A vehicle heterogeneous cooperative platoon control system and method based on elastic safety domain

Abstract

The present invention proposes a control system and method for a heterogeneous collaborative formation of networked vehicles with an elastic safety domain. The present invention obtains information about other vehicle nodes in the formation and shares information about the own vehicle node, and numbers the vehicles in the formation. The information obtained in the vehicle formation is transmitted to the central processing unit through a data processor; the central processing unit determines the elastic safety domain of the vehicle based on the position, speed and acceleration information of the vehicles in the vehicle formation transmitted by the data processor; compares the actual distance of the vehicle with the vehicle safety distance domain, determines the actual safety distance domain between the vehicle and the preceding vehicle, determines the control strategy to be adopted for the vehicle based on the actual safety distance domain where the vehicle is located, obtains the expected acceleration of the vehicle; and performs dynamic control on the vehicle based on the calculated expected acceleration of the vehicle. While ensuring the safety of vehicle driving, the present invention can improve road traffic capacity, improve traffic efficiency, and reduce fuel consumption.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent connected vehicles, and in particular relates to a vehicle heterogeneous collaborative formation control system and method based on elastic safety domain. Background Art

[0002] In recent years, with the development of intelligent transportation systems, a class of intelligent transportation system technologies with broad prospects, represented by vehicle adaptive cruise control and cooperative adaptive cruise control, has continued to emerge. In heavy vehicle platoons, vehicle cooperative platooning control technology can not only improve road traffic capacity and efficiency, but also improve vehicle safety and fuel economy. Studies have shown that achieving only single automation can hardly improve the operating capacity of the overall transportation system, while the industry generally believes that the group of connected / cooperative automated vehicles (CAVs) has great potential in improving road capacity and traffic flow stability. However, when considering the safety distance, the current vehicle cooperative platooning control technology directly designs the safety distance as a fixed value or a value based on the change in the speed and acceleration of the preceding vehicle (this value is also calculated as a fixed value). In actual traffic, the safety level of vehicle distance can be divided into different levels according to the actual situation. The corresponding vehicles are controlled according to the different vehicle risk levels. On the premise of improving vehicle safety, the energy consumption caused by frequent fluctuations in vehicle speed can also be reduced. Based on this, the present invention proposes a vehicle heterogeneous cooperative platooning control method and system based on elastic safety domain. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention proposes a vehicle heterogeneous cooperative formation control system and method based on elastic safety domain.

[0004] The technical solution of the system of the present invention is a vehicle heterogeneous cooperative platoon control system based on elastic safety domain, which specifically includes:

[0005] Data processor, position sensor, lidar sensor, speed sensor, acceleration sensor, wind speed sensor, vehicle execution module, wireless communication module, central processing unit;

[0006] The data processor is connected to the position sensor, lidar sensor, speed sensor, acceleration sensor, wind speed sensor, vehicle actuator, and wireless communication device in sequence through wired means; the wireless communication device is connected to the central processing unit through wireless means;

[0007] The data processor is installed in the vehicle cabin, the position sensor is installed on the top of the vehicle cockpit, the lidar sensor is installed on the front of the vehicle, the speed sensor is installed in the wheel of the vehicle, the wind speed sensor is installed on the front of the vehicle, the acceleration sensor is installed on the front of the vehicle, the wireless communication module is installed on the roof, and the vehicle execution module includes the vehicle brake pedal pressure and throttle opening;

[0008] The laser radar sensor is used to collect the distance between the vehicle and the preceding vehicle in real time, and transmit the collected distance between the vehicle and the preceding vehicle in real time to the data processor;

[0009] The speed sensor is used to collect the vehicle speed in real time and transmit the collected vehicle speed in real time to the data processor;

[0010] The acceleration sensor is used to collect vehicle acceleration in real time and transmit the collected vehicle acceleration in real time to the data processor;

[0011] The wind speed sensor is used to collect the vehicle wind speed in real time and transmit the collected vehicle wind speed in real time to the data processor;

[0012] The data processor wirelessly transmits the real-time collected distance between the vehicle and the preceding vehicle, the vehicle speed, the vehicle acceleration, and the vehicle wind speed to the central processing unit via the wireless communication module;

[0013] The central processing unit obtains the desired acceleration of the vehicle based on the distance between the vehicle and the preceding vehicle, the vehicle speed, the vehicle acceleration, and the vehicle wind speed collected in real time through the vehicle heterogeneous cooperative platooning control method, wirelessly transmits the desired acceleration of the vehicle to the wireless communication module, and wirelessly transmits the desired acceleration to the data processor via the wireless communication module; the data processor converts the desired acceleration into a throttle opening or brake pressure, and transmits the throttle opening or brake pressure signal to the vehicle execution unit;

[0014] The vehicle execution module controls the vehicle throttle opening and brake pressure through an execution mechanism.

[0015] The technical solution of the method of the present invention is a method for controlling heterogeneous cooperative platooning of vehicles in a flexible safety domain, comprising the following steps:

[0016] Step 1: Each vehicle in the platoon is considered a single vehicle node. Vehicle nodes communicate wirelessly with each other to obtain information about other vehicle nodes in the platoon and share information about their own vehicle nodes. Vehicles in the platoon are numbered and the information obtained in the platoon is transmitted to the central processing unit through the data processor.

[0017] Step 2: The central processing unit determines the elastic safety domain of the vehicle based on the position, speed, and acceleration information of the vehicle in the vehicle formation transmitted by the data processor;

[0018] Step 3: The actual distance between vehicles obtained by the vehicle node through the central processing unit is compared with the vehicle safety distance domain to determine the actual safety distance domain between the vehicle and the preceding vehicle. Based on the actual safety distance domain, the control strategy to be adopted by the vehicle is determined to obtain the expected acceleration of the vehicle.

[0019] Step 4: Perform vehicle dynamics control based on the calculated desired vehicle acceleration.

[0020] Preferably, based on step 1, the vehicle node information includes determining the number of vehicles, vehicle types and other information in the heterogeneous vehicle cooperative formation and obtaining the kinematic and dynamic information of the vehicles in the formation.

[0021] Determining the number of vehicles in the heterogeneous vehicle cooperative formation is to count the number of vehicles in the current vehicle formation. During the movement and control of the vehicle formation, no external vehicles are inserted or vehicles in the formation leave the formation. The number of vehicles is represented by N, where N ≥ 2, that is, there are at least two vehicles in the vehicle formation, a leading vehicle and a following vehicle.

[0022] The method of determining the vehicle types in the heterogeneous vehicle cooperative formation is to classify the vehicles in the heterogeneous vehicle formation into two types: C and T, where type C represents cars and type T represents large trucks.

[0023] Vehicles are numbered based on their type and platoon order. For example, if the lead vehicle is a large truck, it is numbered T0. The first following vehicle is a car, numbered C1. The second following vehicle is a large truck, numbered T2. The i-th following vehicle is also a large truck, numbered Ti, and so on.

[0024] The acquisition of vehicle kinematic information includes acquiring vehicle position, velocity, acceleration and other information, wherein position is represented by X and velocity is represented by Expressed as acceleration The subscripts represent the position and type of the vehicle in the formation. For example, represents the speed of the i-th following car.

[0025] The acquisition of vehicle dynamics information includes acquiring vehicle mass, vehicle engine coefficient, throttle opening, brake pedal pressure and other information.

[0026] Preferably, based on Step 2, the elastic safety domain of the vehicle distance includes an emergency safety distance domain, a comfortable safety distance domain, and a loose safety distance domain. The emergency safety distance domain is the maximum braking distance to prevent the vehicle from colliding with the vehicle in front, which is represented by 0 < X < d1; the comfortable safety distance domain is the comfortable distance where the vehicle will not collide and the vehicle distance is in a suitable position without changing the current motion state, which is represented by d1 < X ≤ d2; the loose safety distance is that the vehicle does not collide with the vehicle in front, but since the vehicle distance is too large, it is not conducive to improving the road traffic efficiency, which is represented by X > d2;

[0027] Based on Step 2, the formula for the emergency safety domain is:

[0028]

[0029] where d1 is the critical point between the emergency safety domain and the comfortable safety domain, is the speed of vehicle i, is the speed of vehicle i - 1, t i is the braking system response time of vehicle i, is the maximum braking acceleration of vehicle i, and L is the minimum vehicle distance maintained between vehicle i and the vehicle in front after stopping.

[0030] Based on Step 2, the formula for the comfortable safety domain is:

[0031]

[0032] where d2 is the critical point between the comfortable safety domain and the loose safety domain, is the speed of vehicle i, is the speed of vehicle i - 1, t i is the braking system response time of vehicle i, is the maximum braking acceleration of vehicle i, is the maximum braking acceleration of vehicle i - 1, and L is the minimum vehicle distance maintained between vehicle i and the vehicle in front after stopping.

[0033] Preferably, based on Step 3, when the vehicle is in different safety domains, the calculation models of the desired acceleration of the vehicle are different. In the emergency safety domain, the vehicle should brake as quickly as possible to ensure the safety of the vehicle formation; in the comfortable safety domain, the vehicle speed is at the desired speed and no control is required; in the loose safety domain, the vehicle should accelerate to improve the road traffic efficiency. The calculation method of the desired acceleration of the vehicle is as follows:

[0034]

[0035] In the formula, represents the desired acceleration of vehicle i at time t + T; represents the maximum braking acceleration of vehicle i; represents the acceleration of vehicle i at time t; F(X) represents the expected acceleration function of vehicle i.

[0036] Based on step 3, F(X) is the expected acceleration of the vehicle in the relaxed safety domain. The expected acceleration is calculated as follows:

[0037]

[0038] Where, is the expected acceleration of vehicle i at time t+T, X i (t) represents the position of vehicle i at time t, X i-1 (t) represents the position of vehicle i-1 at time t, p is the length of vehicle i-1, τ is the headway of vehicle i, is the speed of vehicle i at time t, is the speed of vehicle i-1 at time t.

[0039] Preferably, the step 4 is as follows:

[0040] The system transmits information detected by the radar to the central processing unit, which processes and calculates the vehicle's expected acceleration and outputs it to the vehicle control system. The vehicle control system converts the expected acceleration into throttle opening and brake pressure through the engine model. The vehicle execution unit adjusts the brake actuator by outputting the throttle opening acceleration and brake pressure values. The expected brake pressure is derived from the expected acceleration as follows:

[0041]

[0042] Where: P des is the expected braking pressure of the vehicle; m is the vehicle mass; a des is the expected acceleration of the vehicle; C D is the aerodynamic drag coefficient; A is the vehicle's forward area, i.e., the projected area of ​​the vehicle in the direction of travel; ρ is the air density; is the longitudinal velocity of the vehicle; β is the wind speed; g is the acceleration of gravity; f is the rolling resistance coefficient; K b It is the ratio of braking force to brake pressure.

[0043] The advantage of the present invention is that it establishes a heterogeneous vehicle cooperative formation control method and system based on elastic safety domain, divides the distance between vehicles in the formation into three safety distance domains, and can improve road traffic capacity, improve traffic efficiency and reduce fuel consumption while ensuring vehicle driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1: Vehicle platoon control system diagram according to an embodiment of the present invention;

[0045] Figure 2 : Flowchart of the vehicle platoon control method according to an embodiment of the present invention;

[0046] Figure 3 : Flexible security domain model diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] In specific implementation, the method proposed in the technical solution of the present invention can be automatically run by those skilled in the art using computer software technology. System devices that implement the method, such as computer-readable storage media that store the corresponding computer program of the technical solution of the present invention and computer equipment that runs the corresponding computer program, should also be within the scope of protection of the present invention.

[0049] The following combination Figure 1-3 The specific embodiments of the present invention are introduced.

[0050] like Figure 1 As shown, an embodiment of the system of the present invention is a vehicle heterogeneous cooperative platoon control system based on elastic safety domain, specifically including:

[0051] Data processor, position sensor, lidar sensor, speed sensor, acceleration sensor, wind speed sensor, vehicle execution module, wireless communication module, central processing unit;

[0052] The data processor model is i9-12900H;

[0053] The position sensor model is SDM15;

[0054] The laser radar sensor model is Sagitar 1615;

[0055] The speed sensor model is Bosch LSR2.1;

[0056] The acceleration sensor model is FXLS8974CF;

[0057] The wind speed sensor model is Gill Instruments WindSonic 2D;

[0058] The vehicle execution module model is Songling Ranger MINI2.0;

[0059] The wireless communication module model is TL-WDR7651;

[0060] The central processing unit model is NVIDIA DRIVE AGX Xavier;

[0061] The data processor is connected to the position sensor, lidar sensor, speed sensor, acceleration sensor, wind speed sensor, vehicle actuator, and wireless communication device in sequence through wired means; the wireless communication device is connected to the central processing unit through wireless means;

[0062] The data processor is installed in the vehicle cabin, the position sensor is installed on the top of the vehicle cockpit, the lidar sensor is installed on the front of the vehicle, the speed sensor is installed in the wheel of the vehicle, the wind speed sensor is installed on the front of the vehicle, the acceleration sensor is installed on the front of the vehicle, the wireless communication module is installed on the roof, and the vehicle execution module includes the vehicle brake pedal pressure and throttle opening;

[0063] The laser radar sensor is used to collect the distance between the vehicle and the preceding vehicle in real time, and transmit the collected distance between the vehicle and the preceding vehicle in real time to the data processor;

[0064] The speed sensor is used to collect the vehicle speed in real time and transmit the collected vehicle speed in real time to the data processor;

[0065] The acceleration sensor is used to collect vehicle acceleration in real time and transmit the collected vehicle acceleration in real time to the data processor;

[0066] The wind speed sensor is used to collect the vehicle wind speed in real time and transmit the collected vehicle wind speed in real time to the data processor;

[0067] The data processor wirelessly transmits the real-time collected distance between the vehicle and the preceding vehicle, the vehicle speed, the vehicle acceleration, and the vehicle wind speed to the central processing unit via the wireless communication module;

[0068] The central processing unit obtains the desired acceleration of the vehicle based on the distance between the vehicle and the preceding vehicle, the vehicle speed, the vehicle acceleration, and the vehicle wind speed collected in real time through the vehicle heterogeneous cooperative platooning control method, wirelessly transmits the desired acceleration of the vehicle to the wireless communication module, and wirelessly transmits the desired acceleration to the data processor via the wireless communication module; the data processor converts the desired acceleration into a throttle opening or brake pressure, and transmits the throttle opening or brake pressure signal to the vehicle execution unit;

[0069] The vehicle execution module controls the vehicle throttle opening and brake pressure through an execution mechanism.

[0070] like Figure 2 As shown, the technical solution of the method of the present invention is a vehicle heterogeneous cooperative formation control method in a flexible safety domain, comprising the following steps:

[0071] Step 1: Each vehicle in the platoon is considered a single vehicle node. Vehicle nodes communicate wirelessly with each other to obtain information about other vehicle nodes in the platoon and share information about their own vehicle nodes. Vehicles in the platoon are numbered and the information obtained in the platoon is transmitted to the central processing unit through the data processor.

[0072] Based on step 1, the vehicle node information includes determining the number of vehicles, vehicle types and other information in the heterogeneous vehicle cooperative formation and obtaining the kinematic and dynamic information of the vehicles in the formation.

[0073] Determining the number of vehicles in the heterogeneous vehicle cooperative formation is to count the number of vehicles in the current vehicle formation. During the movement and control of the vehicle formation, no external vehicles are inserted or vehicles in the formation are separated. The number of vehicles is represented by N=3.

[0074] The method of determining the vehicle types in the heterogeneous vehicle cooperative formation is to classify the vehicles in the heterogeneous vehicle formation into two types: C and T, where type C represents cars and type T represents large trucks.

[0075] The vehicles are numbered according to the vehicle type and the order of the vehicle formation. For example, if the lead vehicle is a large truck, it is numbered T0, the first following vehicle is a car, it is numbered C1, and the second following vehicle is a large truck, it is numbered T2.

[0076] The acquisition of vehicle kinematic information includes acquiring vehicle position, velocity, acceleration and other information, wherein position is represented by X and velocity is represented by Expressed as acceleration The subscripts represent the position and type of the vehicle in the formation. For example, represents the speed of the i-th following car.

[0077] The acquisition of vehicle dynamics information includes acquiring vehicle mass, vehicle engine coefficient, throttle opening, brake pedal pressure and other information.

[0078] Step 2: The central processing unit determines the elastic safety domain of the vehicle based on the position, speed, and acceleration information of the vehicle in the vehicle formation transmitted by the data processor;

[0079] Based on step 2, the elastic safety domain of the vehicle distance includes an emergency safety distance domain, a comfortable safety distance domain and a dangerous safety distance domain, such as Figure 3 As shown in the figure. The emergency safety distance area is the maximum braking distance to prevent the vehicle from colliding with the vehicle in front, and this area is represented by 0 < X < d1; the comfortable safety distance area is the comfortable distance where the vehicle will not collide and the vehicle spacing is in a suitable position without changing the current motion state, and this area is represented by d1 < X ≤ d2; the loose safety distance is that the vehicle does not collide with the vehicle in front, but due to the excessive vehicle spacing, it is not conducive to improving the road traffic efficiency, and this area is represented by X > d2;

[0080] Based on Step 2, the formula for the emergency safety area is:

[0081]

[0082] where d1 is the critical point between the emergency safety area and the comfortable safety area, is the speed of vehicle i, is the speed of vehicle i - 1, t i is the braking system response time of vehicle i, is the maximum braking acceleration of vehicle i, and L is the minimum vehicle distance maintained between vehicle i and the vehicle in front after stopping.

[0083] Based on Step 2, the formula for the comfortable safety area is:

[0084]

[0085] where d2 is the critical point between the comfortable safety area and the loose safety area, is the speed of vehicle i, is the speed of vehicle i - 1, t i is the braking system response time of vehicle i, is the maximum braking acceleration of vehicle i,<00XX231>is the maximum braking acceleration of vehicle i - 1, and L is the minimum vehicle distance maintained between vehicle i and the vehicle in front after stopping.

[0086] Step 3: Compare the actual distance between vehicles obtained by the vehicle node through the central processing unit with the vehicle safety distance area, determine the actual safety distance area where the vehicle and the vehicle in front are located, and according to the actual safety distance area where the vehicle is located, determine the control strategy that the vehicle needs to take, and obtain the desired acceleration of the vehicle;

[0087] Based on Step 3, when the vehicle is in different safety areas, the calculation model of the desired acceleration of the vehicle is different. In the emergency safety area, the vehicle should brake as fast as possible to ensure the safety of the vehicle formation; in the comfortable safety area, the vehicle speed is at the desired speed and no control is required; in the loose safety area, the vehicle should accelerate to improve the road traffic efficiency. The calculation method of the desired acceleration of the vehicle is as follows:

[0088]

[0089] Where, represents the expected acceleration of vehicle i at time t+T; represents the maximum braking acceleration of vehicle i; represents the acceleration of vehicle i at time t; F(X) represents the expected acceleration function of vehicle i.

[0090] Based on step 3, F(X) is the expected acceleration of the vehicle in the relaxed safety domain. The expected acceleration is calculated as follows:

[0091]

[0092] Where, is the expected acceleration of vehicle i at time t+T, X i (t) represents the position of vehicle i at time t, X i-1 (t) represents the position of vehicle i-1 at time t, p is the length of vehicle i-1, τ is the headway of vehicle i, is the speed of vehicle i at time t, is the speed of vehicle i-1 at time t.

[0093] Step 4: Perform vehicle dynamics control based on the calculated desired vehicle acceleration.

[0094] The step 4 is specifically as follows:

[0095] The system transmits information detected by the radar to the central processing unit, which processes and calculates the vehicle's expected acceleration and outputs it to the vehicle control system. The vehicle control system converts the expected acceleration into throttle opening and brake pressure through the engine model. The vehicle execution unit adjusts the brake actuator by outputting the throttle opening acceleration and brake pressure values. The expected brake pressure is derived from the expected acceleration as follows:

[0096]

[0097] Where: P des is the expected braking pressure of the vehicle; m is the vehicle mass; a des is the expected acceleration of the vehicle; C D is the aerodynamic drag coefficient; A is the vehicle's forward area, i.e., the projected area of ​​the vehicle in the direction of travel; ρ is the air density; is the longitudinal velocity of the vehicle; β is the wind speed; g is the acceleration of gravity; f is the rolling resistance coefficient; K b It is the ratio of braking force to brake pressure.

[0098] Vehicle platoon control process is as follows Figure 3 shown.

[0099] It should be understood that parts not elaborated in detail in this specification belong to the prior art.

[0100] It should be understood that the above description of the embodiments is relatively detailed and cannot be regarded as limiting the scope of protection of the patent of the present invention. Under the guidance of the present invention, ordinary technicians in this field can also make substitutions or modifications without departing from the scope of protection of the claims of the present invention, which all fall within the scope of protection of the present invention. The scope of protection requested by the present invention shall be based on the attached claims.

Claims

1. A vehicle heterogeneous cooperative platoon control method in a flexible safety domain, characterized by: The steps include: Step 1: Each vehicle in the platoon is considered a single vehicle node. Vehicle nodes communicate wirelessly with each other to obtain information about other vehicle nodes in the platoon and share information about their own vehicle nodes. Vehicles in the platoon are numbered and the information obtained in the platoon is transmitted to the central processing unit through the data processor. Step 2: The central processing unit determines the elastic safety domain of the vehicle based on the position, speed, and acceleration information of the vehicle in the vehicle formation transmitted by the data processor; Step 3: The actual distance between vehicles, obtained by the vehicle node through the central processing unit, is compared with the vehicle safety distance domain to determine the actual safety distance domain between the vehicle and the preceding vehicle. Based on the actual safety distance domain, the control strategy to be adopted by the vehicle is determined to obtain the expected acceleration of the vehicle. When the vehicle is in different safety distance domains, the expected acceleration calculation model of the vehicle is different. In the emergency safety distance, vehicles should brake as quickly as possible to ensure the safety of the platoon. In the comfortable safety distance, vehicles maintain their desired speed and do not need to be controlled. In the relaxed safety distance, vehicles should accelerate to improve road traffic efficiency. The expected acceleration of the vehicle is calculated as follows: Where, represents the expected acceleration of vehicle i at time t+T; represents the maximum braking acceleration of vehicle i; represents the acceleration of vehicle i at time t; F(X) represents the expected acceleration function of vehicle i; d1 is the critical point between the emergency safety domain and the comfort safety domain; d2 is the critical point between the comfort safety domain and the relaxed safety domain; Step 4: Perform vehicle dynamics control based on the calculated desired vehicle acceleration.

2. The method for controlling heterogeneous vehicle cooperative platooning in a flexible safety domain according to claim 1 is characterized by: The vehicle node information in step 1 includes determining the number of vehicles in the heterogeneous vehicle cooperative formation, vehicle type information, and obtaining the kinematic and dynamic information of the vehicles in the formation; Determining the number of vehicles in the heterogeneous vehicle cooperative formation is to count the number of vehicles in the current vehicle formation. During the movement and control of the vehicle formation, there is no situation where external vehicles are inserted or vehicles in the current formation leave the formation. The number of vehicles is represented by N, where N ≥ 2, that is, there are at least two vehicles in the vehicle formation, a leading vehicle and a following vehicle.

3. The method for controlling heterogeneous vehicle cooperative platooning in a flexible safety domain according to claim 2 is characterized by: Determining the vehicle types in the heterogeneous vehicle cooperative formation is to classify the vehicles in the heterogeneous vehicle formation into two types: C and T, where type C represents cars and type T represents large trucks; Numbering the vehicles according to the vehicle type and the order of the vehicle formation; The lead car is a car, numbered C0, the first following car is a large truck, numbered T1, the second following car is a car, numbered C2, the i-th following car is a large truck, numbered Ti, and so on; The acquisition of vehicle kinematic information includes acquiring vehicle position, velocity and acceleration information, where position is represented by X and velocity is represented by Expressed as acceleration Indicates; the subscript indicates the position and type of the vehicle in the formation; represents the speed of the i-th following car; The obtaining of vehicle dynamics information includes obtaining vehicle mass, vehicle engine coefficient, throttle opening, and brake pedal pressure information.

4. The method for controlling heterogeneous vehicle cooperative platooning in a flexible safety domain according to claim 3 is characterized by: The elastic safety domain of the vehicle distance described in step 2 includes an emergency safety distance domain, a comfortable safety distance domain, and a loose safety distance domain; The emergency safety distance domain is the maximum braking distance to prevent the vehicle from colliding with the vehicle in front, and this area is represented by 0 < X < d1; the comfortable safety distance domain is the comfortable distance where the vehicle will not collide and the vehicle distance is in a suitable position without changing the current motion state, and this area is represented by d1 < X ≤ d2; the loose safety distance domain means that the vehicle does not collide with the vehicle in front, but due to the excessive vehicle distance, it is not conducive to improving the road traffic efficiency, and this area is represented by X > d2.

5. The vehicle heterogeneous cooperative formation control method for the elastic safety domain according to claim 4, wherein: The formula for the emergency safety distance domain described in step 2 is: in, is the speed of vehicle i, is the speed of vehicle i-1, t i is the braking system response time of vehicle i, is the maximum braking acceleration of vehicle i, and L is the minimum distance between vehicle i and the vehicle in front after it stops.

6. The vehicle heterogeneous cooperative formation control method for the elastic safety domain according to claim 5, wherein: The formula for the comfortable safety distance domain described in step 2 is: in, is the speed of vehicle i, is the speed of vehicle i-1, t i is the braking system response time of vehicle i, is the maximum braking acceleration of vehicle i, is the maximum braking acceleration of vehicle i-1, and L is the minimum distance between vehicle i and the vehicle in front after it stops.

7. The vehicle heterogeneous cooperative formation control method for the elastic safety domain according to claim 1, wherein: F(X) in step 3 is the expected acceleration of the vehicle in the loose safety domain, and the formula for the expected acceleration is as follows: Where, is the expected acceleration of vehicle i at time t+T, X i (t) represents the position of vehicle i at time t, X i-1 (t) represents the position of vehicle i-1 at time t, p is the length of vehicle i-1, τ is the headway of vehicle i, is the speed of vehicle i at time t, is the speed of vehicle i-1 at time t.

8. The vehicle heterogeneous cooperative formation control method for the elastic safety domain according to claim 7, wherein: The specific steps of step 4 are as follows: The system transmits the information detected by the radar to the central processing unit, processes and calculates the expected acceleration of the vehicle and outputs it to the vehicle control system. The vehicle control system converts it into throttle opening and brake pressure through the engine model, and the vehicle execution unit adjusts the brake actuator by outputting the throttle opening acceleration and brake pressure value; the expected brake pressure is derived from the expected acceleration as: Where: P des is the expected braking pressure of the vehicle; m is the vehicle mass; a des is the expected acceleration of the vehicle; C D is the aerodynamic drag coefficient; A is the vehicle's forward area, i.e., the projected area of ​​the vehicle in the direction of travel; ρ is the air density; is the longitudinal velocity of the vehicle; β is the wind speed; g is the acceleration of gravity; f is the rolling resistance coefficient; K b It is the ratio of braking force to brake pressure.

9. A vehicle heterogeneous cooperative platoon control system based on elastic safety domain, characterized in that: The vehicle heterogeneous cooperative formation control system based on the elastic safety domain is used to execute the steps in the vehicle heterogeneous cooperative formation control method based on the elastic safety domain according to any one of claims 1-8, including: A data processor, a position sensor, a lidar sensor, a speed sensor, an acceleration sensor, a wind speed sensor, a vehicle execution module, a wireless communication module, and a central processing unit; The data processor is sequentially connected to the position sensor, lidar sensor, speed sensor, acceleration sensor, wind speed sensor, vehicle execution device, and wireless communication device in a wired manner; the wireless communication device is connected to the central processing unit in a wireless manner; The data processor is installed in the vehicle cockpit, the position sensor is installed in the vehicle chassis, the lidar sensor is installed at the front of the vehicle, the speed sensor is installed inside the vehicle wheels, the wind speed sensor is installed at the front of the vehicle, the acceleration sensor is installed at the front of the vehicle, the wireless communication module is installed on the roof of the vehicle, and the vehicle execution module includes vehicle brake pedal pressure and throttle opening; The lidar sensor is used to collect the distance between the vehicle and the vehicle in front in real time and transmit the collected distance between the vehicle and the vehicle in front to the data processor; The speed sensor is used to collect the vehicle speed in real time and transmit the collected vehicle speed in real time to the data processor; The acceleration sensor is used to collect vehicle acceleration in real time and transmit the collected vehicle acceleration in real time to the data processor; The wind speed sensor is used to collect the vehicle wind speed in real time and transmit the collected vehicle wind speed in real time to the data processor; The data processor wirelessly transmits the real-time collected distance between the vehicle and the preceding vehicle, the vehicle speed, the vehicle acceleration, and the vehicle wind speed to the central processing unit via the wireless communication module; The central processing unit obtains the desired acceleration of the vehicle based on the distance between the vehicle and the preceding vehicle, the vehicle speed, the vehicle acceleration, and the vehicle wind speed collected in real time through the vehicle heterogeneous cooperative platooning control method, wirelessly transmits the desired acceleration of the vehicle to the wireless communication module, and wirelessly transmits the desired acceleration to the data processor via the wireless communication module; the data processor converts the desired acceleration into a throttle opening or brake pressure, and transmits the throttle opening or brake pressure signal to the vehicle execution unit; The vehicle execution module controls the vehicle throttle opening and brake pressure through an execution mechanism.

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