KR100859773B1 - A Device on Optical Guidance for Underwater Docking of Autonomous Underwater Vehicles - Google Patents

Abstract

The present invention is to install a circular light source consisting of light emitting diodes installed in the subsea base using an underwater camera mounted on an autonomous unmanned submersible to recognize the circular light source as an image processing using an underwater camera of an autonomous unmanned submersible, the direction of the autonomous unmanned submersible It is to provide an optical guide device for controlling the control panel to dock to the seabed base.

In the center of the bow of the autonomous unmanned submersible 10, a camera 20 for capturing an image of a target is installed, and an optical guide device 40 having a circular light source composed of a light emitting diode at an inlet side of the docking device 30 of the subsea base. By installing the camera to recognize the circular light source, the autonomous unmanned submersible is docked to the docking device through posture control by controlling the direction control panel of the autonomous unmanned submersible by estimating the distance away from the docking autonomous, the inclination angle and the direction angle In this way, the present invention is implemented by installing a circular light source consisting of a light emitting diode array at the entrance to the docking device of the seabed base to display the target, and adjust the illuminance of the light source according to the distance change.

Optical Guide, Autonomous Submersible, Illumination Control, Underwater Docking, Underwater Camera, Underwater Light, Image Processing

Description

A Device on Optical Guidance for Underwater Docking of Autonomous Underwater Vehicles}

1 is a conceptual diagram of the docking of an autonomous unmanned submersible using an underwater camera

2 is a docking conceptual diagram of an autonomous unmanned submersible using an optical guide device composed of an underwater camera mounted on the autonomous unmanned submersible and an underwater light of a subsea base

3 is a control method of the center of the camera and the underwater target with the control method of the autonomous unmanned submersible.

4 is a conceptual diagram of the illumination control and the attitude control of the autonomous unmanned submersible according to the distance change of the autonomous unmanned submersible

5 is an optical guide device for underwater docking of autonomous unmanned submersible

6 is an enlarged cross-sectional view taken along line A-A 'of FIG.

7 is a configuration diagram of the illuminance control device of the optical guide device
8 is a circuit diagram of the LED light source illuminance control device.

<Description of the symbols for the main parts of the drawings>

10: autonomous unmanned submersible 20: camera

30: docking device 40: optical guide device

41: conical fixing part 43: LED                 

47: protector 49: rubber pad

# 1, # 2, # 3, # 4, # 5: semicircular light source group

The present invention provides an optical guide device for inducing underwater docking of an autonomous unmanned submersible that can be docked precisely underwater to an underwater base when the autonomous unmanned submersible is docked to a sea basin or subsea base. .

The Autonomous Underwater Vehicle (AUV), which can autonomously operate underwater, has its own power supply and operation, so it has to repeat the operation of charging the power and receiving data once, returning to the water to charge the power.

In order to overcome these constraints, it is required to create a submarine base underwater and return it to perform data extraction along with power charging.

As a conventional method of returning to an underwater base, the method of inductively controlling an autonomous unmanned submersible by using an ultrasonic position tracking device between a seabed base and an autonomous unmanned submersible is mainly used.

The above-described induction control method using underwater ultrasonic waves can guide the unmanned submersible submersible to approach the seabed base, but because the error location of the ultrasonic positioning device is large and the signal acquisition time interval is large, A precise navigation system is required separately for step motion control.

Existing methods that do not use ultrasonic waves as a precision navigation device for underwater docking are equipped with an inertial navigation device in an autonomous unmanned submersible to find the location of a subsea base previously input, and integrate it using an ultrasonic speedometer and geomagnetic compass signals. Using the dead-reckoning method, controlling the autonomous submerged submersible by measuring the magnetic field change around the seabed base, and using the underwater camera to identify the seabed base to induce the docking of the final stage. There is this.

Underwater docking using the inertial navigation system has the disadvantage of requiring expensive equipment because it requires the use of a high-precision sensor, and even in the case of a precise sensor, the error increases in proportion to the square of time, thus requiring an auxiliary precision speed sensor. There was a problem.

In addition, the magnetic field method is sensitive to the change in the magnetic field generated by the autonomous unmanned submersible itself and has a disadvantage in that its performance is lower than that of the inertial sensor.

In addition, the method of using an optical camera is not yet common, and the conventional method has a complex disadvantage of using a method of transmitting a control signal by monitoring an autonomous unmanned submersible reaching a subsea base by mounting a camera at the subsea base.

In addition, in order for the autonomous unmanned submersible to dock at the base in the water, when the autonomous unmanned submersible reaches near the seabed base, it is necessary to accurately recognize and precisely track and control the docking point of the seabed base.                         

As an autonomous unmanned submersible, a method using an inertial navigation sensor, an optical method using a general camera, a method using an ultrasonic wave, and a method using a laser are used to recognize a seabed base.

Ultrasonic method has the disadvantage of low resolution and large time lag, and laser method is capable of precise measurement, but autonomous unmanned submersible moves irregularly so that a separate control device that can accurately scan the laser is required. In the case of using the inertial navigation sensor, there is a disadvantage in that the accumulated position error must be corrected until reaching the sea bottom.

Therefore, there is a need for a device that can be docked underwater by implementing a precise navigation device near the docking device while using a general-purpose camera.

In order to solve the above problems, in the present invention, when the autonomous unmanned submersible enters the 20-30 m range near the underwater target by underwater ultrasonic navigation or inertial navigation, precise navigation for later docking is safely docked by the optical guide device. The purpose of this is to install and display an underwater lighting device (light) at the entrance of the docking device of the subsea base so that the autonomous unmanned submersible can recognize the target and control the propeller and the direction control panel.

In order to achieve the above object, the present invention is installed in the center of the bow portion of the autonomous unmanned submersible 10, the camera 20 for capturing the image of the target is installed, docking of the subsea base An optical guide device 40 having a light source is installed at the inlet side of the device 30 to estimate the distance, inclination angle and direction angle to the docking device by using the light source imaged by the camera to control the direction of the autonomous unmanned submersible. It is characterized by moving to find the target point.

The optical guide device 40 is composed of a conical fixing portion 41 of a funnel shape fixed to the inlet side of the docking device 30, a plurality of LEDs connected in parallel to the front of the conical fixing portion 41 The 43 is arranged in two rows so as to maintain a constant interval along the circumferential surface to form a pair of large and small circular light sources by the LED 43, the LED 43 fixed to the conical fixing portion 41 is Waterproofing with a flexible film filled with transparent oil inside the vinyl film, five semi-circular light source groups (# 1) at the inclined positions of up, down, left, right and 45 degrees in the horizontal and vertical directions on the outer circumferential surface of the fixing part 41 , # 2, # 3, # 4, # 5 are installed, and the brightness adjustment of the LED 43 is configured to be controlled by a transistor driving circuit for inputting the distance information of the autonomous unmanned submersible.

An anti-shock rubber pad 49 is installed inside the fixing part 41 of the optical guide device 40, and the protecting part 47 is installed on the fixing part 41 to protect the LED 43. In addition, the guard 47 is characterized in that arranged at equal intervals between the LED 43 is fixed to the fixing portion 41.

Hereinafter, with reference to the accompanying drawings of the present invention will be described in more detail the configuration and effect and the like.

Fig. 1 shows a coordinate system in which a small underwater camera is attached to the center of a player in an autonomous unmanned submersible.

As shown, the target P at any point is projected to point p with a deviation in the horizontal and vertical directions on the CCD plane of the camera.

Since the camera is installed in the center of the bow of the autonomous unmanned submersible, when the autonomous unmanned submersible is advanced while automatically controlling the horizontal and vertical direction control panels of the stern so that the point p projected according to the forward direction of the camera is maintained at the center of the CCD plane, Ultimately, the autonomous unmanned submersible can reach the docking device.

The driving of the direction control plate can control the attitude of the autonomous unmanned submersible by analyzing the motion equation of the underwater hull combined with the optical flow equation of the camera.

2 illustrates a process of reaching the docking apparatus by controlling the positional error of the origin of the target projected to the camera to be zero by the autonomous unmanned submersible far away within the visible range.

The docking device inlet is made of conical shape so that when the autonomous unmanned submersible enters with a slight positional error, it can lubricate to the side and can be successfully docked. Attach to the inner wall of the guide unit.

3 illustrates the concept of controlling the autonomous unmanned submersible to move the projected underwater target on the CCD plane of the camera.

Even when the projected target is kept at the origin of the CCD plane, it may have an inclination angle with the target. At this time, the projected circular light source changes its diameter and changes its ellipticity according to the change in distance and the change in angle.

Therefore, the autonomous submersible can find the distance away from the docking device by the size of the diameter of the projection light source, optimize the ellipse shape and find the inclination angle.

As shown in FIG. 2, when the autonomous unmanned submersible has an inclination angle and the target is located at the center, the projected circular light has an elliptical shape. Thus, the angle of the normal perpendicular to the docking device is taken into consideration by considering the deformation direction of the elliptical shape. You have to find it.

4 shows an overall system schematic of an optical guide device for underwater docking of an autonomous submersible.

By using an additional sensor such as an ultrasonic position tracking device, the brightness of the light source of the docking device can be adjusted to obtain uniform image quality even when the autonomous unmanned submersible is not only at a long distance but also at a short distance.

5 is a view showing the configuration of an optical guide device installed at the entrance of the underwater docking apparatus to which the present invention is applied, if the light source array made of a small LED of a disc at the conical dock entrance is uniformly arranged at regular intervals along the circumferential surface of the dock entrance. The arranged LEDs were configured to form one circle.

By tracking this circular target, the underwater camera of the autonomous unmanned submarine can identify the entrance of the dock.

In addition, the semicircular light source groups # 1 and # 2 in the vertical up and down directions, the light source groups # 3 and # 4 in the horizontal left and right directions, and the light source group # 5 for the angle check are provided. The distance, inclination angle and direction angle from the inlet to the dock entrance can be estimated by image processing the LED light signal.

Since the LED emits light in a hemispherical direction, the front surface of the docking device can detect a circular light source having a uniform illuminance in any direction, thereby reducing the image processing error according to the direction of the general underwater light.

On the other hand, in the present invention, the LED light source is configured to connect the LED 43 array in parallel as shown in Figure 6 so that even if several LEDs are damaged so as not affect the performance of the entire system.

FIG. 6 is a cross-sectional view taken along line A-A 'of FIG. 5, and as shown therein, an annular substrate for installing an LED array is floated in the middle, sealed with a back support plate 41 and a front transparent vinyl film, and transparent oil is placed in the middle. It is waterproof by loading and compensates for the water pressure by using the method that the pressure is transmitted inside even if the outside pressure changes, and the light source array is not damaged even when the autonomous unmanned submersible collides with the front of the vinyl film or hits an external object. Installing the guards 47 at equal intervals so that the optical guide device of the present invention can be used in the deep sea.

In addition, in the present invention, as shown in FIG. 5, instead of separately installing the semicircular light source group in the optical guide device, a separate light source blocking unit 45 may be installed to partially block the light source at five points where the light source group is installed. .

As such, when the light source blocking unit 45 partially blocking the LED light source is formed in the optical guide device 40, the light source group # 1 to # 5 may be installed by checking the image processing by the camera. Similar to the method, the distance to the dock entrance, the inclination angle and the direction angle can be observed.

FIG. 7 shows another embodiment of measuring the posture of the optical guide device to which the present invention is applied, and is arranged in the existing circumferential LED 43 without installing a separate light source group in the optical guide device 40. By installing a light source blocking unit 45, a part of which is omitted, the light source blocking unit 45 may be configured to form a discontinuous point on the circumference of the optical guide device 40.

Then, a separate semicircular light source as described above can reduce the hassle of installing on the outer peripheral surface of the fixing portion.

In addition, since the LED emits light in a hemispherical direction, the front surface of the docking device can detect an annular light source having a uniform illuminance in any direction, thereby reducing an image processing error according to the direction of a general underwater light. .

8 is a circuit diagram of the LED light source illuminance control device.

When the distance of the autonomous unmanned submersible is read by using an ultrasonic position tracking device or an ultrasonic telemeter installed to induce the autonomous unmanned submersible at the seabed base, it converts this information and inputs it to the light illuminance control device having the electronic circuit as shown in the figure. Adjust the brightness of the LED.

As such, the optical guide device of the autonomous unmanned submersible of the present invention uses a method of compensating for external pressure regardless of the working depth of the subsea base, so there is no limitation in the working depth, and even if some LEDs reach the end of life or are damaged, the basic performance is not limited. It has a robust structure of light source with no influence, which is advantageous for use in deep sea.                     

In addition, in the hemispherical region in front of the docking device, it is possible to emit a uniform light source for the docking guide, and the distance from the autonomous unmanned submersible to the docking device can be calculated by using a circular light source. The angle of inclination and direction of the unmanned submersible with the docking device can be estimated by image processing.

In addition, the brightness of the light source can be automatically controlled by inputting the distance information of the unmanned submersible submersible and driving the transistor.

As described above, the optical guide device for underwater docking of the autonomous unmanned submersible has a waterproof structure filled with transparent oil inside the vinyl film to compensate for the external pressure regardless of the working depth of the subsea base, and compensates for the external pressure. Because of its structure, there is no limit on the installation depth of the docking device, and by using LEDs with parallel connection structure, it has a strong structure of light source that does not affect the basic performance even if some LEDs are worn out or damaged. There is an advantage.

In the semi-spherical area in front of the docking device, it is possible to emit a uniform light source for the docking guide. By processing the circular light source, it is possible to calculate the distance of the autonomous unmanned submersible to the docking device. The tilt angle and the direction angle of the submersible can be estimated by the image processing, and the brightness of the light source can be automatically controlled by inputting the distance information of the autonomous unmanned submersible and driving the transistor.

In addition, by installing one waterproof camera in the center of the bow part of the autonomous unmanned submersible, by recognizing the circular light source of the docking device obtained therefrom, the autonomous unmanned submersible obtains information for reaching the docking device through image processing, and the direction of the autonomous unmanned submersible The driving of the control panel generates a control command so that the center of the docking device is located in the center of the image plane of the camera, and the light flow equation of the camera controls the attitude of the autonomous unmanned submersible by interpreting the motion equation of the underwater hull.

Claims (5)

delete In the center of the bow of the autonomous unmanned submersible 10, a camera 20 for capturing an image of a target is installed, and an optical guide device 40 having a light source is installed at the entrance of the docking device 30 of the subsea base. By checking the entrance of the docking device by tracking the light source of the optical guide device 40 which is processed by the image, the distance to the docking device, the inclination angle and the direction angle are calculated to control the direction control panel of the autonomous unmanned submersible submarine 10 An optical guide device for docking a docking device by changing its posture, The optical guide device 40 for guiding the underwater docking of the autonomous unmanned submersible is composed of a funnel-shaped conical fixing part 41 fixed to the inlet side of the docking device 30, and the conical fixing part 41 A plurality of LEDs 43 connected in parallel are arranged in two rows so as to maintain a constant distance along the circumference so that the LEDs 43 form a pair of large and small circular light sources, which are fixed to the conical fixing portion 41. The LED 43 is waterproofed with a flexible film, and five semicircular light source groups (# 1, # 2) are disposed on the outer circumferential surface of the fixing part 41 in the horizontal, vertical, upward, downward, left, right, and 45 degree inclination positions. , # 3, # 4, # 5 are installed, and the brightness adjustment of the LED 43 is controlled by a transistor driving circuit for inputting the distance information of the autonomous unmanned submersible underwater Optical guide device for docking. The optical guide device for underwater docking of an autonomous unmanned submersible according to claim 2, wherein an anti-shock rubber pad (49) is provided inside the fixing part (41) of the optical guide device (40). According to claim 2, wherein the fixing portion 41 is provided with a guard 47 to protect the LED 43, the guard 47 is between the LED 43 is fixed to the fixing portion 41 Optical guide device for underwater docking of the autonomous unmanned submersible, characterized in that arranged at equal intervals. 3. The optical guide device 40 according to claim 2, which guides the docking of the autonomous unmanned submersible, is composed of a funnel-shaped conical fixing part 41 fixed to the inlet side of the docking device 30. A plurality of LEDs 43 connected in parallel to the front of the fixing portion 41 are arranged in two rows so as to maintain a constant interval along the circumferential surface so that the LEDs 43 form a pair of large and small circular light sources. The LED 43 fixed to the fixing part 41 is waterproofed with a flexible film, and the fixing part 41 partially has a light source of the LED at the inclined positions of the top, bottom, left, right and 45 degrees in the horizontal and vertical directions. Five light source blocking units 45 are cut off, and the brightness of the LED 43 is controlled by a transistor driving circuit for inputting distance information of the autonomous unmanned submersible. Optics for Docking De device.

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