CN113071636A

CN113071636A - Underwater optical fairing

Info

Publication number: CN113071636A
Application number: CN202110369827.XA
Authority: CN
Inventors: 张岳; 王新伟; 雷平顺; 周燕
Original assignee: Institute of Semiconductors of CAS
Current assignee: Institute of Semiconductors of CAS
Priority date: 2021-04-06
Filing date: 2021-04-06
Publication date: 2021-07-06

Abstract

The present disclosure provides an underwater optical fairing comprising: the fairing base (7) is fixed on the underwater vehicle (3); a fairing head (5) conformal in structure to the hull of the underwater vehicle (3); wherein, a sealed fairing cavity (6) is formed between the fairing base (7) and the fairing head (5), and the fairing cavity (6) is filled with water. The underwater optical fairing is simple in structure and easy to operate, can be mechanically conformal with an underwater vehicle to reduce the navigation resistance of the underwater vehicle (3), can enable an optical camera (2) of the underwater vehicle (3) to clearly image, and has strong practicability.

Description

Underwater optical fairing

Technical Field

The present disclosure relates to the field of underwater optics technologies, and in particular, to an underwater optical fairing.

Background

The underwater vehicle has wide application in the aspects of marine mineral exploration, underwater pipeline inspection, search and rescue, marine archaeology and the like. With the increasing demands for obstacle avoidance and exploration of underwater vehicle navigation, forward-looking optical cameras are increasingly installed at the front end of the underwater vehicle. In order to enable clear imaging of the forward looking camera, many underwater vehicle front ends are designed as flat transparent windows, and in 2020, russian "warrior" unmanned vehicle front ends employ flat glass windows, as shown in fig. 1. However, the plane transparent window arranged at the front end of the underwater vehicle can increase the navigation resistance of the underwater vehicle, increase the navigation power consumption of the underwater vehicle and shorten the operation time of the underwater vehicle. Therefore, attempts have been made to design the optical fairing to be curved to reduce the problem of drag on the underwater vehicle from the planar optical window. These methods typically employ a variable focal length forward looking optical camera while an algorithm corrects for image distortion. However, due to the limited focal length adjustment range of the camera, it is still difficult to clearly image an image with a severe virtual focus. In addition, in combination with the optical characteristics of water, the lens of the front-view optical camera is developed through a complicated optical design to eliminate virtual focus and aberration caused by an optical fairing. However, lens designs are often complex and the mounting of forward looking optical cameras needs to be very accurate. Furthermore, for each optical fairing, a specially designed lens is required, which means that the optical fairing or lens cannot be changed at will. Therefore, it is necessary to design an optical fairing that reduces the navigation drag of an underwater vehicle and allows for clear imaging of a forward looking optical camera of the underwater vehicle.

Disclosure of Invention

Technical problem to be solved

In view of the above problems, the present disclosure provides an underwater optical fairing for at least partially solving the technical problems of large navigation resistance of an underwater vehicle, difficulty in clear imaging of a forward-looking optical camera, and the like of a conventional planar window.

(II) technical scheme

The present disclosure provides an underwater optical fairing comprising: the fairing base 7 is fixed on the underwater vehicle 3; a fairing head 5, conformal in structure to the hull of the underwater vehicle 3; wherein, a sealed fairing cavity 6 is formed between the fairing base 7 and the fairing head 5, and the fairing cavity 6 is filled with water.

Further, the fairing base 7 is arranged in front of the optical camera 2 in the underwater vehicle 3, and the plane of the fairing base 7 is perpendicular to the optical axis of the optical camera 2.

Further, the fairing base 7 is fixed with the fairing head 5 to ensure the watertight of the fairing cavity 6.

Further, the water filled in the fairing cavity 6 includes clean water and deionized water.

Further, the optical fairings 4 are mounted at different parts of the underwater vehicle 3, including the head, middle, bottom of the underwater vehicle 3.

Further, the fairing base 7 is a transparent rigid flat plate, and the fairing head 5 is a transparent rigid curved surface.

Further, the material of the fairing base 7 and the material of the fairing head 5 are transparent rigid materials, and the transparent rigid materials comprise glass, organic glass, transparent ceramic and sapphire glass.

Further, the thickness ranges of the fairing base 7 and the fairing head 5 are positively correlated with the working water depth, and the underwater optical fairing meets the pressure-resistant requirement under the working water depth.

Further, the fairing base 7 comprises at least one transparent rigid flat plate, each flat plate is fixed with the underwater vehicle 3, and the fairing head 5 is a transparent rigid curved surface.

Further, one of the flat plates of the fairing base 7 is arranged in front of the optical camera 2 in the underwater vehicle 3, and the plane of the flat plate is perpendicular to the optical axis of the optical camera 2.

(III) advantageous effects

According to the underwater optical fairing provided by the disclosure, the fairing with the curved surface is adopted to replace a plane transparent window which is generally arranged at the front end of the existing underwater vehicle 3 provided with the forward-looking optical camera 2, so that the navigation resistance of the underwater vehicle 3 can be effectively reduced; clean water or deionized water is completely filled in the fairing cavity 6, so that the difference between the refractive index of the outside of the fairing head 5 and the refractive index of the inside of the fairing cavity 6 can be eliminated, virtual focus and distortion of the optical camera 2 are prevented, the imaging aberration of the optical camera 2 is reduced, and the optical camera 2 can clearly image; meanwhile, the optical fairing 4 can be arranged at different parts of the underwater vehicle 3 according to requirements, and is flexible and convenient to use.

Drawings

FIG. 1 schematically shows a photograph of an underwater vehicle according to an embodiment of the present disclosure;

FIG. 2 schematically illustrates a structural schematic of an underwater vehicle according to an embodiment of the present disclosure;

FIG. 3 schematically illustrates a structural view of an optical window in the lower portion of an underwater vehicle in accordance with an embodiment of the disclosure;

FIG. 4 schematically illustrates a structural schematic of an underwater optical fairing mounted to the head of an underwater vehicle in accordance with an embodiment of the present disclosure;

FIG. 5 schematically illustrates an underwater optical fairing mounted at the bottom of an underwater vehicle when an optical camera is looking ahead according to an embodiment of the disclosure;

FIG. 6 schematically illustrates an underwater optical fairing mounted at the bottom of an underwater vehicle when viewed from below with an optical camera according to an embodiment of the disclosure;

FIG. 7 schematically illustrates a schematic representation of the effects before and after an underwater optical fairing is employed in accordance with an embodiment of the disclosure;

description of the reference numerals

1 plane transparent window 2 front view optical camera

3 underwater vehicle 4 underwater optical fairing

5 fairing head 6 fairing cavity

7 the fairing base 8 images the field of view.

Detailed Description

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

Fig. 2 and 3 schematically show structural schematic diagrams of an underwater vehicle, namely, a flat glass window 1 is adopted for both, fig. 2 is a case of forward view of an optical camera, and fig. 3 is a case of downward view of the optical camera, and the flat transparent window arranged at the front end of the underwater vehicle can increase the navigation resistance of the underwater vehicle, increase the navigation power consumption of the underwater vehicle and shorten the operation time of the underwater vehicle.

An embodiment of the present disclosure provides an underwater optical fairing 4, see fig. 4, including: the fairing base 7 is fixed on the underwater vehicle 3; a fairing head 5, conformal in structure to the hull of the underwater vehicle 3; wherein, a sealed fairing cavity 6 is formed between the fairing base 7 and the fairing head 5, and the fairing cavity 6 is filled with water.

The optical fairing 4 is a transparent cover conformal with the underwater vehicle 3 and comprises a fairing head 5, a fairing cavity 6 and a fairing base 7, wherein the fairing head 5 is fixed on the fairing base 7, the fairing cavity 6 is sealed by the fairing head 5 and the fairing base 7, clean water or deionized water is completely filled in the fairing cavity 6, and the fairing base 7 is fixed on the underwater vehicle 3. On one hand, the optical fairing conformal to the underwater vehicle is adopted to replace a traditional plane transparent window arranged on the underwater vehicle, so that the navigation resistance of the underwater vehicle can be effectively reduced; on the other hand, the water is completely filled in the water-filled low-resistance optical fairing cavity, so that the difference of refractive indexes outside the fairing and inside the fairing cavity can be eliminated, the virtual focus problem of the optical camera is solved, the imaging distortion of the forward-looking optical camera is reduced, and the optical camera can clearly image.

On the basis of the above embodiment, the fairing base 7 is arranged in front of the optical camera 2 in the underwater vehicle 3, and the plane of the fairing base 7 is perpendicular to the optical axis of the optical camera 2.

The optical camera 2 is arranged in the underwater vehicle 3 and is positioned behind the water-filled low-resistance optical fairing, and the optical axis of the optical camera 2 is vertical to the plane of the fairing base 7, so that clear and distortion-free imaging of the optical camera is facilitated.

On the basis of the above embodiment, the fairing base 7 is fixed to the fairing head 5 to ensure the watertight sealing of the fairing cavity 6.

The water tightness means that after the cavity 6 of the underwater fairing 4 is soaked or filled with water, the structure and corresponding equipment and the like of the underwater fairing keep watertight sealing performance under the action of certain water pressure, so that the tightness of the underwater fairing 4 is ensured, and seawater is prevented from entering the underwater fairing 4 to change the optical property of the underwater fairing 4 and influence the imaging quality of an optical camera.

On the basis of the above embodiment, the water filled in the fairing cavity 6 includes clean water and deionized water.

It should be noted that the fairing cavity 6 cannot use seawater because impurities in seawater can attenuate and scatter light, thereby affecting the imaging definition. The use of clean water or deionized water can prevent virtual focus and distortion of the optical camera 2, and can also reduce water attenuation, so that the optical camera 2 can clearly image.

On the basis of the above embodiment, the optical cowling 4 is mounted at different locations of the underwater vehicle 3, including the head, the middle and the bottom of the underwater vehicle 3.

When the optical camera 2 is located on the head of the underwater vehicle 3, referring to fig. 4, the optical fairing 4 is correspondingly arranged on the head of the underwater vehicle 3 and covers the whole range of the angle of view of the optical camera 2. When the optical camera 2 is located at the bottom or the middle of the underwater vehicle 3, please refer to fig. 5 and 6, the optical fairing 4 is adapted to conform to the cabin of the underwater vehicle 3 to form a complete spindle-like shape, thereby effectively reducing the resistance during underwater navigation. The optical fairing 4 of the present disclosure can be well adapted to underwater vehicles of different shapes, and the optical camera can also image clearly without specially designed lenses.

In addition to the above embodiments, the cowl base 7 is a transparent rigid flat plate, and the cowl head 5 is a transparent rigid curved surface.

The cowl head 5 is curved and the cowl base 7 is flat and made of transparent material. The fairing head 5 is a curved surface, replaces the existing transparent plane window 1, can effectively reduce the navigation resistance of an underwater vehicle, and the fairing base 7 is a planar shape and is used for being fixed with the underwater vehicle 3.

On the basis of the above embodiment, the material of the cowl base 7 and the material of the cowl head 5 include transparent rigid materials such as glass, organic glass, transparent ceramic, sapphire glass, and the like.

The flat glass has good light transmission and is suitable for being tightly fixed with the optical camera 2 in the underwater vehicle 3; transparent rigid materials such as glass, organic glass, transparent ceramic, sapphire glass and the like have certain strength and are suitable for bearing water pressure. The fairing head 5 mainly plays a role in rectifying and drag reduction, and simultaneously ensures that clean water or deionized water inside the underwater optical fairing is not exchanged with water outside the fairing; the fairing base 7 plays a watertight role, and ensures that the optical camera is not contacted with water.

On the basis of the above-described embodiments, the range of thicknesses of the cowl base 7 and the cowl head 5 is dependent on the depth of the operating water.

The underwater vehicle 3 increases one standard atmosphere for about every 10m of submergence. The pressure range of the underwater vehicle 3 under water is 1-1200 standard atmospheric pressures. Of these, 1200 standard atmospheres correspond to about 12000 m. The whole underwater optical fairing needs to meet the pressure-resistant requirement under the depth of the working water. If the thickness of the fairing is too thin, the supporting strength is weak, and the fairing is difficult to bear underwater pressure intensity; too thick a fairing can affect the optical imaging effect and introduce aberrations and distortions.

On the basis of the above embodiment, the fairing base 7 comprises at least one transparent rigid flat plate, each flat plate is fixed with the underwater vehicle 3, and the fairing head 5 is a transparent rigid curved surface.

When the optical camera 2 is located at the bottom (when the optical camera is in front view) or the middle (when the optical camera is in down view) of the underwater vehicle 3, referring to fig. 5 and 6, in order to achieve a conformal effect with the underwater vehicle 3, the fairing base 7 can be configured to be composed of at least one flat plate, wherein one flat plate is located in front of the optical camera 2, other portions are tightly connected with the other portions which are not conformal, the curved surface of the fairing head 5 is structurally conformal with the outer shell of the underwater vehicle 3, and the fairing as a whole is fixed with the underwater vehicle 3.

On the basis of the above embodiment, one of the flat plates of the fairing base 7 is arranged in front of the optical camera 2 in the underwater vehicle 3, and the plane of the flat plate is perpendicular to the optical axis of the optical camera 2.

At least one flat plate in the fairing base 7 is arranged in front of the optical camera 2 and is perpendicular to the optical axis of the optical camera 2, so that the optical camera 2 can clearly image.

The present disclosure is further illustrated by the following detailed description.

The underwater water-filling low-resistance optical fairing 4 is a transparent rigid cover conformal to an underwater vehicle 3 and comprises a fairing head 5, a fairing cavity 6 and a fairing base 7, wherein the fairing head 5 is fixed on the fairing base 7, the fairing cavity 6 is sealed by the fairing head 5 and the fairing base 7, water is completely filled in the fairing cavity 6, the fairing base 7 is fixed on the underwater vehicle 3, an optical camera 2 is arranged in the underwater vehicle 3, the optical axis of the optical camera 2 is perpendicular to the plane of the fairing base 7, and the fairing head 5 and the fairing base 7 are made of transparent materials.

The experiment results are shown in fig. 7 after the underwater water-filling low-resistance optical fairing is adopted. In the experiment, the fairing base is made of circular flat glass and is 5mm in thickness, the fairing head is made of hemispherical organic glass and is 5mm in thickness, the radius of an inner spherical surface is 100mm, deionized water is filled in the fairing cavity, the fairing head and the fairing base are fixed, the watertight of the fairing cavity is guaranteed, the fairing base is fixed at the front end of an underwater vehicle, the forward-looking optical camera is installed in the underwater vehicle, and the optical axis of the forward-looking optical camera is perpendicular to the plane where the fairing base is located.

When the underwater water-filled low-resistance optical fairing is arranged, the forward-looking optical camera has the imaging effect as shown in fig. 7(b), and can clearly image a USAF-1951 resolution target. And an underwater water-filled low-resistance optical fairing is not adopted, namely only the hemispherical organic glass is reserved, a fairing base is not arranged, water is not filled between the forward-looking optical camera and the hemispherical organic glass, and the imaging effect is as shown in figure 7(a), so that clear imaging cannot be realized.

The underwater water-filling low-resistance optical fairing provided by the disclosure is used for replacing a plane transparent window of the existing underwater vehicle with a forward-looking optical camera, so that the purpose of reducing the navigation resistance of the underwater vehicle and simultaneously enabling the forward-looking optical camera of the underwater vehicle to clearly image is achieved.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims

1. An underwater optical fairing, comprising:

the fairing base (7) is fixed on the underwater vehicle (3);

a fairing head (5) conformal in structure to an outer shell of the underwater vehicle (3);

a sealed fairing cavity (6) is formed between the fairing base (7) and the fairing head (5), and the fairing cavity (6) is filled with water.

2. The underwater optical fairing according to claim 1, characterized in that said fairing base (7) is placed in front of an optical camera (2) in said underwater vehicle (3), said fairing base (7) lying in a plane perpendicular to the optical axis of said optical camera (2).

3. The underwater optical fairing of claim 2, wherein the fairing base (7) is secured to the fairing head (5) to ensure water tightness of the fairing cavity (6).

4. The underwater optical fairing of claim 1, wherein the water in the fairing cavity (6) filled with water comprises clean water, deionized water.

5. The underwater optical fairing according to claim 1, characterized in that said optical fairing (4) is mounted at different points of the underwater vehicle (3), including the head, the middle, the bottom of the underwater vehicle (3).

6. The underwater optical fairing of claim 1, wherein the fairing base (7) is a transparent rigid flat plate and the fairing head (5) is a transparent rigid curved surface.

7. The underwater optical fairing according to claim 6, wherein the material of the fairing base (7) and the material of the fairing head (5) are transparent rigid materials, the transparent rigid materials including glass, plexiglass, transparent ceramic, sapphire glass.

8. The underwater optical fairing of claim 7, wherein the thickness of the fairing head (5) and fairing base (7) is positively correlated to the depth of the operating water at which the underwater optical fairing meets pressure requirements.

9. The underwater optical fairing according to claim 1, characterized in that said fairing base (7) comprises at least one transparent rigid flat plate, each flat plate being fixed to said underwater vehicle (3), the fairing head (5) being a transparent rigid curved surface.

10. The underwater optical fairing of claim 9, wherein one of the flat plates of the fairing base (7) is located in front of an optical camera (2) in the underwater vehicle (3), said one of the flat plates lying in a plane perpendicular to the optical axis of the optical camera (2).