CN113246985A

CN113246985A - Intelligent network vehicle merging and changing control method for expressway ramps under mixed-traveling condition

Info

Publication number: CN113246985A
Application number: CN202110687438.1A
Authority: CN
Inventors: 王成; 俄文娟; 陈颖; 王翔; 郑建颖; 陶砚蕴; 马世威
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2021-06-21
Filing date: 2021-06-21
Publication date: 2021-08-13
Anticipated expiration: 2041-06-21
Also published as: CN113246985B

Abstract

The invention discloses a method for controlling merging and changing of an intelligent online vehicle on a ramp of a fast way under a mixed-running condition, which comprises the following steps of: collecting road traffic driving information; analyzing the running states and the optimal safety distance of the vehicle in the accelerating lane and the vehicle in the front of and behind the target lane, and judging whether a lane change decision is generated; and adjusting the acceleration of the vehicle in real time based on the track changing path function during driving, so as to realize safe lane changing. The method is based on the realization of related technologies such as intelligent internet connection, vehicle-road cooperation and the like, and performs decision-making judgment for lane change according to the information such as environment, traffic and the like of roads around the preset range acquired in the communication area, thereby avoiding rear-end collision among vehicles when driving the intelligent internet connection and effectively improving the safety and reliability of automatic driving in the lane change process.

Description

Intelligent network vehicle merging and changing control method for expressway ramps under mixed-traveling condition

Technical Field

The invention relates to the technical field of intelligent traffic, in particular to a method for controlling merging and changing of an intelligent network vehicle of an expressway ramp under a mixed-driving condition.

Background

The intelligent internet automobile senses and identifies the surrounding environment of a running vehicle by means of a vehicle-mounted system and a road test system, analyzes and processes the acquired information such as the position of the vehicle, traffic signals, roads, obstacles and the like, and controls the speed and the steering of the automobile to realize the intelligent driving of the vehicle. The realization of the intelligent internet automobile technology mainly depends on the fusion of a plurality of auxiliary driving technologies, the single auxiliary driving technology can only carry out driving assistance on a driver, and the fusion of the plurality of auxiliary driving technologies can adapt to more scenes and even adapt to unmanned driving under the full scene. According to the degree of automation of intelligent driving, automobiles can be classified into four types, i.e., primary driver-assist automobiles, advanced driver-assist automobiles, autonomous automobiles, and unmanned automobiles. The development path of the intelligent networked automobile mainly starts from two aspects, namely intellectualization and networking. The intellectualization means that the intelligent Driving function of the automobile is realized by a method of combining an on-board sensor and an automatic control System of the automobile by depending on Advanced Driving Assistance technology, such as Advanced Driving Assistance System (ADAS). Networking is mainly realized by means of a vehicle networking system, such as a vehicle to outside information exchange (V2X) system, so that information exchange of vehicles, people, vehicles, roads and platforms is realized, the driving safety of the vehicles is improved, and the road passing efficiency is improved.

The lane changing behavior of the vehicle is a process for describing the driving characteristics of the driver, adjusting the driving state of the driver according to the stimulation of the traffic environment around the vehicle and completing the target strategy. According to the motivation for pursuing benefits, the lane change of the vehicle is generally divided into two modes of free lane change and forced lane change. The mandatory lane change refers to a behavior that has a determined target lane and must implement lane change in a certain section, such as diversion of a ramp, a converging vehicle, a vehicle in an interlacing area and the like, wherein the key of the behavior is the existence of a latest lane change point. The free lane change refers to lane change behavior of a vehicle in a more free driving space when the vehicle encounters a vehicle in a slower front direction in order to pursue a faster vehicle speed.

The method comprises the steps of collecting dynamic traffic information of vehicles which cannot leave, collecting traffic information data on the basis of a traffic information collecting system, and collecting traffic information of the vehicles in a conventional environment in a mode of microwave radar, video, infrared, annular induction coils, floating vehicle traffic information collection and the like. The loop induction coil is generally composed of a loop coil, a transmission feeder line and a detection processing unit, wherein the loop coil is laid on a road and forms a magnetic field nearby the loop coil, and when a vehicle enters the magnetic field, the detection processing unit detects the vehicle and outputs a signal; the system can not only count and detect traffic flow, but also measure speed. The microwave detector is a radar detector, detects vehicles by using Doppler effect, can detect traffic volume and speed, and achieves the purpose of detecting road traffic information. The video monitoring system mainly comprises three parts, namely a front end, a transmission part and a terminal, wherein the front end part mainly comprises a camera, a lens, a holder, a decoder and the like, the transmission part commonly uses optical cables, video cables, telephone wires and the like, and the terminal part is usually a monitor and can display images transmitted from the front end and control front-end equipment; the television monitoring system has the double functions of image monitoring and traffic data acquisition; the installation is simple, and the detection rate is high, and is longe-lived, and the maintenance cost is low. The floating car traffic information acquisition is to exchange real-time information with a traffic data center through vehicles (such as taxies, buses and the like) provided with a global satellite positioning system and a wireless communication device, and has the characteristics of wide acquisition range and low investment, can reflect the change of the running state of a road network, and provides reference for dredging.

In order to ensure that lane change behaviors can be successfully and safely completed under expected space and time conditions, common lane change models are divided into three situations, namely a lane change model based on dynamic repeated games, a lane change model based on utility selection requirements and a lane change model based on a fuzzy logic method. The lane changing behavior ratio of the vehicle is subjected to a dynamic repeated game process based on a lane changing model of the dynamic repeated game, the vehicle needing lane changing and a rear vehicle on a target lane are compared, and the game is carried out for seeking a high-speed and satisfactory driving space between the vehicle needing lane changing and the rear vehicle; and (4) considering speed factors and safety factors, and analyzing various factors influencing the expected speed of the vehicle to obtain a lane changing model of the vehicle. Under the lane changing model based on the utility selection requirement, the satisfaction degree of a driver on different lanes is different when the driver drives on the different lanes, the satisfaction degree can be expressed by the utility, and the utility maximization setting is obeyed, namely the lane where the vehicle is located is certainly the highest satisfaction degree, and once the satisfaction degree of driving on other lanes is higher, the lane changing requirement is generated. The lane change model based on the fuzzy logic method considers that the lane change is a thinking decision process, and the fuzzy logic method adopts linguistic variables for approximate reasoning, so that the lane change model is very suitable for describing a subjective judgment process based on a driver; and comprehensively considering the relation factors of the speed and the distance between the target vehicle and the adjacent vehicle to establish a lane change model based on a fuzzy logic lane change algorithm.

With the continuous development of the car networking technology, great innovation is made especially in the field of automatic driving at present. The traditional traffic flow on roads is gradually changed into the traffic flow formed by mixing automatic driving vehicles and manual driving vehicles. The complex traffic environment has a plurality of random and uncertain influence factors, so that the lane changing state of the vehicle in the hybrid traffic driving mode is also complicated and diversified. Considering that the vehicle lane change has direct influence on the traffic capacity and traffic stability of the road, especially when vehicles on the ramp merge into a main line lane, the road section of the confluence area is easy to be blocked by improper lane change behavior, and even the traffic safety problem is caused. Not only does this affect people's confidence in the automated driving technique, but it also invisibly presents challenges to the development of automated driving techniques. Therefore, for the problem of vehicle lane change of heterogeneous traffic flow in a ramp confluence area, the research on a control method for automatically driving vehicles to merge on the ramp is very meaningful for improving the traffic capacity and the vehicle running efficiency in the confluence area.

However, road side facilities are not comprehensive at the present stage, and intelligent networked vehicles are not popularized yet. In this case, the road surface artificial vehicle can only judge the driving state, and cannot obtain specific dynamic driving data. In addition, the lane changing time required by the conventional lane changing is long, traffic jam is easy to occur on the ramp of the express way, and particularly, in a mixed traffic driving state, the driving behavior of an artificial vehicle owner in a target lane cannot be judged by the conventional vehicle lane changing method, the influence of the mixed vehicle on the lane changing of the vehicle cannot be judged in different driving states, and the decision error of the lane changing of the vehicle is easily caused.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects in the prior art, and provide the control method for the merging and changing lanes of the intelligent on-line vehicle of the express way ramp under the mixed-running condition, which considers the influence of different driving forms of the mixed-running vehicle in the merging area on the changing lanes of the intelligent on-line vehicle and reduces the error in the decision of changing lanes of the intelligent on-line vehicle.

In order to solve the technical problem, the invention provides a method for controlling the merging and changing of an intelligent online vehicle on an expressway ramp under a mixed-driving condition, which comprises the following steps of:

s1: the intelligent internet vehicle serves as a main vehicle M to drive into the expressway confluence area, and the main vehicle M acquires surrounding road environment information in a communication area based on an intelligent vehicle path system and an intelligent vehicle-mounted system;

s2: calculating the triggering time t of the minimum safe distance of the vehicle A around the lane where the main vehicle M is away from according to the surrounding road environment information_i+cTrigger time t according to minimum safety distance_i+cCalculating the minimum safety clearance S_MSD(MA), minimum safety gap S_MSD(MA) ensuring that the host vehicle M does not collide with the surrounding vehicles A when changing lanes;

s3: obtaining the real-time distance S between the main vehicle M and the surrounding vehicles A_real(MA) real-time distance between the host vehicle M and the surrounding vehicles AS_real(MA) minimum safety clearance S_MSD(MA) comparison, if S_real(MA)＜S_MSD(MA), the host M does not generate the lane change motive, executing S4; if S_real(MA)≥S_MSD(MA), the master M generating the lane change motive, performing S5;

s4: the master vehicle M continues to run in the lane or stops to wait for the lane change opportunity, and skips to execute S3 to S_real(MA)≥S_MSD(MA) the host M generating a lane change motive, performing S5;

s5: establishing a driving lane changing track f (x) and a target lane line g (x) of the master vehicle M, calculating an expected path function g (t) taking time as a parameter variable according to the driving lane changing track and the target lane line, and obtaining a speed change function v (t) and an acceleration change function a (t) by the expected path function g (t);

s6: the main vehicle M acquires the surrounding road environment information again and judges whether a front vehicle N and a rear vehicle F exist in the target lane for lane change, and the acceleration a required when the main vehicle M changes lanes is calculated under the three conditions that only the front vehicle N exists, only the rear vehicle F exists, and all the front vehicle N and the rear vehicle F exist_changeThe master vehicle M is accelerated by an acceleration a_changeAnd (5) changing the lane into the target lane, and updating the state information of the intelligent vehicle internet vehicle.

Further, in the step S2, the triggering time t of the minimum safe distance between the host vehicle M and the vehicle a around the lane is calculated according to the surrounding road environment information_i+cThe method specifically comprises the following steps:

triggering time t of minimum safety distance_i+c＝t_i+t_cWherein t is_iAdjustment time t required for passing of the master vehicle M from the initial position to before lane change_cIs the time from the start of lane change to the minimum safe distance from the surrounding vehicle a; minimum safe distance S_min(MA) is a minimum distance at which the host vehicle M does not collide with the surrounding vehicle a in the following state, and is set according to the traveling speed of the vehicle.

Further, the triggering time t according to the minimum safety distance in S2_i+cCalculating the minimum safety clearance S_MSD(MA), specifically:

calculating the longitudinal distance between the head of the main vehicle M and the parking space of the vehicle A

Wherein S_MA(0) The initial distance between the master vehicle M and the vehicle A at the zero time of lane change, alpha is the yaw angle of lane change of the master vehicle M, a_MIs the acceleration of the host vehicle M, a_AAcceleration, v, of vehicle A_M(0) Is the initial velocity, v, of the host vehicle M_A(0) The initial velocity, W, of the vehicle A_MThe width of the main vehicle M is wide;

the minimum safety clearance between the main vehicle M and the vehicle A is obtained by the triggering time of the longitudinal distance, the minimum safety distance and the minimum safety distance between the head of the main vehicle M and the parking space of the vehicle A:

S_MSD(MA)＝max{S_MA(t_i+c),S_min(MA)}。

further, in the step S4, if v is the time v during which the host M continues to run in the lane or stops waiting for the timing to change lanes_M-v_AIs a value greater than a preset speed threshold, v_MIs the current speed, v, of the vehicle M_AThe vehicle M properly decelerates and warns to prompt the surrounding additional vehicle A to accelerate to leave the accelerating lane or decelerates to a time waiting for parking and changing the lane so that the vehicle in front of the accelerating lane changes the lane preferentially; if v is_M-v_AThe value of the speed threshold is less than or equal to the preset speed threshold, and the vehicle M performs a lane change decision at a constant speed or at a proper and uniform acceleration on the premise of ensuring that the vehicle in front of the acceleration lane changes lanes preferentially.

Further, in the step S5, a driving lane change trajectory f (x) and a target lane line g (x) of the host M are established, specifically:

the driving lane change track f (x) of the master vehicle M is obtained by fitting a polynomial function of degree 5:

f(x)＝a₀+a₁x¹+a₂x²+a₃x³+a₄x⁴+a₅x⁵；

the target lane line g (x) is obtained by fitting a polynomial function of degree 4:

g(x)＝b₀x⁰+b₁x¹+b₂x²+b₃x³+b₄x⁴。

further, in the step S5, an expected path function g (t) with time as a parameter variable is calculated according to the driving lane change track and the target lane line, and the expected path function g (t) with time as a parameter variable is:

further, in the S5, a speed change function v (t) and an acceleration change function a (t) are obtained from the expected path function g (t), and the speed change function

Said acceleration change function

Wherein,

v_mindicates the initial speed of lane change, a_mRepresenting initial acceleration of lane change, t representing elapsed time of lane change, b₀Is the position of the target lane on the coordinate system.

Further, when only the front vehicle N is present in S6, the specific process includes:

minimum safe distance S between main vehicle M and vehicle N when setting replacement path_min(MN) according to the minimum safe distance S_min(MN) calculating the minimum safety clearance S between the host vehicle M and the vehicle N_MSD(MN)＝max{S_MN(t_m),S_min(MN); wherein t is_mThe time from the lane change start of the master vehicle M to the minimum safety clearance from the surrounding vehicles N, S_MN(t_m) Is the minimum safety clearance of the host vehicle M from the surrounding vehicles N,

t∈[0,t_m1]，S_MN(0) is a main vehicleInitial distance a between M and vehicle N at zero time of lane change_NIs the acceleration of the vehicle N, a_MIs the acceleration, v, of the vehicle M_N(0) Is the initial velocity, v, of the vehicle N_M(0) Is the initial velocity, t, of the vehicle M_m1The elapsed time for changing lanes of the master vehicle M;

calculating the longitudinal distance between the head of the main vehicle M and the parking spaces of the N vehicles:

wherein S is_NIs the distance N traveled on the target lane, S_N＝V_N*t_M，S_MAs is the distance traveled by the host vehicle M,

L_Nthe length of the vehicle N, W_MThe main vehicle M is in a vehicle width, and theta is a lane changing yaw angle generated by the main vehicle M in the lane changing process;

calculating the real-time distance between the main vehicle M and the vehicle N:

judgment S_real(MN)≥S_MSD(MN) is established, if not, the vehicle M continues to run or stop in the current lane until S_real(MN)≥S_MSD(MN) true;

when S is_real(MN)≥S_MSD(MN) is established, and the distance between the master vehicle M and the vehicle N after the lane change of the master vehicle M is set to be the minimum safe distance S_min(MN) at this time t_m1Satisfy the requirement of

Solved to obtain

Setting the distance between the main vehicle M and the vehicle N after the lane change of the main vehicle M as a critical distance 0, wherein the time for the main vehicle M to pass the lane change is t_m2At this time t_m2Satisfy the requirement of

Solved to obtain

Will t_m1Substituting into acceleration variation function a (t) to obtain a_m1Will t_m2Substituting into acceleration variation function a (t) to obtain a_m2To obtain a_change＝(a_m1,a_m2](ii) a Based on a_change＝(a_m1,a_m2]At t, is required_m2Adjusting acceleration change of the host vehicle M within time to satisfy a_changeWhile ensuring that the pressure drop is at (t)_m2,t_m1]Speed v of the host vehicle M in a time period_mSpeed V of the preceding vehicle N_NAnd when the main vehicle M finishes lane changing, the main vehicle M and the vehicle N in front keep running at a constant speed.

Further, when only the rear vehicle F is present in S6, the specific process is as follows:

minimum safe distance S between main vehicle M and vehicle F when setting a lane change_min(MF) according to the minimum safety distance S_min(MF) calculating the minimum safety clearance S between the host vehicle M and the vehicle N_MSD(MF)＝max{S_MF(t_m'),S_min(MF) }; wherein t is_m'For the time from the lane change start of the master vehicle M to the minimum safety clearance from the surrounding vehicle F, S_MF(t_m') Is the minimum safety clearance of the host vehicle M from the surrounding vehicles F,

t∈[0,t_m1']，S_MF(0) is the initial distance, a, between the master vehicle M and the vehicle F at the zero time of lane change_FIs the acceleration of the vehicle F, a_MIs the acceleration, v, of the vehicle M_F(0) Is the initial velocity v of the vehicle F_M(0) Is the initial velocity, t, of the vehicle M_m1'The elapsed time for changing lanes of the master vehicle M;

calculating the longitudinal distance between the head of the main vehicle M and the parking space of the vehicle F:

wherein S is_FIs the distance traveled by the vehicle F on the target lane, S_F＝V_F*t_M'，S_MAs is the distance traveled by the host vehicle M,

L_Mthe length of the vehicle M, W_MThe main vehicle M is in a vehicle width, and theta is a lane changing yaw angle generated by the main vehicle M in the lane changing process;

calculating the real-time distance S between the main vehicle M and the vehicle F_real(MF)：

Judgment S_real(MF)≥S_MSD(MF) is true, if not, the vehicle M continues to run or stop in the current lane until S_real(MF)≥S_MSD(MF) is established;

when S is_real(MF)≥S_MSD(MF) establishing that the distance between the main vehicle M and the vehicle F after the lane change of the main vehicle M is finished is the minimum safe distance S_min(MF), at this time t_m1'Satisfy the requirement of

Solved to obtain

Setting the distance between the master vehicle M and the vehicle F after the lane change of the master vehicle M as a critical distance 0, wherein the time for the lane change of the master vehicle M is t_m2'At this time t_m2'Satisfy the requirement of

Solved to obtain

Will t_m1'Substituting into acceleration variation function a (t) to obtain a_m1', will t_m2'Substituting into acceleration variation function a (t) to obtain a_m2', obtaining a_change＝(a_m1',a_m2'](ii) a Based on a_change＝(a_m1',a_m2']At t, is required_m2’Inner adjusting mainAcceleration of the vehicle M varies to satisfy a_changeWhile ensuring that the temperature is at (t)_m2,t_m1]Speed v of the host vehicle M in a time period_mEqual to or greater than the speed V of the front vehicle F_F。

Further, in S6, when both the front vehicle N and the rear vehicle F are present, the specific process is as follows:

t∈[0,t_m1]，S_MN(0) the initial distance, a, between the main truck M and the truck N at the zero time of lane change_NIs the acceleration of the vehicle N, a_MIs the acceleration, v, of the vehicle M_N(0) Is the initial velocity, v, of the vehicle N_M(0) Is the initial velocity, t, of the vehicle M_m1The elapsed time for changing lanes of the master vehicle M;

Judgment S_real(MN)≥S_MSD(MN) and S_real(MF)≥S_MSD(MF) is satisfied at the same time, and if not, the vehicle M continues to run in the current lane or stops for waiting until S_real(MN)≥S_MSD(MN) and S_real(MF)≥S_MSD(MF) the same asThe time is right;

when S is_real(MN)≥S_MSD(MN) and S_real(MF)≥S_MSD(MF) is established simultaneously, setting the minimum safe distance S between the vehicles N and F on the target lane_min(NF) according to the minimum safety distance S_min(NF) calculating the minimum safety clearance S between vehicle N and vehicle F_MSD(NF)＝max{S_NF(t), smin (nf) }, wherein S_NF(t)＝S_MN(t)+S_MF(t)＝S_N+S_MN(0)+S_MF(0)-S_F-2L-2W_M*sinθ；

Calculating the real-time distance S between the vehicle N and the vehicle F_real(NF)：

Wherein S_NF(0) The initial distance between the master vehicle N and the vehicle F at the zero time of lane change;

judgment S_real(NF)≥S_MSD(NF) is true, if not, the vehicle M continues to run or stop in the current lane until S_real(NF)≥S_MSD(NF) is true;

when S is_real(NF)≥S_MSD(NF) establishing, keeping the vehicle N and the vehicle F running at a constant speed, and setting the distance between the main vehicle M and the vehicle N after the main vehicle M finishes changing the lane as the minimum safe distance S_min(MN) at this time t_m1Satisfy the requirement of

Solved to obtain

Solved to obtain

Will t_m1Substituting into acceleration variation function a (t) to obtain a_m1Will t_m2Substituting into acceleration variation function a (t) to obtain a_m2；

Setting the distance between the main vehicle M and the vehicle F after the lane change of the main vehicle M as the minimum safe distance S_min(MF), at this time t_m1'Satisfy the requirement of

Solved to obtain

Solved to obtain

Will t_m1'Substituting into acceleration variation function a (t) to obtain a_m1', will t_m2'Substituting into acceleration variation function a (t) to obtain a_m2'；

A at this time is obtained_change＝(a_m1’,a_m2’]∪(a_m1,a_m2]The combination lane change time is generally within 5s, and the vehicle M needs to be in t ═ min { t }_m1，t_m2’5s } adjusting acceleration change of the host vehicle M to satisfy a_changeWhile ensuring that the vehicle speed v of the host vehicle M is made at the time of completion of lane change_mKeeping the speed of the front vehicle F and the rear vehicle N at a constant speed.

Compared with the prior art, the technical scheme of the invention has the following advantages:

(1) considering the condition of the mixed traffic flow, calculating the optimal safety gap distance triggering time and acceleration based on the acquired real-time traffic flow information and the running condition information of surrounding vehicles, optimizing the acceleration and deceleration of the intelligent network vehicle lane change process, and improving the traffic efficiency of the ramp merging area;

(2) the influence of interfering vehicles on lane change of the intelligent networked vehicle under different conditions of coming vehicles before and after lane change is considered, and meanwhile, the feasibility of the method is dynamically evaluated by using the expected path function according to the current traffic environment, so that rear-end collision accidents of the vehicles in the lane change process are avoided, and the safety and reliability of automatic driving in the lane change process are effectively improved;

(3) the method is based on the intelligent internet vehicle driving lane change track expectation function, and analyzes the acceleration change of the vehicle at different moments so as to perform post-adjustment and optimization processing, thereby shortening the lane change time of the intelligent vehicle while ensuring safe lane change.

Drawings

In order that the present disclosure may be more readily and clearly understood, reference will now be made in detail to the present disclosure, examples of which are illustrated in the accompanying drawings.

Fig. 1 is a flowchart for implementing the ramp merging stream switching control provided by the present invention.

FIG. 2 is a diagram of a function of the driving track of the M vehicle entering the target lane in the invention.

Fig. 3 is a schematic diagram of the positional relationship between the adjacent vehicle N and the adjacent vehicle F on the target lane when the M vehicle changes lanes in the present invention.

Fig. 4 is a track diagram illustrating the lane change of the vehicle M to the target lane in the present invention.

Fig. 5 is a communication area information sensing diagram of the expressway turn-merging area in the invention.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

In the description of the present invention, it should be understood that the term "comprises/comprising" is intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of S or elements is not limited to those listed but may alternatively include other S or elements not listed or inherent to such process, method, article, or apparatus.

Referring to the flowchart in fig. 1, an embodiment of the method for controlling the merging and changing of the intelligent networked vehicle on the expressway ramp under the mixed-driving condition in the invention comprises the following steps:

s1: the intelligent internet vehicle serves as a main vehicle M to drive into the expressway confluence area, and the main vehicle M acquires surrounding road environment information in a communication area based on an intelligent vehicle path system and an intelligent vehicle-mounted system; the range of the acquired surrounding road environment information is shown as a broken line range in fig. 5, and the sensing area range is preset to 800m in the present embodiment. The surrounding road environment information includes lane information, vehicle information (vehicle type, vehicle running position and speed information, vehicle running state), and obstacle information;

s2: calculating the triggering time t of the minimum safe distance of the vehicle A around the lane where the main vehicle M is away from according to the surrounding road environment information_i+cTrigger time t according to minimum safety distance_i+cFurther calculating the minimum safety clearance S_MSD(MA), minimum safety gap S_MSD(MA) it is possible to ensure that the host vehicle M does not collide with the surrounding vehicles A at the time of lane change.

S2.1: the triggering time for calculating the minimum safe distance between the master vehicle M and the vehicle A around the lane where the master vehicle M is located according to the surrounding road environment information is obtained according to the minimum safe distance of the master vehicle M, and specifically comprises the following steps:

minimum safe distance S_min(MA) a minimum distance at which the host vehicle M does not collide with the surrounding vehicle a in a following state, set according to a running speed of the vehicle; in the embodiment, the minimum safe distance S is set under the condition that the speed of the main vehicle M is 40km/h_min(MA) 30 m. If the speed of the host vehicle M is faster and the flow rate of the vehicle in the lane is larger, the minimum safe distance is set correspondingly larger.

The triggering time of the minimum safety distance is obtained according to vehicle dynamics and initial vehicle speed difference analysis under the condition that other factors are ignored. That is, the traffic environment in the invention is only an ideal state, and other factors such as weather, road friction, air resistance and the like are not considered.

Triggering time t of minimum safety distance_i+c＝t_i+t_cWherein t is_iFor the main truck M to pass from the initial position to the position before changing lanesElapsed adjustment time, t_cIs the time from the start of the lane change to the minimum safe distance from the surrounding vehicle a.

In this example t_iThe adjustment time t before lane change of the M cars from the initial position_cFrom the adjusted start time to the time when the distance between the two vehicle heads is 30m, namely:

wherein a is_MIs the acceleration of the host vehicle M, a_AAcceleration, v, of vehicle A_M(0) Is the initial velocity, v, of the host vehicle M_A(0) The initial velocity of car a.

S2.2: calculating the minimum safety clearance according to the triggering time of the minimum safety distance, specifically:

s2.2.1: calculating the longitudinal distance between the head of the main vehicle M and the parking space of the vehicle A

Wherein S_MA(0) The initial distance between the master vehicle M and the vehicle A at the zero time of lane change, alpha is the yaw angle of lane change of the master vehicle M, a_MIs the acceleration of the host vehicle M, a_AAcceleration, v, of vehicle A_M(0) Is the initial velocity, v, of the host vehicle M_A(0) The initial velocity, W, of the vehicle A_MThe width of the main vehicle M is wide; in general, the lane-changing yaw angle of the vehicle is between 3 ° and 5 °, so that the value of sin α tends to 0, and the value of cos α tends to 1, and the longitudinal distance between the head of the host vehicle M and the stall of the vehicle a can be simplified as follows:

s2.2.2: the minimum safety clearance between the main vehicle M and the vehicle A is obtained by the triggering time of the longitudinal distance, the minimum safety distance and the minimum safety distance between the vehicle head of the main vehicle M and the vehicle seat A:

S_MSD(MA)＝max{S_MA(t_i+c),S_min(MA)}；

s3: obtaining the real-time distance S between the main vehicle M and the surrounding vehicles A_real(MA) determining a real-time distance S between the host vehicle M and the surrounding vehicle A_real(MA) minimum safety clearance S_MSD(MA) comparison, if S_real(MA)＜S_MSD(MA), the host M does not generate the lane change motive, executing S4; if S_real(MA)≥S_MSD(MA), the master M generating the lane change motive, performing S5;

if v is the time when the main vehicle M continues to run in the lane or stops for waiting for the lane-changing time_M-v_AIs a value greater than a preset speed threshold, v_MIs the current speed, v, of the vehicle M_AThe vehicle M properly decelerates and warns to prompt the surrounding additional vehicle A to accelerate to leave the accelerating lane or decelerates to a time waiting for parking and changing the lane so that the vehicle in front of the accelerating lane changes the lane preferentially; if v is_M-v_AThe value of the speed threshold is less than or equal to the preset speed threshold, and the vehicle M performs a lane change decision at a constant speed or at a proper and uniform acceleration on the premise of ensuring that the vehicle in front of the acceleration lane changes lanes preferentially, so that the vehicle on the current lane can safely and effectively drive away from the acceleration lane. The speed threshold in this embodiment is 20 km/h.

S5: establishing a driving lane changing track f (x) and a target lane line g (x) of the master vehicle M, calculating an expected path function with time as a parameter variable on the basis of the driving lane changing track and the target lane line, and obtaining a speed change function and an acceleration change function by the expected path function;

s5.1: establishing a driving lane changing track f (x) and a target lane line g (x) of the master vehicle M, specifically:

f(x)＝a₀+a₁x¹+a₂x²+a₃x³+a₄x⁴+a₅x⁵；

considering the flexibility of the target lane line, the target lane line g (x) is obtained by fitting a polynomial function of degree 4:

g(x)＝b₀x⁰+b₁x¹+b₂x²+b₃x³+b₄x⁴；

s5.2: calculating an expected path function with time as a parameter variable according to the driving lane change track and the target lane line, and specifically:

s5.2.1: as shown in FIG. 2, the host vehicle M makes a lane change at a constant vehicle speed, and the position of the host vehicle M at the end of the lane change is at the tangent point (x) of the lane change trajectory and the target lane line_m，y_m) In the above case, the curvature of the lane change trajectory of the host vehicle M and the curvature of the target lane line at the tangent point are the same, that is, the curvature of the polynomial function at the tangent point

Wherein, f' (x)_m) The driving change track f (x) of the master M being at point x_mFirst derivative of (a), g' (x)_m) Is a target lane line g (x) at point x_mThe first derivative of (c).

Further unfolding the curvature K yields:

s5.2.2: when the main vehicle M changes the road, the actual road section is in lateral linearity, the influence of the bending degree on the road surface can be ignored to a certain extent, namely b 1-b 2-b 3-b 4-0, and the target road line g (x) can be reduced to g (x) -b₀x⁰＝b₀；

G (x) b₀Substituted into the curvature K to obtain

Solving to obtain the optimal unary quintic polynomial equation, and obtaining the driving lane change track of the main vehicle M as follows:

s5.2.3: the running distance of the main vehicle M

The driving switching track f (x) in S5.2.2 is substituted to obtain the expected path function g (t) with time as a parameter variable, which is:

s5.3: obtaining a speed change function and an acceleration change function from the expected path function, specifically:

obtaining a velocity variation function by performing a derivation on the expected path function g (t)

Carrying out one-time derivation on the speed change function to obtain an acceleration change function

Wherein,

S6: the main vehicle M acquires the surrounding road environment information again and judges whether a front vehicle N and a rear vehicle F exist in the target lane for switching, and under the three conditions that only the front vehicle N exists, only the rear vehicle F exists, and both the front vehicle N and the rear vehicle F exist, the front vehicle N of the target lane for switching to according to the main vehicle M respectivelyAnd the running information of the rear vehicle F calculates the acceleration a required when the main vehicle M changes the lane_changeThe master vehicle M is accelerated by an acceleration a_changeAnd (5) changing the lane into the target lane, and updating the state information of the intelligent vehicle internet vehicle. The vehicle operation change is a dynamic process, so that the environmental information of the surrounding road needs to be acquired in real time, and the host vehicle M acquires the surrounding road environmental information again to determine whether the adjacent preceding and following vehicles on the target lane change the lane.

S6.1: the main vehicle M judges whether a front vehicle N and a rear vehicle F exist in the target lane changed into the lane according to the surrounding road environment information acquired again, and if only the front vehicle N exists, S6.2-S6.7 are executed; if only the rear vehicle F exists, executing S6.8-S6.13; if the front vehicle N and the rear vehicle F are both available, executing S6.14-S6.18;

s6.2: minimum safe distance S between main vehicle M and vehicle N when setting replacement path_min(MN) in the present embodiment, S is set with reference to a domestic vehicle travel safety distance_min(MN) ═ 30 m. According to the minimum safety distance S_min(MN) calculating the minimum safety clearance S between the host vehicle M and the vehicle N_MSD(MN)＝max{S_MN(t_m),S_min(MN)}；

Wherein t is_mThe time from the lane change start of the master vehicle M to the minimum safety clearance from the surrounding vehicles N, S_MN(t_m) Is the minimum safety clearance of the host vehicle M from the surrounding vehicles N, here t_mIs t is obtained as follows_m1，

t∈[0,t_m1]，S_MN(0) The initial distance, a, between the main truck M and the truck N at the zero time of lane change_NIs the acceleration of the vehicle N, a_MIs the acceleration, v, of the vehicle M_N(0) Is the initial velocity, v, of the vehicle N_M(0) Is the initial velocity, t, of the vehicle M_m1The elapsed time for lane change of the master vehicle M.

S6.3: calculating the longitudinal distance between the head of the main vehicle M and the parking spaces of the N vehicles: s_MN(t)＝S_N+S_MN(0)-S_M-L_N-W_M*sinθ；

Wherein S is_MN(0) The initial distance S between the main vehicle M and the vehicle N at the zero time of lane change_NIs the distance N traveled on the target lane, S_MThe distance traveled by the host vehicle M, L_NThe length of the vehicle N, W_MThe main vehicle M is in a vehicle width, and theta is a lane changing yaw angle generated by the main vehicle M in the lane changing process; in the embodiment, the length and the width of the vehicle are respectively 3.4m and 1.8m according to the standard small vehicle.

Solving for S based on vehicle dynamics and physics_N、S_MTo obtain:

S_N＝V_N*t_M

in general, the lane change yaw angle of a vehicle is between 3 ° and 5 °, so that if the value of sin α is close to 0 and the value of cos α is close to 1, the vehicle will have a lane change yaw angle of 3 ° to 5 °

S6.4: calculating the real-time distance S between the main vehicle M and the vehicle N_real(MN), should satisfy:

s6.5: judgment S_real(MN)≥S_MSD(MN) is true, if true, S6.6 is executed; if not, the vehicle M continues to run or stop in the current lane until S_real(MN)≥S_MSD(MN) true, go to S6.6;

s6.6: setting the distance between the master vehicle M and the vehicle N after the lane change of the master vehicle M as the minimum safe distance S_min(MN) at this time t_m1Satisfy the requirement of

Solved to obtain

Solved to obtain

S6.7: will t_m1Substituting acceleration change function

To obtain a_m1Will t_m2Substituting acceleration change function

To obtain a_m2To obtain a_change＝(a_m1,a_m2]. Acceleration a during a lane change_m1、a_m2And time t required for lane change_m1、t_m2Is the corresponding.

Based on a_change＝(a_m1,a_m2]At t, is required_m2Adjusting acceleration change of the host vehicle M within time to satisfy a_changeWhile ensuring that the pressure drop is at (t)_m2,t_m1]Speed v of the host vehicle M in a time period_mSpeed V of the preceding vehicle N_NAnd the main vehicle M and the front vehicle N keep running at a constant speed at the time of finishing lane changing, so that the running safety is further ensured.

S6.8: minimum safe distance S between main vehicle M and vehicle F when setting a lane change_min(MF), in the present embodiment, S is set with reference to a domestic vehicle travel safety distance_min(MF) ═ 40 m. According to the minimum safety distance S_min(MF) calculating the minimum safety clearance S between the host vehicle M and the vehicle N_MSD(MF)＝max{S_MF(t_m'),S_min(MF)}；

Wherein t is_m'For the host vehicle M from lane change to the vehicle around the distanceTime for F to reach minimum safety gap, S_MF(t_m') Is the minimum safety clearance of the host vehicle M from the surrounding vehicle F, here t_m'Is t is obtained as follows_m1'，

t∈[0,t_m1']，S_MF(0) Is the initial distance, a, between the master vehicle M and the vehicle F at the zero time of lane change_FAcceleration, v, of vehicle F_F(0) The initial velocity of the vehicle F.

S6.9: calculating the longitudinal distance between the head of the main vehicle M and the parking space of the vehicle F: s_MF(t)＝S_M+S_MF(0)-S_F-L_M-W_M*sinθ。

Wherein S is_FIs the distance traveled by the vehicle F on the target lane, S_MThe distance traveled by the host vehicle M, L_MThe length of the vehicle M, W_MThe main vehicle M is in a vehicle width, and theta is a lane changing yaw angle generated by the main vehicle M in the lane changing process;

solving for S based on vehicle dynamics and physics_F、S_MTo obtain:

S_F＝V_F*t_M'

in general, the lane change yaw angle of the vehicle is between 3 ° and 5 °, so that the value of sin α tends to 0, the value of cos α tends to 1, and so on

S6.10: calculating the real-time distance S between the main vehicle M and the vehicle F_real(MF), which should satisfy:

s6.11: judgment S_real(MF)≥S_MSD(MF) is true, if true, S6.12 is performed; if not, the vehicle M continues to run or stop in the current lane until S_real(MF)≥S_MSD(MF) true, S6.12 is performed;

s6.12: setting the distance between the main vehicle M and the vehicle F after the lane change of the main vehicle M as the minimum safe distance S_min(MF), where the elapsed time for the lane change of the host vehicle M is t_m1'At this time t_m1'Satisfy the requirement of

Solved to obtain

Solved to obtain

S6.13: will t_m1'Substituting acceleration change function

To obtain a_m1', will t_m2'Substituting acceleration change function

To obtain a_m2', obtaining a_change＝(a_m1',a_m2']。

Based on a_change＝(a_m1',a_m2']At t, is required_m2’Internally adjusting the acceleration change of the main vehicle M to satisfy a_changeWhile ensuring that the temperature is at (t)_m2,t_m1]Speed v of the host vehicle M in a time period_mEqual to or greater than the speed V of the front vehicle F_fFurther guarantee driving safetyAnd (4) completeness.

S6.14: when a vehicle N is in front of the main vehicle M and a vehicle F is in back of the main vehicle M, the main vehicle M needs to find an insertable gap for changing the lane; S6.2-S6.4 are executed to obtain S_MSD(MN) and S_real(MN), executing S6.8-S6.10 to obtain S_MSD(MF) and S_real(MF)；

Judgment S_real(MN)≥S_MSD(MN) and S_real(MF)≥S_MSD(MF) is true at the same time, if true at the same time, perform S6.15; if not, the vehicle M continues to run or stop in the current lane until S_real(MN)≥S_MSD(MN) and S_real(MF)≥S_MSD(MF) is also true, S6.15 is performed;

s6.15: to satisfy the lane change of the host vehicle M in this state, a minimum safe distance S between the vehicle N and the vehicle F on the target lane is set_min(NF), in this embodiment, S is set with reference to the domestic safe driving distance_min(NF)＝S_min(MN)+S_min(MF) ═ 70 m. According to the minimum safety distance S_min(NF) calculating the minimum safety clearance S between vehicle N and vehicle F_MSD(NF)＝max{S_NF(t),Smin(NF)}；

Wherein S_NF(t)＝S_MN(t)+S_MF(t)＝S_N+S_MN(0)+S_MF(0)-S_F-2L-2W_M*sinθ。

S6.16: calculating the real-time distance S between the vehicle N and the vehicle F_real(NF) satisfying:

wherein S is_NF(0) The initial distance between the master vehicle N and the vehicle F at the zero time of lane change is shown.

S6.17: judgment S_real(NF)≥S_MSD(NF) judging whether the speed of the vehicle N and the speed of the vehicle F are equal, if so, keeping the vehicle N and the vehicle F to run at a constant speed, and executing S6.18; if not, the vehicle M continues to run or stop in the current lane until S_real(NF)≥S_MSD(NF) true, go to S6.18;

s6.18: execution of S66 to S6.7 obtaining t_m1、t_m2、a_m1And a_m2Executing S6.12-S6.13 to obtain t_m1'、t_m2'、a_m1' and a_m2'；

A at this time is obtained_change＝(a_m1’,a_m2’]∪(a_m1,a_m2]Considering that the lane change time is about 5s generally, setting the longitudinal acceleration of the main vehicle M to be 0km/h can obtain the speed and the acceleration of the vehicle at different lane change moments based on the running track, and based on the safe lane change time of the traditional vehicle, the vehicle M needs to be in t-min { t } min_m1，t_m2’5s, i.e. it is necessary to complete the lane change at t ═ min { t }_m1，t_m2’5s } adjusting acceleration change of the host vehicle M to satisfy a_changeWhile ensuring that the vehicle speed v of the host vehicle M is made at the time of completion of lane change_mThe speed of the front vehicle F and the speed of the rear vehicle N are kept at a constant speed, and the driving safety is further guaranteed.

The main vehicle M in the invention can change the lane when driving from the ramp to the main road as shown in FIG. 3, or change the lane on a different lane of the main road as shown in FIG. 4.

(2) the influence of interfering vehicles on intelligent network vehicle lane changing under different conditions of coming vehicles before and after lane changing is considered, and meanwhile, the feasibility of the method is dynamically evaluated by using the expected path function according to the current traffic environment, so that rear-end collision accidents of the vehicles in the lane changing process are avoided, and the lane changing process is safer and more reliable;

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operations S to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.

Claims

1. A method for controlling merging and changing of an intelligent online vehicle on an expressway ramp under mixed-traveling conditions is characterized by comprising the following steps of:

2. The intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: in the step S2, the triggering time t of the minimum safe distance of the vehicle A around the lane where the host vehicle M is located is calculated according to the surrounding road environment information_i+cThe method specifically comprises the following steps:

3. The intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: the triggering time t according to the minimum safety distance in the step S2_i+cCalculating the minimum safety clearance S_MSD(MA), specifically:

Wherein S_MA(0) The initial distance between the master vehicle M and the vehicle A at the zero time of lane change, alpha is the yaw angle of lane change of the master vehicle M, a_MIs the acceleration of the host vehicle M, a_AIs that of vehicle AVelocity, v_M(0) Is the initial velocity, v, of the host vehicle M_A(0) The initial velocity, W, of the vehicle A_MThe width of the main vehicle M is wide;

S_MSD(MA)＝max{S_MA(t_i+c),S_min(MA)}。

4. the intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: in the step S4, if v is in the process of the host vehicle M continuing to run in the lane or stopping for waiting for the lane change opportunity_M-v_AIs a value greater than a preset speed threshold, v_MIs the current speed, v, of the vehicle M_AThe vehicle M properly decelerates and warns to prompt the surrounding additional vehicle A to accelerate to leave the accelerating lane or decelerates to a time waiting for parking and changing the lane so that the vehicle in front of the accelerating lane changes the lane preferentially; if v is_M-v_AThe value of the speed threshold is less than or equal to the preset speed threshold, and the vehicle M performs a lane change decision at a constant speed or at a proper and uniform acceleration on the premise of ensuring that the vehicle in front of the acceleration lane changes lanes preferentially.

5. The intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: in the step S5, a driving lane change trajectory f (x) and a target lane line g (x) of the host M are established, specifically:

f(x)＝a₀+a₁x¹+a₂x²+a₃x³+a₄x⁴+a₅x⁵；

g(x)＝b₀x⁰+b₁x¹+b₂x²+b₃x³+b₄x⁴。

6. the intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 5, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: in the step S5, an expected path function g (t) with time as a parameter variable is calculated according to the lane change track and the target lane line, where the expected path function g (t) with time as a parameter variable is:

7. the intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: in the step S5, a velocity change function v (t) and an acceleration change function a (t) are obtained from the expected path function g (t), and the velocity change function

Said acceleration change function

Wherein,

8. The intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: when only the front vehicle N is available in the S6, the specific process is as follows:

S_MN(0) the initial distance, a, between the main truck M and the truck N at the zero time of lane change_NIs the acceleration of the vehicle N, a_MIs the acceleration, v, of the vehicle M_N(0) Is the initial velocity, v, of the vehicle N_M(0) Is the initial velocity, t, of the vehicle M_m1The elapsed time for changing lanes of the master vehicle M;

when S is_real(MN)≥S_MSD(MN) is established, and the main vehicle M is set to finish lane changeThe distance between the rear part and the vehicle N is the minimum safe distance S_min(MN) at this time t_m1Satisfy the requirement of

Solved to obtain

Solved to obtain

9. The intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: when only the rear vehicle F exists in the S6, the specific process is as follows:

minimum safe distance S between main vehicle M and vehicle F when setting a lane change_min(MF) according to the minimum safety distance S_min(MF) calculating the minimum safety clearance S between the host vehicle M and the vehicle N_MSD(MF)＝max{S_MF(t_m'),S_min(MF) }; wherein t is_m'For the main vehicle M to get from the lane change to the vehicle F around the distanceTime to minimum safety gap, S_MF(t_m') Is the minimum safety clearance of the host vehicle M from the surrounding vehicles F,

S_MF(0) is the initial distance, a, between the master vehicle M and the vehicle F at the zero time of lane change_FIs the acceleration of the vehicle F, a_MIs the acceleration, v, of the vehicle M_F(0) Is the initial velocity v of the vehicle F_M(0) Is the initial velocity, t, of the vehicle M_m1'The elapsed time for changing lanes of the master vehicle M;

Solved to obtain

Solved to obtain

Will t_m1'Substituting into acceleration variation function a (t) to obtain a_m1', will t_m2'Substituting into acceleration variation function a (t) to obtain a_m2', obtaining a_change＝(a_m1',a_m2'](ii) a Based on a_change＝(a_m1',a_m2']At t, is required_m2’Internally adjusting the acceleration change of the main vehicle M to satisfy a_changeWhile ensuring that the temperature is at (t)_m2,t_m1]Speed v of the host vehicle M in a time period_mEqual to or greater than the speed V of the front vehicle F_F。

10. The intelligent online vehicle merging and changing control method for the expressway ramps under the mixed-traveling condition according to claim 1, wherein the intelligent online vehicle merging and changing control method comprises the following steps of: in S6, when both the front vehicle N and the rear vehicle F are present, the specific process is as follows:

S_MN(0) the initial distance between the main truck M and the truck N at the zero time of lane changeFrom, a_NIs the acceleration of the vehicle N, a_MIs the acceleration, v, of the vehicle M_N(0) Is the initial velocity, v, of the vehicle N_M(0) Is the initial velocity, t, of the vehicle M_m1The elapsed time for changing lanes of the master vehicle M;

Judgment S_real(MN)≥S_MSD(MN) and S_real(MF)≥S_MSD(MF) is satisfied at the same time, and if not, the vehicle M continues to run in the current lane or stops for waiting until S_real(MN)≥S_MSD(MN) and S_real(MF)≥S_MSD(MF) is established simultaneously;

judgment S_real(NF)≥S_MSD(NF) is true, and if not,the vehicle M continues to run or stop in the current lane until S_real(NF)≥S_MSD(NF) is true;

Solved to obtain

Solved to obtain

Solved to obtain

Solved to obtain