WO2022196380A1

WO2022196380A1 - Work area estimation method, work area estimation system, and recording medium storing work area estimation program

Info

Publication number: WO2022196380A1
Application number: PCT/JP2022/009186
Authority: WO
Inventors: 徹士田中
Original assignee: ヤンマーホールディングス株式会社
Priority date: 2021-03-18
Filing date: 2022-03-03
Publication date: 2022-09-22
Also published as: JP7426960B2; KR20230159377A; JP2022143609A; CN116982067A

Abstract

The present invention makes it possible both to suppress the communication load of transmitting positioning information about the working of a field by a work machine and to accurately record a work area. A work area estimation method that involves: using position information that represents a first plurality of points on a path traveled by a work device through a field to calculate a first area that is included in the field and has a first polygonal shape that includes the first plurality of points; using a first distance that is from a first vertex of the first area that is included in the first plurality of points to the outline of the field to change the first vertex to a first outline point that is the closest point on the outline of the field; estimating a second area that has a second polygonal shape that includes a second plurality of points that is the result of the first vertex of the first plurality of points being changed to the first outline point to be a work area that has been worked by the work device; and outputting work area estimate information that represents the estimated work area to the outside.

Description

Recording medium storing work area estimation method, work area estimation system, and work area estimation program

The present invention relates to a work area estimation method, a work area estimation system using this work area estimation method, and a recording medium storing a work area estimation program used by this work area estimation system.

When a work device such as a work vehicle works in a field, it may work only in a part of the work area of the field. In such a case, if the work area in which the work was performed is recorded, the work can be performed later in the remaining area of the field based on this record.

The work area is recorded by, for example, automatically acquiring the positional information of multiple points on the trajectory where the working device has moved, using a positioning device mounted on the working device, and transmitting the acquired positional information to the server via wireless communication. It can be realized by

In order to reduce the load of wireless communication from the work device to the server, it is preferable to keep the amount of location information as small as possible. Therefore, the positioning sampling period in which the positioning device acquires the position information may be relatively long, or only the remaining position information obtained by thinning out part of the acquired position information may be transmitted to the server. However, in such a case, the probability of acquiring position information for a point close to the contour of the field may be lower than the probability of acquiring position information for a point far from the contour of the field. Therefore, in such a case, an area farther from the contour of the field than the actual working area can be recorded in the server as the working area.

In relation to the above, Patent Document 1 (Japanese Patent Application Laid-Open No. 2020-119025) discloses that when an agricultural vehicle such as a tractor performs various agricultural work in a field, the work area and work content in a specific work period, A technique is disclosed in which a worker is linked and recorded as work information in a work information management server, the work information is checked at a later date, and utilized for work evaluation and creation of a work plan.

In addition, in Patent Document 2 (Japanese Patent No. 6767950), a positioning device is installed, and by positioning by GNSS, positioning information obtained by periodically and repeatedly positioning the position of an agricultural vehicle is transmitted to a management server. A method is disclosed in which the data is recorded, the area corresponding to the convex hull is obtained from the positions of the point groups indicated by each of the positioning information on the server side, and this area is specified as the work area.

JP 2020-119025 A Japanese Patent No. 6767950

Provide a work area estimation method, a work area estimation system, and a work area estimation program that achieve both suppression of communication load and accuracy in recording the work area. Other problems and novel features will become apparent from the description of the specification and the accompanying drawings.

According to one embodiment, the work area estimating method includes a first plurality of points included in a field and a first plurality of points, based on position information representing a first plurality of points on a trajectory traveled by the working device in the field. calculating a first region that is a first polygon containing the points of . In the work area estimation method, based on a first distance from a first vertex of a first area included in the first plurality of points to the contour of the field, the first vertex is determined as the nearest point on the contour of the field. Further including changing to contour points. In the work area estimation method, a second area, which is a second polygon including a second plurality of points obtained by changing a first vertex of the first plurality of points to a first contour point, is generated by the work device. Further including estimating as the work area performed. The work area estimation method further includes outputting work area estimation information representing the estimated work area to the outside.

According to one embodiment, a work area estimation system includes a storage device, an area calculation unit, a point change unit, a work area estimation unit, and an output unit. The storage device stores position information representing a first plurality of points on the trajectory to which the working device has moved in the field, and contour information representing the contour of the field. The area calculator calculates a first area that is a first polygon that is included in the farm field and that includes the first plurality of points. Based on a first distance from a first vertex of a first region included in the first plurality of points to the contour of the field, the point changing unit converts the first vertex to the first contour which is the closest point on the contour of the field. Change to location. The work area estimating unit calculates a second area, which is a second polygon including a second plurality of points obtained by changing a first vertex of the first plurality of points to a first contour point, when the work device performs the work. Estimate as the work area performed. The output unit outputs work area estimation information representing the estimated work area to the outside.

According to one embodiment, a recording medium storing a work area estimation program stores a program for realizing predetermined processing by executing the program. This processing is a first polygon that is included in the field and includes the first plurality of points based on the position information representing the first plurality of points on the trajectory along which the working device has moved in the field. Calculating a first region. Based on the first distance from the first vertex of the first area included in the first plurality of points to the contour of the farm field, this process sets the first vertex to the first contour point which is the closest point on the contour of the farm field. further comprising changing to In this process, a second region, which is a second polygon including a second plurality of points in which the first vertices of the first plurality of points are changed to the first contour points, is processed by the work device. Further including estimating as a working area. This process further includes outputting work area estimation information representing the estimated work area to the outside.

According to one embodiment, it is possible to achieve both suppression of the communication load and accuracy in recording the work area.

FIG. 1 is a diagram showing one configuration example of a work area estimation system according to one embodiment. FIG. 2 is a block circuit diagram showing one configuration example of the vehicle-mounted terminal according to one embodiment. FIG. 3 is a block circuit diagram showing one configuration example of the server according to one embodiment. FIG. 4 is a block circuit diagram showing one configuration example of the external terminal according to one embodiment. FIG. 5 is a flowchart showing an operation example of the work area estimation system according to one embodiment, that is, one configuration example of the work area estimation method according to one embodiment, and one configuration of the work area estimation program according to one embodiment. 4 is a flow chart showing an example; FIG. 6A is a diagram showing one state example in the work area estimation method according to one embodiment. FIG. 6B is a diagram showing another state example in the work area estimation method according to one embodiment. FIG. 6C is a diagram showing yet another state example in the work area estimation method according to one embodiment. FIG. 6D is a diagram showing still another state example in the work area estimation method according to one embodiment. FIG. 6E is a diagram showing still another state example in the work area estimation method according to one embodiment. FIG. 7 is a diagram for explaining a threshold calculation method according to an embodiment. FIG. 8 is a diagram for explaining another threshold calculation method according to an embodiment.

With reference to the accompanying drawings, a description will be given below of a form for implementing a recording medium storing a work area estimation method, a work area estimation system, and a work area estimation program according to the present invention.

(Embodiment)
As shown in FIG. 1 , a work area estimation system 1 according to one embodiment includes at least a server 5 . The in-vehicle terminal 3 is mounted on the working vehicle 2 as a working device, and acquires positioning information representing a plurality of points on the trajectory of the working vehicle 2 during work in the field 8 . The work vehicle 2 may be, for example, a tractor equipped with a tillage machine, a rice planter, a combine harvester, a chemical sprayer, or the like. The work performed by the working vehicle 2 in the field 8 may be, for example, plowing, planting, harvesting, pest control, and the like. The server 5 acquires positioning information from the vehicle-mounted terminal 3 via the network 4 . Positioning information is also called location information. The work area estimation system 1 according to one embodiment may further include an in-vehicle terminal 3 .

On the other hand, the photographing device 7 photographs the field 8 from above to generate photographed data. The server 5 acquires photographed data from the photographing device 7 via the network 4, and prepares farm field contour information representing the position of the contour of the farm field 8 based on this photographed data. The server 5 may obtain the field outline information by performing appropriate image processing on the photographed data. The imaging device 7 may be a moving object such as an artificial satellite, a drone, an aircraft, or a vehicle on which the imaging device 7 is mounted. The work area estimation system 1 according to one embodiment may further include an imaging device 7 .

As shown in FIG. 2, the vehicle-mounted terminal 3 according to one embodiment may include a so-called computer. That is, the vehicle-mounted terminal 3 according to one embodiment includes a bus 30 , an arithmetic device 31 , a storage device 32 , an interface 33 , a communication device 34 and a positioning device 35 . Arithmetic device 31 , storage device 32 , interface 33 , communication device 34 and positioning device 35 are communicably connected to each other via bus 30 .

By executing the positioning program 321 stored in the storage device 32 , the arithmetic device 31 controls the positioning device 35 to acquire position information and stores the position information in the storage device 32 . The vehicle-mounted terminal 3 is mounted on the work vehicle 2, and the position information acquired by the positioning device 35 represents the position where the work vehicle 2 was at that time. Further, the computing device 31 controls the communication device 34 and transmits the position information to the server 5 via the network 4 .

The positioning program 321 may be received from the outside via the interface 33 or the communication device 34 and stored in the storage device 32, or may be read from the recording medium 320 and stored in the storage device 32. may be Recording medium 320 may be non-transitory and tangible.

As shown in FIG. 3, the server 5 according to one embodiment may include a so-called computer. That is, the server 5 according to one embodiment includes a bus 50 , an arithmetic device 51 , a storage device 52 , an interface 53 and a communication device 54 . Bus 50 , computing device 51 , storage device 52 , interface 53 and communication device 54 are communicably connected to each other via bus 50 .

The computing device 51 includes an area calculation unit 511 , a point change unit 512 , a work area estimation unit 513 and an output unit 514 . The area calculation unit 511, the point change unit 512, the work area estimation unit 513, and the output unit 514 perform a plurality of processes realized by the arithmetic device 51 executing the work area estimation program 521 stored in the storage device 52. It is a virtual functional part that performs each. Specific functions of the area calculation unit 511, the point change unit 512, the work area estimation unit 513, and the output unit 514 will be described later.

The work area estimation program 521 may be received from the outside via the interface 53 or the communication device 54 and stored in the storage device 52, or may be read from the recording medium 520 and stored in the storage device 52. It can be anything. Recording medium 520 may be non-transitory and tangible. The storage device 52 further stores field contour information and position information.

As shown in FIG. 4, the external terminal 6 according to one embodiment may include a so-called computer. That is, the external terminal 6 according to one embodiment includes a bus 60 , an arithmetic device 61 , a storage device 62 , an interface 63 and a communication device 64 . Arithmetic device 61 , storage device 62 , interface 63 and communication device 64 are communicably connected to each other via bus 60 .

The computing device 61 implements the functions of the external terminal 6 by executing the confirmation program 621 stored in the storage device 62 . Specific functions of the external terminal 6 will be described later.

The confirmation program 621 may be received from the outside via the interface 63 or the communication device 64 and stored in the storage device 62, or may be read from the recording medium 620 and stored in the storage device 62. may be Recording medium 620 may be non-transitory and tangible.

An operation example of the work area estimation system 1 according to one embodiment, that is, one configuration example of the work area estimation method according to one embodiment will be described with reference to the flowchart of FIG. Note that the flowchart of FIG. 5 also represents one configuration example of the work area estimation program 521 according to one embodiment.

The work area estimation method according to one embodiment may be started when the server 5 starts operating, or may be started when the photographing device 7 transmits photographed data to the server 5 .

When the work area estimation method according to one embodiment starts, step S01 is executed. In step S01, the computing device 51 of the server 5 prepares field contour information. By executing the work area estimation program 521 , the calculation device 51 reads the photographed data transmitted from the photographing device 7 and stored in the storage device 52 . The calculation device 51 prepares field contour information representing the contour of the field 8 by performing appropriate image processing on the photographed data. As an example, if the contour of the farm field 8 is a polygon such as a rectangle, the farm field contour information may include the coordinates of each vertex of this polygon and represent the connection relationship of each side of this polygon. May contain information.

After step S01, step S02 is executed. In step S02, the computing device 51 of the server 5 acquires positioning information. The computing device 51 receives the positioning information transmitted from the computing device 31 of the in-vehicle terminal 3 and stores it in the storage device 52 by executing the work area estimation program 521 . The arithmetic unit 31 of the vehicle-mounted terminal 3 stores the positioning information in the storage device 32 while the work vehicle 2 is working, and transmits the entire positioning information to the server 5 at once after the work vehicle 2 completes the work. You may

The positioning information represents a plurality of points 82A to 82O included inside a field contour 81 that is the contour of the field 8, as shown in FIG. 6A. These points 82A-82O are collectively referred to as points 82 when not distinguished.

After step S02, step S03 is executed. In step S<b>03 , the computing device 51 of the server 5 implements the function of the area calculation unit 511 by executing the work area estimation program 521 . The region calculator 511 calculates a region 83 including the point 82 based on the positioning information, as shown in FIG. 6B.

The region 83 may be a polygon containing a set of multiple points 82, or may be a minimal convex polygon containing a set of these multiple points 82, that is, a convex hull. Some of the points 82 are located at vertices of the region 83 . In the example of FIG. 6B, points 82A-82I are located at the vertices of region 83. In the example of FIG. Since the method of calculating the area 83 based on the plurality of points 82 is well known, detailed description thereof will be omitted.

After step S03, step S04 is executed. In step S<b>04 , the computing device 51 of the server 5 executes the work area estimation program 521 to realize the function of changing the point of the point changing unit 512 . As shown in FIG. 6C , the point changing unit 512 detects a point 82B at which the distance to the field contour 81 is shorter than a predetermined first threshold from among the plurality of points 82, and changes the detected point 82B to the field contour 81. Change to contour point 84B, which is the closest point above. A specific method for determining the first threshold will be described later.

At this time, in the example of FIG. 6C, the distances to the field contour 81 are also shorter than the first threshold for the points 82C to 82I. respectively change, i.e. move to The contour points 84B-84I are collectively referred to as the contour points 84 when not distinguished. In other words, the point changing unit 512 changes some of the plurality of points 82 to the contour point 84 that is the nearest point on the farm field contour 81 based on the distance to the farm field contour 81 . In the example of FIG. 6C, the

points

82A, 82J to 82O are not moved because the distance to the field outline 81 is equal to or greater than the first threshold.

A set of the plurality of points 82 and the contour points 84 is hereinafter referred to as a point set for convenience. The point set may or may not include points 82 that have been moved to contour points 84 among the plurality of points 82 .

Further, as shown in FIG. 6D, the point changing unit 512 determines that the distance to two contour points 84 on each of the two farm field sides intersecting the contour vertex of the contour vertex of the field contour 81 is Any contour vertex shorter than a predetermined second threshold is detected and added to the point set. A specific method for determining the second threshold will be described later.

In the example of FIG. 6D , the point changing portion 512 is positioned on one of two contour sides intersecting the contour vertex 851 from among the plurality of contour points 84, and the distance to the contour vertex 851 is is less than a second predetermined threshold. Further, the point change portion 512 is positioned on the other of the two contour side portions that intersect the contour vertex 851 and is the same distance to the contour vertex 851 from among the plurality of contour points 84 . Detect contour points 84E that are shorter than the threshold. The point changer 512 adds the contour vertex 851 to the point set.

Similarly, the point change portion 512 is positioned on one of two contour sides intersecting the contour vertex 852 from among the plurality of contour points 84, and the distance to the contour vertex 851 is a predetermined distance. Detect contour points 84G that are shorter than a second threshold. Further, the point change portion 512 is positioned on the other of the two contour side portions that intersect the contour vertex 852 and is the same distance to the contour vertex 852 from among the plurality of contour points 84 . Detect contour points 84H that are shorter than the threshold. At this time, the point changing unit 512 adds the contour vertex 852 to the point set.

After step S04, step S05 is executed. In step S<b>05 , the computing device 51 of the server 5 implements the function of estimating the work of the work area estimation unit 513 by executing the work area estimation program 521 . The work area estimation unit 513 calculates an area 86 including a plurality of points 82 included in the point set, contour points 84, and

contour vertices

851 and 852, as shown in FIG. 6E. The method for calculating the area 86 is the same as the method for calculating the area 83 in step S03.

In other words, the work area estimation system 1 according to one embodiment uses the work area estimation method according to one embodiment and the work area estimation program 521 according to one embodiment. Assume that area 86 has been worked on. In addition to the area 83 calculated based on the points 82 from which the positioning information was obtained, the area 86 also includes the area around the field contour 81 .

Generally, the work in the field 8 by the work vehicle 2 is also performed in the area around the field contour 81 . In other words, the possibility of working only in the central area of the field 8 and not working in the area around the field outline 81 is reduced. However, even if the work is performed around the field contour 81, if the sampling period for acquiring the positioning information is relatively long, the probability of acquiring the positioning information in the region around the field contour 81 is lower than the probability in the area. Even in such a case, according to one embodiment, an area 86 that automatically includes an area around the field outline 81 from which positioning information is difficult to obtain can be estimated as the work area.

After step S05, step S06 is executed. In step S<b>06 , the computing device 51 of the server 5 implements the function of the output unit 514 by executing the work area estimation program 521 . The output unit 514 controls the communication device 54 of the server 5 to transmit work area estimation information representing the area 86 to the external terminal 6 via the network 4 . In other words, the output unit 514 outputs work area estimation information.

The external terminal 6 is, for example, a tablet terminal owned by the user who performed the work. When the computing device 61 of the external terminal 6 receives the work area estimation information via the communication device 64 , it executes the confirmation program 621 stored in the storage device 62 . The computing device 61 displays the region 86 represented by the work region estimation information on the display device included in the interface 63 . In other words, the computing device 61 visually outputs the work area estimation information. At this time, the area 86 may be displayed together with map information representing the farm field 8 .

The user confirms the area 86 displayed on the display device of the external terminal 6, and performs an operation to recognize the area 86 as the work area when approving it. Alternatively, the user may correct the area 86 and then perform an operation to recognize the corrected area 86 as the work area. In either case, these operations by the user are performed using an input device such as a touch panel or buttons included in the interface 63 of the external terminal 6, for example.

The computing device 61 of the external terminal 6 generates a response signal based on the user's operation, and controls the communication device 64 to transmit the response signal to the server 5 . The response signal may contain information for recognizing area 86 as a work area, or may contain information for modifying area 86 .

After step S06, step S07 is executed. In step S07, when the output unit 514 of the server 5 receives the response signal transmitted from the external terminal 6, the area information representing the area represented according to the content of this response is used as the work area information representing the work area. Record in the storage device 52 . That is, in step S06, if the user approves the area 86 estimated by the work area estimation unit 513 of the server 5, the area 86 is recorded as the work area as it is. On the contrary, in step S06, when the user modifies the area 86, the work area information representing the modified area 86 as a work area is recorded.

A method for determining the first threshold used in step S04 will be described with reference to FIG. When the work vehicle 2 performs work near the field contour 873, it moves from the point 871 in a direction approaching the field contour 873, changes its movement direction near the field contour 873, and moves in a direction away from the field contour 873. and reaches point 872 . Here, the distance when the positioning point from which the positioning information is acquired is the farthest from the field contour 873 is that the positioning information is acquired at a point 871 and a point 872 at the same distance 874 from the field contour 873, and between It is the distance 874 when the positioning information is not acquired.

In general, the movement speed of the work vehicle 2 is slower in the peripheral area of the field outline 873 than in the central part of the field 8 . This is because the work vehicle 2 changes direction in the peripheral area of the field contour 873 . Therefore, the distance 874 is determined based on the moving speed of the work vehicle 2 in the peripheral area of the field outline 873 . The peripheral area of the field contour 873 may be defined as a first range from the field contour 873 to a predetermined first distance.

As an example, when the average moving speed of the work vehicle 2 in the peripheral area of the field contour 873 is 0.5 m/s (meters per second) and the sampling period of the positioning information is 1 minute, the work vehicle 2 Move 30 m (meters) between sampling periods. When the trajectory of the work vehicle 2 turns back at the field contour 873, the positioning points are farthest from the field contour 873 when positioning is performed at

points

871 and 872 that are 15 m from the field contour 873. Here, the safety factor may be set to about 70% and the first threshold may be determined to be 10m.

A method for determining the second threshold used in step S04 will be described with reference to FIG. When the work vehicle 2 performs work near the top of the field where the

field contours

884 and 885 intersect, the work vehicle 2 moves along the field contour 885 from the point 881 in a direction approaching the field contour 884 and moves toward the field contour 884 near the field contour 884. It changes direction of travel away from 885 and travels away from field contour 884 and parallel to field contour 885 until point 882 is reached. The work vehicle 2 may then change direction further at another location, move parallel to the field contour 885 , pass the point 883 and approach the field contour 884 again.

Generally, the movement speed of the work vehicle 2 in the peripheral area of the field vertex is slower than the movement speed in the peripheral area of the

field contours

884 and 885 . Therefore, the second threshold is determined as a distance shorter than the first threshold based on the moving speed of the work vehicle 2 in the peripheral area of the vertex of the field. In addition, the peripheral area of the field vertex may be defined as a second range from the field vertex to a predetermined second distance.

As an example, when the movement speed of the work vehicle 2 near the vertex of the field is 0.3 m/s and the sampling period of the positioning information is 1 minute, the work vehicle 2 moves 18 m during one sampling period. do. As in the calculation example of the first threshold value, when the trajectory of the work vehicle 2 turns back at the field contour 884, the positioning points are the farthest from the field contour 884 at

points

881 and 882 at a distance of 9 m from the field contour 884. , 883. Here, the safety factor may be set to about 70% and the second threshold may be determined to be 6m.

Note that the second threshold may be determined or adjusted further based on the vehicle width of the work vehicle 2. In the example of FIG. 8, when the vehicle width of the work vehicle 2 is 2 m, the distance 886 between the parallel tracks on which the work vehicle 2 reciprocates is also 2 m, and the second threshold is 6 m, which is three times this distance. , the second threshold is considered reasonable. In other words, the second threshold may be adjusted such that the ratio between the width of the work vehicle 2 and the second threshold falls within a predetermined range.

As described above, according to one embodiment, it is possible to achieve both suppression of the communication load and accuracy in recording the work area.

In one embodiment, an example in which the working vehicle 2 as a working device works in the field 8 has been described, but one embodiment is not limited to this example. For example, drones and helicopters may be used as working devices.

In one embodiment, an example in which step S02 is executed after step S01 has been described, but one embodiment is not limited to this example. For example, step S01 may be executed after step S02, or at least part of step S01 and step S02 may be executed simultaneously.

In one embodiment, an example in which the computing device 51 of the server 5 receives the positioning information in step S02 has been described, but one embodiment is not limited to this example. For example, the positioning information may be stored in the storage device 52 before the work area estimation method is started, and the arithmetic device 51 may acquire the positioning information by reading it from the storage device 52 in step S02.

In one embodiment, in step S02, the calculation device 31 of the vehicle-mounted terminal 3 transmits the entire positioning information to the server 5 at once, but the embodiment is not limited to this example. For example, the computing device 31 may thin out part of the positioning information and transmit only the remaining positioning information to the server 5 . Further, the computing device 31 may sequentially transmit the positioning information to the server 5 before the work vehicle 2 completes the work.

Although the invention made by the inventor has been specifically described above based on the embodiment, it should be noted that the invention is not limited to the embodiment, and that various modifications can be made without departing from the gist of the invention. Not even. Moreover, each feature described in the embodiments can be freely combined within a technically consistent range.

This application claims priority based on Japanese Patent Application No. 2021-44217 filed on March 18, 2021, and incorporates all of its disclosure herein.

Claims

A first polygon that is included in the agricultural field and includes the first plurality of points, based on the position information representing the first plurality of points on the trajectory to which the working device has moved in the agricultural field. calculating an area;
Based on a first distance from a first vertex of the first area included in the first plurality of points to the contour of the farm field, the first vertex is the first closest point on the contour of the farm field. changing to a contour point;
The work device worked on a second area which is a second polygon including a second plurality of points obtained by changing the first vertex of the first plurality of points to the first contour point. estimating as a working area;
and outputting work area estimation information representing the estimated work area to an external device.
In the work area estimation method according to claim 1,
Said changing includes:
A method for estimating a work area, comprising changing said first vertex to said first contour point when said first distance is less than a first predetermined threshold.
In the work area estimation method according to claim 2,
Said changing includes:
A method of estimating a work area, further comprising determining the first threshold based on a first movement speed of the work device in a first range from the contour of the field to a second predetermined distance.
In the work area estimation method according to claim 2 or 3,
based on a third distance from a second vertex of the first area included in the first plurality of points to the contour of the farm field, the second vertex being the closest point on the contour of the farm field; further comprising changing to 2 contour points;
Said estimating is
The first contour point is on the first contour side of a plurality of contour sides that intersect with the first contour vertex of the contour in the agricultural field, and the first contour point is located on the first contour side. A fourth distance to a vertex is shorter than a second predetermined threshold, and the second contour point is on a second contour side of the plurality of contour sides that is different from the first contour side, and and adding said first contour vertex to said second plurality of points when a fifth distance from said second contour point to said first contour vertex is less than said second threshold.
In the work area estimation method according to claim 4,
Changing the second vertex to the second contour point includes:
changing the second vertex to the second contour point when the third distance is less than the first threshold.
In the work area estimation method according to claim 4 or 5,
Said estimating is
A method for estimating a work area, further comprising determining the second threshold based on a second movement speed of the work implement in a second range from the first contour vertex to a predetermined sixth distance.
In the work area estimation method according to any one of claims 1 to 6,
The work area estimation method, wherein the second area is a convex hull as a minimum convex polygon including the second plurality of points.
In the work area estimation method according to any one of claims 1 to 7,
A method for estimating a work area, further comprising: recording area information representing the area represented in the content of the response to the output as work area information.
a storage device for storing position information representing a first plurality of points on a trajectory to which the working device has moved in a field and contour information representing the contour of the field;
an area calculation unit that calculates a first area that is a first polygon that is included in the agricultural field and that includes the first plurality of points;
Based on a first distance from a first vertex of the first area included in the first plurality of points to the contour of the farm field, the first vertex is the closest point on the contour of the farm field. a point changing unit that changes to one contour point;
The work device worked on a second area which is a second polygon including a second plurality of points obtained by changing the first vertex of the first plurality of points to the first contour point. a work area estimating unit for estimating a work area;
A work area estimation system, comprising: an output unit that outputs work area estimation information representing the estimated work area to the outside.
A recording medium storing a program for realizing a predetermined process by executing it,
The processing is
A first polygon that is included in the agricultural field and includes the first plurality of points, based on the position information representing the first plurality of points on the trajectory to which the working device has moved in the agricultural field. calculating an area;
Based on a first distance from a first vertex of the first area included in the first plurality of points to the contour of the farm field, the first vertex is the first closest point on the contour of the farm field. changing to a contour point;
The work device worked on a second area which is a second polygon including a second plurality of points obtained by changing the first vertex of the first plurality of points to the first contour point. estimating as a working area;
and outputting to the outside work area estimation information representing the estimated work area. A recording medium storing a work area estimation program.