A ship water gauge automatic measuring device and method based on wall-climbing robot and double radar fusion

Abstract

The present application relates to the technical field of ship detection equipment, in particular to a ship water gauge automatic measurement device and method based on wall-climbing robot and double radar fusion, comprising a robot main body mechanism, the outer side of the robot main body mechanism is provided with a wave-proof adsorption mechanism and a protection and cleaning mechanism; the present application realizes the autonomous movement measurement, automatic weighing, archiving and report generation of the six-surface water gauge of the ship through double radar fusion, attitude sensing and autonomous cruise of the wall-climbing robot, fills the technical blank of the wall-climbing robot and double radar fusion for water gauge automatic measurement, and improves the measurement efficiency, automation level and data traceability; at the same time, through the wave-proof adsorption mechanism, the adsorption stability and wave resistance of the robot on the inclined hull plate are improved, the measurement operation safety and reliability are ensured, and through the protection and cleaning mechanism, the radar window is ensured to be continuously clean, so that the double radar measurement signal is not blocked and attenuated, the measurement precision is improved and the artificial cleaning and maintenance is reduced.

Description

Technical Field

[0001] This invention relates to the field of ship inspection equipment technology, and in particular to a device and method for non-contact automatic measurement of ship draft using a wall-climbing robot as a platform and radar ranging technology. Background Technology

[0002] Draft surveying is the core method for measuring bulk cargo in international maritime transport. Its measurement accuracy directly affects trade settlement and ship safety. There are various measurement methods, such as manual measurement, which requires riding a small boat close to the ship's side. This method is greatly affected by wind, waves, and tides, and carries the risk of personnel falling into the water or colliding, resulting in poor operational safety. Alternatively, existing radar / laser draft surveying equipment mostly uses a fixed bracket structure, which is cumbersome to install, cannot be moved, and can only achieve single-point measurement, failing to cover the needs of detecting the draft of a ship on all six sides.

[0003] The current water level gauge measurement method has the following main drawbacks: First, existing measuring equipment mostly uses fixed brackets or handheld installation, which cannot move autonomously along the hull plating, making it difficult to meet the multi-point and full-ship coverage measurement requirements of the six sides of the ship's draft gauge; at the same time, it lacks the ability to climb walls and walk, making it impossible to achieve autonomous cruising and positioning measurement of the hull plating.

[0004] Secondly, existing equipment generally lacks effective wave protection and impact resistance design. When operating in windy and wavy weather, waves directly impact the equipment body and sensor windows, causing measurement signal attenuation, component damage, or even equipment detachment. Operational safety and data reliability are difficult to guarantee.

[0005] Finally, the sensor window is easily covered by water film, salt spray, and dirt in the seawater splash environment, which can obstruct the measurement optical path or radar beam. Currently, there is a lack of automatic cleaning mechanisms, requiring frequent manual intervention for maintenance. To address these issues, this invention proposes an automatic draft measurement device and method for ships based on the fusion of a wall-climbing robot and dual radar. Summary of the Invention

[0006] The purpose of this invention is to provide an automatic ship draft measurement device and method based on the fusion of a wall-climbing robot and dual radar, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An automatic draft measurement device for ships based on a wall-climbing robot and dual-radar fusion includes a robot main body. The robot main body is equipped with a wave-resistant adsorption mechanism and a protective cleaning mechanism on its outer side, and the robot main body is adsorbed onto the outer wall of the ship's outer hull. The robot main body includes a robot shell, inside which are arranged a dual-radar mechanism, an attitude sensing unit, a data processing unit, and a wireless communication module. The dual-radar mechanism includes a vertical ranging radar and two lateral scanning radars on its sides. The wave-resistant adsorption mechanism includes a protective top plate and two arc-shaped side plates, with two pairs of hollow vertical pipes on both sides of the protective top plate. The protective cleaning mechanism includes a protective frame, linked rollers, a cleaning scraper, and side vertical plates fixedly connected to both sides of the protective frame.

[0008] Preferably, four arrayed limiting rods are fixedly connected to the top of the robot housing, and springs surround the limiting rods. The springs are located below the protective top plate, and the limiting rods penetrate the protective top plate.

[0009] Preferably, a rubber suction cup is provided at the bottom of the hollow riser, and a one-way port is provided at the top of the hollow riser.

[0010] Preferably, the protective frame is fixedly connected to one end of the robot housing, a protective cover is provided on the inner side of the protective frame, the inner side of the cleaning scraper is tightly fitted to the protective cover, the linkage roller is located below the protective frame, and the protective frame and the protective cover are located around the vertical ranging radar and the lateral scanning radar.

[0011] Preferably, the linkage roller is provided with toothed belts at both ends, the toothed belts are movably connected to the inside of the side plate, a sliding groove is provided on one side of the side plate, a limiting groove is fixedly connected to the inner wall of the sliding groove, a spring piece is provided inside the sliding groove, and the limiting groove is parallelogram-shaped.

[0012] Preferably, the cleaning scraper is fixedly connected to two ends of a slider, which slides up and down inside the groove. The slider has a positioning groove and a connecting groove, and the toothed belt passes through the positioning groove and the connecting groove.

[0013] Preferably, a connecting plate is fixedly connected to the end of the slider away from the cleaning scraper, and the connecting plate is connected below the spring sheet.

[0014] Preferably, the slider has a positioning block that slides left and right inside it, and the positioning block has protruding rods fixedly connected to both sides. The protruding rods are located inside the limiting groove, and the positioning block engages with the inner side of the toothed belt.

[0015] Preferably, a power supply module is provided inside the robot shell, the attitude sensing unit, the data processing unit and the wireless communication module are all located above the power supply module, a drive module is provided on one side of the power supply module, and a permanent magnet adsorption track is provided around the output end of the drive module, with the permanent magnet adsorption track located on both sides of the robot shell.

[0016] A method for automatic ship draft measurement based on wall-climbing robot and dual radar fusion: Step 1: The main body of the terminal control robot (1) on the ship is attached to the outer plate of the ship (8), and the main body of the robot (1) is moved to the target draft measurement area through autonomous cruise or remote control. Step 2: The vertical ranging radar (21) continuously collects distance data from the robot's reference plane to the water surface using high-frequency sampling. At the same time, the lateral scanning radar (22) performs a fan-shaped scan of the water gauge area to obtain water gauge scale point cloud data and complete the water level line positioning. Step 3: The attitude sensing unit (3) synchronously collects the robot's own attitude data and the ship's pitch and roll data; Step 4: The data processing unit (4) performs a combination of sliding window mean filtering and median filtering on the distance data obtained by the vertical ranging radar (21) to suppress wave interference, and performs dual radar data fusion on the data of the vertical ranging radar (21) and the side scanning radar (22), and performs attitude compensation calculation by combining the robot attitude data and the ship's pitch and roll data, and calculates and outputs the standard draft value. Step 5: Upload the standard draft, timestamp, and location information to the shore terminal via the wireless communication module (5); Step 6: The shore terminal automatically completes draft survey, data archiving, and report generation based on the received data.

[0017] Compared with the prior art, the beneficial effects of the present invention are: I. By employing dual-radar fusion, attitude sensing, and autonomous navigation of a wall-climbing robot, the system utilizes a vertical ranging radar to collect high-frequency distance data from the reference plane to the water surface, and a lateral scanning radar to scan the draft gauge scale and generate point cloud data. This data is combined with the robot's tilt and the ship's trim and heel data collected synchronously by the attitude sensing unit. The data processing unit performs sliding window mean and median filtering to suppress wave interference, and calculates the standard draft value through attitude compensation and AI recognition algorithms for the draft gauge scale. Even under complex conditions such as dirt, corrosion, and rough seas, the system can accurately complete draft gauge readings. The measurement data can be uploaded to the shore terminal in real time via a wireless communication module, enabling autonomous movement measurement, automatic weighing, archiving, and report generation of the ship's six draft gauges. This fills the technological gap of using wall-climbing robots and dual-radar fusion for automatic draft gauge measurement, and improves measurement efficiency, automation level, and data traceability capabilities.

[0018] Second, the anti-wave adsorption mechanism, through its design, blocks and buffers the impacting waves during the robot's movement and stationary measurement process, preventing direct impact from the waves and protecting the internal equipment. Simultaneously, the impact of the waves forces the protective top plate closer to the ship's outer hull, causing the hollow riser to move downwards and, through the compression deformation of the rubber suction cups, expelling internal air through a one-way port, creating a vacuum-assisted adsorption. This converts the wave impact energy into a negative pressure effect that enhances adsorption force, significantly improving the robot's adsorption stability and wave resistance on the inclined hull, ensuring safe and reliable measurement operations.

[0019] Third, by setting up a protective cleaning mechanism, a protective frame and a transparent protective cover are set up around the dual radar mechanism to block the direct impact of seawater and debris on the vertical ranging radar and the lateral scanning radar, as well as the adhesion of dirt. At the same time, by utilizing the contact rotation between the linkage roller and the ship's outer plate when the robot moves, the cleaning scraper is driven to automatically reciprocate and clean the surface of the protective cover through the cooperation of toothed belt, slider, positioning block and limit groove. After each measurement, the seawater and attachments on the protective cover are removed in time to ensure that the radar window remains clean, thereby ensuring that the dual radar measurement signal is not blocked or attenuated, improving the measurement accuracy and reducing manual cleaning and maintenance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall disassembled structure in this invention; Figure 3 This is a schematic diagram of the internal structure of the robot's main body mechanism in this invention; Figure 4 This is a schematic diagram of the disassembled structure of the wave-blocking adsorption mechanism in this invention; Figure 5 This is a schematic diagram of the protective cleaning mechanism in this invention; Figure 6 This is a schematic diagram showing the disassembled structure of the protective cleaning mechanism in this invention; Figure 7 This is a schematic diagram of the internal structure of the side plate in this invention; Figure 8 This is a schematic diagram of the cleaning scraper in this invention.

[0021] In the picture: 1. Robot main body structure; 11. Robot shell; 12. Power supply module; 13. Drive module; 14. Permanent magnet adsorption track; 2. Dual radar system; 21. Vertical ranging radar; 22. Lateral scanning radar; 3. Attitude sensing unit; 4. Data processing unit; 5. Wireless communication module; 6. Anti-wave adsorption mechanism; 61. Protective top plate; 62. Arc-shaped side plate; 63. Limiting rod; 64. Spring; 65. Hollow riser; 66. Rubber suction cup; 67. One-way port; 7. Protective cleaning mechanism; 71. Protective frame; 72. Protective cover; 73. Side upright plate; 731. Slide groove; 732. Limiting groove; 74. Linkage roller; 75. Toothed belt; 76. Spring piece; 77. Cleaning scraper; 78. Sliding block; 781. Positioning through groove; 782. Connecting groove; 783. Connecting plate; 79. Positioning block; 791. Protruding rod; 8. Ship outer plating. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0023] Please see Figures 1 to 8 The present invention provides a technical solution: An automatic ship draft measurement device and method based on wall-climbing robot and dual radar fusion includes a robot main body 1, an anti-wave adsorption mechanism 6 and a protective cleaning mechanism 7 on the outside of the robot main body 1, and the robot main body 1 adsorbs onto the outer wall of the ship's outer plate 8. The main body of the robot 1 includes a robot shell 11, and the robot shell 11 is equipped with a dual radar mechanism 2, an attitude sensing unit 3, a data processing unit 4 and a wireless communication module 5. The dual radar system 2 includes a vertical ranging radar 21 and two side-scanning radars 22 on its two sides; The wave-proof adsorption mechanism 6 includes a protective top plate 61 and two arc-shaped side plates 62. Two pairs of hollow vertical pipes 65 are provided on both sides of the protective top plate 61. The protective cleaning mechanism 7 includes a protective frame 71, linkage rollers 74, a cleaning scraper 77, and side uprights 73 fixedly connected to both sides of the protective frame 71. The system includes a vertical ranging radar 21 for measuring the distance from the robot's reference plane to the water surface; a lateral scanning radar 22 positioned horizontally towards the water gauge for scanning the water gauge scale and generating scale point cloud data; a data processing unit 4 for performing wave filtering, data fusion, and attitude compensation on the radar data to calculate the ship's standard draft; attitude compensation includes robot tilt compensation and ship trim and roll error compensation; wave dynamic filtering uses a combination algorithm of sliding window mean filtering and median filtering; the data processing unit 4 also integrates a water gauge scale AI recognition algorithm, which can complete scale recognition in dirty, corroded, or obstructed environments; and a wireless communication module 5 for uploading draft data to a shore terminal, supporting at least one of 4G, Wi-Fi, and Bluetooth communication methods. The robot housing 11 is also equipped with a hanging ring on its back, which can be connected to a safety rope; the ship's outer plate 8 is part of the ship, and there is a terminal on the ship's deck that can control the operation of the robot's main body mechanism 1 and other components, as well as obtain measurement data.

[0024] In this embodiment, four arrayed limiting rods 63 are fixedly connected to the top of the robot housing 11. Springs 64 surround the periphery of the limiting rods 63. The springs 64 are located below the protective top plate 61. The limiting rods 63 penetrate the protective top plate 61. Among them, the spring 64 can provide some buffering for the waves hitting the ship; the lower edge of the arc-shaped side plate 62 does not contact the outer plate 8 of the ship, but it will contact the outer plate 8 after the waves hit it, and will deform to provide secondary buffering.

[0025] In this embodiment, a rubber suction cup 66 is provided below the hollow riser 65, and a one-way port 67 is provided above the hollow riser 65. Among them, the rubber suction cup 66 is a rubber part made of corrosion-resistant material. When the protective top plate 61 moves down with the hollow riser 65, it will compress the rubber suction cup 66, thereby expelling the air in the hollow riser 65 upward; the one-way port 67 is a one-way discharge port, which will enhance the adhesion between the robot's main body 1 and the ship's outer plate 8 through negative pressure after the waves crash.

[0026] In this embodiment, the protective frame 71 is fixedly connected to one end of the robot housing 11, and a protective cover 72 is provided on the inner side of the protective frame 71. The inner side of the cleaning scraper 77 is tightly attached to the protective cover 72. The linkage roller 74 is located below the protective frame 71. The protective frame 71 and the protective cover 72 are located around the vertical ranging radar 21 and the lateral scanning radar 22. The protective cover 72 is made of corrosion-resistant transparent material, which can protect the vertical ranging radar 21 and the lateral scanning radar 22 inside it. The protective cover 72 can be replaced by removing the protective frame 71 from the top and bottom. The linkage roller 74 and the permanent magnet adsorption track 14 are in close contact with the outer plate 8 of the ship. When the robot body mechanism 1 finishes measuring and moves onto the ship, the permanent magnet adsorption track 14 will rotate clockwise, which will cause the linkage roller 74 to rotate synchronously.

[0027] In this embodiment, toothed belts 75 are provided at both ends of the linkage roller 74. The toothed belts 75 are movably connected to the inside of the side plate 73. A sliding groove 731 is provided on one side of the side plate 73. A limiting groove 732 is fixedly connected to the inner wall of the sliding groove 731. A spring piece 76 is provided inside the sliding groove 731. The limiting groove 732 is parallelogram-shaped. The toothed belt 75 has teeth on its inner side to engage with the positioning block 79. Two guide wheels are provided on the inner side of the toothed belt 75, which are rotatably connected to the inside of the side plate 73. The left side of the limiting groove 732 is lower than the right side, and the tops of both are obliquely connected. Therefore, when the slider 78 is below, the positioning block 79 is located on the left side of the limiting groove 732 through the protrusion 791, and at this time the positioning block 79 engages with the toothed belt 75. When the slider 78 is above, the protrusion 791 is located on the right side of the limiting groove 732, and then moves rapidly downward under the counter-push of the spring 76. This cycle repeats, thereby causing the cleaning scraper 77 to reciprocate to clean the protective cover 72.

[0028] In this embodiment, sliders 78 are fixedly connected to both ends of the cleaning scraper 77. The sliders 78 are slidably connected to the inside of the groove 731. The sliders 78 have a positioning groove 781 and a connecting groove 782. The toothed belt 75 passes through the positioning groove 781 and the connecting groove 782. The connecting groove 782 only allows the right side of the toothed belt 75 to pass through, so as not to affect the intermittent connection between the slider 78 and the toothed belt 75 via the positioning block 79.

[0029] In this embodiment, a connecting plate 783 is fixedly connected to the end of the slider 78 away from the cleaning scraper 77, and the connecting plate 783 is connected below the spring piece 76; The connecting plate 783 is used to cooperate with the spring 76, so that the cleaning scraper 77 can be quickly pushed down after the cleaning scraper 77 and the slider 78 move up to the top.

[0030] In this embodiment, a positioning block 79 is slidably connected to the inside of the slider 78. A protruding rod 791 is fixedly connected to both sides of the positioning block 79. The protruding rod 791 is located inside the limiting groove 732. The positioning block 79 engages with the inner side of the toothed belt 75. The slider 78 has a connecting groove at the protrusion 791, which allows the protrusion 791 to be located inside the limiting groove 732. Therefore, the positioning block 79 is restricted by the limiting groove 732, allowing the positioning block 79 to slide left and right within the slider 78.

[0031] In this embodiment, a power supply module 12 is provided inside the robot housing 11. The attitude sensing unit 3, the data processing unit 4 and the wireless communication module 5 are all located above the power supply module 12. A drive module 13 is provided on one side of the power supply module 12. A permanent magnet adsorption track 14 is provided around the output end of the drive module 13. The permanent magnet adsorption track 14 is located on both sides of the robot housing 11. The power supply module 12 itself is a lithium battery. Below the power supply module 12, there is also a main control unit, an anti-fall sensor, a position encoder, and an electromagnetic component, which can stably adhere and crawl on the vertical and curved surfaces of the ship's outer plate 8.

[0032] The working principle of this invention is as follows: Measurement method: The terminal on the ship can control the main body of the robot 1 to adhere to the ship's outer plate 8, and move to the target draft measurement area through autonomous cruise or remote control. At this time, the vertical ranging radar 21 continuously collects the distance data between the robot and the water surface in a high-frequency sampling mode. At the same time, the lateral scanning radar 22 performs a fan-shaped scan of the draft area to obtain the scale point cloud and complete the water level line positioning. The attitude sensing unit 3 synchronously collects the robot's attitude and the ship's tilt data. The data processing unit 4 performs sliding window mean and median combined filtering on the data obtained by the vertical ranging radar 21 to suppress wave interference, and fuses the dual radar data. Combined with the robot's attitude and the ship's pitch / roll, compensation calculation is performed to output the standard draft value. After completion, the draft data, timestamp, and location information can be uploaded to the shore terminal through the wireless communication module 5. Finally, the terminal automatically completes the draft weighing, data archiving, and report generation. During the process of the robot body 1 moving to the measurement area and when it stops in the measurement area, because the ship's outer plate 8 has an inclination, if the waves hit the robot body 1, they will be blocked by the protective top plate 61 and the arc-shaped side plate 62, thus preventing the waves from directly impacting the robot body 1 and forming protection; at the same time, when the waves hit the protective top plate 61 and the arc-shaped side plate 62, they will force the protective top plate 61 and the arc-shaped side plate 62 to approach the ship's outer plate 8, so that the bottom of the rubber suction cup 66 contacts the ship's outer plate 8 and is squeezed and deformed, and the air inside it will be discharged to the outside through the hollow riser 65 and the one-way port 67, thereby forming a vacuum-assisted adsorption; Furthermore, when the waves crash against the main body of the robot 1, some seawater will impact the front end of the dual radar mechanism 2 and be blocked by the protective cover 72. When the robot 1 moves after the measurement is completed, the linkage roller 74 will also contact the outer plate 8 of the ship and rotate, causing the toothed belt 75 to rotate inside the side plate 73. During the rotation, the cleaning scraper 77 will be continuously driven to reciprocate on the surface of the protective cover 72 through the cooperation of the slider 78, positioning block 79, limit groove 732 and spring 76, so that the seawater on the surface of the protective cover 72 can be automatically cleaned after the measurement is completed.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion, comprising a robot main body (1), characterized in that: The robot body (1) is provided with a wave-proof adsorption mechanism (6) and a protective cleaning mechanism (7) on its outer side, and the robot body (1) is adsorbed onto the outer wall of the ship's outer plate (8); The robot body (1) includes a robot shell (11), and the robot shell (11) is equipped with a dual radar mechanism (2), an attitude sensing unit (3), a data processing unit (4) and a wireless communication module (5). The dual radar mechanism (2) includes a vertical ranging radar (21) and side scanning radars (22) on both sides. The wave-proof adsorption mechanism (6) includes a protective top plate (61) and two arc-shaped side plates (62). Two pairs of hollow vertical pipes (65) are provided on both sides of the protective top plate (61). The protective cleaning mechanism (7) includes a protective frame (71), a linkage roller (74), a cleaning scraper (77), and side plates (73) fixedly connected to both sides of the protective frame (71).

2. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 1, characterized in that: Four arrayed limiting rods (63) are fixedly connected to the top of the robot housing (11). Springs (64) surround the limiting rods (63). The springs (64) are located below the protective top plate (61). The limiting rods (63) penetrate the protective top plate (61).

3. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 1, characterized in that: A rubber suction cup (66) is provided below the hollow riser (65), and a one-way port (67) is provided above the hollow riser (65).

4. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 1, characterized in that: The protective frame (71) is fixedly connected to one end of the robot housing (11). A protective cover (72) is provided on the inner side of the protective frame (71). The inner side of the cleaning scraper (77) is tightly attached to the protective cover (72). The linkage roller (74) is located below the protective frame (71). The protective frame (71) and the protective cover (72) are located around the vertical ranging radar (21) and the side scanning radar (22).

5. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 1, characterized in that: The linkage roller (74) is provided with toothed belts (75) at both ends. The toothed belts (75) are movably connected to the inside of the side plate (73). A sliding groove (731) is provided on one side of the side plate (73). A limiting groove (732) is fixedly connected to the inner wall of the sliding groove (731). A spring piece (76) is provided inside the sliding groove (731). The limiting groove (732) is parallelogram-shaped.

6. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 1, characterized in that: The cleaning scraper (77) is fixedly connected to two sliders (78) at both ends. The sliders (78) slide up and down inside the groove (731). The sliders (78) have a positioning groove (781) and a connecting groove (782). The toothed belt (75) passes through the positioning groove (781) and the connecting groove (782).

7. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 6, characterized in that: The slider (78) is fixedly connected to a connecting plate (783) at the end away from the cleaning scraper (77), and the connecting plate (783) is connected below the spring (76).

8. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 6, characterized in that: The slider (78) is slidably connected to a positioning block (79) inside. The positioning block (79) is fixedly connected to two sides with protrusions (791). The protrusions (791) are located inside the limiting groove (732). The positioning block (79) engages with the inner side of the toothed belt (75).

9. The automatic draft measurement device for ships based on wall-climbing robot and dual radar fusion as described in claim 1, characterized in that: The robot housing (11) is equipped with a power supply module (12). The attitude sensing unit (3), data processing unit (4) and wireless communication module (5) are all located above the power supply module (12). A drive module (13) is provided on one side of the power supply module (12). A permanent magnet adsorption track (14) is provided around the output end of the drive module (13). The permanent magnet adsorption track (14) is located on both sides of the robot housing (11).

10. A method for automatic ship draft measurement based on wall-climbing robot and dual radar fusion as described in any one of claims 1-9, characterized in that, The measurement method is as follows: S1: The main body of the terminal control robot (1) on the ship is attached to the outer plate of the ship (8) and moves the main body of the robot (1) to the target water level measurement area through autonomous cruise or remote control. S2: The vertical ranging radar (21) continuously collects distance data from the robot's reference plane to the water surface in a high-frequency sampling manner. At the same time, the lateral scanning radar (22) performs a fan-shaped scan of the water gauge area to obtain water gauge scale point cloud data and complete the water level line positioning. S3: Attitude sensing unit (3) synchronously collects robot's own attitude data and ship's pitch and roll data; S4: The data processing unit (4) performs a combination of sliding window mean filtering and median filtering on the distance data obtained by the vertical ranging radar (21) to suppress wave interference, and performs dual radar data fusion on the data of the vertical ranging radar (21) and the side scanning radar (22), and performs attitude compensation calculation by combining the robot attitude data and the ship's pitch and roll data, and calculates and outputs the standard draft value. S5: Upload the standard draft, timestamp and location information to the shore terminal via the wireless communication module (5); S6: The shore-based terminal automatically completes draft survey, data archiving, and report generation based on the received data.

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