Underwater net cage inspection robot based on side-scan sonar and AUV platform

Abstract

The invention discloses an underwater net cage inspection robot based on a side-scan sonar and an AUV platform and a use method of the underwater net cage inspection robot. The underwater net cage inspection robot comprises a pressure-resistant cabin, a control system in the cabin, a main body frame, a propelling system on the main body frame, a communication device and an inspection operation system. Wherein the inspection operation system comprises a detection camera, an inspection auxiliary side-scan sonar and a navigation technology combining a GPS (Global Positioning System) and an INS (Inertial Navigation System). And the underwater robot determines the position of the underwater robot through combined positioning of the GPS and the INS and keeps communication with the ground station. And after the net cage arrives at a specified inspection area, detecting the position, the shape and the surrounding environment of the net cage by using a side-scan sonar, constructing a detailed seabed image, and planning an inspection path and performing efficient inspection according to the path by cooperating with the synergistic effect of a control system. Meanwhile, the camera is used for monitoring the surface condition of the net cage in real time, the problem of damage or foreign matter attachment can be recognized, and the comprehensiveness and accuracy of inspection work are ensured.

Description

Technical Field

[0001] The present application relates to the technical field of underwater robots, and in particular to an underwater cage inspection robot based on side-scan sonar and an AUV platform. Background Art

[0002] With the rapid development of large-scale integrated aquaculture, deep-water cage farming has gradually become popular as an efficient and environmentally friendly farming model. However, this farming method faces many challenges, such as damaged nets and difficulty in monitoring the growth status of fish. Therefore, regular inspections are essential to ensure the integrity of the cage structure and monitor the health of fish. Although the fixed-point monitoring method reduces human intervention and improves safety to a certain extent, it relies on complex cable laying and is easily affected by the marine environment (such as currents and tides). Sensors are prone to corrosion and biological attachment, resulting in high maintenance costs and difficulty in covering large areas of water. Although remotely operated unmanned submersibles (ROVs) have improved the efficiency and quality of inspections, the umbilical cable limits its range of motion, making it complex to operate and expensive to maintain, and it requires long-term manual monitoring. Summary of the invention

[0003] The purpose of the present invention is to provide an underwater cage inspection robot based on side-scan sonar and AUV platform and a method for using the same. A path planning system is used to plan an inspection path after scanning the underwater environment and update it in real time. At the same time, a cage damage detection tool is used to identify and photograph the damaged parts of the cage and the attachment of foreign objects during the inspection process, so as to realize regular inspection of the cages and reduce the pressure of manual inspection.

[0004] The present invention can be achieved through the following technical solutions:

[0005] An underwater cage inspection robot based on side-scan sonar and AUV platform, characterized in that it includes a pressure-resistant cabin and a control system inside the cabin, a main frame and a propulsion system on the main frame, a communication device and an inspection operation system, wherein the pressure-resistant cabin includes a cabin rear cover, a high-strength transparent flange pipe and a high-strength acrylic hemispherical cover, so as to realize the safety protection of the underwater robot in a deep-water environment and facilitate the real-time observation of the internal conditions of the underwater robot from the outside; the propulsion system includes four horizontal thrusters and two vertical thrusters, wherein the horizontal thrusters are symmetrically installed on the left and right sides of the underwater robot, and the vertical thrusters are symmetrically installed on the front and back of the underwater robot, and the six thrusters are arranged on the left and right sides of the underwater robot. The underwater robot is equipped with an array of equidistant actuators to achieve all-directional movements such as pitch, heave and yaw of the underwater robot; the communication device includes a buoy system and a cable drum device, which allows the robot to control the buoy system to float up and exchange data with the ground station through the cable drum when an abnormality is found in the net cage, thereby ensuring the real-time transmission of inspection information; the control system includes a main control microcontroller and a power distribution device, which are used to realize the motion posture control of the underwater robot, autonomously perform inspection tasks and retract and release the buoy system; the inspection operation system includes a path planning system, a net cage damage detection tool and a positioning system, which are used to patrol and detect net cage damage or foreign matter attachment, take images, and mark coordinate information.

[0006] Furthermore, the buoy system is used to float on the surface and communicate with a ground station, and it includes a wireless communication device; the wireless communication device is embedded in the buoy system, and establishes a connection with the ground station when the buoy stabilizes on the water surface to transmit data and receive instructions; the cable drum device uses the retracted cable to control the release and recovery of the buoy.

[0007] Furthermore, the path planning system is used for seabed image mapping and plans inspection routes through the measured images, and includes a side-scan sonar and a data processing device; the side-scan sonar is symmetrically installed on both sides of the lower part of the main frame, and can emit high-frequency sound wave pulses and receive echo signals reflected from the seabed or the cage; the data processing device is used to process the echo signals and splice them into seabed images, and plan underwater inspection paths.

[0008] Furthermore, the net cage damage detection tool includes a detection camera and a high-brightness fill light strip, which are used to capture damaged parts of the net cage and places where foreign objects are attached, and to take real-time photos of abnormal parts and mark them.

[0009] Furthermore, the positioning system is used to calibrate the robot's inspection coordinate position and depth, so as to effectively record the transmission cage abnormal point information, and includes a combined navigation system of GPS and INS, a depth sensor, and a gyroscope; the combined system of GPS and INS can locate the starting position of each robot inspection and give the starting coordinates of the inspection path; the depth sensor is used to detect the robot's depth in real time and transmit it to the control system, so that it issues instructions to adjust the robot when inspecting cages at different depths; the gyroscope is used to detect the robot's pitch and roll posture, and the transmission control system corrects the robot's posture in real time.

[0010] A method for using an underwater cage inspection robot based on a side-scan sonar and an AUV platform, the method comprising the following steps:

[0011] Step 1: Release the underwater robot from the coast or ship;

[0012] Step 2: The underwater robot follows the navigation system to the work site, marks the starting coordinates of the work site, and uses the side-scan sonar to scan the underwater environment;

[0013] Step 3: Generate underwater images through the data sent back by the side-scan sonar, determine the location of the cages and plan the route for cage inspection;

[0014] Step 4: The underwater robot conducts inspections according to the planned path. When the camera identifies that the cage is damaged or has foreign objects attached, the camera takes a picture of the location and records the coordinate information;

[0015] Step 5: After inspecting ten cages, the underwater robot floats up and releases the buoy system to transmit information back to the ground station;

[0016] Step 6: After the communication is completed, the buoy system is retrieved and the underwater robot continues the inspection;

[0017] Step 7: After the inspection of the cages in the area is completed, they reach the designated end point and float to the surface of the water and are recovered by the ground station.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The underwater cage inspection robot provided in this application can replace manual inspection of deep-sea cage damage and foreign matter attachment, and has the advantages of high detection accuracy and high work efficiency, and has high stability and robustness during movement;

[0020] 2. The buoy system can float to the surface to communicate wirelessly with the ground station, and its working reliability is better than that of equipment that only communicates wirelessly under the sea surface;

[0021] 3. The path planning system can identify the surrounding environment and plan the forward path without touching the cage;

[0022] 4. The cage damage detection tool is equipped with an underwater imaging protective cover, which can surround the damaged imaging area to prevent water flow disturbance from affecting the imaging quality. The image quality and availability are better than traditional imaging methods;

[0023] 5. The positioning device can automatically choose whether to enable INS according to the GPS signal situation. The working reliability is better than the traditional navigation system that only uses GPS, and cooperates with the depth sensor to determine the specific position underwater. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of an underwater cage inspection robot based on side-scan sonar and AUV platform in this application.

[0025] Figure 2 It is a schematic diagram of the structure of the pressure-resistant cabin of the underwater robot in this application.

[0026] Figure 3 It is a schematic diagram of the structure of the internal component group of the pressure-resistant cabin of the underwater robot in this application.

[0027] Figure 4 It is a structural schematic diagram of the main frame of the underwater robot in this application.

[0028] Figure 5 It is a structural schematic diagram of the buoy system of the underwater robot in this application.

[0029] Figure 6 It is a flow chart of a method for using an underwater cage inspection robot based on side-scan sonar and AUV platform in the present application.

[0030] Reference numerals:

[0031] 1-pressure-resistant cabin; 11-cabin rear cover; 12-flange tube; 13-acrylic hemispherical cover; 14-internal component group; 141-internal frame; 142-camera bracket; 143-detection camera; 144-high-brightness fill light strip; 145-navigation system; 146-path planning system; 147-main control microcontroller; 148-power management system; 149-power distribution device;

[0032] 2-main frame; 21-lifting ring; 22-cabin fixing ring; 23-side frame;

[0033] 3-communication device; 31-waterproof sealing cover; 32-buoy system storage; 33-reel bracket; 34-cable reel; 35-brushless motor; 36-buoy system;

[0034] 4- Depth sensor;

[0035] 5-Horizontal thruster;

[0036] 6-vertical thrusters;

[0037] 7-Side scan sonar;

[0038] Specific implementation method

[0039] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Figure 1-6 The described embodiment is only one embodiment of the present invention, not all embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] This application proposes an underwater cage inspection robot based on side-scan sonar and AUV platform, such as Figure 1 As shown, the underwater robot includes a pressure-resistant cabin 1, a main frame 2, a communication device 3, and horizontal thrusters 5 (4 in total), vertical thrusters 6 (2 in total) and side-scan sonars 7 (2 in total) fixed on the main frame 2. The horizontal thrusters 5 (4 in total) are symmetrically distributed on both sides of the main frame, and the vertical thrusters 6 (2 in total) are symmetrically distributed in front and behind the main frame. Driven by the horizontal thrusters 5 and the vertical thrusters 6, the underwater robot can realize various directional movements such as pitch, heave and yaw.

[0041] like Figure 2 As shown, the pressure-resistant cabin 1 includes a cabin rear cover 11, a flange tube 12 and an acrylic hemispherical cover 13. The cabin rear cover 11, the flange tube 12 and the acrylic hemispherical cover 13 are fixed by a plurality of screw connectors. The interlayer is coated with watertight rubber so that the pressure-resistant cabin 1 can maintain good watertightness in a deep water environment. An internal component group 14 is placed in the flange tube 12.

[0042] like Figure 3As shown, the internal component group 14 includes an internal frame 141, a camera bracket 142, a detection camera 143, a high-brightness fill light strip 144, a positioning system 145, a path planning system 146, a main control microcontroller 147, a power management system 148, and a power distribution device 149. The detection camera 143 is installed on the camera bracket 142, and the camera bracket 142 and the positioning system 145 are installed on the internal frame 141 through screw connectors. The path planning system 146 is installed on the front half of the internal frame 141, the main control microcontroller 147 and the power distribution device 149 are stacked and installed on the path planning system 146, and the power management system 148 is installed on the back half of the internal frame 141. The detection camera 143 is responsible for obtaining underwater real-time images. The positioning system 145 includes a combined system of GPS and INS, a depth sensor and a gyroscope. When the GPS signal is unstable in the waters, the INS can be enabled to prevent the underwater robot from losing its path. The path planning system 146 is used to obtain the side-scan sonar feedback data and has a built-in path planning algorithm based on a neural network. The main control microcontroller 147 is used to control the thruster movement and the buoy system communication, and has a built-in algorithm for identifying damaged cages or foreign objects based on a neural network. The power management system 148 can provide power drive for the underwater robot and intelligently distribute voltage and current according to the load size of each component. The power distribution device 149 can control the underwater robot to make corresponding actions in real time according to the instructions given by the main control microcontroller 147.

[0043] like Figure 4 As shown, the main frame 2 includes a cabin fixing ring 22 (a total of 2 pairs) and a side frame 23 (a total of 4). A plurality of lifting rings 21 are provided on the side frame 23 to reduce the weight and facilitate the lifting device to lift the underwater robot. The cabin fixing ring 22 (a total of 2 pairs) is fixed to the side frame 23 by a screw connector, and the front and rear parts of the cabin fixing ring 22 are also connected by a screw connector, so that the pressure-resistant cabin 1 can be locked in the cabin fixing ring 22.

[0044] like Figure 5 As shown, the communication device 3 includes a waterproof sealing cover 31, a buoy system storage place 32, a drum bracket 33, a cable drum 34, a brushless motor 35, and a buoy system 36. The waterproof sealing cover 31 can be automatically opened and closed to release and retrieve the buoy system 36. The drum bracket 33 and the cable drum 34 are fixed to the buoy system storage place 32 by screw connectors. The brushless motor 35 is used to control the rotation of the cable drum 34, thereby driving the buoy system 36 to release and retrieve. The buoy system 36 is used to float to the surface and communicate with the ground.

[0045] The present application also provides a method for using an underwater cage inspection robot based on a side-scan sonar and an AUV platform, such as Figure 6 As shown, the method of use includes:

[0046] Step 1: The ground station releases the underwater robot from the shore or ship, and the lifting device cooperates with the lifting ring on the frame to complete the release of the underwater robot.

[0047] Step 2: After the underwater robot moves to the operation area according to the preset route or GPS coordinates, it marks the coordinates of the operation starting point and uses the side-scan sonar to scan the underwater environment. The preset route and GPS coordinates are provided by the ground station, and can also be calculated and planned by the main control computer and peripheral sensors.

[0048] Step 3: The path planning system obtains the data sent back by the side scan sonar, processes it, and plans the inspection path and transmits it to the main control microcontroller. The path planning system includes a path planning algorithm based on a neural network. The main control microcontroller includes a power drive system.

[0049] Step 4: The detection camera captures the image information of the damaged cage or foreign matter attached and transmits it to the main control microcontroller for identification of the damaged cage or foreign matter attached. The main control microcontroller includes a network-based identification algorithm for the damaged cage or foreign matter attached.

[0050] Step 5: After completing the inspection of ten cages, the underwater robot uses the communication device to transmit the image information of the damaged cages or foreign objects to the ground station. The specific operation is that during the inspection, the detection camera takes multiple images of damaged cages or foreign objects at different angles, and the main control microcontroller records the longitude and latitude information of the damaged cages or foreign objects. After the inspection is completed, the communication device releases the buoy system, and the buoy system floats to the surface to transmit the image and coordinate information to the ground station for manual review.

[0051] Step 6: After confirming that the inspection task at the work site is completed, the underwater robot returns to the deployment point according to the preset path playback or the GPS coordinates of the deployment point and floats up to facilitate the lifting device to lift the underwater robot.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Those skilled in the art should understand that they can still modify or replace the present invention to achieve the same technical effect. Without departing from the overall concept of the present invention, these modifications or replacements should fall within the scope of protection required by the present invention.

Claims

1. An underwater cage inspection robot based on side-scan sonar and AUV platform, characterized by: It includes a pressure-resistant cabin and a control system inside the cabin, a main frame and a propulsion system on the main frame, a communication device and an inspection operation system. The pressure-resistant cabin includes a cabin rear cover, a high-strength transparent flange pipe and a high-strength acrylic hemispherical cover, which realize the safety protection of the underwater robot in a deep water environment and facilitate the real-time observation of the internal conditions of the underwater robot from the outside; the propulsion system includes four horizontal thrusters and two vertical thrusters, wherein the horizontal thrusters are symmetrically installed on the left and right sides of the underwater robot, and the vertical thrusters are symmetrically installed on the front and back of the underwater robot. The six thrusters are arranged in an equidistant array to realize the underwater robot. The communication device includes a buoy system and a cable drum device, which allows the robot to control the buoy system to float up and exchange data with the ground station through the cable drum when an abnormality is found in the cage, so as to ensure the real-time transmission of inspection information; the control system includes a main control microcontroller and a power distribution device, which are used to realize the motion posture control of the underwater robot, autonomously perform inspection tasks and retract and release the buoy system; the inspection operation system includes a path planning system, a cage damage detection tool and a positioning system, which are used to patrol and detect cage damage or foreign matter attachment, take images and mark coordinate information.

2. The underwater robot according to claim 1, characterized in that: The buoy system is used to float on the surface and communicate with the ground station, and includes a wireless communication device; the wireless communication device is embedded in the buoy system, and establishes a connection with the ground station when the buoy stabilizes on the water surface to transmit data and receive instructions.

3. The underwater robot according to claim 1, characterized in that: The path planning system is used for seabed image mapping and plans inspection routes through the measured images, and includes a side-scan sonar and a data processing device; the side-scan sonar is symmetrically installed on both sides of the lower part of the main frame, and can emit high-frequency sound wave pulses and receive echo signals reflected from the seabed or the cage; the data processing device is used to process the echo signals and splice them into seabed images, and plan underwater inspection paths.

4. The underwater robot according to claim 1, characterized in that: The net cage damage detection tool includes a detection camera and a high-brightness fill light strip, which are used to capture the damaged parts of the net cage and the places where foreign objects are attached, and to take real-time photos of abnormal parts and mark them.

5. The underwater robot according to claim 1, characterized in that: The positioning system is used to calibrate the robot's inspection coordinate position and depth, so as to effectively record the transmission cage abnormal point information, and includes a combined navigation system of GPS and INS, a depth sensor, and a gyroscope; the combined system of GPS and INS can locate the starting position of each robot inspection and give the starting coordinates of the inspection path; the depth sensor is used to detect the robot's depth in real time and transmit it to the control system so that it issues instructions to adjust the robot when inspecting cages at different depths; the gyroscope is used to detect the robot's pitch and roll posture, and the transmission control system corrects the robot's posture in real time.

6. A method for using an underwater cage inspection robot based on side-scan sonar and AUV platform, characterized in that: The method is applicable to the underwater robot according to claims 1 to 5, and the method comprises the following steps: Step 1: Release the underwater robot from the coast or ship; Step 2: The underwater robot follows the navigation system to the work site, marks the starting coordinates of the work site, and uses the side-scan sonar to scan the underwater environment; Step 3: Generate underwater images through the data sent back by the side-scan sonar, determine the location of the cages and plan the route for cage inspection; Step 4: The underwater robot conducts inspections according to the planned path. When the camera identifies that the cage is damaged or has foreign objects attached, the camera takes a picture of the location and records the coordinate information; Step 5: After inspecting ten cages, the underwater robot floats up and releases the buoy system to transmit information back to the ground station; Step 6: After the communication is completed, the buoy system is retrieved and the underwater robot continues the inspection; Step 7: After the inspection of the cages in the area is completed, they reach the designated end point and float to the surface of the water and are recovered by the ground station.

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