Method for collecting fan blade image

Abstract

This application discloses a method for acquiring images of wind turbine blades, relating to the field of operation and maintenance technology. The disclosed method includes: determining the linear velocity at the inspection position of the target blade during the rotation of the wind turbine blade, and determining the target rotational angular velocity of the mobile imaging terminal based on the linear velocity; determining the remaining time for the inspection position to reach the imaging point based on the current angle of the target blade, the target angle corresponding to the shooting point of the mobile imaging terminal, and the rotational speed of the target blade; performing delay compensation on the remaining time to obtain the control trigger time of the mobile imaging terminal; and sending a control command to the mobile imaging terminal at the control trigger time so that when the target blade reaches the target angle, the mobile imaging terminal is already at the target rotational angular velocity and takes a picture of the inspection position, thereby obtaining a blade image of the target blade at the inspection position. This solution enables the acquisition of clear blade images in scenarios where the wind turbine remains operational.

Description

Technical Field

[0001] This application relates to the field of operation and maintenance technology, and in particular to a method for acquiring images of wind turbine blades. Background Technology

[0002] As a key component of wind turbine units, wind turbine blades are exposed to harsh natural environments for extended periods, enduring alternating loads, wind and sand erosion, lightning strikes, and ultraviolet radiation. This makes them prone to defects such as cracks, corrosion, gel coat peeling, and leading-edge wear. Failure to detect and address these defects in a timely manner can lead to serious accidents such as blade breakage, resulting in significant economic losses and safety risks. Therefore, regular inspections of wind turbine blades are crucial.

[0003] Currently, during the rotation of wind turbine blades, a synchronous angular velocity method is used to control the mobile shooting terminal to track and shoot the rotating blades. That is, the angular velocity is determined based on the overall rotation speed of the blades, and then the shooting terminal is controlled to rotate and follow at the same angular velocity to achieve synchronous shooting.

[0004] However, the linear velocities at different radial positions on the blades vary significantly, resulting in constant relative motion between the imaging terminal and the inspected position on the blade, leading to image blurring and other problems. Furthermore, the mobile imaging terminal experiences various system delays during actual operation, exacerbating tracking deviations and further affecting image clarity. Therefore, photographing wind turbine blades using the above method suffers from low image clarity and poor image quality.

[0005] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0006] The main purpose of this application is to provide a method for acquiring wind turbine blade images, which aims to solve the technical problem of low clarity in wind turbine blade images acquired under non-stop wind turbine scenarios.

[0007] To achieve the above objectives, this application proposes a method for acquiring images of wind turbine blades, the method comprising: During the rotation of the wind turbine blades, the linear velocity at the inspection position of the target blade is determined, and the target rotation angular velocity of the moving camera terminal is determined based on the linear velocity. Based on the current angle of the target blade, the target angle corresponding to the shooting point of the mobile shooting terminal, and the rotation speed of the target blade, determine the remaining time for the target blade to be inspected to reach the shooting point of the mobile shooting terminal. Delay compensation is applied to the remaining time to obtain the control trigger time of the mobile shooting terminal; Control commands are sent to the mobile imaging terminal at the control trigger time so that when the target blade reaches the target angle, the mobile imaging terminal is already at the target rotational angular velocity and takes a picture of the position to be inspected, thus obtaining a blade image of the target blade at the position to be inspected.

[0008] The present application proposes one or more technical solutions, which have at least the following technical effects: Addressing the significant differences in linear velocity at different radial positions of the blade, while angular velocity is a uniform parameter for the overall blade rotation, the inability of single angular velocity synchronization to adapt to the linear velocity differences at different shooting positions leads to reduced blade image clarity. This application first determines the linear velocity of the target blade's inspection position during the wind turbine blade rotation process, and then calculates the corresponding target rotational angular velocity of the mobile shooting terminal. This allows the rotational motion of the shooting terminal to accurately match the linear velocity at that specific position, thereby achieving linear velocity synchronization between the two. Based on this, the remaining time for the target blade's inspection position to reach the shooting point of the mobile shooting terminal is calculated using the target blade's current angle, target angle, and rotational speed. Delay compensation is applied to this remaining time to obtain the control trigger time. Control commands are sent at this trigger time to ensure that the mobile shooting terminal has reached the preset target rotational angular velocity and completed shooting preparation when the blade reaches the target angle. This effectively offsets deviations caused by various delays, ultimately achieving precise relative stillness between the blade and the mobile shooting terminal in scenarios where the wind turbine does not stop, meeting the requirements for high-precision blade monitoring and improving the clarity of blade images. Attached Figure Description

[0009] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a flowchart illustrating the method for acquiring wind turbine blade images according to Embodiment 1 of this application. Figure 2 This is a flowchart illustrating the second embodiment of the wind turbine blade image acquisition method of this application. Figure 3 This is a flowchart illustrating the third embodiment of the wind turbine blade image acquisition method of this application. Figure 4 This is a schematic diagram of the overall process of acquiring wind turbine blade images according to this application; Figure 5This is a flowchart of the adaptive flight control under dynamic safety boundary constraints in this application; Figure 6 This is a schematic diagram of the structure of the mobile shooting terminal of this application.

[0012] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0013] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0014] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0015] As a key component of wind turbine units, wind turbine blades are exposed to harsh natural environments for extended periods, enduring alternating loads, wind and sand erosion, lightning strikes, and ultraviolet radiation. This makes them prone to defects such as cracks, corrosion, gel coat peeling, and leading-edge wear. Failure to detect and address these defects in a timely manner can lead to serious accidents such as blade breakage, resulting in significant economic losses and safety risks. Therefore, regular inspections of wind turbine blades are crucial.

[0016] Currently, the method of angular velocity synchronization is used to control the mobile shooting terminal to track and shoot the rotating blade. That is, the angular velocity is determined according to the overall rotation speed of the blade, and then the shooting terminal is controlled to rotate and follow at the same angular velocity to achieve synchronous shooting.

[0017] However, the linear velocities at different radial positions on the blade (blade root, blade middle, and blade tip) vary significantly, resulting in constant relative motion between the imaging terminal and the location to be inspected on the blade, leading to image blurring and other problems. Furthermore, the mobile imaging terminal experiences various system delays during actual operation, exacerbating tracking deviations and further affecting image clarity. Therefore, photographing wind turbine blades using the above method suffers from low image clarity and poor image quality.

[0018] To address the aforementioned deficiencies, this application proposes a method for acquiring images of wind turbine blades. The main technical solution includes: determining the linear velocity at the inspection position of the target blade during the rotation of the wind turbine blade, and determining the target rotational angular velocity of the mobile imaging terminal based on the linear velocity; determining the remaining time for the inspection position of the target blade to reach the shooting position of the mobile imaging terminal based on the current angle of the target blade, the target angle corresponding to the shooting point of the mobile imaging terminal, and the rotational speed of the target blade; performing delay compensation on the remaining time to obtain the control trigger time of the mobile imaging terminal; and sending a control command to the mobile imaging terminal at the control trigger time so that when the target blade reaches the target angle, the mobile imaging terminal is already at the target rotational angular velocity and is shooting at the inspection position, thereby obtaining a blade image of the target blade at the inspection position.

[0019] To address the significant differences in linear velocity at different radial positions of the blades, while angular velocity is a uniform parameter for the overall blade rotation, single angular velocity synchronization cannot accommodate the linear velocity differences at different shooting positions, leading to reduced blade image clarity. This application first determines the linear velocity of the target blade's inspection position during the wind turbine blade rotation process, and then calculates the corresponding target rotational angular velocity of the mobile shooting terminal. This allows the shooting terminal's rotational motion to precisely match the linear velocity at that specific position, thus achieving linear velocity synchronization between the two. Based on this, the remaining time for the target blade's inspection position to reach the shooting point of the mobile shooting terminal is calculated using the target blade's current angle, target angle, and rotational speed. Delay compensation is applied to this remaining time to obtain the control trigger time. Control commands are sent at this trigger time to ensure that the mobile shooting terminal has reached the preset target rotational angular velocity and completed shooting preparation when the blade reaches the target angle. This effectively offsets deviations caused by various delays, ultimately achieving precise relative stillness between the blades and the mobile shooting terminal in scenarios where the wind turbine does not stop, meeting the requirements for high-precision blade monitoring and improving the clarity of blade images.

[0020] It should be noted that the execution subject in this embodiment can be a wind turbine blade image acquisition and control device, etc. This wind turbine blade image acquisition and control device can be the mobile shooting terminal described in this application, or a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone. The following description uses a mobile shooting terminal as the execution subject as an example to illustrate this embodiment and the subsequent embodiments.

[0021] Based on this, this application provides a method for acquiring images of wind turbine blades. Unlike traditional angular velocity synchronization, this application first calculates the linear velocity of the current inspection position on the blade to be photographed, and then controls the gimbal camera to rotate in space at the same linear velocity. On this basis, considering various delays, a delay compensation model is constructed to predict and compensate for tracking deviations, so as to achieve precise relative stillness between the blade and the camera and ensure clear images.

[0022] Specifically, refer to Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the wind turbine blade image acquisition method of this application.

[0023] In this embodiment, the method for acquiring wind turbine blade images includes steps S10 to S40: Step S10: During the rotation of the wind turbine blades, determine the linear velocity at the inspection position of the target blade, and determine the target rotational angular velocity of the moving camera terminal based on the linear velocity. Wind turbine blades are the core components installed on wind turbine generators to capture wind energy and convert it into mechanical energy, thereby driving the generator to generate electricity. They are usually composed of three parts: the blade root, the blade middle, and the blade tip. The materials are mostly fiberglass, carbon fiber composite materials, etc. The surface condition of the blade directly affects the power generation efficiency and operational safety of the wind turbine.

[0024] The target blade refers to the specific blade among the many blades of a wind turbine that requires image acquisition and status monitoring. It can be selected based on operational needs, such as blades with potential damage or blades requiring regular inspection. Its purpose is to clearly define the acquisition target, avoid blade confusion during the acquisition process, and ensure that the acquired images correspond to the specified blade. For example, if a wind turbine has three blades, numbered 1, 2, and 3, and the focus of this acquisition is on blade number 2, then blade number 2 is the target blade.

[0025] The location to be inspected refers to the specific location on the target leaf where images need to be collected. It can be determined according to monitoring needs, such as the leaf tip, leaf middle, leaf root, or any point on the front and back of the target leaf other than the leaf tip, leaf middle, and leaf root.

[0026] Linear velocity refers to the distance a target blade's inspected position moves along a circular trajectory per unit time during rotation. It is a physical quantity describing how fast that position moves when the blade rotates, and its magnitude is related to the target blade's rotational speed and the distance from that position to the hub center. For example, if the inspected position moves 5 meters per second along the circumference, then the linear velocity at that position is 5 meters per second.

[0027] A mobile imaging terminal refers to a device with flight or mobility capabilities used to acquire images of wind turbine blades. It can adjust its position and shooting angle according to control commands, and its function is to follow the movement of the target blade and acquire clear images of it. For example, the mobile imaging terminal can be a drone. This mobile imaging terminal includes a LiDAR and a gimbal camera; the LiDAR is used to acquire radar point cloud data, and the gimbal camera is used to capture blade image data. The mobile imaging terminal, through the method of this embodiment, can acquire images of wind turbine blades, improving the quality of the acquired blade images.

[0028] The target rotational angular velocity refers to the rotational angular velocity that the moving imaging terminal needs to achieve in order to maintain linear velocity synchronization with the inspection position of the target blade. It is the angle the moving imaging terminal rotates per unit time. Its function is to ensure that the imaging terminal remains aligned with the inspection position throughout the blade's rotation, avoiding problems such as blurry or offset images. It can be calculated from the linear velocity of the inspection position and the relative distance between the moving imaging terminal and the hub center.

[0029] In one alternative approach, during the normal rotation of the wind turbine blades, a laser rangefinder measures the distance from the location to be inspected to the center of the hub, while a speed sensor collects the speed of the target blades in real time to calculate the linear velocity of the location to be inspected. Then, the distance from the mobile camera terminal to the center of the hub is measured, and the linear velocity calculation formula is used to reverse the calculation to obtain the target rotational angular velocity that the mobile camera terminal needs to achieve, ensuring that the linear velocity of the mobile camera terminal is consistent with the linear velocity of the location to be inspected.

[0030] In another alternative approach, during the rotation of the wind turbine blades, machine vision technology is used to capture the contour image of the target blade in real time. Combined with a pre-set 3D model of the blade, the coordinates of the location to be inspected on the blade are determined, and the rotational radius from that location to the hub center is calculated. Simultaneously, the real-time rotational speed of the target blade is acquired and converted into angular velocity, i.e., angular velocity = 2π. The rotational speed is divided by 60, and then the linear velocity of the location to be inspected is calculated. Subsequently, based on the preset fixed distance between the mobile imaging terminal and the center of the hub, the target rotational angular velocity of the mobile imaging terminal is calculated in reverse, and this angular velocity parameter is transmitted to the control module of the mobile imaging terminal to complete the parameter preset. This method does not require the installation of multiple additional sensors and can utilize data from the existing control system of the wind turbine, reducing equipment deployment costs.

[0031] Understandably, by accurately calculating the linear velocity of the location to be inspected and then determining the target rotational angular velocity of the mobile imaging terminal, the linear velocity of the mobile imaging terminal and the location to be inspected is synchronized, rather than just the angular velocity. This effectively eliminates the relative motion between the mobile imaging terminal and the target location caused by the different rotation radii and linear velocity differences at different positions of the blade (root, middle, and tip). This fundamentally solves the image trailing and blurring problems caused by linear velocity mismatch in traditional methods, laying the foundation for subsequent acquisition of clear blade images.

[0032] Step S20: Based on the current angle of the target blade, the target angle corresponding to the shooting point of the mobile shooting terminal, and the rotation speed of the target blade, determine the remaining time for the target blade to be inspected to reach the shooting point of the mobile shooting terminal. The current angle refers to the rotation angle of the target blade relative to the central axis of the wind turbine nacelle at the current moment. It can be collected in real time by an angle sensor to determine the current position of the target blade. This current angle can be predicted based on the angle and rotational angular velocity of the target blade at the previous moment. Alternatively, it can be obtained by scanning the point cloud data of the target blade with a lidar scanner and performing fitting analysis on the point cloud data.

[0033] The target angle is the angle corresponding to the current shooting point of the mobile imaging terminal. This target angle refers to the expected rotation angle of the target blade relative to the central axis of the wind turbine nacelle at the target time, i.e., the angle that the target blade's inspection position needs to reach during image acquisition. This target angle can be the next moment after the current moment, or any specified moment after the current moment. This target angle can be predicted based on the current angle and current rotational angular velocity of the target blade. Specifically, its calculation formula can be expressed as: ,in, From the perspective of the target, From the current perspective, The instantaneous rotational angular velocity of the blade. For time difference.

[0034] Rotational speed refers to the rotational speed of the target blade, that is, the number of revolutions the blade makes per unit time. It is usually measured in revolutions per minute or revolutions per second and is collected in real time by the fan operating parameters or rotational speed sensor. It is used to calculate the remaining time for the target blade to reach the target angle.

[0035] In one alternative approach, the remaining time for the target blade's inspection position to reach the shooting point of the mobile imaging terminal can be determined using a computational model. Specifically, the difference between the target angle and the current angle of the target blade can be determined, and the remaining time for the target blade's inspection position to reach the shooting point of the mobile imaging terminal can be obtained based on the ratio of this difference to the rotational speed of the target blade.

[0036] In another alternative approach, a pre-established correspondence between the current angle and target angle of the blade and its rotational speed can be constructed. During actual use, the remaining time for the target blade's inspection position to reach the shooting point of the mobile imaging terminal is determined based on the target blade's current angle, target angle, and this correspondence.

[0037] Understandably, by accurately calculating the exact remaining time for the target blade to reach the shooting point of the mobile shooting terminal, an accurate time reference is provided for the subsequent control of the triggering timing of the mobile shooting terminal. This avoids shooting timing deviations caused by the inability to accurately judge the arrival time of the blade, ensuring that the mobile shooting terminal can prepare in advance. This provides reliable time data support for subsequent delay compensation and accurate shooting, further improving the accuracy of image acquisition.

[0038] Step S30: Perform delay compensation on the remaining time to obtain the control trigger time of the mobile shooting terminal; Delay compensation refers to adjusting and correcting the remaining time for various delays that exist during the operation of the mobile shooting terminal, ensuring that the shooting terminal can trigger shooting at the moment when the location to be inspected arrives at the shooting point of the mobile shooting terminal. Its function is to eliminate the impact of delay on shooting timing and avoid shooting timing deviation. For example, if there is a total delay of 0.5 seconds, the remaining time will be reduced by 0.5 seconds through delay compensation to ensure that the moment of triggering shooting is consistent with the moment when the location to be inspected arrives at the shooting point of the mobile shooting terminal.

[0039] The control trigger time refers to the specific moment when the mobile shooting terminal sends the control command. It is obtained by compensating for the remaining time. Its function is to ensure that the mobile shooting terminal has enough time to respond to the command and reach the target rotational angular velocity, which is precisely matched with the moment when the target blade reaches the target angle. For example, after delay compensation, if the control trigger time is determined to be 1.5 seconds after the current moment, the shooting terminal will start shooting after 1.5 seconds.

[0040] In one optional approach, various delay parameters of the mobile shooting terminal are collected, including gimbal start-up delay (the time from receiving the command to starting rotation), control command communication delay (the transmission time from the control module to the mobile shooting terminal), and algorithm processing delay (the calculation time for linear velocity, angular velocity, and remaining time). These delay parameters are statistically summarized to obtain the total delay value at the current moment. Then, this total delay value is added to the calculated remaining time to obtain the control trigger time of the mobile shooting terminal, i.e., the control command is sent before the total delay value, ensuring that the mobile shooting terminal can complete preparation when the blades reach the target angle. For example, if the total delay value is 0.2 seconds and the remaining time is 1.5 seconds, then the control trigger time is the current moment plus 1.3 seconds, achieving delay compensation.

[0041] Understandably, this step effectively solves the tracking deviation problem caused by various system delays in the background technology. By compensating for the delay of the remaining time and sending control commands in advance, it ensures that the mobile shooting terminal has enough time to respond to the commands, start the rotation and reach the target rotational angular velocity, thus offsetting the effects of various delays and avoiding the problem that the mobile shooting terminal cannot keep up with the blade movement in time and miss the best shooting opportunity due to delays. This further ensures the precise relative stillness between the mobile shooting terminal and the target blade.

[0042] Step S40: Send a control command to the mobile imaging terminal at the control trigger time so that when the target blade reaches the target angle, the mobile imaging terminal is already at the target rotation angular velocity and takes a picture of the position to be inspected, so as to obtain the blade image of the target blade at the position to be inspected.

[0043] Control commands are instructions sent by the control module of the mobile shooting terminal to the gimbal and camera of the mobile shooting terminal. They are used to control the gimbal to start rotating, adjust to the target rotation angular velocity, and control the camera to complete image acquisition at a specified time.

[0044] A blade image refers to an image captured by a mobile camera terminal at a shooting point, showing the location of the target blade to be inspected. The image clearly reflects the surface condition of the target blade and can be used for subsequent maintenance work such as blade damage and defect identification, texture analysis, and vibration parameter extraction.

[0045] In one optional approach, a timer is installed inside the mobile shooting terminal to synchronize with the current time in real time. When the timer reaches the control trigger time, the mobile shooting terminal immediately sends a control command, which includes the target rotation angular velocity parameters and the shooting trigger signal. After receiving the command, the mobile shooting terminal starts the gimbal rotation and quickly adjusts the rotation speed according to the preset target rotation angular velocity. Through an angular velocity closed-loop control algorithm, the actual angular velocity of the mobile shooting terminal is fed back in real time and compared with the target rotation angular velocity. The rotation speed is adjusted in a timely manner to ensure that the angular velocity of the mobile shooting terminal is stable within the target rotation angular velocity range when the target blade reaches the target angle. At the same time, the camera built into the mobile shooting terminal automatically triggers shooting the moment the blade reaches the target angle, capturing images of the blade at the inspection location to ensure that the images are clear and distinguishable. After the acquisition is completed, the images are transmitted to the storage module for saving.

[0046] Understandably, by converting the determined target rotational angular velocity, control trigger time, and other parameters into actual control actions, the mobile imaging terminal is ensured to be at a stable target rotational angular velocity the instant the target blade reaches the target angle. This achieves precise relative stillness between the mobile imaging terminal and the inspection location, ultimately acquiring clear, blur-free, and unblurred blade images. This solves the core problems of image blurring and inaccurate tracking in the background technology. At the same time, the acquired clear blade images can accurately reflect the surface condition of the inspection location, providing reliable data support for subsequent blade damage identification and maintenance monitoring, thus improving the accuracy and efficiency of wind turbine blade maintenance.

[0047] In this embodiment, there are significant differences in linear velocity at different radial positions of the blade, while angular velocity is a uniform parameter for the overall rotation of the blade. Synchronizing a single angular velocity cannot accommodate the differences in linear velocity at different shooting positions, leading to reduced image clarity. This application first determines the linear velocity of the target blade's inspection position during the wind turbine blade's rotation, and then calculates the target rotational angular velocity corresponding to the mobile shooting terminal. This allows the shooting terminal's rotational motion to precisely match the linear velocity at that specific position, thus achieving linear velocity synchronization. Based on this, the remaining time for the target blade's inspection position to reach the shooting point of the mobile shooting terminal is calculated using the target blade's current angle, target angle, and rotational speed. Delay compensation is applied to this remaining time to obtain the control trigger time. A control command is sent at this trigger time to ensure that the mobile shooting terminal has reached the preset target rotational angular velocity and completed shooting preparation when the blade reaches the target angle. This effectively offsets deviations caused by various delays, ultimately achieving precise relative stillness between the blade and the mobile shooting terminal in scenarios where the wind turbine does not stop, meeting the requirements for high-precision blade monitoring and improving the clarity of blade images.

[0048] In one feasible implementation, step S10 may include steps S11 to S13: Step S11: Obtain the rotational speed of the target blade, the first distance between the inspection location and the hub center, and the second distance between the mobile imaging terminal and the inspection location; The hub center refers to the axis of rotation of the wind turbine blades. It is the reference point for blade rotation and serves as a reference point for calculating the distance from the location to be inspected to the center of rotation, ensuring the accuracy of linear velocity calculation. Its position is fixed below the nacelle of the wind turbine and is the component connecting the blades and the nacelle.

[0049] The first distance refers to the straight-line distance from the location to be inspected to the center of the hub. It is a key parameter for calculating the linear velocity of the location to be inspected. Its function is to derive the linear velocity by combining the blade rotation speed. For example, if the location to be inspected is at the blade tip and the straight-line distance from the blade tip to the center of the hub is 20 meters, then this 20 meters is the first distance.

[0050] The second distance refers to the straight-line distance between the mobile camera terminal and the location to be inspected. It is a parameter used to calculate the target rotation angular velocity of the mobile camera terminal. Its function is to combine the linear velocity of the location to be inspected to derive the rotation angular velocity that the camera terminal needs to maintain, so as to ensure tracking synchronization. For example, if the mobile camera terminal is 5 meters away from the location to be inspected, then 5 meters is the second distance.

[0051] In one optional approach, a speed sensor mounted on the hub center collects the rotational speed of the target blade in real time. The speed sensor communicates with the wind turbine control system to transmit the speed data in real time. The wind turbine control system then transmits the collected target blade speed to a mobile imaging terminal, enabling the mobile imaging terminal to acquire the target blade speed. The mobile imaging terminal measures a first distance between the inspection location and the hub center using a laser rangefinder. The laser rangefinder is aligned with the hub center, a laser is emitted, and the reflected signal is received. The first distance is calculated based on the laser propagation time. An infrared ranging module mounted on the mobile imaging terminal emits an infrared signal to the inspection location. A second distance between the mobile imaging terminal and the inspection location is calculated based on the reflection time of the infrared signal.

[0052] Step S12: Determine the linear velocity based on the rotational speed of the target blade and the first distance; In one optional method, the linear velocity is calculated using the formula v=nr, where v represents the linear velocity, n represents the rotational speed of the target blade (in revolutions per second), and r represents the first distance (in meters). The rotational speed n and the first distance r are substituted into this formula to calculate the linear velocity at the location to be inspected. For example, if the rotational speed n is 0.1 revolutions per second and the first distance r is 20 meters, then the linear velocity v=0.1. 20 = 2 meters per second.

[0053] In another optional method, the linear velocity is determined using a preset linear velocity lookup table. This table calculates the corresponding linear velocity in advance based on different rotational speeds and initial distances using formulas, and is stored in the mobile shooting terminal's storage module. After obtaining the rotational speed and initial distance, the mobile shooting terminal directly retrieves the corresponding linear velocity value from the lookup table without real-time calculation. For example, the lookup table presets a linear velocity of 12.56 m / s for a rotational speed of 0.1 rpm and an initial distance of 20 meters, which can be used directly after retrieval.

[0054] Step S13: Determine the target rotation angular velocity of the mobile shooting terminal based on the linear velocity and the second distance.

[0055] In one alternative approach, the angular velocity is calculated using the formula ω=v / r, where ω represents the target's rotational angular velocity (unit: radians / second), v represents the linear velocity, and r represents the second distance. Substituting the linear velocity v and the second distance r into the formula, the target's rotational angular velocity is calculated. For example, if the linear velocity v is 12.56 m / s and the second distance r is 5 m, then the target's rotational angular velocity ω=12.56÷5=2.512 radians / second.

[0056] In another optional approach, the linear velocity and the second distance are input into a preset closed-loop control model. The model adjusts the output angular velocity value in real time according to the change of linear velocity to ensure that the target rotational angular velocity can dynamically match the fluctuation of linear velocity. For example, when the linear velocity increases due to the change of blade speed, the closed-loop control model will automatically increase the target rotational angular velocity to ensure that the shooting terminal always synchronously tracks the position to be inspected.

[0057] It is understandable that the linear velocity of the location to be inspected is converted into the rotation control parameters of the mobile imaging terminal, and the rotation speed that the imaging terminal needs to maintain is determined. This ensures that the imaging terminal is always aligned with the location to be inspected during the rotation of the blade, avoiding blurry or offset images caused by the rotation of the blade, and providing a control basis for subsequent accurate acquisition of blade images.

[0058] In this embodiment, by acquiring the rotational speed of the target blade, the first distance between the inspection position and the hub center, and the second distance between the mobile imaging terminal and the inspection position; determining the linear velocity based on the target blade's rotational speed and the first distance; and determining the target rotational angular velocity of the mobile imaging terminal based on the linear velocity and the second distance, a precise correspondence between the linear velocity of the inspection position and the target rotational angular velocity of the mobile imaging terminal is achieved. This ensures that the mobile imaging terminal can dynamically and synchronously track the inspection position of the target blade. Regardless of how the blade's rotational speed changes, the imaging terminal can always be aligned with the inspection position through the precisely calculated rotational angular velocity, avoiding problems such as blurry or offset images and improving the clarity and accuracy of blade image acquisition.

[0059] In one feasible implementation, step S30 may include steps S31 to S33: Step S31: Obtain the delay time of each delay source; The sources of delay refer to various factors that cause a time difference between the mobile shooting terminal receiving control commands and executing shooting actions. Their purpose is to clarify the causes of delays and provide a basis for summarizing delay times and making delay compensation. Specifically, they include at least one of the following: data processing delay, communication delay, mechanical start-up delay of the mobile shooting terminal, and exposure time delay of the mobile shooting terminal.

[0060] Delay time refers to the specific time difference generated by each delay source, that is, the time consumed from the start of the delay factor to the end of its effect. It serves as the basis for calculating delay compensation. For example, a data processing delay of 0.1 seconds means that it takes 0.1 seconds for the data to be received and processed.

[0061] In one optional approach, the data processing delay is collected by a timing module built into the mobile shooting terminal, starting from the time the data is received and stopping when the data processing is completed, to obtain the data processing delay time; the communication delay is collected by a timing module built into the communication module of the mobile shooting terminal, starting from the time the control command is sent and stopping when the shooting terminal receives the command, to obtain the communication delay time; the mechanical start delay is collected by a position sensor on the mechanical component, starting from the time the mechanical component starts and stopping when the preset working position is reached, to obtain the mechanical start delay time; the exposure time delay is collected by a timing module built into the camera, starting from the time the exposure is started and stopping when the exposure is completed, to obtain the exposure time delay time.

[0062] Step S32: Summarize the delay times of each delay source to obtain the total delay time. The delay sources include at least one of data processing delay, communication delay, mechanical start-up delay of the mobile shooting terminal, and exposure time delay of the mobile shooting terminal. Data processing latency refers to the time consumed by the mobile shooting terminal or control terminal to analyze, calculate, and process relevant data, such as blade position data and linear velocity data, after receiving them. It is one of the important sources of latency and reflects the impact of the data processing process on the shooting timing. For example, after the terminal receives linear velocity data, it needs 0.1 seconds to calculate the target rotation angular velocity. This 0.1 seconds is the data processing latency.

[0063] Communication latency refers to the time it takes for control commands to be transmitted from the computing unit of the mobile shooting terminal to the gimbal or camera. For example, if it takes 0.2 seconds for control commands to be transmitted from the computing unit of the mobile shooting terminal to the gimbal, then that 0.2 seconds is the communication latency.

[0064] Mechanical start-up delay refers to the time it takes for the gimbal rotation mechanism of a mobile shooting terminal to start from a stationary state and reach a preset working state after receiving a shooting control command. Its function is to reflect the impact of the mechanical component start-up process on the shooting timing. For example, if it takes 0.15 seconds for the gimbal rotation mechanism to start and adjust to the preset angle, this 0.15 seconds is the mechanical start-up delay.

[0065] Exposure time delay refers to the time taken from the start of exposure to the completion of exposure after the camera of a mobile shooting terminal receives the shooting command. It is a necessary time to ensure that the captured image is sharp, and it is also one of the sources of delay. Its function is to reflect the impact of the exposure process on the shooting timing. For example, if the camera needs 0.05 seconds to complete an exposure, this 0.05 seconds is the exposure time delay.

[0066] Total delay time refers to the sum of delay times from all sources of delay. Its purpose is to clarify the total time deviation in the entire control process and ensure the accuracy of delay compensation. For example, if the data processing delay is 0.1 seconds, the communication delay is 0.2 seconds, the mechanical start-up delay is 0.15 seconds, and the exposure time delay is 0.05 seconds, the total delay time is 0.5 seconds.

[0067] In one alternative approach, the delay times of each delay source are directly added together to obtain the total delay time. For example, if there is a communication delay of 0.2 seconds, a mechanical start-up delay of 0.15 seconds, an exposure time delay of 0.05 seconds, and no data processing delay, then the total delay time = 0.2 + 0.15 + 0.05 = 0.4 seconds.

[0068] In another alternative approach, a weighted coefficient is assigned to each delay source based on its impact on the shooting timing. The delay time of each source is multiplied by its corresponding weighted coefficient, and then all results are summed to obtain the total delay time. For example, if the data processing delay has a weight of 0.2, the communication delay has a weight of 0.4, the mechanical start-up delay has a weight of 0.3, and the exposure time delay has a weight of 0.1, with delay times of 0.1 seconds, 0.2 seconds, 0.15 seconds, and 0.05 seconds respectively, then the total delay time = 0.1. 0.2+0.2 0.4 + 0.15 0.3 + 0.05 0.1 = 0.02 + 0.08 + 0.045 + 0.005 = 0.15 seconds.

[0069] Understandably, integrating the dispersed delay times from various delay sources into a total delay time clarifies the total time deviation throughout the entire control process, providing a unified calculation basis for subsequent delay compensation. This solves the problem that a single delay source cannot fully reflect the total delay, ensuring that delay compensation can cover all delay factors that affect shooting timing.

[0070] Step S33: The remaining time is compensated for by the total delay time to obtain the control trigger time of the mobile shooting terminal.

[0071] In one alternative approach, the control trigger time can be obtained by subtracting the total delay time from the remaining time, i.e., control trigger time = remaining time - total delay time. For example, if the remaining time is 2 seconds and the total delay time is 0.5 seconds, then the control trigger time = 2 - 0.5 = 1.5 seconds, meaning that the shooting is triggered 1.5 seconds after the current moment, ensuring that the inspection position reaches the shooting point of the mobile shooting terminal exactly when the shooting action is completed.

[0072] Understandably, by using the total delay time to compensate for the remaining time, the control trigger time of the mobile shooting terminal can be obtained. This can eliminate the impact of various delays on the shooting timing, ensuring that the mobile shooting terminal can complete the shooting action at the exact moment when it arrives at the shooting point of the mobile shooting terminal at the location to be inspected. This avoids shooting too early or too late due to delay, thereby ensuring that the collected leaf images can accurately cover the location to be inspected and improving the accuracy of image acquisition.

[0073] In this embodiment, by summarizing the delay times of each delay source and using the total delay time to compensate for the remaining time, the control trigger time of the mobile shooting terminal is obtained. This effectively eliminates the impact of various delays such as data processing, communication, mechanical start-up, and exposure on the shooting timing, solves the problem of shooting timing deviation and inaccurate image acquisition caused by delay, and ensures that the shooting terminal can complete the shooting at the exact moment when it arrives at the shooting point of the mobile shooting terminal at the location to be inspected, thereby improving the accuracy and effectiveness of leaf image acquisition.

[0074] Based on the first embodiment of this application, in the second embodiment of this application, the same or similar content as in the first embodiment can be referred to the above description and will not be repeated hereafter. On this basis, based on the real-time angle measurement and predictive matching algorithm of lidar, the dynamic unique identifier of the blade in the rotating state is tracked and the blade number is maintained. The acquired images are automatically bound to the unique identifier of the blade and archived without manual intervention, achieving accurate data collection.

[0075] For details, please refer to Figure 2 After step S40, the method for acquiring wind turbine blade images also includes steps S50 to S70: Step S10: During the rotation of the wind turbine blades, determine the linear velocity at the inspection position of the target blade, and determine the target rotational angular velocity of the moving camera terminal based on the linear velocity. Step S20: Based on the current angle of the target blade, the target angle corresponding to the shooting point of the mobile shooting terminal, and the rotation speed of the target blade, determine the remaining time for the target blade to be inspected to reach the shooting point of the mobile shooting terminal. Step S30: Perform delay compensation on the remaining time to obtain the control trigger time of the mobile shooting terminal; Step S40: Send a control command to the mobile imaging terminal at the control trigger time so that when the target blade reaches the target angle, the mobile imaging terminal is already at the target rotation angular velocity and takes a picture of the position to be inspected, so as to obtain the blade image of the target blade at the position to be inspected.

[0076] Step S50: Obtain the leaf image obtained by the mobile shooting terminal after shooting the location to be inspected; A blade image refers to the image information of the location to be inspected that is obtained after a mobile camera takes a picture of the target blade. This image is used for subsequent blade defect identification. For example, a high-resolution image of the blade tip area taken by a drone camera is a blade image.

[0077] In one alternative approach, after the mobile imaging terminal completes the shooting, it automatically saves the leaf image to its own local storage module. The control terminal accesses the local storage module of the mobile imaging terminal through a communication connection to read and obtain the leaf image.

[0078] In another alternative approach, after the mobile shooting terminal completes the shooting, it does not save the image locally. Instead, it transmits the image of the leaf to the processor of the mobile shooting terminal in real time via high-speed communication methods such as 5G and Wi-Fi. After receiving the image data, the processor of the mobile shooting terminal decodes and stores the image, and at the same time performs noise reduction processing on the image to remove the noise generated during the shooting process and improve the image quality.

[0079] Step S60: Determine the unique identifier of the target blade; A unique identifier for a target blade is a unique identifier assigned to it, distinguishing it from other wind turbine blades. It is unique and cannot be repeated. Its purpose is to clearly identify the specific blade corresponding to the blade image, avoiding confusion between images of different blades and facilitating subsequent tracking, maintenance, and management. The type of this unique identifier is not specifically limited; it can be a number, a QR code, or an RFID tag. For example, blade numbers could be Blade 1, Blade 2, and Blade 3.

[0080] In one alternative approach, a unique physical identifier, such as a QR code, barcode, or unique number, is preset on the surface of each wind turbine blade. The mobile camera terminal captures the physical identifier on the blade surface while capturing the image of the blade. The physical identifier is then analyzed using an image recognition algorithm to obtain the unique identifier of the target blade. For example, the unique number "blade 002" can be obtained by analyzing the QR code on the blade surface.

[0081] In another optional approach, the shooting time of the mobile camera at the location to be inspected is obtained; the actual angle of each wind turbine blade during the shooting time is determined; and a unique identifier for the target blade is determined based on the matching result between the target angle of the target blade and the actual angle of each wind turbine blade. For example, the wind turbine blade whose actual angle is close to the target angle of the target blade can be identified, and the unique identifier of that wind turbine blade can be determined as the unique identifier of the target blade.

[0082] Understandably, by clearly identifying the specific leaf corresponding to the currently acquired leaf image, we can avoid confusion between images of different leaves, provide a foundation for establishing relationships and achieving traceability of leaf images, and ensure that each leaf image corresponds to a specific leaf, which facilitates targeted maintenance and management of the leaves in the future.

[0083] Step S70: Establish the association between the blade image and the unique identifier of the target blade, the time of the blade image capture, the yaw angle of the wind turbine, and the location to be inspected, and store the association.

[0084] The shooting time refers to the specific moment when the mobile shooting terminal takes a picture of the location to be inspected, accurate to the second or millisecond. Its purpose is to record the acquisition time of the leaf image, providing a time basis for subsequent analysis of changes in leaf status and tracing the acquisition process.

[0085] The yaw angle of a wind turbine refers to the angle at which the nacelle rotates around its vertical axis. Its purpose is to record the orientation of the wind turbine when the blade images are acquired, providing a basis for subsequent blade positioning and blade attitude analysis. For example, a yaw angle of 30 degrees means that the nacelle has rotated 30 degrees relative to its initial orientation.

[0086] The association relationship refers to establishing a correspondence between blade images and information such as the unique identifier of the target blade, the shooting time, the wind turbine yaw angle, and the location to be inspected. This ensures that each blade image can be associated with a specific blade, a specific acquisition time, a specific wind turbine status, and a specific acquisition location. Its purpose is to make blade images traceable and manageable, facilitating subsequent querying, analysis, and application.

[0087] Storage refers to saving the established relationships and corresponding blade images and various parameter information to a preset storage device for easy retrieval, querying and analysis later. Its purpose is to ensure that the collected data is not lost and to provide data support for subsequent blade condition monitoring, defect tracking and other work. Storage devices include local storage of mobile shooting terminals, cloud server storage, and storage of ground control terminals.

[0088] In one alternative approach, a record is created in the database for each blade image. The record contains information such as the storage path of the blade image, the unique identifier of the target blade, the shooting time, the yaw angle of the wind turbine, and the location to be inspected. This information is bound together by field association to establish a relationship. Then, the database record is saved to the cloud server or the storage of the mobile shooting terminal to ensure data security and accessibility.

[0089] Another optional approach is to establish a file naming association, assigning a unique filename to each blade image. The filename contains information such as the unique identifier of the target blade, the shooting time, the wind turbine yaw angle, and the location to be inspected. The blade image is directly associated with various types of information through the filename. Then, the named blade image and the corresponding information document are saved together to the cloud server or the storage of the mobile shooting terminal to complete the storage of the association.

[0090] Understandably, by binding blade images with various key information, the traceability and management of blade images can be achieved, making it easier to query image information of a specific blade at a specific time, location, and wind turbine condition, thus providing data support for tasks such as blade defect tracking.

[0091] In this embodiment, the blade images obtained by the mobile camera terminal after capturing images of the location to be inspected are acquired; the unique identifier of the target blade is determined; the association between the blade image and the unique identifier of the target blade, the shooting time of the blade image, the yaw angle of the wind turbine, and the location to be inspected is established and stored. This realizes the acquisition, identification association, and storage of blade images, ensuring that each blade image can correspond to a specific target blade, shooting time, wind turbine yaw angle, and location to be inspected. This solves the problem of chaotic and untraceable blade images and facilitates subsequent classification, management, and querying of blade images.

[0092] In one feasible implementation, step S60 may include steps S60-S64: Step S61: Obtain the shooting time of the mobile shooting terminal at the location to be inspected; The shooting time refers to the specific moment when the mobile shooting terminal takes a picture of the target blade at the location to be inspected, accurate to the second or millisecond. Its function is to serve as a time reference for determining the actual angle of each wind turbine blade at the shooting time.

[0093] In one alternative approach, the shooting time is obtained through the built-in clock module of the mobile shooting terminal. The clock module of the mobile shooting terminal is synchronized with the satellite time to ensure the accuracy of the time. While the shooting action is completed, the clock module automatically records the current time as the shooting time, and then transmits the shooting time to the processing module of the mobile shooting terminal through the communication module.

[0094] Step S62: Determine the actual angle of each wind turbine blade at the shooting time; The actual angle refers to the actual deflection angle of each wind turbine blade relative to a preset reference angle, such as the initial angle, at a specific moment during the shooting time. It is a parameter describing the attitude of the blade at the moment of shooting. Its function is to locate the target blade by comparing it with the target angle of the target blade. For example, at the moment of shooting, the actual angle of blade 1 is 30 degrees, the actual angle of blade 2 is 150 degrees, and the actual angle of blade 3 is 270 degrees.

[0095] The method for determining the actual angle of each wind turbine blade is similar to the method for determining the current angle and target angle in the first embodiment above. For details, please refer to the first embodiment.

[0096] Step S63: Determine the difference between the target angle of the target blade and the actual angle of each wind turbine blade, and determine the wind turbine blade corresponding to the smallest difference. The target angle refers to the angle that the target blade should reach at the preset shooting time. It is a preset reference angle and is used as a comparison benchmark. By comparing it with the actual angle of each blade, it is determined which blade is the target blade. For example, if the target angle of the target blade is 150 degrees, it means that the target blade should be at an angle of 150 degrees at the preset shooting time.

[0097] The difference between the target angle of the target blade and the actual angle of each wind turbine blade refers to the absolute difference between the target angle of the target blade and the actual angle of each wind turbine blade. Its function is to determine the degree of matching between each blade and the target blade. The smaller the difference, the closer the blade is to the target blade. For example, if the target angle is 150 degrees and the actual angle of blade 2 is 150 degrees, the difference is 0; if the actual angle of blade 1 is 30 degrees, the difference is 120 degrees.

[0098] The wind turbine blade with the smallest difference refers to the blade with the smallest difference between its actual angle and the target angle among all wind turbine blades. Its purpose is to determine that this blade is the target blade and to provide a basis for obtaining the unique identifier of the target blade in the future. For example, if the smallest difference is 0, the corresponding blade is blade 2, and then blade 2 is the target blade.

[0099] In one alternative approach, the target angle of the target blade is subtracted from the actual angle of each wind turbine blade, and the absolute value is taken to obtain the difference. Then, all differences are compared, and the wind turbine blade with the smallest difference is identified. For example, if the target angle is 150 degrees, the actual angle of blade 1 is 30 degrees, and the difference is 120 degrees; the actual angle of blade 2 is 150 degrees, and the difference is 0 degrees; the actual angle of blade 3 is 270 degrees, and the difference is 120 degrees. The smallest difference is 0 degrees, and the corresponding blade is blade 2.

[0100] Understandably, by comparing the differences, the target blade can be located from all the wind turbine blades, which solves the problem of distinguishing the target blade in multi-bladed wind turbines and ensures that the unique identifier obtained later can accurately correspond to the target blade, thus providing a guarantee for the association between the blade image and the unique identifier.

[0101] Step S64: Determine the unique identifier of the target blade based on the wind turbine blade corresponding to the smallest difference and the correspondence between the wind turbine blade and the unique identifier.

[0102] The correspondence between wind turbine blades and unique identifiers refers to the pre-established fixed correspondence between each wind turbine blade and its unique identifier. Its function is to quickly find the corresponding unique identifier based on a given target blade, ensuring the accuracy of the unique identifier. For example, blade 1 corresponds to the unique identifier "001", blade 2 corresponds to the unique identifier "002", and blade 3 corresponds to the unique identifier "003".

[0103] In one optional approach, a unique identifier is queried through a preset correspondence table. The correspondence table between wind turbine blades and unique identifiers is stored in the storage module of the mobile shooting terminal. The table clearly records the unique identifier corresponding to each blade. After determining the wind turbine blade corresponding to the smallest difference, the unique identifier corresponding to that blade is searched in the correspondence table, which is the unique identifier of the target blade. For example, the blade corresponding to the smallest difference is blade 2. Blade 2 corresponds to the unique identifier "002" in the correspondence table, so the unique identifier of the target blade is "002".

[0104] Understandably, associating the located target blade with a unique identifier and clarifying the exclusive identifier of the target blade provides a basis for establishing the association between blade images and unique identifiers, ensuring that each blade image can accurately correspond to a specific blade, and realizing the traceability and management of blade images.

[0105] In this embodiment, the shooting time of the mobile shooting terminal at the location to be inspected is obtained; the actual angle of each wind turbine blade at the shooting time is determined; the difference between the target angle of the target blade and the actual angle of each wind turbine blade is determined, and the wind turbine blade corresponding to the smallest difference is determined; based on the wind turbine blade corresponding to the smallest difference and the correspondence between the wind turbine blade and the unique identifier, the unique identifier of the target blade is determined. This solves the problem of difficulty in accurately distinguishing the target blade and determining the unique identifier of the blade in multi-bladed wind turbines. By comparing the shooting time, actual angle, and target angle, the target blade can be accurately located, and its unique identifier can be obtained.

[0106] In one feasible implementation, before step S64, the method further includes constructing the correspondence between the wind turbine blades and the unique identifier, specifically including steps S65-S67: Step S65: Obtain the initial angle of each wind turbine blade; The initial angle refers to the angle of the wind turbine blade relative to a preset reference direction, such as the initial orientation of the wind turbine nacelle, when the blade is in its initial state, such as before the wind turbine starts and when the blade is stationary. It is a basic parameter that assigns a unique identifier to the blade and serves as a reference to distinguish different blades. For example, before the wind turbine starts, the initial angle of blade 1 is 0 degrees, the initial angle of blade 2 is 120 degrees, and the initial angle of blade 3 is 240 degrees.

[0107] In one alternative approach, an initial angle is acquired using an angle sensor. An angle sensor is installed at the root of each wind turbine blade. When the wind turbine is in its initial state, i.e., the blades are stationary and not started, the angle sensor detects and records the angle of each blade relative to a preset reference direction and transmits the angle data to a mobile shooting terminal. The mobile shooting terminal receives and stores the initial angle of each blade. For example, the initial angle of blade 1 is 0 degrees, blade 2 is 120 degrees, and blade 3 is 240 degrees.

[0108] In another alternative approach, a 3D scanning device is used to scan the wind turbine blades and create a 3D model of the blades. A preset reference direction is set in the model, and the angle of each blade relative to the reference direction in its initial state is determined, which is the initial angle of each blade. For example, the initial angle of blade 1 is determined to be 0 degrees, the initial angle of blade 2 is 120 degrees, and the initial angle of blade 3 is 240 degrees.

[0109] Step S66: Based on the initial angle of each wind turbine blade, assign a unique identifier to each wind turbine blade. A unique identifier is a unique identifier assigned to each wind turbine blade, distinguishing it from other blades. It is unique and cannot be repeated. Its purpose is to identify each blade, facilitating subsequent blade image association, blade status tracking, and management. Examples include numerical codes (001, 002), letter combinations (A, B, C), and QR code identifiers.

[0110] In one alternative approach, the initial angles of each blade are sorted in ascending order, and then each blade is assigned a unique identifier according to the sorting result. The blade ranked first is assigned the smallest identifier, and the blade ranked last is assigned the largest identifier. For example, initial angles of 0 degrees (blade 1), 120 degrees (blade 2), and 240 degrees (blade 3) are sorted in ascending order as blade 1, blade 2, and blade 3, and assigned unique identifiers of 001, 002, and 003, respectively.

[0111] In another alternative approach, the initial angle range is divided into different intervals, each interval corresponding to a unique identifier. The initial angle of each blade is assigned to the corresponding interval, and then the unique identifier corresponding to that interval is assigned to the blade. For example, the intervals are divided into 0-119 degrees, 120-239 degrees, and 240-359 degrees, which correspond to identifiers 001, 002, and 003, respectively. The initial angle of blade 1 is 0 degrees, which is assigned to the 0-119 degree interval and is assigned 001; the initial angle of blade 2 is 120 degrees, which is assigned to the 120-239 degree interval and is assigned 002; and the initial angle of blade 3 is 240 degrees, which is assigned to the 240-359 degree interval and is assigned 003.

[0112] Understandably, assigning a unique identifier to each blade based on the difference in initial angles achieves a one-to-one correspondence between blades and identifiers, solving the problem of difficulty in distinguishing blade identities in multi-bladed wind turbines and providing a foundation for subsequently determining the unique identifier of the target blade and establishing the association between blade images and identifiers.

[0113] Step S67: Establish the correspondence between each wind turbine blade and its corresponding unique identifier.

[0114] The correspondence between wind turbine blades and unique identifiers refers to the fixed association established between each wind turbine blade and its assigned unique identifier. Its purpose is to provide a basis for subsequent querying of the unique identifier of the blade and realizing the association between the blade image and the identifier, ensuring that each blade has a corresponding exclusive identifier and that the identifier corresponds one-to-one with the blade. For example, blade 1 corresponds to 001, blade 2 corresponds to 002, and blade 3 corresponds to 003.

[0115] In one optional approach, a correspondence table is established and stored. A correspondence table between wind turbine blades and unique identifiers is created in the storage module of the mobile shooting terminal. The table contains three fields: blade number, initial angle, and unique identifier. The unique identifiers assigned above are filled into the table one-to-one with the corresponding blades and initial angles. This correspondence table is saved for later querying and retrieval. For example, the correspondence table records: Blade 1, initial angle 0 degrees, unique identifier 001; Blade 2, initial angle 120 degrees, unique identifier 002; Blade 3, initial angle 240 degrees, unique identifier 003.

[0116] In this embodiment, the initial angle of each wind turbine blade is obtained; based on the size of the initial angle of each wind turbine blade, a corresponding unique identifier is assigned to each wind turbine blade; a correspondence between each wind turbine blade and its corresponding unique identifier is established, so that each wind turbine blade is assigned a unique identifier. Moreover, the identifier assignment is based on the initial angle and has a clear basis, avoiding the arbitrariness and confusion of identifier assignment, ensuring a one-to-one correspondence between the blade and the identifier, which facilitates the subsequent positioning of the wind turbine blade.

[0117] In one feasible implementation, step S62 includes steps S621 to S624: Step S621: For each wind turbine blade, acquire the blade point cloud data at the moment before the shooting time and the blade point cloud data at the moment after the shooting time. The moment before the shooting time refers to the data acquisition moment that is earlier than the shooting time and closest to the shooting time. Its purpose is to obtain the point cloud data of the leaf before the shooting time, so as to provide basic data for interpolation calculation of the actual angle at the shooting time. For example, if the shooting time is 10:30:25, the moment before the shooting time is 10:30:24.

[0118] The moment after the shooting time refers to the data acquisition moment that is later than the shooting time and closest to the shooting time. Its purpose is to obtain the point cloud data of the leaf after the shooting time and combine it with the point cloud data of the previous moment to achieve interpolation calculation. For example, if the shooting time is 10:30:25, the next moment is 10:30:26.

[0119] Blade point cloud data refers to a set of points acquired by point cloud acquisition devices such as lidar, used to describe the three-dimensional spatial position of the blade surface. Each point contains three-dimensional coordinate information, and its function is to reflect the three-dimensional attitude of the blade at a certain moment, thereby calculating the actual angle of the blade. For example, by scanning the blade with lidar, the three-dimensional coordinates of multiple points on the blade surface are obtained to form blade point cloud data.

[0120] In one alternative approach, a lidar installed on a mobile shooting terminal is used to collect point cloud data of each wind turbine blade in real time at fixed time intervals. The collected point cloud data is then categorized and stored according to the collection time. After obtaining the shooting time, the point cloud data corresponding to the time before and after the shooting time is retrieved from the stored point cloud data. For example, if the shooting time is 10:30:25 and the time interval is 1 second, the point cloud data of 10:30:24 (the previous time) and 10:30:26 (the next time) are retrieved.

[0121] Step S622: Determine the first actual angle corresponding to the blade point cloud data at the previous moment and the second actual angle corresponding to the blade point cloud data at the next moment. The first actual angle refers to the actual angle of the leaf calculated based on the leaf point cloud data at the moment before the shooting time. Its function is to serve as a reference value for interpolation calculation, providing a basis for calculating the actual angle at the shooting time. For example, the first actual angle calculated from the leaf point cloud data at the moment before the shooting time of 10:30:24 is 149 degrees.

[0122] The second actual angle refers to the actual angle of the leaf calculated based on the leaf point cloud data at the moment of shooting. Its function is to serve as another reference value for interpolation calculation. Together with the first actual angle, it can achieve accurate calculation of the actual angle at the shooting time. For example, the second actual angle calculated from the leaf point cloud data at the moment of shooting, 10:30:26, is 151 degrees.

[0123] In one alternative approach, key feature points of the blade, such as the blade tip, the connection point between the blade root and the hub, and the endpoint of the blade's maximum chord length, are extracted from the blade point cloud data. The three-dimensional coordinates of these feature points are determined using the point cloud data. Then, the line connecting the blade tip and the blade root is calculated. Based on the angle between this line and a preset reference direction, the actual angle of the blade is determined. The angle at the previous moment is the first actual angle, and the angle at the next moment is the second actual angle. By extracting feature points and calculating multiple times, the angle calculation error is reduced.

[0124] Understandably, by transforming abstract point cloud data into specific angle parameters, two reference angles required for interpolation calculations are obtained, providing a basis for subsequently obtaining the actual angle of the blade at the shooting time through interpolation, thus realizing the transformation from point cloud data to angle parameters.

[0125] Step S623: Interpolate the first actual angle and the second actual angle to obtain the target actual angle; Interpolation refers to the method of calculating the actual angle at the shooting time based on the first and second actual angles at two known times using a preset interpolation algorithm. Its purpose is to compensate for the deficiency of point cloud data acquisition at the exact shooting time, and to ensure that the actual angle of the blade at the shooting time can be accurately obtained.

[0126] The actual angle of the target refers to the actual angle of the blade at the shooting time, which is calculated through interpolation. Its purpose is to serve as the actual attitude parameter of the blade at the shooting time, providing a basis for subsequent comparison with the target angle and positioning of the target blade. For example, the actual angle of the target at the shooting time of 10:30:25 is calculated to be 150 degrees through interpolation.

[0127] In one alternative approach, the time interval between the previous moment, the shooting time, and the next moment is first calculated. Assuming the time interval between the previous moment and the shooting time is t1, and the time interval between the shooting time and the next moment is t2, the target actual angle is calculated using the formula: target actual angle = first actual angle + (second actual angle - first actual angle). (t1 / (t1+t2)), Substitute the first actual angle, the second actual angle, and the time interval data to calculate the target's actual angle. For example, if the first actual angle is 149.5 degrees, the second actual angle is 150.5 degrees, and t1 and t2 are both 0.5 seconds, then the target's actual angle = 149.5 + (150.5 - 149.5). (0.5 / 1)=150 degrees.

[0128] Understandably, the interpolation algorithm compensates for the lack of direct point cloud data at the time of shooting, calculates the actual angle of the target blade at the time of shooting, and ensures that the blade angle that corresponds exactly to the time of image acquisition can be obtained. This provides accurate angle parameters for subsequent positioning of the target blade and avoids the target blade positioning error due to angle deviation.

[0129] Step S624: Take the actual angle of the target as the actual angle of the wind turbine blade at the shooting time.

[0130] In this embodiment, for each wind turbine blade, the blade point cloud data at the moment before and after the shooting time are acquired; the first actual angle corresponding to the blade point cloud data at the moment before and the second actual angle corresponding to the blade point cloud data at the moment after are determined; the first and second actual angles are interpolated to obtain the target actual angle; and the target actual angle is used as the actual angle of the wind turbine blade at the shooting time. This solves the problem that the actual blade angle cannot be directly obtained when there is no point cloud data to collect at the exact shooting time. By interpolating the point cloud data at the moment before and after, it ensures that the blade angle completely corresponds to the image acquisition time, improving the timeliness and accuracy of the angle data.

[0131] Based on the above embodiments of this application, in the third embodiment of this application, the same or similar content as the above embodiments can be referred to the above description, and will not be repeated hereafter. Based on this, refer to... Figure 3 Before step S10, dynamic flight path planning based on real-time perception is also included. Specifically, during the inspection process of the mobile camera terminal, the yaw angle, blade speed and current blade angle of the wind turbine are obtained in real time through the fusion perception of lidar and vision. Based on these real-time status parameters, the next target waypoint of the mobile camera terminal is dynamically calculated and adjusted to ensure that the mobile camera terminal can always fly to the best observation position facing the predetermined shooting surface of the blade, realizing adaptive planning that moves with the wind.

[0132] Specifically, the method for acquiring wind turbine blade images also includes steps S01 to S05: Step S01: Plan the inspection route of the mobile imaging terminal parallel to the rotation plane of the target blade. The inspection route refers to the preset flight or movement path of the mobile camera terminal during the acquisition of images of wind turbine blades. Its purpose is to standardize the movement trajectory of the camera terminal, ensure that the target blades to be inspected are fully and accurately covered, and avoid omissions or repeated acquisitions.

[0133] The rotation plane of the target blade refers to the circumferential plane formed when the target blade rotates around the center of the hub. This plane is perpendicular to the rotation axis of the hub center. Its function is to provide a reference for planning the inspection route, ensure that the inspection route is synchronized with the blade rotation, and improve the accuracy of shooting.

[0134] In one alternative approach, the inspection route is planned using 3D modeling. First, the wind turbine and target blades are scanned using 3D scanning equipment to create a 3D model of the wind turbine blades. The rotation surface of the target blades is determined in the model. Then, based on the distribution of the locations to be inspected, a route parallel to the rotation surface is planned. The height of the route and the distance from the blades are preset according to the shooting requirements to ensure that the route can cover all the locations to be inspected on the blades, while avoiding other components of the wind turbine, such as the nacelle and hub, to avoid the risk of collision.

[0135] Step S02: Determine the theoretical shooting point of the mobile shooting terminal and the theoretical wind turbine yaw angle corresponding to the theoretical shooting point on the inspection route. The theoretical shooting point refers to the ideal point on the pre-set inspection route for collecting images of the target blade. Its function is to serve as the preset target position of the shooting terminal and to provide a benchmark for subsequent correction of the actual shooting point. For example, the point on the inspection route that is 5 meters away from the location to be inspected and directly opposite the blade surface is the theoretical shooting point.

[0136] The theoretical wind turbine yaw angle refers to the angle at which the wind turbine nacelle rotates around the vertical axis at the theoretical shooting point. This angle matches the theoretical shooting point to ensure that the theoretical shooting point is directly facing the target blade. Its purpose is to provide a benchmark for subsequent comparison of the actual wind turbine yaw angle and correction of the shooting point.

[0137] In one alternative approach, on the planned inspection route, for each location to be inspected, a point is determined as the theoretical shooting point; then, based on the position of the theoretical shooting point and the rotational attitude of the target blade, the theoretical wind turbine yaw angle corresponding to that point is calculated.

[0138] Step S03: Determine the actual wind turbine yaw angle corresponding to the theoretical shooting point; The actual yaw angle of a wind turbine refers to the angle at which the nacelle actually rotates around the vertical axis at the time corresponding to the theoretical shooting point. It is a real-time operating parameter of the wind turbine and its function is to compare it with the theoretical yaw angle to determine the angle deviation and provide a basis for correcting the shooting point.

[0139] In one alternative approach, a yaw angle sensor is installed on the wind turbine nacelle. The sensor detects the rotation angle of the nacelle in real time, i.e., the actual yaw angle of the wind turbine. The detected angle data is transmitted to a mobile shooting terminal in real time via wireless communication. When the mobile shooting terminal reaches the vicinity of the theoretical shooting point, the mobile shooting terminal records the actual yaw angle of the wind turbine transmitted by the sensor at this time, which is used as the actual yaw angle corresponding to the theoretical shooting point. At the same time, the data is filtered to remove noise interference and ensure data accuracy.

[0140] Step S04: Based on the deviation between the actual wind turbine yaw angle and the theoretical wind turbine yaw angle, the theoretical shooting point is corrected to obtain the actual shooting point facing the target blade. The deviation between the actual and theoretical yaw angles of a wind turbine refers to the angular difference between them. Its purpose is to determine whether the theoretical shooting point can be directly aligned with the target blade. If the deviation exceeds the allowable range, the theoretical shooting point needs to be corrected to ensure that the shooting terminal can accurately align with the target blade.

[0141] The actual shooting point refers to the actual point that can be directly facing the target blade after the theoretical shooting point has been corrected. Its purpose is to serve as the final shooting position of the mobile shooting terminal, ensuring that the shooting terminal can accurately capture images of the target blade at this point and avoid shooting deviation caused by the yaw of the wind turbine.

[0142] In one alternative approach, the actual yaw angle and the theoretical yaw angle of the wind turbine can be mapped to the wind turbine coordinate system. Based on the change in the yaw angle, the coordinates of the current theoretical shooting point are rotated and transformed to obtain the coordinates of the actual shooting point facing the target blade.

[0143] It should be noted that, compared to related technologies that change the shooting point by fixing the mobile shooting terminal and adjusting the shooting direction of the gimbal, the gimbal has certain angle limitations, and adjustments cannot be made beyond these limits, thus limiting the adjustment capabilities. In contrast, the embodiments of this application adjust the position of the mobile shooting terminal, which does not have angle limitations, making this method of adjusting the actual shooting point universally applicable.

[0144] Step S05: Control the mobile shooting terminal to fly from the theoretical shooting point to the actual shooting point, so that at the actual shooting point, execute step S10 to determine the linear velocity at the inspection position of the target blade, and determine the target rotational angular velocity of the mobile shooting terminal based on the linear velocity, and execute the subsequent steps of step S10.

[0145] In one optional approach, the processor of the mobile shooting terminal sends flight commands to the flight control system of the mobile shooting terminal. The commands include parameters such as the coordinates of the actual shooting point, flight speed, and flight path. After receiving the commands, the flight control system of the mobile shooting terminal activates the automatic flight mode and flies from the theoretical shooting point to the actual shooting point according to the preset path. During the flight, it provides real-time feedback on its own position information. The processor of the mobile shooting terminal monitors the position in real time. If a position deviation occurs, it sends adjustment commands in a timely manner to ensure accurate arrival at the actual shooting point. After arrival, the mobile shooting terminal can hover and execute the calculation process of linear velocity and target rotation angular velocity and subsequent processes.

[0146] In this embodiment, a patrol route parallel to the rotation plane of the target blade is planned for the mobile imaging terminal; the theoretical shooting point of the mobile imaging terminal and the corresponding theoretical wind turbine yaw angle are determined on the patrol route; the actual wind turbine yaw angle corresponding to the theoretical shooting point is determined; based on the deviation between the actual wind turbine yaw angle and the theoretical wind turbine yaw angle, the theoretical shooting point is corrected to obtain the actual shooting point facing the target blade; the mobile imaging terminal is controlled to fly from the theoretical shooting point to the actual shooting point, so that the linear velocity at the inspection position of the target blade is determined at the actual shooting point, and the target rotation angular velocity of the mobile imaging terminal and subsequent steps are determined based on the linear velocity. Through the correction between the theoretical shooting point and the actual shooting point, the influence of wind turbine yaw deviation on the shooting position is eliminated, ensuring that the imaging terminal can always face the target blade, solving the problem of image offset and blurring caused by wind turbine yaw, and improving the accuracy of image acquisition.

[0147] To ensure the safety of drone inspections, relevant technical solutions typically require the mobile imaging terminal to maintain a considerable distance from the blades. However, long-distance shooting results in the loss of image details, affecting the accuracy of subsequent defect identification. How to achieve high-definition imaging as close to the blades as possible while ensuring flight safety is a pressing technical challenge. Existing technical solutions lack a dynamic safety boundary calculation model, making it impossible to assess and adjust the safety distance based on the real-time status of the wind turbine during flight. To address this deficiency, a three-dimensional dynamic safety zone that follows the wind turbine is constructed based on its real-time yaw angle and blade rotation speed. During the flight and hovering shooting process of the mobile imaging terminal, the boundary distance between its own position and the dynamic safety zone is calculated in real time. Once the distance approaches a danger threshold, trajectory correction or hovering avoidance is immediately triggered, ensuring that the mobile imaging terminal always operates within the safety zone, providing a safety guarantee for close-range shooting.

[0148] Specifically, based on the above embodiments of this application, in the fourth embodiment of this application, the content that is the same as or similar to the above embodiments can be referred to the above description, and will not be repeated hereafter. Based on this, the wind turbine blade image acquisition method of this application further includes: Step S110: During the flight or hovering shooting process of the mobile shooting terminal, determine whether the mobile shooting terminal is located in a dangerous area based on the current position of the mobile shooting terminal. Current location refers to the real-time three-dimensional spatial position of the mobile shooting terminal during flight or hovering shooting. It is usually represented by GPS coordinates or position coordinates relative to the wind turbine. Its function is to determine whether the shooting terminal is in a dangerous area and to provide a basis for safety control.

[0149] Dangerous areas refer to areas where mobile camera terminals are likely to collide with wind turbine components such as blades, nacelles, and hubs during flight or hovering filming. Their purpose is to clearly define prohibited or warning areas for mobile camera terminals.

[0150] In one optional approach, the range parameters of the danger zone are preset in the memory of the mobile shooting terminal, such as an area within a radius of 3 meters centered on the wheel hub, or an area covered by the blade rotation trajectory. The mobile shooting terminal obtains its current GPS coordinates in real time through its built-in GPS module and transmits these coordinates to the processor of the mobile shooting terminal. The processor of the mobile shooting terminal compares the current coordinates with the preset danger zone range. If the current coordinates are within the danger zone range, the mobile shooting terminal is determined to be in the danger zone; if they are outside the range, it is determined not to be in the danger zone. At the same time, the current location information is updated in real time, and the judgment is continuously made.

[0151] Step S120: If the mobile camera terminal is located in a dangerous area, an avoidance strategy is executed on the mobile camera terminal. The avoidance strategy includes one of the following: controlling the mobile camera terminal to climb, controlling the mobile camera terminal to move radially away, or controlling the mobile camera terminal to hover and wait.

[0152] Avoidance strategies refer to a series of control measures taken when a mobile camera is located in a danger zone to avoid equipment damage and data acquisition failure. Their purpose is to promptly remove the camera from the danger zone, ensure the safety of the mobile camera, and ensure that data acquisition can continue. Avoidance strategies include one of the following: controlling the mobile camera to climb, controlling the mobile camera to move radially away, or controlling the mobile camera to hover and wait.

[0153] Controlling the mobile camera terminal to climb refers to using control commands to make the mobile camera terminal fly vertically upwards, increasing the height of the camera terminal and thus escaping the danger zone. Its purpose is to avoid the risk of collision with ground obstacles or the lower parts of the wind turbine by increasing the height. For example, if the height of the camera terminal is lower than the preset safe height, the climbing strategy is executed to rise to the safe height range.

[0154] Controlling the mobile camera to move radially away refers to using control commands to move the camera away from the center of the hub, increasing the distance between the camera and the core components of the wind turbine, thereby moving it away from the danger zone. The purpose is to avoid the risk of collision with components such as blades and hub by increasing the horizontal distance. For example, if the horizontal distance between the camera and the hub is less than a preset distance, the radial moving-away strategy is executed, moving the camera away from the hub until the horizontal distance is greater than the preset distance.

[0155] Controlling the hovering and waiting of a mobile imaging terminal refers to using control commands to keep the mobile imaging terminal stationary in its current position, temporarily stopping flight and imaging, and waiting for the danger to pass before resuming the data collection task. Its purpose is to prevent the imaging terminal from moving and causing a collision when the danger zone is small and the danger is temporary. For example, if the difference between the azimuth angle of the imaging terminal and the yaw angle of the wind turbine temporarily exceeds the preset angle, the hovering and waiting strategy is executed, and the flight can continue after the blades have rotated.

[0156] In one alternative approach, once the processor of the mobile shooting terminal determines that the shooting terminal is located in a dangerous area, it immediately and automatically sends an avoidance command to the shooting terminal without manual intervention. After receiving the command, the mobile shooting terminal automatically selects an appropriate avoidance strategy based on the location of the dangerous area and its own current state until it leaves the dangerous area. After leaving the dangerous area, it automatically resumes the original inspection route or shooting state and continues to complete the data collection work.

[0157] Understandably, the ability to choose the appropriate avoidance method based on the actual danger situation enhances the targeting and effectiveness of avoidance.

[0158] In this embodiment, by monitoring the position status of the mobile shooting terminal in real time, it is possible to promptly detect whether the shooting terminal has entered a dangerous area, thus solving the problem that the shooting terminal is prone to collision with wind turbine components and damage due to interference during the acquisition process, and ensuring equipment safety. Through flexible avoidance strategies, the shooting terminal can be removed in time when it enters a dangerous area, reducing the interruption of the acquisition work, ensuring that the blade image acquisition work can be completed smoothly, and improving acquisition efficiency.

[0159] In one feasible implementation, step S110 includes: Step S111: During the flight or hovering shooting process of the mobile shooting terminal, based on the current position of the mobile shooting terminal, determine the horizontal distance between the mobile shooting terminal and the center of the wheel hub, the azimuth angle of the mobile shooting terminal, and the height of the mobile shooting terminal. Step S112: If any of the following conditions are met: the horizontal distance is less than or equal to the preset distance, the difference between the azimuth angle and the current wind turbine yaw angle is greater than or equal to the preset angle, or the height is outside the preset height range, then the mobile shooting terminal is determined to be in a dangerous area.

[0160] Horizontal distance refers to the straight-line distance between the current position of the mobile shooting terminal and the center of the hub on the horizontal plane, without considering the height difference. Its purpose is to determine whether the horizontal distance between the shooting terminal and the core components of the wind turbine is too close and whether there is a risk of collision.

[0161] Azimuth refers to the horizontal angle of the moving camera terminal relative to a preset reference direction, such as the initial orientation of the wind turbine nacelle. Its function is to describe the horizontal orientation of the camera terminal relative to the wind turbine, providing a basis for determining whether the camera terminal is within the range of the blade rotation trajectory.

[0162] Height refers to the vertical distance between the current position of the mobile shooting terminal and the ground. Its purpose is to determine whether the height of the shooting terminal is within a safe range, so as to avoid equipment damage or data acquisition failure due to excessive height or low height.

[0163] The preset distance refers to the pre-set safe horizontal distance threshold between the mobile shooting terminal and the wind turbine hub. Its function is to determine whether the horizontal distance is too close. If it is less than or equal to the threshold, it is considered that there is a risk of collision. For example, if the preset distance is set to 3 meters, and the horizontal distance is 2.5 meters, it is beyond the safe range.

[0164] The current yaw angle of the wind turbine refers to the actual angle of rotation of the wind turbine nacelle around the vertical axis at the current moment. It is a real-time operating parameter of the wind turbine and is used to compare with the azimuth angle of the camera terminal to determine whether the camera terminal is within the range of the blade rotation trajectory.

[0165] The preset angle refers to the safety angle difference threshold between the preset azimuth angle and the current yaw angle of the wind turbine. Its function is to determine whether the position of the shooting terminal is within the range of the blade rotation trajectory. If the difference is greater than or equal to the threshold, it is considered that there is a risk of collision. For example, if the preset angle is set to 10 degrees, if the difference is 15 degrees, it is beyond the safe range.

[0166] The preset altitude range refers to the pre-set safe flight altitude range of the mobile shooting terminal. Its function is to determine whether the altitude of the shooting terminal is safe. If the altitude exceeds the range, it is considered to be dangerous. For example, if the preset altitude range is 5-50 meters, if the shooting terminal is 3 meters or 55 meters high, it is outside the safe range.

[0167] Dangerous areas refer to areas where mobile shooting terminals are prone to collisions with wind turbine components during flight or hovering shooting, leading to equipment damage or data acquisition failure.

[0168] In one alternative approach, a laser rangefinder, a GPS module, and an electronic compass are installed on the mobile shooting terminal. The laser rangefinder measures the straight-line distance between the shooting terminal and the wind turbine hub in real time. Combined with the three-dimensional coordinates of the shooting terminal and the hub obtained by the GPS module, the horizontal distance between the two is calculated. The electronic compass detects the azimuth angle of the shooting terminal relative to a preset reference direction in real time. The GPS module obtains the altitude of the shooting terminal in real time, which is the height of the shooting terminal. These three parameters are transmitted to the control terminal in real time to ensure the real-time and accuracy of parameter acquisition.

[0169] In another optional approach, the three-dimensional coordinates of the wind turbine hub are pre-stored in the memory of the mobile shooting terminal. The mobile shooting terminal obtains its own three-dimensional coordinates in real time through the GPS module. Based on the formula for calculating the three-dimensional coordinates of two points, the horizontal distance between the shooting terminal and the hub is calculated, which is the square root of the sum of the squares of the differences in the distances between the two points in the X and Y axes. The azimuth angle of the mobile shooting terminal is calculated by using the attitude sensor and electronic compass of the mobile shooting terminal in combination with the preset reference direction. The altitude obtained by the GPS module is directly read as the altitude of the shooting terminal.

[0170] In this embodiment, by clarifying the specific criteria for judging dangerous areas, and by comprehensively judging the three parameters of horizontal distance, azimuth angle, and height, misjudgments caused by judging a single parameter are avoided, thereby improving the accuracy and reliability of dangerous area judgment.

[0171] Based on the above embodiments of this application, in the fifth embodiment of this application, the same or similar content as the above embodiments can be referred to the above description, and will not be repeated hereafter. Furthermore, after step S40 or step S70, the method for acquiring wind turbine blade images further includes step S80: Step S80: Based on the blade image, perform defect identification on the target blade to obtain the defect identification result of the target blade.

[0172] Defect identification results refer to the specific information about the defects of the target blade obtained through the defect identification process, including the type, location, size, and severity of the defects. Its function is to intuitively reflect the health status of the blade and provide core basis for staff to formulate maintenance plans. For example, the identification result is "There is a 5 cm long crack at the tip of the target blade, and the severity is moderate".

[0173] In one alternative approach, a large number of images of wind turbine blade defects of different types and severity are first collected to establish a defect sample database. A deep learning model is then trained based on this database. After training, the blade images captured by the mobile camera terminal are input into the model. The model automatically preprocesses the images, such as noise reduction, enhancement, and segmentation, and then identifies the defects in the images, outputting information such as the type, location, and size of the defects to form a defect identification result. At the same time, the confidence level of the identification result is judged. If the confidence level is lower than a preset threshold, it is marked as a suspected defect, and staff are reminded to conduct a manual review.

[0174] In another alternative approach, a standard, defect-free image of the target blade is acquired. The acquired blade image is then compared with the standard image in terms of pixels and features to identify the areas of difference between them. These areas are marked as suspected defect areas. The suspected defect areas are then analyzed to determine whether the areas of difference are actual defects, and to identify the type, location, and severity of the defects. Finally, a defect identification result is generated. The identification result is then associated with and stored with the blade image and the blade's unique identifier for easy traceability later.

[0175] Another alternative approach is to directly perform depth processing on the acquired blade images after acquisition to obtain the defect information of the target blade. Alternatively, after acquiring the blade image, the image can be associated with and stored along with its corresponding information, including a unique identifier, capture time, and location to be inspected. When a defect analysis command for the blade image is received, the stored data is retrieved for analysis. This approach aims to meet the blade defect analysis needs of different scenarios.

[0176] In this embodiment, by performing in-depth processing on the acquired blade images, the defects of the target blades are identified, and the image data is converted into usable defect information. This solves the problems of low efficiency and large errors in manual identification, and timely detection of blade damage, providing a basis for blade maintenance and repair.

[0177] For example, to help understand the implementation process of the wind turbine blade image acquisition method obtained by combining the above embodiments, please refer to... Figure 4 , Figure 4 A schematic diagram of the overall process for acquiring images of wind turbine blades is provided, taking a drone as an example of a mobile control terminal. Specifically: Step S1: Initialize the wind turbine status and establish the dynamic coordinate system.

[0178] S1_1: The drone takes off according to the preset wind turbine coordinates, flies to a certain height directly above the wind turbine nacelle, and controls the gimbal camera to shoot vertically downwards to obtain an image of the top of the nacelle.

[0179] S1_2: Input the image into the preset nacelle recognition model to identify the rectangular outline of the nacelle and its orientation. Combine the UAV's current heading and position coordinates to calculate the precise three-dimensional coordinates of the wind turbine nacelle's center point. and initial yaw angle .

[0180] S1_3: The drone flies to the front of the wind turbine hub, and its altitude is level with the center of the hub. It then activates the lidar to scan the wind turbine.

[0181] S1_4: Processing the point cloud acquired by the lidar. First, using filtering and clustering algorithms, the blade point cloud and the hub point cloud are separated. Then, spherical fitting is performed on the hub point cloud to obtain the coordinates of the hub center point. Plane fitting is performed on the point cloud of the blade to obtain the normal vector of the blade's rotation plane. .

[0182] S1_5: Based on the above information, establish a system centered on the wheel hub. With the origin as the point, The axis points directly in front of the wind turbine (i.e., the nacelle orientation). The axis points to the left side of the fan (perpendicular to) (axis and direction of gravity). A dynamic wind turbine coordinate system with the axis pointing vertically upwards. Simultaneously, based on the distribution of the blade point cloud in the coordinate system, the initial angles of the three blades are calculated and recorded. (i=1,2,3).

[0183] Step S2: Dynamic route planning based on real-time perception. This corresponds to the content of the third embodiment.

[0184] S2_1: Preset basic inspection route. Based on the blade length L, plan a route parallel to the blade surface in front of and behind the wind turbine blade. The route is set with... Each shooting point has a certain number of shooting points. The distance between adjacent shooting points is calculated based on the camera's field of view and the preset overlap rate to ensure that the images of adjacent points have a certain degree of overlap, so that the acquired images can be stitched together to form a complete wind turbine blade.

[0185] S2_2: Dynamic Real-Time Perception. Before executing a shooting task at each shooting point, the drone hovers and uses LiDAR to scan the point cloud information of the wind turbine again, obtaining the current yaw angle of the wind turbine in real time. and the rotational speed of the target blade .

[0186] S2_3: Calculate waypoint offset. Assume the theoretical coordinates of the current target shooting point are... Because the wind turbine's yaw angle has changed from Become The theoretical shooting position will no longer be directly opposite the wind turbine blades; therefore, it is necessary to adjust the shooting position based on the deviation of the yaw angle. The current waypoint coordinates (i.e., the theoretical shooting point) are rotated and transformed to obtain the corrected actual target waypoint coordinates. That is, the actual shooting point of the target leaf.

[0187] S2_4: The UAV receives the calculated waypoint coordinates. The drone smoothly flies from its current position to the corrected actual target waypoint coordinates.

[0188] Step S3: Acquire linear velocity synchronization data based on delay compensation. After reaching the corrected target waypoint and hovering stably, execute this step. This corresponds to the first embodiment of this application.

[0189] S3_1: Determine the target blade and the location to be inspected. Based on the blade angle tracking established in step S1, lock onto a blade that has not yet been photographed, such as target blade A, and determine the location to be inspected corresponding to the current shooting point of the mobile shooting terminal, and obtain the coordinates of this location in the wind turbine coordinate system. .

[0190] S3_2: Calculate the linear velocity at the location to be inspected. The rotational speed of the target blade is known. The first distance between the location to be inspected and the center of the wheel hub is Then linear velocity The direction of this velocity is perpendicular to the rotation radius of the wind turbine blades.

[0191] S3_3: Calculate the target rotational angular velocity of the gimbal. The second distance between the mobile imaging terminal and the location to be inspected is known. To keep the camera relatively stationary at this distance from the target point, the camera's rotational linear velocity should be equal to... They are equal. Therefore, the target's rotational angular velocity is equal. .

[0192] S3_4: Establish a time delay compensation model. Define the following delay parameters: Algorithm processing latency in edge devices, i.e., data processing latency, includes point cloud processing, coordinate transformation, control command generation time, etc. System communication latency, also known as communication delay, is the time it takes for instructions to be transmitted from the drone's processor to the gimbal controller. : Gimbal mechanical start delay, that is, the mechanical start delay of the mobile shooting terminal, the time from receiving the command to starting uniform motion; Camera exposure time, i.e., the exposure time delay of the mobile shooting terminal, is used to calculate motion blur tolerance; S3_5: Predict synchronization time. Let the current angle of the target blade be... The target angle corresponding to the shooting point of the mobile shooting terminal is The time required for the blade to rotate to the position to be inspected is the remaining time. ; S3_6: Adaptive trigger control. The UAV, based on... The delay time determined by the aforementioned sources of delay, in advance The system sends gimbal control commands and camera trigger signals at specific times. Ensure that the blade rotates exactly to At that time, the gimbal had stabilized at the required angular velocity. Furthermore, the camera shutter opens when the target point passes through the center of the field of view, so that the captured leaf area is located in the center of the image; S3_7: Image Acquisition and Storage. The drone's gimbal camera captures images of the wind turbine blades and associates these images with information such as the blade's unique identifier, the shooting location, the wind turbine's yaw angle, and the shooting time, then stores them.

[0193] Step S4: Adaptive flight control under dynamic safety boundary constraints, the steps are as follows: Figure 5 As shown. This corresponds to the fourth embodiment of this application.

[0194] S4_1: Construct a dynamic safety zone model. Using the central axis of the wind turbine tower as the axis of symmetry, construct a three-dimensional sector-shaped danger zone that rotates with the wind turbine's yaw angle. The parameters of this zone are defined as follows: Preset distance: ,in For safety reasons, For the blade length, The safety margin is used to account for blade flapping and oscillation.

[0195] Preset angle: Based on the current wind turbine surface, extend to both sides. The degree covers the possible sway range of the blades.

[0196] Preset height range: from the center of the wheel hub downwards to the lowest point of the blade tip. Upward to the highest point of the leaf tip .

[0197] S4_2: Real-time location monitoring. Obtains the current location of the drone. .Will Transform to a coordinate system with the center of the wheel hub as the origin, and calculate the horizontal distance from the wheel hub. and azimuth .

[0198] S4_3: The drone performs a safety status assessment. It determines whether the drone's current status meets the following conditions: Condition 1: This indicates a safe horizontal distance. Preset distance; Condition 2: ,in This represents the nacelle yaw angle at the current moment, indicating the angle of deviation from the rotor surface, i.e., not in the direction directly opposite to the blade rotation. Preset angle; Condition 3: This indicates that within the preset height range, Indicates the height of the mobile shooting terminal; If all of the above conditions are met, the drone is determined to be in a safe area; if condition 1 or condition 2 is not met, and If the drone is within a certain altitude range, it is determined that it has entered a dangerous area.

[0199] S4_4: The drone adapts to the safety status and responds accordingly.

[0200] Early warning stage: when or At that time, the system issued an early warning, indicating that it was approaching a dangerous inspection area. and These are preset parameters.

[0201] Avoidance Phase: Upon determining that the system has entered a dangerous area, it immediately interrupts the current shooting task and triggers a preset emergency avoidance strategy. The avoidance strategy includes: a) Vertical Climb: Control the drone to climb vertically upwards and quickly escape the dangerous altitude range; b) Radial departure: If vertical ascent is limited, fly radially outward along the current azimuth angle to increase... until ; c) Hovering and waiting: If neither of the above two methods is feasible, hover and wait for the turbine status to change (such as the yaw angle turning to move the danger zone away), while continuously assessing the situation. Recovery phase: After the drone successfully leaves the danger zone, the system reassesses the current status and attempts to return to the original mission waypoint to continue the unfinished shooting mission.

[0202] Step S5: Blade Unique Identifier Tracking and Data Association. To ensure that data on the same blade captured at different inspection points can be automatically categorized onto each blade, a blade unique identifier tracking mechanism needs to be established. This corresponds to the second embodiment of this application.

[0203] S5_1: Wind turbine coordinate system establishment. Before performing blade tracking, a three-dimensional Cartesian coordinate system with the hub center as the origin is first established: Origin point O: Center point of the wheel hub; X-axis: Pointing directly in front of the wind turbine along the nacelle axis; Y-axis: Perpendicular to the X-axis and parallel to the horizontal plane of the ground, pointing to the left side of the fan; Z-axis: Perpendicular to the XY plane, vertically upward; The coordinate system rotates as a whole with the change of the wind turbine's yaw angle, ensuring that the blade motion can be accurately described in this coordinate system.

[0204] S5_2: Real-time measurement of blade angle.

[0205] Point cloud data acquisition. The lidar onboard the drone continuously scans the wind turbine at a fixed frequency to acquire three-dimensional point cloud data including the blades and nacelle; Leaf point cloud segmentation. After preprocessing the acquired 3D point cloud data, clustering and other algorithms are used to segment the point cloud into several clusters. Based on the geometric features of the clusters, the point cloud clusters belonging to the three leaves are identified and denoted as leaf 1, 2, and 3, respectively.

[0206] Angle calculation. For each blade point cloud cluster, project it onto the YOZ plane of the wind turbine coordinate system, calculate the geometric center or fitted line of the projected point set, and then determine the azimuth angle of the blade in the YOZ plane. that angle That is, the leaf Spatial location at the current moment; S5_3: Dynamic tracking algorithm for unique blade identifiers. At the initial moment... The initial angles of the three blades were obtained through angle measurement. , , (Sorted by numerical value from smallest to largest). The system presets the following unique blade identifier allocation rules: the blade with the smallest angle is assigned as blade 1, the blade with the second smallest angle is assigned as blade 2, and the blade with the largest angle is assigned as blade 3.

[0207] At each subsequent moment, the system predicts the angle of each blade at the current moment based on the angle of each blade at the previous moment and the current blade rotation speed: .

[0208] in, For the predicted blade angle, The angle at the previous moment, The instantaneous rotational angular velocity of the blade. For time difference; The actual angles of the three blades are measured using lidar at the current moment. The three predicted angles are optimally matched with the three measured angles to determine the unique identifier of the blade corresponding to each measured angle at the current moment. Through this prediction-matching mechanism, even if the blade continues to rotate, each blade can maintain its initially assigned unique identifier without changing due to angle transitions. The boundary causes a unique identifier to drift.

[0209] S5_4: Binding mechanism between image and unique leaf identifier.

[0210] Recording the shooting time. When the drone triggers the camera to take a picture at a preset waypoint, the system records the precise shooting timestamp. This refers to the time it takes to capture images of the location to be inspected.

[0211] Blade angle calculation. Since the scanning frequency of the lidar may not be perfectly synchronized with the camera triggering time, the system uses an interpolation method based on... Calculate the lidar data at the previous and next time points. Precise angles of the three blades at any given moment .

[0212] Currently, the blade is being assessed. Let the current preset target angle be... For example, the vertical angle of the blade is 90°. The system calculates the difference between the angle of each blade and the target angle: .

[0213] Pick smallest leaf The blade is the target of the current photograph.

[0214] Image metadata is written. After determining the unique identifier of the leaf being captured, the system saves information such as the leaf number, latitude and longitude, and time at the time the image was captured when saving the image.

[0215] Step S6: Wind turbine blade defect detection and identification. This corresponds to the fifth embodiment of this application.

[0216] S6_1: After the task is completed, export all image data and its metadata collected during this inspection.

[0217] S6_2: Based on the unique leaf identifier and shooting location information in the image metadata, automatically archive the image to the folder corresponding to the leaf.

[0218] S6_3: Defect Detection and Recognition. The categorized image data is input into a pre-set defect detection model for defect recognition, and the defect recognition results are output, including defect type, defect location information, blade number, etc.

[0219] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the method of acquiring wind turbine blade images in this application. Any simple transformations based on this technical concept are within the protection scope of this application.

[0220] Based on the same inventive concept, this application provides a mobile shooting terminal, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the wind turbine blade image acquisition method in the above embodiments.

[0221] like Figure 6 As shown, the mobile shooting terminal may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage device 1003 into a random access memory (RAM) 1004. The RAM 1004 also stores various programs and data required for the operation of the mobile shooting terminal. The processing unit 1001, the ROM 1002, and the RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touchscreen, touchpad, image sensor, microphone, accelerometer, gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; storage devices 1003 including, for example, magnetic tape, hard disk, etc.; and communication devices 1009. The communication device 1009 allows the mobile shooting terminal to communicate wirelessly or wiredly with other devices to exchange data. Although the figures show mobile shooting terminals with various systems, it should be understood that implementing or having all of the systems shown is not required. More or fewer systems may be implemented alternatively.

[0222] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from read-only memory 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0223] The mobile shooting terminal provided in this application, employing the wind turbine blade image acquisition method described in the above embodiments, can solve the technical problem of how to improve the clarity of wind turbine blade images. Compared with the prior art, the beneficial effects of the mobile shooting terminal provided in this application are the same as those of the wind turbine blade image acquisition method provided in the above embodiments, and other technical features of this mobile shooting terminal are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0224] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0225] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for acquiring images of wind turbine blades, characterized in that, The method includes: During the rotation of the wind turbine blades, the linear velocity at the inspection position of the target blade is determined, and the target rotational angular velocity of the mobile imaging terminal is determined based on the linear velocity. Based on the current angle of the target blade, the target angle corresponding to the shooting point of the mobile shooting terminal, and the rotational speed of the target blade, determine the remaining time for the target blade to be inspected to reach the shooting point of the mobile shooting terminal. The remaining time is compensated for to obtain the control trigger time of the mobile shooting terminal; At the control trigger time, a control command is sent to the mobile imaging terminal so that when the target blade reaches the target angle, the mobile imaging terminal is already at the target rotation angular velocity and takes a picture of the position to be inspected, thereby obtaining a blade image of the target blade at the position to be inspected.

2. The method for acquiring wind turbine blade images as described in claim 1, characterized in that, The process of determining the linear velocity at the inspection position of the target blade and determining the target rotational angular velocity of the mobile imaging terminal based on the linear velocity includes: The rotational speed of the target blade, the first distance between the inspection location and the hub center, and the second distance between the mobile imaging terminal and the inspection location are obtained. The linear velocity is determined based on the rotational speed of the target blade and the first distance. The target rotational angular velocity of the mobile shooting terminal is determined based on the linear velocity and the second distance.

3. The method for acquiring wind turbine blade images as described in claim 1, characterized in that, The process of compensating for the remaining time to obtain the control trigger time of the mobile shooting terminal includes: Obtain the delay time of each delay source; The total delay time is obtained by summing the delay times of each delay source, wherein the delay source includes at least one of data processing delay, communication delay, mechanical start-up delay of the mobile shooting terminal, and exposure time delay of the mobile shooting terminal; The control trigger time of the mobile shooting terminal is obtained by using the total delay time to compensate for the remaining time.

4. The method for acquiring wind turbine blade images as described in claim 1, characterized in that, The method for acquiring images of wind turbine blades further includes: The image of the blade is obtained by the mobile camera terminal after it takes a picture of the location to be inspected. Determine the unique identifier of the target blade; Establish and store the association between the blade image, the unique identifier of the target blade, the time the blade image was captured, the wind turbine yaw angle, and the location to be inspected.

5. The method for acquiring wind turbine blade images as described in claim 4, characterized in that, The unique identifier used to determine the target blade includes: The time it takes for the mobile camera to capture images of the location to be inspected is obtained. Determine the actual angle of each of the wind turbine blades at the specified shooting time; Determine the difference between the target angle of the target blade and the actual angle of each of the wind turbine blades, and determine the wind turbine blade corresponding to the smallest difference; The unique identifier of the target blade is determined based on the wind turbine blade corresponding to the minimum difference and the correspondence between the wind turbine blade and the unique identifier.

6. The method for acquiring wind turbine blade images as described in claim 5, characterized in that, Before determining the unique identifier of the target blade based on the wind turbine blade corresponding to the minimum difference and the correspondence between the wind turbine blade and the unique identifier, the method further includes: Obtain the initial angle of each wind turbine blade; Based on the initial angle of each of the wind turbine blades, a unique identifier is assigned to each of the wind turbine blades. Establish a correspondence between each wind turbine blade and its corresponding unique identifier.

7. The method for acquiring wind turbine blade images as described in claim 5, characterized in that, Determining the actual angle of each wind turbine blade at the shooting time includes: For each wind turbine blade, obtain the blade point cloud data at the moment before the shooting time and the blade point cloud data at the moment after the shooting time. Determine the first actual angle corresponding to the blade point cloud data at the previous moment, and the second actual angle corresponding to the blade point cloud data at the next moment; Interpolate the first actual angle and the second actual angle to obtain the target actual angle; The actual angle of the target is taken as the actual angle of the wind turbine blade at the shooting time.

8. The method for acquiring wind turbine blade images as described in claim 1, characterized in that, Before determining the linear velocity at the inspection position of the target blade and determining the target rotation angular velocity of the mobile imaging terminal based on the linear velocity, the method further includes: Plan the inspection route of the mobile shooting terminal parallel to the rotation surface of the target blade; Determine the theoretical shooting point of the mobile shooting terminal and the theoretical wind turbine yaw angle corresponding to the theoretical shooting point on the inspection route; Determine the actual wind turbine yaw angle corresponding to the theoretical shooting point; Based on the deviation between the actual wind turbine yaw angle and the theoretical wind turbine yaw angle, the theoretical shooting point is corrected to obtain the actual shooting point facing the target blade. The mobile imaging terminal is controlled to fly from the theoretical imaging point to the actual imaging point, so as to determine the linear velocity at the inspection position of the target blade at the actual imaging point, and to determine the target rotational angular velocity of the mobile imaging terminal based on the linear velocity.

9. The method for acquiring wind turbine blade images as described in claim 1, characterized in that, The method for acquiring images of wind turbine blades further includes: During the flight or hovering shooting process of the mobile shooting terminal, it is determined whether the mobile shooting terminal is located in a dangerous area based on the current position of the mobile shooting terminal; If the mobile shooting terminal is located in the danger zone, an avoidance strategy is executed on the mobile shooting terminal, wherein the avoidance strategy includes one of: controlling the mobile shooting terminal to climb, controlling the mobile shooting terminal to move away radially, or controlling the mobile shooting terminal to hover and wait.

10. The method for acquiring wind turbine blade images as described in claim 9, characterized in that, During the flight or hovering shooting process of the mobile shooting terminal, determining whether the mobile shooting terminal is located in a dangerous area based on its current position includes: During the flight or hovering shooting process of the mobile shooting terminal, based on the current position of the mobile shooting terminal, the horizontal distance between the mobile shooting terminal and the center of the wheel hub, the azimuth angle of the mobile shooting terminal, and the height of the mobile shooting terminal are determined. If any of the following conditions are met: the horizontal distance is less than or equal to a preset distance, the difference between the azimuth angle and the current wind turbine yaw angle is greater than or equal to a preset angle, or the height is outside the preset height range, then the mobile shooting terminal is determined to be located in the danger zone.

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