JPH0781567A - Train detecting device - Google Patents

Abstract

PURPOSE:To detect the train of the induction loop method where the S/N ratio can be improved and the reliability is high by making use of a spectrum diffusion communicating device excellent in the noise resistance, and using the same carrier wave where the PN sign is different. CONSTITUTION:An induction loop P is formed by a loop-shaped coil of the length to form one closed interval, and ground transmitting parts 10, 20 are connected thereto on the starting point side and the ending point side. The ground transmitting part 10 is provided with a carrier wave generator 11 of the prescribed frequency fC, a prescribed PN sign train CH generator 12, a carrier wave diffusion multiplier 13, and a transmitter 14 to supply the carrier wave to the starting point side of the loop P. The ground transmitting part 20 is provided with a multiplier 22 to multiply the received signal on the loop ending point side with the carrier wave fC, a low pass filter 23, a PN sign detecting part 24 and a train detecting part 25, and filters 33, 34 to operate the input from sign generators 31, 32 to generate the same sign as PN1, PN2 to be contained in the PN sign train CH and the correlation value from the low pass filter 23 and inversion circuit 36-38 are provided.

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 lays a guidance loop along a train running path to detect a train.

[0002]

2. Description of the Related Art Conventionally, an urban traffic train running on rubber tires does not use rails on its running path, so it is not possible to adopt track circuit type train detection using rails.
Inductive loop type train detection is performed. This inductive loop type train detection device lays an inductive loop of a predetermined length along a running path, a so-called loop coil (hereinafter referred to as a loop), and a signal is transmitted from the vehicle (train side) to the loop. Is configured to.

Therefore, on the ground side, when a predetermined signal is received via the loop, it can be detected that the train is located on the loop. Further, in the conventional induction loop type train detection device, a signal suppression system is adopted in order to ensure fail-safety. In this method, a predetermined check signal (hereinafter referred to as a verification signal) consisting of a normal analog single frequency or AM modulated wave is constantly supplied to the start side of the loop (the side where the train exits from the closed section). A receiver is provided at the end of the loop (the side where the train enters the closed section) to constantly detect the verification signal. Then, when the train approaches this loop and the signal from the train is transmitted to the loop and superimposed on the inspection signal, the inspection signal is suppressed and becomes no signal, so that train detection is performed by this no signal detection. It is configured.

[0004]

However, in the conventional train detection system of the induction loop system, the S / N is
There was a problem that was inferior. This is because a train line is laid near the loop and noise increases.
If the S / N is bad, the verification signal is suppressed just by the approach of the train, which causes a problem that the train is detected before the train is present on the loop. In order to eliminate such a problem, measures such as increasing the signal output are taken to improve the S / N.
When the signal output is increased, it results in a new problem that power consumption increases.

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 characteristic, and at the same time, makes it possible to distinguish between the entrance and the exit of a train, and a block logic. It is an object of the present invention to provide a train detection device of the induction loop type that enables the above configuration.

[0006]

For this reason, in the train detection device of the present invention, the induction loop laid in each closed section along the running path of the train and the two different PN codes having the same generation period. And a terrestrial signal spreading means for spreading the carrier wave by a PN code string generated with a periodicity, and the signal spread by the terrestrial signal spreading means to the start end side of the induction loop. A terrestrial signal supplying means for supplying, a terrestrial receiving means for receiving a signal from the terminal side of the induction loop, and a PN code component obtained by demodulating a reception signal received by the terrestrial receiving means with a signal having the same frequency as the carrier wave. And a 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 in one of the PN code strings. First on-board signal spreading means for spreading processing with a PN code of the same type as the PN code and continuously generated, and a signal spread by the first on-board signal spreading means is transmitted from the train head side to the guidance loop. A first on-board signal supply means,
A second on-vehicle signal spreading means for spreading a carrier wave having the same frequency as the carrier wave by a PN code continuously generated of the same type as the other PN code of the PN code string, and spread by the second on-vehicle signal spread means. Second on-board signal supplying means for transmitting the generated signal from the rear end side of the train to the induction loop, and each PN code of the PN code string supplied from the ground signal supplying means by the PN code detecting means. When the PN code supplied from the first on-board signal supply means is detected by the PN code detection means, the train is detected on the induction loop. Upon detection of entry, the PN code supplied by the first on-board signal supply means is not detected by the PN code detection means, and the PN code supplied by the second on-board signal supply means is blocked. Section and Train from the inductive loop when in the detection state at the entry side block section in contact is constituted by a train detection means for detecting that it has advanced.

[0007]

In the above structure, from the start end side of the induction loop, the carrier is spread by the PN code string having the periodicity which is generated by alternately generating two different PN codes having the same generation period. Verification signal is supplied. On the other hand, from the train side, an IN signal for train entry detection, which has been spread 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 verification signal, is at the head part. And an OUT signal for train advancing detection, which is spread with a PN code that is continuously generated of the same type as the other PN code of the PN code string of the verification signal, is transmitted from the rear end. The terrestrial receiving means receives a signal from the end side of the loop, and the extracting means demodulates the received signal with a signal having the same frequency as the carrier wave on the transmitting side to extract a signal containing a PN code component, and from this extracted signal Each PN code is detected by the PN code detecting means.

The train detection means detects that the train does not exist on the induction loop if the PN code detection output is generated in synchronization with the PN code generation cycle of the signal transmitted from the ground from the PN code detection means. When the detection output of the predetermined PN code transmitted from the train head side from the code detection means occurs in a short cycle substantially the same as the predetermined PN code, it is detected that the train has entered the induction loop, and the PN code detection means. Detection output of the train approach detection disappears and the detection output of a predetermined PN code transmitted from the train rear end side is the predetermined PN.
When the PN code detecting means in the closed section and the adjacent closed section on the entry side detects a state that occurs in a short cycle substantially the same as the code, it is detected that the train has advanced from the guidance 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, in which an induction loop (hereinafter, referred to as a loop) P is formed by a loop-shaped coil having a length that forms one closed section. It is laid in each closed section along a running path (not shown).

The ground transmitter 10 is connected to the start side P _{S of the} loop P (the side where the train advances to the front closed section), and the end side P _R of the loop P (the train enters the closed section). The terrestrial receiving section 20 is provided on the side that performs. The terrestrial transmission unit 10 includes a carrier wave generator 11 for generating a carrier wave of a predetermined frequency fc, a PN code string generator 12 for generating a predetermined PN code string CH, and a PN code from the PN code string generator 12 for the carrier wave. It is provided with a multiplier 13 that spread-modulates a carrier by multiplying a column CH, and a transmitter 14 that amplifies the spread signal and supplies the amplified signal to the start side P _S of the loop P via transformers T and T. Has been done. Therefore,
The multiplier 13 corresponds to a terrestrial signal spreading means, and the transmitter 14 corresponds to a terrestrial signal supplying means.

Here, the PN code string generator 12 generates, for example, different PN codes PN1 and PN2 having sharp autocorrelation and low cross-correlation from each PN code generator, and then, The generated frequencies of the PN codes PN1 and PN2 are divided by a frequency divider into, for example, 1/8,
One PN code, for example, PN2 side is provided with a delay circuit to delay the divided output by 1/2 cycle. This allows PN
From the code string generator 12, PN1 and P as shown in FIG.
A PN code string in which N2 and the N2 are alternately arranged at equal intervals and with periodicity is generated, and this serves as a verification signal.

On the other hand, the terrestrial receiving section 20 has a loop termination side P
A multiplier 2 for demodulating the received signal input from _R through the transformers T serving as receiving means and multiplying it by a carrier having the same frequency fc as that of the transmitting side generated from the carrier generator 21.
2, a low-pass filter 23 that passes the output of the multiplier 22 and extracts a PN code component, and a low-pass filter 23.
PN to identify and detect each PN code PN1 and PN2 from
A PN code detecting section 24, which will be described later, as code detecting means,
Train detection for detecting the presence / absence of a train in the closed section (on loop P), the train entry into the closed section, and the train advancement from the closed section to the adjacent closed section based on the detection output from the PN code detection unit 24. Train detection unit 2 described later as means
And 5 are provided. Here, the carrier wave generator 2
1, the multiplier 22 and the low-pass filter 23 constitute an extraction means.

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

Further, the train detection section 25 includes a bandpass filter 41A, a level determination circuit 42A, and a detection circuit 43.
A verification relay CHR connected in series to the A series circuit, a band pass filter 41B, a level determination circuit 42B,
An ingress detection relay INR serially connected to the series circuit of the detection circuit 43B, and an advance detection relay OUTR serially connected to the series circuit of the bandpass filter 41C, the level determination circuit 42C, and the detection circuit 43C are also provided. Here, the bandpass filter 41A is configured to pass a frequency signal corresponding to the PN code generation period of the PN code string CH transmitted from the terrestrial transmission unit 10. Further, the bandpass filters 41B and 41C are configured to pass a frequency signal (frequency signal higher than the pass frequency of the bandpass filter 41A) corresponding to the generation period of PN codes PN1 and PN2 transmitted from the train side described later. Has been done.

On the other hand, the train 1 traveling on the traveling path provided with the loop P is provided with an IN signal transmitting section for transmitting an IN signal for detecting a train entry at the leading end and a train advancing detection at the rear end. An OUT signal transmitting unit for transmitting the OUT signal of is provided. The IN signal transmission unit includes a carrier wave generator 51 for generating a carrier wave having the same frequency fc as the ground side carrier wave.
A PN1 code generator 52 for continuously generating one PN code PN1 included in the check 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 transmitter 53 that spread-modulates a carrier wave and a transmitter 5 that amplifies the spread signal and supplies the amplified signal to the loop P via an antenna 55 provided at the head of the train 1.
And 4 are provided. Here, the multiplier 53
Corresponds to the first on-vehicle signal spreading means, and the transmitter 54 and the antenna 55 constitute the first on-vehicle signal supplying means.

Further, the OUT signal transmission section continuously generates the carrier wave generator 61 similar to the IN signal transmission section and the other PN code PN2 included in the verification signal CH.
A code generator 62, a multiplier 63 that multiplies the carrier by the PN code PN2 and spread-modulates the carrier, and a transmitter 64 that supplies the loop P through an antenna 65 provided at the rear end of the train 1. Is configured. Here, the multiplier 6
3 corresponds to a second on-vehicle signal spreading means, and the transmitter 64 and the antenna 65 constitute a second on-vehicle signal supplying means.

Further, in the train detection device of this embodiment, the train detection device shown in FIG.
It is equipped with the loop disconnection detection circuit shown in. That is, the disconnection detection relay R is connected to the drop contact inr of the approach detection relay INR.
1 and the drop contact outr1 of the advance detection relay OUTR and the relay contact chr1 of the inspection relay CHR are connected in series, and the relay contact inr2 of the intrusion detection relay INR and the drop contact of the inspection relay CH are connected in series. A series circuit of chr2 is provided in parallel and is connected in series to the disconnection detection relay R, and the advance contact out of the advance detection relay OUTR is connected to the advance contact inr2 of the entry detection relay INR.
r2 is connected in parallel.

Next, the train detection 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 start side P _S of the loop P,
From the terrestrial transmitter 10 to a predetermined P shown as a CH signal in FIG.
A signal spread by the N code sequence is supplied. And
Transformer T from the end side P _R of the loop P, PN code string component via the multiplier 23 and the low pass filter 24 is received by this signal on the ground receiving portion 20 via the T is Shosa signal C
It is extracted as H. When this extracted signal is input to the first and second correlation matched filters 33 and 34 of the PN code detector 24 and 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 at a period shown by a in FIG. 3, and a pulse signal is generated from the second correlation matched filter 34 from FIG.
The pulse signal is generated at the cycle indicated by b.

As a result, the flip-flop circuit 36, to which the logical sum output of the outputs of the two correlation matched filters 33 and 34 is input via the OR circuit 35, generates a PN code of a PN code string as shown in FIG. 3C. A rectangular wave output having a frequency fm corresponding to the cycle is generated. Further, the flip-flop circuits 37 and 38 generate rectangular wave outputs having a frequency (half the frequency fm) corresponding to the generation period of the PN codes PN1 and PN2. Bandpass filter 4 to which the rectangular wave output of the flip-flop circuit 36 is input
1A allows a signal of frequency fm to pass therethrough, and therefore, the check relay CHR operates to detect that the train is not on the loop P.

Further, the band-pass filters 41B, 4 to which the rectangular wave outputs of the flip-flop circuits 37, 38 are inputted.
Since 1C has a configuration in which the frequency of the rectangular wave output at this time is not passed, 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 relay contact chr1 of each relay,
The drop contacts inr1 and outr1 are closed, and the disconnection detection relay R is excited to detect that the loop is normal.

Next, the case where the train 1 enters the loop P will be described with reference to FIG. When the head portion of the train 1 approaches the loop P, in addition to the signal from the terrestrial transmission unit 10, the antenna 55 sends to the loop P a continuously generated PN code PN1 shown as an IN signal in FIG. A signal which is spread-modulated by is supplied. Then, the pulse signal from the first correlation matched filter 33 becomes the sum of the correlation output by the CH signal and the correlation output by the IN signal as shown in a of FIG. Therefore, the flip-flop circuit 3
From 7 onwards, PN that is continuously generated as shown in FIG.
A rectangular wave output having a frequency corresponding to the generation period of the code PN1 is generated. The band pass filter 41B passes this frequency, and as a result, the intrusion detection relay INR
Is operated to detect that the leading portion of the train 1 has entered the loop P.

At this time, the output from the flip-flop circuit 36 to which the logical sum output of the two correlation matched filters 33 and 34 is input via the OR circuit 35 is higher than that when the train 1 is not present, as shown in FIG. 4c. Since a rectangular wave output having a frequency is generated and the bandpass filter 41A does not pass this frequency, the check relay CHR drops. Further, the advance detection relay OUTR is maintained in the falling state as it is when there is no train. In this case, the approach detection relay IN
R contact point inr2 and check relay CHR drop contact point c
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. If the entire train 1 exists in the loop P, the signal supplied from the ground transmitter 10 and the IN supplied from the antenna 55 to the loop P
In addition to the signals, from the antenna 65 at the rear end of the train 1 to FIG.
PN code PN that is generated continuously as OUT signal
A signal for train advance detection that is spread and 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 approach detection relay INR operates. Also, the second correlation matched filter 3
The pulse signal from 4 is also 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 by e in FIG. A rectangular wave output having a frequency corresponding to the generation period of the PN code PN2 is generated, and the advance detection relay OUTR also operates via the bandpass filter 41C. As a result, the entry detection relay INR and the entry detection relay OUT
Both Rs operate and it is detected that the train 1 exists on the loop P. Also at this time, the disconnection detection relay R is kept in the excited state.

Next, with reference to FIG. 6, a case where the leading portion of the train 1 advances from the loop P to the next adjacent closed section will be described. When the head part of the train 1 exits from the loop P, the pulse output of the first correlation matched filter 33 is the PN code P from the terrestrial transmitter 10 as shown in FIG.
The period corresponds to the generation period of N1 only. As a result,
The frequency of the rectangular wave output of the flip-flop circuit 37 becomes the same frequency as when there is no train shown in FIG.
It is detected that the entry detection relay INR has fallen and the head portion of the train 1 has come out of the loop P. On the other hand, since the check relay CHR and the advance detection relay OUTR are maintained in the same state, this allows the disconnection detection relay R to be kept in the excited state by the enlarging contact outr2 of the advance detection relay and the loop P to be 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. In addition, train entry /
The IN signal and the OUT signal for the advance detection are distinguished by making the carrier frequency different, but according to the present embodiment, the carrier frequencies are the same and the PN code types are made different to output the respective correlations. By detecting the, it is possible to distinguish between the entry and the exit, and it becomes possible to configure the blocking 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 designated by the same reference numerals and the description thereof will be omitted. The present embodiment is a case where a PN code string having a configuration different from that of the first embodiment is used. That is, the first embodiment is applied to the case of using the PN code string in which the PN codes PN1 and PN2 are alternately arranged at equal intervals intermittently.
This is applied when a PN code string in which 1 and PN2 are not evenly spaced is used.

The part different from the first embodiment is the terrestrial transmitter 1.
0 PN code string generator 12 'and PN of terrestrial receiver 20
The configuration is the same as that of the first embodiment except for the code detecting unit 24 '. Here, the configurations of the PN code string generator 12' and the PN code detecting unit 24 'will be described. In FIG. 7, the PN code string generator 12 'of the present embodiment successively generates different PN codes PN1 and PN2 from the respective PN code generators, and then the respective PN codes PN1 and P.
The generated frequency of N2 is divided into, for example, 1/8 by a frequency divider, but 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 as a CH signal in FIG.
Then, a PN code string arranged in succession is generated, and this becomes a verification signal.

Further, the PN code detecting section 2 of the ground receiving section 20.
4 ', instead of the OR circuit 35 of the first embodiment, outputs the output of the first correlation matched filter 33 to 1 of the PN code PN1.
A delay circuit 71 that delays by a period (same as 1/8 of the divided output of the PN code PN1 on the transmission side), and an adder 72 that adds the delay output of this delay circuit 71 and the correlation output of the second correlation matched filter 34. It is configured 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. From the ground transmitter 10 to FIG.
The signal subjected to spread processing with a predetermined PN code string shown as the CH signal of 1 is supplied to the loop P and received by the ground receiving unit 20. This received signal is processed in the same manner as in the first embodiment to extract the PN code string component and input to the PN code detector 24 '. Then, the first correlation matched filter 33 generates a pulse signal shown by z in FIG. 8, and the second correlation matched filter 34 generates a pulse signal shown by y in FIG. The pulse signal input from the first correlation matched filter 33 to the delay circuit 71 is delayed by a predetermined time, input to the adder 72, and added by the adder 72 with the output of the second correlation matched filter 34. A pulse signal as indicated by x in FIG. 8 is generated. As a result, the flip-flop circuit 36 generates a rectangular wave output having a period twice that of the PN code string, and the bandpass filter 41A passes a signal of this frequency. Therefore, the check relay CHR is It operates to detect that the train is not on loop P.

On the other hand, the rectangular wave output having the same period as that of the flip-flop circuit 36 is also generated from the flip-flop circuits 37 and 38, but the band pass filters 41B and 41C are used.
Has a configuration in which the frequency of the rectangular wave output at this time is not passed, and therefore, the entrance detection relay INR and the entrance 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 approaches the loop P and an IN signal for approach detection as shown in FIG. 9 from the antenna 55 is received in addition to the signal from the ground transmitter 10, The pulse signal from the 1-correlation matched filter 33 is the sum of the correlation output by the CH signal and the correlation output by the IN signal, as indicated by z in FIG. For this reason,
Since the rectangular wave output frequency from the flip-flop circuit 37 becomes high and the band pass filter 41B passes this frequency, as a result, the approach detection relay IN
It is detected that R operates and the head part of the train 1 has entered the loop P.

At this time, the pulse signal input to the flip-flop circuit 36 becomes as shown by x in FIG. 9, the rectangular wave output from the flip-flop circuit 36 has the same frequency as that of the flip-flop circuit 37, and the bandpass filter 4
1A does not pass this frequency, so check relay CH
R falls. The rectangular wave output frequency of the flip-flop circuit 38 is the same as when there is no train, and the advance detection relay OUTR is maintained in the 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 is present in the loop P, and in addition to the signal from the ground transmitter 10 and the IN signal supplied from the antenna 55 to the loop P, the train 65 from the antenna 65 at the rear end of the train 1 is used.
When the OUT signal for advance detection as indicated by 0 is received, the pulse signal from the second correlation matched filter 34 is divided into the correlation output by the CH signal and the correlation output by the OUT signal, as indicated by y in FIG. It becomes the sum. Therefore, the rectangular wave output frequency from the flip-flop circuit 38 also increases, and the bandpass filter 41C passes this frequency. As a result, the approach 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, with reference to FIG. 11, a case where the head portion of the train 1 advances from the loop P to the next adjacent closed section will be described. In this case, as shown in z of FIG.
Since the pulse output of the first correlation matched filter 33 has a period corresponding to the generation period of only the PN code PN1 from the terrestrial transmission unit 10, the rectangular wave output from the flip-flop circuit 37 is when the train 1 does not exist ( In the same manner as in the case of FIG. 8), the entry detection relay INR is dropped and it is detected that the head portion of the train 1 has come out of the loop P.

In this embodiment as well, as in the first embodiment, S /
The N ratio can be improved, and induction loop train detection with excellent noise resistance can be performed. 12 to 15 are time charts.
It shows the case where a PN code string different from the PN code string of the above-mentioned embodiment is used. In this case, the ground receiver 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 is at constant intervals as shown by x in FIG. I am trying to occur in. Therefore, the bandpass filter 41A is replaced by x in FIG.
Flip-flop circuit 3 corresponding to the pulse signal frequency of
The frequency of the rectangular wave output generated from 6 is passed.

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

[0037]

As described above, according to the train detection device of the present invention, by using the spread spectrum communication system having excellent noise resistance, the S / N ratio can be improved and the noise resistance can be improved. It is possible to detect trains with a high frequency induction loop system. In addition, it is possible to detect the entry and departure of a train by simply using the same carrier and different PN codes.
It becomes possible to configure a blocking logic similar to the conventional one, and safety is not impaired.

[Brief description of drawings]

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

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

[Fig. 3] Time chart when the train is not on the loop

[Figure 4] Time chart when train enters the loop

[Figure 5] Time chart when the entire train is on the loop

[Fig. 6] Time chart for when a train leaves the 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: Time chart when train does not exist on loop

[Fig. 9] Time chart when a train enters the loop

FIG. 10: Time chart when the entire train is on a loop

[Fig. 11] Time chart when a train leaves the loop

FIG. 12 is a time chart when there is no train when another PN code string is used in the second embodiment.

[Fig. 13] Time chart when a train enters the loop

FIG. 14: Time chart when the entire train exists on the loop

[Fig.15] Time chart when a train leaves the loop

[Explanation of symbols]

1 train 10 terrestrial transmitter 11, 21, 51, 61 carrier generator 12, 12 'PN code string generator 13, 22, 53, 63 multiplier 14, 54, 64 transmitter 20 terrestrial receiver 23 low-pass filter 24, 24 'PN code detector 25 Train detector 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 Adder circuit CHR Check relay INR Ingress detection relay OUTR Advance detection relay P loop P _S loop start side P _R loop end side

Claims (1)

[Claims] 1. An induction loop laid in each closed section along a running path of a train and two different PN codes having the same generation period are alternately arranged to generate with a periodicity. A terrestrial signal spreading means for spreading the carrier wave by a PN code string, a terrestrial signal supplying means for supplying the signal spread by the terrestrial signal spreading means to the starting end side of the induction loop, and the terminating side of the guiding loop. Ground receiving means for receiving a signal, extracting means for demodulating a received signal received by the ground receiving means with a signal having the same frequency as the carrier wave to extract a signal containing a PN code component, and extracting by the extracting means A PN code detecting means for identifying and detecting each PN code from the generated signal, and a carrier having the same frequency as the carrier is spread by a PN code continuously generated in the same kind as one PN code of the PN code string. A first on-board signal spreading means, a first on-board signal supplying means for transmitting the signal spread by the first on-board signal spreading means from the train head side to the induction loop, and the same frequency as the carrier wave. Second on-board signal spreading means for spreading the carrier wave of the above with a PN code continuously generated of the same type as the other PN code of the PN code string, and the signal spread by the second on-board signal spreading means by a train. The second train signal supply means for transmitting from the rear end side to the induction loop, and the train when the PN code detection means detects only each PN code of the PN code string supplied from the ground signal supply means. That the train has entered the induction loop when the PN code supplied from the first on-board signal supply means is detected by the PN code detection means. Then, the PN code detection In the stage, the PN code supplied from the first on-board signal supply means is in a non-detection state, and the PN code supplied from the second on-board signal supply means is in a detected state in the block section and the adjacent entry side block section. A train detection device, comprising: train detection means for detecting that a train has advanced from above the guidance loop when