阅读说明：本技术 一种基于三角剖分的农机作业面积测量方法和测量装置 (Triangulation-based agricultural machinery working area measuring method and measuring device ) 是由 张良 李明 伍滨涛 许永伟 姚立民 张洪铎 胡鹤鸣 张煜 于 2020-11-18 设计创作，主要内容包括：本发明公开了一种基于三角剖分的农机作业面积测量方法和测量装置,方法包括：使用安装有卫星定位接收天线的农机具进行地面作业,通过卫星定位接收天线获取农机具的作业位置数据；对作业位置数据集进行预处理,以剔除其中的误差位置数据,并采用高斯投影正算将作业位置数据集由大地坐标系投影到平面空间坐标系；基于农机具作业的幅宽和最大速度,对作业位置数据集的所有位置点进行区域划分；针对每个区域,均根据区域内所有作业位置数据,采用三角剖分算法对该区域进行三角网格剖分,通过计算每个三角网格的面积得到该区域的面积；累加所有区域的面积获得农机具的作业总面积。本发明适用于全地形的面积测量,且测量精度高。(The invention discloses a triangulation-based agricultural machinery working area measuring method and device, wherein the method comprises the following steps: carrying out ground operation by using an agricultural implement provided with a satellite positioning receiving antenna, and acquiring operation position data of the agricultural implement through the satellite positioning receiving antenna; preprocessing the working position data set to eliminate error position data in the working position data set, and projecting the working position data set from a geodetic coordinate system to a plane space coordinate system by adopting Gaussian projection forward calculation; based on the width and the maximum speed of the agricultural implement operation, all position points of the operation position data set are subjected to region division; aiming at each area, performing triangulation on the area by adopting a triangulation algorithm according to all operation position data in the area, and calculating the area of each triangulation to obtain the area of the area; and accumulating the areas of all the areas to obtain the total operation area of the agricultural implement. The invention is suitable for area measurement of all terrain and has high measurement precision.)

1. An agricultural machinery working area measuring method based on triangulation is characterized by comprising the following steps:

step 1, carrying out ground operation by using an agricultural implement provided with a satellite positioning receiving antenna, and acquiring operation position data of the agricultural implement through the satellite positioning receiving antenna;

step 2, preprocessing the operation position data set to eliminate error position data in the operation position data set, and projecting the operation position data set from a geodetic coordinate system to a plane space coordinate system by adopting Gaussian projection forward calculation;

step 3, performing region division on all position points of the operation position data set based on the operation width and the maximum speed of the agricultural implement;

step 4, aiming at each area, performing triangulation on the area by adopting a triangulation algorithm according to all operation position data in the area, and calculating the area of each triangulation to obtain the area of the area; and accumulating the areas of all the areas to obtain the total operation area of the agricultural implement.

2. The method according to claim 1, wherein in step 4, an improved triangulation algorithm is used to perform triangulation on each region, and the specific triangulation method is as follows:

step 4.1, determining an envelope triangle;

4.1.1, sorting all operation position data in the area according to the abscissa and the ordinate of a plane space coordinate system respectively;

step 4.1.2, taking the minimum abscissa value x_minAnd a minimum ordinate value y_minPoint of composition (x)_min，y_min) As the first point of the diagonal line of the rectangle, taking the maximum abscissa value x therein_maxAnd a maximum ordinate value y_maxPoint of composition (x)_max，y_max) Constructing to obtain a rectangle as a second point of a diagonal of the rectangle;

step 4.1.3, based on the diagonal triangle of the half rectangle, the diagonal triangle is enlarged by one time according to the similar triangle theorem to obtain the hypotenuse passing point (x) of the right triangle A_max，y_max)；

Step 4.1.4, expanding the bottom edge and the height of the right triangle A, and always keeping the length of the bottom edge of the expanded triangle to be larger than the height according to the expansion principle to obtain a right triangle B;

step 4.1.5, the right-angle triangle B is copied along the high symmetry to form an enveloping triangle enveloping all the operation position points in the area;

step 4.2, mesh generation;

storing the three sides of the enveloping triangle into a side cache array;

step 4.3, establishing a triangular mesh by a point-by-point insertion method;

4.3.1, sequencing all operation position points in the area from small to large according to the abscissa to obtain an operation position point sequence; let i be 2;

step 4.3.2, the i-1 st operation position point D in the operation position point sequence is taken_i-1Connecting the triangle with the end point of each edge in the edge cache array, and putting the connected triangles into a temporary triangle list;

step 4.3.3, traversing the triangles in the temporary triangle list to draw the circumscribed circle, and judging the ith operation position point D in the sequence of the circumscribed circle and the operation position point_iThe relationship between: if the operation position point D_iOn the right side of the triangle circumscribed circle, the triangle is a subdivision small triangle, and the triangle is deleted from the temporary triangle list and is stored in the subdivision triangle list; if the operation position point D_iAt the outer side of the circumscribed circle of the triangle, the triangle is not judged at this time and still stored in a temporary triangle list for the (i + 1) th operation position point D_i+1Judging after inserting; if the operation position point D_iAdding three edges of the triangle into an edge cache array on the inner side of the triangle circumscribed circle, and deleting the triangle from the temporary triangle list;

step 4.3.4, making i equal to i +1, returning to step 4.3.2, and until i equal to N, all triangles in the temporary triangle list form a triangulation connection relation of the working position of the agricultural implement in the plane space coordinate system; wherein N is the number of all operation position points in the region;

step 4.4, space triangulation is carried out;

and (4) introducing elevation data of the operating position of the agricultural implement into the triangulation connection relation of the operating position of the agricultural implement in the plane space coordinate system obtained in the step (4.3) to form space triangulation of the operating position point of the agricultural implement.

3. The method according to claim 1, characterized in that step 2 preprocesses the working position data set to reject error position data therein, in particular: acquiring longitude and latitude and altitude data of an area where an agricultural implement working ground is located, and extracting the maximum longitude L in the latitude and altitude data_maxMinimum longitude L_minMaximum latitude B_maxMinimum latitude B_minThe highest altitude H_maxAnd minimum altitude H_min(ii) a The working position data (L, B, H) of each agricultural implement is compared with L_max、L_min、B_max、B_min、H_maxAnd H_minMaking a comparison if L > L_maxOr L < L_minOr B > B_ma□Or B < B_minOr H > H_maxOr H < H_minAnd if so, the operating position data of the agricultural implement has a positioning error and is removed from the operating position data set.

4. The method according to claim 1, wherein step 2 is further to eliminate the working position data and the static working position data with drift positioning error in the working position data set after projecting the working position data set from the geodetic coordinate system to the planar space coordinate system, specifically:

step 2.1, setting the data acquisition period of the satellite positioning receiving antenna as t and the minimum and maximum running speeds of the agricultural implement operation as V respectively_max、V_maxThe positioning precision of the satellite positioning receiving antenna is b;

step 2.2, based on the position relation of the three adjacent operation position points, judging the sum d of the distances of every two adjacent operation position points in the three operation position points₁+d₂From a maximum distance threshold of 2v_maxMagnitude relation of t +3 b:

if d is₁+d₂≤2v_maxt +3b, no drift positioning error exists in the second and third of the three operation position points;

if d is₁+d₂＞2v_maxt +3b, if the three operation position points have drift positioning error points, further judging and determining the operation position points with the drift positioning errors: if v is_maxt-2b＜d₁＜v_maxt +2b and d₂＞v_maxt +2b, a drift positioning error exists at the third operation position point; if d is₁＞v_maxt +2b and v_maxt-2b＜d₂＜v_maxt +2b, the second operation position point has drift positioning error；

Wherein d is₁Is the distance between the first and second of three adjacent working position points, d₂Is the distance between the second and third of the three adjacent work position points;

and 2.3, judging whether the second operation position point is a static position point or not based on the position relation of the adjacent three operation position points: if d is₁+d₂＜2v_mint, the second operation position point is a static position point, and the average value of all adjacent static position points is used as the operation position data of the point;

and 2.4, traversing all three adjacent operation position points, and removing the operation position points and the static position points with the drifting positioning errors from the operation position data set.

5. The method of claim 1, wherein in step 2, the calculation formula for projecting the working position data set from the geodetic coordinate system to the planar space coordinate system is:

in the formula: b is the latitude of the location point, l is the longitude of the location point, l₀Is the central meridian longitude, and N is the radius of curvature of the meridian; a is₀、a₃、a₄、a₅、a₆Are all intermediate quantities of operation;

wherein, all angles are radians, l ═ l-l₀，Arc seconds;

N＝6399 698.902-[21 562.267-(108.973-0.612cosB²)cosB²]cosB²，

a₀＝32 140.404-[135.3302-(0.7092-0.004cosB²)cosB²]cosB²，

a₄＝(0.25+0.002 52cosB²)cosB²-0.041 66，

a₆＝(0.166cosB²-0.084)cosB²，

a₃＝(0.333 3333+0.001123cosB²)cosB²-0.166 6667，

a₅＝0.0083-[0.1667-(0.1968+0.004cosB²)cosB²]cosB²。

6. the method according to claim 1, wherein the step 3 of performing area division on all the location points of the job location data specifically comprises:

step 3.1, setting coordinate values of the working position points of the agricultural implements as (x, y, y); wherein x is the value of the abscissa of the operating position point of the agricultural implement after the Gaussian orthographic projection, y is the value of the ordinate of the operating position point of the agricultural implement after the Gaussian orthographic projection, and h is the altitude value of the operating position point of the agricultural implement;

step 3.2, dividing the three-dimensional space Q where all the working position points of the agricultural implement are located into L side lengths_nIs cubic in space, andf is the data acquisition frequency, V, of the satellite positioning receiving antenna_maxThe maximum running speed of the agricultural implement operation is obtained, and each space cube at least comprises 1 agricultural implement operation position point;

step 3.3, counting the number of the operating position points of the agricultural implement in each space cube, namely the operating position point density of the agricultural implement; removing the operating position points of the agricultural implement from the space cube in which the number of the operating position points of the agricultural implement is less than 1;

step 3.4, searching connected domains in the three-dimensional space Q, wherein each obtained connected domain is 1 region obtained by region division; the number of the agricultural implement operation position points included in each space cube in each communication area is larger than a preset agricultural implement operation position point number threshold value.

7. An agricultural machinery working area measuring device based on triangulation is characterized by comprising a satellite positioning receiving antenna, an antenna positioning support, a memory and a processor; the antenna positioning support is used for fixing the satellite positioning receiving antenna on the top end of an agricultural implement, and the memory is used for storing computer instructions; the processor is configured to execute the computer instructions stored by the memory, in particular to perform the method according to any one of claims 1 to 6.

8. The apparatus of claim 7, wherein the apparatus comprises 2 satellite positioning receiving antennas aligned with the left and right ends of the implement.

9. The device of claim 8, wherein the dual antenna positioning bracket comprises a detachable beam, and the beam is provided with scale marks for distance measurement; the position of the satellite receiving antenna on the beam is adjustable.

10. The apparatus of claim 8, wherein the satellite positioning receiving antenna is configured to receive Beidou satellite positioning data.

Technical Field

The invention belongs to the technical field of agricultural machinery working area measurement, and particularly relates to a triangulation-based agricultural machinery working area measurement method and device.

Background

Precision agriculture is the main direction of agricultural modernization development, and precision agriculture includes the accurate operation of agricultural machinery. Accurate operation of agricultural machinery mainly includes: accurate cultivation, accurate pesticide and fertilizer application, accurate irrigation and accurate harvesting. The monitoring of the operation amount of the accurate operation of the agricultural machine and the quality analysis of the accurate operation of the agricultural machine generally relate to the measurement of the operation area of the agricultural machine, for example, the operation area of the agricultural machine is combined with the usage amount of chemical fertilizers and pesticides, so that the quality analysis of the accurate fertilization and pesticide application operation of the agricultural machine is realized. Therefore, the accurate measurement of the operating area of the agricultural machine has important significance for the development of agricultural modernization.

The existing agricultural machinery operation area measuring equipment is mainly divided into a handheld type and a vehicle-mounted type.

Hand-held type agricultural machinery operation area measurement equipment mainly includes: professional equipment such as tape gauges and total stations and an area measuring instrument based on a satellite navigation positioning system. (1) The tape measure is used for calculating the operation area by measuring the side length of the operation area of the agricultural machine, and the measuring method is only suitable for the farmland with a rule and a small area; (2) professional equipment such as a total station and the like adopts electronic distance measurement and electronic angle measurement technologies to realize farmland area measurement, and the measurement method is complex in calculation, high in cost and suitable for measuring the operation area of agricultural machinery due to the fact that operators of the professional technologies are needed; (3) the area measuring instrument based on the satellite navigation positioning system calculates the agricultural machinery operation area by recording the boundary of the agricultural machinery operation area, a worker needs to hold the measuring instrument to walk around the agricultural machinery operation area for a circle, the workload is increased, the measuring precision has a large relation with the walking speed of the worker, and the measuring method is unstable.

A vehicle-mounted agricultural machinery working area measuring device is mainly a satellite positioning terminal for recording the agricultural machinery working area. Therefore, the measuring method of the vehicle-mounted agricultural machinery working area measuring equipment mainly comprises the following steps: envelope method, track and breadth product method and grid integral method. (1) The envelope method for measuring the working area of the agricultural machine adopts vehicle-mounted satellite positioning equipment and software to measure and calculate the polygonal area of a working area as the working area of the agricultural machine, the measuring method is simple, but the measurement of the working area of the agricultural machine in the hilly and mountainous areas with fluctuant terrain cannot be accurately calculated; (2) on the basis of acquiring the agricultural machine operation track by the track and width product method based on vehicle-mounted satellite positioning equipment and software, the agricultural machine operation area is obtained by utilizing the product of the track length and the width, the measurement method is simple, but the problem of repeated operation cannot be solved by the method; (3) the grid integration method comprises the steps of firstly calculating an operation boundary according to an operation track of the agricultural machine, carrying out grid segmentation on an operation area according to a certain side length, respectively mapping operation position points to corresponding grids, and finally obtaining the operation area of the agricultural machine by counting the product of the number of the operation position points falling in the grids and the area of each grid. The method effectively solves the problem of repeated operation, but the calculation precision is greatly influenced by the selection of the side length of the grid and the operation speed of the agricultural machine, and the calculation amount is overlarge when the operation area is larger.

Disclosure of Invention

Based on the technical problems of the existing agricultural machinery operation area measuring method, the invention provides the agricultural machinery operation area measuring method based on triangulation, which is suitable for area measurement of all terrains and has high measuring precision.

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

an agricultural machinery working area measuring method based on triangulation comprises the following steps:

step 1, carrying out ground operation by using an agricultural implement provided with a satellite positioning receiving antenna, and acquiring operation position data of the agricultural implement through the satellite positioning receiving antenna;

step 2, preprocessing the operation position data set to eliminate error position data in the operation position data set, and projecting the operation position data set from a geodetic coordinate system to a plane space coordinate system by adopting Gaussian projection forward calculation;

step 3, performing region division on all position points of the operation position data set based on the operation width and the maximum speed of the agricultural implement;

step 4, aiming at each area, performing triangulation on the area by adopting a triangulation algorithm according to all operation position data in the area, and calculating the area of each triangulation to obtain the area of the area; and accumulating the areas of all the areas to obtain the total operation area of the agricultural implement.

Further, in step 4, an improved triangulation algorithm is adopted to perform triangulation on each area, and the specific triangulation method is as follows:

step 4.1, determining an envelope triangle;

4.1.1, sorting all operation position data in the area according to the abscissa and the ordinate of a plane space coordinate system respectively;

step 4.1.2, taking the minimum abscissa value x_minAnd a minimum ordinate value y_minPoint of composition (x)_min,y_min) As the first point of the diagonal line of the rectangle, taking the maximum abscissa value x therein_maxAnd a maximum ordinate value y_maxPoint of composition (x)_max,y_max) Constructing to obtain a rectangle as a second point of a diagonal of the rectangle;

step 4.1.3, based on the diagonal triangle of the half rectangle, the diagonal triangle is enlarged by one time according to the similar triangle theorem to obtain the hypotenuse passing point (x) of the right triangle A_max,y_max)；

Step 4.1.4, expanding the bottom edge and the height of the right triangle A, and always keeping the length of the bottom edge of the expanded triangle to be larger than the height according to the expansion principle to obtain a right triangle B;

step 4.1.5, the right-angle triangle B is copied along the high symmetry to form an enveloping triangle enveloping all the operation position points in the area;

step 4.2, mesh generation;

storing the three sides of the enveloping triangle into a side cache array;

step 4.3, establishing a triangular mesh by a point-by-point insertion method;

4.3.1, sequencing all operation position points in the area from small to large according to the abscissa to obtain an operation position point sequence; let i be 2;

step 4.3.2, the i-1 st operation position point D in the operation position point sequence is taken_i-1Connecting the triangle with the end point of each edge in the edge cache array, and putting the connected triangles into a temporary triangle list;

step 4.3.3, traversing the triangles in the temporary triangle list to draw the circumscribed circle, and judging the ith operation position point D in the sequence of the circumscribed circle and the operation position point_iThe relationship between: if the operation position point D_iOn the right side of the triangle circumscribed circle, the triangle is a subdivision small triangle, and the triangle is deleted from the temporary triangle list and is stored in the subdivision triangle list; if the operation position point D_iAt the outer side of the circumscribed circle of the triangle, the triangle is not judged at this time and still stored in a temporary triangle list for the (i + 1) th operation position point D_i+1Judging after inserting; if the operation position point D_iAdding three edges of the triangle into an edge cache array on the inner side of the triangle circumscribed circle, and deleting the triangle from the temporary triangle list;

step 4.3.4, making i equal to i +1, returning to step 4.3.2, and until i equal to N, all triangles in the temporary triangle list form a triangulation connection relation of the working position of the agricultural implement in the plane space coordinate system; wherein N is the number of all operation position points in the region;

step 4.4, space triangulation is carried out;

and (4) introducing elevation data of the operating position of the agricultural implement into the triangulation connection relation of the operating position of the agricultural implement in the plane space coordinate system obtained in the step (4.3) to form space triangulation of the operating position point of the agricultural implement.

Further, step 2 preprocesses the operation position data set to remove error position data therein, specifically: acquiring longitude and latitude and altitude data of an area where an agricultural implement working ground is located, and extracting the maximum longitude L in the latitude and altitude data_maxMinimum longitude L_minMaximum latitude B_maxMinimum latitude B_minThe highest altitude H_maxAnd minimum altitude H_min(ii) a The working position data (L, B, H) of each agricultural implement is compared with L_max、L_min、B_max、B_min、H_maxAnd H_minMaking a comparison if L > L_maxOr L < L_minOr B > B_maxOr B < B_minOr H > H_maxOr H < H_minAnd if so, the operating position data of the agricultural implement has a positioning error and is removed from the operating position data set.

Further, after the operation position data set is projected to a plane space coordinate system from a geodetic coordinate system, the operation position data and the static operation position data with drift positioning errors in the operation position data set are further removed in step 2, specifically:

step 2.1, setting the data acquisition period of the satellite positioning receiving antenna as t and the minimum and maximum running speeds of the agricultural implement operation as V respectively_max、V_maxThe positioning precision of the satellite positioning receiving antenna is b;

step 2.2, based on the position relation of the three adjacent operation position points, judging the sum d of the distances of every two adjacent operation position points in the three operation position points₁+d₂From a maximum distance threshold of 2v_maxMagnitude relation of t +3 b:

if d is₁+d₂≤2v_maxt +3b, no drift positioning error exists in the second and third of the three operation position points;

if d is₁+d₂＞2v_maxt +3b, there is a drift positioning error in the three operation position pointsAnd (3) performing point difference, and further judging and determining the operation position points with the drift positioning errors: if v is_maxt-2b＜d₁＜v_maxt +2b and d₂＞v_maxt +2b, a drift positioning error exists at the third operation position point; if d is₁＞v_maxt +2b and v_maxt-2b＜d₂＜v_maxt+2b，

Then the second operation position point has drift positioning error;

wherein d is₁Is the distance between the first and second of three adjacent working position points, d₂Is the distance between the second and third of the three adjacent work position points;

and 2.3, judging whether the second operation position point is a static position point or not based on the position relation of the adjacent three operation position points: if d is₁+d₂＜2v_mint, the second operation position point is a static position point, and the average value of all adjacent static position points is used as the operation position data of the point;

and 2.4, traversing all three adjacent operation position points, and removing the operation position points and the static position points with the drifting positioning errors from the operation position data set.

Further, in step 2, the calculation formula for projecting the working position data set from the geodetic coordinate system to the plane space coordinate system is as follows:

in the formula: b is the latitude of the location point, l is the longitude of the location point, l₀Is the central meridian longitude, and N is the radius of curvature of the meridian; a is₀、a₃、a₄、a₅、a₆Are all intermediate quantities of operation;

wherein, all angles are radians, l ═ l-l₀，Arc seconds;

N＝6399 698.902-[21 562.267-(108.973-0.612cosB²)cosB²]cosB²，

a₀＝32 140.404-[135.3302-(0.7092-0.004cosB²)cosB²]cosB²，

a₄＝(0.25+0.002 52cosB²)cosB²-0.041 66，

a₆＝(0.166cosB²-0.084)cosB²，

a₃＝(0.333 3333+0.001123cosB²)cosB²-0.166 6667，

a₅＝0.0083-[0.1667-(0.196 8+0.004cosB²)cosB²]cosB²。

further, the step 3 of performing area division on all position points of the operation position data specifically includes:

step 3.1, setting coordinate values of the working position points of the agricultural implements as (x, y, y); wherein x is the value of the abscissa of the operating position point of the agricultural implement after the Gaussian orthographic projection, y is the value of the ordinate of the operating position point of the agricultural implement after the Gaussian orthographic projection, and h is the altitude value of the operating position point of the agricultural implement;

step 3.2, dividing the three-dimensional space Q where all the working position points of the agricultural implement are located into L side lengths_nIs cubic in space, andf is the data acquisition frequency, V, of the satellite positioning receiving antenna_maxThe maximum running speed of the agricultural implement operation is obtained, and each space cube at least comprises 1 agricultural implement operation position point;

step 3.3, counting the number of the operating position points of the agricultural implement in each space cube, namely the operating position point density of the agricultural implement; removing the operating position points of the agricultural implement from the space cube in which the number of the operating position points of the agricultural implement is less than 1;

step 3.4, searching connected domains in the three-dimensional space Q, wherein each obtained connected domain is 1 region obtained by region division; the number of the agricultural implement operation position points included in each space cube in each communication area is larger than a preset agricultural implement operation position point number threshold value.

An agricultural machinery working area measuring device based on triangulation comprises a satellite positioning receiving antenna, an antenna positioning support, a memory and a processor; the antenna positioning support is used for fixing the satellite positioning receiving antenna on the top end of an agricultural implement, and the memory is used for storing computer instructions; the processor is configured to execute the computer instructions stored in the memory, and specifically, to perform the method according to any of the above technical solutions.

Furthermore, the device comprises 2 satellite positioning receiving antennas which are respectively aligned with the left end and the right end of the agricultural implement.

Furthermore, the double-antenna positioning bracket comprises a detachable beam, and the beam is provided with scale marks for distance measurement; the position of the satellite receiving antenna on the beam is adjustable.

Furthermore, the satellite positioning receiving antenna is used for receiving Beidou satellite positioning data.

Further, the dual antenna positioning bracket comprises: the device comprises a Beidou satellite navigation signal receiving antenna support rod (2), a Beidou satellite navigation signal receiving antenna fixing sleeve (3), a Beidou satellite navigation signal receiving antenna support rod fastening bolt (4), a Beidou satellite navigation double-antenna positioning support column fastening bolt (5), a Beidou satellite navigation double-antenna positioning support column fixing sleeve (6), a Beidou satellite navigation double-antenna positioning support column (7), a strong magnetic base (8) supported by the Beidou satellite navigation double-antenna positioning support, a Beidou satellite navigation double-antenna positioning support graduated scale beam (9), a Beidou satellite navigation double-antenna positioning support beam connecting bolt (10) and a Beidou satellite navigation double-antenna positioning support beam connecting sleeve (11);

the Beidou satellite positioning receiving antenna (1) is connected with a Beidou satellite navigation signal receiving antenna support rod (2) through threads, the Beidou satellite positioning receiving antenna support rod (2) is connected with a fixing sleeve (3) of the Beidou satellite navigation signal receiving antenna through threads, a threaded hole is formed in the other end of the fixing sleeve (3) of the Beidou satellite navigation signal receiving antenna, a Beidou satellite navigation signal receiving antenna support rod fastening bolt (4) is screwed to a Beidou satellite navigation double-antenna support graduated scale cross beam (9) through the threaded hole, the fixing sleeve (3) of the Beidou satellite navigation signal receiving antenna is fixed to a proper position of the Beidou satellite navigation double-antenna positioning support graduated scale cross beam (9) through extrusion, and the Beidou satellite positioning receiving antenna (1) is aligned with one end of an agricultural implement;

the top end of a fixing sleeve (6) of a support column of the Beidou satellite navigation double-antenna positioning support is provided with a threaded hole, a fastening bolt (5) of the support column of the Beidou satellite navigation double-antenna positioning support is screwed to a graduated scale cross beam (9) of the Beidou satellite navigation double-antenna support through the threaded hole, and the fixing sleeve (6) of the support column of the Beidou satellite navigation double-antenna support is fixed to a proper position of the graduated scale cross beam (9) of the Beidou satellite navigation double-antenna positioning support through extrusion; the upper end of support column (7) of the big dipper satellite navigation double-antenna positioning support is connected with the fixed cover (6) of the support column of the big dipper satellite navigation double-antenna positioning support through a thread, the lower end of support column (6) of the big dipper satellite navigation double-antenna positioning support is connected with strong magnetic chassis (8) of the support column of the big dipper satellite navigation double-antenna positioning support through a thread, strong magnetic chassis (8) of the support column of the big dipper satellite navigation double-antenna positioning support is closely attracted with the ceiling made of iron material of agricultural implement, so that the big dipper satellite navigation double-antenna positioning support is fixed on the top end of the agricultural implement.

Advantageous effects

The invention has the following technical effects:

(1) by adopting a triangulation area calculation method, the adaptability to agricultural machine operation areas and fluctuating operation areas with different shapes is good, the measurement precision is high, the influence of repeated operation of the agricultural machine on the calculation of the agricultural machine operation area is effectively overcome, and meanwhile, the agricultural machine operation area in hilly and mountain areas is accurately measured;

(2) the measuring method does not need human intervention, has high automation degree, and improves the efficiency of counting and monitoring the working area of the agricultural machine;

(3) the agricultural machine operation position point is reliable, and positioning errors of the agricultural machine operation position point and interference of a static point are effectively overcome through preprocessing and threshold condition judgment;

(4) two points of the double-antenna fixing device are used for supporting and installing the Beidou navigation satellite receiving antenna, so that the installation stability is improved. And the width of the double-antenna fixing device is adjustable, so that two ends of the satellite receiving antenna are aligned with two ends of the agricultural implement, the operation boundary point of the agricultural implement can be accurately obtained, and the calculation precision of the operation area of the agricultural implement is improved.

Drawings

FIG. 1 is a flowchart illustrating the operation of the method of the present embodiment;

fig. 2 is a schematic view of the installation of the satellite receiving antenna according to the embodiment;

FIG. 3 is a view of the Beidou satellite navigation dual antenna and the fixing bracket according to the embodiment;

FIG. 4 is a cross-beam with graduation marks according to the present embodiment;

FIG. 5 is a schematic view of the working position point of the present embodiment;

FIG. 6 is a schematic view of region segmentation in the present embodiment;

FIG. 7 is a triangulation schematic diagram of the present embodiment in a topographic relief area;

FIG. 8 is a diagram showing the formation of an envelope triangle according to the present embodiment;

FIG. 9 shows an envelope triangle circumscribed circle;

FIG. 10 shows a triangle formed by a point and three sides containing it;

fig. 11 shows a triangle circumscribing a circle.

Detailed Description

The following describes embodiments of the present invention in detail, which are developed based on the technical solutions of the present invention, and give detailed implementation manners and specific operation procedures to further explain the technical solutions of the present invention.

The embodiment provides an agricultural machinery working area measuring method based on triangulation, which is characterized in that working position points of agricultural machinery are obtained through a Beidou satellite positioning system and satellite positioning receiving antennas installed at two ends of a double-antenna fixing support, calculation of the working area of the agricultural machinery is achieved based on a working position error point rejecting method, a working area dividing method and a triangulation space dividing method, and the method is shown in a reference figure 1 and mainly comprises the following steps:

step 1, carrying out ground operation by using an agricultural implement provided with a satellite positioning receiving antenna, and acquiring operation position data of the agricultural implement through the satellite positioning receiving antenna.

In the embodiment, the agricultural implement is provided with two satellite positioning receiving antennas which are main sensors for acquiring operation position data of the agricultural implement, and longitude and latitude and height data of an operation position point of the agricultural implement are calculated and acquired by receiving signals transmitted by a plurality of Beidou navigation satellites. The two satellite positioning receiving antennas are fixed to the top end of the agricultural implement through the double-antenna positioning support with the adjustable width, as shown in fig. 2, the two satellite positioning receiving antennas can be used for adjusting the distance between the two satellite positioning receiving antennas, the two satellite positioning receiving antennas are enabled to be respectively aligned with the left end and the right end of the agricultural implement, therefore, boundary points of operation of the agricultural implement can be accurately measured, and the measuring points can cover all position points of operation of the agricultural implement. And traditional single antenna measurement mode only measures the central point of agricultural implement operation, uses the central point to calculate as agricultural machinery operation position point, when agricultural machinery was in farmland border operation, can lose 1/2 machines width's operation position point, therefore agricultural machinery operation area calculated value is less than actual value, reduces agricultural machinery operation area computational accuracy.

Shown in fig. 3 is a big dipper satellite navigation dual antenna positioning support, includes: big dipper satellite navigation signal receiving antenna bracing piece 2, big dipper satellite navigation signal receiving antenna's fixed cover 3, big dipper satellite navigation signal receiving antenna bracing piece fastening bolt 4, the fastening bolt 5 of big dipper satellite navigation double antenna positioning support column, the fixed cover 6 of big dipper satellite navigation double antenna positioning support column, big magnetic base 8 that big dipper satellite navigation double antenna positioning support held, big dipper satellite navigation double antenna positioning support scale crossbeam 9, big dipper satellite navigation double antenna positioning support crossbeam connecting bolt 10, big dipper satellite navigation double antenna positioning support crossbeam adapter sleeve 11.

Big dipper satellite navigation signal receiving antenna 1 links to each other through screw thread and big dipper satellite navigation signal receiving antenna bracing piece 2, big dipper satellite receiving antenna bracing piece 2 links to each other through screw thread and big dipper satellite navigation signal receiving antenna's fixed cover 3, M5 screw hole of the other end design of big dipper satellite navigation signal receiving antenna's fixed cover 3, big dipper satellite navigation signal receiving antenna bracing piece fastening bolt 4 screws to big dipper satellite navigation double antenna support scale crossbeam 9 through M5 screw hole, fix the fixed cover 3 of big dipper satellite navigation signal reception day to the suitable position of big dipper satellite navigation double antenna positioning support scale crossbeam 9 through the extrusion, guarantee that big dipper satellite navigation signal receiving antenna 1 aligns with the one end of agricultural implement. Big dipper satellite navigation signal receiving antenna 1, big dipper satellite navigation signal receiving antenna bracing piece 2, the fixed cover of big dipper satellite navigation signal receiving antenna 3 and big dipper satellite navigation signal receiving antenna bracing piece fastening bolt 4 adopt threaded connection, and the dismouting is simple, conveniently removes big dipper satellite navigation receiving antenna 1's position.

M5 screw hole of fixed cover 6 top design of big dipper satellite navigation double antenna locating support's support column, the fastening bolt 5 of big dipper satellite navigation double antenna locating support column screws to big dipper satellite navigation double antenna support scale crossbeam 9 through M5 screw hole, fixes the fixed cover 6 of big dipper satellite navigation double antenna support's support column to the suitable position of big dipper satellite navigation double antenna locating support scale crossbeam 9 through the extrusion. The upper end of the support column 7 of the Beidou satellite navigation double-antenna positioning support is connected with the fixed sleeve 6 of the support column of the Beidou satellite navigation double-antenna positioning support through threads, the lower end of the support column 7 of the Beidou satellite navigation double-antenna positioning support is connected with the strong magnetic chassis 8 of the support column of the Beidou satellite navigation double-antenna positioning support through threads, and the tractor ceiling is made of iron materials, 8 and the tractor ceiling are in close attraction, so that the Beidou satellite navigation double-antenna positioning support is fixed on the tractor.

Two same compass navigation double-antenna positioning support graduated scale cross beams 9 are used and respectively placed into compass navigation double-antenna positioning support cross beam connecting sleeves 11, and the graduated scale cross beams enter the compass navigation double-antenna positioning support cross beam connecting sleeves by two centimeters. An M8 threaded hole is designed at the upper end of a connecting sleeve 11 of the Beidou satellite navigation double-antenna positioning support beam, and a connecting bolt 10 of the Beidou satellite navigation double-antenna positioning support beam is screwed to a graduated scale beam of the Beidou satellite navigation double-antenna positioning support through an M8 threaded hole and is connected with the two graduated scale beams of the Beidou satellite navigation double-antenna positioning support through extrusion.

Wherein, on two big dipper satellite navigation double antenna positioning support scale crossbeams, all the design has the scale mark as shown in fig. 4, and the distance between per two scale marks is five centimetres, and the distance between every known little check can get the actual width of agricultural implement through big dipper satellite navigation double antenna positioning support scale crossbeam volume, provides accurate data reference for big dipper satellite navigation signal receiving antenna is fixed on big dipper satellite navigation double antenna positioning support scale crossbeam.

Before using agricultural implement operation, fix big dipper satellite navigation double antenna on big dipper satellite navigation double antenna locating support earlier, then install big dipper satellite navigation double antenna locating support in agricultural machine frame, gather agricultural implement operation data.

Fix in big dipper satellite navigation double-antenna and specifically do on big dipper satellite navigation double-antenna locating support: the method comprises the steps of firstly measuring the width of an agricultural implement by using a compass navigation double-antenna positioning support graduated scale beam, and then splicing the two compass navigation double-antenna positioning support graduated scale beams. Under the condition of the known width of an agricultural implement, the mounting position of a Beidou satellite navigation signal receiving antenna is selected on the Beidou satellite navigation double-antenna positioning support graduated scale beam, and the Beidou satellite navigation signal receiving antenna is extruded to the Beidou satellite navigation double-antenna positioning support graduated scale beam 9 through the Beidou satellite navigation signal receiving antenna support rod fastening bolt 4.

Installing big dipper satellite navigation double antenna positioning support in agricultural frame specifically does: the big dipper satellite navigation double-antenna positioning support fixed with the big dipper satellite navigation double-antenna is arranged on the tractor ceiling through the strong magnetic base 8 of the big dipper satellite navigation double-antenna positioning support supporting column.

When the agricultural machinery works in the field, a Beidou satellite navigation receiver board card power supply is connected, Beidou satellite navigation double-antenna collects agricultural machinery operation position data and uploads the agricultural machinery operation position data to the server end for storage, and the Beidou satellite navigation double-antenna measures agricultural machinery operation position points as shown in figure 5.

And 2, preprocessing the operation position data set to eliminate error position data in the operation position data set, and projecting the operation position data set from a geodetic coordinate system to a plane space coordinate system by adopting Gaussian projection forward calculation.

(1) Firstly, removing large positioning error points in the operation position data set:

it is known that users of agricultural implements live in provinces and cities, and obtain provinces and cities where the agricultural implements operate. The longitude, latitude and altitude data of a province where the farm implements are located are obtained by inquiring the longitude, latitude and altitude data of the province, and the maximum longitude L in the longitude, latitude and altitude data is extracted_maxMinimum longitude L_minMaximum latitude B_maxMinimum latitude B_minThe highest altitude H_maxAnd minimum altitude H_min(ii) a The working position data (L, B, H) of each agricultural implement is compared with L_max、L_min、B_max、B_min、H_maxAnd H_minMaking a comparison if L > L_maxOr L < L_minOr B > B_maxOr B < B_minOr H > H_maxOr H < H_minAnd if so, the operating position data of the agricultural implement has a large positioning error and is removed from the operating position data set.

(2) And (3) Gaussian projection forward calculation, converting the operating position point of the agricultural implement from a geodetic coordinate system to a plane space coordinate system:

the surface of the earth is a curved surface, so that the agricultural machinery operation area is accurately measured and calculated, a Gaussian forward calculation is adopted to spread the agricultural machinery operation farmland from the curved surface to form a plane coordinate system, and the calculation error is reduced. And projecting the longitude and latitude coordinates of the operation position of the agricultural machine and the agricultural implement to Gaussian plane coordinates from an ellipsoid through Gaussian projection forward calculation. The Classofsky ellipsoid parameters are adopted, and the Gaussian projection calculation formula is shown as formula (1):

in the formula: b is the latitude of the location point, l is the location pointLongitude of (a), l₀Is the central meridian longitude, and N is the radius of curvature of the meridian; a is₀、a₃、a₄、a₅、a₆Are all intermediate quantities of operation;

wherein, all angles are radians, l ═ l-l₀，Arc seconds;

N＝6399 698.902-[21 562.267-(108.973-0.612cosB²)cosB²]cosB²，

a₀＝32 140.404-[135.3302-(0.7092-0.004cosB²)cosB²]cosB²，

a₄＝(0.25+0.002 52cosB²)cosB²-0.041 66，

a₆＝(0.166cosB²-0.084)cosB²，

a₃＝(0.333 3333+0.001123cosB²)cosB²-0.166 6667，

a₅＝0.0083-[0.1667-(0.196 8+0.004cosB²)cosB²]cosB²。

(3) further removing the operation position data with drift positioning error and static operation position data in the operation position data set, comprising the following steps:

step 2.1, setting the data acquisition period of the satellite positioning receiving antenna as t and the minimum and maximum running speeds of the agricultural implement operation as V respectively_max、V_maxThe positioning precision of the satellite positioning receiving antenna is b;

step 2.2, based on the position relation of the three adjacent operation position points, judging the sum d of the distances of every two adjacent operation position points in the three operation position points₁+d₂From a maximum distance threshold of 2v_maxMagnitude relation of t +3 b:

if d is₁+d₂≤2v_maxt +3b, no drift positioning error exists in the second and third of the three operation position points;

if d is₁+d₂＞2v_maxt +3b, if the three operation position points have drift positioning error points, further judging and determining the operation position points with the drift positioning errors: if v is_maxt-2b＜d₁＜v_maxt +2b and d₂＞v_maxt +2b, a drift positioning error exists at the third operation position point; if d is₁＞v_maxt +2b and v_maxt-2b＜d₂＜v_maxt +2b, a drift positioning error exists at the second operation position point;

wherein d is₁Is the distance between the first and second of three adjacent working position points, d₂Is the distance between the second and third of the three adjacent work position points;

and 2.3, judging whether the second operation position point is a static position point or not based on the position relation of the adjacent three operation position points: if d is₁+d₂＜2v_mint, the second operation position point is a static position point, and the average value of all adjacent static position points is used as the operation position data of the point;

and 2.4, repeating the step 2.2 and the step 2.3, traversing all three adjacent operation position points, and removing the operation position points and the static position points with the drifting positioning errors from the operation position data set.

Step 3, performing region division on all position points of the operation position data set based on the operation width and the maximum speed of the agricultural implement; the method mainly comprises the following steps:

step 3.1, setting coordinate values of the working position points of the agricultural implements as (x, y, y); wherein x is the value of the abscissa of the operating position point of the agricultural implement after the Gaussian orthographic projection, y is the value of the ordinate of the operating position point of the agricultural implement after the Gaussian orthographic projection, and h is the altitude value of the operating position point of the agricultural implement;

the three-dimensional space coordinate system of the agricultural implement operation position point after the Gaussian forward projection is as follows: taking the projection of the central meridian as an ordinate axis X, and setting the north direction of the X axis as positive; taking the projection of the equator as an abscissa axis Y, and setting the Y axis to the east direction as positive; the Z axis and the X, Y axis form a right-hand rule to form a three-dimensional space coordinate system.

Step 3.2, dividing the three-dimensional space Q where all the working position points of the agricultural implement are located into L side lengths_nIs cubic in space, andf is the data acquisition frequency, V, of the satellite positioning receiving antenna_maxThe maximum running speed of the agricultural implement operation is obtained, and each space cube at least comprises 1 agricultural implement operation position point;

step 3.3, counting the number of the operating position points of the agricultural implement in each space cube, namely the operating position point density of the agricultural implement; the density calculation method can reduce the calculation complexity;

because a transition route for the agricultural implement to transition from one region to another region is a non-operation flow, the transition route needs to be removed from the operation position data to improve the accuracy of the operation area measurement. Because the driving speed of the farm implement during the transition is far greater than the maximum operating speed, the method for eliminating the transition route data comprises the following steps: and eliminating the agricultural implement operation position points in the space cube with the number of the agricultural implement operation position points smaller than 1. In this embodiment, the density threshold is set to be 1, the density value smaller than 1 is low density location data, and the density value larger than 1 is high density location data. The low density location data is rejected from within the cell.

Step 3.4, searching connected domains in the three-dimensional space Q, wherein each obtained connected domain is 1 region obtained by region division; the number of the agricultural implement operation position points included in each space cube in each communication area is larger than a preset agricultural implement operation position point number threshold value.

In this embodiment, the cluster of the operating position points of the agricultural implement is a connected region composed of three-dimensional cells with similar densities. In the clustering process, firstly, a cell is randomly selected from three-dimensional cells with determined density as a starting point, space cube cells with density values smaller than 1 are called density similar cells, or space cube cells with density values larger than 1 are called density similar cells. Classifying the space cells according to density, extracting high-density space cells, traversing the adjacent space cells from small to large according to X coordinate values by taking the space cell containing an agricultural machine operation position point and having the smallest X coordinate value as a starting point until no high-density cells are arranged around the traversed cells, and forming a set by the high-density cells, namely an agricultural machine operation area. And traversing all the operating positions of the agricultural implements to complete the division of the operating area of the agricultural implements, as shown in fig. 6.

The agricultural implement operation area is divided, so that the agricultural implement operation position point and the non-agricultural implement operation position point can be automatically identified; if the agricultural machinery operation area is not divided, a non-operation point is introduced to enable the triangulation area value to be larger than the actual value when the next triangulation calculation is carried out.

Step 4, aiming at each area, performing triangulation on the area by adopting a triangulation algorithm according to all operation position data in the area, and calculating the area of each triangulation to obtain the area of the area; and accumulating the areas of all the areas to obtain the total operation area of the agricultural implement.

In this embodiment, an improved triangulation algorithm is used to perform triangulation on each region, and the specific triangulation method is as follows:

step 4.1, determining an envelope triangle;

step 4.1.1, sorting all operation position data in the area according to the abscissa and the ordinate of a plane space coordinate system respectively;

step 4.1.2, see FIG. 8, with the minimum abscissa value x therein_minAnd a minimum ordinate value y_minPoint of composition (x)_min,y_min) As the first point of the diagonal line of the rectangle, taking the maximum abscissa value x therein_maxAnd a maximum ordinate value y_maxPoint of composition (x)_max,y_max) Constructing to obtain a rectangle as a second point of a diagonal of the rectangle;

step 4.1.3, based on the diagonal triangle of the half rectangle, the right-angled triangle is enlarged by one time according to the similar triangle theoremThe hypotenuse of A passes through point (x)_max,y_max) (ii) a The definition of the half rectangle is that the midpoint connecting line of the upper and lower sides of the rectangle in the transverse axis direction is divided into two parts, and the right half rectangle is selected. The diagonal triangle is formed by connecting the upper left vertex and the lower right vertex of the right half rectangle, dividing the right half rectangle into two triangles and selecting the lower left triangle.

Step 4.1.4, expanding the bottom edge and the height of the right triangle A, and always keeping the length of the bottom edge of the expanded triangle to be larger than the height according to the expansion principle to obtain a right triangle B; in this embodiment, a point with the largest abscissa among the vertices of the right triangle a is taken as a starting point, and is located one unit length distance away from the starting point along the negative direction of the ordinate to determine a point E, and then is taken as a starting point and is located two unit lengths away from the point E along the positive direction of the abscissa to determine a point F. And (3) connecting the maximum point of the ordinate in the vertex A of the right triangle with a point F to form the hypotenuse of the extended right triangle, and intersecting a straight line parallel to the abscissa passing through the point F and an extension line of the height of the right triangle to form an extended triangle, namely the obtained right triangle B.

Step 4.1.5, the right-angle triangle B is copied along the high symmetry to form an enveloping triangle enveloping all the operation position points in the area; the enveloping triangle is the largest triangle for each small triangle obtained by subsequent subdivision, and is the smallest triangle enveloping all the operation position points for all the operation position points.

Step 4.2, mesh generation;

storing the three sides of the enveloping triangle into a side cache array; for the convenience of running a computer program, as an initial step of triangulation, the steps are specifically as follows: the enveloping triangles are put into the temporary triangle list, and the circumcircles are traversed to the triangles in the temporary triangle list, as shown in fig. 9: judging whether all the operation position points in the region are in the circumscribed circle of the enveloping triangle, if not, the enveloping triangle is not the subdivision small triangle, and deleting the enveloping triangle from the temporary triangle list;

step 4.3, establishing a triangular mesh by a point-by-point insertion method;

4.3.1, sequencing all operation position points in the area from small to large according to the abscissa to obtain an operation position point sequence; let i be 2;

step 4.3.2, the i-1 st operation position point D in the operation position point sequence is taken_i-1Connecting the end points of the edge cache array with the end points of each edge in the edge cache array, as shown in fig. 10, and putting the connected triangles into a temporary triangle list;

step 4.3.3, traversing the triangles in the temporary triangle list to draw the circumscribed circle, and judging the ith operation position point D in the sequence of the circumscribed circle of the triangles and the operation position points as shown in FIG. 11_iThe relationship between: if the operation position point D_iOn the right side of the triangle circumscribed circle, the triangle is a subdivision small triangle, and the triangle is deleted from the temporary triangle list and is stored in the subdivision triangle list; if the operation position point D_iAt the outer side of the circumscribed circle of the triangle, the triangle is not judged at this time and still stored in a temporary triangle list for the (i + 1) th operation position point D_i+1Judging after inserting; if the operation position point D_iAdding three edges of the triangle into an edge cache array on the inner side of the triangle circumscribed circle, and deleting the triangle from the temporary triangle list;

step 4.3.4, making i equal to i +1, returning to step 4.3.2, and until i equal to N, all triangles in the temporary triangle list form a triangulation connection relation of the working position of the agricultural implement in the plane space coordinate system; wherein N is the number of all operation position points in the region;

step 4.4, space triangulation is carried out;

and (4) introducing elevation data of the operating position of the agricultural implement into the triangulation connection relation of the Gaussian coordinate system of the operating position of the agricultural implement obtained in the step (4.3), forming space triangulation of the operating position point of the agricultural implement, realizing triangulation of a full-terrain triangular grid, and realizing measurement of the operating area of hilly undulating farmland, such as a triangulation surface of an undulating region in the figure 7.

After the space triangulation of each region for the operation of the agricultural implement is obtained, the side length of each small triangle in the region is calculatedAnd calculating the area of the split small triangle by a Helen formula, and summing the area of the split small triangle to obtain the operating area of the agricultural implement in the area. Calculating the agricultural machinery working area of the complex farmland, calculating the side length of each small triangle after being divided, and calculating the area S of each small triangle after being divided by a Helen formula_iAnd adding the areas of the split triangles to obtain the working area S of the agricultural implement in the area.

S＝∑S_i

In the formula: s_iIs the area of a small triangle; a is_i、b_i、c_iThree side lengths of a small triangle; p is a radical of_iIs the half perimeter of a small triangle.

And finally accumulating the areas of all the areas to obtain the total operation area of the agricultural implement.

The above embodiments are preferred embodiments of the present application, and those skilled in the art can make various changes or modifications without departing from the general concept of the present application, and such changes or modifications should fall within the scope of the claims of the present application.