A method for correcting errors in surveying data of a drone

Abstract

The present application belongs to the technical field of unmanned aerial vehicle surveying and mapping, and discloses a method for correcting errors of unmanned aerial vehicle surveying and mapping data, which comprises the following steps: setting a plurality of parallel flight lines and crossing flight lines for a predicted surveying and mapping area; obtaining the error degree of the overlapping area of the crossing flight lines and the parallel flight lines and the error degree mean of the non-overlapping area, and calculating the area difference coefficient of the crossing flight lines and the parallel flight lines; calculating the visual angle contribution degree of the crossing flight line setting based on the area difference coefficient, combining the flight direction of all the parallel flight lines in the area to be surveyed and the flight direction of the crossing flight line, and calculating the visual angle environment influence performance of the crossing flight line setting to correct the surveying and mapping data correction process weight; introducing the intersection point of the framework flight line into adjustment as the height control, establishing the error equation of the adjustment of the regional network, and correcting the errors of the unmanned aerial vehicle surveying and mapping data by introducing the weight matrix composed of the corrected surveying and mapping data correction process weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of surveying and mapping, in particular to a method for correcting errors in unmanned aerial vehicle (UAV) surveying and mapping data. BACKGROUND

[0002] Currently, the main sources of error in UAV surveying and mapping include positioning errors, image capture errors, data processing errors, and environmental factors. To reduce these errors, existing technologies use global navigation satellite systems (GNSS), differential GPS (DGPS), and real-time kinematic positioning (RTK) to improve positioning accuracy, and ground control points (GCPs) are set up in the surveying and mapping area for post-correction. In addition, by setting reasonable flight heights and image overlap, using high-performance gimbals and image stabilization algorithms, image capture errors can be effectively reduced. In terms of data processing, professional image processing software and optical multi-view reconstruction techniques are used to improve the accuracy of three-dimensional reconstruction. Through meteorological monitoring and multi-spectral sensors, the impact of environmental factors on data quality can be reduced. Error models and external validation data are used for post-correction to ensure the accuracy and reliability of the surveying and mapping results.

[0003] However, the UAV surveying and mapping process is significantly affected by real-time environmental factors, including UAV parameter settings and actual environmental factors during data extraction, which can cause fluctuations in the flight position of the UAV in the flight area, further increasing the error of the surveying and mapping data. By analyzing the data connection status of parallel flight lines and crossing flight lines through flight path planning, the accuracy of error analysis caused by differences in position and light measurement during the surveying and mapping process is improved. This method can correct errors in UAV surveying and mapping data, systematically eliminate cumulative errors caused by positioning, attitude, and environmental factors, and is suitable for scenarios requiring centimeter-level accuracy such as topographic mapping and emergency monitoring. SUMMARY

[0004] To overcome the deficiencies and shortcomings of the prior art, a method for correcting errors in UAV surveying and mapping data is provided.

[0005] To solve the above technical problems, the technical solution adopted by the present application is as follows:

[0006] A method for correcting errors in UAV surveying and mapping data, the method comprising the following steps:

[0007] Setting multiple parallel flight lines and crossing flight lines for the intended surveying and mapping area;

[0008] Obtaining the error degree of the overlapping area of the crossing flight lines and the parallel flight lines and the average error degree of the non-overlapping area, and calculating the area difference coefficient of the crossing flight lines and the parallel flight lines;

[0009] According to the area difference coefficient of the crossing route and the parallel route, the visual angle contribution degree of the crossing route is calculated;

[0010] The flight direction of all parallel routes in the to-be-mapped area and the flight direction of the crossing route are obtained, and the visual angle environment impact performance of the crossing route is calculated in combination with the visual angle contribution degree of the crossing route;

[0011] The visual angle environment impact performance of the crossing route is used to correct the mapping data correction process weight;

[0012] The intersection of the routes of the framework is introduced into adjustment as height control, the error equation of adjustment of the regional network is established, and the error of the unmanned aerial vehicle mapping data is corrected by introducing the weight matrix composed of the corrected mapping data correction process weight.

[0013] Preferably, before setting a plurality of parallel routes and crossing routes for the predicted mapping area, the following steps are further included:

[0014] Based on the existing map information, the mapping area boundary is demarcated, and a safety buffer distance is preset;

[0015] The flight height is inversely calculated according to the mapping scale requirement;

[0016] The heading overlap rate is set;

[0017] The lateral overlap rate is set.

[0018] Preferably, the error degree of the overlapping area of the crossing route and the parallel route and the error degree mean value of the non-overlapping area are obtained, and the area difference coefficient of the crossing route and the parallel route is calculated, including:

[0019] The twice mapping data of the overlapping area of a certain crossing route and a certain parallel route are obtained, including all three-dimensional point cloud data;

[0020] The matching of the actual spatial position is matched, and the distance of each three-dimensional point cloud after matching is obtained;

[0021] The error degree of the overlapping area of a certain crossing route and a certain parallel route is represented by the mean value of the distances of all three-dimensional point clouds after matching;

[0022] The error degree mean value of the non-overlapping area of a certain crossing route and a certain parallel route is obtained;

[0023] According to the error degree of the overlapping area of a certain crossing route and a certain parallel route, and the error degree mean value of the non-overlapping area, the area difference coefficient of a certain crossing route and a certain parallel route is calculated.

[0024] Further, according to the area difference coefficient of the crossing route and the parallel route, the visual angle contribution degree of the crossing route is calculated, including:

[0025] Obtaining the area difference coefficient of a certain crossing route and a certain parallel route;

[0026] Obtaining the average of the area difference coefficients of a certain crossing route and other parallel routes;

[0027] Obtaining the area difference coefficient of a certain crossing route and another parallel route;

[0028] Obtaining the number of overlapping areas of a certain crossing route and other parallel routes;

[0029] Combining the area difference coefficients of a certain crossing route and different parallel routes, the average of the area difference coefficients, and the number of overlapping areas of a certain crossing route and other parallel routes, the visual angle contribution degree of the crossing route setting is calculated.

[0030] Preferably, the flight directions of all parallel routes in the to-be-mapped area and the flight direction of the crossing route are obtained, including:

[0031] Obtaining the mapping data of a single route flight, projecting all three-dimensional point cloud data in the mapping data to the horizontal plane, thereby obtaining the second principal component direction of the mapping data;

[0032] The obtained second principal component direction is used as the flight direction of the mapping area, and the initial direction is based on the flight direction of the first parallel route, thereby obtaining the flight directions of all parallel route mapping areas and the flight direction of a certain crossing route.

[0033] Further, the visual angle environmental impact performance of the crossing route setting is calculated in combination with the visual angle contribution degree of the crossing route setting, including:

[0034] According to the obtained flight directions of the parallel route mapping areas and the flight direction of a certain crossing route, the average difference between the flight directions of different parallel route mapping areas and the flight direction of a certain crossing route is calculated;

[0035] The obtained average difference is normalized using the maximum-minimum value, and the visual angle environmental impact performance of the crossing route setting is calculated in combination with the visual angle contribution degree of the crossing route setting.

[0036] Preferably, the visual angle environmental impact performance of the crossing route setting is used to correct the mapping data correction process weight, including:

[0037] Obtaining the mapping data correction process weight before correction;

[0038] The obtained visual angle environmental impact performance of the crossing route setting is used as a correction coefficient to correct the mapping data correction process weight before correction, thereby obtaining the mapping data correction process weight after correction.

[0039] Preferably, the intersection of the flight path of the framework is introduced into adjustment as height control, the error equation of the adjustment of the regional network is established, the error of the unmanned aerial vehicle surveying data is corrected by introducing the weight matrix composed of the corrected surveying data correction process weight, including:

[0040] The error equation of the adjustment of the regional network is established, and the error equation contains a parameter vector to be solved;

[0041] In order to solve the parameter vector to be solved, the height value of the intersection of the flight path of the framework is taken as a priori control to establish a constraint equation of the constraint error equation;

[0042] The weight matrix is introduced in the constraint equation, so as to obtain the parameter vector to be solved, and then obtain the error equation;

[0043] According to the error equation, the error of the unmanned aerial vehicle surveying data is corrected, so as to realize the correction of the error of the unmanned aerial vehicle surveying data.

[0044] Further, the error equation is defined by a residual vector, a design matrix, an observation value vector and a parameter vector to be solved; the design matrix contains the relationship between the image point coordinates and the object point.

[0045] Further, the constraint equation is established by a constraint matrix, a known height value vector and a parameter vector to be solved.

[0046] Compared with the prior art, the beneficial effects of the present application are:

[0047] The present application sets multiple parallel flight paths and crossing flight paths in the expected surveying area; calculates the regional difference coefficient of the crossing flight path and the parallel flight path according to the error degree of the overlapping area and the error degree average of the non-overlapping area of the crossing flight path and the parallel flight path, and then calculates the visual angle contribution degree of the crossing flight path setting; and combines the flight direction of all parallel flight paths in the area to be surveyed and the flight direction of the crossing flight path, calculates the visual angle environmental influence performance of the crossing flight path setting, to correct the surveying data correction process weight; the error equation is established, and then the weight matrix composed of the corrected surveying data correction process weight is introduced, so as to realize the correction of the error of the unmanned aerial vehicle surveying data.

[0048] The present application can reflect the directionality influence of the local area distribution structure of the buildings or vegetation in the surveying environment through the perspective contribution degree of the crossing route, adjusts the calculation weight of the corresponding surveying data according to the environmental influence, and can effectively correct the surveying data error. The present application can improve the precision and reliability of the surveying data by analyzing the environmental factors and optimizing the route planning in the process of unmanned aerial vehicle surveying. The present application can not only effectively correct the error caused by the flight position deviation, but also systematically eliminate the cumulative error caused by the positioning, attitude and environmental change, so as to ensure that more accurate and consistent surveying results are obtained in the high-precision demand scenarios such as topographic surveying and emergency monitoring. The present application not only enhances the reliability of the data, but also provides a more solid foundation for subsequent decision-making, and promotes the application development in the related field. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is a step flow chart of the method for correcting the surveying data error of the unmanned aerial vehicle according to the present application;

[0050] Figure 2 is a schematic diagram of the parallel route and the crossing route according to the present application;

[0051] Figure 3 is a schematic block diagram of the computer device according to the present application. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. The present application will be described in detail below with reference to the drawings and specific embodiments.

[0053] It should be understood that when used in the specification, the terms "comprise" and "include" indicate the presence of described features, whole, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, whole, steps, operations, elements, components and / or sets thereof.

[0054] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application specification, unless otherwise clear from the context, the singular form "a", "an" and "the" are intended to include the plural form.

[0055] It should be further understood that the term "and / or" used in the description of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0056] Embodiments

[0057] As shown in the figure, a method for correcting errors of unmanned aerial vehicle surveying data, the method comprises the following steps: Figure 1 Setting a plurality of parallel flight lines and crossing flight lines for the planned surveying area;

[0058] Obtaining the error degree of the overlapping area of the crossing flight line and the parallel flight line and the average error degree of the non-overlapping area, and calculating the area difference coefficient of the crossing flight line and the parallel flight line;

[0059] According to the area difference coefficient of the crossing flight line and the parallel flight line, the visual angle contribution degree of the crossing flight line is calculated;

[0060] Obtaining the flight direction of all parallel flight lines in the area to be surveyed and the flight direction of the crossing flight line; combining the visual angle contribution degree of the crossing flight line, the visual angle environmental impact performance of the crossing flight line is calculated;

[0061] The visual angle environmental impact performance of the crossing flight line is used to correct the surveying data correction process weight;

[0062] The intersection point of the framework flight line is introduced as the height control into adjustment, and the error equation of the adjustment of the regional network is established, and the weight matrix composed of the corrected surveying data correction process weight is introduced, and the correction of the unmanned aerial vehicle surveying data error is carried out.

[0063] The visual angle contribution degree of the crossing flight line can reflect the directional influence of the local area distribution structure of the buildings or vegetation in the surveying environment, the calculation weight of the corresponding surveying data is adjusted according to the environmental influence, and the surveying data error can be effectively corrected. The present application can significantly improve the precision and reliability of the surveying data by analyzing the environmental factors in the unmanned aerial vehicle surveying process and optimizing the flight line planning. The present application can not only effectively correct the error caused by the flight position deviation, but also systematically eliminate the cumulative error caused by the positioning, attitude and environmental change, so as to ensure that more accurate and consistent surveying results are obtained in the high-precision demand scene such as topographic surveying and emergency monitoring. The present application not only enhances the reliability of the data, but also provides a more solid foundation for subsequent decision-making, and promotes the application development in the related field.

[0064] In one specific embodiment, before setting a plurality of parallel flight lines and crossing flight lines for the planned surveying area, it further comprises:

[0065]

[0066] ​Based on the existing map information, the surveying and mapping area boundary is demarcated, and a safety buffer distance is preset, such as a safety buffer distance >= 50m, which can be 50m or 60m. The purpose of setting the safety buffer distance is to prevent collision.

[0067] The flight height is inversely calculated according to the mapping scale requirement; for example, 1:500 mapping needs to ensure that the GSD is less than or equal to 4cm, and if the camera parameters such as the physical focal length f = 35mm and the pixel width-height ratio a = 4um, the inversely calculated flight height H is approximately 300m.

[0068] The heading overlap rate is set; for example, the heading overlap rate can be set to 70%, 75%, 80%, etc. By setting the heading overlap rate, the image pair splicing gap can be reduced.

[0069] The lateral overlap rate is set; for example, the lateral overlap rate can be set to 60%, 65%, or 70%. By setting the lateral overlap rate, the area network distortion can be suppressed.

[0070] In this embodiment, the data acquisition is performed in a single surveying and mapping process of the surveying and mapping area, that is, the single surveying and mapping includes multiple parallel flight lines and crossing flight lines set according to the above flight line arrangement requirements, and the flight position of the unmanned aerial vehicle at different times, as well as the heading, speed and other parameter type data on the flight position are recorded.

[0071] In the present application, the unmanned aerial vehicle surveying and mapping data acquisition process is carried out in a covering manner for the surveying and mapping area by multiple flight lines to improve the surveying and mapping accuracy. For the error of the final surveying and mapping result, more is the error of the unmanned aerial vehicle parameter setting and the actual environment influence in the unmanned aerial vehicle surveying and mapping data extraction process. These errors form the fluctuation influence of the flight position of the unmanned aerial vehicle in the flight area, and further increase the surveying and mapping data error. Therefore, it is necessary to further analyze the relationship between the unmanned aerial vehicle flight line setting and the actual environment influence, and to realize the accurate correction of the unmanned aerial vehicle surveying and mapping data error.

[0072] According to the data relationship between the parallel flight lines and the crossing flight lines, the surveying and mapping content has a certain influence on the flight line setting; for example, the original vertical flight is for all cases, but in some surveying and mapping targets, following the corresponding distribution surveying and mapping result is more accurate.

[0073] By analyzing the matching degree of the surveying and mapping data under the perspective, the perspective contribution degree, the data significance of the overlapping part and the non-overlapping part, and the perspective contribution condition reflected by the proportion change size of the two parts. When the terrain change has an influence on the perspective contribution degree, it indicates that the surveying and mapping target has an influence; the terrain change has overall change and slight change, and the change is related to the angle.

[0074] In the present application, the purpose of the parallel flight lines is to cover the area to be surveyed as much as possible, and the purpose of the crossing flight lines is to improve the accuracy of data alignment of the parallel flight lines, including the splicing of boundaries and the data distortion of the overall area network. For the crossing flight lines, the better the calibration result is, the better the perpendicularity to the parallel flight lines is. However, for the environmental factors in the actual surveying area, such as the consistent distribution of corresponding buildings and the direction distribution of flight line perspective, the higher the amount of building surveying information obtained by the unmanned aerial vehicle from the flight path is, the higher the contribution of the flight line perspective is.

[0075] In the present application, the same processing is performed on the unmanned aerial vehicle surveying data obtained in each single flight line process. The unmanned aerial vehicle surveying data obtained in each single flight line process refers to a plurality of surveying areas set according to the preset heading overlap degree and other parameters, and each surveying data obtaining process is the data obtained in the corresponding surveying area by single flight line. The surveying error of the unmanned aerial vehicle surveying data obtained by single flight line is more caused by local wind direction or other accidental factors. Therefore, for the unmanned aerial vehicle surveying data obtained by single flight line, there is an overlapping area with the surveying data obtained by other flight lines, especially the overlapping area with the crossing flight lines. For the surveying area of single flight line, the flight lines with overlapping areas are a plurality of parallel flight lines and a plurality of crossing flight lines, and the specific number is related to the flight plan set, such as 4 parallel flight lines and 2 crossing flight lines, 6 parallel flight lines and 2 crossing flight lines, etc. The schematic diagram of the plurality of parallel flight lines and the plurality of crossing flight lines in the present application is shown in FIG. 1. As shown in FIG. 2, since the flight distance of the parallel flight lines is generally much larger than the flight distance that can be covered by the crossing flight lines, for the surveying area of single flight line, there is certainly an overlapping area and a non-overlapping area. The greater the difference between the overlapping area and the non-overlapping area, the greater the difference in information acquisition of this crossing flight line, and the more important the analysis of surveying error, and the greater the contribution of the perspective to the surveying result. Figure 2 Figure 2

[0076] In a specific embodiment, the error degree of the overlapping area of the crossing flight line and the parallel flight line and the error degree of the non-overlapping area are obtained, and the area difference coefficient of the crossing flight line and the parallel flight line is calculated, including:

[0077] The first crossing flight line and the first parallel flight line are obtained, including all three-dimensional point cloud data;

[0078] The distance of each three-dimensional point cloud after matching is obtained according to the actual spatial position matching;

[0079] ​​The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0080] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0081] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0082] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0083] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0084] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0085] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0086] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0087] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0088] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds

[0089] The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds The error degree of the overlapping area between the first crossing route and the second parallel route is calculated according to the average distance of all the matched three-dimensional point clouds Regional difference coefficient of parallel routes ;

[0090] Get the The number of overlapping areas between the crossing route and other parallel routes ;

[0091] Combined with the The regional difference coefficient between the cross-line route and different parallel lines ( and ), and the mean of the regional difference coefficient , and the The number of overlapping areas between the crossing route and other parallel routes The perspective contribution of the crossing route setting was calculated. .

[0092] The following formula is provided in this embodiment for calculating the perspective contribution of the crossing route setting:

[0093]

[0094] in, Indicates the first The contribution of the perspective of the cross-flight route setting , Indicates the first The crossing route and the first Regional difference coefficient of parallel routes, Indicates the first The mean regional difference coefficient between the crossing route and other parallel routes. Indicates the first The crossing route and the first Regional difference coefficient of parallel routes, Indicates the first The number of areas where a crossing route overlaps with other parallel routes.

[0095] The contribution of the crossing flight path setting described in this invention is analyzed from the perspectives of setting the crossing and parallel flight paths. However, in actual UAV mapping, the local distribution structure of buildings or vegetation in the actual mapping environment can significantly affect the mapping results; for example, mutual occlusion can increase mapping errors. Different setting perspectives of the crossing flight path can reflect the directional influence of the local distribution structure of buildings or vegetation in the mapping environment. Therefore, by adjusting the calculation weights of the corresponding mapping data based on this environmental influence, mapping data errors can be effectively corrected.

[0096] In one specific embodiment, the flight directions of all parallel flight paths within the area to be mapped, as well as the flight directions crossing the flight paths, are obtained, including:

[0097] Obtaining the survey data of the single route flight, projecting all the three-dimensional point cloud data in the survey data to the horizontal plane to obtain the second principal component direction; specifically, the purpose of projecting the three-dimensional point cloud data to the horizontal plane is to reduce the three-dimensional point cloud data to a two-dimensional plane, that is, to convert the three-dimensional data into two-dimensional data; then performing PCA calculation on the two-dimensional data, and obtaining the second principal component (PC2) and its direction after sorting, thereby obtaining the second principal component direction.

[0098] Taking the obtained second principal component direction as the flight direction of the survey area, and taking the flight direction of the first parallel route (the edge parallel route) as the reference of the initial direction, thereby obtaining the flight direction of all the parallel route survey areas (it can be understood that the flight direction of the first parallel route is taken as the flight direction of all the crossing routes), and the flight direction of a certain crossing route.

[0099] In addition, the present application also combines the visual angle contribution degree of the crossing route setting to calculate the visual angle environmental impact performance of the crossing route setting, including:

[0100] According to the obtained flight direction of the parallel route survey area and the flight direction of the first crossing route (that is, the flight direction of the crossing route), the average difference value between the flight direction of different parallel route survey areas and the flight direction of a certain crossing route is calculated.

[0101] The maximum and minimum values of the average difference value are screened out, and the visual angle environmental impact performance of the crossing route setting is calculated by combining the visual angle contribution degree of the crossing route setting.

[0102] The present application provides a calculation formula for calculating the visual angle environmental impact performance of the crossing route setting as follows:

[0103]

[0104] Among them, represents the visual angle environmental impact performance of the first crossing route setting, represents the flight direction of the first parallel route survey area, represents the flight direction of the first crossing route, represents the number of overlapping areas between the first crossing route and other parallel routes, represents the maximum and minimum values of the average difference value in all crossing route ranges, The average difference of the strip crossing routes is normalized by maximum and minimum values, The first The visual angle contribution degree of the strip crossing route is set. In the present application, The greater the ratio is, the greater the influence of the first The strip crossing route on the obtained surveying and mapping data is, the stronger the specificity of the obtained surveying and mapping information is, and the greater the weight of the corresponding error correction process is.

[0105] In a specific embodiment, the visual angle environment influence performance of the strip crossing route is used to correct the surveying and mapping data correction process weight, including:

[0106] The surveying and mapping data correction process weight before correction is obtained;

[0107] The obtained visual angle environment influence performance of the strip crossing route is used as a correction coefficient to correct the surveying and mapping data correction process weight before correction, and the surveying and mapping data correction process weight after correction is obtained.

[0108] The specific correction formula of the surveying and mapping data correction process weight is as follows:

[0109]

[0110] Wherein, The surveying and mapping data correction process weight after correction is represented; The surveying and mapping data correction process weight before correction is represented, The preset value is based on actual experience, and can also be set to 1; The first The visual angle environment influence performance of the strip crossing route is set.

[0111] In a specific embodiment, the strip crossing route of the framework can act as an elevation control point, which is beneficial to reduce the number of control point measurements in the photograph, enhance the continuity between the regional network models, and improve the measurement accuracy of the aerial triangulation adjustment. Therefore, when calculating the aerial triangulation adjustment, the bundle adjustment model can be used for calculation, that is, the least square method with constraints is used, and the intersection point of the framework route is introduced into the adjustment as an elevation control.

[0112] Therefore, the intersection point of the framework route is introduced into the adjustment as an elevation control, the error equation of the adjustment of the regional network is established, the weight matrix composed of the surveying and mapping data correction process weight after correction is introduced, and the error correction of the unmanned aerial vehicle surveying and mapping data is realized, including:

[0113] The error equation of the adjustment of the regional network is established, and the error equation contains a parameter vector to be solved;

[0114] In order to solve for the parameter vector to be determined, the elevation values ​​of the route intersections of the framework are used as prior controls to establish the constraint equations of the constraint error equations.

[0115] By introducing a weight matrix into the constraint equations, the parameter vector to be solved can be obtained, and thus the error equation can be derived.

[0116] The error is corrected by applying the error equation to the UAV mapping data.

[0117] The error equation is defined by the residual vector, the design matrix, the observation vector, and the parameter vector to be determined; the design matrix contains the relationship between the image point coordinates and the object point.

[0118] Specifically, the error equation for the adjustment of the established regional network is as follows:

[0119]

[0120] In the formula, Represents the residual vector (n×1); The design matrix (n×t) contains the relationship between image point coordinates and object points; This represents the parameter vector (t×1) to be determined, which contains the exterior orientation elements and the coordinates of the encryption points; This represents the observation vector (n×1). n represents the number of rows, and t represents the number of columns.

[0121] This invention will construct the route intersection point elevation value This can be used as a priori control to establish the constraint equations for the adjustment equations; the constraint equations are established using the constraint matrix, the known elevation value vector, and the parameter vector to be determined. Specifically, the constraint equations are as follows:

[0122]

[0123] In the formula, G is the constraint matrix (m×t), where m is the number of constraints, and the k-th row corresponds to the elevation constraint (e.g., [0,0,1,0,...]). coordinate); This represents a vector of known elevation values ​​(m x1).

[0124] In the constraint equations, each crossing route has multiple route intersection points within the regional network, which serve as elevation control points, corresponding to each row of the constraint matrix; a weight matrix is ​​introduced into the constraint equations. (Diagonal matrix), then each element of the diagonal matrix corresponds to the weight of the corrected mapping data correction process. Specifically, in the constraint equation, the constraint matrix is ​​multiplied by the weight matrix on the left to obtain the adjusted constraint matrix, and then the corresponding constraint equation is calculated to solve for the parameter vector to be determined.

[0125] Therefore, the application corrects the weight of the obtained modified surveying data according to the modified surveying data to form a modified weight matrix , as the credibility of the unmanned aerial vehicle surveying data of the route intersection at the position, so as to realize the introduction of the route intersection as height control into adjustment to reduce the influence of the surveying error on the final surveying result, thereby realizing the correction process of the error of the unmanned aerial vehicle surveying data.

[0126] Please refer to Figure 3 , Figure 3 is a schematic block diagram of the computer device provided by the embodiment of the application. The computer device 500 is a server, which can be a stand-alone server or a server cluster composed of multiple servers.

[0127] Please refer to Figure 3 , the computer device 500 includes a processor 502, a memory and a network interface 505 connected through a system bus 501, wherein the memory can include a non-volatile storage medium 503 and an internal memory 504.

[0128] The non-volatile storage medium 503 can store an operating system 5031 and a computer program 5032. The computer program 5032, when executed, can enable the processor 502 to execute the correction method of the error of the unmanned aerial vehicle surveying data.

[0129] The processor 502 is configured to provide computing and control capabilities to support the operation of the entire computer device 500.

[0130] The internal memory 504 provides an environment for the execution of the computer program 5032 in the non-volatile storage medium 503, and the computer program 5032, when executed by the processor 502, can enable the processor 502 to execute the correction method of the error of the unmanned aerial vehicle surveying data.

[0131] The network interface 505 is configured to perform network communication, such as providing transmission of data information, etc. Those skilled in the art can understand Figure 3 that the structure shown in the figure is only a block diagram of part of the structure related to the scheme of the application, and does not constitute a limitation on the computer device 500 to which the scheme of the application is applied. The specific computer device 500 can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0132] The processor 502 is configured to run the computer program 5032 stored in the memory to implement the correction method of the error of the unmanned aerial vehicle surveying data disclosed by the embodiment of the application.

[0133] Those skilled in the art can understand Figure 3The embodiments of the computer device shown in the figures do not constitute a limitation on the specific structure of the computer device, and in other embodiments, the computer device can include more or fewer components than shown, or combine certain components, or arrange the components differently. For example, in some embodiments, the computer device can only include the memory and the processor, and in such embodiments, the structure and function of the memory and the processor are consistent with the embodiments shown, and will not be repeated here. Figure 3

[0134] It should be understood that in the embodiments of the present application, the processor 502 can be a central processing unit (CPU), and the processor 502 can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0135] In another embodiment of the present application, a computer readable storage medium is provided. The computer readable storage medium can be a non-volatile computer readable storage medium. The computer readable storage medium stores a computer program, wherein the computer program is executed by a processor to implement the method for correcting errors in surveying data of a UAV disclosed in the embodiments of the present application.

[0136] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices, apparatuses and units can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here. Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been described in the foregoing description in a general manner. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0137] ​In several embodiments provided by the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other manners. For example, the embodiments of the apparatus described above are merely schematic. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation, or a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electric, mechanical or in other forms.

[0138] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0139] In addition, each functional unit in the various embodiments of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0140] The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0141] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the implementation manner of the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for correcting errors in UAV mapping data, characterized in that: The method comprises the following steps: Setting multiple parallel flight lines and crossing flight lines for the predicted mapping area; Obtaining the error degree of the overlapping area of the crossing flight line and the parallel flight line and the average error degree of the non-overlapping area, and calculating the area difference coefficient of the crossing flight line and the parallel flight line; According to the area difference coefficient of the crossing flight line and the parallel flight line, the visual angle contribution degree of the crossing flight line setting is calculated; Obtaining the flight direction of all parallel flight lines in the area to be mapped and the flight direction of the crossing flight line; combined with the visual angle contribution degree of the crossing flight line setting, the visual angle environmental impact performance of the crossing flight line setting is calculated; The visual angle environmental impact performance of the crossing flight line setting is used to correct the mapping data correction process weight; The intersection point of the flight line of the framework is introduced into adjustment as height control, the error equation of adjustment of the regional network is established, and the weight matrix composed of the corrected mapping data correction process weight is introduced to realize the correction of the unmanned aerial vehicle mapping data error; According to the area difference coefficient of the crossing flight line and the parallel flight line, the visual angle contribution degree of the crossing flight line setting is calculated, including: Obtaining the area difference coefficient of a certain crossing flight line and a certain parallel flight line; Obtaining the average area difference coefficient of a certain crossing flight line and other parallel flight lines; Obtaining the area difference coefficient of a certain crossing flight line and another parallel flight line; Obtaining the number of overlapping areas of a certain crossing flight line and other parallel flight lines; Combined with the area difference coefficient of a certain crossing flight line and different parallel flight lines, the average area difference coefficient, and the number of overlapping areas of a certain crossing flight line and other parallel flight lines, the visual angle contribution degree of the crossing flight line setting is calculated; Combined with the visual angle contribution degree of the crossing flight line setting, the visual angle environmental impact performance of the crossing flight line setting is calculated, including: According to the flight direction of the parallel flight line mapping area and the flight direction of a certain crossing flight line, the average difference value of the flight direction of different parallel flight line mapping areas and the flight direction of a certain crossing flight line is calculated; The obtained average difference value is normalized using the maximum-minimum value, and combined with the visual angle contribution degree of the crossing flight line setting, the visual angle environmental impact performance of the crossing flight line setting is calculated.

2. The method of claim 1, wherein: Before setting multiple parallel flight lines and crossing flight lines for the predicted mapping area, it also includes: Based on the existing map information, the mapping area boundary is demarcated, and a safety buffer distance is preset; Reverse the flight height according to the mapping scale requirement; Set the heading overlap rate; Set the lateral overlap rate. 3.The method of claim 1, wherein: Obtaining the error degree of the overlapping area of the crossing flight line and the parallel flight line and the average error degree of the non-overlapping area, and calculating the area difference coefficient of the crossing flight line and the parallel flight line, including: Obtaining twice mapping data of the overlapping area of a certain crossing flight line and a certain parallel flight line, including all three-dimensional point cloud data; The matching of the actual spatial position is matched to obtain the point distance of each three-dimensional point cloud after matching; The average distance of all three-dimensional point clouds after matching represents the error degree of the overlapping area of a certain crossing flight line and a certain parallel flight line; Obtaining the average error degree of the non-overlapping area of a certain crossing flight line and a certain parallel flight line; According to the error degree of the overlapping area of a certain crossing route and a certain parallel route, and the error degree average of the non-overlapping area, the area difference coefficient of the certain crossing route and the certain parallel route is calculated. 4.The method of claim 1, wherein: Obtaining the flight direction of all parallel routes in the area to be surveyed, and the flight direction of the crossing route, including: Obtaining the surveying data of single route flight, projecting all three-dimensional point cloud data in the surveying data to the horizontal plane, thereby obtaining the second principal component direction of the surveying data; Taking the obtained second principal component direction as the flight direction of the surveying area, and taking the flight direction of the first parallel route as the initial direction, thereby obtaining the flight direction of all parallel routes in the surveying area, and the flight direction of the certain crossing route.

5. The method of claim 1, wherein: Using the perspective environmental impact performance set by the crossing route to correct the surveying data correction process weight, including: Obtaining the surveying data correction process weight before correction; Taking the obtained perspective environmental impact performance set by the crossing route as the correction coefficient, correcting the surveying data correction process weight before correction to obtain the surveying data correction process weight after correction.

6. The method of claim 1, wherein: Taking the intersection of the routes of the framework as the height control to introduce into adjustment, establishing the error equation of the adjustment of the regional network, and through the introduction of the weight matrix composed of the surveying data correction process weight after correction, realizing the correction of the error of the unmanned aerial vehicle surveying data, including: Establishing the error equation of the adjustment of the regional network, wherein the error equation contains a parameter vector to be solved; In order to solve the parameter vector to be solved, taking the height value of the intersection of the routes of the framework as the prior control, establishing the constraint equation of the constraint error equation; Introducing the weight matrix in the constraint equation, thereby solving the parameter vector to be solved, and further obtaining the error equation; According to the error equation, the error of the unmanned aerial vehicle surveying data is corrected, thereby realizing the correction of the error of the unmanned aerial vehicle surveying data.

7. The method of claim 6, wherein: The error equation is defined by a residual vector, a design matrix, an observation value vector and a parameter vector to be solved; the design matrix contains the relationship between image point coordinates and object point. 8.The method of claim 6, wherein: The constraint equation is established by a constraint matrix, a known height value vector and a parameter vector to be solved.

Images