Smart connected vehicle platoon merge-exit hierarchical control method

Abstract

The present application relates to a kind of intelligent network connection vehicle queue in-out hierarchical control method, belong to the field of intelligent networking automobile.For the intelligent network connection vehicle queue in-out travel scene, this method designs centralized decision-making layer.Decision-making layer is located in the lead vehicle, is responsible for the decision of key information in the whole cooperative process and exports corresponding signal to control layer.Specifically including request evaluation, in-out position judgment and queue safety interval calculation.And design distributed control layer.Control layer controls queue member vehicle and motor vehicle to complete corresponding cooperative action according to the result exported by decision-making layer.Specifically including queue longitudinal spacing control, in-out trajectory planning, trajectory optimization and trajectory tracking control.The present application ensures the safety, stability and high efficiency of the whole vehicle queue in-out cooperative control process, and simple and easy to implement engineering.

Description

Technical Field

[0001] This invention belongs to the field of intelligent connected vehicles and relates to a hierarchical control method for intelligent connected vehicle queue inflow and outflow. Background Technology

[0002] Vehicle platooning control based on V2X communication is considered the best option for improving traffic flow, safety, and energy efficiency. Because of these obvious benefits, countries around the world have conducted extensive work related to vehicle platooning control over the past few decades. As vehicles are a crucial part of land transportation, how to improve their transport efficiency and safety is increasingly being studied. Intelligent connected vehicle platooning control, by integrating advanced automation and efficient communication technologies, possesses enormous potential for energy saving, safety, and efficiency, making it a research and development direction for the global automotive industry.

[0003] Currently, existing vehicle queuing control technologies, including publicly available patents, are shifting their focus from maintaining the stability of fixed queues to achieving safe and dynamic merging and merging of vehicles into and out of queues. For example, patent CN116682252A, entitled "An Adaptive Merging Vehicle Queue Control Method for Intelligent Connected Vehicles," primarily provides an adaptive merging vehicle queue control method for intelligent connected vehicles. It considers the speed and positional relationship between the queue and merging vehicles, as well as vehicle comfort requirements, and evaluates all candidate merging positions to achieve adaptive selection of the optimal merging position for merging vehicles. However, it neglects collision avoidance safety distances and the underlying dynamic characteristics of actual vehicles, making it difficult to characterize queue control in real-world driving scenarios. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a hierarchical control method for merging and merging intelligent connected vehicle platoons. This method considers the influence of nonlinear vehicle dynamics and designs a hierarchical collaborative control method for merging and merging that includes a centralized decision-making layer and a distributed control layer. The decision-making layer and the control layer cooperate with each other to ensure the safety, stability and efficiency of the entire collaborative control process.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A hierarchical control method for merging and merging intelligent connected vehicle queues, comprising the following steps:

[0007] S1: Consider the vehicle's transmission system, tires, and braking system, and establish a vehicle dynamics model;

[0008] S2: The design is located at the centralized decision-making layer of the lead vehicle. The lead vehicle establishes communication connections with each vehicle and motor vehicle in the queue. The results of each decision-making layer calculation are sent to the cooperating vehicles or merging-out vehicles in the queue through V2V communication to complete the merging-out decision communication, specifically including merging-out request evaluation, merging position judgment, and queue safety distance judgment.

[0009] S3: Design a distributed control layer located on each vehicle. The control layer will control the vehicle to complete the corresponding specific actions according to the instructions output by the decision layer, including inbound-outbound spacing control, trajectory planning and trajectory tracking control.

[0010] S4: Build a simulation environment to verify the effectiveness of the control method. The effectiveness of the hierarchical control method is verified by establishing a co-simulation environment, introducing a sensor system and a communication system.

[0011] Furthermore, in S1, considering the vehicle's transmission system, tires, and braking system, the vehicle dynamics model is established as follows:

[0012]

[0013] In the formula, F xr (t) represents the longitudinal tire force of the rear wheel; F xf (t) represents the longitudinal tire force of the front wheel; ω r (t) represents the rear wheel speed; ω f (t) represents the front wheel speed; ω e (t) represents the engine speed; ω p (t) represents the rotational speed of the hydraulic torque converter; T b (t) represents the braking torque; T e (t) represents the driving torque; p br (t) represents the braking pressure; θ th (t) represents the throttle opening; f tr (*) indicates the torque characteristic of the hydraulic torque converter; f tki (*) indicates the hydraulic torque converter capacity characteristic; MAP(*) indicates the engine torque characteristic; L f Indicates the distance from the front axle to the center of gravity; L r Indicates the distance from the rear axle to the center of gravity; v x (t) represents the longitudinal velocity; r w Indicates the wheel radius; k b Indicates the braking pressure coefficient; C d Indicates the air drag coefficient; v low i represents the longitudinal velocity constant of the wheel. g i0 represents the gear ratio of the transmission; i0 represents the gear ratio of the reducer; μ a ρ represents the rolling resistance coefficient;a A represents air density; B represents frontal area; C represents stiffness factor; D represents shape factor; E represents peak value factor; J represents curvature factor. r J represents the moment of inertia of the rear wheel. e J represents the engine's moment of inertia; f v represents the moment of inertia of the front wheels. y The vehicle's lateral velocity is represented by m; the vehicle's mass is represented by C. f and C r Represents the equivalent sideslip stiffness of the front and rear wheels of the vehicle, respectively; ω represents the yaw rate of the vehicle; β represents the sideslip angle of the center of gravity; ψ represents the front wheel steering angle; I z This represents the moment of inertia of the vehicle about the z-axis.

[0014] Furthermore, S2 specifically includes:

[0015] S21: Request Evaluation: Responsible for analyzing inbound and outbound requests based on the queue's own situation and determining whether to accept the request.

[0016] 1) External vehicle request to join the queue: The lead vehicle needs to evaluate the joining request based on the merged queue length and the current queue status; the specific judgment steps are as follows:

[0017] a) Incoming vehicle T m Sending an inbound request to the queue leader vehicle T0 triggers the queue inbound policy, and the leader vehicle T0 and vehicle T... m Establish a communication connection;

[0018] b) Determine the queue length; based on the current queue length L... a Calculate whether the length of the merged queue is greater than the maximum queue length L. max If the value is greater than 1, the request is rejected directly; if the value is less than or equal to 1, the next step is performed, as shown below.

[0019] L a +1≤L max

[0020] c) Perform queue stability judgment; judge the queue string stability according to the following formula. When the queue is in a stable state, allow the inflow of external vehicles; otherwise, reject the inflow request.

[0021]

[0022] In the formula, j is the imaginary unit; ω is the excitation frequency; |G(jω)| is the amplitude of the vehicle platooning system transfer function;

[0023] d) Incoming vehicle T m Join the queue's self-organizing communication network to proceed with the next step of determining the merge location;

[0024] 2) Internal vehicle merging request: In actual driving, internal vehicles often merge out because they are approaching their destination or their destination has changed, requiring them to enter other lanes to achieve this goal; therefore, the lead vehicle will default to agreeing to the merging request; the specific judgment steps are as follows:

[0025] a) Outgoing vehicle T s Send an outbound request to queue leader vehicle T0 to trigger the queue outbound strategy;

[0026] b) The lead vehicle T0 agrees to the exit request and proceeds to the next step of determining the safe queuing distance;

[0027] 3) After the lead vehicle agrees to the joining request of an external vehicle, it will determine the joining position and then the queue safety distance; if it agrees to the leaving request of an internal vehicle, it will directly determine the queue safety distance.

[0028] S22: Leading vehicle T0 allows merging vehicle T m After receiving the import request, a decision needs to be made regarding the import location;

[0029] 1) The merging position is usually divided into merging at the end of the queue and merging in the middle of the queue. The strategy for determining the merging position is as follows:

[0030] a) If vehicle T m Current location Located at position x of the last car in the queue n The subsequent decision-making strategy is to merge into the queue from the back.

[0031] b) If vehicle T m Current location Located between the first and last cars in the queue, the decision strategy is to merge into the queue;

[0032] 2) Calculate the inflow position p m :

[0033]

[0034] In the formula, p m For vehicle T m The location of the entry; x i Let i be the longitudinal position of vehicle i in the queue;

[0035] 3) After determining the merging location, the lead vehicle will send the merging location to the merging vehicle T. m Then merge into vehicle T m Under the action of the vertical layer controller, it will reach the specified inflow starting point. And wait for the lead vehicle to determine the safe spacing of the queuing; in order to facilitate the adjustment of the spacing between vehicles after merging and shorten the time for the queuing to return to stable driving, the merging starting point will be... Set the same value as the desired position after the vehicle merges; calculate as follows:

[0036]

[0037] In the formula, x mp The position of the vehicle preceding the merging point; d i,des L represents the desired distance between adjacent vehicles; L is the vehicle length.

[0038] S23: Safety Spacing Judgment: Design a queue safety spacing judgment model. The decision layer calculates the queue safety spacing and sends the calculation results to the control layer. The control layer adjusts the spacing between the inbound and outbound positions through the queue vertical layer controller to meet the safety requirements of inbound and outbound.

[0039] 1) Determining the safe distance between merging points

[0040] a) Merge starting point Position x of the vehicle in front mp Minimum safe distance (t): vehicle T during merging m With the car in front T mp A collision may occur; depending on vehicle T m and the car in front T mp Based on the relative positional relationships, the collision avoidance conditions are as follows;

[0041]

[0042] In the formula, x m (t) represents vehicle T m Longitudinal displacement; W is the vehicle's longitudinal displacement. m The width of the vehicle body; x is the angle between the vehicle's velocity direction and the lane centerline; mp (t) represents vehicle T mp Longitudinal displacement;

[0043] Further define S min (T m ,T mp ) for vehicle T m With vehicle T mp The minimum safe distance to avoid a collision is expressed as follows:

[0044]

[0045] In the formula, a m (t) represents vehicle T m longitudinal acceleration; amp (t) represents vehicle T mp longitudinal acceleration; v m (0) represents the vehicle T at the initial time of merging. m longitudinal velocity; v mp (0) represents the vehicle T at the initial time of merging. mp longitudinal velocity; S p (0) represents vehicle T m With vehicle T mp The initial spacing; t∈[t ms ,t mf ] represents the time domain; t ms and t mf These are the start and end times of the import process, respectively.

[0046] b) Merge starting point Position x of the vehicle behind ml Minimum safe distance (t): vehicle T during merging m With the car behind T ml A collision may occur; depending on vehicle T m and the car behind T ml Based on the relative positions, the collision avoidance conditions are as follows:

[0047]

[0048] In the formula, x ml (t) represents vehicle T ml The longitudinal position;

[0049] Furthermore, vehicle T m With the car behind T ml The minimum safe distance to avoid a collision is as follows:

[0050]

[0051] In the formula, S min (T ml ,T m ) represents the minimum safe distance; a ml (t) represents vehicle T ml longitudinal acceleration; v ml (0) represents the vehicle T at the initial time of merging. ml longitudinal velocity; S l (0) represents vehicle T m With vehicle T ml The initial spacing;

[0052] Minimum safety spacing D m (t) is as follows:

[0053] D m (t)=Smin (T m ,T mp )+S min (T ml ,T m )

[0054] 2) Determination of safe distance for outgoing routes

[0055] Outgoing origin Position x of the vehicle in front sp Minimum safe distance (t): based on vehicle T m and the car in front T sp Based on the relative positions of the vehicles, the conditions under which no collision occurs are as follows:

[0056]

[0057] In the formula, a s (t) represents vehicle T s longitudinal acceleration; a sp (t) represents vehicle T sp longitudinal acceleration; v s (0) represents the initial time of vehicle T when merging out. s longitudinal velocity; v sp (0) represents the initial time of vehicle T when merging out. sp longitudinal velocity; S r (0) represents vehicle T s With vehicle T sp The initial spacing; t∈[t ss ,t sf ] represents the time domain; t ss and t sf These are the start and end times of the remittance, respectively.

[0058] Vehicle T at the time of departure s The speed is set to be greater than or equal to the queue speed, at which point vehicle T... s It is impossible to be with the car behind T sl A collision occurs; minimum safe clearance D is required. s (t) is as follows:

[0059] D s (t)=S min (T s ,T sp )

[0060] S24: Obtain the minimum safe distance between inbound and outbound traffic, and send the decision-making information to the corresponding vehicle:

[0061] 1) Obtain the minimum safe distance D for merging. m After (t), the decision-making level will send the calculation result to the following vehicle T. ml;T ml Based on this result, the upper control layer will complete the specified action under the action of the queue vertical layer controller;

[0062] 2) Minimum safe distance D s After (t), the decision-making level will send the calculation results to the outgoing vehicle T. s T s Based on this result, the upper control layer will complete the specified action under the action of the queue vertical layer controller.

[0063] Furthermore, S3 specifically refers to:

[0064] S31: After calculating the safe queue spacing during inbound and outbound flows in the decision-making layer, the control layer needs to control the safe spacing; the specific steps are as follows:

[0065] 1) Vehicle T during merging mp and vehicle T ml The spacing strategy is as follows:

[0066] d ml,des (t)=max(D m (t),αv ml (t)+d min )

[0067] In the formula, d ml,des (t) represents vehicle T mp and vehicle T ml The expected distance between them; max(*) is the maximum value function; αv ml (t)+d min For vehicle T ml Expected spacing under the CTH strategy;

[0068] 2) Vehicle T at the time of departure s and vehicle T sp The spacing strategy between them is as follows:

[0069] d s,des (t)=max(D s (t),αv s (t)+d min )

[0070] In the formula, d s,des (t) represents vehicle T s and vehicle T sp The expected distance between them; αv s (t)+d min For vehicle T s Expected spacing under the CTH strategy;

[0071] 3) All vehicles in the queue are controlled using a distributed longitudinal hierarchical controller as shown below:

[0072]

[0073] In the formula, u f,i (t) represents the corrected desired acceleration; k1, k2, and k3 are the proportional, integral, and derivative gain coefficients of the PID controller, respectively; Δa i (t) represents the error between the desired acceleration and the actual acceleration, Δa i (t)=u i (t)-a i (t); θ th,i (t) and p br,i (t) represents the throttle opening and brake pressure output by the lower-level controller; MAP -1 (*) represents the inverse engine torque characteristic function; ω e,i (t) represents the engine speed of the i-th vehicle; s i (t) represents the sliding surface; c represents the sliding surface gain; For the speed error between vehicles; k, λ, b, γ i and The gain is constant; e i (t) represents the distance error between adjacent vehicles; d i (t) represents the actual distance between adjacent vehicles; L represents the vehicle length; d i,des (t) represents the expected distance between car i and car i-1; h represents the headway; d min The distance between two vehicles when they are stationary;

[0074] S32: Inbound-Outbound Queue Trajectory Planning: Based on the initial and final conditions of the inbound-outbound queue, the expression for the inbound-outbound trajectory is obtained using a cubic polynomial curve as follows:

[0075]

[0076] In the formula, x m and x s These represent the longitudinal positions of the vehicles during the merging and merging processes, respectively; y m and y s These refer to the lateral positions of the vehicles during the merging and merging processes, respectively. and These represent the final vertical and horizontal positions of the merged component; and These represent the final vertical and horizontal positions of the output;

[0077] S33: Optimization of import-export queue trajectory:

[0078] 1) Optimized inflow trajectory.

[0079] a) Establish a merging trajectory cost function based on merging efficiency and passenger comfort to obtain the optimal final longitudinal merging position. The cost function is expressed as follows:

[0080]

[0081] b) The cost function J for outgoing trajectory optimization is expressed as follows:

[0082]

[0083] The optimal inflow trajectory is found by minimizing the cost function J, thus obtaining the optimal longitudinal position of the inflow endpoint. As shown in the following formula:

[0084]

[0085] 2) In addition to considering merging efficiency and passenger comfort, during the actual merging process, merging vehicles should avoid the risk of collision with vehicles in front of or behind the merging position; merging vehicle T m and the car in front T mp The safety clearance model is represented as follows:

[0086]

[0087] In the formula, τ is the reaction time of the lagging vehicle; and For each of the incoming vehicle T m and the car in front T mp initial longitudinal velocity; b m and b mp For each of the incoming vehicle T m and the car in front T mp The maximum deceleration;

[0088] Vehicle T m and the car behind T ml The safety clearance model is represented as follows:

[0089]

[0090] In the formula, For the rear car T ml initial longitudinal velocity; b ml For the rear car T ml The maximum deceleration;

[0091] Will merge into the starting vertical position Defined as 0, the final vertical position of the merge is obtained. The collision avoidance range is shown below:

[0092]

[0093] 3) Combining the cost function module that considers merging efficiency and passenger comfort with the safety distance module that considers collision risk, the final merging trajectory optimization module is obtained. The optimal merging endpoint position is obtained by minimizing the optimization function J. This may not meet the requirements for safe distance to avoid collisions; therefore, in order to avoid collisions, It should fall within the safe collision avoidance distance; adjust the merging starting speed. and weight The specific adjustment logic is as follows:

[0094] when hour, Within the collision avoidance safety distance, no adjustments are needed to obtain the optimal merging trajectory.

[0095] when At that time, that is Exceeding the upper limit of the collision avoidance safety distance; first, determine the merging starting speed. The adjustment, by reducing To achieve the requirements; if If using the maximum deceleration still doesn't meet the requirements, then further adjustments to the weights are needed. To achieve the requirements;

[0096] when At that time, that is Exceeding the lower limit of the collision avoidance safety distance; first, determine the merging starting speed. The adjustment, by increasing To achieve the requirements; if If using maximum acceleration still doesn't meet the requirements, then further adjustments to the weights are needed. To achieve the requirements;

[0097] If passed and Adjustments to achieve the optimal merging endpoint position. If the collision avoidance safety distance requirement is still not met, it means that the current queue environment is not suitable for merging; the merging vehicle will resend the merging request and wait for the response from the lead vehicle;

[0098] S34: Trajectory Tracking Control: Based on the vehicle model in S1, design a controller to implement the inbound-outbound process, as shown below:

[0099]

[0100] In the formula, ω(t) represents the actual yaw rate of the vehicle. desψ represents the ideal yaw rate of the vehicle; s(t) represents the sliding surface; c represents the sliding surface coefficient; ψ c The front wheel steering angle of the vehicle; k, λ, b, γ i and The gain is constant.

[0101] Furthermore, in S4, joint simulation testing is conducted using a simulation environment; where PreScan is mainly used for traffic scene construction, V2X sensor configuration, and 3D simulation animation display, TrcukSim is used to generate vehicle dynamics models, and MATLAB / Simulink is used for loading control algorithms and extracting simulation data.

[0102] Furthermore, the simulation environment includes MATLAB and Simulink+PreScan+TruckSim.

[0103] The beneficial effects of this invention are as follows: This invention proposes a hierarchical collaborative control method for merging and merging, comprising a centralized decision-making layer and a distributed control layer. The decision-making layer, located on the lead vehicle, is responsible for making decisions on key information and outputting corresponding signals to the control layer throughout the collaborative process. Specifically, this includes request evaluation, merging position determination, and calculation of safe queue spacing. The control layer considers the influence of the vehicle's nonlinear vehicle dynamics model and controls queue member vehicles and motor vehicles to complete corresponding collaborative actions based on the results output by the decision-making layer. Specifically, this includes queue longitudinal spacing control, merging-and-merging trajectory planning, trajectory optimization, and trajectory tracking control. The decision-making layer and the control layer cooperate to ensure the safety, stability, and efficiency of the entire collaborative control process.

[0104] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0105] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0106] Figure 1 Diagram illustrating the inflow and outflow scenario for intelligent connected vehicles;

[0107] Figure 2 This is a schematic diagram of the inflow-outflow hierarchical collaborative control method;

[0108] Figure 3 This is a schematic diagram of the vehicle dynamics model;

[0109] Figure 4 Flowchart for the inbound / outbound decision-making process;

[0110] Figure 5 This is a flowchart of the import / export control layer.

[0111] Figure 6 Diagram showing safe distance for collision avoidance;

[0112] Figure 7 Flowchart for trajectory optimization;

[0113] Figure 8 This is a schematic diagram illustrating the effectiveness of the method. Detailed Implementation

[0114] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0115] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0116] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0117] In embodiments of the present invention, such as Figure 1The diagram illustrates the merging and merging scenarios for intelligent vehicle queues: The merging scenario refers to a queue of n+1 intelligent connected vehicles traveling at the same speed and with a desired spacing in the center of the road, where a vehicle in an adjacent lane wishes to merge into the queue. The merging scenario refers to a queue in stable motion where a member vehicle requests to leave the queue. The merging-merging hierarchical collaborative control method proposed in this invention, which includes a centralized decision-making layer and a distributed control layer, is as follows: Figure 2 As shown, the decision-making layer, located on the lead vehicle, is responsible for making decisions on key information and outputting corresponding signals to the control layer throughout the collaborative process. This includes request evaluation, merging position determination, and queue safety spacing calculation. The control layer considers the influence of the vehicle's nonlinear vehicle dynamics model and controls queue member vehicles and motor vehicles to complete corresponding collaborative actions based on the results output by the decision-making layer. This includes queue longitudinal spacing control, merging-out trajectory planning, trajectory optimization, and trajectory tracking control. Finally, the effectiveness of the algorithm is verified in a co-simulation environment that closely resembles a real-world scenario. Experimental results show that the cooperation between the decision-making layer and the control layer ensures the safety, stability, and efficiency of the entire merging-out collaborative control process.

[0118] The specific details of this method are as follows:

[0119] I. For example Figure 3 As shown, considering the vehicle's transmission system, tires, and braking system, the vehicle dynamics model is established as follows:

[0120]

[0121] In the formula, F xr (t) represents the longitudinal tire force of the rear wheel; F xf (t) represents the longitudinal tire force of the front wheel; ω r (t) represents the rear wheel speed; ω f (t) represents the front wheel speed; ω e (t) represents the engine speed; ω p (t) represents the rotational speed of the hydraulic torque converter; T b (t) represents the braking torque; T e (t) represents the driving torque; p br (t) represents the braking pressure; θ th (t) represents the throttle opening; f tr (*) indicates the torque characteristic of the hydraulic torque converter; f tki (*) indicates the hydraulic torque converter capacity characteristic; MAP(*) indicates the engine torque characteristic; L f Indicates the distance from the front axle to the center of gravity; L r Indicates the distance from the rear axle to the center of gravity; v x (t) represents the longitudinal velocity; r w Indicates the wheel radius; kb Indicates the braking pressure coefficient; C d Indicates the air drag coefficient; v low i represents the longitudinal velocity constant of the wheel. g i0 represents the gear ratio of the transmission; i0 represents the gear ratio of the reducer; μ a ρ represents the rolling resistance coefficient; a A represents air density; B represents frontal area; C represents stiffness factor; D represents shape factor; E represents peak value factor; J represents curvature factor. r J represents the moment of inertia of the rear wheel. e J represents the engine's moment of inertia; f v represents the moment of inertia of the front wheels. y The vehicle's lateral velocity is represented by m; the vehicle's mass is represented by C. f and C r Represents the equivalent sideslip stiffness of the front and rear wheels of the vehicle, respectively; ω represents the yaw rate of the vehicle; β represents the sideslip angle of the center of gravity; ψ represents the front wheel steering angle; I z This represents the moment of inertia of the vehicle about the z-axis.

[0122] II. The design incorporates a centralized decision-making layer located in the lead vehicle. The lead vehicle establishes communication connections with every vehicle and motor vehicle in the queue. Therefore, the results of each decision-making layer calculation are sent to collaborating vehicles or merging / exiting vehicles in the queue via V2V communication, thus completing the merging / exit decision communication. This includes merging / exit request evaluation, merging position determination, and queue safety distance determination. Figure 4 As shown, the specific steps are as follows:

[0123] 1. Request Evaluation: Responsible for analyzing inbound and outbound requests based on the queue's own situation and determining whether to accept the request.

[0124] 1) External vehicle request to join the queue: The lead vehicle needs to evaluate the joining request based on the merged queue length and the current queue status. The specific judgment steps are as follows:

[0125] a) Incoming vehicle T m Sending an inbound request to the queue leader vehicle T0 triggers the queue inbound policy, and the leader vehicle T0 and vehicle T... m Establish a communication connection.

[0126] b) Determine the queue length based on the current queue length L. a Calculate whether the length of the merged queue is greater than the maximum queue length L. max If the value is greater than 1, the request is rejected directly; if it is less than or equal to 1, the next step is performed, as shown below.

[0127] L a +1≤Lmax

[0128] c) Perform queue stability assessment. The queue stability is determined using the following formula. If the queue is in a stable state, the inflow of external vehicles is allowed; otherwise, the inflow request is rejected.

[0129]

[0130] In the formula, j is the imaginary unit; ω is the excitation frequency; and |G(jω)| is the amplitude of the vehicle queuing system transfer function.

[0131] d) Incoming vehicle T m Join the queue's self-organizing communication network to proceed to the next step of determining the merge location.

[0132] 2) Internal vehicle merging request: In actual driving, internal vehicles often merge out because they are approaching their destination or their destination has changed, requiring them to enter other lanes to achieve this goal. Therefore, the lead vehicle will default to agreeing to the merging request. The specific judgment steps are as follows:

[0133] a) Outgoing vehicle T s Send an outbound request to queue leader vehicle T0 to trigger the queue outbound strategy.

[0134] b) The lead vehicle T0 agrees to the outgoing request and proceeds to the next step of determining the safe queuing distance.

[0135] 3) After the lead vehicle approves the joining request of an external vehicle, it will determine the joining position and then the queue safety distance. If it approves the leaving request of an internal vehicle, it will directly determine the queue safety distance.

[0136] 2. Leading vehicle T0 allows merging vehicles T to join. m After receiving an import request, a decision needs to be made regarding the import location.

[0137] 1) The merging position is usually divided into merging at the end of the queue and merging in the middle of the queue. The strategy for determining the merging position is as follows:

[0138] a) If vehicle T m Current location Located at position x of the last car in the queue n The subsequent decision strategy was to merge at the back of the queue.

[0139] b) If vehicle T m Current location Located between the first and last cars in the queue, the decision strategy is to merge into the queue.

[0140] 2) Calculate the inflow position p m :

[0141]

[0142] In the formula, p m For vehicle T m The location of the entry; x i Let be the longitudinal position of vehicle i in the queue.

[0143] 3) After determining the merging location, the lead vehicle will send the merging location to the merging vehicle T. m Then merge into vehicle T. m Under the action of the vertical layer controller, it will reach the specified inflow starting point. And wait for the lead vehicle to determine the safe spacing of the queuing. To facilitate the adjustment of vehicle spacing after merging and shorten the time for the queuing to return to stable driving, the merging starting point will be... Set the same value as the desired position after the vehicle merges. Calculate. as follows:

[0144]

[0145] In the formula, x mp The position of the vehicle preceding the merging point; d i,des L represents the desired distance between adjacent vehicles; L is the vehicle length.

[0146] 3. Safety Spacing Judgment: Design a queue safety spacing judgment model. The decision layer calculates the queue safety spacing and sends the calculation results to the control layer. The control layer adjusts the spacing between the inbound and outbound positions through the queue vertical layer controller to meet the safety requirements of inbound and outbound.

[0147] 1) Determining the safe distance between merging points

[0148] a) Merge starting point Position x of the vehicle in front mp Minimum safe distance (t): vehicle T during merging m With the car in front T mp A collision may occur. According to vehicle T... m and the car in front T mp Based on the relative positional relationships, the collision avoidance conditions shown below can be obtained.

[0149]

[0150] In the formula, x m (t) represents vehicle T m Longitudinal displacement; W is the vehicle's longitudinal displacement. m The width of the vehicle body; x is the angle between the vehicle's velocity direction and the lane centerline; mp (t) represents vehicle T mp The longitudinal displacement.

[0151] Further define S min (T m ,T mp ) for vehicle T m With the car in front T mp The minimum safe distance to avoid a collision can be expressed as follows:

[0152]

[0153] In the formula, a m (t) represents vehicle T m longitudinal acceleration; a mp (t) represents vehicle T mp longitudinal acceleration; v m (0) represents the vehicle T at the initial time of merging. m longitudinal velocity; v mp (0) represents the vehicle T at the initial time of merging. mp longitudinal velocity; S p (0) represents vehicle T m With vehicle T mp The initial spacing; t∈[t ms ,t mf ] represents the time domain; t ms and t mf These are the start and end times of the import, respectively.

[0154] b) Merge starting point Position x of the vehicle behind ml Minimum safe distance (t): vehicle T during merging m With the car behind T ml A collision is also possible. (Based on vehicle T) m and the car behind T ml Based on the relative positions, the collision avoidance conditions can be obtained as follows:

[0155]

[0156] In the formula, x ml (t) represents vehicle T ml The vertical position.

[0157] Furthermore, vehicle T m With the car behind T ml The minimum safe distance to avoid a collision is as follows:

[0158]

[0159] In the formula, S min (T ml ,T m ) represents the minimum safe distance; aml (t) represents vehicle T ml longitudinal acceleration; v ml (0) represents the vehicle T at the initial time of merging. ml longitudinal velocity; S l (0) represents vehicle T m With vehicle T ml The initial spacing.

[0160] Minimum safety spacing D m (t) is as follows:

[0161] D m (t)=S min (T m ,T mp )+S min (T ml ,T m )

[0162] 2) Determination of safe distance for outgoing routes

[0163] Outgoing origin Position x of the vehicle in front sp Minimum safe distance (t): based on vehicle T m and the car in front T sp Based on the relative positions of the vehicles, the conditions under which a collision will not occur are as follows:

[0164]

[0165] In the formula, a s (t) represents vehicle T s longitudinal acceleration; a sp (t) represents vehicle T sp longitudinal acceleration; v s (0) represents the initial time of vehicle T when merging out. s longitudinal velocity; v sp (0) represents the initial time of vehicle T when merging out. sp longitudinal velocity; S r (0) represents vehicle T s With vehicle T sp The initial spacing; t∈[t ss ,t sf ] represents the time domain; t ss and t sf These represent the start and end times of the remittance, respectively.

[0166] Vehicle T at the time of departure s The speed is set to be greater than or equal to the queue speed, at which point vehicle T... s It is impossible to be with the car behind T sl A collision has occurred. Minimum safe clearance D is required.s (t) is as follows:

[0167] D s (t)=S min (T s ,T sp )

[0168] 4. Once the minimum safe distance between inbound and outbound traffic is obtained, the decision-making level sends the information to the relevant vehicles:

[0169] 1) Obtain the minimum safe distance D for merging. m After (t), the decision-making level will send the calculation result to the following vehicle T. ml T ml Based on this result, the upper control layer will complete the specified action under the action of the queue vertical layer controller.

[0170] 2) Minimum safe distance D s After (t), the decision-making level will send the calculation results to the outgoing vehicle T. s T s Based on this result, the upper control layer will complete the specified action under the action of the queue vertical layer controller.

[0171] Third, a distributed control layer is designed on each vehicle. This control layer controls the vehicle to perform specific actions based on the instructions output by the decision layer, including inbound-outbound spacing control, trajectory planning, and trajectory tracking control; such as... Figure 5 As shown, the specific steps are as follows:

[0172] 1. After calculating the safe queue spacing during inbound and outbound flows in the decision-making layer, the control layer needs to control this safe spacing. The specific steps are as follows:

[0173] 1) Vehicle T during merging mp and vehicle T ml The spacing strategy is as follows:

[0174] d ml,des (t)=max(D m (t),hv ml (t)+d min )

[0175] In the formula, d ml,des (t) represents vehicle T mp and vehicle T ml The expected spacing between them; max(*) is the maximum value function; hv ml (t)+d min For vehicle T ml Expected spacing under the CTH strategy.

[0176] 2) Vehicle T at the time of departures and vehicle T sp The spacing strategy between them is as follows:

[0177] d s,des (t)=max(D s (t),αv s (t)+d min )

[0178] In the formula, d s,des (t) represents vehicle T s and vehicle T sp The expected distance between them; αv s (t)+d min For vehicle T s Expected spacing under the CTH strategy.

[0179] 3) All vehicles in the queue are controlled using a distributed longitudinal hierarchical controller as shown below:

[0180]

[0181] In the formula, u f,i (t) represents the corrected desired acceleration; k1, k2, and k3 are the proportional, integral, and derivative gain coefficients of the PID controller, respectively; Δa i (t) represents the error between the desired acceleration and the actual acceleration, Δa i (t)=u i (t)-a i (t); θ th,i (t) and p br,i (t) represents the throttle opening and brake pressure output by the lower-level controller; MAP -1 (*) represents the inverse engine torque characteristic function; ω e,i (t) represents the engine speed of the i-th vehicle; s i (t) represents the sliding surface; c represents the sliding surface gain; For the speed error between vehicles; k, λ, b, γ i and The gain is constant; e i (t) represents the distance error between adjacent vehicles; d i (t) represents the actual distance between adjacent vehicles; L represents the vehicle length; d i,des (t) represents the expected distance between car i and car i-1; h represents the headway; d min This is the distance between two vehicles when they are stationary.

[0182] 2. Inbound-Outbound Queue Trajectory Planning: Based on the initial and final conditions of the inbound-outbound queue, the expression for the inbound-outbound trajectory can be obtained using a cubic polynomial curve as follows:

[0183]

[0184] In the formula, x m and x s These represent the longitudinal positions of the vehicles during the merging and merging processes, respectively; y m and y s These refer to the lateral positions of the vehicles during the merging and merging processes, respectively. and These represent the final vertical and horizontal positions of the merged component; and These represent the final vertical and horizontal positions of the output.

[0185] 3. Optimization of import-export queue trajectory:

[0186] 1) Optimized inflow trajectory.

[0187] a) Establish a merging trajectory cost function based on merging efficiency and passenger comfort to obtain the optimal final longitudinal merging position. The cost function is expressed as follows:

[0188]

[0189] b) The cost function J for outgoing trajectory optimization is expressed as follows:

[0190]

[0191] The optimal merging trajectory can be found by minimizing the cost function J, thus obtaining the optimal longitudinal position of the merging endpoint. As shown in the following formula:

[0192]

[0193] 2) In addition to considering merging efficiency and passenger comfort, during the actual merging process, merging vehicles should avoid the risk of collision with vehicles in front of and behind the merging position. A safety distance module that considers collision risk should be designed, such as... Figure 6 As shown. Incoming vehicle T m and the car in front T mp The safety clearance model is represented as follows:

[0194]

[0195] In the formula, τ is the reaction time of the lagging vehicle; and For each of the incoming vehicle T m and the car in front T mp initial longitudinal velocity; b m and b mp For each of the incoming vehicle Tm and the car in front T mp The maximum deceleration.

[0196] Vehicle T m and the car behind T ml The safety clearance model is represented as follows:

[0197]

[0198] In the formula, For the rear car T ml initial longitudinal velocity; b ml For the rear car T ml The maximum deceleration.

[0199] Will merge into the starting vertical position Defining it as 0 allows us to obtain the final vertical position of the merge. The collision avoidance range is shown below:

[0200]

[0201] 3) Combining the cost function module that considers merging efficiency and passenger comfort with the safety distance module that considers collision risk, the final merging trajectory optimization module is obtained, as follows: Figure 7 As shown, the optimal merging endpoint position is obtained by minimizing the optimization function J. This may not meet the requirements for safe collision avoidance distance. Therefore, in order to avoid a collision, It should fall within the safe collision avoidance distance. This can be achieved by adjusting the merging initial speed. and weight The specific adjustment logic is as follows:

[0202] when hour, Within the collision avoidance safety distance, no adjustments are needed, and the optimal merging trajectory can be obtained directly.

[0203] when At that time, that is Exceeding the upper limit of the collision avoidance safety distance. First, determine the merging initial speed. The adjustment, by reducing To meet the requirements. If If using the maximum deceleration still doesn't meet the requirements, then further adjustments to the weights are needed. To meet the requirements.

[0204] when At that time, that is Exceeding the lower limit of the collision avoidance safety distance. First, determine the merging initial speed. The adjustment, by increasing To meet the requirements. If If using maximum acceleration still doesn't meet the requirements, then further adjustments to the weights are needed. To meet the requirements.

[0205] Furthermore, if through and Adjustments to achieve the optimal merging endpoint position. If the required collision avoidance distance is still not met, it means the current queuing environment is not suitable for merging. The merging vehicle will resend the merging request and wait for a response from the lead vehicle.

[0206] 4. Trajectory Tracking Control: Based on the vehicle model in Step 1, design a controller to implement the inbound-outbound process, as shown below:

[0207] In the formula, ω(t) represents the actual yaw rate of the vehicle. des ψ represents the ideal yaw rate of the vehicle; s(t) represents the sliding surface; c represents the sliding surface coefficient; ψ c The front wheel steering angle of the vehicle; k, λ, b, γ i and The gain is constant.

[0208] Fourth, to test the actual performance of this invention under real driving conditions, it is necessary to conduct real vehicle verification or closed-loop testing in a professional vehicle ADAS simulation environment. To save costs, this invention uses a simulation environment (MATLAB / Simulink + PreScan + TruckSim) for joint simulation testing. Among them, PreScan is mainly used for traffic scene construction, V2X sensor configuration and 3D simulation animation display, TruckSim is used to generate vehicle dynamics models, and MATLAB / Simulink is used for loading control algorithms and extracting simulation data.

[0209] To verify the effectiveness of the method proposed in this invention in real-world scenarios, the implementation scheme is described in conjunction with the accompanying drawings.

[0210] First, the detailed parameters for each part are configured. The parameters configured in this embodiment are for reference only and can be adjusted according to the actual scenario. The merging simulation scenario consists of 1 lead vehicle, 3 follow vehicles, and 1 merging vehicle. The merging simulation scenario consists of 1 lead vehicle and 4 follow vehicles.

[0211] In the first part, regarding the establishment of the vehicle dynamics model and the environment model, the detailed vehicle dynamics model parameters used are: L f =1.11m, L r =3.89m, r w =0.51m, C d =0.3, vlow =0.5m / s, i0=4.4, μ a =0.0041, ρ a =1.206kg / m 3 A = 10m 2 , B=11.275, C=1.56, D=2574.8, E=0.4109, J r =14kg·m 2 J e = 2.1 kg·m 2 J f =14kg·m 2 m = 6735 kg, C f =19000N / rad, C r =33000N / rad, I z =2875mNs 2 .

[0212] In the second part, the initial state settings of the vehicle queue and motor vehicles are as follows, with the inbound-outbound application time t = 20s: Inbound: Leading vehicle (84.6,0), Follower vehicle 1 (72.6,0), Follower vehicle 2 (60.6,0), Follower vehicle 3 (48.6,0), Motor vehicle (36.6,5); Outbound: Leading vehicle (100,0), Follower vehicle 1 (88,0), Follower vehicle 2 (64,0), Follower vehicle 3 (52,0), Motor vehicle (76,5);

[0213] In Part Three, the detailed parameters of the controller used are: c = 0.1, k = 1, λ = 1, b = 5, q = 3, γ i =10, h=1s, d min =5m, k1=1.5, k2=0.1, k3=0, L max =10, p m =2, b m =3.5m / s 2 b ml =3.5m / s 2 b mp =3.5m / s 2 , τ=0.7s.

[0214] In the simulation environment (MATLAB / Simulink+PreScan+TruckSim), the first part, vehicle dynamics model establishment, is performed using the above parameters; the second part, inbound-outbound decision communication, is completed using the above parameters; and the third part, the control layer, controls the vehicle to complete the corresponding inbound-outbound actions based on the instructions output by the decision layer. For example... Figure 8As shown in the figure, the information in the figure represents the merging longitudinal velocity, merging acceleration, merging longitudinal velocity, and merging acceleration, respectively. The figure demonstrates that the experimental results ensure the effective merging and merging of vehicles, and guarantee the safety, stability, and efficiency of the entire cooperative control process.

[0215] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A hierarchical control method for merging and merging intelligent connected vehicle queues, characterized in that: This method Includes the following steps: S1: Considering the vehicle's transmission system, tires, and braking system, the vehicle dynamics model is established as follows: In the formula, Indicates the longitudinal tire force of the rear wheel; Indicates the longitudinal tire force of the front wheels; Indicates the rear wheel speed; Indicates the front wheel speed; Indicates engine speed; Indicates the speed of the hydraulic torque converter; Indicates braking torque; Indicates driving torque; Indicates braking pressure; Indicates the throttle opening; This indicates the torque characteristics of the hydraulic torque converter; This indicates the torque-capacity characteristic of hydraulic systems. Indicates engine torque characteristics; Indicates the distance from the front axle to the center of gravity; Indicates the distance from the rear axle to the center of gravity; Indicates longitudinal velocity; Indicates the radius of the wheel; Indicates the braking pressure coefficient; Indicates the air drag coefficient; Represents the longitudinal velocity constant of the wheel; Indicates the gear ratio of the transmission; Indicates the gear ratio of the reducer; Indicates the rolling resistance coefficient; Indicates air density; Indicates the windward area; Indicates the stiffness factor; Represents the shape factor; Indicates the peak factor; Represents the curvature factor; This represents the moment of inertia of the rear wheel; This represents the engine's moment of inertia; This represents the moment of inertia of the front wheels; Indicates the lateral speed of the vehicle; Indicates vehicle mass; and These represent the equivalent lateral stiffness of the front and rear wheels of the vehicle, respectively. Indicates the vehicle's yaw rate; Indicates the centroid sideslip angle; Indicates the front wheel steering angle; Indicates vehicles go around z Moment of inertia of the shaft; S2: The design is located at the centralized decision-making layer of the lead vehicle. The lead vehicle establishes communication connections with each vehicle and motor vehicle in the queue. The results of each decision-making layer calculation are sent to the cooperating vehicles or merging-out vehicles in the queue through V2V communication to complete the merging-out decision communication, specifically including merging-out request evaluation, merging position judgment, and queue safety distance judgment. S3: Design a distributed control layer located on each vehicle. The control layer will control the vehicle to complete the corresponding specific actions according to the instructions output by the decision layer, including inbound-outbound spacing control, trajectory planning and trajectory tracking control. S4: Build a simulation environment to verify the effectiveness of the control method. The effectiveness of the hierarchical control method is verified by establishing a co-simulation environment, introducing a sensor system and a communication system.

2. The intelligent connected vehicle queue inbound-out hierarchical control method according to claim 1, characterized in that: Specifically, S2 is: S21: Request Evaluation: Responsible for analyzing inbound and outbound requests based on the queue's own situation and determining whether to accept the request. 1) External vehicle request to join the queue: The lead vehicle needs to evaluate the joining request based on the merged queue length and the current queue status; the specific judgment steps are as follows: a) Incoming vehicles Send an inbound request to the queue leader vehicle Trigger queue inflow strategy, lead vehicle With merging vehicles Establish a communication connection; b) Determine the queue length; based on the current queue length... Calculate whether the length of the merged queue is greater than the maximum queue length. If the value is greater than 1, the request is rejected directly; if it is less than or equal to 1, the next step is performed, as shown below. c) Perform queue stability judgment; judge the queue string stability according to the following formula. When the queue is in a stable state, allow the inflow of external vehicles; otherwise, reject the inflow request. In the formula, The imaginary unit; For excitation frequency; The amplitude of the transfer function is provided for the vehicle queuing system; d) Merging vehicles Join the queue's self-organizing communication network to proceed with the next step of determining the merge location; 2) Internal vehicle merging request: During actual driving, internal vehicles merge out because their destination is approaching or has changed, requiring them to enter other lanes to achieve this goal; therefore, the lead vehicle will default to agreeing to the merging request; the specific judgment steps are as follows: a) Vehicles departing Send an outbound request to the queue leader vehicle This triggers the queue outflow strategy; b) Lead vehicle The outbound request is approved; proceed to the next step of determining the queue safety distance. 3) After the lead vehicle agrees to the joining request of an external vehicle, it will determine the joining position and then the queue safety distance; if it agrees to the leaving request of an internal vehicle, it will directly determine the queue safety distance. S22: Leading Vehicle Allow vehicles to merge After receiving the import request, a decision needs to be made regarding the import location; 1) The merging position is divided into merging at the end of the queue and merging in the middle of the queue. The strategy for determining the merging position is as follows: a) If the vehicle merges Current location Located at the end of the queue The subsequent decision strategy is to merge into the queue from the back. b) If the vehicle merges Current location Located between the first and last cars in the queue, the decision strategy is to merge into the queue; 2) Calculate the inflow location : In the formula, For merging vehicles The location where the flow ends; For vehicles in the queue The longitudinal position; 3) After the merging location is determined, the lead vehicle will send the merging location to the merging vehicle. Then merge the vehicles. Under the action of the vertical layer controller, it will reach the specified inflow starting point. And wait for the lead vehicle to determine the safe spacing of the queuing; in order to facilitate the adjustment of the spacing between vehicles after merging and shorten the time for the queuing to return to stable driving, the merging starting point will be... Set the same value as the desired position after the vehicle merges; calculate as follows: In the formula, The position of the vehicle preceding the merging point; This represents the desired distance between adjacent vehicles. For the train commander; S23: Safety Spacing Judgment: Design a queue safety spacing judgment model. The decision layer calculates the queue safety spacing and sends the calculation results to the control layer. The control layer adjusts the spacing between the inbound and outbound positions through the queue vertical layer controller to meet the safety requirements of inbound and outbound. 1) Determining the safe distance between merging points a) Merge starting point Position of the vehicle in front Minimum safe distance: During the merging process, merging vehicles With the car in front A collision may occur; depending on the merging vehicles. and the car in front Based on the relative positional relationships, the collision avoidance conditions are as follows; In the formula, For merging vehicles Longitudinal displacement; For merging vehicles The width of the vehicle body; The angle between the vehicle's speed direction and the lane centerline; For vehicles Longitudinal displacement; Further definition For merging vehicles With vehicles The minimum safe distance to avoid a collision is expressed as follows: In the formula, For merging vehicles longitudinal acceleration; For vehicles longitudinal acceleration; To merge vehicles at the initial time longitudinal velocity; To merge the vehicles at the initial moment longitudinal velocity; For merging vehicles With vehicles The initial spacing; For the time domain; and These are the start and end times of the import process, respectively. b) Merge starting point Rear vehicle position Minimum safe distance: vehicles merging during the merging process The vehicle following the merging vehicle A collision may occur; depending on the merging vehicles. and the vehicle following the merging vehicle Based on the relative positions, the collision avoidance conditions are as follows: In the formula, For vehicles The longitudinal position; Furthermore, merged vehicles The vehicle following the merging vehicle The minimum safe distance to avoid a collision is as follows: In the formula, Minimum safe distance; For vehicles longitudinal acceleration; To merge the vehicles at the initial moment longitudinal velocity; For merging vehicles With vehicles The initial spacing; Minimum safety spacing as follows: 2) Determination of safe distance for outgoing routes Outgoing origin Position of the vehicle in front Minimum safe distance: based on merging vehicles and the car in front Based on the relative positions of the vehicles, the conditions for preventing a collision are as follows: In the formula, For outgoing vehicles longitudinal acceleration; For vehicles longitudinal acceleration; Vehicles dispatched at the initial dispatch time longitudinal velocity; For the initial time of vehicle departure longitudinal velocity; For outgoing vehicles With vehicles The initial spacing; For the time domain; and These are the start and end times of the remittance, respectively. When remitting, the remitting vehicle The speed is set to be greater than or equal to the queue speed, at which point vehicles merge. It is impossible to meet the vehicle behind the vehicle that is turning out. A collision occurs; minimum safe distance is required. as follows: S24: Obtain the minimum safe distance between inbound and outbound traffic, and send the decision-making information to the corresponding vehicle: 1) Obtain the minimum safe spacing for merging. Then, the decision-makers will send the calculation results to the vehicles following the merged vehicle. ; Based on this result, the upper control layer will complete the specified action under the action of the queue vertical layer controller; 2) Establish minimum safety distance Afterwards, the decision-makers will send the calculation results to the outgoing vehicle. , Based on this result, the upper control layer will complete the specified action under the action of the queue vertical layer controller.

3. The intelligent connected vehicle queue inbound-out hierarchical control method according to claim 1, characterized in that: Specifically, S3 is: S31: After calculating the safe queue spacing during inbound and outbound flows in the decision-making layer, the control layer needs to control the safe spacing; the specific steps are as follows: 1) Vehicles merging in and vehicles The spacing strategy is as follows: In the formula, For vehicles and vehicles The expected spacing between them; It is a function for maximizing the value; For vehicles Expected spacing under the CTH strategy; 2) Vehicles being remitted at the time of remittance and vehicles The spacing strategy between them is as follows: In the formula, For outgoing vehicles and vehicles The expected spacing between them; For outgoing vehicles Expected spacing under the CTH strategy; 3) All vehicles in the queue are controlled using a distributed longitudinal hierarchical controller as shown below: In the formula, This is the corrected desired acceleration; , , These are the proportional, integral, and derivative gain coefficients of the PID controller, respectively. The error between the desired acceleration and the actual acceleration. ; and This indicates the output throttle opening and brake pressure of the lower-level controller; This represents the inverse engine torque characteristic function; For the first i The engine speed of the vehicle; Indicates the sliding surface; Indicates the sliding surface gain; This refers to the speed error between vehicles; , , , and The gain is constant. This represents the distance error between adjacent vehicles; This refers to the actual distance between adjacent vehicles; The length of the vehicle; for Car and The desired distance between vehicles; This refers to the headway of the train. The distance between two vehicles when they are stationary; S32: Inbound-Outbound Queue Trajectory Planning: Based on the initial and final conditions of the inbound-outbound queue, the expression for the inbound-outbound trajectory is obtained using a cubic polynomial curve as follows: In the formula, and These represent the longitudinal positions of the vehicles during the merging and merging processes, respectively. and These refer to the lateral positions of the vehicles during the merging and merging processes, respectively. and These represent the final vertical and horizontal positions of the merged component; and These represent the final vertical and horizontal positions of the output; S33: Optimization of import-export queue trajectory: 1) Merge trajectory optimization, a) Establish a merging trajectory cost function based on merging efficiency and passenger comfort to obtain the optimal final longitudinal merging position. The cost function is expressed as follows: b) Cost function for outgoing trajectory optimization It is expressed as follows: By minimizing the cost function The optimal merging trajectory is found using this method, and the optimal longitudinal position of the merging endpoint is obtained. As shown in the following formula: 2) In addition to considering merging efficiency and passenger comfort, during the actual merging process, merging vehicles should avoid the risk of collision with vehicles in front of or behind the merging point; merging vehicles and the car in front The safety clearance model is represented as follows: In the formula, This refers to the reaction time of delayed vehicles; and For each of the merging vehicles and the car in front The initial longitudinal velocity; and For each of the merging vehicles and the car in front The maximum deceleration; Incoming vehicles and the vehicle following the merging vehicle The safety clearance model is represented as follows: In the formula, For the following vehicle merging into the vehicle The initial longitudinal velocity; For the following vehicle merging into the vehicle The maximum deceleration; Will merge into the starting vertical position Defined as 0, the final vertical position of the merge is obtained. The collision avoidance range is shown below: 3) Combining the cost function module that considers merging efficiency and passenger comfort with the safety distance module that considers collision risk, the final merging trajectory optimization module is obtained, minimizing the optimization function. The optimal merging endpoint position obtained later This may not meet the requirements for safe distance to avoid collisions; therefore, in order to avoid collisions, It should fall within the safe collision avoidance distance; adjust the merging starting speed. and weight The specific adjustment logic is as follows: when hour, Within the collision avoidance safety distance; At this point, no adjustments are needed, and the optimal merging trajectory is obtained; when At that time, that is Exceeding the upper limit of the collision avoidance safety distance; first, determine the merging starting speed. The adjustment, by reducing To achieve the requirements; if If using the maximum deceleration still doesn't meet the requirements, then further adjustments to the weights are needed. To achieve the requirements; when At that time, that is Exceeding the lower limit of the collision avoidance safety distance; first, determine the merging starting speed. The adjustment, by increasing To achieve the requirements; if If using maximum acceleration still doesn't meet the requirements, then further adjustments to the weights are needed. To achieve the requirements; If passed and Adjustments to achieve the optimal merging endpoint position. If the collision avoidance safety distance requirement is still not met, it means that the current queue environment is not suitable for merging; the merging vehicle will resend the merging request and wait for the response from the lead vehicle. S34: Trajectory Tracking Control: Based on the vehicle model in S1, design a controller to implement the inbound-outbound process, as shown below: In the formula, This indicates the vehicle's actual yaw rate. This represents the ideal yaw rate of the vehicle. Indicates the sliding surface; Indicates the sliding surface coefficient. The steering angle of the vehicle's front wheels; , , , and The gain is constant.

4. The intelligent connected vehicle queue inbound-out hierarchical control method according to claim 1, characterized in that: In S4, joint simulation testing is conducted using a simulation environment; PreScan is mainly used for traffic scene construction, V2X sensor configuration, and 3D simulation animation display, TrcukSim is used to generate vehicle dynamics models, and MATLAB / Simulink is used for loading control algorithms and extracting simulation data.

5. The intelligent connected vehicle queue inbound-out hierarchical control method according to claim 4, characterized in that: The simulation environment includes MATLAB and Simulink+PreScan+TruckSim.

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