JPH029985B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention receives point information onboard the train via an onboard antenna from a loop coil (hereinafter referred to as a ground loop) installed at a predetermined point on a train running path and intersecting the rails. , relates to a point detection device for detecting the running position of a vehicle.

A typical conventional point detection method for detecting the running point of a running train has been based on a so-called variable frequency method, as schematically shown in FIG. That is, Figure a shows an on-board oscillator OSC ₀ that constantly generates a signal with a frequency f ₀ , a bandpass filter BPF ₀ that passes the signal, and an on-board antenna CA ₀ that constitutes a feedback circuit for the oscillator OSC ₀ . This is a block diagram of _{the ground element S 1 , which} consists of the main parts of _the on-board equipment such as When passing, a predetermined point is detected by utilizing the fact that the on-board oscillation frequency f ₀ changes in the direction of the resonance frequency f ₁ of the ground element S ₁ . In addition, Figure b shows that the circumference point shifts depending on the distance (interval) between the onboard coil CA ₀ and the ground coil S ₁ . Large, chart (b) indicates small, and the frequency is
This shows that the time point at which the frequency changes from f ₀ to f ₁ is shifted by d.

As mentioned above, the conventional point detection method using variable frequency type detects fluctuations in the distance between the onboard coil CA ₀ and the ground coil S ₁ ,
The disadvantage is that the frequency change point changes depending on the sensitivity of the receiver.
Another drawback was that it required a resonator with a high Q to be installed on the ground.

In addition, as shown in Fig. 2a, in the point detection method of detecting level changes as shown in Fig. 2b at the twisting points X ₁ and X ₂ of the loop wire laid on the ground, ₁ and X ₂ are determined by counting the points where the level changes and using the counted value, but if the counting is incorrect, all subsequent detections will be erroneous detections.

The present invention installs a ground loop that intersects the rail at right angles under the rail at a detection point, supplies an appropriate value of current to this ground loop so that the induction level differs depending on the point, and Point detection is performed by determining the difference in the levels mentioned above, and the above-mentioned ground loop, which replaces the conventional ground coil, simplifies the ground equipment, and furthermore, it is possible to distinguish multi-point information. The purpose of this invention is to provide a point detection device of this type that can be used without error.

Embodiments of the present invention will be described below with reference to the drawings of FIGS. 3 to 6.

Figure 3 shows the onboard antenna CA shown in the same figure.
This is a schematic diagram showing an example of ground equipment arrangement according to the present invention, and L ₁ , L ₂ , and L ₃ are each a pair of rails R,
Ground loops laid perpendicular to R′, R ₁ , R ₂ , R ₃ are resistors connected to ground loops L ₁ , L ₂ , L ₃ respectively, B ₁ , B ₂ , B ₃ is a junction box that accommodates the resistors R ₁ , R ₂ , R ₃ and the connections between the ground loops L ₁ , L ₂ , L ₃ and the cable CB, and S is the ground loop that is connected to the cable CB. It is an information transmitter. As shown in the enlarged cross-sectional view of the P section of the ground loop L ₃ , the loops L ₁ ,
Each of the loop lines L ₂ and L ₃ is buried underground under the rail R (R'), and the loop interval l is determined from the loop line on the side where the onboard antenna CA is close to the rail R (R'). The distance should be such that only electromagnetic induction occurs. Further, the induction level of each ground loop is adjusted and set by the respective resistors R ₁ , R ₂ , and R ₃ . The on-vehicle antenna CA is an air-core antenna that receives point information p by electromagnetically coupling with a ground loop, and is assumed to move in the direction of the thick arrow shown in the figure.

Figure 4 is a block diagram showing an example of the onboard equipment configuration, including a matching transformer MT that receives point information p received by the onboard antenna CA, and a level adjuster.
ATT, passband filter for received signal frequency
BPF, amplifier A ₁ , A ₂ , A ₃ , point information detector
It consists of SCH ₁ , SCH ₂ , SCH ₃ , anti-coupling reception level resetters RS ₁ , RS ₂ , RS ₃ , etc., which will be described later, and the point information p ₁ of the ground loop L ₁ is obtained by the point information detector SCH ₁ . In addition, point information p ₂ and p ₃ of ground loops L ₂ and L ₃ are obtained from point information detectors SCH ₂ and SCH _3.
They are detected and discriminated respectively.

Next, the point detection function of this device will be described. FIG. 5 shows how the reception level changes when the on-board antenna CA moves in the direction of the arrow, for example, on the ground loop _L1 in FIG.
When the point in time when the center of the onboard antenna CA passes over the ground loop _L1 is set to 0, the reception level generated at the onboard antenna CA before and after that point has two peaks as shown in the figure due to the anti-coupling of the air-core antenna. Can be seen. Therefore, a level judgment range V is set for the point information detector SCH of the on-board device, and the peak point q of the level from the first trigger point s to the next trigger point t in that judgment range is within the judgment range. Only when it is hot, the point information detector operates and sets the trigger point t as the detection point. Reception of a similar level pattern that appears subsequently is reset by the reset device RS.

FIG. 6 shows the ground loops L ₁ , L ₂ ,
The reception level induced to the on-board antenna CA by the currents i ₁ , i ₂ , i ₃ set in L ₃ respectively, and the level judgment set in the on-board point information detectors SCH ₁ , SCH ₂ , SCH ₃ It expresses the relationship with the range,
V ₁ , V ₂ , V ₃ are point information detectors SCH ₁ , SCH ₂ ,
This is the level judgment range set for each SCH ₃ .

When _the on-board antenna CA passes over the ground loop _L1 , _the received level changes as shown in _FIG . When the on-board antenna CA passes over the ground loop _L2 , the received level changes as shown in the loop current _i2 , and only the point information detector _SCH2 to which the level determination range _V2 is set operates. At this time, point information detector SCH ₁ is triggered,
Since the peak value of the received level exceeds the level determination range _V1 , the detector _SCH1 does not operate. Furthermore, when the onboard antenna CA passes over the ground loop _L3 , the level received by the loop current _i3 changes as shown in , and only the point information detector _SCH3 , which is set to the level determination range _V3, operates. .
At this time, the point information detectors SCH ₁ and SCH ₂ are triggered, but since the peak value of the reception level exceeds their level judgment ranges V ₁ and V ₂ , the detectors
SCH ₁ and SCH ₂ do not work. In this way, the point where the ground loop is set can be reliably detected on the vehicle.

As described in the above embodiments, the present invention enables point detection without the need for a conventional ground transducer, and requires only a transmitter, a ground loop, and a signal level setting resistor as ground equipment. This has the effect of simplifying the equipment, and since it is possible to obtain information from multiple points by setting the ground loop current, even if the on-board antenna passes through one point and cannot obtain point information, it can be used at the next point. Correct point detection is possible when passing the point. Furthermore, the ground loop current can be set simply by changing the resistance value of the resistor in the junction box, which not only makes maintenance easier, but also has the advantage that a large amount of information can be obtained at one point by changing the resistance value at one point. There is. Furthermore, by replacing the ground-side transmitter on the train and the on-board detection circuit on the ground, there is an effect that it becomes possible to detect the running point of the train on the ground side. In addition, unlike the loop twisting system, there is no need to run loops around the rails, and there are many advantages, such as less impact on others.

[Brief explanation of drawings]

Figure 1a is a block diagram of the main parts of the frequency change type point detection device, Figure 1b is a chart showing the deviation of the frequency change point,
Figure a is an example of a twisting type ground loop, Figure b is a chart showing the level change of the twisting point, Figure 3 is a layout diagram of the ground equipment which is an embodiment of the present invention, and Figure 4 is a diagram of the same type of ground loop. FIG. 5 is an explanatory diagram showing changes in the level of the received signal, and FIG. 6 is an explanatory diagram showing the level determination range on the vehicle corresponding to the set point. R, R′: Rail, L ₁ , L ₂ , L ₃ : Loop coil,
R ₁ , R ₂ , R ₃ : Resistor, CB: Cable, S: Ground information transmitter, CA: On-board antenna, SCH ₁ , SCH ₂ ,
SCH ₃ : Point information detector, V ₁ , V ₂ , V ₃ : Set level range.

Claims (1)

[Claims] 1. A ground device which has a loop coil installed under the rail at a required point on a train running path and which intersects the rail at right angles, and is equipped with a means for setting the current value supplied to the loop coil to a predetermined value; An air-core on-vehicle antenna that receives a signal at a level corresponding to the supplied current value through electromagnetic coupling with a loop coil, and a range of signal levels received by this antenna are selected, and a peak within the set level range is selected. 1. A point detection device comprising an on-vehicle device provided with means for operating only on signals having a level having a value.