CN111391828A - Method for planning vehicle collision avoidance track under pedestrian crossing working condition - Google Patents

Method for planning vehicle collision avoidance track under pedestrian crossing working condition Download PDF

Info

Publication number
CN111391828A
CN111391828A CN202010176767.5A CN202010176767A CN111391828A CN 111391828 A CN111391828 A CN 111391828A CN 202010176767 A CN202010176767 A CN 202010176767A CN 111391828 A CN111391828 A CN 111391828A
Authority
CN
China
Prior art keywords
vehicle
speed
collision avoidance
time
track
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010176767.5A
Other languages
Chinese (zh)
Other versions
CN111391828B (en
Inventor
王春燕
冯健
匡登明
赵万忠
施帅朋
颜伸翔
何鹏
吴子涵
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nanjing University of Aeronautics and Astronautics
Original Assignee
Nanjing University of Aeronautics and Astronautics
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanjing University of Aeronautics and Astronautics filed Critical Nanjing University of Aeronautics and Astronautics
Priority to CN202010176767.5A priority Critical patent/CN111391828B/en
Publication of CN111391828A publication Critical patent/CN111391828A/en
Application granted granted Critical
Publication of CN111391828B publication Critical patent/CN111391828B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units, or advanced driver assistance systems for ensuring comfort, stability and safety or drive control systems for propelling or retarding the vehicle
    • B60W30/08—Active safety systems predicting or avoiding probable or impending collision or attempting to minimise its consequences
    • B60W30/095—Predicting travel path or likelihood of collision
    • B60W30/0953—Predicting travel path or likelihood of collision the prediction being responsive to vehicle dynamic parameters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units, or advanced driver assistance systems for ensuring comfort, stability and safety or drive control systems for propelling or retarding the vehicle
    • B60W30/08—Active safety systems predicting or avoiding probable or impending collision or attempting to minimise its consequences
    • B60W30/095—Predicting travel path or likelihood of collision
    • B60W30/0956—Predicting travel path or likelihood of collision the prediction being responsive to traffic or environmental parameters

Abstract

The invention discloses a method for planning a vehicle collision avoidance track under the working condition that a pedestrian crosses a street, when the pedestrian suddenly appears in front of the vehicle, a series of collision avoidance candidate tracks are planned, and the method specifically comprises the steps of space path planning and time motion planning; and then transmitting the candidate track to an optimization module to perform multi-objective optimization according to safety, stability and traffic efficiency indexes to obtain an optimal track. The invention plans a safe, stable and efficient track for the vehicle in real time under the working condition that pedestrians cross the street to realize active collision avoidance, and can ensure that the vehicle safely, stably and efficiently avoids obstacles.

Description

Method for planning vehicle collision avoidance track under pedestrian crossing working condition
Technical Field
The invention relates to an advanced auxiliary driving technology, in particular to a method for planning a collision avoidance track of a vehicle under a pedestrian crossing working condition.
Background
Over the last decades, more and more practitioners have been invested in the research of intelligent driving, and there have been great achievements made by google and other high-tech companies in combination with tesla, wolvo and other global automobile companies in the field of advanced assistant driving such as active collision avoidance systems. However, as one of the important components of ADAS, the active collision avoidance system is required to determine a track capable of ensuring safety of various traffic bodies and a long road to be taken by coping with various uncertain factors caused by all complex traffic scenes in a real traffic environment. The traditional active collision avoidance system mainly aims at the obstacle objects of a vehicle which is braked emergently in the longitudinal direction and a vehicle which is switched between adjacent lanes, but according to the report issued by the World Health Organization (WHO) in 2013, the number of road traffic deaths reaches 124 million worldwide every year, wherein the number of pedestrian deaths accounts for 22%.
As two intelligent agents in a traffic environment, on one hand, pedestrians have extremely strong maneuverability, and the decision of the pedestrians is influenced by the motion states of surrounding vehicles, so that the future states of the pedestrians are difficult to accurately predict; on the other hand, the pedestrian movement brings a plurality of uncertain factors to the normal running of the automobile, so that the collision avoidance decision of the driver is disordered. This makes it difficult to use the collision avoidance system for vehicles directly for pedestrian collision avoidance.
In addition, the trajectory planning technology is one of the key technologies of the advanced assistant driving system, and meanwhile, the safety for pedestrian collision avoidance is high, so that high requirements are placed on the motion state of the vehicle, however, traditional trajectory planning research mostly focuses on path planning in space, and motion planning in time is omitted. Therefore, under the condition that pedestrians cross the street, the time movement planning and the space path planning of the vehicle are equally important.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method for planning a vehicle collision avoidance track under a pedestrian crossing working condition aiming at the defects in the background technology.
The invention adopts the following technical scheme for solving the technical problems:
a method for planning a collision avoidance track of a vehicle under a pedestrian crossing working condition comprises the following steps:
step 1), arranging a speed sensor, a GPS and a radar in a vehicle to obtain the position and speed information of the vehicle and the pedestrian in real time;
step 2), taking the time point of detecting the pedestrian as the initial collision avoidance time;
at an initial time: taking a straight line which is perpendicular to the road direction and is formed by the most front point of a vehicle top view as a Y axis, taking the boundary of a road on the right side of the vehicle as an X axis, taking the intersection point of the X axis and the Y axis as an origin, taking the vehicle running direction as the X direction and taking the pedestrian running direction as the Y direction, and converting the positions of the vehicle and the pedestrian into coordinates in a coordinate system;
step 3), planning a geometric path on a driving space in the collision avoidance process of the vehicle:
step 3.1), enabling the pedestrian to cross the street in a direction perpendicular to the road, taking a rectangular area with the projection point of the center of mass of the pedestrian on the ground as a wide middle point, the width of 1 m and the length of the road width at the initial moment as a pedestrian crossing area, namely a collision area, and taking the time point when the vehicle reaches the collision area as the moment of avoiding collision, combining the position of the vehicle at the initial moment of avoiding collision, and fitting the path by utilizing a quintic polynomial:
Figure BDA0002411092360000021
where x is the position of the vehicle in the direction parallel to the road, y is the position of the vehicle in the direction perpendicular to the road, xfAnd yfRespectively the horizontal and vertical coordinate positions of the vehicle at the end-of-collision avoiding moment; a isiIs the coefficient of a fifth-order polynomial;
step 3.2), in the collision avoidance process of the vehicle, determining a according to 6 constraints including initial and final time position information, speed information and acceleration information of the vehicle in the collision avoidance processi：
Figure BDA0002411092360000022
In the formula, yi、
Figure BDA0002411092360000023
And
Figure BDA0002411092360000024
respectively the initial transverse position, the transverse speed and the transverse acceleration of the vehicle in the y coordinate direction in each planning period,
Figure BDA0002411092360000025
and
Figure BDA0002411092360000026
respectively the vehicle terminal transverse speed and transverse acceleration in the y coordinate direction in each planning period, viFor the initial speed of the vehicle, theta, in each planning cycleiSetting an initial course angle of the vehicle in each planning period; x is the number offDetermined by the initial position of the obstacle, yfConstrained by road width;
step 4), planning the speed state of the vehicle in the time direction of the x direction in the collision avoidance process, and dividing the speed planning of the intelligent collision avoidance system under the working condition that pedestrians cross the street into tbc、tbg、tc、tuThe method comprises four stages, wherein the vehicle speed planning steps in each stage are as follows:
step 4.1), tbcThe time period is a period when the brake system overcomes the brake clearance, and the speed of the vehicle and the running state of the vehicle in the time period are as follows:
Figure BDA0002411092360000027
where v (t) is a function of the speed of the vehicle with respect to time t, X (t) is a function of the displacement of the vehicle with respect to time t, XbcFor the displacement of the vehicle travel in the x-axis direction during this time, vveh(0) An initial speed for collision avoidance of the vehicle;
step 4.2), tbgThe time interval is the stage of the brake system overcoming the brake clearance and then rapidly increasing the brake force and the brake deceleration,at this time, the vehicle speed begins to decrease, and the vehicle speed and the distance traveled by the vehicle in the time period are as follows:
Figure BDA0002411092360000031
in which a (t) is a function of the acceleration of the vehicle over time t, XbgIs tbgDisplacement of vehicle travel in x-axis direction within time period, abmaxIs a preset maximum braking deceleration;
step 4.3), tcFor the continuous braking stage, aiming at the sudden extreme condition that pedestrians cross the street, the safety is the first index, so that the vehicle speed is required to be reduced to a controllable speed as quickly as possible, the braking deceleration is kept unchanged at the maximum value, and the vehicle speed is linearly reduced to a variable safe speed vs(ii) a The speed of the vehicle, the time to continue braking to a safe speed, and the distance traveled by the vehicle during this time period are:
Figure BDA0002411092360000032
in the formula: t is tbIs tbcAnd tbgSum of time, XcIs tcDisplacement of vehicle travel in the x-axis direction over a period of time;
step 4.4), last tuIn the constant-speed driving stage until the collision avoidance process is finished, the speed of the vehicle, the driving distance of the vehicle, the constant-speed driving time and the TTCZ in the time period are as follows:
Figure BDA0002411092360000033
in the formula: TTCZ is the time from the moment when the vehicle starts detecting the front obstacle to the time when the vehicle travels to the collision zone; x is the number ofped(0) Is the initial position of the pedestrian in the x-axis direction, tdIs tbAnd tcThe sum of the times;
step 5), generating a candidate track for vehicle collision avoidance according to a geometric path on a driving space in the vehicle collision avoidance process and a speed state in the time of the x direction in the vehicle collision avoidance process;
step 6), optimizing the candidate track by taking safety, stability and traffic efficiency as targets;
step 6.1), the safety target is represented by a safety cost function, the safety cost function is described by the distance between the upward people in the Y direction and the automobile at the end-of-collision moment, the larger the distance is, the higher the collision avoidance safety is, and the reciprocal of the distance is taken to represent the track TkIs a security cost function ca(Tk)：
Figure BDA0002411092360000041
In the formula (I), the compound is shown in the specification,
Figure BDA0002411092360000042
is the relative distance between a man and a vehicle at the end-of-collision moment n, rvehIs the vehicle transverse radius;
step 6.2), the stability target is represented by a stability cost function, the stability cost function is represented by lateral acceleration in the collision avoidance process, and the average value of the absolute values of the lateral acceleration in the collision avoidance process is taken to represent the track TkStability cost function cs(Tk)：
Figure BDA0002411092360000043
In the formula (I), the compound is shown in the specification,
Figure BDA0002411092360000044
the lateral acceleration at the moment j in the collision avoidance process of the vehicle, and n is the time spent on collision avoidance;
and 6.3) representing the traffic high-efficiency target by adopting a traffic high-efficiency cost function, representing the traffic high-efficiency cost function by adopting the difference value of the vehicle speed in the collision avoidance process and the collision avoidance initial vehicle speed, and representing the track T by taking the difference value of the speed in the collision avoidance process and the initial speedkTraffic efficiency cost function ce(Tk)：
Figure BDA0002411092360000045
In the formula (I), the compound is shown in the specification,
Figure BDA0002411092360000046
the vehicle speed at the moment j in the process of vehicle collision avoidance,
Figure BDA0002411092360000047
initial vehicle speed for collision avoidance;
step 6.4), according to the track TkObtaining a comprehensive cost function c from cost functions of collision avoidance performance, vehicle stability and traffic efficiencytotal(Tk)＝ωa·ca(Tk)+ωs·cs(Tk)+ωe·ce(Tk) In the formula, ωa、ωs、ωeAre respectively a preset track TkWeight coefficients of collision avoidance performance, vehicle stability, and traffic efficiency;
and 6.5) calculating a comprehensive cost function of each track, and taking the track with the minimum comprehensive cost function as an optimal track.
Compared with the prior art, the invention adopting the technical scheme has the following technical effects:
1. the invention can realize that the vehicle can plan a safe, stable and efficient track in real time under the emergency working condition that pedestrians pass the street in front of the vehicle.
2. The optimal track generated by the invention considers various boundary conditions of displacement, speed and acceleration, and can realize continuous and real-time planning of the track.
3. Besides planning the path in the space, the invention also plans the motion information in time, thereby being convenient for tracking the operation of the control system.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a schematic diagram of an initial collision avoidance time scenario of the present invention;
FIG. 3 is a schematic diagram of a scene at an end-of-collision avoidance time according to the present invention;
fig. 4 is a motion planning velocity curve according to the present invention.
Detailed Description
The technical scheme of the invention is further explained in detail by combining the attached drawings:
the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.
As shown in fig. 1, the invention discloses a method for planning a collision avoidance track of a vehicle under a pedestrian crossing condition, which comprises the following steps:
step 1), arranging a speed sensor, a GPS and a radar in a vehicle to obtain the position and speed information of the vehicle and the pedestrian in real time;
step 2), taking the time point of detecting the pedestrian as the initial collision avoidance time;
at an initial time: as shown in fig. 2, a straight line perpendicular to the road direction is taken as a Y-axis from a point at the front end of the vehicle in the top view, a boundary of the road on the right side of the vehicle is taken as an X-axis, an intersection point of the X-axis and the Y-axis is taken as an origin, the vehicle driving direction is taken as the X-direction, and the pedestrian walking direction is taken as the Y-direction, so that the positions of the vehicle and the pedestrian are converted into coordinates in a coordinate system;
step 3), planning a geometric path on a driving space in the collision avoidance process of the vehicle:
step 3.1), as shown in fig. 3, making the pedestrian cross the street in a direction perpendicular to the road, taking a rectangular area with a projection point of the center of mass of the pedestrian on the ground at the initial time as a wide center point, a width of 1 meter and a length of the road width as a pedestrian crossing area, namely a collision area, and simultaneously taking the time point when the vehicle reaches the collision area as the end-collision avoidance time, combining the position of the vehicle at the initial collision avoidance time, and fitting a path by utilizing a fifth-order polynomial:
Figure BDA0002411092360000061
where x is the position of the vehicle in the direction parallel to the road, y is the position of the vehicle in the direction perpendicular to the road, xfAnd yfRespectively the horizontal and vertical coordinate positions of the vehicle at the end-of-collision avoiding moment; a isiIs the coefficient of a fifth-order polynomial;
step 3.2), in the collision avoidance process of the vehicle, determining a according to 6 constraints including initial and final time position information, speed information and acceleration information of the vehicle in the collision avoidance processi：
Figure BDA0002411092360000062
In the formula, yi、
Figure BDA0002411092360000063
And
Figure BDA0002411092360000064
respectively the initial transverse position, the transverse speed and the transverse acceleration of the vehicle in the y coordinate direction in each planning period,
Figure BDA0002411092360000065
and
Figure BDA0002411092360000066
respectively the vehicle terminal transverse speed and transverse acceleration in the y coordinate direction in each planning period, viFor the initial speed of the vehicle, theta, in each planning cycleiSetting an initial course angle of the vehicle in each planning period; x is the number offDetermined by the initial position of the obstacle, yfConstrained by road width;
step 4), planning the speed state of the vehicle in the time direction of the x direction in the collision avoidance process, and dividing the speed planning of the intelligent collision avoidance system under the working condition that pedestrians cross the street into tbc、tbg、tc、tuFour stages, as shown in fig. 4, the vehicle speed planning steps in each stage are as follows:
step 4.1), tbcTime period for overcoming brake clearance step of brake systemA segment during which the speed of the vehicle and the state of travel of the vehicle are:
Figure BDA0002411092360000067
where v (t) is a function of the speed of the vehicle with respect to time t, X (t) is a function of the displacement of the vehicle with respect to time t, XbcFor the displacement of the vehicle travel in the x-axis direction during this time, vveh(0) An initial speed for collision avoidance of the vehicle;
step 4.2), tbgThe time interval is a stage that the braking force and the braking deceleration are rapidly increased after the braking system overcomes the braking clearance, the vehicle speed begins to decrease, and the vehicle speed and the vehicle running distance in the time interval are as follows:
Figure BDA0002411092360000071
in which a (t) is a function of the acceleration of the vehicle over time t, XbgIs tbgDisplacement of vehicle travel in x-axis direction within time period, abmaxIs a preset maximum braking deceleration;
step 4.3), tcFor the continuous braking stage, aiming at the sudden extreme condition that pedestrians cross the street, the safety is the first index, so that the vehicle speed is required to be reduced to a controllable speed as quickly as possible, the braking deceleration is kept unchanged at the maximum value, and the vehicle speed is linearly reduced to a variable safe speed vs(ii) a The speed of the vehicle, the time to continue braking to a safe speed, and the distance traveled by the vehicle during this time period are:
Figure BDA0002411092360000072
in the formula: t is tbIs tbcAnd tbgSum of time, XcIs tcDisplacement of vehicle travel in the x-axis direction over a period of time;
step 4.4), last tuThe speed of the vehicle and the vehicle in the time period from the constant speed driving stage to the collision avoidance process endThe driving distance, the constant-speed driving time and the TTCZ are as follows:
Figure BDA0002411092360000073
in the formula: TTCZ is the time from the moment when the vehicle starts detecting the front obstacle to the time when the vehicle travels to the collision zone; x is the number ofped(0) Is the initial position of the pedestrian in the x-axis direction, tdIs tbAnd tcThe sum of the times;
step 5), generating a candidate track for vehicle collision avoidance according to a geometric path on a driving space in the vehicle collision avoidance process and a speed state in the time of the x direction in the vehicle collision avoidance process;
step 6), optimizing the candidate track by taking safety, stability and traffic efficiency as targets;
step 6.1), the safety target is represented by a safety cost function, the safety cost function is described by the distance between the upward people in the Y direction and the automobile at the end-of-collision moment, the larger the distance is, the higher the collision avoidance safety is, and the reciprocal of the distance is taken to represent the track TkIs a security cost function ca(Tk)：
Figure BDA0002411092360000081
In the formula (I), the compound is shown in the specification,
Figure BDA0002411092360000082
is the relative distance between a man and a vehicle at the end-of-collision moment n, rvehIs the vehicle transverse radius;
step 6.2), the stability target is represented by a stability cost function, the stability cost function is represented by lateral acceleration in the collision avoidance process, and the average value of the absolute values of the lateral acceleration in the collision avoidance process is taken to represent the track TkStability cost function cs(Tk)：
Figure BDA0002411092360000083
In the formula (I), the compound is shown in the specification,
Figure BDA0002411092360000084
the lateral acceleration at the moment j in the collision avoidance process of the vehicle, and n is the time spent on collision avoidance;
and 6.3) representing the traffic high-efficiency target by adopting a traffic high-efficiency cost function, representing the traffic high-efficiency cost function by adopting the difference value of the vehicle speed in the collision avoidance process and the collision avoidance initial vehicle speed, and representing the track T by taking the difference value of the speed in the collision avoidance process and the initial speedkTraffic efficiency cost function ce(Tk)：
Figure BDA0002411092360000085
In the formula (I), the compound is shown in the specification,
Figure BDA0002411092360000086
the vehicle speed at the moment j in the process of vehicle collision avoidance,
Figure BDA0002411092360000087
initial vehicle speed for collision avoidance;
step 6.4), according to the track TkObtaining a comprehensive cost function c from cost functions of collision avoidance performance, vehicle stability and traffic efficiencytotal(Tk)＝ωa·ca(Tk)+ωs·cs(Tk)+ωe·ce(Tk) In the formula, ωa、ωs、ωeAre respectively a preset track TkWeight coefficients of collision avoidance performance, vehicle stability, and traffic efficiency;
and 6.5) calculating a comprehensive cost function of each track, and taking the track with the minimum comprehensive cost function as an optimal track.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (1)

1. A method for planning a collision avoidance track of a vehicle under a pedestrian crossing working condition is characterized by comprising the following steps:
step 1), arranging a speed sensor, a GPS and a radar in a vehicle to obtain the position and speed information of the vehicle and the pedestrian in real time;
step 2), taking the time point of detecting the pedestrian as the initial collision avoidance time;
at an initial time: taking a straight line which is perpendicular to the road direction and is formed by the most front point of a vehicle top view as a Y axis, taking the boundary of a road on the right side of the vehicle as an X axis, taking the intersection point of the X axis and the Y axis as an origin, taking the vehicle running direction as the X direction and taking the pedestrian running direction as the Y direction, and converting the positions of the vehicle and the pedestrian into coordinates in a coordinate system;
step 3), planning a geometric path on a driving space in the collision avoidance process of the vehicle:
step 3.1), enabling the pedestrian to cross the street in a direction perpendicular to the road, taking a rectangular area with the projection point of the center of mass of the pedestrian on the ground as a wide middle point, the width of 1 m and the length of the road width at the initial moment as a pedestrian crossing area, namely a collision area, and taking the time point when the vehicle reaches the collision area as the moment of avoiding collision, combining the position of the vehicle at the initial moment of avoiding collision, and fitting the path by utilizing a quintic polynomial:
Figure FDA0002411092350000011
where x is the position of the vehicle in the direction parallel to the road, y is the position of the vehicle in the direction perpendicular to the road, xfAnd yfRespectively the horizontal and vertical coordinate positions of the vehicle at the end-of-collision avoiding moment; a isiIs the coefficient of a fifth-order polynomial;
step 3.2), in the collision avoidance process of the vehicle, determining a according to 6 constraints including initial and final time position information, speed information and acceleration information of the vehicle in the collision avoidance processi：
Figure FDA0002411092350000012
In the formula, yi、
Figure FDA0002411092350000013
And
Figure FDA0002411092350000014
respectively the initial transverse position, the transverse speed and the transverse acceleration of the vehicle in the y coordinate direction in each planning period,
Figure FDA0002411092350000015
and
Figure FDA0002411092350000016
respectively the vehicle terminal transverse speed and transverse acceleration in the y coordinate direction in each planning period, viFor the initial speed of the vehicle, theta, in each planning cycleiSetting an initial course angle of the vehicle in each planning period; x is the number offDetermined by the initial position of the obstacle, yfConstrained by road width;
step 4), planning the speed state of the vehicle in the time direction of the x direction in the collision avoidance process, and dividing the speed planning of the intelligent collision avoidance system under the working condition that pedestrians cross the street into tbc、tbg、tc、tuFour stages, in particular the step of planning the speed of the vehicle in each stageThe following were used:
step 4.1), tbcThe time period is a period when the brake system overcomes the brake clearance, and the speed of the vehicle and the running state of the vehicle in the time period are as follows:
Figure FDA0002411092350000021
where v (t) is a function of the speed of the vehicle with respect to time t, X (t) is a function of the displacement of the vehicle with respect to time t, XbcFor the displacement of the vehicle travel in the x-axis direction during this time, vveh(0) An initial speed for collision avoidance of the vehicle;
step 4.2), tbgThe time interval is a stage that the braking force and the braking deceleration are rapidly increased after the braking system overcomes the braking clearance, the vehicle speed begins to decrease, and the vehicle speed and the vehicle running distance in the time interval are as follows:
Figure FDA0002411092350000022
in which a (t) is a function of the acceleration of the vehicle over time t, XbgIs tbgDisplacement of vehicle travel in x-axis direction within time period, abmaxIs a preset maximum braking deceleration;
step 4.3), tcFor the continuous braking stage, aiming at the sudden extreme condition that pedestrians cross the street, the safety is the first index, so that the vehicle speed is required to be reduced to a controllable speed as quickly as possible, the braking deceleration is kept unchanged at the maximum value, and the vehicle speed is linearly reduced to a variable safe speed vs(ii) a The speed of the vehicle, the time to continue braking to a safe speed, and the distance traveled by the vehicle during this time period are:
Figure FDA0002411092350000023
in the formula: t is tbIs tbcAnd tbgSum of time, XcIs tcDisplacement of vehicle travel in the x-axis direction over a period of time;
step 4.4), last tuIn the constant-speed driving stage until the collision avoidance process is finished, the speed of the vehicle, the driving distance of the vehicle, the constant-speed driving time and the TTCZ in the time period are as follows:
Figure FDA0002411092350000031
in the formula: TTCZ is the time from the moment when the vehicle starts detecting the front obstacle to the time when the vehicle travels to the collision zone; x is the number ofped(0) Is the initial position of the pedestrian in the x-axis direction, tdIs tbAnd tcThe sum of the times;
step 5), generating a candidate track for vehicle collision avoidance according to a geometric path on a driving space in the vehicle collision avoidance process and a speed state in the time of the x direction in the vehicle collision avoidance process;
step 6), optimizing the candidate track by taking safety, stability and traffic efficiency as targets;
step 6.1), the safety target is represented by a safety cost function, the safety cost function is described by the distance between the upward people in the Y direction and the automobile at the end-of-collision moment, the larger the distance is, the higher the collision avoidance safety is, and the reciprocal of the distance is taken to represent the track TkIs a security cost function ca(Tk)：
Figure FDA0002411092350000032
In the formula (I), the compound is shown in the specification,
Figure FDA0002411092350000033
is the relative distance between a man and a vehicle at the end-of-collision moment n, rvehIs the vehicle transverse radius;
step 6.2), the stability target is represented by a stability cost function, the stability cost function is represented by lateral acceleration in the collision avoidance process, and the average value of the absolute values of the lateral acceleration in the collision avoidance process is taken to represent the track TkStability cost function cs(Tk)：
Figure FDA0002411092350000034
In the formula (I), the compound is shown in the specification,
Figure FDA0002411092350000035
the lateral acceleration at the moment j in the collision avoidance process of the vehicle, and n is the time spent on collision avoidance;
and 6.3) representing the traffic high-efficiency target by adopting a traffic high-efficiency cost function, representing the traffic high-efficiency cost function by adopting the difference value of the vehicle speed in the collision avoidance process and the collision avoidance initial vehicle speed, and representing the track T by taking the difference value of the speed in the collision avoidance process and the initial speedkTraffic efficiency cost function ce(Tk)：
Figure FDA0002411092350000041
In the formula (I), the compound is shown in the specification,
Figure FDA0002411092350000042
the vehicle speed at the moment j in the process of vehicle collision avoidance,
Figure FDA0002411092350000043
initial vehicle speed for collision avoidance;
step 6.4), according to the track TkObtaining a comprehensive cost function c from cost functions of collision avoidance performance, vehicle stability and traffic efficiencytotal(Tk)＝ωa·ca(Tk)+ωs·cs(Tk)+ωe·ce(Tk) In the formula, ωa、ωs、ωeAre respectively a preset track TkWeight coefficients of collision avoidance performance, vehicle stability, and traffic efficiency;
and 6.5) calculating a comprehensive cost function of each track, and taking the track with the minimum comprehensive cost function as an optimal track.
CN202010176767.5A 2020-03-13 2020-03-13 Method for planning vehicle collision avoidance track under pedestrian crossing working condition Active CN111391828B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010176767.5A CN111391828B (en) 2020-03-13 2020-03-13 Method for planning vehicle collision avoidance track under pedestrian crossing working condition

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010176767.5A CN111391828B (en) 2020-03-13 2020-03-13 Method for planning vehicle collision avoidance track under pedestrian crossing working condition

Publications (2)

Publication Number Publication Date
CN111391828A true CN111391828A (en) 2020-07-10
CN111391828B CN111391828B (en) 2021-06-15

Family

ID=71424644

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010176767.5A Active CN111391828B (en) 2020-03-13 2020-03-13 Method for planning vehicle collision avoidance track under pedestrian crossing working condition

Country Status (1)

Country Link
CN (1) CN111391828B (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103587524A (en) * 2013-10-25 2014-02-19 江苏大学 Lateral active collision avoidance system and control method thereof
CN107643752A (en) * 2017-05-09 2018-01-30 清研华宇智能机器人（天津）有限责任公司 Omni-directional mobile robots path planning algorithm based on pedestrian track prediction
CN107885932A (en) * 2017-11-07 2018-04-06 长春工业大学 It is a kind of to consider man-machine harmonious automobile emergency collision avoidance layer-stepping control method
CN108780610A (en) * 2016-03-24 2018-11-09 本田技研工业株式会社 For the system and method for unexpected pedestrian's planned trajectory
FR3066731A1 (en) * 2017-05-29 2018-11-30 Peugeot Citroen Automobiles Sa DEVICE AND METHOD FOR LIGHTING ASSISTANCE BASED ON THE POSITION OF A LIVING BEAM LOCATED IN FRONT OF A VEHICLE
WO2019217037A1 (en) * 2018-05-11 2019-11-14 Chase Arnold Passive infra-red guidance system
CN110481544A (en) * 2019-07-30 2019-11-22 江苏大学 A kind of automotive correlation prevention method and anti-collision system for pedestrian
CN110834631A (en) * 2019-11-01 2020-02-25 中国第一汽车股份有限公司 Pedestrian avoiding method and device, vehicle and storage medium

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103587524A (en) * 2013-10-25 2014-02-19 江苏大学 Lateral active collision avoidance system and control method thereof
CN108780610A (en) * 2016-03-24 2018-11-09 本田技研工业株式会社 For the system and method for unexpected pedestrian's planned trajectory
CN107643752A (en) * 2017-05-09 2018-01-30 清研华宇智能机器人（天津）有限责任公司 Omni-directional mobile robots path planning algorithm based on pedestrian track prediction
FR3066731A1 (en) * 2017-05-29 2018-11-30 Peugeot Citroen Automobiles Sa DEVICE AND METHOD FOR LIGHTING ASSISTANCE BASED ON THE POSITION OF A LIVING BEAM LOCATED IN FRONT OF A VEHICLE
CN107885932A (en) * 2017-11-07 2018-04-06 长春工业大学 It is a kind of to consider man-machine harmonious automobile emergency collision avoidance layer-stepping control method
WO2019217037A1 (en) * 2018-05-11 2019-11-14 Chase Arnold Passive infra-red guidance system
CN110481544A (en) * 2019-07-30 2019-11-22 江苏大学 A kind of automotive correlation prevention method and anti-collision system for pedestrian
CN110834631A (en) * 2019-11-01 2020-02-25 中国第一汽车股份有限公司 Pedestrian avoiding method and device, vehicle and storage medium

Also Published As

Publication number Publication date
CN111391828B (en) 2021-06-15

Similar Documents

Publication Publication Date Title
EP3822582A1 (en) Driving environment information generation method, driving control method, driving environment information generation device
US9669827B1 (en) Predicting trajectories of objects based on contextual information
CN103121447B (en) A kind of bend preventing side sliding and side turning autonomous cruise speed system and method
WO2019052567A1 (en) Virtual turnout system and method for virtual rail vehicle
US10510257B2 (en) Object tracking method and object tracking device
CN109035862A (en) A kind of more vehicles collaboration lane-change control method based on truck traffic
CN111071249B (en) Unmanned vehicle emergency steering obstacle avoidance method based on obstacle motion prediction
EP3822945A1 (en) Driving environment information generation method, driving control method, driving environment information generation device
CN108227695A (en) Automatic Pilot control device, the system and method including the device
CN112577506B (en) Automatic driving local path planning method and system
US20200125106A1 (en) Controlling Vehicles Through Multi-Lane Turns
JP2023532482A (en) System and method for detecting open doors
CN108778881A (en) Vehicle control system, control method for vehicle and vehicle control program
CN110271542A (en) Controller of vehicle, control method for vehicle and storage medium
WO2023125754A1 (en) Automatic platooning vehicle system and control method
JP2023504604A (en) System and method for selectively decelerating a vehicle
Aryal Optimization of geometric road design for autonomous vehicle
CN114442630B (en) Intelligent vehicle planning control method based on reinforcement learning and model prediction
CN109656242A (en) A kind of automatic Pilot planning driving path planning system
CN111391828B (en) Method for planning vehicle collision avoidance track under pedestrian crossing working condition
CN112002143B (en) Vehicle operation risk assessment system under multi-vehicle environment based on dynamic risk potential energy field
Wu et al. Dynamic path planning for autonomous driving on branch streets with crossing pedestrian avoidance guidance
CN112462776A (en) Unmanned driving decision-making method based on unstructured road
Khafri et al. Improved Line Tracking System for Autonomous Navigation of High-Speed Vehicle
Guo et al. Game algorithm of intelligent driving vehicle based on left-turn scene of crossroad traffic flow

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant