An autonomous wire-splitting method and system for UAV aeromagnetic survey

Abstract

The present invention relates to the field of airborne magnetic survey, and particularly relates to an autonomous line division method and system for unmanned aerial vehicle (UAV) airborne magnetic survey. The method comprises the following steps: S1. Extracting the kilometer grid projection coordinates of the endpoints of the designed survey lines: Based on a preset survey grid file, parsing the endpoint coordinates of all designed survey lines and converting them into kilometer grid projection coordinates of the same parameter; S2. Classifying the attribution of the survey points to the survey lines: Traversing each survey point in the flight track data file, calculating the projection vertical distance from the survey point to each designed survey line and the sum of the distances from the survey point to the two endpoints of the survey line, and determining the survey line to which the survey point belongs in combination with a distance threshold; S3. Identifying and deleting invalid survey lines: Identifying and deleting the invalid survey lines that do not meet the requirements after line division according to a preset length threshold and the principle of direction consistency. The present invention can quickly and accurately perform autonomous line division on the UAV flight track data, significantly improving the line division efficiency and accuracy, reducing the cost of manual intervention, and is particularly suitable for UAV airborne magnetic survey projects with small and medium-sized areas.

Description

Technical Field

[0001] The present invention relates to the field of airborne magnetic measurement, and particularly to an autonomous line splitting method and system for unmanned aerial vehicle (UAV) airborne magnetic measurement. Background Art

[0002] Aerial magnetic measurement is a geophysical exploration method widely used in fields such as geological exploration and engineering inspection. Traditional aerial magnetic measurement is mostly carried on manned aircraft platforms such as fixed-wing aircraft or helicopters. Its relocation process is cumbersome and costly, and it is mostly used in large projects, making it difficult to popularize to exploration tasks for small and medium-sized areas. In recent years, with the rapid development of UAV technology, UAVs have gradually become an important platform for aerial magnetic measurement due to their high flexibility, low cost, and simple operation. They are particularly suitable for exploration tasks for small and medium-sized areas (the total workload of survey lines is several hundred to several thousand kilometers), such as geological exploration and engineering inspection.

[0003] However, UAV aerial magnetic measurement faces a key problem in data processing: how to quickly and economically perform autonomous line splitting on UAV track data to extract complete and effective survey line measurement data. In traditional methods, the line splitting of aerial magnetic measurement mainly relies on manual operation or large professional software. The manual line splitting method is inefficient, error-prone, and difficult to meet the needs of large-scale data processing; while large professional software can achieve automated line splitting, but its usage cost is high and it is not economical for small and medium-sized projects. In addition, some existing automated line splitting methods often have problems such as incorrect determination of survey line attribution and inaccurate identification of invalid survey lines when processing complex track data, resulting in inaccurate line splitting results and affecting the reliability of subsequent data processing and analysis.

[0004] For example, Patent No. CN104122597B discloses a UAV aerial magnetic detection system and method. This technical solution mainly relates to the overall system architecture of UAV aerial magnetic detection, including the integration of the airborne part and the ground part, and focuses on improving the efficiency and data quality of aerial magnetic detection by optimizing the UAV platform and sensor configuration. However, this patent does not involve the autonomous line splitting technology for track data, especially the determination of survey line attribution and the identification of invalid survey lines in the processing of complex track data. This indicates that there are still deficiencies in the data processing link of UAV aerial magnetic measurement in the existing technology, especially the lack of effective solutions for quickly and economically achieving autonomous line splitting.

[0005] To solve the above problems, the present invention proposes an autonomous line splitting method and system for UAV aerial magnetic measurement. Summary of the Invention

[0006] The purpose of the present invention is to provide an autonomous line splitting method and system for UAV aerial magnetic measurement to solve the problems of low efficiency and poor accuracy in line splitting of track data in the existing technology.

[0007] To achieve the above object, the following technical solutions are adopted.

[0008] An autonomous wire splitting method for unmanned aerial vehicle (UAV) aeromagnetic survey, comprising the following steps:

[0009] 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 of the same parameter.

[0010] S2. Classify the attribution of the measuring points to the survey lines: Traverse each measuring point in the track data file, calculate the projection vertical distance from the measuring point to each designed survey line and the sum of the distances from the measuring point to the two endpoints of the survey line, and determine the survey line to which the measuring point belongs in combination with the distance threshold.

[0011] S3. Identify and delete invalid survey lines: According to the preset length threshold and the principle of direction consistency, identify and delete the invalid survey lines that do not meet the requirements after wire splitting. The invalid survey lines include the survey lines shorter than the length threshold and the intersection parts of the routes with too large deviation from the designed survey line direction.

[0012] Optionally, the setting of the distance threshold in step S2 includes:

[0013] The projection vertical distance threshold is 1 / 2 of the designed survey line spacing H (H / 2), and the threshold of the sum of the distances from the measuring point to the two endpoints of the designed survey line is the sum of the designed survey line length L j and H (L j + H);

[0014] When the projection vertical distance D of the measuring point i to the designed survey line j ij < H / 2, and the sum of the distances from the measuring point i to the two endpoints of the designed survey line j is L ij < L j + H, it is determined that the measuring point i belongs to the survey line j.

[0015] Optionally, step S2 further includes:

[0016] If the measuring point meets the attribution conditions of multiple designed survey lines at the same time, the attribution of the current measuring point to the survey line is dynamically adjusted according to the attribution results of adjacent measuring points, and the continuity of the measuring point sequence is preferably maintained.

[0017] Optionally, the setting of the length threshold in step S3 is:

[0018] The shortest allowable length for wire splitting of the survey line is 2 times the main survey line spacing (2H). When the length of the survey line after wire splitting is less than 2H, it is determined as an invalid survey line and deleted.

[0019] Optionally, the method for judging direction consistency in step S3 is:

[0020] Calculate the direction angle δ between the line connecting the two endpoints of the measured line after line division and the corresponding designed measured line. If δ is greater than the preset angle threshold θ, it is determined as an invalid measured line with inconsistent directions;

[0021] Among them, θ is calculated by the formula where L is the length of the designed measured line and H is the spacing between the main measured lines.

[0022] Optionally, step S3 further includes:

[0023] Control the line division priority of the main measured line and the control line: when both the main measured line and the control line exist in the track data file, first execute the line division process of the main measured line, and then execute the line division process of the remaining measured points for the control line after completion to avoid conflicts in the attribution of measured points.

[0024] Optionally, it further includes:

[0025] For the track segment where line division fails due to flight deviation, output the deviation distance and position information, mark it as an area to be manually reviewed, and trigger a reflight instruction according to the review result.

[0026] Optionally, the conversion of the kilometer grid projection coordinates described in step S1 includes:

[0027] Based on the coordinate system parameters of the survey area, convert the longitude and latitude coordinates of the designed measured line into the plane rectangular coordinates in the Gauss-Kruger projection coordinate system to ensure the system consistency of the coordinates of all measured line endpoints.

[0028] Optionally, it is characterized in that it further includes:

[0029] Generate a distribution map of the measured lines after line division, overlay the original track data and the designed survey network, and mark the valid measured lines, invalid measured lines and unclassified measured points with colors to assist in manually verifying the accuracy of line division.

[0030] An autonomous line division system for unmanned aerial vehicle aeromagnetic survey, including:

[0031] Measured line analysis module: used to extract and convert the endpoint coordinates of the designed measured line;

[0032] Measured point classification module: based on the nearest neighbor algorithm and double distance thresholds, realize the determination of the attribution of measured points to measured lines;

[0033] Invalid measured line filtering module: combine the length threshold and the direction consistency rule to delete invalid measured lines;

[0034] Data interface module: support the standardized input of track data files and the formatted output of line division results.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention proposes an autonomous wire-splitting method for unmanned aerial vehicle (UAV) aeromagnetic surveys. By extracting the kilometer grid projection coordinates of the endpoints of the designed survey lines, classifying the survey points according to the survey lines they belong to, and identifying and deleting invalid survey lines, the problems of low wire-splitting efficiency and poor accuracy in the existing technology are effectively solved. Compared with the existing methods, the present invention can quickly and accurately perform autonomous wire-splitting on the UAV flight track data, significantly improving the wire-splitting efficiency and accuracy, reducing the cost of manual intervention, and is particularly suitable for UAV aeromagnetic survey projects in medium and small areas, with broad popularization and application value.

[0037] Furthermore, the present invention respectively defines and optimizes the specific technical details of the autonomous wire-splitting method, further improving the accuracy and reliability of wire-splitting. For example, the precise setting of the distance threshold can more accurately determine the belonging of the survey points; the conflict handling mechanism for multiple survey lines belonging to the same survey point ensures the continuity of the survey point sequence; the optimization of the identification of invalid survey lines further improves the accuracy of the wire-splitting result; the manual intervention mechanism can effectively handle the situation of wire-splitting failure caused by flight deviation; the coordinate conversion and visualization verification functions further enhance the practicality and reliability of the wire-splitting method. Overall, through a series of optimized designs, the present invention realizes the efficient and accurate wire-splitting of the UAV aeromagnetic survey flight track data, providing a solid foundation for subsequent data processing and analysis, and having significant technical effects and economic benefits. Brief Description of the Drawings

[0038] Figure 1 is a schematic flow chart of the steps of an embodiment of the autonomous wire-splitting method for UAV aeromagnetic surveys of the present invention.

[0039] Figure 2 is a schematic diagram of the UAV aeromagnetic survey network of an embodiment of the autonomous wire-splitting method for UAV aeromagnetic surveys of the present invention.

[0040] Figure 3 is a schematic diagram of splitting survey points according to the sum of the distances from the survey points to the two endpoints of the survey line in an embodiment of the autonomous wire-splitting method for UAV aeromagnetic surveys of the present invention.

[0041] Figure 4 is a schematic diagram of judging "the part of the flight path intersecting the survey line" in an embodiment of the autonomous wire-splitting method for UAV aeromagnetic surveys of the present invention.

[0042] Figure 5 is a schematic diagram of the situation where the survey line measurement route deviates significantly from the designed survey line (greater than H / 2) for a short time in an embodiment of the autonomous wire-splitting method for UAV aeromagnetic surveys of the present invention. Detailed Description of the Embodiment

[0043] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0044] The following detailed descriptions are all exemplary descriptions, aiming to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms adopted by the present invention have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0045] Embodiment 1

[0046] The present invention provides an autonomous wire splitting method for unmanned aerial vehicle (UAV) aeromagnetic survey, aiming to solve the problems of low efficiency and poor accuracy in wire splitting of UAV flight track data in the prior art. The following is a detailed description of the method and its system.

[0047] As Figures 1-5 shown, the autonomous wire splitting method of the present invention mainly includes three core steps: extracting the kilometer grid projection coordinates of the endpoints of the designed survey lines, classifying the attribution of the measuring points to the survey lines, and identifying and deleting invalid survey lines. The following will separately describe each step in detail.

[0048] (1) Extracting the kilometer grid projection coordinates of the endpoints of the designed survey lines

[0049] As Figure 2 shown, in UAV 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. For the convenience of subsequent calculations and processing, these longitude and latitude coordinates need to be converted into kilometer grid projection coordinates of the same parameter. The specific steps are as follows:

[0050] Reading the preset survey grid file: The preset survey grid 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, the starting point and ending point coordinates of each designed survey line can be obtained.

[0051] Coordinate conversion: Converting the endpoint coordinates of the designed survey lines from the longitude and latitude coordinate system to the plane rectangular coordinates in the Gauss-Krüger projection coordinate system. The Gauss-Krüger projection is an equiangular transverse cylindrical projection, which can convert the longitude and latitude coordinates on the earth's surface into plane rectangular coordinates, facilitating the calculation of distance and angle on a two-dimensional plane. The conversion formula is as follows:

[0052] Among them, f and g are transformation functions of the Gauss-Krüger projection, and their specific forms depend on the selected projection parameters (such as the central meridian, projection bandwidth, etc.). Through this transformation, it can be ensured that the endpoint coordinates of all designed survey lines are in the same coordinate system, facilitating subsequent calculations and processing.

[0053] (2) Classification of the attribution of survey points and survey lines

[0054] During the flight of the UAV, a large amount of trajectory data will be recorded in real time, and each data point (survey point) contains the coordinate information of that point. In order to assign these survey points to the corresponding designed survey lines, it is necessary to conduct the classification of the attribution of survey points and survey lines. The specific steps are as follows:

[0055] Traverse the trajectory data file: Read the trajectory data file recorded during the flight of the UAV. This file contains the coordinate information of each survey point (usually also given in the form of longitude and latitude). Similarly, it is necessary to convert the coordinates of these survey points into plane rectangular coordinates in the Gauss-Krüger projection coordinate system so as to compare them with the endpoint coordinates of the designed survey lines in the same coordinate system.

[0056] Calculate the distance from the survey point to the designed survey line: For each survey point, calculate the sum of the projected vertical distance from it to each designed survey line and the distances to the two endpoints of the survey line. The specific calculation method is as follows:

[0057] Projected vertical distance: Calculate the vertical distance D from the survey 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 survey point are (x i , y i ), then the projected vertical distance D ij can be calculated by the following formula:

[0058]

[0059] Sum of the distances to the two endpoints of the survey line: Calculate the sum of the distances L from the survey point to the two endpoints of the designed survey line ij :

[0060]

[0061] Determine the survey line to which the survey point belongs in combination with the distance threshold: Determine the survey line to which the survey point belongs according to the preset distance threshold. The specific threshold setting is as follows:

[0062] Projected vertical distance threshold: Set to half of the designed survey line spacing H, that is, H / 2.

[0063] Threshold of 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 vertical distance D from the projection of measuring point i to the design measuring line j is ij <H / 2,且测点i到设计测线j两端点的距离之和L ij <L j +H, it is determined that measuring point i belongs to measuring line j.

[0064] Furthermore, when a measurement point simultaneously meets the assignment criteria for multiple design lines, conflict resolution is required. This is achieved by dynamically adjusting the assignment of the current measurement point to the designated line based on the assignment results of adjacent measurement points, prioritizing the continuity of the measurement point sequence. For example, if measurement point i meets the assignment criteria for both design lines j and k, but both measurement points i−1 and i+1 belong to design line j, measurement point i is assigned to design line j first to maintain the continuity of the measurement point sequence.

[0065] (III) Identification and deletion of invalid survey lines

[0066] After completing the classification of measurement points and lines, further verification and processing of the line classification results are required to identify and delete invalid measurement lines. Invalid measurement lines mainly include the following two categories:

[0067] Lines shorter than the length threshold: The minimum length allowed for line splits is set to 2 times the main line spacing (2H). When the length of a split line is less than 2H, it is considered an invalid line and deleted. The specific judgment method is to calculate the length L of each split line. line , if L line If the time is less than 2 hours, the measurement line will be marked as invalid and deleted.

[0068] The intersection of the route that deviates too much from the designed survey line direction: Use the direction consistency judgment method to identify such invalid survey lines. The specific steps are as follows:

[0069] Calculate the angle δ between the line connecting the two endpoints of the split survey line and the corresponding design survey line. Assuming the coordinates of the two endpoints of the split survey line are (x3, y3) and (x4, y4), and the coordinates of the two endpoints of the corresponding design survey line are (x1, y1) and (x2, y2), the angle δ can be calculated using the following formula:

[0070]

[0071] If δ is greater than the preset angle threshold θ, it is determined to be an invalid survey line with inconsistent direction. The angle threshold θ is calculated by the following formula:

[0072] Where L is the designed survey line length and H is the main survey line spacing.

[0073] In addition, when both main survey lines and control lines exist in the track data file, it is necessary to control the priority of line division between the main survey lines and the control lines. The specific method is to give priority to executing the line division process for the main survey lines. After completion, the line division process for the remaining survey points is then executed to avoid conflicts in the attribution of survey points.

[0074] Artificial intervention mechanism for abnormal track segments: During actual flight, due to changes in airflows or other factors, the flight of the unmanned aerial vehicle (UAV) may deviate from the predetermined track, resulting in failed line division. For such a situation, the present invention provides an artificial intervention mechanism. The specific steps are as follows:

[0075] For the track segments where line division fails due to flight deviation, output the deviation distance and position information, and mark them as areas to be manually reviewed.

[0076] According to the results of manual review, trigger a re-flight command. For example, if it is found through manual review that a certain track segment has a too large deviation and the data of this segment has an important impact on the measurement results, a re-flight command can be triggered to re-measure this area.

[0077] Visual verification of line division results: To assist in manually verifying 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:

[0078] Generate a distribution map of survey lines after line division, and superimpose the distribution of survey lines after line division on the original track data and the designed survey grid.

[0079] Mark valid survey lines, invalid survey lines, and unclassified survey points through colors. For example, valid survey lines can be represented by green, invalid survey lines can be represented by red, and unclassified survey points can be represented by yellow. Through this visual method, the accuracy of the line division results can be intuitively observed, facilitating further manual verification and adjustment.

[0080] As a specific example, the present invention provides a method for automatically dividing the actual track data file of UAV aeromagnetic measurement. This data file is generally data for one sortie or one flight day. As Figure 1 shown, it specifically includes the following steps:

[0081] S1. Extract the kilometer grid projection coordinates of the endpoints of the designed survey lines.

[0082] The UAV aeromagnetic measurement flight is carried out according to the designed survey grid. This step is to extract the coordinate information of the endpoints of each survey line in the survey grid. This coordinate information should be the kilometer grid projection coordinates (all coordinates mentioned in the present invention are kilometer grid projection coordinates under the same parameters), rather than longitude and latitude coordinates.

[0083] Assume that there are n main survey lines and k cutting lines in the survey grid. The spacing between the main survey lines is H. The length of the j-th main survey line is denoted as Lj , where \(j\in[1,n]\); the length of the \(g\)-th main survey line is denoted as \(L_g\), \(g\in[1,k]\). g

[0084] S2. According to the nearest neighbor algorithm, set a distance threshold to classify the survey points in the data file of the line to be divided into the belonging of survey lines.

[0085] As Figure 3 shown, specifically, it means to determine which survey line the survey points in the track data file belong to based on the projection distance from the survey point to the designed survey line and the sum of the distances from the survey point to the two end points of the designed survey line.

[0086] S2-1. Traverse each survey point of the line to be divided in the track data file and each survey line in the designed survey lines, and calculate the projected vertical distance \(D_{ij}\) from the survey point \(i\) to the designed survey line \(j\) ij and the sum of the distances \(L_{ij}\) from the survey point \(i\) to the two end points of the designed survey line \(j\). ij

[0087] S2-2. Set the threshold of the projected vertical distance from the survey point to the designed survey line as \(H / 2\), and the threshold of the sum of the distances from the survey point to the two end points of the designed survey line as \(L_g + H\). Judge whether the survey point \(i\) simultaneously satisfies the following two conditions j :

[0088] \(D_{ij}\) ij \(< H / 2\) Equation (1)

[0089] \(L_{ij}\) ij \(< L_g\) j + H Equation (2)

[0090] If it is satisfied, it is considered that the survey point \(i\) belongs to the survey line \(j\).

[0091] The basis of Equation (1) is the nearest neighbor algorithm, that is, for a survey point between two survey lines, compare the projected vertical distances from this survey point to these two survey lines respectively. If the distance to one of the survey lines is shorter (less than \(H / 2\)), then it is determined that the survey point belongs to the element on this survey line. In the special case where the two distances are equal, it is determined according to the belonging of the previous or next survey point.

[0092] The basis of Equation (2) is that in any triangle, the length of any side is less than the sum of the lengths of the other two sides. As shown in the appendix Figure 3 shown, it can be known that \(a < b_1 + h\), \(b < b_2 + h\), and \(a + b = L\) ij , \(b_1 + b_2 = L\) j , \(2h\leq H\), then it is easy to obtain that Equation (2) holds.

[0093] S3. Identify and delete the invalid survey lines that have been classified.

[0094] The non-real survey lines include two categories: a. The length is too short, b. The route part that intersects with the designed survey line.

[0095] For type A, judgment and deletion are performed by setting a length threshold: According to the measurement purpose and requirements, set the shortest allowable length of the divided survey lines (such as the length of 2 times the main survey line spacing, i.e., 2H); when the length of the divided survey line is less than this value, this survey line is considered an invalid survey line.

[0096] For type B, judgment and identification are performed through direction consistency. Assume a complete divided survey line, the two endpoints of which are respectively located on both sides of the corresponding designed survey line, and the projection distances to the corresponding designed survey line (with a length of L) are exactly the threshold distance H / 2 (as described in S2, when the perpendicular distance from a measurement point to a certain designed survey line is greater than H / 2, this measurement point does not belong to the elements on this survey line). As shown in the attachment Figure 4 shown. Then the direction angle θ between this actual survey line and the designed survey line is calculated by the following formula:

[0097] At this time, it is stipulated that for a certain divided actual survey line, when the direction angle δ between the line connecting its two endpoints and the corresponding designed survey line is greater than θ, as shown in Figure 4 shown, then it is judged that the directions are inconsistent, and this divided actual survey line is identified as an invalid survey line, which is only "the part of the route that intersects with the designed survey line".

[0098] The flow of the above implementation scheme is as shown in Figure 1 shown, and the following matters need to be noted in the specific implementation:

[0099] (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 survey lines.

[0100] (2) When the file contains both the main survey line and the cutting line, to avoid the same measurement point being divided into both the main survey line and the cutting line at the same time, it is necessary to first perform the automatic division of the main survey line and execute S2 and S3 once (at this time, the survey lines in S2 and S3 refer to the main survey line). Then, for the remaining measurement points after the division of the main survey line, perform the automatic division of the cutting line and execute S2 and S3 again (at this time, the survey lines in S2 and S3 refer to the cutting line).

[0101] (3) For special non-real survey lines that may simultaneously meet both cases ① and ② in the above S3, any one method can be used to judge and delete such non-real survey lines.

[0102] (4) During the normal survey line measurement flight of the unmanned aerial vehicle magnetic survey, due to reasons such as airflow changes, there may be a situation where the flight route deviates from the designed survey line significantly (greater than H / 2) for a short time, as shown in Figure 5As shown. The measurement data in this case may meet the measurement requirements, but will be identified as non-genuine survey lines. At this time, manual judgment is required based on the actual flight track map and measurement requirements to determine whether it is available or to conduct supplementary flights.

[0103] Embodiment 2

[0104] The present invention also provides an autonomous line separation system for unmanned aerial vehicle aeromagnetic measurement. This system is implemented based on the above-mentioned autonomous line separation method and can automatically complete the line separation processing of flight track data. The system mainly includes the following modules:

[0105] Survey line analysis module: This module is used to extract and convert the endpoint coordinates of the designed survey lines. The specific functions include:

[0106] Read the preset survey grid file and analyze the endpoint coordinates of the designed survey lines.

[0107] Convert the longitude and latitude coordinates of the designed survey lines into plane rectangular coordinates in the Gauss-Krüger projection coordinate system to ensure the system consistency of all survey line endpoint coordinates.

[0108] Measuring point classification module: This module realizes the determination of the attribution of measuring points to survey lines based on the nearest neighbor algorithm and double distance thresholds. The specific functions include:

[0109] Traverse each measuring point in the flight track data file, and calculate the projection vertical distance from the measuring point to each designed survey line and the sum of the distances to the two endpoints of the survey line.

[0110] Combine the distance thresholds to determine the survey line to which the measuring point belongs, and dynamically adjust the conflicts in the attribution of measuring points, giving priority to maintaining the continuity of the measuring point sequence.

[0111] Invalid survey line filtering module: This module deletes invalid survey lines by combining the length threshold and the direction consistency rule. The specific functions include:

[0112] Identify and delete survey lines shorter than the length threshold according to the preset length threshold.

[0113] Identify and delete the part of the flight path intersection with too large a deviation from the designed survey line direction according to the direction consistency judgment method.

[0114] Control the line separation priority of the main survey line and the control line to avoid conflicts in the attribution of measuring points.

[0115] Data interface module: This module supports the standardized input of flight track data files and the formatted output of line separation results. The specific functions include:

[0116] Provide a standardized data input interface, which can read flight track data files in different formats.

[0117] Output the line separation results in a preset format for subsequent data processing and analysis.

[0118] Through the collaborative work of the above modules, the autonomous line splitting system of the present invention can automatically complete the line splitting process of the track data of the unmanned aerial vehicle (UAV) aeromagnetic survey, improve the line splitting efficiency and accuracy, reduce the cost of manual intervention, and is particularly suitable for UAV aeromagnetic survey projects with small and medium-sized areas.

[0119] The autonomous line splitting method and system of the present invention have wide popularization value in practical applications. By optimizing the line splitting process of survey lines, it can effectively improve the data processing efficiency and accuracy of UAV aeromagnetic surveys, and provide more reliable technical support for fields such as geological exploration and engineering inspection.

[0120] As is known by common technical knowledge, the present invention can be implemented by other embodiments without departing from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims

1. An autonomous wire splitting method for drone aeromagnetic survey, characterized in that, It includes 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 of the same parameter; S2. Classification of the belonging of survey points to survey lines: Traverse each survey point in the track data file, calculate the projected vertical distance from the survey point to each designed survey line and the sum of the distances to the two endpoints of the survey line, and determine the survey line to which the survey point belongs in combination with the distance threshold; Among them, the setting of the distance threshold includes: The projected vertical distance threshold is 1 / 2 of the main survey line spacing H, that is, H / 2, and the threshold of the sum of the distances from the survey point to the two endpoints of the designed survey line is the sum of the designed survey line length Lj and H, that is, Lj + H; When the projected vertical distance Dij from the survey point i to the designed survey line j < H / 2 and the sum of the distances Lij from the survey point i to the two endpoints of the designed survey line j < Lj + H, it is determined that the survey point i belongs to the survey line j; S3. Identification and deletion of invalid survey lines: According to the preset length threshold and the principle of direction consistency, identify and delete the invalid survey lines that do not meet the requirements after line division. The invalid survey lines include survey lines shorter than the length threshold and the intersection part of the route that deviates too much from the direction of the designed survey line.

2. The autonomous wire splitting method for UAV aeromagnetic measurement according to claim 1, wherein Step S2 also includes: If the survey point meets the belonging conditions of multiple designed survey lines at the same time, dynamically adjust the belonging of the current survey point to the survey line according to the belonging results of adjacent survey points, and give priority to maintaining the continuity of the survey point sequence.

3. An autonomous wire splitting method for unmanned aerial vehicle aeromagnetic survey according to claim 1, characterized in that, The setting of the length threshold in step S3 is: The shortest length allowed for line division of the survey line is 2 times the main survey line spacing, that is, 2H. When the length of the survey line after line division is less than 2H, it is determined as an invalid survey line and deleted.

4. The autonomous wire splitting method for UAV aeromagnetic survey according to claim 1, characterized in that The method for judging direction consistency in step S3 is: Calculate the direction angle δ between the line connecting the two endpoints of the survey line after line division and the corresponding designed survey line. If δ is greater than the preset angle threshold θ, it is determined as an invalid survey line with inconsistent direction; where θ is calculated by the formula where L is the designed survey line length and H is the main survey line spacing.

5. The autonomous wire splitting method for UAV aeromagnetic measurement according to claim 1, wherein Step S3 also includes: Control of the line division priority of the main survey line and the control line: When there are both the main survey line and the control line in the track data file, give priority to executing the line division process of the main survey line. After completion, execute the line division process of the remaining survey points for the control line to avoid conflicts in the belonging of survey points.

6. The autonomous wire splitting method for drone aeromagnetic measurement according to claim 1, characterized in that, It also includes: For the track segment where line division fails due to flight deviation, output the deviation distance and position information, mark it as an area to be manually reviewed, and trigger a reflight instruction according to the review result.

7. The autonomous wire splitting method for drone aeromagnetic survey according to claim 1, wherein The conversion of the kilometer grid projection coordinates in step S1 includes: Based on the survey area coordinate system parameters, convert the longitude and latitude coordinates of the designed survey line into the plane rectangular coordinates in the Gauss-Krüger projection coordinate system to ensure the system consistency of all survey line endpoint coordinates.

8. The autonomous wire splitting method for UAV aeromagnetic measurement according to claim 1, characterized in that, It also includes: Generate a distribution map of the survey lines after line division, overlay the original track data and the designed survey grid, and mark the valid survey lines, invalid survey lines and unclassified survey points with colors to assist in manually verifying the accuracy of line division.

9. An autonomous wire splitting system for UAV airborne magnetic measurement, based on the autonomous wire splitting method for UAV airborne magnetic measurement according to any one of claims 1-8, characterized in that, It includes: Survey line parsing module: used to extract and convert the endpoint coordinates of the designed survey lines; Survey point classification module: based on the nearest neighbor algorithm and distance threshold to realize the determination of the belonging of survey points to survey lines; Invalid survey line filtering module: delete invalid survey lines in combination with the length threshold and the direction consistency rule; Data interface module: support the standardized input of the track data file and the formatted output of the line division results.

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