CN-121999632-A - Vehicle formation driving self-adaptive V2X message transmission method based on information urgency

Abstract

The invention relates to the field of vehicle formation driving, and provides a self-adaptive V2X message transmission method. The method is based on an existing vehicle formation travel control model, and a maximum message transmission delay for maintaining formation stability is determined through a computing system response function. The invention is innovative in that an information urgency index designed for a vehicle formation driving scene is introduced, and the instability of the vehicle formation is quantified, wherein the larger the information urgency value is, the larger the instability is represented, and the basis for identifying and controlling potential instability factors is provided for a system. The invention adopts the Iapunov optimization method, and selects the best sending time of the V2X message by minimizing the information urgency under the condition of meeting the sending frequency limit, thereby enhancing the running stability of the vehicle formation. The method can adaptively adjust the message sending frequency according to the traffic environment change, reduce the collision risk of the vehicle, improve the control precision and effectively utilize the V2X communication resources. Simulation experiment results show that the method has obvious advantages compared with a fixed-interval message transmission method in the aspects of reducing the collision risk of the vehicle, improving the control precision and reducing the consumption of V2X communication resources.

Inventors

• WANG JIARUI
• TAN GUOPING
• CAI WEIHUA

Assignees

• 河海大学

Dates

Publication Date

20260508

Application Date

20241106

Claims (5)

1. 1. The vehicle formation self-adaptive V2X message transmission method based on information urgency and Iyanomv optimization is used for reducing communication overhead while ensuring vehicle formation stability, and is characterized by comprising the following steps of: a) Inputting parameters of a vehicle formation control model; b) Calculating a system response function for the vehicle formation; c) Determining a maximum message transmission delay allowed to maintain vehicle formation stability; d) Calculating information urgency of the vehicle formation in real time, wherein the information urgency is used for quantifying instability of the vehicle formation, and the larger the information urgency value is, the more unstable the vehicle formation is; e) Searching the moment with the lowest information urgency under the condition of meeting the transmission frequency limit by utilizing an Iapunov optimization method so as to determine the optimal transmission time of the V2X message; f) Outputting a V2X message transmission scheme; g) And if the formation of the vehicle is not finished, returning to the step d to continuously calculate the information urgency in real time.
2. 2. The method of claim 1, wherein in step c, the maximum message transmission delay is determined by a vehicle fleet control model and a system response function shaped as follows.
3. 3. The method of claim 1, wherein in step d, the information urgency is calculated taking into account position errors, speed errors and acceleration errors between vehicles.
4. 4. The method according to claim 1, wherein in the step e, the method for optimizing the iyaprunov comprises the steps of: a. an Iapunov function is constructed for solving the optimization problem of the form: Wherein S t is a transmission instruction variable for indicating whether the preceding vehicle has broadcast the vehicle status in the time slot t. When S t =1, it indicates that the preceding vehicle performs broadcasting, and when S t =0, it indicates that the preceding vehicle does not perform broadcasting. U (t) is the information urgency of the current vehicle at the time t, and is defined as follows: Delta represents the length of time since the current vehicle last received the previous vehicle state information, and P (t) represents the time distance between the current vehicle and the previous vehicle at time t. I (Δ) is an update indicating variable to identify whether the current vehicle has not communicated with the preceding vehicle for a long time. B. And obtaining a V2X message sending scheme which is in the shape of realizing minimum Iyanomnikov function value by adjusting the sending time of the V2X message.
5. 5. A vehicle formation adaptive V2X information transmission scheme based on information urgency and eleprenov optimization, characterized in that the system is configured to perform the method of any one of claims 1 to 5.

Description

Vehicle formation driving self-adaptive V2X message transmission method based on information urgency Technical Field The invention relates to the technical field of Internet of vehicles, and particularly provides a vehicle formation control method based on V2X communication. In addition, the invention also provides an innovative solution to the problem of optimizing communication resources in the vehicle formation control process. Background In the current automatic driving field of vehicle formation, research work is mainly focused on two major core directions, namely, on the basis of a vehicle control theory, developing an advanced following algorithm to enhance the stability of the vehicle formation, and on the basis of a vehicle communication technology, researching how factors such as communication delay, information instantaneity and information timeliness affect the dynamic behaviors of vehicles in the vehicle formation and how the factors affect the safety and stability of the running of the vehicle formation. The invention provides a novel information updating strategy based on urgency of vehicle state information, which is more suitable for formation driving scenes of rapid changes of vehicle states than the traditional remote scheduling and updating method based on information freshness. In the present invention, information urgency refers to the severity of all factors affecting fleet stability, such as the need for vehicles to update their state information more frequently during critical mode transitions to maintain fleet synchronization and coordination. If the frequency of status updates is insufficient, the reliability of the system may be reduced and even performance may be reduced to unacceptable levels. In contrast, when the vehicle is in a steady running state, the excessively frequent transmission of state information not only has a limited effect on improvement of performance, but also unnecessarily consumes communication bandwidth and energy. Therefore, in order to ensure timeliness of information transmission and effective utilization of communication resources, the update frequency of the status information needs to be dynamically adjusted according to the real-time environment and changes in the vehicle status, so as to achieve an optimal trade-off between the transmission frequency and the information update efficiency. Disclosure of Invention The invention aims at minimizing the consumption of communication resources and simultaneously applying a strategy based on information urgency to the field of automatic driving of vehicle formation, and creatively proposes a scheme named adaptive V2X information transmission. This approach provides significant improvements in reducing vehicle collision risk and control errors. The self-adaptive V2X information transmission scheme is mainly used for carrying out intensive study and solution on two core problems, namely, on the premise of ensuring the stability of the vehicle formation, how to determine the maximum tolerable communication delay omega of the vehicle formation, and on the premise of ensuring the communication times, how to minimize the information urgency of the vehicle formation. By solving the two problems, the invention can realize high stability of vehicle formation by optimizing the use of communication resources. The invention adopts the following specific technical scheme for solving the technical problems: 1. determining a maximum communication delay delta * allowed for vehicle formation using an optimization algorithm: First, the present invention proposes an optimization method for calculating the maximum communication delay Δ * allowed by the vehicle formation. In short, the stability of the fleet may be maintained as long as the communication interval of the vehicles in the fleet is less than Δ *. In order to describe the relationship between the vehicle formation control system and the communication delay, the present invention obtains its system response function according to the control scheme of the vehicle formation. The function may be capable of describing the stability impact of different communication delays on vehicle formation, and if the modulus of the system response function can be maintained below 1, the vehicle formation system may be considered to be in a steady state. The following is a specific step of establishing a system response function: 1. Defining system state variables-defining state variables of the system including position, speed, acceleration, etc. of the vehicle. 2. And establishing a mathematical model, namely establishing a mathematical model for describing the control behavior of the vehicle formation system according to the dynamics and the control theory of the vehicle. 3. The communication delay is considered by introducing the communication delay into the mathematical model to simulate the influence of the communication delay in the actual communication process on the stabilit