Virtual coupling small marshalling train control system and method based on vehicle-vehicle communication
Technical Field
The invention relates to the technical field of urban rail transit, in particular to a virtual coupling small marshalling train control system and method based on vehicle-to-vehicle communication.
Background
Train control systems for urban rail transit are continuously developed, and a train control technology is revolutionized from a point-mode system which only depends on ground equipment such as a signal machine and a rail circuit to assist train operation to a train automatic control system (hereinafter referred to as a CBTC system for train-ground communication) which realizes train-ground continuous bidirectional communication and is based on communication. The traditional CBTC system has the characteristics that the bidirectional communication between the train and ground equipment is realized by using a wireless communication medium, the transmission information quantity is large, the transmission speed is high, the section running passing capacity is greatly improved, and the train running interval is shortened.
The architecture of a conventional CBTC system for vehicle-to-ground communication is shown in fig. 1. Wherein an automatic train supervision system (ATS) sends a message of an access request to a Zone Controller (ZC) at the trackside and a local ATS at a station, the ZC calculates the mobile authorization according to the position reported by the train, and then sends the mobile authorization to the train. Therefore, in the CBTC system for train-ground communication, a large amount of data information needs to be interacted between the vehicle-mounted control unit and the trackside control unit in real time, and communication delay therein cannot be avoided. Meanwhile, when the train position is calculated, trackside auxiliary positioning equipment such as a transponder and a shaft counter is required to be used, so that the trackside equipment of the system is more, and the maintenance cost is higher.
The current CBTC system for vehicle-ground communication technically realizes the function of mobile blocking. It has some drawbacks, mainly including:
1) the interfaces among the subsystems are too many, so that the complexity of the system is increased;
2) the number of trackside equipment for train-ground communication is large, so that the maintenance cost of the system is high;
3) the train can obtain the running state information of the front train only through the transfer of the ZC, and the information can not be directly obtained, so that the reaction time of the system running is increased, and the performance is reduced;
4) due to the mutual limitation of the subsystems beside the track, the flexibility degree of the system operation is poor.
A series of researches are carried out by related scientific research institutions aiming at vehicle-vehicle communication, and the researches mainly comprise the following two schemes:
the first type: the scheme discloses a train collision protection technology aiming at a high-speed railway, and relates to a CTCS safety superposition train collision protection system and method (201210164949.6) based on train-to-train communication. The scheme is that the speed, position and direction information of the vehicle is transmitted to a certain range in a broadcasting mode through a vehicle-to-vehicle communication subsystem, and the speed, position and direction information broadcasted by other trains is received at the same time. Then, the collision-prevention computer calculates the collision-prevention possibility by combining the speed, position and direction information of the vehicle, the speed, position and direction information of other trains, and the route information of the electronic map database. And finally, sending the calculation result to a human-computer interaction subsystem, and reminding a driver to take measures to avoid the collision of the train through an acousto-optic warning signal. However, this solution has the drawbacks: 1) the method is mainly applied to train collision protection of the high-speed railway, and cannot be applied to urban rail transit to improve the train transportation capacity and the operation efficiency; 2) each train not only needs to carry out one-to-many and many-to-one vehicle-to-vehicle direct communication, but also needs to simultaneously carry out vehicle-to-ground communication with the ground, and the requirement on vehicle-mounted equipment is high. 3) The anti-collision calculation result is sent to the man-machine interaction subsystem, and collision avoidance operation is carried out manually by a driver, and special conditions such as reaction time of the driver need to be considered during execution of the method, so that certain potential safety hazards exist.
The second type: the train operation control system and method (201610799966.5) and the CBTC system scheme taking the train as the core are configured based on the dynamic interval transport capacity, wherein the CBTC system scheme is mentioned in articles such as 'novel CBTC system analysis based on vehicle-vehicle communication' and 'new generation CBTC system scheme research and key technology exploration'. According to the scheme, trackside core function devices such as a Zone Controller (ZC) and an interlock device of a traditional CBTC system are transplanted into vehicle-mounted devices, and ground devices are controlled through an object controller, so that the system structure is optimized, and the quantity of trackside devices is reduced. Meanwhile, a train tracking mode of the relative speed of the 'soft wall collision' is also provided. However, a drawback of this class of solutions is that: 1) the urban rail transit line is long, the train spacing of train-to-train communication is uncertain from hundreds of meters to thousands of meters, part of overhead lines are in open space, the condition of direct communication between trains is complex, and the safe and reliable direct communication technology between trains which can completely meet the requirements of the scheme does not exist at present. Meanwhile, the satellite communication subsystem mentioned in the patent (201610799966.5) has poor effect in the closed space under the urban rail transit. 2) Although some ground equipment is eliminated, the train needs to perform both ground communication and vehicle-to-vehicle communication, which is too demanding for vehicle-mounted equipment. 3) The safety and reliability of the "soft wall" relative speed train tracking technique remain questionable.
Disclosure of Invention
The invention aims to provide a virtual coupling small marshalling train control system and method based on vehicle-vehicle communication, which can greatly improve the running performance of the system, better meet the requirement of flexible operation of urban rail transit, have great development space and potential, and are the future development trend and development direction of an urban rail transit signal system.
The purpose of the invention is realized by the following technical scheme:
a virtual hitching mini-consist train control system based on vehicle-to-vehicle communication, comprising: the front train and the rear train realize point-to-point communication in a certain range based on the vehicle-mounted VOBC to form a virtual connected small marshalling; the vehicle-mounted VOBC includes: the system comprises a vehicle-to-vehicle communication radio station, an antenna, a speed measurement positioning module, a vehicle-to-vehicle communication module and a vehicle-mounted ATO;
in the virtual coupling small marshalling, the rear vehicle carries out full-duplex point-to-point communication with the vehicle-vehicle communication radio station and the antenna of the front vehicle in real time through the vehicle-vehicle communication radio station and the antenna of the rear vehicle, and obtains the running state information of the front vehicle;
the speed measurement and positioning information acquired by the speed measurement positioning module of the rear vehicle and the acquired running state information of the front vehicle are transmitted to the vehicle-mounted ATO through the vehicle-vehicle communication module, and the vehicle-mounted ATO controls the rear vehicle to keep a dynamic safe distance to run along with the front vehicle.
The rear train in a virtual coupling small marshalling is used as a main train, and the running speed curve and the protection distance information of the rear train are calculated in real time, so that the train is controlled to run; the running interval inside the virtual small connected grouping is controlled by the main vehicle, and when the virtual small connected grouping is effective, the rear vehicle does not carry out vehicle-ground communication;
the main vehicle also sends the current speed, position, safety distance, minimum vehicle tail position and vehicle tail safety compensation envelope information to the front vehicle in real time, the front vehicle is responsible for communicating with a ground area controller to obtain the forward access and speed limit information, the information sent by the main vehicle is transmitted to the ground area controller, and the virtual coupling marshalling is tracked in a real-time database as a whole by the ground area controller.
The principle of the main vehicle for tracking the front vehicle is self-adaptive following control, and the main vehicle runs along with the front vehicle according to a certain strategy: the main vehicle follows the acceleration, cruising and deceleration running states of the front vehicle, and the control model takes distance deviation and speed deviation as input, is based on closed-loop feedback control of acceleration, and simultaneously calculates relative safe distance in real time according to the current speed to serve as the safety limiting condition of the control model.
The train-to-train communication between the trains in the virtual coupling small marshalling and the train-to-ground communication between each train and the ground are independent systems, and the system has a mutual redundancy function;
if the train-to-train communication works normally, but the train-to-ground communication equipment fails, all trains are switched to a train-to-train communication mode, and the whole train is virtually linked;
if the train-to-train communication fails, the train-to-ground communication works normally, the ground transponder, the axle counting and DCS network equipment guarantee the driving safety, the small virtually-connected marshalling is compiled, and the train runs in an independent train-to-ground communication mode;
and if the train-to-train communication and the train-ground communication can not work normally, the virtual connected small marshalling is compiled and degraded into manual driving or train emergency braking.
A virtual coupling small marshalling train control method based on vehicle-vehicle communication is realized based on the system and comprises the following steps: the front train and the rear train realize point-to-point communication in a certain range based on the vehicle-mounted VOBC to form a virtual connected small marshalling;
in the virtual coupling small marshalling, the rear vehicle carries out full-duplex point-to-point communication with the vehicle-vehicle communication radio station and the antenna of the front vehicle in real time through the vehicle-vehicle communication radio station and the antenna of the rear vehicle, and obtains the running state information of the front vehicle;
the speed measurement and positioning information acquired by the speed measurement positioning module of the rear vehicle and the acquired running state information of the front vehicle are transmitted to the vehicle-mounted ATO through the vehicle-vehicle communication module, and the vehicle-mounted ATO controls the rear vehicle to keep a dynamic safe distance to run along with the front vehicle.
The rear train in a virtual coupling small marshalling is used as a main train, and the running speed curve and the protection distance information of the rear train are calculated in real time, so that the train is controlled to run; the running interval inside the virtual small connected grouping is controlled by the main vehicle, and when the virtual small connected grouping is effective, the rear vehicle does not carry out vehicle-ground communication;
the main vehicle also sends the current speed, position, safety distance, minimum vehicle tail position and vehicle tail safety compensation envelope information to the front vehicle in real time, the front vehicle is responsible for communicating with a ground area controller to obtain the forward access and speed limit information, the information sent by the main vehicle is transmitted to the ground area controller, and the virtual coupling marshalling is tracked in a real-time database as a whole by the ground area controller.
The principle of the main vehicle for tracking the front vehicle is self-adaptive following control, and the main vehicle runs along with the front vehicle according to a certain strategy: the main vehicle follows the acceleration, cruising and deceleration running states of the front vehicle, and the control model takes distance deviation and speed deviation as input, is based on closed-loop feedback control of acceleration, and simultaneously calculates relative safe distance in real time according to the current speed to serve as the safety limiting condition of the control model.
The train-to-train communication between the trains in the virtual coupling small marshalling and the train-to-ground communication between each train and the ground are independent systems, and the system has a mutual redundancy function;
if the train-to-train communication works normally, but the train-to-ground communication equipment fails, all trains are switched to a train-to-train communication mode, and the whole train is virtually linked;
if the train-to-train communication fails, the train-to-ground communication works normally, the ground transponder, the axle counting and DCS network equipment guarantee the driving safety, the small virtually-connected marshalling is compiled, and the train runs in an independent train-to-ground communication mode;
and if the train-to-train communication and the train-ground communication can not work normally, the virtual connected small marshalling is compiled and degraded into manual driving or train emergency braking.
According to the technical scheme provided by the invention, the vehicle-to-vehicle direct communication mode which is not based on the ground equipment and is provided by the 1) improves the efficiency, relieves the pressure of a Zone Controller (ZC) in the traditional vehicle-to-ground communication CBTC system and reduces the load of a vehicle-to-ground communication network. 2) The vehicle-to-vehicle direct communication system not based on the ground equipment is also used as a safety redundancy scheme of vehicle-to-ground communication, and can ensure that a train can safely run at a certain speed when the vehicle-to-ground communication fails. 3) The virtual coupling technology is introduced into the operation control of the urban rail transit train, a new transportation organization form of small marshalling operation is provided, the train operation efficiency can be improved in a small range, and the more flexible transportation organization form has great advantages for engineering truck rescue and implementation of interconnection and intercommunication. 4) The basic control strategy is applied to small-grouping virtual coupling, and the speed of the main vehicle is adaptive to follow the front vehicle. The strategy is a closed-loop feedback based on acceleration with distance deviation and speed deviation as inputs and considering a safe distance as a limiting condition. The strategy can ensure safe and efficient operation of the train of small marshalling train-to-train communication.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is a schematic diagram of a conventional CBTC system architecture provided in the background of the invention;
FIG. 2 is a schematic diagram of a virtual hitching mini-consist train control system based on vehicle-to-vehicle communication according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a vehicle-mounted VOBC provided in the embodiment of the present invention;
fig. 4 is a flowchart of redundancy rules for vehicle-to-vehicle communication and vehicle-to-ground communication according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
At present of the continuous development of urban rail transit, the capacity of partial large-city subway lines cannot meet the travel demands of people all the time, and due to excessive people flows, the lines are frequently crowded, trampled and other accidents which harm the safety of passengers in the early and late peak periods. There is currently no good solution to this situation: because the external conditions such as the line speed limit, the platform length and the like of the newly-built lines are difficult to change at present, the method for improving the speed and increasing the train marshalling is not suitable; the tracking interval of the existing train-ground communication CBTC signal system is limited by key factors such as train-ground communication delay, reaction time of a plurality of subsystems and the like, and the train running interval is difficult to reduce; meanwhile, the number of interfaces among subsystems in a CBTC (communication based train control) system for train-ground communication is large, a large number of trackside equipment are provided, a series of signal system faults can be caused by any equipment fault, and the normal operation of a train can be influenced by increasing the load of a signal system blindly.
Aiming at the current use requirements and the defects in the prior art, the embodiment of the invention provides a virtual connected small marshalling train control system based on vehicle-to-vehicle communication, which can be used as redundancy and emergency communication of a vehicle-to-ground communication system to ensure the driving safety and can also improve the operation efficiency and the operation flexibility in a small marshalling.
As shown in fig. 2, the virtual coupled small-consist train control system based on train-to-vehicle communication according to the embodiment of the present invention mainly includes: the front train and the rear train realize point-to-point communication in a certain range based on the vehicle-mounted VOBC to form a virtual connected small marshalling; in the virtual coupling small marshalling, the rear vehicle carries out full-duplex point-to-point communication with the vehicle-vehicle communication radio station and the antenna of the front vehicle in real time through the vehicle-vehicle communication radio station and the antenna of the rear vehicle, and obtains the running state information (comprising speed, acceleration, position, running route and the like) of the front vehicle; the speed measurement and positioning information acquired by the speed measurement positioning module of the rear vehicle and the acquired running state information of the front vehicle are transmitted to the vehicle-mounted ATO through the vehicle-vehicle communication module, and the vehicle-mounted ATO controls the rear vehicle to keep a dynamic safe distance to run along with the front vehicle.
The virtual linking command of vehicle-to-vehicle communication can be preset before departure, or can be sent by the ATS in the running process and can be executed only after being judged as a safety command by the ZC. The virtual connection has a certain requirement on the communication distance, and reliable point-to-point information transmission can be carried out only by keeping the distance between two trains within a certain range. For this virtually hitched mini-consist, the ground ZC calculates a maximum virtual trailer length (virtual length for short) and the train behind the mini-consist still tracks the tail of the mini-consist in a train-to-ground communication mode.
As shown in fig. 3, the vehicle-mounted VOBC mainly includes: the vehicle-to-vehicle communication system comprises a vehicle-to-vehicle communication radio station and antenna, a speed measuring and positioning module, a vehicle-to-vehicle communication module and a vehicle-mounted ATO.
In the embodiment of the invention, a rear vehicle in a virtual small connected grouping is used as a main vehicle, and the running speed curve and the protection distance information of the rear vehicle are calculated in real time, so that the running of a train is controlled; the running interval inside the virtual small connected grouping is controlled by the main vehicle, and when the virtual small connected grouping is effective, the rear vehicle does not carry out vehicle-ground communication; the main vehicle also sends the current speed, position, safety distance, minimum vehicle tail position and vehicle tail safety compensation envelope information to the front vehicle in real time, the front vehicle is responsible for communicating with a ground area controller to obtain the forward access and speed limit information, the information sent by the main vehicle is transmitted to the ground area controller, and the virtual coupling marshalling is tracked in a real-time database as a whole by the ground area controller.
In addition, the virtual linkage can only work within a small range of a certain distance, and once the virtual vehicle length is larger than the maximum value, the virtual linkage fails, and the vehicle-mounted system is switched to a vehicle-ground communication mode. Meanwhile, when the two train marshalling inside the virtual connected small marshalling are compiled or the positions are exchanged, the rear train-train tracking target outside the marshalling can be changed from the tail end of the small marshalling to the tail end of the train. The system theoretically supports multi-train marshalling, but the operation efficiency is reduced along with the increase of the number of trains, so that the number of trains in the virtual small marshalling can be determined according to actual conditions.
In the embodiment of the invention, the principle of calculating the main speed curve is as follows: the principle of the main vehicle for tracking the front vehicle is self-adaptive following control, and the main vehicle runs along with the front vehicle according to a certain strategy: the main vehicle follows the acceleration, cruising and deceleration running states of the front vehicle, and the control model takes distance deviation and speed deviation as input, is based on closed-loop feedback control of acceleration, and simultaneously calculates relative safe distance in real time according to the current speed to serve as the safety limiting condition of the control model.
On the other hand, from the safety perspective, the vehicle-to-vehicle direct communication system provided by the embodiment of the invention is also used as a safety redundancy scheme for vehicle-to-ground communication, and vehicle-to-vehicle communication between trains in the virtual connected small marshalling and vehicle-to-ground communication between each train and the ground are independent systems and have a mutual redundancy function; the vehicle-ground communication mainly adopts a GSM-R or LTE mode, and the vehicle-vehicle communication can adopt various modes such as a vehicle-mounted radio station or ultra-short wave. As shown in fig. 4.
1) If the train-to-train communication works normally, but the train-to-ground communication equipment fails, all trains are switched to a train-to-train communication mode, and the whole train is virtually linked;
2) if the train-to-train communication fails, the train-to-ground communication works normally, the ground transponder, the axle counting and DCS network equipment guarantee the driving safety, the small virtually-connected marshalling is compiled, and the train runs in an independent train-to-ground communication mode;
3) and if the train-to-train communication and the train-ground communication can not work normally, the virtual connected small marshalling is compiled and degraded into manual driving or train emergency braking.
The virtual coupling small marshalling train control system based on the vehicle-vehicle communication is a scheme for guaranteeing the driving safety and improving the train operation efficiency. In a small marshalling range, the main vehicle continuously detects the self environmental perception and state data, obtains the environmental perception and state data of the front vehicle through point-to-point direct communication, carries out comparison calculation, forms a control strategy according to the calculation result, and adjusts the rear vehicle to keep a dynamic safe distance to follow the front vehicle to run. The strategy controls the main train to adaptively follow the front train to run, and helps the train in the small marshalling to cooperatively make a correct active vehicle control decision and operation. It mainly has following beneficial effect:
1) the vehicle-to-vehicle direct communication mode not based on ground equipment improves efficiency, relieves the pressure of a Zone Controller (ZC) in a traditional vehicle-to-ground communication CBTC system, and reduces the load of a vehicle-to-ground communication network.
2) The vehicle-to-vehicle direct communication system not based on the ground equipment is also used as a safety redundancy scheme of vehicle-to-ground communication, and can ensure that a train can safely run at a certain speed when the vehicle-to-ground communication fails.
3) The virtual coupling technology is introduced into the operation control of the urban rail transit train, a new transportation organization form of small marshalling operation is provided, the train operation efficiency can be improved in a small range, and the more flexible transportation organization form has great advantages for engineering truck rescue and implementation of interconnection and intercommunication.
4) The basic control strategy is applied to small-grouping virtual coupling, and the speed of the main vehicle is adaptive to follow the front vehicle. The strategy is a closed-loop feedback based on acceleration with distance deviation and speed deviation as inputs and considering a safe distance as a limiting condition. The strategy can ensure safe and efficient operation of the train of small marshalling train-to-train communication.
Another embodiment of the present invention further provides a method for controlling a virtual coupled small-consist train based on vehicle-to-vehicle communication, where the method is implemented based on the system provided in the foregoing embodiment, and mainly includes: the front train and the rear train realize point-to-point communication in a certain range based on the vehicle-mounted VOBC to form a virtual connected small marshalling;
in the virtual coupling small marshalling, the rear vehicle carries out full-duplex point-to-point communication with the vehicle-vehicle communication radio station and the antenna of the front vehicle in real time through the vehicle-vehicle communication radio station and the antenna of the rear vehicle, and obtains the running state information of the front vehicle;
the speed measurement and positioning information acquired by the speed measurement positioning module of the rear vehicle and the acquired running state information of the front vehicle are transmitted to the vehicle-mounted ATO through the vehicle-vehicle communication module, and the vehicle-mounted ATO controls the rear vehicle to keep a dynamic safe distance to run along with the front vehicle.
Furthermore, a rear vehicle in a virtual small connected grouping is used as a main vehicle, and the running speed curve and the protection distance information of the rear vehicle are calculated in real time, so that the running of the train is controlled; the running interval inside the virtual small connected grouping is controlled by the main vehicle, and when the virtual small connected grouping is effective, the rear vehicle does not carry out vehicle-ground communication;
the main vehicle also sends the current speed, position, safety distance, minimum vehicle tail position and vehicle tail safety compensation envelope information to the front vehicle in real time, the front vehicle is responsible for communicating with a ground area controller to obtain the forward access and speed limit information, the information sent by the main vehicle is transmitted to the ground area controller, and the virtual coupling marshalling is tracked in a real-time database as a whole by the ground area controller.
Further, the principle of tracking the front vehicle by the main vehicle is self-adaptive following control, and the main vehicle follows the front vehicle to run according to a certain strategy: the main vehicle follows the acceleration, cruising and deceleration running states of the front vehicle, and the control model takes distance deviation and speed deviation as input, is based on closed-loop feedback control of acceleration, and simultaneously calculates relative safe distance in real time according to the current speed to serve as the safety limiting condition of the control model.
Furthermore, vehicle-to-vehicle communication between trains in the virtual coupling small marshalling and vehicle-to-ground communication between each train and the ground are independent systems, and the system has a mutual redundancy function;
if the train-to-train communication works normally, but the train-to-ground communication equipment fails, all trains are switched to a train-to-train communication mode, and the whole train is virtually linked;
if the train-to-train communication fails, the train-to-ground communication works normally, the ground transponder, the axle counting and DCS network equipment guarantee the driving safety, the small virtually-connected marshalling is compiled, and the train runs in an independent train-to-ground communication mode;
and if the train-to-train communication and the train-ground communication can not work normally, the virtual connected small marshalling is compiled and degraded into manual driving or train emergency braking.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.