CN115662188A - Obstacle avoidance system for vehicles running in queue - Google Patents

Abstract

The invention discloses an obstacle avoidance system for platoon vehicles. In order to solve the problem of avoiding obstacles during platoon driving, the obstacle avoidance system is divided into four modules: a vehicle classification module, an information acquisition module, and an obstacle avoidance condition judgment module , the obstacle avoidance execution module; the vehicle classification module divides the queue vehicles into four types; the information acquisition module obtains the information of each vehicle in the queue, obtains obstacle information and road traffic information, and transmits the acquired vehicle information and environmental information with specific rules The obstacle avoidance condition judging module judges whether the three obstacle avoidance conditions are satisfied according to the obstacle information; the obstacle avoidance execution module executes different obstacle avoidance schemes according to different obstacle avoidance conditions.

Description

An obstacle avoidance system for platooning vehicles

technical field

The invention relates to the field of platooning, in particular to an obstacle avoidance system for platooning vehicles.

Background technique

Platooning refers to a situation where vehicles are traveling while following a leading vehicle, and the platooning vehicles send and receive various driving information through vehicle-to-vehicle communication to control the speed of the vehicles and the inter-vehicle spacing between vehicles, allowing the vehicles to maintain A specific distance between vehicles. Queue driving has great commercial value on commercial vehicles, and countries are also constantly carrying out commercial vehicle platoon driving tests.

When the platoon vehicles encounter obstacles during the driving process, in order to improve the obstacle avoidance ability of the platoon vehicles and ensure the safety of the platoon vehicles and surrounding vehicles and pedestrians, it is urgent to provide an obstacle avoidance method for the platoon vehicles so that the platoon vehicles can avoid obstacles. Surrounding obstacles, to achieve safe and reliable platoon driving.

Contents of the invention

An embodiment of the present invention provides an obstacle avoidance system for platoon vehicles, which can reasonably avoid obstacles when platoon vehicles meet obstacle avoidance conditions, and improve the safety and reliability of platoon driving.

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

An obstacle avoidance system for platooning vehicles, which is divided into four modules, namely a vehicle classification module, an information acquisition module, an obstacle avoidance condition judgment module, and an obstacle avoidance execution module;

The vehicle classification module divides vehicles into four types: A, B, C, and D. Among them, type A vehicles are the vehicles at the front of the queue, and are mainly responsible for collecting road traffic information and planning the route of the queue. Type B vehicles are the vehicles at the end of the queue. , is mainly responsible for collecting road traffic information. Type C vehicles are vehicles located between type A vehicles and type B vehicles, and are responsible for following vehicles and collecting road traffic information. Type D vehicles are vehicles that leave the queue and drive independently; When the queue position changes during driving, different vehicle types can be switched according to the position;

The information acquisition module mainly acquires the information of each vehicle in the queue, obtains obstacle information and road traffic information, and transmits the acquired vehicle information and environmental information according to specific rules; the transmission rules of vehicle information and environmental information are as follows, type B vehicles Collect environmental information with Type C vehicles, and transfer the collected environmental information to Type A vehicles with their own vehicle information. Type A vehicles comprehensively collect vehicle information and environmental information to determine the queue driving status and current queue traffic status. Type A vehicles detect Judgment of obstacle avoidance conditions and determination of obstacle avoidance scheme are carried out when reaching an obstacle. Before the queue implements the obstacle avoidance scheme, type A vehicles send obstacle avoidance operation information to type B vehicles and type C vehicles in advance; when a vehicle leaves the queue, The disengaged vehicle disconnects from the queue vehicle and switches to a D-type vehicle at the same time. The original queue is reclassified according to the position of the queue vehicle; when a D-type vehicle joins the queue, it can send a queue entry request to the A-type vehicle in the queue. After passing through, join the queue and switch the vehicle type according to the position of the queue; when the queues are merged, the queue at the front is regarded as the main queue, and the rest of the queues are regarded as sub-queues, and the A-type vehicles of the sub-queue go to the A of the main queue Vehicles of different types send a request to join the queue. After the request is passed, they are divided into queues to join the main queue, and the merged vehicles switch vehicle types according to their queue positions.

The obstacle avoidance condition judgment module includes: the area from the head of the A-type vehicle to the rear of the B-type vehicle is called the queuing area, and the obstacles whose moving speed is lower than the driving speed of the platoon vehicles are regarded as relatively low-speed obstacles, and the queuing has not yet started obstacle avoidance. The current lane of the system is regarded as the main lane, and the stationary or relatively low-speed obstacles existing in the main lane are regarded as obstacles in the main lane, and the obstacles in the lanes on both sides are regarded as obstacles in the side lane. When an obstacle in the main lane ahead is detected, Enter the obstacle avoidance condition judgment module, and perform corresponding obstacle avoidance operations according to meeting different obstacle avoidance conditions; there are the following three obstacle avoidance conditions, the first obstacle avoidance condition is that there is an obstacle in the main lane ahead, and there are at least There is no obstacle in the side lane within the preset range. When there is only one side lane, the side with no lane is regarded as a continuous stationary side lane obstacle; the second obstacle avoidance condition is that there is an obstacle in the main lane ahead, and both sides There are moving side lane obstacles in the side lane within the preset range; if the above conditions are not met, it will be regarded as the third obstacle avoidance condition; the preset range starts from the front of the Type A vehicle and extends to the direction of the Type A vehicle The bounded area of , the preset range length is half of the length of the queue area;

The obstacle avoidance execution module includes: after obtaining the obstacle information of the main lane, set two obstacle avoidance distances, which are respectively the first set distance L1 and the second set distance L2, and the first set distance L1 is when the platoon vehicles start to change. The second set distance L2 is the distance between the queue vehicles and the obstacles in the main lane when they return to the main lane, and the obstacle avoidance distance changes in a certain relationship with the vehicle status and road conditions;

Different from the obstacle avoidance conditions met, three obstacle avoidance schemes are set. When the first obstacle avoidance condition is met, the first obstacle avoidance scheme is executed. This scheme is the total queue obstacle avoidance scheme, that is, the entire queue is taken as a whole. Obstacle avoidance, and implement different total queue sub-obstacle avoidance schemes according to the main lane obstacle information, specifically including three types of total queue sub-obstacle avoidance schemes; when the second obstacle avoidance condition is met, execute the second obstacle avoidance scheme, which is sub-queue avoidance Obstacle avoidance plan, that is, divide different sub-queues according to the specific information of obstacles in the side lane, and merge into the same queue after the obstacle avoidance is completed; when the third obstacle avoidance condition is met, execute the third obstacle avoidance plan, that is, reduce the driving force or brake The method reduces the speed of vehicles, so that the platoon vehicles maintain a safe distance from the obstacles in the main lane, and at the same time judges the obstacle avoidance conditions. The second obstacle avoidance scheme, according to the design, the first and second obstacle avoidance conditions will not be met at the same time; Different sub-obstacle avoidance schemes.

The overall platoon obstacle avoidance scheme includes: A-type vehicles change lanes to the target lane at a first set speed at a first set distance L1, and all subsequent vehicles in the platoon follow the trajectory of A-type vehicles, and at the first set distance L1 at a speed of Change lane to the target lane at the first set speed;

After arriving at the target lane, implement different total queue sub-obstacle avoidance schemes according to the length of the obstacles in the main lane and the speed requirements of the platoon vehicles. Execute the first obstacle avoidance plan of the general platoon, that is, after the type A vehicle crosses the obstacle, it returns to the main lane at the second set speed at the second set distance L2, and all subsequent vehicles in the platoon follow the track of the A type vehicle, Return to the main lane at the distance L2; when the speed limits of the main lane and the target lane meet the queue driving requirements, and the length of obstacles in the main lane exceeds the total length of the queue, implement the sub-obstacle avoidance scheme 2 of the total queue, that is, type A vehicles continue to drive in the target lane, The entire platoon is switched to the target lane; when the speed limits of the main lane and the target lane meet the platoon driving requirements, and the length of obstacles in the main lane does not exceed the total length of the queuing, execute the sub-obstacle avoidance scheme 3 of the total queuing, that is, according to the environment monitoring of type A vehicles The vehicle density of the target lane and the main lane within the range determines whether to return to the main lane. The area from the head of the A-type vehicle to the rear of the B-type vehicle is set as the queue area, which is divided into three on the main road in front of the A-type vehicle and the target lane respectively. The area with the same length as the queue area, from near to far, is respectively No. 1 area, No. 2 area, and No. 3 area. The vehicles in each area are numbered from 1, respectively called No. 1, No. 2, and No. N , where N is equal to the number of vehicles in the area; calculate the vehicle density in the three areas and multiply the corresponding coefficients to obtain the comprehensive vehicle density of the main lane and the target lane, and return to the main lane when the comprehensive vehicle density of the main lane is lower than the target lane, when When the comprehensive vehicle density of the target lane is lower than the main lane, it will not return to the main lane. The formula for the comprehensive vehicle density is as follows,

ρ _v =f ₁ ·ρ ₁ +f ₂ ·ρ ₂ +f ₃ ·ρ ₃

In the formula, ρ _v is the comprehensive vehicle density of the lane, f is the vehicle density coefficient, a dimensionless value, and the vehicle density coefficient is different in different areas, f ₁ = 1, f ₂ = 1.2, f ₃ = 0.9, ρ ₁ is the _ρ2 is the vehicle density in No. 2 area, _ρ3 is the vehicle density in No. 3 area; the formula for calculating the vehicle density is as follows,

In the formula, ρ is the vehicle density in the area, l _i is the length of the i-th car in the area, L is the length of the queue area, m _j is the length coefficient, a dimensionless value, determined by the length of the vehicle; when the length of the vehicle is not greater than 5 meters , m _j = 1; when the vehicle length is greater than 5 meters and not greater than 10 meters, m _j = 0.9; when the vehicle length is greater than 10 meters and not greater than 15 meters, m _j = 0.85; when the vehicle length is greater than 15 meters, m _j = 0.8.

The queuing obstacle avoidance scheme includes: dividing the queuing area into front, middle, and rear areas of equal length, and calculating the vehicle density of the main lane queuing and the front, middle, and rear areas of the lanes on both sides according to the vehicle density calculation formula. The vehicle density is different according to the vehicle density in each area of the lanes on both sides. When the vehicle density in the area exceeds the vehicle density in the queue, it is marked as a congested state. The vehicle density in the area is less than the vehicle density in the queue and greater than one-third of the vehicle density in the queue. The momentary mark is normal state, and the mark is unblocked state when the area vehicle density is less than one-third of the queue vehicle density;

When the state of the area is crowded, it is not allowed to change lanes to the lanes on both sides of the corresponding area; when the state of the area is normal, it can change lanes to the lanes on both sides of the area in sequence; when the state of the area is unblocked, it can move according to the lanes on both sides The distance and position of obstacles are divided into queues to change lanes; according to the combination of states in different areas, different queues can be selected.

When the number of unobstructed areas in the three areas is not less than 2, the current queue will be split according to the distance and position of the obstacles in the side lane. After the division is completed, each sub-queue will be classified again, and then change lanes to the lanes on both sides. When driving, the queues dispersed to the lanes on both sides follow the real-time road traffic conditions to choose whether to merge with the queues ahead;

In addition to the above, when the number of areas in the normal state or unblocked state among the three areas is not less than 2 and the front area is not in a congested state, the Type A vehicle will leave the current queue at a distance of 50 meters from the first set distance, and the Type A vehicle will leave the current queue. Switch to a D-type car and independently decide the obstacle avoidance route. The first car in the original queue is switched to an A-type car and continues to drive. When the A-type car in the original queue reaches the first set distance of 50 meters, it will leave the original queue and become a D-type car. and decide whether to form a queue with the vehicle in front according to the current road traffic conditions. If a queue is formed, follow the vehicle in front and classify vehicles according to the vehicle classification module. to avoid obstacles;

When the status of the three areas does not meet the first two conditions, the queue cannot avoid obstacles by changing lanes, and braking or deceleration measures should be taken to keep a safe distance between the queue and the obstacles in the main lane, and then avoid obstacles after the above two conditions are met operate;

After the vehicles in the above three situations have successfully avoided obstacles, they will return to the main lane when they reach the second obstacle avoidance distance L2, and form a new queue according to the vehicle configuration and sequence, and the vehicle classification module will classify the vehicles.

The first set distance and the second set distance include: the first set distance L1 is the distance from the obstacle in the main lane when the platoon vehicles start to change lanes, and the calculation formula is as follows,

In the formula, v ₁ is the first set speed, t ₁ is the time for the type A vehicle to change lanes, φ ₁ is the yaw angle when the type A vehicle changes lanes, v ₀ is the speed of obstacles in the main lane, and a is the speed according to The maximum braking deceleration obtained by the brake force of type A vehicles, δ is the safety distance coefficient, a dimensionless value, which is affected by road conditions. When the road conditions meet the maximum braking deceleration a requirement, δ takes the minimum value of 1;

The second set distance L2 is the distance from the obstacles in the main lane when the queuing vehicles return to the main lane, and the calculation formula is as follows,

In the formula, v ₂ is the second set speed, t ₂ is the time for the type A vehicle to change lanes, and φ ₂ is the yaw angle of the type A vehicle when changing lanes.

The obstacle avoidance method for platoon vehicles provided by the embodiment of the present invention has the following advantages or beneficial effects: the above method classifies the platoon vehicles to facilitate the implementation of the obstacle avoidance scheme, and in the process of selecting the obstacle avoidance scheme, the characteristics of the obstacles and the road are considered Influenced by traffic conditions, in the process of obstacle avoidance, the speed of obstacles and performance factors of platoon vehicles are considered, which improves the safety of platoon vehicles in obstacle avoidance process, and also ensures the implementation of obstacle avoidance schemes.

Description of drawings

In the drawings, unless otherwise specified, the same reference numerals designate the same or similar parts or elements throughout the several drawings. The drawings are not necessarily drawn to scale. The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

FIG. 1 is a schematic diagram of area division in the present invention.

Fig. 2 is a schematic diagram of the setting distance of the present invention.

Fig. 3 is a schematic flow diagram of the system of the present invention.

Fig. 4 is a flow chart of the obstacle avoidance judgment module and the obstacle avoidance execution module of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with examples. It should be understood that the specific embodiments described below are only used to explain the present invention, not to limit the present invention.

Referring to Fig. 1, the obstacle avoidance system of a kind of platoon vehicle of the present invention comprises vehicle classification module, information acquisition module, obstacle avoidance condition judging module, obstacle avoidance execution module;

The vehicle classification module divides vehicles into four types: A, B, C, and D. Among them, type A vehicles are the vehicles at the front of the queue, and are mainly responsible for collecting road traffic information and planning the route of the queue. Type B vehicles are the vehicles at the end of the queue. , is mainly responsible for collecting road traffic information. Type C vehicles are vehicles located between type A vehicles and type B vehicles, and are responsible for following vehicles and collecting road traffic information. Type D vehicles are vehicles that leave the queue and drive independently; When the queue position changes during driving, different vehicle types can be switched according to the position.

The information acquisition module mainly acquires the information of each vehicle in the queue, obtains obstacle information and road traffic information, and transmits the acquired vehicle information and environmental information in the following way: B-type vehicles and C-type vehicles collect environmental information, and their own vehicle information The collected environmental information is transmitted to the A-type vehicle, and the A-type vehicle comprehensively collects the collected vehicle information and environmental information to determine the queue driving status and the current queue traffic status. When the A-type vehicle detects an obstacle, it performs obstacle avoidance condition judgment and obstacle avoidance The scheme is determined. Before the queue implements the obstacle avoidance scheme, the A-type vehicle sends the obstacle avoidance operation information to the B-type vehicles and the C-type vehicles in advance; It is a D-type vehicle, and the original queue is reclassified according to the position of the queued vehicles; when a D-type vehicle joins the queue, it can send a queue entry request to the A-type vehicle in the queue, join the queue after the request is passed, and switch vehicles according to the queue position Type; when the queues are merged, the queue at the forefront is regarded as the main queue, and the rest of the queues are regarded as sub-queues. The A-type vehicles in the sub-queues send queue entry requests to the A-type vehicles in the main queue, and the sub-queues are divided after the request is passed. Join the main queue, and the merged vehicles switch vehicle types according to their queue positions.

The obstacle avoidance condition judgment module includes: the area from the head of the A-type vehicle to the rear of the B-type vehicle is called the queuing area, and the obstacles whose moving speed is lower than the driving speed of the platoon vehicles are regarded as relatively low-speed obstacles, and the queuing has not yet started obstacle avoidance. The current lane of the system is regarded as the main lane, and the stationary or relatively low-speed obstacles existing in the main lane are regarded as obstacles in the main lane, and the obstacles in the lanes on both sides are regarded as obstacles in the side lane. When an obstacle in the main lane ahead is detected, Enter the obstacle avoidance condition judgment module, and perform corresponding obstacle avoidance operations according to meeting different obstacle avoidance conditions; there are the following three obstacle avoidance conditions, the first obstacle avoidance condition is that there is an obstacle in the main lane ahead, and there are at least There is no obstacle in the side lane within the preset range. When there is only one side lane, the side with no lane is regarded as a continuous stationary side lane obstacle; the second obstacle avoidance condition is that there is an obstacle in the main lane ahead, and both sides There are moving side lane obstacles in the side lane within the preset range; if the above conditions are not met, it will be regarded as the third obstacle avoidance condition; the preset range starts from the front of the Type A vehicle and extends to the direction of the Type A vehicle The bounded area of , the preset range length is half of the length of the queue area;

The obstacle avoidance execution module includes: according to the different obstacle avoidance conditions met, three obstacle avoidance schemes are set. When the first obstacle avoidance condition is met, the first obstacle avoidance scheme is executed. This scheme is the total queue obstacle avoidance scheme, that is, The entire queue performs obstacle avoidance as a whole, and executes different total queue sub-obstacle avoidance schemes according to the main lane obstacle information, specifically including three types of general queue sub-obstacle avoidance schemes; when the second obstacle avoidance condition is met, execute the second obstacle avoidance scheme, This scheme is a sub-queue obstacle avoidance scheme, which divides different sub-queues according to the specific information of obstacles in the side lane, and merges into the same queue after the obstacle avoidance is completed; when the third obstacle avoidance condition is met, the third obstacle avoidance scheme is implemented, that is, adopt The method of reducing the driving force or braking reduces the speed of the vehicle, so that the platoon vehicles maintain a safe distance from the obstacles in the main lane, and at the same time judge the obstacle avoidance conditions, and execute the first obstacle avoidance plan when the first obstacle avoidance condition is met. When the second obstacle avoidance condition is executed, the second obstacle avoidance plan is executed. According to the design, the first and second obstacle avoidance conditions will not be met at the same time; when the first or second obstacle avoidance condition is met, each obstacle avoidance plan will follow the road and obstacle status are divided into different sub-obstacle avoidance schemes.

Referring to Fig. 2, the queuing area described in the present invention is the area from the front of the A type car to the B type car tail, and is divided into three areas equal to the queuing area on the main road and the target lane in front of the A type car respectively. The distances are No. 1 area, No. 2 area, and No. 3 area. The target lane is any one of the lanes on both sides. At the same time, the queue area is divided into three equal-length areas: front, middle, and rear.

Referring to Figure 3, after obtaining the obstacle information of the main lane, type A vehicles set two obstacle avoidance distances, namely the first set distance L1 and the second set distance L2, and the first set distance L1 is the starting point The distance from the obstacle in the main lane when changing lanes, the second setting distance L2 is the distance from the obstacle in the main lane when the vehicles in the queue return to the main lane, and the obstacle avoidance distance changes in a certain relationship with the vehicle status and road conditions; the first setting The formula for calculating the distance L1 is as follows,

In the formula, v ₁ is the first set speed, t ₁ is the time for the type A vehicle to change lanes, φ ₁ is the yaw angle when the type A vehicle changes lanes, v ₀ is the speed of obstacles in the main lane, and a is the speed according to The maximum braking deceleration obtained by the brake force of type A vehicles, δ is the safety distance coefficient, a dimensionless value, which is affected by road conditions. When the road conditions meet the maximum braking deceleration a requirement, δ takes the minimum value of 1;

The calculation formula of the second setting distance L2 is as follows,

In the formula, v ₂ is the second set speed, t ₂ is the time for the type A vehicle to change lanes, and φ ₂ is the yaw angle of the type A vehicle when changing lanes.

Referring to FIG. 4 , the overall platoon obstacle avoidance scheme includes: A-type vehicles change lanes to the target lane at a first set speed at a first set distance L1, and all subsequent platoon vehicles follow the trajectory of A-type vehicles. At the fixed distance L1, change lanes to the target lane at the first set speed; after reaching the target lane, implement different obstacle avoidance schemes for the main queue according to the length of obstacles in the main lane and the queue driving requirements. When the speed limit of the main lane meets the speed requirements of the queue vehicles When the speed limit of the target lane does not meet the speed requirements of vehicles driving in the platoon, implement the first obstacle avoidance plan of the main platoon, that is, after the type A vehicle crosses the obstacle, it returns to the main lane at the second set speed at the second set distance L2, and all subsequent queuing The driving vehicle follows the trajectory of a type A vehicle and returns to the main lane at the second set distance L2; when the speed limits of the main lane and the target lane meet the queue driving requirements, and the length of the obstacle in the main lane exceeds the total length of the queue, the total queue sub-obstacle avoidance is executed Scheme 2, that is, type A vehicles continue to drive in the target lane, and the entire queue is switched to the target lane; when the speed limits of the main lane and the target lane meet the queue driving requirements, and the length of obstacles in the main lane does not exceed the total length of the queue, the total queue sub- The third obstacle avoidance scheme is to determine whether to return to the main lane according to the vehicle density of the target lane and the main lane within the environmental monitoring range of type A vehicles, and number the vehicles in the No. 1 area, No. 2 area, and No. 3 area from 1, respectively. They are respectively called No. 1, No. 2, and up to No. N, where N is equal to the number of vehicles in the area. Calculate the vehicle density in the three areas and multiply the corresponding coefficients to obtain the comprehensive vehicle density of the main lane and the target lane. When the main lane is integrated Return to the main lane when the vehicle density is lower than the target lane, and do not return to the main lane when the comprehensive vehicle density of the target lane is lower than the main lane. The comprehensive vehicle density formula is as follows,

ρ _v =f ₁ ·ρ ₁ +f ₂ ·ρ ₂ +f ₃ ·ρ ₃

In the formula, ρ _v is the comprehensive vehicle density of the lane, f is the vehicle density coefficient, a dimensionless value, and the vehicle density coefficient is different in different areas, f ₁ = 1, f ₂ = 1.2, f ₃ = 0.9, ρ ₁ is the _ρ2 is the vehicle density in No. 2 area, _ρ3 is the vehicle density in No. 3 area; the formula for calculating the vehicle density is as follows,

In the formula, ρ is the vehicle density in the area, l _i is the length of the i-th car in the area, L is the length of the queue area, m _j is the length coefficient, a dimensionless value, determined by the length of the vehicle; when the length of the vehicle is not greater than 5 meters , m _j = 1; when the vehicle length is greater than 5 meters and not greater than 10 meters, m _j = 0.9; when the vehicle length is greater than 10 meters and not greater than 15 meters, m _j = 0.85; when the vehicle length is greater than 15 meters, m _j = 0.8.

The platoon obstacle avoidance scheme includes: according to the vehicle density calculation formula, respectively calculate the vehicle density of the main lane queuing and the vehicle density in the front, middle and rear areas of the two side lanes, according to the difference in vehicle density in each area of the two side lanes Different states are marked. When the regional vehicle density exceeds the queue vehicle density, it is marked as a crowded state. When the regional vehicle density is less than the queue vehicle density and greater than one third of the queue vehicle density, it is marked as a normal state. The regional vehicle density is less than three times the queue vehicle density. When the state of the area is congested, it is not allowed to change lanes to the lanes on both sides of the corresponding area; when the state of the area is normal, it can change lanes to the lanes on both sides of the area in sequence; When the traffic is smooth, it can be divided into queues to change lanes according to the distance and position of moving obstacles on both sides of the lane; according to the combination of states in different areas, different queues can be selected.

According to the combination of states in different areas, different queue formation methods can be selected, including: when the number of areas in the unblocked state in the three areas is not less than 2, the current queue is split according to the distance and position of obstacles in the side lane , each sub-queue after the division is re-classified, and then changes lanes to the two lanes, and the queues scattered to the two lanes follow the real-time road traffic conditions to choose whether to merge with the front queue; except for the above situations, when three When the area in the normal state or unblocked state is not less than 2 and the front area is not in a congested state, the A-type car will leave the current queue when it is 50 meters away from the first set distance, and the A-type car will switch to the D-type car and decide independently For the obstacle avoidance route, the first car in the original queue is switched to a type A car and continues to drive. When the type A car in the original queue reaches a distance of 50 meters according to the first setting, it will leave the original queue and become a type D car. Decide whether to form a queue with the vehicle in front. If a queue is formed, it will follow the vehicle in front and classify vehicles according to the vehicle classification module. If it does not form a queue, it will independently determine the obstacle avoidance route. The subsequent vehicles in the original queue will avoid obstacles according to the above method; when the three areas When the status does not meet the first two conditions, the queue cannot avoid obstacles by changing lanes. Braking or deceleration measures should be taken to keep the queue at a safe distance from the obstacles in the main lane, and the obstacle avoidance operation should be performed after the above two conditions are met; the above three In this case, after the queue vehicles successfully avoid obstacles, they return to the main lane when they reach the second obstacle avoidance distance L2, and form a new queue according to the vehicle configuration and sequence, and the vehicle classification module classifies the vehicles.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, and it can be easily understood by those skilled in the art Therefore, the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (6)

1. An obstacle avoidance system for a vehicle traveling in a formation, comprising:

this obstacle avoidance system can be divided into four modules: the system comprises a vehicle classification module, an information acquisition module, an obstacle avoidance condition judgment module and an obstacle avoidance execution module;

the vehicle classification module classifies the vehicles into four types of A, B, C and D, wherein the type A vehicle is the vehicle at the forefront of the queue and is mainly responsible for acquiring road traffic information and planning a queue traveling route, the type B vehicle is the vehicle at the rearmost of the queue and is mainly responsible for acquiring the road traffic information, the type C vehicle is the vehicle positioned between the type A vehicle and the type B vehicle and is responsible for following and acquiring the road traffic information, and the type D vehicle is the vehicle which is separated from the queue and independently travels; when the position of the queue of the vehicle changes in the driving process, different vehicle types can be switched according to the position;

the information acquisition module is mainly used for acquiring information of each vehicle in the queue, acquiring barrier information and road traffic information, and transmitting the acquired vehicle information and the acquired environment information according to a specific rule;

obstacle avoidance condition judgment module includes:

the method comprises the steps that the area from the head of a type A vehicle to the tail of a type B vehicle is called a queue area, an obstacle with the moving speed smaller than the running speed of a queue running vehicle is regarded as a relatively low-speed obstacle, the current lane of which the queue does not start obstacle avoidance is regarded as a main lane, the static or relatively low-speed obstacle existing in the main lane is regarded as a main lane obstacle, the obstacles on two side lanes are regarded as side lane obstacles, when the front main lane obstacle is detected, the obstacle avoidance condition judgment module is accessed, and corresponding obstacle avoidance operation is carried out according to the different obstacle avoidance conditions; the method comprises the following three obstacle avoidance conditions, wherein the first obstacle avoidance condition is that a main lane obstacle exists in the front, at least one of lanes on two sides has no side lane obstacle in a preset range, and when only one lane exists, one side without lanes is regarded as a continuous and static side lane obstacle; the second obstacle avoidance condition is that a main lane obstacle exists in the front, and moving side lane obstacles exist in lanes on two sides in a preset range; if the conditions are not met, the obstacle avoidance system is regarded as a third obstacle avoidance condition; the preset range is a bounded area which takes the head part of the type A vehicle as a starting point and extends towards the driving direction of the type A vehicle, and the length of the preset range is half of the length of the queue area;

keep away barrier execution module includes:

after obtaining the information of the main lane obstacle, setting two obstacle avoidance distances which are respectively a first set distance L1 and a second set distance L2, wherein the first set distance L1 is the distance between the queue running vehicle and the main lane obstacle when the queue running vehicle starts changing lanes, the second set distance L2 is the distance between the queue running vehicle and the main lane obstacle when the queue running vehicle returns to the main lane, and the obstacle avoidance distance changes in a certain relation with the vehicle condition and the road condition;

setting three obstacle avoidance schemes according to different satisfied obstacle avoidance conditions, executing the first obstacle avoidance scheme when the first obstacle avoidance condition is satisfied, wherein the first obstacle avoidance scheme is a total queue obstacle avoidance scheme, namely, avoiding obstacles by taking the whole queue as a whole, and executing different total queue sub-obstacle avoidance schemes according to obstacle information of a main lane, and specifically comprises three types of total queue sub-obstacle avoidance schemes; when a second obstacle avoidance condition is met, executing a second obstacle avoidance scheme, wherein the scheme is a sub-queue obstacle avoidance scheme, namely different sub-queues are divided according to specific information of obstacles on a side lane, and the sub-queues are combined into a same queue after obstacle avoidance is finished; when a third obstacle avoidance condition is met, executing a third obstacle avoidance scheme, namely adopting a method of reducing driving force or braking to reduce the speed of the vehicle, keeping a safe distance between the vehicles running in the queue and the obstacle of the main lane, simultaneously judging the obstacle avoidance condition, executing a first obstacle avoidance scheme when the first obstacle avoidance condition is met, executing a second obstacle avoidance scheme when the second obstacle avoidance condition is met, and according to design, the first obstacle avoidance condition and the second obstacle avoidance condition cannot be met simultaneously; and when the first or second obstacle avoidance conditions are met, dividing the obstacle avoidance schemes into different sub-obstacle avoidance schemes according to the conditions of the road and the obstacle according to each obstacle avoidance scheme.

2. The obstacle avoidance system for vehicles running on a queue according to claim 1, wherein the transmitting the acquired vehicle information and the environmental information according to a specific rule comprises:

the method comprises the following steps that a type-B vehicle and a type-C vehicle acquire environmental information and transmit self vehicle information and the acquired environmental information to the type-A vehicle, the type-A vehicle comprehensively acquires the vehicle information and the environmental information to determine a queue driving state and a current queue traffic state, an AA vehicle judges obstacle avoidance conditions and determines an obstacle avoidance scheme when detecting an obstacle, and before the queue executes the obstacle avoidance scheme, the type-A vehicle sends obstacle avoidance operation information to the type-B vehicle and the type-C vehicle; when a vehicle is separated from the queue, the separated vehicle is disconnected from the queue vehicle, meanwhile, the separated vehicle is switched to a D type vehicle, and the original queue is reclassified according to the position of the queue vehicle; when a D-type vehicle joins the queue, a queuing request can be sent to the A-type vehicle of the queue, the vehicle joins the queue after the request passes through, and the vehicle type is switched according to the position of the queue; when the queues are combined, the queue at the forefront is regarded as a main queue, the other queues are regarded as sub-queues, A type vehicles of the sub-queues send enqueue requests to A type vehicles of the main queue, the requests are added into the main queue through the rear sub-queues, and the types of the vehicles are switched according to the positions of the merged vehicles.

3. The obstacle avoidance system for vehicles running on a train as claimed in claim 1, wherein the general train obstacle avoidance scheme comprises:

changing the lane of the type A vehicle to a target lane at a first set speed at a first set distance L1, and changing the lane of all subsequent vehicles in the queue to the target lane at the first set speed at the first set distance L1 after following the track of the type A vehicle;

after the vehicle arrives at the target lane, different main queue sub-obstacle avoidance schemes are executed according to the length of the obstacle of the main lane and the speed requirements of the queue running vehicles, when the speed limit of the main lane meets the speed requirements of the queue running vehicles and the speed limit of the target lane does not meet the speed requirements of the queue running vehicles, a first main queue sub-obstacle avoidance scheme is executed, namely after the type A vehicles cross the obstacle, the type A vehicles return to the main lane at a second set speed at a second set distance L2, all the subsequent queue running vehicles follow the track of the type A vehicles and return to the main lane at the second set distance L2; when the speed limit of the main lane and the speed limit of the target lane both meet the requirement of the queue for driving, and the barrier length of the main lane exceeds the total length of the queue, executing a second total queue obstacle avoidance scheme, namely, the type A vehicles continue to drive on the target lane, and the whole queue is switched to the target lane; when the speed limits of the main lane and the target lane both meet the requirement of queue driving and the length of a barrier of the main lane does not exceed the total length of the queue, executing a third total queue obstacle avoidance scheme, namely determining whether to return to the main lane according to the vehicle density of the target lane and the main lane in the environment monitoring range of the type A vehicles, setting the region from the head of the type A vehicles to the tail of the type B vehicles as a queue region, dividing the region from the front of the type A vehicles to the main lane and the target lane into three regions with the same length as the queue region, respectively forming a first region, a second region and a third region from near to far, numbering the vehicles in each region from 1, respectively called as number 1, number 2 and number N, wherein N is equal to the number of the vehicles in the region; calculating the vehicle density of the three areas and multiplying the vehicle density by corresponding coefficients respectively to obtain the comprehensive vehicle density of the main lane and the target lane, returning to the main lane when the comprehensive vehicle density of the main lane is lower than that of the target lane, not returning to the main lane when the comprehensive vehicle density of the target lane is lower than that of the main lane, wherein the comprehensive vehicle density formula is as follows,

ρ _v ＝f ₁ ·ρ ₁ +f ₂ ·ρ ₂ ⁺ f ₃ ·ρ ₃

in the formula, ρ _v Is the comprehensive vehicle density of the lane, f is the vehicle density coefficient, and has no dimension value, and the vehicle density coefficients of different areas are different, f ₁ ＝1，f ₂ ＝1.2，f ₃ ＝0.9，ρ ₁ Is the vehicle density, rho, in region one ₂ Is the vehicle density, rho, in region two ₃ Is vehicle density in zone three; the vehicle density calculation formula is as follows,

where ρ is the vehicle density in the region, l _i Is the length of the ith vehicle in the area, L is the length of the queue area, m _j Is a length coefficient, a dimensionless value, determined by the vehicle length; when the length of the vehicle is not more than 5 m, m _j =1; when the length of the vehicle is more than 5 m and not more than 10 m, m _j =0.9; when the length of the vehicle is more than 10 meters and not more than 15 meters, m is _j =0.85; when the length of the vehicle is more than 15 meters, m _j ＝0.8。

4. The obstacle avoidance system of the vehicles running on a train as claimed in claim 1, wherein the sub-train obstacle avoidance scheme comprises:

dividing the queue area into three equal-length areas, namely a front area, a middle area and a rear area, respectively calculating the vehicle density of the main lane queue and the vehicle density of the front area, the middle area and the rear area of the lanes on two sides according to a vehicle density calculation formula, marking different states according to different vehicle densities of each area of the lanes on two sides, marking a crowded state when the vehicle density of the area exceeds the vehicle density of the queue, marking a normal state when the vehicle density of the area is less than the vehicle density of the queue and is more than one third of the vehicle density of the queue, and marking a smooth state when the vehicle density of the area is less than one third of the vehicle density of the queue;

when the area state is crowded, the lane change to the lanes on the two sides of the corresponding area can not be performed; when the area state is normal, changing lanes to lanes on two sides of the area in sequence; when the area state is smooth, the lane can be changed in a queue according to the distance and the position of the moving barriers of the lanes on the two sides; different queue splitting modes can be selected according to the state combinations of different areas.

5. The obstacle avoidance system of the vehicles running in a queue according to claim 4, wherein different queue division modes can be selected according to the state combination of different areas, and the method comprises the following steps:

when the number of the areas in the unblocked state in the three areas is not less than 2, splitting the current queue according to the distance and the position of the barriers of the side lanes, newly classifying vehicles in each split queue after the splitting, then changing lanes to the lanes on the two sides, and selecting whether the queues dispersed to the lanes on the two sides are merged with the front queue according to the real-time road traffic condition;

in addition to the above, when the area in the normal state or the clear state is not less than 2 and the front area is not in the crowded state among the three areas, the type a vehicles are separated from the current queue at a distance of 50 meters from the first set distance, the type a vehicles are switched to type D vehicles and autonomously determine an obstacle avoidance route, the first vehicle in the original queue is switched to the type a vehicles and continues to run, the type a vehicles in the original queue are separated from the original queue to type D vehicles when reaching 50 meters from the first set distance, and whether to form a queue with the front vehicle is determined according to the current road traffic condition, if the queue is formed, the front vehicle is followed and the vehicles are classified according to the vehicle classification module, if the queue is not formed, the obstacle avoidance route is autonomously determined, and the vehicles in the subsequent original queue perform obstacle avoidance according to the above method;

when the three area states do not meet the first two conditions, the queues cannot pass lane changing and obstacle avoidance, braking or deceleration measures are adopted to keep the queues and the main lane obstacles at a safe distance, and obstacle avoidance operation is carried out when the two conditions are met;

after the vehicles in the three condition queues successfully avoid the obstacle, the vehicles return to the main lane when reaching the second obstacle avoidance distance L2, form a new queue according to the vehicle configuration and the front-back sequence, and are classified by the vehicle classification module.

6. The obstacle avoidance system for vehicles running on a train according to claim 1, wherein the first set distance and the second set distance comprise:

the first set distance L1 is the distance between the queue running vehicle and the obstacle of the main lane when the queue running vehicle starts changing lanes, and the calculation formula is as follows,

in the formula, v ₁ At a first set speed, t ₁ Time taken for changing lane for type A vehicle, phi ₁ The yaw angle when changing lanes for type A vehicles, v ₀ The speed of the main lane obstacle is a maximum braking deceleration obtained according to the braking force of the A type vehicle brake, delta is a safe distance coefficient, is a dimensionless value and is influenced by road conditions, and when the road conditions meet the requirement of the maximum braking deceleration a, the minimum value of the delta is 1;

the second set distance L2 is the distance between the queue vehicle and the obstacle of the main lane when the queue vehicle returns to the main lane, and the calculation formula is as follows,

in the formula, v ₂ At a second set speed, t ₂ Time taken for changing lane for type A vehicle, phi ₂ Is the yaw angle of the type A vehicle when changing lanes.

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