Field check method and field check system

Abstract

To provide a field confirmation method and a field confirmation system for confirming undulation of a field in order to improve calculation accuracy of a growth value in a configuration for calculating the growth value of a crop based on a distance from a flying device to the crop.SOLUTION: Field undulation information Ae at each position in a field F at a first timing before growth of a crop C is started in the field F is acquired. A field undulation map M1 is generated from the field undulation information Ae, and the undulation information of the field F is displayed.SELECTED DRAWING: Figure 4B

Description

[Technical Field]

[0001] The present invention relates to a farm land confirmation method and a farm land confirmation system. [Background technology]

[0002] Patent Document 1 listed below discloses a technology for determining the Normalized Difference Vegetation Index (NDVI) and plant height values, which are information about the growth status of crops, using sensor devices provided on both the left and right sides of the tractor in the direction of travel. However, although the technology disclosed in Patent Document 1 can be used to detect the NDVI and plant height values ​​around the tractor, it cannot be used when crops are growing in areas of the field that the tractor cannot enter.

[0003] Therefore, a technology has been proposed that calculates NDVI values ​​and the like based on image data captured by a camera mounted on a drone, and observes the growth rate of crops in a field (see Patent Document 2 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-208859 [Patent Document 2] Japanese Patent Application Publication No. 2018-46787 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology disclosed in Patent Document 2 uses a drone to take aerial photographs of crops in a field, making it possible to obtain image data even in narrow areas where a tractor cannot enter. Here, a possible method for observing the growth of crops using a drone is to use a distance sensor attached to the drone, which is different from the technology disclosed in Patent Document 2. The distance from the drone to the crops is affected by the slope and unevenness of the field. In other words, even if the height of the crops is the same, the distance from the drone to crops growing on ground at a high altitude will be shorter than the distance from the drone to crops growing on ground at a low altitude.

[0006] The technology disclosed in Patent Document 2 does not take into consideration the slope or unevenness of the field, and therefore cannot be applied to observing the growth of crops based on the height of the plants measured by a distance sensor. Therefore, one object of the present invention is to provide a field confirmation method and a field confirmation system that confirm the undulations of a field in order to improve the accuracy of calculating growth values ​​in a configuration in which crop growth values ​​are calculated based on the distance from a flying device to the crop. [Means for solving the problem]

[0007] One embodiment of the present invention provides a field confirmation method including a field undulation information acquisition step of acquiring field undulation information at each position in the field at a first timing before crop growth begins in the field, a field undulation map generation step of generating a field undulation map from the field undulation information acquired in the field undulation information acquisition step, and a display step of displaying the field undulation map.

[0008] According to this method, by displaying a field undulation map at each position in the field, the undulation of the field can be easily confirmed. Furthermore, the field undulation map can be used to calculate growth values.

[0009] Another embodiment of the present invention provides a field confirmation system including a field undulation information acquisition unit that acquires field undulation information at each position in the field at a first timing before crop growth begins in the field, a field undulation map generation unit that generates a field undulation map from the field undulation information acquired by the field undulation information acquisition unit, and a display unit that displays the field undulation map.

[0010] According to this configuration, by displaying a field undulation map at each position in the field, the undulation of the field can be easily confirmed. Furthermore, the field undulation map can be used for growth values. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a growth value calculation system according to one embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the electrical configuration of a flying device provided in the growth value calculation system. [Figure 3] FIG. 3 is a schematic diagram showing an example of a flight path taken by the flight device. [Figure 4A] FIG. 4A is a schematic diagram for explaining how the distance measurement sensor provided in the flying device measures the distance between the distance measurement sensor and the ground of the farm field. [Figure 4B] FIG. 4B is a schematic diagram for explaining the state when the distance measurement sensor measures the distance between the distance measurement sensor and the ground surface of the farm field. [Figure 5] FIG. 5 is a block diagram showing the electrical configuration of a growth value calculation server provided in the growth value calculation system. [Figure 6] FIG. 6 is a schematic diagram showing an example of a farm field undulation map generated by the growth value calculation server. [Figure 7] FIG. 7 is a schematic diagram showing an example of a growth value map generated by the growth value calculation server. [Figure 8]FIG. 8 is a schematic diagram for explaining a method for calculating a growth value by measuring the distance between the distance measuring sensor and the crop at multiple times. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 is a schematic diagram showing the configuration of a growth value calculation system 1 according to one embodiment of the present invention. Referring to Fig. 1, the growth value calculation system 1 is a system that calculates, as a growth value, the height (plant height value) of the crop C, which is an index of the growth degree of the crop C at each position in the field F, in order to grasp the growth status of the crop C in the field F.

[0013] The growth value calculation system 1 includes a flying device 3 that acquires information necessary for calculating growth values ​​while flying horizontally at a constant altitude above the field F, and a growth value calculation server 4 that calculates growth values ​​based on the information acquired by the flying device 3. The flight device 3 is capable of wireless communication with the growth value calculation server 4 via a communication network 6. The growth value calculation server 4 is located in a center 5 of a business operator that operates the growth value calculation server 4. The growth value calculation server 4 is operated by an operator in the center 5.

[0014] The flight device 3 is a remotely controlled unmanned aerial vehicle such as a drone. The flight device 3 includes an aircraft body 20, multiple propellers 21 attached to the aircraft body 20, a drive unit 22 such as an electric motor that drives the multiple propellers 21, and a distance sensor 23 as a distance measurement unit that measures the distance between the flight device 3 and an object (crop C or the ground) located below the flight device 3. FIG. 2 is a block diagram showing the electrical configuration of the growth value calculation system 1. As shown in FIG.

[0015] 2, the flight device 3 includes a flight device control unit 40 that controls each unit of the flight device 3. The flight device control unit 40 includes a microcomputer equipped with a CPU and memory (ROM, RAM, etc.) 41. The flight device control unit 40 is connected to a drive unit 22, a positioning data calculation unit 24, an air pressure sensor 25, a distance measurement sensor 23, and a communication unit 26. The positioning data calculation unit 24 is electrically connected to a satellite signal receiving antenna 27 attached to the aircraft body 20. The satellite signal receiving antenna 27 receives signals from positioning satellites that make up a satellite positioning system. The satellite positioning system is, for example, a Global Navigation Satellite System (GNSS).

[0016] The positioning signal received by the satellite signal receiving antenna 27 is input to the positioning data calculation unit 24. The positioning data calculation unit 24 calculates positioning data of the flight device 3 at predetermined time intervals (for example, one-second intervals) based on the positioning signal. The positioning data includes position information (for example, latitude and longitude information) of the flight device 3 (more precisely, the satellite signal receiving antenna 27) and time information corresponding to the position information. The flight device control unit 40 acquires the positioning data calculated by the positioning data calculation unit 24.

[0017] The atmospheric pressure sensor 25 is built into the aircraft body 20. The atmospheric pressure sensor 25 detects the atmospheric pressure around the aircraft body 20 and calculates the altitude H (see FIG. 1) of the flight device 3 based on the detected atmospheric pressure. The altitude H calculated by the atmospheric pressure sensor 25 is, for example, the distance from a predetermined reference position S (see FIG. 1), such as sea level, to the atmospheric pressure sensor 25. As will be described in more detail below, the atmospheric pressure sensor 25 may calculate the altitude H by correcting the distance from the reference position S to the atmospheric pressure sensor 25 to the distance from the reference position S to a reference location provided on the flight device 3. The flight device control unit 40 acquires the altitude H calculated by the atmospheric pressure sensor 25 and the internal time of the atmospheric pressure sensor 25 (the atmospheric pressure sensor time).

[0018] The distance measurement sensor 23 is attached to the outer surface of the aircraft body 20 (see also FIG. 1). The distance measurement sensor 23 is, for example, an ultrasonic distance measurement sensor or a laser distance measurement sensor. The distance measurement sensor 23 is, for example, a TOF (Time of Flight) type that measures the time it takes for a transmission wave transmitted toward an object to be reflected by the object and return, and calculates the distance from the distance measurement sensor 23 to the object based on the measured time.

[0019] As will be described in more detail below, the distance measurement sensor 23 may calculate a distance by correcting the distance from the distance measurement sensor 23 to the target object to the distance from the target object to a reference location provided on the flight device 3. The flight device control unit 40 acquires the measured distance calculated by the distance measurement sensor 23 and the internal time of the distance measurement sensor 23 (distance measurement sensor time). The communication unit 26 is a communication interface for the flight device control unit 40 to communicate with the growth value calculation server 4.

[0020] 3 to 4B, the manner in which the flight device 3 acquires information necessary for calculating growth values ​​will be described. The flight device 3 flies over the field F at a predetermined first timing before planting crops in the field F. FIG. 3 is a schematic diagram showing an example of a flight path R taken by the flight device 3. The flight path R extends, for example, in a meandering manner from one end of the field F to the other in a predetermined direction so that the flight device 3 can fly evenly over the entire field F. The flight device 3 flies horizontally along the preset flight path R, maintaining the aircraft body 20 at a constant altitude.

[0021] FIG. 4A is a schematic diagram illustrating how the distance measurement sensor 23 measures the distance (first distance L1) between the flight device 3 and the ground of the field F. While the flight device 3 flies along the flight path R at the first timing, as shown in FIG. 4A, the distance measurement sensor 23 measures the first distance L1 at predetermined intervals (for example, 10 cm) (first distance measurement step). The distance measurement sensor 23 is an example of a first distance measurement unit.

[0022] The flight device control unit 40 acquires positioning data (position information and time information) at a predetermined time interval (for example, one second intervals) while the flight device 3 flies along the flight path R at the first timing (first position information acquisition process). The flight device control unit 40 is an example of a position information acquisition unit. The locations in the field F where measurements are taken by the distance measurement sensor 23 are called measurement points P. The measurement points P are set at equal intervals within the field F in a planar view (see also Figure 3).

[0023] While flying along flight path R, flight device 3 controls drive unit 22 so that altitude H1 acquired by air pressure sensor 25 remains constant. Altitude H1 remains constant regardless of the height of the ground in field F. Therefore, first distance L1 decreases in areas where the ground is higher in field F and increases in areas where the ground is lower in field F (see flight device 3 shown by the two-dot chain line in Figure 4A). The flight device 3 shown by the two-dot chain line on the left side of Figure 4A illustrates an example in which the measured first distance L1 is equal to altitude H1.

[0024] After flying at the first timing, when the power of the flight device 3 is turned off, the flight device control unit 40 transmits the positioning data obtained from the positioning data calculation unit 24, the altitude H1 and barometric pressure sensor time obtained from the barometric pressure sensor 25, and the first distance L1 and barometric pressure sensor time obtained from the barometric pressure sensor 23 to the growth value calculation server 4 via the communication unit 26.

[0025] Thereafter, at a second timing after crop growth has begun in the field F, the flight device 3 flies above the field F. The flight device 3 flies horizontally along a preset flight path R while maintaining the aircraft body 20 at a constant altitude H. 4B is a schematic diagram illustrating the manner in which the distance measurement sensor 23 measures the distance (second distance L2) between the flight device 3 and the crop C. Referring to FIG. 4B, while the flight device 3 flies along the flight path R at the second timing, the distance measurement sensor 23 measures the second distance L2 at predetermined intervals (for example, 10 cm) to measure the second distance L2 at the same position (measurement point P) as when the distance measurement sensor 23 measured the first distance L1 (second distance measurement step). The distance measurement sensor 23 is an example of a second distance measurement unit.

[0026] The flight device control unit 40 acquires positioning data at predetermined time intervals (for example, one second intervals) while the flight device 3 flies along the flight path R (second position information acquisition step). While flying at the second timing, the flight device 3 controls the drive unit 22 so that the altitude H2 acquired by the air pressure sensor 25 remains constant. Altitude H2 remains constant regardless of the height of the ground in the field F. Therefore, assuming that the growth rate of the crop C is constant, the second distance L2 will be smaller in areas of the field F where the ground is higher and larger in areas of the field F where the ground is lower (see the flight device 3 indicated by the two-dot chain line in Figure 4B). Altitude H2 does not need to be the same as altitude H1 of the flight device 3 at the first timing.

[0027] After flying at the second timing, when the power of the flight device 3 is turned off, the flight device control unit 40 transmits the positioning data obtained from the positioning data calculation unit 24, the altitude H2 and barometric pressure sensor time obtained from the barometric pressure sensor 25, and the second distance L2 and barometric pressure sensor time obtained from the barometric pressure sensor 23 to the growth value calculation server 4 via the communication unit 26.

[0028] FIG. 5 is a block diagram showing the electrical configuration of the growth value calculation server 4. As shown in FIG. The growth value calculation server 4 includes a server control unit 50 that controls the growth value calculation server 4. The server control unit 50 includes a microcomputer equipped with a CPU and memory (ROM, RAM, etc.) 51. A communication unit 52, an operation display unit 53, an operation unit 54, and a memory unit 55 are electrically connected to the server control unit 50.

[0029] The communication unit 52 is a communication interface that allows the server control unit 50 to communicate wirelessly with the flight device 3. The operation display unit 53 is, for example, a touch panel display. The operation unit 54 includes, for example, a keyboard, a mouse, etc. The memory unit 55 is composed of a storage device such as a hard disk or non-volatile memory. The server control unit 50 includes a field undulation information calculation unit 60 that calculates field undulation information Ae at each position within the field F, a field undulation map generation unit 61 that generates a field undulation map M1 by associating the calculated field undulation information Ae with the position information included in the positioning data, a growth value calculation unit 62 that calculates growth values ​​Ce at each position within the field F, and a growth value map generation unit 63 that generates a growth value map M2 based on the calculated growth values ​​Ce and the field undulation map M1.

[0030] The field undulation information Ae at each position is calculated by subtracting the first distance L1 acquired by the ranging sensor 23 at each measurement point P when the flight device 3 is flying horizontally at the first timing from the altitude H1 of the flight device 3 when the flight device 3 is flying horizontally at the first timing (Ae=H1-L1). In this way, the field undulation information calculation process is executed by the field undulation information calculation unit 60.

[0031] As mentioned above, for the flight device 3 shown by the two-dot chain line on the left side of Figure 4A, the measured first distance L1 is equal to the altitude H1. In this case, the field undulation information Ae is "0" (Ae = 0). Here, altitude H1 is the altitude calculated by atmospheric pressure sensor 25, and first distance L1 is the distance calculated by distance measurement sensor 23. In other words, when the values ​​calculated by each sensor 23, 25 are used as altitude H1 and first distance L1, they are affected by the relative heights of distance measurement sensor 23 and atmospheric pressure sensor 25. Specifically, the relative heights of distance measurement sensor 23 and atmospheric pressure sensor 25 are added to the calculated field undulation information Ae. Therefore, it is necessary to correct at least one of altitude H1 and first distance L1.

[0032] For example, the distance measurement sensor 23 may correct the first distance L1 by adding the distance between the distance measurement sensor 23 and the ground surface of the field F to the distance between the distance measurement sensor 23 and the atmospheric pressure sensor 25, and setting this value as the first distance L1. In this case, the first distance L1 is the distance between the atmospheric pressure sensor 25 and the ground surface of the field F. Conversely, although not shown, the atmospheric pressure sensor 25 may correct the altitude H1 by setting the value obtained by subtracting the distance between the distance measuring sensor 23 and the atmospheric pressure sensor 25 from the distance between the atmospheric pressure sensor 25 and the reference position S as the altitude H1. In this case, the altitude H1 is the distance between the distance measuring sensor 23 and the reference position S.

[0033] In addition, the distance measurement sensor 23 may calculate the distance between a predetermined reference location provided on the flight device 3 and the target object, and the air pressure sensor 25 may calculate the distance between a predetermined reference location provided on the flight device 3 and the reference position S. 6 is an example of a field undulation map M1 generated by the field undulation map generator 61. In the field undulation map M1, the field F is divided into a number of meshes m, each containing a number of measurement points P, and field undulation information Ae is assigned to each mesh m. In other words, the field F is assigned the same number of meshes m as the number of measurement points P.

[0034] Each mesh m is numbered in order, starting with the mesh m with the earliest time indicated by the time information included in the positioning data acquired at measurement point P. The field undulation information for the i-th mesh m is given the symbol "Aei". If N meshes m are assigned to the field F, i is a natural number less than or equal to N (1≦i≦N). In this way, the field undulation map generation process is carried out by the field undulation map generation unit 61.

[0035] The growth value calculation unit 62 calculates the altitude (crop altitude Be) of the crop C at each position in the field F by subtracting the second distance L2 measured by the ranging sensor 23 at each measurement point P when the flight device 3 flies horizontally at the second timing from the altitude H2 of the flight device 3 when the flight device 3 flies horizontally at the second timing (Be=H2-L2). The crop altitude in the i-th mesh m is given the symbol "Bei".

[0036] When calculating the crop altitude, in order to eliminate the influence of the relative heights of the distance measurement sensor 23 and the barometric pressure sensor 25, it is necessary to correct at least one of the altitude H2 and the second distance L2, as well as the altitude H1 and the first distance L1. The growth value calculation unit 62 calculates the growth value Ce by correcting the crop height Be with the field undulation information Ae. More specifically, the growth value calculation unit 62 calculates the growth value Ce by subtracting the field undulation information Ae from the crop height Be (Ce = Be - Ae). Figure 7 is an example of a growth value map M2 generated by the growth value map generation unit 63. In this manner, the growth value calculation process is carried out by the growth value calculation unit 62. The crop height in the i-th mesh m is given the symbol "Cei".

[0037] The memory unit 55 includes a flight information memory unit 56 that stores information transmitted from the flight device 3 (positioning data, altitude, first distance, second distance, etc.), an undulation map memory unit 57 that stores the generated field undulation map M1, and a growth value map memory unit 58 that stores the generated growth value map M2. According to this embodiment, the crop height Be calculated by subtracting the second distance L2 from the altitude H2 of the flight device 3 is not used as the crop growth value, but the crop height Be is corrected based on the field undulation information Ae and used as the growth value Ce. Specifically, the growth value Ce is calculated by subtracting the field undulation information Ae from the value obtained by subtracting the second distance L2 from the altitude H2 of the flight device 3. This reduces the influence of the slope and unevenness of the field F on the growth value Ce. As a result, the calculation accuracy of the growth value Ce can be improved.

[0038] Furthermore, according to this embodiment, the field undulation map generator 61 generates a field undulation map M1 by associating the field undulation information Ae with the positioning data (position information acquired by the flight device controller 40). Therefore, regardless of when the second distance L2 is measured during the growth of the crop C, the field undulation map M1 can be used to calculate the growth value Ce, as long as the altitude H2 of the flight device 3 when flying at the second timing is constant.

[0039] The present invention is not limited to the above-described embodiment, and can be embodied in other forms. For example, the growth value Ce may be calculated multiple times by measuring the distance between the flight device 3 and the crops at multiple times after the crops start growing in the field F. By measuring the growth value Ce multiple times, the growth amount De for a predetermined period can also be calculated.

[0040] 8, at a third timing that is later than the second timing, the flight device 3 is caused to fly horizontally at a predetermined altitude H3, and the ranging sensor 23 is caused to measure the distance (third distance L3) between the flight device 3 and the crop C at measurement point P. The growth value calculation unit 62 then calculates the crop altitude Be of the crop C at each position within the field F by subtracting the third distance L3 from the altitude H3 of the flight device 3 when the flight device 3 is flying horizontally at the third timing. The growth value calculation unit 62 then corrects the calculated crop altitude Be with the field undulation information Ae to calculate the growth value Ce at the third timing.

[0041] By subtracting the growth value Ce at the second timing from the growth value Ce at the third timing, the growth amount De of the crop C between the second timing and the third timing can be calculated. Furthermore, when the altitude H2 of the flight device 3 at the second timing is equal to the altitude H3 of the flight device 3 at the third timing, the growth amount De can be calculated by subtracting the third distance L3 from the second distance L2 without calculating the growth value Ce.

[0042] In the above-described embodiment, the field undulation information Ae and growth value Ce are displayed numerically in each mesh m in the field undulation map M1 and the growth value map M2. However, in the field undulation map M1, for example, the mesh m with a higher ground elevation may be colored darker, or the mesh m may be color-coded according to the ground elevation. Similarly, in the growth value map M2, the mesh m with a higher growth value Ce may be colored darker, or the mesh m may be color-coded according to the growth value Ce.

[0043] In addition, various modifications can be made within the scope of the claims.

[0044] (Addendum) The farm field confirmation method and farm field confirmation system described above can be described as follows.

[0045] A farm field confirmation method according to a first aspect includes: a first distance measurement step of flying a flight device along a predetermined flight path at a first timing before the start of crop growth in the field, and measuring a first distance between the ground below the flight device and the flight device at predetermined intervals within the field using a distance measurement unit provided on the flight device; a field undulation information calculation step of calculating field undulation information at each position within the field by subtracting the first distance measured in the first distance measurement step from the altitude of the flight device at the first timing; a position information acquisition process for acquiring position information of the flight device when flying the flight device at the first timing; a field undulation map generating step of generating a field undulation map by associating the field undulation information calculated in the field undulation information calculating step with the position information acquired in the position information acquiring step; and a display step of displaying the field undulation map in different colors according to the elevation of the ground surface of the field.

[0046] A farm field confirmation system according to a second aspect includes: a first distance measurement unit that flies the flight device along a predetermined flight path at a first timing before the start of crop growth in the field and measures a first distance between the ground below the flight device and the flight device at predetermined intervals within the field; a field undulation information calculation unit that calculates field undulation information at each position within the field by subtracting the first distance measured by the first distance measurement unit from the altitude of the flight device at the first timing; a position information acquisition unit that acquires position information of the flight device when flying the flight device at the first timing; a field undulation map generator that generates a field undulation map by associating the field undulation information calculated by the field undulation information calculator with the position information acquired by the position information acquirer; and and a display unit that displays the field undulation map in different colors according to the elevation of the ground surface of the field. [Explanation of symbols]

[0047] 1: Growth value calculation system 3: Flight equipment 60: Field relief information calculation unit 61: Field relief map generation unit 62: Growth value calculation section Ae: Field relief information Aei: Field undulation information Be: Crop altitude Bei: Crop altitude C: Crop Ce: Growth value Cei: Growth value F: Field H:Altitude H1: Altitude H2 : Altitude H3: Altitude L1: 1st distance L2: 2nd distance M1: Field relief map P:Measurement point

Claims

1. a field undulation information acquisition step of acquiring field undulation information at each position in the field at a first timing before crop growth starts in the field; a field undulation map generating step of generating a field undulation map from the field undulation information acquired in the field undulation information acquiring step; and a display step of displaying the field undulation map.

2. a field undulation information acquisition unit that acquires field undulation information at each position in the field at a first timing before crop growth starts in the field; a field undulation map generating unit that generates a field undulation map from the field undulation information acquired by the field undulation information acquiring unit; and a display unit that displays the field undulation map.

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