A vehicle-to-everything (V2X) synchronous control system and method based on virtual coupling

Abstract

This invention discloses a vehicle-to-everything (V2X) synchronization control system and method based on virtual coupling, including synchronization control units respectively located at the front and rear of the vehicle. Each synchronization control unit includes an electronic communication unit, a central control unit, and a virtual coupling control unit. The virtual coupling control unit includes a vehicle tracking distance monitoring module, a relative braking tracking model calculation module, and a safety protection module. The vehicle tracking distance monitoring module is used to acquire the speed of the virtual coupled vehicles and the distance between the vehicles in front and behind in real time. The relative braking tracking model calculation module is used to calculate the speed difference and relative braking distance between the master vehicle and the slave vehicle in real time. The safety protection module is used to control the vehicle's operating status under different operating conditions in real time based on the speed difference and relative braking distance between the master vehicle and the slave vehicle, so as to ensure that the virtual coupled slave vehicle can brake to a stop without collision when the master vehicle applies emergency braking under the most unfavorable conditions.

Description

Technical Field

[0001] This invention relates to the field of virtual coupling technology for rail vehicles, and in particular to a vehicle networking synchronization control system and method based on virtual coupling. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Currently, the headway of urban rail transit is approximately 6-9 minutes. However, due to the large passenger flow during morning and evening rush hours, a 6-minute headway is clearly insufficient to meet the demand. To further increase the passenger capacity of rail vehicles, some cities adopt double-unit train formations. Existing double-unit train formations generally consist of two small trains physically coupled together in a depot. However, the coupling process is limited by factors such as the physical wear and tear on the car body caused by the coupler, the length of the track, and the physical characteristics of the car itself. This limits the number of cars that can be coupled together, and it also requires the participation of dispatchers, drivers, and trackside personnel. It is evident that this formation method is complex, time-consuming, and leads to low passenger efficiency.

[0004] On the other hand, the number of passengers at each station along the subway line varies. Stations in the city center have a larger passenger flow, while those in the suburbs have a smaller passenger flow. If fixed double-unit trains are used, some passengers will still have to wait a long time to board, resulting in a decline in service quality.

[0005] While existing technologies disclose the use of virtual coupling technology to achieve virtual coupling between two vehicles, communication between the two vehicles in virtual coupling relies on the ground signal system, which cannot guarantee the real-time performance and reliability of the communication. In addition, as the speed of rail vehicles continues to increase, the braking distance between the two vehicles becomes longer and the tracking interval becomes larger, which affects the further improvement of transportation efficiency. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a vehicle-to-everything (V2X) synchronous control system and method based on virtual coupling. This system utilizes wireless communication technology to enable vehicles to be grouped and operated in a manner equivalent to physical couplers, breaking the limitations of traditional physical mechanical couplers.

[0007] According to a first aspect of the present invention, a vehicle-to-everything (V2X) synchronization control system based on virtual coupling is provided, comprising synchronization control units respectively disposed at the front and rear of the vehicle, the synchronization control units comprising:

[0008] An electronic communication unit is used to enable data communication between virtual trailer vehicles via wireless communication.

[0009] The central control unit is used to transmit control commands at the rail vehicle level, detect vehicle operating status, and diagnose faults.

[0010] A virtual coupling control unit is used to realize virtual coupling control of vehicles; the virtual coupling control unit includes a vehicle tracking distance monitoring module, a relative braking tracking model calculation module, and a safety protection module;

[0011] The vehicle tracking distance monitoring module is used to obtain the speed of the virtual coupled vehicles and the distance information between the vehicles in front and behind in real time.

[0012] The relative braking tracking model calculation module is used to calculate the speed difference and relative braking distance between the master vehicle and the slave vehicle in real time.

[0013] The safety protection module is used to control the vehicle's operating status in real time under different operating conditions based on the speed difference and relative braking distance between the master vehicle and the slave vehicle, so as to ensure that the virtual coupled slave vehicle can brake to a stop without collision when the master vehicle applies emergency braking to a stop under the most unfavorable conditions.

[0014] When the speed difference between the master vehicle and the slave vehicle exceeds the preset protection value, the safety protection module controls the operating status of the slave vehicle according to its operating conditions: when the slave vehicle is in traction mode, it controls the slave vehicle to block traction; when the slave vehicle is in braking mode, it controls the slave vehicle to apply the maximum service braking.

[0015] When the distance between the master vehicle and the slave vehicle is less than the relative braking distance, the safety protection module outputs a hard-wired command. The hard-wired command is inserted into the vehicle's emergency loop to control the slave vehicle to actively apply emergency braking.

[0016] According to a second aspect of the present invention, a rail vehicle is provided, including the above-described vehicle-to-everything (V2X) synchronization control system based on virtual coupling.

[0017] According to a third aspect of the present invention, a vehicle-to-everything (V2X) synchronization control method based on virtual coupling is provided, comprising:

[0018] The master control vehicle and the slave control vehicle respectively receive the virtual coupling control command and establish a communication connection through wireless addressing communication.

[0019] Adjust the distance between the master vehicle and the slave vehicle to the initial relative braking distance, and control the vehicle to enter the virtual coupling mode;

[0020] For the main control vehicle, after being pulled forward to the desired speed, it is pulled at a constant speed to the parking area, and then the brakes are applied until it comes to a stop;

[0021] For the slave vehicle, the speed difference and relative braking distance between it and the master vehicle are obtained in real time. At the same time, it responds to the braking command of the master vehicle and controls the operation state of the slave vehicle based on the current operating conditions of the slave vehicle. This ensures that the slave vehicle can stop without collision when the master vehicle applies emergency braking to stop under the most unfavorable conditions.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] (1) This invention does not rely on the ground signal system. It builds a virtual coupling synchronization control system with the vehicle network system as the core to realize the conversion of the virtual coupling mode of the train, the virtual coupling operation and the safety protection of the vehicle. At the same time, it proposes an IP conversion rule for cross-vehicle communication when two single-unit trains are virtually coupled to realize the interconnection between any vehicles.

[0024] (2) The vehicle network synchronous control system based on virtual coupling of the present invention can realize the identification and establishment of virtual coupling working conditions of vehicles, can realize the conversion between the hard-wired circuit control system of any vehicle and the virtual coupling system, and can realize the flexible conversion between single-group vehicles and virtual groups in any operating mode (manual driving / CBTC / FAO).

[0025] (3) The present invention controls the relative interval between the master vehicle and the slave vehicle based on the relative braking distance, so as to ensure that the slave vehicle can brake and stop in time without collision under any working conditions.

[0026] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the vehicle-to-everything (V2X) synchronous control system based on virtual coupling in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of wireless addressing communication for virtual vehicle-to-vehicle coupling in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the security protection triggering structure in an embodiment of the present invention;

[0030] Figure 4 This is a flowchart of the vehicle network synchronization control method based on virtual coupling in an embodiment of the present invention. Detailed Implementation

[0031] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0033] Example 1

[0034] In one or more embodiments, a vehicle-to-everything (V2X) synchronization control system based on virtual coupling is disclosed, combined with... Figure 1 Specifically, this includes synchronization control units located at the front and rear of the vehicle, each of which includes:

[0035] (1) Electronic Communication Unit (ECN) is used to realize data communication between virtual trailer vehicles through wireless communication;

[0036] This embodiment uses wireless communication technology to enable rail vehicles to be grouped and operated in a manner equivalent to physical couplers. The equipment adopts cross-vehicle communication IP conversion rules to realize automatic connection between virtual coupled vehicles, ensuring rapid connection and data transmission without human intervention.

[0037] The specific rules for cross-vehicle communication IP conversion are as follows: Figure 2 As shown, before entering virtual coupling mode, vehicles need to exchange their status information via the wireless transmission unit to identify whether they meet the conditions for entering virtual coupling mode. To enable communication between any two trains of vehicles after virtual coupling, the wireless transmission unit uses wireless addressing communication to achieve data exchange between the virtual coupled vehicles. The wireless addressing code is as follows:

[0038] 00001010.10000000.ddddhhhh.ssssssss / 24

[0039] Where s represents the marshalling network ID, h represents the local identifier, and s represents the host identifier.

[0040] The first byte: 00001010, is fixed at 10;

[0041] The second byte: 10000000, is fixed at 128;

[0042] The first 4 bits of the third byte represent the network ID of the device, and the last 4 bits represent the local identifier of the device: that is, the physical location of the device that needs to communicate can be identified through the third byte.

[0043] The fourth byte represents the device host identifier, which is the IP address configured on the device itself that needs to be accessed.

[0044] Figure 2 Based on the actual network configuration of two vehicles on a certain route, the method of vehicle-to-vehicle communication data exchange through the Electronic Communication Unit (ECN) is presented to complete vehicle status exchange and provide information for entering the virtual coupling mode.

[0045] To ensure ease of vehicle maintenance, the IP address of the virtual coupling control unit for each rail vehicle remains consistent, for example... Figure 2 The vehicle-level IP addresses are all 10.1.1 / 4.5. When two vehicles receive a virtual coupling command from the operations control center, which includes the train number of the vehicle to be coupled, the virtual coupling control unit receives the command and establishes a connection through the electronic communication unit (ECN). To avoid conflicts caused by identical IP addresses, the IP addresses of the virtual coupling control units of the two vehicles are converted into two different global IP addresses according to the aforementioned wireless addressing rules. One is the T2T end-to-end communication IP address, and the other is the TG2GT public network communication IP address. For example... Figure 2 The addresses 10.128.65 / 68.5 and 10.128.129 / 132.5 are used for train-level data transmission and reception. The destination IP address is the global IP address, and W-NAT translation is completed through the wireless communication system, thereby realizing the automatic interaction of train-level data between the two train sets.

[0046] (2) Central control unit (CCU) is used to realize the transmission of control commands, detection of train status and fault diagnosis.

[0047] (3) Virtual coupling control unit (VCU) is used to realize the virtual coupling control of the vehicle; it can switch from hard-wired circuit control mode to virtual coupling synchronous control mode, and uses the TRDP protocol Ethernet communication method to access the vehicle network.

[0048] In this embodiment, the virtual coupling control unit includes a vehicle tracking distance monitoring module (TDOM), a relative braking tracking model calculation module (RBOM), and a safety protection module.

[0049] Among them, the vehicle tracking distance monitoring module is used to obtain the speed of the virtual trailer vehicles and the distance information between the vehicles in front and behind in real time;

[0050] The relative braking tracking model calculation module is used to calculate the speed difference and relative braking distance between the master vehicle and the slave vehicle in real time;

[0051] In this embodiment, the formula for calculating the relative braking distance is as follows:

[0052] S rd =K bf (V f (t) 2 -V0 2 )-K bl (V l (t) 2 -V0 2 )+V f (t)*t de +(d0)

[0053] Among them, V f (t) represents the real-time speed of the virtual coupled slave vehicle at time t; V l (t) represents the real-time speed of the virtual coupled master vehicle at time t; K bf For the virtual coupling slave vehicle braking coefficient; K bl The braking coefficient of the virtual coupled master vehicle; V0 is the initial speed of the vehicle when a traction or braking command is applied; t de d0 represents the communication delay time between the vehicle and the controller, and d0 represents the safety margin.

[0054] The safety protection module is used to control the vehicle's operating status in real time under different operating conditions based on the speed difference and relative braking distance between the master vehicle and the slave vehicle, so as to ensure that the virtual coupled slave vehicle can brake to a stop without collision when the master vehicle applies emergency braking to a stop under the most unfavorable conditions.

[0055] Specifically, when the speed difference between the master vehicle and the slave vehicle exceeds the preset protection value, the operating status of the slave vehicle is controlled according to its operating conditions: when the slave vehicle is in traction mode, the slave vehicle is controlled to block traction; when the slave vehicle is in braking mode, the slave vehicle is controlled to apply maximum service braking; when the speed difference is restored, the coordinated control is re-entered.

[0056] When the distance between the master vehicle and the slave vehicle is less than the relative braking distance, a hard-wire command is output to control the slave vehicle to actively apply emergency braking.

[0057] As an optional implementation, when the slave vehicle applies braking force, its expected traction braking force can be adaptively determined based on the actual traction braking force of the master vehicle; specifically:

[0058] F 后 =K*F 前 +R

[0059] Among them, F后 To output the desired traction and braking force from the vehicle control, F 前 K represents the actual value of the main control vehicle's traction braking force; K represents the reward / penalty multiplier; and R represents the vehicle's basic resistance.

[0060] The basic resistance R of a vehicle can be calculated based on the vehicle weight, trailer weight, number of vehicles, and vehicle speed.

[0061] The adaptive coefficient K is calculated using the following formula:

[0062]

[0063] Where λ is the adaptive coefficient during traction, ξ1 and ξ2 are the adaptive coefficients during braking, and V l (t) represents the real-time speed of the virtual coupled main control vehicle at time t, V f (t) represents the real-time speed of the virtual coupled slave vehicle at time t, V0 is the initial speed, and S t Indicates that the vehicle is in the traction phase, S i Indicates the vehicle is in the cruise phase, S b This indicates that the vehicle is in the braking phase; a f This represents the real-time acceleration of the slave vehicle before the virtual coupling at time t.

[0064] When adaptively determining the desired value of the vehicle's traction braking force as described above, the following must always be satisfied:

[0065] Under adaptive control t, the actual distance between the two vehicles is greater than the safe distance; the longitudinal impact of the vehicles is less than 0.75 m / s². 3 To ensure passenger comfort.

[0066] In this embodiment, the security protection module is equipped with a security protection trigger circuit, the specific structure of which is as follows: Figure 3 As shown, the safety protection module has a virtual linkage safety protection function. Switches EB1 and EB2 are connected in parallel to the coil of safety relay K01. The normally open contact of safety relay K01 is connected in series to the vehicle emergency braking loop. Other switches are also connected in series in the vehicle emergency braking loop, such as: driver's cab activation switch (closed when the driver's cab is activated, otherwise open), main air pressure switch (closed when the main air pressure is normal, otherwise open), emergency brake button switch (open when the emergency brake button is pressed, otherwise closed), etc.

[0067] In this embodiment, switches EB1 and EB2 are controlled by the safety DO output of the safety protection module. When the speed difference between the master vehicle and the slave vehicle is detected to be greater than the protection preset value, or when the distance between the master vehicle and the slave vehicle is less than the relative braking distance, the control switches EB1 and EB2 are disconnected. To ensure safety, switches EB1 and EB2 are designed in parallel for redundancy. When one of them is disconnected, the relay K01 coil is de-energized, the vehicle emergency braking loop is disconnected, and the vehicle triggers emergency braking to avoid a collision.

[0068] When the system is powered on normally and the virtual coupling conditions are met, switches EB1 and EB2 are closed, the coil of safety relay K01 is energized, the normally open contact of safety relay K01 is closed, the vehicle emergency braking loop is established normally, the vehicle traction conditions are met, and the vehicle is traction normally. When the slave vehicle safety protection module detects that the actual distance between the two vehicles is less than the safe distance or the speed difference between the two vehicles is greater than the protection preset value, controls EB1 and EB2 are disconnected, the corresponding K01 contact is opened, the virtual coupling slave vehicle automatically triggers emergency braking to ensure vehicle operation safety.

[0069] This embodiment of the synchronous control system does not rely on the ground signal system. It builds a virtual coupling synchronous control system with the vehicle network system as the core to realize the conversion of the virtual coupling mode of the train, the virtual coupling operation, and the safety protection of the vehicle.

[0070] In other embodiments, a rail vehicle is also disclosed, which includes the aforementioned vehicle-to-everything (V2X) synchronization control system based on virtual coupling.

[0071] Example 2

[0072] In one or more embodiments, a vehicle-to-everything (V2X) synchronization control method based on virtual coupling is disclosed, combining... Figure 4 Specifically, it includes the following processes:

[0073] The master control vehicle and the slave control vehicle respectively receive the virtual coupling control command and establish a communication connection through wireless communication.

[0074] Adjust the distance between the master vehicle and the slave vehicle to the initial relative braking distance, and control the vehicle to enter the virtual coupling mode;

[0075] For the main control vehicle, after being pulled forward to the desired speed, it is pulled at a constant speed to the parking area, and then the brakes are applied until it comes to a stop;

[0076] For the slave vehicle, the speed difference and relative braking distance between it and the master vehicle are obtained in real time. At the same time, it responds to the braking command of the master vehicle and controls the operation state of the slave vehicle based on the current operating conditions of the slave vehicle. This ensures that the slave vehicle can stop without collision when the master vehicle applies emergency braking to stop under the most unfavorable conditions.

[0077] When the speed difference between the slave vehicle and the master vehicle is greater than the protection preset value, if the slave vehicle is in traction mode, the slave vehicle will be controlled to block traction; if the slave vehicle is in braking mode, the slave vehicle will be controlled to apply the maximum service braking.

[0078] When the distance between the slave vehicle and the master vehicle is less than the relative braking distance, the slave vehicle is controlled to actively apply emergency braking.

[0079] The relative braking distance between the controlled vehicle and the master vehicle is obtained in real time, specifically:

[0080] S rd =K bf (V f (t) 2 -V0 2 )-K bl (V l (t) 2 -V0 2 )+V f (t)*t de +(d0)

[0081] Among them, V f (t) represents the real-time speed of the vehicle at time t; V l (t) represents the real-time speed of the main control vehicle at time t; K bf K is the braking coefficient of the vehicle. bl The main control vehicle braking coefficient; V0 is the initial speed of the vehicle; t de d0 represents the communication delay time between the vehicle and the controller, and d0 represents the safety margin.

[0082] The above method is based on the synchronous control system described in Example 1, and the specific implementation process will not be repeated here.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A vehicle-to-everything (V2X) synchronous control system based on virtual coupling, characterized in that, This includes synchronization control units located at the front and rear of the vehicle, respectively. The synchronization control units include: An electronic communication unit is used to realize data communication between virtual coupled vehicles through wireless addressing communication. The wireless addressing communication method is as follows: the IP address of the virtual coupled control unit of each rail vehicle is consistent. When two vehicles receive a virtual coupled command, they change their own virtual coupled control unit IP address to the global IP address. Based on the global IP address, automatic interaction of train-level data between the two trains is realized. The global IP address includes at least the train network ID of the vehicle and the vehicle's local identifier. The central control unit is used to transmit control commands at the rail vehicle level, detect vehicle operating status, and diagnose faults. A virtual coupling control unit is used to realize virtual coupling control of vehicles; the virtual coupling control unit includes a vehicle tracking distance monitoring module, a relative braking tracking model calculation module, and a safety protection module; The vehicle tracking distance monitoring module is used to obtain the speed of the virtual coupled vehicles and the distance information between the two vehicles in front and behind in real time. The relative braking tracking model calculation module is used to calculate the speed difference and relative braking distance between the master vehicle and the slave vehicle in real time. The safety protection module is used to control the vehicle's operating status in real time under different operating conditions based on the speed difference and relative braking distance between the master vehicle and the slave vehicle, so as to ensure that the virtual coupled slave vehicle can brake to a stop without collision when the master vehicle applies emergency braking to a stop under the most unfavorable conditions.

2. The vehicle networking synchronous control system based on virtual coupling as described in claim 1, characterized in that, When the speed difference between the master vehicle and the slave vehicle exceeds the preset protection value, the safety protection module controls the operating status of the slave vehicle according to its operating conditions: when the slave vehicle is in traction mode, it controls the slave vehicle to block traction; when the slave vehicle is in braking mode, it controls the slave vehicle to apply the maximum service braking.

3. A vehicle-to-everything (V2X) synchronous control system based on virtual coupling as described in claim 1 or 2, characterized in that, When the distance between the master vehicle and the slave vehicle is less than the relative braking distance, the safety protection module controls the slave vehicle to actively apply emergency braking.

4. The vehicle networking synchronization control system based on virtual coupling as described in claim 3, characterized in that, The safety protection module includes a safety protection trigger circuit, which comprises: switches EB1 and EB2 connected in parallel to the coil of safety relay K01; the normally open contact of safety relay K01 connected in series to the vehicle emergency braking loop; the vehicle emergency braking loop is composed of at least the normally open contact of safety relay K01, a driver's cab activation switch, a main air pressure switch, and an emergency brake button switch connected in series; wherein, when the speed difference between the master vehicle and the slave vehicle is greater than the protection preset value, or when the distance between the master vehicle and the slave vehicle is less than the relative braking distance, switches EB1 and EB2 are disconnected, and the coil of relay K01 is de-energized; otherwise, switches EB1 and EB2 are closed, and the coil of relay K01 is energized.

5. A vehicle-to-everything (V2X) synchronous control system based on virtual coupling as described in claim 1, characterized in that, The relative braking tracking model calculation module calculates the relative braking distance, specifically as follows: in, V f (t) for t The vehicle's real-time speed is constantly monitored; V l (t) for t The real-time speed of the main control vehicle; K bf The braking coefficient of the controlled vehicle; K bl The braking coefficient of the main control vehicle; V 0 represents the vehicle's initial speed; For the delay time of the vehicle control communication, For safety margin.

6. A rail vehicle, characterized in that, Including the vehicle networking synchronous control system based on virtual coupling as described in any one of claims 1-5.

7. A vehicle-to-everything (V2X) synchronization control method based on virtual coupling, characterized in that, include: The master control vehicle and the slave control vehicle respectively receive the virtual coupling control command and establish a communication connection through wireless addressing communication. The wireless addressing communication method is specifically as follows: The virtual coupling control unit IP address of each rail vehicle remains consistent. When two vehicles receive a virtual coupling command, they change their own virtual coupling control unit IP address to the global IP address. When the virtual coupling control units of the two vehicles send and receive train-level data, the destination IP address is the global IP address, realizing automatic interaction of train-level data between the two trains. The global IP address includes at least the train network ID of the vehicle and the vehicle's local identifier. Adjust the distance between the master vehicle and the slave vehicle to the initial relative braking distance, and control the vehicle to enter the virtual coupling mode; For the main control vehicle, after being pulled forward to the desired speed, it is pulled at a constant speed to the parking area, and then the brakes are applied until it comes to a stop; For the slave vehicle, the speed difference and relative braking distance between it and the master vehicle are obtained in real time. At the same time, the slave vehicle responds to the braking command of the master vehicle and controls the operation status of the slave vehicle based on the current operating conditions of the slave vehicle. This allows the slave vehicle to stop without a collision when the master vehicle applies emergency braking under the most unfavorable conditions.

8. The vehicle network synchronization control method based on virtual coupling as described in claim 7, characterized in that, The real-time acquisition of the speed difference and relative braking distance between the slave vehicle and the master vehicle, while responding to the braking commands of the master vehicle, and controlling the operating state of the slave vehicle based on the current operating conditions of the slave vehicle, specifically includes: When the speed difference between the slave vehicle and the master vehicle is greater than the protection preset value, if the slave vehicle is in traction mode, the slave vehicle will be controlled to block traction; if the slave vehicle is in braking mode, the slave vehicle will be controlled to apply the maximum service braking. When the distance between the slave vehicle and the master vehicle is less than the relative braking distance, the slave vehicle is controlled to actively apply emergency braking.

9. The vehicle-to-everything (V2X) synchronization control method based on virtual coupling as described in claim 7, characterized in that, The relative braking distance between the controlled vehicle and the master vehicle is obtained in real time, specifically: in, V f (t) for t The vehicle's real-time speed is constantly monitored; V l (t) for t The real-time speed of the main control vehicle; K bf The braking coefficient of the controlled vehicle; K bl The braking coefficient of the main control vehicle; V 0 represents the vehicle's initial speed; For the delay time of the vehicle control communication, For safety margin.

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