An underwater vehicle net-breaking structure with autonomous net-breaking prevention

Abstract

This invention belongs to the field of underwater unmanned robot technology, specifically relating to an underwater vehicle with an autonomous anti-net-breaking structure. It comprises a drive mechanism, a transmission mechanism, and a bow-mounted retractable rotary cutting mechanism. The drive mechanism provides driving torque to the bow-mounted retractable rotary cutting mechanism via the transmission mechanism. The bow-mounted retractable rotary cutter head mechanism of this invention achieves circumferential cutting to ensure the underwater vehicle can smoothly pass through the fishing net and complete its task. The design of the transmission mechanism allows the expansion and rotation of the bow-mounted retractable rotary cutter head mechanism to be performed independently or as a whole, and limit settings are incorporated into the transmission mechanism to ensure stable net breaking and prevent slippage during rotary expansion cutting.

Description

Technical Field

[0001] This invention belongs to the field of underwater unmanned robot technology, specifically relating to an underwater vehicle with an autonomous anti-net-breaking structure, which has the function of autonomously breaking free when the underwater unmanned vehicle encounters fishing nets during operation. Background Technology

[0002] The marine fishing industry typically involves fishing vessels, fishing gear, and other related fishing equipment, playing a fundamental supporting role in the development of the overall fisheries industry chain. Various types, materials, sizes, and shapes of nets, such as gillnets, hand nets, trawls, hanging nets, drift nets, and aquaculture nets, can cover large areas of the ocean. Nets can be anchored and tightly strung together, or loosely and pliably arranged, or have floats added to the top and weights suspended at the bottom to distribute weight and create tension. Ships and underwater vehicles can encounter these nets from various directions, causing physical obstacles to their operations, especially in coastal areas where fishing activities are concentrated.

[0003] Unmanned underwater vehicles (UUVs) are autonomous underwater vehicles equipped with sensors and various mission modules that perform a variety of tasks, making significant contributions to information gathering in ports and coastal waters. For example, UUVs can perform critical tasks in underwater surveillance, reconnaissance, monitoring, tracking, mine detection, mine laying, relay communication, tactical oceanography, navigation, anti-submarine warfare, as well as hydrographic surveying and oceanographic research, demonstrating high autonomy and a wide exploration range. However, due to the high degree of randomness and uncertainty in UUV underwater navigation, they cannot penetrate fishing nets, severely hindering their mission performance.

[0004] Currently, the main method for breaking fishing nets involves using a manual surface salvage vessel to assist in breaking the net. After a land-based base station determines that an underwater drone is entangled in a fishing net, a salvage vessel is dispatched to the incident site to retrieve the underwater drone and manually break the net. Obviously, this method is slow in response and consumes a lot of manpower and resources, failing to meet the requirements for emergency and long-distance net breaking.

[0005] Therefore, there is a need for a device, system, and method that, while ensuring the operational functions of underwater unmanned vehicles, adds their autonomous net-breaking capabilities to facilitate and quickly penetrate nets and other objects. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing underwater unmanned vehicles (UAVs) by providing an autonomous net-breaking device and method that can be mounted on an underwater vehicle. This invention solves the problem of penetrating nets and other objects by using a net-breaking cutting component to cut the fishing net lines. The designed net-breaking device is integrated into the bow of the underwater UAV through a lightweight and modular design. The net-breaking area can be increased by expanding the net-breaking cutter disc, ensuring that appendages on the underwater UAV can smoothly penetrate fishing nets and other objects.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A fishing net breaking device for an underwater unmanned vehicle includes a drive mechanism, a transmission mechanism, and a bow-mounted retractable rotary cutting mechanism. The drive mechanism is used to provide driving torque to the bow-mounted retractable rotary cutting mechanism through the transmission mechanism.

[0009] The bow-mounted retractable rotary cutting mechanism includes a rotating disk, a pair of U-shaped cutter discs, multiple bidirectional cutting blades, a rack, a limiting groove, a limiting pin, a cutter end plate, and a cutter disc base. The pair of U-shaped cutter discs are located in the middle of the horizontal cross-section of the rotating disk and are mounted on the cutter end plate. The limiting groove is provided in the middle of the pair of U-shaped cutter discs. One end of the pair of U-shaped cutter discs is horizontally staggered and attached to each other by the rack and the limiting pin. The other end of the U-shaped cutter discs is connected to the cutter disc base. The multiple bidirectional cutting blades are mounted on the side of the cutter disc base facing away from the underwater unmanned vehicle.

[0010] The transmission mechanism includes a pair of transmission spur gears and an inner ring gear. One of the transmission spur gears meshes with the rack to achieve the extension and retraction of the tool end plate. The other of the transmission spur gears meshes with the inner ring gear to achieve the rotation of the bow retractable rotary cutting mechanism. The first transmission spur gear, the second transmission spur gear, and the inner ring gear are located at the center of the rotating disk, inside the circumferential edge, and on the circumferential surface, respectively.

[0011] According to one embodiment of the present invention, a streamlined tool box is tightly fastened to the tool end plate, and the rack passes through a pre-reserved gap in the tool box. The tool box is designed to make the bow of the vehicle streamlined, reduce drag, and prevent impurities in the seawater from entering the internal meshing gears, limiting grooves, and other structures, causing jamming.

[0012] According to one embodiment of the present invention, the drive mechanism includes a drive motor, a controller, a reducer, a coupling, an output shaft, and a motor bracket. The controller is mounted to the rear end of the drive motor, the reducer is mounted to the front end of the drive motor, one end of the coupling is mounted on the reducer shaft and connected by a key, and the other end of the coupling is connected to a first output shaft. The other end of the first output shaft is connected to a first transmission spur gear of the transmission mechanism by a key, providing active output torque to the transmission mechanism to enable the extension and retraction of the bow retractable rotary cutter head mechanism; the other end of the second output shaft is connected to a second transmission spur gear of the transmission mechanism by a key, providing active output torque to the transmission mechanism to enable the rotary cutting action of the bow retractable rotary cutting mechanism.

[0013] According to one embodiment of the present invention, the first and second output shafts of the drive mechanism are respectively engaged with one and the other of the transmission spur gears of the transmission mechanism.

[0014] According to one embodiment of the present invention, the drive motor in the drive mechanism is mounted on the inner wall of the underwater unmanned vehicle via a motor bracket and screws.

[0015] According to one embodiment of the present invention, the bidirectional cutting blade is a double-sided three-blade cutting blade, and the bidirectional cutting blade is made of an alloy material with a sandblasted surface.

[0016] According to one embodiment of the present invention, the limiting pin is a screw structure and is installed on the tool end plate by a threaded connection.

[0017] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0018] 1. The cutting mechanism of the present invention is equipped with a rotating cutter head structure that can be expanded to a sufficiently large size to break the net. The retractable rotating cutter head mechanism at the bow enables circumferential cutting to ensure that the underwater vehicle passes smoothly through the fishing net and completes its work.

[0019] 2. The design of the drive mechanism of the present invention allows the expansion and rotation of the bow telescopic rotating cutter head mechanism to be carried out independently or as a whole, and limits the transmission mechanism so that the rotating cutter can stably break the net and is not prone to slippage when performing rotational expansion cutting. Attached Figure Description

[0020] Figure 1 This is an overall external view of the unmanned autonomous vehicle and fishing net breaking device of the present invention.

[0021] Figure 2 This is a structural diagram of the fishing net breaking cutter head of the present invention.

[0022] Figure 3This is a structural diagram of the U-shaped cutter head of the present invention.

[0023] Figure 4 This is a structural diagram of the bidirectional cutting blade of the present invention.

[0024] Figure 5 This is a layout and structural diagram of the drive mechanism of the present invention.

[0025] Figure 6 This is a structural diagram of the drive motor of the present invention.

[0026] Figure 7 This is a schematic diagram of the installation of the mesh breaking cutter head of the present invention.

[0027] Figure 8 This is a flowchart of the mesh breaking cutter head drive process of the present invention.

[0028] Reference numerals: Bow-mounted telescopic rotating cutting mechanism 1, first U-shaped cutter head 101, limiting groove 102, limiting pin 103, second U-shaped cutter head 104, bidirectional cutting blade 105, rack 106, cutter end plate 107, cutter head base 108, cutter slit 109, bearing plate 110, drive mechanism 2, first drive motor 201, second drive motor 202, first motor bracket 203, second motor bracket 204, first coupling 205, second coupling 206, inner ring gear 207, first transmission spur gear 208, second transmission spur gear 209, controller 2011, reducer 2012, first output shaft 2013, controller 2021, reducer 2022, second output shaft 2023. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0030] The invention will now be further described with reference to the accompanying drawings:

[0031] like Figure 1 As shown, the general structure of an unmanned autonomous vehicle includes appendages such as wing panels and communication antennas. Therefore, the designed bow-mounted retractable rotating cutting mechanism 1 needs to cut out a sufficiently large area so that the appendages can pass smoothly through the fishing net. The external view shows that the bow-mounted retractable rotating cutting mechanism 1 is installed inside the bow of the unmanned autonomous vehicle.

[0032] like Figure 2As shown, the bow-mounted retractable rotary cutting mechanism 1 includes a first U-shaped cutter disc 101 and a second U-shaped cutter disc 104. The two cutter discs are connected by four limiting pins 103, ensuring that the first U-shaped cutter disc 101 and the second U-shaped cutter disc 104 fit tightly together and move along the limiting groove 102 during the unfolding and retraction process. A rack 106 is designed on one side of each of the first U-shaped cutter disc 101 and the second U-shaped cutter disc 104 to facilitate engagement with the second transmission spur gear 209 to achieve the unfolding and retraction actions. Sufficiently large slots are cut on both sides of the cutter end plate to allow the cutter disc base 108 to pass smoothly when the first U-shaped cutter disc 101 and the second U-shaped cutter disc 104 unfold and retract along the slots. Four bidirectional cutting blades 105 are mounted on the cutter disc base 108, enabling bidirectional cutting when the cutter disc rotates clockwise or counterclockwise.

[0033] Figure 3 For further illustration of the U-shaped cutter head structure, Figure 4 This is a structural diagram of a bidirectional cutting blade.

[0034] Figure 5 This is a layout and structural diagram of the drive mechanism. The drive mechanism 2 is installed inside the pressure-resistant housing and mainly includes drive motors 201 and 202, motor brackets 203 and 204, couplings 205 and 206, inner ring gear 207, transmission spur gear 208 and transmission spur gear 209. Figure 6 To further illustrate the structure of the drive motor, the diagram mainly includes the controller 2011, reducer 2012, and output shaft 2013 of drive motor 201, and the controller 2021, reducer 2022, and output shaft 2023 of drive motor 202. When the cutter head needs to be unfolded, the controller 2011 of drive motor 201 sends a signal, and drive motor 201 starts working. After being reduced in speed by reducer 2012, it drives output shaft 2013 to rotate through coupling 205. At the same time, output shaft 2013 is connected to transmission spur gear 209 through a key. The rotation of transmission spur gear 209 drives rack 106, causing rack 106 to unfold to both sides until the maximum stroke is reached. The cutter head unfolding action is completed, and drive motor 201 stops working. When it is necessary to break the net, the controller 2021 of the drive motor 202 sends a signal, and the drive motor 202 starts to work. After being reduced in speed by the reducer 2021, it drives the output shaft 2023 to rotate through the coupling 202. At the same time, the output shaft 2023 is connected to the transmission spur gear 208 through a flat key, which drives the inner ring gear 207 to rotate. The cutter head structure at the bow of the aircraft begins to rotate to break the net. After the net is broken, the drive motor 201 repeats the above reverse action to retract the cutter head.

[0035] like Figure 7As shown, the cutter end plate 107 of the bow-mounted retractable rotary cutting mechanism 1 is arranged on the inner wall of the pressure hull. During rotary cutting, in addition to the cutting resistance from the fishing net, it is also subject to friction from the inner wall of the pressure hull. To reduce friction, six bearing plates 110 are evenly arranged on the surface of the inner wall. This also ensures that the cutter end plate 107 is subjected to uniform load and facilitates the alignment of the two concentric circles. It should be noted that this part of the structure can be replaced by bearing structures such as ball bearings or needle bearings, but not limited to bearing plate structures. A cutter box is also arranged on the cutter head base 108. The cutter box is mainly to prevent impurities and other items in the seawater from entering the internal structure and causing jamming. Cutter slots 109 are opened on both sides of the cutter box so that the rack 106 can move smoothly out through these slots. Furthermore, the cutter box structure is designed in a streamlined shape to make the bow of the vehicle streamlined, reducing drag, reducing the power consumption of the vehicle, and facilitating the achievement of long-range requirements.

[0036] like Figure 8 As shown, the net-breaking process follows these logical steps to complete the detection and breaking of the net. First, a minimum threshold speed is given to the underwater vehicle. When the underwater vehicle control center receives the speed signal, it determines whether the speed is below the minimum threshold speed. If it is below the threshold speed, sonar image recognition is activated to detect whether a fishing net-like obstacle is detected. If the speed is equal to or greater than the threshold speed, the vehicle is not trapped by the fishing net. Since fishing nets vary in wire diameter, material, and color, sonar image recognition cannot reliably identify them. Therefore, water jet propulsion is activated to determine if the speed is below the minimum threshold speed. If the speed is equal to or greater than the threshold speed, the vehicle is not trapped by the fishing net. If the speed is below the threshold speed, the vehicle is determined to be trapped by the fishing net. At this point, the cutting blade is deployed, and the net-breaking mechanism is activated. After the net is broken, the net-breaking mechanism is retrieved.

[0037] Further optimization involves the use of a screw structure for the limit pin 103, which is installed on the tool end plate 107 via a threaded connection to prevent the tool disc structure from moving axially.

[0038] Further optimized, the bidirectional cutting blade 105 is a two-sided, three-blade cutting blade, meaning that the two sides and the front are cutting blades.

[0039] Further optimization involves welding the bidirectional cutting blade 105 onto the blade disc base, and the number of cutting blades should not be excessive to avoid cutting multiple fishing net lines simultaneously, resulting in excessive cutting force and high motor power consumption.

[0040] Further optimization involves using rust- and corrosion-resistant materials for all structural components in this section, since the entire structure is located in seawater. These materials include, but are not limited to, stainless steel, high-strength plastics, titanium, carbon fiber, and coated steel. A hardened surface coating, such as titanium nitride or a low-friction material, can be applied to the bidirectional cutting blade 105 to increase wear resistance and reduce power requirements.

[0041] Further optimization involves arranging all drive mechanism modules inside the pressure-resistant housing, isolating them from external seawater. Only the first output shaft 2013 and the second output shaft 2023 extend out to mesh with the gear and rack in the immersion chamber for transmission. Rotational dynamic seals are installed on the first output shaft 2013 and the second output shaft 2023.

[0042] Further optimization involves fixing the first motor bracket 203 and the second motor bracket 204 to the inner wall of the pressure hull, respectively, and fastening them together with screws.

[0043] Further optimization involves fastening the load-bearing plate 110 to the inner wall of the pressure hull with screws.

[0044] The specific actions for detecting fishing net targets in this embodiment are as follows: When the underwater vehicle encounters a fishing net while performing a mission, its speed drops to 0 upon impact. The vehicle's onboard speed sensor determines that its speed is below a set threshold. The sonar is then activated to identify the fishing net target. If the fishing net obstacle is detected, the net-breaking mechanism is activated. Since fishing nets vary in wire diameter, material, and color, sonar image recognition cannot reliably identify them. In this case, the water jet propulsion is activated to determine if the speed is below a minimum threshold speed. If the speed is equal to or greater than the threshold, the vehicle is not trapped by the net. If the speed is below the threshold, the vehicle is determined to be trapped by the net, and the cutting blades are deployed, activating the net-breaking mechanism.

[0045] The specific actions of unfolding the net-breaking mechanism are as follows: First, the controller 2011 of the first drive motor 201 sends a start signal, and the drive motor 201 starts to work. After being reduced in speed by the reducer 2012, it drives the first output shaft 2013 to rotate through the first coupling 205. At the same time, the first output shaft 2013 is connected to the second transmission spur gear 209 through a flat key. The rotation of the second transmission spur gear 209 drives the rack 106, causing the rack 106 to unfold to both sides. The first U-shaped cutter disc 101 slides in the limiting groove 102 through the limiting pin 103 until the maximum stroke is limited. The unfolding action of the cutter disc is completed, and the drive motor 201 stops working.

[0046] The specific actions of the rotating net-breaking mechanism are as follows: When net breaking is required, the controller 2021 of the second drive motor 202 sends a signal, and the drive motor 202 starts to work. After being reduced in speed by the reducer 2021, it drives the second output shaft 2023 to rotate through the second coupling 206. At the same time, the second output shaft 2023 is connected to the first transmission spur gear 208 through a flat key, which drives the inner ring gear 207 to rotate. The overall structure of the cutter head at the bow of the aircraft begins to rotate and break the net. After the net breaking is completed, the first drive motor 201 repeats the above reverse action and retracts the net-breaking mechanism.

[0047] After the net is breached, the speed sensor and sonar detect the vehicle's speed again. If the next detected speed signal is still lower than the set threshold speed, it means that the net breaching is not complete. The net breaching mechanism will be redeployed and the above actions will be repeated to initiate a second net breaching until the vehicle recovers to a speed or exceeds the activation threshold speed.

[0048] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fishing net breaking device for underwater unmanned vehicles, characterized in that, It includes a drive mechanism, a transmission mechanism, and a bow-mounted retractable rotary cutting mechanism. The drive mechanism is used to provide driving torque to the bow-mounted retractable rotary cutting mechanism through the transmission mechanism. The bow-mounted retractable rotary cutting mechanism includes a rotating disk, a pair of U-shaped cutter discs, multiple bidirectional cutting blades, a rack, a limiting groove, a limiting pin, a cutter end plate, and a cutter disc base. The pair of U-shaped cutter discs are located in the middle of the horizontal cross-section of the rotating disk and are mounted on the cutter end plate. The limiting groove is provided in the middle of the pair of U-shaped cutter discs. One end of the pair of U-shaped cutter discs is horizontally staggered and attached to each other by the rack and the limiting pin. The other end of the U-shaped cutter discs is connected to the cutter disc base. The multiple bidirectional cutting blades are mounted on the side of the cutter disc base facing away from the underwater unmanned vehicle. The transmission mechanism includes a pair of transmission spur gears and an inner ring gear. One of the transmission spur gears meshes with the rack to achieve the extension and retraction of the cutter end plate. The other of the transmission spur gears meshes with the inner ring gear to achieve the rotation of the bow retractable rotary cutting mechanism. The first transmission spur gear, the second transmission spur gear, and the inner ring gear are located at the center of the rotating disk, inside the circumferential edge, and on the circumferential surface, respectively. The drive mechanism includes a drive motor, a controller, a reducer, a coupling, an output shaft, and a motor bracket. The controller is installed at the rear end of the drive motor, and the reducer is installed at the front end of the drive motor. One end of the coupling is installed on the reducer shaft and connected by a key. The other end of the coupling is connected to the first output shaft. The other end of the first output shaft is connected to the first transmission spur gear of the transmission mechanism by a key, providing the transmission mechanism with active output torque to enable the extension and retraction of the bow retractable rotary cutter head mechanism. The other end of the second output shaft is connected to the second transmission spur gear of the transmission mechanism by a key, providing the transmission mechanism with active output torque to enable the rotary cutting action of the bow retractable rotary cutting mechanism.

2. The fishing net breaking device for underwater unmanned vehicles according to claim 1, characterized in that, A streamlined tool box is tightly fastened to the tool end cap, and the rack passes through a pre-reserved gap in the tool box.

3. The fishing net breaking device for underwater unmanned vehicles according to claim 1, characterized in that, The first and second output shafts of the drive mechanism are respectively engaged with one and the other of the transmission spur gears of the transmission mechanism.

4. The fishing net breaking device for underwater unmanned vehicles according to claim 1, characterized in that, The drive motor in the drive mechanism is installed on the inner wall of the underwater unmanned vehicle via a motor bracket and screws.

5. The fishing net breaking device for underwater unmanned vehicles according to claim 1, characterized in that, The bidirectional cutting blade is a two-sided, three-bladed blade made of an alloy material with a sandblasted surface.

6. The fishing net breaking device for underwater unmanned vehicles according to claim 1, characterized in that, The limiting pin is a screw structure and is installed on the tool end plate via a threaded connection.

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