Non-signalized intersection vehicle group collaborative ecological driving method in intelligent network connection environment

Abstract

The invention discloses a non-signalized intersection vehicle group cooperative ecological driving method in an intelligent network connection environment, and relates to the technical field of intelligent network connection vehicles, and the method comprises the steps: collecting intersection data and vehicle state updating, and uploading the intersection data and the vehicle state updating to a cloud platform; dividing a control area of the non-signalized intersection, and dividing the control area into a formation area, an adjustment area and a passage area; an optimal safety gap model before and after passing is constructed, and a comprehensive evaluation index is formulated; building a non-signalized intersection group collaborative ecological driving model to solve and generate an optimal ecological driving control strategy and an optimal ecological driving movement track; and meanwhile, a motorcade passing protection mechanism is set, and real-time safety verification is carried out on the optimization strategy. According to the method, the static bottleneck that a traditional non-signalized intersection depends on an artificial game can be broken through, the passing efficiency and safety of the non-signalized intersection are remarkably improved, cooperative ecological driving of an intelligent network connection vehicle group is achieved, and core support is provided for intelligent city development of urban road network de-signalized management and control.

Description

Technical Field

[0001] This invention relates to the field of intelligent connected vehicle technology, and in particular to a method for collaborative ecological driving of vehicle groups at signalless intersections in an intelligent connected environment. Background Technology

[0002] With the rapid evolution of intelligent connected vehicles and autonomous driving technologies, and against the backdrop of fully implementing the national strategy of building a strong transportation nation and promoting the construction of new infrastructure, modern urban transportation systems are accelerating their transformation towards intelligence and connectivity. However, the traffic congestion, energy consumption, and environmental pollution caused by the continuous growth of urban motor vehicle ownership remain pressing technical challenges that need to be addressed. Intersections, as key bottleneck nodes in urban road networks, suffer from significant technical limitations in existing intersection traffic strategies and control systems. These traditional control strategies are insufficiently perceptive of dynamic changes in traffic flow, respond slowly, and struggle to perform refined and adaptive resource allocation based on instantaneous and heterogeneous traffic demands.

[0003] Especially in the management and planning of unsignaled intersections in cities, their large number and high management difficulty make their optimized management a crucial aspect of urban road network development. Traditional unsignaled intersection traffic strategies mainly rely on fixed right-of-way allocation rules, such as setting stop / yield or slow-down signs, or determining priority based on the relationship between primary and secondary roads. These traditional strategies have significant technical drawbacks. First, their operational safety heavily depends on drivers' real-time observation, accurate judgment, and the interplay between drivers, leading to numerous conflict points within the intersection and high traffic safety risks. Second, when traffic volume increases, vehicles on secondary roads may face excessively long waiting times, resulting in unnecessary stopping, idling, and restarting processes, significantly reducing intersection efficiency and increasing fuel consumption and emissions. However, with the increasing prevalence of intelligent connected vehicles, these vehicles possess high-precision perception, positioning, and V2X real-time communication capabilities. Therefore, traditional unsignaled intersection management methods are no longer suitable for the collaborative operation needs of intelligent connected vehicles, nor can they leverage their technological advantages.

[0004] Therefore, existing technologies have the following drawbacks: traditional unsignalized intersections rely on driver experience, have crude traffic strategies, and pose high safety risks, as well as the technical defects of existing intelligent strategies in making insufficient use of spatiotemporal resources. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a method for collaborative ecological driving of vehicle groups at unsignalized intersections in an intelligent connected environment. By dynamically and functionally dividing the intersection control area through a cloud platform, a dynamic vehicle grouping and traffic sequence optimization model is constructed to achieve collaborative management of vehicle groups and fine-grained control of traffic gaps. The cloud platform issues collaborative control commands and smooth traffic guidance strategies to the vehicle group, thereby achieving efficient utilization of spatiotemporal resources at unsignalized intersections and ecological driving of vehicle groups.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for cooperative ecological driving of vehicle groups at unsignalized intersections in an intelligent connected environment, proposed according to the present invention, includes:

[0008] Step A: Collect dynamic status data of all connected vehicles (CVs) and intelligent connected vehicles (CAVs) entering the sensing range of an intersection without a signal in real time, and upload the dynamic status data and the intersection scene data without a signal to the cloud platform in real time for all connected vehicles in the intersection to share.

[0009] Step B: Divide the intersection control area into functional zones: formation zone, adjustment zone, and passage zone.

[0010] Step C: Based on the intersection control area defined in Step B, platoon the CV and CAV vehicles entering the intersection control area at different times. Using vehicle status data from the cloud platform, obtain the vehicle status and travel intentions of the vehicles in front and behind within the same platoon at the intersection, determine if there is a conflict between the vehicles. If a conflict exists, identify the conflict type and calculate the optimal safety gap between the vehicles in front and behind under the identified conflict type. ;

[0011] Step D: Use the energy consumption utility function To evaluate the energy efficiency of a convoy, a safety utility function is also introduced. and driving comfort utility function To assess the vehicle's safety and passenger comfort at intersections, and to establish a comprehensive evaluation index. ;

[0012] Step E: Based on the comprehensive evaluation indicators established in Step D A collaborative eco-driving model for unsignalized intersections is constructed, and the optimal eco-driving trajectory of each vehicle in each convoy is obtained by solving the collaborative eco-driving model for unsignalized intersections. ;

[0013] Step F, based on the results obtained in step E After the adjustment in the designated area is completed, each group of vehicles will proceed at their respective desired speeds. After completing passage through the unsignalized intersection within the passage area, the cloud platform will monitor vehicle operation in real time within the passage area. If the vehicle fails to maintain the expected speed within the passage area, the optimal safety gap from step C will be used as a reference. Perform real-time control.

[0014] As a further optimization scheme of the intelligent connected vehicle group cooperative ecological driving method in the intelligent connected environment described in this invention, in step A, the dynamic status data of all CVs and intelligent connected vehicles CAVs entering the perception range of the unsignaled intersection are collected in real time by the roadside units (RSUs) deployed in the entrance lanes and central areas of the urban unsignaled intersection and the vehicle wireless communication module mounted on the connected vehicle (CV).

[0015] The sensing range of an unsignalized intersection is the communication range covered by all RSUs within that intersection; CV refers to a manually driven vehicle capable of real-time communication with infrastructure or other vehicles; CAV refers to a connected vehicle; and the unsignalized intersection scenario data includes the length of the approach lanes. Lane width and curb radius Vehicle status data includes speed. acceleration Vehicle length Vehicle width Distance between the front of the car and the stop line at the intersection .

[0016] As a further optimization scheme for the intelligent connected vehicle group cooperative ecological driving method in an unsignalized intersection under the present invention, in step C, the traffic intention includes going straight, turning left, and turning right; the conflict types include following conflict, straight and straight conflict, straight and left-turn conflict, and left-turn and left-turn conflict.

[0017] As a further optimization of the intelligent connected vehicle group cooperative ecological driving method for unsignalized intersections in an intelligent connected environment described in this invention, in step F, the desired passage speed of the vehicles... To optimize the energy consumption, safety, and comfort of the fleet system, the travel speed is calculated via a cloud platform.

[0018] As a further optimization scheme for the intelligent connected vehicle group cooperative ecological driving method at signalless intersections in the present invention, in step B...

[0019] Formation area: the distance between the four approach lanes and the intersection stop line at an unsignalized intersection. This is the boundary line of the control area, and also the entry boundary line of the formation area, i.e., when vehicles cross... When the vehicle is on the edge line, it enters the perception range of the intersection. The vehicle drives freely within the formation area according to the driving rules. The vehicle completes the lane change operation within the formation area. Lane changes are not allowed in other control areas. The cloud platform obtains information on all CAV and CV vehicles in the formation area and performs formation processing.

[0020] Adjustment zone: the distance between the four approach lanes of an unsignalized intersection and the intersection stop line. This is the entry line to the adjustment zone, and also the exit line to the formation zone; that is, when vehicles cross... When crossing the boundary line, vehicles move from the formation area to the adjustment area. Within the adjustment area, vehicles are centrally coordinated and controlled by the cloud platform. CAVs and CVs travel in convoy formation within the adjustment area, and the cloud platform follows the crossing sequence. The initial passage sequence of the convoy is determined by the order of movement at the edge lines. Based on the status of the vehicle preceding it in the passage sequence, action signals are issued to control the trajectory of each vehicle in the convoy. Finally, when the vehicles leave the adjustment zone, their speeds are adjusted to the desired passage speed at the intersection. The gap between the vehicle and the preceding vehicle in the traffic sequence is adjusted to the optimal safe gap. The acceleration is adjusted to 0, meaning each vehicle maintains its desired speed. Enter the next area at a constant speed;

[0021] Passage area: the distance between the four approach lanes and the intersection stop line at an unsignalized intersection. This is the entry line to the passage zone and also the exit line to the adjustment zone, i.e., when CAV and CV cross... When crossing the boundary line, vehicles enter the passage area from the adjustment area. In the passage area, vehicles maintain the speed they had when leaving the adjustment area and drive at a constant speed. Vehicles continue to drive in convoy form in the passage area, passing through and leaving the intersection at a constant speed.

[0022] As a further optimization of the intelligent connected vehicle group cooperative ecological driving method for unsignalized intersections in the present invention, in step B, all CAVs and CVs within the platooning area are platooned. The specific platooning rule is: the last vehicle of the current platoon passes through... When the side line is reached, the next vehicle arrives. The CAV or CV on the sideline is defined as the lead car of the next group of teams, and at this time the distance... The CAV or CV closest to the edge line is defined as the last car of the next platoon. At this point, the distance from all vehicles in the approach lanes to the stop line, and the remaining CAVs and CVs located between the first and last cars of this newly defined platoon, are defined as vehicles in the next platoon. If at any given moment there is only one CAV or CV in the formation area, that vehicle is considered a separate platoon. If at any given moment there are no vehicles in the formation area, then until a vehicle arrives... The CAV or CV on the sideline is used to define that car as the lead car of the next group of vehicles.

[0023] As a further optimization scheme for the intelligent connected vehicle group cooperative ecological driving method at unsignalized intersections in the present invention, in step C, the optimal safety gap between vehicles passing each other under different conflict types is calculated. Specifically, it includes the following steps:

[0024] Step C1: Calculate the physical distance of the conflict zone between straight-going vehicles. The specific formula is as follows:

[0025]

[0026] Step C2: Calculate the physical distance of the conflict zone between vehicles going straight and vehicles turning left. The specific formula is as follows:

[0027]

[0028] Step C3: Calculate the physical distance of the conflict zone between left-turning vehicles. The specific formula is as follows:

[0029]

[0030] Step C4) Calculate the optimal safety clearance between vehicles passing each other under different conflict types. The specific formula is as follows:

[0031]

[0032] in, The minimum safe clearance between vehicles passing each other; For safety protection gaps; The passage sequence in vehicle N is as follows The expected speed of the vehicle; The passage sequence in vehicle N is as follows The expected speed of the vehicle; Physical distance to the conflict zone; Physical distances between conflict zones for different conflict types; For vehicles The length of the vehicle; For vehicles The width of the car.

[0033] As a further optimization scheme for the intelligent connected vehicle group cooperative ecological driving method at signalless intersections in the present invention, step D involves constructing a comprehensive evaluation index. Specifically, it includes the following steps:

[0034] Step D1: Calculate the energy consumption utility function The specific formula is as follows:

[0035]

[0036] in, For the fleet of N vehicles At any moment The acceleration;

[0037] Step D2: Calculate the security utility function The specific formula is as follows:

[0038]

[0039] in, This is the total value of the safety assessment. and Safety performance factor; The collision time; Penalty for maintaining a safe distance; The pass sequence is The vehicle in the same lane as the vehicle in front The distance between the front ends of the vehicles; The pass sequence is The vehicle in the same lane as the vehicle in front The speed difference between them; This is the minimum following distance; The pass sequence is The distance of the vehicle from the stop line of its respective entrance lane at time t; For those located in the passage sequence The distance between the vehicle in front of it in the same lane and the stop line of its own lane at time t; For those located in the passage sequence The length of the vehicle in front in the same lane as the vehicle. The pass sequence is The speed of the vehicle at time t; For those located in the passage sequence The speed of the vehicle in front of it in the same lane at time t;

[0040] Step D3: Calculate the comfort utility function The specific formula is as follows:

[0041]

[0042] in, , and For comfort performance factors; The rate of change of vehicle acceleration; For vehicles Longitudinal acceleration utility function; For vehicles Speed ​​comfort ratio function; This represents the maximum permissible acceleration at an unsignalized intersection. This is the minimum allowable acceleration at an unsignalized intersection; This is the longitudinal acceleration penalty coefficient; Maximum comfortable speed at an unsignalized intersection; For the fleet of N vehicles At any moment The acceleration;

[0043] Step D4) Calculate the comprehensive evaluation index The specific formula is as follows:

[0044] .

[0045] As a further optimization of the vehicle-group cooperative ecological driving method for unsignalized intersections in an intelligent connected environment described in this invention, step E, which involves building a vehicle-group cooperative ecological driving model for unsignalized intersections, specifically includes the following steps:

[0046] Step E1: Construct a collaborative ecological driving model for unsignalized intersections. The specific formula is as follows:

[0047]

[0048] in, , and Assign vehicle state weights; For vehicles arrive The time of the edge line; For vehicles arrive The time of the edge line; Let N be the total system target value for the fleet. For vehicles exist The distance from the stop line of the current entrance lane at all times; For vehicles exist The distance from the stop line of the current entrance lane at all times; For vehicles The optimal safety clearance; For vehicles exist The speed of time; For vehicles Expected traffic speed; For vehicles exist Acceleration at any moment;

[0049] Step E2: Construct the constraints for the collaborative ecological driving model of unsignalized intersections. The specific formula is as follows:

[0050]

[0051] in, For the team The lead car in time The distance from the front of the car to the stop line; For the team The last car in time The distance from the front of the car to the stop line; This is the minimum speed allowed at an unsignalized intersection; This refers to the maximum speed allowed at an unsignalized intersection. The length of the last car in the convoy; For vehicles exist Acceleration at any moment; For vehicles exist The speed of time; For vehicles exist The distance from the stop line of the current entrance lane at all times; For vehicles exist The distance from the stop line of the current entrance lane at all times; For the vehicle to arrive The time of the edge line; For the vehicle to arrive The time of the edge line;

[0052] Step E3: Solve the unsignalized intersection group cooperative eco-driving model according to the constraints to obtain the optimal eco-driving trajectory of each vehicle in each platoon. .

[0053] The present invention, by adopting the above technical solution, has the following beneficial effects:

[0054] (1) This invention proposes a collaborative ecological driving method for vehicle groups at unsignalized intersections in an intelligent connected environment. It pre-defines and details the method for dividing functional areas of the intersection and the management logic for dynamic vehicle grouping, providing theoretical and technical support for optimizing collaborative control strategies at unsignalized intersections in the current vehicle-to-everything (V2X) environment. A multi-dimensional optimization model of traffic sequence and gaps is constructed through a cloud platform to ensure the scientific and optimized nature of the traffic plan. Vehicle-road cooperative technology is used to collect vehicle status and traffic flow data in real time, thereby constructing a real-time decision database for the cloud control platform, providing fundamental support for dynamic matching of traffic demands with real-world scenarios.

[0055] (2) Through vehicle-to-cloud communication technology, this method realizes real-time group management and collaborative trajectory guidance of vehicles, and sets certain control redundancy and safety boundaries to ensure the accuracy and safety of collaborative passage of the group convoy. Faced with complex traffic flow merging from multiple directions at unsignalized intersections, the cloud platform sends the corresponding real-time passage sequence, dynamic group processing and smooth passage speed curve to the vehicles in the convoy through vehicle-to-cloud communication technology, so as to complete the adaptive control adjustment of vehicles from discrete individuals to collaborative groups.

[0056] (3) This method effectively ensures the traffic order inside the unsignaled intersection, fundamentally reduces the probability of road traffic accidents caused by traditional manual game, and greatly reduces the ineffective acceleration, deceleration and idling waiting time of vehicles by realizing smooth group passage, significantly reduces the vehicle energy consumption of the intersection system, improves the robustness, safety and operating efficiency of the intelligent connected traffic system in the unsignaled intersection scenario, and achieves the goal of ecological driving. Attached Figure Description

[0057] Figure 1 This is a flowchart of a collaborative ecological driving method for vehicle groups at an unsignalized intersection in an intelligent connected environment, according to the present invention.

[0058] Figure 2 This is a schematic diagram of the topology of a collaborative ecological driving scenario at an unsignalized intersection, as described in this invention. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] To further understand this method, preferred embodiments are described below with reference to examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of this method, and not for limiting the scope of the claims. The descriptions in this section pertain only to typical embodiments, and this method is not limited to the scope described in the embodiments. Combinations of different embodiments, substitution of some technical features in different embodiments, and substitution of identical or similar prior art with some technical features in the embodiments are also within the scope of this method's description and protection.

[0061] To address the issues in the background technology and fully leverage the "vehicle-road-cloud" collaborative perception and control advantages of intelligent connected vehicles, a cloud-based control platform is needed to collaboratively control the vehicle trajectories and timing at unsignalized intersections. This will guide vehicles towards eco-friendly driving, significantly improving the traffic efficiency, safety, and energy consumption of such intersections. Therefore, there is an urgent need to research a collaborative eco-friendly driving method for unsignalized intersections based on intelligent connected vehicles. This involves rationally dividing the intersection control area into functional zones, deploying advanced traffic sensing equipment, and combining it with efficient system optimization algorithms to implement group management of vehicles. The cloud-based control platform will then allow for precise control of vehicle spacing based on optimized traffic sequences, fully exploring the potential of the traffic space. Ultimately, the goal is to control vehicles to achieve smooth passage and eco-friendly driving in a collaborative convoy formation, systematically solving the comprehensive problems of safety, efficiency, and energy consumption in existing technologies.

[0062] Example: This example provides a method for cooperative driving of vehicle groups at signalless intersections in an intelligent connected environment, referencing... Figure 1 As shown, it includes the following steps:

[0063] A. Intersection Data Acquisition and Vehicle Status Update: By deploying roadside units (RSUs) and connected vehicles (CVs) on their own vehicle wireless communication modules at the approach lanes and central areas of unsignalized intersections in the city, dynamic status data of all CVs and connected and autonomous vehicles (CAVs) entering the perception range of the unsignalized intersection are collected in real time. The vehicle status data and unsignalized intersection scene data are uploaded to the cloud platform in real time for all connected vehicles in the intersection to share.

[0064] In this context, the perception range of an unsignalized intersection is the communication range covered by all RSUs within the intersection; CV refers to a manually driven vehicle capable of real-time communication with infrastructure or other vehicles; CAV refers to a connected vehicle; and the data for unsignalized intersection scenarios includes the length of approach lanes. Lane width and curb radius Vehicle status data includes speed. acceleration Vehicle length Vehicle width Distance between the front of the car and the stop line at the intersection ;

[0065] In this embodiment, to further understand the group cooperative ecological driving method at unsignalized intersections, it will be based on... Figure 2 This is used for model recognition in specific scenarios. Figure 2 It is a two-way six-lane unsignalized intersection, and its intersection topology is shown in Table 1.

[0066] Table 1 shows the topological properties of the unsignalized intersection group cooperative eco-driving method in this embodiment of the invention.

[0067]

[0068] Step B. Functional Division of Control Area at Unsignalized Intersections: By functionally dividing the intersection control area according to rules, the organization and management of passing vehicles can be achieved. The control area of ​​an unsignalized intersection is functionally divided into a platooning area, a repositioning area, and a passage area;

[0069] The rules for dividing the control area at the unsignalized intersection and the area functions include:

[0070] 1) Formation Zone: The distance between the four approach lanes of an unsignalized intersection and the intersection stop line. This is the boundary line of the control area, and also the entry boundary line of the formation area, i.e., when vehicles cross... When approaching the intersection, the vehicle enters the intersection's sensing range and drives according to the platooning rules. The vehicle completes lane-changing operations within the platooning zone; lane-changing is not permitted in other control areas. The cloud platform acquires information on all CAVs and CVs within the platooning zone and processes the platooning.

[0071] 2) Adjustment Zone: The distance between the four approach lanes of an unsignalized intersection and the intersection stop line. This is the entry line to the adjustment zone, and also the exit line to the formation zone; that is, when vehicles cross... When crossing the boundary line, vehicles move from the formation area into the adjustment area and drive according to the adjustment area rules. CAVs and CVs travel in convoys within the adjustment area, and the cloud platform follows the crossing rules. The initial passage sequence of the convoy is determined by the order of movement at the edge lines. Based on the status of the vehicle preceding it in the passage sequence, action signals are issued to control the trajectory of each vehicle in the convoy. Finally, when the vehicles leave the adjustment zone, their speeds are adjusted to the desired passage speed at the intersection. The gap between the vehicle and the preceding vehicle in the traffic sequence is adjusted to the optimal safe gap. The acceleration is adjusted to 0, meaning each vehicle maintains its desired speed. Enter the next area at a constant speed;

[0072] 3) Passage area: the distance between the four approach lanes and the intersection stop line at an unsignalized intersection. This is the entry line to the passage zone and also the exit line to the adjustment zone, i.e., when CAV and CV cross... When approaching the intersection, vehicles move from the adjustment area into the passage area and drive according to the passage area rules. Vehicles maintain a convoy formation within the passage area, passing through and leaving the intersection at a constant speed.

[0073] Preferably, The value is 100m. The value is 70m. The value is 25m.

[0074] All CAVs and CVs within the formation area are grouped together, with the specific formation rules being: the last vehicle of the current platoon passes through... When the side line is reached, the next vehicle arrives. The CAV or CV on the sideline is defined as the lead car of the next group of teams, and at this time the distance... The CAV or CV closest to the edge line is defined as the last car of the next platoon. At this point, the distance from all vehicles in the approach lanes to the stop line, and the remaining CAVs and CVs located between the first and last cars of this newly defined platoon, are defined as vehicles in the next platoon. If at any given moment there is only one CAV or CV in the formation area, that vehicle is considered a separate platoon. If at any given moment there are no vehicles in the formation area, then until a vehicle arrives... The vehicle on the edge of the formation (CAV or CV) is designated as the lead car for the next platoon. The cloud platform uses this rule to perform cyclical formation processing on all CAVs and CVs within the formation area.

[0075] In this embodiment, the control functional area of ​​the unsignalized intersection is divided according to step B, and the above-mentioned queuing rules are used for cyclic processing to queuing the example vehicles. The vehicle status and queuing results at a certain simulation moment are shown in Table 2.

[0076] Table 2 shows the vehicle status and formation results at a certain simulation moment in this example of the invention.

[0077]

[0078] C. Calculation of Optimal Safety Clearance Between Vehicles Passing Ahead and Behind: Based on the intersection control area defined in step B, CVs and CAVs entering the intersection control area at different times are grouped together. Using vehicle status data from the cloud platform, the vehicle status and intentions of vehicles passing ahead and behind within the same platoon at the intersection are obtained. It is then determined whether there is a conflict between the vehicles passing ahead and behind. If a conflict exists, the conflict type is identified, and the optimal safety clearance between the vehicles passing ahead and behind under that conflict type is calculated. ;

[0079] Among them, the vehicle's traffic intentions include going straight, turning left, and turning right; the conflict types include following conflict, straight-on conflict, straight-on and left-turn conflict, and left-turn and left-turn conflict;

[0080] Calculate the optimal safety clearance between vehicles traveling in front and behind each other under different conflict types. Specifically, it includes the following steps:

[0081] Step C1: Calculate the physical distance of the conflict zone between straight-going vehicles. The specific formula is as follows:

[0082]

[0083] Step C2: Calculate the physical distance of the conflict zone between vehicles going straight and vehicles turning left. The specific formula is as follows:

[0084]

[0085] Step C3: Calculate the physical distance of the conflict zone between left-turning vehicles. The specific formula is as follows:

[0086]

[0087] Step C4) Calculate the optimal safety clearance between vehicles passing each other under different conflict types. The specific formula is as follows:

[0088]

[0089] in, The minimum safe clearance between vehicles passing each other; For safety protection gaps; The passage sequence in vehicle N is as follows The expected speed of the vehicle; The passage sequence in vehicle N is as follows The expected speed of the vehicle; Physical distance to the conflict zone; Physical distances between conflict zones for different conflict types; For vehicles The length of the vehicle; For vehicles The width of the car.

[0090] D. Comprehensive Evaluation Index Formulation: To enable coordinated and eco-friendly driving for each convoy at unsignalized intersections in the city, an energy consumption utility function is adopted. To evaluate the energy efficiency of a convoy, a safety utility function is also introduced. and driving comfort utility function To assess the vehicle's safety and passenger comfort at intersections, and to establish a comprehensive evaluation index. ;

[0091] Constructing comprehensive evaluation indicators Specifically, it includes the following steps:

[0092] Step D1) Calculate the energy consumption utility function The specific formula is as follows:

[0093]

[0094] in, For the fleet of N vehicles At any moment The acceleration;

[0095] Step D2) Calculate the security utility function The specific formula is as follows:

[0096]

[0097] in, and Safety performance factor; The collision time; Penalty for maintaining a safe distance; The pass sequence is The vehicle in the same lane as the vehicle in front The distance between the front ends of the vehicles; The pass sequence is The vehicle in the same lane as the vehicle in front The speed difference between them; For vehicles The length of the vehicle; This is the minimum following distance. Preferably, The value is -1. The value of is 1. The value of is 2m;

[0098] Step D3) Calculate the comfort utility function The specific formula is as follows:

[0099]

[0100] in, , and For comfort performance factors; The rate of change of vehicle acceleration; For vehicles Longitudinal acceleration utility function; For vehicles Speed ​​comfort ratio function; This represents the maximum permissible acceleration at an unsignalized intersection. This is the minimum allowable acceleration at an unsignalized intersection; This is the longitudinal acceleration penalty coefficient; The maximum comfortable speed at an unsignalized intersection; preferably, The value is -1. The value is -1. The value of is 1. The value is 3m / s 2 , The value is -3m / s 2 , The value is 9. The value is 50 km / h;

[0101] Step D4) Calculate the comprehensive evaluation index The specific formula is as follows:

[0102]

[0103] In this embodiment, the various evaluation indicators and comprehensive evaluation indicators of each vehicle group at that moment are calculated according to step D, so as to provide the cloud platform with the basis for making decisions on the action instructions at the next moment and to dynamically adjust the example vehicles, as shown in Table 3.

[0104] Table 3 shows the results of various evaluation indicators and comprehensive evaluation indicators of the vehicle at a certain simulation moment in the embodiments of the present invention.

[0105]

[0106] E. Establishment of a collaborative ecological driving model for unsignalized intersections: based on the comprehensive evaluation indicators established in step D. A collaborative eco-driving model for unsignalized intersections was constructed, and the optimal eco-driving trajectory of each vehicle in each convoy was obtained by solving the model. This enables collaborative ecological driving and passage of vehicles in each convoy, optimizing the energy consumption of the entire convoy system and ensuring high safety and comfort throughout the passage process.

[0107] The construction of a collaborative ecological driving model for unsignalized intersections includes the following steps:

[0108] Step E1) Construct a collaborative ecological driving model for unsignalized intersections, using the following formula:

[0109]

[0110] in, , and Assign vehicle state weights; For vehicles arrive The time of the edge line; For vehicles arrive The time of the edge line; preferably, The value is -1. The weight is -1. The weight is -1;

[0111] Step E2) Construct model constraints, the specific formulas are as follows:

[0112]

[0113] in, For the team The lead car in time The distance from the front of the car to the stop line; For the team The last car in time The distance from the front of the car to the stop line; This is the minimum speed allowed at an unsignalized intersection; The maximum permissible speed at an unsignalized intersection; preferably, The value is 15km / h. The value is 60km / h;

[0114] Step E3) Solve the unsignalized intersection group cooperative eco-driving model according to the constraints to obtain the optimal eco-driving acceleration control strategy for each vehicle in each platoon. and optimal ecological driving trajectory .

[0115] In this embodiment, by... Figure 2For unsignalized intersections, scene data acquisition and vehicle status updates are performed. The intersection control area is functionally divided, and a multi-dimensional, dynamically updated comprehensive evaluation index system is constructed to build a collaborative ecological driving model for unsignalized intersections. The ecological driving model can be solved using either genetic algorithms or reinforcement learning algorithms. In this example, reinforcement learning is used to obtain the acceleration of each vehicle at the next decision moment. Expected traffic speed and optimal safety clearance As shown in Table 4.

[0116] Table 4 shows the model solution results in the embodiments of the present invention.

[0117]

[0118] F. Vehicle passage protection mechanism setting: based on the eco-driving trajectory obtained in step E. After each group of vehicles completes the adjustment in the designated area, they will proceed through the unsignalized intersection at their respective desired speeds. If, due to communication delays or interference from the intersection environment, a vehicle fails to maintain its desired speed in the designated area, the cloud platform will monitor the vehicle operation in the designated area in real time and, based on the safety protection gaps left by the model in step E, determine the appropriate speed. Real-time control is implemented to ensure the safe passage of vehicles in each convoy at unsignalized intersections.

[0119] The description and application of the present invention herein are illustrative and not intended to limit the scope of the invention to the embodiments described above. The effects or advantages described in the specification may not be apparent in actual experimental cases due to uncertainties in specific conditions or other factors, and such descriptions are not intended to limit the scope of the invention. Variations and modifications to the embodiments disclosed herein are possible, and various substitutions and equivalents of the components in the embodiments are well known to those skilled in the art. It should be understood by those skilled in the art that the invention can be implemented in other forms, structures, arrangements, proportions, and with other components, materials, and parts without departing from the spirit or essential characteristics of the invention. Other variations and modifications can be made to the embodiments disclosed herein without departing from the scope and spirit of the invention.

Claims

1. A method for cooperative ecological driving of vehicle groups at signalless intersections in an intelligent connected environment, characterized in that, include: Step A: Collect dynamic status data of all connected vehicles (CVs) and intelligent connected vehicles (CAVs) entering the sensing range of an intersection without a signal in real time, and upload the dynamic status data and the intersection scene data without a signal to the cloud platform in real time for all connected vehicles in the intersection to share. Step B: Divide the intersection control area into functional zones: formation zone, adjustment zone, and passage zone; Step C: Based on the intersection control area defined in Step B, platoon the CV and CAV vehicles entering the intersection control area at different times. Using vehicle status data from the cloud platform, obtain the vehicle status and travel intentions of the vehicles in front and behind within the same platoon at the intersection, determine if there is a conflict between the vehicles. If a conflict exists, identify the conflict type and calculate the optimal safety gap between the vehicles in front and behind under the identified conflict type. ; Step D: Use the energy consumption utility function To evaluate the energy efficiency of a convoy, a safety utility function is also introduced. and driving comfort utility function To assess the safety and ride comfort of the vehicle fleet at intersections, and to establish a comprehensive evaluation index. ; Step E: Based on the comprehensive evaluation indicators established in Step D A collaborative eco-driving model for unsignalized intersections is constructed, and the optimal eco-driving trajectory of each vehicle in each convoy is obtained by solving the collaborative eco-driving model for unsignalized intersections. ; Step F, based on the results obtained in step E After the adjustment in the designated area is completed, each group of vehicles will proceed at their respective desired speeds. After completing passage through the unsignalized intersection within the passage area, the cloud platform will monitor vehicle operation in real time within the passage area. If the vehicle fails to maintain the expected speed within the passage area, the optimal safety gap from step C will be used as a reference. Perform real-time control.

2. The method for cooperative ecological driving of vehicle groups at signalless intersections in an intelligent connected environment according to claim 1, characterized in that, In step A, the dynamic status data of all CVs and intelligent connected vehicles (CAVs) entering the sensing range of the unsignalized intersection are collected in real time by the roadside units (RSUs) deployed at the approach lanes and central areas of the unsignalized intersection and the vehicle wireless communication modules mounted on the connected vehicles (CVs). The sensing range of an unsignalized intersection is the communication range covered by all RSUs within that intersection; CV refers to a manually driven vehicle capable of real-time communication with infrastructure or other vehicles; CAV refers to a connected vehicle; and the unsignalized intersection scenario data includes the length of the approach lanes. Lane width and curb radius Vehicle status data includes speed. acceleration Vehicle length Vehicle width Distance between the front of the car and the stop line at the intersection .

3. The method for cooperative ecological driving of vehicle groups at signalless intersections in an intelligent connected environment according to claim 1, characterized in that, In step C, the traffic intentions include going straight, turning left, and turning right; the conflict types include following-car conflict, straight-on-straight-on conflict, straight-on-left-turn conflict, and left-turn-left-turn conflict.

4. The method for cooperative ecological driving of vehicle groups at signalless intersections in an intelligent connected environment according to claim 1, characterized in that, In step F, the desired speed of the vehicle. To optimize the energy consumption, safety, and comfort of the fleet system, the travel speed is calculated via a cloud platform.

5. The method for cooperative ecological driving of vehicle groups at signalless intersections in an intelligent connected environment according to claim 1, characterized in that, In step B, Formation area: the distance between the four approach lanes and the intersection stop line at an unsignalized intersection. This is the boundary line of the control area, and also the entry boundary line of the formation area, i.e., when vehicles cross... When the vehicle is on the edge line, it enters the perception range of the intersection. The vehicle drives freely within the formation area according to the driving rules. The vehicle completes the lane change operation within the formation area. Lane changes are not allowed in other control areas. The cloud platform obtains information on all CAV and CV vehicles in the formation area and performs formation processing. Adjustment zone: the distance between the four approach lanes of an unsignalized intersection and the intersection stop line. This is the entry line to the adjustment zone, and also the exit line to the formation zone; that is, when vehicles cross... When crossing the boundary line, vehicles move from the formation area to the adjustment area. Within the adjustment area, vehicles are centrally coordinated and controlled by the cloud platform. CAVs and CVs travel in convoy formation within the adjustment area, and the cloud platform follows the crossing sequence. The initial passage sequence of the convoy is determined by the order of movement at the edge lines. Based on the status of the vehicle preceding it in the passage sequence, action signals are issued to control the trajectory of each vehicle in the convoy. Finally, when the vehicles leave the adjustment zone, their speeds are adjusted to the desired passage speed at the intersection. The gap between the vehicle and the preceding vehicle in the traffic sequence is adjusted to the optimal safe gap. The acceleration is adjusted to 0, meaning each vehicle maintains its desired speed. Enter the next area at a constant speed; Passage area: the distance between the four approach lanes and the intersection stop line at an unsignalized intersection. This is the entry line to the passage zone and also the exit line to the adjustment zone, i.e., when CAV and CV cross... When crossing the boundary line, vehicles enter the passage area from the adjustment area. In the passage area, vehicles maintain the speed they had when leaving the adjustment area and drive at a constant speed. Vehicles continue to drive in convoy form in the passage area, passing through and leaving the intersection at a constant speed.

6. The method for cooperative ecological driving of vehicle groups at unsignalized intersections in an intelligent connected environment according to claim 5, characterized in that, In step B, all CAVs and CVs within the formation area are formed into a platoon. The specific formation rule is: the last vehicle of the current platoon passes through... When the side line is reached, the next vehicle arrives. The CAV or CV on the sideline is defined as the lead car of the next group of teams, and at this time the distance... The CAV or CV closest to the edge line is defined as the last car of the next platoon. At this point, the distance from all vehicles in the approach lanes to the stop line, and the remaining CAVs and CVs located between the first and last cars of this newly defined platoon, are defined as vehicles in the next platoon. If at any given moment there is only one CAV or CV in the formation area, that vehicle is considered a separate platoon. If at any given moment there are no vehicles in the formation area, then until a vehicle arrives... The CAV or CV on the sideline is used to define that car as the lead car of the next group of vehicles.

7. The method for cooperative ecological driving of vehicle groups at unsignalized intersections in an intelligent connected environment according to claim 1, characterized in that, In step C, the optimal safety clearance between vehicles passing each other is calculated under different conflict types. Specifically, it includes the following steps: Step C1: Calculate the physical distance of the conflict zone between straight-going vehicles. The specific formula is as follows: ； Step C2: Calculate the physical distance of the conflict zone between vehicles going straight and vehicles turning left. The specific formula is as follows: ； Step C3: Calculate the physical distance of the conflict zone between left-turning vehicles. The specific formula is as follows: ； Step C4) Calculate the optimal safety clearance between vehicles passing each other under different conflict types. The specific formula is as follows: ； in, The minimum safe clearance between vehicles passing each other; For safety protection gaps; The passage sequence in vehicle N is as follows The expected speed of the vehicle; The passage sequence in vehicle N is as follows The expected speed of the vehicle; Physical distance to the conflict zone; Physical distances between conflict zones for different conflict types; For vehicles The length of the vehicle; For vehicles The width of the car.

8. The method for cooperative ecological driving of vehicle groups at unsignalized intersections in an intelligent connected environment according to claim 7, characterized in that, In step D, a comprehensive evaluation index is constructed. Specifically, it includes the following steps: Step D1: Calculate the energy consumption utility function The specific formula is as follows: ； in, For the N vehicles in the fleet At any moment The acceleration; Step D2: Calculate the security utility function The specific formula is as follows: ； in, This is the total value of the safety assessment. and Safety performance factor; The collision time; Penalty for maintaining a safe distance; The pass sequence is The vehicle in the same lane as the vehicle in front The distance between the front ends of the vehicles; The pass sequence is The vehicle in the same lane as the vehicle in front The speed difference between them; This is the minimum following distance; The pass sequence is The distance of the vehicle from the stop line of its respective entrance lane at time t; For those located in the passage sequence The distance between the vehicle in front of it in the same lane and the stop line of its own lane at time t; For those located in the passage sequence The length of the vehicle in front in the same lane as the vehicle. The pass sequence is The speed of the vehicle at time t; For those located in the passage sequence The speed of the vehicle in front of it in the same lane at time t; Step D3: Calculate the comfort utility function The specific formula is as follows: ； in, , and For comfort performance factors; The rate of change of vehicle acceleration; For vehicles Longitudinal acceleration utility function; For vehicles Speed ​​comfort ratio function; This represents the maximum permissible acceleration at an unsignalized intersection. This is the minimum allowable acceleration at an unsignalized intersection; This is the longitudinal acceleration penalty coefficient; Maximum comfortable speed at unsignalized intersections; For the N vehicles in the fleet At any moment The acceleration; Step D4) Calculate the comprehensive evaluation index The specific formula is as follows: 。 9. The method for cooperative ecological driving of vehicle groups at unsignalized intersections in an intelligent connected environment according to claim 8, characterized in that, Step E involves building a collaborative ecological driving model for unsignalized intersections, which includes the following steps: Step E1: Construct a collaborative ecological driving model for unsignalized intersections. The specific formula is as follows: ； in, , and Assign weights to vehicle states; For vehicles arrive The time of the edge line; For vehicles arrive The time of the edge line; Let N be the total system target value for the fleet. For vehicles exist The distance from the stop line of the current entrance lane at all times; For vehicles exist The distance from the stop line of the current entrance lane at all times; For vehicles The optimal safety clearance; For vehicles exist The speed of time; For vehicles Expected traffic speed; For vehicles exist Acceleration at any moment; Step E2: Construct the constraints for the collaborative ecological driving model of unsignalized intersections. The specific formula is as follows: ； in, For the team The lead car in time The distance from the front of the car to the stop line; For the team The last car in time The distance from the front of the car to the stop line; This is the minimum speed allowed at an unsignalized intersection; This represents the maximum permissible speed at an unsignalized intersection. The length of the last car in the convoy; For vehicles exist Acceleration at any moment; For vehicles exist The speed of time; For vehicles exist The distance from the stop line of the current entrance lane at all times; For vehicles exist The distance from the stop line of the current entrance lane at all times; For the vehicle to arrive The time of the edge line; For the vehicle to arrive The time of the edge line; Step E3: Solve the unsignalized intersection group cooperative eco-driving model according to the constraints to obtain the optimal eco-driving trajectory of each vehicle in each platoon. .

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