JP4574556B2 - Interference detection device between transmission and reception - Google Patents

Description

  The present invention relates to a transmission / reception system, and more particularly, to a device for detecting contact between transmission and reception, in which it is easy to determine that a transmission side signal has reached a reception side without passing through a transmission path, and which is safe and reliable.

  In a transmission / reception system including a reception means having a main signal reception means for receiving a transmission signal, a signal transmitted by a transmission / reception means having a signal generation means and a power conversion means passes through the transmission line. It was important to detect a touch that would reach the receiving means from the transmitting means without passing through.

  In particular, in the railway field, the method of detecting an increase in amplitude (hereinafter referred to as level) of a received signal described in Patent Document 1 calculates an increase change per predetermined unit time of the received level. When the received change in the reception level indicates the state of contact, the contact is detected.

Also, as shown in Patent Document 2, the presence / absence of a train is determined based on the fact that a transmission signal has passed through a legitimate transmission path, and it is extremely important to detect contact between transmission and reception. It was. In Patent Document 2, as a touch detection, a DC voltage for measurement is applied as a touch detection means between cables of a train detection system, and a change in the DC voltage for measurement is detected due to the touch to detect the touch. Met.
JP 2001-171520 A Japanese Patent Laid-Open No. 2005-199838

  However, the method of Patent Document 1 is accompanied by the addition of equipment such as a measurement DC voltage generator for detecting contact, a branching resistor, and a measurement cable, and an increase in cost. Further, in the method of Patent Document 2, since the time change of the reception level is used for the detection of the mixed touch, it is necessary to set in advance a threshold value for the time change of the reception level determined as the mixed touch. In particular, it is difficult to calculate the change of the reception level per unit time and set the threshold for the failure mode of all systems considered as incompatibility, considering the number of facilities and the number of failure modes.

  The contact detection means between the transmission and reception of the present invention comprises a transmission means for transmitting a frequency signal, a first reception means for receiving the frequency signal transmitted by the transmission means, and the transmission means and the reception means. A second receiving means connected in parallel with the first receiving means, and the second receiving means extracts a frequency signal in an attenuation band of the transmission path. And detecting that the level of the frequency signal in the attenuation band exceeds a predetermined threshold, thereby detecting a signal that has reached the receiving means without passing through the transmitting means.

In the present invention, detection of incompatibility is performed by detecting the level of a signal wave that occurs in the frequency attenuation band of the transmission line as a secondary signal when the main signal is generated. The reception level observed at the receiving end is greatly attenuated in the transmission path, and a large level difference occurs between the signal passing through the transmission path and the signal not passing through the transmission path. It has the effect of facilitating the comparison between normal reception and contact.
In addition, there is no need to provide a threshold for unit time change of the reception level, and there is an effect of shortening the time related to condition setting.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a first embodiment of the present invention. 1 is a transmission signal generation means, 2 is a power conversion means having a carrier wave, 3 is a transmission means, 4 is a transmission means having frequency attenuation characteristics, 5 is a main signal reception means, 6 is a frequency selection means, 7 is a level detection means , 8 is a touch detection means including the frequency selecting means 6 and the level detection means 7, and 9 is a reception means including the main signal receiving means 5 and the touch detection means 8.

First, the signal generation means 1 generates the main signal 10 shown in FIG. 2 and the secondary sideband wave 11 including the harmonics accompanying the modulation process of the main signal, and passes to the power conversion means 2. . In the two-power converter, when the main signal 10 is amplified, the main signal 10 is modulated using the carrier wave 12. Of the signal amplified by the power conversion means 2, signals other than the frequency component of the main signal 10 become unnecessary signals. The sideband wave 11 and the carrier wave 12 are transferred to the transmission means 4 having the frequency attenuation characteristic 13 shown in FIG. 3 and attenuated by the 13 attenuation characteristic of the transmission means 4, the main signal 10, the sideband wave 11, and the carrier wave 12 is passed to the receiving means 9. In the receiving means 9, the main signal 10 is received by the main signal receiving means 5 to perform the original communication function.

  As the contact detection function, the sideband wave 11 and the carrier wave 12 are determined in advance by the frequency selecting means 6 from the signal wave including the main signal 10, the sideband wave 11, and the carrier wave 12 obtained from the transmission means 4. The detected threshold value is compared with the detected threshold level.

  FIG. 4 is a diagram showing a second embodiment of the present invention. Reference numeral 14 denotes an arithmetic unit that creates and modulates a TD signal, which is the main signal 10 for train detection, passes the signal to the A / D converter 15, and the power converter 16 '' having a carrier wave modulates the carrier wave. The signal wave is modulated by the amplifier 16 ', and the signal is amplified by the power amplifier 16, and the output band-pass filter 17, the transmission cable 18, the matching transformer 19, the transmission cable 20, the matching transformer 21, and the track resistor 22, one track circuit 2T24, track resistor 25, matching transformer 26, receiving cable 27, matching transformer 28, band-pass filter 29 for receiving a TD signal, reception It reaches the receiving end of the reception attenuator 31 through the cable 30. The signal received by the reception attenuator 31 passes through the A / D converter 32 and is passed to the arithmetic unit 33 for signal reception processing.

  Here, the output band-pass filter 17, the transmission cable 18, the matching transformer 19, the transmission cable 20, the matching transformer 21, the track resistor 22, and one track circuit 2T24 of the track circuit 23 targeted by the second embodiment. The track resistor 25, the matching transformer 26, the receiving cable 27, the matching transformer 28, the band-pass filter 29 for receiving the TD signal, and the receiving cable 30 form a transmission line having frequency attenuation characteristics.

  Reference numeral 34 denotes a transmitter / receiver device including the arithmetic unit 14, the A / D converter 15, the reception attenuator 31, the A / D converter 32, and the arithmetic unit 33 for signal reception processing.

  When performing the original train detection, if the train 35 is not present in the single track circuit 2T24, the TD signal as the main signal 10 is transmitted through the output bandpass filter 17 to the receiving cable 30 having a frequency attenuation characteristic. The signal passes through the passband, propagates with little attenuation, passes through the reception attenuator 31 to the A / D converter 32, and the arithmetic device 33 processes the level of the TD signal and the TD message included in the signal, Judged as a non-train line.

  A means for detecting the touch from the received signal will be described with reference to the flowchart of FIG. The received signal wave is processed by the signal reception processing unit 33. First, the received signal is quantized to a level per unit time by the received signal sampling in step 36, and the sideband 11 and the carrier wave 12 from the received signal by the attenuation frequency separation method configured by the digital filter in step 37, Is selected, and by the conditional branching whether it is equal to or higher than the threshold level of step 38, the mixed touch detection output of step 39 is reached.

  As shown in FIG. 4, the output bandpass filter 17, the transmission cable 18, the matching transformer 19, the transmission cable 20, the matching transformer 21, the track resistor 22, and the track targeted for the second embodiment are included in the transmission path. The circuit 23 includes a single track circuit 2T24, a track resistor 25, a matching transformer 26, a receiving cable 27, a matching transformer 28, a band-pass filter 29 for receiving a TD signal, and a receiving cable 30. When this occurs, it is also possible to detect the occurrence path of the contact by detecting the frequency signal corresponding to the different attenuation band in consideration of the frequency attenuation characteristic for each device in the transmission path.

  In the above description, the frequency selection is performed using the digital filter arithmetic means of the CPU 33. However, as shown in FIG. 1, when the mixing detection unit of the receiving unit is separated as a physical component, an analog filter is used, There is also a method for reducing the calculation time required for digital filter processing. There is also a method of performing frequency selection using only an analog filter.

  In the transmission / reception means for wireless communication including satellite communication, side signals and subcarriers, which are secondary signals generated by amplification and modulation of the main signal on the transmission side, are used in the atmosphere, outer space, transmission / reception antennas, etc. The frequency attenuation characteristics of the transmission path including, and can be applied to intrusion detection means that considers that it is equal to or greater than the level threshold of the secondary signal as received intrusion without passing through a legitimate transmission path. .

  In transmission / reception means for telephone communication and telecom communication, a side signal, a carrier wave, which is a secondary signal generated by amplification and modulation of the main signal on the transmission side, a signal cable, a filter, etc. Utilizing the frequency attenuation characteristic, it can be applied to the intrusion detection means that regards that it is equal to or greater than the level threshold of the secondary signal as the intrusion received without passing through a legitimate transmission path.

It is a conceptual block diagram for demonstrating the intrusion detection means of Example 1 of this invention. It is a figure which shows the frequency characteristic of the signal transmitted to the transmission means for demonstrating the principle of the tactile detection of this invention. It is a figure which shows the frequency characteristic of the transmission means for demonstrating the principle of the intrusion detection of this invention. It is a conceptual block diagram when the intrusion detection means of Example 2 of this invention is applied to a train detection apparatus. It is a flowchart which shows the control operation of the tactile detection of Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Signal generation means 2 Power converter which has a carrier wave 3 Transmission means,
4 Transmission means having frequency attenuation characteristics 5 Main signal receiving means 6 Frequency selection means,
7 level detection means 8 contact detection means 9 reception means 10 main signal 11 sideband including harmonics 12 carrier wave 13 frequency attenuation characteristic of transmission means 14 arithmetic unit 15 D / A converter 16 power amplifier 16 ′ modulator 16 having carrier wave '' Power converter having carrier wave 17 Output band pass filter 18 Transmission cable 19 Matching transformer 20 Transmission cable 21 Matching transformer 22 Orbit resistor 23 Orbit circuit 24 Single orbit circuit 2T
Reference Signs List 25 Orbit Resistor 26 Matching Transformer 27 Reception Cable 28 Matching Transformer 29 Band Pass Filter for TD Signal Reception 30 Reception Cable 31 Reception Attenuator 32 A / D Converter 33 Calculator for Signal Reception Processing 34 Transmitter / Receiver 35 Train 36 Received signal sampling 37 Digital filter 38 Threshold level judgment 39 Touch detection output judgment

Claims (5)

A transmission means for transmitting a frequency signal;
First receiving means for receiving the frequency signal transmitted by the transmitting means;
A transmission means having a frequency attenuation characteristic for connecting the transmission means and the reception means and passing through a main signal and attenuating a noise signal ;
In a transmission / reception system having
Second receiving means connected in parallel with the first receiving means;
The second receiving means extracts a frequency signal in an attenuation band that attenuates a noise signal other than the frequency band passing through the main signal of the transmission means ,
By level of the frequency signal in the attenuation band is detected that exceeds a predetermined threshold, between transmission and reception, characterized by detecting that the frequency signal arrives to the receiving means without passing through said transmission means Intrusion detection device. In the intrusion detection apparatus between transmission and reception according to claim 1,
When the main signal is modulated using a carrier wave as a frequency signal in the attenuation band, a power converter carrier that is subtracted into the main signal is extracted and used. apparatus. In the intrusion detection apparatus between transmission and reception according to claim 1,
A device for detecting contact between transmission and reception , wherein a sideband wave including a harmonic generated as a secondary signal when a main signal is generated is extracted and used as a frequency signal in the attenuation band. In the intrusion detection apparatus between transmission and reception according to claim 1,
When the main signal is modulated using the carrier wave, the frequency signal in the attenuation band includes the carrier wave of the power converter that is subtracted into the main signal and the harmonics that are generated secondarily when the main signal is generated. A device for detecting contact between transmission and reception, wherein sidebands are extracted and used. In the intrusion detection apparatus between transmission and reception according to claim 1,
The transmission means includes a signal cable and band-pass filters and track resistance element of the matching transformer and the track circuit,
Said second receiving unit performs the extraction of the frequency signals in the attenuation band to attenuate the noise signal other than the frequency band passing through the main signal having the said transmission means,
By level of the frequency signal in the attenuation band is detected that exceeds a predetermined threshold, for the track circuit and detects that the signal has reached the said receiving means without passing through the said track circuit Interference detection device between transmission and reception.

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