Tillage control method, tillage control system, and tillage control program

Abstract

To reduce a burden of leveling work.SOLUTION: A tillage control method includes determining a reference altitude on the basis of positioning information indicating a first position and a first altitude of a work vehicle at each time when the work vehicle moves on a first field in a first period during which the first field is used as a paddy field, and a second position of the tillage vehicle that performs a tilling operation on the first field in a second period after the first period and before application of water to the first field. The tillage control method also includes determining a tillage depth for the tilling operation on the basis of a difference in altitude between the reference altitude and a second altitude at the second position of the tillage vehicle.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a tillage control method, a tillage control system, and a tillage control program.

Background Art

[0002] When watering a field to use it as a paddy field, a leveling operation is performed to make the height of the ground surface of the field horizontal.

[0003] Patent Document 1 discloses a technique for performing a leveling operation on a field using a laser leveler.

[0004] The leveling operation using a laser leveler is burdensome. For this reason, Patent Document 2 discloses a technique for specifying an area where a leveling operation is required in a field and limiting the area where the leveling operation is performed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When continuously using a field as a paddy field, the workload can be reduced by performing the leveling operation on a part of the field. However, when changing from a dry field to a paddy field, the leveling operation needs to be performed on the entire field. For this reason, even when using the technique of Patent Document 1, the operator may not be able to reduce the burden of the leveling operation.

[0007] In view of the above situation, one of the objectives of the present disclosure is to reduce the burden of the leveling operation. Other objectives can be understood from the following description and the explanation of the embodiments.

Means for Solving the Problem

[0008] The means for solving the problem will be described below using the numbers and symbols used in the embodiments for carrying out the invention. These numbers and symbols are added in parentheses for reference to show an example of the correspondence relationship between the description of the claims and the embodiments for carrying out the invention. Therefore, the claims should not be construed in a limiting manner based on the description in parentheses.

[0009] A tillage control method according to an embodiment for achieving the above object includes determining a reference height based on the positioning information representing the first position (610) and the first height of the work vehicle (30) at each time when the first field (500) is moved at a first time during the period when the first field (500) is used as a paddy field, and the second position (620) of the tillage vehicle (30) that performs the tillage operation on the first field (500) at a second time after the first time and before flooding in the first field (500). The tillage control method also includes determining the tillage depth (700) in the tillage operation based on the height difference (650) between the reference height and the second height at the second position (620) of the tillage vehicle (30).

[0010] A tillage control system (1000) according to an embodiment for achieving the above object includes a reference height determination unit (160, 160B) and a tillage depth determination unit (170). The reference height determination unit (160, 160B) determines the reference height based on the positioning information representing the first position (610) and the first height of the work vehicle (30) at each time when the first field (500) is moved at a first time during the period when the first field (500) is used as a paddy field, and the second position (620) of the tillage vehicle (30) that performs the tillage operation on the first field (500) at a second time after the first time and before flooding in the first field (500). The tillage depth determination unit (170) determines the tillage depth (700) in the tillage operation based on the height difference (650) between the reference height and the second height at the second position (620) of the tillage vehicle (30).

[0011] A tillage control program (400) according to an embodiment for achieving the above object causes an arithmetic unit (120, 220) to determine a reference altitude based on the positioning information representing the first position (610) and the first altitude of the work vehicle (30) at each time when the first field (500) is moved at a first time during a period in which the first field (500) is used as a paddy field, and based on the second position (620) of a tillage vehicle (30) that performs tillage work on the first field (500) at a second time after the first time and before flooding in the first field (500). Further, the tillage control program (400) causes the arithmetic unit (120, 220) to determine a tillage depth (700) in the tillage work based on the altitude difference (650) between the reference altitude and the second altitude at the second position (620) of the tillage vehicle (30).

Advantages of the Invention

[0012] According to the above aspect, the burden of the leveling work by the user can be reduced.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

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Figure 13

[0014] (Embodiment 1) The tillage control system 1000 according to the present embodiment of the present invention will be described with reference to the drawings. In the present embodiment, as shown in FIG. 1, the tillage control system 1000 includes a tillage control device 100 and an information management device 200. The tillage control device 100 is mounted on a tillage vehicle 30 that operates in a farm field 500 and is communicably connected to the tillage vehicle 30. Further, the tillage control device 100 is communicably connected to the information management device 200 via a network 20, for example, the Internet.

[0015] The tillage vehicle 30 performs tillage work while moving in the farm field 500. For example, the tillage vehicle 30 performs tillage work before flooding in a levelled farm field 500 used as a paddy field. For example, as shown in FIG. 2, the tillage vehicle 30 pulls a tillage machine 35, for example, a rotary, that performs tillage work in the farm field 500. For example, the tillage vehicle 30 lowers the tillage machine 35 so as to contact the ground and moves while rotating the claws 36 of the tillage machine 35 to perform work in the farm field 500. Further, when the tillage vehicle 30 is performing tillage work, the rear cover 37 of the tillage machine 35 contacts the ground and flattens the soil agitated by the claws 36.

[0016] The tillage control device 100 includes a positioning device 115 that measures position. The tillage control device 100 is mounted, for example, on the driver's seat of the tillage vehicle 30, and outputs positioning information representing the horizontal position and the vertical altitude of the tillage vehicle 30 moving in the field 500 to the information management device 200. As shown in FIG. 3, the positioning information represents a positioning position 610 indicating the position at each moment on the track 600 along which the tillage vehicle 30 has moved. The positioning position 610 represents the horizontal position and the vertical altitude of the tillage vehicle 30.

[0017] The information management device 200 stores the altitude information of the tillage vehicle 30 when it is moving in the field 500. For example, the information management device 200 stores altitude information representing the altitude of the tillage vehicle 30 at each position when moving in the levelled field 500.

[0018] The field 500 may be used as a dry field after cultivating crops, such as rice, in a paddy field. For example, ridges are provided when the field 500 is used as a dry field. Therefore, unevenness may be provided on the ground surface of the field 500. Thereafter, the field 500 may be used as a paddy field again.

[0019] When the field 500 is used as a paddy field again, before flooding, the tillage vehicle 30 performs tillage work in the field 500. At this time, the tillage control device 100 provided on the tillage vehicle 30 acquires altitude information from the information management device 200.

[0020] For example, as shown in FIG. 4, the tillage vehicle 30 moves on the uneven ground surface 520. Therefore, the altitude of the current position 620 measured by the tillage control device 100 of the tillage vehicle 30 moving on the ground surface 520 represents the altitude on the second positioning altitude 625 corresponding to the height of the tillage vehicle 30 measured on the ground surface 520. On the other hand, since the altitude information acquired from the information management device 200 represents the altitude corresponding to the first positioning altitude 615 of the tillage vehicle 30 when moving on the levelled field 500, it represents a position in a plane close to the horizontal plane corresponding to the levelled field 500.

[0021] The tillage control device 100 determines the tillage depth 700 in tillage operations using the altitude information acquired from the information management device 200. For example, the tillage control device 100 determines the tillage depth 700 based on the current position 620 representing the altitude of the current tillage vehicle 30 and the first surveyed altitude 615 represented in the altitude information. For example, the tillage control device 100 determines the tillage depth 700 based on the altitude difference 650 between the current position 620 and the first surveyed altitude 615. The tillage depth 700 is determined such that it becomes larger as the altitude difference 650 becomes larger. For example, the tillage depth 700 is determined such that the tillage bottom surface 710, which is the lower end of the soil agitated by the tillage vehicle 30, becomes a surface parallel to the first surveyed altitude 615.

[0022] Therefore, for example, the soil on the hill portion 530 of the farm field 500 is moved to the valley portion 540 by the rear cover 37 of the tillage vehicle 30. For example, the soil on the first hill portion 530-1 is moved to the immediately following first valley portion 540-1. Also, the soil on the second hill portion 530-2 is moved to the immediately following second valley portion 540-2. For this reason, the ground surface of the farm field 500 approaches the ground surface when the first surveyed altitude 615 was measured when it was leveled. Thereby, the farm field 500 is leveled. Also, when the soil on the hill portion 530 is agitated, the soil on the hill portion 530 may collapse and move to the valley portion 540 adjacent to the hill portion 530, for example, the immediately preceding valley portion 540.

[0023] In this way, the tillage control system 1000 controls the tillage depth 700 so that the tillage vehicle 30 performs a leveling operation on the farm field 500 using the positioning information of the tillage vehicle 30 during the first period of the period when it is used as a paddy field, for example, in the operation before flooding. Thereby, the operator can level the farm field 500 with less burden than the leveling operation using a laser leveler.

[0024] (Configuration of the tillage control system) The configuration of the tillage control device 100 included in the tillage control system 1000 shown in FIG. 1 will be described. As shown in FIG. 5, the tillage control device 100 includes an input / output device 110, a positioning device 115, an arithmetic device 120, a communication device 130, and a storage device 140. The tillage control device 100 includes, for example, a computer, a tablet, a mobile terminal, and the like. Information for the arithmetic device 120 to execute processing is input to the input / output device 110. Further, the input / output device 110 outputs the result of the processing executed by the arithmetic device 120. The input / output device 110 includes various input devices and output devices, and includes, for example, a keyboard, a mouse, a microphone, a display, a speaker, a touch panel, buttons, lamps, and the like.

[0025] The positioning device 115 may include, for example, a receiver of GNSS (Global Navigation Satellite System), a quantum compass, etc., and acquire positioning information representing the position of the tillage vehicle 30 at each time. The positioning information represents the position of the tillage vehicle 30 in the horizontal direction and the altitude in the vertical direction at each time. The acquired positioning information is output to the arithmetic device 120.

[0026] The communication device 130 is communicably connected to the tillage vehicle 30. For example, the communication device 130 is connected to the tillage vehicle 30 by wire and transfers a signal acquired from the tillage vehicle 30 to the arithmetic device 120. Further, the communication device 130 transfers a signal generated by the arithmetic device 120 to the tillage vehicle 30. The communication device 130 may be directly connected to the tillage vehicle 30 wirelessly, for example, by wireless LAN (Local Area Network), and communicate with the tillage vehicle 30.

[0027] In addition, the communication device 130 is communicably connected to the network 20 and communicates with each device via the network 20. For example, the communication device 130 transfers a signal acquired from the information management device 200 to the arithmetic device 120. Also, it transfers the signal generated by the arithmetic device 120 to the information management device 200. Further, the communication device 130 may acquire information from other devices not connected via the network 20. For example, the communication device 130 may acquire information from other devices via an arbitrary storage medium, such as a memory card, a USB (Universal Serial Bus) memory, etc. The communication device 130 includes various interfaces such as a transceiver used for wireless communication such as a wireless LAN (Local Area Network) or a cellular network, a NIC (Network Interface Card), a USB, and a communication terminal.

[0028] The storage device 140 stores various data for determining the tillage depth 700 when the tillage vehicle 30 performs a leveling operation on the field 500, such as a tillage control program 400. The storage device 140 is used as a non-transitory tangible storage medium for storing the tillage control program 400. The tillage control program 400 may be provided as a computer program product recorded on a computer-readable storage medium 1, or may be provided as a computer program product downloadable from a server.

[0029] The arithmetic device 120 reads and executes the tillage control program 400 from the storage device 140 and performs various data processes for determining the tillage depth 700. For example, the arithmetic device 120 includes a central processing unit (CPU; Central Processing Unit), etc.

[0030] By reading and executing the tilling control program 400, the arithmetic unit 120, as shown in FIG. 6, cooperates with the storage device 140 to realize the information output unit 150, the reference altitude determination unit 160, the tilling depth determination unit 170, and the tilling depth control unit 180. The information output unit 150, in cooperation with the positioning device 115, measures the position of the tillage vehicle 30 at each moment when the tillage vehicle 30 moves during the first period of the period in which the field 500 is used as a paddy field. Further, the information output unit 150 outputs the positioning information representing the measured position to the information management device 200. The reference altitude determination unit 160 determines the reference altitude at the position of the tillage vehicle 30 based on the altitude information of the field 500 acquired from the information management device 200. The tilling depth determination unit 170 determines the tilling depth 700 based on the reference altitude and the altitude of the current position 620 of the tillage vehicle 30. The tilling depth control unit 180 controls the height of the tillage machine 35 of the tillage vehicle 30 to control the tilling depth 700 representing the depth of the soil agitated by the tillage vehicle 30.

[0031] Next, the configuration of the information management device 200 shown in FIG. 1 will be described. As shown in FIG. 7, the information management device 200 includes an input / output device 210, an arithmetic unit 220, a communication device 230, and a storage device 240. The information management device 200 is a computer including, for example, a cloud server or the like. Information for the arithmetic unit 220 to execute processing is input to the input / output device 210. Further, the input / output device 210 outputs the result of the processing executed by the arithmetic unit 220. The input / output device 210 includes various input devices and output devices, and includes, for example, a keyboard, a mouse, a microphone, a display, a speaker, a touch panel, and the like. The input / output device 210 may be omitted.

[0032] The communication device 230 is communicably connected to the network 20 and communicates with each device via the network 20. The communication device 230 transfers, for example, the positioning information acquired from the tillage control device 100 to the arithmetic device 220. Also, it transfers the signal generated by the arithmetic device 220 to the tillage control device 100. Further, the communication device 230 may acquire information from other devices not connected via the network 20. For example, the communication device 230 may acquire information from other devices via an arbitrary storage medium, such as a memory card, a USB (Universal Serial Bus) memory, etc. Also, the communication device 230 may acquire information from other devices directly connected by a USB or the like. The communication device 230 includes various interfaces such as, for example, a NIC (Network Interface Card), a USB, etc.

[0033] The storage device 240 stores various data for determining altitude information representing the altitude at each position when the tillage vehicle 30 moves in the levelled field 500, such as altitude data 410, and an information management program 420. The storage device 240 is used as a non-transitory tangible storage medium for storing the information management program 420. The information management program 420 may be provided as a computer program product recorded on a computer-readable storage medium 2, or may be provided as a computer program product downloadable from a server.

[0034] The altitude data 410 stores altitude information representing the altitude at each position when the tillage vehicle 30 moves in the levelled field 500. The altitude information represents the altitude of the tillage vehicle 30 at a plurality of positions in the field 500 and is represented in association with the corresponding field 500. The altitude data 410 may store information representing the area of each field 500, for example, the range of each field 500 in the horizontal direction.

[0035] The arithmetic unit 220 shown in FIG. 7 reads and executes the information management program 420 from the storage device 240, and performs various data processes for determining high-precision information. For example, the arithmetic unit 220 includes a central processing unit (CPU).

[0036] By reading and executing the information management program 420, the arithmetic unit 220 realizes the information management unit 250 in cooperation with the storage device 240 as shown in FIG. 6. The information management unit 250 stores high-precision data 410. For example, the information management unit 250 stores the positioning information acquired from the tillage control device 100 as high-precision information in the high-precision data 410.

[0037] (Operation of the tillage control system) The operation of the tillage control system 1000 will be described. First, a method for determining the high-precision information stored in the high-precision data 410 will be described. For example, during the first period before flooding in the period when the field 500 is used as a paddy field, the operator starts a drive device of the tillage vehicle 30, such as an engine or a motor, in order to perform tillage work. When the drive device is started, the arithmetic unit 120 of the tillage control device 100 reads and executes the tillage control program 400. When the tillage control program 400 is read and executed, the arithmetic unit 120 executes the process shown in FIG. 8 which is a part of the tillage control method.

[0038] In step S110, the information output unit 150 realized by the arithmetic unit 120 measures the position of the tillage vehicle 30 at each time using the positioning device 115. The information output unit 150 measures a positioning position 610 representing the position of the tillage vehicle 30 in the horizontal direction and the altitude in the vertical direction. For example, the information output unit 150 measures the position of the tillage vehicle 30 at a predetermined interval (for example, at 10-second intervals).

[0039] In step S120, the information output unit 150 outputs the positioning information representing the measured positioning position 610 to the information management device 200. For example, each time the information output unit 150 measures the positioning position 610, it sequentially outputs the positioning information to the information management device 200. Also, the information output unit 150 may sequentially output to the information management device 200 the positioning information representing the positioning positions 610 acquired during that interval at a predetermined interval, for example, an interval longer than the interval at which the position of the tillage vehicle 30 is measured (for example, a 10-minute interval). Further, when the drive device of the tillage vehicle 30 stops, the information output unit 150 may output to the information management device 200 the positioning information representing the positioning positions 610 from when the drive device is started until it stops.

[0040] In step S130, the information management unit 250 of the information management device 200 stores, based on the received positioning information, altitude information representing the altitude of the tillage vehicle 30 at each position in the field 500 in the altitude data 410. For example, the information management unit 250 stores the positioning information associated with the field 500 where the tillage vehicle 30 has performed tillage operations in the altitude data 410 as the altitude information of the field 500. In this case, as shown in FIG. 3, the altitude information represents the altitude of the tillage vehicle 30 at each positioning position 610, for example, the first positioning position 610-1, the second positioning position 610-2, etc. The altitude information may include information representing the trajectory 600 along which the tillage vehicle 30 has moved during the tillage operation.

[0041] Note that the field 500 where the tillage vehicle 30 has performed tillage operations is specified, for example, by the positioning position 610 of the tillage vehicle 30. The information management unit 250 specifies, as the field 500 where tillage operations have been performed by the tillage vehicle 30, the field 500 among those stored in the altitude data 410 that includes the positioning position 610 in its area.

[0042] In this way, the tillage control system 1000 stores the altitude information in the field 500 in the altitude data 410.

[0043] Next, a method for determining the tillage depth 700 of the tillage operation performed for leveling in the uneven field 500 will be described. This method is performed after breaking the ridges when the field 500 was used as a farmland to reduce the unevenness to a certain extent. Also, this method may be performed before breaking the ridges. Further, as shown in FIG. 3, the tillage vehicle 30 moves along the track 600 where the tillage operation was performed in the first period in the leveled field 500 to perform the tillage operation.

[0044] When starting the tillage operation, the operator inputs a setting operation for setting an initial depth representing the depth of stirring the soil at the start of the operation in the field 500 into the input / output device 110 of the tillage control device 100. When the setting operation is input to the input / output device 110, the arithmetic unit 120 of the tillage control device 100 reads and executes the tillage control program 400. When the tillage control program 400 is read and executed, the arithmetic unit 120 executes the process shown in FIG. 9 which is part of the tillage control method.

[0045] In step S210 shown in FIG. 9, the reference altitude determination unit 160 realized by the arithmetic unit 120 requests the altitude information of the field 500 from the information management device 200. For example, the reference altitude determination unit 160 outputs information representing the current position 620 of the tillage vehicle 30 to the information management device 200.

[0046] In step S220, the information management unit 250 of the information management device 200 outputs the altitude information of the field 500 in response to the request from the tillage control device 100. For example, the information management unit 250 identifies the field 500 where the tillage vehicle 30 performs the operation based on the current position 620 of the tillage vehicle 30 acquired from the tillage control device 100. For example, the information management unit 250 identifies the field 500 including the current position 620 of the tillage vehicle 30 as the field 500 where the operation is performed by the tillage vehicle 30. The information management unit 250 outputs the altitude information of the identified field 500 to the tillage control device 100.

[0047] In step S230, the reference altitude determination unit 160 of the tillage control device 100 determines an initial depth representing the depth of stirring the soil at the start of the tillage operation in the field 500. The initial depth represents the tillage depth 700 at the start of the tillage operation, and determines the altitude of the tillage lower end surface 710 in FIG. 4. For example, when starting the tillage operation, the operator inputs to the input / output device 110 the depth of stirring the soil at the position where the tillage vehicle 30 is currently placed. The reference altitude determination unit 160 determines the input depth as the initial depth.

[0048] Note that the tillage vehicle 30 has been moved to the position where the operation started when performing the tillage operation in the levelled field 500, for example, the position where the movement of the track 600 starts. For example, based on the track 600 represented in the altitude information, the reference altitude determination unit 160 displays on the input / output device 110 the position where the operation started when performing the tillage operation in the levelled field 500, for example, the position where the movement of the track 600 starts. The operator moves the tillage vehicle 30 to the displayed position and prepares to perform the tillage operation along the track 600.

[0049] In step S240, the reference altitude determination unit 160 determines a reference altitude based on the altitude information of the field 500 and the current position 620 of the tillage vehicle 30. For example, the reference altitude determination unit 160 determines, in the altitude information of the field 500, the altitude at the current position 620 of the tillage vehicle 30 as the reference altitude. For example, when the current position 620 of the tillage vehicle 30 represents the first positioning position 610-1 shown in FIG. 3, the reference altitude determination unit 160 determines the altitude represented by the first positioning position 610-1 measured in the first period as the reference altitude. For example, the reference altitude determination unit 160 extracts from the altitude information the position closest to the current position 620 in the horizontal direction and determines the altitude at the extracted position as the reference altitude.

[0050] In step S250 shown in FIG. 9, the tillage depth determination unit 170 determines the tillage depth 700 at the current position 620 of the tillage vehicle 30 based on the reference altitude, the altitude of the current position 620, and the initial depth. For example, the tillage depth determination unit 170 determines the tillage depth 700 based on the altitude difference 650 between the reference altitude and the altitude of the current position 620 and the initial depth. For example, the altitude difference 650 represents the difference in altitude of the current position 620 with respect to the reference altitude, and represents the value obtained by subtracting the reference altitude from the altitude of the current position 620. In this case, the tillage depth determination unit 170 determines a larger tillage depth 700 as the altitude difference 650 is larger. For example, the tillage depth determination unit 170 determines the tillage depth 700 using formula (1). [Number] Here, d(t) represents the tillage depth 700 at time t, and Δ(t) represents the altitude difference 650 at time t. Δ(0) represents the altitude difference 650 at the position where the tillage operation starts, and d(0) represents the initial depth.

[0051] For example, in the horizontal direction, when the tillage vehicle 30 is at the same first current position 620-1 as the first positioning position 610-1 at the start of the tillage operation, the reference altitude represents the altitude of the first positioning position 610-1 shown in FIG. 4. The tillage depth determination unit 170 determines the tillage depth 700 at the first current position 620-1 based on the altitude difference 650 between the first current position 620-1 and the first positioning position 610-1, which is the reference altitude, and the initial depth. Here, in formula (1), at the start of the tillage operation, the tillage vehicle 30 is at the altitude of the first current position 620-1 and the reference altitude is the altitude of the first positioning position 610-1. Therefore, Δ(0) represents the altitude difference 650 between the first current position 620-1 and the first positioning position 610-1. Similarly, Δ(t) also represents the altitude difference 650 between the first current position 620-1 and the first positioning position 610-1. For this reason, when the tillage vehicle 30 is at the first current position 620-1, the tillage depth determination unit 170 determines the initial depth d(0) as the tillage depth 700.

[0052] In step S260 shown in FIG. 9, the tillage depth control unit 180 controls the height of the tillage machine 35 of the tillage vehicle 30 so that it becomes the determined tillage depth 700. Thereby, the tillage vehicle 30 performs tillage work at the determined tillage depth 700 at the first current position 620-1.

[0053] In step S270, the tillage depth control unit 180 determines whether the tillage work has ended. For example, when the drive device of the tillage vehicle 30 is stopped, the tillage depth control unit 180 determines that the tillage work has ended. Also, when an operation indicating the end of the tillage work is input to the input / output device 110 by the operator, the tillage depth control unit 180 determines that the tillage work has ended. When the tillage work has ended (YES), the process ends. When the tillage work has not ended (NO), the tillage vehicle 30 moves along the track 600 shown in FIG. 3, the process returns to step S240, and is repeated.

[0054] For example, the process returns to step S240 shown in FIG. 9, and the reference altitude determination unit 160 determines the reference altitude based on the altitude information of the field 500 and the current position 620 of the tillage vehicle 30. For example, as shown in FIG. 4, when the tillage vehicle 30 is moving to the second current position 620-2, the reference altitude determination unit 160 determines the reference altitude at the second current position 620-2. For example, the reference altitude determination unit 160 determines the altitude of the second positioning position 610-2 closest to the second current position 620-2 in the altitude information as the reference altitude.

[0055] In step S250 shown in FIG. 9, the tillage depth determination unit 170 determines the tillage depth 700 at the current position 620 of the tillage vehicle 30 based on the reference altitude, the altitude of the current position 620, and the initial depth. For example, using the above-described mathematical formula (1), the tillage depth determination unit 170 determines d(t) representing the tillage depth 700.

[0056] For example, as shown in FIG. 4, Δ(t) representing the altitude difference 650 represents the altitude of the second current position 620-2 with respect to the altitude of the second positioning position 610-2, and represents a value obtained by subtracting the altitude of the second positioning position 610-2 from the altitude of the second current position 620-2. Also, d(0) represents the initial depth, and Δ(0) represents the altitude of the first current position 620-1 with respect to the altitude of the first positioning position 610-1. Here, since the altitude difference 650 obtained by subtracting the altitude of the second positioning position 610-2 from the altitude of the second current position 620-2 is larger than the altitude difference 650 obtained by subtracting the altitude of the first positioning position 610-1 from the altitude of the first current position 620-1, the tillage depth 700 becomes larger.

[0057] In step S260 shown in FIG. 9, the tillage depth control unit 180 controls the height of the tillage machine 35 of the tillage vehicle 30 to be the determined tillage depth 700. Since the tillage depth 700 becomes larger, the tillage depth control unit 180 controls the height of the tillage machine 35 to decrease with respect to the ground surface 520. Thereby, as shown in FIG. 4, the depth of the soil to be agitated becomes larger than the tillage depth 700 at the first current position 620-1. Therefore, at the second current position 620-2, the depth of the soil to be agitated can reach the tillage lower end surface 710.

[0058] In this way, when the tillage vehicle 30 moves on the ground surface 520, the tillage depth control unit 180 controls to lower the tillage machine 35 with respect to the ground surface 520 at the mountain part 530 where the ground surface 520 is high. Also, the tillage depth control unit 180 controls to raise the tillage machine 35 with respect to the ground surface 520 at the valley part 540 where the ground surface 520 is low. For this reason, the rear cover 37 of the tillage machine 35 moves relatively downward with respect to the ground surface 520 at the mountain part 530 and moves relatively upward with respect to the ground surface 520 at the valley part 540. As a result, the soil at the mountain part 530 moves to the valley part 540, and the unevenness of the farm field 500 is reduced and leveled.

[0059] (Embodiment 2) In Embodiment 1, an example of using positioning information as high-precision information was shown, but the present invention is not limited thereto. For example, as shown in the first positioning altitude 615 in FIG. 4, the tillage control system 1000 may determine the altitude of each position on the track 600 including positions other than the positioning position 610 based on the positioning position 610. For example, the altitude of each position on the track 600 may be represented by an approximate formula of the altitude of the positioning position 610. In this case, the accuracy of the tillage depth 700 at the current position 620 of the tillage vehicle 30 can be improved.

[0060] (Configuration of Tillage Control System) The configuration of the tillage control system 1000 is the same as that of Embodiment 1 except for the reference altitude determination unit 160B realized by the arithmetic unit 120 of the tillage control device 100 and the vehicle altitude determination unit 260 realized by the arithmetic unit 220 of the information management device 200, as shown in FIG. 10. Therefore, detailed descriptions are omitted except for the reference altitude determination unit 160B and the vehicle altitude determination unit 260.

[0061] The reference altitude determination unit 160B determines the reference altitude at the position of the tillage vehicle 30 based on the altitude information of the field 500 acquired from the information management device 200, in the same manner as in Embodiment 1. However, the altitude information is represented by, for example, an approximate formula of the altitude of the positioning position 610.

[0062] The vehicle altitude determination unit 260 determines the altitude of the tillage vehicle 30 at each position on the track 600 based on the positioning position 610 of the tillage vehicle 30 that has performed tillage operations in the levelled field 500. For example, the altitude of the tillage vehicle 30 is represented by an approximate formula. The altitude information representing the altitude of the tillage vehicle 30 at each determined position on the track 600 is stored in the altitude data 410.

[0063] (Operation of Tillage Control System) The operation of the tillage control system 1000 will be described. First, a method for determining the altitude information stored in the altitude data 410 will be described. Similar to the first embodiment, for example, during the first period before flooding in the period when the field 500 is used as a paddy field, the operator starts a driving device of the tillage vehicle 30, such as an engine or a motor, in order to perform tillage work. When the driving device is started, the arithmetic unit 120 of the tillage control device 100 reads and executes the tillage control program 400. When the tillage control program 400 is read and executed, the arithmetic unit 120 executes the process shown in FIG. 11, which is part of the tillage control method.

[0064] Since the process of step S110 and the process of step S120 are the same as those in the first embodiment, the description thereof will be omitted.

[0065] In step S125, the vehicle altitude determination unit 260 determines the altitude at each position of the trajectory 600 based on the positioning information representing each positioning position 610. For example, as shown in FIG. 4, for the moving distance representing the distance traveled by the tillage vehicle 30 since starting the tillage work, an approximate formula representing the positioning position 610 is determined. For example, the approximate formula may represent a linear function. Also, the approximate formula may represent a polynomial. Note that the distance traveled by the tillage vehicle 30 since starting the tillage work is determined by, for example, the length of a line (for example, a plurality of linear line segments) connecting the measured positioning positions 610 in the order in which they are measured while the tillage work is being performed.

[0066] In step S130B shown in FIG. 11, the information management unit 250 stores the determined approximate formula associated with the corresponding field 500 as altitude information in the altitude data 410. The altitude information may include information representing the trajectory 600 along which the tillage vehicle 30 has moved during the tillage work.

[0067] In this way, the tillage control system 1000 stores altitude information representing the altitude at each position of the trajectory 600 along which the tillage vehicle 30 has moved in the field 500 in the altitude data 410.

[0068] Next, a method for determining the tillage depth 700 of the tillage operation performed for leveling in the uneven field 500 will be described. This method is performed after breaking the ridges when the field 500 was used as a field, similar to the first embodiment, to reduce the unevenness to some extent. Also, this method may be performed before breaking the ridges. Further, as shown in FIG. 3, the tillage vehicle 30 moves along the track 600 where the tillage operation was performed in the first period in the leveled field 500 to perform the tillage operation.

[0069] Similar to the first embodiment, when starting the tillage operation, the operator inputs a setting operation for setting an initial depth representing the depth of stirring the soil at the start of the operation in the field 500 to the input / output device 110 of the tillage control device 100. When the setting operation is input to the input / output device 110, the arithmetic unit 120 of the tillage control device 100 reads and executes the tillage control program 400. When the tillage control program 400 is read and executed, the arithmetic unit 120 executes the process shown in FIG. 12 which is part of the tillage control method.

[0070] The processes from step S210 to step S230 are the same as those in the first embodiment, so detailed description thereof will be omitted.

[0071] In step S240B, the reference altitude determination unit 160B determines the reference altitude based on the altitude information of the field 500 and the current position 620 of the tillage vehicle 30, similar to the first embodiment. For example, the reference altitude determination unit 160B determines the altitude at the current position 620 of the tillage vehicle 30 in the altitude information of the field 500 as the reference altitude. For example, the reference altitude determination unit 160B determines the reference altitude based on the approximate formula represented in the altitude information and the distance traveled by the tillage vehicle 30 since starting the tillage operation. For example, the reference altitude determination unit 160B calculates the reference altitude by inputting the distance traveled by the tillage vehicle 30 since starting the tillage operation into the approximate formula represented in the altitude information. The distance traveled by the tillage vehicle 30 since starting the tillage operation is determined, for example, by the length of a line (for example, a plurality of linear line segments) connecting the currently measured positions 620 in the order of measurement while performing the tillage operation.

[0072] The processes from step S250 to step S270 are the same as those in the first embodiment, and thus detailed descriptions thereof are omitted.

[0073] Thereby, the tillage control system 1000 can more accurately determine the reference altitude at the current position 620 that is different from the measured position 610 measured in the horizontal direction. For this reason, the tillage vehicle 30 can perform a more accurate leveling operation.

[0074] (Modification example) The configurations described in the embodiments are examples, and the configurations can be changed as long as the functions are not inhibited. For example, in step S250 shown in FIG. 9 or FIG. 12, the tillage depth determination unit 170 may determine the position to be set to the determined tillage depth 700 based on the horizontal distance 38 between the position where the positioning device 115 is installed and the position where the soil is agitated as shown in FIG. 2. The position measured by the tillage control device 100 is the position where the positioning device 115 is installed. On the other hand, the position to be leveled is the position where the soil is agitated. For this reason, in the horizontal direction, the measured position, for example, the installation position of the positioning device 115 may be different from the position where the soil is actually agitated, for example, the position of the claw 36 of the tillage machine 35. For this reason, in step S250, the tillage depth determination unit 170 may treat the determined tillage depth 700 as the tillage depth 700 at the position where the tillage vehicle 30 has advanced by the distance 38 from the current position 620 of the tillage vehicle 30. For example, when the tillage vehicle 30 is at the second current position 620-2 shown in FIG. 4, the tillage depth determination unit 170 sets the tillage depth 700 determined at this time as the tillage depth 700 when the tillage vehicle 30 reaches the position advanced by the distance 38 from the second current position 620-2. Thereby, when the tillage vehicle 30 advances by the distance 38 from the second current position 620-2, the tillage machine 35 agitates the soil at the second current position 620-2 with the tillage depth 700 corresponding to the second current position 620-2. Thus, more accurate leveling is performed.

[0075] Also, in step S220 shown in FIG. 9 or FIG. 12, the information management device 200 may identify the field 500 where the tilling operation is performed in any method. For example, the field 500 where the tilling operation is performed may be selected by the user. In this case, the reference altitude determination units 160, 160B of the tilling control device 100 display a list of fields 500 on the input / output device 110. The user selects the field 500 for performing the tilling operation from the displayed list. The reference altitude determination units 160, 160B output information representing the selected field 500 to the information management device 200.

[0076] Also, in step S240 shown in FIG. 9, the reference altitude determination unit 160 may determine, in any method, the altitude corresponding to the current position 620 in the horizontal direction from the altitude information as the reference altitude. For example, the reference altitude determination unit 160 may determine the reference altitude based on the moving distance representing the distance that the tilling vehicle 30 has moved along the track 600. For example, the reference altitude determination unit 160 determines the moving distance as the distance that the tilling vehicle 30 has moved based on the length of the line connecting the currently measured positions 620 at each time in the order of measurement. Also, the reference altitude determination unit 160 extracts the positioning position 610 closest to the position where the length of the line connecting the positioning positions 610 measured in the first period in the order of measurement has reached the determined moving distance from the plurality of positioning positions 610. The reference altitude determination unit 160 determines the altitude of the extracted positioning position 610 as the reference altitude.

[0077] Also, the reference altitude determination unit 160 may determine the reference altitude based on the time elapsed since the start of the tilling operation. For example, the reference altitude determination unit 160 determines the elapsed time representing the time elapsed since the tilling vehicle 30 started the tilling operation. The reference altitude determination unit 160 extracts the positioning position 610 measured at the time closest to the time determined by adding the determined elapsed time to the time when the tilling operation started in the first period from the plurality of positioning positions 610. The reference altitude determination unit 160 determines the altitude of the extracted positioning position 610 as the reference altitude.

[0078] Also, in step S125 shown in FIG. 11, the vehicle altitude determination unit 260 may determine, as an approximate expression representing the positioning positions 610, an expression representing a line connecting the positioning positions 610 in the order of the times at which they were measured. For example, the vehicle altitude determination unit 260 may determine, as an approximate expression representing the positioning positions 610, an expression representing a line formed by connecting the positioning positions 610 with straight line segments in the order of the times at which they were measured.

[0079] Further, the vehicle altitude determination unit 260 may determine an approximate expression representing the altitude of the tillage vehicle 30 with respect to the time elapsed since the start of the tillage operation. In this case, in step S240B shown in FIG. 12, the reference altitude determination unit 160 may calculate the reference altitude by inputting the time elapsed since the tillage vehicle 30 started the tillage operation into the determined approximate expression.

[0080] Also, in step S125 shown in FIG. 11, the vehicle altitude determination unit 260 may determine the altitude of the tillage vehicle 30 at each position of the trajectory 600 by any method. For example, using the determined approximate expression, the vehicle altitude determination unit 260 may determine the altitude of the tillage vehicle 30 at a plurality of positions and store the altitudes at the determined plurality of positions in the altitude data 410 as altitude information. Further, the vehicle altitude determination unit 260 may set one or more positions between two adjacent positioning positions 610 at the measured times and determine the altitude at the set one or more positions. For example, the vehicle altitude determination unit 260 sets one or more positions on a straight line segment connecting the first positioning position 610-1 and the second positioning position 610-2 shown in FIG. 3. The vehicle altitude determination unit 260 determines the altitude of the set position based on the altitude of the first positioning position 610-1 and the altitude of the second positioning position 610-2. For example, the vehicle altitude determination unit 260 determines the altitude between the altitude of the first positioning position 610-1 and the altitude of the second positioning position 610-2 as the altitude of the set position. In this way, the vehicle altitude determination unit 260 may determine the altitude of the tillage vehicle 30 at positions other than the positioning positions 610 on the trajectory 600.

[0081] In this case, in step S240B shown in FIG. 12, the reference altitude determination unit 160B may determine the reference altitude at the current position 620 of the tillage vehicle 30 by any method based on the altitude of each position represented by the altitude information. For example, as in step S240 shown in FIG. 9, the reference altitude determination unit 160B may determine, as the reference altitude, the altitude of the position that is closest to the current position 620 in the horizontal direction among the positions represented by the altitude information.

[0082] Also, in step S125 shown in FIG. 11, the vehicle altitude determination unit 260 may determine the altitude of the tillage vehicle 30 at each position of the field 500 based on the positioning position 610. For example, the vehicle altitude determination unit 260 may determine an approximate surface, for example, an approximate plane, representing the altitude of the tillage vehicle 30 at each position of the field 500 based on the positioning position 610. For example, the vehicle altitude determination unit 260 may determine an approximate formula representing the altitude of the tillage vehicle 30 with respect to the position in the first direction in the horizontal plane and the position in the second direction in the horizontal plane that is not parallel to the first direction based on the positioning position 610. For example, the first direction represents the direction in which the latitude line extends, and the second direction represents the direction in which the longitude line extends. Also, the approximate formula may represent a plane or may represent a curved surface by a polynomial.

[0083] Also, as shown in FIG. 13, the vehicle altitude determination unit 260 may determine a plurality of planar divided surfaces 617 representing the altitude of the tillage vehicle 30 in the region divided using the positioning position 610 as an approximate surface representing the altitude of the tillage vehicle 30 at each position of the field 500. For example, the vehicle altitude determination unit 260 performs Delaunay division on the positioning position 610 and determines a divided surface 617 representing the altitude of the tillage vehicle 30 in the region divided by the Delaunay division. The divided surface 617 represents, for example, a plane passing through three vertices of the divided surface 617. For example, the first divided surface 617-1 represents a plane passing through the first positioning position 610-1, the second positioning position 610-2, and the third positioning position 610-3. Note that the Delaunay division represents a process of dividing the convex hull with respect to the positioning position 610 into triangular regions with three positioning positions 610 as vertices so that the positioning position 610 is not included in the interior of the circumscribed circle.

[0084] In this case, in step S240B shown in FIG. 12, the reference altitude determination unit 160B determines the reference altitude at the current position 620 based on the position in the first direction represented by the current position 620 of the tillage vehicle 30 and the position in the second direction. For example, the reference altitude determination unit 160B determines the altitude of the approximate surface or the divided surface 617 at the position in the first direction and the position in the second direction represented by the current position 620 of the tillage vehicle 30 as the reference altitude. Note that, in this case, the tillage vehicle 30 may move on a track different from the track 600.

[0085] Also, the positioning device 115 shown in FIG. 2 may be provided in the vertical direction of the grounding position 39 where the tillage vehicle 30 contacts the ground.

[0086] Also, during the first period of the period when it is used as a paddy field, the vehicle that moves in the leveled field 500 and measures the positioning position 610 is not limited to the tillage vehicle 30, and may be any work vehicle that moves in the leveled field 500. For example, the work vehicle may include a harvester such as a combine that performs work after flooding, a rice transplanter, and the like.

[0087] The embodiments and modifications described above are examples, and the configurations described in each embodiment and modification may be arbitrarily changed or / and arbitrarily combined within a range that does not inhibit the functions. Further, if the required functions can be realized, some of the functions described in the embodiments and modifications may be omitted. For example, a part or all of the processing of the information management device 200 may be executed by the tillage control device 100. Also, a part of the processing of the tillage control device 100 may be executed by the information management device 200. Also, the tillage control device 100 may be incorporated into the tillage vehicle 30. In this case, the arithmetic device 120 of the tillage control device 100 may be an ECU (Electronic Control Unit).

[0088] Also, the tillage control program 400 may include the information management program 420.

[0089] Further, a part of the tillage control device 100, for example, the tillage depth control unit 180, may be provided outside the tillage control system 1000, for example, on the tillage vehicle 30. In this case, the tillage depth determination unit 170 of the tillage control device 100 outputs tillage depth information representing the determined tillage depth 700 and the corresponding position to the tillage vehicle 30. The tillage vehicle 30 controls the height of the tillage machine 35 so as to be the corresponding tillage depth 700 at the position represented by the received tillage depth information according to the received tillage depth information.

[0090] Also, a part of the tillage control device 100 may not be mounted on the tillage vehicle 30 and may wirelessly acquire positioning information from the positioning device 115 mounted on the tillage vehicle 30.

[0091] (Supplementary Note) The tillage control method, the tillage control system, and the tillage control program described in each embodiment can be described as follows.

[0092] The tillage control method according to the first aspect is Based on the positioning information representing the first position and the first altitude of the work vehicle at each moment when the first field is moved at the first time during the period when the first field is used as a paddy field, and a second position of a tillage vehicle that performs tillage work on the first field at a second time after the first time and before flooding in the first field, determining a reference altitude; Determining the tillage depth in the tillage work based on the altitude difference between the reference altitude and the second altitude at the second position of the tillage vehicle; and including.

[0093] The tillage control method according to the second aspect is the tillage control method according to the first aspect, wherein determining the tillage depth is at the second position, determining the tillage depth so that it increases as the value obtained by subtracting the reference altitude from the second altitude in the vertical direction of the tillage vehicle increases. and including.

[0094] The tillage control method according to the third aspect is the tillage control method according to the first or second aspect, wherein the second position represents the position of the tillage vehicle measured when the tillage vehicle moves along the trajectory of the work vehicle when it moves in the first period.

[0095] The tillage control method according to the fourth aspect is the tillage control method according to the third aspect, wherein further includes determining the altitude of the work vehicle at each position of the trajectory based on the first position and the first altitude at each time represented by the positioning information, determining the reference altitude includes determining the reference altitude based on the altitude of the work vehicle at each position of the trajectory and the second position. including.

[0096] The tillage control method according to the fifth aspect is the tillage control method according to the fourth aspect, wherein determining the reference altitude includes determining a second distance that the tillage vehicle has moved from the work start position, and determining, as the reference altitude, the altitude of the position that has moved by the second distance from the work start position in the trajectory determined based on the positioning information. including.

[0097] The tillage control method according to the sixth aspect is the tillage control method according to the first or second aspect, wherein further includes determining the altitude of the work vehicle when it exists at each position of the first field in the first period based on the first position and the first altitude at each time represented by the positioning information including. determining the reference altitude includes determining the reference altitude based on the altitude of the work vehicle when it exists at each position of the first field and the second position. including.

[0098] The tillage control method according to the seventh aspect is the tillage control method according to the sixth aspect, wherein determining the tillage depth includes determining, as the reference height, the height of the work vehicle when it is present at the second position among the heights of the work vehicle when it is present at each position of the first field. is included.

[0099] The tillage control method according to the eighth aspect is the tillage control method according to any one of the first to fourth and sixth aspects, wherein determining the tillage depth includes determining, as the reference height, the height of the work vehicle at the position closest to the second position in the horizontal direction. is included.

[0100] The tillage control method according to the ninth aspect is the tillage control method according to any one of the first to eighth aspects, wherein the work vehicle represents the tillage vehicle.

[0101] The tillage control system according to the tenth aspect includes a reference height determination unit that determines a reference height based on position measurement information representing a first position and a first height of a work vehicle at each time when the first field is moved at a first time during a period when the first field is used as a paddy field, and a second position of a tillage vehicle that performs a tillage operation on the first field at a second time after the first time and before flooding in the first field; a tillage depth determination unit that determines a tillage depth in the tillage operation based on a height difference between the reference height and a second height at the second position of the tillage vehicle; and is provided with.

[0102] The tillage control program according to the eleventh aspect Positioning information representing the first position and the first altitude of the work vehicle at each time when the first field is moved during the first period of the period in which the first field is used as a paddy field, and based on the second position of the tillage vehicle that tills the first field in the second period after the first period and before flooding in the first field, determining a reference altitude; determining the tillage depth in the tillage operation based on the altitude difference between the reference altitude and the second altitude at the second position of the tillage vehicle; causing an arithmetic unit to execute.

Explanation of Signs

[0103] 1, 2: Storage medium 20: Network 30: Tillage vehicle (work vehicle) 35: Tillage machine 36: Claw 37: Rear cover 38: Distance 39: Ground contact position 100: Tillage control device 110: Input / output device 115: Positioning device 120: Arithmetic unit 130: Communication device 140: Storage device 150: Information output unit 160: Reference altitude determination unit 170: Tillage depth determination unit 180: Tillage depth control unit 200: Information management device 210: Input / output device 220: Arithmetic unit 230: Communication device 240: Storage device 250: Information management unit 400: Tillage control program 410: Altitude data 420: Information management program 500: Field 520: Ground surface 530: Hill part 540: Grains section 600: Orbit 610: Position measurement position (first position) 615: First position measurement height 617: Division plane 620: Current position (second position) 625: Second position measurement height 650: Height difference 700: Cultivation depth 710: Lower end surface of cultivation 1000: Cultivation control system

Claims

1. Positioning information representing the first position and the first altitude of the work vehicle at each moment when the first field is moved during the first period within the period when the first field is used as a paddy field, and after the first period and at the second period before flooding in the first field, determining a reference altitude based on the second position of the tillage vehicle that tills the first field; determining the tillage depth in the tillage operation based on the altitude difference between the reference altitude and the second altitude at the second position of the tillage vehicle; A tillage control method comprising the above.

2. Determining the tillage depth comprises, at the second position, determining the tillage depth such that it increases as the value obtained by subtracting the reference altitude from the second altitude of the tillage vehicle in the vertical direction becomes larger. The tillage control method according to claim 1, comprising the above.

3. The second position represents the position of the tillage vehicle measured when the tillage vehicle moves along the trajectory when the work vehicle moves in the first period. The tillage control method according to claim 1 or 2.

4. further comprising determining the altitude of the work vehicle at each position of the trajectory based on the first position and the first altitude at each moment represented by the positioning information; Determining the reference altitude comprises determining the reference altitude based on the altitude of the work vehicle at each position of the trajectory and the second position. The tillage control method according to claim 3, comprising the above.

5. Determining the reference altitude comprises determining the second distance that the tillage vehicle has moved from the work start position; and determining the altitude of the position that has moved the second distance from the work start position in the trajectory determined based on the positioning information as the reference altitude. The tillage control method according to claim 4, comprising the above.

6. further comprising determining the altitude of the work vehicle when it exists at each position of the first field in the first period based on the first position and the first altitude at each moment represented by the positioning information; Determining the reference altitude comprises determining the reference altitude based on the altitude of the work vehicle when it exists at each position of the first field and the second position. The tillage control method according to claim 1 or 2, comprising the above.

7. Determining the tillage depth ​ Determining, as the reference altitude, the altitude of the work vehicle when it is at the second position among the altitudes of the work vehicle when it is at each position in the first field The tillage control method according to claim 6, including this

8. Determining the tillage depth In the horizontal direction, determining, as the reference altitude, the altitude of the work vehicle at the position closest to the second position The tillage control method according to claim 1 or 2, including this

9. The work vehicle represents the tillage vehicle The tillage control method according to claim 1 or 2

10. Positioning information representing the first position and the first altitude of the work vehicle at each time when the first field is moved in the first period during which the first field is used as a paddy field, and a second position of the tillage vehicle that performs the tillage operation on the first field in the second period after the first period and before flooding in the first field. A reference altitude determination unit that determines a reference altitude based on this, A tillage depth determination unit that determines the tillage depth in the tillage operation based on the altitude difference between the reference altitude and the second altitude at the second position of the tillage vehicle A tillage control system comprising this

11. Based on the positioning information representing the first position and the first altitude of the work vehicle at each time when the first field is moved in the first period during which the first field is used as a paddy field, and the second position of the tillage vehicle that performs the tillage operation on the first field in the second period after the first period and before flooding in the first field, determining a reference altitude, Based on the altitude difference between the reference altitude and the second altitude at the second position of the tillage vehicle, determining the tillage depth in the tillage operation, A tillage control program that causes an arithmetic device to execute this

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