CN109640354B

CN109640354B - Method for detecting train-ground wireless message delay

Info

Publication number: CN109640354B
Application number: CN201910049024.9A
Authority: CN
Inventors: 韩涛; 陈俊; 李宏洋; 夏明�; 侯晓伟; 张炳坤; 赖昊
Original assignee: Casco Signal Ltd
Current assignee: Casco Signal Ltd
Priority date: 2019-01-18
Filing date: 2019-01-18
Publication date: 2022-07-15
Anticipated expiration: 2039-01-18
Also published as: CN109640354A

Abstract

The invention relates to a train-ground wireless message delay detection method, which introduces train running speed into a calculation factor and comprises the following steps: 1) recording a train-ground timestamp and a train speed provided in the train-ground message each time when an effective train-ground wireless message is received, and establishing a wireless message timestamp list and a train running speed list by taking a receiving sequence as a reference; 2) acquiring a time stamp of the CTCS when the train-ground wireless message is received; 3) when a new train-ground wireless message is received each time, delay time calculation is carried out based on the created wireless message time stamp list and the train running speed list, and a final message delay time parameter delta Tdelay is obtained; 4) and judging whether the delta Tdelay exceeds a set delay time parameter threshold value, and if so, processing according to a fault reversal safety method. Compared with the prior art, the method has the advantages that the train running speed is introduced into the calculation factor, and whether the train-ground wireless message is delayed or not when the train running speed exceeds more than 200km/h can be detected.

Description

Method for detecting train-ground wireless message delay

Technical Field

The invention relates to a railway signal system, in particular to a method for detecting train-ground wireless message delay for an inter-city railway train control system.

Background

Chinese patent application No. CN201610159952.7 discloses a method for detecting inter-city railway GSM-R wireless message delay, which is applied to inter-city railway lines in CTCS-2+ ATO mode, the main function of a Communication Control server (Communication and Control System, hereinafter referred to as CCS) is an important device for realizing wireless Communication between trackside and vehicle, the CCS receives a screen door opening and closing command from a vehicle-mounted System, so as to realize management of the screen door opening and closing command, and the CCS forwards an operation plan received from a dispatching centralized management System to the vehicle-mounted System, so as to meet the requirement that the vehicle-mounted System can automatically drive according to the operation plan. The CCS is connected with the vehicle-mounted system through a GSM-R wireless network, and the CCS has certain requirements on the real-time performance of wireless messages based on the GSM-R. Therefore, the method mainly judges whether the vehicle-mounted wireless message is delayed or not and carries out protection processing on the delayed message.

However, the method can only be applied to the inter-city railway line of the CTCS-2+ ATO mode, and the detection precision of the method cannot be ensured when the train running speed is high.

Disclosure of Invention

The present invention is directed to a method for detecting a wireless message delay between a vehicle and an earth, which overcomes the above-mentioned drawbacks of the prior art.

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

a method for detecting train-to-ground wireless message delays that incorporates train operating speed into a calculation factor, said method comprising the steps of:

1) recording a train-ground timestamp T _ TRAIN (n) and a train running speed L _ train _ speed (n) provided in the train-ground message every time when a valid train-ground wireless message is received, and creating a wireless message timestamp list and a train running speed list by taking a receiving sequence as a reference;

2) corresponding to T _ TRAIN (n) in 1), acquiring a timestamp T _ CTCS (n) of CTCS when a vehicle-ground wireless message is received, and corresponding to T _ TRAIN (n), recording the T _ CTCS (n) to a wireless message timestamp list; corresponding to L _ train _ speed (n) in the step 1), recording the L _ train _ speed (n) into a train running speed list;

3) when a new train-ground wireless message is received each time, delay time calculation is carried out based on the created wireless message time stamp list and the train running speed time list, and a final message delay time parameter delta Tdelay is obtained;

4) and judging whether the delta Tdelay exceeds a set delay time parameter threshold, and if so, processing according to a fault reversal safety method.

Preferably, n in T _ train (n) is the master operation cycle number of the current CTCS.

Preferably, the time information of at most 9 latest received wireless messages is maintained in the wireless message time stamp list; and maintaining the train running information of the latest received 9 wireless messages at most in the train running speed list.

Preferably, the delay time is calculated as follows:

i. after the valid vehicle-ground messages are received in the nth period, calculating the difference value delta TT (n-1) between the time stamp of the currently received vehicle-ground messages and the time stamp of the vehicle-ground messages in the (n-1) th period;

calculating the difference value deltaCT (n-1) between the time stamp of the CTCS when the train-ground message is received currently and the time stamp of the CTCS when the train-ground message is received in the (n-1) th period;

calculating a difference Δ T (n-1) ═ Δ CT (n-1) - Δtt (n-1) between Δ CT (n-1) and Δ TT (n-1);

traversing the latest received 9 pieces of radio message time information maintained in the radio message time stamp list, and calculating corresponding Δ T according to steps i, ii and iii to obtain a group of Δ Ti (i ═ n-1, n-2, … n-9);

and v, performing weight operation processing on the calculated delta Ti and the train speed L _ train _ speed (n) of each train-ground message in the created train running speed list by adopting a Fibonacci sequence to obtain a final message delay time parameter delta Tdelay.

Preferably, when the train running speed is 400km/h, the Doppler frequency shift is +/-333.3 HZ, and in the LTE-R network, the train can support the train running speed of 400km/h at most by the existing Doppler compensation method, so that 400km/h is taken as the threshold value of the train running speed.

Preferably, the method is suitable for detecting the GSM-R system and simultaneously suitable for the delayed detection of the vehicle-ground wireless message of the future LTE-R system.

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

1. the method is not only suitable for detecting the GSM-R system, but also suitable for the delay detection of the vehicle-ground wireless message of the LTE-R system in the future.

2. The original method only considers the method for detecting the train-ground wireless message delay in the intercity railway line with the train running speed of 200 km/h. The method introduces the train running speed into the calculation factor, and can detect whether the train-ground wireless message is delayed when the train running speed exceeds more than 200 km/h.

3. The higher the train speed, the greater the doppler shift caused by the train speed. When the running speed of the train is 400km/h, through a Doppler frequency shift calculation formula:

the doppler shift can be calculated: and +/-333.3 Hz, wherein the train running speed at the moment seriously influences the time delay of the train-ground wireless message, the running speed of the train can be supported to be 400km/h at most by compensating the Doppler frequency shift, and 400km/h is selected as the maximum running speed of the train in the method.

Drawings

FIG. 1 is a flow chart of the operation of the present invention;

FIG. 2 is a diagram illustrating the operation of the present invention.

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 improves a method for detecting intercity railway GSM-R wireless message delay: the invention is not only applied to the inter-city railway line of the CTCS-2+ ATO mode, but also applied to the CTCS-3 and CTCS-4 and a train operation control system completely based on wireless communication (LTE-R) transmission information in the future; the invention introduces train speed factor in the original method to support higher train running speed, whether train-ground wireless message is delayed; the invention considers the condition of compensating the Doppler frequency shift deviation, and the train can support the highest running speed.

The process flow of the method is depicted in the schematic diagram 1. The method mainly comprises the following steps:

step 1, starting a task of the method, creating a time stamp list and finishing initialization;

step 2, judging whether the time stamp list is available for the newly received message, if not, not judging whether the message is delayed (when the n is less than 9, judging whether the message is effective because the acquired time information is not sufficient and whether the wireless message is delayed is not judged); if so, proceed to step 3.

Step 3, if the timestamp list is available, sequentially extracting the wireless message timestamp information (T _ train (i), T _ ctcs (i)) from the timestamp list, and performing calculation to obtain a set of values (Δ tt (i) and Δ ct (i)), and calculating to obtain Δ T (i) according to the values (Δ T), (i) and Δ tt (i), where the calculation code is mainly as follows, as shown in fig. 2:

step 4, circularly traversing the timestamp list, judging whether all recorded timestamp information is completely traversed, if so, entering step 5, and if not, continuing to execute step 3;

step 5, weighting the train speed corresponding to the train-ground message in the group of 9 (delta TT (i) and delta CT (i)) and the time stamp list obtained by the operation according to Fibonacci arrangement, and calculating to obtain final delay time; the specific calculation method is as follows:

i. selecting a set of Fibonacci array numbers (1,1,2,3,5,8,13,21, 34);

summing the number of permutations and dividing and summing the number of values in each permutation to obtain a new combination (1/80,1/80,2/80,3/80,5/80,8/80,13/80,21/80, 34/80);

and iii, performing weight calculation by using the obtained new arrangement to obtain final delay time, wherein the calculation formula is as follows:

△Tdelay＝△T(n-1)*(34/80)*l_train_speed(n-1)+△T(n-2)*21/80*l_train_speed(n-2)+△T(n-3)*13/80*l_train_speed(n-3)+△T(n-4)*8/80*l_train_speed(n-4)+△T(n-5)*5/80*l_train_speed(n-5)+△T(n-6)*3/80*l_train_speed(n-6)+△T(n-7)*2/80*l_train_speed(n-7)+△T(n-8)*1/80*l_train_speed(n-8)+△T(n-9)*1/80*l_train_speed(n-9)；

the main implementation code is as follows:

and 6, judging according to the calculated delay time, namely if the calculated delay time is greater than an allowable threshold value, considering that the wireless message is invalid, and finishing the processing of the message. Otherwise, the message is considered to be valid, and the timestamp information (T _ Train, T _ CTCS) of the message is recorded in the timestamp list.

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. A method for detecting train-to-ground wireless message delay that incorporates train operating speed into a calculation factor, said method comprising the steps of:

2) corresponding to T _ TRAIN (n) in 1), acquiring a timestamp T _ CTCS (n) of CTCS when a vehicle-ground wireless message is received, and corresponding to T _ TRAIN (n), recording the T _ CTCS (n) to a wireless message timestamp list; corresponding to the L _ train _ speed (n) in the step 1), recording the L _ train _ speed (n) into a train running speed list;

4) judging whether the delta Tdelay exceeds a set delay time parameter threshold value, and if so, processing according to a fault reverse safety method;

the specific process of the delay time is as follows:

calculating the difference value deltaCT (n-1) between the time stamp of the CTCS when the vehicle-ground message is received currently and the time stamp of the CTCS when the vehicle-ground message is received in the (n-1) th period;

v, performing weight operation processing on the calculated delta Ti and the train speed L _ train _ speed (n) of each train-ground message in the created train running speed list by adopting a Fibonacci number sequence to obtain a final message delay time parameter delta Tdelay.

2. The method as claimed in claim 1, wherein n in T _ train (n) is the master operation cycle number of the current CTCS.

3. A method as claimed in claim 1, wherein the time information of at most 9 latest received messages is maintained in the time stamp list of messages; and maintaining the train running information of the latest received 9 wireless messages at most in the train running speed list.

4. The method as claimed in claim 1, wherein the doppler shift is ± 333.3HZ when the train runs at 400km/h, and in the LTE-R network, the train can support the train running at 400km/h at maximum by using the existing doppler compensation method, so that 400km/h is used as the threshold of the train running speed.

5. A method for detecting vehicular-to-terrestrial wireless message delay according to claim 1, wherein the method is adapted to detect GSM-R system and to detect the delay of vehicular-to-terrestrial wireless message of LTE-R system in future.