JPS6054607B2 - Mobile position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the current position of a mobile object such as a crane or vehicle moving along a fixed travel path on the side of fixed ground equipment (hereinafter referred to as a ground station). It has the great advantage that it can be obtained continuously and in an absolute address format, and the structure of the device is simple and inexpensive.

In position detection using conventional guided radio methods, the route of a moving object is divided into an arbitrary number of sections, each section is given an absolute address using a binary code, and the location of the vehicle is assigned to the route according to the 1 and 0 of the address code. A number of crossing pattern formats have been proposed so far, in which a plurality of parallel two-wire guiding lines are generally crossed along the line, and the phase of the induced electric field is inverted at the intersection.

One of these is a fixed point detection method that detects changes in the amplitude level of the induced voltage when a moving object is running, and the other is a continuous absolute address detection method that uses phase difference detection to compare the phase of the induced voltage with a reference phase signal. All of them are in practical use. However, the fixed point detection method has the disadvantage of being susceptible to noise and level fluctuations, and the phase difference detection method detects the phase difference between the induced voltages from multiple guiding wires and performs logical processing to locate the moving object. There is a method for determining this, but the circuit configuration becomes complicated, and the reference phase signal is transmitted to the position detection circuit using a frequency different from that of the position information signal, whose phase is inverted at each intersection of the guide lines, or by using a different guide line. There are other methods, but the disadvantage of all of them is that they require expensive equipment. The present invention was developed to eliminate these drawbacks, and it is possible to perform continuous absolute address type position detection with a simple configuration, and since position detection is performed by phase difference detection, it is free from noise and level fluctuations. High-precision position detection is performed at the intersection point without being affected by the interference, and the frequency for transmitting other digital information can be shared, so the circuit configuration and the cost of the guide line can be reduced.

The present invention will be specifically explained below with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of equipment on the ground station side in which the present invention is implemented.

1 to 4 and 2'' to 4'' in the figure are guide lines extending parallel to each other so that they are all in the same plane along the moving vehicle travel path.
Among them, 1 is a guide line extending parallel to 2 and 2'' at the center between crossing parallel two-wire guide lines 2 and 2'', and 2 and 2'' are a pair of guide lines that divide the running line into sections 1 to 8. Each section is crossed to represent the 7 digits of the assigned section code (address code). 3 and 3" and 4 and 4" are pairs of crossed parallel two-wire guide wires, respectively. and 3'' represent the 21st digit of the interval code, and 4 and 4'' represent the 22nd digit of the interval code, respectively.

That is, in this example, an alternating binary code (GRAY code) given to each section is constructed by three pairs of guide lines. Now, assuming that the section code of section (1) is 000, the section codes for the crossing pattern in FIG. 1 are as shown in Table 1 below. Next, 5 to 8 are coupling transformers, and 6 is 1 and 2.
, 52", and the primary coil is connected between the 2 and 2" wires. The transformer connected between the coil neutral point is the coupling transformer for the induction wires 1 and 2, 2'', 7 is the Z-digit transformer connected to one end of the induction wires 3 and 3'', and 8 is the induction wire It is a 7-digit transformer connected to one end of the 4.4".

9, 9″ 10, 11 are terminal impedances or resistors connected to the other ends of each of the above-mentioned guide wires, 12 to 1 as shown in the figure.
5 is a signal amplification and amplitude limiter (denoted as A above), 16 to 18
is a phase discriminator (denoted as PD), 19 to 21 are square wave conversion circuits including a low-pass p-wave filter (LPF), 22 is an address code output circuit, Dp is an address code output, and the circuits 12 to 22 are integrated. It can be called an address code detection circuit.

Furthermore, when interval codes are given as shown in the table above, in this alternating binary signal, the distance between codes in adjacent intervals is 1 bit, so generation of error codes is suppressed. Note that when natural binary codes are given sequentially, the distance between codes in adjacent sections is 1 to 3 bits, but if there are two or more intersections on the same segmentation point, it is difficult to match multiple intersection detection points. This is difficult and may result in the output of an erroneous code and therefore an erroneous address, which poses a practical problem. Figure 2 shows moving body side equipment a corresponding to the ground side equipment in Figure 1.
FIG. 2 is an explanatory diagram b of the inductive coupling phase characteristics between the guide lines 1, 2, and 2'' in FIG. 1.

In Fig. 2a, 23 is, for example, the LF band (30KHz~
300KHz) or VLF band frequency oscillator, 24
25 is a cross-shaped loop coil that crosses at the center, and 25 is a non-cross-type loop coil. Note that both coils 24 and 25 serve as antennas, and are configured, for example, as air-core coils or as a combination of one or more magnetic core rod-shaped antennas, so-called par antennas. The broken line [1] [2] [2″] in figure a is the parallel three-wire guide line 1 in figure 1.
, 2, 2'' and the loop coils 24, 25. The intersection of the loop coil 24 always moves opposite the guide wire 1. Figure b shows each section of A, B, and C. The above parallel three-line guiding line 1 when intersecting at the dividing point of
2,2''.To explain the signal transmission path in FIG.
is supplied to First, in the induction wires 1, 2, 2'' connected to the crossed loop coil 24, induced signal currents having a phase relationship shown by the solid line arrows in Figure b flow into the loop circuit including the transformers 5 and 6. In the induction wires 2, 2'' connected to the crossed loop coil 25, induced signal currents having a phase relationship indicated by dashed arrows flow into a loop circuit including only the transformer 6. As is clear from FIG. b, the current induced by the loop coil 24 is in the same direction and the same phase in each section of A, B, and C, whereas the current induced by the loop coil 25 is in opposite phase at each intersection. Therefore, when a moving object equipped with equipment consisting of 23, 24, and 25 moves along a running route, the phase of the induced output current, that is, the signal taken out from the transformer 5, will be the same regardless of the section in which the moving object is located. In contrast to the constant continuous phase, the phase of the signal taken out from the transformer 6 is reversed each time it passes through a point of intersection, that is, it shifts by π radians. Next, detection of the position of a moving body using a plurality of guide lines provided with intersections of alternating binary encoding patterns as shown in FIG. 1 will be described.

The signal output from the transformers 5 and 6 at the ends of the parallel three-wire induction wire composed of 1, 2, and 2'' is a signal with a constant continuous phase when the moving object is running as explained in Fig. 2 above. The transformer 5 outputs a signal, and the transformer 6 outputs a signal whose phase changes by π radians each time the cross point is passed.

In addition, other parallel two-wire intersecting guide wires 3, 3'' and 4,4'' extended in parallel with the parallel three-wire guide wires 1, 2, 2'' are coupled to the non-crossing loop coil 25 on the movable body side for guidance. line 2,2
'', signals whose phase changes by π radians each time they pass through the intersection point are output from the - terminal transformers 7 and 8, respectively.The loop coil 25 is mainly 1, 2, 2'' as shown in FIG. Even when arranged to couple with the guide wire, these two-wire guide wires are actually stretched closely parallel to the three-wire guide wire, so the degree of coupling is sufficient, and the loop coil can be used as needed. Just extend the dimensions of. Moreover, the signal of the crossed loop coil 24 is not induced in these two-wire guide wires 3,3'' and 4,4''. Now transformers 5, 6, 7
. Since it is a signal with a constant continuous phase that is unrelated to the crossing of lines,
This is used as a reference phase signal and the next stage phase discriminator (PD) 16
, 17, and 18.

The signal of the guide wire 2, 2'' is passed through the path 13 on the transformer 6-A to P.
It becomes another input of Dl6, the phase difference with the reference phase signal is discriminated, and the result is sent to the square wave conversion circuit STl9.
If it is a (+) level input, it is converted to an H level, and zero and (-) level inputs are converted to an L level. Furthermore, PD
Since the phase difference between the two inputs of PDl6 is not necessarily maintained in an ideal phase relationship because the transmission paths are different, a phase correction circuit is added to the input side of PDl6 so that the two inputs are in the same phase or opposite phase. Correct it. Therefore, the output of PDl6 will be (+) level if the two inputs are in phase, and (-) if the two inputs are in phase.
Output each level. Similarly, PD17 and PD18 also include phase correction circuits. Next, PDl7
The output of the guide wires 3, 3'' is inputted through the path 14 on the transformer 7-A, and its phase discrimination output is input to the square wave conversion circuit ST2O.
The signal is sent to H and L levels and output.

Similarly, the output of the induction wire 4,4'' is connected to the transformer 8-
Input via path 15 on A, and its phase discrimination output is ST2l
The signal is converted to H and L levels and output. These ST
When each output of 19, ST2O, and ST2l is sent to the address code output circuit P22, the address code Dp is output. For example, loop coils 24 and 2 placed on a moving body
5. In particular, when the non-intersecting loop coil 25 is located in one section of FIG. When a moving object enters the section 2 in Figure 1, only the output of ST19 changes to H level, and ST2
O, ST2l remains at L level output, so P22
will output the code for address 2. Next, when entering section 3 in Figure 1, the outputs of ST19 and ST2O are at H level.
The output of ST2l is at L level, and the code of address 3 is output from P22. It will be understood that as the vehicle travels in the direction from 1 to 8 in FIG. 1 or in the opposite direction, the address code as shown in the first table is obtained. The above explanation divides the running route into sections 1 to 8 and assigns the section addresses 1, 2, 2.
This is an example in which three sets of guide lines, ``3, 3'' and 4, 4'', are crossed according to the alternating binary code so that the ground station can detect them. What is necessary is to further increase the number of parallel two-wire guide lines.

In other words, if the number of section addresses is M and the number of intersecting parallel 3-wire guide wires is n, then M x 2n + 1, and in addition to the parallel 3-wire guide wires, n parallel 2-wire guide wires are required. It is. It can also be said that the number of parallel guide lines required is equal to the number of digits of the assigned address code. Next, as can be easily inferred from the above explanation, instead of using the oscillator 23 on the mobile body as a simple continuous wave generator, for example, it can be modulated using a digitally encoded information signal (on-off keying, frequency shift, phase shift, etc.). ) may be used as an LF wave transmitter, and since the digital modulation signal induced in each guide line is not affected by the crossing of the guide lines in the 12 paths above transformer 5-A in Figure 1, even if it is an intermittent signal, is used as a reference phase wave with a constant continuous phase even if
Since the signal on the path of the -A/L1 male transformer 8-A 15 changes by π radians with the crossing position as a boundary, the address code can be obtained from P22 as described above.

At the same time, if the output of the transformer 5 is guided to a demodulator (not shown) and demodulated in accordance with the modulation format on the transmitting side, information on the mobile side can be received at the ground station. As explained in detail above, in the present invention, by simply providing a mobile object with a simple single-frequency oscillator or a low-power transmitter that can be modulated with information, and a pair of loop coils, It is possible to detect the address where a moving object exists in the section number on the ground side and continuously determine the position of the moving object in absolute address format, so when performing automatic control or automatic driving of cranes, vehicles, etc. The position of a moving object can be detected with high accuracy without error even if it is on an intersection position (it is not affected by changes in signal amplitude because it uses phase discrimination means).In order to receive information signals from the moving object side, guidance for position detection is required. Since wires, loop coils, coupling transformers, etc. can be shared, significant practical effects such as being economical can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating an example of the configuration of ground-side equipment according to the present invention, and FIG. 2 is an explanatory diagram illustrating the connection between the configuration example a of the equipment on the moving body side according to the present invention and the guide line in FIG. 1. 1, 2, 2'', 3, 3'', 4, 4''... Guide wire, 5, 6, 7, 8... Coupling transformer, 9, 9''
, 10, 11...Terminal resistor, 12-15...
...Amplification and amplitude limiter (A top), 16-18...
...Phase difference detector (PD), 19-21...LP
F, square wave generator (ST), 22...Address code output circuit (P).

Claims (1)

[Claims] 1. As a device for detecting the position of a moving object such as a vehicle traveling on a fixed running route on the ground fixed equipment side, a device is installed parallel to the running route in the same plane along the running route, and is used for each section where the running route is divided. The number of digits of the address code with the given alternating binary code (
N) of parallel two-wire guide lines, each assigned to each digit and having intersections at section dividing points according to code changes, at least one of which has the above-mentioned intersections on the two lines. A guide wire group that is a parallel three-wire guide wire with one line extended parallel to the two wires added at the center between these two wires, a terminal impedance group that terminates one end of each of the above guide wires, and others. The 2nd, 3rd, and 2nd, 3rd, and 2nd, 3rd,
...The neutral point of the primary coil of each N+1 transformer and the second transformer whose primary coil is connected between the other end of the central wire and the two outer wires of the parallel three-wire induction wire. A first transformer with the primary coil connected therebetween, and an address code detection device that uses the output of the first transformer as a reference phase output and outputs the address code of the current section of the moving object from the outputs of the other transformers. a ground fixed facility equipped with a circuit; a non-crossing type loop coil placed on a moving body and inductively coupled to the above-mentioned guide wire group; a crossing-type loop coil coupled to the above-mentioned three-wire guide wire; 1. A position detecting device for a moving object, comprising: moving side equipment comprising an oscillator or a transmitter that supplies a signal of a single constant frequency or a signal modulated with a digital code.