CN113978462B

CN113978462B - Main target screening method, track planning method and system of self-adaptive cruise system

Info

Publication number: CN113978462B
Application number: CN202111338108.8A
Authority: CN
Inventors: 陈禹行; 张志华
Original assignee: Beijing Yihang Yuanzhi Technology Co Ltd
Current assignee: Beijing Yihang Yuanzhi Technology Co Ltd
Priority date: 2021-11-12
Filing date: 2021-11-12
Publication date: 2024-07-02
Anticipated expiration: 2041-11-12
Also published as: CN113978462A

Abstract

The invention relates to a main target screening method, a track planning method and a system of a self-adaptive cruise system, wherein the track planning method solves the optimal longitudinal track by constructing longitudinal track functions under different working modes, and the longitudinal track is solved by the functions, so that constraint conditions and optimization targets under different working modes are considered. In addition, due to the technical scheme provided by the invention, the motion state of the main target and the cruising parameters set by the user can be obtained, and the working mode of the current vehicle is judged according to the motion state, so that the automatic switching of the working mode of the current vehicle is realized, and the problems of low system active cruising capability and poor user experience caused by frequent cancellation and setting of cruising control of a driver in the prior art are solved.

Description

Main target screening method, track planning method and system of self-adaptive cruise system

Technical Field

The invention relates to the technical field of intelligent driving, in particular to a main target screening method, a track planning method and a track planning system of a self-adaptive cruise system.

Background

As the degree of automotive intelligentization increases, adaptive cruise systems (Adaptive Cruise Control, ACC) have gradually become one of the more popular configurations for passenger vehicles.

The adaptive cruise system is an intelligent automatic control system that has evolved based on the already existing cruise control technology. During running of the vehicle, a distance sensor (radar) mounted at the front of the vehicle continuously scans the road ahead of the vehicle, while a wheel speed sensor collects a vehicle speed signal.

When the distance between the ACC control unit and the front vehicle is too small, the ACC control unit can make the wheels brake properly through coordination action with a braking anti-lock system and an engine control system, and reduce the output power of the engine so as to keep a safe distance between the vehicle and the front vehicle all the time.

Adaptive cruise control allows a vehicle cruise control system to adapt to traffic conditions by adjusting speed. A radar installed in front of the vehicle is used to detect whether a slower vehicle is present on the own forward road. If there is a slower vehicle, the ACC system will reduce the speed and control the clearance or time gap with the vehicle in front. If the system detects that the preceding vehicle is not on the road of the vehicle, the speed of the vehicle is accelerated to return to the speed set before. This operation achieves autonomous deceleration or acceleration without driver intervention. The main way the ACC controls the vehicle speed is through engine throttle control and proper braking.

The ACC control unit can judge the road condition according to the moving speed of an object approaching the vehicle through the feedback signal of the vehicle distance sensor and control the running state of the vehicle; the ACC control unit may decide whether to perform cruise control by feedback-type accelerator pedal-perceived force exerted on the pedal by the driver, so as to alleviate fatigue of the driver. The adaptive cruise system can help a driver to remove feet from pedals, and fatigue caused by long-distance driving can be greatly reduced as long as the driver focuses on the steering wheel.

The first step of the adaptive cruise system is ACC main target screening, so that the establishment of an accurate and effective target recognition algorithm is the guarantee of effective work of the adaptive cruise system.

The vehicle radar is a sensor which is the most important and special in the self-adaptive cruise system, and directly relates to the performance of the whole system. The 77GHz millimeter wave radar is recognized as a better scheme for solving the detection problem of the vehicle-mounted radar due to good real-time performance, high precision, reliable operation, insusceptibility to environmental factors such as weather and the like. According to the related protocol, after radar information is acquired, the radar information needs to be further processed, and accurate identification and tracking of motion information of a main target vehicle are a precondition for realizing ACC. The conventional ACC system generally performs screening on the target vehicle by using a lateral distance threshold to perform the same lane distinction, and then selecting an effective target according to the nearest rule of the same lane. However, practice shows that under complex road conditions, such as curve conditions and complex urban road conditions, the screening accuracy of a main target vehicle (hereinafter referred to as a main target for short) in the prior art is not high, so that the control accuracy of the adaptive cruise system is not high, and the driving safety is poor.

After ACC main target screening is completed, the screened main target needs to be tracked, and in the tracking process of the main target, the problem of track planning of vehicles is involved.

The related technology provides a track planning method for lane centering auxiliary self-adaptive cruising, which mainly comprises the following steps: 1) The camera acquires a lane line equation and generates a vehicle region of interest; 2) Combining the interested area and millimeter wave radar information, and selecting the obstacle with the largest cost as a target obstacle; 3) The longitudinal speed and longitudinal trajectory of the own vehicle are planned in combination with the vehicle state information of the own vehicle. The method solves the problems of longitudinal speed and track planning with shielding and without positioning information, but directly calculates the target acceleration according to the relative speed and the relative distance, and reduces the comfort degree of a driver.

The related art also provides a wireless communication-based near intersection scattered cooperative self-adaptive cruise control method, which mainly comprises the following steps: 1) Establishing a longitudinal vehicle motion model and calculating tracking errors; 2) Reducing tracking errors based on a particle swarm algorithm; 3) Determining an optimal track and distributing road space by adopting a track planning and space management method; 4) And (5) recombining the motorcade by considering performance characteristics such as vehicle safety, comfort and the like. The method considers traffic efficiency and vehicle performance limitation to control the motorcade, but can be realized only based on the V2X technology, and the particle swarm algorithm is easy to fall into local optimum, so that the solving quality is difficult to guarantee.

The related art also provides a self-adaptive cruise control method and a system based on the prediction of the side vehicle driving path, which mainly comprise the following steps: 1) The vehicle body sensor collects the motion parameters of the vehicle and predicts the motion trail of the vehicle in a period of time; 2) The sensing sensor collects information of the side vehicle and predicts the motion trail of the side vehicle in the same time period; 3) And judging whether the two vehicles interfere according to the prediction results of the vehicle and the side vehicle, and executing the self-adaptive cruise control. The method considers the prediction of the driving paths of the self-vehicle and the side vehicle, but the speed planning is simpler, and the continuity of the acceleration change cannot be ensured.

The related art also proposes an adaptive cruise method, mainly comprising: 1) Setting a cruising mode, collecting a vehicle state by a sensor, and calculating the curvature of a road; 2) Setting a cruising speed or a tracking distance, and deciding the control quantity acceleration to be executed by an execution unit; 3) An obstacle ahead of the same lane is identified, and a control target is reset according to the speed of the obstacle. The method utilizes the existing ESP sensor information, saves cost, but the cruise mode and the tracking mode are preset, and can not solve the problems that a driver frequently cancels and sets cruise control.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for screening a main target of an adaptive cruise system, a method for planning a trajectory, and a system thereof, so as to solve the problems of low accuracy of screening the main target, low control precision of the adaptive cruise system, and poor driving safety in the prior art; and/or, the path planning of the self-adaptive cruise system in the prior art is simple, the continuity of acceleration change cannot be ensured, and the problems of unsmooth control and influence on driving experience are caused.

According to a first aspect of an embodiment of the present invention, there is provided a main target screening method of an adaptive cruise system, including:

determining all vehicles running in front of the current vehicle at the current moment as target vehicles;

For any target vehicle, predicting the running track of the current vehicle according to the position of the target vehicle, and calculating the relative distance between the current vehicle and the target vehicle according to the running track of the current vehicle;

predicting the driving dynamics of the target vehicle according to the current vehicle operation information, the target vehicle operation information, the relative distance and the change rate of the relative distance;

Screening main targets from all target vehicles according to the driving dynamics of all target vehicles;

the driving dynamics of the target vehicle at least comprise: the method comprises the steps of determining whether a target vehicle is in a lane and the lane change intention of the target vehicle, and judging whether collision risk exists between the target vehicle and the current vehicle.

According to a second aspect of an embodiment of the present invention, there is provided a trajectory planning method of an adaptive cruise system, including:

The main target screening method of the self-adaptive cruise system;

Further comprises:

Acquiring motion information of a main target and cruising parameters set by a user;

Determining the safe driving distance of the current vehicle according to the motion information and the cruising parameters;

Judging the working mode of the current vehicle according to the safe driving distance;

Constructing longitudinal track functions in different working modes, and solving coefficients of the longitudinal track functions according to constraint conditions and optimization targets in the different working modes to obtain an optimal longitudinal track;

judging whether the optimal longitudinal track meets the vehicle motion limit constraint condition or not, and taking the optimal longitudinal track meeting the vehicle motion limit constraint condition as a current vehicle longitudinal track planning result.

According to a third aspect of an embodiment of the present invention, there is provided a primary object screening system of an adaptive cruise system, comprising:

The determining module is used for determining all vehicles running in front of the current vehicle at the current moment as target vehicles;

The calculation module is used for predicting the running track of the current vehicle according to the position of any target vehicle and calculating the relative distance between the current vehicle and the target vehicle according to the running track of the current vehicle;

the prediction module is used for predicting the driving dynamics of the target vehicle according to the running information of the current vehicle, the running information of the target vehicle and the relative distance and the change rate of the relative distance;

The screening module is used for screening main targets from all target vehicles according to the driving dynamics of all target vehicles;

According to a fourth aspect of an embodiment of the present invention, there is provided a trajectory planning system of an adaptive cruise system, comprising:

the above-mentioned main target screening system further includes:

The acquisition module is used for acquiring the motion information of the main target and the cruising parameters set by the user;

the determining module is used for determining the safe driving distance of the current vehicle according to the motion information and the cruising parameters;

the judging module is used for judging the working mode of the current vehicle according to the safe driving distance;

The solving module is used for constructing longitudinal track functions in different working modes, and solving coefficients of the longitudinal track functions according to constraint conditions and optimization targets in the different working modes to obtain an optimal longitudinal track;

The judging module is further used for judging whether the optimal longitudinal track meets the vehicle motion limit constraint condition or not, and taking the optimal longitudinal track meeting the vehicle motion limit constraint condition as a current vehicle longitudinal track planning result.

According to a fifth aspect of an embodiment of the present invention, there is provided an electronic apparatus including:

A processor and a memory, wherein program instructions are stored in the memory;

The processor is used for executing the program instructions stored in the memory and executing the main target screening method of the adaptive cruise system; and/or executing the track planning method of the adaptive cruise system.

According to a sixth aspect of embodiments of the present invention, there is provided a computer-readable storage medium having stored thereon an erasable computer program;

When the computer program runs on the computer equipment, the computer equipment is caused to execute the main target screening method of the adaptive cruise system; and/or executing the track planning method of the adaptive cruise system.

The technical scheme provided by the embodiment of the invention can comprise the following beneficial effects:

for any target vehicle, the relative distance between the current vehicle and the target vehicle is calculated by predicting the running track of the current vehicle, the running information of the target vehicle and the running dynamic of the target vehicle are predicted according to the running information of the current vehicle, the running information of the relative distance and the change rate of the relative distance, and the main targets are screened out from all target vehicles according to the running dynamic of all target vehicles.

By constructing longitudinal track functions under different working modes, solving to obtain an optimal longitudinal track, and because the longitudinal track is solved through the functions, constraint conditions and optimization targets under different working modes are considered, compared with the prior art that target acceleration is obtained by directly calculating based on the speed and the relative distance of a main target, the technical scheme provided by the invention can realize smooth control of vehicle acceleration, improve comfort of self-adaptive cruising and improve driving safety.

Further, due to the technical scheme provided by the invention, the motion state of the main target and the cruising parameters set by the user can be obtained, the safe driving distance of the current vehicle is determined according to the motion state and the cruising parameters, and the working mode of the current vehicle is judged according to the safe driving distance, so that the automatic switching of the working mode of the current vehicle is realized, and the problems of low system active cruising capability and poor user experience caused by the need of selecting the working mode by a driver and frequently taking out and setting cruising control by the driver in the prior art are solved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a flowchart illustrating a primary target screening method for an adaptive cruise system according to an exemplary embodiment;

FIG. 2 is a schematic diagram illustrating calculating a relative distance of a current vehicle to a target vehicle, according to an example embodiment;

FIG. 3 is a schematic flow diagram illustrating predicting a lane in which a target vehicle is located, according to an example embodiment;

FIG. 4 is a schematic diagram of a screening master target shown according to an example embodiment;

FIG. 5 is a schematic block diagram of a primary target screening system of an adaptive cruise system, according to an exemplary embodiment;

FIG. 6 is a flowchart illustrating a method of trajectory planning for an adaptive cruise system according to an exemplary embodiment;

FIG. 7 is a schematic block diagram of a trajectory planning system of an adaptive cruise system, according to an exemplary embodiment.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the invention. Rather, they are merely examples of apparatus and methods consistent with aspects of the invention as detailed in the accompanying claims.

Example 1

FIG. 1 is a flow chart illustrating a method of primary target screening for an adaptive cruise system, according to an exemplary embodiment, as shown in FIG. 1, the method comprising:

step S11, determining all vehicles running in front of the current vehicle at the current moment as target vehicles;

Step S12, predicting the running track of the current vehicle for any target vehicle according to the position of the target vehicle, and calculating the relative distance between the current vehicle and the target vehicle according to the running track of the current vehicle;

Step S13, predicting the driving dynamics of the target vehicle according to the running information of the current vehicle, the running information of the target vehicle and the relative distance and the change rate of the relative distance;

Step S14, screening main targets from all target vehicles according to the driving dynamics of all target vehicles;

It should be noted that, application scenarios applicable to the technical solution provided in this embodiment include, but are not limited to: automatic driving, assisted driving, etc. of the vehicle. The technical scheme provided by the embodiment can be loaded in a central control system of a current vehicle for use in actual use, and can also be loaded in electronic equipment for use; the electronic device includes, but is not limited to: vehicle-mounted computer and external computer equipment.

The "master target" refers to a "master target vehicle".

A millimeter wave radar is installed at a middle position of a front intake grill of a current vehicle for ranging.

In step S11, "all vehicles traveling ahead of the current vehicle are determined as target vehicles" is because:

Only all vehicles running in front of the current vehicle are likely to interfere with the running in the autonomous circulation mode of the current vehicle, so the technical scheme provided by the embodiment only needs to install the millimeter wave radar in the middle position of the front air inlet grille of the current vehicle, and therefore only all vehicles in front of the current vehicle are determined to be target vehicles.

In specific practice, in step S12, "for any target vehicle, a travel track of a current vehicle is predicted according to a position of the target vehicle, and a relative distance between the current vehicle and the target vehicle is calculated according to the predicted travel track of the current vehicle", including:

1. calculating the curvature radius of the lane where the current vehicle is located:

According to the formula The curvature radius of the lane where the current vehicle is calculated, wherein K _current is the curvature of the lane where the current vehicle is, R is the curvature radius, yaw_Rate is the Yaw Rate measured by a Yaw Rate sensor of the current vehicle, v _r is the speed of the current vehicle, and the Yaw Rate and the speed CAN be directly obtained from the CAN bus of the current vehicle, so that no additional sensor is needed.

2. Judging whether the lane where the current vehicle is located is a curve or not according to the curvature radius:

if the curvature radius R is infinite, the lane where the current vehicle is located can be judged to be a straight road, otherwise, the lane where the current vehicle is located is judged to be a curve.

3. If the lane where the current vehicle is located is a curve, predicting the running track of the current vehicle as follows: and circumferentially driving the vehicle to the curvature radius of the target vehicle at the constant speed within a preset time period:

Referring to fig. 2, at time T, the current vehicle is located at point a on lane 2, the target vehicle is located at point C on lane 1, assuming that during the duration of Δt, the current vehicle will be moving circumferentially at a constant speed v _r at a constant radius of curvature R, at time t+Δt, the current vehicle will be located at point a 'on lane 2, and O, A', C are located on the same radius of curvature. Wherein A, A' and C are the rear axle center of the vehicle, and O is the steering center of the vehicle.

4. The method comprises the steps that a connecting line AC between the rear axle center A of a current vehicle and the rear axle center C of a target vehicle at the current moment and the running direction of the current vehicle at the current moment are recorded as a first included angle theta;

The included angle between the connecting line AA 'of the rear axle center A' of the current vehicle and the rear axle center A of the current vehicle at the current moment after the preset time length and the running direction of the current vehicle at the current moment is recorded as a second included angle

According to the curvature radius R, the first included angle theta and the second included angleCalculating the relative distance between the current vehicle and the target vehicle; the relative distance includes: a relative transverse distance Dy, and a relative longitudinal distance Dx.

Referring to fig. 2, considering that the millimeter wave radar is installed at a position, and that the detection distance of the millimeter wave radar is far greater than the longitudinal length of the current vehicle, it can be approximately considered that the distance L _AC of the rear axle center of the current vehicle from the rear axle center of the target vehicle minus the longitudinal length L of the current vehicle is the relative distance ρ detected by the millimeter wave radar, i.e., L _AC =ρ+l.

Referring to fig. 2, the acute angle between the line segment AC and the current vehicle running direction is θ, that is, the relative phase angle of the millimeter wave radar output is a known quantity; the acute angle between the line segment AA' and the current vehicle driving direction is Dy is the relative lateral distance between the current vehicle and the target vehicle and is half of the corresponding central angleThe relative longitudinal distance of the current vehicle and the target vehicle is denoted Dx.

Referring to fig. 2, it can be obtained according to the geometric relationship and sine theorem:

Wherein,

Solving to obtainThe values are:

Then the first time period of the first time period,

When the vehicle is traveling on a straight road, the road curvature radius R can be regarded as infinity, as can be seen from fig. 2Dy＝(ρ+L)*sin(θ)，Dx＝(ρ+L)*cos(θ)。

In specific practice, the step S13 of predicting the driving dynamics of the target vehicle according to the current vehicle operation information, the target vehicle operation information, and the relative distance and the change rate of the relative distance includes:

1. Predicting the lane where the target vehicle is located according to the relative lateral distance, including:

if the current vehicle is in the lane of the vehicle, the driving direction of the current vehicle is taken as a visual angle reference, the left adjacent lane of the vehicle is defined as an outer adjacent lane, the right adjacent lane of the vehicle is defined as an inner adjacent lane (the current vehicle is in the lane, and the target vehicles out of the three lane ranges of the outer adjacent lane and the inner adjacent lane are temporarily out of consideration);

if the relative transverse distance is within the range of one half of the width of the lane on the left side and the right side of the center line of the vehicle lane, judging that the target vehicle is on the vehicle lane; and/or the number of the groups of groups,

If the relative transverse distance is within the left half lane width and the left three-half lane width of the center line of the own lane, judging that the target vehicle is on the outer adjacent lane; and/or the number of the groups of groups,

And if the relative transverse distance is within the range of one-half lane width on the right side and three-half lane width on the right side of the center line of the self-vehicle lane, judging that the target vehicle is on the inner adjacent lane.

According to the national highway technical standard, the width of the urban road lane is between 3.25 and 3.75m, and in specific practice, the lane width l _wide =3.5 m can be taken. Referring to fig. 3, predicting the lane in which the target vehicle is located according to the following rule includes:

if the relative transverse distance Dy epsilon [ -l _wide/2,lw_ide/2 ], judging that the target vehicle is on the own vehicle lane;

if the relative transverse distance Dy epsilon (l _wide/2,3*l_wide/2), judging that the target vehicle is on the outer adjacent lane;

If the relative transverse distance Dy is epsilon (-3*l _wide/2,-l_wide/2), judging that the target vehicle is on the inner adjacent lane;

if the relative transverse distance Dy E (-, -a ratio of 3*l _widde/2]||[3*l_wide/2, in +++). And judging that the target vehicle is out of the three lane ranges of the lane where the current vehicle is and the lane which is adjacent to the outside and the lane which is adjacent to the inside, and temporarily disregarding the target vehicle.

2. Predicting the lane change intention of the target vehicle according to the lane in which the target vehicle is located, the size of the relative transverse distance and the change rate of the relative transverse distance, wherein the lane change intention comprises the following steps:

(1) If the target vehicle is on the self-vehicle lane, displaying a left boundary line close to the self-vehicle lane relative to the size of the transverse distance, and judging that the target vehicle has a lane changing intention of driving to an outer lane when the change rate of the transverse distance is positive;

That is, if the target vehicle is on the own lane, and Judging that the target vehicle has a lane changing intention of driving towards an outer lane; where ε is the distance that the target vehicle deviates from the own lane centerline, in specific practice ε=l _wide/2 may be set.

(2) If the target vehicle is on the self-vehicle lane, displaying a right boundary line close to the self-vehicle lane relative to the size of the transverse distance, and judging that the target vehicle has a lane changing intention of approaching the lane to the inner side if the change rate of the transverse distance is negative;

That is, if the target vehicle is on the own lane, and And judging that the target vehicle has a lane changing intention of approaching a lane towards the inner side.

(3) If the target vehicle is on the outer adjacent lane, the relative transverse distance is displayed near the left boundary of the self-vehicle lane, and the change rate of the relative transverse distance is negative, judging that the target vehicle has a lane changing intention for driving the self-vehicle lane;

that is, if the target vehicle is on an outside lane, and And judging that the target vehicle has a lane changing intention for traveling in a self-vehicle lane.

(4) If the target vehicle approaches the lane on the inner side, displaying a right boundary line close to the lane of the vehicle by the size of the relative transverse distance, and judging that the target vehicle has a lane changing intention for traveling in the lane of the vehicle by the change rate of the relative transverse distance being positive;

That is, if the target vehicle is on an inner adjacent lane, and And judging that the target vehicle has a lane changing intention for traveling in a self-vehicle lane.

3. Predicting whether the target vehicle and the current vehicle have collision risk according to the running information of the current vehicle and the running information of the target vehicle, comprising:

predicting the length TTC for collision when the current vehicle and the target vehicle run at the current speed:

If the time length for collision is smaller than a threshold TTC which is smaller than Th _TTC, judging that the collision risk exists between the target vehicle and the current vehicle, otherwise, judging that the collision risk does not exist between the target vehicle and the current vehicle.

In specific practice, the step S14 "select the main target from all the target vehicles according to the driving dynamics of all the target vehicles" includes:

If the current lane where the vehicle is located is a vehicle lane, defining an inner adjacent lane and an outer adjacent lane adjacent to the vehicle lane as adjacent lanes;

if no target vehicle exists on the adjacent lane, screening the target vehicle with the closest relative longitudinal distance to the current vehicle on the own vehicle lane as a main target;

if the target vehicle exists on the adjacent lane and the lane changing intention does not exist, screening the target vehicle which is closest to the current vehicle in the longitudinal distance on the own lane as a main target;

If the target vehicle exists on the adjacent lane and has the lane changing intention and collision risk with the current vehicle, screening the target vehicle which is closest to the current vehicle in the relative longitudinal distance on the adjacent lane as a main target;

If the target vehicle exists on the adjacent lane and the lane changing intention exists, but the collision risk does not exist with the current vehicle, the first target vehicle which is closest to the current vehicle in the adjacent lane and the second target vehicle which is closest to the current vehicle in the own lane are fused to be the main targets.

Referring to fig. 4, the driving dynamics of the target vehicle are divided into four regions: areal-have lane change intention and risk of collision; area 2-no lane change intention and collision risk; area 3-no lane change intention and no collision risk; area 4-has lane change intention and no risk of collision.

When the target vehicles on the adjacent lanes do not have lane changing intention (Area 2, area 3), screening the target vehicles on the own lanes, which are closest to the current vehicle in the longitudinal direction, as main targets;

when the target vehicle on the adjacent lane has a lane changing intention and has collision risk (Area 1), screening the target vehicle on the adjacent lane, which is closest to the current vehicle in the relative longitudinal distance, as a main target;

when the target vehicle on the adjacent lane has a lane changing intention and has no collision risk (Area 4), the first target vehicle on the adjacent lane and closest to the current vehicle in the relative longitudinal distance and the second target vehicle on the own lane and closest to the current vehicle in the relative longitudinal distance are fused as main targets, specifically:

According to the preset fusion coefficient lambda, the relative longitudinal distance Dx _adjt between the first target vehicle and the current vehicle and the relative longitudinal distance Dx _init between the second target vehicle and the current vehicle are weighted and summed to obtain the relative longitudinal distance Dx _main between the main target after fusion and the current vehicle,

Dx_main＝λDx_init+(1-λ)Dx_adjt；

The fusion coefficient lambda is determined according to the relative transverse distance Dy _adjt between the first target vehicle and the current vehicle and the relative transverse distance Dy _init between the second target vehicle and the current vehicle:

it can be understood that, according to the technical scheme provided by the embodiment, after the main target screening is completed, parameters that can be output include:

A relative lateral distance Dy of the current vehicle from the target vehicle, a relative longitudinal distance Dx, a main target vehicle speed v _p, a main target acceleration a _p, wherein,

V _r、a_r is the speed and acceleration of the current vehicle, respectively, and these two parameters CAN be directly obtained through the CAN bus of the current vehicle.

It can be appreciated that, in the technical solution provided in this embodiment, for any target vehicle, by predicting the driving track of the current vehicle, calculating the relative distance between the current vehicle and the target vehicle, and predicting the driving dynamics of the target vehicle according to the running information of the current vehicle, the running information of the target vehicle, and the relative distance and the change rate of the relative distance, and selecting the main target from all target vehicles according to the driving dynamics of all target vehicles.

Example two

Fig. 5 is a schematic block diagram of a primary target screening system 100 of an adaptive cruise system, according to an exemplary embodiment, as shown in fig. 5, the system 100 includes:

a determining module 101, configured to determine all vehicles traveling in front of the current vehicle at the current time as target vehicles;

The calculating module 102 is configured to predict, for any target vehicle, a driving track of a current vehicle according to a position of the target vehicle, and calculate a relative distance between the current vehicle and the target vehicle according to the driving track of the current vehicle;

A prediction module 103, configured to predict a driving dynamics of the target vehicle according to the current operation information of the vehicle, the operation information of the target vehicle, the relative distance, and the rate of change of the relative distance;

The screening module 104 is configured to screen a main target from all target vehicles according to driving dynamics of all target vehicles;

The "master target" refers to a "master target vehicle".

It should be noted that, because the implementation manner of each module in the embodiment can refer to the related description of the corresponding step in the first embodiment, the description of the embodiment is omitted.

Example III

An electronic device is shown according to an exemplary embodiment, comprising:

the processor is configured to execute program instructions stored in the memory to perform the primary target screening method of the adaptive cruise system according to embodiment one.

It should be noted that the electronic device includes, but is not limited to: vehicle-mounted computer and external computer equipment. Processors include, but are not limited to: CPU, singlechip, PLC controller, FPGA controller, etc.

Example IV

A computer readable storage medium having stored thereon a computer program that is erasable according to an exemplary embodiment is shown;

the computer program, when run on a computer device, causes the computer device to perform the primary object screening method of the adaptive cruise system as described in embodiment one.

The computer-readable storage medium disclosed in the present embodiment includes, but is not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

Example five

FIG. 6 is a flowchart illustrating a method of trajectory planning for an adaptive cruise system, according to an exemplary embodiment, as shown in FIG. 6, the method comprising:

Step S21, acquiring a motion state of a main target and a cruising parameter set by a user;

s22, determining the safe driving distance of the current vehicle according to the motion state and the cruising parameters;

Step S23, judging the working mode of the current vehicle according to the safe driving distance;

s24, constructing longitudinal track functions in different working modes, and solving coefficients of the longitudinal track functions according to constraint conditions and optimization targets in the different working modes to obtain an optimal longitudinal track;

And S25, judging whether the optimal longitudinal track meets the vehicle motion limit constraint condition, and taking the optimal longitudinal track meeting the vehicle motion limit constraint condition as a current vehicle longitudinal track planning result.

The "master target" refers to a "master target vehicle".

It can be understood that the adaptive cruise system mainly comprises recognition and tracking of a main target, and the track planning problem of the vehicle is only involved in the process of tracking the main target, so that the technical scheme provided by the embodiment needs to be performed on the basis that the system completes the recognition of the main target.

After the system completes the identification of the main target, the motion state of the main target is obtained, wherein the motion state is estimated in a main target identification algorithm according to the motion state of the current vehicle and the sensor perception information.

In the step S21, the motion state of the main target at least includes:

the speed of the main target, the acceleration of the main target, the relative longitudinal distance between the current vehicle and the main target, and the relative transverse distance between the current vehicle and the main target.

According to the technical scheme provided by the embodiment, the 'motion state of the main target' is only used for 'the speed of the main target, the acceleration of the main target and the relative longitudinal distance between the current vehicle and the main target'.

In the step S21, the cruise parameters set by the user at least include:

minimum stopping distance, time distance coefficient, cruising distance threshold, cruising vehicle speed threshold and cruising acceleration threshold. Wherein, the setting range of the minimum parking distance is 2.5-3.5 meters.

In specific practice, the step S22 "determining the safe driving distance of the current vehicle according to the motion state and the cruise parameter" includes:

1. according to the motion state and the cruising parameters, determining the target following distance of the current vehicle, specifically:

Determining the product of the main target vehicle speed v _p and the time interval coefficient tau and the sum of the minimum parking distance D ₀ as the target following distance of the current vehicle: d _{tar get}＝D₀+v_p x τ;

where τ is a time interval coefficient in seconds, the larger the value, the greater the target following distance.

2. And determining the safe driving distance of the current vehicle according to the target following distance, the motion state of the main target and the cruising parameter, wherein the method comprises the following steps of:

(1) If the relative longitudinal distance Dx between the current vehicle and the main target is greater than the cruising distance threshold S _h, or the main target vehicle speed v _p is greater than or equal to the cruising vehicle speed threshold v _h, determining that there is no vehicle in front or the main target vehicle speed is too fast, and determining the cruising distance threshold S _h as the safe driving distance of the current vehicle:

that is, if (Dx > S _h)||(v_p≥v_h),S_safe＝S_h;

Wherein, S _h is related to the speed of the current vehicle, which can be approximately considered to be proportional to the speed of the current vehicle, the value of S _h does not exceed the maximum detection distance of the millimeter wave radar, and if the relative longitudinal distance Dx between the current vehicle and the main target is greater than the cruising distance threshold S _h, it is determined that there is no vehicle in front;

The value of v _h is related to the maximum vehicle speed specified by traffic regulations; for example, the basic ACC speed working interval is 30-150 km/h; the speed working interval of the full-speed ACC is 0-200 km/h, and v _h can be set to 120km/h for the speed limit of the expressway.

(2) If the relative longitudinal distance Dx between the current vehicle and the main target is greater than or equal to the target following distance D _target and less than or equal to the cruising distance threshold S _h, the main target vehicle speed v _p is less than the cruising vehicle speed threshold v _h, and the main target acceleration a _p is greater than or equal to the cruising acceleration threshold a _h, determining that the main target is a trackable target vehicle, and determining the difference between the relative longitudinal distance Dx between the current vehicle and the main target and the target following distance D _target as the safe driving distance of the current vehicle:

i.e. ,if(D_target≤Dx≤S_h)&&(v_p＜v_h)&&(a_p≥a_h),S_safe＝Dx-(D₀+v_p*τ).

(3) If the relative longitudinal distance Dx between the current vehicle and the main target is smaller than the target following distance D _taraet and the main target speed v _p is smaller than the cruising speed threshold v _h, judging that the main target is a new target appearing in the front vicinity, and determining that the safe driving distance of the current vehicle is zero;

I.e. if (Dx < D _target)&&(v_p＜v_h),S_safe =0.

(4) If the main target acceleration a _p is smaller than the cruising acceleration threshold a _h and the main target vehicle speed v _p is smaller than the cruising vehicle speed threshold v _h, determining that the main target is suddenly decelerated, and determining that the safe driving distance of the current vehicle is zero:

I.e., if (a _p＜a_h)&&(v_p＜v_h),S_safe =0, where a _h < 0.

It can be appreciated that the technical scheme provided by the embodiment considers the situation that a new target appears suddenly in front of a lane and a vehicle in front of the lane suddenly decelerates, so that the method can be suitable for various complex road conditions, such as curve road conditions, urban road conditions with various emergency conditions, and the like.

In specific practice, the step S23 "determining the current vehicle working mode according to the safe driving distance" includes:

If the cruising distance threshold is determined to be the safe running distance of the current vehicle, determining that the working mode of the current vehicle is a constant speed cruising mode, namely: s _safe＝S_h, the current vehicle is in a constant-speed cruising mode;

if the relative longitudinal distance between the current vehicle and the main target is determined to be the safe driving distance of the current vehicle, the working mode of the current vehicle is determined to be a cruise following mode,

Namely: s _safe＝Dx-(D₀+v_p x tau), then the current vehicle is in cruise following mode;

if the safe driving distance of the current vehicle is zero, determining that the working mode of the current vehicle is a braking and parking mode, namely: s _safe = 0, then the current vehicle is in braking park mode.

In specific practice, the step S24 "constructs a longitudinal track function in different working modes, and solves coefficients of the longitudinal track function according to constraint conditions and optimization targets in different working modes to obtain an optimal longitudinal track", which specifically includes:

determining the constraint conditions of the longitudinal running of the current vehicle under different working modes;

determining a function expression of the current vehicle longitudinal track according to the number of the constraint conditions;

Establishing a coefficient solving equation of the function expression according to the constraint condition and the function expression;

determining an optimization target of the longitudinal running of the current vehicle;

setting a loss function of the coefficient solving equation according to the optimization target;

and according to the loss function, solving the coefficient of the longitudinal track function to obtain the optimal longitudinal track.

For easy understanding, the construction and solving methods of the longitudinal trajectory function in different working modes will now be explained as follows:

(1) Constant speed cruise mode

Because the system does not care about the position of the main target in the constant-speed cruising mode, the longitudinal running of the current vehicle has five constraint quantities: since five equations can be established for the starting position, the starting speed, the starting acceleration, the ending speed, and the ending acceleration, for simplifying the calculation, a fourth-order polynomial is used as the longitudinal trajectory function, wherein the longitudinal displacement function s (t), the velocity function v (t), and the acceleration function a (t) are respectively as follows:

s(t)＝b₀+b₁*t+b₂*t²+b₃*t³+b₄*t⁴

v(t)＝b₁+2b₂*t+3b₃*t²+4b₄*t³

a(t)＝2b₂+6b₃*t+12b₄*t²

Setting the starting position to be 0, the starting time to be 0, and the ending time to be t _e,t_e to represent the time for the current vehicle to reach the target cruising speed v _set after the adaptive cruising system is started, five constraint conditions can be obtained: s (0) =0, v (0) =v _r,a(0)＝a_r,v(t_e)＝v_set,a(t_e) =0;

wherein v _set is the target cruising speed of the adaptive cruising, which is set by the adaptive cruising system, v _r is the speed of the current vehicle, and a _r is the acceleration of the current vehicle.

Writing the five constraint conditions into a matrix form:

The matrix is recorded as TC=P, and if the matrix T is reversible, a coefficient solving equation C=T ^-1 P is obtained;

solving the coefficient solving equation can obtain a coefficient b ₀、b₁、b₂、b₃、b₄, wherein the coefficient b ₃、b₄ contains an unknown parameter t _e, and solving an optimal curve s (t), namely solving an optimal parameter t _e.

The optimization targets for determining the longitudinal running of the current vehicle are as follows: 1) The time taken to reach the target cruising speed in the constant speed cruising mode is as short as possible; 2) The acceleration change is as stable as possible; 3) Maximum vehicle speed and maximum acceleration limit, then determine the loss function J:

Wherein k ₁、k₂、k₃ is a weight coefficient, t _max is the maximum time for the current vehicle to reach the set vehicle speed after the adaptive cruise system is started, v _max is the maximum vehicle speed set by the adaptive cruise system, a _max is the maximum acceleration set by the adaptive cruise system, q _max is the maximum acceleration change rate set by the adaptive cruise system, and all four values are preset by the adaptive cruise system.

According to the loss function, the unknown parameter t _e is solved, the value of the coefficient b ₃、b₄ is obtained, and then the optimal longitudinal track s (t) can be determined.

(2) Cruise following mode

In cruise following mode, there are six constraints on the longitudinal travel of the current vehicle: since six equations can be established, including the start position, the start speed, the start acceleration, the end position, the end speed, and the end acceleration, a longitudinal trajectory function is a quintic polynomial, wherein the longitudinal displacement function s (t), the velocity function v (t), and the acceleration function a (t) are respectively as follows:

s(t)＝b₀+b₁*t+b₂*t²+b₃*t³+b₄*t⁴+b₅*t⁵

v(t)＝b₁+2b₂*t+3b₃*t²+4b₄*t³+5b₅*t⁴

a(t)＝2b₂+6b₃*t+12b₄*t²+20b₅*t³

setting the starting position to be 0, the starting time to be 0, and the ending time to be t _e,t_e to represent the time taken for the current vehicle to reach the target following distance S _safe and the following speed v _p after the adaptive cruise system is started, six constraint conditions can be obtained:

s(0)＝0,v(0)＝v_r,a(0)＝a_r,s(t_e)＝S_safe,v(t_e)＝v_p,a(t_e)＝0：

Writing the five constraint conditions into a matrix form:

Solving the coefficient solving equation can obtain a coefficient b ₀、b₁、b₂、b₃、b₄、b₅, wherein the coefficient b ₃、b₄、b₅ contains an unknown parameter t _e, and solving an optimal curve s (t), namely solving an optimal parameter t _e.

The optimization targets for determining the longitudinal running of the current vehicle are as follows: 1) The time for reaching the target following distance and the following speed in the cruise following mode is as short as possible; 2) The acceleration change is as stable as possible; 3) Maximum vehicle speed and maximum acceleration limit, then determine the loss function J:

According to the loss function, the unknown parameter t _e is solved, the value of the coefficient b ₃、b₄、b₅ is obtained, and then the optimal longitudinal track s (t) can be determined.

(3) Braking parking mode

In a braking parking mode, when the millimeter wave radar detects that a new target or a main target suddenly decelerates in the front, the system automatically sends a control signal to the execution mechanism to reduce the speed of the vehicle so as to ensure the running safety, wherein the parking position is the position of the main target detected by the millimeter wave radar.

In the same cruise following mode, there are six constraint amounts for the longitudinal running of the current vehicle: starting position, starting speed, starting acceleration, ending position, ending speed, ending acceleration, six equations can be established, using a fifth order polynomial as the longitudinal trajectory function.

Setting the starting position to be 0, the starting time to be 0, and the ending time to be t _e,t_e to represent the time taken for the current vehicle to brake to completely stop after the adaptive cruise system is started, six constraint conditions can be obtained:

s(0)＝0，v(0)＝v_r,a(0)＝a_r,s(t_e)＝D_y,v(t_e)＝0,a(t_e)＝0；

and the optimal longitudinal track s (t) is obtained through the same optimization and solving in the same calculation process in the cruise following mode.

It can be understood that, for the optimal longitudinal track obtained by solving the three working modes, the position, the speed and the acceleration value corresponding to any sampling time point in the planning time can be obtained according to the discretization of the sampling period.

The step S25 "determines whether the optimal longitudinal trajectory satisfies the vehicle motion limit constraint condition, and uses the optimal longitudinal trajectory satisfying the vehicle motion limit constraint condition as the current vehicle longitudinal trajectory planning result", specifically because:

The optimal longitudinal track output in the step S14 needs to be used as input of a lower control module, the control module executes the optimal longitudinal track by controlling a steering wheel, a brake, an accelerator and the like of the automobile, but the execution mechanisms have a plurality of constraints, and when the optimal longitudinal track output in the step S14 is not within the input constraint condition range of the execution mechanism, the optimal longitudinal track cannot be executed, and the track which cannot be executed by the automobile is meaningless. Meanwhile, constraints caused by dynamics and vehicle body stability of the vehicle are also required to be considered, so that the optimal longitudinal track output in the step S14 also meets a plurality of motion limiting conditions caused by a non-complete constraint system of the vehicle, the tracks which do not meet the limiting conditions are removed, and the tracks are returned to the adaptive cruise system for re-track planning so as to ensure feasibility and driving safety of the planned optimal longitudinal track.

It can be understood that, according to the technical scheme provided by the embodiment, the optimal longitudinal track is obtained by constructing the longitudinal track functions under different working modes, and because the longitudinal track is obtained by solving the functions, and constraint conditions and optimization targets under different working modes are considered, compared with the prior art that the target acceleration is obtained by directly calculating based on the speed and the relative distance of the main target, the technical scheme provided by the embodiment can provide the smooth control of the vehicle acceleration, improve the comfort of self-adaptive cruising and improve the driving safety.

Further, due to the technical scheme provided by the embodiment, the motion state of the main target and the cruising parameters set by the user can be obtained, the safe driving distance of the current vehicle is determined according to the motion state and the cruising parameters, and the working mode of the current vehicle is judged according to the safe driving distance, so that the automatic switching of the working mode of the current vehicle is realized, and the problems of low system active cruising capability and poor user experience caused by the need of selecting the working mode by a driver and frequently taking out and setting cruising control by the driver in the prior art are solved.

Example six

Fig. 7 is a schematic block diagram of a trajectory planning system 100 of an adaptive cruise system according to an exemplary embodiment, as shown in fig. 7, the system 200 includes:

An obtaining module 201, configured to obtain a motion state of a main target and a cruise parameter set by a user;

a determining module 202, configured to determine a safe driving distance of the current vehicle according to the motion state and the cruise parameter;

a judging module 203, configured to judge a current working mode of the vehicle according to the safe driving distance;

the solving module 204 is configured to construct longitudinal trajectory functions in different working modes, and solve coefficients of the longitudinal trajectory functions according to constraint conditions and optimization targets in the different working modes to obtain an optimal longitudinal trajectory;

the judging module 203 is further configured to judge whether the optimal longitudinal trajectory meets the vehicle motion limit constraint condition, and take the optimal longitudinal trajectory meeting the vehicle motion limit constraint condition as a current vehicle longitudinal trajectory planning result.

The "master target" refers to a "master target vehicle".

Example seven

An electronic device is shown according to an exemplary embodiment, comprising:

The processor is configured to execute program instructions stored in the memory and perform the trajectory planning method of the adaptive cruise system according to embodiment five.

Example eight

The computer program, when run on a computer device, causes the computer device to perform the trajectory planning method of the adaptive cruise system as described in embodiment five.

It is to be understood that the same or similar parts in the above embodiments may be referred to each other, and that in some embodiments, the same or similar parts in other embodiments may be referred to.

It should be noted that in the description of the present invention, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Furthermore, in the description of the present invention, unless otherwise indicated, the meaning of "plurality" means at least two.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and further implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.

It is to be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.

Those of ordinary skill in the art will appreciate that all or a portion of the steps carried out in the method of the above-described embodiments may be implemented by a program to instruct related hardware, where the program may be stored in a computer readable storage medium, and where the program, when executed, includes one or a combination of the steps of the method embodiments.

In addition, each functional unit in the embodiments of the present invention may be integrated in one processing module, or each unit may exist alone physically, or two or more units may be integrated in one module. The integrated modules may be implemented in hardware or in software functional modules. The integrated modules may also be stored in a computer readable storage medium if implemented in the form of software functional modules and sold or used as a stand-alone product.

The above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, or the like.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. A method for screening a primary target of an adaptive cruise system, comprising:

Screening main targets from all target vehicles according to the driving dynamics of all target vehicles; the method for screening the main targets from all target vehicles comprises the following steps: if the current lane where the vehicle is located is a vehicle lane, defining an inner adjacent lane and an outer adjacent lane adjacent to the vehicle lane as adjacent lanes; if no target vehicle exists on the adjacent lane, screening the target vehicle with the closest relative longitudinal distance to the current vehicle on the own vehicle lane as a main target; if the target vehicle exists on the adjacent lane and the lane changing intention does not exist, screening the target vehicle which is closest to the current vehicle in the longitudinal distance on the own lane as a main target; if the target vehicle exists on the adjacent lane and has the lane changing intention and collision risk with the current vehicle, screening the target vehicle which is closest to the current vehicle in the relative longitudinal distance on the adjacent lane as a main target; if the target vehicle exists on the adjacent lane and the lane changing intention exists, but the collision risk does not exist between the target vehicle and the current vehicle, fusing a first target vehicle which is closest to the current vehicle in the adjacent lane and is closest to the current vehicle in the longitudinal distance, and a second target vehicle which is closest to the current vehicle in the own lane as a main target;

2. The method according to claim 1, wherein predicting the current vehicle travel track based on the target vehicle position comprises:

calculating the curvature radius of the lane where the current vehicle is located;

Judging whether the lane where the current vehicle is located is a curve or not according to the curvature radius;

If the lane where the current vehicle is located is a curve, predicting the running track of the current vehicle as follows: circumferentially driving the vehicle to the curvature radius of the target vehicle at a constant speed within a preset duration;

And calculating the relative distance between the current vehicle and the target vehicle according to the predicted running track of the current vehicle, wherein the relative distance is specifically as follows:

the method comprises the steps that a connecting line between the center of a rear axle of a current vehicle at the current moment and the center of a rear axle of a target vehicle and an included angle between the connecting line and the running direction of the current vehicle at the current moment are recorded as a first included angle;

the connecting line between the center of the rear axle of the current vehicle and the center of the rear axle of the current vehicle at the current moment after the preset time length and the running direction of the current vehicle at the current moment are recorded as a second included angle;

calculating the relative distance between the current vehicle and the target vehicle according to the curvature radius, the first included angle and the second included angle; the relative distance includes: a relative transverse distance, and a relative longitudinal distance.

3. The method of claim 2, wherein predicting the driving dynamics of the target vehicle comprises:

Predicting a lane in which the target vehicle is located according to the relative transverse distance;

Predicting the lane change intention of the target vehicle according to the lane in which the target vehicle is located, the size of the relative transverse distance and the change rate of the relative transverse distance;

and predicting whether the target vehicle and the current vehicle have collision risk according to the running information of the current vehicle and the running information of the target vehicle.

4. A method according to claim 3, wherein predicting the lane in which the target vehicle is located based on the relative lateral distance comprises:

if the lane where the current vehicle is located is a self-vehicle lane, taking the running direction of the current vehicle as a visual angle reference, defining a left adjacent lane of the self-vehicle lane as an outer adjacent lane, and defining a right adjacent lane of the self-vehicle lane as an inner adjacent lane;

5. The method of claim 3, wherein predicting the lane change intention of the target vehicle based on the lane in which the target vehicle is located, the magnitude of the relative lateral distance, and the rate of change of the relative lateral distance, comprises:

If the target vehicle is on the self-vehicle lane, displaying a left boundary line close to the self-vehicle lane relative to the size of the transverse distance, and judging that the target vehicle has a lane changing intention of driving to an outer adjacent lane when the change rate of the transverse distance is positive; and/or the number of the groups of groups,

If the target vehicle is on the self-vehicle lane, displaying a right boundary line close to the self-vehicle lane relative to the size of the transverse distance, and judging that the target vehicle has a lane changing intention of approaching the lane to the inner side if the change rate of the transverse distance is negative; and/or the number of the groups of groups,

If the target vehicle is on the outer adjacent lane, the relative transverse distance is displayed near the left boundary of the self-vehicle lane, and the change rate of the relative transverse distance is negative, judging that the target vehicle has a lane changing intention for driving the self-vehicle lane; and/or the number of the groups of groups,

And if the target vehicle approaches the lane on the inner side, displaying the right boundary line close to the self-vehicle lane by the size of the relative transverse distance, and judging that the target vehicle has the lane changing intention of driving towards the self-vehicle lane if the change rate of the relative transverse distance is positive.

6. A method according to claim 3, wherein predicting whether there is a risk of collision between the target vehicle and the current vehicle based on the current vehicle's operation information and the target vehicle's operation information comprises:

predicting the length of time for collision when the current vehicle and the target vehicle run at the current vehicle speed:

if the time length used for collision is smaller than a threshold value, judging that the collision risk exists between the target vehicle and the current vehicle, otherwise, judging that the collision risk does not exist between the target vehicle and the current vehicle.

7. The method of claim 1, wherein fusing a first target vehicle in an adjacent lane that is closest to the current vehicle in a longitudinal direction and a second target vehicle in an own lane that is closest to the current vehicle in a longitudinal direction as a primary target comprises:

according to a preset fusion coefficient, the relative longitudinal distance between the first target vehicle and the current vehicle and the relative longitudinal distance between the second target vehicle and the current vehicle are weighted and summed to obtain the relative longitudinal distance between the fused main target and the current vehicle;

the fusion coefficient is determined according to the relative transverse distance between the first target vehicle and the current vehicle and the relative transverse distance between the second target vehicle and the current vehicle.

8. A track planning method for an adaptive cruise system, comprising:

a primary objective screening method of an adaptive cruise system according to any one of claims 1 to 7;

Further comprises:

9. The method of claim 8, wherein determining the safe driving distance of the current vehicle based on the motion information and the cruise parameter comprises:

Determining the target following distance of the current vehicle according to the motion information and the cruising parameters;

And determining the safe driving distance of the current vehicle according to the following distance of the target, the motion information of the main target and the cruising parameter.

10. The method of claim 9, wherein the step of determining the position of the substrate comprises,

The motion information of the main target at least comprises: a main target vehicle speed;

the cruise parameters at least comprise: minimum stopping distance and time distance coefficient;

The target following distance of the current vehicle is determined according to the motion information and the cruising parameters, and the method specifically comprises the following steps:

And determining the sum of the product of the main target speed and the time interval coefficient and the minimum parking distance as the target following distance of the current vehicle.

11. The method of claim 10, wherein the step of determining the position of the first electrode is performed,

The motion information of the main target at least further comprises: acceleration of the main target, relative longitudinal distance between the current vehicle and the main target; the cruise parameters further include at least: a cruise distance threshold, a cruise vehicle speed threshold, and a cruise acceleration threshold;

The determining the safe driving distance of the current vehicle according to the target following distance, the motion information of the main target and the cruising parameter comprises the following steps:

if the relative longitudinal distance between the current vehicle and the main target is greater than the cruising distance threshold, or the speed of the main target is greater than or equal to the cruising speed threshold, judging that no vehicle is in front or the speed of the main target is too fast, and determining the cruising distance threshold as the safe driving distance of the current vehicle;

if the relative longitudinal distance between the current vehicle and the main target is greater than or equal to the target following distance and is less than or equal to the cruising distance threshold, the speed of the main target is less than the cruising speed threshold, the acceleration of the main target is greater than or equal to the cruising acceleration threshold, the main target is judged to be a trackable target vehicle, and the difference between the relative longitudinal distance between the current vehicle and the main target and the target following distance is determined to be the safe driving distance of the current vehicle;

If the relative longitudinal distance between the current vehicle and the main target is smaller than the target following distance, and the main target speed is smaller than the cruising speed threshold, judging that the main target is a new target appearing in the front vicinity, and determining that the safe driving distance of the current vehicle is zero;

and if the main target acceleration is smaller than the cruising acceleration threshold value and the main target speed is smaller than the cruising speed threshold value, judging that the main target rapidly decelerates, and determining that the safe driving distance of the current vehicle is zero.

12. The method of claim 11, wherein determining the current vehicle operating mode based on the safe distance traveled comprises:

if the cruising distance threshold is determined to be the safe running distance of the current vehicle, determining that the working mode of the current vehicle is a constant-speed cruising mode;

If the relative longitudinal distance between the current vehicle and the main target is determined to be the safe driving distance of the current vehicle, determining that the working mode of the current vehicle is a cruise following mode;

And if the safe driving distance of the current vehicle is zero, determining that the working mode of the current vehicle is a braking parking mode.

13. The method according to claim 8, characterized in that the construction of the longitudinal trajectory functions in different modes of operation is in particular:

And determining a functional expression of the current vehicle longitudinal track according to the number of the constraint conditions.

14. The method of claim 13, wherein said solving for coefficients of said longitudinal trajectory function results in an optimal longitudinal trajectory, comprising:

15. A primary target screening system for an adaptive cruise system, comprising:

the screening module is used for screening main targets from all target vehicles according to the driving dynamics of all target vehicles; the method is particularly used for: if the current lane where the vehicle is located is a vehicle lane, defining an inner adjacent lane and an outer adjacent lane adjacent to the vehicle lane as adjacent lanes; if no target vehicle exists on the adjacent lane, screening the target vehicle with the closest relative longitudinal distance to the current vehicle on the own vehicle lane as a main target; if the target vehicle exists on the adjacent lane and the lane changing intention does not exist, screening the target vehicle which is closest to the current vehicle in the longitudinal distance on the own lane as a main target; if the target vehicle exists on the adjacent lane and has the lane changing intention and collision risk with the current vehicle, screening the target vehicle which is closest to the current vehicle in the relative longitudinal distance on the adjacent lane as a main target; if the target vehicle exists on the adjacent lane and the lane changing intention exists, but the collision risk does not exist between the target vehicle and the current vehicle, fusing a first target vehicle which is closest to the current vehicle in the adjacent lane and is closest to the current vehicle in the longitudinal distance, and a second target vehicle which is closest to the current vehicle in the own lane as a main target;

16. A trajectory planning system for an adaptive cruise system, comprising:

the primary targeting screening system of claim 15, further comprising:

17. An electronic device, comprising:

The processor being adapted to execute program instructions stored in a memory for performing a primary object screening method of an adaptive cruise system according to any one of claims 1-7; and/or performing a trajectory planning method of an adaptive cruise system according to any one of claims 8 to 14.

18. A computer-readable storage medium comprising,

A computer program stored thereon that is erasable;

when the computer program is run on a computer device, causing the computer device to perform the primary target screening method of an adaptive cruise system according to any one of claims 1-7; and/or performing a trajectory planning method of an adaptive cruise system according to any one of claims 8 to 14.