An online sonar system based on scour monitoring of offshore wind pile foundation

Abstract

The present application relates to the technical field of high-precision detection and collection of underwater acoustic signals, and particularly relates to an online sonar system based on offshore wind pile foundation scour monitoring. The system comprises a monitoring terminal, a wireless radio data transmission module, an AD / DC power supply module, a data acquisition and storage device, a communication and power supply cable and a sonar probe. The AD / DC power supply module is connected to the data acquisition and storage device. The data acquisition and storage device is connected to the sonar probe through the communication and power supply cable. The monitoring terminal is connected to the data acquisition and storage device through the wireless radio data transmission module. The present application can achieve three-dimensional imaging sonar, multi-beam depth finder and double-axis scanning sonar, which can meet the requirement of accurate depth measurement and provide point array topography and water depth data. The system can work in the adjacent area near the foundation, and there is no blind area within 15 m, so that the system can be normally used.

Description

Technical Field

[0001] This invention relates to the field of high-precision underwater acoustic signal detection and acquisition technology, and can be used in the underwater acoustic field for the acquisition and processing of analog signals, as well as in other fields such as marine mapping and marine engineering surveying that require high-precision sonar sensors. In particular, it relates to an online sonar system based on the monitoring of scour of offshore wind turbine pile foundations. Background Technology

[0002] For over a century since the invention of sonar technology, humans have developed a wide variety of sonar products to achieve underwater detection and communication. Early sonar systems, whether used for underwater communication, target identification, or terrain measurement, were widely applied in the military field. With the development of computer technology and the improvement of sonar data storage, display, and visualization interfaces, sonar products are increasingly being used in the civilian market. From marine scientific research, marine surveying, and marine geological exploration to marine fisheries and inland waterway hydrological surveys, various sonar systems are required. Due to the physical characteristics that visible light and electromagnetic waves cannot transmit over long distances in water, underwater information collection and acquisition can only rely on acoustics. Therefore, sonar technology is an essential means for current underwater detection, target identification, and various monitoring technologies. For monitoring the scour of offshore wind power pile foundations, only detection methods based on sonar technology can currently be effectively implemented.

[0003] Traditional methods for surveying the topography and geomorphology of offshore wind farms and monitoring wind turbine foundations have several drawbacks: 1) Poor safety: Unlike the sandy seabed commonly found in European offshore wind farms, the continental shelf where my country's offshore wind farms are located is often near river estuaries. The nearshore seabed is mostly formed by alluvial deposits of silt and sand, with high mud content and low bearing capacity. Furthermore, due to the alternating influence of maritime and continental climates, the wave cycle varies significantly. Under the influence of various loads such as waves, tides, and tidal surges, the wind turbine foundation structure is subjected to reciprocating horizontal impacts over a long period, causing localized scouring of the soil around the foundation, forming scour pits of varying depths and radii. The formation of scour pits reduces the stability of infrastructure such as pile foundations and submarine cables. Over time, if scour pits continue to develop, they will affect the performance of the foundation structure. Furthermore, due to the frequent occurrence of extreme weather events such as typhoons in the eastern coastal areas, pile foundation structures face even harsher environmental challenges. The combined effects of long-term continuous and short-term extreme weather may lead to pile foundation instability, power transmission line rupture, or even tower collapse, seriously threatening the overall safety of offshore wind power structures. 2) Poor efficiency: Maintenance personnel need to regularly scan and monitor changes in foundation scour pits, and promptly take measures to protect the foundation from scour, such as filling with sandbags or sand blankets. Nearshore mudflats have many exposed areas, and the intertidal tidal cycles have a significant impact. During low tide, maintenance vessels have difficulty accessing these areas, resulting in a short effective maintenance time. Meanwhile, the weather at sea is complex and changeable, often with strong winds, dense fog, and thunderstorms. In spring and summer, it is also affected by extreme weather such as typhoons and tropical storms. Under the combined effects of wind, waves, and weather, the accessibility of offshore wind farm sites is poor. The monitoring efficiency of operation and maintenance personnel is also affected by the actual sea conditions, waves, currents, weather, and shipping routes, making it difficult to carry out continuous monitoring and surveying work as planned. This results in problems such as long basic monitoring intervals, small data volume, unclear data logic, and incalculable data errors, making it difficult to provide scientific and reliable data support for the planning and timing of operation and maintenance measures. 3) High cost: As wind turbines need to provide critical support for at least 25 years of operation in harsh weather conditions and complex geographical environments, the foundation structure accounts for as much as 20% to 30% of the total investment in offshore wind farms. To ensure safety, operation and maintenance require continuous monitoring and management of factors that may affect the stability of the foundation structure, and the adoption of various measures, including manual measurement of the foundation structure, sea sweeping monitoring and anti-scour protection measures. At the same time, the timing and necessity of operation and maintenance measures such as backfilling must be assessed. The pile foundation operation and maintenance expenditure, which can easily reach millions of yuan, poses a huge challenge to the economics of operation.

[0004] Therefore, based on the above analysis, the main technical problems to be solved by this invention are as follows:

[0005] 1) The sonar system only outputs topographic images and does not simultaneously acquire array-type water depth data. 2) Although the sonar scan range is reasonable, it fails to cover all areas comprehensively. 3) The area near the pile foundation is a key area, but near-object acoustic scattering interference is severe. 4) Although the sonar scan speed is appropriate, repeatability and stability are difficult to meet requirements. 5) Unattended operation lacks reliability, and the required maintenance-free cycle is too short. Summary of the Invention

[0006] The purpose of this invention is to provide an online sonar system for monitoring the scour of offshore wind turbine foundations, thereby solving the aforementioned problems.

[0007] To address the aforementioned technical problems, this invention provides an online sonar system for monitoring scour of offshore wind turbine foundations, comprising: a monitoring terminal, a radio data transmission module, an AD / DC power supply module, a data acquisition and storage unit, a communication and power supply cable, and a sonar probe; the AD / DC power supply module is connected to the data acquisition and storage unit, the data acquisition and storage unit is connected to the sonar probe via the communication and power supply cable, and the monitoring terminal is communicatively connected to the data acquisition and storage unit via the radio data transmission module.

[0008] Preferably, the sonar probe includes: a high-frequency narrow-beam underwater acoustic transducer, a horizontal and vertical dual-axis precision rotation system, and a sonar sound-transmitting protective cover; the sonar sound-transmitting protective cover is provided on the outside of the high-frequency narrow-beam underwater acoustic transducer, and the drive end of the high-frequency narrow-beam underwater acoustic transducer is connected to the horizontal and vertical dual-axis precision rotation system, thereby driving the high-frequency underwater acoustic transducer to precisely rotate and pitch in two geometric dimensions: horizontal circumferential and vertical.

[0009] Preferably, the horizontal and vertical dual-axis precision rotation system consists of two internal rotary motors.

[0010] Preferably, the data acquisition and storage unit also includes a connected signal processing unit for implementing functions such as instruction parsing and control, transmission signal generation, transmission signal amplification and matching, reception signal conditioning and acquisition, and data instruction transmission and reception.

[0011] Preferably, the communication and power supply cable is a multi-core watertight cable for communication and power supply, which is a 15-core shielded cable that includes power supply, control, communication and detection functions.

[0012] Preferably, the monitoring terminal is a laptop computer, which serves as the operating platform for display and control software, the hardware terminal for sonar control human-computer interaction, and the data transmission and storage node.

[0013] Preferably, the monitoring terminal also includes installed data processing and display control software, which includes a human-machine interface for sonar parameter setting and operation control, an equipment status check and self-test operation management interface, online display of dense matrix water depth and geomorphological data 3D profile cloud map, and storage and playback viewing functions.

[0014] Preferably, the AD / DC power supply module includes DC / DC conversion, noise suppression, isolation, and purification functions for a series of power supplies required by the transmitting and receiving circuits and the detection and control circuits.

[0015] Preferably, the sonar probe operates at a frequency of 600kHz, has a beamwidth of ≤1.5° under -3dB conditions, a scanning range of ≥25m under conditions where the water depth is not shallower than 10m, a range resolution of ≤1cm, a maximum suitable water depth of ≥30m, a horizontal viewing angle of 0~360°, a vertical viewing angle of +10°~-90°, a minimum scanning angle step of ≤0.225°, and a power supply requirement of 24VDC.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) Three-dimensional imaging sonar, multibeam echo sounder and dual-axis scanning sonar can meet the requirements of accurate depth measurement and provide matrix-style geomorphic water depth data.

[0018] (2) It can work in the vicinity of the foundation, and there are basically no blind spots within 15m, so it can be used normally.

[0019] (3) In comparison, single-beam dual-axis scanning sonar has a fine and concentrated beam, which is less susceptible to interference from scattered sound waves from nearby objects. It can still maintain good scanning accuracy in important areas vertically below the wind turbine foundation. Dual-head scanning sonar has a unique advantage in maintaining scanning quality, especially in data quality in important areas vertically below.

[0020] (4) The dual-axis online scanning sonar acoustic system has the simplest structure, with a large transducer unit area and large capacitance, and its stability is relatively easy to ensure; in addition, it is designed with a sound-transmitting protective cover, which can effectively avoid the influence of temperature changes, flow field disturbances, etc. on the measurement results.

[0021] (5) One of the important advantages of online monitoring is that it can significantly reduce the workload of offshore operations. Once the equipment is installed, it is desirable to minimize or even eliminate maintenance. Attached Figure Description

[0022] Figure 1 This is a functional block diagram of the online sonar system for monitoring the scour of offshore wind turbine foundations, based on the present invention.

[0023] Figure 2 This is a diagram of the sonar software display interface of the present invention. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0025] like Figures 1-2 As shown, this embodiment of the invention provides an online sonar system for monitoring the scour of offshore wind turbine foundations, comprising: a monitoring terminal 100, a radio data transmission module 200, an AD / DC power supply module 300, a data acquisition and storage unit 400, a communication and power supply cable 500, and a sonar probe 600; the AD / DC power supply module 300 is connected to the data acquisition and storage unit 400, the data acquisition and storage unit 400 is connected to the sonar probe 600 via the communication and power supply cable 500, and the monitoring terminal 100 is communicatively connected to the data acquisition and storage unit 400 via the radio data transmission module 200.

[0026] The sonar probe 600 includes: a high-frequency narrow-beam underwater acoustic transducer, a horizontal and vertical dual-axis precision rotation system, and a sonar protective cover. The high-frequency narrow-beam underwater acoustic transducer is externally protected by the sonar protective cover. The drive end of the high-frequency narrow-beam underwater acoustic transducer is connected to the horizontal and vertical dual-axis precision rotation system, thereby driving the high-frequency underwater acoustic transducer to precisely rotate and pitch in both the horizontal circumferential and vertical geometric dimensions. The horizontal and vertical dual-axis precision rotation system consists of two internal rotary motors. The data acquisition and storage unit 400 also includes a connected signal processing unit for implementing command parsing and control, transmitted signal generation, transmitted signal amplification and matching, received signal conditioning and acquisition, and data command transmission and reception functions. The communication and power supply cable 500 uses a multi-core watertight cable, which consists of 15 shielded cores containing power, control, communication, and detection components. The monitoring terminal 100 uses a laptop computer as the operating platform for the display and control software, the human-machine interface hardware terminal for sonar control, and the data transmission and storage node. The monitoring terminal 100 also includes installed data processing and display control software. This software includes a human-machine interface for sonar parameter settings and operation control, an equipment status check and self-test operation management interface, online display of dense matrix water depth and geomorphological data 3D profile cloud maps, and storage and playback functions. The AD / DC power supply module 300 includes DC / DC conversion, noise suppression, isolation, and purification functions for a series of power supplies required by the transmitting and receiving circuits and the detection and control circuits; see Table 1 below for details.

[0027] Table 1:

[0028]

[0029] The sonar probe 600 operates at a frequency of 600kHz, with a beamwidth of ≤1.5° under -3dB conditions, a scanning range of ≥25m under water depths not shallower than 10m, a range resolution of ≤1cm, a maximum suitable water depth of ≥30m, a horizontal viewing angle of 0~360°, a vertical viewing angle of +10°~-90°, a minimum scanning angle step of ≤0.225°, and a power supply requirement of 24VDC. For details, please refer to Table 2 below.

[0030] Table 2:

[0031]

[0032]

[0033] This invention can perform precise and intensive scanning and recording of the water depth and geomorphology of the surrounding waters in an online manner, according to its own settings, within a set time period or cycle, and in a set area. By monitoring the changes in the seabed geomorphology around the pile foundation at different times, the risk of water erosion around the pile foundation can be analyzed and assessed more timely and accurately. When the sonar is working, the high-frequency underwater acoustic transducer inside its probe can be precisely rotated and pitched in two geometric dimensions: horizontal circumferential and vertical. This allows the sonar probe to use a fine beam of 600 to accurately illuminate and scan the surrounding terrain, thereby densely collecting water depth and geomorphological data of the surrounding seabed in the form of a spatial array. The sonar can not only store, manage, and share the data in an orderly manner, but also visually display this dense water depth and geomorphological data in the form of a 3D profile cloud map on the display of the monitoring terminal 100 workstation.

[0034] The main functional characteristics of the sonar probe 600 of this invention are as follows: ① The maximum effective monitoring range of each sonar probe 600 is not less than 25 meters (under good hydrological conditions, ignoring factors such as topographical undulations and obstruction). ② It is designed to be used in water depths of 10m or more, and can also be used in shallow water areas of 6m (the effective monitoring range may be slightly smaller). ③ The monitoring period, monitoring cycle, scanning range, and scanning density of the sonar can all be set. ④ It has the function of online display of 3D profile cloud maps of dense point matrix water depth and geomorphological data and data playback display. ⑤ The scanned water depth and geomorphological data can be digitally stored and shared. ⑥ The entire system is suitable for quick on-site installation, calibration, and maintenance. ⑦ The design life of the sonar probe 600 is not less than 3 years (based on a working intensity of no less than 2 full-area scans per week). ⑧ The maintenance-free operation cycle of the sonar is not less than 1 year. ⑨ Storage temperature range: -10~50℃; operating temperature: 0~25℃.

[0035] The present invention also includes the following structural parameters of the sonar probe 600: ① Diameter ≤ 215mm; ② Height ≤ 550mm (excluding cable); ③ Empty weight ≤ 30kg (in air); ④ Wet weight ≤ 15kg (in water); ⑤ Hydrostatic pressure resistance ≥ 0.4MPa; ⑥ Control dimension of internal rotating motor: two-dimensional; ⑦ Material: the structural material is preferably naval copper, 316L stainless steel, engineering plastics and other seawater corrosion resistant materials; ⑧ The sound-permeable protective cover is preferably made of low water permeability high frequency sound-permeable rubber material such as PU.

[0036] The software interface and data effects in this invention: The software mainly includes two functional modules: sonar control and display and data acquisition. The sonar control includes acoustic parameter settings, communication interface settings and sonar image display, etc. The data acquisition module includes 3D display and storage of data and post-processing functions, etc.

[0037] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. An online sonar system for monitoring scour of offshore wind turbine foundations, characterized in that, include: The system includes a monitoring terminal, a radio data transmission module, an AD / DC power supply module, a data acquisition and storage device, a communication and power supply cable, and a sonar probe. The AD / DC power supply module is connected to the data acquisition and storage device, the data acquisition and storage device is connected to the sonar probe via the communication and power supply cable, and the monitoring terminal is communicatively connected to the data acquisition and storage device via the radio data transmission module. The sonar probe includes: a high-frequency narrow-beam underwater acoustic transducer, a horizontal and vertical dual-axis precision rotation system, and a sonar sound-transmitting protective cover. The high-frequency narrow-beam underwater acoustic transducer is provided with a sonar sound-transmitting protective cover. The drive end of the high-frequency narrow-beam underwater acoustic transducer is connected to the horizontal and vertical dual-axis precision rotation system, thereby driving the high-frequency narrow-beam underwater acoustic transducer to perform precise rotation and pitch in two geometric dimensions: horizontal circumferential direction and vertical direction. The data acquisition and storage unit also includes a connected signal processing unit, which is used to realize the functions of instruction parsing and control, transmission signal generation, transmission signal amplification and matching, reception signal conditioning and acquisition, and data instruction transmission and reception. The communication and power supply cable adopts a multi-core watertight cable for communication and power supply. The multi-core watertight cable is a 15-core shielded cable that includes power supply, control, communication and detection. The AD / DC power supply module includes DC / DC conversion, noise suppression, isolation, and purification functions for a series of power supplies required by the transmitting and receiving circuits and the detection and control circuits. The sonar probe operates at a frequency of 600kHz, with a beamwidth of ≤1.5° under -3dB conditions, a scanning range of ≥25m under conditions where the water depth is not shallower than 10m, a range resolution of ≤1cm, a maximum suitable water depth of ≥30m, a horizontal viewing angle of 0~360°, a vertical viewing angle of +10°~-90°, a minimum scanning angle step of ≤0.225°, and a power supply requirement of 24VDC.

2. The online sonar system for monitoring offshore wind turbine pile scour as described in claim 1, characterized in that, The horizontal and vertical dual-axis precision rotation system consists of two internal rotary motors.

3. The online sonar system for monitoring scour of offshore wind turbine foundations as described in claim 1, characterized in that, The monitoring terminal uses a laptop computer as the operating platform for the display and control software, the sonar control human-computer interaction hardware terminal, and the data transmission and storage node.

4. The online sonar system for monitoring scour of offshore wind turbine foundations as described in claim 3, characterized in that, The monitoring terminal also includes installed data processing and display control software, which includes a human-machine interface for sonar parameter setting and operation control, an equipment status check and self-test operation management interface, online display of dense matrix water depth and geomorphological data 3D profile cloud map, and storage and playback viewing functions.

Images