Underwater Laser Rendezvous and Docking System for Unmanned Underwater Vehicles and Its Application Method

Abstract

This invention relates to an underwater laser rendezvous and docking system for unmanned underwater vehicles (UUVs) and its method of use. The underwater laser rendezvous and docking system for UUVs includes a target UUV section and a tracking UUV section. The target UUV section includes an illumination source and an optical cooperative target, while the tracking UUV section includes a capture and tracking CCD module, an underwater lidar, a servo mechanism, and a comprehensive processing module. The laser rendezvous and docking distance accuracy of this invention can reach the centimeter level, and the angle measurement accuracy can reach 0.1°, significantly improving the accuracy of rendezvous and docking.

Description

Technical Field

[0001] This invention relates to the field of underwater optoelectronic technology, and in particular to an underwater laser rendezvous and docking system for unmanned underwater vehicles and its usage method. Background Technology

[0002] As unmanned underwater vehicles (UUVs) spend increasingly longer periods underwater, the accumulated errors of existing inertial navigation systems are unsatisfactory, and these UUVs cannot surface frequently. While existing GPS satellite positioning can correct for inertial navigation errors, it may reduce their operational time due to the back-and-forth movement.

[0003] Traditional UUVs or AUVs use underwater acoustic detection technology for rendezvous and docking with their mother ships. This involves employing a short baseline measurement principle to acquire angle and distance information between the target UUV and the mother ship, thereby enabling rendezvous and docking and subsequent UUV recovery. However, its distance measurement accuracy is relatively low, typically 0.2m, and its angle accuracy is 0.2°. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art and provides an underwater laser rendezvous and docking system for unmanned underwater vehicles and a method for using it.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an underwater laser rendezvous and docking system for unmanned underwater vehicles, comprising a target UUV part and a tracking UUV part. The target UUV part includes an illumination source and an optical cooperative target, and the tracking UUV part includes a capture and tracking CCD module, an underwater lidar, a servo mechanism, and an integrated processing module.

[0006] The illumination source, set on the target UUV, is used to provide coarse guidance for the acquisition and tracking CCD module, enabling the underwater lidar to track optically cooperative targets;

[0007] The optical cooperative target is set on the target UUV to provide a target for the underwater lidar, so that the emitted laser beam returns along the original path;

[0008] The acquisition and tracking CCD module includes a CCD detector and an image processing unit that are interconnected on the tracking UUV. It is used to acquire the illumination source emitted by the target UUV, extract the miss distance, and send the miss distance to the servo mechanism to adjust the azimuth and elevation of the underwater lidar in a timely manner so that the underwater lidar beam illuminates the optical cooperative target in real time.

[0009] The underwater lidar includes a laser emitting unit, a laser docking unit, an optical unit, a distance and angle calculation unit, and a power supply unit, which are interconnected on the UUV being tracked, and are used to complete the distance and angle measurement of the target UUV.

[0010] The servo mechanism includes an azimuth motor, a pitch motor, and a servo processing unit mounted on the tracking UUV. The azimuth motor and the pitch motor are respectively connected to the servo processing unit, and the azimuth motor is fixed to the output shaft of the pitch motor. The underwater lidar is mounted on the output shaft of the azimuth motor to complete the acquisition and tracking of the target UUV, adjust the angle of the underwater lidar's emission light source in a timely manner to align with the optical cooperative target, measure in real time, and output angle information in real time to complete the positioning of the target UUV.

[0011] The integrated processing module is used to communicate with the tracking UUV, output distance and angle information, and provide power to the tracking UUV as well as control of the entire system.

[0012] Specifically, the lighting source is a blue light source with a wavelength of 450nm.

[0013] Specifically, the diameter of the optical cooperation target is 30mm.

[0014] Specifically, the CCD detector has a pixel count of no less than 1024×1024 and a field of view of 30°.

[0015] Specifically, the underwater lidar uses a green laser light source with a wavelength of 532nm, a laser emission repetition rate of not less than 5Hz, a laser receiver aperture of 30mm, a data output frame rate of 5Hz, and a power supply voltage of 24V.

[0016] Specifically, the azimuth pitch angle of the servo mechanism is not less than 30°, and the pointing accuracy is not less than 0.05°.

[0017] Specifically, the integrated processing module includes a communication interface and a power supply interface. The communication interface is connected to the acquisition and tracking CCD module, the underwater lidar, and the servo mechanism, respectively. The power supply interface is connected to the acquisition and tracking CCD module, the underwater lidar, and the servo mechanism, respectively.

[0018] A method for using an underwater laser rendezvous and docking system for an unmanned underwater vehicle includes the following steps:

[0019] Step 1: The target UUV emits an illumination source, the CCD detector of the tracking UUV captures the light source, the image processing unit performs image processing to obtain the relative angle information of the target UUV, controls the servo mechanism on the tracking UUV to point the laser source of the underwater lidar at the target UUV, and completes the guidance between the target UUV and the tracking UUV.

[0020] Step 2: The laser beam emitted by the guiding laser emitting unit is directed onto the optical cooperative target on the target UUV. The laser docking unit acquires the laser signal reflected by the optical cooperative target and further acquires the deviation between the target UUV and the tracking UUV through the CCD detector. The direction of the laser beam is adjusted in real time to complete the closed-loop tracking of the target UUV by the tracking UUV.

[0021] Step 3: The distance and angle calculation unit calculates the distance information between the target UUV and the tracking UUV based on the time of the emitted and received laser signals from the underwater lidar. By acquiring the azimuth and pitch information of the servo mechanism, it completes the relative angle information between the target UUV and the tracking UUV, thereby completing the rendezvous and docking between the target UUV and the tracking UUV.

[0022] The beneficial effects of this invention are as follows: the laser rendezvous and docking distance accuracy can reach the centimeter level, and the angle measurement accuracy can reach 0.1°, which greatly improves the accuracy of rendezvous and docking; the underwater lidar, with its high spatiotemporal resolution, greatly enhances the navigation and positioning capabilities of the unmanned underwater vehicle; at the same time, the high-resolution lidar technology significantly reduces the detection error of the unmanned underwater vehicle, which can meet the mission execution requirements in complex environments, and compared with aquatic detection technology, the system can be further reduced in size, making it possible to design a smaller unmanned underwater vehicle, thereby improving the vehicle's flexibility and maneuverability, and reducing energy consumption. Attached Figure Description

[0023] Figure 1 This is a block diagram of the underwater laser rendezvous and docking system of the present invention;

[0024] Figure 2 This is a preliminary installation schematic diagram of the underwater laser rendezvous and docking system of the present invention;

[0025] In the diagram: 1-Underwater laser rendezvous and docking system; 2-Optical cooperative target; 3-Acquisition and tracking CCD module; 31-CCD detector; 32-Image processing unit; 4-Underwater lidar; 41-Laser emission unit; 42-Laser docking unit; 43-Optical unit; 44-Distance angle calculation unit; 45-Power supply unit; 5-Servo mechanism; 51-Azimuth motor; 52-Pitch motor; 53-Servo processing unit; 6-Integrated processing module; 61-Communication interface; 62-Power supply interface;

[0026] The following will describe in detail, with reference to the accompanying drawings, embodiments of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to embodiments:

[0028] like Figures 1-2As shown, an underwater laser rendezvous and docking system for unmanned underwater vehicles includes a target UUV section and a tracking UUV section. The target UUV section includes an illumination source 1 and an optical cooperative target 2. The tracking UUV section includes a capture and tracking CCD module 3, an underwater lidar 4, a servo mechanism 5, and an integrated processing module 6.

[0029] Illumination source 1 is set on the target UUV to provide coarse guidance for the acquisition and tracking CCD module 3, enabling the underwater lidar 4 to track the optical cooperative target 2; Illumination source 1 is a blue light source with a wavelength of 450nm, and the number can be set to 4;

[0030] Optical cooperative target 2 is set on the target UUV to provide a target for underwater lidar 4, so that the emitted laser beam returns along the original path; optical cooperative target 2 has a diameter of 30mm.

[0031] The acquisition and tracking CCD module 3 includes a CCD detector 31 and an image processing unit 32 connected to each other on the tracking UUV. It is used to acquire the illumination source 1 emitted by the target UUV, extract the miss distance, and send the miss distance to the servo mechanism 5 to adjust the azimuth and elevation of the underwater lidar 4 in a timely manner so that the beam emitted by the underwater lidar 4 illuminates the optical cooperative target 2 in real time. The CCD detector 31 has a pixel size of not less than 1024×1024 and a field of view of 30°.

[0032] The underwater lidar 4 includes a laser emitting unit 41, a laser docking unit 42, an optical unit 43, a distance and angle calculation unit 44, and a power supply unit 45, which are interconnected on the UUV being tracked. It is used to complete the distance and angle measurement of the target UUV. The light source of the underwater lidar 4 is a green laser light source with a wavelength of 532nm, the laser emission repetition rate is not less than 5Hz, the laser receiving aperture is 30mm, the data output frame rate is 5Hz, and the power supply voltage is 24V.

[0033] The servo mechanism 5 includes an azimuth motor 51, a pitch motor 52, and a servo processing unit 53 mounted on the tracking UUV. The azimuth motor 51 and the pitch motor 52 are respectively connected to the servo processing unit 53, and the azimuth motor 51 is fixed to the output shaft of the pitch motor 52. The underwater lidar 5 is mounted on the output shaft of the azimuth motor 51 and is used to capture and track the target UUV. It adjusts the angle of the emitted light source of the underwater lidar 4 in a timely manner to align with the optical cooperative target 2, measures in real time, and outputs angle information in real time to complete the positioning of the target UUV. The azimuth and pitch angle of the servo mechanism 5 is not less than 30°, the pointing accuracy is not less than 0.05°, and the structure is a two-axis frame.

[0034] The integrated processing module 6 is used to communicate with the tracking UUV, output distance and angle information, and provide power supply for the tracking UUV and control of the entire system. The integrated processing module 6 includes a communication interface 61 and a power supply interface 62. It is connected to the acquisition and tracking CCD module 3, the underwater lidar 4, and the servo mechanism 5 through the communication interface 61, and to the acquisition and tracking CCD module 3, the underwater lidar 4, and the servo mechanism 5 through the power supply interface 62.

[0035] A method for using an underwater laser rendezvous and docking system for an unmanned underwater vehicle includes the following steps:

[0036] Step 1: The target UUV emits illumination source 1, the CCD detector 31 of the tracking UUV captures the light source, the image processing unit 32 performs image processing to obtain the relative angle information of the target UUV, and controls the servo mechanism 5 on the tracking UUV to make the laser source of the underwater lidar 4 point to the target UUV, thus completing the guidance between the target UUV and the tracking UUV.

[0037] Step 2: The laser beam emitted by the laser emitting unit 41 is directed to the optical cooperative target 2 on the target UUV. The laser docking unit 42 acquires the laser signal reflected by the optical cooperative target 2 and further acquires the deviation between the target UUV and the tracking UUV through the CCD detector 31. The direction of the laser beam is adjusted in real time to complete the closed-loop tracking of the target UUV by the tracking UUV.

[0038] Step 3: The distance angle calculation unit 44 calculates the distance information between the target UUV and the tracking UUV based on the time of the laser signal emitted and received by the underwater lidar 4. By acquiring the azimuth and pitch information of the servo mechanism 5, it completes the relative angle information between the target UUV and the tracking UUV, thereby completing the rendezvous and docking between the target UUV and the tracking UUV.

[0039] The measurement distance in the above method is not less than 50m; the measurement accuracy is 1cm; the data refresh rate is not less than 5Hz; the field of view of the CCD detector 31 is 30°; the laser wavelength is 532nm; and the size of the optical cooperative target 2 is as follows: Target UUV light source: Blue light source 450nm.

[0040] The laser rendezvous and docking distance accuracy of this invention can reach the centimeter level, and the angle measurement accuracy can reach 0.1°, which greatly improves the accuracy of rendezvous and docking. Underwater lidar 4, with its high spatiotemporal resolution, greatly enhances the navigation and positioning capabilities of unmanned underwater vehicles. At the same time, high-resolution lidar technology significantly reduces the detection error of unmanned underwater vehicles, which can meet the mission execution requirements in complex environments. Compared with aquatic detection technology, this system can be further reduced in size, making it possible to design smaller unmanned underwater vehicles, thereby improving the flexibility and maneuverability of the underwater vehicles and reducing energy consumption.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] The present invention has been described above by way of example. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or direct application to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. An underwater laser rendezvous and docking system for unmanned underwater vehicles, comprising a target UUV and a tracking UUV, characterized in that, The target UUV part includes an illumination source (1) and an optical cooperative target (2), and the tracking UUV part includes a capture and tracking CCD module (3), an underwater lidar (4), a servo mechanism (5), and an integrated processing module (6). An illumination source (1) is set on the target UUV to provide coarse guidance for the acquisition and tracking CCD module (3), enabling the underwater lidar (4) to track the optical cooperative target (2); Optical cooperative target (2) is set on the target UUV to provide a target for the underwater lidar (4) so ​​that the emitted laser beam returns along the original path; The capture and tracking CCD module (3) includes a CCD detector (31) and an image processing unit (32) connected to each other on the tracking UUV. It is used to capture the illumination source (1) emitted by the target UUV, extract the miss distance, send the miss distance to the servo mechanism (5), and adjust the azimuth and elevation of the underwater laser radar (4) in time so that the underwater laser radar (4) emits a beam that illuminates the optical cooperative target (2) in real time. The underwater lidar (4) includes a laser emitting unit (41), a laser docking unit (42), an optical unit (43), a distance and angle calculation unit (44), and a power supply unit (45) that are connected to each other on the tracking UUV, and is used to complete the distance measurement and angle measurement of the target UUV. The servo mechanism (5) includes an azimuth motor (51), a pitch motor (52), and a servo processing unit (53) mounted on the tracking UUV. The azimuth motor (51) and the pitch motor (52) are respectively connected to the servo processing unit (53), and the azimuth motor (51) is fixed on the output shaft of the pitch motor (52). The underwater laser radar (4) is mounted on the output shaft of the azimuth motor (51) to complete the capture and tracking of the target UUV, adjust the angle of the emitted light source of the underwater laser radar (4) in a timely manner to align with the optical cooperative target (2), measure in real time, and output angle information in real time to complete the positioning of the target UUV. The integrated processing module (6) is used to communicate with the tracking UUV, output distance and angle information, and provide power supply for the tracking UUV and control of the entire system.

2. The underwater laser rendezvous and docking system for unmanned underwater vehicles according to claim 1, characterized in that, The lighting source (1) is a blue light source with a wavelength of 450nm.

3. The underwater laser rendezvous and docking system for unmanned underwater vehicles according to claim 1, characterized in that, The diameter of the optical cooperation target (2) is 30 mm.

4. The underwater laser rendezvous and docking system for unmanned underwater vehicles according to claim 1, characterized in that, The CCD detector (31) has a pixel count of not less than 1024×1024 and a field of view of 30°.

5. The underwater laser rendezvous and docking system for unmanned underwater vehicles according to claim 1, characterized in that, The underwater lidar (4) uses a green laser light source with a wavelength of 532nm, a laser emission repetition rate of not less than 5Hz, a laser receiver aperture of 30mm, a data output frame rate of 5Hz, and a power supply voltage of 24V.

6. The underwater laser rendezvous and docking system for unmanned underwater vehicles according to claim 1, characterized in that, The azimuth pitch angle of the servo mechanism (5) is not less than 30° and the pointing accuracy is not less than 0.05°.

7. The underwater laser rendezvous and docking system for unmanned underwater vehicles according to claim 1, characterized in that, The integrated processing module (6) includes a communication interface (61) and a power supply interface (62). The communication interface (61) is connected to the acquisition and tracking CCD module (3), the underwater lidar (4), and the servo mechanism (5) respectively. The power supply interface (62) is connected to the acquisition and tracking CCD module (3), the underwater lidar (4), and the servo mechanism (5) respectively.

8. A method of using an underwater laser rendezvous and docking system for an unmanned underwater vehicle according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: The target UUV emits an illumination source (1), the CCD detector (31) of the tracking UUV captures the light source, and the image processing unit (32) performs image processing to obtain the relative angle information of the target UUV. The servo mechanism (5) on the tracking UUV is controlled to make the laser source of the underwater lidar (4) point to the target UUV, thus completing the guidance between the target UUV and the tracking UUV. Step 2: The laser beam emitted by the laser emitting unit (41) is directed to the optical cooperative target (2) on the target UUV. The laser docking unit (42) acquires the laser signal reflected by the optical cooperative target (2), and further acquires the deviation between the target UUV and the tracking UUV through the CCD detector (31). The direction of the laser beam is adjusted in real time to complete the closed-loop tracking of the target UUV by the tracking UUV. Step 3: The distance angle calculation unit (44) calculates the distance information between the target UUV and the tracking UUV based on the time of laser signal transmission and laser signal reception of the underwater lidar (4). By acquiring the azimuth and pitch information of the servo mechanism (5), it completes the relative angle information between the target UUV and the tracking UUV, and then completes the rendezvous and docking between the target UUV and the tracking UUV.

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