JPS62185507A - Detector of position of installation of underwater cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention provides an underwater cable for detecting from which direction the underwater cable is being introduced into the cable entry port of the undergrounding device when the underwater cable is buried using a burying device. The present invention relates to an introduction position detection device.

2. Description of the Related Art Conventionally, there have been the following devices for detecting the introduction position of an underwater cable into a buried device, but each of them had drawbacks.

(1) TV camera TV cameras require lights for illumination as the depth increases, and when excavating with water jets, sand and mud from the seabed fly up due to the water current, obstructing the TV camera's view.
Cable direction detection is not possible.

(2) A device with a magnetic detection device attached to the tip of the manipulator This device detects the cable introduction position by attaching a magnetic detection device to the tip of the manipulator and detects the magnetic field generated in the energized cable, but the manipulator has a complicated structure. Control is also complex.

(3) Method of using only ultrasonic waves The ultrasonic transmitting device is shown in Fig. 8, (a) a view from the opening direction, and (b) a side view.

As shown in the figure, a plurality of ultrasonic transmitter/receivers 1 are arranged vertically and horizontally in the cable inlet tube body 2, or a small number of them are moved to transmit ultrasonic waves, receive signals reflected on the cable, or transmit ultrasonic waves to the cable section. This device detects the position by receiving attenuated signals on the other side of the cable, but if sand, mud, etc. fly up between the cable and the ultrasonic transceiver may be difficult to identify.

(4) The vertical introduction angle of the mechanical detection device is determined by the rotation angle of the support arm of the roller 3 as the roller 3 moves up and down in accordance with the vertical direction of the cable 7, as shown in the mechanical detection device for vertical detection in Fig. 9. However, the left and right positions can be detected as shown in Figure 10 (horizontal) of the figure (a) seen from the opening direction of the inlet pipe body 2 and the figure (b) seen from the side of the inlet pipe body 2. As shown in the mechanical detection device for direction finding, a support arm 5 with a roller 3 is pressed against the cable from the left and right by a torsion spring 6, liquid pressure, etc., and the rotation angle in the forward direction is detected by the angle detection device 4 in the support arm 50 diagram. It is a detection structure, and it is necessary to install two sets of detection devices, one for the top and bottom and one for the left and right. In addition, the left and right detection devices tend to become clogged with sand or the like in the spring 6, resulting in malfunction.

Furthermore, when the cable connection is introduced, the connection may become stuck and fail.

(5) Method using magnetic sensors This method detects the magnetic field generated by energizing a cable or by electromagnetic induction. Conventionally, three or more magnetic sensors are used,
Alternatively, the position is detected using a combination of multiple magnetic sensors with two directivity, which has the disadvantage that a large number of magnetic sensors are required and the magnetic sensor has a complicated structure.

Problems to be Solved by the Invention The present invention makes it possible to reliably detect the direction in which the underwater cable is being introduced even when sand and mud are thrown up when burying the underwater cable using a burying device. When the underwater cable is deviated from the direction of burial, or when the amount of slack in the underwater cable is small and the buried equipment is pulled up by the cable, the cable payout speed can be controlled from the ship to increase or decrease the slack in the underwater cable, or It is possible to control the burying direction with the burying device, and to control the burying direction by the direction in which the underwater cable is introduced, and through these operations, it is possible to prevent the burying device from falling over and damage the cable, and to ensure the operation of the burying device. The goal is to make it possible to bury the waste safely and reliably.

Means for Solving the Problems The present invention fixes an inlet tube having a cable as an inlet to a burial device main body, and extends the inlet end of the inlet tube to the outside of a line extending in the axial direction. Two magnetic sensors with a single directivity are fixed to the buried device main body at the left and right ends and at the upper or lower end to constitute an underwater cable introduction position detection member, and a magnetic detection circuit is connected to the magnetic sensors. , a signal cable connects the scanner, an A/D conversion circuit, an interface device, and a computer to a display device, and a power supply circuit is connected to the scanner via a current detection circuit;
A calculation formula incorporating the distance 2 between the two magnetic sensors is stored in the computer in advance, a cable is inserted from the entrance of the inlet tube, and the strength of the magnetic field in the magnetic sensor due to the current of the cable is calculated. The strength of the detected magnetic field Hlx −, H2x or HIY %
H2Y % However, HIXH2X is the horizontal magnetic field component of the magnetic sensor when the pointing directions of each magnetic sensor are the same, and HIYsH2Y is the vertical magnetic field component of the magnetic sensor when the pointing directions of each magnetic sensor are set at right angles or parallel to each other. The magnetic field component is input to the computer, the horizontal distance and the vertical distance of the cable are calculated by the computer, and are displayed on the display device.

Function The present invention simply fixes two magnetic sensors having a single directionality to the main body of the burying device at the left and right ends and the upper end or the lower end of the front part of the cable introduction entrance, and This device uses a magnetic sensor to measure the strength of the generated magnetic field and detects the cable position.

Therefore, when compared with conventional technology, the structure is simple and allows the direction of cable introduction to be detected reliably even in turbid water.
Since there are no moving parts, it is robust and inexpensive.

In addition, the only device attached to the detection position of the buried device is the magnetic sensor, which requires less installation space and can be configured to be compact and lightweight.

In the case of reflected images from TV cameras and ultrasound, it is necessary to transmit a large amount of information to the ship, but this device only needs information on the strength of the magnetic field from two magnetic sensors, so the amount of information transmitted is small. It's over.

Mechanical cable introduction direction detection devices measure the distance between the ship and the buried equipment and the distance that the underwater cable connection has been let out from the ship in advance to avoid catching the cable connection. When the cable reaches the distance to be introduced into the device, it is necessary to perform operations such as raising the roll part of the device, but this device does not come into contact with the cable, and the above operations are not necessary.

Conventional cable position detection devices using magnetic sensors detect the position using three or more magnetic sensors, or a combination of two or more magnetic sensors with two directional characteristics, and many magnetic sensors are required. The disadvantage was that the sensor had a complicated structure.

Embodiment FIG. 1 is a structural layout diagram of an embodiment of the underwater cable introduction position detecting device (hereinafter referred to as the device) of the present invention, and FIG. A view from the direction is shown.

The configuration of the device of the present invention will be explained.

2 is a cable inlet pipe body, 7 is a cable introduced into the burial device, 9 is a burial device main body, IOA, 1. OE indicates a search coil type magnetic sensor.

Search coil type magnetic sensor 10A, 1. The OBs are attached to the burial device main body 9 at symmetrical positions in the front part of the inlet pipe body 2, with the magnetic sensing direction aligned with the horizontal direction of the burial device main body 9. Its mounting position is outside the extension of the inlet pipe body 2. Therefore, it will not get caught on the cable 7. Further, when the magnetic sensor is mounted on the buried device main body 9, it can also be mounted by being buried inside the main body if the position is a non-magnetic material.

Since search coil type magnetic sensors 1OA and IOB are used on the seabed etc., search coil type magnetic sensors 10A and 1 are used.
0B is sealed in a non-magnetic, non-conductive watertight container such as plastic. Further, the signal lines from the search coil magnetic sensors 1OA and IOB are also insulated to prevent seawater from entering.

Two search coil type magnetic sensors1. OA, IO
The output VX obtained by B is given by the relative permeability μ8, the vacuum permeability μo, the cross-sectional area of one coil S1, the number of turns N, and so on.
Obtain the magnetic field strength HX.

This magnetic detection circuit [1] is shown in FIG. FIG. 3 shows a search coil type magnetic sensor 10A, 1. After the output voltage generated by the OB is integrally amplified by the integral amplifier circuit 20, the dividing circuit 21 divides the output voltage by μ8 μ. It is divided by the voltage equivalent to NS, and when AC current is passed through the cable, it is an AC output, so the square circuit 22 and the average circuit 2
3. The effective value is output through the open circuit 24.

Two search coil type magnetic sensors 10A, , IO
The magnetic field strength components H1x1H2x, H1Y, and H2Y in the directional direction B are cable currents measured onboard the ship after being transmitted to the ship through the signal cable 12. At the same time, the signal output is input to a scanner 13 which sequentially extracts the signal output by scanning. The magnetic field strength and current value taken out in order by the scanner 13 are converted into digital signals by the A/D conversion circuit 4, and input to the CPU (computer) 16 through the interface device 15, where they are subjected to arithmetic processing and the cable position is determined. Output to the display device 17.

Here, the cable 7 generates a magnetic field, so the power source 18
The cable is used to pass an alternating current, but the outgoing route of current is carried out using the conductor of the cable, and the return route is carried out by leading the conductor from one end of the cable section that has already been laid into seawater, and using seawater.

In the case of alternating current energization, the current value is converted into an effective value output by the current detection circuit 19 and inputted to the CPU (computer) 16 through the scanner 13, A/D conversion circuit 14, and interface device 15.

Here, as shown in FIG. 4, the current detection circuit 19 sums the current flowing through the cable 7, adds the resistor inserted in the cable circuit to R8, and calculates the current flowing through the resistor R1 of the measuring circuit to R8.
If the voltage across the resistor R is Vl, then the current flowing through the cable 7 can be detected by the current detection amplifier circuit 25. In order to make the detection result an effective output, it is passed through a squaring circuit 26, an averaging circuit 27, and an opening circuit 28.

For calculation processing by the CPU (computer) 16, calculation formulas are created in advance using software.

Then, the magnetic sensor distance 2 is built into the software at the front, and the value of the current flowing through the cable 7 is measured onboard the cable 7 at the time of position detection, and the CPU (computer) 1
6, the horizontal and vertical distances between the magnetic sensor and the cable are output to the display device 17.

Next, a method of calculating the couple horizontal distance and vertical distance using the apparatus of the present invention will be explained.

(1) Search coil type magnetic sensor 10A, IOB
When the orientation directions of the search coil type magnetic sensors 10A and IOB are made the same, the codes of the search coil type magnetic sensors 10A and IOB in that case are set to 29.30, and the magnetic field generated around them is as shown in FIG. Here, Distance between the magnetic sensors Vertical distance between the magnetic sensors and the cable h Horizontal distance between the magnetic sensors 29, 30 and the cable XlX2 magnetic sensors 29, 30
The angle between the line connecting the cable and the perpendicular direction
Distance between the θ1θ2 magnetic sensors 29 and 30 and the cable Strength of the magnetic field that intersects with the γ1γ2 magnetic sensors 29 and 30 Magnetic field component in the pointing direction of the HIH2 magnetic sensor 29 (output of the magnetic sensor 29) Magnetic field in the pointing direction of the HIX magnetic sensor 30 If the component (output of the magnetic sensor 30) is H2X, then Xt + Xt = -e...
(3) Xi +h −γ1 ・・・・・・・・・
(4)x22 +b2-γ2'...
...(5) From (1) to (5), we obtain the following result. That is, the cable position (horizontal distance x1, vertical distance h) can be known from HIX N H2X %, 1) detected by the coil of the magnetic sensor and distance 0.

(2) Search coil type magnetic sensor 1OA, I
When the OE directions are installed so that they are perpendicular to each other, the search coil type magnetic sensor in that case, 1. OA
, IOB's code is 31.32, and the magnetic field generated around it is as shown in FIG.

Here, Distance between magnetic clasps Vertical distance between Numa magnetic sensors and cable h Magnetic sensor 3
1, 32 and the cable horizontal distance
Strength of the magnetic field intersecting with H1H2 Magnetic field component in the pointing direction of the magnetic sensor 31 (output of the magnetic sensor 31) Magnetic field component in the pointing direction of the H1Y magnetic sensor 32 (output of the magnetic sensor 32) H2y, (2) ~ From (6), where α=HIY2 engineering. 2+H2x2(4π-6H1y-ko
)2(3) Search coil type magnetic sensor 10A, I
When the OB orientation directions are installed parallel to each other, the search coil type magnetic sensor 10A in that case,
The sign of IOB is assumed to be 31.32, and the magnetic field generated around it is as shown in FIG.

Here, H engineering Y is the same as (6), and H2Y is (3
) to (force), and in both the second and third cases, the cable position (horizontal distance x□, vertical distance h) can be known from the coil output and p1.

Note that in this calculation method, a search coil type magnetic sensor is used as the magnetic sensor, but the search coil type magnetic sensor can only measure alternating current magnetic fields. However, the coil 2
A magnetic sensor using a combination of double-frequency shadow magnetic modulators can measure even direct current magnetic fields. Further, in the case of direct current, a square circuit, an average circuit, and an open circuit for outputting an effective value are not required in the current and magnetic field detection circuit.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention has two magnetic sensors with one directionality fixed at the left and right ends and at the upper or lower end of the front part of the entrance of the cable inlet pipe body, and the magnetic sensors are energized. This method detects the cable position by measuring the strength of the magnetic field generated in the circumferential direction of the cable using a magnetic sensor, so it can reliably detect the cable introduction position and direction even in muddy water such as sand and mud. The structure is simple and there are no moving parts, making it robust and inexpensive.

Only two magnetic sensors with single directivity are required.

Further, the only device attached to the detection position of the buried device is the magnetic sensor, which requires less installation space and can be configured to be compact and lightweight.

In the case of reflected images from TV cameras and ultrasonic waves, it is necessary to transmit a large amount of information to the ship, but this device only needs information on the strength of the magnetic field from two magnetic sensors, so the amount of transmitted information is small. It's over.

Mechanical cable introduction direction detection devices measure the distance between the ship and the buried equipment and the distance that the underwater cable connection has been let out from the ship in advance to avoid catching the cable connection. When the cable reaches the distance to be introduced into the device, it is necessary to perform operations such as raising the roll part of the device, but the device of the present invention does not come into contact with the cable.
The above-mentioned operation is also unnecessary.

[Brief explanation of drawings]

FIG. 1 is a structural layout diagram of an embodiment of the underwater cable introduction position detection device of the present invention, FIG. The figure is a block diagram of the magnetic field detection circuit of the present invention.
The figures show the current detection circuit of the present invention, Fig. 5, Fig. 6, and Fig. 7.
The figure shows a diagram of the magnetic field around the magnetic sensor and an explanatory diagram of calculation. Figure 8 shows a cable introduction direction detection device using an ultrasonic sensor.
Figure 9 shows a mechanical detection device for vertical detection, Figure 10 shows a mechanical detection device for horizontal detection, and (A) shows the inlet pipe body 2.
Figure (B) shows a view from the side of the inlet pipe body.

Claims (1)

[Claims] An inlet tube body with a cable as an inlet is fixed to the burial device main body, and two magnetic sensors having a single directivity are placed outside a line extending in the axial direction from the edge of the inlet part of the inlet tube body. are fixed to the buried device main body at the left and right ends and at the upper or lower end to constitute an underwater cable introduction position detection member, a magnetic detection circuit is connected to the magnetic sensor, and a signal cable is used to connect a scanner and an A/D conversion circuit. , a display device via an interface device and a computer, a power supply circuit connected to the scanner via a current detection circuit, and a calculation formula incorporating the distance l between the two magnetic sensors in advance into the computer. Insert a cable from the inlet of the inlet tube, detect the strength of the magnetic field in the magnetic sensor due to the current of the cable, and determine the strength of the detected magnetic field H_1_X, H_2_X or H_1_Y, H_
2_Y, where H_1_X and H_2_X are the horizontal magnetic field components of the magnetic sensors when the pointing directions of each magnetic sensor are the same, and H_1_Y and H_2_Y are the magnetic sensors when the pointing directions of each magnetic sensor are set at right angles or parallel to each other. An underwater cable introduction position detecting device configured to input a vertical magnetic field component into the computer, calculate a horizontal distance and a vertical distance of the cable by the computer, and display the results on the display device.