JP3306722B2 - Train detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a train detection device,
In particular, the present invention relates to a train detection device that performs a train detection by laying an induction loop along a train travel path.

[0002]

2. Description of the Related Art Conventionally, a city traffic type train running on rubber tires does not use a rail on a traveling path, so that a track circuit type train detection using a rail cannot be adopted.
Induction loop type train detection is being performed. In this train detection device of the induction loop type, an induction loop of a predetermined length along a traveling path, that is, a so-called loop coil (hereinafter, referred to as a loop) is laid, and a signal is transmitted from the vehicle (train side) toward the loop. It is configured to:

[0003] Therefore, on the ground side, when a predetermined signal is received through a loop, it is possible to detect that the train is located on the loop. Further, in the conventional train detection device of the induction loop system, a signal suppression system is adopted in order to secure fail-safety. According to this method, a predetermined check signal (hereinafter, referred to as a reference signal) composed of a normal analog single frequency or AM modulated wave is always supplied to the beginning of the loop (the side where the train advances from the closed section). A receiver is provided at the end of the loop (the side where the train enters the closed section), which constantly detects the check signal. Then, when a train enters this loop and a signal from the car is transmitted to the loop and superimposed on the check signal, the check signal is suppressed and becomes no signal, and train detection is performed by detecting this no signal. It is configured.

[0004]

However, in the above conventional train detection apparatus of the induction loop type, the S / N
Is inferior. This is because a train line is laid near the loop and noise increases.
If the S / N is poor, the inspection signal is suppressed just by the approach of the train, and a problem occurs that the train is detected before the train exists on the loop. In order to solve such a problem, measures such as increasing the signal output to improve the S / N have been taken.
Increasing the signal output has resulted in a new problem of increased power consumption.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and improves the S / N by applying a spread spectrum communication system having a good noise resistance, and enables a discrimination between a train entry and a departure, thereby providing a blockage logic. It is an object of the present invention to provide an induction loop type train detection device which enables the configuration described above.

[0006]

For this reason, in the train detection device of the present invention, an induction loop laid for each closed section along a train travel path and two different PN codes having the same occurrence cycle are provided. And a terrestrial signal spreading means for spreading a carrier with a PN code string generated with a periodicity, and a signal spread by the terrestrial signal spreading means to a starting end of the guidance loop. Terrestrial signal supply means for supplying, a terrestrial reception means for receiving a signal from the end of the induction loop, and a PN code component by demodulating a reception signal received by the terrestrial reception means with a signal having the same frequency as the carrier wave. Extracting means for extracting a signal including the following, PN code detecting means for identifying and detecting each PN code from the signal extracted by the extracting means, and a carrier having the same frequency as the carrier being one of the PN code trains. First on-vehicle signal spreading means for performing spreading processing with a PN code continuously generated of the same type as the PN code, and transmitting the signal spread by the first on-vehicle signal spreading means from the train head to the guidance loop. First on-board signal supply means;
A second on-vehicle signal spreading unit for performing spreading processing on a carrier having the same frequency as the carrier with a PN code continuously generated of the same type as the other PN code of the PN code sequence; Second on-board signal supply means for transmitting the obtained signal from the rear end of the train to the guidance loop, and the PN code detection means detects only each PN code of the PN code string supplied from the ground signal supply means. When the PN code supplied from the first onboard signal supply unit is detected by the PN code detection unit, the train is detected on the induction loop. detects that approach was, the PN code PN code supplied from the first on-board signal supply means by the detection means becomes a non-detection state and the PN code supplied from the second vehicle on the signal supply means
And a train detecting means for detecting that the train head has advanced from the guidance loop when in the detection state in the closed section .

[0007]

In the above arrangement, the carrier wave is intermittently spread from the starting end side of the induction loop by a PN code string having a periodicity in which two different PN codes having the same generation cycle are generated alternately. And a check signal is supplied. On the other hand, from the train side, an IN signal for detecting train entry, which has been subjected to spreading processing with a continuously generated PN code of the same type as one of the two PN codes included in the PN code string of the reference signal, is provided at the beginning. , And an OUT signal for train advance detection, which is subjected to spreading processing with a continuously generated PN code of the same type as the other PN code in the PN code string of the check signal, is transmitted from the rear end. The terrestrial receiving means receives a signal from the end of the loop, and the extracting means demodulates the received signal with a signal having the same frequency as the carrier on the transmitting side to extract a signal containing a PN code component, and from the extracted signal Each PN code is detected by the PN code detection means.

The train detecting means detects that the train does not exist on the guidance loop when the detection output of the PN code is generated in synchronization with the PN code generation cycle of the transmission signal from the ground from the PN code detecting means. If the detection output of the predetermined PN code transmitted from the train head from the code detection means is generated at substantially the same short cycle as the predetermined PN code, it is detected that the train has entered the guidance loop, and the PN code detection means is detected. And the detection output of the train entry detection disappears, and the detection output of the predetermined PN code transmitted from the rear end of the train is the predetermined PN code.
The conditions occurring substantially at the same short period as a code to detect that the train head section when in the detection state at the PN code detecting means of the block section is advanced from the inductive loop.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a train detection device according to a first embodiment of the present invention, and an induction loop (hereinafter, referred to as a loop) P is formed by a loop-shaped coil having a length forming one closed section. , Are laid for each closed section along a traveling path (not shown).

[0010] A ground transmission unit 10 is connected to the starting end P _{S of the} loop P (the side on which the train advances to the front closed section), and the terminal P _R of the loop P (the train enters the closed section). The ground receiving unit 20 is provided on the side that performs the communication. The terrestrial transmitter 10 includes a carrier generator 11 for generating a carrier having a predetermined frequency fc, a PN code sequence generator 12 for generating a predetermined PN code sequence CH, and a PN code from the PN code sequence generator 12 for the carrier. a multiplier 13 for spreading modulation a carrier by multiplying the column CH, amplifies the spread signal, constituted by a transmitter 14 for supplying the starting end side P _S of loop P through the transformer T, T Have been. Therefore,
The multiplier 13 corresponds to terrestrial signal spreading means, and the transmitter 14 corresponds to terrestrial signal supply means.

Here, the PN code sequence generator 12 generates, for example, different PN codes PN1 and PN2 having sharp autocorrelation and low cross-correlation from the PN code generators, respectively. The generated frequencies of the PN codes PN1 and PN2 are frequency-divided by a frequency divider, for example, to 1/8.
A delay circuit is provided for one PN code, for example, the PN2 side, to delay a half cycle of the frequency-divided output. Thereby, PN
The code string generator 12 outputs PN1 and P as shown in FIG.
A PN code string is generated in which N2 and N2 are alternately arranged at regular intervals intermittently and periodically, and this becomes a check signal.

On the other hand, the ground receiving unit 20
A multiplier 2 that demodulates a received signal input from _R through a transformer T, T as a receiving means, by multiplying the carrier generated by the carrier generator 21 and having the same frequency fc as the transmitting side.
2, a low-pass filter 23 that passes the output of the multiplier 22 to extract the PN code component, and a low-pass filter 23
To identify and detect each PN code PN1 and PN2 from
A PN code detection unit 24 described later as code detection means,
Train detection for detecting the presence / absence of a train in a closed section (on loop P) based on the detection output from the PN code detecting section 24, the train entry into the closed section, and the train advance from the closed section to an adjacent closed section. Train detection unit 2 described later as means
5 is provided. Here, the carrier generator 2
1, the multiplier 22, and the low-pass filter 23 constitute an extracting means.

The PN code detecting unit 24 is configured to detect each PN code PN included in a predetermined PN code string CH used on the transmitting side.
A PN1 code generator 31 and a PN2 code generator 32 that generate the same code as that of the PN code 1 and PN2 respectively, a PN code input from the corresponding code generators 31 and 32 and a PN code signal input from the low-pass filter 23. First and second correlation matched filters 33, 3 for respectively calculating the correlation values of
4, an OR circuit 35 for inputting the outputs from both correlation matched filters 33 and 34, and the OR circuit 35, and each T-type flip-flop which inverts the output each time the output from each correlation matched filter 33 and 34 is input. Loop circuits 36-38
It is composed of

The train detecting section 25 includes a band pass filter 41A, a level determining circuit 42A, and a detecting circuit 43.
A, a check relay CHR connected in series to the series circuit of A, a band-pass filter 41B, a level determination circuit 42B,
It comprises an entry detection relay INR connected in series to the series circuit of the detection circuit 43B, and an entry detection relay OUTR also connected in series to the series circuit of the bandpass filter 41C, the level determination circuit 42C, and the detection circuit 43C. Here, the band-pass filter 41A is configured to pass a frequency signal corresponding to the PN code generation cycle of the PN code string CH transmitted from the terrestrial transmission unit 10. The band-pass filters 41B and 41C are configured to pass frequency signals (frequency signals higher than the pass frequency of the band-pass filter 41A) corresponding to the generation periods of the PN codes PN1 and PN2 transmitted from the train side described later. Have been.

On the other hand, the train 1 traveling on the running path on which the loop P is laid is provided with an IN signal transmitting section for transmitting an IN signal for detecting train entry at the head and a train entry detecting section at the rear end. OUT signal transmitting section for transmitting the OUT signal of the above is provided. The IN signal transmitting unit includes a carrier generator 51 for generating a carrier having the same frequency fc as a carrier on the ground.
And a PN1 code generator 52 that continuously generates one PN code PN1 included in the inspection signal CH, and a carrier wave from the carrier wave generator 51 multiplied by a PN code PN1 from the PN1 code generator 52. A multiplier 53 for spreading and modulating a carrier wave, and a transmitter 5 for amplifying the spread signal and supplying the amplified signal to the loop P via an antenna 55 provided at the head of the train 1
4 is provided. Here, the multiplier 53
Corresponds to the first on-board signal spreading means, and the transmitter 54 and the antenna 55 constitute the first on-board signal supply means.

The OUT signal transmitting section includes a carrier generator 61 similar to the IN signal transmitting section, and a PN2 for continuously generating the other PN code PN2 included in the inspection signal CH.
A code generator 62; a multiplier 63 for multiplying the carrier by a PN code PN2 to spread-modulate the carrier; and a transmitter 64 for supplying the loop P via an antenna 65 provided at the rear end of the train 1. It is configured. Here, the multiplier 6
Reference numeral 3 corresponds to a second on-board signal spreading unit, and the transmitter 64 and the antenna 65 constitute a second on-board signal supply unit.

Further, in the train detection device of the present embodiment, FIG.
The loop disconnection detection circuit shown in FIG. That is, the falling contact inr of the entry detection relay INR is connected to the disconnection detection relay R.
1 and a series circuit of a falling contact outr1 of the advance detection relay OUTR and a lifting contact chr1 of the checking relay CHR are connected in series, and a lifting circuit inr2 of the entering detection relay INR and a falling contact of the checking relay CH are connected in series with these relay contacts. A series circuit of chr2 is provided in parallel and connected in series to the disconnection detection relay R. A lifting contact out of the advance detection relay OUTR is connected to a lifting contact inr2 of the entry detection relay INR.
r2 are connected in parallel.

Next, the train detecting operation of the apparatus of this embodiment will be described with reference to the time charts of FIGS.
First, a case where the train 1 does not exist on the loop P will be described with reference to FIG. At the starting end PS of the loop P,
A predetermined P shown as a CH signal in FIG.
A signal that has been spread by the N code string is supplied. And
This signal is received by the terrestrial receiving unit 20 from the terminal side PR of the loop P via the transformers T and T, and the PN code string component is passed through the multiplier 22 and the low-pass filter 23 to the reference signal C.
Extracted as H. The extracted signal is input to the first and second correlation matched filters 33 and 34 of the PN code detection unit 24, and is processed using the PN codes PN1 and PN2 from the corresponding code generators 31 and 32. A pulse signal is generated from the first correlation matched filter 33 in the cycle shown in FIG.
A pulse signal is generated in a cycle indicated by b.

As a result, a PN code generation of a PN code string as shown in FIG. 3C is performed from the flip-flop circuit 36 to which the OR output of the outputs of the two correlation matched filters 33 and 34 is input via the OR circuit 35. A rectangular wave output having a frequency fm corresponding to the cycle is generated. In addition, the flip-flop circuits 37 and 38 generate a rectangular wave output having a frequency corresponding to the generation cycle of each of the PN codes PN1 and PN2 (a half of the frequency fm). Band-pass filter 4 to which the rectangular wave output of the flip-flop circuit 36 is input
1A is for passing the signal of the frequency fm. Therefore, the checking relay CHR is operated to detect that the train does not exist on the loop P.

Each band-pass filter 41B, 4 to which the rectangular wave output of the flip-flop circuit 37, 38 is input.
1C does not allow the frequency of the rectangular wave output at this time to pass, so that the entry detection relay INR and the entry detection relay OUTR do not operate. In this case, in the loop disconnection detection circuit shown in FIG. 2, the lifting contact chr1 of each relay,
The falling contacts inr1 and outr1 are closed, the disconnection detection relay R is excited, and it is detected that the loop is normal.

Next, a case where the train 1 enters the loop P will be described with reference to FIG. When the head of the train 1 reaches the loop P, the continuously generated PN code PN1 shown as the IN signal in FIG. Is supplied. Then, the pulse signal from the first correlation matched filter 33 is the sum of the correlation output by the CH signal and the correlation output by the IN signal as shown in FIG. Therefore, the flip-flop circuit 3
7, the PN generated continuously as shown in FIG.
A rectangular wave output having a frequency corresponding to the generation cycle of the code PN1 is generated. The band pass filter 41B passes this frequency, and as a result, the entry detection relay INR
Operates to detect that the head of the train 1 has entered the loop P.

At this time, the output from the flip-flop circuit 36 to which the OR output of the two correlation matched filters 33 and 34 is input via the OR circuit 35 is higher than when the train 1 does not exist as shown in FIG. A rectangular wave output of the frequency is generated, and the bandpass filter 41A does not pass this frequency, so that the check relay CHR falls. Further, the advance detection relay OUTR is maintained in the falling state as in the case where no train exists. In this case, the entry detection relay IN
R lifting contact inr2 and falling contact c of control relay CHR
The disconnection detection relay R is maintained in the excited state by hr2, and it is detected that the loop P is normal.

Next, a case where the entire train 1 exists on the loop P will be described with reference to FIG. When the entire train 1 exists in the loop P, the signal from the ground transmission unit 10 and IN supplied to the loop P from the antenna 55
In addition to the signals, the antenna 65 at the rear end of the train 1
PN code PN generated continuously as an OUT signal
A signal for detecting a train advance which is spread-modulated in 2 is supplied. Therefore, a pulse signal similar to that in the case of FIG. 4 is generated from the first correlation matched filter 33, and the entry detection relay INR operates. Also, the second correlation matched filter 3
The pulse signal from 4 also becomes the sum of the correlation output by the CH signal and the correlation output by the OUT signal as shown in FIG. 5B, and is continuously generated from the flip-flop circuit 38 as shown in FIG. 5E. A rectangular wave output having a frequency corresponding to the generation cycle of the PN code PN2 is generated, and the advance detection relay OUTR operates via the band-pass filter 41C. As a result, the entry detection relay INR and the entry detection relay OUT
Both R operate to detect that train 1 is on loop P. Also at this time, the disconnection detection relay R is kept in the excited state.

Next, a case where the head of the train 1 has advanced from the loop P to the next adjacent block section will be described with reference to FIG. When the head of the train 1 leaves the loop P, as shown in FIG. 6A, the pulse output of the first correlation matched filter 33 outputs the PN code P
This is a cycle corresponding to the generation cycle of only N1. As a result,
The frequency of the rectangular wave output of the flip-flop circuit 37 is also the same as that in the case where there is no train shown in FIG.
It is detected that the entry detection relay INR has fallen and the head of the train 1 has exited the loop P. On the other hand, since the checking relay CHR and the advance detection relay OUTR are maintained as they are, the disconnection detection relay R is maintained in the excited state by the lifting contact outr2 of the advance detection relay, and the loop P is normal. Is detected.

As described above, the apparatus of this embodiment can improve the S / N ratio by using the spread spectrum communication system having excellent noise resistance. Conventionally, train entry and
The IN signal and the OUT signal for detecting the advance are distinguished by making the carrier frequency different, but according to the present embodiment, the carrier frequency is made the same and the type of the PN code is made different so that each correlation output is made. , It is possible to discriminate between the entry and the exit, and it is possible to configure the closing logic using the spread spectrum communication method.

Next, a second embodiment of the present invention will be described. FIG. 7 is a schematic configuration diagram of a second embodiment of the train detection device of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, a PN code string having a different configuration from that of the first embodiment is used. That is, the first embodiment, for though is to apply to the case of using the PN code string intermittently arranged at equal intervals PN code PN1, PN2 alternately, the second embodiment, the PN code P
This is applied when N1 and PN2 use PN code strings that are not equally spaced.

The difference from the first embodiment is that the terrestrial transmitter 1
0 PN code string generator 12 ′ and the PN code
The configuration is the same as that of the first embodiment except for the code detector 24 'only. Here, the configurations of the PN code sequence generator 12' and the PN code detector 24 'will be described. In FIG. 7, the PN code sequence generator 12 'of this embodiment generates PN codes PN1 and PN2 different from each other continuously from the PN code generators, and then generates the PN codes PN1 and P
The frequency of the generated N2 is divided into, for example, 1/8 by the frequency divider. One PN code, for example, the PN2 side is delayed by 1/8 cycle of the divided output. This allows
The PN code string generator 12 'outputs PN1 and PN2 in one cycle of the PN code string as shown in FIG.
And a PN code string in which と and とare successively generated, and this becomes a check signal.

The PN code detector 2 of the ground receiver 20
Reference numeral 4 'designates the output of the first correlation matched filter 33 as the 1 of the PN code PN1 instead of the OR circuit 35 of the first embodiment.
A delay circuit 71 for delaying by a period (same as 1/8 of the divided output of the PN code PN1 on the transmission side), and an adder 72 for adding the delay output of the delay circuit 71 and the correlation output of the second correlation matched filter 34 It is provided with.

Next, the train detection operation of the second embodiment will be described with reference to the time charts of FIGS. First, a case where the train 1 does not exist on the loop P will be described with reference to FIG. 8 from the ground transmission unit 10
Are supplied to the loop P and are received by the terrestrial receiving unit 20. This received signal is processed in the same manner as in the first embodiment, a PN code string component is extracted, and input to the PN code detection unit 24 '. Then, a pulse signal indicated by z in FIG. 8 is generated from the first correlation matched filter 33, and a pulse signal indicated by y in FIG. 8 is generated from the second correlation matched filter. The pulse signal input from the first correlation matched filter 33 to the delay circuit 71 is input to the adder 72 after being delayed by a predetermined time, and is added to the output of the second correlation matched filter 34 by the adder 72. A pulse signal as shown by x in FIG. 8 is generated. As a result, a rectangular wave output having a period twice as long as the PN code string is generated from the flip-flop circuit 36, and the band-pass filter 41A passes a signal of this frequency. It operates and detects that a train does not exist on loop P.

On the other hand, rectangular wave outputs having the same period as the flip-flop circuit 36 are also generated from the flip-flop circuits 37 and 38, but the respective band-pass filters 41B and 41C
Are configured so as not to pass the frequency of the rectangular wave output at this time, so that the entry detection relay INR and the entry detection relay O
UTR does not work. Next, a case where the train 1 enters the loop P will be described with reference to FIG.

When the head of the train 1 reaches the loop P, and an IN signal for detecting the entry from the antenna 55 as shown in FIG. The pulse signal from the one-correlation matched filter 33 is the sum of the correlation output by the CH signal and the correlation output by the IN signal, as shown by z in FIG. For this reason,
Square wave output frequency from the flip-flop circuit 37 is high, since the band-pass filter 41B Ru der lets through the frequencies, so that the approach detecting relay IN
It is detected that R operates and the head of the train 1 has entered the loop P.

At this time, the pulse signal input to the flip-flop circuit 36 is as shown by x in FIG. 9, and the rectangular wave output from the flip-flop circuit 36 has the same frequency as that of the flip-flop circuit 37.
1A does not pass this frequency, so the check relay CH
R falls. The output frequency of the rectangular wave output of the flip-flop circuit 38 is not changed from that when no train is present, and the advance detection relay OUTR is maintained in a falling state.

Next, a case where the entire train 1 exists on the loop P will be described with reference to FIG. The entire train 1 exists in the loop P. In addition to the signal from the ground transmission unit 10 and the IN signal supplied to the loop P from the antenna 55, the train 1 shown in FIG.
When the OUT signal for detecting the advance as shown by 0 is received, the pulse signal from the second correlation matched filter 34 becomes the correlation output between the CH signal and the OUT signal as shown by y in FIG. It becomes sum. Therefore, the rectangular wave output frequency from the flip-flop circuit 38 also increases, and the band-pass filter 41C passes this frequency. As a result, the entry detection relay INR
At the same time, the advance detection relay OUTR also operates to detect that the entire train 1 exists on the loop P.

Next, a case where the head of the train 1 has advanced from the loop P to the next adjacent block section will be described with reference to FIG. In this case, as shown in FIG.
Since the pulse output of the first correlation matched filter 33 has a period corresponding to the period of generation of only the PN code PN1 from the terrestrial transmission unit 10, the rectangular wave output from the flip-flop circuit 37 indicates that the train 1 does not exist ( In the same manner as in the case of FIG. 8), it is detected that the entry detection relay INR has fallen and the head of the train 1 has exited the loop P.

In this embodiment, as in the first embodiment, S / S
The N ratio can be improved, and an induction loop type train detection excellent in noise resistance can be performed. The time charts of FIG. 12 to FIG.
This shows a case where a PN code sequence different from the PN code sequence of the above-described embodiment is used. In this case, the ground receiving unit 20
When the pulse signal of the first correlation matched filter 33 is delayed in the PN code detection unit 24 'on the side, the addition output with the pulse signal of the second correlation matched filter 34 becomes a constant interval as shown by x in FIG. It is made to occur in. Therefore, the band-pass filter 41A is connected to x
Flip-flop circuit 3 corresponding to the pulse signal frequency of
6 is configured to pass the frequency of the rectangular wave output generated.

Thus, the presence / absence of a train on the loop P and the entry / exit of the train can be detected by the same operation principle as described with reference to FIGS.

[0037]

As described above, according to the train detection apparatus of the present invention, the S / N ratio can be improved by using the spread spectrum communication system excellent in noise resistance, and the reliability is excellent in noise resistance. It becomes possible to detect trains in a highly guided loop system. In addition, by simply using the same carrier and different PN codes, it is possible to detect entry and exit of a train,
It becomes possible to configure the same closing logic as before, and the security is not impaired.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a train position detecting device according to the present invention.

FIG. 2 is a circuit diagram of a loop disconnection detection circuit according to the embodiment.

FIG. 3 is a time chart when a train does not exist on a loop.

FIG. 4 is a time chart when a train enters a loop.

FIG. 5 is a time chart when the entire train exists on a loop.

FIG. 6 is a time chart when a train advances from a loop.

FIG. 7 is a schematic configuration diagram of a second embodiment of the train position detecting device according to the present invention.

FIG. 8 is a time chart when a train does not exist on a loop.

FIG. 9 is a time chart when a train enters a loop.

FIG. 10 is a time chart when the entire train exists on a loop.

FIG. 11 is a time chart when a train advances from a loop.

FIG. 12 is a time chart when a train does not exist when another PN code string is used in the second embodiment.

FIG. 13 is a time chart when a train enters a loop.

FIG. 14 is a time chart when the entire train exists on a loop.

FIG. 15 is a time chart when a train advances from a loop.

[Explanation of symbols]

Reference Signs List 1 train 10 ground transmission unit 11, 21, 51, 61 carrier generator 12, 12 'PN code string generator 13, 22, 53, 63 multiplier 14, 54, 64 transmitter 20 ground reception unit 23 low-pass filter 24, 24 'PN code detecting unit 25 Train detecting unit 31, 52 PN1 code generator 32, 62 PN2 code generator 33 First correlation matched filter 34 Second correlation matched filter 35 OR circuit 36, 37, 38 Flip-flop circuit 55, 65 antenna 71 delay circuit 72 addition circuit CHR Shosa relay INR enters sensing relay OUTR advanced sensing relay P loop P _S loop start end P _R loop end side

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B61L 3/22 H04J 13/00

Claims (1)

(57) [Claims] 1. An induction loop laid along a running path of a train for each closed section, and two different PN codes having the same occurrence cycle are alternately arranged and generated with periodicity. Terrestrial signal spreading means for spreading a carrier with a PN code string, terrestrial signal supplying means for supplying a signal spread by the terrestrial signal spreading means to the start end of the induction loop, Terrestrial receiving means for receiving a signal; extracting means for demodulating a received signal received by the terrestrial receiving means with a signal having the same frequency as the carrier to extract a signal containing a PN code component; PN code detecting means for identifying and detecting each PN code from the obtained signal, and spreading a carrier having the same frequency as the carrier with a PN code continuously generated in the same type as one PN code of the PN code sequence. A first on-vehicle signal spreading means, a first on-vehicle signal supply means for transmitting a signal spread by the first on-vehicle signal spreading means from the train head to the guidance loop, and the same frequency as the carrier wave. A second on-board signal spreading means for spreading the carrier wave of the same type with a PN code continuously generated of the same type as the other PN code of the PN code sequence, and trains the signal spread by the second on-board signal spreading means. A second on-board signal supply means for transmitting from the rear end to the guidance loop, and a train when only each PN code of the PN code string supplied from the ground signal supply means is detected by the PN code detection means. Is detected not to be on the guidance loop, and when the PN code detection means detects the PN code supplied from the first on-board signal supply means, it is detected that the train has entered the guidance loop. And detecting the PN code On inductive loop when the PN code PN code supplied from the first on-board signal supply means stage is supplied from and the second drive on the signal supply means in a non-detection state is in a detection state in the block section A train detection device, comprising: a train detection unit configured to detect that a train head has advanced from.