US-12625279-B2 - Beidou satellite-based initial train positioning calculation method and positioning system

US12625279B2US 12625279 B2US12625279 B2US 12625279B2US-12625279-B2

Abstract

The present disclosure provides a Beidou satellite-based initial train positioning calculation method, and a positioning system. The initial train positioning calculation method includes the following operations: S1: receiving Beidou satellite signals to obtain Beidou navigation data, and verifying the validity of the data; S2: obtaining a track electronic map file, and verifying the validity of the file; S3: based on the Beidou navigation data and the track electronic map file, screening out possible track sections of the current position of the train as candidate track sections, and putting the candidate track sections into a set TrackList; S4: determining whether the number of the candidate track sections in the TrackList is 1; and S5: according to the determination result, selecting to execute a single track position comparison algorithm or a non-single track position comparison algorithm.

Inventors

Xianliang XU
Ziwei LI
Yazhong ZHANG
Fengwei YANG
Hongfei AN
Wen Yang
Dening CAO

Assignees

CASCO SIGNAL LTD.

Dates

Publication Date: 20260512
Application Date: 20221110
Priority Date: 20220530

Claims (16)

1 . A method of operating a train, comprising: receiving satellite signals to obtain navigation data; obtaining a track electronic map file; based on the navigation data and the track electronic map file, selecting one or more track sections of a current position of the train as candidate track sections, and putting each of the candidate track sections into a set TrackList; determining whether a number of the candidate track sections in the set TrackList is 1; according to the determination result, selecting a single track position comparison algorithm or a non-single track position comparison algorithm to execute to determine an initial train position of the train; and controlling the train to operate according to the initial train position, wherein the non-single track position comparison algorithm comprises: performing initialization, and taking out all the track sections of the TrackList and respectively denoting the track sections as T1, T2, . . . , Tn, a variable x=1; obtaining current navigation data, performing a map matching algorithm on the current navigation data and each of the track sections T1, T2 . . . Tn, and according to the map matching result, generating a track-based one-dimensional train position MTLx comprising a station number, a track number and a parallel track offset; determining whether the MTLx is valid or not; determining whether {MTL1, . . . , MTLn} has only a unique valid value; in response to {MTL1 . . . MTLn} does not have only a unique valid value, exiting; and initializing the unique valid one-dimensional train position as the initial train position, such that the initial train position is determined successfully.
2 . The method according to claim 1 , wherein the according to the determination result, selecting the single track position comparison algorithm or the non-single track position comparison algorithm comprises: in response to the number of the candidate track sections in the set TrackList is greater than 1, executing the non-single track position comparison algorithm; in response to the number of the candidate track sections in the set TrackList is equal to 1, determining, based on the track electronic map file, whether the candidate track sections have other parallel track sections; in response to the candidate track sections have other parallel track sections, putting each of the parallel track sections into the set TrackList, and executing the non-single track position comparison algorithm; and in response to the candidate track sections do not have other parallel track, executing the single track position comparison algorithm.
3 . The method according to claim 1 , wherein the one-dimensional train position MTLx further comprises a vertical track offset; and wherein the determining whether the MTLx is valid or not comprises: determining whether an absolute value of the vertical track offset of MTLx is less than or equal to Threshold1, Threshold1 being a non-single track offset threshold, Threshold1>0: in response to the absolute value of the vertical track offset of MTLx is less than or equal to Threshold1, MTLx is valid, and in response to the absolute value of the vertical track offset of MTLx is not less than or equal to Threshold1, MTLx is invalid.
4 . The method according to claim 1 , further comprises: setting a valid train position counter N=0; and the non-single track position comparison algorithm further comprises: increasing the valid train position counter to be an updated valid train position counter, determining whether the updated valid train position counter is larger than or equal to N1, N 1 being a non-single track valid train position counting threshold and being an integer greater than 0: in response to the updated valid train position counter is larger than or equal to N1, initializing the unique valid one-dimensional train position as the initial train position, and in response to the updated valid train position counter is not larger than or equal to N1, obtaining current navigation data, performing a map matching algorithm on the current navigation data and each of the track sections T1, T2 . . . , Tn, and according to the map matching result, generating a track-based one-dimensional train position MTLx comprising a station number, a track number and a parallel track offset.
5 . The method according to claim 1 , wherein the single track position comparison algorithm comprises: obtaining current navigation data, performing a map matching algorithm on the current navigation data and the candidate track sections, and according to the map matching result, generating a track-based one-dimensional train position MTLD comprising a station number, a track number and a parallel track offset; determining whether the MTLD is valid: in response to determining whether the MTLD is valid, exiting; and initializing the MTLD as the initial train position, such that the initial train position is determined successfully.
6 . The method according to claim 5 , wherein the one-dimensional train position MTLD further comprises a vertical track offset; and wherein the determining whether the MTLD is valid comprises: determining whether |the vertical track offset of MTLD|≤Threshold2, Threshold2 being a single track offset threshold.
7 . The method according to claim 5 , further comprising: performing initialization, setting a valid train position counter N=0; and increasing the valid train position counter to be an updated valid train position counter, determining whether the updated valid train position counter is larger than or equal to N2, N2 being a single track valid track position counting threshold and being an integer greater than 0: in response to the updated valid train position counter is larger than or equal to N2, initializing the MTLD as the initial train position, and in response to the updated valid train position counter is not larger than or equal to N2, obtaining current navigation data, performing a map matching algorithm on the current navigation data and the candidate track sections, and according to the map matching result, generating a track-based one-dimensional train position MTLD comprising a station number, a track number and a parallel track offset.
8 . A satellite positioning system, comprising: a vehicle-mounted subsystem comprising: a first navigation receiver being capable of receiving the satellite signal and obtain the track electronic map file; at least one processor; and a memory coupled to the at least one processor to store instructions, which when executed by the at least one processor, cause the satellite positioning system to perform operations, the operations comprising: based on the navigation data and the track electronic map file, selecting one or more track sections of a current position of a train as candidate track sections, and putting each of the candidate track sections into a set TrackList; determining whether a number of the candidate track sections in the set TrackList is 1; according to the determination result, selecting a single track position comparison algorithm or a non-single track position comparison algorithm to execute to determine an initial train position of the train; and controlling the train to operate according to the initial train position, wherein the non-single track position comparison algorithm comprises: performing initialization, and taking out all the track sections of the TrackList and respectively denoting the track sections as T1, T2, . . . , Tn, a variable x=1; obtaining current navigation data, performing a map matching algorithm on the current navigation data and each of the track sections T1, T2, . . . Tn, and according to the map matching result, generating a track-based one-dimensional train position MTLx comprising a station number, a track number and a parallel track offset; determining whether the MTLx is valid or not; determining whether {MTL1, . . . MTLn} has only a unique valid value: in response to {MTL1, . . . MTLn} does not have only a unique valid value, exiting; and initializing the unique valid one-dimensional train position as the initial train position, such that the initial train position is determined successfully.
9 . The satellite positioning system according to claim 8 , further comprising: a second navigation receiver mounted on the train, being identical and mutually backup to the first navigation receiver.
10 . The satellite positioning system according to claim 9 , wherein the first navigation receiver and the second navigation receiver respectively perform operation to output data, the validity of the data is determined by a comparison algorithm, and the final valid train position is obtained when the data from the first navigation receiver and the second navigation receiver are consistent.
11 . The satellite positioning system according to claim 8 , further comprising a ground subsystem comprising a navigation receiver base station, wherein the navigation receiver base station receives a satellite signal and transmits a carrier phase differential signal to the vehicle-mounted subsystem, and is configured to assist the vehicle-mounted subsystem in performing a train position differential correction to improve a train positioning precision.
12 . The satellite positioning system according to claim 8 , wherein the according to the determination result, selecting the single track position comparison algorithm or the non-single track position comparison algorithm comprises: in response to the number of the candidate track sections in the set TrackList is greater than 1, executing the non-single track position comparison algorithm; in response to the number of the candidate track sections in the set TrackList is equal to 1, determining, based on the track electronic map file, whether the candidate track sections have other parallel track sections; in response to the candidate track sections have other parallel track sections, putting each of the parallel track sections into the set TrackList, and executing the non-single track position comparison algorithm; and in response to the candidate track sections do not have other parallel track, executing the single track position comparison algorithm.
13 . The satellite positioning system according to claim 8 , wherein the one-dimensional train position MTLx further comprises a vertical track offset; and wherein the determining whether the MTLx is valid or not comprises: determining whether an absolute value of the vertical track offset of MTLx is less than or equal to Threshold1, Threshold1 being a non-single track offset threshold, Threshold1>0: in response to the absolute value of the vertical track offset of MTLx is less than or equal to Threshold1, MTLx is valid, and in response to the absolute value of the vertical track offset of MTLx is not less than or equal to Threshold1, MTLx is invalid.
14 . A non-transitory machine-readable medium having instructions stored therein, which when executed by at least one processor, cause the at least one processor to perform operations, the operations including: receiving satellite signals to obtain navigation data; obtaining a track electronic map file; based on the navigation data and the track electronic map file, selecting one or more track sections of a current position of the train as candidate track sections, and putting each of the candidate track sections into a set TrackList; determining whether a number of the candidate track sections in the set TrackList is 1; according to the determination result, selecting a single track position comparison algorithm or a non-single track position comparison algorithm to execute to determine an initial train position of the train; and controlling the train to operate according to the initial train position, wherein the non-single track position comparison algorithm comprises: performing initialization, and taking out all the track sections of the TrackList and respectively denoting the track sections as T1, T2, . . . , Tn, a variable x=1; obtaining current navigation data, performing a map matching algorithm on the current navigation data and each of the track sections T1, T2, . . . Tn, and according to the map matching result, generating a track-based one-dimensional train position MTLx comprising a station number, a track number and a parallel track offset; determining whether the MTLx is valid or not; determining whether {MTL1, . . . , MTLn} has only a unique valid value: in response to {MTL1, . . . , MTLn} does not have only a unique valid value, exiting; and initializing the unique valid one-dimensional train position as the initial train position, such that the initial train position is determined successfully.
15 . The non-transitory machine-readable medium according to claim 14 , wherein the according to the determination result, selecting the single track position comparison algorithm or the non-single track position comparison algorithm comprises: in response to the number of the candidate track sections in the set TrackList is greater than 1, executing the non-single track position comparison algorithm; in response to the number of the candidate track sections in the set TrackList is equal to 1, determining, based on the track electronic map file, whether the candidate track sections have other parallel track sections; in response to the candidate track sections have other parallel track sections, putting each of the parallel track sections into the set TrackList, and executing the non-single track position comparison algorithm; and in response to the candidate track sections do not have other parallel track, executing the single track position comparison algorithm.
16 . The non-transitory machine-readable medium according to claim 14 , wherein the one-dimensional train position MTLx further comprises a vertical track offset; and wherein the determining whether the MTLx is valid or not comprises: determining whether an absolute value of the vertical track offset of MTLx is less than or equal to Threshold1, Threshold1 being a non-single track offset threshold, Threshold1>0: in response to the absolute value of the vertical track offset of MTLx is less than or equal to Threshold1, MTLx is valid, and in response to the absolute value of the vertical track offset of MTLx is not less than or equal to Threshold1, MTLx is invalid.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Stage of International Application No. PCT/CN2022/131080 filed on Nov. 10, 2022, which claims priority to Chinese Patent Application No. 202210600655.7 filed on May 30, 2022. Both of the aforementioned applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present disclosure relates to the field of train positioning, and in particular to a Beidou satellite-based initial train positioning calculation method, and a positioning system. BACKGROUND Train positioning is a key technology of a train operation control system. High-precision train position information and accurate track occupancy information are crucial to the safe operation of trains in an interval and the crossing, intersection or shunting operation in a station. As the basis of the reliable operation of the train, rapidly confirming the position of the train will greatly improve the operation efficiency of railways, which is of great significance in calculating the moving direction of the train and applying resources. At present, the initial train position is widely confirmed by the position of a transponder that the train passes through, but this method requires a large number of ground devices, which brings the problems of high construction cost and difficult maintenance and also limits the operation efficiency of the train. A satellite positioning technology has received widespread attention and application due to the real-time, high-precision and all-weather characteristics. In particular, in 2020, the Beidou 3 satellite was networked successfully. The Beidou navigation system independently developed by China further expands the service range and already has the positioning precision comparable to that of the GPS navigation system. With the differential positioning system, the positioning error can be shortened to below a meter level, and the ability of being applied to train positioning can be fully achieved. The Beidou satellite navigation is applied to the field of train positioning, so that the initial position can be calculated in the case of not moving the train after starting, the advantages of low cost and high autonomy can be greatly exerted, and the carrying efficiency of the train can be improved. SUMMARY An objective of the present disclosure is to provide a Beidou satellite-based initial train positioning calculation method, and a positioning system, so that the defects in the prior art can be overcome, the initial position can be calculated by utilizing the all-weather and real-time characteristics of satellite positioning in the case of not moving the train after starting, and the carrying efficiency of vehicles can be improved. To achieve the above objective, the present disclosure is implemented by the following technical solutions: A satellite-based initial train positioning calculation method includes the following steps: S1: receiving Beidou satellite signals to obtain Beidou navigation data;S2: obtaining a track electronic map file;S3: based on the Beidou navigation data and the track electronic map file, screening out possible track sections of current positions of the train as candidate track sections, and putting each of the candidate track sections into a set TrackList;S4: determining whether the number of the candidate track sections in the set TrackList is 1; andS5: according to the determination result, selecting to execute a single track position comparison algorithm or a non-single track position comparison algorithm. In one embodiment, the operation S5 includes: if the number of the candidate track sections in the set TrackList is greater than 1, executing the non-single track position comparison algorithm;if the number of the candidate track sections in the set TrackList is equal to 1, determining, based on the track electronic map file, whether the candidate track sections have other parallel track sections;if yes, putting each of the parallel track sections into the set TrackList, and executing the non-single track position comparison algorithm; andif not, executing the single track position comparison algorithm. In one embodiment, the non-single track position comparison algorithm includes the following operations: F1: performing initialization, and taking all the track sections out of the TrackList and respectively denoting same as T1, T2, . . . , Tn, a variable x=1;F2: obtaining current Beidou navigation data, performing a map matching algorithm on the current Beidou navigation data and Tx, and according to the map matching result, generating a track-based one-dimensional train position MTLx, including a station number, a track number and a parallel track offset;F3: determining whether MTLx is valid or not;F4: x=x+1, determining whether x>n:if yes, performing Operation F5, andif not, returning to Operation F2;F5: determining whether only unique value of {MTL1, . . . , MTLn} is valid:if not, exiting; an