JPH11295423A - Apparatus for detecting underwater obstacle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an obstacle present under a shallow water depth region. SOLUTION: A blue green laser transmitter 11 for oscillating a blue green laser light, and a blue green laser receiver 12 for receiving a reflected light from an obstacle, are set to a gimbals mechanism 13 which scans the laser light by shaking its head. A controller 15 is connected via a cable 14 to the blue green laser transmitter 11, blue green laser receiver 12 and gimbals mechanism 13. The controller 15 supplies a power source, controls a direction of the gimbals mechanism 13, processes a detection signal of the blue green laser receiver 12 and displays processed results.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater obstacle detecting device for detecting an underwater obstacle.

[0002]

2. Description of the Related Art In order to detect an underwater object, an apparatus using sound waves is used. FIG. 3 is a diagram showing a schematic configuration of a conventional underwater obstacle detection device. A sound wave is propagated into the water from a sonar 32 installed at a position below the water surface of the ship 31, and a reverberation sound from the obstacle 33 is received to detect an object.

[0003]

The above-described underwater obstacle detection device is widely used for detecting a target in water. However, when the operation area is a shallow sea area with a water depth of several meters, it may be subject to tides and waves. There has been a problem that operation is difficult due to noise or the traveling noise of the ship itself. An object of the present invention is to provide an underwater obstacle detection device capable of detecting an underwater object even in a shallow water depth region.

[0004]

Means for Solving the Problems The present invention is configured as follows to achieve the above object. The present invention (claim 1) provides a light source that irradiates light obliquely to a water surface, and an incident light emitted from the light source is reflected by hitting an underwater obstacle, and follows a path substantially the same as the path of the incident light. A reflected light detecting unit that detects reflected light that follows, a position calculating unit that calculates a position at which light emitted from the light source is incident on the water surface, a detection signal of the reflected light detecting unit, and a position calculated by the position calculating unit. And an obstacle determining unit that determines the presence or absence of an underwater obstacle based on the position information.

[0005] A preferred embodiment of the present invention is shown below.
The light source is a laser oscillator that emits blue-green laser light having a wavelength of about 5 μm.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an underwater obstacle detection device according to an embodiment of the present invention. FIG. 2 shows an appearance in which the underwater obstacle detection device of FIG. 1 is actually installed on a ship.

A blue-green laser transmitter 11 that oscillates blue-green laser light and a blue-green laser receiver 12 that receives reflected light from an obstacle are installed on a gimbal mechanism 13 that scans the laser light by oscillating motion. Have been.

A controller 15 is connected to the blue-green laser transmitter 11, the blue-green laser receiver 12, and the gimbal mechanism 13 via a cable 14. Controller 15
Performs power supply, controls the orientation of the gimbal mechanism 13, processes the received signal of the blue-green laser receiver 12, and displays the processing result.

The blue-green laser transmitter 11, the blue-green laser receiver 12, and the gimbal mechanism 13 are desirably installed at a high position on a boat 21 overlooking the water surface, as shown in FIG. Further, the controller 15
1 is desirably installed.

Next, the operation of the present apparatus will be described. The blue-green laser transmitter 11 transmits blue-green laser light toward the water surface in front of the ship 21. The transmitted blue-green laser light is
It propagates in the atmosphere and enters the water surface. Part of the blue-green laser light that has entered the water surface is refracted and enters the water.

When the obstacle 22 exists in the optical path of the blue-green laser light, the blue-green laser light is reflected by the obstacle. Then, the reflected light follows the substantially same path as the incident light and is received by the blue-green laser receiver 12.

The received signal is transmitted to the controller 15 via the cable 14, and detects that an obstacle 22 exists in the water. Then, the controller 15 calculates the incident position on the water surface from the height of the blue-green laser transmitter 11 from the water surface and the irradiation angle of the blue-green laser transmitter 11.
Then, the distance from the ship 21 to the incident position is calculated.
Then, the controller 15 displays the direction of the obstacle 22 and the distance to the incident position of the laser beam.

Further, by performing the above operation while moving the gimbal mechanism 13 according to a control signal from the controller 15, it is possible to display the size of the obstacle below the water surface.

For example, when an obstacle located 300 m in front of a ship and 5 m deep is detected using blue-green laser light having a wavelength of 5 μm and an output of 100 mJ. The output P _r of the received reflected light of blue-green laser receiver, P _r = 100 mJ (oscillation output) × exp [-0.19 × 0.3 × 2] (300m of atmospheric attenuation: round trip) × exp [-0.1 × 7.5 × 2] (atmospheric attenuation of 300 m: round trip) × 0.41 ² (water surface transmittance) × 0.0001 (obstacle reflectance) = 0.00033 mJ. This value is a sufficiently receivable level, and it is possible to sufficiently detect an object 300 m ahead and 5 m deep.

According to this embodiment, by irradiating blue-green laser light with little attenuation to water to the water and detecting the reflected light from the obstacle, the influence of the surrounding noise can be obtained. Since there is no obstacle, an obstacle below the water surface can be detected even in a shallow water depth area.

Also, by using light, FRP which is difficult to find with conventional surface search radars
Pleasure boats can also be detected. Note that the present invention is not limited to the above embodiment. For example, the light emitted from the light source is not limited to blue-green, and light having a wavelength that is less attenuated by water can be used. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0017]

As described above, according to the present invention, by detecting underwater obstacles by using light, there is no influence of noise from the surroundings, and therefore, the present invention is applicable to a shallow water depth region. Even underwater obstacles can be detected.
Also, the blue-green laser has little attenuation with respect to water,
Obstacles in deeper areas can be detected.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an underwater obstacle detection device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation example of the underwater obstacle detection device in FIG. 1;

FIG. 3 is a diagram showing a configuration of a conventional underwater obstacle detection device.

[Explanation of symbols]

 11 Blue-green laser transmitter 12 Blue-green laser receiver 13 Gimbal mechanism 14 Cable 15 Controller 21 Ship 22 Obstacle

Claims (2)

[Claims] 1. A light source for irradiating light obliquely to a surface of water, and incident light emitted from the light source is reflected by an obstacle in the water, and reflected light that follows a path substantially the same as the path of the incident light. A reflected light detection unit for detecting, a position calculation unit for calculating a position at which the light emitted from the light source is incident on a water surface, a detection signal of the reflected light detection unit, and position information calculated by the position calculation unit. An underwater obstacle detection device, comprising: an obstacle determination unit that determines the presence or absence of an underwater obstacle based on the information. 2. The apparatus according to claim 1, wherein the light source is a laser oscillator that emits blue-green light having a wavelength of about 5 μm.