JPS6048763B2 - Mobile object position detection method - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a mobile body position detection method using guided radio, particularly a mobile body position detection method suitable for continuously detecting the position of a linear motor car on the ground side. It is related to the method.

[Background of the invention]

In automatic operation of linear motor cars, the position of the car body within the range of motor poles arranged at regular intervals along the running route is periodically and continuously measured on the ground side, and the field is adjusted accordingly. Rational adjustment of the frequency, amplitude, phase, etc. of current is considered to be an essential requirement for smooth and safe operation of vehicles.

We will explain what has been proposed as a typical technology that meets this demand.

In FIG. 1, reference numeral 4 indicates an inductive radio line laid along the travel path of the moving object, and 5 indicates an antenna (frame-shaped loop coil) mounted on the moving object.

The guided radio line 4 is composed of three conductors 1, 2, and 3. Each conductor 1, 2, and 3 has a shape bent at a period P, and each conductor 1, 2, and 3 is bent at a period P/ They are arranged offset by an interval of 3.

Although the shape of each conductor 1, 2, and 3 is trapezoidal, it may also be a Ξ-angle wave or a rectangular wave. A high frequency current of 50 to 200 KHz is applied to the antenna 5, and the inductive radio line 4 is excited by the magnetic field.

Now, let the distance d from the terminal of the line 4 to the antenna 5 be z, and the adjacent conductors 1-2, 2-3, 3- measured at the line terminal
The voltages between them are V12, V23, and V3l, respectively.
In this case, by appropriately selecting the dimensions and height of the antenna 5, it is possible to make Vl2, V23, and V3l sinusoidal with respect to z. That is, Vl2=K
COs(2π/P)z ι V23=KcOs(2π/P)(z+P/3)=KcO
s((2π/P)z+2π/3)V3l=KCOs(2
π/P)(z+2P/3)=KcOs((2π/P)z
-2π/3)...(1: It can be expressed as follows.

Here, k is a constant.

Now, the positive sequence voltage Vp for Vl2, V23, and V3l
and negative phase voltage Vn are defined as in the following equation.

Vp=Vl2+e −J2π13V23+Ej2π1a
V3lVn=Vl2+Ej゜πI'V23+e−J゜π
I°V3l (2) From equations (1) and (2), the following is obtained: J2πz/P Vp=(312)Ke Vn=(3 no 2)Ke−J2πZIP (3).

The phase difference φ between Vp and Vn is determined as follows: φ=ZVp−ZVn=4πz/P (4).

Z: Symbol meaning declination angle This means that if a signal processing circuit is placed at the terminal of line 4,
) to calculate the phase difference φ=ZVp−ZVn by performing analog calculations corresponding to equation (4), the moving body position z can be continuously known at a period of P/2 as shown in Figure 2. be able to.

Therefore, when applying to automatic operation of a linear motor car, the period P is selected to be twice the interval between the motor poles of the linear motor car, and the motor station is set so that the position where φ = ZVp - ZVn is 0 or 2π coincides. If the line 4 is laid in the area, the field current can be rationally adjusted, and remote and safe operation becomes possible.

FIG. 3 shows a typical example of a signal processing circuit.

Voltages Vl2, V23 between conductors 1-2, 2-3, 3-1,
Parts of V3l are buffer amplifiers 6p, 6p, respectively.

, 6P3 to be converted into an unbalanced voltage, and then to a phase shift circuit 7p. , 7p. 0° and -12 respectively due to the action of
The signals undergo a phase shift of 0° and +120° and are added by an adder 8p. The adder 8p performs an operation to obtain Vp in equation (2), and its output is equal to Vp. Adder 8 in exactly the same way
The output of n will be equal to Vn. Vp and Vn are phase meter 9
The value of Z can be determined by measuring the five phase differences between Vp and Vn. However, the above-mentioned method has the following problems.

When using in an environment with a large noise magnetic field, for example,
As shown in the figure, band-pass filters 10p, 1 for noise removal are provided on the input side of each buffer amplifier 6p, 6p2, 6P3.
It is necessary to insert 0p2 and 10p3 (buffer amplifier 6
n,,6le,6n.

(The same applies to) In this case, in order for this method to work theoretically, 5 must have three filters 10p, 10p2,
It is necessary that the amplitude and phase characteristics of 10p3 be completely equal. Although it is relatively easy to keep the amplitude characteristics equal, the phase characteristics tend to fluctuate under the influence of changes in ambient temperature and aging of the element itself, and it is extremely difficult to keep them always equal. In addition, when operating a linear motor car, it is normal to divide the running route into power supply sections of 1 to 2 krfL, and one discharge station is in charge of the power supply section of 10 to 2 krfL, and the vehicle body position of the linear motor car is detected. is carried out every 5 intervals in each power supply area. FIG. 5 shows the system, and signals are transmitted to the substation 11 via communication lines 12 from the terminals of each guided radio line 4 laid along each power supply section.

Note that 13 is a relay amplifier provided as necessary. With such a system, position detection signals are intensively processed and used as power system control signals.

The use of this centralized management system stems from the need for convenient system maintenance. However, since the transmission characteristics of the communication line 12 vary due to changes in ambient temperature, and the characteristics of the repeater amplifier 13 also change over time, there are many difficulties in accurately transmitting phase and amplitude information regarding the position detection signal. is expected. In this case, it seems that the transmission of amplitude information can be handled relatively easily due to the recent development of M°C technology, but accurate transmission of phase information is difficult because the technology is still undeveloped. [Object of the Invention] The present invention has been made based on the above, and is capable of accurately detecting the position of a moving object based only on its amplitude characteristics, without relying on phase information of voltage induced in a line conductor. The purpose is to provide a method.

[Summary of the invention]

In the position detection method of the present invention, three conductors are bent or spirally formed with a repetition period of P, and each conductor is shifted by P/3 in the longitudinal direction. An inductive radio line is formed in which a sinusoidal voltage is induced between the conductors, and by exciting this inductive radio line with an antenna mounted on a mobile object, the voltages induced between the three conductors are Vl2 and V23. ,V3l
, then the distance z from the guided radio line terminal to the mobile object is ι − , A /UI. It is characterized in that it is measured at a period of P/2 from the relationship: / - -.

Now, if the voltage between each adjacent conductor 1-2, 2-3, and 3-1 in FIG. 1 is linearly detected and its absolute value is determined, the following is obtained.

Finding the square of this value, we get Here, the Vp tree and the Vn tree are defined by the following equations.

From equations (6) and (7), the following equation is obtained.

Let the argument angles of Vp tree and Vn* be ZVp* and ZVn*, respectively.
Then, it becomes. Furthermore, the following equation can be obtained from equation (7).

Here, the real part of the Vp tree and Vn Song are Re) the imaginary part is Im
Then, it becomes.

Also, since -■p*=ZVn*, if φ=-ZVp tree=ZVn tree (12), then the following is obtained.

In other words, knowing the absolute value of the voltage envelope between each adjacent conductor,
By calculating equations (11) and (13), φ can be known, and based on this, the argument angles of the Vp tree and Vn tree can be determined, and the value of z can be set to P/2 by using equation (9). It can be known from the period of

Such calculations can also be processed analogously, but
Digital processing is more accurate.

Especially when the detection range is long, there will be a large level difference in Vl2, V23, and V3l when the moving object is close to the track terminal and when it is far away.
It becomes even larger due to the calculation to obtain IV3112, so
In the case of analog processing, the dynamic range may become excessive and accuracy may decrease. In the case of power conversion and digital methods, this risk does not exist. 'Here, Re
and Im are positive or negative, respectively, and φ
= π/2, the value of Tan-゛ becomes flash, so φ
Although there are multiple calculations to digitally obtain the numerical value of , it can be solved, for example, by the following method.

First, φo is defined by φo =Tan-111m/Rel (14).

If Ilm/Rel<1 (φo<π/4), φ.

The value of can be easily determined by using a series or by searching a numerical table. Ilm/Rel<1, Re>0, I
In the case of m/0, φ=φo, and in the case of Ilm/ReI<1, Re>0, Im<0, φ
=2π−φo.

Next, if 1Im/ReI>1, φo'=Tan-111m/Rel(Re/Im<1)
...(15) φ.

′ is defined. If Re>0, Im>0, φ=(π/2)−φo' If Re>0, Im<O(7), then φ=(3π/2)+φ.

'.

Generally, the value of φ can be determined as follows.

(1)! When Im/Rel≦1, Re>0, Im>O
If φ=φ0 Re>O) If Im<o then φ=2π−φ0Re<0,
If Im>0 then φ=π-φ0Re<O) If Im<0 then φ=π+φo (2) If 1Im/Rel>1 then Re>0, if Im>0 then φ=(π/2) - If Re>0NIm<O then φ=(3π/2)+φo' If Re<0NIm>o then φ=(π/2)+φo' If Re<0, Im<0 then φ=π 1φo' [Embodiment of the invention]? Hereinafter, one embodiment of the present invention will be described with reference to FIG.

In FIG. 6, 14 is a buffer amplifier, 15 is a bandpass filter, 16 is a detection circuit, and 17 is an A-D (analog)
18 is an arithmetic θ processing device.

By passing a high frequency current through the antenna 5, the line 4
The voltage V induced in the adjacent conductors 1-2, 2-3, 3-1
l2, V23, and V3l pass through a buffer amplifier 14, and a bandpass filter 15 removes noise components.

The detection circuit 16 then performs linear detection on each input to obtain (
5) Output signals corresponding to 1V121, 1V231, and 1V3 in the equation. The output from the detection circuit 16 is converted into a digital value by an A-D converter 17, and the output is converted to a digital value by an arithmetic processing unit 18.
is entered.

The arithmetic processing unit 18 performs a squaring operation on the input value, and calculates the ! of equation (6). Vl2l゜, lV23! ',IV3
Find the value corresponding to lI'. Next, the values of the real part Re and the imaginary part Im of equation (11) are calculated. Ilm/Rel>
1 or IIm/Rel<1, and in the former case, φ in equation (14). In the latter case, φ in equation (15). ′
, and then perform the above-mentioned judgment process to determine Vn Song (or Vp
*) and display or output the result. By performing the calculation z=Rφ/4π, it is also possible to obtain the value of the position z. The embodiment shown in Figure 6 uses three systems each of buffer amplifiers, bandpass filters, detection circuits, and A-D converters, but it is not possible to insert a multiplexer (signal switch) into the input section of any of the devices. , and subsequent devices can be combined into one system.

FIG. 7 shows an embodiment in which a multiplexer 19 is inserted into the input section of the bandpass filter 15.
The voltages Vl2, V23, V3l induced in adjacent conductors pass through the buffer amplifier 14, and their respective outputs sequentially conduct the contacts in the multiplexer 19. Voltage Vl2, V23,
V3l sequentially passes through a bandpass filter and is connected to the detection circuit 16.
The signal is then linearly detected, and further converted into a digital value by the A/D converter 17 and input to the arithmetic processing unit.

The arithmetic processing unit 18 performs the same arithmetic operations as in the embodiment shown in FIG. 6, and can obtain the argument value φ or the position value z. The arithmetic processing unit 18 in the embodiments of FIGS. 6 and 7 is 1
The number is not limited to one, but a plurality can be used to divide the calculation and improve the processing speed. Also,
By providing the arithmetic processing device with the function of determining the absolute value of the voltage between conductors and the function of a digital filter, the digital filter and the detection circuit can be omitted.

The conductor laying shape of the guided radio line in the present invention is not limited to the trapezoidal wave shape as shown in FIG.
It may have a triangular wave shape as shown in the figure or a rectangular wave shape as shown in FIG. 9.

Further, instead of having a planar shape, the shape may be a spiral shape as shown in FIG. 10. In short, any structure that induces a sinusoidal voltage between each conductor will suffice (even if the structure is as shown in Figures 8 and 9, the size of the antenna or the antenna and guided radio line may vary). By selecting the distance appropriately, a sinusoidal voltage can be obtained). [Effects of the Invention] As explained above, according to the present invention, the position of a moving object can be accurately detected using only amplitude information without relying on phase information regarding the induced voltage between conductors of an inductive radio line. becomes possible.

Therefore, when a noise removal filter is inserted on the input side of a signal processing circuit, almost no measurement error occurs even if the phase characteristics of the filter change due to the influence of ambient temperature, etc., and stable operation is guaranteed. Ru. Furthermore, it becomes possible to develop a large-scale system in which a large number of position detection systems are centrally managed by a remote base station.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a guided radio line, Fig. 2 is a graph showing the relationship between the phase difference between positive-sequence voltage and negative-sequence voltage and the position of a moving object, and Figs. 3 and 4 are signal processing circuits in conventional examples. FIG. 5 is a schematic explanatory diagram of a system for centrally managing multiple systems, FIG. 6 is an explanatory diagram of an embodiment of a signal processing circuit according to the present invention, and FIG. 7 is an explanatory diagram of an embodiment of a signal processing circuit according to the present invention. FIGS. 8 to 10 are explanatory diagrams of other embodiments of the guided radio line used in J of the present invention, respectively. 1, 2, 3: conductor, 4: guided radio line, 5: antenna,
14: Buffer amplifier, 15: Band pass filter, 16:
Detection circuit, 17: A-D converter, 18: Arithmetic processing unit.

Claims (1)

[Claims] 1. By arranging three conductors bent or spirally formed with a repetition period P and shifted by P/3 in the longitudinal direction, the distance between each conductor increases as the position of the moving object changes. An inductive radio line is constructed such that a sinusoidal voltage is induced between the conductors, and by exciting this inductive radio line with an antenna mounted on a mobile object, the voltages induced between the three conductors are V12, V23, and V31. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ When the distance z from the guided radio line terminal to the mobile object is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ The relationship between A moving body position detection method characterized by measuring at a period of P/2 from P/2. 2. The moving object position detection method according to claim 1, wherein the value of 2 tan^-^1 (Im/Re) is determined by digital data processing.