CN109118502B

CN109118502B - Operation coverage area real-time reconstruction method and system based on breakpoint segmentation

Info

Publication number: CN109118502B
Application number: CN201811211985.7A
Authority: CN
Inventors: 张昆; 崔静莹; 赵龙
Original assignee: Xinyang Normal University
Current assignee: Xinyang Normal University
Priority date: 2018-10-18
Filing date: 2018-10-18
Publication date: 2021-11-02
Anticipated expiration: 2038-10-18
Also published as: CN109118502A

Abstract

The invention relates to the technical field of agricultural engineering, in particular to a real-time operation coverage area reconstruction method and system based on breakpoint segmentation. The method comprises the following steps: performing binarization processing on boundary vertexes of two areas needing to be combined, and dividing the boundary vertexes into effective vertexes and ineffective vertexes; extracting breakpoints of the regions according to the effective vertexes and the ineffective vertexes, segmenting effective connection sections of the two regions according to the breakpoints, obtaining intersecting lines of the two regions according to the breakpoints, solving intersection points of the intersecting lines according to the intersecting lines, and taking the intersection points closest to the breakpoints as connection points for region combination; and connecting the effective connecting sections of the two regions at the connecting point according to the effective connecting sections of the two regions to form a new closed region as a result of the real-time reconstruction of the regions. The system comprises: a processing module; an extraction module; and a reconstruction module. The invention utilizes the real-time unmanned aerial vehicle operation parameter information in the unmanned aerial vehicle operation process to construct the operation coverage area in real time so as to reconstruct the areas of missed spray and excessive heavy spray.

Description

Operation coverage area real-time reconstruction method and system based on breakpoint segmentation

Technical Field

The invention relates to the technical field of agricultural engineering, in particular to a real-time operation coverage area reconstruction method and system based on breakpoint segmentation.

Background

In the operation process of the plant protection unmanned aerial vehicle, a better operation route can be planned according to a route planning algorithm, but the unmanned aerial vehicle with low route flight precision cannot accurately fly along the planned route, so that various operation effect parameters of real operation are poor, and spray leakage or phytotoxicity can be caused; and the unmanned aerial vehicle with higher air route control precision is also influenced by external environmental factors, so that the operation area parameters are difficult to ensure to be consistent with theoretical planning, the actual coverage area of the liquid medicine is inconsistent with theoretical calculation, and the operation effect in the whole operation area is inconsistent. At present, three main ways are available for evaluating the operation coverage area of the plant protection unmanned aerial vehicle: and fog drops in the operation area are manually collected, remote sensing image information is extracted, and the operation effect is observed by human eyes at the later stage. When the fog drops in the operation area are manually collected, a collection card, test paper, a measuring cup and the like are mainly adopted, so that the method is suitable for qualitatively and quantitatively analyzing the fog drop drift rule to construct a fog drop drift model, and is not suitable for real-time online evaluation of the fog drop coverage condition in the operation process; moreover, the method is time-consuming, and workers need to be in a medicine dispersion environment for a long time, which may cause harm to the health of the workers. Remote sensing image information extraction is suitable for large-area analysis and is a research hotspot at present, the method has high requirements on image quality, and the images of the operation area need to be collected again in the air by using equipment for analysis under a better weather condition after the unmanned aerial vehicle operation is finished; the method for observing the operation effect by human eyes needs to be carried out for a period of time after the operation is finished, the operation effect is analyzed by observing the crop pest and disease damage and growth information in the operation area, the workload of workers is large, the observation result is easily influenced by the subjectivity of the workers, and at the moment, if the areas with missed spray and excessive heavy spray are found, the optimal period for pest control is often missed, and the loss caused by pest is difficult to be recovered by secondary control.

Disclosure of Invention

The invention provides a real-time reconstruction method and a real-time reconstruction system for an operation coverage area based on breakpoint segmentation, aiming at the defects and the defects of the existing method for evaluating the operation coverage area of a plant protection unmanned aerial vehicle. The method utilizes the real-time unmanned aerial vehicle operation parameter information in the unmanned aerial vehicle operation process to construct the operation coverage area in real time so as to evaluate the areas needing key inspection, such as missed spray and excessive re-spray, and has the advantages of real time, rapidness, accuracy and less occupied computing resources.

In order to achieve the purpose, the invention adopts the following technical scheme:

the real-time reconstruction method of the operation coverage area based on breakpoint segmentation comprises the following steps:

step 1: performing binarization processing on boundary vertexes of two areas needing to be combined, and dividing the boundary vertexes into an effective vertex and an invalid vertex, wherein the effective vertex is a vertex used for forming a new area boundary after the areas are combined, and the invalid vertex is a vertex which cannot be used for forming the new area boundary after the areas are combined;

step 2: extracting breakpoints of the regions according to the effective vertexes and the ineffective vertexes, segmenting effective connection sections of the two regions according to the breakpoints, obtaining intersecting lines of the two regions according to the breakpoints, solving intersection points of the intersecting lines according to the intersecting lines, and taking the intersection points closest to the breakpoints as connection points for region combination;

and step 3: and connecting the effective connecting sections of the two regions at the connecting point according to the effective connecting sections of the two regions to form a new closed region as a result of the real-time reconstruction of the regions.

Further, before the step 1, the method further comprises:

and obtaining boundary information of the operation coverage sub-area at the current moment and the operation coverage area at the previous moment through the unmanned aerial vehicle operation parameters, wherein the boundary information comprises a boundary vertex.

Further, in the binarization processing process, a binary flag is generated for each vertex, the vertex with the binary flag of 0 is an invalid vertex, the vertex with the binary flag of 1 is an effective vertex, and the connected segment with the vertex binary flags of 1 is called an effective connected segment.

Further, the binarization processing of the boundary vertices of the two regions to be merged specifically includes: and judging the relation between the boundary vertex of the region and a polygon formed by the boundary of another region by adopting a revolution number method, and carrying out binarization processing on the boundary vertex array of the region. When the union of the two regions is solved, if the boundary vertex of the region is inside the polygon formed by the boundary of the other region, the binary flag corresponding to the boundary vertex of the region is 0, and if the boundary vertex of the region is outside the polygon formed by the boundary of the other region or on the boundary line, the binary flag corresponding to the boundary vertex of the region is 1.

In the revolution number method, the counterclockwise direction is defined as positive, and the clockwise direction is defined as negative.

Further, still include:

and setting the effective vertex when the vertex binary flag is changed as a region breakpoint.

Further, the step 3 comprises:

when the areas are merged, the area with more effective connecting sections is set as an active area, and the other area is set as a passive area;

dividing the situation into two situations of conventional area combination and special area combination according to the number of the broken points of the active area and the passive area; when the active area and the passive area have no break points, merging the special areas; when the number of the broken points in the active area is more than 2, carrying out conventional area combination; the regular region merging includes: according to the boundary vertex, the breakpoint, the intersection point and the invalid vertex of the active region and the passive region, carrying out region combination;

the special region merging includes: and according to the boundary vertex and the invalid vertex of the active region and the passive region, performing region combination.

Real-time reconstruction system of operation coverage area based on breakpoint segmentation includes:

the processing module is used for carrying out binarization processing on boundary vertexes of two regions needing to be combined and dividing the boundary vertexes into an effective vertex and an invalid vertex, wherein the effective vertex is a vertex used for forming a new region boundary after the regions are combined, and the invalid vertex is a vertex which cannot be used for forming the new region boundary after the regions are combined;

the extraction module is used for extracting breakpoints of the regions according to the effective vertexes and the invalid vertexes, segmenting effective connection sections of the two regions according to the breakpoints, obtaining intersecting lines of the two regions according to the breakpoints, solving intersection points of the intersecting lines according to the intersecting lines, and taking the intersection points closest to the breakpoints as connection points for region combination;

and the reconstruction module is used for connecting the effective connecting sections of the two areas at the connecting point according to the effective connecting sections of the two areas to form a new closed area as a result of real-time reconstruction of the areas.

Further, still include:

and the area boundary information acquisition module is used for acquiring the boundary information of the operation coverage sub-area at the current moment of the operation at the current moment and the operation coverage area at the previous moment through the unmanned aerial vehicle operation parameters, and the boundary information comprises a boundary vertex.

Further, still include:

and the setting module is used for setting the effective vertex when the vertex binary flag changes as the region breakpoint.

Compared with the prior art, the invention has the following beneficial effects:

the invention carries out binarization processing on the boundary vertexes of two areas needing to be combined, and divides the boundary vertexes into an effective vertex and an ineffective vertex; extracting breakpoints of the regions according to the effective vertexes and the ineffective vertexes, segmenting effective connection sections of the two regions according to the breakpoints, obtaining intersecting lines of the two regions according to the breakpoints, solving intersection points of the intersecting lines according to the intersecting lines, and taking the intersection points closest to the breakpoints as connection points for region combination; and connecting the effective connecting sections of the two regions at the connecting point according to the effective connecting sections of the two regions to form a new closed region as a result of the real-time reconstruction of the regions.

The method can quickly and effectively solve the problem of area merging of two areas which are only intersected at the area breakpoint, and utilizes the real-time unmanned aerial vehicle operation parameter information in the unmanned aerial vehicle operation process to construct the operation coverage area in real time so as to reconstruct the areas with missed spray and excessive heavy spray, and has the advantages of real time, quickness, accuracy and less occupied computing resources.

Drawings

Fig. 1 is a basic flowchart of a method for reconstructing a work coverage area in real time based on breakpoint division according to an embodiment of the present invention.

Fig. 2 is a schematic view of a plant protection unmanned aerial vehicle operation map construction of an operation coverage area real-time reconstruction method based on breakpoint segmentation in the embodiment of the present invention.

Fig. 3 is a basic schematic diagram of an algorithm implementation when performing region merging on a region a and a region B in the real-time job coverage region reconstruction method based on breakpoint segmentation according to the embodiment of the present invention.

Fig. 4 is a basic flowchart of the construction of the operation coverage sub-region of the real-time reconstruction method of the operation coverage region based on breakpoint division according to the embodiment of the present invention.

Fig. 5 is a schematic diagram illustrating determination of a relationship between a vertex and a polygon in a real-time reconstruction method of an operation coverage area based on breakpoint segmentation according to an embodiment of the present invention.

Fig. 6 is a schematic diagram illustrating an intersection situation of two line segments in the real-time reconstruction method of an operation coverage area based on breakpoint segmentation according to the embodiment of the present invention.

Fig. 7 is a flowchart illustrating a determination of region merging situation in a method for real-time reconstruction of an operation coverage region based on breakpoint division according to an embodiment of the present invention.

Fig. 8 is a flowchart of a special area merging process of a real-time job coverage area reconstruction method based on breakpoint division according to an embodiment of the present invention.

Fig. 9 is a flowchart of a conventional region merging process of a breakpoint-segmentation-based real-time reconstruction method of an operation coverage region according to an embodiment of the present invention.

Fig. 10 is a schematic structural diagram of a system for real-time reconstruction of an operation coverage area based on breakpoint division according to an embodiment of the present invention.

Fig. 11 is a second schematic diagram of a real-time reconstruction system of an operation coverage area based on breakpoint division according to an embodiment of the present invention.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

the first embodiment is as follows:

as shown in fig. 1, a method for reconstructing a work coverage area in real time based on breakpoint segmentation according to the present invention includes the following steps:

step S101: performing binarization processing on boundary vertexes of two areas needing to be combined, and dividing the boundary vertexes into an effective vertex and an invalid vertex, wherein the effective vertex is a vertex used for forming a new area boundary after the areas are combined, and the invalid vertex is a vertex which cannot be used for forming the new area boundary after the areas are combined;

step S102: extracting breakpoints of the regions according to the effective vertexes and the ineffective vertexes, segmenting effective connection sections of the two regions according to the breakpoints, obtaining intersecting lines of the two regions according to the breakpoints, solving intersection points of the intersecting lines according to the intersecting lines, and taking the intersection points closest to the breakpoints as connection points for region combination;

step S103: and connecting the effective connecting sections of the two regions at the connecting point according to the effective connecting sections of the two regions to form a new closed region as a result of the real-time reconstruction of the regions.

Example two:

the invention discloses another real-time operation coverage area reconstruction method based on breakpoint segmentation, which comprises the following steps:

the reconstruction of the operation coverage area of the plant protection unmanned aerial vehicle comprises the construction of an operated area map and the construction of an unoperated area map. As shown in FIG. 2, the region to be worked is defined by the vertex B₀～B_nIn the operation process that the plant protection unmanned aerial vehicle moves from the left position to the right position in the figure, the operation coverage sub-areas covered by paths through which two adjacent coordinate points on the operation route pass are A1-An, and the operation coverage area A of the unmanned aerial vehicle at the current moment is An area obtained by merging all the operation coverage sub-areas A1-An, namely the area A is A1U A2U … U A; the effective operation coverage area C is an area to be operated which is covered in the operation process, that is, the intersection of the area a and the area B is taken to obtain C ═ a ≈ B; the non-operation coverage area D, i.e. the spray leakage area, is a gray area in the figure and is a complement of the area C in the area B, i.e. D is equal to C_BC; the repeated spraying area, namely the re-spraying coverage area, is the intersection of the operation coverage sub-areas.

For ease of understanding, "region a" and "region B" in the subsequent description are explained as follows: when the operated coverage area at the current moment is solved, the solved result is a union of two areas, wherein the area A and the area B respectively refer to one of the operated coverage area at the previous moment and the operated coverage sub-area at the current moment, namely if the area A refers to the operated coverage area at the previous moment, the area B refers to the operated coverage sub-area at the current moment, and if the area B refers to the operated coverage area at the previous moment, the area A refers to the operated coverage sub-area at the current moment; when the effective operation coverage area is solved, the intersection of the two areas is solved, the area A and the area B respectively refer to one of the operated coverage area and the area to be operated at the current moment, namely if A refers to the operated coverage area at the current moment, B refers to the area to be operated, and if B refers to the operated coverage area at the current moment, A refers to the area to be operated; when the missed spray area is solved, the solution is a complementary set of an area in the other area, the area A and the area B respectively refer to one of an operated coverage area and an area to be operated, namely if A refers to the operated coverage area, B refers to the area to be operated, and if B refers to the operated coverage area, A refers to the area to be operated; when the re-spraying area is solved, the intersection of the two areas is solved, the area A and the area B respectively refer to one of the re-spraying area at the previous moment and the operation coverage sub-area at the current moment, namely if the area A refers to the re-spraying area at the previous moment, the area B refers to the operation coverage sub-area at the current moment, and if the area B refers to the re-spraying area at the previous moment, the area A refers to the operation coverage sub-area at the current moment. Unless otherwise specified, "region a" and "region B" appearing hereinafter are to be understood in accordance with the description of this paragraph.

The basic schematic diagram of the algorithm implementation when performing region merging on the region a and the region B is shown in fig. 3, and first, as shown in part (a) of fig. 3, the boundary vertex a of the two regions is set_nAnd B_nAnd performing binarization processing, namely dividing the binary image into two types, namely an effective vertex and an invalid vertex, wherein the effective vertex is a vertex which is used for forming a new region boundary after the region is merged, and the invalid vertex is a vertex which cannot be used for forming the new region boundary after the region is merged.

Extracting the break position of the region, namely the break point of the region according to the effective vertex and the ineffective vertex, wherein the break point of the region A is the vertex A₀And A₃The breakpoint of region B is vertex B₀And B₂Further, the intersection line of the two regions, i.e., the boundary line A of the intersection position, as shown in part (b) of FIG. 3 can be obtained₀A₁And B₃B₀、A₂A₃And B₂B₃(ii) a Effective connection section A of region A is divided according to break points₃-A₄-A₀And the effective connection section B of the area B₀-B₁-B₂. Respectively solve out the intersecting line A₀A₁And B₃B₀Point of intersection C₁，A₂A₃And B₂B₃Point of intersection C₂Point of intersection C₁And C₂Is the corresponding connection location of the two zone boundary lines.

The number of the broken points of the two areas is equal, and one area is selected as an active area, for example, the area A is selected as the active area. Since the effective connection segment arrangement order of the region A is not suitable for direct region merging, the boundary vertex sequence is rearranged based on the region break points, and for the region A, the vertex array should be converted into A' before the region merging [5 ]]＝{A₀，A₄，A₃，A₂，A₁Renumbering the vertex, i.e. A₄Reprogramming to A₁A is₃Reprogramming to A₂. As shown in part (c) of FIG. 3, the breakpoint of region A at this time becomes A₀And A₂The effective connection segment becomes A₀-A₁-A₂. First from the off position A of the area A₀Initially, the active connection segment of region A is connected to the intersection C of the two regions₂Position at the intersection point C₂The positions are reversely connected with the effective connection sections of the corresponding areas B to the disconnection positions B in sequence₀At this time, the region intersection C corresponding to the position₁Also the open position A of the area A₀Connecting the corresponding intersection point to A again₀Forming a new closed region A₀-A₁-A₂-C₂-B₂-B₁-B₀-C₁Namely, the product is A ^ B ^ U ^ B.

At the boundary vertex A of the two regions_nAnd B_nBefore binarization processing is carried out, boundary information of a current operation coverage sub-area and a previous operation coverage sub-area is obtained through unmanned aerial vehicle operation parameters, and the boundary information comprises boundary vertexes of the two areas; the unmanned aerial vehicle operation parameters include: real-time position of unmanned aerial vehicleInformation, course angle, spray width.

In the unmanned aerial vehicle spraying operation process, the position information of the unmanned aerial vehicle is collected in real time, a real-time operation air route is generated, and then an operation sub-area covered by adjacent coordinate points on the operation air route is constructed. In order to simplify the solution model, the fog drop drift influence caused by external conditions is ignored in the preliminary estimation, the fog drop coverage model in the unmanned aerial vehicle operation process is idealized, namely the unmanned aerial vehicle spray amplitude is considered to be fixed, and the operation coverage area is determined by real-time position coordinates and a course angle. The construction rule of the work coverage sub-area under this ideal condition is shown in FIG. 4, point P_n-1And P_nRepresenting a real-time location of the drone; d represents the spray amplitude and vector of the unmanned plane

And

representing real-time heading, P 'of the drone'_n、P′_n-1、P″_nAnd P ″)_n-1The top point of the boundary of the operation subarea, and the dotted line represents the boundary of the operation covering subarea; real-time position coordinate of unmanned aerial vehicle is P_n(x_n，y_n) The boundary vertex coordinates of the work coverage sub-region are P'_n(x′_n，y′_n) And P ″)_n(x″_n，y″_n) The rotation angle when the positive direction of the coordinate axis X rotates to the same direction as the working course is alpha, wherein the line segment P'_nP″_nPerpendicular to the working course and at a point P_nIs line segment P'_nP″_nThe midpoint of (1) can be found to be point P'_nAnd P ″)_nThe coordinates of (a) are as follows:

when alpha is more than or equal to 0 and less than pi/2 or 3 pi/2 and less than or equal to alpha and less than or equal to 2 pi:

when pi/2 is more than or equal to alpha and less than pi or pi is more than or equal to alpha and less than 3 pi/2:

in the test aiming at a specific machine type, the accurate operation coverage sub-area model of each machine type can be calibrated through experimental test and is led into the system, and the method can be used for accurately constructing the operation coverage sub-area at each moment.

The specific process of this embodiment is as follows:

(1) vertex binarization

In merging region a and region B, a ≡ B, A ℃ B, C exists_AB and C_BAnd A, four cases. When solving for A ≈ B or C for region A_AIn case B, the vertex of the area A inside the area B is an effective vertex, the vertex of the area A outside the area B is an ineffective vertex, and the special vertex of the area A on the boundary of the area B is an effective vertex; when solving for either A $ B or C_BIn case a, the vertices of the area a inside the area B are invalid vertices, the vertices of the area a outside the area B are valid vertices, and particularly, the vertices of the area a on the boundary of the area B are valid vertices. When solving for A ≈ B or C for region B_BIn case A, the vertex of the area B inside the area A is an effective vertex, the vertex of the area B outside the area A is an ineffective vertex, and the vertex of the area B on the boundary of the area A is an effective vertex; when solving for either A $ B or C_AIn case B, the vertices of the area B inside the area a are invalid vertices, the vertices of the area B outside the area a are valid vertices, and particularly, the vertices of the area B on the boundary of the area a are valid vertices.

The binary flag of the valid vertex is 1, and the binary flag of the invalid vertex is 0. Therefore, according to the relation between the boundary vertex and the polygon formed by another region boundary, the boundary vertex array is subjected to binarization processing, and the region break points are extracted. The relationship between the points and the polygon is determined by the revolution method in the present invention, as shown in fig. 5. Wherein P is an arbitrary point, A₀、A₁、A₂、A₃……A_nIs a polygon vertex; theta₀Is a vector

Rotate to vector

Angle of rotation of position, θ₁Is a vector

Rotate to vector

Angle of rotation of position, θ₂Is a vector

Rotate to vector

Angle of rotation of position, θ_nIs a vector

Rotate to vector

The angle of rotation of the position.

Wherein any point P is connected with each vertex of the polygon in sequence to form a series of vectors

By vectors

Rotate to vector

A series of rotation angles theta are obtained when the position of_nThe counterclockwise rotation direction is defined as positive, and the clockwise rotation direction is defined as negative. Let the coordinates of each point in the graph be P (x, y), A_i(x_i，y_i)、A_i+1(x_i+1，y_i+1)、A₀(x₀，y₀)，When i is more than or equal to 0 and less than or equal to n-1, the ith rotation angle theta can be obtained_i：

N-th rotation angle theta_n：

The coordinate values of each point are substituted into the formula (3) and the formula (4) to obtain: the sum of all rotation angles can then be determined

When θ is 2 π, the vertex is inside the polygon.

(2) Extracting break points and intersecting lines

The validity of each vertex can be judged by using a revolution number method, each vertex correspondingly generates a binary flag bit, if the boundary vertex of a region is in the interior of a polygon formed by the boundary of another region, the boundary vertex of the region corresponds to the binary flag to be 0, and the vertex with the binary flag to be 0 is an invalid vertex; if the boundary vertex of a region is on the outer part or boundary line of a polygon formed by the boundary of another region, the boundary vertex of the region corresponds to a binary flag 1, and the vertex with the binary flag 1 is a valid vertex. The region is broken at the location of the vertex attribute change, i.e., the location of the binary flag change, which may be from 0 to 1 or from 1 to 0. In order to facilitate the region connection directly at the breakpoint position, the effective vertex when the vertex binary flag changes is defined as a region breakpoint. Boundary vertex { A ] of region A in FIG. 3₀，A₁，A₂，A₃，A₄The binary flag array of the symbol is A_A[5]1, 0, 0, 1, and vertex a₀And vertex A₁Between vertex binary flag is changed from 1 to 0, vertex A₂And vertex A₃The binary flag of the middle vertex is changed from 0 to 1, and the effective vertex A is known from the definition of the break point₀And A₃Are all breakpoints. Breakpoint a₀The binary flag at the vertex changes from 1 to 0, i.e. A₀For a valid vertex when changing from valid to invalid, breakpoint A₃At the vertex, the binary flag changes from 0 to 1, i.e. A₃Is the active vertex when changing from inactive to active.

At the disconnection position of the region, the two regions must intersect, and therefore the intersecting line is defined as a line segment formed by the two vertices where the vertex binary flag changes. As defined by the intersecting line, one of the two end points of the intersecting line is the breakpoint of the region, and the other end point is the invalid vertex adjacent to the breakpoint. As shown by the intersection line A in part (b) of FIG. 3₀A₁Of the two vertices of (1), vertex A₀Is the breakpoint of region A, vertex A₁Is an invalid vertex with a binary flag of 0.

(3) Solving for region intersections at intersecting lines

And after the two regions to be solved are subjected to breakpoint segmentation, searching the intersection position and the intersection point of the two regions according to the intersection line. And when the intersection points are simultaneously positioned in two intersecting line segments, the intersection points are effective intersection points, and the two regions intersect at the breakpoint positions of the two intersecting lines.

The intersecting lines are line segments, and the positional relationship between the two line segments mainly includes six cases of parallel non-intersection, parallel intersection, perfect coincidence, parallel inclusion, non-parallel intersection and non-parallel non-intersection. Shown as line segment A in part (a) of FIG. 6_n-1A_nAnd line segment B_n-1B_nThe case of parallel disjointing; as in the case of part (b) and part (d) in fig. 6, it can be solved that there are two intersections for both line segments, and both intersections belong to boundary vertices, and when generating effective intersections, a vertex that is closer to the breakpoint of the active region and is not itself should be extracted as an effective intersection. Assume region B as the active region and the breakpoint as B_n-1Then, the effective intersection points in the part (b) and the part (d) in FIG. 6 are A_nAnd A_n-1. While figure showsIn the case where the two segments in section (c) of 6 completely coincide, there are also two intersections, but the point of intersection itself should be taken as the effective intersection. While the two segments in section (e) of fig. 6 do not intersect in parallel, there must be an intersection point, which is the effective intersection point.

In the solved intersection points, one breakpoint may correspond to a plurality of intersection points, and the intersection point closest to the breakpoint needs to be solved as a connection point for region merging.

(4) Formulating regional reorganization rules

In the process of region merging, a vertex sequence formed by vertexes with the same binary signs is called a connecting segment, the connecting segment with the binary signs of the vertexes being 1 is called an effective connecting segment, and the connecting segment with the binary signs of the vertexes being 0 is called an ineffective connecting segment. The area merging process is to extract the effective connection sections of the two areas, and connect the effective connection sections of the two areas by taking the intersection point as a connection point at the corresponding intersection point position.

The zone boundary line is a vertex sequence formed by connecting a series of vertexes according to a certain sequence, for example, each vertex of the zone A is A₀、A₁、A₂、A₃……A_nSegment A₀A₁、A₁A₂、A₂A₃……A_n-1A_nAnd A_nA₀And the boundary lines of the closed areas A can be formed by connecting the two parts in sequence. The vertexes are connected one by one in sequence, a point is arranged on each of the front side and the rear side of each vertex, every two adjacent boundary lines are intersected at the vertex position, and the non-adjacent boundary lines are not intersected necessarily. When the region boundary is constructed, the region boundary can be drawn by connecting any vertex as a starting point and all the vertices in sequence. Therefore, in order to facilitate the effective connection of the segments of the direct connection region, the vertex arrays are usually reordered, i.e., the vertex arrays are rearranged starting from the break point. As with region A in FIG. 3, the vertex array should be converted to A' 5 before region merging]＝{A₀，A₄，A₃，A₂，A₁Renumbering the vertex, only the point A' 0 is needed to extract the valid connection segment]As a starting point, 3 vertices may be extracted.

In the process of connecting the regions, the number of breakpoints of at least one of the two regions must be the same as the number of all intersection points of the two regions, i.e. the two regions intersect only at the intersection line. When the areas are merged, the areas are divided into two situations of normal area merging and specific area merging according to the number of the broken points of the two areas. The program flow chart is shown in FIG. 7, where region A has m vertices, region B has n vertices, region A has j breakpoints, and the double vertex coordinate array X [2m ] of active region A needs to be input]And Y2 m]Breakpoint index number array N [ i ]]And the intersecting line index number array N₁[2i](ii) a Double vertex coordinate array X' 2n of passive region B]And Y' [2n ]]Breakpoint index number array N' [ j ]]And the intersecting line index number array N₂[2j]。

When the number of the broken points i of the active area A is less than 2, the number of the broken points of the area is an even number, so that i is 0, namely, the active area has no broken point, and because the number of the broken points j of the area B is less than or equal to i, the area B has no broken point, and at the moment, a special area merging rule is adopted to merge the areas to obtain a new area.

When i is larger than or equal to 2, the breakpoint exists in the region A, every two adjacent breakpoints of the region A are divided into one group and are divided into 0.5i groups, and the effective connecting sections between the breakpoints of each group can be combined with the corresponding positions of the passive regions to form a new region. Firstly, the initial index number n of the active region connection segment can be obtained₁＝N[a]With a termination index number n₂＝N[a+1]Break point, break point

Corresponding intersecting line

With index number of two end points of b₁＝N₁[2a]And b₂＝N₁[2a+1]. Solving intersecting lines

The intersection points of all the intersecting lines of the passive region B are found out if the intersection points exist

The closest intersection (x, y) is the final intersection, and the breakpoint index n 'at this time is recorded'₁(ii) a If there is no breakpoint between the intersecting lines of the two regions, solving the intersecting lines

Finding the distance break point at the intersection point of all boundary lines of the passive region B

The closest intersection (x, y) is the final intersection, and the vertex index n 'at that time is recorded'₁. Breaking point can be obtained by the same way

Corresponding intersecting line

With index number of two end points of b₁＝N₁[2a+2]And b₂＝N₁[2a+3]Finding the distance break point

The nearest intersection (x ', y') is taken as the final intersection and the vertex index n 'of the intersection is recorded'₂. And based on the obtained intersection point coordinates and the corresponding vertex index number of the region B, obtaining a new region after combination by using a conventional region combination rule.

The special region merge subroutine is shown in FIG. 8, and requires to input the double vertex coordinate arrays X [2m ] and Y [2m ] of the active region A, and the invalid vertex index number array K [ K ]; the double vertex coordinate arrays X '2 n and Y' 2n for passive region B, and the invalid vertex index number array K 'K'. The rules for special area merging are discussed in four cases:

when solving A ≧ B, when k is 0, that is, all the vertexes of the area A are effective vertexes, the area A is completely located inside the area B, whether the vertexes of the area B are effective or not does not influence the area merging result, and a new area is merged into the area A. When k is not equal to 0, k is m, namely all vertexes of the area A are invalid vertexes, and when k' is 0, namely all vertexes of the area B are valid vertexes, the area B is completely positioned in the area A, and a new area is merged into the area B; when k '≠ 0, k' ═ n, that is, when all the vertices of the region B are invalid vertices, the region a and the region B do not intersect, and the region merging result is an empty set.

When solving A ≠ B, when k ≠ 0, k ═ m, that is, when all vertexes of the region A are invalid vertexes, k ═ 0, all vertexes of the region B must be valid vertexes, and at this time, the region A is completely positioned in the region B, and a new region is merged into the region B. When k is 0, namely all the vertexes of the area A are effective vertexes, and when k' is 0, namely all the vertexes of the area B are effective vertexes, the area A and the area B are not intersected, and two new areas are merged into the area A and the area B; when k '≠ 0, k' ═ n, that is, when all the vertices of the region B are invalid vertices, the region B is completely located inside the region a, and a new region is merged into the region a.

When solving for C_AAnd B, when k is equal to 0, that is, all the vertexes of the area a are effective vertexes, and k' is equal to 0, all the vertexes of the area B must be effective vertexes, and at this time, the area a is completely positioned in the area B, and a hollow area is merged, wherein the inner boundary of the area is the area a, and the outer boundary of the area is the area B. When k is not equal to 0, k is m, namely all vertexes of the area A are invalid vertexes, and when k' is 0, namely all vertexes of the area B are valid vertexes, the area A is outside the area B, the two areas are not intersected, and a new area is merged into the area B; when k '≠ 0, k' ═ n, that is, when all vertices of region B are invalid vertices, region B is completely inside region a, and the merged region is an empty set.

When solving for C_BWhen k ≠ 0, k ═ m, that is, when all the vertices of the region a are invalid vertices, k ═ n, all the vertices of the region B are necessarily invalid vertices, and at this time, the region a is completely located inside the region B, and the merged region is an empty set. When k is 0, namely all the vertexes of the area A are effective vertexes, and when k' is 0, namely all the vertexes of the area B are effective vertexes, the area B is completely positioned in the area A, and a hollow area is merged, wherein the inner boundary of the area is the area B, and the outer boundary of the area is the area BA region A; when k '≠ 0, k' ═ n, that is, when all the vertices of the region B are invalid vertices, the region B is outside the region a, and the two regions do not intersect, and a new region is merged into the region a.

A flow chart of a conventional region merging subroutine is shown in FIG. 9, which requires the input of a double vertex coordinate array X [2m ] of the active region]And Y2 m]Index number n of two breakpoints of active region₁And n₂Region intersection coordinates (x, y) and (x ', y') generated at two breakpoints, vertex index n 'of passive region where corresponding breakpoints with active region generate intersections'₁And n'₂Breakpoint index number array N' j of passive region]Double vertex coordinate array X' 2n of passive region]And Y' [2n ]]Invalid vertex index number array K' of passive region]。

When the region connection is carried out, the effective connection segments of the active region are fixed to have index number values from n₁To n₂And then connecting the intersection points generated at the breakpoints at the two ends to the two ends of the connecting section. The first element of the vertex coordinates array for the new region at this time is X "[ 0 ]]＝x，Y″[0]Y; 1 st to n₂-n₁The coordinate value of +1 vertex is X' [ p +1 ]]＝X[n₁+p]，Y″[p+1]＝Y[n₁+p](ii) a N th₂-n₁The coordinate value of +2 vertexes is X' [ n ]₂-n₁+2]＝x′，Y″[n₂-n₁+2]＝y′。

The connection segment of the passive region depends on the values of the two breakpoints, when n'₁＝n′₂Then let N' [ p ]]＝n′₁I.e. look for n'₁Whether it is an element of the breakpoint index number array for a passive region. When p ≠ -1, n'₁Is the p +1 th element of the breakpoint index number array of the passive region, when N' [ p +1 ]]＝n′₁The p +2 th element of the breakpoint index number array is also n'₁I.e. n'₁Is a double breakpoint, and it is only necessary to connect the breakpoint to the end of the active region active connection segment, i.e. the last vertex coordinate of the new region is X' [ n ]₂-n₁+3]＝X′[n′₁]，Y″[n₂-n₁+3]＝Y′[n′₁](ii) a When N' [ p +1 ]]≠n′₁I.e. n'₁The active region is intersected twice instead of the double breakpoint, and the breakpoint is discarded at this time, and the solved connection segment of the active region is directly used as the vertex coordinate of the new region. N 'when p is-1'₁The breakpoint index number array element is not an element of the breakpoint index number array of the passive region and intersects with the active region twice, and at this time, the solved connection segment of the active region is also directly used as the vertex coordinate of the new region. Is n'₁>n′₂When the reaction is carried out, let K' [ d ]]＝n′₂+1, i.e. find breakpoint n'₂Then index number n'₂Whether the point of +1 is an element of the invalid vertex index number array for the passive region. When d ≠ -1, the index number of the passive region is n'₂The vertex of +1 is an invalid vertex, at which time the passive region effectively links the segment starting index a ═ n'₁End index number b ═ n + n'₂Index number solving flag bit B _c1 is ═ 1; when d is-1, the index number of the passive area is n'₂The vertex of +1 is the active vertex, in which case a ═ n'₂，b＝n′₁，B_c＝-1。

Is n'₁<n′₂When the reaction is carried out, let K' [ d ]]＝n′₁+1. When d ≠ -1, the index number of the passive region is n'₁The point of +1 is an invalid vertex, a ═ n'₂，b＝n+n′₁，B _c1 is ═ 1; when d ═ 1, it is the index number n 'of the passive region'₁The dot of +1 is not an invalid vertex, a ═ n'₁，b＝n′₂，B_c＝-1。

Constructional intermediate variables

Such that B is_cWhen the connecting section of the passive region is equal to-1, the connecting section of the passive region is connected with the connecting section of the active region in a positive direction, namely X' [ n ]₂-n₁+3+p]＝X′[a+p]，Y″[n₂-n₁+3+p]＝Y′[a+p](ii) a When B is present_cWhen the value is 1, the connecting section of the passive region is reversely connected with the connecting section of the active region, namely X' [ n ]₂-n₁+3+p]＝X′[b-p]，Y″[n₂-n₁+3+p]＝Y′[b-p]And finally outputting a boundary vertex coordinate array of the new area.

In the conventional area merging process, a merging result may generate a plurality of new areas, and the subordination relationship between the areas needs to be judged, so that the boundary of the new area is accurately obtained.

When reconstructing the operated coverage area, solving the union of all the operated coverage sub-areas A1-An, wherein when solving A1U A2U … U An, if the merged result is a single area, the new area is a solid area A; if the new region is composed of a plurality of regions, the new region is a region with a plurality of hollow parts, wherein the region with the largest area is the outer boundary of the region, and the other regions are the inner boundaries of a plurality of mutually independent hollow regions. After the hollow areas are combined, the area combination at the next moment is obtained by taking and combining the outer boundary of the hollow area and the operation sub-area An +1 to obtain a new outer boundary of the area; taking the inner boundary and the operation sub-region as C_An+1And A, obtaining the inner boundary of the hollow area of the new operated coverage area.

When reconstructing the effective operation coverage area, the intersection of the operated area a and the area to be operated B needs to be solved, i.e. a ∞ B is solved. When the area A is a solid area, if the combination result is a single area, the combined new area is a solid area C; if the result of the combination is a plurality of regions, the new region is composed of a plurality of mutually independent regions C_nAnd (4) forming. When the region a is a hollow region, the region where the outer boundary of the region a and the region B are merged is the outer boundary of a single solid region or a new hollow region, and the region where the inner boundary of the region a and the region B are merged is the inner boundary of the new hollow region.

When reconstructing the non-operational coverage area, solution C is needed_AB. When the area A is a solid area and the combination result is a single area, the combined new area is a solid area D; if the result of the combination is a plurality of regions, the new region is composed of a plurality of mutually independent regions D_nAnd (4) forming. When the area a is a hollow area, intersection of each inner boundary of the hollow area and the area B to be operated needs to be solved, and solution C is performed on the outer boundary of the hollow area and the area B_AB set, new areaThe domain is composed of all these mutually independent regions D_nAnd (4) forming.

Example three:

as shown in fig. 10, a system for reconstructing a work coverage area in real time based on breakpoint segmentation according to an embodiment of the present invention includes:

a processing module 301, configured to perform binarization processing on boundary vertices of two regions that need to be merged, and divide the boundary vertices into two types, namely effective vertices and invalid vertices, where the effective vertices are vertices used to form a new region boundary after region merging, and the invalid vertices are vertices that cannot be used to form the new region boundary after region merging;

the extraction module 302 is configured to extract breakpoints of the regions according to the effective vertices and the invalid vertices, segment effective connection segments of the two regions according to the breakpoints, obtain intersecting lines of the two regions according to the breakpoints, solve intersection points of the intersecting lines according to the intersecting lines, and use intersection points closest to the breakpoints as connection points for region merging;

and the reconstruction module 303 is configured to connect the effective connection segments of the two regions at the connection point according to the effective connection segments of the two regions, so as to form a new closed region as a result of the real-time region reconstruction.

Example four:

as shown in fig. 11, another system for reconstructing a work coverage area in real time based on breakpoint segmentation according to an embodiment of the present invention includes:

the area boundary information obtaining module 401 is configured to obtain, through the operation parameters of the unmanned aerial vehicle, boundary information of an operation coverage sub-area at a current time and an operation coverage area at a previous time, where the boundary information includes a boundary vertex.

A processing module 402, configured to perform binarization processing on boundary vertices of two regions that need to be merged, and divide the boundary vertices into two types, namely effective vertices and invalid vertices, where the effective vertices are vertices used to form a new region boundary after region merging, and the invalid vertices are vertices that cannot be used to form the new region boundary after region merging;

an extracting module 403, configured to extract breakpoints of the regions according to the effective vertices and the invalid vertices, segment effective connection segments of the two regions according to the breakpoints, obtain intersecting lines of the two regions according to the breakpoints, solve an intersection point of the intersecting lines according to the intersecting lines, and use an intersection point closest to the breakpoints as a connection point for region merging;

a setting module 404, configured to set the valid vertex when the vertex binary flag changes as a region breakpoint.

And a reconstruction module 405, configured to connect the effective connection segments of the two regions at the connection point according to the effective connection segments of the two regions, so as to form a new closed region as a result of the real-time region reconstruction.

The above shows only the preferred embodiments of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. The real-time reconstruction method of the operation coverage area based on breakpoint segmentation is characterized by comprising the following steps:

step 1: performing binarization processing on boundary vertexes of two areas needing to be combined, and dividing the boundary vertexes into an effective vertex and an invalid vertex, wherein the effective vertex is a vertex used for forming a new area boundary after the areas are combined, and the invalid vertex is a vertex which cannot be used for forming the new area boundary after the areas are combined; the binarization processing process correspondingly generates a binary flag for each vertex, the vertex with the binary flag of 0 is an invalid vertex, the vertex with the binary flag of 1 is an effective vertex, and the connecting segment with the binary flags of 1 at the vertex is called an effective connecting segment;

step 2: setting an effective vertex when the vertex binary sign changes as a region breakpoint, extracting the region breakpoint according to the effective vertex and the invalid vertex, segmenting an effective connection section of the two regions according to the breakpoint, obtaining an intersecting line of the two regions according to the breakpoint, solving an intersection point of the intersecting line according to the intersecting line, and taking the intersection point closest to the breakpoint as a connection point for region combination;

2. The method for reconstructing a work coverage area based on breakpoint segmentation in real time according to claim 1, further comprising, before the step 1:

3. The method for reconstructing the operation coverage area in real time based on the breakpoint segmentation as claimed in claim 1, wherein the binarizing processing the boundary vertex of the two areas to be merged is specifically: judging the relation between the boundary vertex of the region and a polygon formed by the boundary of another region by adopting a revolution number method, and carrying out binarization processing on the boundary vertex array of the region; when the union of the two regions is solved, if the boundary vertex of the region is inside the polygon formed by the boundary of the other region, the binary flag corresponding to the boundary vertex of the region is 0, and if the boundary vertex of the region is outside the polygon formed by the boundary of the other region or on the boundary line, the binary flag corresponding to the boundary vertex of the region is 1.

4. The method according to claim 3, wherein the clockwise direction of rotation is positive and the clockwise direction of rotation is negative.

5. The method for reconstructing the work coverage area based on the breakpoint division according to claim 1, wherein the step 3 comprises:

6. The real-time reconstruction system of the work coverage area based on the breakpoint division based on the real-time reconstruction method of the work coverage area based on the breakpoint division according to any one of claims 1 to 5, comprising:

7. The system for real-time reconstruction of a work coverage area based on breakpoint segmentation according to claim 6, further comprising:

8. The system for real-time reconstruction of a work coverage area based on breakpoint segmentation according to claim 6, further comprising: