JPS593765B2 - Mobile position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a system for determining the position of cranes, trolleys, etc. on a running road on a fixed running road by (absolute) address system.
This relates to a device detected by a ground station (hereinafter referred to as a ground station), and belongs to a method that uses guided radio.

In conventional guided radio type moving body position address detection devices, the required area of the travel route is subdivided into subdivisions, and each subdivision is given an appropriate address code (binary code) of 30, and for example, the digits of these address codes are A group of guide wires consisting of a plurality of guide wires equal to the number of guide wires and reference phase signal guide wires is extended and erected in the required area of the running route, and the guide wires other than the reference phase signal guide wires (
In general, each parallel two-wire system is crossed at the 35th point of the block according to the address code, and the mobile unit is equipped with an oscillator of a specific frequency and an antenna for coupling and transmitting its output to each guide wire. A method of detecting an address code by comparing the phase difference between the induced output of each of the above-mentioned guide wires and the induced output of the reference phase signal guide wire, or a method of detecting the address code by using a plurality of parallel two-wire guides equal to the number of digits of the address code. Lines are laid along the travel route by intersecting at the block division points according to the address code, and a signal oscillator and antenna with a specific frequency are installed on the moving object and connected to each of the above guide lines. A method is used to detect the address code by using an amplitude detection circuit connected to one end to detect that the signal output disappears every time the moving object reaches the crossing point of each guide line.
In the former case, if the number of digits in the address code is small, the economical burden of the guide wire for the reference phase signal is large; in the latter case, the absolute address must be entered at the first operation of the device, or the line must return once to the reference position ( The disadvantage is that it requires homing (homing) and is difficult to operate.

The present invention has been made to eliminate these drawbacks, and will be explained below with reference to the drawings. An overview of the present invention will first be described.

In the present invention, an alternating binary code is used for the address assigned to each small section divided along the running route, and a plurality of parallel guide lines equal to the number of digits of this code are extended along the running route, and the guide line corresponding to each digit is extended. The line shall be a parallel two-line guide line that intersects when the address bit codes before and after the dividing point are different at the subsection dividing point, and the output of a specific frequency (this will be referred to as F) will be outputted to the moving object. /n (n is an integer of 2 or more) waves, and a coupling antenna such as a loop antenna installed to couple with each guide wire, and transmitting equipment to supply it, shall be installed at the ground station. . F modulated by /n. The main component is a position detector that detects the address code of the area where the mobile object is located from waves, and is particularly characterized by the configuration of the position detector that increases the reliability of position detection. FIG. 1 is a diagram illustrating a wiring example of a plurality of parallel two-wire guide lines laid in a required travel section S along a travel path of a moving body. The S section is divided into arbitrary small sections and given an address code to each. In Figure 1, it is divided into 24 = 16 addresses and a 4-digit (4-bit) alternating binary code (also called Gray code) is given to each. In this case, the number of guiding wires N is 4, which is equal to the number of digits of the address, and 2,
21, 22, and 23 are guide lines representing each digit of the alternating binary code. For assigned addresses from (0) to (to), intersection is performed only when the code is different from the adjacent subsection at the subsection division point, but as is well known, in the case of a police box binary code, the Hamming distance between adjacent address codes is 1, therefore, only one of the plurality of guide lines intersects at the section dividing point. Note that L in the figure is a terminal resistor of each guide wire, and 6 is a loop antenna attached to the moving body and coupled to each guide wire. A position detector is connected to the other end of each girder guide wire, which will be explained later with reference to FIG. FIG. 2 is a diagram showing an example of the configuration of the equipment on the mobile side, and 1 in the diagram indicates a specific frequency F.

oscillator, 2 is F. Frequency divider (DI) that divides the wave to 1/n
V), where n is an integer of 2 or more. 3 is a sine wave amplifier (A
MP), 4 is amplitude modulation (AM) or frequency modulation (FM)
), 5 is an output amplifier, and 6 is the loop antenna.

The output of oscillator 1 is sent to frequency divider 2 and modulator 4, where frequency divider 2 has input F. The wave is F. /n, and its output is amplified to a required level by a sine wave amplifier 3 and then given to a modulator 4 as a modulation input. If the modulator 4 is now an AM modulator, the carrier wave F from the oscillator 1. The input is the modulated wave F from amplifier 3. /n is output, and after being amplified to a required level by an amplifier 5, it is sent to a loop antenna 6. Next, the signals induced into each guide wire by the modulated wave current in the loop antenna 6 of the mobile object pass through couplers 9 to 12 connected to one end of each guide wire, and an example of the circuit configuration is shown in FIG. It is introduced into the position sensor 13 shown.

In Figure 3, 7 is F. /n wave extraction circuit, 8 is F. 7-wave reference phase signal generation circuit, 14 to 17 are phase discriminators (PD
), 18 to 21 are low-pass filters (LPF), and FO
/n wave extraction circuit 7 has amplitude modulated wave detectors 71 and 72, and F which is their detection output.

/n wave synthesizer 73 and bandpass filter (BPF) 74, and the FJ wave generation circuit 8 is a frequency multiplication type frequency generator using a known phase locked loop circuit or PLL (phase locked loop) circuit. Synthesizer (for example, Hideo Tsunoda, "Basics and Applications of PLL", pp. 112-113, 1972)
(Tokyo Denki University Press), which forms the phase (difference)
It is composed of a discriminator (phase detector) PD8l, an LPF82, a 1/n frequency divider 83, and a voltage controlled oscillator (VCO)84.

Next, the operation of each part will be explained.

In FIG. 3, the outputs of the guide wires corresponding to the digits 2 and 21 are passed through couplers 9 and 10, respectively, to F.
/n-wave extraction circuit 7 manually, and the two modulation frequencies FO obtained by detection by the detectors 71 and 72, respectively.
/n component outputs are combined in the combiner 73, and then the BP
F through F74. /n wave is extracted and sent to the circuit 8.
Here we will explain the reason for combining the outputs of the two detectors and its effects. Of the above two guide wire outputs, the output of the loop antenna in which the center line of the loop antenna surface of the moving object and the intersecting guide wire are inductively coupled at the intersection point is the antenna induction from the guide wire on the left and right of the intersection point. Since the phase of the voltage is reversed, it becomes zero. However, when crossing as shown in Figure 1,
Even if the moving object moves within the required traveling section S, the crossing positions of the guide lines of each digit will not overlap, so the guide lines of any two digits (for example, 2 and 21 or 22 and 22, etc.) will not overlap. If we synthesize the induced outputs from (combination), we get F. /n component output never falls below a certain level. Now F.

The wave generating circuit 8 uses the oscillation frequency F from the VCO 84. ″
A part of the output of is divided by 1/n by a frequency divider 83, and the output F. The 7/n wave becomes one input of the next stage phase discriminator PD8l.

The other input of PD8l is F above. /n wave extraction circuit 7
More F. /n wave, and detection of the phase difference between the FO7n wave and the FO/n wave is performed in this momme. In other words, PD8l is F. /n wave and F. When the 7n waves are in the same phase, the output is zero, FO/
F from n wave.

If the 7n wave has a phase advance of π/2 radians (=90n), the maximum positive output is F than the FO/n wave.

If the 7n wave is delayed by π/2 radians, the maximum negative output is F.

/n wave and FO7n wave are in opposite phase (π radian or 18
00), it has the characteristic of generating an average DC voltage proportional to the error, as if the output was zero. The phase difference proportional voltage output of this phase discriminator PD8l is transmitted to the next stage low-pass filter LP.
F82 to remove noise and phase jitter, and its output is applied to the control terminal of voltage controlled oscillator VCO84 to set its oscillation frequency F. '' of the voltage controlled oscillator VCO 84 of the NL.PLL circuit is controlled so that it approaches F.'' is F. It is necessary to adjust the dimensions so that they are approximately equal and the difference is within the retraction range. To explain in more detail, for example, FJ/n>FO/n (f♂ is F.

If the phase is more advanced), the positive phase discriminator output is input to the VCO. Since the VCO has the characteristic that the frequency is controlled to the lower side by positive input, the oscillation frequency FJ of the VCO and therefore F
. 7n is controlled in a slow phase direction with respect to FO/n.

On the contrary, F. 7n<FO/n (FO' is F.

(later phase), the negative phase discriminator output is input to the VCO. VCO has the characteristic of being controlled in the direction of high frequencies by negative human power. 7n is F.

/n is controlled in a phase advancing direction. In addition, the phase difference versus output characteristic of the phase discriminator is such that if the phase difference is large (maximum π/2), it will output a large output, if the phase difference is small, it will output a small output, and if they are in phase, the output will be zero. From, F
O7n and F. The phases of /n converge to the same phase. Further, the LPF 82 is usually used with a cutoff frequency of 5 to 10 Hz, which removes unnecessary high frequency noise and performs DC smoothing. It should be selected so that it can sufficiently follow the normal fluctuations of the waves. With such a PLL circuit configuration, the oscillation frequency F of the oscillator 1 on the moving body side.

F of 1/n of. /n wave and F which is 1/n of the oscillation frequency FJ of the VCO on the ground station side. By matching with the 7O wave, it becomes f♂-FO.

Therefore F. F synchronized to the wave. The wave output is used as a reference phase signal to detect the phase change of each guide wire.On the other hand, the guide wire output of each digit of 2nd detection to 23 that has passed through couplers 9 to 12 is sent to phase discriminators PDl4, PDl5, PDl6, respectively. ,P
The phase difference with the above reference phase signal from the VCO 84 is detected by manually inputting it to Dl7, and this detection output is output to LPFl8,L.
After communicating with PFl9, LPF2O, and LPF2l, respectively, it is output as four-digit position detection outputs El, e2, e3, and e4. FIG. 4 is an explanatory diagram of the reason why the position detection outputs e1 to E4 are converted into section address codes.

The numbers (0) to (7) at the top of the figure indicate some of the same section addresses as in FIG. Note that the intersections of the digit guide lines in FIG. 1 are made in accordance with the following changes in the alternating binary code. First, the loop antenna of the mobile object is located at the address (
When connected to the guide wire at 0), 2 as shown in Figure 4.
~23 Phase discriminator PDl4~PDl from the guide wire of each digit
The phases of the human input signals to oscillator 7 are all 00, and the reference phase signal from oscillation circuit 8 undergoes a unique phase shift in circuits 7 and 8, so the output side of oscillator VCO 84 is It is necessary to insert a phase correction circuit that sets the phase to 00 to bring the inputs from each guide wire into the same phase.

In this way, as shown in Figure 4, at address (0), all human power from the guide line is in phase, that is, the phase difference with the FJ wave is 0.
0, and at the next address (1), only the input from 2 and the digit guide wire is inverted and becomes 180), that is, the π phase, and the others are O phase,
At address (2), the input from 2 and 21 is π phase, 22 and 2
The input from 3 changes to O phase, etc.
In addition, in Figure 4, the human power from the 23-digit guide line is (0) ~ (
The section 7) is omitted because it is all in O phase. Now, outputs corresponding to the phase difference between these human forces and the reference phase signal (FO" wave) are generated from PDl4 to PDl7 in FIG. 3, respectively, and are outputted as e1 to E4 through LPFl8 to LPF2l, but EI-E4 is As shown in Figure 4, if the input from the guide wire is O phase, it will be level (E), and if it is π phase, it will be level (E).Furthermore, at the intersection of the guide wires, the coupling loss is maximum and the phase is reversed, so the output level is zero. So, e1
~E4 Each output is inputted to a square wave conversion circuit (not shown) that uses the O level as the slice level, and the output is 1゛ or H (high) level for the (A) level, and 1゛ or H (high) level for the O and (H) levels. If the outputs E1 to E4 are respectively converted to 40" or L (low) level, the address code output at address (0) is 1111 as shown in Figure 4. At address (1), it is 0111, (2) The address is obtained as 0011..., and the position of the moving object can be converted from these codes into addresses (0), (1), (2), etc. and read directly. In the above explanation, the antenna on the moving body side is a loop coil antenna with a high degree of coupling, but there is no need to limit it to this, and a magnetic core bar antenna or a combination of multiple antennas can also be used. As explained in detail above, in the present invention, an address code using a police box binary code is given to each section into which the traveling route is divided.
A group of guiding lines are used that intersect according to the address code according to the dividing point of the divided section, but since the distance between adjacent address codes is set to 1 bit, an error address will be output. Without this, the reference phase signal is F. Since the system is synchronized by /n waves, the conventional guide wire for obtaining the reference phase signal is omitted, and the tolerance for coupling loss fluctuation between the antenna and the guide wire due to the movement of the moving object during phase difference discrimination is also reduced. is large, so high-precision position detection can be performed with economical equipment even in environments where noise interference is likely to occur. Therefore, it has a wide range of uses as an absolute address type position detection device for moving objects such as cranes and trolleys, and is also extremely effective as a highly reliable device that can detect addresses from the initial movement.

[Brief explanation of the drawing]

Figure 1 is an example of the wiring of guide wires, Figure 2 is an example of the configuration of the equipment on the moving body side, Figure 3 is an example of the configuration of the ground side position detector, and Figure 4 is the output of the position detector and address code. FIG. 1...1...-FO oscillator, 2... Frequency divider,
4...Modulator, 3, 5...Amplifier, 6
......loop antenna, 7゜゜゛゜...FO/n
Wave extraction circuit, 8...FO'' wave (reference phase signal)
Generation circuit, 9-12...Coupler, 13...
...Position detector, 14-17... Phase discriminator (
PD), 18-21...1 low frequency filter (LPF)
, 71, 72...detector, 73...F
O/n wave combiner, 74...Band filter (BP
F), 81...PD, 82...LPF
, 83... Frequency divider, 84... Voltage controlled oscillator (VCO).

Claims (1)

[Claims] 1. As a device for detecting the position of a mobile object moving on a fixed travel route on the ground fixed side, the required area along the travel route is divided into multiple sections, and each section is assigned an address code based on a police box binary code. Accordingly, a number of parallel two-wire guide wires equal to the number of digits of the address code are laid in parallel along the travel route in the above-mentioned required area, and each guide wire corresponds to the change in the address code at the assigned digit. The guide wires are crossed at the section dividing point, and one end is terminated with a resistor, and the other end is connected to a ground-side position detector via each coupler, and a group of guide wires mounted on a moving object. Then, the output of an oscillator with a specific frequency (f_0) and its oscillation output is modulated by the divided wave output of frequency f_0/n (n is an integer of 2 or more) obtained from the oscillation output, and the output is inductively coupled with the above guide wire group. a modulator and an amplifier for supplying the antenna to the antenna, and two detectors installed on the ground fixed side to detect any two outputs of the coupler outputs for the group of guide wires. , an f_0/n wave extraction circuit consisting of a synthesizer that combines the f_0/n waves that are the detection outputs of these, and a band filter that extracts only the f_0/n wave from this synthesizer output, and an f_0/n wave extraction circuit that is equal to the above f_0. A voltage controlled oscillator that oscillates the frequency (f_0'), a frequency divider that divides a part of its output into 1/n, and f_0' from this frequency divider.
_0'/n wave and f from the above f_0/n wave extraction circuit
A phase discriminator that compares the phase between _0/n waves and generates an average DC voltage proportional to the error, inputs this error voltage to remove unnecessary high frequency noise, and sends its output to the control terminal of the voltage controlled oscillator. A phase-locked loop (PLL) circuit is formed with a low-pass filter to be added, and the specific frequency f_0 wave of the mobile equipment and the oscillation frequency f of the voltage controlled oscillator are
An f_0' wave reference phase signal generation circuit that operates to synchronize the frequency and phase with _0', and a guide wire of each digit from each coupler using the input from the controlled voltage controlled oscillator as a reference phase signal. It is equipped with a ground fixed position detector consisting of a phase discriminator that detects the phase difference with the output and generates a signal output for each digit as an address code, and a set of several digits of a low-pass filter. A moving object position detection device characterized by: