Autonomous branching method and system for aeromagnetic measurement of unmanned aerial vehicle

Abstract

The invention relates to the field of aeromagnetic measurement, in particular to an autonomous branching method and system for aeromagnetic measurement of an unmanned aerial vehicle. Comprising the following steps: S1, extracting end point kilometer network projection coordinates of design measuring lines: analyzing the end point coordinates of all design measuring lines based on a preset measuring network file, and converting the end point coordinates into kilometer network projection coordinates with the same parameter; s2, measuring point and measuring line attribution classification: traversing each measuring point in the track data file, calculating the sum of the projection vertical distance from the measuring point to each design measuring line and the distance from the measuring point to two end points of the measuring line, and judging the measuring line to which the measuring point belongs by combining a distance threshold value; s3, identifying and deleting invalid measuring lines: identifying and deleting invalid measuring lines which do not meet requirements after branching according to a preset length threshold value and a direction consistency principle. The method can rapidly and accurately carry out measuring line autonomous branching on the unmanned aerial vehicle track data, obviously improves the branching efficiency and accuracy, reduces the manual intervention cost, and is especially suitable for small and medium-sized unmanned aerial vehicle aeromagnetic measurement items.

Description

Technical Field

[0001] The present invention relates to the field of aeromagnetic measurement, and in particular to an autonomous line division method and system for unmanned aerial vehicle aeromagnetic measurement. Background Art

[0002] Airborne magnetic survey (aeromagnetic survey) is a geophysical method widely used in geological exploration, engineering inspection and other fields. Traditional aeromagnetic surveys are mostly carried on manned platforms such as fixed-wing aircraft or helicopters. The relocation process is cumbersome and costly, and it is mostly used in large projects, making it difficult to popularize it to small and medium-sized area detection tasks. In recent years, with the rapid development of drone technology, drones have gradually become an important platform for aeromagnetic surveys due to their high flexibility, low cost, and easy operation. They are especially suitable for small and medium-sized area detection tasks (total survey line workload is hundreds to thousands of kilometers), such as geological surveys, engineering inspections, etc.

[0003] However, UAV aeromagnetic surveying faces a key problem in data processing: how to quickly and economically autonomously divide the survey lines of UAV track data to extract complete and valid survey line measurement data. In traditional methods, the division of aeromagnetic surveys mainly relies on manual operation or the help of large-scale professional software. Manual division methods are inefficient, prone to errors, and difficult to meet the needs of large-scale data processing; while large-scale professional software can achieve automatic division, the cost of use is high and it is not economical for small and medium-sized projects. In addition, some existing automatic division methods often have problems such as incorrect survey line attribution and inability to accurately identify invalid survey lines when processing complex track data, resulting in inaccurate division results, affecting the reliability of subsequent data processing and analysis.

[0004] For example, patent number CN104122597B discloses a UAV aeromagnetic detection system and method. This technical solution mainly involves the overall system architecture of UAV aeromagnetic detection, including the integration of the airborne part and the ground part, and focuses on improving the efficiency and data quality of aeromagnetic detection by optimizing the UAV platform and sensor configuration. However, the patent does not involve the autonomous line division technology of track data, especially in the determination of line attribution and identification of invalid lines in the processing of complex track data. This shows that the existing technology still has deficiencies in the data processing link of UAV aeromagnetic measurement, especially in the lack of effective solutions for the rapid and economical realization of autonomous line division.

[0005] In order to solve the above problems, the present invention proposes an autonomous line division method and system for unmanned aerial vehicle aeromagnetic measurement. Summary of the invention

[0006] The purpose of the present invention is to provide an autonomous line splitting method and system for unmanned aerial vehicle aeromagnetic measurement, so as to solve the problems of low efficiency and poor accuracy of track data line splitting in the prior art.

[0007] To achieve the above purpose, the following technical solution is adopted.

[0008] An autonomous line division method for unmanned aerial vehicle aeromagnetic measurement comprises the following steps: S1. Extract the kilometer grid projection coordinates of the endpoints of the designed survey lines: Based on the preset survey grid file, parse the endpoint coordinates of all designed survey lines and convert them into kilometer grid projection coordinates with the same parameters; S2. Classification of measurement points and lines: traverse each measurement point in the track data file, calculate the sum of the vertical distance from the measurement point to each designed measurement line and the distance to the two end points of the measurement line, and determine the measurement line to which the measurement point belongs based on the distance threshold; S3. Identification and deletion of invalid survey lines: According to the preset length threshold and direction consistency principle, invalid survey lines that do not meet the requirements after line division are identified and deleted. The invalid survey lines include survey lines shorter than the length threshold and route intersections that deviate too much from the designed survey line direction.

[0009] Optionally, the setting of the distance threshold in step S2 includes: The projection vertical distance threshold is 1 / 2 of the design survey line spacing H (H / 2), and the threshold of the sum of the distances from the measuring point to the two end points of the design survey line is the design survey line length L. j and H (L j +H); When the vertical distance D from the projected point i to the designed measuring line j ij <H / 2, and the sum of the distances from measuring point i to the two end points of the designed measuring line j is L ij <L j +H, it is determined that measuring point i belongs to measuring line j.

[0010] Optionally, step S2 further includes: If a measuring point meets the attribution conditions of multiple designed measuring lines at the same time, the attribution of the current measuring point will be dynamically adjusted according to the attribution results of the adjacent measuring points, giving priority to maintaining the continuity of the measuring point sequence.

[0011] Optionally, the length threshold in step S3 is set as follows: The shortest length allowed for a branch line is twice the main line spacing (2H). When the length of a branched line is less than 2H, it is considered an invalid line and deleted.

[0012] Optionally, the direction consistency determination method in step S3 is: Calculate the angle δ between the line connecting the two end points of the survey line after the division and the direction of the corresponding design survey line. If δ is greater than the preset angle threshold θ, it is determined to be an invalid survey line with inconsistent direction. Here, θ is given by the formula Calculation shows that L is the length of the designed survey line and H is the main survey line spacing.

[0013] Optionally, step S3 further includes: Priority control of the division of the main survey line and the control line: When the main survey line and the control line exist in the track data file at the same time, the main survey line division process is executed first, and then the control line division process is executed for the remaining survey points after completion to avoid conflicts in the ownership of survey points.

[0014] Optionally, also include: For the track segment where line division fails due to flight deviation, the deviation distance and position information are output, marked as the area to be manually reviewed, and the re-flight instruction is triggered according to the review result.

[0015] Optionally, the conversion of kilometer grid projection coordinates in step S1 includes: Based on the coordinate system parameters of the survey area, the longitude and latitude coordinates of the designed survey line are converted into plane rectangular coordinates under the Gauss-Krüger projection coordinate system to ensure the systematic consistency of the coordinates of all survey line endpoints.

[0016] Optionally, the method further comprises: Generate a survey line distribution map after line division, overlay the original track data and the designed survey network, and use color to mark valid survey lines, invalid survey lines and unclassified survey points to assist manual verification of line division accuracy.

[0017] An autonomous line splitting system for unmanned aerial vehicle aeromagnetic measurement, comprising: Survey line analysis module: used to extract and convert the endpoint coordinates of the designed survey line; Measuring point classification module: It realizes the determination of measuring point and measuring line attribution based on the nearest neighbor algorithm and double distance threshold; Invalid survey line filtering module: Combine length threshold and direction consistency rule to delete invalid survey lines; Data interface module: supports the standardized input of track data files and the formatted output of line division results.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention proposes an autonomous line division method for UAV aeromagnetic measurement, which effectively solves the problem of low efficiency and poor accuracy of track data line division in the prior art by extracting the kilometer network projection coordinates of the endpoints of the designed survey line, classifying the survey points into survey lines, and identifying and deleting invalid survey lines. Compared with the existing methods, the present invention can quickly and accurately autonomously divide the survey lines of UAV track data, significantly improves the line division efficiency and accuracy, and reduces the cost of manual intervention. It is particularly suitable for UAV aeromagnetic measurement projects of small and medium areas, and has a wide range of promotion and application value.

[0019] Furthermore, the present invention defines and optimizes the specific technical details of the autonomous line division method, further improving the accuracy and reliability of the line division. For example, the precise setting of the distance threshold can more accurately determine the ownership of the measuring point; the conflict handling mechanism for the same measuring point to belong to multiple measuring lines ensures the continuity of the measuring point sequence; the optimization of invalid measuring line identification further improves the accuracy of the line division results; the manual intervention mechanism can effectively handle the line division failure caused by flight deviation; the coordinate conversion and visualization verification functions further improve the practicality and reliability of the line division method. Overall, the present invention realizes the efficient and accurate line division of UAV aeromagnetic measurement track data through a series of optimization designs, provides a solid foundation for subsequent data processing and analysis, and has significant technical effects and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a schematic flow chart of the steps of an autonomous line separation method for unmanned aerial vehicle aeromagnetic measurement.

[0021] Figure 2 The present invention is a schematic diagram of an unmanned aerial vehicle aeromagnetic survey network according to an embodiment of an autonomous line division method for unmanned aerial vehicle aeromagnetic survey.

[0022] Figure 3 The present invention is a schematic diagram of dividing the measuring point lines according to the sum of the distances from the measuring point to the two end points of the measuring line in an embodiment of an autonomous line division method for unmanned aerial vehicle aeromagnetic measurement.

[0023] Figure 4 It is a schematic diagram of judging "the route portion intersecting with the survey line" in an embodiment of an autonomous line division method for unmanned aerial vehicle aeromagnetic measurement of the present invention.

[0024] Figure 5 It is a schematic diagram of a situation in which the survey line measurement route of an embodiment of an autonomous line division method for unmanned aerial vehicle aeromagnetic measurement of the present invention temporarily deviates from the designed survey line by a large amount (greater than H / 2). DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0026] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention.

[0027] Example 1

[0028] The present invention provides an autonomous line division method for UAV aeromagnetic measurement, aiming to solve the problem of low efficiency and poor accuracy of UAV track data line division in the prior art. The following is a detailed description of the implementation of the method and its system.

[0029] like Figure 1-Figure 5 As shown, the autonomous line division method of the present invention mainly includes three core steps: extracting the kilometer network projection coordinates of the endpoints of the designed survey line, classifying the survey points and survey lines, and identifying and deleting invalid survey lines. Each step is described in detail below.

[0030] 1. Extract the kilometer grid projection coordinates of the endpoints of the design survey line like Figure 2 As shown in the figure, in drone aeromagnetic survey, the designed survey line is a pre-planned flight path, and its endpoint coordinates are usually given in the form of longitude and latitude. In order to facilitate subsequent calculations and processing, these longitude and latitude coordinates need to be converted into kilometer grid projection coordinates with the same parameters. The specific steps are as follows: Read the preset survey network file: The preset survey network file contains the endpoint coordinate information of all designed survey lines. These coordinate information are usually stored in the form of longitude and latitude (longitude, latitude). By parsing this file, you can get the start and end coordinates of each designed survey line.

[0031] Coordinate conversion: Convert the endpoint coordinates of the designed survey line from the longitude and latitude coordinate system to the plane rectangular coordinates under the Gauss-Krüger projection coordinate system. The Gauss-Krüger projection is a compliant cross-cylindrical projection that can convert the longitude and latitude coordinates on the earth's surface into plane rectangular coordinates, making it easier to calculate distances and angles on a two-dimensional plane. The conversion formula is as follows:

[0032] Among them, f and g are the conversion functions of the Gauss-Krüger projection, and the specific form depends on the selected projection parameters (such as central meridian, projection bandwidth, etc.). Through this conversion, it can be ensured that the endpoint coordinates of all designed survey lines are in the same coordinate system, which is convenient for subsequent calculation and processing.

[0033] 2. Classification of measuring points and lines During the flight of the drone, a large amount of track data will be recorded in real time. Each data point (measurement point) contains the coordinate information of the point. In order to assign these measurement points to the corresponding design measurement lines, it is necessary to classify the measurement points and measurement lines. The specific steps are as follows: Traverse the track data file: Read the track data file recorded during the UAV flight. This file contains the coordinate information of each measurement point (usually given in the form of longitude and latitude). Similarly, it is necessary to convert the coordinates of these measurement points into plane rectangular coordinates in the Gauss-Krüger projection coordinate system for comparison with the endpoint coordinates of the designed survey line in the same coordinate system.

[0034] Calculate the distance from the measurement point to the designed survey line: For each measurement point, calculate the sum of the projected perpendicular distance to each designed survey line and the distances to the two endpoints of the survey line. The specific calculation method is as follows: Projected perpendicular distance: Calculate the perpendicular distance D from the measurement point to the designed survey line ij . Assume that the coordinates of the two endpoints of the designed survey line are (x1, y1) and (x2, y2) respectively, and the coordinates of the measurement point are (x i , y i ), then the projected perpendicular distance D ij can be calculated by the following formula:

[0035] Sum of the distances to the two endpoints of the survey line: Calculate the sum of the distances L from the measurement point to the two endpoints of the designed survey line ij :

[0036] Determine the survey line to which the measurement point belongs in combination with the distance threshold: Determine the survey line to which the measurement point belongs according to the preset distance threshold. The specific threshold settings are as follows: Projected perpendicular distance threshold: Set to half of the designed survey line spacing H, that is, H / 2.

[0037] Threshold for the sum of the distances to the two endpoints of the survey line: Set to the sum of the designed survey line length L j and H, that is, L j +H. When the projected perpendicular distance D from the measurement point i to the designed survey line j ij <H / 2, and the sum of the distances L from the measurement point i to the two endpoints of the designed survey line j ij <L j +H, it is determined that the measurement point i belongs to the survey line j.

[0038] In addition, when the measurement point satisfies the attribution conditions of multiple designed survey lines at the same time, conflict handling is required. The specific method is to dynamically adjust the survey line attribution of the current measurement point according to the attribution results of adjacent measurement points, and give priority to maintaining the continuity of the measurement point sequence. For example, if the measurement point i satisfies the attribution conditions of both the designed survey line j and the designed survey line k at the same time, but both the measurement point i−1 and the measurement point i+1 belong to the designed survey line j, then the measurement point i is preferentially attributed to the designed survey line j to maintain the continuity of the measurement point sequence.

[0039] 3. Identification and deletion of invalid survey lines After completing the classification of measurement points and lines, it is necessary to further verify and process the line classification results to identify and delete invalid measurement lines. Invalid measurement lines mainly include the following two categories: Lines shorter than the length threshold: Set the minimum length allowed for line splitting to 2 times the main line spacing (2H). When the length of the line after splitting is less than 2H, it is considered an invalid line and deleted. The specific judgment method is to calculate the length L of each line after splitting. line , if L line <2H, the measurement line is marked as invalid and deleted.

[0040] The route intersection part with the direction deviation from the designed survey line is too large: use the direction consistency judgment method to identify such invalid survey lines. The specific steps are as follows: Calculate the direction angle δ between the line connecting the two end points of the survey line after the division and the corresponding design survey line. Assuming that the coordinates of the two end points of the survey line after the division are (x3, y3) and (x4, y4), and the coordinates of the two end points of the corresponding design survey line are (x1, y1) and (x2, y2), the direction angle δ can be calculated by the following formula:

[0041] If δ is greater than the preset angle threshold θ, it is determined to be an invalid measurement line with inconsistent direction. The angle threshold θ is calculated by the following formula:

[0042] Among them, L is the designed survey line length, and H is the main survey line spacing.

[0043] In addition, when the main survey line and the control line exist in the track data file at the same time, the priority of the main survey line and the control line needs to be controlled. The specific method is to first execute the main survey line division process, and then execute the control line division process for the remaining survey points after completion to avoid conflicts in the ownership of survey points.

[0044] Manual intervention mechanism for abnormal track segments: In actual flight, due to airflow changes or other factors, the UAV may deviate from the predetermined track, resulting in line separation failure. For this situation, the present invention provides a manual intervention mechanism. The specific steps are as follows: For the track segments where line division fails due to flight deviation, the deviation distance and position information are output and marked as areas for manual review.

[0045] According to the manual review results, the make-up flight instruction is triggered. For example, if the manual review finds that a certain section of the track deviates too much and the data of this section has a significant impact on the measurement results, the make-up flight instruction can be triggered to re-measure the area.

[0046] Visual verification of line division results: In order to assist manual verification of the accuracy of line division, the present invention also provides a method for visual verification of line division results. The specific steps are as follows: Generate a survey line distribution map after line division, and superimpose the survey line distribution after line division on the original track data and the designed survey network.

[0047] Valid measurement lines, invalid measurement lines and unclassified measurement points are marked by color. For example, valid measurement lines can be represented by green, invalid measurement lines can be represented by red, and unclassified measurement points can be represented by yellow. Through this visualization method, the accuracy of the line division results can be intuitively observed, which is convenient for manual further verification and adjustment.

[0048] As a specific example, the present invention provides a method for automatically dividing the actual track data file of the UAV aeromagnetic measurement, which is generally the data of a flight or a flight day. Figure 1 As shown, the specific steps include: S1. Extract the kilometer grid projection coordinates of the endpoints of the designed survey line.

[0049] The UAV aeromagnetic survey flight is carried out according to the designed survey network. This step is to extract the endpoint coordinate information of each survey line in the survey network. The coordinate information should be the kilometer grid projection coordinates (the coordinates described in the present invention are all kilometer grid projection coordinates under the same parameters), rather than the longitude and latitude coordinates.

[0050] Assume that there are n main survey lines and k cutting lines in the survey network. The distance between the main survey lines is H. The length of the jth main survey line is L j , j∈[1,n]; the length of the g-th main survey line is recorded as L g , g∈[1,k].

[0051] S2. According to the nearest neighbor algorithm, a distance threshold is set and the measurement points in the data file to be divided into lines are classified into measurement line categories.

[0052] like Figure 3 As shown, specifically, it means determining which survey line a survey point in the track data file belongs to based on the sum of the projection distance from the survey point to the designed survey line and the distance from the survey point to the two end points of the designed survey line.

[0053] S2-1. Traverse each measuring point to be divided and each measuring line in the designed measuring line in the track data file, and calculate the projected vertical distance D from measuring point i to designed measuring line j ij , the sum of the distances from measuring point i to the two end points of the designed measuring line j L ij .

[0054] S2-2. Set the vertical distance threshold from the measuring point to the design line as H / 2, and the sum of the distances from the measuring point to the two end points of the design line as L.j +H. Determine whether the measuring point i satisfies the following two conditions at the same time D ij <H / 2 Formula (1) L ij <L j +H Formula (2) If it is satisfied, then the measuring point i is considered to belong to the measuring line j.

[0055] Formula (1) is based on the nearest neighbor algorithm, that is, for a point between two measuring lines, the vertical distances of the projections of the point to the two measuring lines are compared. If the distance to the measuring line is shorter (less than H / 2), the point is determined to belong to the element on the measuring line. In the special case where the distances between the two points are equal, the belonging is determined based on the previous or next measuring point.

[0056] The basis of formula (2) is that in any triangle, the length of any side is less than the sum of the lengths of the other two sides. Figure 3 As shown, we can see that a<b1+h, b<b2+h, and a+b=L ij , b1+b2=L j , 2h≤H, it is easy to conclude that the above formula (2) holds.

[0057] S3. Identify and delete the invalid measurement lines that have been divided There are two types of non-real survey lines: a. those that are too short, and b. those that intersect with the designed survey line.

[0058] For category a, judgment and deletion are carried out by setting a length threshold: according to the measurement purpose and requirements, the shortest length allowed for the branching of the survey line is set (such as twice the length of the main survey line spacing, i.e. 2H); when the length of the branched survey line is less than this value, the survey line is considered to be invalid.

[0059] For category b, the direction consistency is used for judgment and identification. Assume that the two end points of a complete survey line are located on both sides of the corresponding design survey line, and the projection distance to the corresponding design survey line (length L) is exactly the threshold distance H / 2 (S2 has been mentioned. When the vertical distance from the survey point to a design survey line is greater than H / 2, the survey point does not belong to the element on the survey line.), as shown in the attached figure. Figure 4 As shown. Then the direction angle θ between the actual survey line and the designed survey line is calculated by the following formula:

[0060] At this time, it is stipulated that for a certain actual survey line, when the angle δ between the connecting line of its two end points and the direction of the corresponding design survey line is greater than θ, Figure 4 As shown, it is judged that the two directions are inconsistent, and the actual survey line that has been divided is identified as an invalid survey line, which is only the "route part that intersects with the designed survey line."

[0061] The process of the above implementation scheme is as follows Figure 1 The following points should be noted during the specific implementation: (1) When the file to be processed contains only the main survey line or only the cutting line, execute S2 and S3 once according to the above steps to complete the automatic division of the survey line.

[0062] (2) When there are both main survey lines and cutting lines in the file, in order to avoid the same survey point being divided into both the main survey line and the cutting line at the same time, the main survey line must be automatically divided first, and the above S2 and S3 must be executed once (the survey lines in S2 and S3 refer to the main survey line at this time). Then, for the remaining survey points after the main survey line is divided, the cutting line is automatically divided, and the above S2 and S3 must be executed again (the survey lines in S2 and S3 refer to the cutting line at this time).

[0063] (3) For special non-real survey lines, they may satisfy both conditions ① and ② in S3 above. Either method can be used to judge and delete such non-real survey lines.

[0064] (4) During the normal flight of the UAV aeromagnetic survey, due to airflow changes and other reasons, the route may temporarily deviate from the designed survey line by a large amount (greater than H / 2), such as Figure 5 In this case, the measured data may meet the measurement requirements, but will be identified as a non-real measurement line. At this time, manual judgment is required based on the actual track map and measurement requirements to determine whether it is available or to perform a supplementary flight.

[0065] Example 2

[0066] The present invention also provides an autonomous line division system for UAV aeromagnetic measurement, which is based on the above autonomous line division method and can automatically complete the line division processing of track data. The system mainly includes the following modules: Survey line analysis module: This module is used to extract and convert the endpoint coordinates of the designed survey line. Specific functions include: Read the preset survey network file and parse the endpoint coordinates of the designed survey line.

[0067] The longitude and latitude coordinates of the designed survey line are converted into plane rectangular coordinates under the Gauss-Krüger projection coordinate system to ensure the systematic consistency of the coordinates of all survey line endpoints.

[0068] Measuring point classification module: This module implements the determination of measuring point and line attribution based on the nearest neighbor algorithm and dual distance threshold. Specific functions include: Traverse each measuring point in the track data file and calculate the sum of the projected vertical distance from the measuring point to each designed measuring line and the distance to the two end points of the measuring line.

[0069] The distance threshold is used to determine the measuring line to which the measuring point belongs, and the measuring point ownership conflicts are dynamically adjusted, giving priority to maintaining the continuity of the measuring point sequence.

[0070] Invalid survey line filtering module: This module combines the length threshold and direction consistency rules to delete invalid survey lines. Specific functions include: According to the preset length threshold, the lines shorter than the length threshold are identified and deleted.

[0071] According to the direction consistency judgment method, the route intersection parts with excessive deviation from the designed survey line direction are identified and deleted.

[0072] Control the branching priority of the main measuring line and the control line to avoid conflicts in the ownership of measuring points.

[0073] Data interface module: This module supports the standardized input of track data files and the formatted output of line splitting results. Specific functions include: Provides a standardized data input interface that can read track data files in different formats.

[0074] The line separation results are output in a preset format to facilitate subsequent data processing and analysis.

[0075] Through the collaborative work of the above modules, the autonomous line splitting system of the present invention can automatically complete the line splitting processing of the track data of the UAV aeromagnetic measurement, improve the line splitting efficiency and accuracy, and reduce the cost of manual intervention. It is especially suitable for UAV aeromagnetic measurement projects of small and medium areas.

[0076] The autonomous line division method and system of the present invention have wide promotion value in practical applications. By optimizing the line division process, the data processing efficiency and accuracy of UAV aeromagnetic measurement can be effectively improved, providing more reliable technical support for geological exploration, engineering detection and other fields.

[0077] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. An autonomous line division method for unmanned aerial vehicle aeromagnetic measurement, characterized in that: The following steps are involved: S1. Extract the kilometer grid projection coordinates of the endpoints of the designed survey lines: Based on the preset survey grid file, parse the endpoint coordinates of all designed survey lines and convert them into kilometer grid projection coordinates with the same parameters; S2. Classification of measurement points and lines: traverse each measurement point in the track data file, calculate the sum of the vertical distance from the measurement point to each designed measurement line and the distance to the two end points of the measurement line, and determine the measurement line to which the measurement point belongs based on the distance threshold; S3. Identification and deletion of invalid survey lines: According to the preset length threshold and direction consistency principle, invalid survey lines that do not meet the requirements after line division are identified and deleted. The invalid survey lines include survey lines shorter than the length threshold and route intersections that deviate too much from the designed survey line direction.

2. The autonomous line division method for UAV aeromagnetic measurement according to claim 1 is characterized in that: The setting of the distance threshold in step S2 includes: The projection vertical distance threshold is 1 / 2 of the design survey line spacing H, that is, H / 2. The threshold of the sum of the distances from the measuring point to the two end points of the design survey line is the design survey line length L. j The sum of L and H is j +H; When the vertical distance D from the projected point i to the designed measuring line j ij <H / 2, and the sum of the distances from measuring point i to the two end points of the designed measuring line j is L ij <L j +H, it is determined that measuring point i belongs to measuring line j.

3. The autonomous line division method for UAV aeromagnetic measurement according to claim 2 is characterized in that: Step S2 also includes: If a measuring point meets the attribution conditions of multiple designed measuring lines at the same time, the attribution of the current measuring point will be dynamically adjusted according to the attribution results of the adjacent measuring points, giving priority to maintaining the continuity of the measuring point sequence.

4. The autonomous line division method for UAV aeromagnetic measurement according to claim 1 is characterized in that: The length threshold in step S3 is set as: The shortest length allowed for a branch line is twice the main line spacing, i.e. 2H, where H is the main line spacing. When the length of a branched line is less than 2H, it is considered an invalid line and deleted.

5. The autonomous line division method for UAV aeromagnetic measurement according to claim 1, characterized in that: The direction consistency determination method in step S3 is: Calculate the angle δ between the line connecting the two end points of the survey line after the division and the direction of the corresponding design survey line. If δ is greater than the preset angle threshold θ, it is determined to be an invalid survey line with inconsistent direction. Here, θ is given by the formula Calculation shows that L is the length of the designed survey line and H is the main survey line spacing.

6. The autonomous line division method for UAV aeromagnetic measurement according to claim 1, characterized in that: Step S3 also includes: Priority control of the division of the main survey line and the control line: When the main survey line and the control line exist in the track data file at the same time, the main survey line division process is executed first, and then the control line division process is executed for the remaining survey points after completion to avoid conflicts in the ownership of survey points.

7. The autonomous line division method for UAV aeromagnetic measurement according to claim 1, characterized in that: Also includes: For the track segment where line division fails due to flight deviation, the deviation distance and position information are output, marked as the area to be manually reviewed, and the re-flight instruction is triggered according to the review result.

8. The autonomous line division method for UAV aeromagnetic measurement according to claim 1, characterized in that: The conversion of kilometer grid projection coordinates in step S1 includes: Based on the coordinate system parameters of the survey area, the longitude and latitude coordinates of the designed survey line are converted into plane rectangular coordinates under the Gauss-Krüger projection coordinate system to ensure the systematic consistency of the coordinates of all survey line endpoints.

9. The autonomous line division method for UAV aeromagnetic measurement according to claim 1, characterized in that: Also includes: Generate a survey line distribution map after line division, overlay the original track data and the designed survey network, and use color to mark valid survey lines, invalid survey lines and unclassified survey points to assist manual verification of line division accuracy.

10. An autonomous line division system for unmanned aerial vehicle aeromagnetic measurement, based on an autonomous line division method for unmanned aerial vehicle aeromagnetic measurement according to any one of claims 1 to 9, characterized in that: include: Survey line analysis module: used to extract and convert the endpoint coordinates of the designed survey line; Measuring point classification module: It realizes the determination of measuring point and measuring line attribution based on the nearest neighbor algorithm and double distance threshold; Invalid survey line filtering module: Combine length threshold and direction consistency rule to delete invalid survey lines; Data interface module: supports the standardized input of track data files and the formatted output of line division results.

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