Water depth measuring device and method based on unmanned aerial vehicle technology

Abstract

The application discloses a water depth measuring device and method based on unmanned aerial vehicle technology, which comprises a depth sounding weight, a measuring rope, a float, a swing damper, a depth sounding control module and an unmanned aerial vehicle platform, the depth sounding weight is arranged at the lower end of the measuring rope, the upper end of the measuring rope is arranged at the bottom of the float, the depth sounding control module is arranged at the bottom of the unmanned aerial vehicle platform, and the bottom of the depth sounding control module is connected with the top of the float through a traction rope; the swing damper is connected to the measuring rope; the unmanned aerial vehicle platform is equipped with a high-precision GNSS positioning system, an attitude stabilizing device and a flight control module, and the depth sounding control module comprises a master control module, a GNSS / IMU module, a tension sensor, a time synchronization module, a data recording module and a wire disconnecting device. The unmanned aerial vehicle technology is introduced to construct the unmanned aerial vehicle hanging depth sounding weight depth sounding system, efficient, accurate and safe water depth measurement is realized, and the application has the advantages of simple operation, high measurement precision and strong adaptability.

Description

Technical Field

[0001] This invention relates to a water depth measurement device and method based on unmanned aerial vehicle (UAV) technology, belonging to the field of traffic safety detection technology. Background Technology

[0002] In fields such as water conservancy, oceanography, and geological exploration, water depth measurement is an extremely important fundamental task. Traditional water depth measurement methods mostly rely on vessels carrying depth sounding equipment or manual dropping of sounding hammers. These methods have drawbacks such as high operating costs, low efficiency, and significant susceptibility to environmental factors. For example, in difficult areas such as shallow waters, manual RTK measurements and sounding rods are mainly used, which involves high labor intensity. Especially in complex waters, shallows, or inaccessible areas (such as areas with soft, silty bottoms or areas overgrown with weeds), personnel and vessels cannot enter, making it difficult to conduct measurements, thus limiting the application of traditional water depth measurement methods.

[0003] The following problems exist in the current field of water depth measurement: (1) Traditional water depth measurement methods, such as using large ships to carry depth sounding equipment, are not only expensive to purchase and maintain, but also require professional operators, which greatly increases the total cost of operation. (2) The speed of ships is limited and greatly affected by water conditions (such as water flow and waves), resulting in slow measurement speed. Especially in complex waters or shallow areas, the maneuverability of ships is restricted, further reducing the efficiency of operation. (3) In some areas such as swamps, wetlands, shallow waters or steep coastlines, due to complex terrain, large changes in water depth or the presence of obstacles, it is difficult for ships to approach or operate safely, making water depth measurement in these areas a difficult problem. (4) Traditional manual dropping of depth sounding hammers or diving measurement methods require personnel to enter waters or dangerous areas, facing risks such as drowning and collisions. Especially in bad weather or unstable water conditions, the safety risks are significantly increased. (5) Traditional methods may be affected by various factors (such as water flow, waves, and ship swaying), resulting in errors in measurement data. In addition, manual operation may also introduce human error, affecting the accuracy and reliability of the data. (6) Although UAV technology has made significant progress in other fields, its application in water depth measurement is relatively lagging. Existing UAV depth measurement systems often suffer from problems such as high equipment costs, limited depth measurement capabilities, complex operation, and insufficient data processing capabilities, making it difficult to meet actual needs. In summary, the current field of water depth measurement faces several technical problems, including high operating costs, low efficiency, poor environmental adaptability, high safety risks, and issues with data accuracy and reliability.

[0004] This invention proposes a water depth measurement device and method based on unmanned aerial vehicle (UAV) technology. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes a water depth measurement device and method based on unmanned aerial vehicle (UAV) technology. By introducing UAV technology, a UAV-mounted sounding hammer system can be constructed to achieve efficient, accurate, and safe water depth measurement.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows:

[0007] In a first aspect, the present invention provides a water depth measurement device based on UAV technology, comprising a sounding hammer, a measuring rope, a buoy, a swing damper, a depth control module, and a UAV platform. The sounding hammer is disposed at the lower end of the measuring rope, the upper end of the measuring rope is disposed at the bottom of the buoy, and the depth control module is disposed at the bottom of the UAV platform. The bottom of the depth control module is connected to the top of the buoy via a traction rope. The swing damper is attached to the measuring rope and is used to reduce the swing amplitude and stabilization time of the sounding hammer caused by UAV movement and environmental factors.

[0008] The UAV platform is equipped with a high-precision GNSS positioning system, an attitude stabilization device, and a flight control module. The attitude stabilization device and the high-precision GNSS positioning system ensure the stability and accuracy of the UAV during flight, while the flight control module is responsible for the UAV's flight trajectory planning and stability control.

[0009] The depth sounding control module includes a main control module, a GNSS / IMU module, a tension sensor, a time synchronization module, a data recording module, and a wire-removal device. The main control module is connected to the GNSS / IMU module, the tension sensor, the data recording module, the wire-removal device, and the UAV platform. The time synchronization module is connected to the main control module, the GNSS / IMU module, and the tension sensor. The GNSS / IMU module is connected to a high-precision GNSS positioning system.

[0010] As one possible implementation of this embodiment, the GNSS / IMU module utilizes a shore-based GNSS ground station to perform differential and combined navigation calculations on the raw GNSS and IMU data acquired by the UAV to obtain high-precision carrier motion trajectory and attitude. The main control module filters the tension data measured by the tension sensor at the moment when the sounding hammer enters the water due to buoyancy and when the tension data returns to zero upon touching the bottom, and calculates the bottom elevation point and water depth data. At the same time, the time of the sounding hammer touching the water and touching the bottom is converted into the same time reference through the time synchronization module. Finally, underwater topographic results are generated based on the water depth measurement data.

[0011] As one possible implementation of this embodiment, the process by which the main control module calculates the underwater elevation point and water depth data is as follows:

[0012] Let the coordinate offset between the mooring point P of the measuring rope and the phase center of the GNSS antenna be (Δx, Δy, Δz), and the distance from the lower end of the sounding hammer to the mooring point P be h. Let the coordinates of the GNSS antenna phase center in the WGS84 Cartesian coordinate system when the sounding hammer touches the water or the bottom be (x0, y0, z0). Let the attitude measurement value of the carrier in the GNSS / IMU module be (R, P, H). Then the coordinates of the mooring point P in the WGS84 Cartesian coordinate system are (X0, Y0, Z0):

[0013]

[0014] In the formula, This is the transformation matrix from the inertial platform coordinate system to the local horizontal reference coordinate system. This is the transformation matrix from the local horizontal reference coordinate system to the WGS84 spatial rectangular coordinate system, where B and L are the latitude and longitude, respectively.

[0015] The coordinates (X1, Y1, Z1) of the elevation point when the sounding hammer touches the water or the bottom in the WGS84 rectangular coordinate system are:

[0016]

[0017] Since the drone moves vertically downwards during water depth measurement, the measured water depth value H is the difference between the elevation of the sounding hammer when it touches the water and the elevation of the sounding hammer when it touches the bottom.

[0018] H = Z 触水时 -Z 触底时 (3)

[0019] Continuous measurements were taken at other measuring points to obtain the underwater elevation and water depth data for all measuring points.

[0020] As one possible implementation of this embodiment, the main control module filters, corrects, and calculates the water depth information based on the changes in tension at the moment the sounding hammer hits the water and touches the bottom, and the relevant data of the sounding hammer.

[0021] The buoy is a small buoy attached to the measuring rope and that floats on the water surface after it falls off. It is used for positioning and retrieval after the sounding hammer falls off.

[0022] The tension sensor is used to accurately measure changes in the tension of the sounding hammer.

[0023] The GNSS / IMU module uses data from shore-based GNSS ground base stations to perform differential and combined navigation calculations on the raw GNSS and IMU data acquired by the UAV to obtain the motion trajectory of the UAV carrier. The motion trajectory of the UAV carrier includes the position and attitude information of the UAV.

[0024] The time synchronization module mainly aligns the time acquired by the GNSS / IMU module with the tension sensor data measured by the main control module to obtain the position of the UAV when the sounding hammer enters the water or touches the bottom.

[0025] The data recording module stores the tensile sensor data, GNSS / IMU-recorded trajectory data, and measurement time data obtained during measurement in real time to facilitate subsequent data analysis.

[0026] The derailment device is located near the traction rope. When the measuring hammer is stuck by an underwater object, the device determines that the measuring hammer has encountered an accident based on the tension data and derails the traction rope.

[0027] As one possible implementation of this embodiment, the specific methods by which the flight control module plans the flight trajectory of the UAV include five route generation methods: cross-sectional scanning route, equidistant line scanning route, uniformly distributed route based on Voronoi polygons, manually planned route, and route imported through KML files.

[0028] As one possible implementation of this embodiment, during the process of generating the cross-section scanning route, the starting, passing and ending positions of the measured route are determined, and a series of waypoints are automatically generated according to the flight altitude and measurement point interval set by the user. Measurement actions can be performed automatically at each waypoint.

[0029] During the process of generating equidistant line scanning routes, the boundary of the measurement area is first determined, and a series of parallel routes are automatically generated based on the measurement line interval, measurement point spacing and flight altitude set by the user.

[0030] In the process of generating routes based on Voronoi polygons, a Voronoi map is generated according to preset measurement points. Each polygon corresponds to a measurement point, and waypoints are generated evenly distributed within these polygons.

[0031] When using the manual route planning method, the location of waypoints is manually specified according to specific measurement needs and regional characteristics;

[0032] When importing flight routes via KML files, flight routes are designed in other software and exported as KML format. These files are then read and the corresponding flight routes are automatically generated.

[0033] As one possible implementation of this embodiment, the measuring rope includes a depth sounding rope with a specification of 6mm, 8mm or 10mm.

[0034] Secondly, an embodiment of the present invention provides a water depth measurement method based on unmanned aerial vehicle (UAV) technology, comprising the following steps:

[0035] Step 1: Plan the flight path for the UAV to conduct water depth measurements;

[0036] Step 2: Perform water depth measurement tasks according to the planned route and obtain measurement data;

[0037] Step 3: Calculate the underwater elevation points and water depth data based on the measurement data, and generate underwater topographic results.

[0038] As one possible implementation of this embodiment, in step 1, the method of planning the route for the UAV to perform water depth measurement includes:

[0039] Generate cross-section scanning route: Determine the start, path and end positions of the measurement route, and automatically generate a series of waypoints according to the flight altitude and measurement point interval set by the user. Measurement actions can be performed automatically at each waypoint.

[0040] Generate equidistant line scanning routes: Determine the boundary of the measurement area and automatically generate a series of parallel routes based on the user-set line intervals, measurement point spacing, and flight altitude;

[0041] Generate a route based on Voronoi polygons. Generate a Voronoi map based on preset measurement points. Each polygon corresponds to a measurement point, and waypoints are generated evenly distributed within these polygons.

[0042] Generate manually planned routes: Manually specify the location of waypoints based on specific measurement needs and regional characteristics;

[0043] Importing flight routes via KML files: Design flight routes in other software and export them as KML format. Read the KML file and automatically generate the corresponding flight route.

[0044] As one possible implementation of this embodiment, step 2 includes the following steps:

[0045] Perform a series of initializations and checks: When the mission starts, check the flight control status of the UAV. If it is found that another mission is already in progress, terminate the launch of the new mission. Check whether the mission contains a valid waypoint. If there is no waypoint, the mission will not start.

[0046] Once the mission officially begins, the starting point of the mission is marked, and the mission is restored to the position of the last interruption as needed. At this time, the mission status is updated to in progress, and a timer is started to periodically update the flight data collected during the mission.

[0047] During the mission, the drone flies to each preset waypoint in sequence, and monitors the flight status between each waypoint to ensure that the drone executes the plan. When the drone reaches a waypoint, it hovers for a few seconds to keep the suspended sounding hammer stable. If the mission is manually aborted during this process, the mission is stopped immediately and safety procedures are followed.

[0048] Each time the drone reaches a waypoint, it monitors and analyzes the data from the tension sensor. If the tension value is detected to be lower than a preset threshold, it will identify potential anomalies and immediately terminate the mission, instructing the drone to return to base. Otherwise, it will control the drone's throttle to begin the descent process, continuously analyzing the tension data during descent to determine if the sounding plumb bob has touched the bottom. When the tension reaches the set threshold, it is considered that the sounding plumb bob has touched the bottom, and the drone stops further descent. During the descent, the drone's altitude is monitored to ensure that it does not fall below the predetermined height above the water surface to avoid touching the water. After confirming that the sounding plumb bob has touched the bottom, the drone hovers briefly to stabilize its position and then begins to ascend until it returns to the preset flight altitude.

[0049] This process of determining waypoints continues until the mission is complete. If a landing point is specified for the mission, the drone will fly to the landing point and land automatically. If no landing point is specified, the drone will return directly to its takeoff position. After the entire mission is completed, the mission status is cleared, and the user is notified that the mission has been completed.

[0050] As one possible implementation of this embodiment, step 3 includes the following steps:

[0051] The tensile data measured by the tensile sensor at the moment when the sounding hammer enters the water and the moment when the tensile data returns to zero upon touching the bottom is filtered.

[0052] The underwater elevation point and water depth data were calculated.

[0053] The time of the measuring hammer's contact with water and bottom is converted into the same time reference through a time synchronization module, and finally, underwater topographic results are generated based on the water depth measurement data.

[0054] As one possible implementation of this embodiment, the specific process of calculating the seabed elevation point and water depth data is as follows:

[0055] Let the coordinate offset between the mooring point P of the measuring rope and the phase center of the GNSS antenna be (Δx, Δy, Δz), and the distance from the lower end of the sounding hammer to the mooring point P be h. Let the coordinates of the GNSS antenna phase center in the WGS84 Cartesian coordinate system when the sounding hammer touches the water or the bottom be (x0, y0, z0). Let the attitude measurement value of the carrier in the GNSS / IMU module be (R, P, H). Then the coordinates of the mooring point P in the WGS84 Cartesian coordinate system are (X0, Y0, Z0):

[0056]

[0057] In the formula, This is the transformation matrix from the inertial platform coordinate system to the local horizontal reference coordinate system. This is the transformation matrix from the local horizontal reference coordinate system to the WGS84 spatial rectangular coordinate system, where B and L are the latitude and longitude, respectively.

[0058] The coordinates (X1, Y1, Z1) of the elevation point when the sounding hammer touches the water or the bottom in the WGS84 rectangular coordinate system are:

[0059]

[0060] Since the drone moves vertically downwards during water depth measurement, the measured water depth value H is the difference between the elevation of the sounding hammer when it touches the water and the elevation of the sounding hammer when it touches the bottom.

[0061] H = Z 触水时 -Z 触底时 (3)

[0062] Continuous measurements were taken at other measuring points to obtain the underwater elevation and water depth data for all measuring points.

[0063] The technical solutions of the embodiments of the present invention can have the following beneficial effects:

[0064] This invention introduces UAV technology to construct a UAV-mounted sounding hammer system for measuring water depth, achieving efficient, accurate, and safe water depth measurement. It has advantages such as simple operation, high measurement accuracy, and strong adaptability.

[0065] This invention enables the drone to quickly reach the measurement area, improving measurement efficiency, reducing manpower and material resources, and shortening the measurement cycle. Through high-precision sensors and a data processing system, this invention ensures the accuracy and reliability of measurement results, improving the precision of water depth measurement. The drone's flexible flight, unrestricted by terrain or water conditions, makes it suitable for water depth measurement in various complex environments, enhancing its adaptability. Furthermore, this invention allows measurement work to be completed without personnel entering hazardous areas, improving operational safety and reducing safety risks. This drone-mounted sounding hammer system has significant technical advantages and application prospects, and will bring revolutionary changes to water depth measurement work in fields such as water conservancy, oceanography, and geological exploration. Attached Figure Description

[0066] Figure 1 This is a schematic diagram illustrating a water depth measurement device based on unmanned aerial vehicle (UAV) technology according to an exemplary embodiment;

[0067] Figure 2 This is a schematic diagram of a depth sounding control module according to an exemplary embodiment;

[0068] Figure 3 This is a flowchart illustrating a water depth measurement method based on unmanned aerial vehicle (UAV) technology according to an exemplary embodiment;

[0069] Figure 4 This is a flowchart illustrating a specific implementation of a depth sounding and positioning process according to an exemplary embodiment. Detailed Implementation

[0070] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0071] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components, processing techniques, and processes are omitted in this invention to avoid unnecessarily limiting the invention.

[0072] like Figure 1As shown in the figure, an embodiment of the present invention provides a water depth measurement device based on UAV technology, including a sounding hammer 1, a measuring rope 2, a buoy 3, a swing damper 7, a depth control module 4, and a UAV platform 5. The sounding hammer 1 is located at the lower end of the measuring rope 2, and the upper end of the measuring rope 2 is located at the bottom of the buoy 3. The depth control module 4 is located at the bottom of the UAV platform 5, and the bottom of the depth control module 4 is connected to the top of the buoy 3 via a traction rope 6. The swing damper 7 is attached to the measuring rope and is used to reduce the swing amplitude and stabilization time of the sounding hammer caused by UAV movement and environmental factors.

[0073] The unmanned aerial vehicle (UAV) platform uses a multi-rotor UAV suitable for carrying heavy loads and with good stability as the carrier. It is equipped with a high-precision GNSS positioning system, an attitude stabilization device, and a flight control module. The attitude stabilization device and the high-precision GNSS positioning system ensure the stability and accuracy of the UAV during flight, while the flight control module is responsible for the UAV's flight trajectory planning and stable control.

[0074] This invention uses a drone to carry a sounding hammer for precise water depth measurement, and has the advantages of simple operation, high measurement accuracy, and strong adaptability.

[0075] The drone-mounted sounding hammer system can plan a reasonable flight route and measurement points according to the survey area. After the drone reaches the target point, it begins to descend. When the sounding hammer touches the water surface, the tension will change. When the sounding hammer touches the bottom of the water, the tension will approach zero. When the point measurement is completed, the tension data is recorded throughout the process.

[0076] By combining RTK positioning data from drones, the underwater elevation and depth data of the test point are obtained through tensile data analysis.

[0077] Due to the varied underwater topography in shallow water areas, and considering that if the weight gets stuck, the drone may be unable to detach and cause significant equipment damage, the system has been equipped with an automatic detachment device to ensure the safety of the drone and equipment in the event of an accident.

[0078] Regarding the impact of the environment on the measurement results, due to swaying and wind, the survey line is generally not in a vertical state during actual operations. However, when the drone is stationary and the wind is light, the survey line can be in a vertical state. Considering that the weight can quickly come to a stop after entering the water due to water damping, and that the guy wire is very thin and light and is less affected by the wind (the wire length is generally 5-10 meters), the plane offset of the weight is not large, and it has little impact on the accuracy of the underwater topographic data. Therefore, this impact will not be considered for the time being.

[0079] like Figure 2As shown, the depth sounding control module includes a main control module, a GNSS / IMU module, a tension sensor, a time synchronization module, a data recording module, and a wire-removal device. The main control module is connected to the GNSS / IMU module, the tension sensor, the data recording module, the wire-removal device, and the UAV platform. The time synchronization module is connected to the main control module, the GNSS / IMU module, and the tension sensor. The GNSS / IMU module is connected to a high-precision GNSS positioning system. The depth sounding control module integrates time synchronization, data recording, and the main control module onto a single board, with a unified design, layout, and manufacturing process. The main control module contains a microcontroller or a micro-control circuit. Its interfaces primarily connect to the GNSS / IMU module interface (or the GNSS / IMU data interface provided by the UAV), the tension data interface, the wire-removal device interface, the UAV flight control module communication interface, and the power interface. The GNSS / IMU module interface is connected to the feed port of the GNSS antenna, providing real-time, high-precision position and attitude information for the UAV.

[0080] The main control module filters, corrects, and calculates the water depth information based on the changes in tension at the moment the sounding hammer hits the water and touches the bottom, as well as the relevant data from the sounding hammer.

[0081] The tension sensor can accurately measure changes in tension with a measurement error of less than 0.15%. It can detect changes in tension when the sounding hammer enters the water and when the tension approaches zero at the bottom of the water in a timely and accurate manner.

[0082] The time synchronization module mainly aligns the time acquired by the GNSS / IMU module with the tension sensor data measured by the main control module to obtain the UAV's position when the sounding hammer enters the water or touches the bottom.

[0083] The data recording module stores the tension sensor data, GNSS / IMU-recorded trajectory data, and measurement time data obtained during measurement in real time for later data analysis.

[0084] The derailment device is located near the traction rope. When the measuring hammer is stuck by an underwater object, the device determines that the measuring hammer has encountered an accident based on the tension data and derails the traction rope.

[0085] The sounding hammer can be a lightweight and sturdy type.

[0086] The buoy is a small buoy attached to the measuring rope and that floats on the water surface after detachment. It is used for positioning and retrieval after the sounding hammer falls off.

[0087] This invention can also support route planning, real-time measurement data visualization, data recording and storage, and can display measurement results in the form of charts, making it convenient for users to analyze and apply them.

[0088] As one possible implementation of this embodiment, the GNSS / IMU module utilizes a shore-based GNSS ground station to perform differential and combined navigation calculations on the raw GNSS and IMU data acquired by the UAV to obtain high-precision carrier motion trajectory and attitude, including position and attitude information. If the UAV itself has a GNSS / IMU positioning and attitude determination module, it can access the high-precision motion trajectory data through the UAV communication interface. The main control module filters the tension data measured by the tension sensor at the moment when the sounding hammer enters the water due to buoyancy and when the tension data returns to zero upon touching the bottom, and calculates the bottom elevation point and water depth data. At the same time, the obtained hammer contact time and bottom contact time are converted to the same time reference (generally GNSS time) through the time synchronization module. Finally, underwater topographic results are generated based on the water depth measurement data.

[0089] As one possible implementation of this embodiment, the process by which the main control module calculates the underwater elevation point and water depth data is as follows:

[0090] Let the coordinate offset between the mooring point P of the measuring rope and the phase center of the GNSS antenna be (Δx, Δy, Δz), and the distance from the lower end of the sounding hammer to the mooring point P be h, where h includes the length of the sounding hammer, the length of the measuring rope, the height of the buoy, and the length of the traction rope. Let the coordinates of the GNSS antenna phase center in the WGS84 Cartesian coordinate system when the sounding hammer touches the water or the bottom be (x0, y0, z0), and the attitude measurement value of the carrier in the GNSS / IMU module be (R, P, H). Then, the coordinates of the mooring point P in the WGS84 Cartesian coordinate system are (X0, Y0, Z0).

[0091]

[0092] In the formula, This is the transformation matrix from the inertial platform coordinate system to the local horizontal reference coordinate system. This is the transformation matrix from the local horizontal reference coordinate system to the WGS84 spatial rectangular coordinate system, where B and L are the latitude and longitude, respectively.

[0093] The coordinates (X1, Y1, Z1) of the elevation points on the water surface (when the sounding hammer touches the water) or the water bottom (when the sounding hammer touches the bottom) in the WGS84 rectangular coordinate system are:

[0094]

[0095] Specifically, the coordinates (X, Y) of the water surface (at contact with water) elevation point in the WGS84 spatial rectangular coordinate system. 触水时 ,Y 触水时 Z 触水时 )for:

[0096]

[0097] The coordinates (X, Y) of the elevation point at the bottom (when touching the bottom) in the WGS84 rectangular coordinate system 触底时 ,Y 触底时 Z 触底时 )for:

[0098]

[0099] Since the UAV moves vertically downwards during water depth measurement, its planar coordinate changes are small and negligible. Therefore, the measured water depth value H is the difference between the elevation of the sounding hammer when it touches the water and the elevation when it touches the bottom.

[0100] H = Z 触水时 -Z 触底时 (3)

[0101] Continuous measurements were taken at other measuring points to obtain the underwater elevation and water depth data for all measuring points.

[0102] As one possible implementation of this embodiment, the specific methods for the flight control module to plan the flight trajectory of the UAV include five route generation methods: cross-sectional scanning route, equidistant line scanning route, uniformly distributed route based on Voronoi polygons, manually planned route, and route imported through KML files.

[0103] During the process of generating the cross-section scanning route, the starting, passing and ending positions of the measurement route are determined, and a series of waypoints are automatically generated according to the flight altitude and measurement point interval set by the user. Measurement actions can be performed automatically at each waypoint. The cross-section scanning route is suitable for underwater topographic measurement of river cross sections.

[0104] During the generation of equidistant line scanning routes, the boundary of the measurement area is first determined, and a series of parallel routes are automatically generated based on the measurement line interval, measurement point spacing and flight altitude set by the user. The equidistant line scanning routes are suitable for underwater topographic measurement of area.

[0105] In the process of generating routes based on Voronoi polygons, a Voronoi map is generated according to the preset measurement points. Each polygon corresponds to a measurement point, and waypoints are generated evenly distributed within these polygons. Routes based on Voronoi polygons can ensure that the routes are evenly distributed throughout the entire area, making the sampling of measurement points more uniform. It is suitable for tasks that require high precision and uniform data distribution, and is suitable for underwater topographic measurement of area.

[0106] When using the manual route planning method, the location of waypoints is manually specified according to specific measurement needs and regional characteristics. The manual route planning method is the most flexible and suitable for special task scenarios that require precise control.

[0107] When importing flight paths via KML files, the flight path is designed in other software and exported as KML format. These files are then read and the corresponding flight paths are automatically generated. This method allows users to perform more complex planning in external tools and apply the results directly to drone missions.

[0108] Flight path generation is a crucial logical component of the application, responsible for planning how the UAV should move during mission execution to ensure effective coverage of the measurement area and acquisition of necessary data. When generating the flight path, the UAV's flight altitude, speed, distances between waypoints, and other parameters must be considered to ensure the path meets measurement requirements while guaranteeing safe and efficient flight execution. Once the flight path is generated, the system saves the data for use in subsequent missions.

[0109] As one possible implementation of this embodiment, the measuring rope includes a depth sounding rope with a specification of 6mm, 8mm or 10mm.

[0110] like Figure 3 As shown in the figure, an embodiment of the present invention provides a water depth measurement method based on UAV technology, which includes the following steps:

[0111] Step 1: Plan the flight path for the UAV to conduct water depth measurements;

[0112] Step 2: Perform water depth measurement tasks according to the planned route and obtain measurement data;

[0113] Step 3: Calculate the underwater elevation points and water depth data based on the measurement data, and generate underwater topographic results.

[0114] As one possible implementation of this embodiment, in step 1, the method of planning the route for the UAV to perform water depth measurement includes the following optional methods:

[0115] Generate cross-section scanning route: Determine the start, path and end positions of the measurement route, and automatically generate a series of waypoints according to the flight altitude and measurement point interval set by the user. Measurement actions can be performed automatically at each waypoint.

[0116] Generate equidistant line scanning routes: Determine the boundary of the measurement area and automatically generate a series of parallel routes based on the user-set line intervals, measurement point spacing, and flight altitude;

[0117] Generate a route based on Voronoi polygons. Generate a Voronoi map based on preset measurement points. Each polygon corresponds to a measurement point, and waypoints are generated evenly distributed within these polygons.

[0118] Generate manually planned routes: Manually specify the location of waypoints based on specific measurement needs and regional characteristics;

[0119] Importing flight routes via KML files: Design flight routes in other software and export them as KML format. Read the KML file and automatically generate the corresponding flight route.

[0120] Cross-section scanning routes are suitable for underwater topographic surveying of river cross sections; equidistant line scanning routes are suitable for underwater topographic surveying of planar areas; routes based on Voronoi polygons can ensure that the route is evenly distributed throughout the entire area, making the sampling of measurement points more uniform, suitable for tasks requiring high precision and uniform data distribution, and suitable for underwater topographic surveying of planar areas; manually planning and generating routes offers the highest flexibility and is suitable for special task scenarios requiring precise control; importing routes via KML files allows users to perform more complex planning in external tools and directly apply the results to UAV missions.

[0121] Flight path generation is a crucial logical component of the application, responsible for planning how the UAV should move during mission execution to ensure effective coverage of the measurement area and acquisition of necessary data. When generating the flight path, the UAV's flight altitude, speed, distances between waypoints, and other parameters must be considered to ensure the path meets measurement requirements while guaranteeing safe and efficient flight execution. Once the flight path is generated, the system saves the data for use in subsequent missions.

[0122] As one possible implementation of this embodiment, step 2 includes the following steps:

[0123] Perform a series of initializations and checks: When the mission starts, check the flight control status of the UAV. If it is found that another mission is already in progress, terminate the launch of the new mission. Check whether the mission contains a valid waypoint. If there is no waypoint, the mission will not start.

[0124] Once the mission officially begins, the starting point of the mission is marked, and the mission is restored to the position of the last interruption as needed. At this time, the mission status is updated to in progress, and a timer is started to periodically update the flight data collected during the mission. This data will be used to monitor the mission progress in real time.

[0125] During the mission, the drone flies to each preset waypoint in sequence, and monitors the flight status between each waypoint to ensure that the drone executes the plan. When the drone reaches a waypoint, it hovers for a few seconds to keep the suspended sounding hammer stable. If the mission is manually aborted during this process, the mission is stopped immediately and safety procedures are followed.

[0126] Each time the drone reaches a waypoint, it monitors and analyzes the data from the tension sensor. If the tension value is detected to be lower than a preset threshold, it will identify potential anomalies and immediately terminate the mission, instructing the drone to return to base. Otherwise, it will control the drone's throttle to begin the descent process, continuously analyzing the tension data during descent to determine if the sounding plumb bob has touched the bottom. When the tension reaches the set threshold, it is considered that the sounding plumb bob has touched the bottom, and the drone stops further descent. During the descent, the drone's altitude is monitored to ensure that it does not fall below the predetermined height above the water surface to avoid touching the water. After confirming that the sounding plumb bob has touched the bottom, the drone hovers briefly to stabilize its position and then begins to ascend until it returns to the preset flight altitude.

[0127] This process of determining waypoints continues until the mission ends. If a landing point is specified for the mission, the drone will fly to the landing point and land automatically. If no landing point is specified, the drone will return directly to its takeoff position. After the entire mission is completed, the mission status is cleared, and the user is notified that the mission is complete. At the same time, the timer will be canceled at the end of the mission, stopping data updates and recording.

[0128] The entire water depth measurement mission fully considered safety during mission execution and real-time data monitoring to ensure that the UAV could complete the mission safely and accurately.

[0129] As one possible implementation of this embodiment, step 3 includes the following steps:

[0130] The tensile data measured by the tensile sensor at the moment when the sounding hammer enters the water and the moment when the tensile data returns to zero upon touching the bottom is filtered.

[0131] The underwater elevation points and water depth data were calculated.

[0132] The time of the measuring hammer's contact with water and bottom is converted into the same time reference through a time synchronization module, and finally, underwater topographic results are generated based on the water depth measurement data.

[0133] As one possible implementation of this embodiment, such as Figure 4 As shown, the specific process for calculating the underwater elevation point and water depth data is as follows:

[0134] Let the coordinate offset between the mooring point P of the measuring rope and the phase center of the GNSS antenna be (Δx, Δy, Δz), and the distance from the lower end of the sounding hammer to the mooring point P be h, where h includes the length of the sounding hammer, the length of the measuring rope, the height of the buoy, and the length of the traction rope. Let the coordinates of the GNSS antenna phase center in the WGS84 Cartesian coordinate system when the sounding hammer touches the water or the bottom be (x0, y0, z0), and the attitude measurement value of the carrier in the GNSS / IMU module be (R, P, H). Then, the coordinates of the mooring point P in the WGS84 Cartesian coordinate system are (X0, Y0, Z0).

[0135]

[0136] In the formula, This is the transformation matrix from the inertial platform coordinate system to the local horizontal reference coordinate system. This is the transformation matrix from the local horizontal reference coordinate system to the WGS84 spatial rectangular coordinate system, where B and L are the latitude and longitude, respectively.

[0137] The coordinates (X1, Y1, Z1) of the elevation points on the water surface (when the sounding hammer touches the water) or the water bottom (when the sounding hammer touches the bottom) in the WGS84 rectangular coordinate system are:

[0138]

[0139] Specifically, the coordinates (X, Y) of the water surface (at contact with water) elevation point in the WGS84 spatial rectangular coordinate system. 触水时 ,Y 触水时 Z 触水时 )for:

[0140]

[0141] The coordinates (X, Y) of the elevation point at the bottom (when touching the bottom) in the WGS84 rectangular coordinate system 触底时 ,Y 触底时 Z 触底时 )for:

[0142]

[0143] Since the UAV moves vertically downwards during water depth measurement, its planar coordinate changes are small and negligible. Therefore, the measured water depth value H is the difference between the elevation of the sounding hammer when it touches the water and the elevation when it touches the bottom.

[0144] H = Z 触水时 -Z 触底时 (3)

[0145] Continuous measurements were taken at other measuring points to obtain the underwater elevation and water depth data for all measuring points.

[0146] This invention uses a drone to carry a sounding hammer for precise water depth measurement, and has the advantages of simple operation, high measurement accuracy, and strong adaptability.

[0147] The drone-mounted sounding hammer system can plan a reasonable flight route and measurement points according to the survey area. After the drone reaches the target point, it begins to descend. When the sounding hammer touches the water surface, the tension will change. When the sounding hammer touches the bottom of the water, the tension will approach zero. When the point measurement is completed, the tension data is recorded throughout the process.

[0148] By combining RTK positioning data from drones, the underwater elevation and depth data of the test point are obtained through tensile data analysis.

[0149] Due to the varied underwater topography in shallow water areas, and considering that if the weight gets stuck, the drone may be unable to detach and cause significant equipment damage, the system has been equipped with an automatic detachment device to ensure the safety of the drone and equipment in the event of an accident.

[0150] Regarding the impact of the environment on the measurement results, due to swaying and wind, the survey line is generally not in a vertical state during actual operations. Considering that the weight can quickly come to a stop after entering the water due to water damping, and that the guy wire is very thin and light, with minimal wind influence (the wire length is generally 5-10 meters), the horizontal displacement of the weight is not significant, and its impact on the accuracy of underwater topographic data is minimal. Therefore, this impact will not be considered for the time being.

[0151] This invention has the following advantages over traditional methods:

[0152] Improve measurement efficiency: Drones can quickly reach the measurement area, reducing the investment of manpower and resources and shortening the measurement cycle.

[0153] Improve measurement accuracy: Ensure the accuracy and reliability of measurement results through high-precision sensors and data processing systems.

[0154] Enhanced adaptability: UAVs are flexible in flight and are not limited by terrain and water conditions, making them suitable for water depth measurement in various complex environments.

[0155] Reduced safety risks: Personnel can complete measurement work without entering dangerous areas, improving operational safety.

[0156] In summary, the UAV-mounted sounding hammer sounding system of the present invention has significant technical advantages and application prospects, and will bring revolutionary changes to water depth measurement work in fields such as water conservancy, oceanography, and geological exploration.

[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A water depth measuring device based on unmanned aerial vehicle technology, characterized in that, The depth measuring system comprises a sounding weight, a measuring rope, a float, a swing damper, a depth control module and a UAV platform, the sounding weight is arranged at the lower end of the measuring rope, the upper end of the measuring rope is arranged at the bottom of the float, the depth control module is arranged at the bottom of the UAV platform, and the bottom of the depth control module is connected with the top of the float through a traction rope; the swing damper is connected to the measuring rope, and is used for reducing the swing amplitude and the recovery time of the sounding weight caused by the movement of the UAV and environmental factors; The UAV platform is equipped with a high-precision GNSS positioning system, an attitude stabilizing device and a flight control module, the attitude stabilizing device and the high-precision GNSS positioning system ensure the stability and accuracy of the UAV during flight, and the flight control module is responsible for flight trajectory planning and stable control of the UAV; whenever the UAV reaches a waypoint, it hovers for a few seconds to keep the suspended sounding weight stable, and monitors and analyzes the data of the tension sensor; If the detected tension value is lower than the preset threshold value, it is judged that an abnormal situation may occur, and the task is immediately suspended when the abnormal situation occurs, and the UAV is instructed to return; otherwise, the throttle of the UAV is controlled to start the descending process, the tension data is continuously analyzed during the descending process, and it is judged whether the sounding weight has reached the bottom; when the tension reaches the set threshold value, it is considered that the sounding weight has reached the bottom, and the further descent of the UAV is stopped; during the descending process, the height of the UAV is monitored and it is ensured that the height will not be lower than the predetermined height above the water surface, so as to avoid touching the water surface; after it is determined that the sounding weight has reached the bottom, the UAV hovers for a moment to stabilize the position, and then starts to ascend until it returns to the preset flight height; The depth control module comprises a main control module, a GNSS / IMU module, a tension sensor, a time synchronization module, a data recording module and a line cutting device, the main control module is connected with the GNSS / IMU module, the tension sensor, the data recording module, the line cutting device and the UAV platform respectively, the time synchronization module is connected with the main control module, the GNSS / IMU module and the tension sensor respectively, and the GNSS / IMU module is connected with the high-precision GNSS positioning system; the line cutting device is arranged near the traction rope, and when the measuring weight is stuck by an underwater object, the line cutting device is used for judging that the measuring weight is in an accident according to the tension data and cutting the traction rope; The GNSS / IMU module utilizes a shore-based GNSS ground station to perform differential and combined navigation calculation on the GNSS and IMU raw data obtained by the UAV, so as to obtain a high-precision carrier motion trajectory and attitude; the main control module performs filtering processing on the tension data measured by the tension sensor when the tension data suddenly changes due to buoyancy when the sounding weight enters water and when the tension data is zero at the moment when the sounding weight reaches the bottom, calculates water bottom elevation points and water depth data, converts the sounding weight water entering time and the sounding weight bottom reaching time into the same time reference through the time synchronization module, and finally generates an underwater geological result according to the water depth measurement data; The process of calculating the water bottom elevation points and the water depth data by the main control module is as follows: Let the cable mooring base point position P of the measuring rope and the GNSS antenna phase center coordinate offset be (Δx, Δy, Δz), the distance from the lower end of the sounding weight to the mooring base point position P be h, and let the coordinates of the GNSS antenna phase center in the WGS84 space rectangular coordinate system when the sounding weight touches water or the bottom be (x0, y0, z0), the attitude measurement value of the carrier coordinate system measured by the GNSS / IMU module be (R, P, H), and the coordinates (X0, Y0, Z0) of the mooring base point position P in the WGS84 space rectangular coordinate system be: wherein is the inertial platform coordinate system to local horizontal reference coordinate system transformation matrix, is the conversion matrix from the local horizontal reference coordinate system to the WGS84 spatial rectangular coordinate system, and B and L are the latitude and longitude, respectively; The coordinates (X1, Y1, Z1) of the elevation point when the sounding weight touches water or the bottom in the WGS84 space rectangular coordinate system are: Since the unmanned aerial vehicle measures water depth vertically from top to bottom at this time, the water depth value H measured is the difference between the elevation when the sounding weight touches water and the elevation when the sounding weight touches the bottom: H = Z 触水时 - Z 触底时 (3) Continuous measurement is performed on other measurement points to obtain the water bottom elevation points and water depth data of all measurement points.

2. The water depth measuring device based on UAV technology according to claim 1, characterized in that, The specific way in which the flight control module plans the flight trajectory of the unmanned aerial vehicle includes five flight path generation methods: cross-section scanning flight path, equidistant line scanning flight path, uniform distribution flight path based on Voronoi polygon, manually planned flight path, and flight path imported through KML file. 3.The water depth measuring device based on UAV technology according to claim 2, characterized in that, In the cross-section scanning flight path generation process, the starting, passing, and ending positions of the measurement flight path are determined, and a series of waypoints are automatically generated according to the user-set flight height and measurement point interval, and measurement actions can be performed at each waypoint; In the equidistant line scanning flight path generation process, the boundary of the measurement area is first determined, and a series of parallel flight paths are automatically generated according to the user-set measurement line interval, measurement point interval, and flight height; In the flight path generation process based on Voronoi polygon, a Voronoi diagram is generated according to the pre-set measurement points, each polygon corresponds to a measurement point, and uniform distribution waypoints are generated within these polygons; When the manually planned flight path generation method is used, the positions of the waypoints are manually specified according to specific measurement requirements and regional characteristics; When the flight path is imported through the KML file, the flight path is designed in other software and exported in KML format, and the corresponding flight path is automatically generated by reading the files in this format.

4. A method for measuring water depth based on the unmanned aerial vehicle technology using the device for measuring water depth based on the unmanned aerial vehicle technology according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: Step 1: planning the flight path of the unmanned aerial vehicle for water depth measurement; Step 2: performing the water depth measurement task according to the planned flight path to obtain measurement data; Step 3: calculating the water bottom elevation points and water depth data according to the measurement data, and generating underwater geological results; In step 1, the way in which the flight path of the unmanned aerial vehicle for water depth measurement is planned includes: Generating a cross-section scanning flight path: determining the starting, passing, and ending positions of the measurement flight path, and automatically generating a series of waypoints according to the user-set flight height and measurement point interval, and measurement actions can be performed at each waypoint; Generating an equidistant line scanning flight path: determining the boundary of the measurement area, and automatically generating a series of parallel flight paths according to the user-set measurement line interval, measurement point interval, and flight height; Generating a route based on Voronoi polygons, generating a Voronoi diagram according to a preset measuring point, each polygon corresponding to a measuring point, and generating evenly distributed waypoints within the polygons; Generating a manually planned route: manually specifying the location of the waypoints according to specific measurement requirements and regional characteristics; Importing a route through a KML file: designing a route in other software and exporting it in KML format, reading the KML format file and automatically generating the corresponding route; The step 2 comprises the following steps: A series of initializations and checks are performed: when the task starts, the flight control state of the UAV is checked, and if it is found that there is already another task being performed, the start of the new task is terminated, and the task is checked to see if it contains valid waypoints, if there are no waypoints, the task will not start; After the task officially starts to execute, the starting point of the task is marked, and the position at the last interruption is recovered as needed; at this time, the task state is updated to in progress, and a timer is started to update the flight data collected during the task process periodically; During the execution of the task, the UAV flies to each preset waypoint in turn, and between each waypoint, the flight state is monitored to ensure that the UAV executes according to the plan; when the UAV reaches a certain waypoint, it hovers for a few seconds to keep the suspended depth probe stable; if the task is manually interrupted during this process, the task is immediately stopped and safety processing is performed; Whenever the UAV reaches a waypoint, the data of the tension sensor is monitored and analyzed; if the tension value is detected to be lower than the preset threshold, it will be judged that an abnormal situation may occur, and the task will be immediately terminated and the UAV will be instructed to return; otherwise, the UAV throttle is controlled to start the descent process, and the tension data is continuously analyzed during the descent process to determine whether the depth probe has reached the bottom; when the tension reaches the set threshold, it is considered that the depth probe has reached the bottom, and the UAV is stopped from further descending; during the descent process, the height of the UAV is monitored to ensure that it does not fall below the predetermined height above the water surface to avoid touching the water surface; after it is determined that the depth probe has reached the bottom, the UAV hovers for a moment to stabilize the position, and then starts to ascend until it returns to the preset flight height; This way, each waypoint is measured until the task is completed; if a landing point is specified, the UAV will fly to the landing point and perform automatic landing; if no landing point is specified, the UAV will directly return to the takeoff position; after the entire task is completed, the task state is cleaned up, and the user is notified that the task has been completed; The step 3 comprises the following steps: Filtering the tension sensor measurement tension data when the tension data suddenly changes due to buoyancy when the depth probe enters the water and when the tension data returns to zero when the depth probe reaches the bottom; Calculating the water bottom elevation point and water depth data; Converting the obtained depth probe water entry and bottom touch time into the same time reference through a time synchronization module, and finally generating an underwater geological result according to the water depth measurement data. 5.The water depth measurement method based on UAV technology according to claim 4, characterized in that, The specific process of calculating the water bottom elevation point and water depth data is: Let the cable mooring base point position P of the measuring rope and the GNSS antenna phase center coordinate offset be (Δx, Δy, Δz), the distance from the lower end of the sounding weight to the mooring base point position P be h, and let the coordinates of the GNSS antenna phase center in the WGS84 space rectangular coordinate system when the sounding weight touches the water or the bottom be (x0, y0, z0), the attitude measurement value of the carrier coordinate system measured by the GNSS / IMU module be (R, P, H), and the coordinates (X0, Y0, Z0) of the mooring base point position P in the WGS84 space rectangular coordinate system be: wherein is the inertial platform coordinate system to local horizontal reference coordinate system transformation matrix, is the conversion matrix from the local horizontal reference coordinate system to the WGS84 spatial rectangular coordinate system, and B and L are the latitude and longitude, respectively; The coordinates (X1, Y1, Z1) of the elevation point when the sounding weight touches the water or the bottom in the WGS84 space rectangular coordinate system are: Since the unmanned aerial vehicle measures water depth vertically from top to bottom at this time, the measured water depth value H is the difference between the elevation when the sounding weight touches the water and the elevation when the sounding weight touches the bottom: H = Z 触水时 - Z 触底时 (3) Continuous measurement is performed on other measurement points to obtain the water bottom elevation point and water depth data of all measurement points.

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