JPS6354588B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention receives a vehicle detection signal from above the vehicle via an induction loop installed at each blockage section along the vehicle travel path, and continuously detects the vehicle at each blockage section. The present invention relates to a vehicle detection device that performs vehicle detection.

FIG. 1 is a diagram showing the general configuration of this type of vehicle detection device, in which a guide loop 3 on the ground is installed at each blocked section 1T, 2T, 3T, etc. along a track 2 on which a vehicle 1 runs. , a reference signal f _CH which is an amplitude modulated wave is sent from the reference signal generator 4 on the ground, and this reference signal f _CH is received by the receiver 5 on the ground. Now, focusing on the blocked section 2T, in a normal state where the vehicle 1 has not entered the blocked section 2T, the output of the receiving section 5 causes the check relay CHR to
is energized and its contact is lifted up, thereby outputting a determination signal indicating that no vehicle is present. By transmitting a signal from the on-board equipment installed in the vehicle 1 to this ground equipment and receiving this signal by the guidance loop 3 on the ground, the closed sections 1T, 2T, 3T
. . . The approach and exit of the vehicle 1 is detected. Conventionally, the following two methods have been used to send a signal from the vehicle 1.

(1) A check-in signal f _1N is transmitted from the front of the vehicle 1 to suppress the check signal f _CH flowing to the guidance loop 3 and detect the entry of the vehicle 1 into the blocked section, and A method of transmitting a checkout signal f _put to detect the advance of

However, with this method, for some reason, one vehicle
moves backward, and as shown in Fig. 2, the blockage section 2T
When only the rear of vehicle 1 enters the blocked section 1T from the blocked section 1T, the suppressing effect on the reference signal f _CH cannot be obtained on the blocked section 1T side, so vehicle 1 cannot be detected, and the security of rear protection decreases. do.

(2) As shown in Fig. 3, the _f1 signal is transmitted from the front of the vehicle ₁ , and _{the f2} signal is transmitted from the rear,
By providing each signal with a function to suppress the reference signal f _CH , the blockage sections 1T, 2T, and 3T
. . . and detects the vehicle's departure from the blocked section using the _f2 signal that is received for a short time in both blocked sections when the vehicle 1 passes through the boundary of each blocked section.

That is, as shown in FIG. 3, the receiving section 5 is
Vehicle entry detection unit 5 suppresses the reference signal f _CH regardless of whether the f ₁ signal or the f ₂ signal is received, drops the reference relay CHR, and detects vehicle entry.
A and a circuit part 5B that activates relay f _2R when the f ₂ signal is received, and the blockage logic is configured by the combination of the reference relay CHR and relay f _2R . This is to detect the entry or exit of a person.

However, in this method, the _reference signal f _CH
In addition to _the same function as _the f ₁ signal, which suppresses Therefore, the carrier frequencies of the f ₁ signal and the f ₂ signal cannot be made the same. Moreover _, as shown in _{FIG .}
This had to be a wide-bandwidth filter that allowed all of the signals to pass through, which had the drawback of reducing the S/N ratio due to noise contamination.

It is an object of the present invention to provide a vehicle detection device that eliminates the above-mentioned conventional drawbacks, has high security such as rear protection, and can secure a sufficient S/N ratio by narrowing the bandwidth of a noise filter. With the goal.

In order to achieve the above object, the present invention provides a guide loop installed in each closed section along a vehicle travel path, a transmitter that transmits a reference signal from one end of the guide loop, and a transmitter that transmits an inspection signal from one end of the guide loop. A vehicle that transmits a signal that suppresses the inspection signal flowing through the guidance loop, and also transmits a superimposed signal of a signal that suppresses the inspection signal from the rear of the vehicle and a signal that detects that the vehicle has exited the blocked section. an upper device;
A vehicle entry detection unit connected to the other end of the guidance loop and extracting the inspection signal, and separating a signal for detecting that the vehicle has exited the blocked section from the superimposed signal transmitted from the rear of the vehicle. a receiving unit including a vehicle entry detection unit for extraction, and determines that a vehicle has entered the blocked section when the signal extracted by the vehicle entry detection unit disappears;
After that, when the signal extracted by the vehicle advance detection section disappears, it is determined that the vehicle has exited the blocked section.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically described below with reference to the accompanying drawings, which are examples. FIG. 5A is a diagram showing the configuration of the on-board equipment of the vehicle detection device according to the present invention, and FIG. 5B is a diagram showing the configuration of the ground equipment. Fifth
In Figures A and B, the same reference numerals as in Figures 1 to 3 indicate functionally identical components.

In this embodiment, vehicle 1 has on-vehicle antennas 6 and 7 at the front and rear parts, and these on-vehicle antennas 6 and 7 are connected to signal generators 8 and 9, respectively. The signal generator 8 includes an oscillator 8a and an amplifier 8b, and outputs a continuous wave check-in signal _f1N . This check-in signal _f1N is a check signal flowing through the ground guidance loop 3.
f Has the function of suppressing _CH .

The signal generating section 9 includes an f' _lN generating section 10 that generates an f' _lN signal that exerts a suppressing effect on the reference signal f _CH ;
Detecting that vehicle 1 has moved out of the blocked section
f _R generating section 11 that generates the f _R signal, and the f' _lN signal from both generating sections 10 and 11 and the f _R signal.
The signals are combined by a hybrid transformer 12, further amplified by an amplifier 13, and supplied to the on-vehicle antenna 7. Therefore, from the on-board antenna 7, a signal is obtained by superimposing the f′ _lN signal and the f _R signal,
That is, a signal of f′ _lN +f _R =f _put is transmitted. The f _R signal generating section 11 is configured to amplitude-modulate the continuous wave signal f _CR , which is the oscillation output of the oscillator 11a, using the square wave output signal f _nR of the oscillator 11b, using the modulator 11c, and output the f _R signal. ing.

On the other hand, the inspection signal generator 4 that constitutes the ground equipment
converts the continuous wave output signal f _C-CH of the oscillator 4a to the modulator 4 using the square wave output signal f _n-CH of the oscillator 4b.
The signal is amplitude-modulated by c, amplified by an amplifier 4d, and an amplitude-modulated reference signal f _CH is output.

The reception unit 5 includes a vehicle entry detection unit 5A that detects that the vehicle 1 has entered the closed section 2T, and a vehicle entry detection unit 5A that detects that the vehicle 1 has entered the closed section 2T.
The vehicle advances from the closed section 2T. The vehicle entrance detection unit 5A includes a noise removal filter 5a ₁ , a limiter 5a ₂ , a demodulator 5a ₃ , a filter 5a ₄ for extracting the f _n-CH component, and a Schmitt circuit 5 for level determination.
A ₅ and amplifier 5a ₆ , with a level above the specified level.
When there is an f _n-CH component, it is extracted by the filter _5a4 , and the level is judged by the Schmidt circuit _5a5 , and then
Amplify with amplifiers 5a and ₆ , and use the amplified output as a reference relay.
The structure is such that the CHR is excited and lifted.

Further, the vehicle advance detection section 5B includes a filter 5b ₁ for noise removal, a demodulator 5b ₂ , a filter 5b ₃ for extracting the f _R component, and a Schmitt circuit 5b ₄ for level determination.
and an amplifier _5b5 , the output of which operates the relay _fR .

Next, the operation will be explained.

In a normal state in which the vehicle 1 does not enter the blockade section 2T, the only signal that enters the receiving section 5 is the reference signal f _CH , and the f _n-CH component at the specified level is extracted, so the reference relay The CHR is energized and raised, thereby detecting that the vehicle 1 is not within the closed section 2T.

When the front of the vehicle 1 enters the closed section 2T and the f _lN signal transmitted from the front of the vehicle 1 is received by the induction loop 3, the level relationship between the reference signal f _CH and the f _lN signal ( f _CH ≪ f _lN ), a suppressing effect occurs on the reference signal f _CH in the limiter 5a ₂ , and the level of the f _n-CH component output from the demodulator 5a ₃ decreases, which is extracted by the filter 5a ₄ . Since the level of the f _n-CH component does not reach the specified level, there is no output from the Schmitt circuit _5a5 and the amplifier _5a6 .
As a result, the inspection relay CHR falls, and it is detected that the vehicle 1 has entered the closed section 2T.

Next, when the rear of the vehicle 1 enters the closed section 2T and the f _put signal transmitted from the on-board antenna 7 is received by the induction loop 3, the f′ _lN component included in the f _put signal generates a reference signal. The f _CH is suppressed in the same way as the f _lN signal, which causes the reference relay to
The CHR continues to fall even if the front part of vehicle 1 advances from the blocked section 2T. Further, while the rear part of the vehicle 1 is entering the closed section 2T, the f _R component included in the f _put signal is guided to the filter 5b ₃ via the noise filter 5b ₁ and the demodulator 5b ₂ , and 5
Since it is extracted by b ₃ , the relay f _R is energized and lifted.

When the rear of vehicle 1 advances from blockade section 2T,
At the same time as the suppression effect on the reference signal f _CH disappears, the f _R component also disappears, so that the reference relay CHR is lifted up and the relay f _R falls at the same time. As a result, it is detected that the vehicle 1 has advanced from the blocked section 2T. When the vehicle 1 backs up and reenters the blocked section 2T from the blocked section 3T, the f′ _lN component and f _R component included in the f _put signal are received again,
Since the inspection relay CHR falls and the relay f _R is lifted up, the security of rear protection is extremely high.

In addition, since the f _R component is exclusively used as a signal for detecting vehicle advance and is functionally separated from the f _lN and f′ _lN signals for vehicle entry detection, the f _R component is f _lN , f′ _lN , f _CH
It is now possible to set the frequency completely independently of the noise, and the bandwidth of the noise removal filters 5a ₁ and 5b ₁ is accordingly narrowed to prevent noise from entering and improve the S/N ratio. becomes possible.
That is, as shown in FIG.
The input filter _5a1 of A is independent of the f _R component,
It is only necessary to have a narrow bandwidth that is sufficient to pass each component of f _lN , f′ _lN , f _CH , and the vehicle advance detection unit 5
The input filter _5b1 of the input filter 5B of B is,
It only needs to be sufficiently isolated from the f _lN , f′ _lN , and f _CH components and have a narrow enough bandwidth to pass the f _R component.

In addition, when detecting the entry or exit of the vehicle 1, a combination of the check relay CHR and the relay f _R constitutes a blockage logic, which ultimately drives the track relay.
There are various methods of configuring the closure logic.

As described above, the present invention includes a guide loop installed in each closed section along a vehicle travel route, a transmitter that transmits a reference signal from one end of the guide loop, and a transmitter that transmits a reference signal from one end of the guide loop. transmitting a signal that suppresses the inspection signal flowing through the induction loop;
an on-vehicle device that transmits a superimposed signal of a signal for suppressing the inspection signal from the rear of the vehicle and a signal for detecting that the vehicle has exited the blocked section; Consisting of a vehicle entry detection unit that extracts a signal, and a reception unit that includes a vehicle entry detection unit that separates and extracts a signal for detecting that the vehicle has exited the blocked section from the superimposed signal transmitted from the rear of the vehicle. When the signal extracted by the vehicle entry detection section disappears, it is determined that the vehicle has entered the blocked section, and thereafter, when the signal extracted by the vehicle entry detection section disappears, it is determined that the vehicle has exited the blocked section. As a result, it is possible to provide a vehicle detection device that has high rearward protection security and can further increase the S/N ratio by narrowing the bandwidth of the noise filter.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the general configuration of a vehicle detection device, FIG. 2 is a diagram explaining the drawbacks of a conventional vehicle detection device, FIG. 3 is a diagram showing the configuration of a conventional vehicle detection device, and FIG. 4 5 is a frequency attenuation characteristic diagram that also explains the drawbacks, FIG. 5A is a diagram showing the configuration of on-board equipment of the vehicle detection device according to the present invention, FIG. The figure is also a frequency attenuation characteristic diagram. 1... Vehicle, 2... Track, 3... Guidance loop,
4... Check signal generation section, 5... Receiving section.

Claims (1)

[Claims] 1. A guide loop installed in each blocked section along the vehicle travel path, a transmitter that transmits a reference signal from one end of the guide loop, and a transmitter that suppresses the reference signal flowing from the front of the vehicle to the guide loop. an on-vehicle device that transmits a signal that suppresses the inspection signal from the rear of the vehicle and a signal that detects that the vehicle has exited the blocked section; and the other end of the induction loop. a vehicle entry detection unit that is connected to the side and extracts the inspection signal; and a vehicle entry detection unit that separates and extracts a signal for detecting that the vehicle has exited the blocked section from the superimposed signal transmitted from the rear of the vehicle. It is determined that the vehicle has entered the blocked section when the signal extraction by the vehicle entry detection section disappears, and thereafter, when the signal extraction by the vehicle entry detection section disappears, the vehicle is determined to have entered the blocked section. A vehicle detection device characterized by determining that a vehicle has escaped from the blocked section.