CN118269907A

CN118269907A - Method and device for generating slow-recovery braking force based on passive safety vehicle distance maintenance

Info

Publication number: CN118269907A
Application number: CN202410437039.3A
Authority: CN
Inventors: 许杰; 王群; 孟然; 柴华; 王新乐; 李明; 张建法
Original assignee: Xining Public Transportation Co ltd; Zhongke Huiyan Tianjin Electronics Co ltd
Current assignee: Xining Public Transportation Co ltd; Zhongke Huiyan Tianjin Electronics Co ltd
Filing date: 2024-04-12
Publication date: 2024-07-02

Abstract

The embodiment of the invention discloses a method and a device for generating a buffered braking force based on passive safety distance maintenance, wherein the method comprises the following steps: responding to a braking instruction, calculating braking force and braking receiving force, wherein the braking force is calculated according to a preset safety distance, and the braking receiving force is calculated according to the current relative speed of a target vehicle and an obstacle; and taking the smaller one of the braking force and the braking force as the current force output value. The technical problem of the poor driving safety and travelling comfort that the improper control of braking dynamics leads to in prior art is solved.

Description

Method and device for generating slow-recovery braking force based on passive safety vehicle distance maintenance

Technical Field

The invention relates to the technical field of automatic driving, in particular to a method and a device for generating slow-recovery braking force based on passive safety vehicle distance maintenance.

Background

With the development of ADAS (Advanced Driving Assistance System) advanced driving assistance systems, safety-based assisted driving is becoming a necessary function for improving the safety of vehicles, and in addition, the brake feel becomes one of the problems that the ADAS system has to consider on the premise of pursuing driving safety. In a passive safety distance keeping system, the system monitors the safety distance between the vehicle and a front vehicle in real time on the premise of ensuring the first driving priority of a driver, when danger occurs, the system is passively triggered, and further braking control of the safety distance keeping is performed, unlike an ACC self-adaptive cruise system, the passive safety distance keeping function is triggered by the dangerous following distance on the premise of ensuring the high driving priority of the driver, and further the system is passively triggered, because the passive system cannot brake in advance to keep the safety speed and the distance at an earlier time, the average braking force is large, the problem of the feeling of braking is necessarily considered in the braking control, particularly the driving behavior of the driver cannot be excessively interfered on the premise of ensuring the priority of the driving control, the braking time and the force control are particularly important, and the safety driving and the comfort of the driver are seriously affected once the driver receives the braking to cause the inertia to generate obvious forward leaning or backward leaning of the body.

Disclosure of Invention

Therefore, the embodiment of the invention provides a method and a device for generating a slow-release braking force based on passive safety vehicle distance maintenance, which aim to at least partially solve the technical problems of poor driving safety and comfort caused by improper braking force control in the prior art.

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

A method for generating a buffered braking force based on passive safe distance maintenance, the method comprising:

responding to a braking instruction, calculating braking force and braking receiving force, wherein the braking force is calculated according to a preset safety distance, and the braking receiving force is calculated according to the current relative speed of a target vehicle and an obstacle;

And taking the smaller one of the braking force and the braking force as the current force output value.

In some embodiments, calculating the braking force according to a preset safety distance specifically includes:

acquiring the current distance between a target vehicle and an obstacle;

Setting the braking force to be 0 under the condition that the current vehicle distance is larger than a preset safe vehicle distance;

under the condition that the current vehicle distance is smaller than the safe vehicle distance, calculating an ideal safe vehicle speed V1 of the target vehicle corresponding to the current vehicle distance;

The calculation method of V1 is as follows:

The preset HMWT is t, the actual vehicle distance at the current moment is d, and the ideal safe vehicle speed is:

V1 = d/t;

And calculating a difference value V2 between the current vehicle speed and V1, and obtaining a target braking force A_1 positively related to V2 by taking V2 as a parameter, wherein A_1=F (V2).

In some embodiments, the braking force is calculated according to the current relative vehicle speed of the target vehicle and the obstacle, and specifically includes:

the braking force A_2 is a value positively correlated with the current relative vehicle speed and is adjusted through a preset parameter T2;

Wherein, a_2=t2×rv, rv is the relative speed of two vehicles and is greater than zero, T2 is a preset braking force coefficient [ 0.1-10 ], and when the relative speed is less than zero, no braking action is performed, and the braking force is 0.

In some embodiments, in response to a braking command, further comprising:

Determining a braking interval according to the time sequence, and taking a preset duration in the braking interval as a target interval;

and calculating the braking force in the target interval.

In some embodiments, the target interval is a time domain interval in which the target braking force a_1 is greater than zero and the relative vehicle speed is greater than zero.

In some embodiments, obtaining the current relative vehicle speed of the target vehicle and the obstacle further comprises:

and increasing an adjustment coefficient for the current relative speed.

In some embodiments, the adjustment coefficient is B, and the value range of B is [ 1-2.5 ], and the specific adjustment method is as follows:

when Rv is 2 or less, b=1.0;

when Rv is greater than 2 and less than 5, b=rv 0.5;

When Rv is 5 or more, b=2.5;

The braking force of the adjusting coefficient B is increased to be as follows: a2=t2 (rv×b).

The invention also provides a device for generating the buffered braking force based on the passive safety vehicle distance maintenance, which comprises the following steps:

the data acquisition unit is used for responding to a braking instruction, calculating braking force and braking force, wherein the braking force is calculated according to a preset safety distance, and the braking force is calculated according to the current relative speed of the target vehicle and the obstacle;

And the result generating unit is used for taking the smaller one of the braking force and the braking force as the current force output value.

The invention also provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the method as described above when executing the program.

The invention also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method as described above.

According to the method for generating the slow-down braking force based on the passive safety distance maintenance, the braking force and the braking force are calculated according to the preset safety distance by responding to the braking instruction, and the braking force is calculated according to the current relative speed of the target vehicle and the obstacle; and taking the smaller one of the braking force and the braking force as the current force output value. The method ensures that no pause is generated when two calculation methods are switched, because the two calculation methods have identical force values at the force switching point, and a discrete system is considered, the two calculation methods are only poor in the normal range of force curve change, no pause is generated, the two calculation methods are fused, the aim of slowly recovering the braking force is achieved by switching the braking end into recovering the braking force, and the smooth force switching is ensured by automatically calculating the switching point, so that the technical problem of poor driving safety and comfort caused by improper control of the braking force in the prior art is solved.

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. It will be apparent to those of ordinary skill in the art that the drawings in the following description are exemplary only and that other implementations can be obtained from the extensions of the drawings provided without inventive effort.

The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the ambit of the technical disclosure.

FIG. 1 is a schematic flow chart of a method for generating a buffered braking force based on passive safe distance maintenance according to the present invention;

FIG. 2 is a second flow chart of the method for generating a braking force based on passive safety distance maintenance according to the present invention;

FIG. 3 is a graph of the results of calculating braking force by distance in a specific scenario;

FIG. 4 is a graph of the results of calculating the braking effort per vehicle speed in one specific scenario;

FIG. 5 is a graph of the fusion result of braking force and braking force in a specific scenario;

FIG. 6 is a graph showing the results of braking force after increasing the adjustment coefficient in a specific scenario;

FIG. 7 is a graph showing the result of delayed braking after increasing the adjustment coefficient in one specific scenario;

FIG. 8 is a graph showing the result of early braking after increasing the adjustment coefficient in one specific scenario;

FIG. 9 is a resulting simulation of one embodiment;

FIG. 10 is a block diagram of a device for generating a braking force based on passive safety distance maintenance according to the present invention;

Fig. 11 is a schematic diagram of an entity structure of an electronic device according to the present invention.

Detailed Description

Other advantages and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, by way of illustration, is to be read in connection with certain specific embodiments, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, fig. 1 is a schematic flow chart of a method for generating a buffered braking force based on passive safe distance maintenance according to the present invention.

In a specific embodiment, the method for generating the slow-release braking force based on passive safety vehicle distance maintenance provided by the invention comprises the following steps:

S110: responding to a braking instruction, calculating braking force and braking receiving force, wherein the braking force is calculated according to a preset safety distance, and the braking receiving force is calculated according to the current relative speed of a target vehicle and an obstacle;

S120: and taking the smaller one of the braking force and the braking force as the current force output value.

In principle, the whole workflow of passive safety distance maintenance is shown in fig. 2, when the sensing decision module determines that the current state needs to perform braking calculation, the braking calculation module is started to be called, and the braking calculation module performs 3 operations:

1. Judging whether to start braking, namely: calculating a brake starting point;

2. once braking is started, a braking force calculation module is entered;

3. Meanwhile, the system monitors in real time whether braking is needed to be finished, and if braking is needed to be finished, the braking force calculation output target deceleration is completely cleared;

In the above-mentioned process, in order to ensure the feel of the braking body, when the relative speed of two vehicles is 0, the braking is required to be finished, and the goal when the system starts to brake is to keep the safe distance between vehicles, the triggering condition is distance, the ending condition is relative speed, and the reference indexes of different modes are required to be perfectly and seamlessly fused into the braking force control.

acquiring the current distance between a target vehicle and an obstacle;

Under the condition that the current vehicle distance is smaller than the safe vehicle distance, calculating an ideal safe vehicle speed V1 of the target vehicle corresponding to the current vehicle distance; the calculation method of V1 comprises the following steps: the preset HMWT is t, the actual vehicle distance at the current moment is d, and the ideal safe vehicle speed is: v1=d/t;

Calculating a difference V2 between the current vehicle speed and V1, and obtaining a target braking force A1 positively related to V2 by taking V2 as a parameter, wherein A_1=F (V2)

Specifically, the method for calculating the braking force according to the preset safety distance comprises the following steps:

Step1, judging whether the current vehicle distance is smaller than a preset safe vehicle distance or not;

step2, if the current vehicle distance is greater than the safe vehicle distance, the braking force is 0;

Step3, if the current vehicle distance is smaller than the safe vehicle distance, entering Step4;

step4, calculating HMWT (HEAD WAY WARNING TIME, headway) as a preset value, and an ideal safe vehicle speed V1 corresponding to the current vehicle distance;

Step5, calculating a difference V2 between the current vehicle speed and V1 calculated in Step4, for example, the value range of V2 is 0-V1;

Step6, taking V2 calculated in Step5 as a parameter to obtain a target braking force A1 positively related to V2, wherein the range of the A1 is 。

the braking force A2 is a value positively correlated with the current relative vehicle speed and is adjusted through a preset parameter T2;

Wherein, a_2=t2 is Rv, rv is the relative speed of two vehicles, T2 is a preset braking force coefficient, the value range is 0.1-10, when the relative speed is less than zero, no braking action is performed, and the braking force is 0; it should be appreciated that when the desired safe vehicle speed is greater than the lead vehicle speed, the relative vehicle speed is greater than zero and vice versa.

In some embodiments, in response to a braking command, further comprising:

and calculating the braking force in the target interval.

In some embodiments, the target interval is a time domain interval in which the target braking force a_1 is greater than zero and the relative vehicle speed is greater than zero, and it should be understood that the interval is a dynamic interval and is comprehensively influenced by factors such as the actual vehicle speed, the relative vehicle speed, the running state of the front vehicle, the corresponding delay of the self-vehicle brake and the like.

An adjustment factor is added to the current relative speed, in particular, an adjustment factor is required for all scenes, which determines the early and late of the braking opportunity, and may be a dynamic adjustment factor related to the system parameters.

In some embodiments, the adjustment coefficient is B, and the value range of B is 1-2.5; the larger the adjustment coefficient B is, the later the braking time is, and the stronger the body feeling is; the smaller the adjustment coefficient B is, the earlier the braking time is, and the softer the body feeling is.

In order to facilitate understanding, a specific use scenario is taken as an example to briefly describe the implementation process of the method for generating the buffered braking force provided by the invention.

Through analysis, the braking and the receiving braking can be regarded as two different force calculation requirements, so that the key of the problem is converted into the problem of smooth and continuous switching of two calculation methods during force output, and the following solution is provided for the problem:

as shown in fig. 3, the braking force a_1 is normally calculated according to the safety distance without considering the problem of taking into account braking;

As shown in fig. 4, according to the relative vehicle speed, the braking force a_2 is calculated, and only the last segment is considered;

comparing the two force calculation results in real time, and taking the smaller one as output A=min (A_1, A_2);

the thick solid line in fig. 5 represents the final force output curve.

The method ensures that no pause is generated when the two calculation methods are switched, because the strength of the two calculation methods is consistent at the strength switching point, and the discrete system is considered, the difference of the two calculation methods is only in the normal range of the change of the strength curve, and the pause is not generated in actual measurement. In addition, the above method effectively merges two dynamics calculation methods, and in practical application, the two dynamics calculation methods can be adjusted, for example: when the force is calculated according to the relative speed, the relative speed can be scaled and adjusted, and the time for receiving the brake is adjusted by adding an adjusting coefficient, as shown in fig. 6-8.

The method combines two force control methods, achieves the aim of braking slowly by switching the brake end into braking force, ensures smooth force switching by automatically calculating the switching point, and has equal force values at the switching point as shown in the simulation result in fig. 9.

In the specific embodiment, according to the method for generating the slow-release braking force based on the passive safety distance maintenance, the braking force and the braking force are calculated according to the preset safety distance by responding to the braking instruction, and the braking force is calculated according to the current relative speed of the target vehicle and the obstacle; and taking the smaller one of the braking force and the braking force as the current force output value. The method ensures that no pause is generated when two calculation methods are switched, because the two calculation methods have identical force values at the force switching point, and a discrete system is considered, the two calculation methods are only poor in the normal range of force curve change, no pause is generated, the two calculation methods are fused, the aim of slowly recovering the braking force is achieved by switching the braking end into recovering the braking force, and the smooth force switching is ensured by automatically calculating the switching point, so that the technical problem of poor driving safety and comfort caused by improper control of the braking force in the prior art is solved.

The invention also provides a device for generating the buffered braking force based on the passive safety vehicle distance maintenance, as shown in fig. 10, the device comprises:

A data obtaining unit 1010, configured to calculate a braking force and a braking force in response to a braking instruction, where the braking force is calculated according to a preset safety distance, and the braking force is calculated according to a current relative vehicle speed of the target vehicle and the obstacle;

And a result generating unit 1020 for taking the smaller one of the braking force and the braking force as the current force output value.

acquiring the current distance between a target vehicle and an obstacle;

and calculating a difference value V2 between the current vehicle speed and V1, and obtaining a target braking force A_1 positively related to V2 by taking V2 as a parameter.

wherein, a_2=t2 is Rv, rv is the relative speed of two vehicles, T2 is a preset braking force coefficient, when the relative speed is less than zero, no braking action is performed, and the braking force is 0.

In some embodiments, in response to a braking command, further comprising:

and calculating the braking force in the target interval.

In some embodiments, the target interval is a time domain interval in which the target braking force a_1 is greater than zero and the relative vehicle speed is greater than zero is less than a_1 and greater than a_2.

and increasing an adjustment coefficient for the current relative speed.

In some embodiments, the adjustment coefficient is B, and the value range of B is 1 to 2.5.

In the specific embodiment, the slow-release braking force generating device based on passive safety vehicle distance maintenance calculates braking force and braking force according to a preset safety distance by responding to a braking instruction, wherein the braking force is calculated according to the current relative vehicle speed of a target vehicle and an obstacle; and taking the smaller one of the braking force and the braking force as the current force output value. The device ensures that no pause is generated when two calculation methods are switched, because the two calculation methods are in the position of a force switching point, the two calculation methods have the same force, and a discrete system is considered, the two calculation methods are only poor in the normal range of force curve change, no pause is generated, the two calculation methods are fused, the purpose of slowly recovering the braking force is achieved by switching the brake tail end into the braking force recovering mode, the smooth force switching is ensured by automatically calculating the switching point, and the technical problem of poor driving safety and comfort caused by improper control of the braking force in the prior art is solved.

Fig. 11 illustrates a physical structure diagram of an electronic device, as shown in fig. 11, which may include: processor 1110, communication interface Communications Interface 1120, memory 1130, and communication bus 1140, wherein processor 1110, communication interface 1120, memory 1130 perform communication with each other through communication bus 1140. Processor 1110 may call logic instructions in memory 1130 to perform the methods described above.

Further, the logic instructions in the memory 1130 described above may be implemented in the form of software functional units and sold or used as a stand-alone product, stored on a computer-readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

In another aspect, the present invention also provides a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, are capable of performing the methods described above.

In yet another aspect, the present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, is implemented to perform the above methods.

The apparatus embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.

Those skilled in the art will appreciate that in one or more of the examples described above, the functions described in the present invention may be implemented in a combination of hardware and software. When the software is applied, the corresponding functions may be stored in a computer-readable medium or transmitted as one or more instructions or code on the computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The foregoing detailed description of the invention has been presented for purposes of illustration and description, and it should be understood that the foregoing is by way of illustration and description only, and is not intended to limit the scope of the invention.

Claims

1. A method for generating a buffered braking force based on passive safety distance maintenance is characterized by comprising the following steps:

2. The method for generating the buffered braking force based on the passive safety distance maintenance according to claim 1, wherein the braking force is calculated according to a preset safety distance, specifically comprising:

acquiring the current distance between a target vehicle and an obstacle;

3. The method for generating the slow-release braking force based on the passive safety distance maintenance according to claim 1, wherein the slow-release braking force is calculated according to the current relative vehicle speed of the target vehicle and the obstacle, and specifically comprises the following steps:

4. The method of generating a buffered braking effort based on passive safe distance maintenance of claim 3, further comprising, in response to a braking command:

and calculating the braking force in the target interval.

5. The method for generating the buffered braking force based on the passive safety distance maintenance according to claim 4, wherein the target interval is a time interval in which the target braking force a_1 is greater than zero and the relative vehicle speed is greater than zero.

6. The method for generating a braking effort based on passive safe distance maintenance according to claim 5, wherein the step of obtaining the current relative vehicle speed of the target vehicle and the obstacle, further comprises:

and increasing an adjustment coefficient for the current relative speed.

7. The method for generating the slow-release braking force based on the passive safety distance maintenance according to claim 6, wherein the adjustment coefficient is B, and the value range of B is [ 1-2.5 ].

8. A device for generating a buffered braking force based on passive safe distance maintenance, the device comprising:

9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any one of claims 1 to 7 when the program is executed by the processor.

10. A non-transitory computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method according to any one of claims 1 to 7.