JPS6312268B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable tracking system for tracking the position of laid or buried cables.

On land, to protect cables from external forces,
Burying cables underground has been practiced for a long time. On the other hand, when laying cables in the sea or rivers, it has become popular in recent years to bury the cables under the seabed or riverbed to prevent them from being damaged by fishing nets, ship anchors, etc. . There are two methods for burying cables: the simultaneous laying and burying method, in which a burying machine is used to bury the cable at the same time as the cable is being laid, and the other is the simultaneous laying and burying method, in which the cable is once laid on the seabed and then a burying machine is used to bury the cable. There is a post-burying method. Additionally, if a problem occurs in a buried cable, it is necessary to dig up the cable near the part where the problem occurred, pull it up onto the ship, repair it, lay it, and then bury it again. In order to bury a cable that has been laid on the seabed, such as the above-mentioned post-burying method or re-burying work after repair, the burying machine must be placed precisely over the cable at the start of the burying work. During installation and burying work, the cable position must be accurately tracked (hereinafter referred to as tracking) in order for the burying machine to run along the cable.
Technology to accurately control buried machinery is essential.
Conventionally, in shallow water locations, divers visually control the burying machine to bury cables after the cable has been buried, but with this method, the depth at which burying work can be performed is limited by the diver's work ability. Furthermore, if the water clarity is extremely poor even in a shallow place, it will be difficult to confirm the location of the cable, reducing the efficiency of burying the cable.

The purpose of the present invention is to provide a cable tracking method that solves the drawbacks of the conventional technology as described above. A pattern indicating the level of the detection signal of each magnetic field detection sensor is displayed on the display, and the cable position is determined by the pattern indicating the distribution shape of the level. It is characterized by detecting the direction of placement.

According to the present invention, since the position and arrangement direction of the cable can be easily detected, the cable burying machine can be guided and controlled safely and reliably.

The present invention will be explained in detail below with reference to the drawings.

1 and 2 are configuration examples of the cable tracking system of the present invention. In FIG. 1, a signal current is supplied from one end of a cable 5 to be tracked by an AC signal supply unit 4, and an AC magnetic field generated around the cable 5 is thereby detected by a magnetic field detection sensor unit 1. The magnetic field detection sensor section 1 is
It is composed of a plurality of magnetic field detection coils arranged so that the directions of maximum sensitivity of detection directivity coincide with each other. The magnetic field signal detected by the magnetic field detection sensor section 1 is
Since the signal level is low and includes noise, only the magnetic field signal component is detected by the signal receiving section 2. The signal processing display section 3 displays the position and arrangement direction of the cable 5 using a display pattern obtained using the signal from the signal receiving section 2.

In the configuration example shown in FIG. 2, a signal current is supplied to a signal current supply cable 6 separately provided around the cable 5, and the alternating magnetic field generated around the cable 6 is thereby detected by the magnetic field detection sensor section 1. It is something to detect. By arranging the cables 5 and 6 in close proximity, the detected signals can be handled in the same way as in the configuration example shown in FIG.

FIG. 3 shows an example of the configuration of the magnetic field detection sensor section 1. As shown in FIG. In FIG. 3A, coils 101 to 114 wound around a coil support rod 120 are arranged at a predetermined distance from each other as shown in the figure, and are connected by a connecting rod 121. The lead wires 115 of each of the coils 101 to 114 pass through the inside of the connecting rod 121, are collected into a connecting wire 116, and are connected to the signal receiving section 2 of FIG. 1 or 2. FIG. 3b shows the magnetic field detection directivity of the coil 101 used in FIG. 3a, and as shown in FIG. Detection output
V ₀ is expressed as V ₀ =aHcosθ. Here, a is the magnitude of the magnetic field interlinking with the coil 101 and the coil 10
This is a constant that indicates the relationship between the magnitude of the voltage induced at 1 and the magnitude of the voltage. FIG. 3c is for explaining the positional relationship between the cable 5 and the coil 101 and the detection output V ₀ of the coil at that time. When the cable 5 is on the Z axis of the orthogonal coordinate axes, if the coil 101 is arranged so that its directivity axis is parallel to the X axis,
The signal current I flowing through the cable 5 causes the coil 1 to
The voltage V ₀ induced in 01 is expressed as V ₀ =a·2Ih ₀ /h ₀ ² +l ₀ ² (1). Here, l ₀ and h ₀ are the horizontal and vertical distances between the center of the coil 101 and the cable. As is clear from the above equation, at the same vertical distance from the cable, the induced voltage V ₀ is
01 is maximum when directly above the cable 5, that is, at l ₀ =0.

4 to 7 show examples of circuit configurations of this system.

In FIG. 4a, each magnetic field detection coil 101 to 114
The signals detected in the respective band amplifiers 201 to 201
214 and detectors 221 to 234 to enter each signal processor 301 to 314. Signal processor 301~
314 detects the level of the signal and lights up the display LED arrays 341 to 354 in accordance with the level.

Figure 4b shows the signal processor 301 and display LED.
An example of the circuit configuration of the array 341 is shown. In FIG. 4, the output signal V ₁ from the detector 221 is converted to a set voltage E ₁ by each level comparison circuit 3011 to 3020.
~ E ₁₀ respectively, and level comparison circuits 3011 to 302 are used only when V ₁ is larger than each set voltage.
Each output starts from 0. Level comparison circuit 3011~
Each output of 3020 is LED drive circuit 3051-3
060 is operated to light up LEDs 3401 to 3410. In FIG. 4, the level comparison circuit 30
Set voltage E ₁ to _{E 10} for 11 to 3020 as E ₁ > E ₂ >
... _E10 , the number of LEDs 341 lit will change depending on the level of the input voltage _V1 , and the higher the level of the input voltage _V1 , the greater the number of LEDs 341 lit.

FIG. 5 shows an example of the configuration of the displays 341 to 354. When the configuration of the magnetic field detection sensor section 1 is shown in FIG. 3a, LED arrays 341 to 354 are arranged in the display section corresponding to the respective coils 101 to 114.

FIGS. 6 and 7 are for explaining display examples by the display shown in FIG. 5. FIG. Figure 6 shows
This is a view of the magnetic field detection sensor section 1 shown in FIG. 3a viewed from above, and it is assumed that cables 501 to 503 are provided below the sensor section 1 as shown in the figure.
Now, assuming that the cable 501 exists for the magnetic field detection sensor unit 1, the output of the detection coil directly above the cable 501 is the largest according to equation (1) already mentioned, so each LED array 341 to 354 It lights up as indicated by the diagonal lines in Figure 7a. When the cable 502 or 503 is present with respect to the magnetic field detection sensor unit 1, the display lights up as shown in the display patterns shown in FIGS. 7b and 7c, respectively. The line connecting the positions of LED arrays with a large number of lit LEDs on the display shown in FIG. 7 roughly corresponds to the actual position and arrangement direction of the cable.

FIG. 8a shows another example of the circuit configuration of the method of the present invention. In the configuration example shown in FIG. 8a, there are two signal receiving sections 2, 2' (bandwidth amplifier 201, detector 221) for the magnetic field detection sensor sections 1, 1', and the input and output terminals of each signal receiving section are switch circuits S1, S2, S
3. Using S4, the switch is switched by the switch switching circuit 300, and the plurality of sensors 101-1
07, 108 to 114 are received and displayed.

FIG. 8b shows the signal processor 301 and the display 341.
An example of the configuration is shown below. FIG. 8b shows a circuit configuration in which memory circuits 3031 to 3040 are added to the circuit configuration of FIG.
040, the display is held until the next input is made by switching the switch.
The configuration and display method of the display 341 have already been
This is the same as shown in FIGS.

FIG. 9 shows another example of the circuit configuration of the method of the present invention. In FIG. 9, a cathode ray tube oscilloscope 380 is used as a display. In FIG. 9, the signals detected by the detection coils 101 to 107 and 108 to 114 are sequentially transferred to the signal receivers 2 and 2' (bandwidth amplifier 2
01, is sent to the detector 221). The outputs of the signal receivers 2, 2' are sent to vertical axis signal inputs Y1 and _Y2 of a cathode ray tube oscilloscope ₃₈₀ , respectively, through integrators 360, 360'. on the other hand,
The switching position detector 370 of the switch changer 301 sends the position signals of the switches S1 and S3 to the horizontal axis signal input X of the cathode ray tube oscilloscope 380.

FIG. 10 is a diagram for explaining a configuration example of the switch changer 300 and the switch changeover position detector 370. As shown in FIG. 10a, a rotary switch 361 is used as the switch, a potentiometer is used as the switch switching position detector 370, and a pulse motor 363 is used as the rotary drive machine.
use. Now, if these rotating shafts are connected to each other, the pulse motor 363 will be rotated by the pulse motor controller 364, thereby switching the rotary switch 361.
At the same time, the rotation shaft of the potentiometer 370 also rotates, so by electrically connecting the potentiometer 370 as shown in FIG. 10b, the voltage corresponding to the rotational position of the rotary switch 361 can be
V _P is obtained.

FIG. 11 is an example of a display on the cathode ray tube oscilloscope 380 having the configuration shown in FIG. If the positional relationship between the magnetic field detection sensor section 1 and the cables 501 to 503 is as shown in FIG.
502 and 503, the diagrams indicated by solid lines 381 to 386 in FIG. 11a, b, and c are displayed on the cathode ray tube oscilloscope 380. The positions and arrangement directions of the cables 501 to 503 roughly correspond to the positions and arrangement directions indicated by broken lines 390 to 392.

FIG. 12 shows an example of application of the cable tracking method of the present invention. A cable re-burying machine 400 is controlled from a mother ship 401 via a control cable 402, and the cable re-burying machine 400 is controlled from a mother ship 401 via a control cable 402. The cable 40 travels with a traveling mechanism 403 such as
5. The above-described magnetic field detection sensor unit 1 is mounted between the left and right traveling mechanisms 403 of the cable re-burying machine 400, and the signal receiving unit 2 is mounted on the cable re-burying machine 400.
Equipped with The output signal of the signal receiving section 2 is transmitted to the signal processing section 3 of the mother ship 401 via the control cable 402, and processed and displayed. While looking at the position of the cable displayed on the display 341 in the signal display section 3, the display on the display indicates that the position of the cable is at the center of the reburial machine 400, as shown in FIG. 7a or FIG. 11a, for example. So that the re-burying machine 4
By controlling 00, burial can be carried out safely and reliably without damaging the initial installation of a burying machine or the cable. 40 in Figure 12
6 is a control device, 407 is a traveling mechanism drive unit, 408
is the seabed surface, and 409 is a jet water jet discharge nozzle.

FIG. 13 shows another application example of the tracking method of the present invention, in which a cable search device 410 is equipped with a magnetic field detection sensor section 1, and a cable search device 410 is installed to detect the position of a buried cable 405 that has become an obstacle.
05, locate the point of failure, and drop an ultrasonic generator or the like on the point of failure to improve the efficiency of cable repair work. The signal from the magnetic field detection sensor section 1 is received by the signal receiver 2, transmitted to the mother ship 401 via the control cable 402, processed by the signal processing and display section 3, and the position is displayed.
Therefore, the cable 4 displayed on the display 341
While observing the position of 05, the propulsion device 411 mounted on the cable search device 400 is controlled using the control device 406, and the cable search device 410 can be accurately moved along the cable 405. When the explorer 410 passes the fault point, the signal detected by the sensor unit 1 disappears, so the display 3
By paying attention to the display of 41, the point of failure can be easily detected.

The above is an example of application to cables on the seabed, but it goes without saying that the cables are not limited to the seabed, but can also be used on land or in rivers. Further, the number of coils in the magnetic field detection sensor section may be plural as long as it is not limited to the structure shown in FIG. 3. Furthermore, although an example has been described in which an induction coil is used as the magnetic field detection sensor, a flux gate type sensor may also be used, for example.

[Brief explanation of the drawing]

Figures 1 and 2 are block diagrams showing an example of the configuration of the cable tracking system of the present invention, and Figures 3a, b, and c are perspective views and characteristic diagrams showing actual examples of the magnetic field detection sensor section used in the present invention. , Figure 4a,
b, FIG. 5, FIG. 6, FIG. 8 a, b, FIG. 9, FIG. Figures a, b, c
12 and 13 are schematic diagrams showing examples of application of the present invention. 1... Magnetic field detection sensor section, 2... Signal receiving section,
3...Signal processing display unit, 4...AC signal supply unit,
5... Cable, 6... Current supply cable, 1
01-114... Magnetic field detection coil, 115... Lead wire, 116... Connection wire, 120... Coil support rod, 121... Connection rod, 201-214... Bandwidth amplifier, 221-234... Detector, 300...
...Switching circuit, 301-314...Signal processor, 3
41-354...Indicator, S1, S2, S3, S
4... Switch circuit, 360, 360'... Integrator, 361... Rotary switch, 363...
Pulse motor, 364... Pulse motor controller, 370... Switching position detector, 380... Braun tube oscilloscope, 400... Cable re-burying machine, 401... Mother ship, 402... Control cable, 403... Traveling mechanism, 404 ... Jet water discharge mechanism, 405 ... Cable, 40
6...Control device, 407...Traveling mechanism drive unit, 4
08... Seabed surface, 409... Jet water discharge nozzle, 410... Cable search machine, 411... Propulsion device, 501, 502, 503... Cable,
3011-3020...Level comparison circuit, 303
1-3040...Memory circuit, 3401-341
0...LED, 3051-3060...LED drive circuit.

Claims (1)

[Claims] 1. A magnetic sensing body comprising multiple rows of magnetic sensing sensors arranged at desired intervals so that the directional principal axes indicating the maximum sensitivity direction coincide with each other Detecting the level of an alternating current signal induced in each of the plurality of magnetic detection sensors by magnetism caused by an alternating current, and displaying the detected level, thereby displaying a pattern indicating the position and arrangement direction of the cable to be detected. Cable tracking system with display means.