An active anti-collision method for offshore wind turbine monopile foundation

Abstract

This invention discloses an active collision avoidance method for offshore wind turbine monopile foundations, aiming to provide a method that combines the advantages of active collision avoidance early warning with passive collision avoidance, thus providing better protection for offshore wind turbine monopile foundations. Potential collision objects are classified and identified: if the potential collision object is not a ship, a collision limit safety zone S1 is defined within the monitoring range; if the potential collision object enters the collision limit safety zone S1, the water level is determined and a collision avoidance device is deployed. If the potential collision object is a ship, the collision limit safety zone S1, a key monitoring area S2, and a tracking and identification area S3 are defined within the monitoring range. The ship's trajectory is predicted, and a risk assessment of the collision between the ship and the wind turbine monopile foundation is performed. A collision early warning threshold is generated, and the risk assessment result is compared with the collision early warning threshold; it is determined whether the collision early warning threshold is exceeded; if the threshold is exceeded, an alarm is issued and monitoring continues.

Description

Technical Field

[0001] This invention relates to the field of collision avoidance monitoring for offshore wind turbine foundations, and more specifically, to an active collision avoidance method for offshore wind turbine monopile foundations. Background Technology

[0002] With the rapid development of the global economy, issues such as energy, environment, and climate change are becoming increasingly prominent, and traditional fossil fuels can no longer meet the requirements of sustainable social development. Wind energy is an inexhaustible and clean energy source, and its development and utilization, especially offshore wind energy, are receiving increasing attention from countries around the world.

[0003] Currently, the main types of offshore wind turbine foundation structures under construction or already built include monopile, multipile, and jacket foundations. Among these, monopile foundations dominate due to their simple structure, low construction cost, and convenient construction. The marine environment is complex and variable. Offshore wind farm sites often border or overlap with shipping routes and traditional fishing grounds, significantly increasing the probability of collisions between offshore wind turbine foundations and ships or ice floes. Furthermore, monopile foundations have relatively weak horizontal stiffness, making them highly susceptible to damage from collisions with ships or sea ice, potentially leading to tilting and collapse.

[0004] With the development of technologies such as remote communication and monitoring, it has become possible to issue timely proactive warnings before collisions occur by installing monitoring devices, cameras, and alarm systems on offshore wind turbine foundations, thus preventing accidents. However, proactive warnings are often ineffective against collisions with floating ice or out-of-control vessels, in which case collision avoidance devices are often necessary to reduce foundation collision damage. However, harsh marine hydrological conditions and complex environmental loads, with reciprocating wave loads being the primary stress, easily cause structural fatigue damage to collision avoidance devices. Furthermore, due to long-term direct contact with seawater, corrosion damage to collision avoidance devices urgently needs to be addressed. Summary of the Invention

[0005] The purpose of this invention is to address the technical deficiencies in the existing technology by providing an active anti-collision method for offshore wind turbine monopile foundations that combines the advantages of active anti-collision warning with passive anti-collision, thereby providing better protection for offshore wind turbine monopile foundations.

[0006] The technical solution adopted to achieve the purpose of this invention is:

[0007] An active collision avoidance method for offshore wind turbine monopile foundations includes the following steps:

[0008] Step 1: Acquire real-time hydrological data, meteorological data, and potential collision object data;

[0009] Step 2: Classify and identify potential collision objects;

[0010] If the potential collision object is a ship, then within the monitoring range, determine the collision limit safety zone S1, the key monitoring zone S2, and the tracking and identification zone S3 based on the data from step 1, and proceed to step 3.

[0011] If the potential collision object is not a ship, then within the monitoring range, the collision limit safety zone S1 is defined according to the data in step 1; the location information of the potential collision object is obtained; if the potential collision object enters the collision limit safety zone S1, the water level height at this time is determined and the anti-collision device is immediately lowered and step 5 is executed; if the potential collision object leaves the monitoring range S, step 5 is executed.

[0012] Step 3: Determine whether the vessel has valid track information through the AIS system. If so, filter the data required for trajectory prediction from the track information, delete abnormal data, generate the input data required for trajectory prediction, and execute step 3.2. If there is no track information, execute step 3.1.

[0013] Step 3.1: Obtain the vessel's trajectory information within the tracking and identification area S3, generate the input data required for trajectory prediction, and execute step 3.2;

[0014] Step 3.2: Input the generated trajectory prediction data into the ship trajectory prediction system to predict the ship's trajectory;

[0015] Step 3.3: Conduct a hazard assessment of the collision between the ship and the wind turbine monopile foundation, generate a collision warning threshold, and compare the hazard assessment results with the collision warning threshold.

[0016] Step 4: Determine whether the hazard assessment result exceeds the collision warning threshold. If it does not exceed the collision warning threshold, proceed to step 4.1. If it exceeds the collision warning threshold, proceed to step 4.2.

[0017] Step 4.1: Determine the vessel's location based on the warning area identified in Step 2; if the vessel is in the tracking and identification area S3, obtain the vessel's position information at the next time step h; if it is in the key monitoring area S2, obtain the vessel's position information at the next time step h / 2, where the time interval cannot be less than the sampling period of the monitoring equipment, i.e., h > 2 / f, where f is the sampling frequency of the monitoring equipment; add the obtained latest vessel trajectory information to the input data required for the generated trajectory prediction, and execute Step 3.2; if the vessel is in the collision limit safety area S1, determine the water level at this time and immediately lower the anti-collision device, and execute Step 5; if the vessel leaves the monitoring range S, execute Step 5;

[0018] Step 4.2: Issue an alarm; monitor changes in the vessel's trajectory and speed; if the vessel's trajectory or speed changes, proceed as described in Step 4.1 above; if the vessel's trajectory or speed does not change, mark the vessel as an abnormal vessel, determine the current water level, immediately lower the anti-collision device, and proceed to Step 5.

[0019] Step 5: End the warning; if the anti-collision device is deployed and a collision occurs, contact the operation and maintenance center to conduct a collision damage assessment; if the anti-collision device is deployed but no collision occurs, raise the anti-collision device to its initial position; if the anti-collision device is not deployed and no collision occurs, continue monitoring.

[0020] The anti-collision device is a buffer energy-absorbing structure surrounding the outside of the wind turbine monopile foundation. The buffer energy-absorbing structure is driven by a lifting motor to slide up and down along a sliding groove to realize the active lifting and lowering of the anti-collision device. The sliding groove is set outside the wind turbine monopile foundation.

[0021] The collision limit safety zone S1 refers to the area where, if a potential collision object enters, the water level is determined and an anti-collision device is immediately deployed. The minimum area of ​​this zone cannot be less than the area required for the wind turbine monopile foundation to deploy the anti-collision device before a collision occurs.

[0022] The area S of the collision limit safety zone S1 area-1 The calculation is shown in equation (1):

[0023]

[0024] In the formula: r s1 Let S1 be the radius of the collision limit safety zone.

[0025] T f Indicates the time required for the anti-collision device to be lowered;

[0026] v w v is the velocity of the potential collision object; if the potential collision object is a ship, then v w This represents the ship's speed; if the potential collision object is not a ship, then v is used. w Indicates the speed of a non-potential collision object;

[0027] R w R is the wind speed coefficient; when the wind speed is greater than 30 m / s, w =0.65, when the wind speed is greater than 10m / s and less than 30m / s, R w =0.9, when the wind speed is less than 10m / s, R w =1.0;

[0028] R l R is the sea state coefficient; when the wave height is greater than 6m,l =0.65, when the wave height is greater than 1.25m and less than 6m, R l =0.9, when the wave height is less than 1.25m, R l =1.0.

[0029] The key monitoring area S2 refers to the area where the ship is more likely to collide with the wind turbine monopile foundation and requires close monitoring of the ship; its minimum area cannot be less than the area calculated by formula (2);

[0030] S area-2 =π(r² + r) s1 ) 2 -S area-1 (2);

[0031] In the formula: r2 is the braking stroke of the ship;

[0032] S area-2 The area of ​​S2 is the key monitoring area.

[0033] The tracking and identification area S3 refers to the area where the ship may still collide with the wind turbine monopile foundation, which is the area outside the collision limit safety area and the key monitoring area within the monitoring range.

[0034] The risk assessment χ uses the model shown in equation (3):

[0035]

[0036] In the formula: r s1 r is the radius of the collision limit safety zone S1; s The radius of the monitoring range S; d represents the closest distance between the ship and the wind turbine foundation under the predicted trajectory; R w R is the wind speed coefficient; when the wind speed is greater than 30 m / s, w =0.65, when the wind speed is greater than 10m / s and less than 30m / s, R w =0.9, when the wind speed is less than 10m / s, R w =1.0; R v R is the visibility factor; when visibility is less than 3 miles, R... v =0.7, visibility less than 5 miles and greater than 3 miles, R v =0.85, when visibility is greater than 5 miles, R v =1.0; R b R is the fan position correction factor. b =exp((θ-π / 2), where θ is the turning angle of the ship relative to the wind turbine; R l R is the sea state coefficient; when the wave height is greater than 6m, l=0.65, when the wave height is greater than 1.25m and less than 6m, R l =0.9, when the wave height is less than 1.25m, R l =1.0; R d R is the density coefficient of ships within the monitoring range S. When the ship density within the monitoring range S is low, R d =1, when the ship density within the monitoring range S is the average density, R d =0.8, when the ship density within the monitoring range S is high, R d =0.6.

[0037] The calculation model for the collision warning threshold φ is shown in equation (4).

[0038]

[0039] In the formula: φ0 is the base value of the early warning threshold; R w R is the wind speed coefficient; when the wind speed is greater than 30 m / s, w =0.65, when the wind speed is greater than 10m / s and less than 30m / s, R w =0.9, when the wind speed is less than 10m / s, R w =1.0; R v R is the visibility factor; when visibility is less than 3 miles, R... v =0.7, visibility less than 5 miles and greater than 3 miles, R v =0.85, when visibility is greater than 5 miles, R v =1.0; R l R is the sea state coefficient; when the wave height is greater than 6m, l =0.65, when the wave height is greater than 1.25m and less than 6m, R l =0.9, when the wave height is less than 1.25m, R l =1.0.

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] 1. The active anti-collision method for offshore wind turbine monopile foundations of the present invention can accurately identify potential ship collision hazards around the wind turbine monopile foundation, and then issue timely warnings to avoid collision risks. In the event of non-ship collisions or unavoidable ship collisions, the active lifting anti-collision device can provide better protection for the offshore wind turbine monopile foundation, while avoiding damage to the anti-collision device caused by long-term seawater corrosion and wave loads.

[0042] 2. The method of the present invention takes into account both the ship collision problem faced by the monopile foundation of offshore wind turbines and the possibility of non-ship collisions during the actual operation of offshore wind turbines. Different measures are taken for different collision situations to achieve all-round protection of the monopile foundation of offshore wind turbines, improve the pertinence of anti-collision measures, and improve the efficiency of monitoring and early warning.

[0043] 3. The method of the present invention can autonomously judge the motion state of potential collision objects within the monitoring range, autonomously identify collision risks and take corresponding preventive measures, thereby achieving the purpose of protecting the monopile foundation of offshore wind turbines. The whole process is efficient and convenient and does not require human intervention. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall process of the active anti-collision method for offshore wind turbine monopile foundations of the present invention;

[0045] Figure 2 This is a flowchart of the active anti-ship collision method for offshore wind turbine monopile foundations according to the present invention;

[0046] Figure 3 This is a flowchart of the active non-ship collision prevention method for offshore wind turbine monopile foundations according to the present invention;

[0047] Figure 4 The diagram shown is a schematic representation of the area division.

[0048] Figure 5 The diagram shows the active lifting mechanism of the anti-collision device. Detailed Implementation

[0049] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0050] The active lifting anti-collision structure used in the active anti-collision method for offshore wind turbine monopile foundations of this invention adds a lifting mechanism to the existing anti-collision device to achieve active lifting of the anti-collision device. The lifting mechanism can take various forms; this embodiment uses a motor-driven lifting mechanism. A schematic diagram of the active lifting of the anti-collision device in this embodiment is shown below. Figure 5 As shown, the anti-collision device is a buffer energy-absorbing structure 2 surrounding the outside of the wind turbine monopile foundation 1. The buffer energy-absorbing structure 2 is driven by a lifting motor 4 to slide up and down along the slide groove 3 to realize the active lifting and lowering of the anti-collision device. The slide groove 3 is set outside the wind turbine monopile foundation 1.

[0051] The active anti-collision method for offshore wind turbine monopile foundations of the present invention includes the following steps:

[0052] Step 1: Obtain real-time hydrological data, meteorological data, and potential collision object data.

[0053] The hydrological data includes wave information and current velocity; the meteorological data includes real-time wind speed, wind direction, and visibility; and the potential collision object data includes images, speed, and heading of the potential collision object. Data can be acquired through various data acquisition devices. For example, wave information (including wave height, wave period, etc.) and current velocity can be acquired by deploying wave buoys with real-time communication capabilities around the wind turbine; wind speed, wind direction, and visibility data can be acquired by installing wind speed and direction sensors, visibility sensors, or other sensor devices with similar functions on the wind turbine tower; images can be acquired by tracking potential collision objects using cameras; and speed and heading data can be acquired through radar, the BeiDou Navigation Satellite System, etc.

[0054] Step 2: Use visual recognition algorithms to classify and identify potential collision objects.

[0055] Step 2.1: If the potential collision object is a ship, then within the monitoring range S, determine the collision limit safety zone S1, the key monitoring zone S2, and the tracking and identification zone S3 based on the data from Step 1, and proceed to Step 3.

[0056] The monitoring range S is the area or range that the monitoring equipment can cover or monitor. A schematic diagram of the area division within the monitoring range S is shown below. Figure 4 As shown, the collision limit safety zone S1 refers to the area where, if a potential collision object enters, the water level is determined and an anti-collision device is immediately deployed. Generally, the minimum area of ​​this zone cannot be smaller than the area required for deploying the anti-collision device before a collision occurs on the wind turbine monopile foundation.

[0057] In this embodiment, the collision limit safety zone S1 has an area S area-1 The preferred calculation formula is shown in equation (1):

[0058]

[0059] In the formula: r s1 Let S1 be the radius of the collision limit safety zone.

[0060] T f Indicates the time required for the anti-collision device to be lowered;

[0061] v w v is the velocity of the potential collision object; if the potential collision object is a ship, then v w Indicates the ship's speed;

[0062] R w R is the wind speed coefficient; when the wind speed is greater than 30 m / s, w =0.65, when the wind speed is greater than 10m / s and less than 30m / s, R w=0.9, when the wind speed is less than 10m / s, R w =1.0;

[0063] R l R is the sea state coefficient; when the wave height is greater than 6m, l =0.65, when the wave height is greater than 1.25m and less than 6m, R l =0.9, when the wave height is less than 1.25m, R l =1.0.

[0064] The key monitoring area S2 refers to the area where the ship is more likely to collide with the wind turbine monopile foundation, and the ship needs to be closely monitored. Its minimum area cannot be less than the area calculated by formula (2).

[0065] S area-2 =π(r² + r) s1 ) 2 -S area-1 (2);

[0066] In the formula: r2 is the braking stroke of the ship.

[0067] The tracking and identification area S3 refers to the area where the ship may still collide with the wind turbine monopile foundation. In this embodiment, it is the area within the monitoring range excluding the collision limit safety zone and the key monitoring area. area-3 =S area -S area-1 -S area-2 S area To monitor the area S, S area-1 S represents the area of ​​the collision limit safety zone S1. area-2 This indicates the area of ​​the key monitoring region S2, where S... area-3 This represents the area of ​​the tracking and identification region S3.

[0068] Step 2.2: If the potential collision object is not a ship, then within the monitoring range S, the collision limit safety zone S1 is defined based on the data from Step 1. For the case where the potential collision object is not a ship, the definition and area calculation of the collision limit safety zone S1 are similar to those for a ship as a potential collision object. The collision limit safety zone S1 refers to the area where, as soon as a potential collision object enters, the water level is determined and an anti-collision device is immediately deployed. Generally, the minimum area of ​​this zone cannot be less than the area required for the wind turbine monopile foundation to deploy the anti-collision device before a collision occurs. In this embodiment, the formula for calculating the area of ​​the collision limit safety zone S1 is shown in equation (1). If the potential collision object is not a ship, v in equation (1)... wThe speed of the non-ship potential collision object is determined. The position of the potential collision object is tracked and obtained through a monitoring system, radar system, or positioning system. If the potential collision object enters the collision limit safety zone S1, the water level is determined and the anti-collision device is lowered, and step 5 is executed. If it leaves the monitoring range S, step 5 is executed again.

[0069] Step 3: Use the AIS system (AIS is an abbreviation for Automatic Identification System) to determine whether the ship has valid track information. If so, filter the data required for trajectory prediction from the track information, delete abnormal data, and generate the input data required for trajectory prediction (mainly including the latitude and longitude coordinates of the ship's historical track points, etc.). Then execute step 3.2. If there is no track information, execute step 3.1.

[0070] Step 3.1: Obtain the ship's trajectory information within the tracking and identification area S3 through the installed radar system or positioning system, generate the input data required for trajectory prediction, and then execute step 3.2.

[0071] Step 3.2: Input the generated trajectory prediction data into the ship trajectory prediction system to predict the ship's trajectory. The ship trajectory prediction system adopts existing ship trajectory prediction technology, and its prediction model can be a neural network model or other approximate model.

[0072] Step 3.3: Conduct a current risk assessment of the collision between the ship and the wind turbine monopile foundation. At the same time, generate a current collision warning threshold by combining hydrological and meteorological data and relevant experience. The risk assessment can be calculated by membership function or probability model. In this embodiment, the calculation model of the current collision warning threshold φ is shown in Equation (3), and the collision risk χ assessment model is shown in Equation (4).

[0073]

[0074]

[0075] In the formula: φ0 is the base value of the early warning threshold, which can be preset in combination with data such as the location of the wind turbine from the route or fishing ground, and historical collision accidents. In this embodiment, φ0 can be taken as 0.9.

[0076] r s The radius of the monitoring range S;

[0077] d represents the closest distance between the ship and the wind turbine foundation under the predicted trajectory;

[0078] R v R is the visibility factor; when visibility is less than 3 miles, R... v=0.7, visibility less than 5 miles and greater than 3 miles, R v =0.85, when visibility is greater than 5 miles, R v =1.0;

[0079] R b R is the wind turbine position correction factor, which is related to the ship's position relative to the wind turbine. b =exp((θ-π / 2), where θ is the turning angle of the ship relative to the wind turbine. The smaller the turning angle, the greater the risk.

[0080] R d R is the density coefficient of ships within the monitoring range S. When the ship density within the monitoring range S is low, R d =1, when the ship density within the monitoring range S is the average density, R d =0.8, when the ship density within the monitoring range S is high, R d =0.6.

[0081] The collision risk level χ and the current collision warning threshold are evaluated and compared using the above model.

[0082] Step 4: Determine whether the hazard assessment result exceeds the collision warning threshold. If it does not exceed the collision warning threshold, proceed to step 4.1. If it exceeds the collision warning threshold, proceed to step 4.2.

[0083] Step 4.1: Based on the warning area determined in Step 2, determine the vessel's location. If the vessel is in the tracking and identification area S3, obtain the vessel's position information at the next time step h. If it is in the key monitoring area S2, obtain the vessel's position information at the next time step h / 2. The time interval between each data acquisition set must not be less than the sampling period of the monitoring equipment, i.e., h > 2 / f, where f is the sampling frequency of the monitoring equipment. Add the latest vessel trajectory information to the input data required for the generated trajectory prediction and execute Step 3.2. If the vessel is in the collision limit safety area S1, determine the current water level and immediately deploy the anti-collision device, then execute Step 5. If the vessel leaves the monitoring range S, execute Step 5.

[0084] Step 4.2: The early warning system installed on the wind turbine will issue an alarm. The early warning system may include sea sweeping lights, sirens, etc. If the ship is equipped with an AIS system, it can also send early warning signals to the ship through the AIS system and monitor changes in the ship's trajectory and speed. If the ship's trajectory or speed changes, proceed according to step 4.1 above. If the ship's trajectory or speed does not change, mark the ship as an abnormal ship, determine the current water level, and immediately lower the anti-collision device, then proceed to step 5.

[0085] Step 5: End the alert. Add the generated trajectory prediction input data as a training set to the trajectory prediction system to strengthen the trajectory prediction model and further improve prediction accuracy. If the anti-collision device is deployed and a collision occurs, contact the operations and maintenance center to conduct a collision damage assessment. If the anti-collision device is deployed but no collision occurs, raise the anti-collision device to its initial position. If the anti-collision device is not deployed and no collision occurs, continue monitoring.

[0086] The active anti-collision method for offshore wind turbine monopile foundations of this invention accurately identifies potential ship collision hazards around the wind turbine monopile foundation, and then issues timely warnings to avoid collision risks. Furthermore, in the event of non-ship collisions or unavoidable ship collisions, an active lifting anti-collision device provides better protection for the offshore wind turbine monopile foundation, while avoiding damage to the anti-collision device from long-term seawater corrosion and wave loads. Experiments have shown good anti-collision performance. This method is suitable for the design of anti-collision systems for existing and planned new monopile offshore wind turbine foundations, and has a wide range of applications.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An active anti-collision method for offshore wind turbine monopile foundations, characterized in that, Includes the following steps: Step 1: Acquire real-time hydrological data, meteorological data, and potential collision object data; Step 2: Classify and identify potential collision objects; If the potential collision object is a ship, then within the monitoring range, determine the collision limit safety zone based on the data from step 1. S 1 Key monitoring areas S 2 and tracking and identification area S 3 Proceed to step 3; If the potential collision object is not a ship, then within the monitoring range, the collision limit safety zone is delineated based on the data from step 1. S 1 ; Obtain the location information of potential collision objects; if a potential collision object enters the collision limit safety zone... S 1 If the water level is determined, the anti-collision device is immediately lowered, and step 5 is executed; if the potential collision object leaves the monitoring range... S Then proceed to step 5; Step 3: Determine whether the vessel has valid track information through the AIS system. If so, filter the data required for trajectory prediction from the track information, delete abnormal data, generate the input data required for trajectory prediction, and execute step 3.

2. If there is no track information, execute step 3.

1. Step 3.1: Obtain the vessel's location within the tracking and identification area. S 3 The system uses the flight path information to generate the input data required for trajectory prediction and then executes step 3.

2. Step 3.2: Input the generated trajectory prediction data into the ship trajectory prediction system to predict the ship's trajectory; Step 3.3: Conduct a hazard assessment of the collision between the ship and the wind turbine monopile foundation, generate a collision warning threshold, and compare the hazard assessment results with the collision warning threshold. Step 4: Determine whether the hazard assessment result exceeds the collision warning threshold. If it does not exceed the collision warning threshold, proceed to step 4.

1. If it exceeds the collision warning threshold, proceed to step 4.

2. Step 4.1: Determine the area where the vessel is located based on the monitoring range determined in Step 2; if the vessel is within the tracking and identification area... S 3 Then the ship's next time step is obtained as h Location information at any time; if in a key monitoring area S 2 Then the ship's next time step is obtained as h The location information at time / 2, where the time interval cannot be less than the sampling period of the monitoring equipment, i.e. h >2 / f , f To monitor the sampling frequency of the equipment; add the latest ship trajectory information obtained above to the input data required for the generated trajectory prediction, and execute step 3.2; if the ship is in the collision limit safety zone S 1 If the water level is determined, the anti-collision device is immediately deployed, and step 5 is executed; if the vessel leaves the monitoring range... S Then proceed to step 5; Step 4.2: Issue an alarm; monitor changes in the vessel's trajectory and speed; if the vessel's trajectory or speed changes, proceed as described in Step 4.1 above; if the vessel's trajectory or speed does not change, mark the vessel as an abnormal vessel, determine the current water level, immediately lower the anti-collision device, and proceed to Step 5. Step 5: End the warning; if the anti-collision device is deployed and a collision occurs, contact the operation and maintenance center to conduct a collision damage assessment; if the anti-collision device is deployed but no collision occurs, raise the anti-collision device to its initial position; if the anti-collision device is not deployed and no collision occurs, continue monitoring.

2. The active anti-collision method for offshore wind turbine monopile foundations according to claim 1, characterized in that, The anti-collision device is a buffer energy-absorbing structure surrounding the outside of the wind turbine monopile foundation. The buffer energy-absorbing structure is driven by a lifting motor to slide up and down along a sliding groove to realize the active lifting and lowering of the anti-collision device. The sliding groove is set outside the wind turbine monopile foundation.

3. The active anti-collision method for offshore wind turbine monopile foundations according to claim 1 or 2, characterized in that, The collision limit safety zone S 1 This means that as soon as a potential collision object enters the area, the water level is determined and the anti-collision device is immediately deployed. The minimum area of ​​this area cannot be less than the area required for the wind turbine monopile foundation to deploy the anti-collision device before a collision occurs.

4. The active anti-collision method for offshore wind turbine monopile foundations according to claim 3, characterized in that, Collision Limit Safety Zone S 1 area S area-1 The calculation is shown in equation (1): （1）； In the formula: r s1 For the collision limit safety zone S 1 radius, ; T f Indicates the time required for the anti-collision device to be lowered; v w The speed of the potential collision object; If the potential collision object is a ship, then v w This indicates the ship's speed; if the potential collision object is not a ship, then... v w Indicates the speed of a non-potential collision object; R w This is the wind speed coefficient; when the wind speed is greater than 30 m / s, R w =0.65, when the wind speed is greater than 10 m / s and less than 30 m / s. R w =0.9, when the wind speed is less than 10 m / s, R w =1.0; R l This is the sea state coefficient; when the wave height is greater than 6m, R l =0.65, when the wave height is greater than 1.25m and less than 6m. R l =0.9, when the wave height is less than 1.25m, R l =1.

0.

5. The active anti-collision method for offshore wind turbine monopile foundations according to claim 4, characterized in that, The key monitoring areas S 2 This refers to the area where there is a high probability of collision between the ship and the wind turbine monopile foundation, requiring close monitoring of the ship; its minimum area cannot be less than the area calculated by formula (2); （2）； In the formula: r 2 For the braking stroke of a ship; S area-2 Key monitoring areas S 2 The area.

6. The active anti-collision method for offshore wind turbine monopile foundations according to claim 1, characterized in that, The tracking and identification area S 3 This refers to the area where the ship still has the potential to collide with the wind turbine monopile foundation, which is the area outside the collision limit safety zone and key monitoring area within the monitoring range.

7. The active anti-collision method for offshore wind turbine monopile foundations according to claim 1, characterized in that, The risk assessment χ uses the model shown in equation (3): （3）； In the formula: r s1 For the collision limit safety zone S 1 The radius; r s For monitoring scope S The radius; d This indicates the closest distance between the ship and the wind turbine foundation under the predicted trajectory; R w This is the wind speed coefficient; when the wind speed is greater than 30 m / s, R w =0.65, when the wind speed is greater than 10 m / s and less than 30 m / s. R w =0.9, when the wind speed is less than 10 m / s, R w =1.0; R v This is the visibility factor, which is used when visibility is less than 3 miles. R v =0.7, visibility less than 5 miles and greater than 3 miles. R v =0.85, when visibility is greater than 5 miles. R v =1.0; R b This is the correction factor for the fan position. R b =exp(( θ-π / 2), θ This refers to the turning angle of the ship relative to the wind turbine; R l This is the sea state coefficient; when the wave height is greater than 6m, R l =0.65, when the wave height is greater than 1.25m and less than 6m. R l =0.9, when the wave height is less than 1.25m, R l =1.0; R d The monitoring range is the ship density coefficient within the monitoring range S. S When the internal ship density is low, R d =1, monitoring range S When the density of the internal ships is the average density, R d =0.8, monitoring range S When the density of ships inside is high R d =0.

6.

8. The active anti-collision method for offshore wind turbine monopile foundations according to claim 1, characterized in that, Collision warning threshold The computational model is shown in equation (4). （4）； In the formula: This serves as the base value for the early warning threshold. R w This is the wind speed coefficient; when the wind speed is greater than 30 m / s, R w =0.65, when the wind speed is greater than 10 m / s and less than 30 m / s. R w =0.9, when the wind speed is less than 10 m / s, R w =1.0; R v This is the visibility factor, which is used when visibility is less than 3 miles. R v =0.7, visibility less than 5 miles and greater than 3 miles. R v =0.85, when visibility is greater than 5 miles. R v =1.0; R l This is the sea state coefficient; when the wave height is greater than 6m, R l =0.65, when the wave height is greater than 1.25m and less than 6m. R l =0.9, when the wave height is less than 1.25m, R l =1.0.

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