JP2591490B2 - Sea area monitoring system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sea area monitoring system, and more particularly to a system for monitoring a certain area of sea area from a mooring buoy.

[0002]

2. Description of the Related Art FIG. 6 is a schematic diagram showing an example of a conventional sea area monitoring system. The mooring buoy 101 is moored by a mooring device 102 on the sea floor, and a land-based radar 201 monitors whether or not the vessel 104 has entered a boundary 103 having a radius R from the mooring buoy 101. When the radar 201 confirms the approach of the ship 104, the dispatcher 202 transmits a radio signal to the ship approach warning device 10 provided on the mooring buoy 101.
5 to the ship 10 by siren and light emission signal, etc.
Warn 4

[0003]

However, in the above-mentioned conventional system, it is necessary to install the radar 201 for monitoring the approach of the ship on the ground, and there is a problem that the system becomes large-scale. . In addition, since an alarm is issued by wireless remote control, the device configuration of the system is complicated.

An object of the present invention is to provide a sea area monitoring system that does not require ground facilities and remote control.

[0005]

A marine area monitoring system according to the present invention comprises at least three receivers which are arranged orthogonally on the seabed directly below a mooring buoy and convert sound waves emitted by a marine navigation vehicle into electric signals, and these receivers. Determination value calculating means for calculating a determination value that changes according to the distance between the mooring buoy and the marine navigation vehicle based on the phase difference between the received signals respectively output from the vessels, A memory means for pre-storing the value indicated by the determination value as a reference value when located on a line, and a comparison for determining whether the marine navigation vehicle has entered a certain range of sea area by comparing the determination value with the reference value Means,
It is characterized by consisting of.

[0006]

According to the present invention, a sound wave emitted from a marine navigation body is received by a receiver provided on the seabed immediately below a mooring buoy, and the received signal is transmitted from the mooring buoy of the marine navigation body based on a phase difference between the receivers. A determination value according to the distance is calculated and compared with a reference value calculated in advance to monitor whether or not the marine navigation vehicle has entered a predetermined sea area.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a sea area monitoring system according to the present invention. The mooring buoy 1 is connected by a mooring cable 2 to a mooring device 3 fixed to the sea floor. The mooring cable 2 has a built-in line for transmitting a signal.

The mooring device 3 has a built-in sea area judging device 4. The sea area judging device 4 detects a radiated sound 6 emitted from the propulsion unit of the ship 5 as described later, and issues an alarm of a radius R from the mooring buoy 1. It is determined whether or not the ship 5 has entered the sea area 7.

When it is determined that the ship 5 has entered the warning sea area 7, the sea area judgment device 4 transmits a judgment signal 501 to the alarm device 8 through the line of the mooring cable 2, and an alarm means such as an alarm sound and a light emission signal. A warning is issued to the ship 5 by the command.

FIG. 2 shows a sea area judging device 4 in this embodiment.
FIG. 3 is a block diagram showing a circuit configuration of FIG. The sea area determination device 4 has three receivers Sx, Sy, and Sc, and these receivers are arranged such that a straight line connecting Sx and Sc and a straight line connecting Sy and Sc are orthogonal (orthogonal arrangement). ) (See FIG. 4).

The receivers Sx, Sy, and Sc receive the radiated sound 6 emitted from the ship 5 at each position, and receive the receiver Sx
And Sc are output to the phase difference detection circuit 401, and the reception signals of the receivers Sy and Sc are output to the phase difference detection circuit 402. The phase difference signals φx and φy output from the phase difference detection circuits 401 and 402 are respectively squared by multipliers 403 and 404, and their outputs φx ² and φy ² are added by an adder 405 to obtain an addition value φx ² + Φy ² is input to the comparator 406 as a judgment value.

[0013] The comparator 406 compares the determination value .phi.x ² + [phi] y ² and decision data (reference value) Cpi, vessels 5 the radius R
Is determined inside or outside the warning sea area 7, and a determination signal 501 is output to the warning device 8 through the cable 2.

The judgment data Cpi is stored in the judgment data memory 40.
7, the judgment data output circuit 409 reads out the data from the memory 407 and outputs it to the comparator 406 in accordance with the depth Hi measured by the depth unit 408.

FIG. 3 is a schematic diagram showing an example of data stored in the determination data memory 407 in this embodiment. Determination data Cpi is stored corresponding to each of the depths Hi.

[0016] waters determination method Figure 4 is a wave receiver Sx waters judging device 4 in this embodiment,
FIG. 5 is a coordinate diagram showing a positional relationship between Sy and Sc and the ship 5, and FIG. 5 is a coordinate diagram for explaining a reception phase difference of the receiver.

First, in FIG. 4, the following equation is established from the formula of the direction cosine.

1 = cos ² θx + cos ² θy + cos ² θz (1) where θx is the angle between the X axis and a straight line connecting the receiver Sc and the ship position P, and θy is the receiver Sc and the ship The angle between the straight line connecting the position P and the Y axis and θz are the angle between the straight line connecting the receiver Sc and the ship position P and the Z axis.

As shown in FIG. 5, since there is a distance difference d · cos θx between the receivers Sx and Sc with respect to the sound wave plane of the radiated sound 6, the reception of the receivers A phase difference φx corresponding to the distance difference occurs between the signals. Similarly, a phase difference φy occurs between the reception signals of the receivers Sy and Sc. Where d is the receivers Sx and Sc
And the distance between the receivers Sy and Sc.

The phase difference φx and φy and the direction cosine angle θx
And θy, the following equations are satisfied.

Cos θx = λφx / 360d (2) cos θy = λφy / 360d (3) where λ is the wavelength of the radiated sound 6.

By substituting equations (2) and (3) into equation (1), φx ² + φy ² = 360d (1-cos ² θz) / λ ² (4) θz = arctan (D / H) ... (5) Here, D is the distance between the position Po of the mooring buoy 1 and the ship position P, and H is the distance (depth) of the receiver Sc from the sea surface.
It is.

Therefore, the judgment data Cpi stored in the judgment data memory 407 is given as the right side of the equation (4), and Cpi = 360d (1-cos ² θz) / λ ² (6) where θz = arctan (R / Hi). That is, the determination data Cpi corresponding to the depth Hi is calculated in advance using Expression (6), and is stored in the memory 407.

The judgment data output circuit 409 is provided with a depth unit 408.
Is input, and as shown in FIG. 3, the determination data Cpn corresponding to the depth is stored in the memory 40.
7 and output to the comparator 406.

The comparator 406 calculates a square addition value φx of the phase difference calculated from the reception signals of the receivers Sx, Sc, and Sy.
² + φy ² is compared with the read determination data Cpn,
φx ² + φy ² ≦ Cpn if the ship position P is the decision signal 501 determines that the area of the radius R and '1', φx ²
If + φy ² > Cpn, the ship position P is determined to be outside the area of the radius R, and the determination signal 501 is set to '0'.

The alarm device 8 of the mooring buoy 1 outputs a judgment signal 50
Only when “1” is “1”, an alarm is issued by means such as a siren or a light emission signal, and the ship 5 is notified that it is approaching the alarm sea area 7.

[0027]

As described in detail above, the sea area monitoring system according to the present invention receives sound waves emitted from a marine navigation vehicle by at least three receivers provided on the seabed directly below a mooring buoy. Calculate a determination value according to the distance of the marine navigation vehicle from the mooring buoy based on the phase difference between the receivers of the received signal, and compare it with a previously calculated reference value to a predetermined sea area of the marine navigation vehicle. Monitor for any ingress. For this reason, it is possible to monitor the sea area simply by installing a receiver and a mooring device that accommodates the circuits required for computation on the sea floor directly below the mooring buoy, eliminating the need for conventional ground equipment and remote control by radio Becomes

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a sea area monitoring system according to the present invention.

FIG. 2 is a block diagram illustrating a circuit configuration of the sea area determination device 4 according to the present embodiment.

FIG. 3 is a schematic diagram illustrating an example of data stored in a determination data memory 407 according to the present embodiment.

FIG. 4 is a diagram illustrating a receiver S of the sea area determination device 4 according to the embodiment.
FIG. 3 is a coordinate diagram showing a positional relationship between x, Sy, and Sc and a ship 5.

FIG. 5 is a coordinate diagram for explaining a reception phase difference of the receiver in the embodiment.

FIG. 6 is a schematic configuration diagram illustrating an example of a conventional sea area monitoring system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mooring buoy 2 Cable 3 Mooring device 4 Sea area judging device 5 Ship 6 Radiated sound 7 Warning sea area 8 Alarm device Sx, Sy, Sc Receiver Cpi Judgment data (reference value)

Claims (4)

(57) [Claims] 1. A system for monitoring a certain range of sea area centered on a mooring buoy, wherein at least three receiving waves are arranged orthogonally on the seabed immediately below the mooring buoy and convert sound waves emitted by a marine navigation vehicle into electric signals. A determination value calculating unit that calculates a determination value that changes in accordance with a distance between the mooring buoy and the marine navigation vehicle, based on a phase difference between reception signals output from the receiver. A memory means for pre-storing a value indicated by the determination value as a reference value when the marine navigation vehicle is located on a boundary of the sea area in the certain range; and comparing the determination value with the reference value to obtain the marine navigation vehicle. And a comparing means for determining whether or not has entered the certain area of the sea area. 2. The detection value calculation means, comprising: a phase difference detection means for respectively detecting a phase difference between received signals output from two receivers arranged in two directions orthogonal to each other; 2. The sea area monitoring system according to claim 1, further comprising: a multiplying unit that calculates a square of the phase difference; and an adding unit that adds a square of the phase difference. 3. 3. A depth measuring device for measuring a vertical distance between a sea surface and the receiver, wherein the memory stores a reference value corresponding to the measured depth in a table format. The sea area monitoring system according to claim 1. 4. A mooring device installed on a seabed and the mooring buoy moored to the mooring device by a cable, wherein the mooring device includes the at least three receivers, the determination value calculating means, The cable includes a line for transmitting a judgment signal of the comparison unit, and the mooring buoy receives the judgment signal from the line of the cable and issues an alarm. The sea area monitoring system according to any one of claims 1 to 3, further comprising an alarm unit.