-duty automobile enters the engine-motor-hydraulic retarder combined braking mode for a preset time period;

wherein, the condition that hydraulic retarber solenoid valve opening shifted up includes: under the tenth condition, the first condition is that,

the tenth condition is: the acceleration of the heavy-duty vehicle is greater than the second acceleration limit.

Optionally, in a specific embodiment, the control unit includes: a sixth control sub-unit for controlling the operation of the motor,

the sixth control subunit is used for controlling the engine and the hydraulic retarder to jointly provide braking power for auxiliary braking when the operation parameters meet the condition of entering the combined braking mode of the engine and the hydraulic retarder;

wherein the condition for entering the combined braking mode of the engine-hydraulic retarder comprises the following conditions: under the eleventh condition, the first condition is that,

the eleventh condition is: the brake pedal opening is greater than a first opening limit.

Optionally, in a specific embodiment, the control unit includes: a seventh control sub-unit for controlling the operation of the motor,

the seventh control subunit is used for controlling the engine to provide braking power for auxiliary braking when the operation parameters meet the condition of entering the auxiliary braking mode of the engine;

wherein the condition for entering the engine auxiliary braking mode comprises: in the twelfth condition, it is assumed that,

the twelfth condition is: the auxiliary operation brake handle is opened, the opening degree of a brake pedal is not larger than a first opening degree limiting value, the opening degree of the brake pedal is larger than a second opening degree limiting value, and the first opening degree limiting value is larger than the second opening degree limiting value.

Note that, the first opening degree limit > the second opening degree limit > the third opening degree limit, and the first acceleration limit > the second acceleration limit.

The embodiment of the invention provides an auxiliary brake control device of a heavy-duty car, which comprises: an acquisition unit 501, a comparison unit 502, and a control unit 503. An obtaining unit 501, configured to obtain an operation parameter related to braking of an automobile; a comparison unit 502, configured to compare the operating parameter with a condition for entering each braking mode, where each braking mode corresponds to at least one braking device, and the braking device of the vehicle includes: the system comprises an engine, a motor and a hydraulic retarder; and the control unit 503 is configured to, when the operating parameter meets a condition for entering one of the braking modes, control the braking device corresponding to the braking mode to perform auxiliary braking. The embodiment of the invention judges under what condition, adopts one or more auxiliary braking devices corresponding to the condition to ensure that the braking effect is optimal. The optimal braking effect comprises the following three aspects:

under the working condition of a long slope, the invention can recover the braking energy to the maximum extent and reduce the use frequency of the service brake on the basis of ensuring the driving safety.

According to the invention, the auxiliary brake handle is operated by a driver only once, and gear switching is not required according to working conditions such as vehicle speed and gradient, so that the driving strength is reduced, and the driving comfort is improved.

The invention fully considers the situation that the driver does not take risk avoiding measures under the condition of emergency braking, and takes reasonable and effective braking measures according to the opening degree of the brake pedal.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.