JPH0450541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a system for continuously detecting the position of a moving object using guided radio.

[Background of the Invention] For example, in the automatic operation of a linear motor car, the position of the car body is constantly detected on the ground within the distance between motor poles (propulsion coils) placed at regular intervals along the running route. , it is considered essential for the smooth operation of this vehicle to rationally adjust the frequency, amplitude, and phase of the magnetic field current accordingly.

Currently, a method using guided radio is considered to be a promising means to meet this demand.
This method consists of two methods: a method in which the voltage induced in the guided radio line by the excitation of an antenna mounted on a mobile object is processed on the ground, and the position of the moving object is directly detected from this (ground detection), and a method in which the position of the moving object is directly detected from the voltage induced on the guided radio line by the excitation of the antenna mounted on the moving object. There is a method (on-vehicle detection) in which the voltage is received by an antenna mounted on a mobile body, the position is detected by signal processing on the mobile body, and this is encoded and transmitted wirelessly to a ground base station.

Although the ground detection method has the advantage of directly obtaining control signals on the ground, it has the disadvantage of causing measurement errors when the amount of crosstalk in the guided radio line is large.
In addition, while the on-vehicle detection method does not have any problem with crosstalk in the guided radio line, it encodes position information.
This needs to be transmitted wirelessly, which has the disadvantage of complicating the system, so it is difficult to compare the superiority of the two methods.

A position detection method currently proposed as an on-vehicle detection method will be described with reference to FIGS. 1 and 2.

In Figure 1, Figure 1 a is a plan view, Figure 1 b
is a sectional view taken along line A-A'. 1 and 2 are conductors, 3 is an inductive radio line formed by conductors 1 and 2, and 4-
1 and 4-2 are antennas mounted on a mobile object.

The conductors 1 and 2 are bent into a waveform shape (shown here as a trapezoidal wave) with a period P on a plane, and are arranged with a shift of P/3 from each other. Moreover, trapezoidal loop coils are used as the antennas 4-1 and 4-2, and are fixed on the moving body with a mutual shift of P/4.

When a high frequency current of 50 to 200 KHz is supplied from the ground transmitter 5 to the line 3, an induced magnetic field is formed around the line 3, and a voltage is induced in the antennas 4-1 and 4-2.

The amplitude of the voltage induced in each antenna 4-1, 4-2 can be controlled by appropriately selecting the distance between the line 3 and the antennas 4-1, 4-2 and the dimensions of the antennas 4-1, 4-2. z (distance from the terminal of the line 3 to the antenna 4-1) can be made sinusoidal.

Here, the reason why the envelope of the antenna induced voltage has a sinusoidal shape with respect to z will be explained.

As shown in FIG. 7, the corrugated conductor 1a and the conductor 1b
Consider a line 33 consisting of. FIG. 7a is a plan view, and FIG. 7b is a sectional view taken along line A-A'. Currents I and -I are applied to the waveform conductor 1a as the forward path and the conductor 1b as the return path, respectively. P is the conductor pitch. The antenna 32 uses a trapezoidal loop coil, and the line 33
Move it in the z direction while maintaining the height h. Then, the induced voltage Va(z) of the antenna 32 is
It is a periodic function with respect to z having a period of P. When the length L of the antenna 32 and the distance h between the antenna 32 and the line 33 are both extremely small, as shown in FIG. This includes high-order spatial harmonic components.

As L and h are gradually increased, the spatial harmonics of the construction work in Va(z) rapidly decrease, and when L is P/7 to P/5 and h is more than twice the track width d, It is known that if Va(z) is taken, it will almost consist only of sine wave components. This is because as L increases, the electromotive force corresponding to the harmonic component tends to cancel out within the antenna, and as h increases, the magnetic flux corresponding to the harmonic component rapidly decreases. It is being said.

For this reason, in Fig. 1, the voltages induced in antennas 4-1 and 4-2 are respectively
If V ₁ (z) and V ₂ (z), then V ₁ (z)=kcos2πz/P V ₂ (z)=kcos2π(z+P/4)/P=Kcos{2πz/P)
+π/2}...(1) K: Can be expressed as a constant.

Here, when the following relationship holds between the two voltages V ₁ and V ₂ , V ₁ = V _p , V ₂ = V _p e ^j 〓 ^/2 (1-1), V ₁ and V ₂ are It is called the positive sequence voltage of the phase equation, and its value is represented by V _p , and when the following relationships hold, V ₁ = V _o , V ₂ = V _o e ^-j 〓 ^/2 ... ( _1-2 ) , V ₂ is called a two-phase negative phase voltage, and its value is represented by V _o . (By convention, V _p is sometimes called the negative sequence voltage, and V _o is sometimes called the positive sequence voltage.) In general, any two voltages
V ₁ and V ₂ can be expressed as the sum of a positive sequence voltage and a negative sequence voltage.

That is, V ₁ =V _p ′+V _o ′ V ₂ =V _p ′e ^j 〓 ^/2 +V _o ′e ^-j 〓 ^/2 … (1-3) This immediately results in 2V _p ′=V ₁ +e ^{- j} 〓 ^/2 V ₂ 2V _o ′=V ₁ +e ^j 〓 ^/2 V ₂ ...(1-4) is derived.

Here, for convenience of calculation, 2V _p ′ is the positive sequence voltage
V _p (z), 2V _o ′ are expressed as the negative sequence voltage V _o (z), and the positive sequence voltage
V _p (z) and negative phase voltage V _o (z) are defined by the following equations.

V _p (z)＝V ₁ (z)＋e ^-j 〓 ^/2 V ₂ (z) V _o (z)＝V ₁ (z)＋e ^j 〓 ^/2 V ₂ (z) ……(2) (1 ), V ₁ (z)=(1/2)k(e ^j2 〓 ^z/P +e ^-j2 〓 ^z/P ) V ₂ (z)=(1/2)k(e ^j2 〓 ^z/P+j 〓 ^/2 +e ^-j2 〓 ^z/Pj 〓 ^/2
)...(2-1) By substituting the relationship in equation (2-1) above into equation (2), the following equation is obtained.

V _p (z)=(1/2)k{e ^j2 〓 ^z/P +e _-j2 〓 _z/P +e ^-j 〓 ^/2 (e ^j
2 〓 ^z/P+j 〓 ^/2 +e ^-j2 〓 ^z/Pj 〓 ^/2 )}=Ke ^j2 〓 ^z/P V _o (z)=(1/2)k{e ^j2 〓 ^z/P +e _{- j2} 〓 _z/P +e ^j 〓 ^/2 (
e ^j2 〓 ^z/P+j 〓 ^/2 +e ^-j2 〓 ^z/Pj 〓 ^/2 )｝=Ke ^-j2 〓 ^z/P …
…(3) If the phase difference between V _p (z) and V _o (z) is Φ(z), then Φ(z)=∠V _p (z)−∠V _o (z)=4πz/P … …(4) (∠: symbol meaning declination angle).

In other words, Φ(z) is defined as z is P/ as shown in Figure 2.
Every increase by 2 indicates a linear increase of 2π, and by measuring Φ(z), the position of the moving object can be continuously measured at a period of P/2.

Therefore, when applying this to the position detection of a linear motor car, P is equal to 2 of the distance between motor poles.
The desired purpose can be achieved by doubling the distance and laying the line in a position synchronized with the motor pole.

However, the above method has the following drawbacks.

In other words, the period P of each conductor 1 and 2 must be equal to twice the distance between the poles of a linear motor car, but in a practical linear motor car, the distance between the motor poles is expected to be approximately 6 m.
Therefore, the conductor period P must be approximately 12 m.

For this reason, manufacturing of the line 3 may become difficult and expensive.

In addition, in order to realize this method, it is necessary that the induced voltage between each conductor has a pure sine wave shape with respect to z, as shown in equation (1), and therefore the length L of the antenna 5 is It becomes extremely large, P/7 to P/5 (1.7 to 2.4 m when P=12 m). When attaching an antenna to a car body, it is necessary to provide a notch in the car body to avoid the effects of eddy currents flowing through the car body, but it is not desirable from the viewpoint of the mechanical strength of the car body that this becomes large.

In order to solve the above problems, the present inventor devised a position detection method using three antennas, and this method will be explained with reference to FIG. 3.

In Figure 3, Figure 3a is a plan view and Figure 3b is a plan view.
is a sectional view taken along line A-A'. 11 and 12 are conductors, respectively, and the conductor 11 is bent into a waveform shape (shown here as a trapezoidal wave) with a period P, and the conductor 12 is arranged in a straight line in parallel with the conductor 11. A guided radio line 13 is formed by. Reference numerals 14-1, 14-2, and 14-3 are antennas mounted on the moving body, and each antenna is fixed to the moving body at an interval of P/3.

When a high frequency current of 50 to 200 KHz is supplied from the ground transmitter 15 to the line 13, an induced magnetic field is formed around the line 13, and a voltage is induced in the antennas 14-1, 14-2, and 14-3.

The guided radio line 13 shown in FIG. 3, the line 43 shown in FIG.
It can be understood as a combination with the line 53 whose return route is .

The voltage induced in the antenna from the line 43 in FIG. 9a has a sinusoidal waveform as described above, and has a waveform as shown in FIG. 10a. A voltage with a uniform amplitude as shown in FIG. 10b is induced from the line 53 in FIG. 9b, and when both are combined, a voltage having a waveform as shown in FIG. 10c is obtained. Expressed mathematically, it is as follows.

V(z)=k ₁ {1+K ₂ cos2πz/P}...(4-
1) However, k ₁ and k ₂ are constants.

In this way, if the distance from the terminal of the line 13 to the antenna is z, each of these antennas 14-
Voltage V ₁ (z) induced in 1, 14-2, 14-3,
V ₂ (z) and V ₃ (z) are expressed as shown below.

V ₁ (z)=k ₁ {1+K ₂ cos2πz/P} V ₂ (z)=k ₁ {1+K ₂ cos2π(z+P/3)/P} V ₃ (z)=k ₁ {1+K ₂ cos2π(z+2P/ 3)/P}...(5) k ₁ , k ₂ : Constants Since 0<k ₂ <1, the right side of equation (5) is always positive.

Therefore, by linearly detecting V ₁ (z), V ₂ (z), and V ₃ (z), their envelopes |V ₁ (z)|, |V ₂ (z)|, |V ₃ (z) )| is calculated as follows.

｜V ₁ (z)｜=V ₁ (z) ｜V ₂ (z)｜=V ₂ (z) ｜V ₃ (z)｜=V ₃ (z) ...(6) Here, the high frequency ω ₀ Modulate the new carrier wave with each voltage in equation (6) and convert them into V _u ′(z), V _v ′(z), and V _w ′
(z), the following equation is obtained.

V _u ′(z)=｜V ₁ (z)｜e ^j 〓 ^ot =k ₁ (1+K ₂ cos2πz/P)
・e ^j 〓 ^ot V _v ′(z)=｜V ₂ (z)｜e ^j 〓 ^ot =k ₁ [1+K ₂ cos2π(z+P
/3)/P]・e ^j 〓 ^ot V _w ′(z)=｜V ₃ (z)｜e ^j 〓 ^ot =k ₁ [1+K ₂ cos2π(z−P
/3)/P]・e ^j 〓 ^ot ……(7) Here, in general, any three voltages V _u ′, V _v ′,
It is known that V _w ' can be expressed as the sum of a positive sequence voltage V _p , a negative sequence voltage V _o and a zero sequence voltage V ₀ as shown in the following equation.

V _u ′＝V _p ＋V _o ＋V ₀ V _v ′＝V _p e ^j2 〓 ^/3 ＋V _o e ^-j2 〓 ^/3 ＋V ₀ V _w ′＝V _p e ^-j2 〓 ^/3 ＋V _o e ^j2 〓 ^/3 +V ₀
...(7-1) 1+e ^j2 〓 ^/3 +e ^-j2 〓 ^/3 =0 ...(7-2) By focusing on the relationship, the following equation can be derived from equation (7-1).

3V _p =V _u ′+e ^-j2 〓 ^/3 V _v ′+e ^j2 〓 ^/3 V _w ′ 3V _o =V _u ′+e ^j2 〓 ^/3 V _v ′+e ^-j2 〓 ^/3 V _w ′ 3V ₀ =V _u ′+V _v ′+V _w ′ ……(7-3) Here, for convenience of calculation, 3V _p is the positive sequence voltage V _p
(z), 3V _o is expressed as a negative sequence voltage V _o ′(z), and the positive sequence voltage V _p ′(z) and negative sequence voltage V _{o ′} (z) are defined by the following equation.

V _p ′(z)=V _u ′(z)+e ^-j2 〓 ^/3 V _v ′(z)+e ^j2 〓 ^/3 V _w ′(z) V _o ′(z)=V _u ′(z)+e ^j2 〓 ^/3 V _v ′(z)＋e ^-j2 〓 ^/3 V _w ′(z)
...(8) The following formula is derived from the mathematical formula, cos2πz/P=(e ^j2 〓 ^z/P +e ^-j2 〓 ^z/P )/2 cos(2πz/P+2π/3) = (e ^j2 〓 ^{z /P+j2} 〓 ^z/3 +e ^-j2 〓 ^z/P-j2 〓 ^z/3 )/2 cos (2πz/P-2π/3) = (e ^j2 〓 ^z/P-j2 〓 ^z/3 +e ^{- j2} 〓 ^z/P+j2 〓 ^z/3 )/2
...(8-1) Substitute this equation (8-1) into equation (7), and then
Substituting equation (7) into equation (8) and focusing on the relationship 1 + e ^j2 〓 ^/3 + e ^-j2 〓 ^/3 = 0 ... (8-2), we can obtain the equation (7) which corresponds to the zero-sequence voltage. The first term in the braces on the right side of each equation disappears, and the following equation is obtained.

V _p ′(z)=(3/2)k ₁ k ₂ e ^(j2 〓 ^z/P)+j 〓 ^ot V _o ′(z)=(3/2)k ₁ k ₂ e ^-(j2 〓 ^{z /P)+j} 〓 ^ot ……(9) By comparing V _p ′(z) or V _o ′(z) with the reference phase signal derived from the carrier wave power source, Φ′(z) of the following equation is obtained.
can be found.

Φ′(z)=∠V _p ′(z)−∠e ^j 〓 ^ot =−(∠V _o ′(z)−∠e ^j
〓 ^ot )=2πz/P……(10) In other words, through the measurement of Φ′(z), the moving body position z
can be known continuously with a period of P.

Note that the right-hand side of each equation (5) actually contains some spatial harmonic components, but by using three antennas, harmonics of integer multiples of three such as the 3rd, 9th, and 15th The harmonic components of will disappear during the signal processing of equation (8), which has the advantage of improving position detection accuracy compared to the system using two antennas as shown in FIG.

Furthermore, detection can be performed not only by the above-mentioned analog method but also by a digital method.

That is, from equations (7) and (8), V _p ′(z)={|V ₁ (z)|+e ^-j2 〓 ^/3 |V ₂ (z)+e ^j2 〓 ^/3 |V ₃
(z)｝e ^j 〓 ^ot ……(10−1), and Φ′(z)=∠V _p ′(z)−∠e ^j 〓 ^ot =∠｛｜V ₁ (z)｜＋e ^-j2
〓 ^/3 ｜V ₂ (z)＋e ^j2 〓 ^/3 ｜V ₃ (z)｝ =∠｛｜V ₁ (z)｜+(-1/2-j√32)｜V ₂ (z)
|+(-1/2+j√32)|V ₃ (z)|} =∠[|V ₁ (z)|-(1/2){|V ₂ (z)|+|V ₃ (z)
|｝+j(√32){−|V ₂ (z)|+|V ₃ (z)|}] =tan ^-1 [(√32){−|V ₂ (z)|+|V ₃ (z) )｜／
{｜V ₁ (z)｜−(1/2) (｜V ₂ (z)｜+｜V ₃ (z)｜)}
]
...(11) Therefore, z=(P/2π)tan ^-1 [(√32){−|V ₂ (z)|+
｜V ₃ (z)｜}/{｜ _{V 2} (z)｜−(1/2)
｜V ₃
(z)｜)}] ...(12) That is, |V ₁ (z)|, |V ₂ (z)|, |V ₃ (z)| are A/
D is converted into a digital quantity by a converter, and then
By digitally processing the calculation of equation (12), the moving body position z can be known.

The above method can be applied to detecting the position of various types of moving objects, but can be particularly suitably adopted for automatic operation of linear motor cars.

In this case, the guided radio line can be formed by laying a conductor in a predetermined shape parallel to the track of the linear motor car, but the propulsion coil of the linear motor car can also be used.

FIG. 4 shows an outline of a propulsion coil for a linear motor car, in which rectangular loop coils u, v, and w form motor poles. A traveling wave magnetic field is formed by passing a positive or negative phase current of about 0 to 30 Hz through the loop coils u, v, and w, and this acts on the electromagnet on the vehicle to generate thrust. Each loop coil u, vw forming this propulsion coil is
Since it has a periodic structure of P shifted by P/3, either one of these can be used in correspondence with the conductor 11 in FIG.

In the operation of a linear motor car, the detection of the vehicle body position is required to adjust the magnetic field current, as mentioned earlier, and if the loop coil can be used as part of the inductive wireless line in the present invention, there will be an advantage. big.

FIG. 5 shows an example in which a propulsion coil of a linear motor car is used as an inductive radio line of the present invention.

15 is a transmitter, 16 is a transformer, 17, 18, 1
9 is a conductor connecting each loop coil u, v, w, 12
is a straight conductor. By connecting the conductors 17, 18, and 19 as shown in the figure, it is possible to form an inductive radio line with the loop coil u as the outward path and the straight conductor 12 as the return path, and position detection can be performed in the same way as the method explained in FIG. 3. It can be performed.

However, according to the inventor's study, the voltage induced in the antenna (for example, V ₁ (z)) reaches its maximum value every time the antenna passes directly above the loop coil u, as shown in FIG. It has been confirmed that although it takes a shape close to a half-sine wave in the vicinity, it becomes a flat shape above the loop coils v and w, and this has a fairly wide range.

That is, such a waveform has severe vertical asymmetry, and therefore, if expanded into a Fourier series, it will contain large even-order harmonic components, leading to position detection errors.

This is because the waveform shape of one of the conductors forming the guided radio line is a rectangular wave, and this problem occurs not only when using the propulsion coil of a linear motor car, but also when the waveform shape of the conductor is a rectangular wave or a rectangular wave. This problem also occurs when a general guided radio line having a shape similar to this is used.

[Object of the invention] The present invention can make the position detection period of a moving body equal to the conductor period P of the track, and when this is applied to automatic operation of a linear motor car, the conductor period P can be made equal to the distance between motor poles. Furthermore, it is possible to miniaturize the on-board antenna and facilitate the manufacture of the guided radio line, and furthermore, even if the waveform shape of the guided radio line is a rectangular wave or a shape close to this, position detection errors will not occur. The purpose is to provide a method for detecting the position of a moving object.

[Summary of the Invention] The gist of the present invention is that a conductor is formed by repeating the same shape at a constant period P along the travel path of a moving object;
A guided radio line consisting of a straight conductor parallel to this conductor is laid, while a P/3
Two sets of antenna element arrays each consisting of three antenna elements arranged at an interval of (The induced voltages of each element in one antenna element are V _1a (z), V _2a (z), and V _3a (z), respectively, and the induced voltages of each element in the other antenna element row are respectively
Let V _1b (z), V _2b (z), and V _3b (z)) be linearly detected and their envelopes (inclusive envelopes corresponding to each of the above voltages are |V _1a (z)|, |V, respectively). _2a (z)｜, ｜V _3a (z)｜, ｜V _1b (z)
|, |V _2b (z)|, |V _3b (z)|) and convert these voltages into digital quantities to obtain V _1e (z)= |V _1a (z)|−|V _1b (z)｜V _2e (z)=｜V _2a (z)｜−｜V _2b (z)｜ V _3e (z)=｜V _3a (z)｜−｜V _3b (z)｜, and z =(P/2π) tan ^-1 [(√32)−V _2e (z) +V _3e (z)}/{V _1e (z)−(1/2)}V _2e (z) +V _3e
(z)}] The purpose of this method is to continuously detect the position z of a moving body at a period P by performing the calculation.

The principle of the present invention will be explained based on FIG.

In Fig. 6, Fig. 6 a is a plan view, Fig. 6 b
is a sectional view taken along line A-A'. 20 and 21 are conductors, respectively, and the conductor 20 is bent into a rectangular wave shape so as to have a rectangular portion with a length of P/3 and a period P. In this way, the conductor 20 only needs to repeat the same shape at a constant period P,
In addition to the rectangular wave shape shown in the conductor 20 in FIG. 6, examples include triangular wave (sawtooth), trapezoidal, and sine wave shapes shown in FIGS. 13a, b, and c. .
The conductor 21 is arranged linearly in parallel with the conductor 20, thereby forming a guided radio line 22.

23-1a, 23-2a, 23-3a, 23-
1b, 23-2b, 23-3b are antenna elements, respectively, and antenna elements 23-1a, 23
Antenna element row 23 by -2a and 23-3a
-a is the antenna element 23-1b, 23-2b,
23-3b respectively form antenna elements 23-b, and the antenna element row 23-a and the antenna element row 23-b are mounted on the moving body with an interval of 3P/2.

When a high frequency current of 50 to 200 KHz is supplied from the ground transmitter 24 to the line 22, an induced magnetic field is formed around the line 22, and a voltage is induced in the rectangular antenna element. The voltages induced in antenna elements 23-1a, 23-2a, and 23-3a are V _1a (z), V _2a (z), and V _3a (z), respectively.
and antenna elements 23-1b, 23-2b, 2
The voltage induced in 3-3b is V _1b (z),
Let V _2b (z) and V _3b (z).

Linearly detect each voltage to find its envelope (absolute value of each voltage), and calculate V _1e (z), V _2e by calculating the following formula.
(z), derive V _3e (z).

V _1e (z)＝｜V _1a (z)｜−｜V _1b (z)｜ V _2e (z)＝｜V _2a (z)｜−｜V _2b (z)｜ V _3e (z)＝｜V _3a (z) | − | V _3b (z) | ...(13) Antenna elements 23-1a, 23-1b, 23-
The intervals between 2a and 23-2b and between 23-3a and 23-3b are each an odd multiple of P/2, and if we look at each term on the right side of each equation (13), we can see that even-order spatial harmonic components are in phase, and the fundamental wave and odd-numbered spatial harmonic components are out of phase, so all even-numbered spatial harmonic components cancel each other out and disappear. Therefore, the right side of equation (13) is almost a perfect sine wave, so V _1e (z), V _2e (z),
V _3e (z) can be expressed as the following equations similarly to equation (5).

V _1e (z)=k ₁ {1+K ₂ cos2πz/P} V _2e (z)=k ₁ {1+K ₂ cos2π(z+P/3)/P} V _3e (z)=k ₁ {1+K ₂ cos2π(z+2P/ 3)/P}
...(14) Here, V _u ″(z), V _v ″(z), and V _w ″(z) are defined by the following equations.

V _u ″(z)＝V _1e (z)e ^j 〓 ^ot V _v ″(z)＝V _2e (z)e ^j 〓 ^ot V _w ″(z)＝V _3e (z)e ^j 〓 ^ot …… (15) These voltages transform the carrier waves of angular frequency ω ₀ derived from the new carrier power source into V _1e (z), V 2e (z), and V _2e (z), respectively.
It can be obtained by modulating with V _3e (z).

Next, as described in equations (7-1) to (7-3), the positive sequence voltage V _p ″(z) and the negative sequence voltage V _o ″(z)
is defined by the following equation.

V _p ″(z)={V _1e (z)＋e ^-j2 〓 ^/3 V _2e (z) +e ^-j2 〓 ^/3 V _3e (z)}e ^j 〓 ^ot V _o ″(z)={V _1e (z)＋e ^j2 〓 ^/3 V _2e (z) +e ^-j2 〓 ^/3 V _3e (z)｝e ^j 〓 ^ot The following formula is derived from the mathematical formula, and cos2πz/P = (e ^-j2 〓 ^{z/ P} +e ^-j2 〓 ^z/P )/2 cos(2πz/P+2π/3) = (e ^-j2 〓 ^z/P+j2 〓 ^/3 +e ^-j2 〓 ^z/P-j2 〓 ^/3 )/2 cos( 2πz/P-2π/3) =e ^-j2 〓 ^z/P-j2 〓 ^/3 +e ^-j2 〓 ^z/P+j2 〓 ^/3 )/2
...(16-1) Substitute this equation (16-1) into equation (14), and then
Substituting equation (14) into equation (16) and focusing on the relationship 1 + e ^j2 〓 ^/3 + e ^-j2 〓 ^/3 = 0 ... (16-2), we can obtain the equation (14) which corresponds to the zero-sequence voltage. The first term in the braces on the right side of each equation disappears, and the following equation is obtained.

V _p ″(z)＝3k ₁ k ₂ e ^(j2 〓 ^z/P)+j 〓 ^ot V _o ″(z)＝3k ₁ k ₂ e ^-(j2 〓 ^z/P)+j 〓 ^ot ……( 17) By comparing the phase of V _p ″(z) or V _o ″(z) with the reference phase signal derived from the carrier wave power source, Φ″(z) in the following equation can be obtained.

Φ″(z)=∠V _p ″(z)−∠e ^j 〓 ^ot =−(∠V _o ″(z)−∠e ^j 〓 ^ot )=2πz/P ……(18) That is, Φ″( z), the moving body position z
can be obtained continuously with a period of P. Also
Substituting V _p ″(z) in equation (16) into the first equation of equation (18) yields the following equation.

Φ″(z)＝∠［{V _1e (z)＋e ^-j2 〓 ^/3 V _2e (z)＋e ^j2 〓 ^/3 V _3e (
z)}e ^j 〓 ^ot −∠e ^j 〓 ^ot =∠{V _1e (z)＋(−1/2−j√3/2)V _2e (z)＋(
−1/2+j√3/2)V _3e (z)} =∠[V _1e (z)−1/2{V _2e (z)+V _3e (z)}+j√3/2
) {−V ₂ (z)+V ₃ (z)}] =tan ^-1 [(√3/2) {−V _2e (z)+V _3e (z)}/{V _1e
(z)−(1/2)(V _2e (z)+V _3e (z)}]……(19) Therefore, z=(P/2π)tan ⁻¹ [(√3/2){− V _2e (z)＋V _3e (
z)}/{V _1e (z)−(1/2)(V _2e (z)+V _3e (z)}]...
(20) That is, |V _1a (z)|, |V _2a (z)|, |V _3a (z)|, |
V _1b (z) |, |V _2b (z)|, |V _3b (z)| are converted into digital quantities by an A/D converter, and the calculations of equations (13) and (20) are performed digitally by a digital computer. The position z of the moving object can be detected at the period P by processing the above-mentioned information.

As mentioned above, the present invention is applicable to detecting the position of various types of moving objects, including the automatic operation of the Niria motor car, but it goes without saying that the propulsion coil can be used as shown in Fig. 5 in the automatic operation of the Niria motor car. It is.

[Embodiment of the Invention] An embodiment of the present invention will be described based on FIGS. 6 and 7.

FIG. 7 shows an example of the configuration of a signal processing device mounted on a mobile object, and shows 25-1a, 25-2
a, 25-3a, 25-1b, 25-2b, 25
-3b is a buffer amplifier, 26-1a, 26-2a,
26-3a, 26-1b, 26-2b, 26-3
b is a bandpass filter, 27-1a, 27-2a,
27-3a, 27-1b, 27-2b, 27-3
b is a detector, 28-1a, 28-2a, 28-3
a, 28-1b, 28-2b, 28-3b are A/
D converter, 29, digital computer, 30
is a digital display device.

Transmitter 2 provided at the terminal of guided radio line 22
4, when a high frequency current is fed through the conductor 20 as the forward path and the conductor 21 as the return path, the antenna element 23-
1a, 23-2a, 23-3a, 23-1b, 2
A voltage is induced in 3-2b and 23-3b.

Each antenna element 23-1a, 23-2a, 23
The voltages induced in -3a, 23-1b, 23-2b, and 23-3b are applied to buffer amplifiers 25-1 and 23-3b, respectively.
a, 25-2a, 25-3a, 25-1b, 25
-2b, 25-3b into an unbalanced voltage, and bandpass filters 26-1a, 26-2a, 2
6-3a, 26-1b, 26-2b, 26-3b
The noise component is removed by the detector 27-1.
a, 27-2a, 27-3a, 27-1b, 27
-2b and 27-3b perform linear detection. Next, these voltages are applied to A/D converters 28-1a and 28-1a.
8-2a, 28-3a, 28-1b, 28-2
b, 28-3b, it is converted into a digital quantity and guided to the digital computer 29. The digital computer 29 digitally processes the calculations of equations (13), (19), and (20), and calculates the moving body position z.
is determined and this quantity is displayed on the digital display device 30.

The calculations in equations (19) and (20) are all four arithmetic operations, and can be processed extremely easily. Additionally, calculations for calculating tan ^-1 using a computer have already been established, including those that use series and those that search numerical tables.

Although the explanation has been given using a linear motor car as an example of application of the present invention, the present invention is not limited to this, but it is also applicable to vehicles that move along a fixed running route such as railway vehicles, various new transportation systems, cranes, and transportation vehicles. It is widely applicable to body position detection.

[Effects of the Invention] As explained above, according to the present invention, the detection period of the moving body position can be made equal to the period P of the conductor shape of the guided radio line. That is, compared to the conventional method in which the detection period is P/2, the same detection period can be obtained even if the conductor period is halved. Therefore, manufacturing of the line becomes easy and the price of the line can be reduced. In addition, if the period of the conductor is shortened, the size of the antenna mounted on a mobile object can be reduced in proportion.
The antenna can be easily attached to the vehicle body, and there is no need to provide a large cutout in the vehicle body, which eliminates concerns regarding the strength of the vehicle body.

Furthermore, the present invention seeks to determine the difference in voltages induced in arrays of antenna elements arranged at intervals of an odd multiple of P/2, thereby making it possible for the guided radio line to have a waveform shape close to a rectangular wave. Even if there is a problem, it can be removed by harmonic components and position detection errors can be eliminated.

When the present invention is applied to the position detection of a linear motor car, the ground propulsion coil can be used for multiple purposes as a guided radio line for position detection, and it can greatly contribute to the economicalization of the system configuration. .

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the conventional method, Figure 2 is an explanatory diagram of the relationship between moving body position z and phase difference, Figures 3 and 11.
1 and 12 are explanatory diagrams of a position detection system using an inductive radio line similar to the present invention and three antennas, FIG. 4 is a schematic explanatory diagram of a ground propulsion coil for a linear motor car, and FIG. A schematic explanatory diagram of the case where the ground propulsion coil of a linear motor car is used as an inductive radio line, FIG. 6 is an explanatory diagram of the principle and one embodiment of the present invention, and FIG. 7 is a diagram of the signal processing device used in the present invention. An explanatory diagram of one embodiment, Fig. 8 is an explanatory diagram of the waveform of the voltage induced between the conductors, Figs. 9 and 10 are explanatory diagrams of the induced voltage induced in the antenna, and Fig. 13 is an explanation of the waveform conductor. It is a diagram. 20: Waveform conductor, 21: Straight conductor, 22: Guided radio line, 23-a, 23-b: Antenna element array, 24: Ground transmitter, 25-1a, 25-2
a, 25-3a, 25-1b, 25-2b, 25
-3b: Buffer amplifier, 26-1a, 26-2a,
26-3a, 26-1b, 26-2b, 26-3
b: band pass filter, 27-1a, 27-2a,
27-3a, 27-1b, 27-2b, 27-3
b: Detector, 28-1a, 28-2a, 28-3
a, 28-1b, 28-2b, 28-3b: A/
D converter, 29: Digital computer, 3
0: Digital display device.

Claims (1)

[Claims] 1. A guided radio line consisting of a conductor having the same shape repeated at a constant period P and a linear conductor parallel to the conductor is laid along the travel path of the moving object, On the other hand, two sets of antenna element arrays each consisting of three antenna elements arranged at an interval of P/3 are mounted on the mobile object at an interval of an odd multiple of P/2, and a high-frequency current is applied to the guided radio line. When the above voltages are induced in each antenna element (the induced voltages of each element in one antenna element row are V _1a (z), V _2a (z), and V _3a (z), respectively), the voltages induced in each antenna element in the other antenna element row are Let the induced voltage of each element be V _1b (z),
Let V _2b (z) and V _3b (z)) be linearly detected and their envelopes (inclusive envelopes corresponding to each of the above voltages are respectively |
V _1a (z)｜, ｜V _2a (z)｜, ｜V _3a (z)｜, ｜V _1b (z)｜, ｜V _2
b
(z)|, |V _3b (z)|) and convert these voltages into digital quantities to obtain V _1e (z)= |V _1a (z)|−|V _1b (z)| V _2e (z)=|V _2a (z)|−|V _2b (z)| V _3e (z)=|V _3a (z)|−|V _3b (z)| is obtained, and z=(P/2π ) tan ^-1 [(√3/2){−V _2e (z)＋V _3e (
z)}/{V _1e (z)−(1/2)}V _2e (z)+V _3e (z)}] The position z of the moving object is continuously detected with a period P. A mobile object position detection method characterized by: