JPS6031619A - Method for detecting position of moving body - Google Patents

Abstract

PURPOSE:To obtain a moving body detecting method prevented from a detection error by receiving radio waves from a folded conductor of a period P and a straight conductor by antennas of a moving body which are arranged at prescribed intervals and digitizing the received voltages. CONSTITUTION:An inductive radio line 22 consisting of the folded conductor 20 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 antennas 23-1a-23-3a having the interval of P/3 and the antennas 23-1b-23-3b having the interval of P/3 and separated from the former antennas by the odd multiple of P/2 are mounted on the moving body. Radio waves from the line 22 are received by respective antennas 23-1, 23-b, the received voltages are straight detected respectively by detectors 27-1a- 27-3a, 27-1b-27-3b, their envelope voltages V1a(Z)-V3a(Z), V1b(z)-V3b(z) are A/D converted, and their digital signals are inputted to a computer 29. The computer 29 calculates the formula (A) from the input signals, calculates the position Z of the moving body from the calculated result on the basis of the formula (B) and displays the position Z on a digital display device 30.

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 the antenna mounted on the mobile object, the signal is processed on the mobile object to detect the position, and this is encoded and transmitted wirelessly to the 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 may occur if there are large crosstalk stars in the guided radio line. In addition, while the on-vehicle detection method does not have any problem with crosstalk in the guided radio line, it has the disadvantage of complicating the system as it requires encoding position information and transmitting it wirelessly, so both methods have their advantages and disadvantages. hard.

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

In FIG. 1, 1 and 2 are conductors, 3 is an inductive radio line formed by the conductor 1.2, and 4-1 and 4-2 are antennas mounted on a mobile object.

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

When a high frequency current of 50 to 200 KHz is supplied to the line 3 from the ground transmission [5], 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 antenna 4-1 and 4-2 can be adjusted. 2 (the distance from the terminal of the line 3 to the antenna 4-1) can be made sinusoidal.

The voltages induced in antennas 4-1 and 4-2 are expressed by Vl(z) and V2(2) toss levers, V1(z), respectively.
== k cos2yr z/PV 2(z) :=
k cos2 yr (z+P/4>/P:=l<co
s ((2πz/P)+yt72”r...(1) 1(: 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 equations (1) and (2).

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

In other words, as shown in Figure 2, Φ(2) linearly increases by 2π every time 2 increases by P/2, and φ(
Through the measurement of 2), 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, 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 approximately 6 m.
Therefore, the conductor period P is approximately 1
It will have to be 2m.

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 (+). Therefore, the length I of the antenna 5 is P/7~P15 (1.7~2.
4rn), which is 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 the large size of this cutout is undesirable from the viewpoint of the mechanical strength of the car body.

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 FIG. 3, 11 and 12 are conductors, respectively,
The conductor 11 is bent into a waveform shape with a period P, and the conductor 12 is arranged linearly in parallel with the conductor 11, thereby forming the guided radio line 13. 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.

50-200 Ktlz from ground transmitter 15 to track 13
When a high frequency current is supplied, an induced magnetic field is formed around the antenna, and a voltage is induced in the antenna +4-1.14-2.14-3.

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)
, V 2 (z), and V 3 (z) are expressed as shown below.

Vl(z)=kl (I to 2 cos2πz/P)
V2(Z)=kl (++2 cos2π(z+P
/3)/P)V 3(z)=k 1 (1+k 2
cos2i (z+2P/3)/P)...(5) kl, 2: Constant.

Since 0<k2<l, the right side of equation (5) is always positive.

Therefore, Vl(z), V2(z), V3(z)
is linearly detected and its envelope I Vl(z)l , l V
Subtracting 2(2)I, lV3(2)1 gives the following equation.

l V I(2) l = V 1(z)l V 2(
z) l = V 2 (z) + V 3 (2) I =
V 3 (Z) ・ ・ ・ ・ (6) Here, the new carrier wave of angular frequency ω0 is modulated with each voltage in equation (6), and they are respectively Vu ′ (z) and Vv ′
(z) and Vw' (z), the following equation is obtained.

= k + (++ k 2 cos2 nz/P)
jωO1 壽 e = k l[++k 2 C0827I (z+P/3
)/P JωOt ◆ e = k I[I0k 2 C0827[(z-P/3)
/P]JωO1·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' (2) = (3/2) kl - k2 (j2
πz/P)+jωot ・e Vn' (z) = (3/2)
2πz/P)+jωot・e...(9) Find 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. be able to.

JωOt = −(lVn' (z) −1e )=2πz/P
Through the measurement of . . . (lO), that is, Φ' (2), the moving body position 2 can be continuously known at 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 3, such as the 3rd, 9th, and 15th orders, are The wave component is (
This will disappear during the signal processing of equation 8), which has the advantage of improving position detection accuracy compared to the method using two antennas in FIG.

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

The following equation is obtained from equations (8) 2 to (11).

1 Φ' (z) = t, an [(v'3/2) (-I
V2(z) l + l V3(z)I ) / (
l Vl(2)I −(+/2)(I V2(z) l
+, l V3(z) l ) ) ]...(11
) or 1 z = (P/2π) jan [(v'3/2) (-
1V2(z)l + l V3(z)l ) / (l
Vl(z)l −(+/2XI V2(z)1+ I
V3(zN))] ・ ・ ・ ・(12) That is, l Vl(Z)l , l V2(2)I ,
The moving body position 2 can be found by converting lV3(z)l into digital data using an A/D converter and then digitally processing the calculation of equation (12).

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.

Figure 4 shows an outline of the propulsion coil of a linear motor car, and is a rectangular loop coil II.

V and W form motor poles. loop coil U,
When a positive or negative phase current of about 0 to 3011z 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 field 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. It's 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, +7, 18, 19 is a connection conductor for each loop coil u, v, w, and 12 is a linear conductor. By connecting each conductor +7, 18, and 19 as shown in the figure, it is possible to form an inductive radio line with the loop coil 1 as the outward path and the straight conductor 12 as the return path. Detection can be performed.

However, according to the inventor's study, the voltage induced in the antenna (for example, V ](z) takes a maximum value every time the antenna passes directly above the loop coil 1), as shown in FIG. 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.

[Object 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, the position detection error 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 to
An inductive radio line consisting of a conductor bent into a waveform at P and a straight conductor parallel to this conductor is laid, while a moving object has three antenna elements arranged at intervals of P/3. 2411 antenna element arrays are mounted at intervals of an odd multiple of P/2, and when a high frequency current is passed through the inductive radio line, the respective voltages induced in each antenna element (one antenna element array The induced voltage of each element is Vla(z) + V2a(z) + V
3a(z), and the induced voltages of each element in the other antenna element row are Vllll(2) and V2+1(2
), V3b(z)) are linearly detected and their envelopes (envelopes corresponding to each of the above voltages are respectively l Via
(z) l, I V2a(z) I, I V3a(
2) l, 1VIb(z) 1. 1V2b(2) I
, 1V3b(z)1), convert these voltages into digital quantities and get Vle(z) = l Via(z) l -I V,
1b(2) IV2e(z) = IV2a(z)
, 1- I V2b(2) IV3e(z) = l
V3a(z) l --I V3b(2) Obtain 1, l Z = (P/2yz)tan [(v'3/2) (-
V2e(z) + V3e(z) ) / (Vl'e
(z) −(1/2) (V2e(z) +V3e(2
) ) ] By performing the calculation, the position 2 of the moving body is determined by the period P
The purpose is to continuously detect the

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 2I is
The guided radio line 22 is formed by being arranged linearly in parallel with the guide line 22.

23-1a, 23-2a, 23-3a, 23-1b, 2
3-2b and 23-3b are antenna elements, respectively, and antenna elements 23-1a, 23-2a, 23-3a
Accordingly, the antenna element row 23-a becomes the antenna element 23-a.
-11], 23-2b, and 23-3b form an antenna element row 23-1], respectively, and an antenna element row 2
3-a and 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 is supplied from the ground transmitter 24 to the line 22, an induced magnetism is formed around the line 22, and a voltage is induced in each antenna element.

The voltages induced in the antenna elements 23''la, 23-2a, and 23-3a are respectively V + a(z) + V 2a
(z) + V 3a(z), antenna element 23-
The voltages induced in Ill, 23-2b, and 23-3b are expressed as V Ib (z), V 2 (z), V 3b, respectively.
(z).

Linearly detect each voltage to find its envelope (absolute value of each voltage), and calculate 'J 1e(z) , V 2 by calculating the following formula.
e(Z), derive v 3e(z).

Vle(z) = l Vla(z) l −l Vl
b(z) 1V2e(z) = l V2a(z) l
-I V2b(2) IV3e(z) = l V3
a(z) l -I V3b(2) 1...(13
) Antenna elements 231a and 23-1b, 23-2a and 23-2b.

The spacing between 23-3a and 23-3b is an odd multiple of P/2, and if we look at each term on the right side of equation (13), the even-order spatial harmonic components are in-phase, fundamental, and Since the odd-order spatial harmonic components have opposite phases, all the even-order spatial harmonic components cancel each other out and disappear.

Therefore, since the right side of equation (13) is almost a perfect sine wave, V Ie(z); V 2e(z), and V 3e(z) can be expressed as the following equations, similar to equation (5). I can do it.

Vie (z) = kl (1+ to 2 C0827I2/
P ) V2e(z) = kl (1+ to 2 cos2
π(z+P/3)/P > V3e(z) = k 1
(1+ to 2 cos27 [(z+2P/3)/P)...
...(14) Here, Vu ″(z) + Vv ″(z),
Vw'' (z) is defined by the following equation.

Jω01 Vu ″(z) = V1e(z) e ″ω01 Vv ″ (2) = V2e(z) e・・・(1
5) These voltages transform the carrier wave of angular frequency ω0 derived from the new carrier wave power source to V 1e(z) and V2e(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 + eV 3e(z) J2π13 Vn ″(2) =: V Ie(z) + e V2
e(z) (16) The following equation is immediately obtained from equations (14) to (16).

(17) By comparing the phase of Vp''(z) or Vn''(z) with the reference phase signal derived from the carrier wave power source, Φ''(z) in the following equation can be determined.

=2πZ/P (18) In other words, through the measurement of Φ” (2), the moving body position 2 can be changed to P
It can be changed continuously with a period of .

Further, the following equation can be derived from equations (16) to (18).

1 Φ″(z) = tan [(v'3/2) (-V2
e(z) +V3e(z) )/(Vie(z) −
(1/2) (V2e(z)+■3e(2))]...
・(19) Or, 1 z = (P/2yr)jan [(73/2) (
−V2e(z) + V3e(z) 't / (Vi
e(z) −(+/2) (V2e(z) +V3e(
2) ) ] ...(2o) That is, I Vla(z) I , l V2a(z)
I, I V3a(2) l, 1V1b(2) l,
1V2b(2) I, 1V3b(2) 1 should be converted into a digital base by an A/D converter. 13) Equation and (20)
The position 2 of the moving object can be detected at the period P by digitally processing the calculation of the equation using a digital computer.

As mentioned above, the present invention can be applied to detecting the position of various types of moving objects, including the automatic operation of linear motor cars, but it goes without saying that propulsion coils can be used as shown in FIG. 5 in automatic operation of linear motor cars. 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 body, 25-1a, 25-2a, 25-3a.
, 25-'Ib, 25-2b, 25-3b are buffer amplifiers, 26-1a, 26-2a, 26-3a, 26-1it
, 26-2b, 26-3b are band pass filters, 27-1
a, 27-2a, 27-3a, 27-1b, 27-2b
, 27-3b is a detector, 28-Ia, 28-2a, 28
-3a, 28-1b, 28-2b, 28-3 are A/D converters, 29 is a digital computer, and 30 is a digital display device.

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 21 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, 23-2b.

The voltage induced in 23-3b is applied to the buffer amplifier 2, respectively.
5-1a, 25-2a, 25-3a, 25-1b, 25
-2h, 25-3h IZ is converted to unbalanced voltage, band pass filter 26-1a, 26-2a, 26-3a
, 26-1b, 26-2b, and 26-3b.
7-3a, 27-11), 27-2b.

Linear detection is performed by 27-3b.

Next, these voltages are applied to A/D converters 28-1a and 2B-
2a.

The signals are converted into digital data at 2B-3a, 28-1b, 28-2b, and 28-3b, and guided to the digital computer 29. In the digital computer 29 (1
The calculations of equations (3), (19), and (20) are digitally processed, the moving body position 2 is determined, and this amount is displayed on the digital display device 30.

The calculations in equation (Ie) or equation (2o) are all four arithmetic operations, and can be processed extremely easily. Additionally, calculations for calculating jan-1 using a computer have already been established, including methods using series and methods based on searching a numerical table.

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 can also be used as a railway vehicle, various new transportation systems, cranes, and general transportation vehicles that move along a fixed running route. It is widely applicable to detecting the position of moving objects.

[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. In other words, the detection period is P/2
Compared to the conventional method, the same detection period can be obtained even if the conductor period is 172. Therefore, manufacturing of the line becomes easy and the cost of the line can be reduced. In addition, 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 it is not necessary to provide a large cutout 8 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 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]

Fig. 1 is an explanatory diagram of the conventional method, Fig. 2 is an explanatory diagram of the relationship between the moving object position 2 and the phase difference, and Fig. 3 is a diagram of the position using the same guided radio line as the present invention and three antennas. An explanatory diagram of the detection method, Fig. 4 is a schematic explanatory diagram of the ground propulsion coil of a linear motor car, Fig. 5 is a schematic explanatory diagram of the case where the ground propulsion coil of a linear motor car is used as a guided radio line, and Fig. 6 is a schematic explanatory diagram of the ground propulsion coil of a linear motor car. Explanatory diagram of the principle and one embodiment of the present invention, No. 7
The figure is an explanatory diagram of one embodiment of the signal processing device used in the present invention, and FIG. 8 is an explanatory diagram of the waveform of voltage induced between conductors. 20: Waveform conductor, 21: Straight conductor, 22: Guided radio line, 23-a, 23-b: Antenna element array, 24: Ground transmitter, 25-1a, 2! r2a, 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, 28-1a, 2B
-2a, 28-3a, 28-1'b, 2B-2b, 28
-3b: A/D converter, 29: Digital computer, 30: Digital display device.

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 sets of antenna element arrays each consisting of three antenna elements arranged at an interval of /3 are mounted 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 Each voltage induced in the element (the induced voltage of each element in one antenna element row is expressed as Via (
z) IV2a(z) and V3a(z), and the induced voltage of each element in the other antenna element row is Vlb(
z), V2b(z), and V3h(Z)) and their envelopes (the envelopes corresponding to each of the above voltages are 1V1a(Z) 1. 1V2a(z) +,
IV3a(z)l, 1. Vlb(Z) l, IV
2+1(Z) l, I V3b(z) l)
, convert these voltages into digital quantities and obtain Vle(
z) = l Via(z) l −I Vlb(z)
IV2e(z) = l V2a(z) l −I
V2b(2) IV3e(z) = IV3a(z)
l -l V31) (2) Obtain 1, 1 z = (P/2π)jan [(v'3/2) (-
V, 2e(z) + V 3e(z) ) / (Vi
e(z) −(+/2) (■2e(z) +V3e(
z) ) ] By performing the calculation, the position 2 of the moving body is changed to the period P
A moving object position detection method that is characterized by continuous detection.