KR100694512B1 - Method for correcting train positioning error in wayside radio station - Google Patents

Abstract

The present invention relates to a train positioning error correction method in a ground radio station that can determine the position more accurately by correcting the error that may occur when positioning the mobile chain train moving along a certain line.

In order to accomplish this, the present invention provides a method for extracting a sampling signal from a phase information signal received by a terrestrial radio station receiver and a reference signal generated by a signal generator of a terrestrial radio station and a signal transmitted by a next-generation radio station corresponding to the reference signal. Finding a sample whose sign is changed in the sampling signal of the reference signal and the phase information signal, calculating f (t) = 0 having a magnitude of zero in the sample whose sign is changed, Obtaining the time difference t _b -t _a using the time t _a of the reference signal and the time t _b of the phase information signal of t with f (t) = 0, and the time difference in the database of the ground radio station. The invention is characterized in that it comprises a step of searching for the position of the next wireless radio station, and outputting the searched position information.

Phase difference, train tracking, location tracking, ground radio station, car radio station, error correction

Description

Method for correcting train positioning error in wayside radio station             

1 is a block diagram of transmission and reception between a mobile radio station and a mobile radio station according to the present invention;

2 is a diagram illustrating a sampling signal of a position information signal and a reference signal according to the present invention;

3 is a flowchart illustrating a position correction method according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10 (WRS1, WRS2, WRS3)-terrestrial radio stations,

11-generator, 13-transmitter,

14-receiver, 16-computer,

20 (VRS)-Onboard Radio Station, 21-Receiver,

23-transmitter.

The present invention relates to a position tracking system for a mobile chain train moving along a certain line, and more particularly, to locate a train in a ground radio station to correct a position error more accurately by positioning errors. It relates to a correction method.

The train position detection is the most important information required to control the distance between trains between stations, and to control the course of trains in stations.It is installed on trains in situations where safety and reliability are considered as the top priority. The accuracy of location tracking is more important than factors such as the size, power consumption and cost of mobile stations.In unmanned driving systems such as lightweight trains, the location of each railway vehicle must be accurately identified so that these vehicles can be controlled and operated efficiently. It is supposed to be.

Conventionally, the position tracking technology used is a GPS (Global Positioning System) technology, which is a position tracking system using satellites, a time of arrival (TOA) method using propagation delay time between fixed and mobile stations on the ground as a method of arrival time, TDOA (Time Difference Of Arrival) method using the time difference that the radio wave transmitted from mobile station reaches each base station as arrival time difference method, AOA (Angle Of) using the angle at which radio wave transmitted from mobile station reaches fixed station as arrival angle method And methods using the strength of radio waves transmitted from mobile stations are introduced.

The GPS-based method can be used in the case where the moving range is wide because the position can be tracked anywhere without obstacles by the receiving terminal. However, it is difficult to apply to a system that operates mainly in the city center or underground, such as light rail. The method of using the strength of radio waves received by fixed radio stations and AOA is difficult to apply due to many obstacles and underground sections in the case of lightweight trains, so the TOA or TDOA is currently mainly used. However, even in the case of the TOA or TDOA, there is a problem that it is difficult to synchronize the time of each fixed radio station and an error occurs accordingly.

Therefore, it is important not only to select and use appropriate methods according to the environment and object of application, but also to have reliability.

Accordingly, the present invention has been invented a position tracking method using a phase difference that can maintain a safe train interval through the above method, which can increase the reliability of the railroad, received when the train moves on the track according to the presence or absence of a branch point Comparing the phase information signal and the reference signal to obtain the phase information of the train, the position of the moving station is determined by estimating the position of the vehicle radio station in the ground radio station. The purpose is to provide a train tracking system.

According to an aspect of the present invention, a sampling signal is respectively obtained from a phase information signal received by a terrestrial radio station receiver from a reference signal generated by a computer in a signal generator of a terrestrial radio station and a signal transmitted by a next-generation radio station corresponding to the reference signal. Extracting, finding a sample whose sign is changed in the sampling signal of the reference signal and the phase information signal, calculating f (t) = 0 having a magnitude of zero in the sample whose sign is changed, and f (t) = 0 Obtaining the time difference t _b -t _a using the time t _a of the reference signal of t and the time t _b of the phase information signal of t with f (t) = 0, and time difference in the database of the ground radio station. And searching for the location of the next wireless radio station for the step of outputting the searched location information.

In the above, the step of extracting the sampling signal from the reference signal and the phase information signal is characterized in that to extract the signal from the signal generator and receiver of the terrestrial radio station after removing the DC component through the capacitor.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of transmission and reception between a next-generation radio station and a mobile radio station according to the present invention.

As shown in the accompanying drawings, ground radio stations (10: WRS1, WRS2, WRS3 ....) are installed around the track, and trains are equipped with a vehicle radio station (20: VRS). In the track area Zone1, the position of the train is calculated by the ground radio station WRS1, and in the track area Zone2, the train position is calculated by the ground radio station WRS2.

Hereinafter, the process of tracking the position of the train wirelessly from the ground radio station and the process of correcting the error will be described in detail.

The signal generator 11 generates a sine wave signal or a triangle wave signal necessary for positioning as a reference signal. In order to cut off the DC signal that may be included in the signal generated by the signal generator 11, the signal is electrically connected to the condenser 12. The interval between the ground radio stations installed around the line is determined by the frequency of the signal generated by the signal generator 11. The higher the frequency, the higher the distance between ground radio stations, and the lower the distance, the greater the distance between ground radio stations.

The capacitor 12 electrically connected in series between the signal generator 11 and the transmitter 13 blocks the DC signal (DC signal) from the signal generated by the signal generator 11 and transmits only the AC signal (AC signal). (13) serves to deliver.

The reference signal of the signal generator 11 passing through the condenser 12 enters the input terminal of the transmitter 13. This signal is modulated by the transmitter 11 and loaded on the channel 1 (CH1) of the carrier wave and sent to the receiver 21 of the next-generation radio station 20.

The signal input to the input terminal of the transmitter 13 is defined as in Equation 1 below.

Where A is the magnitude of the signal, f is the frequency of the signal, c is the magnitude of the velocity of the radio wave (the magnitude of the speed of light), and x is the position variable (here, the next-generation radio station for the transmitter 13 of the terrestrial radio station 10) 20 means a variable of the position of the receiver 21, t is a time variable (depending on the position of the receiver 21 of the on-board radio station 20 from the transmitter 13 of the terrestrial radio station 10 to the receiver 21). Time variable for the signal to be delivered).

The receiver 21 of the on-board radio station 20 receives a signal from the transmitter 13 of the terrestrial radio station 10 and demodulates the signal from the carrier wave. The channel of the carrier sent from the transmitter 13 of the ground radio station 10 to the receiver 21 of the next-order radio station 20 should use the same channel. The receiver 21 of the on-board radio station 20 and the condenser 22 are electrically connected to each other, and the demodulated signal from the receiver 21 of the on-board radio station 20 is transmitted to the condenser 22.

The condenser 22 removes the DC component from the demodulated signal of the receiver 21 of the on-vehicle radio station 20, and then sends a signal from which the DC component is removed to the transmitter 23 of the on-vehicle radio station 20. The signal passing through the condenser 22 in the on-board wireless station 20 is represented by Equation 2 below.

)이 있을 것이다.In Equation 2, the phase delay caused by the time delay t ₁ taken from the transmitter 13 of the terrestrial radio station 10 to the receiver 21 of the next radio station 20 and the transceiver 21 and the condenser. (22) Phase delay term that occurs when passing

Will be).

The transmitter 23 of the onboard wireless station 20 is electrically connected in series with the capacitor 22. Therefore, the signal passing through the condenser 22 enters the input terminal of the transmitter 23, and this signal is modulated and transmitted to the receiver 14 of the terrestrial radio station 10 wirelessly. When transmitting from the transmitter 23 of the on-board radio station 20 to the receiver 14 of the terrestrial radio station 10, the carrier channel is used by the transmitter 13 of the terrestrial radio station 10 and the receiver 21 of the on-board radio station 20. Carrier channels that are not used should be used. In FIG. 1, channel 4 (CH 4) is used in the sense that a channel different from channel 1 (CH 1) is used. If the adjacent channel is used, the adjacent channel is not used because there is signal interference. Preferably, carriers of different frequency bands may be used.

The receiver 14 of the terrestrial radio station 10 receives and demodulates a signal sent from the transmitter 23 of the on-board radio station 20. The demodulated signal removes the direct current component through the condenser 15. The signal whose DC component is filtered by the condenser 15 becomes a phase information signal having the phase information of the on-vehicle wireless station 20. If this is expressed as an equation, Equation 3 is obtained.

)이 있다. 이 신호를 컴퓨터(16)에서 검출하면 위상정보신호로 이용할 수 있다.In the above Equation 3, the phase delay term generated by the time delay of t _{1 which} is doubled according to the position of the next wireless radio station 20 and the phase delay term generated in the system (

There is). When this signal is detected by the computer 16, it can be used as a phase information signal.

The computer 16 calculates and compares the distance from the ground radio station WRS1 to the next-order radio station VRS by correcting an error generated by sampling and sampling the phases of the phase information signal and the reference signal. The phase information signal uses a signal through which the signal has passed through the capacitor 15 via the ground radio station 10 receiver 14. The reference signal uses a signal generated by the signal generator 11 through the condenser 12. Sampling and comparing these two signals can damage important phase information between samples. Therefore, it is necessary to correct this as follows.

2 illustrates a sampling signal of a position information signal and a reference signal according to the present invention, and FIG. 3 illustrates a method of determining a position of a next-generation radio station, that is, a train, by extracting sampling signals of the reference signal and the phase information signal from the computer 16. It is a flowchart showing.

Since the frequency of the reference signal and the phase information signal is the same in the computer 16 of FIG. 1, a more accurate phase delay value is calculated if the exact time at which the sign changes in the sample and the sample size can be calculated. In Figure 2, the horizontal axis represents the number of the sample signal and the vertical axis represents the magnitude of the signal.

First, the computer 16 extracts a sampling signal from the reference signal generated by the signal generator 11 and passed through the condenser 12, and passes through the condenser 15 through the receiver 14 of the ground radio station 10. A step of extracting a sampling signal from the phase information signal is performed, and a step of finding a sample whose sign is changed in each of the reference signal and the phase information signal sample values is performed.

The extracted signal is as shown in FIG. 2, and as shown in FIG. 2, the sign is changed in Sample 1 and Sample 2, the sign is changed in Sample 8 and Sample 9, and the sign is changed in Sample 14 and Sample 15. The sign is also changed in Sample 21 and Sample 22. This change in sign will be repeated in a similar period because the frequency is constant.

인 t를 계산한다. 신호의 크기가 0인 값은 다음과 같이 계산할 수 있다. 사인파 신호나 삼각파 신호는 크기가 0인 곳에서 선형적으로 증가하거나 감소하는 것으로 근사화 시킬 수 있다. 샘플링폭(sampling width)이

[sec]일 때 샘플링번호(sampling number) n번째에서 신호의 크기

은 0보다 작고, 샘플링번호 (n+1) 번째에서 신호의 크기

은 0보다 크다면 Δn과 Δ(n+1) 사이에서

인 t의 값을 계산 할 수 있다. 여기서 다음 수학식 4의 직선의 방정식을 유도할 수 있다.Then, in the sample where the sign changes

Calculate t. The value of zero signal can be calculated as follows. A sinusoidal or triangular signal can be approximated by linearly increasing or decreasing at a zero magnitude. Sampling width

Signal size at n th sampling number when [sec]

Is less than 0, and the magnitude of the signal at sampling number (n + 1) th

Is greater than 0 between Δn and Δ (n + 1)

We can calculate the value of t. Here, the equation of the straight line of Equation 4 may be derived.

,

)을 대입하면 b의 값을 계산할 수 있다. In Equation 4 above (

,

) Can be used to calculate the value of b.

Here, the time t with f (t) = 0 can be calculated.

[sec]

[sec]

인 기준신호의 시간(t_a)와

인 위상정보신호의 시간(t_b)를 계산해서 시간차(t_b-t_a)를 계산하는 단계를 수행한다. 시간차가 한 주기의 시간(1/f[sec]) 내에서 변하도록 지상무선국(WRS)은 설치한다. 그리고 지상무선국(WRS)에는 차상무선국(VRS)의 위치에 대한 데이터베이스 정보가 있다. 그러므로 데이터베이스 정보에서 시간차에 대한 차상무선국(VRS)의 위치를 찾는 단계를 수행한다.Using the equation (6), the computer 16 of FIG.

And the time t _a of the reference signal

The time difference t _b -t _a is calculated by calculating the time t _b of the in-phase information signal. The ground radio station (WRS) is installed so that the time difference varies within a period of time (1 / f [sec]). The WRS has database information on the location of the VRS. Therefore, the step of finding the position of the VRS with respect to the time difference in the database information.

As described above, the present invention has the advantage of enabling efficient train spacing control by increasing the accuracy of location tracking even in areas where there are many limitations in tracking the location of a mobile chain train such as a tunnel or a downtown.                     

Although the technical concept of the method for correcting the train positioning error in the ground radio station of the present invention has been described based on the exemplary drawings, the present invention has been described by way of example only, and it is not intended to limit the claims of the present invention. no. It will be apparent to those skilled in the art that various modifications and imitations can be made without departing from the scope of the technical idea of the present invention.

Claims (3)

Extracting, by the computer, a sampling signal from a phase information signal received by a terrestrial radio station receiver and a reference signal generated from a signal generator of the terrestrial radio station and a signal transmitted by the next-order radio station corresponding to the reference signal, respectively, the reference signal and the phase information Finding a sample whose sign is changed in the sampling signal of the signal, calculating a f (t) = 0 having a magnitude of zero in the sample whose sign is changed, and the time t _a of the reference signal of t with f (t) = 0. And calculating the time difference t _b -t _a using the time t _b of the phase information signal of t with f (t) = 0 and searching for the position of the next-order radio station with respect to the time difference in the database of the ground radio station. And outputting the searched position information. The method of claim 1, wherein the step of extracting the sampling signal from the reference signal and the phase information signal comprises extracting the signal from the signal generator and the receiver of the ground radio station after removing the DC component through the capacitor. Train positioning error correction method. 2. The train positioning error of the ground radio station as set forth in claim 1, wherein the time difference tb-ta is set so as to change within one cycle of time (1 / f [sec]) when the ground radio station is positioned. Correction method.

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