CN106781435B - Non-signal control intersection vehicle formation passing method based on wireless communication - Google Patents

Abstract

The invention relates to a vehicle formation passing method at a non-signal-controlled intersection based on wireless communication. broadcast; the service platform obtains the ID number, position, speed and acceleration information of all connected vehicles, determines the virtual front vehicle of each connected vehicle, and compares the identity number of the real vehicle corresponding to the virtual front vehicle of each connected vehicle Broadcasting; each networked vehicle obtains the identity number of the real vehicle corresponding to its own virtual vehicle in front, and then obtains the position, speed and acceleration information of the real vehicle corresponding to the virtual vehicle in front according to the identity number, and performs coordinate conversion to become equal The vehicle in front is automatically controlled to track the vehicle in front until it leaves the intersection. The invention can largely avoid the deceleration, parking and starting process of the vehicle at the non-signal-controlled intersection, reduce the passing time, improve the passing efficiency of the non-signal-controlled intersection, and simultaneously reduce the demand for communication.

Description

A vehicle formation passing method at non-signal-controlled intersections based on wireless communication

technical field

The invention relates to the field of intelligent traffic systems, in particular to a method for passing vehicles in formation at a non-signal-controlled intersection based on wireless communication.

Background technique

While the invention and development of automobile technology has brought convenience to mankind, it has also brought a series of problems, and traffic congestion is one of the most important problems. Statistics show that the average direct and indirect economic losses caused by traffic congestion in Beijing every working day are at the level of tens of millions of yuan. Therefore, how to improve the traffic efficiency at intersections has become a research focus in the field of automobiles and traffic. In recent years, the rapid development of CV (Connected Vehicles) technology can provide new ideas to solve the above problems, and thus has attracted extensive attention in the fields of automobiles and transportation. Through the communication between vehicles and vehicles, between vehicles and roadside infrastructure, and between vehicles and the Internet, connected vehicles can obtain more extensive information about the surrounding environment, so as to realize vehicle-vehicle and vehicle-road collaboration at the levels of perception, decision-making and control. On the basis of connected car technology, multiple vehicles travel in formation at a shorter inter-vehicle distance than under free driving conditions to form a vehicle queue, which can not only reduce wind resistance and fuel consumption, but also reduce the overall length of the traffic flow and traffic flow. time and improve traffic efficiency.

However, although vehicle platooning helps to shorten the length of traffic flow and reduce the passing time, it is greatly restricted at traffic bottlenecks such as intersections. At the intersection with signal control, the vehicle queue may be cut off by the red light, and the continuous passage of the entire queue cannot be guaranteed; at the intersection without signal control, vehicle queues in different directions will interfere with each other, and they can only pass in order according to the priority. In this process, the low-priority vehicle queue has a high probability to go through the process of deceleration, parking, and restarting, so the advantage of the vehicle queue in improving traffic efficiency is greatly reduced. For this reason, how to carry out vehicle formation control at intersections and avoid the above-mentioned limitations has become a major bottleneck for the practical application of vehicle formations.

There is no relevant patent about the vehicle formation passing method at the non-sign control intersection. The existing technologies similar to it are mainly the corresponding solutions proposed for vehicle conflict resolution or vehicle speed guidance at non-signal-controlled intersections. The method for resolving traffic conflicts between two vehicles at unsignalized intersections proposed by Beijing University of Aeronautics and Astronautics and the method for resolving traffic conflicts between two vehicles at unsignalized intersections proposed by Xi'an University of Electronic Science and Technology both design the conflict identification, classification and resolution methods for two vehicles. Focusing on vehicle safety, it is difficult to apply to formations that focus on vehicle traffic efficiency. The conflict resolution and vehicle speed guidance method at non-signal-controlled intersections proposed by the Zhangjiagang Industrial Technology Research Institute of Soochow University aims to guide the driver's speed. The calculation of the speed trajectory is relatively complicated, and it is not suitable for the application of vehicle platoons. The vehicle platooning method and system based on vehicle-road coordination technology proposed by Chongqing University of Posts and Telecommunications and the vehicle platooning management method based on vehicle-road coordination technology proposed by Chongqing Yuntu Transportation Technology Co., Ltd. do not consider the intersection situation.

There are still some conflict resolution and intersection management methods at non-signal-controlled intersections in the prior art, which are difficult to apply to vehicle formation control. For example, research on coordinated control of intersections under the environment of vehicle-road coordination, research on intersection coordination methods based on vehicle-road coordination technology, and research on cooperative vehicle control at unsignalized intersections. Speed tracking, but cannot be applied to vehicle formations. This shows that there is no effective and practical method for the formation of vehicles passing through non-signal-controlled intersections at present.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a method for passing vehicles in formation at non-signal-controlled intersections based on wireless communication. The networked vehicles can pass through the intersection in turn, thereby avoiding the process of deceleration, parking, and starting of the vehicle, reducing the passing time, and improving the passing efficiency of non-signature-controlled intersections.

In order to achieve the above object, the present invention adopts the following technical solutions: a method for passing vehicles at a non-signal-controlled intersection based on wireless communication, which is characterized in that it includes the following steps: 1) when a networked vehicle approaches a non-signal-controlled intersection, use Wireless communication broadcasts its own identity number, position, speed and acceleration information; 2) The service platform uses wireless communication to obtain the identity number, position, speed and acceleration information of all networked vehicles driving into non-signature-controlled intersections, and coordinates Conversion, to determine the virtual front vehicle of each networked vehicle; 3) The service platform uses wireless communication to broadcast the identity number of the real vehicle corresponding to the virtual front vehicle of each networked vehicle, and each networked vehicle uses wireless communication to obtain its own 4) Each networked vehicle obtains the position, velocity and acceleration information of the real vehicle corresponding to the virtual front vehicle through wireless communication, and performs coordinate conversion to become an equivalent front vehicle, Then the vehicle is automatically controlled to track the equivalent preceding vehicle until it leaves the intersection.

Described step 2) in, utilize coordinate transformation, the method for determining virtual vehicle in front and equivalent vehicle in front is as follows: 2.1) set up the virtual lane that has direction, pass through intersection central point; Calculate the distance from each connected vehicle to the center point of the intersection; the total number of connected vehicles is N; 2.3) For the connected vehicles that have passed the intersection, their positions are sequentially calculated based on the center point of the intersection. Rotate clockwise or counterclockwise, and project to the upper right of the virtual lane to form a virtual vehicle; 2.4) For networked vehicles that have not passed the intersection, rotate their position clockwise or counterclockwise with the center point of the intersection, and project to the virtual lane 2.5) After all networked vehicles are projected, a virtual queue composed of virtual vehicles is formed on the virtual lane, and the total number of virtual vehicles is also N, and each virtual vehicle in the virtual queue is divided by virtual lane In the opposite direction, number 1~N from small to large, then define virtual vehicle j as the virtual front vehicle corresponding to the real vehicle corresponding to virtual vehicle j+1 according to the number, where 1≤j≤N-1; 2.6) The real vehicles respectively The real vehicle corresponding to the virtual front vehicle is projected to the front of the real lane where it is located, and becomes an equivalent vehicle, then the equivalent vehicle is the equivalent front vehicle of the real vehicle.

In the step 2), coordinate conversion is used to determine the calculation method of the equivalent vehicle ahead of the networked vehicle as follows: 2.1) Set the total number of networked vehicles at a non-signal-controlled intersection at a certain moment as N, and number each networked vehicle separately is 1 to N, and record the i-th networked vehicle as R _i ; let the absolute distance between the networked vehicle R _i and the center point of the non-signal-controlled intersection be d _i , and define the distance between the networked vehicle R _i and the non-signal-controlled intersection The directional distance of the central point is D _i , satisfying D _i = μ _i d _i , 1≤i≤N; 2.2) sorting the directional distance D _i from large to small, and the ordered subscript set is S={ s ₁ ,s ₂ ,...,s _N }, where 1≤j≤N-1; 2.3) Suppose there is a hypothetical vehicle E _j , which is located in the and the front of the car is forward, and connected vehicles distance Its speed, acceleration and connected vehicles are the same, then define the imaginary vehicle E _j as a networked vehicle The equivalent preceding vehicle.

In the step 2.1), if the networked vehicle R _i has passed the center point of the intersection, then μ _i =1; if the networked vehicle R _i has not passed the center point of the intersection, then μ _i =-1.

The operating process of the service platform is as follows: 3.1) Utilize wireless communication to obtain the identity numbers, positions, speeds and acceleration information of all connected vehicles newly entering the non-signature-controlled intersection; 3.2) judge whether there is no virtual queue, if there is no In the virtual queue, coordinate transformation is performed on the networked vehicle information to construct a virtual queue; when there is a virtual queue, the networked vehicles that newly enter the intersection are added to the tail of the virtual queue in order to form a new virtual queue; 3.3) According to the formed virtual queue, determine the virtual front vehicle of each connected vehicle, and broadcast the identity number of the real vehicle corresponding to the virtual front vehicle to each connected vehicle, and return to step 3.1).

The service platform is set up on a cloud server, or on the roadside of a non-trusted intersection, or randomly set up on a networked vehicle at the non-trusted intersection.

In the step 4), the process of each networked vehicle leaving the intersection is as follows: 4.1) each networked vehicle always broadcasts its own identity number, position, speed and acceleration information through wireless communication; 4.2) when judging that the networked vehicle When the vehicle is approaching a non-signature-controlled intersection, enter step 4.3), otherwise repeat step 4.2) to continue to judge; 4.3) Obtain the identity number of the real vehicle corresponding to the virtual front vehicle from the service platform through wireless communication; 4.4) Obtain through wireless communication The position, speed and acceleration information of the real vehicle corresponding to the virtual vehicle in front, and coordinate transformation, becomes the equivalent vehicle in front; 4.5) Judging the inter-vehicle distance between the self-vehicle and the equivalent vehicle in front, when the inter-vehicle distance is less than the preset expectation When the inter-vehicle distance, it will automatically control the tracking of the equivalent vehicle in front; otherwise, it will perform constant speed cruise according to the set speed, or keep tracking the equivalent vehicle in front to form an uninterrupted vehicle queue; intersection, return to step 4.2), otherwise return to step 4.5).

In the step 4.5), when the automatic control is used to track the equivalent front vehicle, the gas pedal and the brake pedal of the connected vehicle are controlled by using PID, linear or nonlinear control, model predictive control, sliding mode control or robust control methods to realize Control of the acceleration or speed of connected vehicles.

The present invention has the following advantages due to the adoption of the above technical scheme: 1. The present invention realizes the formation passing of vehicles at non-signal-controlled intersections based on wireless communication, and can realize the simultaneous passage of conflicting traffic flows (referring to each direction without experiencing deceleration, parking and starting) process), which helps to reduce the time of traffic flow and improve the efficiency of intersections while ensuring safety. 2. After each Internet-connected vehicle obtains the identity number of the real vehicle corresponding to the virtual vehicle in front, the present invention only needs to obtain the information of the Internet-connected vehicle corresponding to the identity number through wireless communication, without obtaining the information of other Internet-connected vehicles. Can greatly reduce the demand for communication, such as reducing the amount of information transmission and communication frequency.

Description of drawings

Fig. 1 is the virtual formation that the present invention builds, the schematic diagram that determines virtual front car and equivalent front car;

Fig. 2 is a schematic diagram of the operation flow of the service platform of the present invention;

Fig. 3 is a schematic diagram of the operation flow of the networked vehicle of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

The present invention provides a method for passing vehicles in formation at a non-signal-controlled intersection based on wireless communication, which includes the following steps:

1) When a networked vehicle approaches a non-signal-controlled intersection, it uses wireless communication to broadcast its own identity number, position, speed and acceleration information; among them, the identity number of each networked vehicle is unique;

2) The service platform uses wireless communication to obtain the identity number, position, speed and acceleration information of all connected vehicles entering the non-signature-controlled intersection, performs coordinate conversion, constructs a virtual vehicle queue, determines the passing sequence of connected vehicles, and then determines Virtual front vehicle for each connected vehicle;

3) The service platform uses wireless communication to broadcast the identity number of the real vehicle corresponding to the virtual vehicle in front of each networked vehicle, and each networked vehicle uses wireless communication to obtain the identity number of the real vehicle corresponding to its own virtual vehicle in front;

Among them, the service platform can be set up on the cloud server, or on the roadside of the non-trust-controlled intersection, or on a networked vehicle at the non-trust-controlled intersection.

4) Each networked vehicle obtains the position, speed and acceleration information of the real vehicle corresponding to the virtual vehicle in front through wireless communication, and performs coordinate transformation to become an equivalent vehicle in front, and then automatically controls the vehicle to track the equivalent vehicle in front until driving away from the intersection.

In above-mentioned step 2), utilize coordinate transformation, construct virtual formation, the method for determining virtual vehicle in front and equivalent vehicle in front is as follows:

2.1) Establish a directional virtual lane passing through the center point of the intersection, as shown by the arrow pointing from the lower left to the upper right in Figure 1;

2.2) Utilize the position information of the networked vehicles R1～RN at the non-signature-controlled intersection to calculate the distance from each networked vehicle to the center point of the intersection; where N is the total number of networked vehicles, and in this embodiment, 8 Take a connected vehicle as an example.

2.3) For the networked vehicle that has passed the intersection, rotate its position clockwise or counterclockwise from the center point of the intersection, and project it to the upper right of the virtual lane to form a virtual vehicle, as shown in the solid arc arrow in Figure 1 Projected as virtual vehicles V1~V4;

2.4) For the networked vehicles that have not passed the intersection, rotate their position clockwise or counterclockwise from the center point of the intersection, and project it to the lower left of the virtual lane to form a virtual vehicle, as shown in the solid arc arrow in Figure 1 Projected as virtual vehicles V5-V8;

2.5) After all networked vehicles are projected, a virtual queue composed of virtual vehicles is formed on the virtual lane, and each virtual vehicle in the virtual queue is numbered V1, V2, ..., V8 from small to large according to the reverse direction of the virtual lane, as shown in the figure As shown in 1, the virtual vehicles V1, V2, V3, ..., V8 respectively correspond to the real vehicles R1, R7, R3, ..., R8, and the virtual vehicles V1, V2, ..., V7 are respectively defined as the real vehicles R7, R3,…, R8's virtual front car;

2.6) The real vehicles R7, R3,..., R8 respectively project their respective virtual front vehicles V1, V2,..., V7 to the front of the real lane where they are located, as shown by the dotted arc arrows in Figure 1, and become equal to The equivalent vehicles E1, E2, ..., E7 are the equivalent preceding vehicles of the real vehicles R7, R3, ..., R8 respectively. As shown in Figure 1, the virtual vehicle V2 corresponds to the real vehicle R7, and the virtual front vehicle V1 of the real vehicle R7 is projected to the front of the real vehicle R7 to become an equivalent vehicle E1, then the equivalent vehicle E1 is the equivalent front vehicle of the real vehicle R7 .

In the above step 2), the virtual queue is constructed by using coordinate transformation, and the calculation method for determining the equivalent vehicle ahead of the connected vehicle is as follows:

2.1) Ignore the size of intersections and vehicles, set the total number of networked vehicles at non-signal-controlled intersections at a certain moment as N, number each networked vehicle from 1 to N, and record the i-th vehicle (1≤i≤N ) connected vehicle is R _i . Let d _i be the absolute distance between the networked vehicle R _i and the center point of the non-signal-controlled intersection, and define the directed distance between the networked vehicle R _i and the center point of the non-signal-controlled intersection as D _i , satisfying D _i = μ _i d _i .

Wherein, if the Internet-connected vehicle R _i has passed the center point of the intersection, then μ _i =1; if the network-connected vehicle R _i has not passed the center point of the intersection, then μ _i =-1.

2.2) Sorting the directional distance D _i from large to small, the ordered subscript set is S={s ₁ , s ₂ ,...,s _N }. where 1≤j≤N-1.

2.3) Suppose there is a hypothetical vehicle E _j , which is located in the and the front of the car is forward, and connected vehicles distance Its speed, acceleration and connected vehicles same (direction both forward or backward). Then define the imaginary vehicle E _j as a networked vehicle The equivalent preceding vehicle.

In the above step 2), step 3), as shown in Figure 2, the operation process of the service platform is as follows:

3.1) Use wireless communication to obtain the identity number, position, speed and acceleration information of all networked vehicles newly entering the non-signature-controlled intersection;

3.2) Determine whether there is a virtual queue. When there is no virtual queue, perform coordinate conversion on the networked vehicle information to construct a virtual queue; when there is a virtual queue, add the new networked vehicles entering the intersection to the virtual queue in order At the end of the queue, a new virtual queue is formed;

3.3) According to the formed virtual queue, determine the virtual front vehicle of each connected vehicle, and broadcast the identity number of the real vehicle corresponding to the virtual front vehicle to each connected vehicle, and return to step 3.1).

In the above step 4), the process of each connected vehicle leaving the intersection is:

4.1) Each connected vehicle always broadcasts its own identity number, location, speed and acceleration information through wireless communication;

4.2) When it is judged that the connected vehicle is approaching a non-signature-controlled intersection, proceed to step 4.3), otherwise repeat step 4.2) to continue the judgment;

4.3) Obtain the identity number of the real vehicle corresponding to the virtual front vehicle from the service platform through wireless communication;

4.4) Obtain the position, speed and acceleration information of the real vehicle corresponding to the virtual front vehicle through wireless communication, and perform coordinate transformation to become an equivalent front vehicle;

4.5) Judging the inter-vehicle distance between the self-vehicle and the equivalent vehicle in front, when the inter-vehicle distance is less than the preset expected inter-vehicle distance, it will automatically control the tracking of the equivalent vehicle in front; otherwise, perform constant speed cruise according to the set speed, or keep tracking all the time Equivalent to the vehicle in front to form an uninterrupted vehicle queue;

4.6) Return to step 4.2) when it is judged that the connected vehicle is leaving the non-signature-controlled intersection, otherwise return to step 4.5).

In the above step 4.5), when the automatic control tracks the equivalent preceding vehicle, various control methods such as PID, linear or nonlinear control, model predictive control, sliding mode control or robust control can be used to control the accelerator pedal and brake of the connected vehicle. Move the pedals to control the acceleration or speed of the connected vehicle.

The above-mentioned embodiments are only used to illustrate the present invention, and the order and content of each step can be changed. For example, the order and content of each step can be readjusted in consideration of intersections and vehicle sizes. On the basis of the technical solution of the present invention, any improvement and equivalent transformation of individual steps according to the principle of the present invention shall not be excluded from the protection scope of the present invention.

Claims (5)

1. A method for passing vehicles in formation at a non-signal-controlled intersection based on wireless communication, characterized in that it may further comprise the steps: 1) When the networked vehicle approaches a non-signal-controlled intersection, it uses wireless communication to broadcast its own identity number, position, speed and acceleration information; 2) The service platform uses wireless communication to obtain the identity number, position, speed and acceleration information of all connected vehicles entering the non-signature-controlled intersection, and performs coordinate conversion to determine the virtual front vehicle of each connected vehicle. The specific process is as follows: 2.1) Establish a directional virtual lane passing through the center point of the intersection; 2.2) Utilize the position information of the networked vehicles at the non-signature-controlled intersection to calculate the distance from each networked vehicle to the center point of the intersection; the total number of networked vehicles is N; 2.3) For the networked vehicle that has passed the intersection, rotate its position clockwise or counterclockwise from the center point of the intersection, and project it to the upper right of the virtual lane to form a virtual vehicle; 2.4) For connected vehicles that have not passed the intersection, rotate their position clockwise or counterclockwise from the center point of the intersection, and project it to the lower left of the virtual lane to form a virtual vehicle; 2.5) After all networked vehicles are projected, a virtual queue composed of virtual vehicles is formed on the virtual lane, and the total number of virtual vehicles is also N, and each virtual vehicle in the virtual queue is numbered from small to large according to the reverse direction of the virtual lane. ～N, according to the number definition, the virtual vehicle j is the virtual vehicle in front of the real vehicle corresponding to the virtual vehicle j+1, where 1≤j≤N-1; 2.6) The real vehicles respectively project the real vehicles corresponding to their respective virtual vehicles ahead to the front of their own real lanes to become equivalent vehicles, then the equivalent vehicle is the equivalent vehicle ahead of the real vehicle; 3) The service platform uses wireless communication to broadcast the identity number of the real vehicle corresponding to the virtual vehicle in front of each networked vehicle, and each networked vehicle uses wireless communication to obtain the identity number of the real vehicle corresponding to its own virtual vehicle in front; 4) Each networked vehicle obtains the position, speed and acceleration information of the real vehicle corresponding to the virtual vehicle in front through wireless communication, and performs coordinate transformation to become an equivalent vehicle in front, and then automatically controls the vehicle to track the equivalent vehicle in front until driving From the intersection, where, using coordinate transformation, the calculation method to determine the equivalent vehicle ahead of the connected vehicle is as follows: 4.11) Assuming that the total number of networked vehicles at a non-signal-controlled intersection at a certain moment is N, each networked vehicle is numbered from 1 to N, and the _i -th networked vehicle is recorded as R _i ; The absolute distance of the center point of the non-signal-controlled intersection is d _i , and the directional distance between the connected vehicle R _i and the center point of the non-signal-controlled intersection is defined as D _i , which satisfies D _i =μ _i d _i , 1≤i≤N ; If the networked vehicle R _i has passed the center point of the intersection, then μ _i =1; if the networked vehicle R _i has not passed the center point of the intersection, then μ _i =-1; 4.12) Sorting the directional distance D _i from large to small, the ordered subscript set is S=s ₁ , s ₂ ,...,s _N , where 1≤j≤N-1; 4.13) Suppose there is a hypothetical vehicle E _j , which is located in the and the front of the car is forward, and connected vehicles distance Its speed, acceleration and connected vehicles are the same, then define the imaginary vehicle E _j as a networked vehicle The equivalent preceding vehicle. 2. A kind of non-signal control intersection vehicle formation passing method based on wireless communication as claimed in claim 1, is characterized in that: the operating process of described service platform is as follows: 3.1) Use wireless communication to obtain the identity number, position, speed and acceleration information of all networked vehicles newly entering the non-signature-controlled intersection; 3.2) Judging whether there is no virtual queue, when there is no virtual queue, coordinate conversion is performed on the information of networked vehicles to construct a virtual queue; when there is a virtual queue, new networked vehicles entering the intersection are added to the virtual queue in order to form a new virtual queue; 3.3) According to the formed virtual queue, determine the virtual front vehicle of each connected vehicle, and broadcast the identity number of the real vehicle corresponding to the virtual front vehicle to each connected vehicle, and return to step 3.1). 3. A kind of non-signal control intersection vehicle formation passing method based on wireless communication as claimed in claim 1, is characterized in that: described service platform is set up on cloud server, or is set up on the roadside of non-signal control intersection, Or randomly set up on a networked vehicle at the non-trusted intersection. 4. A kind of non-signal-controlled intersection vehicle formation passing method based on wireless communication as claimed in claim 1, is characterized in that: in described step 4), the process of each networked vehicle leaving the intersection is: 4.1) Each connected vehicle always broadcasts its own identity number, location, speed and acceleration information through wireless communication; 4.2) When it is judged that the connected vehicle is approaching a non-signature-controlled intersection, proceed to step 4.3), otherwise repeat step 4.2) to continue the judgment; 4.3) Obtain the identity number of the real vehicle corresponding to the virtual front vehicle from the service platform through wireless communication; 4.4) Obtain the position, speed and acceleration information of the real vehicle corresponding to the virtual front vehicle through wireless communication, and perform coordinate transformation to become an equivalent front vehicle; 4.5) Judging the inter-vehicle distance between the self-vehicle and the equivalent vehicle in front, when the inter-vehicle distance is less than the preset expected inter-vehicle distance, it will automatically control the tracking of the equivalent vehicle in front; otherwise, perform constant speed cruise according to the set speed, or keep tracking all the time Equivalent to the vehicle in front to form an uninterrupted vehicle queue; 4.6) Return to step 4.2) when it is judged that the connected vehicle is leaving the non-signature-controlled intersection, otherwise return to step 4.5). 5. A kind of non-signal-controlled intersection vehicle formation passing method based on wireless communication as claimed in claim 4, it is characterized in that: in described step 4.5), when automatic control tracks equivalent front vehicle, utilizes PID, linear or Nonlinear control, model predictive control, sliding mode control, or robust control methods control the accelerator pedal and brake pedal of the connected vehicle to realize the acceleration or speed control of the connected vehicle.