CN113554886B - A method for resolving traffic conflict at a coordinated vehicle-road intersection - Google Patents

Abstract

The invention discloses a method for resolving traffic conflict at a vehicle-road coordinated intersection. The vehicle-mounted unit and the roadside unit are used to collect real-time dynamic traffic information of the intersection in full time and space, and the intersection control center performs fusion processing on the received traffic data information. Provide driving behavior suggestions for the vehicle, so that the vehicle can adjust the driving state in advance in the control area, control the distance between the vehicle and the vehicle ahead to the optimal gap, and maintain this state to drive into the buffer zone and intersection at a constant speed, so that the traffic flow in the conflict direction can be Use this gap to alternately pass through the intersection conflict area, so as to achieve conflict resolution. The invention can make the vehicle no longer limited by the control of the traditional signal light, reduce the fixed delay caused by the traffic signal control to the vehicle, greatly improve the traffic capacity of the intersection and the traffic efficiency of the vehicle on the premise of ensuring the driving safety, and realize the time and space of the intersection. full utilization of resources.

Description

A method for resolving traffic conflict at a vehicle-road coordinated intersection

technical field

The invention relates to the technical field of vehicle control at road intersections, in particular to a method for resolving traffic conflict at a vehicle-road coordinated intersection.

Background technique

Intersection, as the hub node of traffic collection, turning and evacuation, is the concentration of road traffic conflicts, and is also the focus of urban road traffic design and organization management. Therefore, an efficient and reasonable strategy for resolving traffic conflicts at intersections is the key to solving the problem of urban traffic congestion, and it is also the bottleneck that restricts the efficiency of urban traffic operation and the traffic capacity of road intersections.

Under the prior art, in order to ensure vehicle safety and smooth traffic flow, the signal light control method of "stop at red light and go at green light" is generally adopted at intersections to guide vehicles in all directions to pass in an orderly manner. In this control mode, one party in the conflicting traffic flow at the intersection provides a safe passage space for the other party by stopping and avoiding, so as to achieve the purpose of conflict resolution. But obviously, this conflict resolution method can't make every minute count for signal timing, and it can't make every inch of land compete for traffic channelization, so there is a certain amount of free time and free area in the intersection, resulting in the intersection of time and space resources. of waste.

In the vehicle-road collaborative environment, intelligent vehicles and intelligent roads can conduct real-time information exchange, and extensively collect and fuse road full-time and space-time dynamic traffic information. On the basis of this technical support, vehicles in the intersection area can carry out active vehicle control and road collaborative management through information perception and interactive sharing, so as to achieve more intelligent and autonomous traffic conflict resolution, so that all vehicles at the intersection can Vehicles can always be in an orderly and efficient operation state to achieve the control effect of ensuring driving safety and improving traffic efficiency.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention discloses a method for resolving traffic conflict at a vehicle-road coordinated intersection, which enables vehicles at the intersection to adjust the driving state in advance to control the distance with the vehicle ahead to the optimal gap, so that the conflicting direction can be adjusted. Traffic flow can alternately pass through the intersection conflict area to achieve conflict resolution.

To achieve the above object, the present invention adopts the following technical solutions:

A vehicle flow conflict resolution method at a vehicle-road coordinated intersection, which divides the connecting section of a road intersection into three functional areas: a lane change area, a control area, and a buffer area according to different distances. The unit and the intersection control center perform corresponding information interaction respectively;

Each lane in the lane change area is provided with road markings for left turn, straight ahead and right turn, and each vehicle enters the lane change area and changes to the corresponding guide lane in advance according to the driving requirements;

All vehicles in the control area are prohibited from changing lanes and overtaking. When each vehicle enters the control area, it receives an instruction signal from the intersection control center, adjusts the current driving speed, and controls the distance from the vehicle ahead. to the optimal gap;

All vehicles in the buffer zone keep moving at a constant speed. After entering the buffer zone, each vehicle has reached the driving status required by the command of the intersection control center, and maintains a specific optimal relationship with the vehicle ahead. gap;

The on-board unit transmits vehicle information and driving status information to the intersection control center in real time, including vehicle size, vehicle position, travel time, travel speed, acceleration, and travel direction, and simultaneously receives the instruction information sent by the intersection control center, and provides information to the vehicle. control the operating status;

The roadside unit conducts real-time perception and monitoring of the road environment conditions in each functional area, and transmits relevant data information to the intersection control center in real time, including the traffic flow of each lane, lane occupancy, vehicle trajectory, lane width, wet road condition;

The intersection control center receives all the traffic data information collected by the vehicle-mounted unit and the roadside unit, performs information fusion processing, determines the position of the vehicle in the conflict area at the intersection according to the traveling directions of different vehicles, and calculates all traffic data information collected by the vehicle-mounted unit and the roadside unit. Calculate the optimal gap that needs to be maintained between the vehicle and the preceding vehicle based on the driving status information of the vehicle and the vehicle in the conflict direction, and send the optimal gap instruction information to the vehicle's On-board unit.

As a further preference of the present invention, the left-turn, straight-turn, and right-turn lanes at the intersection are all independent lanes. Vehicles are not allowed to merge or divide before and after entering the intersection. During the passage of vehicles at the intersection, they are all along the centerline of each lane. Driving; the length of the lane change area in the connecting section of the intersection is set to 300m, the length of the control area is set to 500m, and the length of the buffer zone is set to 200m. Of course, the length of each functional area can be based on the actual traffic at different intersections. According to the planning and adjustment of the situation, it should be ensured that the vehicle can complete the corresponding driving operation in each functional area; the roadside units are arranged at the even interval of 10m on both sides of the road in each functional area and the area around the intersection, so as to realize all the functions of the intersection. All-time, low-latency, and highly reliable real-time information perception for passing vehicles.

As a further preference of the present invention, the method for resolving traffic conflict at a vehicle-road coordinated intersection is specifically:

After the vehicle enters the lane change area of the intersection, it changes to the corresponding guide lane in advance according to the driving demand of the vehicle, and the control center judges whether the vehicle has a traffic conflict in the intersection according to the direction of the vehicle and other vehicles . If there is no conflict, the vehicle in the control area moves quickly according to the command of the control center, and passes the intersection safely under the condition of no conflict and interference; Calculate the corresponding driving clearance of the vehicle in each conflict area, take the maximum driving clearance value as the optimal clearance that should be maintained between the vehicle and the preceding vehicle, and feed back the optimal clearance value to the The vehicle's onboard unit. After receiving the command information from the control center, the vehicle adjusts the current driving speed in the control area, controls the distance between the vehicle and the vehicle in front to the optimal gap, and maintains this state to drive into the buffer zone and the intersection at a constant speed. When the vehicle enters the intersection with the optimal gap, the vehicle in the conflict direction of the vehicle can use the gap to safely pass through the conflict area, so as to achieve conflict resolution.

As a further preference of the present invention, the method for determining the position of the conflict zone of the vehicle in the intersection is specifically:

Taking the WL direction as an example, the guidance lanes that conflict with the vehicles in the WL direction at the intersection are SL, NS, ES, and NL. Taking the WS direction as an example, the guidance lanes in the intersection with the vehicles in the WS direction are in conflict. Lanes are NS, SL, EL, SS four directions. When the vehicle enters the corresponding guide lane in the lane change area, the control center determines whether there is a vehicle in the guide lane in the direction of the vehicle conflict between the lane change area and the intersection area according to the received traffic data information. If there is a vehicle, the overlapping area of the conflict direction and the vehicle's driving track is the conflict area, so the geographic location information of the conflict area can be determined by using GPS positioning identification and electronic map.

As a further preference of the present invention, the calculation method of the optimal gap that needs to be maintained between the vehicle and the preceding vehicle is as follows:

Assuming that vehicle V _i and vehicle V _i+1 are passing vehicles in direction D1, and vehicle V _j and vehicle V _j+1 are passing vehicles in direction D2 that conflict with direction D1, the sequence of vehicles passing through the conflict area is: V _i →vehicle Vj →vehicle V _i+1 →vehicle V _{j +1} , and when the vehicle V _i completely leaves the conflict zone, the vehicle V _j in the conflict direction just begins to enter the conflict zone; when the vehicle V _j completely leaves the conflict zone In the conflict zone, the vehicle V _i+1 in the conflict direction just begins to enter the conflict zone, that is, the vehicles in the two traffic flows in the conflict direction can alternately pass through the conflict zone, so as to achieve intersection conflict resolution.

Setting: U _i-i+1 represents the driving gap that needs to be maintained between vehicle V _i and vehicle V _i+1 in direction D1; U _j-j+1 represents vehicle V _j and vehicle V _j+1 in conflict direction D2 The driving gap that needs to be maintained between them; _l1 represents the action distance of the conflict area to the vehicle in the direction D1; _l2 represents the action distance of the conflict area to the vehicle in the conflict direction D2; s represents the length of the vehicle; v represents the speed of the vehicle.

The intersection control center analyzes and predicts the traffic flow conflict at the intersection according to the vehicle driving state information and road condition information, determines the position information of the traveling vehicle in each conflict area in the intersection, and calculates the driving gap that the vehicle needs to maintain when passing through each conflict area, and takes the The maximum value is used as the optimal clearance between the vehicle and the preceding vehicle when passing through the intersection.

As a further preference of the present invention, the adjustment process of the driving state of the vehicle in the control area is as follows:

After calculating the optimal clearance between the vehicle and the preceding vehicle, the intersection control center feeds back the optimal clearance instruction information to the on-board unit of each vehicle. After the vehicle receives the command information, it adjusts the driving state of the vehicle in the control area, and controls the distance between the vehicle and the vehicle in front to the optimal gap, as follows:

When a traffic flow W in a certain direction of the intersection enters the intersection control area, the control center divides it into several continuous sub- _convoys W ₁ , W ₂ , . . . Vehicle status adjustment. Among them, all the vehicles in each sub-convoy encounter the same conflict situation in the intersection passing area, so the vehicles belonging to the same sub-convoy all travel at the same speed and keep the same optimal gap at a constant speed.

Assuming that there are n vehicles in the sub-convoy W _k , when the vehicles in the convoy enter the road section of the intersection control area, the vehicles need to adjust from the current driving state A to the target state B, so as to maintain the best distance between each vehicle and the preceding vehicle. Excellent clearance. Setting: x _ai , v _ai , a _ai , t _ai , and u _ai represent the initial position, driving speed, acceleration, time of entering the control area, and the distance between the vehicle _Vi and the preceding vehicle, respectively, in the control area of the intersection. x _bi , v _b , and u _b respectively represent the position of the vehicle in the target state of the intersection control area, the driving speed, and the optimal gap maintained between it and the preceding vehicle; t _bi represents the time after the state adjustment is completed; l _adjust indicates the length of the intersection control area.

The adjustment process is as follows:

Depending on the vehicle's uniform acceleration/deceleration in this stage of state adjustment, the vehicle state adjustment time Δt _i is:

Since the vehicle needs to complete the state adjustment within the length of the intersection control area, the constraints on the state adjustment time are as follows:

The beneficial effects of the present invention are:

(1) The vehicle-road coordination intersection traffic conflict resolution method can make the vehicle no longer limited by the control of the traditional signal light, reduce the fixed delay caused by the traffic signal control to the vehicle, and greatly improve the intersection on the premise of ensuring the driving safety. Traffic capacity and vehicle traffic efficiency, alleviating traffic congestion.

(2) By adopting a "fluid" space-time separation method, it provides fragmented and discretized safe passage space-time gaps for intersection vehicles, so that conflicting traffic flows alternately pass through the intersection conflict area by using the driving gaps, so as to achieve the goal of conflict resolution. The purpose is to realize the full utilization of the time and space resources of the intersection.

Description of drawings

1 is a schematic diagram of a road intersection in a vehicle-road collaborative environment in an embodiment of the present invention;

FIG. 2 is a flowchart of traffic conflict resolution in an embodiment of the present invention;

3 is a schematic diagram of vehicle state adjustment in an embodiment of the present invention;

FIG. 4 is a schematic diagram of the location of a conflict area at an intersection in an embodiment of the present invention;

FIG. 5 is a schematic diagram of resolving traffic conflict in an intersection conflict area according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the vehicle-road coordination environment, real-time information exchange can be carried out between smart cars and smart roads. The full-time and space-time dynamic traffic information of the intersection can be collected in real time through the on-board unit and the roadside unit, and the intersection control center can receive the information in real time. The effective information is fused and processed to provide driving behavior suggestions for vehicles, so that vehicles at the intersection can adjust the driving state in advance to control the distance between the vehicle and the vehicle in front to the optimal gap, so that the traffic flow in the conflict direction can alternately pass through the intersection conflict. area to achieve conflict resolution.

A vehicle flow conflict resolution method at a vehicle-road coordinated intersection, which divides the connecting section of a road intersection into three functional areas: a lane change area, a control area, and a buffer area according to different distances. The unit and the intersection control center perform corresponding information interaction respectively.

After the vehicle enters the lane change area of the intersection, it changes to the corresponding guide lane in advance according to the driving demand of the vehicle, and the control center judges whether the vehicle has a traffic conflict in the intersection according to the direction of the vehicle and other vehicles . If there is no conflict, the vehicle in the control area moves quickly according to the command of the control center, and passes the intersection safely under the condition of no conflict and interference; Calculate the corresponding driving clearance of the vehicle in each conflict area, take the maximum driving clearance value as the optimal clearance that should be maintained between the vehicle and the preceding vehicle, and feed back the optimal clearance value to the The vehicle's onboard unit.

Taking the WL direction as an example, the guidance lanes that conflict with the vehicles in the WL direction at the intersection are SL, NS, ES, and NL. Taking the WS direction as an example, the guidance lanes in the intersection with the vehicles in the WS direction are in conflict. Lanes are NS, SL, EL, SS four directions. When the vehicle enters the corresponding guide lane in the lane change area, the control center determines whether there is a vehicle in the guide lane in the direction of the vehicle conflict between the lane change area and the intersection area according to the received traffic data information. If there is a vehicle, the overlapping area of the conflict direction and the vehicle's driving track is the conflict area, so the geographic location information of the conflict area can be determined by using GPS positioning identification and electronic map.

Assuming that vehicle V _i and vehicle V _i+1 are passing vehicles in direction D1, and vehicle V _j and vehicle V _j+1 are passing vehicles in direction D2 that conflict with direction D1, the sequence of vehicles passing through the conflict area is: V _i →vehicle Vj →vehicle V _i+1 →vehicle V _{j +1} , and when the vehicle V _i completely leaves the conflict zone, the vehicle V _j in the conflict direction just begins to enter the conflict zone; when the vehicle V _j completely leaves the conflict zone In the conflict zone, the vehicle V _i+1 in the conflict direction just begins to enter the conflict zone, that is, the vehicles in the two traffic flows in the conflict direction can alternately pass through the conflict zone, so as to achieve intersection conflict resolution.

Setting: U _i-i+1 represents the driving gap that needs to be maintained between vehicle V _i and vehicle V _i+1 in direction D1; U _j-j+1 represents vehicle V _j and vehicle V _j+1 in conflict direction D2 The driving gap that needs to be maintained between them; _l1 represents the action distance of the conflict area to the vehicle in the direction D1; _l2 represents the action distance of the conflict area to the vehicle in the conflict direction D2; s represents the length of the vehicle; v represents the speed of the vehicle.

The intersection control center analyzes and predicts the traffic flow conflict at the intersection according to the vehicle driving state information and road condition information, determines the position information of the traveling vehicle in each conflict area in the intersection, and calculates the driving gap that the vehicle needs to maintain when passing through each conflict area, and takes the The maximum value is used as the optimal clearance between the vehicle and the preceding vehicle when passing through the intersection.

After calculating the optimal clearance between the vehicle and the preceding vehicle, the intersection control center feeds back the optimal clearance instruction information to the on-board unit of each vehicle. After the vehicle receives the command information, it adjusts the driving state of the vehicle in the control area, and controls the distance between the vehicle and the vehicle in front to the optimal gap, as follows:

When a traffic flow W in a certain direction of the intersection enters the intersection control area, the control center divides it into several continuous sub- _convoys W ₁ , W ₂ , . . . Vehicle status adjustment. Among them, all the vehicles in each sub-convoy encounter the same conflict situation in the intersection passing area, so the vehicles belonging to the same sub-convoy all travel at the same speed and keep the same optimal gap at a constant speed.

Assuming that there are n vehicles in the sub-convoy W _k , when the vehicles in the convoy enter the road section of the intersection control area, the vehicles need to adjust from the current driving state A to the target state B, so as to maintain the best distance between each vehicle and the preceding vehicle. Excellent clearance. Setting: x _ai , v _ai , a _ai , t _ai , and u _ai represent the initial position, driving speed, acceleration, time of entering the control area, and the distance between the vehicle _Vi and the preceding vehicle, respectively, in the control area of the intersection. x _bi , v _b , and u _b respectively represent the position of the vehicle in the target state of the intersection control area, the driving speed, and the optimal gap maintained between it and the preceding vehicle; t _bi represents the time after the state adjustment is completed; l _adjust indicates the length of the intersection control area.

The adjustment process is as follows:

Depending on the vehicle's uniform acceleration/deceleration in this stage of state adjustment, the vehicle state adjustment time Δt _i is:

Since the vehicle needs to complete the state adjustment within the length of the intersection control area, the constraints on the state adjustment time are as follows:

After receiving the command information from the control center, the vehicle adjusts the current driving speed in the control area, controls the distance between the vehicle and the vehicle in front to the optimal gap, and maintains this state to drive into the buffer zone and the intersection at a constant speed. When the vehicle enters the intersection with the optimal gap, the vehicle in the conflict direction of the vehicle can use the gap to safely pass through the conflict area, so as to achieve conflict resolution. Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present invention should also belong to the present invention. the scope of protection of the invention.

Claims (2)

1. A method for eliminating traffic conflict at a vehicle-road cooperative intersection is characterized in that a road intersection connecting section is divided into three functional areas, namely a lane changing area, a regulation area and a buffer area according to different distances, and a vehicle-mounted unit, a road side unit and an intersection control center respectively execute corresponding information interaction in the range of the different functional areas;

the lane change area is internally provided with left-turn, straight-going and right-turn road marking lines, and each vehicle is changed to a corresponding guide lane in advance according to the driving requirement after entering the lane change area;

all vehicles in the regulation and control area are prohibited from changing lanes and overtaking, and each vehicle receives an instruction signal sent by the intersection control center when entering the regulation and control area, adjusts the current driving speed and controls the distance between the vehicle and the front vehicle to be the optimal clearance;

all vehicles in the buffer area keep running in a constant speed state, all vehicles reach a running state required by the intersection control center instruction after entering the buffer area, and a specific optimal gap is kept between the vehicles and the front vehicles;

the vehicle-mounted unit transmits vehicle information and running state information to the intersection control center in real time, wherein the vehicle information and the running state information comprise vehicle size, vehicle position, running time, running speed, acceleration and running direction, and meanwhile receives instruction information sent by the intersection control center to regulate and control the running state of the vehicle;

the road side unit carries out real-time sensing monitoring on road environment conditions in each functional area and transmits relevant data information to an intersection control center in real time, wherein the relevant data information comprises traffic flow, lane occupancy, vehicle driving track, lane width and road surface slippery state of each lane;

the intersection control center receives all traffic data information collected by the vehicle-mounted unit and the road side unit, performs information fusion processing, determines the position of a collision area of the vehicle at the intersection according to the traveling directions of different vehicles, calculates the range of each collision area of the vehicle at the intersection, calculates the optimal clearance required to be kept between the vehicle and the front vehicle by combining the traveling state information of the vehicles in the collision directions, and sends the optimal clearance instruction information to the vehicle-mounted unit of each vehicle in real time;

the left-turn lanes, the straight lanes and the right-turn lanes of the intersection are independent lanes, the vehicles are not allowed to merge and shunt before and after entering the intersection, and the vehicles all run along the center lines of the lanes in the crossing passing process; the length of the lane changing area of the intersection connection road section is set to be 300m, the length of the regulating area is set to be 500m, the length of the buffer area is set to be 200m, and the length range of each functional area is planned and adjusted according to the actual traffic conditions of different intersections, but the vehicles can be ensured to complete corresponding driving operation in each functional area; the road side units are uniformly distributed at intervals of 10m on both sides of the road of each functional area and the surrounding area of the intersection, so that all passing vehicles at the intersection can be subjected to full-time-space, low-delay and high-reliability real-time information sensing;

after a vehicle enters a lane changing area of an intersection, the vehicle is changed to a corresponding guide lane in advance according to the driving requirement of the vehicle, and a control center judges whether traffic conflict exists in the intersection or not according to the driving track directions of the vehicle and other vehicles; if no conflict exists, the vehicle in the regulation and control area rapidly moves according to the instruction of the control center and safely passes through the intersection under the condition of no conflict interference; if the conflict exists, the control center identifies and senses the position of the conflict area of the vehicle in the intersection, respectively calculates the corresponding running clearance of the vehicle in each conflict area, takes the maximum running clearance value as the optimal clearance to be kept between the vehicle and the front vehicle, and feeds the optimal clearance value back to the vehicle-mounted unit of the vehicle; after receiving the command information of the control center, the vehicle adjusts the current driving speed in the regulation and control area, controls the distance between the vehicle and the front vehicle to the optimal gap, and keeps the state to drive into a buffer area and an intersection at a constant speed; when the vehicle enters the intersection at the optimal gap, the vehicles in the conflict directions of the vehicle can safely pass through the conflict area by using the gap, so that conflict resolution is realized;

the method for determining the position of the conflict zone of the vehicle in the intersection specifically comprises the following steps:

taking the WL direction as an example, the guidance lanes in the intersection where there is a collision relationship with the vehicle in the WL direction are respectively SL, NS, ES, NL; taking the WS direction as an example, the guide lanes in the intersection which have conflict relationship with the vehicle in the WS direction are respectively NS, SL, EL and SS directions; after a vehicle drives into a corresponding guide lane in a lane change area, the control center judges whether the guide lane of the vehicle collision direction has the vehicle in the lane change area to a crossing area according to the received traffic data information, if the vehicle exists, the overlapping area of the collision direction and the vehicle driving track is the collision area, and therefore the geographic position information of the collision area can be determined by using GPS positioning identification and an electronic map;

the method for calculating the optimal clearance to be maintained between the vehicle and the front vehicle comprises the following steps:

suppose a vehicle V_iAnd a vehicle V_i+1For passing vehicles in direction D1, vehicle V_jAnd a vehicle V_j+1For a passing vehicle in direction D2 that conflicts with direction D1, the order in which the vehicles pass through the conflict zone is: vehicle V_i→ vehicle V_j→ vehicle V_i+1→ vehicle V_j+1And when the vehicle V_iVehicle V in conflict direction when completely driving away from conflict area_jJust start entering the conflict area; when the vehicle V_jVehicles V in conflicting directions when completely driven away from conflicting zones_i+1The vehicles in the two traffic flows in the conflict direction can alternately penetrate through the conflict area, so that conflict resolution at the intersection is realized;

setting: u shape_i-i+1Indicating a vehicle V in a direction D1_iAnd a vehicle V_i+1The running clearance required to be kept; u shape_j-j+1Indicating vehicle V in conflicting directions D2_jAnd a vehicle V_j+1The running clearance required to be kept; l₁Indicating the distance traveled by the collision zone to the vehicle in direction D1; l₂Indicating that the collision zone is getting on the vehicle in the collision direction D2The range of the vehicle; s represents a vehicle length; v represents a vehicle running speed;

and the intersection control center analyzes and predicts the traffic flow conflict of the intersection according to the vehicle running state information and the road condition information, respectively calculates the driving clearance required to be kept when the vehicle passes through each conflict area after determining the position information of the running vehicle in each conflict area in the intersection, and takes the maximum value as the optimal clearance required to be kept between the vehicle and the front vehicle when the vehicle passes through the intersection.

2. The method for resolving the traffic conflict at the vehicle-road cooperative intersection according to claim 1, characterized in that the driving state of the vehicle in the regulation and control area is adjusted as follows:

after calculating the optimal clearance required to be kept between the vehicle and the front vehicle, the intersection control center feeds back the optimal clearance instruction information to the vehicle-mounted unit of each vehicle; after the vehicle receives the instruction information, the vehicle running state is adjusted in the regulation and control area, and the distance between the vehicle and the front vehicle is controlled to be the optimal gap, which is as follows:

when a traffic flow W of an entrance way in a certain direction of the intersection enters the intersection control area, the control center divides the traffic flow W into a plurality of continuous sub-fleets W₁、W₂、…、W_mAnd adjusting the vehicle state by taking the sub-fleet as a unit; the collision conditions of all vehicles in each sub-fleet in the crossing passing area are the same, so that the vehicles belonging to the same sub-fleet travel at the same optimal interval at the same speed;

suppose W_kThe sub-fleet comprises n vehicles, and when the vehicles in the fleet enter the intersection regulation and control areaAfter the period, the vehicles need to be adjusted from the current driving state A to the target state B, so that the optimal clearance is kept between each vehicle and the front vehicle; setting: x is the number of_ai、v_ai、a_ai、t_ai、u_aiRespectively representing vehicles V of sub-fleets_iThe initial position, the running speed, the acceleration, the time for driving into the regulation and control area and the clearance distance between the front vehicles at the intersection regulation and control area; x is the number of_bi、v_b、u_bRespectively representing the position, the running speed and the optimal clearance kept between the vehicle and the front vehicle in the intersection regulation and control area under the vehicle target state; t is t_biIndicating the time after the state adjustment is completed; l_adjustIndicating the length of the intersection regulation and control area;

the adjustment process is as follows:

the vehicle state adjustment time Deltat is determined according to the fact that the vehicle performs uniform acceleration/deceleration running in the state adjustment of the current stage_iComprises the following steps:

because the vehicle needs to complete state adjustment within the length range of the intersection regulation and control area, the constraint conditions of the state adjustment time are as follows:

Images