An unmanned ship quick response and fallen target positioning system for large water surface reservoir fishery emergency rescue

Abstract

The application discloses an unmanned ship quick response and fallen target positioning system for large water surface reservoir fishery emergency rescue, which is composed of an unmanned ship body, a power propulsion module, a navigation positioning module, a fallen target detection module, a rescue execution module and a control communication module. The unmanned ship body adopts a catamaran structure and is equipped with double propellers to provide high-speed navigation capability. The fallen target detection module integrates a visible light camera, an infrared thermal imager and a radar detector to realize all-weather multi-sensor fusion detection. The rescue execution module adopts an automatic throwing lifesaving ring and a towing rope mode to implement rescue. The control communication module realizes remote control and data transmission through a 4G or 5G network. The application has the advantages of fast response speed, high positioning accuracy and strong all-weather operation capability, and is suitable for large water surface reservoir fishery emergency rescue scenes.

Description

Technical Field

[0001] This invention relates to the field of water surface emergency rescue technology, specifically to an unmanned surface vessel rapid response and water-falling target positioning system for fishery emergency rescue in large water surface reservoirs. Background Technology

[0002] With the development of reservoir aquaculture and lake fisheries, the number of people working in large bodies of water is increasing, and the safety of fishery workers at sea is becoming increasingly prominent. Traditional water rescue methods mainly rely on manpower and small lifeboats, which have problems such as slow response speed, low search efficiency, and high safety risks to rescuers.

[0003] CN112947587A discloses an intelligent unmanned surface vessel (USV) search and rescue system and method, including a main control console, USV body, positioning module, navigation module, search module, and rescue module. This system can autonomously locate and navigate near the accident site to search for rescue targets. CN109515645A discloses a surface rescue USV and rescue method, which uses a rescue cavity and buoyancy cavity, and an air propeller to change the USV's buoyancy to float a person in the water into the USV for rescue. CN109533230A discloses a maritime rescue USV and rescue method, including a main hull and a retrieval frame, using a retrieval manipulator to achieve maritime rescue.

[0004] Existing surface rescue unmanned surface vessels (USVs) are primarily designed for marine or general water environments, failing to adequately address the specific needs of large-scale reservoir fishing operations. Large reservoirs present complex environments with vast water areas, dispersed fishing sites, and operations concentrated in the low-light hours of early morning and late evening. This places high demands on the rescue system's rapid response capabilities, target positioning accuracy, and nighttime identification capabilities. Current systems often employ single sensors for target detection, which can easily lead to missed detections or misjudgments in complex water environments, impacting rescue efficiency.

[0005] Therefore, it is necessary to develop an unmanned surface vessel rescue system that can respond quickly, locate precisely, and operate around the clock, specifically tailored to the characteristics of emergency rescue scenarios in fisheries in large reservoirs. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a rapid response and target positioning system for unmanned surface vessels used in emergency rescue of fisheries in large reservoirs, solving the problems of slow rescue response speed, low target positioning accuracy and insufficient nighttime identification capability in the existing technology.

[0007] To achieve the above objectives, the technical solution of this invention is to design a rapid response and target location system for unmanned surface vessels (USVs) used in emergency rescue operations for fisheries in large reservoirs. The system comprises an USV body, a propulsion module, a navigation and positioning module, a target detection module, a rescue execution module, and a control and communication module. The USV body adopts a catamaran structure with floating hulls on both sides and an equipment compartment in the middle. The propulsion module includes two electric thrusters mounted at the stern of the floating hulls on either side. The navigation and positioning module includes a GPS positioning unit, an electronic compass, and an inertial measurement unit. The target detection module includes a visible light camera, an infrared thermal imager, and a radar detector. The rescue execution module includes a lifebuoy throwing device and a towing structure. The control and communication module includes a main controller, a wireless communication unit, and a shore-based remote control terminal.

[0008] A further technical solution is that the towing structure is a towing rope; the unmanned surface vessel (USV) body is 2 to 4 meters long and 1 to 2 meters wide; each thruster has a power of 800 to 1500 watts, providing a speed of 8 to 12 knots; the visible light camera is a high-definition network camera with a resolution of no less than 1920×1080 pixels, mounted on a gimbal fixed at the front of the equipment compartment, which can achieve 360-degree horizontal rotation and pitch adjustment from -30 degrees to +30 degrees.

[0009] A further technical solution is that the infrared thermal imager has a detection range of no less than 300 meters and can identify targets whose water temperature differs from human body temperature by more than 5 degrees Celsius. It is installed at the front of the equipment compartment. The radar detector is a millimeter-wave radar with a detection range of 100 to 500 meters and a scanning angle of no less than 120 degrees. It is installed on the top of the equipment compartment.

[0010] A further technical solution is that the life ring throwing device includes a throwing cylinder, a compressed air cylinder, and a life ring storage compartment. The throwing cylinder is connected to a fixed base via a rotating shaft. An electric push rod is provided on the rotating shaft to control the tilt angle of the throwing cylinder. The tilt angle adjustment range is 30 degrees to 60 degrees, and the throwing distance is 8 to 25 meters.

[0011] A further technical solution is that the main controller adopts an embedded industrial computer with an operating frequency of not less than 1GHz and a memory of not less than 2GB. It is connected to various sensors and actuators through interfaces to receive sensor data for image processing and route calculation. The bottom of the unmanned surface vessel is equipped with a collision protection plate made of high-strength rubber or polyurethane material with a thickness of 10 to 20 millimeters.

[0012] A further technical solution is to fill the floating chamber with polyurethane foam material to ensure that the unmanned surface vessel still has positive buoyancy even if the equipment compartment is flooded.

[0013] The present invention also provides an emergency rescue method for an unmanned surface vessel (USV) rapid response and water-fall target positioning system for emergency rescue in fisheries of large water surface reservoirs, comprising the following steps: Step 1: Receiving alarm information. After receiving the water-fall alarm, the operator inputs the coordinates of the water-fall location or selects a suspicious area after receiving the alarm from the shore-based remote control terminal; Step 2: The USV quickly departs. The main controller calculates the route based on the current position and the target position and controls the power propulsion module to start; Step 3: Area search. After the USV reaches the target area, it reduces its speed and starts the water-fall target detection module to scan and search; Step 4: Target identification. The main controller processes the acquired images and marks the target position; Step 5: Approaching the target. The main controller controls the USV to navigate towards the target position; Step 6: Rescue is carried out. The lifebuoy throwing device throws the lifebuoy to the person in the water and tows them to a safe area at low speed; Step 7: Returning to standby. After completing the rescue, the USV returns to the standby position.

[0014] A further technical solution is that, in step 4, when target identification occurs, a target is determined to be a valid target if at least two of the sensors among the visible light camera, infrared thermal imager, and radar detector simultaneously detect the target at the same location.

[0015] The advantages and beneficial effects of this invention are as follows: The use of unmanned surface vessels (USVs) for automated rescue avoids the risks to rescue personnel, improving rescue safety. Equipped with dual propulsion systems and a high-speed battery system, the USV can reach speeds of 8 to 12 knots, significantly reducing arrival time. The use of a fusion detection method combining visible light cameras, infrared thermal imagers, and radar detectors improves target positioning accuracy and all-weather operational capabilities, adapting to the complex environments of large reservoirs. Equipped with automatic lifebuoy and towing rope devices, it simplifies rescue operations. Utilizing 4G or 5G wireless communication and remote control, it offers wide coverage, suitable for emergency rescue needs at dispersed locations in large reservoirs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a first embodiment of the unmanned surface vessel rapid response and water-falling target positioning system for emergency rescue of fisheries in large reservoirs according to the present invention; Figure 2 yes Figure 1 A schematic diagram of a mid-visible light camera and its surrounding components; Figure 3 yes Figure 1 A schematic diagram of the upper rear surface of the equipment compartment; Figure 4 yes Figure 3 A cross-sectional view of the middle throwing tube; Figure 5 This is a schematic diagram of Embodiment 4 of the present invention; Figure 6 yes Figure 5 A schematic diagram of the central equipment compartment; Figure 7 yes Figure 6 Side view; Figure 8 This is a schematic diagram of Embodiment 5 of the present invention; Figure 9 yes Figure 8 A schematic diagram of the throwing and storage box; Figure 10 yes Figure 9 Top view of the storage box; Figure 11 This is an exploded view of the disposable towing assembly; Figure 12 yes Figure 11 A schematic diagram of the state of the damping plates of a mid-floating damper after they are folded up. Figure 13 yes Figure 8 A schematic diagram of the state of the medium-throwing tube before throwing; Figure 14 yes Figure 8 A schematic diagram of the working state immediately after casting; Figure 15 yes Figure 8 A diagram illustrating the operational status at the moment of completion of the rescue operation.

[0017] In the image: 1. Unmanned surface vessel (USV) body; 2. Left floating hull; 3. Right floating hull; 4. Equipment compartment; 5. Left thruster; 6. Right thruster; 7. GPS positioning unit; 8. Electronic compass; 9. Inertial measurement unit; 10. Visible light camera; 11. Infrared thermal imager; 12. Radar detector; 13. Drop tube; 14. Compressed gas cylinder; 15. Life ring; 16. Towing rope; 17. Base plate; 18. Drainage hole; 19. Antenna; 20. Fixing ring; 21. Heat sink; 22. Gimbal; 23. 24. Rotating shaft; 25. Fixed base; 26. Electric push rod; 27. Support column; 28. Drainage area; 29. ​​Battery compartment; 30. Controller; 31. Water inlet; 32. Guide plate; 33. Storage box; 34. Partition; 35. Metal ring; 36. Rubber rope; 37. Guide pulley; 38. Support rope; 39. Gas cylinder; 40. Inflation valve; 41. Guide rope hole; 42. First fixing ring; 43. Trigger pull rope; 44. Second fixing ring; 45. Float; 46. Tie ring; 47. Short pipe; 48. Damping plate. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0019] Example 1: As Figure 1 and Figure 4 As shown (for ease of illustration), Figure 1(Rescue execution module not shown) This invention is a rapid response and target location system for unmanned surface vessels (USVs) used in emergency rescue operations for fisheries in large reservoirs. It includes the USV body 1, a propulsion module, a navigation and positioning module, a target detection module, a rescue execution module, and a control and communication module. The USV body 1 adopts a catamaran structure. The left floating hull 2 ​​and the right floating hull 3 are fixed together by transverse connecting plates, which are bolted to the floating hulls, forming an equipment compartment 4 in the middle. The USV body 1 has a total length of 3.2 meters, a total width of 1.5 meters, and a depth of 0.4 meters. The left floating hull 2 ​​and the right floating hull 3 are made of fiberglass, each hull being 2.8 meters long, 0.3 meters wide, and 0.35 meters high. The floating hulls are filled with closed-cell polyurethane foam material with a density of 80 kg / m³. 3 This ensures sufficient buoyancy even if the cabin is damaged. The equipment compartment 4 is 1.5 meters long, 0.8 meters wide, and 0.3 meters high. It is assembled with an aluminum alloy frame and waterproof plastic panels, and houses the main controller, battery compartment, and rescue execution module.

[0020] The propulsion module includes a left thruster 5 and a right thruster 6, installed at the stern of the left floating hull 2 ​​and the right floating hull 3, respectively. Each thruster has a power output of 1000 watts and uses a brushless DC motor to drive a three-bladed propeller with a diameter of 120 mm. The thrusters are fixed to the bottom of the floating hulls via mounting brackets made of stainless steel. The left and right thrusters can be independently controlled for speed and direction, enabling the unmanned surface vessel (USV) to navigate in a straight line, turn, and rotate in place. When both thrusters are operating at full power, the USV can reach a speed of 10 knots.

[0021] The navigation and positioning module is installed on the top of equipment compartment 4, including a GPS positioning unit 7, an electronic compass 8, and an inertial measurement unit 9. The GPS positioning unit 7 uses a BeiDou-GPS dual-mode positioning chip, achieving a positioning accuracy better than 3 meters and an update frequency of 10Hz. The electronic compass 8 uses a three-axis magnetic sensor, providing a heading accuracy better than 2 degrees. The inertial measurement unit 9 integrates a three-axis accelerometer and a three-axis gyroscope, providing roll, pitch, and bow angle information for the unmanned surface vessel, with an attitude measurement accuracy better than 1 degree. Data from the three sensors is input to the main controller for processing to obtain high-precision position and attitude information.

[0022] The target detection module includes a visible light camera 10, an infrared thermal imager 11, and a radar detector 12. The visible light camera 10 is mounted on a gimbal 22, which is fixed to the front of the equipment compartment 4. The visible light camera 10 is a 2-megapixel high-definition network camera with a resolution of 1920×1080 and a horizontal field of view of 60 degrees. The gimbal 22 is a two-axis motorized gimbal with a horizontal rotation range of 360 degrees and a pitch angle range of -30 degrees to +30 degrees. The infrared thermal imager 11 is mounted next to the gimbal 22 and uses an uncooled infrared detector with a resolution of 384×288 pixels, a thermal sensitivity better than 50mK, and a detection range of up to 400 meters under a temperature difference of 10 degrees Celsius. The radar detector 12 is mounted on the top of the equipment compartment 4 and uses a 24GHz millimeter-wave radar with a detection range of 300 meters, a horizontal scanning angle of 120 degrees, a distance resolution of 1 meter, and an angular resolution of 5 degrees.

[0023] The rescue execution module includes a lifebuoy throwing device and a towing rope 16. The throwing device is installed at the rear of the equipment compartment 4 and includes a throwing tube 13, a compressed air cylinder 14, and a storage compartment for lifebuoys 15. The throwing tube 13 is made of stainless steel tubing with an inner diameter of 160 mm and a length of 600 mm. The inner wall is coated with polytetrafluoroethylene to reduce the coefficient of friction. The bottom is connected to a fixed base 24 via a pivot 23. The fixed base 24 is fixed at the rear of the equipment compartment 4. An electric push rod 25 is installed on the pivot 23, which controls the elevation angle of the throwing tube 13 to be adjusted within the range of 30 degrees to 60 degrees.

[0024] Lifebuoy 15 is an inflatable lifebuoy with an outer diameter of 700 mm and an inner diameter of 400 mm after inflation, providing a buoyancy of no less than 15 kg. Lifebuoy 15 is made of TPU thermoplastic polyurethane material with a wall thickness of 0.4 mm. Lifebuoy 15 is normally stored in a semi-inflated state. When inflated to 30% of its working pressure, its outer diameter is approximately 350 mm, forming a flat ring with a thickness of approximately 80 mm and a weight of 800 grams. The semi-inflated lifebuoy is flattened into a long strip and inserted into the throwing tube 13, its elasticity ensuring a tight fit against the tube wall. An inflation assembly, including an 8-gram carbon dioxide cylinder and a pull-cord trigger valve, is installed at the top of lifebuoy 15. A fixing ring 20 is located at the bottom of lifebuoy 15 for connecting to the towing rope 16. The pull-cord trigger valve is connected to the fixing ring via a 0.5-meter-long trigger rope.

[0025] The compressed gas cylinder 14 has a volume of 2 liters and a filling pressure of 8 MPa, allowing for multiple throws. It is connected to the bottom of the throwing cylinder 13 via a solenoid valve. The throwing cylinder 13 contains a thrust piston with a diameter of 158 mm and a thickness of 30 mm, located at the bottom of the lifebuoy 15. During throwing, the main controller opens the solenoid valve, allowing compressed gas to enter the throwing cylinder 13 and push the piston, which in turn propels the lifebuoy 15 out at high speed. The main controller retrieves the corresponding throwing cylinder elevation angle from a pre-stored range parameter table based on the target distance and wind conditions. This range parameter table is established and stored in the main controller based on actual test range data under different wind conditions.

[0026] The towing rope 16 is made of high-strength polyethylene braided rope, 8 mm in diameter, 30 meters long, and with a tensile strength of 2000 N. One end is fixed to the rope drum at the rear of the equipment compartment 4, and the other end is connected to the bottom fixing ring of the lifebuoy 15. The rope is made of a buoyant material and can float on the water surface. The rope drum is equipped with a friction braking device to provide constant resistance and ensure smooth rope deployment. After the lifebuoy 15 is launched, the towing rope 16 deploys accordingly. During deployment, the rope's speed is naturally limited by air resistance and the resistance of the friction braking device. After the lifebuoy 15 enters the water, the rope continues to deploy. When the rope reaches a certain length, it becomes taut. The tension of the rope is transmitted to the trigger pull rope through the fixing ring. The pull rope pulls the trigger valve, opening the gas cylinder valve. Carbon dioxide is injected into the lifebuoy within 2 seconds, inflating it from a half-inflated state to the working pressure, expanding its outer diameter to 700 mm.

[0027] The control and communication module includes a main controller, a wireless communication unit, and a shore-based remote control terminal. The main controller is an embedded industrial computer equipped with an ARM Cortex-A53 quad-core processor with a clock speed of 1.2GHz, 2GB of RAM, 32GB of storage, and runs a Linux operating system. The main controller connects to various sensors and actuators via RS232, RS485, and Ethernet interfaces to collect sensor data and send control commands. After receiving image data, the main controller compares it with preset human characteristic parameters, including a temperature 5 to 20 degrees Celsius higher than the water surface temperature, a target size between 0.2 and 1.2 square meters, and an aspect ratio between 1.2 and 2.5. When all three characteristics are met, it is determined to be a valid target and the target coordinates are output. The navigation path is calculated based on the target coordinates and the current position. The wireless communication unit uses a 4G full-network module, supporting the LTE Cat4 communication standard with a downlink speed of 150Mbps and an uplink speed of 50Mbps. The main controller connects to the wireless communication unit via a serial port or Ethernet interface. The wireless communication unit connects to the mobile communication network via antenna 19 to transmit data with the shore-based remote control terminal. The shore-based remote control terminal includes a laptop, a display screen, and mission planning software. The mission planning software, developed based on the Qt framework, features electronic chart display, route planning, remote control operation, and data logging. Operators can select target locations on the electronic chart, and the software automatically generates a route and sends it to the unmanned surface vessel (USV). The display screen shows the USV's position, heading, speed, battery level, and camera images in real time.

[0028] The unmanned surface vessel (USV) 1 has a collision protection plate installed on its bottom, made of 15mm thick polyurethane rubber sheet, bonded and fixed along the front and outer sides of the floating body compartment, capable of absorbing collision energy and protecting the hull structure. The battery compartment is installed at the bottom of the equipment compartment 4, using a waterproof and sealed structure. The battery pack uses lithium-ion batteries with a nominal voltage of 48V, a capacity of 50Ah, and a total energy of 2.4kWh. The battery pack is monitored for voltage, current, and temperature by a battery management system to prevent overcharging and over-discharging. The dual thrusters have a total power of 2000 watts, and other equipment consumes an average of about 400 watts. At a speed of 10 knots, the power consumption is 2400 watts, with an endurance of 1 hour; at a search speed of 4 knots, the power consumption is about 800 watts, with an endurance of about 2.5 hours.

[0029] The emergency rescue method based on the above system includes the following steps: Step 1, Receiving Alarm Information. Upon receiving an alarm from a fisherman who has fallen into the water, the reservoir management center activates the shore-based remote control terminal and marks the location of the fall on the electronic nautical chart in the mission planning software. Step 2, Rapid Departure of the Unmanned Surface Vessel (USV). The main controller calculates the course based on the current and target positions and controls the left and right thrusters to operate at full power, propelling the USV towards the target area at a speed of 10 knots. Step 3, Area Search. After the USV reaches the vicinity of the fall location, the main controller reduces the speed to 4 knots and initiates the search mode. The search path adopts a spiral expansion path centered on the fall location, with a spiral spacing of 30 meters and a maximum search radius of 300 meters. The visible light camera 10, the infrared thermal imager 11, and the radar detector 12 operate simultaneously for scanning. Due to the low light conditions at dusk, the infrared thermal imager 11 plays a major role. Step 4, Target Identification. After searching for 5 minutes, the infrared thermal imager 11 detects a high-temperature target at a bearing of 120 degrees and a distance of 180 meters from the USV. The target's temperature is 8 degrees Celsius higher than the surrounding water surface. The main controller compares the image data with preset human characteristic parameters. If the temperature, size, and shape all meet the preset conditions, it is determined to be a valid target and its coordinates are output. Radar detector 12 also detects a reflected signal in the same location. The main controller issues an alarm. Step 5: Approaching the target. The main controller plans a straight path from the current position to the target position, controlling the unmanned surface vessel (USV) to turn 120 degrees and proceed towards the target at a speed of 6 knots. During the approach, the main controller continuously tracks the target position and dynamically adjusts its course based on water flow. When radar detector 12 shows a distance of 15 meters from the target, the main controller reduces its speed to 3 knots; when the distance is 8 meters, the main controller stops the propellers, and the USV continues forward using inertia while gradually decelerating; when the radar shows a stable distance between 5 and 8 meters and the USV's speed drops below 0.5 knots, the main controller determines that the USV has essentially come to a stop. Step 6: Rescue operation. Based on the target distance measured by radar detector 12 and the wind direction and speed measured by electronic compass 8, the main controller looks up the corresponding throwing tube elevation angle from the pre-stored range parameter table and controls electric push rod 25 to rotate throwing tube 13 to that angle. After confirming the target location by viewing the camera image through the shore-based remote control terminal, the operator sends a throwing command. The main controller opens the solenoid valve, and compressed gas propels the lifebuoy 15 out of the throwing tube 13. The lifebuoy 15 flies in a parabolic trajectory and enters the water, landing approximately 3 meters from the person in the water. After the lifebuoy 15 enters the water, the tow rope 16 continues to unfold. When the rope becomes taut, inflation is triggered, and the lifebuoy fully inflates and floats to the surface within 2 seconds. The person in the water swims to the location of lifebuoy 15 and grabs it. The main controller controls the left and right thrusters to operate at low speed, tauts the tow rope 16, and the unmanned surface vessel tows the person in the water at a speed of 2 knots to the shore 800 meters away, where rescue personnel meet and bring the person ashore.If the operator observes through the camera that the landing point deviates from the target by more than 5 meters, a recovery command can be sent. The main controller will then guide the unmanned surface vessel (USV) to the location of the lifebuoy. The operator will manually retrieve the rope and lifebuoy, adjust the USV's position, and then perform a second drop. Step 7: Return to standby. After completing the rescue, the USV returns to the reservoir management center dock. The main controller records data such as the rescue trajectory, target location, and rescue time, and uploads it to the shore-based remote control terminal. The operator replaces the battery and lifebuoy, replenishes the compressed gas cylinder, and the USV returns to standby status. The entire rescue process includes approximately 8 minutes of navigation, 5 minutes of search, 2 minutes of approach, and 10 minutes of dropping and towing, totaling approximately 25 minutes, with battery power consumption of approximately 40%.

[0030] Example 2: The difference from Example 1 lies in the rescue scenario and sensor usage. This example focuses on a nighttime rescue scenario where a fisherman accidentally falls into the water while hauling in his nets at 10 PM. Due to the complete darkness at night, visible light cameras cannot acquire effective images, so the rescue relies primarily on an infrared thermal imager and radar detectors. Infrared thermal imagers are most effective at night; human body temperature is approximately 36 degrees Celsius, while water surface temperature is approximately 20 degrees Celsius, a temperature difference of 16 degrees Celsius, and a detection range exceeding 500 meters. The main controller sets the infrared thermal imager as the primary detector and the radar detector as an auxiliary detector. The search path uses an S-shaped reciprocating search with a path width of 40 meters and a speed of 3 knots, providing a more detailed search than in Example 1. The infrared thermal imager acquires one frame per second, and the main controller processes the images, extracting areas with temperatures more than 5 degrees Celsius above the ambient temperature as suspicious targets. During the search, the infrared thermal imager detected three high-temperature targets. The main controller processed three targets. The first target, with a temperature of 28 degrees Celsius, was 8 degrees Celsius higher than the surface temperature of 20 degrees Celsius, meeting the temperature characteristics. However, its irregular shape and aspect ratio of 4.2 exceeded the preset range, leading to its identification as floating debris. The second target, with a temperature of 50 degrees Celsius, was 30 degrees Celsius higher than the surface temperature, also exceeding the preset temperature range, and was identified as heat dissipation from a nearby fishing boat engine. The third target, with a temperature of 34 degrees Celsius, was 14 degrees Celsius higher than the surface temperature of 20 degrees Celsius, with a size of 0.7 square meters and an aspect ratio of 1.8. All three characteristics met the preset conditions, making it a valid target. The main controller directed the unmanned surface vessel to the third target to carry out the rescue. The operator monitored the rescue process using thermal imaging images from a shore-based remote control terminal. An LED warning light was installed on each side of the towing rope, flashing periodically to indicate the rope's location to the person in the water, helping them find the lifebuoy in the dark. The throwing process is the same as in Example 1. The main controller controls the throwing tube to rotate to a 50-degree elevation angle, and the landing point is about 4 meters away from the person who fell into the water. After the person in the water grabs the life ring, he is dragged to the shore.

[0031] Example 3: This example differs from Example 1 in that it employs a multi-vessel search method. When multiple people fall into the reservoir or the location of the fall is unclear and requires a large-scale search, 2 to 3 unmanned surface vessels (USVs) can be deployed simultaneously. The task planning software of the shore-based remote control terminal divides the search area into several sub-regions and assigns them to each USV. For example, a 6-square-kilometer search area is divided into three 2-square-kilometer sub-regions, each assigned to one of the three USVs. Each USV searches independently within its respective region, and the search data is uploaded to the shore-based remote control terminal in real time. The operator simultaneously monitors the positions and detection images of the three USVs on the display screen. The USVs exchange position information and search status every 5 seconds via wireless communication units. After receiving the position data sent by other USVs through wireless communication units, the main controller calculates the distance to other USVs. When the distance is less than 100 meters, the main controller automatically reduces its speed to avoid collision. When a USV's infrared thermal imager detects a suspected target, the USV sends the target's coordinates to the other USVs, who then determine whether the target is within their search area. Once a vessel confirms the location of a person in the water, it immediately enters rescue mode and simultaneously sends a "do not approach" command to other vessels to prevent multiple vessels from repeatedly rescuing the same target. Other vessels continue searching within their respective areas or proceed to new search areas according to instructions from the shore-based remote control terminal. If the person in the water is unconscious and unable to grasp a lifebuoy, the shore-based remote control terminal operator can coordinate two unmanned surface vessels (USVs) to approach the person from different angles and use towing ropes to jointly support and tow the person. Multi-vessel searches significantly improve search efficiency; the search efficiency of three USVs working simultaneously is approximately 2.5 times that of a single vessel, making it suitable for emergency rescue scenarios in large reservoirs with a water area greater than 5 square kilometers.

[0032] Example 4: The difference from Example 1 is that, as shown in Example 4... Figures 5 to 7 As shown, an unmanned surface vessel (USV) for emergency fishery rescue in large reservoirs includes the USV body 1, a propulsion module, a navigation and positioning module, a target detection module, and a control and communication module. The USV body adopts a catamaran structure, with left and right floating hulls fixed by transverse connecting plates, forming an equipment compartment 4 in the middle. The equipment compartment is 1.5 meters long, 0.8 meters wide, and 0.3 meters high, assembled from an aluminum alloy frame and waterproof plastic sidewalls. The equipment compartment floor 17 is made of 2 mm thick aluminum plate, with the front section remaining horizontal and the rear section sloping downwards for 300 mm to create a 3 mm drop. Drainage holes 18 with a diameter of 20 mm are located 150 mm to the left and right of the centerline at the rear of the floor, leading to the outside of the vessel.

[0033] A heat sink 21 is installed inside the equipment compartment. The heat sink is a 3mm thick aluminum plate, 1.4m long and 0.75m wide, stamped into a gently sloping shape with a 4mm height difference between the front and back. Support columns 26 are welded to the bottom of the four corners of the heat sink. The height from the bottom surface of each support column to the bottom surface of the heat sink is 18mm. The bottom surface of the support columns is fixed to the base plate, forming a drainage space between the bottom surface of the heat sink and the base plate after installation. This space has a front height of 18mm and a rear height of 14mm. A 200mm drainage area 27 is left along the length of the rear end of the heat sink, spanning the entire 750mm of the heat sink along the width. Within the drainage area, 23mm edges are left on both sides along the width, with 20 rows of holes spaced at 37mm intervals in the middle. Along the length of the drainage area, 20mm edges are left at both the front and back, with 5 rows of holes spaced at 40mm intervals in the middle. There are 100 holes in 20 columns and 5 rows, each 3 mm in diameter, arranged in a matrix. The actual area occupied by the holes is 703 mm wide and 160 mm long, all within a 750 mm wide and 200 mm long area, and will not exceed the boundary of the heat sink. The front and middle sections of the heat sink are flat and without holes for mounting heat-generating components.

[0034] The battery compartment 28 has an aluminum alloy shell with a bottom area of ​​0.15 square meters. It is bolted to the front of the heat sink 21, and the contact surface is coated with thermally conductive silicone grease. The battery pack has a nominal voltage of 48 volts and a capacity of 50 amp-hours. The shell temperature can reach 50 degrees Celsius when fully discharged. Two thruster controllers 29 are installed on the left and right sides of the middle section of the heat sink. Each controller has a base plate area of ​​0.02 square meters. Thermally conductive silicone grease is applied between the base plate and the heat sink before bolting. The shell temperature is approximately 45 degrees Celsius under full load.

[0035] Several water inlets 30 are distributed along the length of the equipment compartment, 30 mm above the still waterline, on the left and right side walls. Each water inlet is a rectangular hole 50 mm long and 10 mm wide, with a thin aluminum guide vane 31 installed inside. The guide vane 31 is tilted downwards and inwards at approximately 30 degrees to guide splashed water towards the surface of the heat sink. No water enters when the waterline is below the inlet in still water conditions. Water enters through the inlets when waves generate spray or when the unmanned surface vessel turns and tilts. The number of water inlets can be adjusted according to actual heat dissipation requirements and wave conditions, typically 3 to 5 on each side.

[0036] During operation, water enters and forms a thin film on the surface of the heat sink. This film flows gently backward along the slope of the heat sink, and as it passes through the battery compartment and controller area, the aluminum plate conducts heat to the surface. The water film absorbs heat upon contact with the plate surface, heating up and partially evaporating. The water film flows to the rear of the heat sink and drains through the drain hole, landing on the bottom plate below. Because the rear section of the bottom plate slopes downward, the water flows backward along the slope, collecting at the lowest point of the bottom plate, i.e., the middle rear section, and is discharged outside the ship through the drain hole.

[0037] Heat dissipation primarily relies on natural convection between the heat exchange plates and the air. Air flows in from the front and sides of the equipment compartment, carries away heat across the heat exchange plate surface, and is then exhausted from the rear. The flow and evaporation of the water film play a secondary role in heat dissipation; water has a high specific heat capacity and absorbs latent heat of vaporization during evaporation. Higher winds and waves increase water intake and enhance heat dissipation, while lower winds and waves reduce water intake, but the ship's speed is usually lower, resulting in reduced heat generation.

[0038] To prevent electronic components from getting damp, the circuit boards of the main controller, navigation module, and communication module are coated with conformal coating, and critical parts are potted with epoxy resin, achieving an IP65 protection rating. Sensor and actuator interfaces use waterproof plugs. The battery compartment shell is welded and sealed, and waterproof aviation connectors are used at the wiring points. The water film thickness on the heat sink surface does not exceed 1 mm and is continuously flowing, preventing water accumulation inside the compartment under normal operating conditions. The equipment compartment top cover has a transparent observation window, allowing visual inspection of the compartment's condition during maintenance. If water accumulation on the bottom plate exceeds 5 mm, it indicates a blocked drain hole, requiring unblocking with compressed air or a thin steel wire.

[0039] This design transforms the vulnerability of the equipment compartment to wave splashing into a favorable condition for auxiliary heat dissipation, eliminating the need for power-consuming fans or complex water-cooling systems. The heat sink is formed into a gentle slope and perforated through stamping, a simple and low-cost process. Routine maintenance only requires periodic cleaning of the drain holes; there is no need to replace fans or clean the heat sinks, resulting in high reliability and convenient maintenance. Traditional heat dissipation designs typically prioritize sealing and waterproofing the equipment compartment, relying on fans or water-cooling systems to actively remove heat, with water ingress considered a negative factor to be eliminated. This design takes the opposite approach. Considering that splashing water from waves is difficult to completely avoid in large-scale water surface operations, it does not employ measures to block water ingress. Instead, it actively incorporates water inlets on the side walls of the equipment compartment, using guide vanes to direct the water flow. This allows splashed water to fall onto the surface of the heat sink, forming a water film. The flow and evaporation of this water film remove the heat generated by the heat-generating components, replacing the role of fans or water-cooling systems in traditional solutions. Thus, the water ingress factor that originally needed to be prevented is transformed into an effective medium for heat dissipation. The equipment does not require active heat dissipation components such as fans, avoiding the high failure rate of such components in humid and high-salt environments.

[0040] Example 5: The difference from Example 1 is that, as shown in Example 5... Figures 8 to 15 As shown, an unmanned surface vessel (USV) for emergency rescue in fisheries in large reservoirs includes the USV body 1, a power propulsion module, a navigation and positioning module, a target detection module, a rescue execution module, and a control and communication module. The USV body adopts a catamaran structure, with a total length of 3.2 meters and a total width of 1.5 meters, forming an equipment compartment 4 in the middle.

[0041] The rescue execution module includes a throwing device and a towing structure, with the towing structure being a disposable towing assembly. The throwing device includes a throwing cylinder 13, a compressed gas cylinder 14, and a solenoid valve, installed at the rear of equipment compartment 4. The throwing cylinder 13 is a stainless steel tube with an inner diameter of 160 mm and a length of 600 mm, fixed to a support at an elevation angle of 45 degrees. The compressed gas cylinder 14 has a volume of 2 liters and a filling pressure of 8 MPa, and is connected to the bottom of the throwing cylinder via the solenoid valve. The main towing rope storage box 32 is installed on the rear deck of equipment compartment 4. The box body is made of reinforced plastic, with a length of 500 mm, a width of 400 mm, and a height of 120 mm. The storage box 32 has three vertical partitions 33 that divide the space into four areas. The partitions 33 are 100 mm high. When the towing rope 16 is coiled, it crosses the partitions 33 and coils continuously. The partitions 33 serve as guides. A mooring point is located at the center of the bottom of the storage box 32, consisting of a metal ring 34, a rubber rope 35, and a guide pulley 36. The rubber rope 35 is made of natural rubber with a diameter of 6 mm and a length of 600 mm. One end is fixed to the rear side of the bottom of the storage box, and the other end passes over the guide pulley 36 and is connected to the metal ring 34, so that the rubber rope 35 extends backward in the horizontal direction when the towing rope 16 is pulled out.

[0042] The disposable towing assembly includes a lifebuoy 15, a towing rope 16, a support rope 37, and a floating damper. The lifebuoy 15 is inflatable, with an outer diameter of 700 mm and a buoyancy of no less than 15 kg after inflation. An 8-gram carbon dioxide cylinder 38 and an inflation valve 39 are mounted on the top of the lifebuoy, and two retaining rings are located at the bottom. The towing rope 16 is an 8 mm diameter, high-strength polyethylene braided rope, 18 meters long, with a tensile strength of 2000 N. One end of the towing rope is attached to a metal ring 34, and the rope continuously coils in a serpentine pattern, starting from the first area and passing through each area sequentially. The other end of the towing rope passes through a guide hole 40 on the side wall of the storage box and connects to the first retaining ring 41 at the bottom of the lifebuoy 15. One end of a trigger pull rope 42 is fixed to the first retaining ring 41, and the other end is connected to the inflation valve 39. The support rope 37 is a 6 mm diameter rope of the same material, 3 meters long, with one end connected to the second retaining ring 43 at the bottom of the lifebuoy 15 and the other end connected to the floating damper.

[0043] The floating damper consists of a float 44 and fixed damping plates. The float 44 is a rigid PVC plastic tube, 600 mm long, 80 mm in outer diameter, and 3 mm thick, filled with closed-cell foam, providing a net buoyancy of approximately 2 kg. The top of the float has a conical end cap with a tethering ring 45 connecting to a support rope 37. The bottom of the float has an outward-flaring opening forming a base, with an outer diameter of 120 mm. At the center of the base is a short stainless steel tube 46, with its top welded to the inner top wall of the float 44. The short tube 46 has an outer diameter of 20 mm, a length of 850 mm, and a wall thickness of 2 mm. The damping plates 47 are cross-shaped engineering plastic plates, each 300 mm long, 80 mm wide, and 2 mm thick. Vertical slots are cut into the center of both plates, with pre-drilled hinge connection holes. The two plates are hinged to the bottom of the short tube by stainless steel pins and can be folded axially along the short tube 46. In the folded state, the two plates are tightly pressed against the short tube 46 and parallel to each other. In the unfolded state, the two plates intersect perpendicularly to form a cross structure. A torsion spring is installed at the hinge, and the spring preload causes the damping plate 47 to automatically unfold into a cross shape when there is no external constraint. The floating damper, lifebuoy 15, and towing rope 16 are loaded into the throwing tube 13. During loading, the two plates of the damping plate are folded and retracted along the axial direction of the short tube 46 by hand, so that the diameter of the entire floating damper does not exceed 120 mm. After being loaded into the throwing tube, it is held in a folded state by the tube wall. After being launched out of the tube, the damping plate automatically unfolds into a cross shape under the action of the torsion spring. To facilitate this, the conical end of the float is inserted into the throwing tube first, so that the damping plate can be released from the throwing tube more smoothly.

[0044] During deployment, the main controller opens the solenoid valve, and compressed gas pushes the piston to launch the lifebuoy, rope, and floating damper. After the lifebuoy is launched, the main towing rope is sequentially pulled out from the storage box, and a partition guides the rope's unfolding. When the rope is pulled to the last metal ring, the rubber rope gradually extends from 600 mm to 1200 mm, absorbing impact energy during the extension process to avoid sudden reverse pulling on the unmanned surface vessel. The floating damper falls into the water with the lifebuoy, the float floats on the surface, and the cross-shaped damping plate and short tube sink underwater.

[0045] After the main controller completes the casting, it initiates a 5-second delay timer. After 5 seconds, it controls the thruster to briefly reverse, and the main towing rope is tightened. The pulling force is transmitted through the first fixing ring of the lifebuoy to the trigger pull rope. The pull rope pulls the inflation valve to open the carbon dioxide cylinder, and the gas fills the lifebuoy within 2 seconds. The lifebuoy inflates to an outer diameter of 700 mm and floats to the surface.

[0046] When the rope is taut and pulls the lifebuoy, the branch rope is also moved, the floating damper moves with the lifebuoy, the float floats on the water surface, and the cross damping plate is vertically immersed in the water, generating continuous resistance during the movement.

[0047] After the person overboard grabs the lifebuoy, the main controller controls the unmanned boat to sail towards the shore at a speed of 3 knots. The main tow rope bears the towing force to pull the lifebuoy and the person overboard to move forward. The floating damper is connected to a position about 3 meters behind the lifebuoy via a branch rope, moves along with the lifebuoy and generates continuous resistance in the water. This resistance keeps the main tow rope in a substantially tensioned state, preventing the rope from becoming completely slack due to water flow disturbance or movements of the person overboard, so that the impact force when the rope is re-tightened is reduced, and the instantaneous pulling force on the person overboard is lowered. The branch rope is 3 meters long, the damper is close to the lifebuoy, and the branch rope will not get tangled with the main tow rope.

[0048] After reaching the shore, rescuers first assist the person overboard to get ashore, and then cut the main tow rope and the branch rope with scissors. The lifebuoy, ropes and floating damper are left in the water as disposable consumables, and the surface of the float is coated with orange fluorescent paint to facilitate search and recovery.

[0049] After eliminating the traditional electric rope reel and recovery mechanism, the equipment compartment saves about 0.12 cubic meters of space and 7 kilograms of weight, and can store 7 sets of disposable towing assemblies. The total weight of a single set of assembly is about 2 kilograms. A single deployment of the unmanned boat can continuously perform 7 rescues without returning for resupply. After completing one rescue, the operator takes out a new main tow rope from the spare assembly, starts serpentine coiling from the first area into each area of the storage box, loads the lifebuoy and the floating damper into the throwing cylinder, and the entire replacement process takes about 1 minute, which is much faster than the 3 to 5 minutes required for manually recovering and winding the rope in the traditional manner. The floating damper is made of standard plastic pipes and engineering plastic plates, with a unit cost of about 20 yuan, which is far lower than the hundreds of yuan cost and maintenance cost of the electric reel.

[0050] Traditional rope-throwing rescue devices are usually equipped with electric reels, guide wheels and tension control mechanisms to realize the recovery and reuse of ropes. Such mechanisms have complex structures, and on-site rope recovery and sorting take a long time. The design idea of this scheme is opposite, no rope recovery mechanism is provided, but the entire assembly composed of the main tow rope, lifebuoy and floating damper is used as a disposable part, and the rope is directly cut and discarded in the water after the rescue is completed, without the need for recovery and sorting. The space and weight saved in the cabin after removing the recovery mechanism are used to store multiple sets of spare assemblies, so that the unmanned boat can continuously complete multiple rescues in a single deployment. This design omits the rope recovery link which is a core function in the traditional scheme, and replaces rope recovery by increasing the number of spare assemblies, which reduces the complexity of the mechanical structure and the probability of failure, and shortens the preparation time between single rescues.

[0051] The above description is merely the preferred embodiment of the present invention, and it should be noted that for those of ordinary skill in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications shall also be regarded as falling within the protection scope of the present invention.

Claims

1. A rapid response and target location system for unmanned surface vessels (USVs) used in emergency rescue operations for fisheries in large reservoirs, characterized in that: It consists of an unmanned surface vessel (USV) body, a propulsion module, a navigation and positioning module, a target detection module, a rescue execution module, and a control and communication module. The USV body adopts a catamaran structure with floating hulls on both sides and an equipment compartment in the middle. The propulsion module includes two electric thrusters mounted at the stern of the floating hulls on both sides. The navigation and positioning module includes a GPS positioning unit, an electronic compass, and an inertial measurement unit. The target detection module includes a visible light camera, an infrared thermal imager, and a radar detector. The rescue execution module includes a lifebuoy throwing device and a towing structure. The control and communication module includes a main controller, a wireless communication unit, and a shore-based remote control terminal.

2. The rapid response and target location system for unmanned surface vessels used in emergency rescue of fisheries in large reservoirs according to claim 1, characterized in that, The towing structure is a towing rope; the unmanned surface vessel (USV) body is 2 to 4 meters long and 1 to 2 meters wide; each thruster has a power of 800 to 1500 watts, providing a speed of 8 to 12 knots; the visible light camera is a high-definition network camera with a resolution of no less than 1920×1080 pixels, mounted on a gimbal fixed to the front of the equipment compartment, and can achieve 360-degree horizontal rotation and pitch adjustment from -30 degrees to +30 degrees.

3. The rapid response and target location system for unmanned surface vessels used in emergency rescue of fisheries in large reservoirs according to claim 2, characterized in that, The infrared thermal imager has a detection range of no less than 300 meters and can identify targets where the temperature difference between the water and the human body is more than 5 degrees Celsius. It is installed at the front of the equipment compartment. The radar detector is a millimeter-wave radar with a detection range of 100 to 500 meters and a scanning angle of not less than 120 degrees. It is installed on the top of the equipment cabin.

4. The rapid response and target location system for unmanned surface vessels used in emergency rescue of fisheries in large reservoirs according to claim 3, characterized in that, The life ring throwing device includes a throwing cylinder, a compressed air cylinder, and a life ring storage compartment. The throwing cylinder is connected to a fixed base via a rotating shaft. An electric push rod is provided on the rotating shaft to control the tilt angle of the throwing cylinder. The tilt angle adjustment range is 30 degrees to 60 degrees, and the throwing distance is 8 to 25 meters.

5. A rapid response and target location system for unmanned surface vessels used in emergency rescue of fisheries in large reservoirs according to claim 4, characterized in that, The main controller is an embedded industrial computer with an operating frequency of no less than 1GHz and a memory of no less than 2GB. It is connected to various sensors and actuators through interfaces to receive sensor data for image processing and route calculation. The bottom of the unmanned surface vessel is equipped with a collision protection plate made of high-strength rubber or polyurethane material with a thickness of 10 to 20 mm.

6. The rapid response and target location system for unmanned surface vessels used in emergency rescue of fisheries in large reservoirs according to claim 5, characterized in that, The floating chamber is filled with polyurethane foam material to ensure that the unmanned surface vessel still has positive buoyancy even if the equipment compartment is flooded.

7. An emergency rescue method based on the rapid response and overboard target positioning system for unmanned surface vessels used in fisheries emergency rescue in large-scale reservoirs as described in any one of claims 1 to 6, characterized in that, The process includes the following steps: Step 1: Receiving alarm information. After receiving the overboard alarm, the operator inputs the coordinates of the overboard location or selects a suspicious area. Step 2: The unmanned surface vessel (USV) quickly departs. The main controller calculates the route based on the current and target locations and controls the power propulsion module to start. Step 3: Area search. After reaching the target area, the USV reduces its speed and activates the overboard target detection module to scan and search. Step 4: Target identification. The main controller processes the acquired images and marks the target location. Step 5: Approaching the target. The main controller controls the USV to navigate towards the target location. Step 6: Rescue operation. The lifebuoy throwing device throws a lifebuoy to the person in the water and tows them to a safe area at low speed. Step 7: Returning to standby. After completing the rescue, the USV returns to its standby position.

8. The emergency rescue method according to claim 7, characterized in that, In step 4, when the target is identified, it is determined to be a valid target if at least two of the sensors, namely the visible light camera, the infrared thermal imager, and the radar detector, detect the target at the same location simultaneously.

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