JPS6012805B2 - How to adjust the transmitting and receiving waveforms of guided radio antennas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adjusting the transmission and reception waveforms of an inductive radio antenna that can be employed in mobile communications, particularly in position detection systems for mobile bodies.

When transporting a super high-speed train using linear motors,
It is necessary to continuously detect the train's position with high precision.

One of the position detection methods is to receive a continuous signal from a train-mounted transmitting antenna on a guided radio track with a predetermined pattern laid along the train track, and the amount of electromagnetic coupling changes depending on the pattern of the guided radio track. There is a method that takes advantage of this.

This method will be briefly explained with reference to FIG.

U1, U2, V1, V2, W1, W2 are respectively open parts la, lb, ... and closed parts 2a, 2b, ...
・A pair of wires alternately having open parts la, l
b, . W
2, a predetermined pattern is formed.

Now, when the train-mounted antenna moves in the x-axis direction, U1
, U2 are shown without taking phase into account, waveforms as shown at A and A in the figure, respectively, are obtained.

Expressing the waveform of C as a formula, U(X)2COS2
...[1}.

Similarly, from V1, V2 and W1, W2, respectively, V(X) ni COS {(2 bamboo X/P) 14 汀/3}.・
...・'21W(X) ni COS {2 shores X/P) + 2 waves/3
}...[A waveform expressed by equation 31 is obtained.

Here, t of cos in the formula '1}, cos (t + 4w/3) in the formula [2}, and cos (mountain t12m/3) in the formula '31.
) and take the sum of these, we get P(X)ni(3/2)
COS (mountain t-12 lights x no P). ...[4] is obtained,
Continuous position detection is possible due to the phase difference 2x/P between cos and t.

However, when the antenna is attached to a moving object such as a train, the waveform changes significantly due to the influence of metal objects around the antenna, and the waveform is not ideal as shown in C, but has a sufficiently wide waveform as shown in 2. I ended up getting something that wasn't there.

If the waveform is disturbed in this way, a position detection error will naturally occur in a position detection method using a phase difference, considering the yield process of the {4-type].

The present invention has been made based on the above, and an object of the present invention is to provide a method that can easily compensate for disturbances in transmitted and received waveforms.

The present invention forms a closed conductor loop around a loop antenna, and compensates for disturbances in waveforms of signals transmitted and received by the loop antenna by adjusting the interval between the loop antenna and the closed conductor loop.

Since the signal waveform is generally adjusted after the antenna is mounted on the mobile object, it is preferable to adjust the signal waveform by keeping the size of the loop antenna constant and varying the size of the closed conductor loop. . An embodiment of the present invention will be described with reference to FIG.

3 is a loop antenna, and 4 is a closed conductor loop provided around the loop antenna 3. The closed conductor loop 4 is 4
It consists of conductors 5, 6, 7 and 8, and the signal waveform is adjusted by moving the conductors 7 and 8 left and right in the figure.

In order to facilitate the transfer of the conductors 7, 8, the conductors 5, 6 are provided with long holes 9 for screw fixing. In addition, the closed conductor loop 4
The size may be adjusted by moving all of the four conductors 5, 6, 7, and 8, or by moving the opposing conductors 5 and 6.

Here, the reason why the signal waveform can be adjusted by changing the size of the closed conductor loop 4 will be explained.

The received voltage waveforms received by the units composing the guided radio line from the antenna mounted on the mobile object are the waveforms received directly from the loop antenna 3 as shown in Figure 3A, and the waveforms blocked by the loop antenna 3 as shown in Figure 3B. The waveform is a composite of waveforms caused by the current induced in the conductor loop 4.

The waveform shown in FIG. 3 is in reverse phase with the waveform shown in FIG. 3A, and as the size of the closed conductor loop 4 increases, the spread d of the waveform increases; When becomes small, d becomes small.

Therefore, when the size of the closed conductor loop 4 is reduced, the spread D of the received voltage waveform of a unit pair increases as shown by the dotted line in Figure 4, and the ideal waveform as shown in Figure 1C is obtained. This will allow you to get closer. Although the case where a signal from a loop antenna is received by a guided radio line has been described so far, the signal waveform can be adjusted in the same way when a signal from a guided radio line is received by a loop antenna.

As explained above, according to the present invention, it becomes possible to easily compensate for disturbances in the waveforms of transmitted and received signals in the loop antenna mounted on a mobile object, and by applying this to a mobile object position detection method, the position detection accuracy can be improved. You will be able to improve your

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a moving object position detection system, FIG. 2 is an explanatory diagram of an embodiment of the present invention, and FIGS. 3 and 4 are diagrams of signal waveforms received by a unit pair of guided radio lines. It is an explanatory diagram. 3: Loop antenna, 4 three closed conductor loops. Sai 3 Diagram 4 Diagram O' Prisoner Z Diagram

Claims (1)

[Claims] 1. A loop antenna and a closed conductor loop provided around the loop antenna are mounted on a mobile object,
A method for adjusting transmission and reception waveforms of an inductive radio antenna, the method comprising adjusting an interval between the loop antenna and the closed conductor loop.