Device and method for detecting tidal current energy potential of offshore narrow water channel by using underwater unmanned aerial vehicle

Abstract

A device for detecting tidal current energy potential of an offshore narrow water channel through an underwater unmanned aerial vehicle comprises the underwater unmanned aerial vehicle capable of being operated in a remote control mode, a flow velocity detector used for measuring the flow velocity of seawater is arranged on the top of the underwater unmanned aerial vehicle, and the flow velocity detector comprises a main support vertically installed on the underwater unmanned aerial vehicle. A plurality of transverse supports which are transversely arranged are sequentially installed on the main support from top to bottom, and a plurality of propeller type flow meters are installed on the transverse supports. The invention further provides a method for detecting the tidal current energy potential of the offshore narrow water channel through the underwater unmanned aerial vehicle, the flow velocity and tidal current energy of offshore multilayer seawater can be efficiently and accurately detected, and the method has important significance in improving the accuracy and efficiency of marine environment detection and developing the tidal current energy.

Description

Technical Field

[0001] The present invention relates to the technical field of water current energy detection, in particular to a device for detecting the potential of tidal current energy in narrow offshore waterways by an underwater drone, and also relates to a method for detecting the potential of tidal current energy in narrow offshore waterways by an underwater drone. Background Art

[0002] Tidal current energy is a kinetic energy resource contained in the periodic flow of seawater caused by the gravitational action of the moon and the sun, and has great development potential. However, the development of tidal current energy faces a series of technical challenges. The tidal current velocity vector field has significant vertical stratification characteristics. As the water depth increases, the flow velocity generally shows a decreasing dynamic characteristic. This shear flow effect has a dual impact on the development of tidal current energy: on the one hand, the high-flow velocity water body near the surface contains rich kinetic energy resources; on the other hand, the vertical gradient change directly affects the load distribution of the water turbine unit. Therefore, accurately obtaining the flow velocity profile data of multiple depth layers has become a key technical link in the development of tidal current energy.

[0003] In order to obtain flow velocity data, some technologies have been applied to the field of tidal current energy development. For example, a complementary method for observing water body flow fields at multiple spatial scales with the authorization patent number CN201910413123.0 combines various means such as an ADCP current meter, a drone, and a GPS buoy. The vertical flow velocity distribution of the water body at the location of the instrument is obtained through the ADCP current meter, the drone tracks and photographs tracer particles to obtain a relatively fine surface flow field map of the local water body, and the coordinate feedback of the GPS buoy is used to obtain the surface flow field map of the entire water body. However, this technology has many defects: a large number of measuring instruments need to be placed, which are easy to lose and troublesome to recover later; the signal reception is unstable and the data is easy to be distorted; and the tidal current energy calculation data cannot be obtained in real time.

[0004] Another technology is a hydrological monitoring method and system based on an intelligent current measuring robot with the authorization patent number CN202111187506.4. This method obtains the basic information of the intelligent current measuring robot, dynamically draws the number of monitoring points, and starts the intelligent current measuring robot to obtain the status message and measurement data in real time. However, this technology also has certain defects: the installation and maintenance are relatively troublesome; it can only measure the fluid velocity of a fixed river section, and can only measure the flow velocity at the place where the river contacts the river channel, and cannot determine the difference in the flow velocity inside the fluid.

[0005] In summary, although the existing tidal current energy development technologies have made certain progress, there are still many deficiencies and need to be further improved and innovated. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide, in view of the deficiencies of the prior art, an underwater drone detection device for the tidal energy potential of narrow offshore waterways, which can efficiently and accurately detect the flow velocity of multi-layer seawater in the offshore area and tidal energy, and is of great significance for improving the accuracy and efficiency of marine environment detection and the development of tidal energy.

[0007] Another technical problem to be solved by the present invention is to provide a method for detecting the tidal energy potential of narrow offshore waterways by an underwater drone.

[0008] The technical problem to be solved by the present invention is achieved through the following technical solutions. The present invention is an underwater drone detection device for the tidal energy potential of narrow offshore waterways. The device includes a remotely operable underwater drone. At the top of the underwater drone, a flow velocity detector for measuring the seawater flow velocity is equipped. The flow velocity detector includes a main bracket vertically installed on the underwater drone. On the main bracket, a number of horizontally arranged transverse brackets are successively installed from top to bottom. On each transverse bracket, a number of propeller-type flow meters are installed.

[0009] The technical problem to be solved by the present invention can also be further achieved through the following technical solutions. For the above-mentioned underwater drone detection device for the tidal energy potential of narrow offshore waterways, a lighting lamp, a camera, a propeller and a thruster are also installed on the underwater drone. The thruster includes 4 groups of brushless ducted thrusters, which are used to support six-degree-of-freedom motion, including forward, backward, ascending, descending, lateral movement, pitching, yawing and rolling.

[0010] The technical problem to be solved by the present invention can also be further achieved through the following technical solutions. For the above-mentioned underwater drone detection device for the tidal energy potential of narrow offshore waterways, the internal core part of the underwater drone is sealed with acrylic tubes and epoxy resin, and a double-layer O-shaped silica gel ring is provided at the cabin joint.

[0011] The technical problem to be solved by the present invention can also be further achieved through the following technical solutions. For the above-mentioned underwater drone detection device for the tidal energy potential of narrow offshore waterways, the flow velocity detector further includes a data processing, storage and transmission integrated box installed on the main bracket. A data interface for connecting with the underwater drone is provided on the data processing, storage and transmission integrated box, and a cable socket matching the data interface is provided on the underwater drone.

[0012] The technical problem to be solved by the present invention can also be further achieved through the following technical solutions. For the above-mentioned underwater drone detection device for the tidal energy potential of narrow offshore waterways, the flow velocity detector is connected to the top of the underwater drone through a snap-type mechanical interface.

[0013] The technical problem to be solved by the present invention can also be further achieved through the following technical solutions. For the above-mentioned underwater UAV device for detecting tidal energy potential in offshore narrow waterways, there are two transverse brackets, which are respectively installed on the top and the middle of the main bracket. Each transverse bracket is provided with three propeller current meters. The three propeller current meters on the same transverse bracket are respectively installed on both sides and the middle of the transverse bracket, which are used for two-layer flow velocity observation and three vertical section flow velocity detection.

[0014] The technical problem to be solved by the present invention can also be further achieved through the following technical solutions. For the underwater drone device for detecting tidal energy potential in offshore narrow waterways described above, the underwater drone adopts a modular structure as a whole and has a built-in high-energy-density lithium battery pack.

[0015] The technical problem to be solved by the present invention can be further achieved by the following technical solutions. For the above-mentioned underwater drone detection of tidal energy potential in offshore narrow waterways, a method for underwater drone detection of tidal energy potential in offshore narrow waterways is provided, and the steps are as follows:

[0016] (1) Assemble the detection device based on the tidal flat characteristics and environmental characteristics of the observation area

[0017] Consult the nautical charts of the observation area and conduct on-site investigations to understand the approximate depth and flow rate of the target strait waterway, ensure that the battery has sufficient power, assemble the underwater drone, conduct laboratory tests on the underwater drone to ensure good performance, test the flow rate detector, and conduct indoor tests on flow rate collection, data calculation, data storage, and data transmission;

[0018] (2) Deploy the device to the target sea area

[0019] Place an underwater drone in seawater, remotely control the drone, deploy it at a specific water depth, detect the tidal energy potential at a specific water depth, and observe the tidal energy at a specific cross section;

[0020] (3) By remotely controlling the position of underwater drones, tidal current energy can be observed at different sections and water depths;

[0021] (4) Maintenance and recovery device

[0022] After the detection is completed, the underwater drone is recovered by remote control and maintenance is carried out.

[0023] The technical problem to be solved by the present invention can also be further realized by the following technical solutions. For the method for detecting the tidal current energy potential of narrow offshore waterways by an underwater drone described above, this method is used to observe the tidal current energy of multi-layer seawater in the offshore area. Multiple-point flow velocity observations are carried out by a sectional multi-layer flow velocity detector, and the average value is taken, and then the tidal current energy is further calculated. Specifically:

[0024] Estimate the tidal current energy through the seawater flow velocity measured in real time. The tidal current energy is expressed by the tidal current energy density, and its calculation formula is:

[0025]

[0026] In the formula:

[0027] E represents the tidal energy per unit volume, and the unit is J / m 3 ;

[0028] ρ is the seawater density, and the unit is kg / m 3 ;

[0029] v represents the seawater flow velocity, and the unit is m / s;

[0030] Calculate the energy density layer by layer and accumulate it, and generate a heat map of the regional tidal current energy distribution;

[0031] Further evaluate the energy volatility and introduce the turbulence intensity factor:

[0032]

[0033] In the formula:

[0034] σ v is the standard deviation of the flow velocity;

[0035] V av g is the average flow velocity.

[0036] Compared with the prior art, the technology proposed by the present invention can overcome the limitations of the prior art, realize the acquisition and transmission of the real-time state of the multi-layer seawater flow velocity in the offshore area, so as to more comprehensively understand the characteristics of ocean flow. By obtaining the flow velocity data of different depth water layers in real time, the present invention can conduct a comprehensive analysis of the multi-layer flow velocity data, reveal the vertical structure and horizontal distribution characteristics of ocean flow, which not only helps to further calculate the tidal current energy potential and provide more accurate basic data for ocean scientific research and the development of new ocean energy, but also can determine high energy density sea areas (such as narrow straits), providing an important reference for the development of new ocean energy. In addition, the present invention can also be used to analyze the correlation between ocean currents and global climate models, support ocean dynamics research, and provide strong support for the in-depth understanding and rational utilization of the ocean environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the underwater drone of the present invention;

[0038] Figure 2 Bottom view of the structure of the underwater drone of the present invention;

[0039] Figure 3 Schematic diagram of the structure of the integrated bracket of the flow velocity detector of the present invention;

[0040] Figure 4 Schematic diagram of the structure of the vane of the current meter of the present invention;

[0041] Figure 5 Schematic diagram of the structure of the propeller current meter of the present invention. Detailed implementation manners

[0042] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0043] Refer to Figures 1-5 The present invention aims to provide a device and method based on the underwater drone 1 designed specifically for detecting the tidal energy potential in narrow offshore waterways. This solution significantly improves the underwater travel speed and stability of the drone by optimizing its structure and control logic. At the same time, the integrated high-precision flow velocity measurement device can accurately measure the flow velocities of multiple layers of seawater in the offshore area, providing indispensable data support for the development of tidal energy.

[0044] The underwater drone 1 of the present invention is a flexible and remotely controllable underwater drone 1, which is specifically composed of key components such as a lighting lamp 2, a camera 3, a propeller 6, a thruster 5, and a cable connection socket 4. Its core area is tightly sealed with acrylic tubes and epoxy resin, and through pressure chamber testing verification, it can withstand the extreme environment at a depth of 85 meters underwater (equivalent to a pressure of 8.5 MPa); double-layer O-shaped silicone rings are carefully configured at the cabin joints to ensure the reliability of the underwater drone 1 during long-term underwater operations.

[0045] The thruster 5 consists of four groups of brushless ducted thrusters 5, and the thrust of each group is as high as 20 N, jointly supporting the underwater drone 1 to achieve six-degree-of-freedom movements, including forward / backward, ascending / descending, lateral movement, pitching, yawing, and rolling; the underwater drone 1 can carry various styles of flow velocity detectors according to needs, facilitating the simultaneous measurement of lateral or longitudinal fluid velocities.

[0046] Based on the STM32H7 microcontroller, the underwater drone 1 runs a real-time operating system (RTOS) and integrates a PID algorithm to accurately control the power distribution of the thruster 5 to ensure stable hovering even in a turbulent environment. The drone hovers at a preset depth interval (for example, one layer every 5 meters) and accurately collects flow velocity data of each water layer through a flow meter.

[0047] The flow rate detector is quickly connected to the top of the underwater drone 1 through an innovative snap-on mechanical interface, which is convenient for disassembly and transportation, while effectively protecting the underwater drone 1 and the flow rate meter from damage; the propeller flow meter (such as LJ20A) is the preferred option, with a rotation diameter of 60mm, a horizontal pitch of 120mm, a measurement range of 0.06m / s to 8m / s, a measurement error of less than or equal to 1.5%, an applicable temperature range of -20℃ to 60℃, and a relative error of less than or equal to 5%.

[0048] The underwater drone 1 of the present invention can withstand underwater pressure of up to 85 meters and has a wide measurement range. Its modular design facilitates maintenance and replacement of components. The built-in high-energy-density lithium battery pack (48V / 20Ah) supports continuous operation for 12 hours and is suitable for flow velocity measurement in narrow sea waterways without being affected by fluid temperature and quality.

[0049] The underwater drone 1 can navigate and hover underwater at a preset depth, capture flow velocity data of a specified section, and then analyze tidal current energy conditions; if the blades of the velocity meter are entangled in seaweed and the signal is abnormal, the drone can be autonomously floated to a shallow layer through remote control commands, making it easy to manually disassemble and replace the spare velocity meter.

[0050] Combining PID hovering control and USBL positioning technology, the underwater drone 1 can eliminate the impact of wave disturbances on measurement and ensure the spatial consistency of data; its modular design reduces maintenance costs, and can be equipped with ADCP, CTD and other expansion modules according to actual needs, and can be flexibly applied to scientific research and engineering fields.

[0051] The key points of the present invention are:

[0052] 1. The underwater drone 1 can realize 6-dimensional movement: forward / backward, ascending / diving, left / right translation, 360° left / right roll, 360° left / right rotation, 360° up / down pitch. The power supply system adopts lithium battery power supply, which can not only meet the power demand of the underwater drone 1 itself, but also provide power for flow velocity detection, data calculation storage, transmission and calculation;

[0053] 2. The flow velocity detector includes a transverse bracket 7, a main bracket and 6 suspended paddle flow meters 8. The optional propeller flow meters are installed on the transverse bracket 7 at equal intervals, which can realize the flow velocity observation of two layers and the flow velocity detection of three vertical sections;

[0054] 3. The suspended propeller current meter 8 includes a propeller blade 12, a rotating member, and a support. The propeller blade 12 and the rotating shaft 13 are used to passively sense the water flow and rotate around the horizontal support shaft under the driving force of the water flow. The support is used to be fixed on the transverse bracket 7.

[0055] 4. The data processing, transmission, and storage integration box 10 calculates the energy flux density data used to characterize the tidal energy potential from the current velocity data, and completes the storage and transmission of the data. A connection interface 9 is provided in the data processing, transmission, and storage integration box 10 for docking with the cable connection socket 4 on the underwater drone 1. Secondly, the data processing, transmission, and storage integration box 10 can also be placed inside the underwater drone 1 and sufficient waterproof treatment is carried out to maintain its stability and reliability.

[0056] The present invention also provides a method for an underwater drone 1 to detect the tidal energy potential in a narrow offshore waterway:

[0057] (1) Combine the tidal flat characteristics and environmental features of the observation area to assemble the detection device.

[0058] Consult materials such as nautical charts of the observation area and conduct on-site investigations to understand the general depth and approximate flow velocity of the target strait waterway. Ensure that the battery has sufficient power. Assemble the underwater drone 1 and conduct laboratory tests on the unmanned underwater robot to ensure excellent performance. Also, test the detectors on the drone and conduct indoor tests on current velocity acquisition, data calculation, data storage, and data transmission.

[0059] (2) Deploy the device to the target sea area.

[0060] Place the underwater drone 1 in the sea water, remotely control the drone, deploy the device at a specific water depth, detect the tidal energy potential at the specific water depth, and conduct observations on the tidal energy of a specific cross-section.

[0061] (3) Through remotely controlling the position of the underwater drone 1, conduct observations on the tidal energy of different cross-sections and different water depths.

[0062] (4) Maintain and recover the device.

[0063] Remotely control and recover the underwater drone 1 and conduct maintenance and servicing.

[0064] The present invention is mainly used to observe the tidal energy of multi-layer sea water in the offshore area. Through the cross-section multi-layer current meter, multi-point current velocity observations are carried out, and the average value is taken to further calculate the tidal energy.

[0065] Through the real-time measurement of the sea water flow velocity, the tidal energy can be estimated. The tidal energy is usually expressed by the tidal energy density, and its calculation formula is:

[0066]

[0067] In the formula:

[0068] E represents the tidal energy per unit volume (J / m 3 )

[0069] ρ is the seawater density (kg / m 3 )

[0070] v represents the seawater flow velocity (m / s)

[0071] Calculate the energy density layer by layer and accumulate it, and a thermal map of the regional tidal current energy distribution can be generated;

[0072] Furthermore, the energy volatility can be evaluated by introducing a turbulence intensity factor:

[0073]

[0074] In the formula:

[0075] σ v is the standard deviation of the flow velocity

[0076] v avg is the average flow velocity.

[0077] By optimizing the design and control strategy of the unmanned aerial vehicle, the present invention improves its underwater traveling speed and stability. At the same time, by carrying high-precision flow velocity measurement equipment, accurate measurement of the flow velocity of multi-layer seawater in the offshore area and detection of tidal current energy can be achieved, providing an important reference for the development of tidal current energy.

Claims

1. An underwater drone device for detecting the tidal energy potential of a narrow offshore waterway, characterized in that: The device includes an underwater drone that can be remotely controlled. A flow rate detector for measuring the flow rate of seawater is equipped on the top of the underwater drone. The flow rate detector includes a main bracket vertically installed on the underwater drone, and a plurality of transverse brackets arranged laterally are installed on the main bracket from top to bottom, and a plurality of propeller-type flow meters are installed on each of the transverse brackets.

2. The underwater drone device for detecting tidal energy potential in offshore narrow waterways according to claim 1 is characterized in that: The underwater drone is also equipped with lights, cameras, propellers and thrusters. The thrusters include four sets of brushless ducted thrusters to support six degrees of freedom movement, including forward, backward, lifting, lateral movement, pitch, yaw and roll.

3. The underwater drone device for detecting tidal energy potential in offshore narrow waterways according to claim 1 or 2, characterized in that: The inner core part of the underwater drone is sealed with acrylic tube and epoxy resin, and a double-layer O-type silicone ring is arranged at the joint of the cabin.

4. The underwater drone device for detecting tidal energy potential in offshore narrow waterways according to claim 1 is characterized in that: The flow rate detector also includes a data processing, storage and transmission integrated box installed on the main bracket, a data interface for connecting to an underwater drone is provided on the data processing, storage and transmission dust collection box, and a cable socket matching the data interface is provided on the underwater drone.

5. The underwater drone device for detecting tidal energy potential in offshore narrow waterways according to claim 1 or 4, characterized in that: The flow velocity detector is connected to the top of the underwater drone via a snap-on mechanical interface.

6. The underwater drone device for detecting tidal energy potential in offshore narrow waterways according to claim 1 is characterized by: There are two transverse supports, which are respectively installed on the top and the middle of the main support. Each transverse support is provided with three propeller flow meters. The three propeller flow meters on the same transverse support are respectively installed on both sides and the middle of the transverse support, and are used for two-layer flow velocity observation and three vertical section flow velocity detection.

7. The underwater drone device for detecting tidal energy potential in offshore narrow waterways according to claim 1 is characterized by: The underwater drone adopts a modular structure as a whole and has a built-in high-energy-density lithium battery pack.

8. A method for detecting the tidal energy potential of a narrow offshore waterway using an underwater drone, characterized in that: The method uses the underwater drone described in any one of claims 1 to 7 to detect the tidal energy potential device of a narrow offshore waterway, and the steps are as follows: (1) Assemble the detection device based on the tidal flat characteristics and environmental characteristics of the observation area Consult the nautical charts of the observation area and conduct on-site investigations to understand the approximate depth and flow rate of the target strait waterway, ensure that the battery has sufficient power, assemble the underwater drone, conduct laboratory tests on the underwater drone to ensure good performance, test the flow rate detector, and conduct indoor tests on flow rate collection, data calculation, data storage, and data transmission; (2) Deploy the device to the target sea area Place an underwater drone in seawater, remotely control the drone, deploy it at a specific water depth, detect the tidal energy potential at a specific water depth, and observe the tidal energy at a specific cross section; (3) By remotely controlling the position of underwater drones, tidal current energy can be observed at different sections and water depths; (4) Maintenance and recovery equipment After the detection is completed, the underwater drone is recovered by remote control and maintenance is carried out.

9. The method for detecting the tidal energy potential of a narrow offshore waterway using an underwater drone according to claim 8, characterized in that: This method is used to observe the multi-layer seawater tidal energy in the near sea. The multi-point flow velocity is observed through the cross-section multi-layer flow velocity detector, and the average value is taken to further calculate the tidal energy. Specifically: The tidal energy is estimated by measuring the seawater flow rate in real time. The tidal energy is expressed by the tidal energy density, and its calculation formula is: Where: E represents the tidal energy per unit volume, in J / m 3 ; ρ is the density of seawater, in kg / m 3 ; v represents the velocity of seawater, in m / s; The energy density is calculated and accumulated layer by layer, and a regional tidal energy distribution heat map is generated; the energy fluctuation rate is further evaluated and the turbulence intensity factor is introduced: Where: σ v is the standard deviation of flow rate; V av g is the average flow velocity.

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