CN112550368A

CN112550368A - Post-station unmanned automatic turn-back method suitable for urban railway

Info

Publication number: CN112550368A
Application number: CN202011506444.4A
Authority: CN
Inventors: 张雅静; 汪涛; 徐先良; 陈智新; 纳吉庆; 郭亮; 刘华祥
Original assignee: Casco Signal Ltd
Current assignee: Casco Signal Ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-03-26
Anticipated expiration: 2040-12-18
Also published as: CN112550368B

Abstract

The invention relates to a post-station unmanned automatic turn-back method suitable for urban railways, which is characterized in that through increasing a through communication line, vehicle-mounted equipment at two ends of a locomotive group is communicated, a train automatically enters a turn-back traction line and is stopped and then is activated into a working state through a data through line, the turn-back end-changing time of the train is greatly shortened, the utilization rate of the turn-back line is improved, and the operation requirement that the turn-back time of public transport operation of the urban railways is less than 3 minutes is met. Compared with the prior art, the method has the advantages of greatly shortening the end changing time of the vehicle-mounted equipment on the retrace line, solving the potential safety hazard that an unmanned retrace train mistakenly drives into a non-retrace line and enters other lines after the existing station with the line crossing function of the state railway is stopped, and the like.

Description

Post-station unmanned automatic turn-back method suitable for urban railway

Technical Field

The invention relates to a signal control system of an urban railway, in particular to a post-station unmanned automatic turning-back method suitable for the urban railway.

Background

At present, the development of urban railways in China lags behind, the effective supply capacity is insufficient, and the urban public transport development short plate becomes. The national development committee "guidance on promoting development of urban (suburban) railways" (article 1173) gives a definition of urban railways: the urban (suburb) railway is a commuting, rapid and large-traffic rail transit system between adjacent town groups connected with urban central urban areas and the town groups.

Therefore, the main function positioning of the urban railway is to provide urban public traffic service and relieve urban traffic congestion; providing commuting traffic in a city range and promoting novel urbanization construction; the commuting traffic across the city range is provided, and the urban circle development requirement is better met. The operation speed of the urban railway is determined to be more suitable between 120km/h and 200km/h through the functional positioning of the urban railway, the transportation mode is the combination of station stop and large station stop, meanwhile, the method has the very important characteristics of public transportation operation, the passenger flow has a tidal site, the operation tracking interval is usually 4-20 minutes and can reach 3 minutes at least, the long-term planned urban railway has the expectation of 2.5 minutes tracking interval, this requires that the train meet a3 minute end-to-end turnaround interval and that the ATO function be present, meanwhile, the urban railway needs to realize cross-line operation with the high-speed trunk railway and the regional inter-city railway, and the urban railway needs to be interconnected and intercommunicated with the urban rail transit, so that the integration development of the national trunk railway, the inter-city railway, the urban railway and the urban rail transit is met, and the integration development provides unprecedented challenges for a signal system adopted by the urban railway.

The operating speed of national trunk railways and inter-city railways is generally 250 km/h-350 km/h, the adopted signal standard is CTCS2/3 grade, and the adopted standard is issued by the national railway administration. At present, the China railway CTCS2/3 has mature ATO operation performance, but national trunk railways and inter-city railways have no urgent requirement of turning back for 3 minutes due to function positioning, and the CTCS2/3 level relevant technical specifications and management regulations related to driving made by various railway bureaus cannot meet the requirement of turning back for 3 minutes in the public transportation operation of the urban railway. At present, the CTCS2+ ATO train control system which is opened and operated in China has circuits of Guanhui, Fozhao and Yunquan, and the foldback on the circuits adopts two modes of folding back before the station and automatically folding back by someone after the station, and the folding back interval is about 6-15 minutes. The folding process is shown in figure 1.

A mainstream signal system adopted by urban rail transit at home is a CBTC (communication based train control) system, the automation level is applied to GoA3 level and GoA4 level, the turning-back mode realizes unmanned automatic turning-back after the station, the turning-back interval meets the requirement of 3 minutes, but the operation speed of the CBTC system is lower than 120km/h, the commuting requirement between urban railway cities cannot be met, and more importantly, the CBTC system cannot realize cross-line operation with national trunk railways and intercity railways and cannot meet the interconnection requirement.

Therefore, how to technically upgrade the fold-back function on the basis of the CTCS2+ ATO system and break the long fold-back interval time becomes a technical problem to be solved at present.

Disclosure of Invention

The invention aims to solve the problem that the existing national railway station with the cross-line function is unmanned to return after the station, the train returning time meets the 3-minute operation interval, and meanwhile, the potential safety hazard that a train mistakenly enters a non-return line and enters other lines can be prevented.

The purpose of the invention can be realized by the following technical scheme:

according to one aspect of the invention, the method is characterized in that through adding a through communication line, vehicle-mounted equipment at two ends of a locomotive group is communicated, a train automatically enters a return pull-out line and is stopped and then is activated to enter a working state through automatic end switching of a data through line, the time for returning and changing the end of the train is greatly shortened, the utilization rate of the return line is improved, and therefore the operation requirement that the time for returning the urban railway in public transportation operation is less than 3 minutes is met.

As a preferred technical solution, the method is implemented based on two safety criteria, namely a safety criterion one and a safety criterion two.

As a preferred technical solution, the first safety criterion is: and setting an ATB automatic turn-back area, wherein when the train in the ATB turn-back mode is automatically turned back without people, the train is ensured to be carried out in the area, otherwise, the train is carried out with EB emergency braking.

As a preferred technical solution, the implementation process of the first security criterion specifically includes:

active transponder protection: an active responder at an outbound signal machine in the direction from a platform to a return line sets an ATB return area range data packet, a vehicle receives ATB return area range data packet link information after a train correctly drives into the return line, and otherwise, ATP outputs EB braking;

TSRS route protection: after the CTC transacts the return route, the TCC sends the return route number to the TSRS for checking, the TSRS verifies that the return route is the return route, then the TSRS sends an ATB departure permission command to the vehicle, the ATB button flickers, otherwise, the ATB is prohibited to enter;

ATP software protection: after a driver pulls out a key from a platform, the vehicle-mounted electronic parking system enters an ATB mode, the vehicle-mounted equipment exits the ATB mode after the vehicle-mounted equipment enters the platform again and inserts the key, and if the position of the vehicle-mounted equipment receiving a transponder is wrong in the ATB mode, the vehicle-mounted EB stops.

As a preferred technical solution, the second safety criterion is: after the automatic end switching activation of the return line is carried out by the vehicle-mounted equipment without people, the vehicle-mounted equipment still needs to be in an ATB (automatic train bus) activation state in a keyless state and the running direction is correct.

As a preferred technical solution, the implementation process of the second safety criterion is specifically as follows:

after the train stops stably on the return line, the ATP of the home terminal activates a cab of the non-home terminal through a through data line, sets the direction to be forward, pulls the zero position of a brake handle, the ATO is in an effective state, and sets the A terminal to be in a dormant state, wherein the home terminal is the A terminal, and the non-home terminal is the B terminal.

Preferably, the ATB retracing mode is a special operation state when performing a retracing operation in the train automatic driving operation mode.

As a preferred technical solution, the entry condition of the ATB foldback mode satisfies the following conditions at the same time:

a1) the vehicle receives the turn-back permission from the TSRS;

a2) the traction handle of the cab at the non-home terminal is zero;

a3) the speed of the train is zero;

a4) ATO is active mode.

Preferably, the exit condition of the ATB fold back mode satisfies the following conditions:

b1) stopping the train platform stably;

b2) opening a door of the train;

b3) the driver enters the cab and inserts the key.

As a preferred technical scheme, the method specifically comprises the following steps:

(1) the train enters a turn-back mode and enters a turn-back rail process:

step 1: the TSRS transmits ATB retrace permission (CTCS-22 is 1) to the vehicle every period under the condition that the train stops on a receiving station track and a retrace route is cleared for the train according to the position report of the train, the retrace route report of TCC and the train plan of CTC;

step 2: the ATP obtains an ATB (CTCS-22 is 1) retrace permission from the TSRS, the retrace permission is effective in a set time, and after the retrace permission is overtime, the ATP deletes the retrace permission; if the last time of the retrace permission is not expired and a new retrace permission is received, using the new retrace permission and restarting countdown of the validity period of the new permission; if the TSRS does not receive the acknowledgement message of the ATP within the specified time, resending the retracing permission;

and step 3: the ATP obtains ATB turn-back permission of the TSRS, meets the precondition of entering turn-back, and if the ATP is not in the turn-back state, the ATP informs the ATO of lighting an ATB button lamp to flicker, and prompts a driver end to press an ATB button and enter an automatic turn-back state;

and 4, step 4: the driver end presses an ATB button to apply to switch to an ATB state and output an ATB activation signal;

and 5: after the vehicle receives the ATB activation signal, the signal replaces a key to output a cab activation signal, and handle combination zero position information is output, so that the vehicle-mounted automatic driving mode can be still maintained after the handle is pulled out; the vehicle also sends an ATB activation signal to CAB-B, so that the CAB-B at the opposite end can acquire the ATB state of the CAB-A at the local end;

step 6: the ATP informs the turn-back state of the ATP to the ATO, the ATO lights the light on the ATB button to be steady according to the state, and the ATO displays the ATB icon on the DMI through the ATP;

and 7: after the ATP is switched into the ATB state, the driver end pulls out the key and uses the ATB activation signal output by the ATP to replace the cab activation signal of the key;

and 8: when the ATP receives the locomotive permission code, the driver end pushes an ATO departure button to depart, and the train automatically drives into a return traction line from a receiving station track;

(2) train return rail end changing

And step 9: after the ATO drives the train to enter the retracing traction line, the ATO stops under an ATP protection curve, the ATP keeps an ATB activation signal, and after the ATP finds that the train changes from moving to zero speed, a CAB at the CAB-B end is activated through a vehicle through line, the setting direction is forward, the zero position of a traction brake handle is realized, and the ATO is in an automatic driving mode;

step 10: after the CAB at the CAB-B end is activated, the CAB automatically enters an SB mode, and the CAB-A end is switched into an SL sleep mode; CAB-B uses train data sent by the A end to register and automatically enter a PS mode, ATP receives a locomotive permission code, ATP sets the state of an ATO departure relay to be 1 to inform ATO of automatic departure, and a retracing traction line is driven out;

(3) the process that the train exits the turn-back mode when exiting the turn-back rail:

step 11: after the ATO drives the train to enter the departure station track and stop stably, the train is automatically opened, the driver end is inserted with a key, the CAB-B end exits from the ATB activation state, the CAB-A is informed to exit from the ATB activation state, and the train exits from the ATB retracing mode.

Compared with the prior art, the invention has the following advantages:

(1) the invention changes the center CCS equipment into TSRS equipment on the CTCS2+ ATO system, other existing center equipment, ground equipment and interfaces are kept unchanged, the TSRS equipment is used for checking the route command of the train in the return-returning working mode, if the route command is the route to the return line, the ATB command of allowing departure is sent to the vehicle, if the route is the non-return line, the ATB command of allowing departure is not sent to the vehicle, at this time, even if the route is already processed, the vehicle can not send the train, manual intervention confirmation is needed, the safety of the automatic return-returning function of no person after the station is realized at the return station with the cross-line function of the state railway is ensured, the train can not drive into the non-return line under the unmanned driving condition because of wrong handling of the route, the state railway realizes the unmanned return after the station once the safety can be ensured, and the working strength of drivers is relieved, the time of turning back after shortening the station improves the efficiency of turning back of the station, all will have a qualitative promotion.

(2) On the premise that TSRS route check ensures unmanned automatic return safety after a state railway station, after a train automatically enters a return line and stops stably, a non-home terminal is automatically activated by a through data line additionally arranged on vehicle-mounted equipment at two ends to enter a working state, the home terminal automatically shifts to a sleep mode, the steps of running time of a change-end driver, network re-registration, train data input and the like are omitted, the end change time is shortened by more than 10 times compared with the return time after a traditional C2+ ATO station (the ATP change end is promoted to 9 seconds from 122 seconds), and the end change time is greatly shortened so that the return interval is less than 180 seconds.

(3) In conclusion, the two improvement points of the invention realize the scheme of unmanned turning back after the three-minute station of the complex cross-line station of the state railway. The technical bottleneck that the turn-back interval of a CTCS2+ ATO signal system adopted by urban railways cannot meet three minutes is solved, and the method is possible for realizing interconnection and intercommunication cross-line operation among national trunk railways, inter-city railways, urban railways and urban rail transit.

Drawings

FIG. 1 is a diagram of a prior art foldback process;

FIG. 2 is a schematic diagram of an unmanned automatic reentry route after a TSRS check station according to the present invention;

FIG. 3 is a flowchart of a terminal change procedure according to the present invention;

FIG. 4 is a timing diagram of a single vehicle turn back;

FIG. 5 is a schematic illustration of a list of single-vehicle hours of operation;

FIG. 6 is a schematic diagram of a multi-station post-reentry scenario 1;

FIG. 7 is a schematic diagram of a multi-station post-reentry scenario 2;

FIG. 8 is a schematic diagram of a multi-station post-reentry scenario 3;

fig. 9 is a timing diagram of multi-car station-turning-back tracking.

Detailed Description

The technical solutions in the embodiments of the present invention will be 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 some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

The invention provides a CTCS2+ ATO signal system-based automatic post-station turning-back method which is suitable for national railway lines designed according to requirements of 'design specifications of intercity railways', urban railways and the like, meets the requirement of turning-back interval of 3 minutes, and realizes the public transportation operation requirement of the urban railways.

The invention is suitable for the post-station unmanned automatic retracing method of the urban railway, and the method solves the potential safety hazard that an unmanned retracing train mistakenly drives into a non-retracing line and enters into other lines after the post-station unmanned retracing train of a retracing station yard with a line crossing function of the existing state railway is carried out on the basis of the automatic retracing after the existing CTCS2+ ATO station; the communication of vehicle-mounted equipment at two ends of the train set is realized by adding a through communication line, and the train automatically enters a return traction line and is stopped and then is activated by automatically changing the end through the data through line to enter a working state, so that the return change time of the train is greatly shortened, and the utilization rate of the return line is improved; therefore, the operation requirement that the turn-back time of urban railway public transport operation is less than 3 minutes is met.

The implementation of the invention is based on two safety criteria:

safety criterion 1: setting an Automatic Turn-Back (Automatic Turn Back) area, wherein when the train in the ATB Turn-Back mode is automatically turned Back by no person, the train must be ensured to be carried out in the area, otherwise, the train carries out EB emergency braking;

the security criterion 1 is implemented by the following scheme:

active transponder protection: and the active responder of the station signal machine towards the direction of the return line sets an ATB return area range data packet, the vehicle-mounted correct return line receives the link information of the ATB return area range data packet, and otherwise, the ATP outputs EB braking.

TSRS route protection: after the CTC transacts the return route, the TCC sends the return route number to the TSRS for checking, the TSRS verifies that the return route is the return route, then the TSRS sends an ATB departure permission command to the vehicle, the ATB departure button flickers, otherwise, the ATB departure command is forbidden.

ATP software protection: after a driver pulls out a key from a platform, the vehicle-mounted electronic parking system enters an ATB mode, the vehicle-mounted electronic parking system enters the platform again and inserts the key into the platform, and the vehicle-mounted electronic parking system exits the ATB mode.

Security criteria 2: after the unmanned automatic end switching of the vehicle-mounted device at the return line is activated, the vehicle-mounted device is still in an ATB activated state in a keyless state and the running direction is kept correct;

the security criterion 2 is implemented by the following scheme:

after the train stops stably on the return line, the ATP (end A) of the lead end activates a cab of a non-lead end (end B) through a through data line, the setting direction is forward, the zero position of a traction brake handle is realized, the ATO is in an effective state, and the end A is set to be in a dormant state.

The ATB retracing mode is a special operating state when performing a retracing operation in the train automatic driving operating mode.

The conditions for entering the ATB foldback mode by the post-station unmanned automatic foldback method are as follows:

1) the vehicle receives a turn-back permission command from the TSRS;

2) zero position of traction handle of non-head cab

3) The speed of the train is zero

4) ATO as an active mode

Conditions for exit of fold-back mode:

1) stopping the train platform stably;

2) opening a door of the train;

3) a driver enters a cab and inserts a key;

the invention relates to a post-station unmanned automatic turning-back process which comprises the following steps:

step 2: ATP obtains an ATB grant (CTCS-22 ═ 1) from TSRS, and the retrace grant is valid for a certain time, and after the retrace grant times out, ATP should delete the retrace grant. If the last time of the retrace permission is not expired and a new retrace permission is received, using the new retrace permission and restarting countdown of the validity period of the new permission; if the TSRS does not receive the acknowledgement message of the ATP within the specified time, the turn-back permission is sent again;

and step 3: the ATP obtains ATB turn-back permission of the TSRS, meets the precondition of entering turn-back, and if the ATP is not in the turn-back state, the ATP informs the ATO that an ATB button lamp is lighted to flicker, and prompts a driver to press an ATB button and enter an automatic turn-back state;

and 4, step 4: the driver presses an ATB button to apply to switch to an ATB state and output an ATB activation signal;

and 5: after the vehicle receives the ATB activation signal, the signal replaces a key to output an operator cab activation signal, and handle combination zero position information is output, so that the vehicle-mounted automatic driving mode can be still maintained after the handle is pulled out. The vehicle also sends an ATB activation signal to CAB-B, so that the CAB-B at the opposite end can acquire the ATB state of the CAB-A at the local end;

step 6: ATP informs ATO of the self-turning-back state, and the ATO lights the light on the ATB button to be steady according to the state. ATO displays the ATB icon on DMI through ATP;

and 7: after the ATP transitions to the ATB state, the driver unplugs the key. Using the ATB activation signal output by the ATP to replace the cab activation signal of the key;

and 8: when the ATP receives the locomotive permission code, the driver pushes an ATO departure button to send the vehicle. The train automatically drives into the return traction line from the train receiving station track.

(2) Train return rail end changing

step 10: after the CAB at the CAB-B end is activated, the CAB automatically enters an SB (standby mode) standby mode, and the CAB-A end is switched into an SL (sleeping mode) sleep mode; CAB-B uses train data sent by the end A to register and automatically enter a PS (partial Supervision mode) partial monitoring mode, ATP receives a locomotive permission code, ATP sets the state of an ATO departure relay to be 1 to inform ATO of automatic departure, and a retracing lead is output;

step 11: after the ATO drives the train to enter the departure station track and stop stably, the train is automatically opened, the driver inserts the key, the CAB-B end exits from the ATB activation state, the CAB-A is informed to exit from the ATB activation state, and the train exits from the ATB retracing mode.

Based on the turn-back scheme, the turn-back time after the traditional C2+ ATO station can be greatly reduced, the three parts are different from the traditional method, firstly, the TSRS checks the turn-back route, the national railway turn-back station type is complex compared with the subway station type, the turn-back station is usually a junction station with a line crossing function, no person automatically turns back the turn-back train after the station is adopted, the risk of entering other lines is caused, the scheme protects the risk, the turn-back route sent by the CTC under the ATB automatic turn-back working mode is sent to the TSRS by the TCC, the TSRS checks that the turn-back route is really the turn-back route, the TSRS sends an ATB turn-back permission command to the vehicle, and the vehicle can drive the train to automatically enter the turn-back line after receiving the TSRS turn-back command. The TSRS checks the reentry route data flow as shown in fig. 2.

Based on the scheme, the second part is different from the traditional C2+ ATO turning-back method, as can be seen from fig. 1, under the condition that a person turns back the train behind the traditional bead-delta station, 202 seconds are needed for activating the driving CAB at the other end, the scheme automatically activates a non-home terminal (CAB-B) driving CAB through data through wires additionally arranged on vehicle-mounted equipment at two ends, a home terminal ATP (CAB-A) automatically activates the driving CAB at a non-home terminal (CAB-B), the setting direction is forward, the zero position of a traction brake handle is zero, the ATO is in an automatic driving mode, the CAB-B automatically enters a standby mode after being activated, and the CAB-A is switched into a.

Based on the scheme, the third part is different from the traditional C2+ ATO turning-back method in that the registration time after the train end is changed is greatly shortened compared with the traditional C2+ ATO registration time, through vehicle-mounted equipment data through lines at two ends, a CAB-A end vehicle transmits information for train registration such as a driver number, a radio station ID, a train length and the like to a CAB-B end, and the CAB-B end automatically completes registration to enter a partial monitoring mode. Table 1 compares the conventional C2+ ATO zapping time to the zapping time for this scheme.

TABLE 1

After the train platform gets off a passenger, the TSRS sends an ATB turn-back permission command, a driver pulls out a key, gets off the train and presses an ATO departure button on the platform, the train automatically enters a turn-back rail, and after the train is stopped stably through an accurate responder arranged on the turn-back rail, the non-home-end driving platform is automatically activated to enter a working state, various ATP parameters do not need to be input, and the home-end driving platform automatically shifts to a sleep mode. The whole end changing process is finished in about 9 seconds, and after the return departure route is opened, the train automatically drives out the return line and enters the departure platform. Compared with the traditional C2+ ATO terminal-changing time, the method has the advantage that the terminal-changing time is greatly increased.

The following implementation is based on the same turn-back sequence of a single-pass vehicle. The detailed turn-back timing diagram of the bicycle is shown in fig. 4.

The single-train turning-back time sequence is divided into three parts according to the train operation purpose: the time of receiving a car, the time of returning a car, and the time of departure a car are shown in fig. 5.

The specific implementation of the scheme is explained in more detail by the following three vehicles in a typical post-station reentry working scene.

Scene 1: after a first vehicle enters the return line 1, transacting a vehicle receiving access path of a second vehicle IIG platform in the same direction (figure 6);

scene 2: a first vehicle leaves a clear turnout 1DG/7DG and enters an departure station IG, a turning line 1 and a turnout 1DG/7DG access section are unlocked in advance, and a second vehicle enters a receiving access of a turning rail 1 (figure 7);

scene 3: the first station IG is driven out of the station after passengers get on, the second vehicle is driven into the return rail 1, and the third vehicle processes a receiving route. (FIG. 8)

The train works at a turn-back station, and three main operation areas are respectively: and a time sequence diagram 9 of tracking three vehicles to enter a turn-back station is obtained according to the turn-back time sequence of the single vehicle and the time occupied in the operation area.

In fig. 9, under the condition that the time from the handling of the train entering the receiving station IIG to the driving of the train away from the departure station IG of each train is the same, since the trains are all the returning operation for handling the entering return route 1, in order to maximize the use efficiency of the station and the return route, when the front train leaves the switch area in front of the return route 1 (the second 80 seconds of the first train are finished), the second train enters the return route of the return route 1 (the first 80 seconds of the second train are started), and thus the time for handling the receiving station track IIG of the second train can be 169 seconds after the first train handles the receiving route. Therefore, the arrival interval of the receiving station track can be deduced to be 148, 35, 9, 26, 54, 14, 63 and 26 for 169 seconds. Since the total operation time of each vehicle is the same, the departure track departure interval is 169 seconds, and the 3-minute vehicle receiving interval and the departure interval of the turn-back station are met.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The method is characterized in that through adding a through communication line, vehicle-mounted equipment at two ends of a locomotive group is enabled to communicate, a train automatically enters a return lead line and is stopped and then is activated to enter a working state through a data through line, the time for returning and changing ends of the train is greatly shortened, the utilization rate of the return line is improved, and therefore the operation requirement that the time for returning the urban railway in public transport operation is less than 3 minutes is met.

2. The method according to claim 1, wherein the method is implemented based on two safety criteria, namely a first safety criterion and a second safety criterion.

3. The method according to claim 2, wherein the first safety criterion is: and setting an ATB automatic turn-back area, wherein when the train in the ATB turn-back mode is automatically turned back without people, the train is ensured to be carried out in the area, otherwise, the train is carried out with EB emergency braking.

4. The method according to claim 3, wherein the first safety criterion is implemented by the following steps:

5. The method according to claim 2, wherein the second safety criterion is: after the automatic end switching activation of the return line is carried out by the vehicle-mounted equipment without people, the vehicle-mounted equipment still needs to be in an ATB (automatic train bus) activation state in a keyless state and the running direction is correct.

6. The method according to claim 5, wherein the implementation process of the second safety criterion is as follows:

7. The method according to claim 2, wherein the ATB retracing mode is a special operation state during retracing operation in an automatic train driving mode.

8. The method according to claim 7, wherein the entry conditions of the ATB foldback mode simultaneously satisfy the following conditions: