Control method for enhancing CAV fleet formation intensity in mixed traffic flow under vehicle-road cooperation

Abstract

The invention discloses a control method for enhancing CAV fleet formation intensity in a mixed traffic flow under vehicle-road cooperation. The method comprises the following steps: determining a to-be-compiled vehicle and a target fleet according to the method provided by the invention; interaction between the road side unit and the vehicle communication unit is adopted to obtain driving information and road environment information of all vehicles in the communication radius range of the target motorcade and the compiled vehicles, and the obtained information is exchanged through inter-vehicle communication; and controlling the compiled vehicles or the motorcade to run to a to-be-compiled area according to the obtained information, realizing speed coordination through a speed management module, decelerating the tail vehicles of the target motorcade to expand a gap, and after the to-be-expanded gap is enough to meet the space-time condition of safe compilation of the compiled vehicles, controlling the compiled vehicles or the motorcade to be compiled into the target motorcade in sequence from the rear part. According to the control method, interference of other surrounding vehicles on CAV vehicles or small-sized CAV motorcades in the mixed traffic flow can be reduced, and the CAV vehicles or small-sized CAV motorcades can be safely and efficiently incorporated into the CAV motorcades, so that the formation intensity of the CAV motorcades is enhanced, and the road traffic capacity is improved.

Description

Technical Field

[0001] The present invention relates to the field of traffic control systems for road vehicles, and in particular to a control method for enhancing the formation strength of a CAV fleet in mixed traffic flow under vehicle-road collaboration. Background Art

[0002] Intelligent networked autonomous driving vehicles (CAVs) are equipped with advanced on-board sensors, controllers, actuators and other devices, and integrate modern communication and network technologies to achieve V2X intelligent information exchange and sharing. They have complex environmental perception, intelligent decision-making, collaborative control and execution functions, and can achieve safe, comfortable, energy-saving and efficient driving, and can eventually replace human operation. In recent years, the platooning of intelligent networked autonomous driving vehicles has attracted great attention. In a platoon of intelligent networked autonomous driving vehicles, the vehicles in the platoon can be adjusted to maintain the same required speed and maintain a pre-set vehicle-to-vehicle distance. Previous theoretical analysis and practice have confirmed that vehicle platooning can achieve higher traffic efficiency, better safety and lower energy consumption.

[0003] However, it is still very difficult for intelligent networked autonomous vehicles to achieve a 100% penetration rate. With the gradual deployment of autonomous vehicles, it is inevitable that there will be a long period of time in the future when road traffic will be in a mixed traffic state, that is, autonomous vehicles and human-driven vehicles will coexist. The uncertainty of human driving behavior is difficult to quantify, which will also bring certain challenges to the platooning of intelligent networked autonomous vehicles. Faced with the mixed traffic flow conditions that will exist for a long time in the future, the intelligent networked autonomous vehicles will inevitably encounter interference from surrounding human-driven vehicles in the process of enhancing the strength of the formation, which will affect the efficiency and safety of the formation. Therefore, it is urgent to explore methods to enhance the safe and efficient formation control of intelligent networked autonomous vehicles in mixed traffic flows. Summary of the invention

[0004] The purpose of the present invention is to provide a control method for enhancing the strength of CAV fleet formation in mixed traffic flow under vehicle-road collaboration, by expanding the space of the target fleet, so that the vehicles or fleets to be organized can be safely and efficiently incorporated into the target fleet, so as to achieve the purpose of enhancing the strength of the fleet formation.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] The control method for enhancing the CAV platoon formation strength in mixed traffic flow under vehicle-road collaboration is as follows:

[0007] S1. The intelligent connected autonomous driving fleet publishes the remaining capacity of the fleet to all intelligent connected autonomous driving vehicles or small intelligent connected autonomous driving fleets within the communication radius of the fleet;

[0008] Intelligent connected autonomous vehicles (CAVs) can sense the road environment and share information in real time;

[0009] The remaining capacity of the convoy is the number of vehicles that can be incorporated into the convoy, which is equal to the difference between the number of vehicles in the maximum convoy length and the number of vehicles in the current convoy;

[0010] As the length of the convoy increases, it has a negative contribution to the traffic capacity and traffic flow stability. A longer convoy length will reduce the lateral mobility of the convoy and increase the difficulty of vehicle merging and leaving the queue. It also poses a great challenge to the control of the convoy. Therefore, the maximum convoy length is 10 vehicles.

[0011] The communication radius is a circular range of 0 to 1000 meters;

[0012] S2. The specific situations in which an intelligent connected autonomous driving vehicle or a small intelligent connected autonomous driving fleet with a platooning requirement sends a platooning request to the intelligent connected autonomous driving fleet and determines the number of vehicles that can be incorporated are divided into the following two situations:

[0013] 1. When the remaining capacity of the fleet is greater than or equal to the small intelligent networked autonomous driving fleet, all small intelligent networked autonomous driving fleets will be used as fleets to be organized;

[0014] 2. When the remaining capacity of the fleet is less than that of the small intelligent connected autonomous driving fleet, the small intelligent connected autonomous driving fleet will be split.

[0015] The small intelligent connected autonomous driving fleet is half or less than the number of vehicles in the maximum formation length;

[0016] The splitting principle is: splitting from the front or rear of the small fleet according to the relative position of the target fleet and the small intelligent connected autonomous driving fleet, the number of split vehicles is the remaining capacity of the fleet, or the target fleet invites other vehicles or fleets as included vehicles;

[0017] S3: After screening, the intelligent networked autonomous driving fleet invites the intelligent networked autonomous driving vehicle or small intelligent networked autonomous driving fleet that has made the request as the fleet to be organized. The fleet to be organized determines the intelligent networked autonomous driving fleet as the target fleet, and the number of vehicles in the target fleet is greater than or equal to the number of vehicles to be organized into the fleet;

[0018] The specific steps of the screening are as follows:

[0019] S3.1. Screen all received requests, first screen the fleets whose number of vehicles to be incorporated into the fleet is equal to the remaining capacity of the target fleet, if there is one, send an invitation to it and confirm that the fleet is the fleet to be incorporated, if not, screen the fleets whose number of vehicles to be incorporated into the fleet is greater than the remaining capacity of the target fleet;

[0020] S3.2. Select the fleets whose number of vehicles to be incorporated is greater than the remaining capacity of the target fleet. If there is one, send an invitation to the fleet with the least number of vehicles remaining after the split and confirm that the new fleet split from the fleet is the fleet to be incorporated. If there is no one, continue to select the fleets whose number of vehicles to be incorporated is less than the remaining capacity of the target fleet;

[0021] S3.3. Filter the fleets whose number of vehicles to be incorporated into the fleet is less than the remaining capacity of the target fleet. If there are fleets, send an invitation to incorporate to the fleet with the largest number of vehicles and confirm that the fleet is the fleet to be incorporated. If there are no fleets, send an invitation to incorporate to the single vehicle that made the request and confirm that it is the vehicle to be incorporated.

[0022] S4. Acquire the driving information and road environment information of all vehicles within the communication radius of the target fleet and the incorporated vehicles through the roadside unit and the vehicle communication unit, and exchange information through vehicle-to-vehicle communication;

[0023] The driving information and road environment information include: the spatial position of the target convoy and the vehicles to be organized on the road, the convoy speed, acceleration and deceleration, the speed and acceleration and deceleration of the front and rear vehicles, the driving conditions and spatial positions of the vehicles in the adjacent lanes of the target convoy, the number of lanes on the road, the road line type, and the weather conditions;

[0024] Among them, according to the spatial position relationship between the obtained target convoy and the convoy or convoy to be organized, the vehicles or convoys to be organized can be classified as being located behind or in front of the target convoy. The classification is based on the target gap of the target convoy. The specific positions of the vehicles or convoys to be organized relative to the target convoy can be divided into six categories, namely, distributed in front of or behind the same lane of the target convoy, in front of or behind the adjacent lane, and in front of or behind the cross-lane lane;

[0025] S5: The convoy to be organized drives to the adjacent lane of the target convoy, accelerates or decelerates according to the driving information and road environment information to enter the area to be organized, and realizes speed coordination through the speed management module;

[0026] The target convoy and the convoy or convoy to be organized have different relative positions and different ways of entering the area to be organized. The vehicles or convoys to be organized that are distributed in front of or behind the same lane of the target convoy enter the area to be organized by accelerating or decelerating after changing lanes to the adjacent lane of the target convoy; the vehicles or convoys to be organized that are distributed in front of or behind the adjacent lane of the target convoy enter the area to be organized by accelerating or decelerating; the vehicles or convoys to be organized that are distributed in front of or behind the cross-lane of the target convoy enter the area to be organized by changing lanes to the adjacent lane of the target convoy and accelerating or decelerating;

[0027] The waiting area is: with the road centerline as the horizontal axis and the vertical axis perpendicular to the road centerline as the vertical axis, when the horizontal coordinate of the vehicle body position at the tail end of the target gap of the target fleet has the same horizontal coordinate value as the adjacent lane where the incorporated vehicle or fleet is located, the position is called the waiting area; if incorporated into a small intelligent networked autonomous driving fleet, the small intelligent networked autonomous driving fleet should completely enter the waiting area;

[0028] The specific steps of implementing speed coordination through the speed management module are as follows:

[0029] S5.1. When there are no obstacle vehicles in front of the incoming vehicle or convoy and the target convoy, the following expression should be satisfied:

[0030] v in =v p

[0031] In the formula, v in The speed required to integrate a vehicle or convoy, v p is the target convoy speed;

[0032] S5.2. When there is an obstacle vehicle in front of the incoming vehicle or convoy, and there is no obstacle vehicle in front of the target convoy, the following expression should be satisfied:

[0033]

[0034] In the formula, Speed ​​of the leading vehicle or convoy vehicle;

[0035] S5.3. When there is no obstacle in front of the incoming vehicle or convoy, and there is an obstacle in front of the target convoy, the following expression should be satisfied:

[0036]

[0037] In the formula, is the speed of the front vehicle in the target convoy;

[0038] S5.4. When there are obstacle vehicles in front of both the incoming vehicle or convoy and the target convoy, the following expression should be satisfied:

[0039]

[0040] S6: The vehicle at the rear of the target convoy slows down to expand the gap. When the gap is large enough to meet the conditions for the safe integration of the convoy to be formed, it is incorporated into the convoy. If it is a small convoy, it is incorporated from the rear of the small convoy in sequence until the formation is completed. The specific expression is as follows:

[0041] and

[0042] In the formula, The longitudinal distance d between the target convoy gap rear vehicle and the vehicle to be assembled in the waiting area l-g , the longitudinal distance d between the front vehicle in the target convoy and the vehicle to be assembled in the area to be assembled f-g , the longitudinal safety distance between the target convoy’s rear vehicle and the vehicles to be assembled in the waiting area The longitudinal safety distance between the front vehicle in the target convoy and the vehicles to be assembled in the waiting area Gap rear vehicle speed v l -g , gap front vehicle speed v f-g , length of the convoy or vehicle l, speed of the vehicle or convoy v, reaction time of the connected autonomous vehicle (CAV) Braking delay time t delay , minimum acceleration a min ;

[0043] Furthermore, a controller is used to widen the target gap and control the integration of vehicles or convoys into the target convoy. The controller consists of two parts: a lateral controller and a longitudinal controller. The lateral controller is intended to minimize the lateral position error, and the longitudinal controller is intended to minimize the gap error.

[0044] Beneficial Effects of the Invention

[0045] 1. The control method of the present invention for enhancing the formation strength of an intelligent networked autonomous driving fleet in mixed traffic flow under vehicle-road cooperative conditions slows down the rear vehicle of the intelligent networked autonomous driving fleet to expand the target gap. The target gap can ensure that the target gap can provide a safe space for vehicles to be organized or small fleets in the area to be organized. When the penetration rate of intelligent networked autonomous driving vehicles has not reached 100%, the interference of non-intelligent networked autonomous driving vehicles around the intelligent networked autonomous driving fleet can be reduced, so that the vehicles to be organized or small fleets can be safely and efficiently organized into the fleet to achieve the purpose of platoon driving.

[0046] 2. In order to ensure the speed coordination between the vehicles to be organized or the small fleet in the area to be organized and the target fleet, the present invention proposes a speed management module, whose control logic can ensure accurate and safe speed coordination between the target fleet and the vehicles to be organized or the small fleet when there are no human-driven vehicles in front of the target fleet and the vehicles to be organized or the small fleet.

[0047] 3. The present invention proposes a screening mechanism for determining that intelligent networked autonomous driving vehicles or small intelligent networked autonomous driving fleets operating on roads are vehicles to be formed, which can determine that the vehicles to be formed are the optimal choice under the current environment, thereby improving the efficiency of the target fleet to become the maximum formation length, reducing the number of times to form the maximum formation length, and to a certain extent reducing the impact of the formation process caused by formation needs on traffic flow.

[0048] 4. In the mixed traffic flow driving environment, the CAV vehicles drive in formation, which can greatly reduce the headway between vehicles, improve driving efficiency and safety, and thus greatly improve the road capacity.

[0049] 5. The present invention enhances the formation strength of the CAV fleet, allowing CAVs to gather better, the CAV queue length reaches the maximum and the headroom interval is reduced, and the road traffic capacity will be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A flow chart of a control method for enhancing the strength of a CAV convoy formation in mixed traffic flow under vehicle-road collaboration;

[0051] Figure 2 A schematic diagram of a control method for enhancing the CAV platoon formation strength in mixed traffic flow under vehicle-road collaboration;

[0052] Figure 3 It is a rolling horizon control framework;

[0053] Figure 4 Parameter illustration of the control method for enhancing the CAV platoon formation strength in mixed traffic flow under vehicle-road collaboration. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0055] The present invention provides a control method for enhancing the strength of a platoon of intelligent networked autonomous driving vehicles in a mixed traffic flow under vehicle-road cooperative conditions, and the specific steps are as follows:

[0056] like Figure 1 and Figure 2 As shown in FIG, a control method for enhancing the formation strength of a CAV fleet in mixed traffic flow under vehicle-road collaboration is provided. The specific steps are as follows:

[0057] S1. The intelligent connected autonomous driving fleet publishes the remaining capacity of the fleet to all intelligent connected autonomous driving vehicles or small intelligent connected autonomous driving fleets within the communication radius of the fleet;

[0058] Intelligent connected autonomous vehicles (CAVs) can sense the road environment and share information in real time;

[0059] The remaining capacity of the convoy is the number of vehicles that can be incorporated into the convoy, which is equal to the difference between the number of vehicles in the maximum convoy length and the number of vehicles in the current convoy;

[0060] As the length of the convoy increases, it has a negative contribution to the traffic capacity and traffic flow stability. A longer convoy length will reduce the lateral mobility of the convoy and increase the difficulty of vehicle merging and leaving the queue. It also poses a great challenge to the control of the convoy. Therefore, the maximum convoy length is 10 vehicles.

[0061] The communication radius is a circular range of 0 to 1000 meters;

[0062] S2. The specific situations in which an intelligent connected autonomous driving vehicle or a small intelligent connected autonomous driving fleet with a platooning requirement sends a platooning request to the intelligent connected autonomous driving fleet and determines the number of vehicles that can be incorporated are divided into the following two situations:

[0063] 1. When the remaining capacity of the fleet is greater than or equal to the small intelligent networked autonomous driving fleet, all small intelligent networked autonomous driving fleets will be used as fleets to be organized;

[0064] 2. When the remaining capacity of the fleet is less than that of the small intelligent connected autonomous driving fleet, the small intelligent connected autonomous driving fleet will be split.

[0065] The small intelligent connected autonomous driving fleet is half or less than the number of vehicles in the maximum formation length;

[0066] The splitting principle is: splitting from the front or rear of the small fleet according to the relative position of the target fleet and the small intelligent connected autonomous driving fleet, the number of split vehicles is the remaining capacity of the fleet, or the target fleet invites other vehicles or fleets as included vehicles;

[0067] S3: After screening, the intelligent networked autonomous driving fleet invites the intelligent networked autonomous driving vehicle or small intelligent networked autonomous driving fleet that has made the request as the fleet to be organized. The fleet to be organized determines the intelligent networked autonomous driving fleet as the target fleet, and the number of vehicles in the target fleet is greater than or equal to the number of vehicles to be organized into the fleet;

[0068] The specific steps of the screening are as follows:

[0069] S3.1. Screen all received requests, first screen the fleets whose number of vehicles to be incorporated into the fleet is equal to the remaining capacity of the target fleet, if there is one, send an invitation to it and confirm that the fleet is the fleet to be incorporated, if not, screen the fleets whose number of vehicles to be incorporated into the fleet is greater than the remaining capacity of the target fleet;

[0070] S3.2. Select the fleets whose number of vehicles to be incorporated is greater than the remaining capacity of the target fleet. If there is one, send an invitation to the fleet with the least number of vehicles remaining after the split and confirm that the new fleet split from the fleet is the fleet to be incorporated. If there is no one, continue to select the fleets whose number of vehicles to be incorporated is less than the remaining capacity of the target fleet;

[0071] S3.3. Filter the fleets whose number of vehicles to be incorporated into the fleet is less than the remaining capacity of the target fleet. If there are fleets, send an invitation to incorporate to the fleet with the largest number of vehicles and confirm that the fleet is the fleet to be incorporated. If there are no fleets, send an invitation to incorporate to the single vehicle that made the request and confirm that it is the vehicle to be incorporated.

[0072] S4. Acquire the driving information and road environment information of all vehicles within the communication radius of the target fleet and the incorporated vehicles through the roadside unit and the vehicle communication unit, and exchange information through vehicle-to-vehicle communication;

[0073] The driving information and road environment information include: the spatial position of the target convoy and the vehicles to be organized on the road, the convoy speed, acceleration and deceleration, the speed and acceleration and deceleration of the front and rear vehicles, the driving conditions and spatial positions of the vehicles in the adjacent lanes of the target convoy, the number of lanes on the road, the road line type, and the weather conditions;

[0074] Among them, according to the spatial position relationship between the obtained target convoy and the convoy or convoy to be organized, the vehicles or convoys to be organized can be classified as being located behind or in front of the target convoy. The classification is based on the target gap of the target convoy. The specific positions of the vehicles or convoys to be organized relative to the target convoy can be divided into six categories, namely, distributed in front of or behind the same lane of the target convoy, in front of or behind the adjacent lane, and in front of or behind the cross-lane lane;

[0075] S5: The convoy to be organized drives to the adjacent lane of the target convoy, accelerates or decelerates according to the driving information and road environment information to enter the area to be organized, and realizes speed coordination through the speed management module;

[0076] The target convoy and the convoy or convoy to be organized have different relative positions and different ways of entering the area to be organized. The vehicles or convoys to be organized that are distributed in front of or behind the same lane of the target convoy enter the area to be organized by accelerating or decelerating after changing lanes to the adjacent lane of the target convoy; the vehicles or convoys to be organized that are distributed in front of or behind the adjacent lane of the target convoy enter the area to be organized by accelerating or decelerating; the vehicles or convoys to be organized that are distributed in front of or behind the cross-lane of the target convoy enter the area to be organized by changing lanes to the adjacent lane of the target convoy and accelerating or decelerating;

[0077] The waiting area is: with the road centerline as the horizontal axis and the vertical axis perpendicular to the road centerline as the vertical axis, when the horizontal coordinate of the vehicle body position at the tail end of the target gap of the target fleet has the same horizontal coordinate value as the adjacent lane where the incorporated vehicle or fleet is located, the position is called the waiting area; if incorporated into a small intelligent networked autonomous driving fleet, the small intelligent networked autonomous driving fleet should completely enter the waiting area;

[0078] The specific steps of implementing speed coordination through the speed management module are as follows:

[0079] S5.1. When there are no obstacle vehicles in front of the incoming vehicle or convoy and the target convoy, the following expression should be satisfied:

[0080] v in =v p

[0081] In the formula, v in The speed required to integrate a vehicle or convoy, v p is the target convoy speed;

[0082] S5.2. When there is an obstacle vehicle in front of the incoming vehicle or convoy, and there is no obstacle vehicle in front of the target convoy, the following expression should be satisfied:

[0083]

[0084] In the formula, Speed ​​of the leading vehicle or convoy vehicle;

[0085] S5.3. When there is no obstacle in front of the incoming vehicle or convoy, and there is an obstacle in front of the target convoy, the following expression should be satisfied:

[0086]

[0087] In the formula, is the speed of the front vehicle in the target convoy;

[0088] S5.4. When there are obstacle vehicles in front of both the incoming vehicle or convoy and the target convoy, the following expression should be satisfied:

[0089]

[0090] S6: The vehicle at the rear of the target convoy slows down to expand the gap. When the gap is large enough to meet the conditions for the safe integration of the convoy to be formed, it is incorporated into the convoy. If it is a small convoy, it is incorporated from the rear of the small convoy in sequence until the formation is completed. The specific expression is as follows:

[0091] and

[0092] In the formula, The longitudinal distance d between the target convoy gap rear vehicle and the vehicle to be assembled in the waiting area l-g , the longitudinal distance d between the front vehicle in the target convoy and the vehicle to be assembled in the area to be assembled f-g , the longitudinal safety distance between the target convoy’s rear vehicle and the vehicles to be assembled in the waiting area The longitudinal safety distance between the front vehicle in the target convoy and the vehicles to be assembled in the waiting area Gap rear vehicle speed v l -g , gap front vehicle speed v f -g , length of the convoy or vehicle l, speed of the vehicle or convoy v, reaction time of the connected autonomous vehicle (CAV) Braking delay time t delay , minimum acceleration a min ;

[0093] Furthermore, a controller is used to widen the target gap and control the integration of vehicles or convoys into the target convoy. The controller consists of two parts: a lateral controller and a longitudinal controller. The lateral controller is intended to minimize the lateral position error, and the longitudinal controller is intended to minimize the gap error.

[0094] The controller is decomposed into horizontal targets and vertical targets, as follows:

[0095] Lateral objective: CAVs in a platoon or convoy change lanes sequentially. The lateral objective of the proposed controller is to minimize the lateral position error. The lateral position error is defined as follows:

[0096]

[0097] Among them, y j is the lateral position of the jth CAV; Initially, it is the lateral position of the centerline of the current lane. When the target gap is sufficient to satisfy the jth vehicle lane change, is the lateral position of the target lane centerline.

[0098] Longitudinal objective: Each CAV follows its adjacent rear CAV. Therefore, the longitudinal objective of the proposed controller is to minimize the following gap error. The definition is as follows:

[0099]

[0100] Among them, x j is the longitudinal position of the jth CAV; g desIt is the following gap required to integrate into a vehicle or convoy. The following gap includes the length of the vehicle.

[0101] The controller adopts a rolling horizon control framework, such as Figure 3 As shown in the figure, the rolling optimization optimizes the performance index at each moment only for a limited time in the future from that moment, and at the next moment, this optimization time moves forward at the same time, and the online optimization is continuously performed. At each moment, a set of future control actions is obtained, and only the control actions at this moment are implemented. At the next moment, a new set of controls is re-predicted and optimized, and only a new control action is implemented. Each step is feedback correction. With predictive control having foresight, rolling optimization and feedback correction can better adapt to the actual system and have stronger robustness.

[0102] In each rolling step, the longitudinal planning trajectory is first calculated and then passed to the lateral planning. Finally, the longitudinal and lateral commands are passed together to the driving layer.

[0103] In order to make the incoming convoy follow the rear vehicles in the target convoy in sequence during the convoy process, the state equation is used as the prediction model, and the state space is designed to be inverted. The state and control vector of the controller are as follows:

[0104] When the vehicle is a small convoy, the longitudinal state vector ξ x,n , longitudinal control vector u x,n , the lateral state vector ξ y,n and the lateral control vector u y,n is defined as follows:

[0105]

[0106]

[0107] In the formula, v j is the speed of the jth CAV; x j is the longitudinal position of the jth CAV; g des is the required following clearance; a j is the acceleration of the jth CAV; is the heading angle of the jth CAV; y j is the lateral position of the jth CAV; Initially, it is the lateral position of the centerline of the current lane. When the target gap is sufficient to satisfy the jth vehicle lane change, is the lateral position of the target lane centerline. ; is the angle of the front wheel of the jth CAV.

[0108] In order to make the platooning stable, with the goal of maintaining a consistent form of queue length propagation, a state space representation is developed based on a two-degree-of-freedom model of the CAV longitudinal position and the CAV lateral position, such as Figure 4 As shown, the dynamic model of the CACC system is established as follows:

[0109]

[0110] Bring it into the longitudinal and lateral decoupled CACC dynamic model formulation as follows:

[0111]

[0112] In the formula,

[0113] κ is the road curvature.

[0114] In order to speed up the calculation, the goal of the controller is to minimize the total state cost within the control range. The operating cost L consists of the state cost and the control cost. By adjusting the weighting factor, a balance can be achieved between the following stability and control minimization, the specific expression is as follows:

[0115]

[0116] In the formula, J x and J y are the vertical cost and the horizontal cost respectively; τ is the control time domain; Q x,n , R x,n , Q y,n , R y,n are all non-negative weight matrices. They consist of weighting factors, including the velocity error weighting factor q ν , gap error weighting factor q g , acceleration weighting coefficient r a , heading angle weighting coefficient Transverse position error weighting coefficient q y and the front wheel angle weighting coefficient r δ By adjusting these weight factors, different driving objectives can be achieved, and I is the identity matrix.

[0117] The controller is constrained by collision avoidance, required speed range, geometric boundaries, acceleration capabilities, and yaw angle constraints. Intra-platoon collision avoidance is achieved by adjusting the intra-platoon gap as follows:

[0118]

[0119] Here is the safe following gap in the CACC convoy;

[0120] Front and rear collision avoidance ensures collision avoidance between convoys, as follows:

[0121]

[0122] Among them, x f-P is the longitudinal position of the leading vehicle in the convoy; x l-P is the longitudinal position of the rear vehicle in the convoy, is the safe following gap between CAVs;

[0123] The vehicle should travel within the geometric boundaries of the road. The specific expression is as follows:

[0124] y min ≤y≤y max

[0125] Acceleration should be limited by vehicle performance and comfort:

[0126] a min ≤a≤a max

[0127] The vehicle's front wheel turning angle should be within its steering range:

[0128] δ fmin ≤δ f ≤aδ fmax

[0129] The parameters configured for the controller are as follows:

[0130] Table 1 Controller parameter configuration

[0131]

[0132]

Claims

1. A control method for enhancing the strength of a CAV fleet in mixed traffic flow under vehicle-road collaboration, characterized in that: The following steps are involved: S1. The intelligent connected autonomous driving fleet publishes the remaining capacity of the fleet to all intelligent connected autonomous driving vehicles or small intelligent connected autonomous driving fleets within the communication radius of the fleet; S2. An intelligent connected autonomous driving vehicle or a small intelligent connected autonomous driving fleet that has a need for platooning sends a platooning request to the intelligent connected autonomous driving fleet and determines the number of vehicles that can be included; S3: After screening, the intelligent networked autonomous driving fleet invites the intelligent networked autonomous driving vehicle or small intelligent networked autonomous driving fleet that has made the request as the fleet to be organized, and the fleet to be organized determines the intelligent networked autonomous driving fleet as the target fleet; S4. Acquire the driving information and road environment information of all vehicles within the communication radius of the target fleet and the incorporated vehicles through the roadside unit and the vehicle communication unit, and exchange information through vehicle-to-vehicle communication; S5: The convoy to be organized drives to the adjacent lane of the target convoy, accelerates or decelerates according to the driving information and road environment information to enter the area to be organized, and realizes speed coordination through the speed management module; S6. The rear vehicle of the target convoy slows down and widens the gap. When the gap is large enough to allow the convoy to be safely incorporated, the vehicle is incorporated into the convoy.

2. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 1 is characterized by: The remaining capacity of the fleet is the number of vehicles that can be incorporated into the fleet, and the number of vehicles that can be incorporated into the fleet is equal to the difference between the number of vehicles in the maximum fleet length and the number of vehicles in the current fleet.

3. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 1, characterized in that: The specific situations in which the intelligent networked autonomous driving vehicle or small intelligent networked autonomous driving fleet with platooning requirements sends a platooning request to the intelligent networked autonomous driving fleet and determines the number of vehicles that can be incorporated are divided into the following two situations: When the remaining capacity of the fleet is greater than or equal to the small intelligent connected autonomous driving fleet, all small intelligent connected autonomous driving fleets will be used as fleets to be organized; When the remaining capacity of the fleet is less than that of the small intelligent connected autonomous driving fleet, the small intelligent connected autonomous driving fleet will be split.

4. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 3 is characterized by: The small intelligent connected autonomous driving fleet is half or less than the number of vehicles in the maximum formation length; The splitting principle is: split from the front or rear of the small fleet according to the relative position of the target fleet and the small intelligent connected autonomous driving fleet, and the number of split vehicles is the remaining capacity of the fleet, or the target fleet invites other vehicles or fleets as incorporated vehicles.

5. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 1, characterized in that: After screening, the intelligent networked autonomous driving fleet invites the intelligent networked autonomous driving vehicle or small intelligent networked autonomous driving fleet that has made the request as the fleet to be organized, and the fleet to be organized determines the intelligent networked autonomous driving fleet as the target fleet, wherein the number of vehicles in the target fleet is greater than or equal to the number of vehicles to be organized into the fleet; The specific steps of the screening are as follows: S3.

1. Screen all received requests, first screen the fleets whose number of vehicles to be incorporated into the fleet is equal to the remaining capacity of the target fleet, if there is one, send an invitation to it and confirm that the fleet is the fleet to be incorporated, if not, screen the fleets whose number of vehicles to be incorporated into the fleet is greater than the remaining capacity of the target fleet; S3.

2. Select the fleets whose number of vehicles to be incorporated is greater than the remaining capacity of the target fleet. If there is one, send an invitation to the fleet with the least number of vehicles remaining after the split and confirm that the new fleet split from the fleet is the fleet to be incorporated. If there is no one, continue to select the fleets whose number of vehicles to be incorporated is less than the remaining capacity of the target fleet; S3.

3. Filter the fleets whose number of vehicles to be incorporated into the fleet is less than the remaining capacity of the target fleet. If there are fleets, send an invitation to incorporate to the fleet with the largest number of vehicles and confirm that the fleet is the fleet to be incorporated. If there are no fleets, send an invitation to incorporate to the single vehicle that made the request and confirm that it is the vehicle to be incorporated.

6. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 1, characterized in that: The driving information and road environment information include: the spatial position of the target convoy and the vehicles to be organized in the road, the formation speed, acceleration and deceleration, the speed and acceleration and deceleration of the front and rear vehicles, the driving conditions and spatial positions of the vehicles in the adjacent lanes of the target convoy, the number of lanes of the road, the road line type, and weather conditions.

7. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 1, characterized in that: The area to be organized is: with the center line of the road as the horizontal axis and the vertical axis perpendicular to the center line of the road. When the horizontal coordinate of the vehicle body position at the tail end of the target gap of the target fleet has the same horizontal coordinate value as the adjacent lane where the vehicle or fleet is to be organized, the position is called the area to be organized; if it is organized into a small intelligent connected autonomous driving fleet, the small intelligent connected autonomous driving fleet should completely enter the area to be organized.

8. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 1, characterized in that: The specific steps of implementing speed coordination through the speed management module are as follows: S5.

1. When there are no obstacle vehicles in front of the incoming vehicle or convoy and the target convoy, the following expression should be satisfied: v in =v p In the formula, v in The speed required to integrate a vehicle or convoy, v p is the target convoy speed; S5.

2. When there is an obstacle vehicle in front of the incoming vehicle or convoy, and there is no obstacle vehicle in front of the target convoy, the following expression should be satisfied: In the formula, Speed ​​of the leading vehicle or convoy vehicle; S5.

3. When there is no obstacle in front of the incoming vehicle or convoy, and there is an obstacle in front of the target convoy, the following expression should be satisfied: In the formula, is the speed of the front vehicle in the target convoy; S5.

4. When there are obstacle vehicles in front of both the incoming vehicle or convoy and the target convoy, the following expression should be satisfied:

9. The control method for enhancing the CAV fleet formation strength in mixed traffic flow under vehicle-road cooperation according to claim 1, characterized in that: The specific expression for the target convoy to slow down and expand the gap is as follows: In the formula, The longitudinal distance d between the target convoy gap rear vehicle and the vehicle to be assembled in the waiting area l-g , the longitudinal distance d between the front vehicle in the target convoy and the vehicle to be assembled in the area to be assembled f-g , the longitudinal safety distance between the target convoy’s rear vehicle and the vehicles to be assembled in the assembly area The longitudinal safety distance between the front vehicle in the target convoy and the vehicles to be assembled in the waiting area Gap rear vehicle speed Gap front vehicle speed The length of the convoy or vehicle l, the speed of the vehicle or convoy v, and the reaction time of the intelligent networked autonomous driving vehicle Braking delay time t delay , minimum acceleration a min .

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