Power line sag detection method based on SAR image

Abstract

The invention discloses a power line sag detection method based on an SAR image, and relates to the field of detection path analysis, and the method comprises a data acquisition step, a preliminary analysis step, an environment monitoring step, a power line change analysis step and a power line detection analysis step. The power line sag data set corresponding to the target power line and the environment information corresponding to the area where the target power line is located are combined and analyzed to obtain the detection route corresponding to the target power line, the inspection route can be shortened through an optimized route planning algorithm, power line detection is completed in the shortest time, and the detection efficiency is improved. According to performance parameters of radar equipment, route optimization is carried out, various hidden dangers can be effectively found through detection, the route can be adjusted according to real-time environment information and unmanned aerial vehicle state information, and stable flight and effective detection can still be kept under severe weather such as strong wind and rainstorm.

Description

Technical Field

[0001] The present application relates to the field of detection path analysis, and in particular to a power line sag detection method based on SAR images. Background Art

[0002] With the advancement of technology, drone inspections have entered the industry. Drones have significant advantages such as low cost and easy operation, and can quickly reach designated areas for inspections. However, in the context of the booming power industry today, existing technologies still have the following shortcomings: Existing technologies rely on inspectors to patrol power lines on foot or with the help of simple transportation, which is inefficient. In complex terrain areas such as mountainous areas and jungles, on-foot inspections are difficult. Some remote or difficult-to-reach sections of the line are even difficult to reach, which makes it difficult to detect potential power line hazards in a timely manner. Summary of the Invention

[0003] The object of the present invention is to provide a power line sag detection method based on SAR images to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: a power line sag detection method based on SAR images, comprising: Data acquisition step: for performing image monitoring of the area where the target power line is located, and analyzing the area in combination with the power planning map corresponding to the area where the target power line is located to obtain basic power line data of the area where the target power line is located; Environmental monitoring step: used to monitor the environment of the area where the target power line is located and obtain environmental information corresponding to the area where the target power line is located; Preliminary analysis step: used to obtain the power construction log corresponding to the power line, and perform preliminary analysis based on the basic power line data in the area where the target power line is located to obtain the power line sag change set corresponding to the target power line; Power line detection and analysis step: used to analyze the power line sag change set corresponding to the target power line and the environmental information corresponding to the area where the target power line is located, and obtain the drone monitoring and control results corresponding to the target power line.

[0005] In a preferred embodiment of this solution, the data acquisition step is specifically performed as follows: Use high-precision satellite remote sensing technology to monitor and obtain a set of remote sensing satellite images corresponding to the area where the target power line is located. Use a high-precision contour scanner to scan the set of remote sensing satellite images corresponding to the area where the target power line is located to establish a three-dimensional geographic model corresponding to the area where the target power line is located. Extract data from the three-dimensional geographic model corresponding to the area where the target power line is located, and obtain the terrain height corresponding to each coordinate base point in the three-dimensional geographic model corresponding to the area where the target power line is located; Obtain the position coordinates of each power tower corresponding to the target power line area through the power planning map corresponding to the target power line area, and perform data matching on the position coordinates of each power tower corresponding to the target power line area with the three-dimensional geographic model corresponding to the target power line area to obtain the terrain height of each power tower corresponding to the target power line area and the spatial position coordinates of the corresponding coordinate base point, wherein the spatial position coordinates of the corresponding coordinate base point of each power tower refer to the spatial position coordinates of the corresponding bottom of each power tower; Get the height of the tower corresponding to the power line; Obtain the tilt angle and rotation angle of each power tower corresponding to the target power line area through the tilt sensors preset in each power tower. The tilt angle refers to the degree of tilt in the vertical direction, and the rotation angle refers to the degree of offset in the horizontal direction. Obtain the actual height and spatial position coordinates of the tops of the power towers corresponding to the target power line area by calculating the terrain height, tower height, tilt angle, and rotation angle of the power towers corresponding to the target power line area; Obtaining the corresponding adjacent power towers in the area where the target power line is located according to the power connection sequence corresponding to the area where the target power line is located, and obtaining the actual height difference of the adjacent power towers according to the actual height of the corresponding tower tops of the adjacent power towers; The spatial position coordinates of the tops of the corresponding power towers are calculated to obtain the spatial straight-line distances corresponding to the adjacent power towers, and the spatial straight-line distances corresponding to the adjacent power towers are recorded as the basic power line data of the area where the target power line is located.

[0006] In the preferred embodiment of this scheme, the specific implementation method of the environmental monitoring step is as follows: Environmental information corresponding to the target power line area is obtained by presetting an environmental monitoring instrument in the target power line area, wherein the environmental information includes the ambient temperature, wind speed and wind direction corresponding to the target power line area.

[0007] In the preferred embodiment of this scheme, the specific implementation of the preliminary analysis step is as follows: Establishing a data extraction relationship between the preliminary analysis step and the database to extract the power line density and power line diameter corresponding to each power line type stored in the database; Extracting each power line sag model stored in the database, wherein the power line sag model includes a power line sag curve corresponding to a combination of straight-line distance, actual power line length, height difference between both ends, and power line weight; Obtain the power construction log corresponding to the area where the target power line is located, and extract data from the power construction log to obtain the type of power line corresponding to the area where the target power line is located and the actual power line length corresponding to each adjacent power tower; The density and diameter of the power lines corresponding to the target power line are obtained by screening the power line types corresponding to the area where the target power line is located. The weight of the power lines corresponding to the adjacent power towers is calculated based on the actual power line usage length corresponding to each adjacent power tower and the density and diameter of the power lines corresponding to the target power line. Extracting thermal expansion and contraction models corresponding to various types of power lines stored in a database, wherein the thermal expansion and contraction models refer to the contraction or expansion ratios of various types of power lines at different temperatures; The contraction or expansion ratio of the power line corresponding to the target power line is obtained based on the ambient temperature corresponding to the area where the target power line is located and the type of power line corresponding to the target power line. The actual length of the power line corresponding to each adjacent power tower of the target power line is calculated to obtain the changed power line corresponding to each adjacent power tower of the target power line and the actual length of the changed power line. The power line sag curves corresponding to the adjacent power towers are obtained by screening according to the actual lengths of the power lines after the changes, the weights of the power lines, the height differences and the spatial straight-line distances of the adjacent power towers, and are recorded as the changed power line sag curves corresponding to the adjacent power towers. The changed power line sag curves corresponding to the adjacent power towers are recorded as the power line sag change set corresponding to the power line.

[0008] In a preferred embodiment of this solution, the power line detection and analysis steps are specifically performed as follows: Obtaining a set of operating parameters for a radar used for power line detection in the drone, including the radar's effective detection angle and the radar's power line monitoring accuracy at various parallel distances under a preset cruising speed and a windless environment. The parallel distance refers to the parallel distance between the radar and the power line. Obtaining a task requirement data set corresponding to a target power line, wherein the task requirement data set includes a monitoring accuracy and an average detection rate of a power line corresponding to the target power line; Establish a wind field model for the target power line area based on the wind speed and wind direction corresponding to the target power line area; Perform angle analysis between the wind field model of the target power line area and the actual height and spatial position coordinates of the tops of the power towers corresponding to the target power line area, and obtain the angle between the sag curve of the changed power line and the wind corresponding to each adjacent power tower; Calculate the windward area of the power lines after the adjacent power towers are changed according to the actual lengths of the power lines and the diameters of the power lines after the adjacent power towers are changed; Calculate the wind force corresponding to the power lines after the changes of each adjacent power tower according to the preset wind force model; The angle between the power lines of each adjacent power tower and the vertical direction after the change is obtained by calculating the wind force corresponding to the power lines of each adjacent power tower and the weight of the power lines of each adjacent power tower, and the angle is recorded as the offset angle of the power lines of each adjacent power tower after the change. The changed power line sag curves corresponding to the adjacent power towers are deflected and controlled according to the wind direction and the offset angle to obtain the power line sag curves corresponding to the deflection changes of the adjacent power towers. The power line sag curves corresponding to the deflection changes of the adjacent power towers are recorded as the initial monitoring route of the UAV; Extracting a power line oscillation model stored in a database, the power line oscillation model including the oscillation amplitude and oscillation frequency corresponding to the power line under different wind force and weight combinations, extracting the monitoring difficulty increase coefficient corresponding to each power line oscillation amplitude and oscillation frequency stored in the database, and obtaining the monitoring difficulty increase coefficient corresponding to the power line sag curve after the deflection change of each adjacent power tower by screening the wind force and weight corresponding to the power line sag curve after the deflection change of each adjacent power tower; Extracting a drone oscillation model stored in a database, wherein the drone oscillation model includes the drone oscillation amplitude and oscillation frequency corresponding to different wind speeds, and extracting the monitoring accuracy impact ratio corresponding to each drone oscillation amplitude and oscillation frequency stored in the database; The impact ratio of the drone's monitoring accuracy is obtained by the wind speed in the area where the target power line is located; Data analysis was performed based on the impact ratio of the drone's monitoring accuracy, the monitoring difficulty increase coefficient corresponding to the power line sag curve after the deflection changes of each adjacent power tower, and the radar's operating parameter set. The horizontal detection distance between the drone and the power line sag curve after the deflection changes of each adjacent power tower was obtained. Based on the effective detection angle of the radar in the UAV, the horizontal detection distance between the UAV and the power line sag curve after the deflection change of each adjacent power tower, and the power line sag curve after the deflection change of the adjacent power tower, a data model is established and analyzed to obtain the actual cruising speed and actual patrol path corresponding to the UAV. The actual cruising speed and actual patrol path corresponding to the UAV are recorded as the UAV monitoring and control results corresponding to the target power line.

[0009] Compared with the prior art, the present invention has the following beneficial effects: The present invention monitors the image and environment of the area where the target power line is located, and obtains the detection route corresponding to the target power line by combining and analyzing the power line sag dataset corresponding to the target power line and the environmental information corresponding to the area where the target power line is located. Through the optimized route planning algorithm, the inspection time can be shortened and the power line detection can be completed in the shortest time. The route is optimized according to the performance parameters of the radar equipment, which can effectively detect various hidden dangers. The route can be adjusted according to real-time environmental information and drone status information, and stable flight and effective detection can still be maintained in severe weather such as strong winds and heavy rains. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention is further described with reference to the accompanying drawings. However, the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the connection steps of an embodiment of the present invention. DETAILED DESCRIPTION

[0012] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0013] See also Figure 1 , the present invention provides a power line sag detection method based on SAR images, the method comprising a data acquisition step, an environment monitoring step, a preliminary analysis step and a power line detection and analysis step; The data acquisition step is connected with the preliminary analysis step, the environment monitoring step is connected with the preliminary analysis step and the power line detection and analysis step, and the preliminary analysis step is connected with the power line detection and analysis step.

[0014] The data acquisition step is used to perform image monitoring of the area where the target power line is located, and analyze the area in combination with the power planning map corresponding to the area where the target power line is located to obtain basic power line data of the area where the target power line is located; Furthermore, the specific execution method of the data acquisition step is as follows: Use high-precision satellite remote sensing technology to monitor and obtain a set of remote sensing satellite images corresponding to the area where the target power line is located. Use a high-precision contour scanner to scan the set of remote sensing satellite images corresponding to the area where the target power line is located to establish a three-dimensional geographic model corresponding to the area where the target power line is located. Extract data from the three-dimensional geographic model corresponding to the area where the target power line is located, and obtain the terrain height corresponding to each coordinate base point in the three-dimensional geographic model corresponding to the area where the target power line is located; Obtain the position coordinates of each power tower corresponding to the target power line area through the power planning map corresponding to the target power line area, and perform data matching on the position coordinates of each power tower corresponding to the target power line area with the three-dimensional geographic model corresponding to the target power line area to obtain the terrain height of each power tower corresponding to the target power line area and the spatial position coordinates of the corresponding coordinate base point, wherein the spatial position coordinates of the corresponding coordinate base point of each power tower refer to the spatial position coordinates of the corresponding bottom of each power tower; Get the height of the tower corresponding to the power line; Obtain the tilt angle and rotation angle of each power tower corresponding to the target power line area through the tilt sensors preset in each power tower. The tilt angle refers to the degree of tilt in the vertical direction, and the rotation angle refers to the degree of offset in the horizontal direction. Obtain the actual height and spatial position coordinates of the tops of the power towers corresponding to the target power line area by calculating the terrain height, tower height, tilt angle, and rotation angle of the power towers corresponding to the target power line area; Obtaining the corresponding adjacent power towers in the area where the target power line is located according to the power connection sequence corresponding to the area where the target power line is located, and obtaining the actual height difference of the adjacent power towers according to the actual height of the corresponding tower tops of the adjacent power towers; The spatial position coordinates of the tops of the corresponding power towers are calculated to obtain the spatial straight-line distances corresponding to the adjacent power towers, and the spatial straight-line distances corresponding to the adjacent power towers are recorded as the basic power line data of the area where the target power line is located.

[0015] The environmental monitoring step is used to monitor the environment of the area where the target power line is located, and obtain environmental information corresponding to the area where the target power line is located; Furthermore, the specific implementation of the environmental monitoring step is as follows: Environmental information corresponding to the target power line area is obtained by presetting an environmental monitoring instrument in the target power line area, wherein the environmental information includes the ambient temperature, wind speed and wind direction corresponding to the target power line area.

[0016] The preliminary analysis step is used to obtain the power construction log corresponding to the power line, and perform preliminary analysis based on the basic power line data in the area where the target power line is located to obtain the power line sag change set corresponding to the target power line; Furthermore, the specific execution method of the preliminary analysis step is as follows: Establishing a data extraction relationship between the preliminary analysis step and the database to extract the power line density and power line diameter corresponding to each power line type stored in the database; Extracting each power line sag model stored in the database, wherein the power line sag model includes a power line sag curve corresponding to a combination of straight-line distance, actual power line length, height difference between both ends, and power line weight; Obtain the power construction log corresponding to the area where the target power line is located, and extract data from the power construction log to obtain the type of power line corresponding to the area where the target power line is located and the actual power line length corresponding to each adjacent power tower; The density and diameter of the power lines corresponding to the target power line are obtained by screening the power line types corresponding to the area where the target power line is located. The weight of the power lines corresponding to the adjacent power towers is calculated based on the actual power line usage length corresponding to each adjacent power tower and the density and diameter of the power lines corresponding to the target power line. Extracting thermal expansion and contraction models corresponding to various types of power lines stored in a database, wherein the thermal expansion and contraction models refer to the contraction or expansion ratios of various types of power lines at different temperatures; The contraction or expansion ratio of the power line corresponding to the target power line is obtained based on the ambient temperature corresponding to the area where the target power line is located and the type of power line corresponding to the target power line. The actual length of the power line corresponding to each adjacent power tower of the target power line is calculated to obtain the changed power line corresponding to each adjacent power tower of the target power line and the actual length of the changed power line. The power line sag curves corresponding to the adjacent power towers are obtained by screening according to the actual lengths of the power lines after the changes, the weights of the power lines, the height differences and the spatial straight-line distances of the adjacent power towers, and are recorded as the changed power line sag curves corresponding to the adjacent power towers. The changed power line sag curves corresponding to the adjacent power towers are recorded as the power line sag change set corresponding to the power line.

[0017] The power line detection and analysis step is used to analyze the power line sag change set corresponding to the target power line and the environmental information corresponding to the area where the target power line is located, and obtain the drone monitoring and control results corresponding to the target power line.

[0018] Furthermore, the specific execution method of the power line detection and analysis step is as follows: Obtaining a set of operating parameters for a radar used for power line detection in the drone, including the radar's effective detection angle and the radar's power line monitoring accuracy at various parallel distances under a preset cruising speed and a windless environment. The parallel distance refers to the parallel distance between the radar and the power line. Obtaining a task requirement data set corresponding to a target power line, wherein the task requirement data set includes a monitoring accuracy and an average detection rate of a power line corresponding to the target power line; Establish a wind field model for the target power line area based on the wind speed and wind direction corresponding to the target power line area; Perform angle analysis between the wind field model of the target power line area and the actual height and spatial position coordinates of the tops of the power towers corresponding to the target power line area, and obtain the angle between the sag curve of the changed power line and the wind corresponding to each adjacent power tower; Calculate the windward area of the power lines after the change corresponding to each adjacent power tower based on the actual length of the power lines and the diameter of the power lines after the change corresponding to each adjacent power tower; Calculate the wind force corresponding to the power lines after the changes of each adjacent power tower according to the preset wind force model; The angle between the power lines of each adjacent power tower and the vertical direction after the change is obtained by calculating the wind force corresponding to the power lines of each adjacent power tower and the weight of the power lines of each adjacent power tower, and the angle is recorded as the offset angle of the power lines of each adjacent power tower after the change. The changed power line sag curves corresponding to the adjacent power towers are deflected and controlled according to the wind direction and the offset angle to obtain the power line sag curves corresponding to the deflection changes of the adjacent power towers. The power line sag curves corresponding to the deflection changes of the adjacent power towers are recorded as the initial monitoring route of the UAV; Extracting a power line oscillation model stored in a database, the power line oscillation model including the oscillation amplitude and oscillation frequency corresponding to the power line under different wind force and weight combinations, extracting the monitoring difficulty increase coefficient corresponding to each power line oscillation amplitude and oscillation frequency stored in the database, and obtaining the monitoring difficulty increase coefficient corresponding to the power line sag curve after the deflection change of each adjacent power tower by screening the wind force and weight corresponding to the power line sag curve after the deflection change of each adjacent power tower; Extracting a drone oscillation model stored in a database, wherein the drone oscillation model includes the drone oscillation amplitude and oscillation frequency corresponding to different wind speeds, and extracting the monitoring accuracy impact ratio corresponding to each drone oscillation amplitude and oscillation frequency stored in the database; The wind speed in the area where the target power line is located is used to obtain the corresponding monitoring accuracy impact ratio of the drone; Data analysis was performed based on the impact ratio of the drone's monitoring accuracy, the monitoring difficulty increase coefficient corresponding to the power line sag curve after the deflection changes of each adjacent power tower, and the radar's operating parameter set. The horizontal detection distance between the drone and the power line sag curve after the deflection changes of each adjacent power tower was obtained. Supplementary explanation of the above specific data analysis process: For example, the monitoring accuracy impact ratio corresponding to the drone and the monitoring difficulty increase coefficient corresponding to the power line sag curve after the deflection change of each adjacent power tower are marked as A and B respectively; For example, the radar's monitoring accuracy is 0.2 square centimeters. This means that the radar can identify power line defects or power line anomalies with a size of 0.2 square centimeters. The actual radar monitoring accuracy after the influence of wind = 0.2×(1+A+B); Based on the radar's operating parameter set and the monitoring accuracy of the target power line, a reverse analysis is performed to obtain the horizontal distance that meets the monitoring accuracy of the target power line. This distance is recorded as the horizontal detection distance of the power line sag curve after the deflection change between the UAV and each adjacent power tower. Based on the effective detection angle of the radar in the UAV, the horizontal detection distance between the UAV and the power line sag curve after the deflection change of each adjacent power tower, and the power line sag curve after the deflection change of the adjacent power tower, a data model is established and analyzed to obtain the actual cruising speed and actual patrol path corresponding to the UAV. The actual cruising speed and actual patrol path corresponding to the UAV are recorded as the UAV monitoring and control results corresponding to the target power line.

[0019] Supplementary explanation of the above analysis process: Perform statistical calculations on the horizontal detection distances of the power line sag curves corresponding to the deflection changes between the UAV and each adjacent power tower to obtain a weighted average of the horizontal detection distances. This weighted average is recorded as the stable control horizontal detection distance. Obtain the curve segments of the power line sag curve corresponding to the deflection change of each adjacent power tower at a stable control horizontal detection distance, and record them as the preliminary inspection paths of the UAV corresponding to each adjacent power tower; Compare the horizontal detection distance between the UAV and the power line sag curve after the deflection change corresponding to each adjacent power tower with the stable control horizontal detection distance. If the horizontal detection distance is less than the stable control horizontal detection distance, perform route control so that the horizontal distance between the route and the power line sag curve after the deflection change is equal to the horizontal detection distance corresponding to the power line sag curve after the deflection change, and obtain the actual inspection path of each adjacent power tower that is less than the stable control horizontal detection distance. If the horizontal detection distance is greater than or equal to the stable control horizontal detection distance, do not perform route control, and record the preliminary inspection paths corresponding to each adjacent power tower that is greater than or equal to the stable control horizontal detection distance as the actual inspection path. Statistically obtain the actual inspection path corresponding to each adjacent power tower and the length of the actual inspection path; Connect the actual inspection paths of adjacent power towers with straight lines from beginning to end, obtain the straight line paths and straight line distances of each connection, and record the actual inspection paths of adjacent power towers and the straight line paths of each connection as the actual inspection paths corresponding to the target power line; The sum of the length of the actual inspection path of each adjacent power tower and the straight-line distance of each connection is recorded as the actual inspection path length corresponding to the target power line; The actual cruising speed of the UAV is calculated based on the average power line detection rate of the power line corresponding to the target power line and the actual inspection path length corresponding to the target power line.

[0020] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for detecting power line sag based on SAR images, characterized by: include: Data acquisition step: for performing image monitoring of the area where the target power line is located, and analyzing the area in combination with the power planning map corresponding to the area where the target power line is located to obtain basic power line data of the area where the target power line is located; Environmental monitoring step: used to monitor the environment of the area where the target power line is located and obtain environmental information corresponding to the area where the target power line is located; Preliminary analysis step: used to obtain the power construction log corresponding to the power line, and perform preliminary analysis based on the basic power line data in the area where the target power line is located to obtain the power line sag change set corresponding to the target power line; Power line detection and analysis step: used to analyze the power line sag change set corresponding to the target power line and the environmental information corresponding to the area where the target power line is located, and obtain the drone monitoring and control results corresponding to the target power line.

2. The method for detecting power line sag based on SAR images according to claim 1, wherein: The specific execution method of the data acquisition step is as follows: Use high-precision satellite remote sensing technology to monitor and obtain a set of remote sensing satellite images corresponding to the area where the target power line is located. Use a high-precision contour scanner to scan the set of remote sensing satellite images corresponding to the area where the target power line is located to establish a three-dimensional geographic model corresponding to the area where the target power line is located. Extract data from the three-dimensional geographic model corresponding to the area where the target power line is located, and obtain the terrain height corresponding to each coordinate base point in the three-dimensional geographic model corresponding to the area where the target power line is located; Obtain the position coordinates of each power tower corresponding to the target power line area through the power planning map corresponding to the target power line area, and perform data matching on the position coordinates of each power tower corresponding to the target power line area with the three-dimensional geographic model corresponding to the target power line area to obtain the terrain height of each power tower corresponding to the target power line area and the spatial position coordinates of the corresponding coordinate base point, wherein the spatial position coordinates of the corresponding coordinate base point of each power tower refer to the spatial position coordinates of the corresponding bottom of each power tower; Get the height of the tower corresponding to the power line; Obtain the tilt angle and rotation angle of each power tower corresponding to the target power line area through the tilt sensors preset in each power tower. The tilt angle refers to the degree of tilt in the vertical direction, and the rotation angle refers to the degree of offset in the horizontal direction. Obtain the actual height and spatial position coordinates of the tops of the power towers corresponding to the target power line area by calculating the terrain height, tower height, tilt angle, and rotation angle of the power towers corresponding to the target power line area; Obtaining the corresponding adjacent power towers in the area where the target power line is located according to the power connection sequence corresponding to the area where the target power line is located, and obtaining the actual height difference of the adjacent power towers according to the actual height of the corresponding tower tops of the adjacent power towers; The spatial position coordinates of the tops of the corresponding power towers are calculated to obtain the spatial straight-line distances corresponding to the adjacent power towers, and the spatial straight-line distances corresponding to the adjacent power towers are recorded as the basic power line data of the area where the target power line is located.

3. The method for detecting power line sag based on SAR images according to claim 1, wherein: The specific implementation of the environmental monitoring step is as follows: Environmental information corresponding to the target power line area is obtained by presetting an environmental monitoring instrument in the target power line area, wherein the environmental information includes the ambient temperature, wind speed and wind direction corresponding to the target power line area.

4. The method for detecting power line sag based on SAR images according to claim 3, wherein: The specific implementation of the preliminary analysis step is as follows: Establishing a data extraction relationship between the preliminary analysis step and the database to extract the power line density and power line diameter corresponding to each power line type stored in the database; Extracting each power line sag model stored in the database, wherein the power line sag model includes a power line sag curve corresponding to a combination of straight-line distance, actual power line length, height difference between both ends, and power line weight; Obtain the power construction log corresponding to the area where the target power line is located, and extract data from the power construction log to obtain the type of power line corresponding to the area where the target power line is located and the actual power line length corresponding to each adjacent power tower; The density and diameter of the power lines corresponding to the target power line are obtained by screening the power line types corresponding to the area where the target power line is located. The weight of the power lines corresponding to the adjacent power towers is calculated based on the actual power line usage length corresponding to each adjacent power tower and the density and diameter of the power lines corresponding to the target power line. Extracting thermal expansion and contraction models corresponding to various types of power lines stored in a database, wherein the thermal expansion and contraction models refer to the contraction or expansion ratios of various types of power lines at different temperatures; The contraction or expansion ratio of the power line corresponding to the target power line is obtained based on the ambient temperature corresponding to the area where the target power line is located and the type of power line corresponding to the target power line. The actual length of the power line corresponding to each adjacent power tower of the target power line is calculated to obtain the changed power line corresponding to each adjacent power tower of the target power line and the actual length of the changed power line. The power line sag curves corresponding to the adjacent power towers are obtained by screening according to the actual lengths of the power lines after the changes, the weights of the power lines, the height differences and the spatial straight-line distances of the adjacent power towers, and are recorded as the changed power line sag curves corresponding to the adjacent power towers. The changed power line sag curves corresponding to the adjacent power towers are recorded as the power line sag change set corresponding to the power line.

5. The method for detecting power line sag based on SAR images according to claim 4, characterized in that: The specific execution method of the power line detection and analysis step is as follows: Obtaining a set of operating parameters for a radar used for power line detection in the drone, including the radar's effective detection angle and the radar's power line monitoring accuracy at various parallel distances under a preset cruising speed and a windless environment. The parallel distance refers to the parallel distance between the radar and the power line. Obtaining a task requirement data set corresponding to a target power line, wherein the task requirement data set includes a monitoring accuracy and an average detection rate of a power line corresponding to the target power line; Establish a wind field model for the target power line area based on the wind speed and wind direction corresponding to the target power line area; Perform angle analysis between the wind field model of the target power line area and the actual height and spatial position coordinates of the tops of the power towers corresponding to the target power line area, and obtain the angle between the sag curve of the changed power line and the wind corresponding to each adjacent power tower; Calculate the windward area of the power lines after the change corresponding to each adjacent power tower based on the actual length of the power lines and the diameter of the power lines after the change corresponding to each adjacent power tower; Calculate the wind force corresponding to the power lines after the changes of each adjacent power tower according to the preset wind force model; The angle between the power lines of each adjacent power tower and the vertical direction after the change is obtained by calculating the wind force corresponding to the power lines of each adjacent power tower and the weight of the power lines of each adjacent power tower, and the angle is recorded as the offset angle of the power lines of each adjacent power tower after the change. The changed power line sag curves corresponding to the adjacent power towers are deflected and controlled according to the wind direction and the offset angle to obtain the power line sag curves corresponding to the deflection changes of the adjacent power towers. The power line sag curves corresponding to the deflection changes of the adjacent power towers are recorded as the initial monitoring route of the UAV; Extracting a power line oscillation model stored in a database, the power line oscillation model including the oscillation amplitude and oscillation frequency corresponding to the power line under different wind force and weight combinations, extracting the monitoring difficulty increase coefficient corresponding to each power line oscillation amplitude and oscillation frequency stored in the database, and obtaining the monitoring difficulty increase coefficient corresponding to the power line sag curve after the deflection change of each adjacent power tower by screening the wind force and weight corresponding to the power line sag curve after the deflection change of each adjacent power tower; Extracting a drone oscillation model stored in a database, wherein the drone oscillation model includes the drone oscillation amplitude and oscillation frequency corresponding to different wind speeds, and extracting the monitoring accuracy impact ratio corresponding to each drone oscillation amplitude and oscillation frequency stored in the database; The wind speed in the area where the target power line is located is used to obtain the corresponding monitoring accuracy impact ratio of the drone; Data analysis was performed based on the impact ratio of the drone's monitoring accuracy, the monitoring difficulty increase coefficient corresponding to the power line sag curve after the deflection changes of each adjacent power tower, and the radar's operating parameter set. The horizontal detection distance between the drone and the power line sag curve after the deflection changes of each adjacent power tower was obtained. Based on the effective detection angle of the radar in the UAV, the horizontal detection distance between the UAV and the power line sag curve after the deflection change of each adjacent power tower, and the power line sag curve after the deflection change of the adjacent power tower, a data model is established and analyzed to obtain the actual cruising speed and actual patrol path corresponding to the UAV. The actual cruising speed and actual patrol path corresponding to the UAV are recorded as the UAV monitoring and control results corresponding to the target power line.

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