JP2891678B2 - Rotary underwater laser viewing 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 rotary underwater laser visual recognition device, and more particularly to a technique for improving workability in photographing.

[0002]

2. Description of the Related Art There is a laser visual recognition device that uses a laser beam to clearly recognize a visual target placed in water with poor transparency. Conventionally, this type of laser visual recognition device irradiates a laser pulse to an object to be viewed and fixes an irradiation light receiving device that receives the reflected light in water through a pan-tilt device, and operates the pan-tilt device to operate the laser pulse. , That is, the direction of the irradiation light receiving device. A laser oscillator for supplying a laser pulse to the irradiation / light receiving device is arranged separately from the irradiation / light receiving device on a mother ship or the like on water.

[0003]

By the way, in the above-mentioned conventional laser visual recognition device, the irradiation / light receiving device is provided in a pressure-resistant container and supported by a pan-tilt device so as to be able to resist water pressure. Therefore, since the irradiation and light receiving device becomes heavy, it is necessary to use a relatively large pan and tilt device. When such a large-sized pan / tilt apparatus is used, it is inconvenient to carry it, so that the workability of fixing work in water is poor, and the workability of moving a fixed object once is also poor.

It is also known that a clearer image of a visible object can be obtained by improving the intensity of a laser pulse. However, conventionally, an underwater irradiation / light receiving device is provided from a laser oscillator on a mother ship to an optical fiber cable. The intensity of the laser pulse that can be applied to the viewing target is limited by the optical transmission capacity of the optical fiber cable. Therefore, it was not possible to obtain a clear image of the visual recognition target, and the deterioration of the image was remarkable especially when the visual recognition distance was increased. Further, as a laser oscillator, YAG-OPO (Optical Parametric
Oscilator) and the like, there is also a problem that power consumption is large.

The present invention has been made in view of the above-mentioned problems, and has the following objects. (1) To provide a rotary underwater laser viewing device capable of changing the irradiation direction of a laser pulse without using a large-sized pan / tilt device. (2) To provide a rotary underwater laser visual recognition device that can easily move a shooting place in water. (3) To provide a rotary underwater laser visual recognition device capable of photographing a visual target with good workability. (4) To provide a rotary underwater laser viewing device capable of obtaining a clearer image of a viewing target object. (5) To provide a rotary underwater laser visual recognition device capable of reducing power consumption.

[0006]

In order to achieve the above object, as a first means, a laser pulse is applied to a visual object arranged in water, and the visual object is reflected based on the reflected light of the laser pulse. In an underwater laser visual recognition device that generates an image of, an irradiation light receiving unit that emits a laser pulse and receives the reflected light to generate an image of an object to be viewed, and a path of the laser pulse emitted from the irradiation light receiving unit. A second direction perpendicular to the first direction or the first direction;
And a light path setting device for setting the path of the reflected light incident from the first or second direction to the light receiving optical axis of the irradiation light receiving means, the light path setting apparatus, and the irradiation light receiving means And a pressure-resistant container provided with first and second light transmitting windows for transmitting the laser pulse and the reflected light thereof set by the light path setting device, and fixed to a support, and And a mounting means for rotatably supporting the pressure vessel with the direction of the rotation axis as the direction of the rotation axis.

As a second means, in the first means, the power supply device of the irradiation and light receiving means is housed in a power supply pressure-resistant container provided separately from the pressure-resistant container. Is connected by a power cable.

As a third means, in the first or second means, means for forming each light transmitting window in a flat plate shape is employed.

As a fourth means, in any one of the first to third means, a part of the laser pulse is transmitted toward the first light transmitting window and a part of the laser pulse is transmitted as the light path setting device. A means is employed in which a translucent mirror reflecting toward the second light transmitting window is applied.

As a fifth means, in any one of the first to fourth means, the light-path setting device is supported so as to be rotatable in a direction perpendicular to the reflection surface, and has a variable rotation angle to change the laser pulse. Is applied to the first light transmission window or a total reflection mirror that reflects the light to the second light transmission window is applied.

As a sixth means, in any one of the first to fifth means, a means is employed in which an underwater navigation device for navigating underwater is used as a support.

As a seventh means, in any one of the first to sixth means, a means is employed in which a YAG laser oscillator for generating a second harmonic light is applied as a laser oscillator.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2,
An embodiment of the rotary underwater laser visual recognition device according to the present invention will be described.

First, the external configuration of the present embodiment will be described with reference to FIG. In this figure, reference numeral 1 denotes a cylindrical pressure-resistant container, and both ends 1a, 1b are provided with shafts 1c, 1 having the center axis L of the cylindrical pressure-resistant container 1 as the center of rotation.
d is provided. A circular light-transmitting window 1e for transmitting light is provided at the center of the end surface 1a of the pressure-resistant container 1, and light is also transmitted in the direction orthogonal to the peripheral surface 1f of the pressure-resistant container 1, that is, the center axis L near the light-transmitting window 1e. A transmission window 1g is provided. The light transmission windows 1e and 1g are formed of a glass or acrylic flat plate.

That is, the shaft 1c provided on the end face 1a is hollow, and when facing the end face 1a from the arrow X direction,
As shown in FIG. 1B, the light transmission window 1e is formed so as to be seen. And each axis 1c of the pressure-resistant container 1
1d is a U-shaped mounting base (mounting means) 2
Are rotatably supported by both ends 2a and 2b via bearings or the like. That is, the pressure-resistant container 1 is supported so as to be sandwiched between both ends 2 a and 2 b of the mounting base 2.

A gear 1h is provided at the tip of a shaft 1d of the pressure-resistant container 1 supported on the end 2b of the mounting base 2, and the gear 1h meshes with a gear 3a attached to the shaft of the motor 3. Have been. The motor 3 is a stepping motor capable of setting a rotation angle with high precision, and is supported by the mounting base 2 via a bracket 3b. At the end 2a of the mounting base 2, a hole 2c is provided at a position corresponding to the light transmitting window 1e, and as described above, the arrow X
The light transmission window 1e can be seen from the direction. Such a mounting base 2 is attached to, for example, a self-contained navigation device that independently travels in water under remote control, or a navigation device that travels underwater under auxiliary operation by a diver.

The pressure-resistant container 1 is constructed so as to be able to withstand a water pressure at a depth of about 10 meters, and keeps the inside of the container tightly sealed against surrounding water. Inside such a pressure-resistant container 2, various devices for acquiring an image of a visual target placed in water, that is, a laser transmitting and receiving device 4
(Irradiation and light receiving means), a light path setting device 5, and a power supply 6 and a control device 7 are housed therein.

Next, the configuration of the laser transmitting and receiving device 4 will be described with reference to FIG. In this figure, reference numeral 4a is a cylindrical housing having a waterproof function. Inside the housing 1, a laser oscillator 4b, an optical system 4c, and an imaging device 4d are arranged and fixed via a common mount 4e, and also for balancing the pressure-resistant container 1 in water and cooling the laser oscillator 4b. A water tank 4f is provided for the operation. The laser oscillator 4b is YA
A G (Yttrium Aluminum Garnet) laser oscillator that generates second harmonic light (wavelength: 532 nm) is applied. For example, a laser pulse having a repetition rate of 50 Hz and a pulse width of 5 ns (nanosecond) is oscillated, and an optical system is generated. The light is emitted toward 4c.

The optical system 4c subjects the laser pulse to optical processing such as collimation. The imaging device 4d receives reflected light obtained by reflecting the laser pulse on the viewing target, and generates a video signal of the viewing target based on the reflected light. The intensity of the reflected light is weak, and the imaging device 4d amplifies such a weak reflected light and selectively causes the light receiving element to receive the reflected light in synchronization with the pulse cycle of the laser pulse. It has an intensifier.

The cylindrical casing 1 has a pressure resistance such that the central axis L is the central axis, that is, in a direction concentric with the pressure-resistant container 1 and in a direction in which the end face portion 4g faces parallel to the light transmitting window 1e. It is fixed in the container 1. The end face portion 4g is provided with a laser pulse transmitting window 4h for transmitting a laser pulse and a reflected light transmitting window 4i for transmitting reflected light. The optical system 4c has an optical axis parallel to the central axis L and transmits the laser pulse. The imaging device 4d is fixed to the housing 1 so as to coincide with the window 4h and the optical axis thereof is parallel to the central axis L and coincides with the reflected light transmission window 4i.

The laser pulse transmitting window 4h and the reflected light transmitting window 4i are formed of a flat plate made of glass or acrylic, and as shown in FIG. It is formed in such a positional relationship and size as to overlap with the window 1e.

The light path setting device 5 is a total reflection mirror 5a provided between the laser transmitting and receiving device 4 and the end face 1a of the pressure vessel 1 and supported on a rotating shaft 5a.
The rotating shaft 5a is provided in a direction orthogonal to the flat light transmitting window 1g and the central axis L, and is driven by an actuator such as a stepping motor. The control device 7 controls the operation of the laser oscillator 4b and the image pickup device 4d in a centralized manner, and includes a CPU, a memory storing a control program, and the like.

The power supply 6 supplies power to the laser oscillator 4b, the imaging device 4d, and the imaging device 4d. In particular, the power consumption of the laser oscillator 4b and the image intensifier is large, and the capacity of the power supply 6 is set in accordance with the power consumption of these devices. Reference numeral 8 denotes an umbilical cable for outputting a video signal of a visual recognition target to the outside and inputting operation information input from the outside to the control device 7.

Next, the operation of the rotary underwater laser visual recognition device will be described. The rotary underwater laser visual recognition device is used by being attached to a navigation device or the like that navigates underwater as described above, and in this case, the end face 1a is set to the navigation direction (forward). Then, operation information of the operation means provided in the navigation device is input to the control device 7 via the umbilical cable 8, and the photographing is started.

When photographing is started, the laser pulse is output from the laser oscillator 4b and emitted forward through the optical system 4c and the laser pulse transmission window 4h. Here, when the visual recognition target is a structure provided in front of the navigation device, the control device 7 operates the light path setting device 5 so that the total reflection mirror 5b does not block the path of the laser pulse. You. As a result, the laser pulse is selectively incident on the light transmission window 1e, and is irradiated on the visual recognition target located in front. The laser pulse is reflected by the object to be viewed, and the reflected light is incident on the light transmission window 1e.

Further, the reflected light is incident on the image pickup device 4d through the reflected light transmitting window 4i, and a video signal of an object to be viewed facing the viewing device at a predetermined distance in water is generated. This video signal is taken out of the imaging device 4d via the umbilical cable 8, and is input and displayed on a monitor provided on a navigation device or a monitor provided on a waterborne mother ship, for example.

Subsequently, in the case where an attempt is made to take a picture of the state of the water bottom in place of the above-mentioned structure, the light path setting device 5
Is driven, and the reflection surface angle of the total reflection mirror 5b is set so that the laser pulse emitted from the laser transmission / reception device 4 is incident on the light transmission window 1g. As a result, the laser pulse is applied to the water bottom in a direction orthogonal to the front of the navigation device, and the pressure vessel 1 is rotated about the center axis L by operating the motor 3. Therefore, the irradiation direction of the laser pulse is changed in a plane orthogonal to the central axis L.

The laser pulse whose irradiation direction is set as described above is reflected at the bottom of the water or the like, and the reflected light is transmitted to the light transmitting window 1g.
Is incident on the total reflection mirror 5b through the
, And a video signal of the water bottom is generated. In this case, since the irradiation direction of the laser pulse can be changed without changing the direction of the navigation device, it is possible to improve the workability of photographing.

By the way, in the above-described embodiment, a structure is adopted in which a relatively heavy power source is arranged in the pressure vessel. However, the light weight of the pressure vessel fixed to the navigation device is easier to operate. The workability of shooting is good. Therefore, as another embodiment, it is conceivable to arrange the power supply in another pressure-resistant container for power supply and connect the power supply to the pressure-resistant container fixed to the navigation device with a power cable. In this case, the pressure-resistant container for the power supply is arranged relatively close to the navigation device.

Further, according to the rotary underwater laser visual recognition device described above, the laser oscillator 4b is used as a YAG-SHG.
Since a device that outputs light is applied, YAG-OPO
(Optical Parametric Oscilator), the capacity of the power supply 6 can be greatly reduced, for example, to about 1/10. That is, in the present rotary type underwater laser visual recognition device, the power consumption required for laser pulse oscillation is significantly reduced as compared with the related art.

[0031]

As described above, the rotary underwater laser visual recognition device according to the present invention has the following effects. (1) In an underwater laser visual recognition device, an irradiation light receiving means for emitting a laser pulse and receiving a reflected light to generate an image of an object to be viewed, and a path of the laser pulse emitted from the irradiation light receiving means in a first direction. Alternatively, an optical path setting device that sets the path of reflected light incident from the first or second direction to the light receiving optical axis of the irradiation light receiving means while setting the path in a second direction orthogonal to the first direction. A pressure-resistant container containing the light-path setting device and the irradiation / light-receiving means, and having first and second light transmission windows for transmitting a laser pulse and a reflected light thereof set by the light-path setting device. And a mounting means fixed to the support and rotatably supporting the pressure vessel with the first direction as the direction of the rotation axis. Ku, second laser pulse orthogonal to the visual target object or the first direction is positioned in a first direction
Is irradiated on the viewing target in the direction of, and an image of each viewing target can be captured. Moreover, since the pressure vessel is rotated with the first direction as the direction of the rotation axis, it is possible to easily set the irradiation direction of the laser pulse in a plane orthogonal to the first direction and perform photographing. Therefore, it is possible to improve the workability of photographing the visible object underwater, and to photograph the visible object by changing the irradiation direction of the laser pulse without using a large pan-tilt device as in the related art. be able to. (2) The power supply device of the irradiation and light receiving means is housed in a power supply pressure-resistant container provided separately from the pressure-resistant container, and the pressure-resistant container and the power supply pressure-resistant container are connected by a power cable, whereby Movement in water is easier because the weight is reduced. (3) Since each light transmission window is formed in a flat plate shape, the laser pulse and the reflected light are largely refracted when transmitting through the light transmission window as compared with the case where a bent light transmission window is used. Therefore, it is possible to suppress the image distortion of the visual recognition target object due to the light transmission window. (4) Since it is not necessary to transmit a laser pulse from above water to underwater by an optical fiber cable as in the related art, it is possible to increase the intensity of the laser pulse applied to the object to be viewed, and therefore, compared with the related art. It is possible to obtain a clear image of the visual recognition target object. (5) The light trajectory setting device transmits a part of the laser pulse to the first
A semi-transparent mirror that transmits light toward the light transmission window and reflects a part of the light toward the second light transmission window, or is rotatably supported in a direction perpendicular to the reflection surface. The laser pulse to the first light transmission window or to the second
The structure is simple because it is composed of a total reflection mirror that reflects light from the light transmission window. (6) When an underwater navigation device that navigates underwater is used as a support, movement underwater is further facilitated, thereby improving the workability of photographing. (7) Y that generates second harmonic light as a laser oscillator
Since an AG laser oscillator is used, power consumption can be significantly reduced as compared to a case where a laser pulse is oscillated using, for example, a parametric oscillation type laser oscillator.

[Brief description of the drawings]

FIG. 1 is a front view and a side view showing an external configuration of an embodiment of a rotary underwater laser visual recognition device according to the present invention.

FIG. 2 is a front view and a side view showing a configuration of a laser transmitting and receiving device in one embodiment of the rotary underwater laser viewing device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure-resistant container 1a, 1b Both end surfaces of pressure-resistant container 1c, 1d shaft 1e, 1g Light transmission window 1h, 3a Gear 1f Surface of pressure-resistant container 2 Mounting frame (mounting means) 2a, 2b End of mounting frame 3 Motor 3b Bracket 2c hole 4 laser transmission / reception device (irradiation / reception means) 4a laser transmission / reception device housing 4b laser oscillator 4c optical system 4d imaging device 4e common mount 4f water tank 4g end face 4h laser pulse transmission window 4i reflected light transmission window 5 light Path setting device 6 Power supply 7 Control device 8 Umbilical cable

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Hirose 4-3778 Irifunecho, Niigata City, Niigata Prefecture Inside the Niigata Machinery Maintenance Office, First Port Construction Bureau, Ministry of Transport (72) Inventor Hirotoshi Igarashi 4- Irifunecho, Niigata City, Niigata Prefecture 3778 Inside the Niigata Machinery Maintenance Office, First Port Construction Bureau, Ministry of Transport (72) Inventor Junichi Akizono 3-1-1 Nagase, Yokosuka City, Kanagawa Prefecture Inside the Port and Harbor Research Institute, Ministry of Transport (72) Eiji Sato Nagase, Yokosuka City, Kanagawa Prefecture 3-1-1, Inside the Port and Harbor Research Institute, Ministry of Transport (72) Inventor Yoshiaki Takahashi 2-1-1, Toyosu, Koto-ku, Tokyo Ishikawa Shima-Harima Heavy Industries Co., Ltd.Tokyo First Plant (72) Inventor Toshiki Saito 3-1-1-15 Toyosu, Koto-ku Ishikawa Shima-Harima Heavy Industries Co., Ltd.In the Toji Technical Center (56) References JP 10-132938 JP, A) JP Akira 63-131682 (JP, A) JitsuHiraku Akira 63-149669 (JP, U) (58 ) investigated the field (Int.Cl. ^6, DB name) H04N 5/225 G01S 7/48

Claims (7)

(57) [Claims] 1. An underwater laser visual recognition device that irradiates a laser pulse to a visual target arranged in water and generates an image of the visual target based on reflected light of the laser pulse, and emits the laser pulse. And an irradiation light receiving means (4) for receiving the reflected light and generating an image of the visual recognition target object; and a path of the laser pulse emitted from the irradiation light receiving means is orthogonal to the first direction or the first direction. An optical path setting device (5) that sets the optical path of reflected light incident from the first or second direction on the light receiving optical axis of the irradiation light receiving means, while setting the optical path in the second direction. A pressure-resistant container (1) containing the irradiation and light-receiving means and having first and second light transmission windows (1e, 1g) for transmitting a laser pulse set by the light-path setting device and reflected light thereof. ) Mounting means (2) fixed to a support and rotatably supporting the pressure vessel with the first direction being a direction of a rotation axis;
A rotary underwater laser visual recognition device, comprising: 2. The rotary underwater laser visual recognition device according to claim 1, wherein the power supply device of the irradiation light receiving means is housed in a power supply pressure-resistant container provided separately from the pressure-resistant container. A rotary underwater laser visual recognition device, characterized in that it is connected to the pressure-resistant container by a power cable. 3. The rotary underwater laser visual recognition device according to claim 1, wherein each light transmission window is formed in a flat plate shape. 4. The rotary underwater laser visual recognition device according to claim 1, wherein the light path setting device comprises:
A part of the laser pulse is transmitted toward the first light transmission window (2a), and a part of the laser pulse is transmitted to the second light transmission window (2a).
A rotary underwater laser visual recognition device, which is a translucent mirror reflecting toward b). 5. The rotary underwater laser visual recognition device according to claim 1, wherein the light path setting device comprises:
A total reflection mirror rotatably supported in a direction orthogonal to a reflection surface, wherein a rotation angle is variable to propagate a laser pulse to a first light transmission window or reflect a laser pulse to a second light transmission window. A rotary underwater laser visual recognition device characterized by the following. 6. The rotary underwater laser visual recognition device according to claim 1, wherein the support is an underwater navigation device that navigates underwater. 7. The rotary underwater laser visual recognition device according to claim 1, wherein the laser oscillator comprises:
YAG (Yttrium Aluminum Gar) that generates second harmonic light
net) Rotary underwater laser visual recognition device characterized by being a laser oscillator.