JPS5934982B2 - Mobile object position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detection device for detecting the position of a moving object, such as a train or a crane, running along a fixed track on a ground-fixed side.

Figure 1 is a diagram showing the principle of construction of the device of the present invention, in which 1 is a parallel two-wire guide wire extended parallel to the traveling path of a moving object, 2 is a terminal resistor thereof, and 3 is a detector for signals guided and received by the guide wire. ,al,a
Reference numeral 2 denotes two antennas installed on the moving body, which move parallel to the plane of the guiding wire 1 as the moving body moves, and the coupling between these two antennas and the guiding wire is kept constant. shall be taken as a thing.

The guide wire 1 is crossed according to a given pattern, and the antennas a1. In a2, a carrier wave having the same frequency fc and the same phase is modulated by an oscillator mounted on a moving body (not shown) and a modulated wave having opposite phases (frequency fP).

A signal subjected to amplitude modulation with fP<fc) is supplied respectively.

Further, signals induced from these antennas to the guide wires are received and detected by the detector 3.

Since the interval d between antennas a1 and a2 is smaller than the minimum value e of the intersection point interval of the guide lines, when the moving body moves, there is no intersection between antennas a and 32 (in their opposing planes). There are two cases: (case A in the figure) and case (B) where it is included, and the output of the detector 3 in each case is different.

This will be explained next. Now there are two antennas a1. If the signals supplied to a2 are Sl and S2, respectively, then 51=A(1+5in2πfp t)sin(2yrf
ot+ψ) −(1)S 2=A(1-5in2 π
f pt ) sin(2yrf ot+ψ) ・(2
), and the human input signal G1 of the detector when there is no intersection between the two antennas is G1 = 1 (1 + 5 input, ) sin (ωt + ψ) +
, (1-sinpt) sin (ωt+ψ) = 2
K15in(ωt+ψ) ・(3) 1 is a constant of proportionality, P=2πf9. ω−2πf.

It is.

This equation (3) shows that G1 consists of only a carrier wave.

Next, when a crossover part is included between the two antennas, the relative phase of the induced received signal differs by 180 degrees, so the combined detector human input signal G2 is calculated as G2 = 2 (1 −)sinpt )sin(ωt +
cp )-to 2 (1-5inpt) sin(ω
t + cp ) = 2 K2sinp tsin(ω
t+ψ) −(4), which is 2 sinpt
sinωt = sin (ω+p) as ten sin (ω-
p) As is clear from t, the waveform has a phase inversion at a constant period, and the frequency components are only in both side bands.

FIG. 2 shows Sl, S2. G1. An example of the waveform of G2 is shown, and FIG. 3 shows the frequency spectrum of each wave in FIG. 2 in consideration of the phase.

Next, to identify the G1 and G2 waveforms in the detector 3, for example, envelope detection of the input signal wave can be performed and the presence or absence of the modulation frequency fp acid component in the output can be determined. It is necessary to configure the device strictly against fluctuations in .

Further, it is possible to perform identification using delayed detection by utilizing the fact that the waveform of equation (4) of G2 is a waveform in which the phase is inverted at a constant period, but the disadvantage is that the circuit becomes complicated.

Therefore, in the present invention, (3) and (4) 01. G2 Focusing on the frequency components of each wave, the detector 3 is connected to the carrier wave (ω) component and one of the sidebands. For example, a receiving circuit equipped with an Oki transducer that extracts only the lower sideband component and the center frequency are set to the frequency of the sideband and the carrier. The detector is configured to include a frequency discriminator circuit that selects a frequency intermediate to the frequency p, fc in this example, but in this case, when the G1 signal is being received, the input to the detector is only the fc acid component.
When receiving the G2 signal, the human power required is only for both sidebands (the output of the frequency discrimination circuit is f in the above example).

-fp), the detection outputs are converted into two types (positive and negative) of DC voltage levels, G1 and 0.
2 can be easily identified.

Note that such detectors are fo and f.

-fp or f. and f. Since this is a type of FSK (frequency shift keyed wave) demodulation device using two waves of +fp, it can be easily realized with a known circuit configuration.

In addition, in order to extract only one of the carrier wave and the sideband, the frequency of the human input signal may be converted to a lower frequency. It has the advantage of being resistant to fluctuations and noise and can be used as is.

Next, FIG. 4 shows the configuration of the guide wire of the position sensing device according to the present invention.

1-1.1-2, 1-3. Reference numerals 1-4 are all parallel two-wire parallel guide wires, which are laid along the travel path of the moving object, as in FIG. 1, and D1-D4 are the same detectors as 3.

In this example, an address is given to each position along the travel route using a binary code, and a guiding line equal to the number of bits required for the binary code is provided. Four corresponding guide lines are used, and each guide line crosses if the bit has a sign of "0" and does not cross if the bit is "1" to form a pattern as shown in the figure.

Note that since the antennas of the mobile body are coupled to each guide wire, the antennas are not limited to a pair of two antennas, but may be a pair of multiple antennas.

When the distance d between a pair of antennas of a moving object is smaller than e, that is, the address distance, as the moving object moves, D1 to D4 corresponding to each bit detector include an intersection between the two antennas as described above. Two types of level outputs are detected depending on whether the address is detected or not, and from this, a binary code corresponding to the address or a decimal coded representation of the same can be easily obtained.

Note that various display and transmission devices may be used after the two types of level output as required, but since these are well known, illustrations thereof will be omitted.

As is clear from the above description, according to the present invention, detection of the position of a moving object is performed in the same way as binary code detection using the frequency shift method, and is resistant to level fluctuations and noise, which are the advantages of the frequency shift method. The advantages can be obtained directly, and the multiple guide wires are actually conductors or printed wiring attached to an insulating board installed along the running path, and the pattern is often repeated in a certain pattern, so the cost is low. Practical effects such as low cost and easy maintenance can be obtained.

[Brief explanation of drawings]

Figure 1 is a diagram of the configuration principle of the device of the present invention, Figure 2 is the waveform section of the antenna current of the mobile object and detector input voltage, Figure 3 is a frequency spectrum diagram of the multiplexing of Figure 2, and Figure 4 is a diagram of the waveform of the antenna current of the mobile object and the detector input voltage. FIG. 3 is a side view of the guide wire configuration of the position sensing device. 1.1-1 to 1-4...guiding wire, 2...
・Terminal paper/resistance, 3. D1-D4...Detector, a
l, a2...Transmission antenna of the mobile object.

Claims (1)

[Claims] 1. A group of guide wires consisting of a plurality of two parallel wires laid parallel to each other along the traveling path of a moving object, a detector connected to one end of each of the above guide wires, and at least one or more guide wires placed on the moving object. A pair of transmitting antennas made up of antenna coils and spaced apart at a fixed ratio along a travel path, and an oscillator that separately modulates the same carrier wave of each of these pair of antennas with modulated waves whose phases are different from each other by 180 degrees. Each of the guiding lines is assigned each digit of the address of a binary code having the number of bits of the guiding line given to each position, and a crossover is performed to represent the bit code 1 (or 0), and
The distance between the pair of transmitting antennas of the moving object is set to be smaller than the minimum value of the crossing distance between the respective guiding wires, and each of the detectors determines whether or not the crossing of the guiding wires is included between the pair of antennas. The frequency component of the composite voltage induced in the guide wire, which is detected by the included P-wave discriminator circuit, is detected depending on whether it is only a sideband frequency or only a carrier wave, and is binary encoded to determine the position of the moving object. A moving body position detection device characterized by knowing the position of a moving object.