JPS6031616A - Method for detecting position of moving body - Google Patents

Abstract

PURPOSE:To measure the position of a moving body continuously by small-sized antennas at every period P by laying a conductor folded at the period P and a straight conductor along the travelling course of the moving body and mounting three antennas on the moving body at an interval P/3. CONSTITUTION:An inductive radio line 13 consisting of the conductor 11 folded like a wave at the period P and the straight conductor 12 arranged in parallel with the conductor 11 is laid along the travelling course of the moving body and three antennas 14-1-14-3 are mounted on the moving body at the interval P/3. When high frequency current is supplied from a transmitter 15 to the conductors 11, 12, voltage induced to the antennas 14-1-14-3 are respectively amplified 20-1-20-3, detected straight by detectors 22-1-22-3 through BPFs 21-1-21-3 and guided into modulators 23-1-23-3. The modulators 23-1-23-3 modulate carrier from a carrier power supply 25 at its amplitude and outputs from respective modulators 23-1-23-3 are guided to an adder 26 directly and after phase-deflected through phase units 24-2, 24-3 by -120 deg., 120 deg.. The phase difference between the added output and a reference phase signal from a power supply 25 is indicated 27 and the position Z of the moving body is continuously measured at every period P.

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. , the frequency, 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 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 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 a conductor], an inductive radio line formed from 2Z, 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,
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 Ktlz is supplied from the ground transmitter a15 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 antenna 4-1 and 4-2 can be controlled. 2 (distance from the terminal of track 3 to Antinato l)
can be sinusoidal.

If the voltages induced in the antinatos 1 and 4-2 are Vl(z) and V2(z), respectively, then V I(z
) = k cos2712/PV 2(z) = k
CO327[(2+P/4)/P=l<cos ((2
*z/P)+π/2)...(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 V p (z) and V n (z) is Φ (2), then Φ (2) = l V p (z) - l V n (
z)=4πz/P (4) (z: symbol meaning declination angle).

In other words, as shown in Figure 2, φ(2) shows a linear increase of 2π when 2 increases by P/2, and φ(2)
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 1,20 period P of each conductor 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 is about 12
It will have to be 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 L of the antenna 5 is P
/7~P15 (1.7~2.4m if P=12Il
) becomes extremely large. When installing antennas on the 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.

[Object of the invention] The present invention can make the position detection period of a moving body equal to the conductor circumference P of the track, and when this is applied to the automatic operation of a linear motor car, the conductor period P can be made equal to the distance between motor poles. The object of the present invention is to provide a moving body position detection system that can achieve the same characteristics as the above, miniaturize the on-board antenna, and facilitate the manufacture of railway tracks.

[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. , - Three antennas are mounted on the blade movable body at intervals of P/3, and when a high frequency current is passed through the inductive radio line, the respective voltages induced in each of the above antennas are linearly detected and detected. The same amplitude derived from the new carrier wave power source, including the envelope,
Taking the positive phase or negative phase components of the three voltages obtained by modulating the carrier wave of the same phase with each of the above envelopes, calculate the phase of the reference phase signal derived from the carrier wave power source and the positive phase or negative phase component. The purpose is to continuously detect the position of a moving body at a period P by comparing the positions.

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

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.
14-2 and 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 to 200 K11z from ground transmitter 15 to track 13
When a high frequency current of 14-1.14-2.14-3 is supplied, an induced magnetic field is formed around the antenna 14-1.14-2.14-3, and a voltage is induced in the antenna 14-1.14-2.14-3.

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

Vl (z) = kl (2 cos2πz/P to l+
)V2(z)=k 1 (]+2 C0827[(
2+P/3)/P)V 3(z)=k1(1+
k 2 cos2yc (z+2P/3)/P)...
・(5) R1, K2: constants.

Since 0<K2<l, the right side of equation (5) is always positive.

Therefore, V I(z), V 2(z), V 3
(z) is linearly detected and its envelope I V 1(z) I
,, I V2(z) I , l V3(2) Subtracting 1 gives the following equation.

l V 1 (z) I = V 1 (z) + 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 by each voltage in equation (6), and the voltages are respectively Vu' (z) and Vv'
(z) and Vw' (z), the following equation is obtained.

= R+(++k 2 cos2π2/P) JωO1 ・ e Jω01 Vv' (z) = l V2(z) l e= k
l[l+k 2 cos2w (z+r'/3)/P
koJ ωOt @ e = k I[l+k 2 cos2π(z-P/3)/
P]jωOt·e······(7) Here, the positive sequence voltage Vp' (z) and the negative sequence voltage Vn' (z) are defined by the following equations.

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

v'p' (z) = (3/2) kl ・K2(j
2πz/P)+jωot ・e Vn' (z) = (3/2) lc I -k2-
(J2πz/P) + jωO1 φ e ・ ・ ・ ・ (9) By comparing Vp ′ (z) or Vn ′ (z) with the reference phase signal derived from the carrier wave power source, the following equation φ′(2) can be obtained. I can travel and do things.

=2πz/P...(lO) In other words, through the measurement of φ'(2), the moving body position 2 can be changed to P
It can be known continuously in the period of .

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 in equation 8), which has the advantage of improving position detection accuracy compared to the method using two antennas shown in FIG.

The present invention is applicable to detecting the position of various types of moving objects, and can be particularly suitably applied to automatic and dynamic 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 U.

V and W form motor poles. loop coil U,
When a positive or negative phase current of about 0 to 30112 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 above, and if the loop coil can be used as part of the inductive wireless line in the present invention, The benefits are great.

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

15 is a transmitter, 16 is a transformer, 17, 18, 19 are connecting conductors for each loop coil IJ, V, W, and 12 is a linear conductor. By connecting the conductors 17, 18, and 19 as shown in the figure, an inductive wireless line can be formed with the loop coil +1 as the outward path and the straight conductor 12 as the return path, and the position can be detected using the same method as explained in Fig. 3. It can be performed.

[Embodiment of the Invention] An embodiment of the present invention will be described based on FIGS. 3 and 6.

FIG. 6 shows an example of the configuration of a signal processing device mounted on a mobile object, where 20-1.20-2.20-3 is a buffer amplifier, 21-1.21-2.21-3 is a buffer amplifier, and 21-1.21-2.21-3 is a buffer amplifier. is a bandpass filter, 22-1.

22-2, 22-3 are detectors, 23-1.23-2.
23-3 is a modulator, 24-2.24-3 is a phase shifter, 25
2Ei is a carrier wave power supply, 2Ei is an adder, and 27 is a phase meter.

When a high frequency current is supplied by the transmitter 15 provided at the terminal of the guided radio line 13 using the conductor 11 as an outgoing path and the conductor 12 as a return path, mobile object mounted antennas 14-1, 14-2.
A voltage is induced at 14-3.

The voltage induced in each antenna is converted into an unbalanced voltage by the buffer amplifiers 20-1' 20-2, 20-3, and the noise component is removed by the bandpass filter 21-1.21-2.21-3. is removed, then the detector 22-1.22-
2. After linear detection by 22-3, the modulator 23-
1.23-2.23-3, and here, the carrier wave of angular frequency ω0 guided from the carrier wave power source 25 is amplitude-modulated.

The operation in each modulator 23-1, 23-2, and 23-3 corresponds to the calculation on the right side of equation (7).

The outputs of the modulators 23.1, 23-2, and 23-3 are guided to the adder 26, but the output of the modulator 23-1 is directly guided to the adder 26, whereas the output of the modulator 23-2.23 is guided directly to the adder 26. -3
The outputs of -
After receiving the phase shift of 1206 and 120@, adder 2
6. The action of the adder 26 corresponds to the calculation of the first equation of equation (8), and its output is Vp' (2) of equation (9).
becomes.

The output of the adder 26 is guided to the phase meter 27 together with the reference phase signal derived from the carrier wave power supply 25, the phase difference between the two is indicated, and the position 2 of the moving body can be continuously measured with a period P through this value. I can do it. The phase meter 27 performs an operation corresponding to equation (10).

Although the explanation has been given using a linear motor car as an example of application of the present invention, it is not limited to this, but railway vehicles, various new transportation systems, cranes, and transportation vehicles that move along a constant running path. 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. 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.

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 moving body position 2 and phase difference, Fig. 3 is an explanatory diagram of the principle and one embodiment of the present invention, and Fig. 4 is an explanatory diagram of the linear motor. A schematic explanatory diagram of the ground propulsion coil of a car, FIG. 5 is a schematic explanatory diagram of the case where the ground propulsion coil of a linear motor car is used as the guided radio line of the present invention, and FIG. 6 is a signal processing device used in the present invention. FIG. 2 is an explanatory diagram of one embodiment of the invention. 11: bent conductor, 12: straight conductor, 13: guided radio line, +4-1.14-2.14-3: mobile tower-mounted antenna, 20-1.20-2.20-3: buffer amplifier,
21-1.21-2.2l-3 = bandpass filter, 22
-], 22-2.22-3: Detector, 23-1.23
-2.23-3: Modulator, 24-2.24-3: Phase shifter, 25: Carrier wave power supply, 26: Adder, 27: Phase shifter.

Claims (1)

[Claims] (1) Along the travel path of the 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. Three antennas are mounted on the tower at intervals of P, /30, and when a high-frequency current is passed through the guided radio line, the voltages induced in each antenna are linearly detected, their envelopes are found, and a new The positive phase or negative phase components of the three voltages obtained by modulating the carrier wave of the same amplitude and the same phase derived from the carrier wave power source by the above-mentioned respective envelopes are used to determine the reference phase signal derived from the carrier wave power source and the above positive phase component. Alternatively, a moving body position detection method is characterized in that the position of the moving body is continuously detected at a period P by comparing the phase with an antiphase component.