A wind turbine tower clearance monitoring system and method

Abstract

The application provides a wind turbine tower clearance monitoring system, comprising a high-definition camera, a data acquisition and transmission module and a central processor, the high-definition camera is installed at the bottom of the cabin, the data acquisition and transmission module is further connected with an infrared thermal imager and a control module, the infrared thermal imager is also installed at the bottom of the cabin, and the infrared thermal imager faces the direction from the high position of the blade to the tower, the installation angle of the high-definition camera and the infrared thermal imager is adjustable; a laser spotlight is installed at the bottom of the tower; the control module is connected with the infrared thermal imager and the laser spotlight, a light sensor is arranged in the control module, and the application further provides a monitoring method of the monitoring system, the video clearance monitoring and the infrared thermal imaging monitoring technology are combined to monitor the tower clearance, the effective monitoring of the tower clearance under low light intensity can be ensured, and the monitoring precision is high and the accuracy is good.

Description

Technical Field

[0001] This invention relates to the field of wind turbine tower clearance monitoring technology, and in particular to a wind turbine tower clearance monitoring system and monitoring method. Background Technology

[0002] The tower clearance of a wind turbine refers to the minimum distance between the blade tip and the tower when the blade passes over it during rotor rotation. Insufficient tower clearance may pose a risk of blade collision with the tower. To ensure the safe operation of wind turbine generators, it is necessary to monitor the tower clearance. Real-time monitoring of tower clearance has become a crucial technology in the industry.

[0003] Currently, methods for monitoring airspace clearance include video monitoring (such as patent publications CN115830484A, CN111336073A, and CN111911364A), lidar monitoring (such as patent publications CN112267980A, CN113586367A, and CN115807741A), and infrared thermal imaging monitoring (such as patent publications CN112539143A and CN217002157U). Among these, video airspace clearance monitoring is a relatively mainstream technology, characterized by its maturity and monitoring capabilities. While lidar offers high precision, it suffers from drawbacks such as insufficient imaging of blade tips and large monitoring accuracy errors in low-light conditions like nighttime, sandstorms, or fog. LiDAR monitoring is also significantly affected by weather and atmospheric conditions, with accuracy being greatly impacted in heavy rain, dense smoke, or foggy mornings. Infrared thermal imaging monitoring technology, on the other hand, inevitably captures the ground when the infrared thermal imaging lens is pointed at the tower or blades. The high ground temperature and significant temperature differences at different locations result in high brightness of the ground area in the image, and these brightness differences negatively affect monitoring accuracy. Summary of the Invention

[0004] To address the aforementioned shortcomings in the existing technology, this invention provides a wind turbine tower clearance monitoring system. This system combines video clearance monitoring with infrared thermal imaging monitoring technology to monitor the tower clearance, ensuring effective monitoring of the tower clearance even in low light conditions, with high monitoring accuracy and precision.

[0005] The technical solution adopted to achieve the above-mentioned objectives of this invention is as follows:

[0006] A wind turbine tower clearance monitoring system includes at least a high-definition camera, a data acquisition and transmission module, and a central processing unit connected in sequence. The high-definition camera is installed at the bottom of the nacelle between the tower and the blades, facing downwards towards the tower and blade tips. The data acquisition and transmission module is also connected to an infrared thermal imager and a control module. The infrared thermal imager is also installed at the bottom of the nacelle between the tower and the blades, with its mounting surface on the nacelle and the mounting surface of the high-definition camera on the same plane. The angle λ between the mounting surfaces of the infrared thermal imager and the high-definition camera on the nacelle is 90°. When looking from the tower towards the blades, the infrared thermal imager is located to the left of the high-definition camera, and its orientation changes from high to low towards the tower. The mounting angles of the high-definition camera and the infrared thermal imager are adjustable. A laser spotlight is installed at the bottom of the tower, illuminating the tower and blade tips.

[0007] The control module is connected to the infrared thermal imager and the laser spotlight. The control module is equipped with a light sensor, which monitors the ambient light intensity and transmits the monitored data to the control module and the data acquisition and transmission module. The control module controls the infrared thermal imager and the laser spotlight to turn on or off based on the magnitude of the light intensity data.

[0008] Under windless conditions, the angle θ between the center line of the lens of the infrared thermal imager and the horizontal plane satisfies -5°≤θ≤15°.

[0009] The high-definition camera is mounted on the bottom of the cabin via a first mounting bracket. The first mounting bracket includes a first mounting plate, a first upper adjustment plate, a first lower adjustment plate, and a camera mounting plate. The first mounting plate and the first upper adjustment plate are fixedly connected in a T-shape, and the first lower adjustment plate and the camera mounting plate are also fixedly connected in a T-shape. The first upper adjustment plate has a first fixing hole and a first adjustment hole on its side. The first adjustment hole is arc-shaped with the first fixing hole as its center. The first lower adjustment plate has two corresponding first mounting holes on its side away from the camera mounting plate. The two first mounting holes are fixedly connected to the first fixing hole and the first adjustment hole respectively by bolts. By changing the position of the bolts in the first adjustment holes, the installation angle between the first upper adjustment plate and the first lower adjustment plate can be adjusted. The high-definition camera is fixed to the side of the camera mounting plate away from the first lower adjustment plate, and the side of the first mounting plate away from the first upper adjustment plate is fixed to the bottom of the cabin, thereby mounting the high-definition camera on the bottom of the cabin.

[0010] The first mounting plate is installed at the bottom of the cabin by bolting or gluing, and the camera mounting plate is connected to the high-definition camera by bolting or gluing.

[0011] The infrared thermal imager is mounted on the bottom of the cabin via a second mounting bracket. The second mounting bracket includes a second mounting plate, a second upper adjusting plate, a second lower adjusting plate, and an infrared thermal imager mounting plate. The second mounting plate and the second upper adjusting plate are fixedly connected in a T-shape, and the second lower adjusting plate and the infrared thermal imager mounting plate are also fixedly connected in a T-shape. The second upper adjusting plate has a second fixing hole and a second adjusting hole on its side away from the second mounting plate. The second adjusting hole is arc-shaped with the second fixing hole as its center. The second lower adjusting plate has two corresponding second mounting holes on its side away from the infrared thermal imager mounting plate. The two second mounting holes are fixedly connected to the second fixing hole and the second adjusting hole respectively by bolts. By changing the position of the bolts within the second adjusting holes, the installation angle between the second upper adjusting plate and the second lower adjusting plate can be adjusted. The infrared thermal imager is fixed to the side of the infrared thermal imager mounting plate away from the second lower adjusting plate, and the side of the second mounting plate away from the second upper adjusting plate is fixed to the bottom of the cabin, thus mounting the infrared thermal imager on the bottom of the cabin.

[0012] The second mounting plate is installed at the bottom of the cabin by bolting or bonding, and the infrared thermal imager mounting plate is connected to the infrared thermal imager by bolting or bonding.

[0013] The present invention also provides a monitoring method for a wind turbine tower clearance monitoring system, including the following steps: (1) Install a high-definition camera and adjust the installation angle of the high-definition camera so that the high-definition camera can capture images of the tower and blade tips below in real time, and record the angle α between the center line of the lens of the high-definition camera and the installation surface of the high-definition camera on the nacelle;

[0014] (2) Install the infrared thermal imager and adjust its installation angle so that the mounting surface of the infrared thermal imager on the nacelle and the mounting surface of the high-definition camera on the nacelle are on the same plane, and the angle λ between the mounting surface of the infrared thermal imager on the nacelle and the mounting surface of the high-definition camera on the nacelle is 90°. The infrared thermal imager captures images of the blade tip and records the angle θ between the center line of the lens of the infrared thermal imager and the horizontal plane, as well as the angle β between the center line of the lens of the infrared thermal imager and the mounting surface of the infrared thermal imager on the nacelle. At the same time, record the front-to-back distance L1 and the left-to-right distance L2 between the mounting surface of the high-definition camera on the nacelle and the mounting surface of the infrared thermal imager on the nacelle.

[0015] (3) Based on the structural dimensions of the high-definition camera and its mounting components, the infrared thermal imager and its mounting components, and the above parameters L1, L2, α, β, determine the relative position and relative shooting angle of the lens of the high-definition camera and the lens of the infrared thermal imager in three-dimensional space.

[0016] (4) Connect the infrared thermal imager and laser spotlight to the control module, connect the high-definition camera, infrared thermal imager and control module to the data acquisition and transmission module, and connect the data acquisition and transmission module to the central processing unit.

[0017] During the operation of the wind turbine, the light sensor in the control module monitors the ambient light intensity, and the data acquisition and transmission module receives image information captured by the high-definition camera and the infrared thermal imager, as well as the ambient light intensity signal monitored by the light sensor.

[0018] (5) When the ambient light intensity is greater than the set threshold, the control module does not turn on the infrared thermal imager and laser spotlight. The central processing unit determines the position and relative distance of the tower and the blade tip in the image based on the image of the tower and the blade tip captured by the high-definition camera, according to the shape characteristics and grayscale comparison of the tower and the blade tip. Then, based on the ratio of the image size to the actual size, the minimum distance between the tower and the blade tip, i.e. the tower clearance value, is calculated.

[0019] (6) When the ambient light intensity is less than or equal to the set threshold, the control module turns on the infrared thermal imager and the laser spotlight, captures the image of the blade tip through the infrared thermal imager, captures the image of the tower through the high-definition camera, and transmits the image data to the central processing unit through the data acquisition and transmission module; the image processing software of the central processing unit synthesizes the image of the blade tip captured by the infrared thermal imager and the image of the tower captured by the high-definition camera based on the relative position and relative shooting angle of the lens of the high-definition camera and the lens of the infrared thermal imager in three-dimensional space; the blade tip images of the same blade at different positions during one revolution of the impeller are connected into a line, and the line is extended to the position of the tower in the synthesized image. The distance between the extended line and the tower in the synthesized image is the representation of the tower clearance value in the image. The actual tower clearance value can be calculated according to the ratio of the image size to the actual size.

[0020] (7) When the tower clearance value reaches the set threshold, an early warning message will be issued.

[0021] Compared with the prior art, the technical solution provided by the present invention has the following advantages:

[0022] 1. The wind turbine tower clearance monitoring system provided by this invention captures images of the tower using a high-definition camera and images of the blade tips using an infrared thermal imager in low-light conditions such as at night. Based on the relative positions and shooting angles of the high-definition camera lens and the infrared thermal imager lens in three-dimensional space, the system uses central processing unit image processing software to perform high-precision image synthesis, thereby accurately identifying and calculating the tower clearance value, ensuring the effective accuracy of tower clearance monitoring in low light conditions.

[0023] 2. In the wind turbine tower clearance monitoring system provided by the present invention, the high-definition camera is installed at the bottom of the nacelle via the first mounting bracket, and the infrared thermal imager is installed at the bottom of the nacelle via the second mounting bracket, which is stable and reliable. Moreover, the first and second mounting brackets have simple structures and can conveniently and quickly adjust the installation angle of the high-definition camera and the infrared thermal imager, thereby adjusting the shooting direction of the high-definition camera and the infrared thermal imager.

[0024] 3. In this invention, the angle θ between the center line of the infrared thermal imager's lens and the horizontal plane satisfies -5°≤θ≤15°. In low-light conditions such as at night, when photographing the leaf tip, the infrared thermal imager uses the sky as a background. The background temperature is relatively uniform with minimal differences, allowing for clear comparison and display of the leaf shape characteristics, thus effectively identifying the leaf tip. This effectively avoids the problem in existing technologies where the infrared thermal imager lens points to the ground, resulting in high ground temperature and large temperature differences at different locations, leading to high brightness and significant brightness variations in the ground area in the image, which affects monitoring accuracy.

[0025] 4. In this invention, a laser spotlight is installed at the bottom of the tower to ensure that the high-definition camera can clearly capture images of the tower in low-light conditions such as at night, further improving the accuracy of tower clearance monitoring in low light conditions.

[0026] 5. In this invention, both the laser spotlight and the infrared thermal imager are connected to the control module. The control module is equipped with a light sensor, which monitors the ambient light intensity and transmits the monitored data to the control module and the data acquisition and transmission module. The control module controls the infrared thermal imager and the laser spotlight to turn on or off based on the magnitude of the light intensity data. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the installation of the high-definition camera and infrared thermal imager on the wind turbine in this invention;

[0028] Figure 2 This is a schematic diagram showing the connection between the first mounting plate and the first upper adjusting plate of the first mounting bracket in this invention;

[0029] Figure 3 This is a schematic diagram showing the connection between the first lower adjusting plate of the first mounting bracket and the camera mounting plate in this invention;

[0030] Figure 4 This is a schematic diagram of the connection structure between the first mounting bracket and the high-definition camera in this invention;

[0031] Figure 5 This is a schematic diagram showing the connection between the second mounting plate and the second upper adjusting plate of the second mounting bracket in this invention;

[0032] Figure 6This is a schematic diagram showing the connection between the second lower adjustment plate of the second mounting bracket and the infrared thermal imager mounting plate in this invention;

[0033] Figure 7 This is a schematic diagram showing the connection between the second mounting bracket and the infrared thermal imager in this invention;

[0034] Figure 8 for Figure 1 A schematic diagram showing the relative positions of a medium-to-high-definition camera and an infrared thermal imager;

[0035] Figure 9 This is a side view of the installation of the high-definition camera in this invention;

[0036] Figure 10 This is a front view of the infrared thermal imager installed in this invention;

[0037] Figure 11 This is a top view showing the relative positions of the high-definition camera and the infrared thermal imager in this invention;

[0038] Figure 12 A schematic diagram showing the representation of the tower clearance D in the composite image;

[0039] In the diagram: 1-High-definition camera, 2-Infrared thermal imager, 31-Tower, 32-Blade, 33-Nacelle, 4-First mounting bracket, 41-First mounting plate, 42-First upper adjustment plate, 421-First fixing hole, 422-First adjustment hole, 43-First lower adjustment plate, 431-First mounting hole, 44-Camera mounting plate, 5-Second mounting bracket, 51-Second mounting plate, 52-Second upper adjustment plate, 521-Second fixing hole, 522-Second adjustment hole, 53-Second lower adjustment plate, 531-Second mounting hole, 54-Infrared thermal imager mounting plate, 6-Mounting surface of the high-definition camera on the nacelle, 7-Mounting surface of the infrared thermal imager on the nacelle, 8-Image of the tower taken by the high-definition camera, 9-Image of the blade tip of the same blade at different positions during one revolution of the impeller. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0041] The wind turbine tower clearance monitoring system provided by the present invention includes a high-definition camera 1, an infrared thermal imager 2, a laser spotlight, a control module, a data acquisition and transmission module, and a central processing unit (the laser spotlight, control module, data acquisition and transmission module, and central processing unit are not shown in the figure).

[0042] The high-definition camera is installed at the bottom of the nacelle 33, between the tower 31 and the blade 32, facing downwards towards the tower and blade tips to capture images of these areas. In this embodiment, the installation angle of the high-definition camera is adjustable. Specifically, the high-definition camera is installed at the bottom of the nacelle via a first mounting bracket 4. The first mounting bracket includes a first mounting plate 41, a first upper adjusting plate 42, a first lower adjusting plate 43, and a camera mounting plate 44. The first mounting plate and the first upper adjusting plate are fixedly connected in a T-shape, and the first lower adjusting plate and the camera mounting plate are also fixedly connected in a T-shape. To ensure a stable connection, ribs are fixedly connected between the first mounting plate and the first upper adjusting plate, and between the first lower adjusting plate and the camera mounting plate. The first upper adjustment plate has a first fixing hole 421 and a first adjustment hole 422 on its side. The first adjustment hole is arc-shaped with the first fixing hole as its center. The first lower adjustment plate has two corresponding first mounting holes 431 on its side away from the camera mounting plate. These two mounting holes are respectively fixed to the first fixing hole and the first adjustment hole by bolts. By changing the position of the bolts within the first adjustment holes, the installation angle between the first upper and first lower adjustment plates can be adjusted. The high-definition camera is fixed to the side of the camera mounting plate away from the first lower adjustment plate by bolting or gluing. The side of the first mounting plate away from the first upper adjustment plate is fixed to the bottom of the cabin by bolting or gluing, thus mounting the high-definition camera to the bottom of the cabin. All connections are bolted. When the installation angle between the first upper and first lower adjustment plates is adjusted, the installation angle of the high-definition camera is adjusted accordingly. Figures 2-4 As shown.

[0043] The infrared thermal imager is also installed at the bottom of the nacelle, between the tower and the blades. The mounting surface 7 of the infrared thermal imager on the nacelle and the mounting surface 6 of the high-definition camera on the nacelle are on the same plane. The angle λ between the mounting surfaces of the infrared thermal imager and the high-definition camera on the nacelle is 90°. (See...) Figure 11In this embodiment, the installation angle of the infrared thermal imager is adjustable. Specifically, the infrared thermal imager is installed on the bottom of the cabin via a second mounting bracket 5. The structure of the second mounting bracket is similar to that of the first mounting bracket, including a second mounting plate 51, a second upper adjusting plate 52, a second lower adjusting plate 53, and an infrared thermal imager mounting plate 54. The second mounting plate and the second upper adjusting plate are fixedly connected to form a T-shaped structure, and the second lower adjusting plate and the infrared thermal imager mounting plate are also fixedly connected to form a T-shaped structure. To ensure a stable connection, ribs are fixedly connected between the first mounting plate and the first upper adjusting plate, and between the first lower adjusting plate and the camera mounting plate. The second upper adjusting plate has a second fixing hole 521 and a second adjusting hole 522 on the side away from the second mounting plate. The second adjusting hole is arc-shaped with the second fixing hole as its center. The second lower adjusting plate has two corresponding second mounting holes 531 on the side away from the infrared thermal imager mounting plate. These two mounting holes are respectively fixed to the second fixing hole and the second adjusting hole by bolts. By changing the position of the bolts within the second adjusting holes, the installation angle between the second upper and lower adjusting plates is adjusted. The infrared thermal imager is fixed to the side of the infrared thermal imager mounting plate away from the second lower adjusting plate by bolting or bonding. The side of the second mounting plate away from the second upper adjusting plate is fixed to the bottom of the cabin by bolting or bonding, thus installing the infrared thermal imager at the bottom of the cabin. All connections are bolted. When the installation angle between the second upper and lower adjusting plates is adjusted, the installation angle of the infrared thermal imager is adjusted accordingly. Figures 5-7 As shown. When looking at the blade from the tower, the infrared thermal imager is located to the left of the high-definition camera, and the infrared thermal imager is facing the blade from a high position towards the tower, as shown. Figure 1 and Figure 8 As shown.

[0044] Specifically, under windless conditions, the angle θ between the center line of the infrared thermal imager's lens and the horizontal plane satisfies -5°≤θ≤15°. At night or in low-light conditions, when photographing the blade tip, the infrared thermal imager uses the sky as a background. The background temperature is relatively uniform with minimal differences, allowing for clear comparison and display of the blade's shape characteristics, thus effectively identifying the blade tip. This effectively avoids the problem in existing technologies where the infrared thermal imager lens points to the ground, resulting in high ground temperature and large temperature differences at different locations, leading to high brightness and significant brightness variations in the ground area in the image, which affects monitoring accuracy.

[0045] The laser spotlight is installed at the bottom of the tower, illuminating the tower and the blade tips. The control module is connected to the infrared thermal imager and the laser spotlight. The control module is equipped with a light sensor that monitors the ambient light intensity and transmits the monitored data to the control module. The control module controls the infrared thermal imager and the laser spotlight to turn on or off based on the intensity of the light.

[0046] The high-definition camera, infrared thermal imager, and control module are all connected to the data acquisition and transmission module. The data acquisition and transmission module receives image data captured by the high-definition camera and infrared thermal imager, as well as ambient light intensity signals monitored by the light sensor. The data acquisition and transmission module is connected to the central processing unit via wired or wireless means, thereby transmitting the received data to the central processing unit. The central processing unit can analyze the images and identify the position of the tower and blade tips based on shape features and grayscale characteristics.

[0047] The monitoring method of the wind turbine tower clearance monitoring system provided by the present invention includes the following steps: (1) Installing a high-definition camera and adjusting the installation angle of the high-definition camera so that the high-definition camera can capture images of the tower and blade tips below in real time, and recording the angle α between the center line of the lens of the high-definition camera and the mounting surface of the high-definition camera on the nacelle (i.e., the mounting surface of the first mounting plate), such as Figure 9 As shown;

[0048] (2) Install the infrared thermal imager and adjust its installation angle so that the mounting surface of the infrared thermal imager on the nacelle (i.e., the mounting surface of the second mounting plate) and the mounting surface of the high-definition camera on the nacelle (i.e., the mounting surface of the first mounting plate) are on the same plane, and the angle λ between the mounting surface of the infrared thermal imager on the nacelle and the mounting surface of the high-definition camera on the nacelle is 90°, that is, the angle between the length direction of the second mounting plate and the length direction of the first mounting plate is 90°. The infrared thermal imager captures images of the blade tips, and records the angle θ between the center line of the lens of the infrared thermal imager and the horizontal plane, and the angle β between the center line of the lens of the infrared thermal imager and the mounting surface of the infrared thermal imager on the nacelle; at the same time, record the front-to-back distance L1 and the left-to-right distance L2 between the mounting surface of the high-definition camera on the nacelle and the mounting surface of the infrared thermal imager on the nacelle, such as Figure 11 As shown;

[0049] (3) Based on the structural dimensions of the high-definition camera and its mounting components (first mounting bracket), the infrared thermal imager and its mounting components (second mounting bracket), and the aforementioned parameters L1, L2, α, θ, β, determine the relative position and relative shooting angle of the lens of the high-definition camera and the lens of the infrared thermal imager in three-dimensional space.

[0050] (4) Connect the infrared thermal imager and laser spotlight to the control module, connect the high-definition camera, infrared thermal imager and control module to the data acquisition and transmission module, and connect the data acquisition and transmission module to the central processing unit.

[0051] During the operation of the wind turbine, the light sensor in the control module monitors the ambient light intensity, and the data acquisition and transmission module receives image information captured by the high-definition camera and the infrared thermal imager, as well as the ambient light intensity signal monitored by the light sensor.

[0052] (5) When the ambient light intensity is greater than the set threshold, the control module does not turn on the infrared thermal imager and laser spotlight. The central processing unit determines the position and relative distance of the tower and the blade tip in the image based on the image of the tower and the blade tip captured by the high-definition camera, according to the shape characteristics and grayscale comparison of the tower and the blade tip. Then, based on the ratio of the image size to the actual size, the minimum distance between the tower and the blade tip, i.e. the tower clearance value, is calculated.

[0053] (6) When the ambient light intensity is less than or equal to a set threshold, the control module turns on the infrared thermal imager and laser spotlight, captures images of the blade tip through the infrared thermal imager, captures images of the tower through the high-definition camera, and transmits the image data to the central processing unit through the data acquisition and transmission module; the image processing software of the central processing unit synthesizes the blade tip image captured by the infrared thermal imager and the tower image 8 captured by the high-definition camera based on the relative positions and relative shooting angles of the lens of the high-definition camera and the lens of the infrared thermal imager in three-dimensional space; the blade tip images 9 of the same blade at different positions during one revolution of the impeller are connected into a line, and the line is extended to the position of the tower in the synthesized image. The distance D between the extended line and the tower in the synthesized image is the representation of the tower clearance value in the image, such as Figure 12 As shown, the actual tower clearance value can be calculated based on the ratio of the image size to the actual size.

[0054] (7) When the tower clearance value reaches the set threshold, an early warning message will be issued.

Claims

1. A wind turbine tower clearance monitoring system, comprising at least a high-definition camera, a data acquisition and transmission module, and a central processing unit connected in sequence, characterized in that: The high-definition camera is installed at the bottom of the nacelle, between the tower and the blades, facing downwards towards the tower and blade tips. The high-definition camera is mounted on the bottom of the nacelle via a first mounting bracket, which includes a first mounting plate, a first upper adjusting plate, a first lower adjusting plate, and a camera mounting plate. The first mounting plate and the first upper adjusting plate are fixedly connected in a T-shape, as are the first lower adjusting plate and the camera mounting plate. The first upper adjusting plate has a first fixing hole and a first adjusting hole on its side. The first adjusting hole is arc-shaped with the first fixing hole as its center. The first lower adjusting plate has two corresponding first mounting holes on its side away from the camera mounting plate. These two first mounting holes are fixed to the first fixing hole and the first adjusting hole respectively using bolts. By changing the position of the bolts within the first adjusting holes, the installation angle between the first upper and first lower adjusting plates can be adjusted. The high-definition camera is fixed to the side of the camera mounting plate away from the first lower adjusting plate, and the side of the first mounting plate away from the first upper adjusting plate is fixed to the bottom of the nacelle, thus mounting the high-definition camera at the bottom of the nacelle. The data acquisition and transmission module is also connected to an infrared thermal imager and a control module. The infrared thermal imager is also installed at the bottom of the nacelle, located between the tower and the blade. The mounting surface of the infrared thermal imager on the nacelle is on the same plane as the mounting surface of the high-definition camera on the nacelle. The angle λ between the mounting surface of the infrared thermal imager and the mounting surface of the high-definition camera on the nacelle is 90°. When looking from the tower towards the blade, the infrared thermal imager is located to the left of the high-definition camera, and the infrared thermal imager faces the blade from a high position to the tower. The mounting angles of the high-definition camera and the infrared thermal imager are adjustable. The infrared thermal imager is installed at the bottom of the nacelle via a second mounting bracket. The second mounting bracket includes a second mounting plate, a second upper adjustment plate, a second lower adjustment plate, and an infrared thermal imager mounting plate. The second mounting plate and the second upper adjustment plate are fixedly connected in a T-shape. The second lower adjustment plate and the infrared thermal imager mounting plate are also fixedly connected in a T-shape. A second fixing hole and a second adjustment are provided on the side of the second upper adjustment plate away from the second mounting plate. The second adjustment hole is an arc-shaped hole with the second fixing hole as its center. Two second mounting holes are correspondingly provided on the side of the second lower adjustment plate away from the infrared thermal imager mounting plate. These two mounting holes are fixed to the second fixing hole and the second adjustment hole respectively by bolts. The installation angle between the second upper adjustment plate and the second lower adjustment plate is adjusted by changing the position of the bolts within the second adjustment holes. The infrared thermal imager is fixed to the side of the infrared thermal imager mounting plate away from the second lower adjustment plate. The side of the second mounting plate away from the second upper adjustment plate is fixed to the bottom of the nacelle, thus mounting the infrared thermal imager at the bottom of the nacelle. A laser spotlight is installed at the bottom of the tower, illuminating the tower and blade tips. The control module is connected to the infrared thermal imager and the laser spotlight. The control module contains a light sensor that monitors the ambient light intensity and transmits the monitored data to the control module and the data acquisition and transmission module. The control module controls the opening or closing of the infrared thermal imager and the laser spotlight based on the intensity of the light data.

2. The wind turbine tower clearance monitoring system according to claim 1, characterized in that: Under windless conditions, the angle θ between the center line of the lens of the infrared thermal imager and the horizontal plane satisfies -5°≤θ≤15°.

3. The wind turbine tower clearance monitoring system according to claim 1, characterized in that: The first mounting plate is installed at the bottom of the cabin by bolting or gluing, and the camera mounting plate is connected to the high-definition camera by bolting or gluing.

4. The wind turbine tower clearance monitoring system according to claim 1, characterized in that: The second mounting plate is installed at the bottom of the cabin by bolting or bonding, and the infrared thermal imager mounting plate is connected to the infrared thermal imager by bolting or bonding.

5. A monitoring method for the wind turbine tower clearance monitoring system according to claim 2, characterized in that... Includes the following steps: (1) Install a high-definition camera and adjust the installation angle of the high-definition camera so that the high-definition camera can capture images of the tower and blade tips below in real time, and record the angle α between the center line of the lens of the high-definition camera and the mounting surface of the high-definition camera on the nacelle. (2) Install the infrared thermal imager and adjust its installation angle so that the mounting surface of the infrared thermal imager on the nacelle and the mounting surface of the high-definition camera on the nacelle are on the same plane, and the angle λ between the mounting surface of the infrared thermal imager on the nacelle and the mounting surface of the high-definition camera on the nacelle is 90°. The infrared thermal imager captures images of the blade tip and records the angle θ between the center line of the lens of the infrared thermal imager and the horizontal plane, as well as the angle β between the center line of the lens of the infrared thermal imager and the mounting surface of the infrared thermal imager on the nacelle. At the same time, record the front-to-back distance L1 and the left-to-right distance L2 between the mounting surface of the high-definition camera on the nacelle and the mounting surface of the infrared thermal imager on the nacelle. (3) Based on the structural dimensions of the high-definition camera and its mounting components, the infrared thermal imager and its mounting components, and the above parameters L1, L2, α, β, determine the relative position and relative shooting angle of the lens of the high-definition camera and the lens of the infrared thermal imager in three-dimensional space. (4) Connect the infrared thermal imager and laser spotlight to the control module, connect the high-definition camera, infrared thermal imager and control module to the data acquisition and transmission module, and connect the data acquisition and transmission module to the central processing unit. During the operation of the wind turbine, the light sensor in the control module monitors the ambient light intensity, and the data acquisition and transmission module receives image information captured by the high-definition camera and the infrared thermal imager, as well as the ambient light intensity signal monitored by the light sensor. (5) When the ambient light intensity is greater than the set threshold, the control module does not turn on the infrared thermal imager and laser spotlight. The central processing unit determines the position and relative distance of the tower and the blade tip in the image based on the image of the tower and the blade tip captured by the high-definition camera, according to the shape characteristics and grayscale comparison of the tower and the blade tip. Then, based on the ratio of the image size to the actual size, the minimum distance between the tower and the blade tip, i.e. the tower clearance value, is calculated. (6) When the ambient light intensity is less than or equal to the set threshold, the control module turns on the infrared thermal imager and the laser spotlight, captures the image of the blade tip through the infrared thermal imager, captures the image of the tower through the high-definition camera, and transmits the image data to the central processing unit through the data acquisition and transmission module; the image processing software of the central processing unit synthesizes the image of the blade tip captured by the infrared thermal imager and the image of the tower captured by the high-definition camera based on the relative position and relative shooting angle of the lens of the high-definition camera and the lens of the infrared thermal imager in three-dimensional space; the blade tip images of the same blade at different positions during one revolution of the impeller are connected into a line, and the line is extended to the position of the tower in the synthesized image. The distance between the extended line and the tower in the synthesized image is the representation of the tower clearance value in the image. The actual tower clearance value can be calculated according to the ratio of the image size to the actual size. (7) When the tower clearance value reaches the set threshold, an early warning message will be issued.

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