JPS6015028B2 - How to detect the position of a moving object - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the position of a moving object using guided radio.

2. Description of the Related Art Detecting the position of a moving object using a guided radio line laid along the path of the moving object has been conventionally performed.

For example, as shown in FIG. 5, there is a known position detection method using a guided radio line in which four conductors 51, 52, 53, and 54 are spirally wound at the same and constant pitch around the outer periphery of a columnar body 55. There is.

In this case, a pair of opposing conductors 51 and 52 are used as the outward path, and conductors 53 and 54 are used as the return path.

However, it is said that it is extremely difficult to manufacture such concessional radio lines with high accuracy, and deterioration in manufacturing accuracy increases crosstalk between lines and deteriorates position detection accuracy. That is, if there is a small geometric error in the arrangement of the conductors 51, 52, 53, 54, the conductors 51, 52 and the conductors 53, 54
The repeating line formed by this constitutes a third line, causing secondary crosstalk, and deteriorating position detection accuracy. Also known is a position detection method that utilizes a guided radio line consisting of multiple sets of intersecting parallel pairs with intersections provided at predetermined intervals. This method necessarily requires a large number of lines (wire pairs), increasing the cost of the guided radio line, and the influence of inter-line crosstalk on measurement accuracy cannot be ignored.
The present invention solves the problems of the prior art described above.
The object of the present invention is to provide a method for detecting the position of a moving body that is economical and enables highly accurate position detection.

A feature of the present invention is that a transfer radio line is constructed by winding three conductors around a columnar body at a pitch of P, and winding each conductor in a spiral shape with a shift of P/3. On the other hand, the moving body is equipped with an antenna configured such that the length along the guided radio line is P/2 or an integral multiple thereof, and the guided radio line is excited by the antenna mounted on the moving body. When the positive sequence voltage Vp and the negative sequence voltage Vn for the voltages V, 2, V23, and V3 induced between the three conductors are defined as follows,
Vp Ni V, 20 V evil e-j 2 strokes/30 V31 ej 2 bamboo/
3 Vn ni V120V23ej2/3 10V3, e-j2m/3 The present invention is characterized in that the position of the moving body is detected by determining the phase difference between the positive phase voltage Vp and the negative phase voltage Vn.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

In Fig. 1, 1, 2, and 3 are conductors, and 4 is a columnar body. Each conductor 1, 2, and 3 is shifted by P/3, and is wound spirally around the outer periphery of the columnar body 4 with a period of P. Then, the guided radio line 5 is constructed.

Reference numeral 6 denotes a mobile antenna, and its length along the longitudinal direction of the transfer radio line 5 is P/2.

Here, voltages are induced between the conductors 1, 2, and 3 by the magnetic field formed by the antenna 6, and these voltages take on a sinusoidal shape as the position of the moving body changes. The voltages generated between conductors 1 and 2, 3 and 3, and 3 and 1 and reaching the receiving end are V. 2, V23, V3, then V,2=k COS8 V23 k COS (812 w/3) V31 k COS (8-2 w/3) . ...--[1] It is expressed as:

Here, 8=(2 lights/P)z z = position along track 5 - k = constant determined by line structure It is.

For each voltage in formula '1}, positive sequence voltage Vp, negative sequence voltage Vn
and zero-sequence voltage Vo are defined as shown below.

Vp Ni V, 20 V tomorrow j2 middle/30 V3, ej2 m/3 Vn=V, 20 V23 ej2 m'8 10 V3, e-j2 m'3 Vo=V, 20 V20 V3.・
...If you substitute the formula [21'1} into the formula ■ and rearrange it, you will get the following formula.

Vp=(3/2)keja Vn=(3'2)ke-jo Vo=0...{3
'If we suddenly consider the phase difference between Vp and Vn, ◇=kuVp-kuV
n=4mz/p.・・・． ...be on the side.

2: Symbol meaning declination angle.

In other words, as shown in Fig. 2, J shows an increase of 2 immediately before each increase of z by P/2, and the position of the moving object is continuously determined at a period of P/2 through the measurement of 0. can be known.

FIG. 3 shows an example of a signal processing circuit used in the present invention.

7-1, 7-2, 7-3 are buffer amplifiers, 8-2a,
8-3b is a -1200 phase shifter, 8-2b and 8-3a are 11200 phase shifters, 9-1 and 9-2 are adders, and 10 is a phase meter.

The adders 9-1 and 9-2 perform signal processing to obtain Vp and Vn in equation '3', and the phase meter 10 performs processing in equation '4-, and based on this, the position of the moving object is known. I can do it.

In the present invention, high frequency components of an order that is an integral multiple of 3 can be removed by the above-described signal processing.
By setting the length of P/2 or an integral multiple thereof, even-order high frequency components can be removed, and this point will be explained below.

In order to simplify the explanation, we will consider the case where the antenna 6 side is the receiving side, but the same applies to the case where the line 5 is the receiving side. If the angular frequency of the signal is N, the number of turns of the antenna 6 is N, the length is removed, and the antenna 6 is located at a position from Z- (kuno 2) to Z+ (so/2), the voltage appearing on the antenna 6 is V. is given by the following equation.

V:QaE...'5'
Qa is the Q of the antenna 6, and E is the electromotive force of the antenna 6, which is given by the following equation. E=i's skin
...'6'M=N tickets 0.

≧, mn.・・・．・In the state side formula, '71 formula, 1 is the amplitude of the current flowing through each conductor 1, 2, and 3, and the peak 0 is the magnetic permeability in vacuum. Further, mn corresponds to a spatial harmonic component, and when the dimensions of each part are given as shown in FIG. 4, the following is obtained.

m. =Tei-(ki)Sin8-Sin sheep・e-i enemyp・m2=ware (hatake) 2Sin28・Sin prince-ej4〆′p m3ni0 Misaki-device (one thing)4Sin48・Sinhan・e-j8bamboo 2/p Chapter - Sowing Zen) 5Sin58・SinMiko・e arc〆/p nk=0...
As is clear from the formula {8}, mn (m3·m6...) becomes 0 when n=3, 6..., and high frequency components of orders that are integral multiples of 3 can be removed.

Also, if the length of the antenna 6 is P/2, then sin2
Since myu/p, sin4chuyu/p becomes 0, m2, similar・
... becomes 0, and even-order harmonic components can be removed.

The effects of the present invention described above are as follows.

○} Only three conductors are required to make up the guided radio line, so it can be manufactured easily. In the 4-conductor system, the center of gravity line forms the 3rd line, and the position detection accuracy may deteriorate due to crosstalk between the lines, whereas in the 3-conductor system as in the present invention, the 3rd line constitutes the 3rd line. This becomes a zero-phase line, and since it is a ground return circuit, it has a high loss, so the influence of secondary crosstalk can be ignored, and highly accurate position detection becomes possible.

[The 314-conductor system cannot eliminate the 3rd harmonic component, but the 3-conductor system eliminates the influence of the 3rd harmonic, and by making the antenna length 1/2 or an integral multiple of the pitch P, even-numbered harmonics can be eliminated. Wave components can also be eliminated, distortion of the combined distribution waveform can be reduced, and highly accurate position detection becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of one embodiment of the present invention;
FIG. 2 is an explanatory diagram of the relationship between the position of a moving body and a phase difference, FIG. 3 is an explanatory diagram of an embodiment of a signal processing circuit used in the present invention, and FIG. 4 is an explanatory cross-sectional diagram of FIG. 1. , FIG. 5 is an explanatory diagram of a conventional example of a five-guide radio line.

Figure 1 Figure 3 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] 1. A guided radio line is constructed by winding three conductors around a columnar body in a spiral manner with a pitch of P, and each conductor is shifted by P/3 and is wound in a spiral shape, and is laid along the travel path of a moving object.
On the other hand, the moving body is equipped with an antenna configured such that the length along the guided radio line is P/2 or an integral multiple thereof, and by exciting the guided radio line with the antenna mounted on the moving body, The voltage V induced between each conductor of the book
When defining the positive sequence voltage Vp and negative sequence voltage Vn for _1_2, V_2_3, and V_3_1 as in the following formula,
Vp=V_1_2+V_2_3e^-^j^2π/^3
+V_3_1e^j^2π/^3Vn=V_1_2+V
_2_3e^j^2π/^3+V_3_1e-^j^2
π/^3 A method for detecting the position of a moving body, characterized in that the position of the moving body is detected by determining the phase difference between the positive phase voltage Vp and the negative phase voltage Vn.