JPH0219431B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention is applicable to, for example, automatic train control (abbreviated as ATC).
Alternatively, electromagnetic coupling may be caused between an on-board antenna installed on a vehicle moving on a certain route and a loop coil installed on the ground, which is equipped with speed control information transmission means such as automatic train operation (abbreviated as ATO). The present invention relates to a vehicle position detection method for transmitting ground position information to a vehicle.

A typical point detection method in which a traveling vehicle detects its own passing point has conventionally been carried out by a method called a variable frequency method, which has a circuit configuration schematically shown in FIG. In other words, a in the same figure is a block diagram showing the main part of the variable frequency on-board device, in which a signal of frequency ₀ oscillated by the oscillator OSC with the on-board antenna CA as a feedback circuit is passed through the band filter BPF _0.
It is constantly outputting through. However, when the on-board antenna CA passes over the ground element G consisting of a resonant circuit of frequency ₁ , which is shown as a block in the same figure (b), at the time of passing, the oscillation frequency ₀ on the car is attracted in the direction of the frequency ₁ and modulated. However, as the output from the filter BPF ₀ is lost, the location of the ground element G is detected on the vehicle. However, this method requires the installation of a resonant element with a high Q called a ground element, separate from the speed control information transmission line installed on the ground, and the difference in the Q characteristics of each ground element is required. According to
The reception level of location information received onboard the vehicle fluctuates, resulting in some drawbacks such as reception loss.

In the present invention, loop coils of twisted suspension combination into which speed control signals are introduced are arranged at required points on the vehicle running path, and a twisted reception loop antenna is also vertically installed on the vehicle, and from the loop coils. This system is designed to detect locations by receiving location information onboard the vehicle, which simplifies ground equipment by eliminating the installation of the conventional beacon, and furthermore, speed control information that is received at the same time as location information. Using the reception level of
The purpose of this system is to eliminate the above-mentioned drawbacks of conventional ground transducers by compensating for fluctuations in the level of location information reception.

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

Figure 2 shows an example in which a loop line is used for transmitting speed control information in each block section set on a vehicle running _route . Along the driving path 1
The cable is laid over the block section, and this loop L ₁
The speed control information V is transmitted from the transmitter S. Loop L ₂ is a loop that uses a part of loop L ₁ and twists as shown in the figure to form multiple loops, which are arranged at predetermined points and used as a source of point information p instead of the conventional ground wire G. It is a coil. Also, the antenna
CA ₁ is an on-vehicle antenna for receiving speed control information V, and antenna CA ₂ is an on-vehicle antenna for receiving point information P, which is formed by twisting like loop L ₂ . In addition, the symbols (a), (b), (c), etc. shown in the same figure are
This shows the direction of the magnetic field lines that occur when the information current flowing through loop L ₁ is in the direction of the arrow.
This shows that the direction of the magnetic field lines passing through the inner surface of L ₂ is reversed at the loop twist. Since loop L ₂ is formed in this way, on-board antenna CA ₁
Even if CA 2 passes over loop L ₂ , it is difficult to receive the signal from loop L ₂ , and conversely, the on-board antenna CA ₂ passes over loop L ₂ .
Since it is formed in the same shape as , it is possible to efficiently receive information p from loop _L2 .

Figure 3 shows the state of electromagnetic coupling for signal transmission and reception between the ground loop L ₁ that transmits speed control information V and _the on-board antenna CA ₂ for receiving point information. The lines of magnetic force generated when the speed control information current flows in the direction shown by the arrow inside the pipe-shaped line are in the direction shown by the curved arrow, and when the lines of magnetic force pass through the inner surface of the on-board antenna CA ₂ . , the direction of the current induced in the antenna CA ₂ is the direction shown by the straight arrow in the antenna CA ₂ , and they cancel each other out inside the antenna, so that the information that the antenna CA ₂ receives from the loop L ₁ is greatly attenuated.

Figure 4 shows the electromagnetic coupling state when the on-board antenna CA ₂ passes over the loop L ₂ , and the induced current generated in the antenna CA ₂ due to the information current in the direction of the arrow shown in the loop L ₂ . The orientation of antenna CA ₂
The point information p is output in the direction of the arrow shown in . FIG _. 5 also shows that when antenna CA ₂ moves in the direction of arrow r on loop L ₂ shown in FIG. This shows that this occurs over a moving distance approximately equal to the length L.

Further, FIG. 6 shows an example of the configuration of an on-board receiving antenna for point detection in a case where the return line for train current or the like in the vehicle is installed near the on-board receiving antenna for point detection. In this case, if the antenna is formed like the antenna CA ₃ shown in the same figure, the current induced in the antenna CA ₃ by the train current I of the return line F will be directed to the antenna CA ₃ in the direction shown by the solid line and broken line arrows. Since the two currents flow and cancel each other out, it is possible to provide large attenuation to the noise component of the train current.

FIG. 7 shows an on-vehicle receiving circuit for speed control information and point information, which shows that when there is a change in the point information reception level, part of the speed control information is used to compensate for the change in the point information reception level. FIG. In the figure, a shows a receiving circuit for speed control information, and b _shows a receiving circuit for point information.
MT ₂ is a matching transformer, ATT ₁ and ATT ₂ are level adjusters, BPF ₁ and BPF ₂ are band filters, and A ₁ and A ₂ are amplifiers. The output of the amplifier A1 shown in FIG. _1A is supplied to the speed control information processing circuit VC, and the output of the amplifier A2 shown in FIG. _1B is outputted as position information p via the position information detector SHC.

So, some signal is of amplifier A ₁ is transferred to amplifier A ₂
It compensates for fluctuations in the point information reception level and stabilizes the detection level at the position information detector SHC. i.e. ATC or
It is an absolute requirement that the speed control information transmitted from the ground to the vehicle, such as ATO, be maintained at the required level at any point along the transmission path, and equipment is installed to ensure this. Therefore, since the signal level in the amplifier _A1 of the circuit shown in FIG. 7a is always maintained at the required level, by level-compensating the signal level from the amplifier _A1 to the amplifier _A2 of the circuit shown in FIG. _A2 's output signal can be held at the desired level.

In the above embodiment _, the loop L ₂ is provided inside _{the loop L 1 as} shown in FIG. Similar performance can be obtained. Furthermore, instead of the on-vehicle antenna _CA1 , it is also possible to use a pair of known on-vehicle antennas Ca and Cb shown in FIG. Furthermore, instead of loop L ₁ ,
For example, even when a pair of rails is used as a transmission path for speed control information, such as in a track circuit, by supplying a signal current from an information current supply source to the rails to loop L ₂ via a matching transformer, As in the embodiment, it is possible to transmit location information onto the vehicle.

As explained in the above embodiments, according to the present invention, there is no need for a conventional ground coil, and
It is possible to perform point detection, and when using loop L ₁ in Fig. 2, point detection loop L ₂ can be established by monitoring the current of speed control information.
Since it is possible to detect a failure in the system, and also to detect a point by using a portion of the speed control information loop, it has many effects such as simplifying ground equipment.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an outline of a device for implementing a conventional variable frequency vehicle position detection method, and FIG. 2 is a schematic diagram of a circuit configuration showing an example of equipment for implementing the vehicle position detection method of the present invention. Figure 3 is an explanatory diagram of the electromagnetic coupling state between the above-mentioned equipment's speed control information transmission ground loop and the on-board antenna for point detection, and Figure 4 is an explanatory diagram of the electromagnetic coupling state between the ground loop for point detection and the on-vehicle antenna. , Fig. 5 is an explanatory diagram of the induced current generation state due to electromagnetic coupling as above, Fig. 6 is an example of the formation of an on-board antenna for point detection to prevent the influence of the train current return line on the car, and Fig. 7 is an illustration of the level A block diagram of a speed control information on-board receiving circuit and a point detection information on-board receiving circuit is shown to explain the compensation relationship, and FIG. 8 is a schematic diagram of an example of use showing another example of the speed control information on-board receiving antenna. V: Vehicle speed control information, _L1 : Speed control information transmission line, _L2 : Loop coil for generating point information, _CA2 :
On-board antenna for receiving location information, FIG. 7a: Vehicle speed control information on-board receiving circuit, FIG. 7b: On-board receiving circuit for location information, IS: Level compensation signal.

Claims (1)

[Scope of Claims] 1. At required points on the vehicle travel path where a transmission path is provided for transmitting vehicle speed control information from the ground to the vehicle,
A loop coil twisted into a plurality of loops is arranged so that the directions of magnetic lines of force generated by the current flowing through the loop coil are opposite to each other, and a current of the vehicle speed control information is introduced into the loop coil to serve as a point information generation source. At the same time, in addition to the on-board antenna for receiving vehicle speed control information, an on-board antenna twisted in the same shape as the loop coil is installed vertically on the vehicle so as to be able to face the loop coil, so that the vehicle becomes the point information source. The vehicle position is characterized in that when passing over the vehicle, point information is received on the vehicle and the position of the vehicle is detected through the twisted vehicle antenna without being affected by the vehicle speed control information. Detection method. 2. At required points on the vehicle route where transmission lines are installed to transmit vehicle speed control information from the ground to the vehicle,
A loop coil twisted into a plurality of loops is arranged so that the directions of magnetic lines of force generated by the current flowing through the loop coil are opposite to each other, and a current of the vehicle speed control information is introduced into the loop coil to serve as a point information generation source. At the same time, in addition to an on-board antenna for receiving vehicle speed control information, an on-board antenna twisted in the same shape as the loop coil is installed vertically on the vehicle so as to be able to face the loop coil, so that the vehicle can generate the point information. An on-vehicle receiving circuit for receiving point information on the vehicle without affecting the vehicle speed control information via the twisted on-board antenna when passing over the vehicle speed control information. A vehicle position detection method comprising: compensating a point information reception level by introducing a required signal level from an on-board receiving circuit for vehicle speed control information via an on-board antenna.