JP4257992B2 - Train detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a train detection apparatus using an uninsulated track circuit, and in particular, applies a spread spectrum communication system.
[0002]
[Prior art]
Conventionally, in order to detect a train position using a track circuit, each track circuit (detection section) is defined as a track in a closed section formed by dividing a rail (track) into predetermined lengths. A transmitter is connected to the end of the circuit on the train advance side, and a receiver is connected to the end of the train entrance side to detect the presence or absence of a train in the track circuit.
[0003]
FIG. 2 is a schematic configuration diagram of a conventional train detection device described in, for example, Japanese Patent Application Laid-Open No. 9-99836 of Patent Document 1. As shown in the figure, the rail on which the train 19 travels is divided into a plurality (three in the illustrated example) of track circuits 1T14, 2T15, 3T16, and one of the track circuits 1T14, 2T15,. However, a receiver 4 is connected to the other side.
[0004]
In FIG. 2, the transmitter 5 and the receiver 4 are shown only in the track circuit 1T14 in order to simplify the drawing. However, the transmitter 5 and the reception are similarly shown in the other track circuits 2T15, 3T16,. A device 4 is connected. Hereinafter, description will be made centering on the transceiver of the illustrated track circuit 1T14.
[0005]
In FIG. 2, the transmitter 5 includes a carrier generation circuit 8 that outputs a carrier wave (f1) having a predetermined frequency assigned to the track circuit 1T14, and a PN code that assigns the output carrier wave (f1) to the track circuit 1T14. That is, as shown in FIG. 3, a predetermined reference PN code (PN ₁ (θ ₀ )) is spread using a PN code (PN ₁ (θ ₁ )) assigned with a predetermined phase difference. And a transmission circuit 6 for sending the spread signal to the track circuit 1T14.
[0006]
2, the receiver 4 includes a receiving circuit 17 that receives the signal transmitted from the transmitting circuit 6, a first despreading circuit 101 that performs despreading conversion on the signal received by the receiving circuit 17, and a second despreading circuit 101. Despreading circuit 102, adding circuit 18 for adding the output signals, and processing the signal output from adding circuit 18 to detect the level of the desired signal (carrier wave from transmitter 5) and And a level determination circuit 11 for determining the absence line.
[0007]
Next, the operation will be described.
The first despreading circuit 101 performs despreading conversion using the same PN code (PN ₁ (θ ₁ )) as the PN code used in the spreading circuit 71 of the transmitter 5. The second despreading circuit 102 uses an inverting circuit / delay circuit 121 to convert the PN code (PN ₁ (θ ₁ )) to several bits (for example, PN ₁ (θ ₁ ) is 7 bits). And despreading conversion using a PN code whose code is reversed by an inverting circuit.
[0008]
In FIG. 2, when the train 19 is not present in the detection section 1T14, the signal from the transmitter 5 is not short-circuited by the axle of the train 19, so that it is input to the receiving circuit 17 of the receiver 4 at a predetermined level. Is done. The output signal of the receiving circuit 17 is input to the despreading circuits 101 and 102, respectively.
[0009]
First, when one of the signals input from the receiving circuit 17 is despread and converted by the first despreading circuit 101, the phase of the PN code (PN ₁ (θ ₁ )) on the transmitter / receiver 4 or 5 side is desired. Since it matches the signal (carrier wave), the maximum signal can be obtained.
The other signal input from the receiving circuit 17 is despread and converted by the second despreading circuit 102. The PN code used here has a phase of several bits by the inverting circuit / delay circuit 121. Since the signal is shifted, the signal remains as it is spread and becomes an inverted signal.
[0010]
Next, the outputs of the two despreading circuits 101/102 are added by the adding circuit 18. By the way, if the output level after the diffusion conversion by the first despreading circuit 101 is “1”, the output level of the second despreading circuit 102 is 1 / N (in the case of 7 bits, the reference PN code is 1 / N). 1/7). That is, the output of the first despreading circuit 102 and the output of the second despreading circuit 101 are sufficiently large values, and the determination circuit indicates a train non-existence line.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-99836
[Problems to be solved by the invention]
Since the train detection device receives and transmits the same PN code signal shifted by several bits for each detection section as described above, it is necessary to adjust the phase of the PN code with very high accuracy. When the phase is shifted and the synchronization of the second despreading circuit coincides, there is a problem that false detection may occur.
[0013]
The present invention has been made to solve the above-described problems, and in an uninsulated track circuit, the influence of leakage from another track circuit is eliminated while using a different PN code, and the train detection is operated. The purpose is to obtain a device.
[0014]
[Means for Solving the Problems]
The train detection apparatus according to the first invention is
At one end of each detection section formed by dividing the rail on which the train travels into a plurality, a transmitter for sending a signal subjected to spread conversion using a different PN code in spectrum communication for each detection section;
It is provided at the other end of each detection section, and a necessary signal is extracted from the signal from the transmitter and the signal superimposed from another detection section,
Based on the result of despreading the extracted signal using the PN code assigned for each detection interval,
And a receiver for determining the presence or absence of a train in each detection section.
[0015]
Then, the necessary signal is extracted by removing the signal from the transmitter in the adjacent detection section from the received signal.
[0016]
In the train detection apparatus according to the second invention,
The receiver in each detection section and the transmitter in the adjacent detection section are integrated through one distributor / synthesizer.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a train detection device according to an embodiment. A rail on which a train 19 travels is divided into a plurality (three in the illustrated example) of track circuits 1T14, 2T15, and 3T16. A section is formed.
A combination of the matching circuit 1, the distribution synthesizer 2, the transmitter 5, and the receiver 4 is connected to the track circuit boundary of each track circuit 1T14, 2T15,.
[0018]
Further, in FIG. 1, in order to simplify the drawing, the above-described device set is shown only for the track circuit 1T14. However, the matching circuit 1 and the distribution synthesizer 2 are similarly applied to the other track circuits 2T15, 3T16. A combination of the transmitter 5 and the receiver 4 is connected as a set.
In addition, since the transmitter / receiver of each track circuit 1T14, 2T15... Has the same configuration, the transmitter / receiver of the track circuit 1T14 shown in the figure will be mainly described below.
[0019]
In FIG. 1, 1A and 1B are matching circuits for impedance matching with rails, 2A and 2B are distribution synthesizers for distributing / combining signals entering the transmitters 5A and 5B and receivers 4A and 4B, and 4A and 4B are tracks. Cancelers 3A and 3B that receive only signals from the adjacent track circuit out of the main signal from the rail and the signal output from the transmitter for the adjacent track circuit, and a canceller 3A. 3B includes despreading circuits 10A and 10B that receive and despread and convert output signals from 3B, and level determination circuits 11A and 11B that detect the presence / absence of a line by detecting the level of the output signal.
[0020]
In FIG. 1, reference numeral 5A denotes a transmitter that sends a signal to the rail, and a signal from the transmitter 5A is sent to the receiver 4B.
The transmitter 5A uses a carrier wave generation circuit 8A that outputs a carrier wave (f1) having a predetermined frequency assigned to the track circuit 1T14, and a PN code that assigns the output carrier wave (f1) to the track circuit 1T14. It comprises a spreading circuit 7A that performs spreading processing and a transmission circuit 6A that sends the spread signal to the rail.
[0021]
Next, the operation of the train detection device will be described by taking the case of the track circuit 1T14 as an example.
In the above configuration, in each section in which the rail is divided into a plurality of parts, signals are transmitted and received between the transmitter 5 and the receiver 4 provided at both ends of each section.
For example, in the track circuit 1T14, signals are transmitted and received between the transmitter 5A and the receiver 4B.
[0022]
A predetermined carrier wave is output from the carrier wave transmission circuit 8A of the transmitter 5A to the spreading circuit 7A. In the spreading circuit 7A, using code PN ₁ assigned to the track circuit 1T14, performing diffusion mappings for the input carrier.
The spread-converted signal is input from the transmission circuit 6A to the distributor / synthesizer 2A, and sent to the rail through the matching circuit 1A.
[0023]
Similarly, at one end of the track circuit 2T15 in the section adjacent to the track circuit 1T14, a transmission signal is sent from the transmitter 5B provided for the track circuit 2T15 to the rail.
In the transmitter 5B, the carrier wave signal from the carrier wave transmission circuit 8B is spread and converted by the spreading circuit 7B. In the spreading circuit 7B, performs spreading converted by code PN ₂ allocated to track circuits 2T15, diffusion converted signal is output from the transmission circuit 6B, sent to the rail via distributor / combiner 2B, a matching circuit 1B Is done.
[0024]
In this way, the transmission signal output from the transmission circuit 6B to the reception circuit 4C (not shown) provided at the other end of the track circuit 2T15 passes through the distributor / synthesizer 2B and the matching circuit 1B on the rail. While flowing into the difference circuit 9B of the canceller 3B through the distributor / synthesizer 2B.
Accordingly, the difference circuit 9B of the receiver 4B receives the leakage of the transmission signal from the transmitter 5B for the track circuit 2T15 and the received signal from the track circuit 1T14.
[0025]
Specifically, the transmission signal output from the transmitter 5B for the track circuit 2T15 is input to the distributor / synthesizer 2B, and the adjustment provided in the canceller 3B in the receiver 4B for the track circuit 1T14. It is also input to the device 12B. The transmission signal input to the canceller 3B is adjusted in phase, amplitude, and delay amount by the adjuster 12B, and input to the difference circuit 9B.
[0026]
This difference circuit 9B works in conjunction with the adjuster 12B for the track circuit 2T15 in order to remove the signal flowing from the transmitter 5B for the track circuit 2T15 into the difference circuit 9B of the canceller 3B through the distributor / synthesizer 2B. The transmission signal is output to the despreading circuit 10B after the phase, amplitude, and delay amount are adjusted so that the transmission signal is minimized and the transmission signal output from the transmitter 5A for the track circuit 1T14 that is originally required is extracted.
[0027]
The signal output from the difference circuit 9B of the canceller 3B is input to the determination circuit 11B through the despreading circuit 10B.
The determination circuit 11B monitors the signal strength of the input signal input from the despreading circuit 10B. If the signal strength is equal to or higher than a certain level, the train is absent on the track circuit, and if the train is below the certain level, the train is present. judge.
[0028]
Since the train detection device is configured as described above, if the train 19 in FIG. 1 is not in the track circuit 1T14, the superimposed 2T15 transmission signal is removed by the canceller 3B, and the originally required track The signal for the circuit 1T14 can be received at a constant level, the output subjected to the despreading process by the despreading circuit 10B has a sufficiently large value, and the determination circuit 11B indicates a train non-existence line.
[0029]
When the train 19 is on the track circuit 1T14, the signal from the transmitter 5A for the track circuit 1T14 is short-circuited by the train 19, so only the adjacent 2T15 signal is received (actually the detection section). 2T15 is also input from 3T16, etc. adjacent to 2T15, but the input level is sufficiently small so as not to cause a problem.) Since this received signal is removed by the above method, it is input to determination circuit 11B. The signal level becomes small and it can be determined that the current line is present.
[0030]
In this way, a signal transmitted from a transmitter assigned with a different PN code for each detection interval is subjected to spread processing by a spread spectrum method, and the signal is received by a receiver corresponding to each transmitter. The necessary signals are extracted from the superimposed signals from the transmitters in the other detection intervals, and despreading is performed with the PN code corresponding to each detection interval. And the presence / absence of the train can be determined based on the received signal.
[0031]
In this case, the receiver of the track circuit 1T14 and the transmitter of 2T15 adjacent to the transmitter / receiver transmit and receive via one distributor / synthesizer. However, the present invention is not limited to this.
In addition, by taking signals from other track circuits into the canceller 3, the signal components for train detection can be easily and reliably extracted from the superimposed received signals, as in the above configuration.
[0032]
【The invention's effect】
As described above, according to the present invention, only a necessary signal is extracted from a signal obtained by superimposing a signal from an original transmitter and a transmission signal from another track circuit by using a different PN code for each transmitter. The effect of being able to determine the presence / absence of a train from the signal is obtained.
[0033]
The train detection apparatus according to the first aspect of the present invention transmits a signal subjected to diffusion conversion using a different PN code at each detection section at one end of each detection section formed by dividing the rail on which the train travels into a plurality of sections. A transmitter to
It is provided at the other end of each detection section, and a necessary signal is extracted from the signal from the transmitter and the signal superimposed from another detection section,
Based on the result of despreading the extracted signal using the PN code assigned for each detection interval,
Since it has a receiver for determining the presence or absence of a train in each detection section, a signal component necessary for train detection can be easily obtained.
[0034]
Furthermore, the receiver of the train detection apparatus according to the present invention takes out the necessary signal by removing the signal from the transmitter in the adjacent detection section from the received signal, so that the reliability with improved noise resistance is obtained. Train detection is possible.
[0035]
In the train detection apparatus according to the second aspect of the present invention, the receiver in each detection section and the transmitter in the detection section adjacent to each other are integrated through one distributor / combiner, so that the reliability is simplified with a simple apparatus configuration. Train detection is possible.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a train detection apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a conventional train detection device.
FIG. 3 is a configuration diagram showing the operation of a conventional train detection device.
[Explanation of symbols]
1A, 1B matching circuit, 2A, 2B distributor / synthesizer, 3A, 3B canceller,
4A, 4B receiver, 5A, 5B transmitter, 6A, 6B transmission circuit,
7A, 7B spreading circuit (PN ₁ ), 8A, 8B carrier wave transmission circuit,
9B differential circuit, 10A, 10B despreading circuit (PN ₁ ),
11A, 11B determination circuit, 12B adjuster, 14 track circuit 1T,
15 track circuit 2T, 16 track circuit 3T, 17 receiving circuit,
18 addition circuits, 19 trains

Claims (2)

At one end of each detection section formed by dividing the rail on which the train travels into a plurality, a transmitter for sending a signal subjected to spread conversion using a different PN code in spread spectrum communication for each detection section;
Provided at the other end of each detection section, comprising a receiver that receives signals from the transmitter and signals superimposed from other detection sections ,
The receiver takes out a necessary signal by removing a signal from the transmitter in the adjacent detection section from the received signal using a signal transmitted from a transmitter in the adjacent detection section , and the extracted signal respect, based on the result of despreading conversion using the PN code assigned to each detection section, the train detection device comprising a Turkey to determine the presence or absence of the train within the detection zone. Transmitter detection section adjacent to the receiver of each sensing interval, one distributor / combiner that are integrated via the claims 1 Symbol placement of train detector and said.

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