JPS6031618A - Method for detecting position of moving body - Google Patents

Abstract

PURPOSE:To detect the position of a moving body continuously at a period P by laying a folded conductor of the period P and a straight conductor along the travelling course of the moving body, mounting two groups of three antennas on the moving body at an interval of P/3 and using inductive radio. CONSTITUTION:An inductive radio line 22 consisting of the folded conductor of the period P and the straight conductor 21 is laid along the travelling course of the moving body and high frequency current is supplied from a transmitter 24 to both the conductors. The three antennas 23-1a-23-3a having the interval of P/3 and the three antennas 23-1b-23-3b having the interval of P/3 and separated from the former antennas by 3P/2 are mounted on the moving body. Induced voltages of respective antennas are straight detected 27-1a-27-3a, 27-1b-27-3b to obtain envelope voltages, the differences between antennas separated by 2P/3 respectively are found out by subtractors 28-1-28-3 and a carrier from an oscillator 31 is modulated by modulators 29-1-29-3 on the basis of the outputs of the subtractors 28-1-28-3. Signals obtained by phase-shifting the outputs of the modulators 29-2, 29-3 by -120 deg., 120 deg. are added to the output of the modulator 29-1 by an adder 32 and the phase difference between the added output and a reference phase signal from the oscillator 31 is indicated by a phase shifter 33 to detect the position of the moving body.

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. , correspondingly the frequency and amplitude of the field current,
Rational adjustment of the phase is considered to be an essential requirement for smooth operation of this vehicle.

Currently, a method using guided radio is considered to be a promising means to meet this demand.

This method includes a method in which the voltage induced in the guided radio line by the excitation of the antenna mounted on the mobile object is processed on the ground, and the position of the mobile object is directly detected from this (ground detection);
A method in which the voltage supplied to the guided radio line is received by an antenna mounted on a mobile object, the signal is processed on the mobile object, the C position is detected, this is encoded, and it is transmitted wirelessly to a ground base station (on-vehicle detection). There is.

Although the ground detection method has the advantage that control signals can be obtained directly on the ground, it has the disadvantage that measurement errors occur when the amount of crosstalk in the guided radio line is large. In addition, while crosstalk in the guided radio line is not a problem in the car-detection method,
It is necessary to encode location information and transmit it wirelessly.
Both methods have the disadvantage of complicating the system, and it is difficult to compare them with each other.

A position detection method currently proposed as a detection method for vehicles will be explained with reference to FIGS. 1 and 2.

In FIG. 1, 1 and 2 are conductors, 3 is an inductive radio line formed by the conductors 1 and 2, and 4-1 and 4-2 are mobile antennas.

The conductors 1 and 2 are bent into a waveform shape with a period P on a plane, and are arranged offset from each other by P/3. Also,
Frame-shaped loop coils are used as the antennas 4-1 and 4-2, and are fixed on the moving body with a mutual offset of P/4.

When a high frequency current of 50 to 200 K11z 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.

By appropriately selecting the distance between the line 3 and the antennas 4-1 and 4-2 and the dimensions of the antennas 4-1 and 4-2, the amplitude of the voltage induced in each anti-nato I and 4-2 can be reduced to 2( (distance from the terminal of the line 3 to the antenna 4-1) can be made sinusoidal.

If the voltages induced in antennas 4-1 and 4-2 are V I (z) and V2 (z), respectively, V I (Z
): k CO527[Z/PV 2(Z): l(C
082π(2+P/4)/P= I< cos ((2
x z/P) + π/2)・・・・・(1) I(: Constant.

It can be expressed as

Here, the positive sequence voltage V p (z) and the negative sequence voltage V n (z
) is defined by the following formula.

...(2) The following equation is immediately obtained from equation (+) and equation (2).

...(3) If the phase difference between V p(z) and V n(z) is φ(2), then Φ(z) = z v p(z) −1V n(z
)=4πz/P ・◆・・(4) (/: symbol meaning declination angle).

In other words, as shown in Part 2, φ(2) linearly increases by 2π every time 2 increases by P/2, and φ(2) increases linearly by 2π every time 2 increases by P/2.
z), it is possible to continuously measure the position of the moving object at a period of P/2.

Therefore, when applying this to the position detection of a linear motor car, the desired purpose can be achieved by setting P to twice the distance between the motor poles and laying the track at a position synchronized with the motor poles. I can do it.

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 circumference 111P 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 2, as shown in equation (1), and therefore the length I of the antenna 5 is P/7~P15 (1.7~2.4 if P=12m
m) becomes extremely large. 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 having a large cutout is not desirable from the viewpoint of the mechanical strength of the car body.

The present inventor devised a position detection method using three antennas in order to solve the problems mentioned in section 2. This method will be explained with reference to FIG. 3.

In FIG. 3, 11 and 12 are conductors, respectively,
The conductor 11 is bent into a wavy shape with a circumference P, and the conductor 12 is arranged in a straight line in parallel with the conductor 11, so that the conductor 12 can be guided with ease. ((The line path 13 is formed.14
-1. +4-2, 14-3 are antennas mounted on the mobile body, and each antenna is fixed to the mobile body at an interval of P/3.

When a high frequency current of 50 to 200 KH2 is supplied from the ground transmitter 15 to the line 13, an induced magnetic field is formed around the antenna 14-L 14-2. A voltage is induced in u-:k.

Assuming that the distance from the terminal of the line 13 to the antenna 14-1 is 2, the voltage induced in each of these antennas Vl(z)
, V2(z), and V3(z) are expressed as follows.

Vl(z) = kl H+2 cos2πz/P)
V2(z)=R+ (1+ to 2 CO527[(2+
P/3)/l'')V 3(z)=k l (1+k
2 C0827 [(z+2P/3)/P)...(
5) kl, k2: constants.

Since Q<l (2<1), the right side of equation (5) is always positive.

Therefore, Vl(2), V2(Z), V3(2)
Linear detection of the envelope I Vl(2)l , l V
Subtracting 2(2)I, I V3(2)1, we get t as shown in the following formula.
This will happen.

l V 1(z) l : V I(z)l V 2(
z) l = V 2 (z) l V 3 (z) l =
, V 3 (z) ・ ・ ・ ・ (6) Here, the new carrier wave of angular frequency ω0 is modulated with each voltage in equation (6), and each becomes VLI ' (z), Vv
'(z), Vw' (z), the following equation is obtained.

= k l(1+k 2 cos2πz/P)j(lJ
oL ・e = k I[I0k 2 cos2π(z0P/3)/
P CoJ ωOL number e = l< l[I+k 2 cos2π(z-P/3)
/P]J et al+ot e (7) Here, the positive phase voltage Vp' (z) and the negative phase voltage Vn' (z) are defined by the following equations.

・　・　・・(8) The following equation is immediately obtained from equations (7) and (8).

Vp' (z) = (3/2) kl ・1(2(+
2 yt z/P)+j ωot number e Vn' (z)=(3/2)kl ・k2−(J2
πz/P) + jωot e ・ ・ ・ ・ (9) Determine Φ′ (2) in the following equation by comparing Vp ′ (z) or Vn ′ (z) with the reference phase signal derived from the carrier wave power source. I can do it.

= −(/Vn' (zn-le)=2πz/
P .

Note that the right-hand side of each equation (5) actually contains some spatial harmonic components, but by using three antennas, the 3rd, 9th, 15th, etc.: integral multiples of 3 harmonic components are included. The harmonic components are eliminated during the signal processing of equation (8), which has the advantage of improving position detection accuracy compared to the method using two antennas shown in FIG.

Although the above method can be applied to detecting the position of various moving bodies, it 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 the propulsion system of a linear motor car, and includes a rectangular loop coil 11.

V and W form motor poles. loop coil U,
When a positive-phase or negative-phase current of about 0 to 30 tlz is passed through V and W to form a traveling wave magnetic field, this acts on the electromagnet on the vehicle to generate thrust. Each of the loop coils U, V, and W forming this propulsion coil has a periodic structure of P with a shift of P/3, so one of these is used in correspondence with the conductor 11 in Fig. 3. Is possible.

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

FIG. 5 shows an example of the case where the propulsion coil of a linear motor car is used as the guided radio line of the above-mentioned position detection method.

15 is a transmitter, 16 is a transformer, 17, 18, and 19 are connecting conductors for each loop coil t+, v, and w, and 12 is a linear conductor. By connecting each conductor I7, 18, and 19 as shown in the figure, an inductive radio line with loop coil [1 as an outgoing path and straight conductor 12 as a return path can be formed. Detection can be performed.

However, according to the inventor's study, the voltage induced in the antenna (for example, Vl(z)) reaches its maximum value every time the antenna passes directly over the loop coil in summer, as shown in Figure 8. It was confirmed that the shape was close to a half-sine wave in the vicinity, but it became a flat shape above the loop coils V and W, and that this range was quite wide.

In other words, such a waveform has severe vertical asymmetry;
Therefore, if expanded into a Fourier series, large even-order harmonic components will be included, leading to position detection errors.

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

[Purpose of the Invention] The present invention makes it possible to make the position detection period of a moving body equal to the conductor period P of the guided wireless line, and when this is applied to the automatic operation of a linear motor car, the conductor period P can be made equal to the conductor period P of the motor pole. In addition, the on-board antenna can be made smaller, and the production of the guided wireless line can be made easier. Furthermore, even if the waveform shape of the guided wireless line is rectangular or close to this, position detection errors can be reduced. The purpose of this invention is to provide a position detection method that does not cause problems.

[Summary of the Invention] The main point of the present invention is that a guided radio line consisting of a conductor bent into a waveform with a period P and a straight conductor parallel to the conductor is laid along the travel path of a moving object. On the other hand, two sets of antenna element rows each consisting of three antenna elements arranged at an interval of P/30 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. The respective voltages induced in each of the above antenna elements when energized (the induced voltages of each element in one antenna element row are Via(z) + V2a(z), V3a(z), respectively, and the voltages induced in the antenna elements in the other antenna element row are Let the induced voltage of each element be Vlb(z), V2b(z), V3b(z
) is linearly detected and its envelope (envelopes corresponding to each of the above voltages are l, Via(z) l , I
V2a(z) l,l V3a(2) I, 1VIb
(2) 1. IV2b(z) l, 1V3b(2)1
), Vie(z) = I Vla(z) l −I Vl
b(2) IV2e(z) = l V2a(z) l
-1'V2b(z) IV3e(z) = l V3
Vie(z) obtained by a(z) I −, I V3b(z) 1, V2e(z), V,3e(z
), the positive phase or negative phase components of the three voltages obtained by amplitude modulating the carrier wave with the same amplitude and same phase derived from the new carrier wave power source, and the reference phase derived from the new single wave transmitting power source mentioned above. The purpose of this method is to continuously detect the position of a moving object in cycles by comparing the phase of the signal with the above-mentioned positive phase or negative phase component.

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

In FIG. 6, 20 and 21 are conductors, respectively,
The conductor 20 is bent into a waveform shape so as to have a rectangular portion with a length of P/3 with a period P'', and the conductor 21 is arranged in a straight line in parallel with the conductor 20, thereby forming an inductive radio line 22. has been done.

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

50 to 200 KI+2 from ground transmitter 24 to track 22
When a high frequency current is supplied, an induced magnetic field is formed around the antenna element, and a voltage is induced in each antenna element.

The voltages induced in the antenna elements 23-1a, 23-2a, and 23-3a are expressed as V 1a(z) and V 2a(
z), V 3a(z), and the antenna element 23-1b
, 23-2b, and 23-3b as V Ib(z), V 2b(z), and V 3b(z), respectively.
shall be.

Linearly detect each voltage, find its envelope (absolute value of each voltage), and calculate V 1e (2) + V 2e (
z), leading to V 3e(z).

Vie(z) = I Via(z) l −I Vl
b(2) IV2e(z) = I V2a(2) I
−IV2b(z), IV3e(z), = l
V3a(z) I-I V3b(2) 1・ ・ ・
・(11) Antenna elements 23-1a and 23-1b, 23-2a
The intervals between and 23-2b, 23-3a and 23-3b are each an odd multiple of P/2, and looking at each term on the right side of equation (11), the even-order spatial harmonic component is Since the in-phase, fundamental wave, and odd-order spatial harmonic components have opposite phases, all the even-order spatial harmonic components cancel each other out and disappear.

Therefore, the right side of equation (11) becomes an almost perfect sine wave, so V 1e(z), V 2e(z), V 3e(z)
can be expressed as the following equations similarly to equation (5).

Vle(z) =kl H+2 cos2πz/P
”jV2e(z) = k l (2 cos2 to I+
i(z+P/3)/I')V3e(z) = k I
(]+2 cos2i (z+2P/3)/P)・
...(12) Here, Vu'' (z), Vv'' (z),
Vw'' (z) is defined by the following equation.

V ν ” (z) = v 2e (z) e■・Responsibility・
)=V3・(・)Pa°°1 ・ ・ ・ ・ (13) These voltages transform the carrier wave of angular frequency ω0 derived from the new carrier power source into V te (z) and V 2e, respectively.
(z), V 3e (z).

Next, the positive sequence voltage Vp'' (z) and the negative sequence voltage vn'' (2
) is defined by the following formula.

−j2π/3 V p ” (z) = V Ie(z) + e V
2e(z)...(14) (12) The following equation is immediately obtained from equations 2 to (14).

Vp ” (z) = 31° 1 to 2 (j2i z/P)
+j°o t.

−(J2πz/P)+jωot Vn ” (z) =3 kl k2 e・ ・ ・
-(15) By comparing the phase of vp''(2) or Vn''(z) with the reference phase signal derived from the carrier wave power source, Φ''(z) in the following equation can be determined.

=27Lz/P (16) In other words, through the measurement of Φ”(z), the moving body position 2 can be changed to P.
It can be changed continuously with a period of .

As mentioned above, the present invention is applicable to the automatic operation of a linear motor car and to the detection of the position of various moving objects. However, in the automatic operation of a linear motor car, the propulsion coil can be used as shown in Fig. 5. Of course.

[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 body, in which 25-1a, 25-2a, 25-3a
, 25-Ib, 25-2b, 35-3b are buffer amplifiers,
26-1a, 26-2a, 26-3a, 26-1b, 2
6-2b, 26-3b are band pass filters, 27-1a,
27-2a, 27-3a, 27-1b, 27-2b, 2
7-3b is a detector, 28-1, 28-2, 28-3
is a subtracter, 29-1, 29-2, 29-3 are modulators, 30-2, 30-3 is a phase shifter, 31 is a carrier wave power source, 3
2 is an adder, and 33 is a phase meter.

When a high frequency current is supplied by the transmitter 24 provided at the terminal of the guided radio line 22 using the conductor 20 as the outgoing path and the conductor 2I as the return path, the antenna elements 23-1a, 23-2a, 2
Voltages are induced in 3-3a, 23-1b, 23-2b, and 23-3b.

Each antenna element 23-1a, 23-2a, 23-3a,
23-1b, 2372b.

The voltage induced in 23-3b is applied to the buffer amplifier 2, respectively.
5-1a, 25-2a, 25-3a, 25-1b, 25
-2b, 25-3b into an unbalanced voltage, and bandpass filters 26-1a, 26-2a, 26-3a, 26
-1b, 26-2b, 26-3b remove noise components, and detectors 27-1a, 27-2a, 27-3a, 2
7-1b, 27-2b.

Linear detection is performed by 27-3b.

Next, in the subtracter 28-1, the detectors 27-1a and 27-
1b is detected by the detector 27 in the subtracter 28-2.
The difference between the outputs of the detectors 27-3a and 27-311 is determined by the subtracter 2-3.

That is, in the subtracters 28-1.28-2.28-3, an operation corresponding to equation (11) is performed.

The outputs of the subtracters 28-1.28-2.28-3 are the amplitudes of the carrier waves of angular frequency ω0 guided by the modulators 29-1.29-2.29-3, 2W, tL, and 31, respectively. Modulate.

The effects of the modulators 29-1, 29-2, and 29-3 are (1
2) Corresponds to the calculation of Eq.

Next, the output of the modulator 29-1.29-2.29-3 is guided to the adder 32, but the output of the modulator 29-1 is guided to the direct 1a adder 32, whereas the output of the modulator 29- 2.29-
The outputs of 3 receive phase shifts of -1206 and 1206 in phase shifters 30-2 and 30-3, respectively, and are then led to adder 32.

The action of the adder 32 corresponds to the operation of the first equation for calculating Vp″(z) in equation (14).

The output of the adder 32 is guided to the phase meter 33 together with the reference phase signal derived from the carrier wave power supply 31, and the phase difference between the two is indicated.
It can be measured continuously every time. The phase meter 33 performs an operation corresponding to equation (15).

Although the description 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, and the present invention is not limited to this. It is widely applicable to body position detection.

[Effects of the Invention] As described above, according to the present invention, the detection cycle of the moving body position can be made equal to the circumference fillP 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. For this reason,
It becomes easier to manufacture the line, and the price of the line can be reduced. Additionally, if the period of the conductor is shortened, the dimensions of the mobile tower-mounted antenna can be reduced in proportion to this, making it easier to attach the antenna to the vehicle body, and eliminating the need to provide a large cutout in the vehicle body. This eliminates concerns about the strength of the vehicle body.

Furthermore, the present invention is intended to reduce the difference in voltages induced in antenna element rows arranged at an interval of an odd multiple of P/2. However, harmonic components can be removed and position detection errors can be eliminated.

When the present invention is applied to detecting the position of a linear motor car, the two propulsion coils can be used for multiple purposes as a guided radio line for position detection, greatly contributing to the economicalization of the system configuration. I can do it.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the conventional method, 2nd PjJ is moving body position 2
Fig. 3 is an explanatory diagram of the position detection method using an inductive radio line similar to the present invention and three antennas, and Fig. 4 is an explanatory diagram of the relationship between Schematic explanatory diagram, Figure 5 is the location of the linear motor car.
A schematic explanatory diagram when the propulsion coil 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 an explanatory diagram of one embodiment of the signal processing device used in the present invention. The explanatory diagram, FIG. 8, is an explanatory diagram of the waveform of the voltage induced between the conductors. 20: Waveform conductor, 21: Straight conductor, 22: Guided radio line, 23-a, 23-b: Antenna element array, 24: Ground transmitter, 25-1a, 25-2a, 25-3a, 25
-1b, 25-2b, 25-3b: Buffer amplifier, 26
-1a, 26-2a, 26-3a, 26-1b, 26-
2b, 26-3b: band pass filter, 27-1a, 27
-2a, 27-3a, 27-1b. 27-2b, 27-3b: Detector, 28-1.28-
2.28-3: Subtractor, 29-1, 29-2, 29
-3: Modulator, 30-2.30-3: Phase shifter, 31:
1 general transmission power supply, 32: adder, 33: phase shifter.

Claims (1)

[Claims] (1) Along the travel path of a moving object, a guided radio line consisting of a conductor bent into a waveform with a period P and a straight conductor parallel to this conductor is laid. Two antenna element rows consisting of three antenna elements arranged at an interval of /3 are mounted on the tower at an interval of an odd multiple of P/2, and when a high frequency current is passed through the guided radio line, each of the above antennas The respective voltages induced in the elements (the induced voltages of each element in one antenna element row are respectively Vla(
z). V2a(z) and V3a(z), and the induced voltages of each element in the other antenna element row are Vlb(z) and Vlb(z), respectively.
, V2b(z), V3b(2)) and their envelopes (envelopes corresponding to each of the above voltages are 1VIa(2)l, 1V2a(2)l, 1V3a, respectively)
(z)l,1VIb(2)l,lV2b(z)
l , l V3b(z)l), Vle(z) = l Vla(z) I −I Vl
b(z) 1V2e(z) = I V2a(z) I
-I V2b(2) IV3e(z) = l V3
a(z) l -I V3b(2) Amplitude modulates the carrier waves of the same amplitude and phase derived from the new carrier wave power source by Vle(z), 'V2e(z), and V3e(z) obtained by 1. The position of the moving object is determined by the period P by comparing the phase of the reference phase signal derived from the new carrier power source and the positive phase or negative phase component of the obtained three voltages. A moving object position detection method that is characterized by continuous detection.