A virtual marshalling train dynamic marshalling method suitable for rail transit

Abstract

The present application relates to a kind of virtual marshalling train dynamic marshalling method suitable for rail transit, belong to rail transit technical field.The train to be marshalled operates in CBTC mode;The train to be marshalled receives marshalling process start command;After the train to be marshalled judges to meet marshalling start condition, enter marshalling mode, in this mode, marshalling train controls driving speed according to relative speed, distance, acceleration;After the train to be marshalled judges driving distance and speed to meet requirement, consider that marshalling is completed, enter following mode.When it is necessary to be uncoupled, marshalling train enters uncoupling mode.In this mode, marshalling train adjusts driving distance and relative speed.After driving distance and speed meet uncoupling requirement, uncoupling is completed, and each train exits uncoupling mode and continues to operate in CBTC mode respectively.The present application can realize dynamic quick marshalling for various scenes.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of rail transit, and particularly relates to a dynamic marshalling method of a virtual marshalling train suitable for rail transit. BACKGROUND

[0002] Rail transit is an important part of the public transportation system in China. In recent years, rail transit has occupied a dominant position in the public transportation system due to its large capacity, high speed, high punctuality, high safety, and low unit transportation cost. In order to adapt to the rapid growth of domestic economy and social development, rail transit needs to further improve the overall transportation capacity and system flexibility by optimizing the signal system algorithm on the basis of the existing lines. The development of train-to-train communication technology and train-to-ground communication technology makes it possible to share state information between trains, thereby providing strong technical support for realizing dynamic cooperative marshalling operation of multiple trains, i.e., virtual marshalling VCS (Virtual Coupling System).

[0003] VCS technology has been explored in many aspects at home and abroad, and certain progress has been made. VCS technology has been listed by ERTMS / ETCS (European Railway Traffic Management System / European Train Control System) as one of the important research directions of train technology solutions (S2R, Shift2Rail) focusing on research and innovation and market-driven [1]. The existing research and simulation results have preliminarily proved the feasibility of the method. Among them, [2] introduces the basic concept and research direction of VCS, [3] gives the overall state transition diagram of VCS for marshalling and unmarshalling, and preliminarily discusses the train control logic of important nodes in the process, but lacks the calculation method of important operating parameters such as marshalling and unmarshalling speed and position; [4] proposes a calculation method of the minimum driving distance of VCS trains in the main line or turnout state, and gives a calculation method of the optimal solution marshalling position, but its train control logic is relatively simple; [5] calculates the improvement of transportation capacity by using VCS technology in multiple scenarios according to the existing new line vehicles and platform line infrastructure distribution, but does not discuss the specific implementation method of VCS.

[0004] In China, the research and development of VCS have also attracted widespread attention. Among them, the top research and development teams in the industry such as China Railway Signal & Communication Corporation Limited, Beijing Railway Communication Signal Research and Design Institute Group Co., Ltd., BYD Co., Ltd., and Beijing Jiaotong University have conducted in-depth research on this direction and proposed solutions.

[0005] Patent application CN 113928342, the invention name is a train operation method based on virtual marshalling, electronic equipment and storage medium. The invention puts forward a train operation scheme adjustment method based on VCS from the operation angle, realizes the optimization scheduling through the calculation of the travel cost objective function, and gives the equipment composition for realizing the scheme. But the invention does not involve the specific processing flow and calculation method of train marshalling and tracking operation.

[0006] Patent application CN 114407985, the invention name is a train tracking method and control system based on virtual marshalling. The invention puts forward the flow processing of VCS train tracking, and gives the processing method of the following train in different running states. But the invention content does not contain the overall solution of how to establish VCS, and does not contain the corresponding calculation model.

[0007] Patent application CN 114524005, the invention name is a method, device, system, vehicle and storage medium for vehicle marshalling. The invention discloses a flow for realizing vehicle marshalling in vehicle operation, and gives the device required for realizing the system. But the invention content does not involve the specific parameter calculation method for realizing marshalling.

[0008] Patent application CN 114834503, the invention name is a virtual marshalling train control method based on elastic tracking model. The invention designs a virtual marshalling train control method based on elastic tracking model, according to the dynamic change of the tracking interval between the front and rear trains in the marshalling, realizes the stable tracking between the marshalling trains by introducing virtual repulsive force and attractive force. But the design scheme lacks the overall solution of VCS establishment and unmarshalling, and the elastic model is quite different from the current vehicle ATP processing method.

[0009] From the above, the shortcomings of the current research and technical scheme include:

[0010] (1) The calculation model is difficult to use in the current vehicle ATP;

[0011] (2) Lack of specific implementation method for dynamic group marshalling;

[0012] (3) Lack of calculation method for speed limit, position judgment and other operation parameters in dynamic marshalling process;

[0013] (4) Lack of verification for typical scenarios.

[0014] In view of the above shortcomings, the invention patent puts forward a dynamic group marshalling algorithm based on virtual marshalling train, and the algorithm characteristics are:

[0015] (1) IEEE 1474 calculation model is adopted, which can be directly applied to the current vehicle ATP system;

[0016] (2) Propose calculation methods for important process control parameters in dynamic assembly, including speed limit, distance, etc.;

[0017] (3) Determine the A / B type grouping strategy based on the process control parameters, and then realize a complete dynamic grouping scheme. Under the premise of realizing safety protection function, shorten the grouping time and reduce energy consumption;

[0018] (4) Complete the verification of several typical scenarios. Summary of the Invention

[0019] (a) Technical problems to be solved

[0020] The technical problem to be solved by this invention is how to provide a dynamic formation method for virtual train formation applicable to rail transit, so as to overcome the shortcomings of existing research and technical solutions.

[0021] (II) Technical Solution

[0022] To address the aforementioned technical problems, this invention proposes a dynamic formation method for virtual train formation applicable to rail transit, comprising the following steps:

[0023] S1. Trains to be assembled will operate in CBTC mode;

[0024] S2. The train to be assembled receives the command to begin the assembly process;

[0025] S3. After the train to be assembled determines that the conditions for starting the assembly are met, it enters the assembly mode. In this mode, the train assembling controls its speed based on relative speed, distance, and acceleration information.

[0026] S4. Once the trains to be assembled are deemed to have met the requirements for travel distance and speed, the assembly is considered complete and the trains enter the following mode. In this mode, each train in the assembly maintains the same speed and ensures a safe travel distance. The signaling system controls the assembled trains as a whole.

[0027] S5. When it is necessary to de-marshalling, the train enters the de-marshalling mode. In this mode, the train adjusts the running distance and relative speed.

[0028] S6. Once the train distance and speed meet the decoupling requirements, the decoupling is completed, and each train exits the decoupling mode and continues to operate in CBTC mode.

[0029] (III) Beneficial Effects

[0030] This invention proposes a dynamic formation method for virtual train formation applicable to rail transit. The key points of this invention are:

[0031] 1. A / B type grouping strategy judgment method, based on discriminant μ(V A VB

[0032]

[0033] 2、B type group strategy, the highest car speed V M The calculation method is based on the calculation formula:

[0034]

[0035] 3、A / B type group strategy, according to the speed control method of deceleration scale distance θ (V A ,V B ) can be calculated by calculating the deceleration scale distance to control the speed of the vehicle, and quickly complete the group process;

[0036] 4、Based on the virtual group train group process of the above running process control parameters and strategies.

[0037] The beneficial effects of the present application are:

[0038] 1、According to the characteristics of several scenes in the group process, a complete processing flow is provided, which can realize dynamic and rapid marshalling for various scenes;

[0039] 2、Propose a calculation method of running process control parameters;

[0040] 3、Propose A / B type group strategy, which can complete the marshalling according to different environment;

[0041] 4、Propose a group mathematical model containing delay and safety braking model, which can ensure the safety of VCS driving in fault scene. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is the VCS control logic diagram;

[0043] Figure 2 is the control process of the rear car after the group mode (including uniform speed section);

[0044] Figure 3 is the control process of the rear car after the group mode (without uniform speed section);

[0045] Figure 4 is the process flow of the rear car after the group mode;

[0046] Figure 5 is the standard group scene;

[0047] Figure 6 is the front car forced uniform speed scene;

[0048] Figure 7 is the front car braking scene. DETAILED DESCRIPTION​

[0049] In order to make the purpose, content and advantages of the present application more clear, the specific embodiments of the present application are described in further detail below in combination with the drawings and examples.

[0050] Term explanation:

[0051] ERTMS: European Railway Traffic Management System

[0052] ETCS: European Train Control System

[0053] VCS: Virtual Coupling System

[0054] FAO: Fully Automatic Operation

[0055] CBTC: Communication-Based Train Control

[0056] ATP: Automatic Train Protection

[0057] 1. Grouping process design

[0058] 1.1. Basic flow of virtual grouping

[0059] In the present application, the basic flow of the dynamic grouping method of the virtual grouping train is as follows:

[0060] S1, the train to be grouped runs in CBTC mode;

[0061] S2, the train to be grouped receives a grouping process start command;

[0062] S3, after the train to be grouped judges that the grouping start condition is met, it enters the grouping mode, in which the grouping train controls the running speed according to the relative speed, distance, acceleration and other information;

[0063] S4, after the train to be grouped judges that the running distance and speed meet the requirements, it considers that the grouping is completed and enters the following mode. In this mode, each grouping train maintains the same speed and ensures the running safety distance; the signal system controls the grouping train as a whole;

[0064] S5, when it is necessary to perform ungrouping, the grouping train enters the ungrouping mode. In this mode, the grouping train adjusts the running distance and relative speed;

[0065] S6, the driving distance and speed meet the requirements of the uncoupling, the uncoupling is completed, and each train exits the uncoupling mode and continues to run in the CBTC mode.

[0066] According to the above process, in the application, the virtual coupling control logic mode is composed of the coupling mode, the following mode and the uncoupling mode, and the conversion between the modes is as shown in the following table. Figure 1

[0067] (1) Coupling mode

[0068] After the train to be coupled is determined to meet the VCS (Virtual Coupling System) condition, the coupling mode is entered. In the coupling process, the front train should keep uniform motion at a speed of V A , and V A should be less than the maximum allowed overtaking speed V CM . The rear train adjusts the speed to V A through the acceleration-uniform speed-deceleration process, and at the same time, shortens the distance between the two trains to the VCS following distance, and the coupling is completed.

[0069] (2) Following mode

[0070] After the coupling is completed, the front and rear trains enter the following mode. In this mode, the two trains exchange position, speed and acceleration information through train-to-train communication, to ensure that the two trains travel at the same speed and the distance is not less than the following distance.

[0071] (3) Uncoupling mode

[0072] When the uncoupling command is received, or the two trains are determined to be unable to maintain the following mode, the uncoupling mode is entered. In this mode, the front train should keep uniform motion at a speed of V A , and the rear train expands the distance between the two trains to the CBTC driving interval distance S CBTC through a deceleration-acceleration process, and restores the speed to V A after the uncoupling is completed.

[0073] After the uncoupling is completed, the front and rear trains both keep the CBTC running mode.

[0074] Note: The application only describes the coupling mode related process calculation, and does not involve the following mode and uncoupling mode content.

[0075] 1.2. Minimum safety distance calculation

[0076] In the CBTC running mode, the CBTC minimum driving safety distance at any time is determined by the absolute braking distance S ABD and the safety interval S M . Wherein S M ​Used to compensate for driving reaction time, signal system delay, position uncertainty, etc. Absolute braking distance S ABD A fixed value, calculated according to the safety braking model, determined by the maximum operating speed of the line and the minimum guaranteed emergency braking rate.

[0077] CBTC The minimum driving safety distance calculation formula is:

[0078] S CBTC (t) = S ABD + S M

[0079] Without considering vehicle communication delay, logic calculation and actuator delay, and under the ideal state of the front vehicle maintaining uniform motion, the minimum driving safety distance of VCS at any time is determined by the front vehicle speed V A , the rear vehicle speed V B , the rear vehicle deceleration b B , and the safety interval S M . The ideal VCS minimum driving safety distance calculation formula is:

[0080]

[0081] When the marshalling is completed, V A = V B At this time,

[0082] S ideal (t) = S M

[0083] Compared with the CBTC mode, VCS uses relative braking distance instead of absolute braking distance, so that the minimum driving safety distance can be significantly reduced when marshalling is completed, and the operation efficiency is improved.

[0084] In actual driving, the vehicle communication delay, logic calculation and actuator delay between the trains to be marshalled need to be considered. On the other hand, the most unfavorable scenario under emergency braking needs to be considered: the first vehicle does not consider the safety braking model and decelerates to a stop with the shortest distance; At the same time, after considering various delays t d , the rear vehicle outputs emergency braking and calculates the emergency braking distance according to the safety braking model until the train stops. In this scenario, after the two vehicles stop, the envelopes of the two vehicles should still not overlap. Assuming that in the safety braking model, the emergency braking trigger speed-distance mapping relationship is:

[0085] S eb = φ(V eb )

[0086] Assuming that the speeds of the first and last vehicles are V A , V B, the first vehicle starts at t = 0 with deceleration b A B d

[0087]

[0088] VC

[0089] Note: the emergency braking trigger speed-distance mapping relationship φ(V eb ) meets the IEEE1474 standard, and the present application does not involve related content.

[0090] 1.3. Marshalling mode design

[0091] Under the marshalling mode, the front vehicle maintains a uniform motion at speed V A . To make the marshalling time shortest, the rear vehicle should accelerate as soon as possible to reach the maximum marshalling pursuit speed allowed by the line design, and reduce the vehicle speed to the front vehicle speed V A through a deceleration process, and at the same time shorten the distance between the two vehicles to S M . The method includes the following steps:

[0092] S31, check the marshalling start conditions, including:

[0093] (1) the front and rear vehicles both receive the marshalling command before marshalling;

[0094] (2) the front and rear vehicles are both in CBTC / FAO operation mode;

[0095] (3) the current distance between the front and rear vehicles is greater than the actual VCS minimum driving safety distance S VC (t).

[0096] If all the above conditions are met, marshalling is started.

[0097] S32, the rear vehicle judges the marshalling pursuit mode:

[0098] Let the rear vehicle speed be V B at the start of marshalling, and the maximum allowed pursuit speed be V CM . V CM is a fixed value, usually determined by the current line speed limit. During the pursuit process, the average acceleration of the rear vehicle is a B , and the average deceleration is b B . Then the rear vehicle calculates the marshalling type discriminant:

[0099] ​​​​​

[0100] wherein, for a certain line, S ABD is a fixed value determined by the maximum operating speed of the line and the minimum guaranteed emergency braking rate, which is obtained by the safety braking model calculation, and the present application will not be described S ABD The relevant calculation process. If μ(V A ,V B )≥0, the rear vehicle adopts A-type group organization strategy, which includes uniform acceleration-uniform speed-uniform deceleration process to complete the pursuit, and its composition is as shown in Figure 2

[0101] If μ(V A ,V B )<0, the rear vehicle adopts B-type group organization strategy, which includes uniform acceleration-uniform deceleration process to complete the pursuit, and its composition is as shown in Figure 3

[0102] For A-type group organization strategy, the subsequent steps include:

[0103] S33A. The rear vehicle calculates the maximum pursuit speed of this organization:

[0104] The rear vehicle sets the maximum pursuit speed as V CM .

[0105] S34A. The rear vehicle calculates the deceleration scale distance θ(V A ,V B ):

[0106]

[0107] S35A. The rear vehicle performs the pursuit, wherein:

[0108] The rear vehicle starts at a speed V B , accelerates at an average acceleration a B until it reaches the maximum pursuit speed V CM ; then continuously checks the distance from the front vehicle, and if the distance from the front vehicle is less than the deceleration scale distance θ(V A ,V B ), decelerates at an average deceleration b B until it reaches the front vehicle speed V A . That is, the organization is completed.

[0109] For B-type group organization strategy, the subsequent steps include:

[0110] S33B. The rear vehicle calculates the maximum pursuit speed of this organization, and the calculation method is:

[0111]

[0112] Note that V M ​​The real-time calculation is obtained, and V M ≤V CM .

[0113] S34B. The rear vehicle calculates the deceleration scale distance θ(V A ,V B ):

[0114]

[0115] S35B. The rear vehicle performs the overtaking, wherein:

[0116] The rear vehicle starts at a speed V B , accelerates at an average acceleration a B , until the distance from the front vehicle is less than the deceleration scale distance θ(V A ,V B ); then decelerates at an average deceleration b B , until the speed of the front vehicle V A is reached. That is, the marshalling is completed.

[0117] Based on the above calculations, the marshalling process of the rear vehicle in the marshalling mode can be summarized as shown in FIG. 8. Figure 4

[0118] During the marshalling process, the front vehicle should maintain a uniform speed as much as possible.

[0119] 2. Typical scenario verification

[0120] 2.1. Definition of VCS vehicle operating parameters

[0121] The present application verifies several typical scenarios in dynamic marshalling. The parameters used by the VCS vehicle during the verification process are shown in the following table:

[0122] Table 1 Simulation parameter definition

[0123]

[0124]

[0125] 2.2. Marshalling scenario verification

[0126] 2.2.1. Standard marshalling scenario

[0127] This scenario is a typical marshalling scenario. After the system issues a VCS command, the two vehicles complete marshalling according to the vehicle control algorithm, and the scenario description is as follows:

[0128] Table 2 Standard marshalling scenario event description

[0129]

[0130] Considering the delay and safety braking model, the scenario verification result is as follows​Figure 5

[0131] In this scenario, both trains run in CBTC mode, and the front train maintains a constant speed of 70 km / h. The distance between the two trains is 557.1 m before starting VCS. After receiving the marshalling command, the rear train uses the A-type marshalling strategy and completes marshalling in 220.0 s, entering the following mode. When marshalling is completed, the rear train speed is 70 km / h, and the distance from the front train is 76.58 m, which is much smaller than the CBTC braking distance S ABD = 226 m.

[0132] 2.2.2. Front train forced constant speed scenario

[0133] This scenario is used to describe the situation when the front train needs to maintain a constant speed after marshalling starts. The scenario is described as follows:

[0134] Table 3 Event description of front train forced constant speed scenario

[0135]

[0136]

[0137] The scenario verification results are shown in Figure 6

[0138] In this scenario, both trains run in CBTC mode. Unlike the standard marshalling scenario, the front train's speed has not reached the cruising speed of 70 km / h when it receives the VCS command. To ensure that marshalling is completed as soon as possible, the front train maintains its current speed (30.24 km / h) at a constant speed after the marshalling process begins; the rear train uses the A-type marshalling strategy and completes marshalling in about 36 s, entering the following mode.

[0139] After entering the following mode, the marshalling train starts to accelerate until the front train reaches the cruising speed. The rear train adjusts the distance between the two trains according to the front train's speed. After the speed of the marshalling train stabilizes, it maintains an internal train distance of 77.29 m.

[0140] During the stopping process, the rear train adjusts the distance according to the front train's speed. When both trains are stopped, the distance is 15.61 m, which is the theoretical minimum safety interval S M .

[0141] 2.2.3. Front train braking scenario

[0142] This scenario is used to describe the situation when the front train decelerates to a stop due to an emergency during marshalling. It observes whether the rear train can adjust the distance in time to ensure safety. The scenario is described as follows:

[0143] Table 4 Event description of front train braking scenario

[0144] ​​

[0145]

[0146] The scene verification result is as shown in the figure: Figure 7

[0147] In this scene, the first vehicle runs in CBTC mode, and the tail vehicle normally performs the marshalling operation. At time 200s, the first vehicle starts to decelerate until it stops, at this time, the distance between the first and tail vehicles is 286.4m, the speed of the first vehicle is 70km / h, and the tail vehicle is in the process of marshalling, and the speed is 80km / h. The tail vehicle starts to decelerate according to the safety braking model from time 208s. After the first vehicle stops stably, the tail vehicle cancels the emergency braking and appropriately accelerates to reduce the distance between the two vehicles. After the tail vehicle stops stably, the distance between the tail vehicle and the first vehicle is 42.3m, which ensures the safety of the vehicle.

[0148] The key points of the application are:

[0149] 1. A / B type marshalling strategy judgment method, according to the discriminant μ(V A ,V B ):

[0150]

[0151] 2. In the B type marshalling strategy, the calculation method of the highest pursuit vehicle speed V M , according to the calculation formula:

[0152]

[0153] 3. In the A / B type marshalling strategy, the speed control method according to the deceleration scale distance θ(V A ,V B ) can control the speed of the vehicle through the calculation of the deceleration scale distance, and quickly complete the marshalling process;

[0154] 4. The virtual marshalling train marshalling process based on the above operation process control parameters and strategies.

[0155] The beneficial effects of the application are:

[0156] 1. According to the characteristics of several scenes in the marshalling process, a complete processing flow is provided, which can realize dynamic and rapid marshalling for various scenes;

[0157] 2. The calculation method of the operation process control parameter is provided;

[0158] 3. The A / B type marshalling strategy is provided, which can complete the marshalling according to different environments;

[0159] 4. The marshalling mathematical model containing delay and safety braking model is provided, which can ensure the VCS vehicle safety in the fault scene.​

[0160] The above description is only preferred embodiments of the present application, it should be pointed out that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and variations can be made, which should be considered as the protection scope of the present application.

Claims

1. A method for dynamic formation of virtual trains applicable to rail transit, characterized in that, The method includes the following steps: S1. Trains to be assembled will operate in CBTC mode; S2. The train to be assembled receives the command to begin the assembly process; S3. After the train to be assembled determines that the conditions for starting the assembly are met, it enters the assembly mode. In this mode, the train assembling controls its speed based on relative speed, travel distance, and acceleration information. S4. Once the trains to be assembled are deemed to have met the requirements for travel distance and speed, the assembly is considered complete and the trains enter the following mode. In this mode, each train in the assembly maintains the same speed and ensures a safe travel distance. The signaling system controls the assembled trains as a whole. S5. When it is necessary to de-marshalling, the train enters the de-marshalling mode. In this mode, the train adjusts the running distance and relative speed. S6. Once the train distance and speed meet the decoupling requirements, the decoupling is completed, and each train exits the decoupling mode and continues to operate in CBTC mode. in, Step S3 specifically includes the following steps: S31. Check the grouping start conditions. If all conditions are met, then start the grouping process. S32, Follower vehicle judgment grouping and chasing mode Let the speed of the following vehicle at the start of the group formation be... The speed of the car in front is The maximum permissible speed for retracing a vehicle is , This is a fixed value, usually determined by the current speed limit on the route. During a reversal, the average acceleration of the following vehicle is... The average deceleration is Then the discriminant for the grouping type of the following vehicle is calculated: For a certain line, the absolute braking distance S ABD The value is determined by the line's maximum operating speed and the minimum guaranteed emergency braking rate, and is a fixed value calculated by the safety braking model. like Then the following vehicle adopts the A-type grouping strategy, which includes a process of uniform acceleration-uniform speed-uniform deceleration to complete the chase. like Then the following vehicle adopts a B-type grouping strategy, which includes a uniform acceleration-uniform deceleration process to complete the chase.

2. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 1, characterized in that, In step S3, after the train to be assembled is determined to meet the VCS (Virtual Coupling System) conditions, it enters the assembly mode. During the assembly process, the leading train should maintain a speed of [missing information]. The uniform motion, and It should be less than the maximum permissible speed for retracing vehicles. The following vehicle adjusted its speed through a process of acceleration-constant speed-deceleration. At the same time, the distance between the two vehicles is shortened to the VCS following distance to complete the formation.

3. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 2, characterized in that, In step S4, after the grouping is completed, the front and rear vehicles enter the following mode. In this mode, the two vehicles communicate with each other through vehicle-to-vehicle communication to exchange position, speed and acceleration information, ensuring that the two vehicles travel at the same speed and the distance between them is not less than the following distance.

4. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 3, characterized in that, In step S5, when a disengagement command is received, or when both vehicles determine that they cannot maintain the following mode, the vehicle enters disengagement mode. In this mode, the leading vehicle should maintain a speed of [missing information]. The following vehicle moves at a constant speed, and through a deceleration-acceleration process, increases the distance between the two vehicles to the CBTC driving interval. And after decompilation, the recovery speed is .

5. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 2, characterized in that, In CBTC operation mode, the minimum safe driving distance at any given time is determined by the absolute braking distance. and safety interval Confirmed, among which Used to compensate for driving reaction time, signal system delays, and positional uncertainties, absolute braking distance It is a fixed value, determined by the maximum operating speed of the line and the minimum guaranteed emergency braking rate, based on the safety braking model. The formula for calculating the minimum safe driving distance in CBTC is: Ignoring vehicle communication delays, logic calculation delays, and various delays in actuators, and assuming the preceding vehicle maintains a constant speed, the minimum safe driving distance of the VCS at any given time is determined by the speed of the preceding vehicle. The speed of the car behind The following car decelerates and safety interval Confirmed; the formula for calculating the minimum safe driving distance for an ideal VCS is: When the grouping is completed, there is At this time there is In actual train operation, it is necessary to consider the communication delays, logic calculation delays, and actuator delays between trains to be assembled. On the other hand, it is also necessary to consider the worst-case scenario under emergency braking: that is, the preceding train does not consider a safe braking model and decelerates to a stop in the shortest distance; while the following train considers various delays. Then, the emergency braking is output, and the emergency braking distance is calculated according to the safety braking model until the train comes to a complete stop. In this scenario, after the two trains come to a complete stop, it should still be ensured that the envelopes of the two trains do not overlap. In the safety braking model, the emergency braking trigger speed-distance mapping relationship is assumed to be: in, For emergency braking trigger speed, Let be the emergency braking distance; assuming the speeds of the front and rear vehicles are respectively... The car in front is From the moment on, with deceleration The vehicle undergoes uniform deceleration, while the following vehicle accelerates. Duration of uniformly accelerated motion Afterwards, deceleration begins based on the safety braking model. Therefore, during the driving process, the actual minimum safe driving distance according to the VCS should be set to... During the assembly process, the distance between the two vehicles should be no less than [amount missing] at any given time. .

6. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 5, characterized in that, The specific conditions for step S31 include: both the trains before and after the formation have received the formation command; both the trains before and after the formation are in CBTC / FAO operating mode; and the current distance between the trains before and after the formation is greater than the actual VCS minimum safe driving distance. .

7. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 5, characterized in that, For the Type A grouping strategy, the subsequent steps include: S33A. The following vehicle calculates the maximum tracking speed of this trainset: The following vehicle is set to a maximum tracking speed of ; S34A. The following vehicle calculates the deceleration gauge distance. S35A. The following vehicle pursued the other vehicle, among which: Rear vehicle starting speed With average acceleration Accelerate until maximum tracking speed is reached. Afterwards, continuously check the distance to the vehicle in front. If the distance to the vehicle in front is less than the distance indicated on the deceleration gauge... Then, with average deceleration Decelerate until you reach the speed of the vehicle in front. This means the grouping is complete.

8. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 5, characterized in that, For the Type B grouping strategy, the subsequent steps include: S33B. The following vehicle calculates the maximum tracking speed of this formation, using the following method: Obtained through real-time calculation, and should meet the following requirements. ; S34B. The following vehicle calculates the distance indicated by the deceleration gauge. S35B. The following vehicle pursued the other vehicle, in which: Rear vehicle starting speed With average acceleration Accelerate until the distance to the vehicle in front is less than the distance indicated by the deceleration scale. Then, with average deceleration Decelerate until you reach the speed of the vehicle in front. This means the grouping is complete.

9. The method for dynamic formation of virtual trains applicable to rail transit as described in claim 5, characterized in that, During the formation process, the lead vehicle should maintain a constant speed.

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