阅读说明：本技术 一种电子驻车制动力智能分级方法 (Intelligent grading method for electronic parking braking force ) 是由 邱文兵 邓清华 廖程亮 游瀚 沈迎港 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种电子驻车制动力智能分级方法,电子驻车制动系统静态驻车根据条件不同分为普通模式和转毂模式；在普通模式下,通过车辆内部的纵向加速度传感器输出值,对当前坡度进行判断。根据坡度值,选择相应的路径,确定输出驻车制动力的级别；在普通模式下,输出驻车制动力分为3段,具体力值通过理论计算同时考虑极限情况和安全冗余预设,通过标定对应执行器的电流特性。在转毂模式下,通过程序智能识别车辆工况,输出满足法规要求的驻车制动力；进入转毂模式后,拉起EPB开关不放,驻车制动力分两段输出,时间间隔Ts＝0.5s。(The invention discloses an intelligent classification method for electronic parking braking force.A static parking braking system of an electronic parking braking system is divided into a common mode and a hub rotating mode according to different conditions; in the normal mode, the current gradient is determined from the output value of the longitudinal acceleration sensor inside the vehicle. Selecting a corresponding path according to the gradient value, and determining the level of the parking braking force; in a common mode, the output parking braking force is divided into 3 sections, the specific force value is calculated by theory, the limit condition and safety redundancy presetting are considered at the same time, and the current characteristic of the corresponding actuator is calibrated. Under a hub rotating mode, intelligently identifying the working condition of the vehicle through a program, and outputting parking braking force meeting the requirements of regulations; after the hub rotating mode is entered, the EPB switch is pulled up and is not released, the parking braking force is output in two sections, and the time interval Ts is 0.5 s.)

1. An intelligent classification method for electronic parking braking force is characterized in that: the method comprises the following steps:

s001: pulling up EPB switch trigger mode identification, wherein a specific trigger signal is an EPB switch state signal;

s002: judging whether the EPB is in a release state; if yes, entering S003; if not, the operation goes to S013; at the moment, the vehicle is in a parking state, and the parking is not required to be executed again, so that the process is finished directly;

s003: judging whether the vehicle is in a static state or not, and if so, entering S004; if not, the process goes to S012, the vehicle is dynamic, and is processed by the logic of other modules;

s004: judging whether the vehicle is in a hub rotating mode or not; if yes, entering S104 hub rotating mode, and outputting the parking force according to the logic output of the hub rotating mode; if not, the vehicle is in a parking operation of normal running at the moment, the normal mode is entered in S005, the mode is a daily use mode, and the output of the parking braking force is output according to the logic of the normal mode.

2. The intelligent classification method for the electronic parking brake force according to claim 1, characterized in that:

the S005 normal mode comprises three gradient values of S006, S008 and S011, and a corresponding path is selected according to the gradient values to determine the level of the parking braking force.

3. The intelligent classification method of electronic parking brake force according to claim 2, characterized in that:

the slope corresponding to S006 is 0 < S < 10%, and the corresponding S007 outputs the parking brake force F1.

4. The intelligent classification method of electronic parking brake force according to claim 2, characterized in that:

the slope corresponding to S008 is 10% and S < 20%, and the parking brake force corresponding to S009 is F2.

5. The intelligent classification method of electronic parking brake force according to claim 2, characterized in that:

the slope corresponding to the S011 is S ≧ 20%, and the corresponding S010 output parking braking force is F3.

6. The intelligent classification method for the electronic parking brake force according to claim 1, characterized in that:

the S104 hub rotation mode includes the steps of:

starting from said S003: judging whether the vehicle is in a static state or not; if yes, entering S101; if not, the process goes to S012, the vehicle is dynamic, and is processed by the logic of other modules;

s101: judging whether the engine is in a starting state, if so, entering S102; if not, entering an S005 common mode;

s102: judging whether the gear of the gearbox is neutral or not, and if so, entering S002; if not, entering an S005 common mode;

s002: judging whether the EPB is in a release state; if yes, entering S103; if not, entering S013, wherein the vehicle is in a parking state, the bench test brake test cannot be executed, and the process is finished directly;

s103: judging whether the wheel speed meets the requirement; if yes, entering S104 hub rotating mode; if not, entering an S005 common mode;

s104: entering a hub rotating mode: when the logic judgment of the front end is yes and the duration reaches 3 seconds or more, the program automatically identifies to enter an S104 hub rotating mode, at the moment, the instrument has corresponding prompt, and the parking braking force output on the flat ground in the mode is larger than that in the common mode;

s105: the EPB switch is pulled up, and the parking braking force Fr is output.

7. The intelligent classification method of electronic parking brake force according to claim 6, characterized in that:

the specific wheel speed requirement in S103 is that the front wheel speed is less than 0.25km/h, and the rear wheel speed is more than or equal to 1.9 and less than or equal to 9 km/h; the speed difference of the left wheel and the right wheel is less than 1.8 km/h.

8. The intelligent classification method of electronic parking brake force according to claim 6, characterized in that:

in S105, the parking brake force Fr is larger than the parking brake force F1 output in the normal mode, and the parking brake force Fr is output in two stages with a time interval Ts equal to 0.5S.

Technical Field

The invention relates to the technical field of electronic parking, in particular to an intelligent grading method for electronic parking braking force.

Background

The parking brake force of the existing electronic parking system generally outputs only a single maximum parking brake force. Namely, the parking braking force with the maximum fixed output is unified without distinguishing the use working conditions. According to the mode, for parking under a small slope frequently used in daily life, the parking braking force exceeds the actual requirement of the vehicle more, the problems that the parking braking response is slow, the comfort experience is poor and the like are caused, meanwhile, the actuating mechanism works under the maximum parking braking force for a long time, and the service life is relatively short. Therefore, effective solutions to solve the above problems need to be proposed.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to provide an intelligent electronic parking brake force grading method, the electronic parking brake force is divided into a common mode and a hub rotating mode according to different conditions, and the output of the parking brake force by adopting the method is smaller than the output of a single maximum parking brake force, so that the parking brake response is faster, the comfort experience is better, and the service life of a parking actuating mechanism can be prolonged.

In order to achieve the purpose, the invention adopts the following technical scheme:

an intelligent grading method for electronic parking braking force comprises the following steps:

s001: pulling up EPB switch trigger mode identification, wherein a specific trigger signal is an EPB switch state signal;

s002: judging whether the EPB is in a release state; if yes, entering S003; if not, the operation goes to S013; at the moment, the vehicle is in a parking state, and the parking is not required to be executed again, so that the process is finished directly;

s003: judging whether the vehicle is in a static state or not, and if so, entering S004; if not, the process goes to S012, the vehicle is dynamic, and is processed by the logic of other modules;

s004: judging whether the vehicle is in a hub rotating mode or not; if yes, entering S104 hub rotating mode, and outputting the parking force according to the logic output of the hub rotating mode; if not, the vehicle is in a parking operation of normal running at the moment, the normal mode is entered in S005, the mode is a daily use mode, and the output of the parking braking force is output according to the logic of the normal mode.

Further, the S005 normal mode includes three gradient values of S006, S008, and S011, and according to the gradient values, a corresponding path is selected, and a level of outputting the parking braking force is determined.

Further, the slope corresponding to S006 is 0 ≦ S10%, and the corresponding S007 outputs the parking brake force F1.

Further, the slope corresponding to S008 is 10% ≦ S ≦ 20%, and the corresponding S009 output parking brake force is F2.

Further, S ≧ 20% is a gradient corresponding to S011, and F3 is a parking brake force corresponding to S010.

Further, the S104 hub rotation mode includes the following steps:

starting from said S003: judging whether the vehicle is in a static state or not; if yes, entering S101; if not, the process goes to S012, the vehicle is dynamic, and is processed by the logic of other modules;

s101: judging whether the engine is in a starting state, if so, entering S102; if not, entering an S005 common mode;

s102: judging whether the gear of the gearbox is neutral or not, and if so, entering S002; if not, entering an S005 common mode;

s002: judging whether the EPB is in a release state; if yes, entering S103; if not, entering S013, wherein the vehicle is in a parking state, the bench test brake test cannot be executed, and the process is finished directly;

s103: judging whether the wheel speed meets the requirement; if yes, entering S104 hub rotating mode; if not, entering an S005 common mode;

s104: entering a hub rotating mode: when the logic judgment of the front end is yes and the duration reaches 3 seconds or more, the program automatically identifies to enter an S104 hub rotating mode, at the moment, the instrument has corresponding prompt, and the parking braking force output on the flat ground in the mode is larger than that in the common mode;

s105: the EPB switch is pulled up, and the parking braking force Fr is output.

Further, the specific wheel speed requirement in S103 is that the front wheel speed is less than 0.25km/h, and the rear wheel speed is more than or equal to 1.9 and less than or equal to 9 km/h; the speed difference of the left wheel and the right wheel is less than 1.8 km/h.

Further, the parking brake force Fr in S105 is larger than the parking brake force F1 output in the normal mode on a flat basis, and is output in two stages with a time interval Ts of 0.5S.

The invention has the beneficial effects that:

the intelligent classification method of the electronic parking braking force is different from the traditional method that only a single maximum parking braking force is output by the electronic parking braking force, estimation is carried out according to the current gradient in a common mode, and a proper parking braking force is output by combining a strategy to meet the parking requirement of a vehicle; parking on a daily frequently-applied small slope, the method is adopted to output the parking braking force to be smaller than the method which only outputs a single maximum parking braking force, so that the parking braking response is faster, the comfort experience is better, and the service life of the parking actuating mechanism can be prolonged; when the parking braking force is checked on the bench test at the time of vehicle offline or annual inspection, the working condition of the vehicle can be intelligently identified through a program, the vehicle automatically enters a hub rotating mode, and the parking braking force meeting the standard requirement is output.

Drawings

FIG. 1 is a block diagram of a parking brake force staging strategy in a normal mode according to an embodiment of the present invention;

FIG. 2 is a logic diagram of the operation of the hub mode of the present invention;

fig. 3 is a diagram illustrating a parking brake force output strategy in a hub rotating mode according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

According to the requirements of GB 7258-.

The parking braking force of the electronic parking system corresponding to the invention is calculated through the gradient, and the appropriate clamping force is output, so that the parking response speed is improved, and the service life of the parking system is prolonged. And when the braking performance is tested by the bench test required by the national standard, the parking brake is generally arranged on the flat ground, and the parking force output by the electronic parking system according to the gradient is small, so that the national standard requirement cannot be met.

Therefore, the invention provides an intelligent grading method of electronic parking braking force, which estimates according to the current gradient in a common mode and outputs proper parking braking force by combining strategies to meet the parking requirement of a vehicle; under the hub rotating mode, the working condition of the vehicle is intelligently identified through a program, and the parking braking force meeting the requirements of the regulations is output.

As shown in table 1, the present invention proposes a method for intelligent classification of electronic parking brake force. The parking braking force output under the static condition has two modes, wherein the mode 1 is a common mode, namely the parking braking used by a driver daily, and the parking braking force is divided into 3 sections F1, F2 and F3. Estimating according to the current gradient during parking, and selecting the corresponding parking braking force grade by combining strategies to meet the parking requirement of the vehicle; and the mode 2 is a hub rotating mode, the working condition of the vehicle is intelligently identified through a program, and the parking braking force meeting the requirements of the regulations is output. Fr of the hub rotating mode is larger than F2, and the force value is a variable force value, so that the national standard requirement can be met.

TABLE 1

In the normal mode, the parking brake force classification strategy diagram is shown in fig. 1 and comprises the following steps: s001: pulling up EPB switch trigger mode identification, wherein a specific trigger signal is an EPB switch state signal;

s002: judging whether the EPB is in a release state; if yes, entering S003; if not, the operation goes to S013; at the moment, the vehicle is in a parking state, and the parking is not required to be executed again, so that the process is finished directly;

s003: judging whether the vehicle is in a static state or not, wherein the specific static judgment can be realized by four-wheel vehicle speed signals; if yes, entering S004; if not, the process goes to S012, the vehicle is dynamic, and is processed by the logic of other modules;

s004: judging whether the vehicle is in a hub rotating mode or not; if yes, entering S104 hub rotating mode, and outputting the parking force according to the logic output of the hub rotating mode; if not, the vehicle is in a parking operation of normal running at the moment, the normal mode is entered in S005, the mode is a daily use mode, and the output of the parking braking force is output according to the logic of the normal mode.

The S005 common mode comprises three gradient values of S006, S008 and S011, wherein the gradient corresponding to S006 is 0 < S < 10%, and the corresponding S007 output parking braking force is F1; s008 corresponds to a gradient of 10% ≦ S < 20%, and corresponding S009 outputs parking braking force F2; s011 corresponds to a gradient S ≧ 20%, and S010 corresponds to an output parking brake force F3.

S006, S008, and S011 determine the current gradient from the output value of the longitudinal acceleration sensor inside the vehicle. And selecting a corresponding path according to the gradient value, and determining the level of the parking braking force.

And S007, S009 and S010 correspond to different parking braking forces according to different gradient values, the parking braking forces are calculated theoretically, limit conditions and safety redundancy presetting are considered at the same time, and current characteristics of corresponding actuators are calibrated.

In the hub mode, the logic diagram for operation is shown in FIG. 2. The method comprises the following steps: starting from said S003: judging whether the vehicle is in a static state or not, wherein the specific static judgment can be realized by four-wheel vehicle speed signals; if yes, entering S101; if not, the process goes to S012, the vehicle is dynamic, and is processed by the logic of other modules;

s101: judging whether the engine is in a starting state or not, wherein the judgment can be specifically carried out by an ignition switch signal and an engine rotating speed signal; if yes, entering S102; if not, entering an S005 common mode;

s102: judging whether the gear of the gearbox is neutral or not, specifically judging through an internal gear signal, wherein the condition is that a roller reaction type automobile brake inspection bench (meeting GB/T13564) of vehicle offline detection equipment is used for driving tires to rotate by rolling when in work, so that the detected vehicle cannot have driving force or is in a parking gear; if yes, entering S002; if not, entering an S005 common mode;

s002: judging whether the EPB is in a release state; if yes, entering S103; if not, entering S013, wherein the vehicle is in a parking state, the bench test brake test cannot be executed, and the process is finished directly;

s103: judging whether the wheel speed meets the requirement; and if the EPB is in a release state according to the judgment result of S002, the front wheels of the vehicle do not rotate, and the rear wheels rotate at the specified rotating speed of the offline detection equipment roller reaction type automobile brake inspection bench. Specific wheel speed conditions were as follows: the speed of the front wheel is less than 0.25km/h, and the speed of the rear wheel is more than or equal to 1.9 and less than or equal to 9 km/h; the speed difference of the left wheel and the right wheel is less than 1.8 km/h. If yes, entering S104 hub rotating mode; if not, entering an S005 common mode;

s104: entering a hub rotating mode: when the logic judgment of the front end is yes and the duration reaches 3 seconds or more, the program automatically identifies to enter an S104 hub rotating mode, at the moment, the instrument has corresponding prompt, and the parking braking force output on the flat ground in the mode is larger than that in the common mode;

s105: the EPB switch is pulled up, the parking braking force Fr is output, the parking braking force F1 is output in a flat manner in the normal mode, the clamping frequency is 2 times, the interval time Ts of the step clamping is 0.5s, namely the parking braking force Fr is output in two stages, and the time interval Ts is 0.5 s. The output strategy for Fr is shown in fig. 3 below.

In specific implementation, an electronic parking system ECU is integrated in an ESC module, and software is integrated according to VDA305 and 100 specifications; the static parking is divided into a common mode and a hub rotating mode according to different conditions;

the working logic in the normal mode conforms to fig. 1, and the current gradient is judged according to the output value of the longitudinal acceleration sensor in the vehicle. Selecting a corresponding path according to the gradient value, and determining the level of the parking braking force;

in a common mode, the output parking braking force is divided into 3 sections, the specific force value is calculated by theory, the limit condition and safety redundancy presetting are considered at the same time, and the current characteristic of the corresponding actuator is calibrated.

In the hub rotating mode, the working logic accords with the figure 2, the working condition of the vehicle is intelligently identified through a program, and the parking braking force meeting the national standard requirement is output;

the bench test brake inspection equipment corresponding to the rotary hub mode is a roller reaction type automobile brake inspection bench, and the specific technical requirements meet GB/T13564;

after the hub rotating mode is entered, the EPB switch is pulled up and is not released, the parking braking force is output in two sections according to the logic of figure 3, and the time interval Ts is 0.5 s.

Example one

The electronic parking system ECU is integrated into the ESC module and the software is integrated according to VDA305-100 specifications. The static parking is divided into a common mode and a hub rotating mode according to different conditions;

the working logic in the normal mode conforms to fig. 1, and the current gradient is judged according to the output value of the longitudinal acceleration sensor in the vehicle. Selecting a corresponding path according to the gradient value, and determining the level of the parking braking force; the calculation method is as follows:

when the vehicle is on a slope with a gradient s, the sensor output value a indicates that the gradient s is tan (arcsin (a/9.8)). Positive values are uphill and negative values are downhill.

In a common mode, the output parking braking force is divided into 3 sections, the specific force value is calculated by theory, the limit condition and safety redundancy presetting are considered at the same time, and the current characteristic of the corresponding actuator is calibrated. The full vehicle weight in the example is 2800kg, wheel specification 255/60R 18. The current of the EPB calipers installed on the rear wheel is controlled, the clamping force output by the calipers is controlled, and the brake disc is clamped to implement parking.

Clamping force segmentation	Clamping force value (kN)	Current (A)
			F1	7	4.7
F2	14	8.2
			F3	21	12.5

Working logic in a hub rotating mode accords with the figure 2, vehicle working conditions are intelligently identified through a program, and parking braking force meeting the requirements of the regulations is output;

the test braking inspection equipment corresponding to the hub rotating mode is a roller counter-force type automobile braking inspection table, the speed per hour of a roller is 5km/h when the parking force of the equipment in the example is detected, the equipment takes 10 numbers per second, and then the maximum value within 5 seconds is taken;

after the hub rotating mode is entered, the EPB switch is pulled up and is not released, the parking braking force is output in two sections according to the logic of figure 3, and the time interval Ts is 0.5 s. The parking output force Fr 1-14 kN and Fr 2-21 kN correspond to fig. 3.

The invention is different from the traditional electronic parking braking force which only outputs single maximum parking braking force, estimates according to the current gradient in the common mode, and outputs proper parking braking force by combining with the strategy to meet the parking requirement of the vehicle. When the parking brake is used for parking on a daily frequently-applied small slope, the method for outputting the parking brake force is smaller than the method for outputting only a single maximum parking brake force, so that the parking brake response is faster, the comfort experience is better, and the service life of the parking actuating mechanism can be prolonged.

Meanwhile, when the parking braking force is subjected to bench test inspection on the condition that the vehicle is off-line or annual inspection, the working condition of the vehicle can be intelligently identified through a program, the vehicle automatically enters a hub rotating mode, and the parking braking force meeting the requirements of regulations is output.

The above is an embodiment of the present invention. The embodiments and specific parameters in the embodiments are only for the purpose of clearly illustrating the verification process of the invention and are not intended to limit the scope of the invention, which is defined by the claims, and all equivalent structural changes made by using the contents of the specification and the drawings of the present invention should be covered by the scope of the present invention.