JPH0418794B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to mobile bodies (such as linear motor cars, various transportation systems) that use guided radio to move along a certain running route (track, etc.). , industrial transport engines) on the ground periodically and continuously.

[Prior Art] In the automatic operation of a linear motor car, the position of the vehicle body (mobile body position) is determined within the range of the interval between propulsion coils (motor pole interval) arranged at regular intervals along the running path (track). It is considered essential to periodically and continuously detect this on the ground.

Position information regarding the vehicle body is used as basic data for controlling the frequency, amplitude, and phase of the current flowing to the propulsion coil within the substation.

A typical technique that has been proposed to meet such demands will be explained with reference to FIG. 9.

1, 2, and 3 are conductors, and a guided radio line 4 is formed by laying these conductors along the running path of the linear motor car. 5 is an antenna (frame-shaped loop coil) fixed to the vehicle body, and a high frequency current of 50 to 200 kHz is applied to it.

Each of the conductors 1, 2, and 3 is bent into a waveform shape with a period of P on a plane, and is arranged at intervals of P/3, so that the guided radio line 4 as a whole has a period of P.
It has a repeating structure.

Note that the period P is determined so that P/2 coincides with the distance between motor poles. Further, 6 is a signal processing circuit, 7 is a display device, 8 is a propulsion coil current control device, and 9 is a transmitter.

If the distance from the terminal of the guided radio line 4 to the antenna 5 is z, and the voltages induced between the conductors 1-2, 2-3, and 3-1 are _V12 , _V23 , and _V31 , respectively, then _V12 , V ₂₃ , and V ₃₁ are all functions of z,
By appropriately selecting the separation distance between the guided radio line 4 and the antenna 5 and the dimensions of the antenna 5,
The waveform can be sinusoidal in z.

The induced voltages V ₁₂ , V ₂₃ , and V ₃₁ between the conductors that have propagated along the guided radio line 4 to its starting end are received by the signal processing circuit 6, where linear detection is performed to determine the amplitude of each, and this is After converting into digital quantities, the value of z (position of the vehicle body) is calculated digitally based on these data, and the processing results are output to the display device 7 and the propulsion coil current control device 8.

The propagation constant of the guided radio line 4 is γ, and γ=α+
If expressed as jβ (α: attenuation constant, β: phase constant), the induced voltages V ₁₂ (z), V ₂₃ ( z),
V ₃₁ (z) can be expressed by the following form.

V ₁₂ (z)=ke ^- 〓 ^zj 〓 ^z・cos(2π/P)z・e ^j 〓 ^t V ₂₃ (z)=ke ^- 〓 ^zj 〓 ^z・cos {(2π/P)z+(2π/3 )}・e ^j 〓 ^t V ₃₁ (z)=ke ^- 〓 ^zj 〓 ^z・cos {(2π/P)z−(2π/3)}・e ^j 〓 ^t …
(1) Here, k is a constant determined by the shapes and dimensions of the guided radio line 4 and the antenna 5, the distance between them, the magnitude of the current, and the frequency, and ω is the angular frequency of the current of the antenna 5.

Linear detection of these voltages and finding the amplitude of the envelope are as follows.

｜V ₁₂ (z)｜＝e ^- 〓 ^z・｜kcos(2π/P)z｜ ｜V ₂₃ (z)｜=e ^- 〓 ^z・｜kcos {(2π/P)｜z+(2π/3)} ｜ ｜V ₃₁ (z)｜=e ^- 〓 ^z・｜kcos {(2π/P) z−(2π/3)}｜…(2
) Converting each value in equation (2) into a digital quantity and finding its square value yields the following.

｜V ₁₂ (z)｜ ² = e ² 〓 ^z k ² cos ² (2π/p) z = (1/2) k ² e ^-2 〓 ^z・{1+cos(4π/P)
z｝ ｜V ₂₃ (z)｜ ² = (1/2)k ² e ^-2 〓 ^z・[1+cos{(4π/P)z−(2π/3)}] ｜V ₃₁ (z)｜ ² = (1/2) k ² e ^-2 〓 ^z・[1+cos {(4π/P) z+(2π/3)}]
…(3) Here, |V ₁₂ (z) | ² , |V ₂₃ (z) | ² , |V ₃₁ (
z)
| Define the negative sequence voltage V _o for ² as follows.

V _o =｜V ₁₂ (z)｜ ² +e ^j2 〓 ³ ｜V ₂₃ (z)｜ ² +e ^-j2 〓 ³ ｜V ₃₁ (z)｜ ² …(4) Formula (3) becomes formula (4) By substituting and rearranging, we get the following formula.

V _o = (3/4)k ² e ^-2 〓 ^z e ^j4 〓 ^{z p} …(5) If the phase angle of V _o is expressed as ∠V _o , ∠V _o = (4π/P)z . That is, z=(P/4π)∠V _o (6), and it can be seen that there is a proportional relationship between ∠V _o and z.

Furthermore, the following equation can be obtained from equation (4).

V _o = { | V ₁₂ (z) | ² − (1/2) | V ₂₃ (z) | ² − (1/2) | V ₃₁ (z) | ² + (j√32)(|V ₂₃ (z)| ² -|V ₃₁ (z)| ² )} ・e ^-2 〓 ^z …(7) From equations (6) and (7), the following relationship is obtained.

z=(P/4π) tan ^-1 (I _n /R _e ) = (P/4π) tan ^-1 {(√32)(|V ₂₃ (z)
| ² −|V ₃₁ (z)| ² )}/{|V ₁₂ (z)| ² −(1/2)(|V ₂₃ (z)| ² +|V ₃₁ (z)| ² )}... (8) Here, R _e is the real part of V _o and I _n is the imaginary part of V _o .

As is clear from equations (6) and (8), the vehicle body position z
Every time ∠V _o increases by P/2, ∠V o shows an increase of 2π, but
Since it is virtually impossible to distinguish between 0 and 2nπ (n: an integer) for the phase angle, the relationship between ∠V _o and z is as shown in FIG.

In other words, the vehicle body position z is expressed as P/2 (distance between motor poles) through the value of ∠V _o determined by equation (7).
Periodic and continuous detection is possible within the range of . Note that for line 4, ∠V _o is 0 (or
2π) is installed so that the position coincides with the motor pole.

[Problems to be Solved by the Invention] However, the following two problems have been pointed out in the above mobile body position detection method.

The detection period of the vehicle body (moving body) position is P/2, so the period P of the line conductors 1, 2, and 3 needs to be twice the distance between the motor poles.For example, if the distance between the motor poles is For 4.2 m and 6.3 m, the values of P must be 8.4 m and 12.6 m, respectively. It is extremely difficult to realize the structure of the guided radio line with such a long period, and the accuracy of laying the conductors 1, 2, and 3 is reduced, which in turn leads to a reduction in the accuracy of detecting the vehicle body position.

Furthermore, as shown in equation (1) or (2), the preconditions for the above vehicle body position detection to be successful are the induced voltages V ₁₂ (z), V ₂₃ (z), and V ₃₁ between the guided radio line conductors. (z)
are respectively sinusoidal functions of z (coordinates for displaying the vehicle body position), and for this purpose, it is necessary to set the length of the on-vehicle antenna in the range of P/5 to P/7. Therefore, when P = 8.4m (distance between motor poles 4.2m), the antenna length is approximately 1.2~
It is large at 1.7m. Therefore, the antenna becomes expensive and difficult to attach to the vehicle body, and in some cases, it may be necessary to cut a part of the vehicle body member, which may threaten the strength of the vehicle body.

The present invention is based on the above, and the mobile body position detection period is made equal to the guided radio line conductor period P,
The purpose of this invention is to facilitate the manufacture of guided radio lines and to reduce the size of antennas.

[Means for solving the problem] The present invention provides a high-frequency current with an angular frequency ω ₁ and an angular frequency ω ₂ obtained by doubling the high-frequency current.
A high-frequency current of V ₁₂ (z) is applied between adjacent conductors at the angular frequencies ω ₁ and ω ₂ at the terminal of the inductive radio line.
V ₂₃ (z), V ₃₁ (z) are selectively received, and the envelopes of the respective induced voltages are calculated as V ₁₂ ′(z), V ₂₃ ′(z),
When V ₃₁ '(z), the phase difference between the induced voltage at angular frequency ω ₂ and the voltage obtained by doubling the induced voltage at angular frequency ω ₁ is φ ₁₂ , φ ₂₃ , _φ31
is −π/2≦φ ₁₂ , φ ₂₃ , φ ₃₁ ≦π/2, it is determined that V ₁₂ ′(z), V ₂₃ ′(z), V ₃₁ ′(z)>0, When π/2≦ _φ12 , _φ23 , _φ31 ≦3π/2, it is determined that V ₁₂ ′(z), V ₂₃ ′(z), V ₃₁ ′(z)<0, and the guided radio line The distance z from the terminal to the mobile antenna is z=(P/2π) tan ^-1 {(√32)(V ₂₃ ′(z)
− V ₃₁ ′(z))}/{V ₁₂ ′(z)−(1/2)
(V ₂₃ ′(z) +V ₃₁ ′(z))} The present invention is characterized in that the position of the moving object is periodically and continuously detected at a constant period P by calculating based on the following equation.

That is, the induced voltage between conductors V ₁₂ (z), V ₂₃ (z),
In addition to means for determining the absolute value of the envelope of V ₃₁ (z), a means for identifying its sign is added, and the obtained data is digitally processed to calculate the position z.

Induced voltage between conductors V ₁₂ (z), V ₂₃ (z), V ₃₁ (z)
is divided into a part that displays the phase e ^-j 〓 ^z+j 〓 ^t and other parts and is expressed as follows.

V ₁₂ (z)=V ₁₂ ′(z)e ^-j 〓 ^z+j 〓 ^t V ₂₃ (z)=V ₂₃ ′(z)e ^-j 〓 ^z+j 〓 ^t V ₃₁ (z)=V ₃₁ ′(z)e ^-j 〓 ^z+j 〓 ^t …(9) V ₁₂ ′(z), V ₂₃ ′(z), V ₃₁ ′(z) are each V ₁₂
(z), V ₂₃ (z), and V ₃₁ (z), and as is clear from equation (1), it can be written as follows.

V ₁₂ ′(z)=ke ^- 〓 ^z・cos(2π/P)z V ₂₃ ′(z)=ke ^- 〓 ^z・cos{(2π/P)z+(2π/3)} V ₃₁ ′(z )=ke ^- 〓 ^z・cos {(2π/P)z−(2π/3)} …(10) Also, ｜V ₁₂ ′(z)｜=｜V ₁₂ (z)｜ ｜V ₂₃ ′(z )｜=｜V ₂₃ (z)｜｜V ₃₁ ′(z)｜=｜V ₃₁ (z)｜…(11).

Here, the positive sequence voltage V _p ′ for V ₁₂ ′(z), V ₂₃ ′(z), and V ₃₁ ′(z) is defined as follows.

V _p ′=V ₁₂ ′(z)+e ^-j2 〓 ^/3 V ₂₃ ′(z) +e ^j2 〓 ³ V ₃₁ ′(z) …(12) Substituting equation (10) into equation (12) yields the following equation It becomes like that.

V _p ′=(3/2)ke _- 〓 _z e ^j2 〓 ^Z/P ...(13) The following equation is obtained from equations (12) and (13).

z=(P/2π)∠V _p ′ = (P/2π) tan ^-1 {(√32)(V ₂₃ ′(z) −V ₃₁ ′(z))}/{V ₁₂ ′(z) − (1/2) (V ₂₃ ′ (z) + V ₃₁ ′ (z))}
…(14) Therefore, if we know the absolute values and signs of V ₁₂ ′(z), V ₂₃ ′(z), and V ₃₁ ′(z), we can calculate the value on the right side of equation (14). , the vehicle body position z can be detected with a period of P through this value.

Here, the envelopes V ₁₂ ′(z), V ₂₃ ′(z), V ₃₁ ′(
z)
In order to determine the sign of , take the following steps.

That is, a high-frequency current having an angular frequency ω ₁ and an angular frequency ω ₂ obtained by doubling the angular frequency ω 1 is fed to the on-vehicle antenna, and the guided radio line is excited by an alternating magnetic field of two frequencies. At the inductive radio line terminal, conductor-induced voltages with angular frequencies ω ₁ and ω ₂ are selectively received, and the voltages at ω ₁ or ω ₂ are linearly detected to obtain V ₁₂ ′ (z), V ₂₃ ′ (z), V ₃₁ In addition to finding the absolute value of ′(z), the voltage of ω ₁ is doubled to convert it to the voltage of ω ₂ , and this is used as the reference phase signal as V ₁₂ ′(z),
Determine the sign (positive or negative) of V ₂₃ ′(z) and V ₃₁ ′(z).

[Embodiment] FIG. 1 is an overall explanatory diagram of an embodiment of the present invention, and in FIG. 9, the same reference numerals as in the conventional example are given the same reference numerals.

On-board transmitters 9 _-1 and 9 _-2 output high-frequency currents with angular frequencies ω ₁ and ω ₂ , respectively, and both of these currents are supplied to the on-board antenna 5. here,
The angular frequency ω ₂ is obtained by doubling ω ₁ .

FIG. 2 is a detailed explanatory diagram of the signal processing circuit 6. As shown in FIG. 11 _-1 , 11 _-2 , 11 _-3 are buffer amplifiers Buff,
12 _-21 , 12 _-22 , 12 _-23 and 12 _-11 , 12
_-12 , 12 _-13 are bandpass filters BPF whose passbands are angular frequencies ω ₂ and ω ₁ , respectively; 13 _-1 , 13 _-2 , 1
3 _-3 is a linear detector DET, 14 _-21 , 14 _-22 , 14
_-23 and 14 _-11 , 14 _-12 , 14 ² _-13 are waveform shaping circuits for signals with angular frequencies ω ₂ and ω ₁ , respectively; 15 _-1 ,
_15-2 , _15-3 are analog-digital converters A/D, _16-1 , _16-2 , _16-3 are double multiplier circuits,
17 _-1 , 17 _-2 , 17 _-3 are phase comparator circuits PD, 1
8 is an OR circuit, 19 is a microcomputer MC
It is.

Buffer amplifiers _Buff11-1 , _11-2 , and _11-3 convert the interconductor voltages V ₁₂ (z), V ₂₃ (z), and V ₃₁ (z), respectively, into unbalanced voltages, and this output is passed through a bandpass filter. 12
_-21 , 12 _-22 , 12 _-23 and 12 _-11 , 12 _-12 ,
12 _-13 . Bandpass filter 12 _-21 , 1
The outputs of 2 _-22 and 12 _-23 are linear detectors DET13 _-1 ,
13 _-2 , 13 _-3 and waveform shaping circuit 14 _-21 , 1
Linear detector DET13 is guided by 4 _-22 and 14 _-23 .
_-1 , 13 _-2 , 13 _-3 , the absolute value of the envelope of the voltage between the conductors |V ₁₂ ′(z) |, |V ₂₃ ′(z) |, |V ₃₁ ′(
z)｜
_{Voltage proportional to}
is input. In addition, the waveform shaping circuit 14 _-21 , 1
At _4-22 and _14-23 , it is converted into a rectangular wave pulse train (unipolar) with a repetition angular frequency ω _{2 and} output.
It is input to one terminal on the input side of the phase comparator circuits _PD17-1 , _17-2 , and _17-3 .

The outputs of the bandpass filters 12 _-11 , 12 _-12 , 12 _-13 are converted into a rectangular wave pulse train with a repetition angular frequency ω ₁ in waveform shaping circuits 14 _-11 , 14 _-12 , 14 _-13 and outputted. Multiplier circuit 16 _-1 , 16 _-2 , 1
6 _-3 , respectively, and the repetition angular frequency ω ₂ (ω ₂ =
2ω ₁ ) and input to the OR circuit 18. The output of the OR circuit 18 is the phase comparison circuit PD17.
_-1 , 17 _-2 , and 17 _-3 are led to the other terminal on the input side.

The phase comparator circuits _PD17-1 , _17-2 , and _17-3 detect the phase difference of the pulse train (repetition angular frequency is ω ₂ for both) input to each of the two terminals as a digital quantity, and output this to the microcomputer MC19. .

The microcomputer MC19 includes an input interface _19-1 , a ROM _19-2 that stores an input data processing program, a CPU _19-4 that processes the input data according to the program, and a RAM _19-3 that temporarily stores intermediate results. , an output interface 19 _-5 that outputs data processing results to the display unit 7 and the propulsion coil current control device 8.
It is made up of.

In such a configuration, the conductors 1-2, 2 in the guided radio line 4 excited by the on-board antenna 5
The instantaneous value of the induced voltage between -3 and 3-1 can be written as follows for angular frequencies ω ₁ and ω ₂ , respectively.

V ₁₂ (ω ₁ , z, t) = k ₁ e ^- 〓 ^{1 zj} 〓 ^{1 z}・cos (2π/P)ze ^j 〓 ^{1 t} V ₂₃ (ω ₁ , z, t) = k ₁ e ^- 〓 ^{1 zj} 〓 ^{1 z}・cos {(2π/P) z + (2π/3)}e ^j 〓 ^{1 t} V ₃₁ (ω ₁ , z, t)=k ₁ e ^- 〓 ^{1 zj} 〓 ^{1 z}・cos {(2π /P)z−(2π/3)}e ^j 〓 ^{1 t}
…(15) V ₁₂ (ω ₂ , z, t) = k ₂ e ^- 〓 ^{2 zj} 〓 ^{2 z}・cos (2π/P)ze ^j 〓 ₂ ^t V ₂₃ (ω ₂ , z, t) = k ₂ e ^- 〓 ^{2 zj} 〓 ^{2 z}・cos {(2π/P)z+(2π/3)}e ^j 〓 ^{2 t} V ₃₁ (ω ₂ , z, t)=k ₂ e ^- 〓 ^{2 zj} 〓 ^{2 z}・cos {(2π/P)z−(2π/3)}e ^j 〓 ^{2 t}
...(16) Here, the subscripts 1 and 2 attached to k, α, and β mean that they are numerical values corresponding to the angular frequencies ω ₁ and ω ₂ , respectively.

If both sides of equations (15) and (16) are separated into a part representing the phase and a part other than that (ie, the envelope), it can be written as the following equation.

V ₁₂ (ω ₁ , z, t) = V ₁₂ ′ (z)e ^-j 〓 ^{1 z+j} 〓 ^{1 t} V ₂₃ (ω ₁ , z, t) = V ₂₃ ′ (z)e ^-j 〓 ^{1 z+j} 〓 ^{1 t} V ₃₁ (ω ₁ , z, t) = V ₃₁ ′ (z)e ^-j 〓 ^{1 z+j} 〓 ^{1 t}
…(17) V ₁₂ (ω ₂ , z, t) = k ₃ V ₁₂ ′ (z)e ^-j 〓 ^{2 z+j} 〓 ₂
^t V ₂₃ (ω ₂ , z, t)=k ₃ V ₂₃ ′ (z)e ^-j 〓 ^{2 z+j} 〓 ^2
t V ₃₁ (ω ₂ , z, t)=k ₃ V ₃₁ ′ (z)e ^-j 〓 ^{2 z+j} 〓 ^2
t
...(18) Here, V' ₁₂ (z) = k ₁ e ^- 〓 ^{1 z} cos (2π/P) z V' ₂₃ (z) = k ₁ e ^- 〓 ^{1 z} cos {(2π/P) z + (2π
/
3)} V′ ₃₁ (z)=k ₁ e ^- 〓 ^{1 z} cos {(2π/P)z−(2π
/
3)} …(19) k ₃ = k ₂ e ^-( 〓 ^2- 〓 ^1)z , and V ₁₂ ′(z), V ₂₃ ′(z), and V ₃₁ ′(z) are real numbers (positive or negative), k ₃ is an integer.

Here, focusing on V ₁₂ (ω ₁ , z, t), if the on-board antenna 5 is located between AB as shown in FIG. 3 and V ₁₂ '(z)>0, then V ₁₂ ′(z)=|V ₁₂ ′(z)| Therefore, V ₁₂ (ω ₁ , z, t) = |V ₁₂ ′(z) | e ^-j 〓 ^{1 z+j} 〓 ^1
t
…(20) V ₁₂ (ω ₂ , z, t) = k ₃ |V ₁₂ ′(z) |
e ^-j 〓 ^{2 z+j} 〓 ^{2 t} …(21) is obtained.

V ₁₂ (ω ₁ , z, t) multiplied by 2 is DV ₁₂
When expressed as (ω ₁ , z, t), it becomes as follows.

DV ₁₂ (ω ₁ , z, t) = |V ₁₂ ′(z) |
e ^-j2 〓 ^{1 z+j2} 〓 ^{1 t} …(22) If the phase difference between V ₁₂ (ω ₂ , z, t) and DV ₁₂ (ω ₁ , z, t) is φ ₁₂ , φ ₁₂ is φ ₁₂ = V ₁₂ (ω ₂ , z, t) − DV ₁₂ (ω ₁ , z, t) = (−β ₂ z + ω ₂ t) − (−2β ₁ z + 2ω ₁ t) = (2β ₁ − β ₂ )z+(ω ₂ −2ω ₁ )t…(23) Here, if we set (2β ₁ −β ₂ )z=δ, 2ω ₁ =ω ₂
From the relationship, it can be seen that φ ₁₂ = δ (24).

As shown in FIG. 4, the on-board antenna 5 is located between BC and when V ₁₂ ′(z)<0, V ₁₂ ′(z)=−|V ₁₂ ′(z)|. Therefore, V ₁₂ (ω ₁ , z, t)=−|V ₁₂ ′(z)|
e ^-j 〓 ^{1 z+j} 〓 ₁ ^t = |V ₁₂ ′(z)｜e ^-j 〓 ^{1 z+j} 〓 ^+j 〓 ^{1 t} …(25) V ₁₂ (ω ₂ , z, t) = k ₃ ｜V ₁₂ ′(z)｜
e ^-j 〓 ^{2 z+j} 〓 ^+j 〓 ₂ ^t …(26) is obtained.

When V ₁₂ (ω ₁ , z, t) in equation (25) is doubled and expressed as DV ₁₂ (ω ₁ , z, t), the following equation is obtained.

DV ₁₂ (ω ₁ , z, t) = k ₃ |V ₁₂ ′(z) | e−j2β1
z+j2ω1 t (27) The phase difference φ ₁₂ between V ₁₂ (ω ₂ , z, t) and DV ₁₂ (ω ₁ , z, t) is as follows.

φ ₁₂ = V ₁₂ (ω ₂ , z, t) − DV ₁₂ (ω ₁ , z, t) = δ + π (28) Now, if the absolute value of the maximum value of δ that can be assumed is δ _nax , then ( As is clear from equations 23) and (27), V ₁₂ ′(z)>0(−δ _nax ≦φ ₁₂ ≦δ _nax ) V ₁₂ ′(z)<0(π−δ _nax ≦φ ₁₂ ≦π+δ _nax )
…(29) In other words, through the value of _φ12
It is possible to determine whether the sign of V ₁₂ ′(z) is positive or negative. In a normal line, 2β ₁ ≈β ₂ , and in many cases the value of δ is small. Therefore, by setting δ _nax =π/2, all cases can be dealt with.
Therefore, the relationship V ₁₂ ′(z)>0(−π/2≦φ ₁₂ ≦π/2) V ₁₂ ′(z)<0(π/2≦φ ₁₂ ≦3π/2)…(30) From this, it is always possible to determine whether the sign of V ₁₂ ′(z) is positive or negative.

_{DV 23 (} ω _{1 ,} z _, t) and DV ₃₁ ( _{ω 1} ,
As is clear from equations (17), (18), (22), and (27), ∠DV ₁₂ (ω ₁ , z, t) = ∠DV ₂₃ (ω ₁ , z, t) =∠DV ₃₁ (ω ₁ , z, t), and the sign of V ₁₂ ′(z) can be determined using any of the three voltages as the reference phase signal.

Here, φ ₂₃ =∠V ₂₃ (ω ₂ , z, t)−∠DV ₁₂ (ω ₁ , z,
t) φ ₃₁ =∠V ₃₁ (ω ₂ , z, t) − ∠DV ₁₂ (ω ₁ , z,
t), then _{V 23 ′} ( _z ),
The sign of V ₃₁ ′(z) can be determined in the same way as for V ₁₂ ′(z).

The above principle will be explained below while comparing it with the operation of the signal processing circuit 6.

Among the induced voltages between conductors 1, 2, and 3, the voltages with angular frequency ω ₂ are V ₁₂ (ω ₂ , z, t), V ₂₃ (ω ₂ , z, t),
V ₃₃₁ (ω ₂ , z, t) are each bandpass filter BPF
After passing through _12-21 , _12-22 , _12-23 , it is divided into two and input to linear detectors _DET13-1 , _13-2 , _13-3 and waveform shaping circuits _14-21 , _14-22 , _14-23. .

Linear detectors DET13 _-1 , 13 _-2 , 13 _-3 are respectively |V ₁₂ (ω ₂ , z, t) |, |V ₂₃ (ω ₂ , z, t) |, |
A voltage proportional to V ₃₁ (ω ₂ , z, t) | is output, and these are converted into digital quantities by A/D converters 15 _-1 , 15 _-2 , 15 _-3 and then input to the microcomputer MC19. Input in parallel to interface _19-1 .

On the other hand, waveform shaping circuits 14 _-21 , 14 _-22 , 14 _-23
The input component is converted into a rectangular wave pulse train with a repetition angular frequency ω ₂ and sent to the phase comparator circuits 17 _-1 , 17
_-2 , 17 Enter in _-3 .

Furthermore, among the induced voltages between the conductors 1, 2, and 3, the voltages V ₁₂ ( _{ω 1 ,} z, t) and V ₂₃ (ω ₁ , z,
t), V ₃₁ (ω ₁ , z, t) are band-pass filters, respectively.
BPF12 _-11 , 12 _-12 , 12 _-13 , waveform shaping circuit 1
4 _-11 , 14 _-12 , 14 _-13 , double multiplier circuit 16 _-1 , 1
6 _-2 and 16 _-3 , it becomes a rectangular wave pulse train with a repetition angular frequency of 2ω ₁ (=ω ₂ ) and is sent to the OR circuit 18.
Enter.

Here, V ₁₂ (ω ₁ , z, t), V ₂₃ (ω ₁ , z, t),
The amplitude of V ₃₁ (ω ₁ , z, t) becomes zero alternately at a period of P/2, and along with this, the waveform shaping circuit 14 _-11 ,
The pulse trains output from 14 _-12 and 14 _-13 are also zero or very small. Even in this case, since two of the pulse trains input to the OR circuit 18 have sufficient amplitude, the OR of these three inputs can be output.

As will be described later, this pulse train has V ₁₂ (ω ₂ ,
z, t), V ₂₃ (ω ₂ , z, t), V ₃₁ (ω ₂ , z, t)
functions as a reference phase signal for code discrimination.

The phase comparison circuits _PD17-1 , _17-2 , _17-3 receive the pulse train input from the waveform shaping circuits _14-21 , _14-22 , _14-23, respectively, and the pulse train input from the OR circuit 18 (both with repetition angular frequency ω ₂ ) is detected, and its output is input as a digital quantity to the input interface 19 _-1 of the microcomputer MC19. Phase comparison circuit PD17 _-1 ,
The operations of 17 _-2 and 17 _-3 are as described above for φ ₁₂ , φ ₂₃ and φ 23 , respectively.
This corresponds to the calculation to obtain _φ31 .

In the microcomputer MC19, it is taken internally by the input interface 19 _-1 .
V ₁₂ ′(z)｜, ｜V ₂₃ ′(z)｜, ｜V ₃₁ ′(z)｜,
_φ12 ,
Various data of φ ₂₃ and φ ₃₁ are processed by the program stored in ROM19 _-2 , and V ₁₂ ′(z),
Determination of the signs of V ₂₃ ′ (z) and V ₃₁ ′ (z) (determination using equation (28) or (29) described above) and calculation for determining the moving object position z (calculation using equation (13) described above) ) is performed, and the results are outputted to the display device 7 and the propulsion coil current control device 8 via the output interface 19 _-5 .

Figures 5 and 6 are for the case δ≒0 (this assumption is valid in many cases), respectively.
V ₁₂ when V ₁₂ ′(z)>0 (corresponds to Figure 3)
(ω ₂ , z, t) and DV ₁₂ (ω ₁ , z, t).

Moreover, in FIGS. 7 and 8, V ₁₂ ′(z)>0
and waveform shaping circuit 14 when V ₁₂ ′(z)<0.
_-21 , _14-11 and a timing chart showing the output waveforms of the doubler circuit _16-1 .

It goes without saying that the present invention is not limited to the above embodiments, and that the following cases are also included within the scope of the present invention.

(1) In Fig. 1, the high frequency currents of ω ₁ and ω ₂ are supplied to the same on-board antenna 5, but two on-board antennas are arranged at an interval P in the z direction, and the high frequency currents of ω 1 and ω ₂ are supplied to the same on-board antenna 5. When supplying high frequency current of ω ₂ .

(2) The absolute value of the envelope of the voltage between conductors was detected through the voltage at ω ₂ , but when it is detected using the voltage at ω ₁ .

(3) The output of the OR circuit that functions as the reference phase signal at the end of the sign determination of the envelope is V ₁₂ (ω ₁ , z, t),
It was obtained as the logical sum of rectangular wave pulse trains derived from the three voltages V ₂₃ (ω ₁ , z, t) and V ₃₁ (ω ₁ , z, t), but one of the three input voltages was omitted. However, there is no practical problem.

(4) In addition to detecting the position of linear motor cars,
It can be widely applied to detecting the position of various moving objects (cranes, transport vehicles, new transportation systems, etc.) that move along a certain travel route.

[Effects of the Invention] As explained above, the position detection method of the present invention has the following effects:
A three-phase, three-conductor inductive radio line laid along the moving route is excited by a moving body-mounted antenna to which a current of angular frequency ω ₁ and angular frequency ω ₂ , which is twice the angular frequency ω 2, is applied. At the terminal, the induced voltage appearing at the terminal between square conductors is selectively received for ω ₁ and ω ₂ , the voltage of ω ₁ is doubled, and this is used as a reference phase signal to determine the sign (positive or negative) of the envelope of the induced voltage. This makes it possible to calculate the moving object position based on the envelope and sign of the induced voltage between each conductor, and the moving object position z can be measured periodically and continuously at a period equal to the conductor period P. It becomes possible to do so.

Therefore, the conductor period P can be shortened for a given detection period, making it easier to manufacture the guided radio line and downsizing the on-vehicle antenna.

[Brief explanation of drawings]

FIG. 1 is an overall explanatory diagram of one embodiment of the present invention, and FIG.
The figure is a detailed diagram of an example of a signal processing circuit, Figures 3 and 4 are explanatory diagrams of the relationship between the on-board antenna position and the sign of the envelope of the induced voltage between conductors, and Figures 5 and 6 are
The figure is an explanatory diagram of the relationship between the phase of the induced voltage between the conductors and the sign of the envelope. Figures 7 and 8 are explanatory diagrams of the rectangular wave pulse train derived from the induced voltage between the conductors. Figure 9 is the conventional An explanatory diagram of an example, FIG. 10 is an explanatory diagram of the relationship between the phase angle ∠V _o of the negative phase voltage and the position z of the antenna. 1, 2, 3...Conductor, 4...Guided radio line, 5
...Mobile-mounted antenna, 6...Signal processing circuit.

Claims (1)

[Claims] 1. 3 bent into a waveform shape at a constant period P.
A guided radio line consisting of strip conductors shifted by P/3 in the longitudinal direction of the track is laid along the travel path of a moving object, and this guided radio line is controlled by a high-frequency magnetic field formed by an antenna mounted on the moving object. In a method of periodically and continuously detecting the position of a moving body based on the voltage induced between the respective conductors, a high-frequency current with an angular frequency ω ₁ and an angular frequency ω obtained by doubling this current are used. A high frequency current of ₂ is applied to the antenna mounted on the mobile object, and at the terminal of the inductive radio line, the induced voltage V ₁₂ (z) between adjacent conductors at the angular frequencies ω ₁ and ω ₂ is
V ₂₃ (z), V ₃₁ (z) are selectively received, and the envelopes of the respective induced voltages are calculated as V ₁₂ ′(z), V ₂₃ ′(z),
When V ₃₁ '(z), the phase difference between the induced voltage at angular frequency ω ₂ and the voltage obtained by doubling the induced voltage at angular frequency ω ₁ is φ ₁₂ , φ ₂₃ , _φ31
is −π/2≦φ ₁₂ , φ ₂₃ , φ ₃₁ ≦π/2, it is determined that V ₁₂ ′(z), V ₂₃ ′(z), V ₃₁ ′(z)>0, When π/2≦ _φ12 , _φ23 , _φ31 ≦3π/2, it is determined that V ₁₂ ′(z), V ₂₃ ′(z), V ₃₁ ′(z)<0, and the guided radio line The distance z from the terminal to the mobile antenna is z=(P/2π) tan ^-1 {(√32)(V ₂₃ ′(z)
− V ₃₁ ′(z))}/{V ₁₂ ′(z)−(1/2)
(V ₂₃ ′(z) +V ₃₁ ′(z))} A moving object position detection system characterized by periodically and continuously detecting the position of a moving object with a constant period P by calculating based on method.