An unmanned aerial vehicle based ship draft measurement system and method

Abstract

The application discloses a kind of ship draft measurement systems and methods based on unmanned aerial vehicle, contain unmanned aerial vehicle and mobile terminal, unmanned aerial vehicle is wirelessly connected with mobile terminal, the lower side of unmanned aerial vehicle is provided with support foot, the lower end of support foot is provided with detachable buoy, the upper end of buoy is provided with first bolt and second bolt, first bolt and second bolt are vertically arranged on the upper side of buoy, two insertion holes matched with first bolt and second bolt are opened on support foot, and bolt locking mechanism is arranged in two insertion holes.The buoy is increased below the unmanned aerial vehicle, to ensure that it can continue to take water image after falling into water, inflatable air bag can ensure that unmanned aerial vehicle is not sunk even if the wind and wave are very large, and the application also provides how to control unmanned aerial vehicle and the method for shooting after unmanned aerial vehicle falls into water, to truly realize the ship draft measurement based on unmanned aerial vehicle without the influence of weather environment.

Description

Technical Field

[0001] This invention relates to a ship draft measurement system and method, and more particularly to a ship draft measurement system and method based on unmanned aerial vehicles (UAVs), belonging to the field of ship technology. Background Technology

[0002] With the increasing size of ships, bulk carriers of 300,000-400,000 tons, container ships of 20,000 TEU, and very large crude carriers (VLCCs) of 300,000 tons have emerged. During the lightship weight measurement test, the lightship weight affects the ship's deadweight, and shipowners are very concerned about the accuracy of the lightship weight. Currently, shipyards mainly use Archimedes' principle to weigh the ship to obtain the lightship weight. This method requires high accuracy in the ship's draft measurement, because a few centimeters of draft error can lead to a change of hundreds of tons in the lightship weight.

[0003] Workers need extensive training to determine a ship's actual draft by observing its draft gauges. To overcome measurement errors caused by individual personnel, multiple teams typically conduct independent observations, and the results are then compared, synthesized, and averaged to obtain the final draft of the ship.

[0004] Visually estimating a ship's draft is often subjective and difficult to overcome environmental factors. Data from manual observations is limited to a small and few observation points, making statistical analysis impossible. Human observation is also significantly affected by the skill and condition of the personnel, requiring lengthy training. In poor sea conditions, with significant fluctuations in the water surface due to waves or currents, visual estimations are prone to error. While glass draft gauges are used, they require small boats or tugboats to reach the draft marker, making water sampling difficult and dangerous in strong currents or large waves. Patent application number 201710469202.4 discloses a drone-based ship draft measurement system, but the drone is prone to falling into the water in strong winds. Therefore, it is necessary to invent a drone system and method for draft observation to meet the requirements of shipyards or docks in different environments, reduce the cost and difficulty of draft measurement, and improve the safety of draft observation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a ship draft measurement system and method based on unmanned aerial vehicles (UAVs) to solve the problem of UAVs falling into the water.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A ship draft metering system based on unmanned aerial vehicles (UAVs) includes a UAV and a mobile terminal. The UAV and the mobile terminal are wirelessly connected. The UAV is equipped with support feet on its underside, and the lower end of the support feet is equipped with a detachable float.

[0007] Furthermore, the upper end of the float is provided with a first pin and a second pin, which are vertically arranged on the upper side of the float. The support foot has two insertion holes that match the first pin and the second pin, and the two insertion holes are provided with a pin locking mechanism.

[0008] Furthermore, the pin locking mechanism includes a first wedge-shaped latch, a second wedge-shaped latch, a first latch rod, a second latch rod, a first slider, a second slider, a locking spring, a first connecting rod, a second connecting rod, a first lever, and a second lever. The first pin has a first notch matching the first wedge-shaped latch on the side facing the center of the float, and the second pin has a second notch matching the second wedge-shaped latch on the side facing the center of the float. The float has a first groove matching the first and second wedge-shaped latches. The first and second latch rods are arranged along the length of the first groove and located within it. One end of the first latch rod is fixed to the first wedge-shaped latch, and one end of the second latch rod is fixed to the second wedge-shaped latch. The first slider is fixed to the first latch rod, and the second slider is fixed to the second latch rod. The locking spring... One end of the spring is sleeved on the other end of the first locking tongue rod, and one end of the locking spring abuts against the side of the first slider. The other end of the locking spring is sleeved on the other end of the second locking tongue rod, and the other end of the locking spring abuts against the side of the second slider. The upper side of the float has a second sliding groove that matches the first and second paddles. The first and second paddles are slidably disposed in the second sliding groove and are located at opposite ends of the second sliding groove. A first through groove is opened on the lower side of one end of the second sliding groove, and a second through groove is opened on the lower side of the other end of the second sliding groove, which in turn communicates with the first sliding groove. The first locking tongue rod and the first paddle are fixedly connected by a first connecting rod, and the first connecting rod is slidably disposed in the first through groove. The second locking tongue rod and the second paddle are fixedly connected by a second connecting rod, and the second connecting rod is slidably disposed in the second through groove.

[0009] Furthermore, the tips of the first and second pins are tapered.

[0010] Furthermore, a limiting block is provided at the upper end of the float corresponding to the first pin and the second pin respectively. The upper side of the limiting block has a groove that matches the lower end of the support foot, and the first pin and the second pin are located in the groove of the limiting block.

[0011] Furthermore, the float is equipped with an inflatable airbag, an automatic water-drop valve, and a compressed air cylinder. The float has a hollow cavity, in which the inflatable airbag is folded. The outlet of the compressed air cylinder is connected to one end of the automatic water-drop valve, and the other end of the automatic water-drop valve is connected to the inflation port of the inflatable airbag. An airbag outlet groove is opened on the side of the float facing the inside of the drone, and a sealing diaphragm is installed in the airbag outlet groove.

[0012] Furthermore, the automatic drain valve includes a slide gate valve body, a valve stem, a support spring, a piston, absorbent resin, a resin box, and a metal mesh. The lower end of the valve stem is fixedly connected to the valve plate inside the slide gate valve body, and the upper end of the valve stem is fixedly connected to the lower side of the piston. The support spring is sleeved on the outside of the valve stem and located between the slide gate valve body and the piston. The lower end of the resin box is fixed to the upper side of the slide gate valve body. The piston is slidably disposed in the resin box in a vertical direction. The absorbent resin is disposed in the resin box cavity above the piston. The metal mesh is fixed to the upper end of the resin box. The upper end of the resin box has an inlet that penetrates the upper side of the float.

[0013] Furthermore, the outlet of the compressed air cylinder is equipped with a manual valve, and the outlet of the compressed air cylinder is connected to one end of the automatic drain valve via a hose.

[0014] Furthermore, a camera is mounted on the underside of the drone. The camera is fixed on a three-axis platform, which includes a fixed base, a turntable, a Z-shaped bracket, and a C-shaped bracket. The base is fixed on the underside of the drone. The turntable is rotatably mounted on the underside of the base and driven to rotate by a first motor. The upper end of the Z-shaped bracket is fixed on the lower side of the turntable. The C-shaped bracket is rotatably mounted on the lower end of the Z-shaped bracket and driven to rotate by a second motor. The two sides of the camera are rotatably mounted on the C-shaped bracket and driven to rotate by a third motor.

[0015] A method for propagating draft measurement based on unmanned aerial vehicles (UAVs), and a UAV-based ship draft measurement system, includes the following steps: S1. The drone establishes a wireless connection with the mobile terminal; S2. The mobile terminal activates flight mode, obtains the shooting start command, and reads the combination control commands associated with the preset automatic shooting mode; S3. Send the combined control command to the drone, so that the drone can perform the corresponding series of actions in sequence according to the combined control command, so as to approach the waterline mark, lock the waterline mark, and take pictures of the ship's waterline. S4. When the drone accidentally falls into the water due to force majeure or when the wind is too strong for the drone to fly, the drone will automatically flip and adjust its attitude when it touches the water surface. The drone will float on the water surface using its own floats. The mobile terminal will switch to the water surface navigation mode and send instructions to the drone. After receiving the control instructions, the drone will navigate to the vicinity of the ship's draft mark through the water surface navigation drive device and continue to take pictures of the ship's draft. S5. The drone wirelessly transmits the captured draft images to the mobile terminal via the communication module. S6. The mobile terminal receives the images captured by the drone and stores them in the mobile terminal's storage medium. S7. The image captured is processed by the image processing module in the mobile terminal to automatically detect the draft mark reading at the location of the waterline; S8. Repeatedly analyze multiple images of the same hull part to obtain the ship's draft and take the statistical average. S9. Based on the draft data from multiple points on the port and starboard sides (bow, midship, and stern), and the input hydrostatic data, automatically calculate the ship's displacement.

[0016] Compared with the prior art, the present invention has the following advantages and effects: The present invention provides a ship draft measurement system based on drones. By adding a float under the drone, it can be ensured that the drone can continue to take draft images after it falls into the water. The inflatable airbag can ensure that the drone will not be sunk even if the wind and waves are very strong. At the same time, the present invention also provides a method for controlling and taking pictures of the drone after it falls into the water, thus truly realizing ship draft measurement based on drones that is not affected by weather conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a drone-based ship draft metering system according to the present invention.

[0018] Figure 2 This is a side view of a drone, which is part of the UAV-based ship draft metering system of the present invention.

[0019] Figure 3 This is a schematic diagram of the float of the present invention.

[0020] Figure 4 This is a partially enlarged view of the float of the present invention. Detailed Implementation

[0021] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0022] like Figure 1 and Figure 2 As shown, the present invention provides a ship draft metering system based on a drone, comprising a drone and a mobile terminal. The drone 1 is wirelessly connected to the mobile terminal. The drone 1 is provided with a support foot 2 on its lower side, and a detachable float 3 is provided at the lower end of the support foot 2.

[0023] like Figure 3As shown, the upper end of the float 3 is provided with a first pin 4 and a second pin 5. The first pin 4 and the second pin 5 are vertically arranged on the upper side of the float 3. The support foot 2 has two insertion holes that match the first pin 4 and the second pin 5. The two insertion holes are provided with a pin locking mechanism.

[0024] The latch locking mechanism includes a first wedge-shaped latch 6, a second wedge-shaped latch 7, a first latch rod 8, a second latch rod 9, a first slider 10, a second slider 11, a locking spring 12, a first connecting rod 13, a second connecting rod 14, a first lever 15, and a second lever 16. The first latch 4 has a first notch on the side facing the middle of the float 3 that matches the first wedge-shaped latch 6. The second latch 5 has a second notch on the side facing the middle of the float 3 that matches the second wedge-shaped latch 7. The float 3 has a first groove inside that matches the first wedge-shaped latch 6 and the second wedge-shaped latch 7. The first latch rod 8 and the second latch rod 9 are arranged along the length of the first groove and are located within the first groove. One end of the first latch rod 8 is fixed to the first wedge-shaped latch 6, and one end of the second latch rod 9 is fixed to the second wedge-shaped latch 7. The first slider 10 is fixed to the first latch rod 8, and the second slider 11 is fixed to the second latch rod 9. The locking spring 12... One end of the first locking tongue rod 8 is sleeved on the other end of the first locking tongue rod 8, and one end of the locking spring 12 abuts against the side of the first slider 10. The other end of the locking spring 12 is sleeved on the other end of the second locking tongue rod 9, and the other end of the locking spring 12 abuts against the side of the second slider 11. The upper side of the float 3 has a second sliding groove that matches the first paddle 15 and the second paddle 16. The first paddle 15 and the second paddle 16 are slidably disposed in the second sliding groove and are located at both ends of the second sliding groove. A first through groove is opened on the lower side of one end of the second sliding groove, and a second through groove is opened on the lower side of the other end of the second sliding groove, which is in communication with the first sliding groove. The first locking tongue rod 8 and the first paddle 15 are fixedly connected by the first connecting rod 13, and the first connecting rod 13 is slidably disposed in the first through groove. The second locking tongue rod 9 and the second paddle 16 are fixedly connected by the second connecting rod 14, and the second connecting rod 14 is slidably disposed in the second through groove. During installation, simply insert the first pin 4 and the second pin 5 at the upper end of the slider 3 into the corresponding holes on the support foot 2. Once inserted, the two pins are locked in place by the pin locking mechanism. When disassembly is required, push the first lever 15 and the second lever 16 towards the center simultaneously by hand. This will cause the first wedge-shaped locking tongue 6 and the second wedge-shaped locking tongue 7 to disengage from the first recess of the first pin 4 and the second recess of the second pin 5. At this point, the float block 3 can be directly pulled out of the hole for disassembly.

[0025] The tops of the first pin 4 and the second pin 5 are tapered, which makes it easy for the pins to be inserted into the socket.

[0026] A limiting block 17 is provided at the upper end of the float 3, corresponding to the first pin 4 and the second pin 5 respectively. The upper side of the limiting block 17 has a groove that matches the lower end of the support foot 2, and the first pin 4 and the second pin 5 are located in the groove of the limiting block 17. Through the structural design of the limiting block 17, the structure is more stable when the float 3 is installed on the lower side of the support foot 2.

[0027] like Figure 4 As shown, the float 3 is equipped with an inflatable airbag 18, an automatic water-drop valve, and a compressed air cylinder 19. The float 3 has a hollow cavity, and the inflatable airbag 18 is folded into the hollow cavity inside the float 3. The air outlet of the compressed air cylinder 19 is connected to one end of the automatic water-drop valve, and the other end of the automatic water-drop valve is connected to the inflation port of the inflatable airbag 18. The side of the float 3 facing the inside of the UAV 1 has an airbag outlet groove, and a sealing diaphragm 20 is provided in the airbag outlet groove.

[0028] The automatic drain valve includes a slide gate valve body 21, a valve stem 22, a support spring 23, a piston 24, absorbent resin 25, a resin box 26, and a metal mesh 27. The lower end of the valve stem 22 is fixedly connected to the valve plate inside the slide gate valve body 21, and the upper end of the valve stem 22 is fixedly connected to the lower side of the piston 24. The support spring 23 is sleeved on the outside of the valve stem 22 and located between the slide gate valve body 21 and the piston 24. The lower end of the resin box 26 is fixed to the upper side of the slide gate valve body 21. The piston 24 is slidably disposed in the resin box 26 in a vertical direction. The absorbent resin 25 is disposed in the cavity of the resin box 26 above the piston 24. The metal mesh 27 is fixed to the upper end of the resin box 26. The upper end of the resin box 26 has an inlet 28 that penetrates the upper side of the float 3.

[0029] The compressed air cylinder 19 has a manual valve at its outlet, and the outlet of the compressed air cylinder 19 is connected to one end of the automatic drain valve via a hose 29. The hose 29 is threadedly connected to the outlet of the compressed air cylinder 19 via a threaded connector.

[0030] A camera 30 is mounted on the underside of the drone 1. The camera 30 is fixed to a three-axis platform, which includes a base 31, a turntable 32, a Z-shaped bracket 33, and a C-shaped bracket 34. The base 31 is fixed to the underside of the drone 1. The turntable 32 is rotatably mounted on the underside of the base 31 and rotated by a first motor. The upper end of the Z-shaped bracket 33 is fixed to the lower side of the turntable 32. The C-shaped bracket 34 is rotatably mounted on the lower end of the Z-shaped bracket 33 and rotated by a second motor. The camera 30 is rotatably mounted on the C-shaped bracket 34 on both sides and rotated by a third motor. The three-axis platform enables the camera 30 to rotate horizontally and in two vertical planes, allowing for free angle adjustment and shooting.

[0031] A method for propagating draft measurement based on unmanned aerial vehicles (UAVs), and a UAV-based ship draft measurement system, includes the following steps: S1. The drone establishes a wireless connection with the mobile terminal.

[0032] S2. The mobile terminal activates flight mode, obtains a shooting start command, and reads the combined control commands associated with the preset automatic shooting mode. The mobile terminal can detect predefined events and obtain the shooting start command when a predefined event is detected. The mobile terminal can also display a shooting start control and detect operations on the shooting start control to obtain the corresponding shooting start command.

[0033] S3. Send the combined control command to the drone, so that the drone can perform the corresponding series of actions in sequence according to the combined control command, so as to approach the waterline mark, lock the waterline mark, and take pictures of the ship's waterline.

[0034] The series of actions includes drone flight maneuvers, shooting field of view adjustment maneuvers, shooting distance adjustment maneuvers, and shooting parameter adjustment maneuvers.

[0035] Shooting parameters include image size, resolution, ISO, focal length, and autofocus mode. The shooting field of view adjustment includes panning and zooming. The mobile terminal can control the rotation of the drone or shooting device to achieve panning, and can also zoom in and out by moving the drone or adjusting the focal length of the shooting device. The final goal of adjusting the shooting field of view is to ensure that the image simultaneously includes the boundary between the ship and the seawater (i.e., the waterline), the ship's draft gauge (which must include at least one 'M' character), and the seawater. The ship's waterline should be located approximately one-third of the way down in the captured image. The waterline should be kept as horizontal as possible. This facilitates image analysis by the mobile terminal's built-in image processing module.

[0036] S4. If the drone accidentally falls into the water due to force majeure or if the wind is too strong for the drone to fly, the drone will automatically flip and adjust its attitude when it touches the water surface. The drone will float on the water surface using its own floats. The mobile terminal will switch to the water surface navigation mode and send instructions to the drone. After receiving the control instructions, the drone will navigate to the vicinity of the ship's draft mark through the water surface navigation drive device and continue to take pictures of the ship's draft.

[0037] S5. The drone wirelessly transmits the captured draft images to the mobile terminal via the communication module.

[0038] S6. The mobile terminal receives the images captured by the drone and stores them in the mobile terminal's storage medium.

[0039] S7. The image captured is processed by the image processing module in the mobile terminal, and the draft mark reading at the location of the waterline is automatically detected.

[0040] S8. Repeatedly analyze multiple images of the same hull part to obtain the ship's draft and take the statistical average.

[0041] S9. Based on the draft data from multiple points on the port and starboard sides (bow, midship, and stern), and the input hydrostatic data, automatically calculate the ship's displacement.

[0042] This invention provides a ship draft measurement system based on unmanned aerial vehicles (UAVs). By adding a buoy under the UAV, it can continue to take draft images after it falls into the water. The inflatable airbag can ensure that the UAV will not sink even in strong winds and waves. This invention also provides a method for controlling and taking pictures of the UAV after it falls into the water, truly realizing UAV-based ship draft measurement that is not affected by weather conditions.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A ship draft metering system based on unmanned aerial vehicles (UAVs), characterized in that: It includes a drone and a mobile terminal. The drone and the mobile terminal are wirelessly connected. The drone is equipped with support feet on its lower side, and the lower end of the support feet is equipped with a detachable float. The upper end of the float is provided with a first pin and a second pin, which are vertically arranged on the upper side of the float. Two insertion holes matching the first and second pins are opened on the support foot, and a pin locking mechanism is provided in the two insertion holes. The pin locking mechanism includes a first wedge-shaped latch, a second wedge-shaped latch, a first latch rod, a second latch rod, a first slider, a second slider, a locking spring, a first connecting rod, a second connecting rod, a first lever, and a second lever. A first notch matching the first wedge-shaped latch is opened on the side of the first pin facing the middle position of the float, and a second notch matching the second wedge-shaped latch is opened on the side of the second pin facing the middle position of the float. A first sliding groove matching the first and second wedge-shaped latches is opened inside the float. The first latch rod and the second latch rod are arranged along the length of the first sliding groove and located within the first sliding groove. One end of the first latch rod is fixed to the first wedge-shaped latch, and one end of the second latch rod is fixed to the second wedge-shaped latch. The locking tongue is fixed, the first slider is fixed on the first locking tongue rod, the second slider is fixed on the second locking tongue rod, one end of the locking spring is sleeved on the other end of the first locking tongue rod and the end of the locking spring abuts against the side of the first slider, the other end of the locking spring is sleeved on the other end of the second locking tongue rod and the end of the locking spring abuts against the side of the second slider, the upper side of the float has a second sliding groove matching the first and second paddles, the first and second paddles are slidably disposed in the second sliding groove and are respectively located at the two ends of the second sliding groove, the lower side of one end of the second sliding groove has a first through groove communicating with the first sliding groove, the lower side of the other end of the second sliding groove has a second through groove communicating with the first sliding groove, the first locking tongue rod and the first paddle are fixedly connected by a first connecting rod and the first connecting rod is slidably disposed in the first through groove, the second locking tongue rod and the second paddle are fixedly connected by a second connecting rod and the second connecting rod is slidably disposed in the second through groove.

2. The ship draft metering system based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that: The top ends of the first and second pins are tapered.

3. The ship draft metering system based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that: The upper end of the float is provided with a limiting block corresponding to the first pin and the second pin respectively. The upper side of the limiting block has a groove that matches the lower end of the support foot. The first pin and the second pin are located in the groove of the limiting block.

4. The ship draft metering system based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that: The float is equipped with an inflatable airbag, an automatic water-drop valve, and a compressed air cylinder. The float has a hollow cavity, and the inflatable airbag is folded inside the hollow cavity. The outlet of the compressed air cylinder is connected to one end of the automatic water-drop valve, and the other end of the automatic water-drop valve is connected to the inflation port of the inflatable airbag. The side of the float facing the inside of the drone has an airbag outlet groove, and a sealing diaphragm is installed in the airbag outlet groove.

5. A ship draft metering system based on unmanned aerial vehicles (UAVs) according to claim 4, characterized in that: The automatic drain valve includes a slide gate valve body, a valve stem, a support spring, a piston, absorbent resin, a resin box, and a metal mesh. The lower end of the valve stem is fixedly connected to the valve plate inside the slide gate valve body, and the upper end of the valve stem is fixedly connected to the lower side of the piston. The support spring is sleeved on the outside of the valve stem and located between the slide gate valve body and the piston. The lower end of the resin box is fixed to the upper side of the slide gate valve body. The piston slides vertically inside the resin box. The absorbent resin is placed inside the resin box cavity above the piston. The metal mesh is fixed to the upper end of the resin box. The upper end of the resin box has an inlet that penetrates the upper side of the float.

6. A ship draft metering system based on unmanned aerial vehicles (UAVs) according to claim 4, characterized in that: The compressed air cylinder has a manual valve at its outlet, and the outlet is connected to one end of an automatic drain valve via a hose.

7. A ship draft metering system based on unmanned aerial vehicles (UAVs) according to claim 1, characterized in that: A camera is mounted on the underside of the drone. The camera is fixed on a three-axis platform, which includes a fixed base, a turntable, a Z-shaped bracket, and a C-shaped bracket. The base is fixed to the underside of the drone. The turntable is rotatably mounted on the underside of the base and driven to rotate by a first motor. The upper end of the Z-shaped bracket is fixed to the lower side of the turntable. The C-shaped bracket is rotatably mounted on the lower end of the Z-shaped bracket and driven to rotate by a second motor. The camera is rotatably mounted on the C-shaped bracket on both sides and driven to rotate by a third motor.

8. A method for measuring ship draft based on unmanned aerial vehicles (UAVs), based on the UAV-based ship draft measurement system according to any one of claims 1-7, characterized in that... Includes the following steps: S1. The drone establishes a wireless connection with the mobile terminal; S2. The mobile terminal activates flight mode, obtains the shooting start command, and reads the combination control commands associated with the preset automatic shooting mode; S3. Send the combined control command to the drone, so that the drone can perform the corresponding series of actions in sequence according to the combined control command, so as to approach the waterline mark, lock the waterline mark, and take pictures of the ship's waterline. S4. When the drone accidentally falls into the water due to force majeure or when the wind is too strong for the drone to fly, the drone will automatically flip and adjust its attitude when it touches the water surface. The drone will float on the water surface using its own floats. The mobile terminal will switch to the water surface navigation mode and send instructions to the drone. After receiving the control instructions, the drone will navigate to the vicinity of the ship's draft mark through the water surface navigation drive device and continue to take pictures of the ship's draft. S5. The drone wirelessly transmits the captured draft images to the mobile terminal via the communication module. S6. The mobile terminal receives the images captured by the drone and stores them in the mobile terminal's storage medium. S7. The image captured is processed by the image processing module in the mobile terminal to automatically detect the draft mark reading at the location of the waterline; S8. Repeatedly analyze multiple images of the same hull part to obtain the ship's draft and take the statistical average. S9. Based on the draft data from multiple points on the port and starboard sides (bow, midship, and stern), and the input hydrostatic data, automatically calculate the ship's displacement.

Images