Flight path generating system and unmanned flying craft

Abstract

This flight path generating system is mounted to an unmanned flying craft, said system comprising an acquisition device for acquiring data about a predetermined flight path, a sensor that measures wind directions and outputs sensor data indicating the wind directions, and a processing device that updates the flight path in accordance with the wind directions indicated by the sensor data.

Description

Flight path generation system and unmanned aerial vehicle

[0001] The present disclosure relates to a flight path generation system and an unmanned aerial vehicle.

[0002] An unmanned aerial vehicle (UAV) is an aircraft that cannot carry a person due to its structure and can fly by remote control or automatic pilot. Rotary-wing unmanned aerial vehicles are unmanned aerial vehicles that obtain lift using propellers, i.e., rotors, that rotate around an axis. Small unmanned aerial vehicles equipped with multiple rotors (multi-rotor UAVs) are also called "drones," "multirotors," or "multicopters," and are widely used for applications such as aerial photography, surveying, logistics, and pesticide spraying.

[0003] Unmanned aerial vehicles equipped with sensors for measuring wind speed and wind direction are known. Patent Document 1 describes a technology for controlling the flight of an unmanned aerial vehicle along a flight path based on the wind speed and wind direction measured during flight of the unmanned aerial vehicle.

[0004] Japanese Patent Application Laid-Open No. 2021-75277

[0005] When using unmanned aerial vehicles for the purpose of spraying pesticides, it is necessary to properly spray the pesticides in the target area on the ground where the pesticides are to be sprayed.

[0006] The present disclosure provides a flight path generation system and unmanned aerial vehicle that enable pesticides to be properly sprayed in a target area in a relatively simple manner, even when wind is blowing in the sky.

[0007] In an exemplary and non-limiting embodiment, the flight path generation system of the present disclosure is a flight path generation system mounted on an unmanned aerial vehicle, and includes an acquisition device that acquires data on a predetermined flight path, a sensor that measures wind direction and outputs sensor data indicating the wind direction, and a processing device that updates the flight path according to the wind direction indicated by the sensor data.

[0008] In an exemplary and non-limiting embodiment, the unmanned aerial vehicle of the present disclosure includes multiple rotors and the above-described flight path generation system.

[0009] According to an embodiment of the present disclosure, a flight path generation system is provided that enables pesticides to be appropriately sprayed in a target area in a relatively simple manner, even when wind is blowing in the sky, and an unmanned aerial vehicle equipped with the flight path generation system is provided.

[0010] 1 is a block diagram schematically showing several examples of a rotary drive device that rotates rotors in an unmanned aerial vehicle with multiple rotors. FIG. 2 is a plan view schematically showing one basic configuration example of an unmanned aerial vehicle with multiple rotors. FIG. 3 is a side view schematically showing one basic configuration example of an unmanned aerial vehicle with multiple rotors. FIG. 4 is a plan view schematically showing another basic configuration example of an unmanned aerial vehicle with multiple rotors. FIG. 5 is a block diagram showing an example basic configuration of a battery-powered multicopter. FIG. 6 is a block diagram showing an example basic configuration of a series hybrid drive multicopter. FIG. 7 is a block diagram showing an example basic configuration of a parallel hybrid drive multicopter. FIG. 8 is a diagram schematically showing a flight path set above a field for spraying materials. FIG. 9 is a diagram schematically showing a flight path shifted by Δx1 in the direction opposite to the wind direction. FIG. 10 is a diagram schematically showing a flight path shifted by Δx2 in the direction opposite to the wind direction. FIG. 11 is a diagram for explaining an example of determining an offset amount for each main portion and shifting the main portions by the determined offset amount. FIG. 1 is a diagram schematically showing an example of a spraying situation after the multicopter has flown along a changed flight path. FIG. 2 is a diagram schematically showing an example of a further flight path for spraying materials in an estimated uncompleted area. FIG. 3 is a block diagram showing an example of the hardware configuration of a control device. FIG. 4 is a schematic diagram showing an example in which a multicopter, an agricultural machine, a server, and a terminal device are connected via a communication network.

[0011] An unmanned aerial vehicle with multiple rotors includes a rotary drive unit that rotates the rotors (hereinafter sometimes referred to as "propellers"). Hereinafter, such an unmanned aerial vehicle will be referred to as a "multicopters."

[0012] There are various configurations of the rotary drive device provided in a multicopter. Fig. 1A is a block diagram schematically illustrating four examples of the rotary drive device 3 in the present disclosure.

[0013] The first rotation drive device 3A shown in FIG. 1A has a plurality of electric motors (hereinafter referred to as "motors") 14 that rotate a plurality of rotors, and a battery 52 that stores power to be supplied to each motor 14. The battery 52 is, for example, a secondary battery such as a polymer lithium-ion battery. Each rotor 2 is connected to the output shaft of the corresponding motor 14 and is rotated by the motor 14. In order to increase the payload and / or flight time, it is necessary to increase the power storage capacity of the battery 52. ​​The power storage capacity of the battery 52 can be increased by increasing the size of the battery 52, but increasing the size of the battery 52 results in an increase in weight.

[0014] The second rotation drive device 3B shown in FIG. 1A includes a power transmission system 23 mechanically connected to the rotor 2 and an internal combustion engine 7a that provides driving force (torque) to the power transmission system 23. The power transmission system 23 includes mechanical components such as gears or belts, and transmits torque from the output shaft of the internal combustion engine 7a to the rotor 2. The internal combustion engine 7a can efficiently generate mechanical energy by burning fuel. Examples of the internal combustion engine 7a include a gasoline engine, a diesel engine, and a hydrogen engine. The number of internal combustion engines 7a included in the rotation drive device 3B is not limited to one.

[0015] The third rotary drive device 3C shown in FIG. 1A includes multiple motors 14, a power buffer 9 that stores power to be supplied to each motor 14, a power generator 8 such as an alternator that generates power, and an internal combustion engine 7a that provides mechanical energy for the power generator 8 to generate electricity. A typical example of the power buffer 9 is a battery such as a secondary battery, but it may also be a capacitor. In the third rotary drive device 3C, even if the power buffer 9 does not have a large storage capacity, the power generator 8 generates power using the driving force (mechanical energy) of the internal combustion engine 7a, thereby enabling an increase in payload and / or flight time. This type of drive is called a "series hybrid drive." The power generator 8 and internal combustion engine 7a in the series hybrid drive are called a "range extender" because they extend the flight distance of the multicopter.

[0016] 1A includes a plurality of motors 14, a power buffer 9 that stores power to be supplied to each motor 14, a power generator 8 such as an alternator that generates power, an internal combustion engine 7a that provides driving force for generating power to the power generator 8, and a power transmission system 23 that transmits the driving force generated by the internal combustion engine 7a to a rotor 2 to rotate the rotor 2. At least one rotor 2 of the plurality of rotors 2 is rotated by the internal combustion engine 7a, and the other rotors 2 are rotated by the motor 14. In the fourth rotary drive device 3D, the mechanical energy generated by the internal combustion engine 7a can also be used to rotate the rotor 2 without being converted into electric power, thereby improving energy utilization efficiency. This type of drive is called a "parallel hybrid drive."

[0017] Fig. 1B is a plan view schematically illustrating one basic configuration example of multicopter 10. The configuration example of Fig. 1B includes the first rotational drive device 3A shown in Fig. 1A as the rotational drive device 3. That is, the rotational drive device 3 (3A) in this example includes a motor 14 and a battery 52. ​​Fig. 1C is a side view schematically illustrating the multicopter.

[0018] 1B and 1C includes a plurality of rotors 2, an airframe 4, and an airframe frame 5 that supports the rotors 2 and the airframe 4. The airframe frame 5 supports the airframe 4 at its center and rotatably supports the plurality of rotors 2 with a plurality of arms 5A extending outward from the center. A motor 14 that rotates the rotor 2 is provided near the tip of each arm 5A.

[0019] 1B, the multicopter 10 is a quad-type multicopter (quadcopter) having four rotors 2. The rotors 2 located on one diagonal line rotate in the same direction (clockwise or counterclockwise), while the rotors 2 located on different diagonal lines rotate in opposite directions.

[0020] The main body 4 includes a control device 4a that controls the operation of devices and components mounted on the multicopter 10, a group of sensors 4b connected to the control device 4a, a communication device 4c connected to the control device 4a, and a battery 52.

[0021] The control device 4 a may include, for example, a flight control device such as a flight controller and a host computer (companion computer). The companion computer can perform advanced arithmetic processing such as image processing, obstacle detection, and obstacle avoidance based on the sensor data acquired by the sensor group 4 b.

[0022] The sensor group 4b may include an acceleration sensor, an angular velocity sensor, a geomagnetic sensor, a barometric pressure sensor, an altitude sensor, a temperature sensor, a wind speed sensor, a wind direction sensor, a flow rate sensor, an imaging device, a laser sensor, an ultrasonic sensor, an obstacle contact sensor, and a Global Navigation Satellite System (GNSS) receiver. The acceleration sensor and the angular velocity sensor may be mounted on the airframe main body 4 as components of an IMU (Inertial Measurement Unit). Examples of the laser sensor may include, for example, a laser range finder used to measure the distance to the ground, and a two-dimensional or three-dimensional LiDAR.

[0023] The communication device 4c may include a wireless communication module for transmitting and receiving signals via an antenna to a transmitter or ground station (Ground Control Station (GCS)) on the ground, a mobile communication module using a cellular communication network, etc. The communication device 4c may receive signals such as control commands transmitted from the ground and transmit sensor data such as image data acquired by the sensor group 4b as telemetry information. The communication device 4c may have a function for communicating between multicopters and a satellite communication function. The control device 4a can be connected to a computer on the cloud via the communication device 4c. Some or all of the functions of the companion computer may be performed by the computer on the cloud.

[0024] The battery 52 is a secondary battery that stores power by charging and supplies power to the motors 14 by discharging. The battery 52 and the multiple motors 14 operate to rotate the multiple rotors 2, making it possible to generate a desired thrust.

[0025] Each of the multiple rotors 2 generally has multiple blades with a fixed pitch angle and generates thrust by rotation. The pitch angle may be variable. The multiple rotors 2 do not all need to have the same diameter (propeller diameter); one or more rotors 2 may have a larger diameter than the other rotors 2. The thrust (static thrust) generated by a rotating rotor 2 is generally proportional to the cube of the rotor 2 diameter. Therefore, when rotors 2 with different diameters are included, the rotor 2 with a relatively larger diameter may be referred to as the "main rotor," and the rotor 2 with a relatively smaller diameter may be referred to as the "sub-rotor." Note that, regardless of the diameter, the configuration of the rotary drive device 3 may include a rotor 2 capable of generating a relatively larger thrust and a rotor 2 with a relatively smaller thrust. In this case, the rotor 2 capable of generating a relatively larger thrust may be referred to as the "main rotor," and the rotor 2 with a relatively smaller thrust may be referred to as the "sub-rotor." For example, the rotor 2 that generates a relatively large thrust per rotation may be referred to as the "main rotor," and the rotor 2 that generates a relatively small thrust per rotation may be referred to as the "sub-rotor." In one example, the main rotor may be positioned more inward than the sub-rotors. In other words, each rotor 2 may be positioned so that the distance from the center of the airframe to the rotation axis of each main rotor is shorter than the distance from the center of the airframe to the rotation axis of each sub-rotor.

[0026] In this example, the rotary drive device 3 includes a plurality of motors 14. As mentioned above, the rotary drive device 3 may include an internal combustion engine 7a.

[0027] 1D is a plan view schematically illustrating an example of the basic configuration of a multicopter 10 including a second rotational drive device 3B as the rotational drive device 3. In the example shown in FIG. 1D, an internal combustion engine 7a is supported by the airframe main body 4. In this example, the driving force generated by the internal combustion engine 7a is transmitted to multiple rotors 2 via multiple power transmission systems 23, causing each rotor 2 to rotate. The control device 4a can change the rotational speed of each rotor 2 by controlling each power transmission system 23.

[0028] In a "parallel hybrid drive" in which some of the multiple rotors 2 are rotated by the internal combustion engine 7a and the other rotors 2 are rotated by the motor 14, the internal combustion engine 7a and the battery 52 are supported on the aircraft body 4. At least one rotor 2 of the multiple rotors 2 is connected to the internal combustion engine 7a via the power transmission system 23, and the other rotors 2 are connected to the motor 14.

[0029] In such a parallel hybrid drive, the diameter of one or more rotors 2 rotated by the internal combustion engine 7a may be larger than the diameter of the other rotors 2 rotated by the motor 14. In other words, the internal combustion engine 7a may be used to rotate the main rotor, and the motor 14 may be used to rotate the sub-rotor. In such a case, the main rotor is mainly used to generate thrust, and the sub-rotor is used to generate thrust and for attitude control. The main rotor may also be called a "booster rotor," and the sub-rotor may also be called an "attitude control rotor."

[0030] In the case of parallel hybrid drive, the internal combustion engine 7a is used for both thrust generation and power generation. By selectively transmitting the driving force (torque) generated by the internal combustion engine to one or both of the rotor and the power generator, it is possible to achieve a good balance between thrust generation and power generation.

[0031] Equipping a multicopter with an internal combustion engine 7a and using the internal combustion engine 7a to generate thrust and / or electricity contributes to an increase in payload and flight time. It is desirable to control the attitude of a multicopter by rotating the propellers with a motor, which has better response characteristics than an internal combustion engine. Therefore, in applications where precise control of the attitude of a multicopter is required, it is desirable to employ a parallel hybrid drive or a series hybrid drive to increase the payload and flight time.

[0032] Increased payload and flight time may further expand the applications of multicopters. For example, in the agricultural field, multicopters are currently being used for spraying pesticides or monitoring crop growth conditions. However, by connecting various ground implements (hereinafter, sometimes simply referred to as "implements") to a multicopter, various agricultural tasks can be performed from the air. Agricultural implements are sometimes called "implements." Examples of implements include sprayers that spray pesticides on crops, mowers, seeders, spreaders, rakes, balers, harvesters, plows, harrows, or rotary tillers. Work vehicles such as tractors are not included in the "implements" of this disclosure.

[0033] In the example shown in FIG. 1C , a work implement 200 is coupled to the multicopter 10. The work implement 200 can spray, for example, pesticides or fertilizers on a field or crops within the field. Increasing the payload and flight time allows for a larger and / or more versatile work implement 200. For example, by changing the work implement 200 coupled to the multicopter 10, a variety of ground tasks (agricultural operations) can be performed, including liquid and granular application of pesticides, fertilization, thinning, weeding, transplanting, direct seeding, and harvesting. The work implement 200 may be equipped with a mechanism such as a robotic hand. In this case, a single work implement 200 can perform a variety of ground tasks. Furthermore, if the work implement 200 has a sufficient space to accommodate the materials, the work implement 200 can also transport agricultural materials or harvested products over a wide area.

[0034] 1C , the multicopter 10 includes a power supply device 76. The power supply device 76 is a device that supplies power to the work machine 200 from a drive energy source, such as the battery 52 or the power generation device 8, included in the multicopter 10. Various functions of the work machine 200 can be performed using this power. The work machine 200 includes actuators such as motors that operate using power obtained from the power supply device 76 of the multicopter 10. The work machine 200 preferably includes a battery that stores power.

[0035] 2A is a block diagram showing an example of the basic configuration of a battery-powered multicopter 10. The battery-powered multicopter 10 includes a plurality of rotors 12, a plurality of motors 14 that rotate the rotors 12, a plurality of ESCs (electric speed controllers) 16 each having a motor drive circuit that drives the motors 14, a battery 52 that supplies power to the corresponding motor 14 via each ESC 16, a control device 4a that controls the plurality of ESCs 16 to control attitude while flying, a sensor group 4b, a communication device 4c, and a power supply device 76 electrically connected to the battery 52. ​​The rotor 12 is an example of a rotor 2. The control device 4a, the sensor group 4b, the communication device 4c, and other devices are connected to each other so that they can communicate with each other, for example, via a controller area network (CAN) bus. 2A, for simplicity, the rotor 12, the motor 14, and the ESC 16 are each shown as a single block, but there are actually multiple rotors 12, motors 14, and ESCs 16. This also applies to FIGS. 2B and 2C.

[0036] The control device 4a can receive control commands wirelessly from, for example, a ground station 6 located on the ground via the communication device 4c. The number of ground stations 6 is not limited to one, and they may be distributed across multiple locations. The communication device 4c can also receive control commands wirelessly from a control device of a pilot on the ground. The control device 4a may have a function to automatically or autonomously perform takeoff, flight, obstacle avoidance, and landing operations based on sensor data obtained from the sensor group 4b.

[0037] The control device 4a may be configured to communicate with the work machine 200 connected to the power supply device 76 and to acquire a signal indicating the state of the work machine 200 from the work machine 200. The control device 4a may also provide a signal to the work machine 200 that controls the operation of the work machine 200. Furthermore, the work machine 200 may generate a signal instructing the operation of the multicopter 10 and transmit the signal to the control device 4a. Such communication between the control device 4a and the work machine 200 may be performed wired or wirelessly.

[0038] FIG. 2B is a block diagram showing an example of the basic configuration of a series hybrid drive multicopter 10. Similar to the battery-powered multicopter 10, the series hybrid drive multicopter 10 includes multiple rotors 12, multiple motors 14, multiple ESCs 16, a control device 4a, a sensor group 4b, and a communication device 4c. The illustrated series hybrid drive multicopter 10 further includes an internal combustion engine 7a, a fuel tank 7b for storing fuel for the internal combustion engine 7a, a power generation device 8 driven by the internal combustion engine 7a to generate electric power, a power buffer 9 for temporarily storing the electric power generated by the power generation device 8, and a power supply device 76 electrically connected to the power buffer 9. The power buffer 9 is, for example, a battery such as a secondary battery. The electric power generated by the power generation device 8 is supplied to the motor 14 via the power buffer 9 and the ESC 16. The electric power generated by the power generation device 8 may also be supplied to the work machine 200 via the power supply device 76.

[0039] 2C is a block diagram showing an example of the basic configuration of a parallel hybrid drive multicopter 10. Similar to the series hybrid drive multicopter 10, the parallel hybrid drive multicopter 10 includes multiple rotors 12, multiple motors 14, multiple ESCs 16, a control device 4a, a sensor group 4b, a communication device 4c, an internal combustion engine 7a, a fuel tank 7b, a power generator 8, a power buffer 9, and a power supply device 76. The parallel hybrid drive multicopter 10 further includes a drive train 27 that transmits the driving force of the internal combustion engine 7a, and a rotor 22 that rotates by receiving the driving force of the internal combustion engine 7a from the drive train 27. The rotor 22 is an example of a rotor 2. The number of rotors 22 connected to the drive train 27 and rotating may be one or more.

[0040] In the parallel hybrid drive multicopter 10, the internal combustion engine 7a not only drives the power generation device 8 to generate electricity, but also mechanically transmits energy to the rotor 22 to rotate the rotor 22. On the other hand, in the series hybrid drive multicopter 10, all of the rotors 12 are rotated by the electric power generated by the power generation device 8. For this reason, in the series hybrid drive multicopter 10, if the power generation device 8 is, for example, a fuel cell, the internal combustion engine 7a is not an essential component.

[0041] A multicopter according to an embodiment of the present disclosure is equipped with a flight path generation system including an acquisition device that acquires data on a predetermined flight path, a sensor that measures wind direction and outputs sensor data indicating the wind direction, and a processing device that updates the flight path according to the wind direction indicated by the sensor data. The flight path is typically defined by a group of waypoints, each of which includes latitude and longitude information. The waypoints may further include altitude information.

[0042] The multicopter according to the embodiment of the present disclosure is not limited to a quad-type multicopter, but may be, for example, a hexa-type multicopter (hexacopter) having six rotors or an octo-type multicopter (octocopter) having eight rotors. The control device 4a described above may be programmed to enable autonomous flight of the multicopter. In this case, the multicopter can fly autonomously along a predetermined flight path.

[0043] In this specification, an example will be described in which updating or changing a flight path in response to wind direction is primarily used for spraying materials by a multicopter, but the application is not limited to this. As shown in FIG. 1C , a multicopter according to an embodiment of the present disclosure may further include a sprayer as a work machine 200 for spraying granular or liquid agricultural materials (hereinafter simply referred to as "materials") on the ground. Examples of materials include liquid or granular chemicals such as herbicides or insecticides, water, and seeds.

[0044] A processing device is a device that includes one or more semiconductor integrated circuits (eg, a processor).

[0045] The acquisition device in this embodiment is, for example, the communication device 4c described above. The acquisition device acquires data of the predetermined flight path from, for example, a cloud server. The acquisition device may further store the acquired data of the flight path in a storage device. The storage device may be, for example, a semiconductor memory, a magnetic storage device, an optical storage device, or a combination thereof.

[0046] The sensor measures wind direction. The sensor may be further configured to measure wind speed. Examples of sensors include a wind direction sensor, a wind speed sensor, and a wind speed and direction sensor configured to measure both wind direction and wind speed.

[0047] Figure 3 is a schematic diagram showing a flight path P set above a field F for spraying materials. The flight path P shown in Figure 3 is a predetermined initial flight path. For reference, Figure 3 also shows an X-axis and a Y-axis that are orthogonal to each other. The X-axis and the Y-axis are located in a horizontal plane perpendicular to the vertical direction. For example, the arrow on the X-axis points south, and the arrow on the Y-axis points west.

[0048] When a farmer uses a terminal device or a mobile terminal to create a work plan or a multicopter flight plan, the farmer determines the flight path taking into consideration the type of multicopter, the shape of the field, etc. As shown in Figure 3, the farmer can create a flight path by displaying the field F (a map showing the field F and the outline of the field F) on the screen of the terminal device or mobile terminal and drawing the flight path on the field F.

[0049] In an embodiment of the present disclosure, the flight path may be determined by taking into consideration at least one of the type, size, and weight of the material. Examples of agricultural workers include a manager who manages the field, a worker who performs farm work in the field, and a pilot who remotely operates the multicopter. Data on the flight path determined in this manner may be transmitted from, for example, a terminal device or a mobile terminal to a cloud server and temporarily stored in cloud storage on the cloud server. The multicopter can access the cloud server, for example, when it is powered on, to download the flight path data via a network. The downloaded data is stored in the flight path generation system or the storage device of the multicopter.

[0050] As illustrated in FIG. 3 , the flight path P includes multiple main portions 91 and multiple sub-portions 92. Each of the multiple main portions 91 includes a straight portion. Each main portion 91 may include a curved portion in addition to a straight portion. In the illustrated example, multiple main portions 91 are shown, each of which includes a straight portion parallel to the Y-axis direction and does not include a curved portion. The multiple main portions 91 are positioned at equal intervals from each other along the X-axis direction. Each of the multiple sub-portions 92 includes an arc-shaped portion along which the multicopter 10 turns. The multiple sub-portions 92 are located at both ends of the multiple main portions 91 and connect the multiple main portions 91.

[0051] The flight path P includes a start point S at which the multicopter 10 begins flight along the flight path P, and an end point E at which the multicopter 10 ends flight along the flight path P. As shown in FIG. 3 , the flight path P is set in a predetermined work area F1 within an area representing a farm field F. The work area F1 is, for example, an area where crops are cultivated or an area where crops are planned to be cultivated. The work area F1 can be determined by operating a terminal device or a mobile terminal, and can be determined by, for example, shifting the outline of the farm field F inward by several tens of centimeters to several meters through a predetermined operation.

[0052] The multicopter 10 sprays materials in a work area F1 by flying back and forth along a flight path P from a start point S to an end point E along multiple main sections 91 that are parallel to the Y-axis direction. Hereinafter, for convenience of explanation, the area where the materials are sprayed and the work area F1 are the same, so the area in the spraying work will be referred to as the "spraying target area 95." The spraying target area 95 is an area located within the field F where the materials will be sprayed. For example, crops are planted in the spraying target area 95.

[0053] When a multicopter flies along a predetermined initial flight path, if the wind is strong in the sky, the materials sprayed from the multicopter into the sky will be affected by the wind. As a result, it becomes difficult to properly spray the materials in the intended target area. In an embodiment of the present disclosure, the processing device determines whether to update the data of the initial flight path based on the wind speed measured by a sensor at a measurement point above the field F before the multicopter 10 reaches the starting point S. Specifically, before the multicopter 10 begins flying along the flight path P, the wind speed and wind direction are measured at a measurement point above the field F. The wind speed and wind direction are preferably measured at multiple measurement points above the field F. For example, the processing device may calculate an average or integrated value of the wind speeds measured at multiple measurement points above the field F and determine the wind speed (representative value of the wind speed) above the field F from the average or integrated value. Similarly, the processing device can determine the wind direction (representative wind direction) above the field F from the wind directions measured at multiple measurement points above the field F. The multiple measurement points include, for example, points above the center of the spraying target area 95 and points above the corners that define the outline of the spraying target area 95.

[0054] As another example, the multicopter 10 may fly along the initial flight path before spraying materials to measure wind speed and direction. This type of flight is called a pre-flight before spraying materials. During the pre-flight, the multicopter 10 may measure wind speed and direction, for example, each time it flies along one main portion 91 and then turns in one sub-portion 92. Alternatively, the multicopter 10 may measure wind speed and direction at multiple measurement points while flying along one main portion 91. In this way, the multicopter 10 can collect wind speed and direction data at multiple measurement points above the field F.

[0055] In this specification, not only the wind speed measured by a sensor at a measurement point above a field, but also the representative value of the wind speed obtained from the wind speeds measured by a sensor at multiple measurement points above a field is referred to as the "wind speed measured by a sensor" or simply the "measured wind speed."

[0056] In an embodiment of the present disclosure, the processing device adopts the flight path indicated by the data pre-stored in the storage device if the wind speed measured by the sensor is below a threshold, and updates the flight path data stored in the storage device if the wind speed measured by the sensor is equal to or greater than the threshold. The threshold can be set, for example, in the range of 0 m / s to 1.0 m / s. The threshold can also be set by a farmer using, for example, a terminal device or a mobile terminal. Note that if the threshold is set to 0 m / s, the processing device updates the flight path data according to the wind speed.

[0057] The processing device updates the flight path in accordance with the wind direction measured by the sensor or a representative wind direction determined from the wind direction measured by the sensor. In this specification, not only the wind direction measured by the sensor but also the representative wind direction determined from the wind direction measured by the sensor is referred to as the "wind direction measured by the sensor" or simply the "measured wind direction." In accordance with the wind direction measured by the sensor, the processing device in the embodiment of the present disclosure updates the flight path by shifting at least one of the multiple main portions 91 in a direction opposite to the wind direction.

[0058] Figure 4 is a schematic diagram showing a flight path P shifted by Δx1 in the direction opposite to the wind direction. In Figure 4, the start point Sa of the original flight path P before the change (or offset) is shown by a white circle, and the start point Sb of the flight path P after the change (or offset) is shown by a black circle. In the example shown in Figure 4, assume that wind W1 having a wind speed equal to or greater than a threshold is blowing above field F in the direction of the arrow on the X-axis.

[0059] The sensor measures wind speed and wind direction before the multicopter passes the starting point. In other words, the sensor measures wind speed and wind direction before the multicopter starts flying along the original or modified flight path. In the example shown in Figure 4, the processing device determines that the wind speed measured by the sensor is equal to or greater than a threshold.

[0060] Next, the processing device can update the flight path by shifting all of the main portions 91 in the direction opposite to the wind direction according to the wind direction measured by the sensor. Shifting the flight path P in the direction opposite to the wind direction is equivalent to shifting the flight path P to the upwind side, which means shifting the flight path P in the direction opposite to the direction of the X-axis arrow in the example shown in Figure 4.

[0061] The processing device can determine, in response to the measured wind speed, an offset amount for shifting at least one of the plurality of main portions 91 in a direction opposite to the wind direction. The processing device increases the offset amount as the wind speed increases, and decreases the offset amount as the wind speed decreases.

[0062] In the example shown in Figure 4, the processing device determines an offset amount Δx1 for shifting each of the multiple main portions 91 in the direction opposite to the wind direction, based on the wind speed measured before spraying materials. The offset amount Δx1 corresponds to the distance in the X-axis direction between the pre-change start point Sa and the post-change start point Sb. In this way, the processing device can shift the entire flight path P by moving the pre-change start point Sa by Δx1 in the direction opposite to the wind direction. In other words, the processing device can shift the entire flight path P by moving each main portion 91 by Δx1 in the direction opposite to the wind direction.

[0063] FIG. 5 is a schematic diagram showing a flight path P shifted by Δx2 in the direction opposite to the wind direction. In FIG. 5, the start point Sa of the flight path P before the change is indicated by a white circle, and the start point Sb of the flight path P after the change is indicated by a black circle. In the example shown in FIG. 5, assume that wind W2, which has a wind speed equal to or greater than a threshold and is stronger than wind W1 shown in FIG. 4, is blowing in the direction of the arrow on the X-axis above field F. The wind speed of wind W2 is greater than the wind speed of wind W1. As described with reference to FIG. 4, before the multicopter passes the start point, a sensor measures the wind speed and direction above field F. In the example shown in FIG. 5, the processing device determines that the measured wind speed is equal to or greater than a threshold.

[0064] Next, the processing device can update the flight path P by shifting all of the multiple main portions 91 in the direction opposite to the wind direction, depending on the wind direction measured by the sensor. At this time, the processing device determines an offset amount Δx2 for shifting each of the multiple main portions 91 in the direction opposite to the wind direction, depending on the wind speed measured before spraying the material. The offset amount Δx2 corresponds to the distance in the X-axis direction between the start point Sa before the change and the start point Sb after the change. The offset amount Δx2 is greater than the offset amount Δx1. In this way, the processing device can shift the entire flight path P by moving each main portion 91 by Δx2 in the direction opposite to the wind direction.

[0065] FIG. 6 is a schematic diagram illustrating a flight path P shifted in a direction opposite to the direction of a wind blowing from an oblique direction. In FIG. 6, the start point Sa of the flight path P before the change is indicated by a white circle, and the start point Sb of the flight path P after the change is indicated by a black circle. In the example shown in FIG. 6, assume that wind W3 having a wind speed equal to or greater than a threshold is blowing from a diagonal direction intersecting the X-axis or Y-axis direction, i.e., a direction intersecting multiple main portions 91. As described with reference to FIG. 4, before the multicopter passes the start point, a sensor measures the wind speed and direction above the field F. In the example shown in FIG. 6, the processing device determines that the measured wind speed is equal to or greater than a threshold.

[0066] Next, the processing device may update the flight path P by shifting all of the main portions 91 in the direction opposite to the wind direction, depending on the wind direction measured by the sensor. At this time, the processing device determines an offset amount Δx3 for shifting each of the main portions 91 in the X-axis direction, depending on the X-axis component of the wind speed of the wind W3. Furthermore, the processing device determines an offset amount Δy3 for shifting each of the main portions 91 in the Y-axis direction, depending on the Y-axis component of the wind speed of the wind W3. The offset amount Δx3 corresponds to the distance between the pre-change start point Sa and the post-change start point Sb in the X-axis direction, and the offset amount Δy3 corresponds to the distance between the pre-change start point Sa and the post-change start point Sb in the Y-axis direction. In this way, even when the wind is blowing obliquely, the processing device can shift the entire flight path P by moving each main portion 91 by Δx3 and Δy3 in the X-axis and Y-axis directions, respectively, in the direction opposite to the wind direction.

[0067] In the above example, the entire flight path is shifted in accordance with the wind speed and direction measured by the sensor before the multicopter passes the starting point of the flight path or before the multicopter starts flying along the flight path, but the present disclosure is not limited to this. As described below, the processing device may determine an offset amount and a shift direction for each main segment in accordance with the wind speed and wind direction measured at multiple measurement points while the multicopter is flying along one main segment, and shift each main segment in accordance with the determined offset amount and shift direction.

[0068] Figure 7 is a diagram illustrating an example in which an offset amount is determined for each main segment and the main segments are shifted by the determined offset amount. In Figure 7, of the multiple main segments included in the pre-change flight path, the main segment 91a-1 connected to the start point Sa, the main segment 91a-2 connected to the main segment 91a-1 via a sub-segment, and the main segment 91a-3 connected to the main segment 91a-2 via a sub-segment are each shown by dashed lines. Furthermore, of the multiple main segments included in the post-change flight path, the main segment 91b-1 connected to the start point Sb, the main segment 91b-2 connected to the main segment 91b-1 via a sub-segment, and the main segment 91b-3 connected to the main segment 91b-2 via a sub-segment are each shown by dashed lines. The three main segments 91a-1, 91a-2, and 91a-3 correspond to the three main segments 91b-1, 91b-2, and 91b-3, respectively.

[0069] Before the multicopter starts flying along each main segment, the sensor may measure the wind speed for each main segment. The processing device may determine an offset amount for each main segment according to the measured wind speed, and update the flight path by offsetting each main segment in a direction opposite to the wind direction by the determined offset amount. For example, the processing device may determine an offset amount for the next main segment based on an average or integrated value of wind speeds measured at multiple measurement points while the multicopter is flying along one main segment, and shift the main segment in a direction opposite to the wind direction by the determined offset amount.

[0070] In the example shown in Figure 7, the wind is blowing in the direction of the arrow on the X-axis. First, a sensor measures the wind speed of wind W1 blowing in the sky before the multicopter starts flying along the flight path. The processing device determines an offset amount Δx1 according to the measured wind speed of wind W1, and shifts main portion 91a-1 in the direction opposite to the direction of the arrow on the X-axis by the determined offset amount Δx1. This changes main portion 91a-1 on the flight path to main portion 91b-1.

[0071] Next, while the multicopter flies along the main portion 91b-1, a sensor measures the wind speed of wind W2 blowing in the sky at multiple measurement points. In the example shown in FIG. 7, the wind speed of wind W2 is greater than the wind speed of wind W1. The processing device determines an offset amount Δx2 greater than the offset amount Δx1 based on the average or integrated value of the wind speed of wind W2 measured at the multiple measurement points, and shifts the main portion 91a-2 in the direction opposite to the direction of the X-axis arrow by the determined offset amount Δx2. This changes the main portion 91a-2 in the flight path to the main portion 91b-2.

[0072] Next, while the multicopter flies along the main portion 91b-2, a sensor measures the wind speed of wind W3 blowing in the sky at multiple measurement points. In the example shown in FIG. 7, the wind speed of wind W3 is greater than the wind speed of wind W2. The processing device determines an offset amount Δx3 greater than the offset amount Δx2 based on the average or integrated value of the wind speed of wind W3 measured at multiple measurement points, and shifts the main portion 91a-3 in the direction opposite to the direction of the X-axis arrow by the determined offset amount Δx3. This changes the main portion 91a-3 in the flight path to the main portion 91b-3.

[0073] In this way, the processing device may shift each of the multiple main segments included in the flight path by an offset amount determined based on the wind speed measured while the multicopter was flying along the previous main segment. The processing device can update the entire flight path by repeatedly performing this process for each of the multiple main segments. Depending on the field, there may be areas where spraying of materials is prohibited (spraying prohibited areas). This method can change the flight path according to the offset amount and shift direction determined for each main segment. Therefore, flying the multicopter along the changed flight path is advantageous in preventing material spraying in spraying prohibited areas.

[0074] According to a flight path update method according to an embodiment of the present disclosure, a processing device determines a shift direction and offset amount of the flight path or a main segment included in the flight path based on wind speed and wind direction measured by a sensor before the multicopter starts flying along the flight path. This calculation does not require real-time processing, which is required for control such as attitude control during flight of the multicopter, and therefore the calculation load on the control device can be reduced. In this way, it is possible to change or update the flight path in response to wind speed and wind direction with relatively simple processing.

[0075] As shown in FIG. 1C , a sprayer for spreading materials on the ground can be connected to the multicopter according to an embodiment of the present disclosure as work machine 200. The processing device can determine an offset amount for shifting at least one of the multiple main portions in a direction opposite to the wind direction, taking into account at least one of the type, size, and weight of the material. The processing device according to an embodiment of the present disclosure can determine the offset amount based on at least one of the type, size, and weight of the material and the wind speed.

[0076] Even if the wind speed and direction are the same, the horizontal distance that materials sprayed from the air reach the ground or the spraying conditions on the ground can vary depending on the type, size, and weight of the materials. By taking into account at least one of the type, size, and weight of the materials when determining the offset amount, it is possible to more precisely change the flight path according to the wind speed and wind direction. As a result, it is possible to improve the accuracy of material spraying and to perform spraying work more efficiently.

[0077] The multicopter according to an embodiment of the present disclosure may further include a sensing device that senses the spraying status of materials by the sprayer. Examples of the sensing device include a LiDAR and an imaging device. The sensing device acquires sensing data indicating the spraying status after the multicopter flies along the changed flight path. The spraying status may be estimated, for example, by applying image analysis to images acquired by the imaging device. Alternatively, the spraying status may be estimated from wind speed, wind direction, and an offset amount relative to each main segment or the entire flight path measured while the multicopter flies along the flight path.

[0078] The wind speed and / or wind direction measured by the sensors before the multicopter begins flying along the flight path may differ from the wind speed and / or wind direction measured as the multicopter flies along each main segment of the flight path. Furthermore, even while the multicopter is flying along the same main segment, the wind speed and / or wind direction may change depending on the section of the main segment. Therefore, when the multicopter flies along the changed flight path, the degree of material spraying on the field may be uneven.

[0079] FIG. 8 is a diagram schematically illustrating an example of the spraying situation after the multicopter flies along the changed flight path. In FIG. 8, two adjacent main segments 91-1 and 91-2 among the multiple main segments 91 included in the flight path are indicated by dashed lines. Consider a case in which, while the multicopter is flying along the main segment 91-1, the wind speed measured in sections Z1 and Z3 of the main segment 91-1 differs from the wind speed measured in section Z2. In the illustrated example, the wind temporarily weakens in section Z2, and the wind speed measured in section Z2 is lower than the wind speed measured in sections Z1 or Z3. Therefore, the reach distance in the X-axis direction of the materials sprayed while the multicopter is flying in section Z2 is shorter than the reach distance in the X-axis direction of the materials sprayed while the multicopter is flying in section Z1 or Z3. 8, the size of completed spraying area 95-2 within spraying target area 95, where spraying has been completed, is smaller than the size in the X-axis direction of each of completed spraying areas 95-1 and 95-3 within spraying target area 95. As a result, the degree of material spraying becomes uneven, resulting in an incomplete area 96-1 within spraying target area 95 (entire area) on the ground where spraying of materials is not complete.

[0080] Similarly, consider a case where, while a multicopter is flying along the main portion 91-2, the wind speed measured in section Z4 of the main portion 91-2 is different from the wind speed measured in section Z5. In the illustrated example, the wind temporarily weakens in section Z4, and the wind speed measured in section Z4 is lower than the wind speed measured in section Z5. Therefore, the reach distance in the X-axis direction of the materials scattered while the multicopter is flying through section Z4 is shorter than the reach distance in the X-axis direction of the materials scattered while the multicopter is flying through section Z5. In the example shown in FIG. 8 , the size in the X-axis direction of the completed spraying region 95-4 within the spraying target area 95 is smaller than the size of the completed spraying region 95-5 within the spraying target area 95. As a result, an incomplete area 96-2, where spraying has not been completed, is created within the spraying target area 95.

[0081] The processing device may, for example, apply image analysis to image data output from the imaging device to estimate the geographical coordinates and / or size on the ground of such incomplete areas that may exist within the scattering target area 95. Alternatively, the processing device may estimate the geographical coordinates and / or size on the ground of the incomplete areas from, for example, latitude and longitude information included in the flight path, wind speed and direction measured while the multicopter flies along the flight path, and offset amounts relative to each main segment or the entire flight path.

[0082] The processing device may generate a further flight path for spraying materials in the estimated incomplete areas and fly the multicopter along the further flight path. FIG. 9 is a diagram schematically illustrating an example of a further flight path for spraying materials in the estimated incomplete areas. In the example shown in FIG. 9, there are three incomplete areas 96-1, 96-2, and 96-3 within a target spraying area 95 on the ground where spraying has not been completed. In this case, the processing device may generate a further flight path for re-spraying materials in the three incomplete areas 96-1, 96-2, and 96-3 and fly the multicopter along the further flight path. This can reduce unevenness in material spraying that may occur due to wind or reduce the proportion of incomplete areas in the overall target spraying area. In other words, if re-spraying of materials is necessary, it can prevent double spraying of completed spraying areas.

[0083] The sprayer may be equipped with a nozzle with an angle adjustment mechanism for adjusting the direction in which materials are sprayed into the air. While the multicopter is flying along its flight path, a sensor may periodically measure wind speed and direction, and the angle adjustment mechanism may be controlled in accordance with the measurement results, thereby adjusting the direction in which materials are sprayed in real time. Alternatively, one main section of the flight path may be divided into multiple straight sections, and the wind speed and direction measured for each section may be fed back sequentially to update the flight path. This allows for precise setting of a flight path according to wind speed and direction. Furthermore, combining such flight path setting with control of the nozzle angle adjustment mechanism may improve the accuracy of material spraying.

[0084] As described above, according to the embodiments of the present disclosure, optimization of material spraying by a multicopter is realized by taking into account wind speed and wind direction, and further, rationalization of material spraying can be realized by taking into account at least one of the type, size, and weight of the material.

[0085] The control device 4a in the embodiment of the present disclosure can be realized by a digital computer system programmed to execute the above-described processes.

[0086] 10 is a block diagram showing an example of the hardware configuration of the control device 4a. The control device 4a includes a processing device 34, a read-only memory (ROM) 35, a random access memory (RAM) 36, a storage device 37, and a communication I / F 38. These components are interconnected via a bus 39. The bus 39 is, for example, a controller area network (CAN) bus.

[0087] The processing device 34 is a device including one or more semiconductor integrated circuits (e.g., processors). The processor is also called a central processing unit (CPU) or a microprocessor. The processor sequentially executes computer programs stored in the ROM 35 to perform the above-described processing. The term "processor" is broadly interpreted as including a field programmable gate array (FPGA), a graphic processor unit (GPU), an application specific integrated circuit (ASIC), or an application specific standard product (ASSP) equipped with a CPU.

[0088] The ROM 35 is, for example, a writable memory (e.g., a PROM), a rewritable memory (e.g., a flash memory), or a read-only memory. The ROM 35 stores a program that controls the operation of the processor. The ROM 35 does not have to be a single recording medium, but may be a collection of multiple recording media. Some of the collection of multiple recording media may be removable memories.

[0089] The RAM 36 provides a working area for temporarily loading the programs stored in the ROM 35 at boot time. The RAM 36 does not have to be a single recording medium, but can be a collection of multiple recording media.

[0090] The communication I / F 38 is an interface for communication between the control device 4a and other electronic components or electronic control units (ECUs). For example, the communication I / F 38 can perform wired communication in accordance with various protocols. The communication I / F 38 may perform wireless communication in accordance with the Bluetooth (registered trademark) standard and / or the Wi-Fi (registered trademark) standard. Both standards include wireless communication standards using frequencies in the 2.4 GHz band.

[0091] The storage device 37 may be, for example, a semiconductor memory, a magnetic storage device, an optical storage device, or a combination thereof. The storage device 37 may store, for example, map data useful for the autonomous flight of the multicopter 10, flight path data, and various sensor data acquired by the multicopter 10 during flight.

[0092] The processing device 34 can function as a processing device for the flight path generation system described above, and the storage device 37 can function as a storage device for the flight path generation system.

[0093] As described above, the control device 4a may include, for example, a flight control device such as a flight controller and a host computer (companion computer). The companion computer may perform various processes necessary to update the flight path, and flight-related commands based on the results of these processes may be transmitted from the companion computer to the flight controller or the flight path generation system. Furthermore, some or all of the functions of the electrical components such as the control device 4a mounted on the multicopter 10 or the flight path generation system may be implemented by one or more servers (computers) 500 or terminal devices (including portable and fixed types) 600 connected to the communication device 4c of the multicopter 10 via a communication network N, as shown in FIG. 11 . An agricultural machine 700 such as a tractor may be connected to such a communication network N, and communication may be performed between the multicopter 10 and the agricultural machine 700. Some of the data used in the processing of the control device 4a and control signals for the multicopter 10 may be transmitted from the agricultural machine 700 to the multicopter 10 via the communication network N.

[0094] A system providing various functions in the embodiments can also be retrofitted to a multicopter that does not have those functions. Such a system can be manufactured and sold independently of the multicopter. A computer program used in such a system can also be manufactured and sold independently of the multicopter. The computer program can be provided, for example, by being stored in a computer-readable non-transitory storage medium. The computer program can also be provided by downloading via a telecommunications line (e.g., the Internet).

[0095] This specification discloses the solutions described in the following items.

[0096] [Item 1] A flight path generation system to be mounted on an unmanned aerial vehicle, comprising: an acquisition device that acquires data on a predetermined flight path; a sensor that measures wind direction and outputs sensor data indicating the wind direction; and a processing device that updates the flight path according to the wind direction indicated by the sensor data.

[0097] [Item 2] The flight path generation system described in Item 1, wherein the flight path includes a plurality of main segments and a plurality of sub-segments, each sub-segment connecting the main segments, and the processing device updates the flight path by shifting at least one of the plurality of main segments in a direction opposite to the wind direction according to the wind direction indicated by the sensor data.

[0098] [Item 3] The flight path generation system according to Item 2, wherein each of the plurality of main segments includes a straight segment.

[0099] [Item 4] A flight path generation system as described in Item 2 or 3, wherein the flight path includes a starting point that causes the unmanned aerial vehicle to begin flight along the flight path, the sensor measures the wind direction before the unmanned aerial vehicle passes the starting point, and the processing device updates the flight path by shifting all of the multiple main segments in a direction opposite to the wind direction according to the measured wind direction.

[0100] [Item 5] The flight path generation system according to item 2 or 3, wherein the sensor is configured to further measure wind speed, and the processing device determines an offset amount for shifting at least one of the plurality of main portions in a direction opposite to the wind direction according to the wind speed.

[0101] [Item 6] A flight path generation system as described in Item 5, wherein before the unmanned aerial vehicle starts flying along each of the plurality of main portions, the sensor measures the wind speed for each main portion, and the processing device determines the offset amount for each main portion according to the measured wind speed, and updates the flight path by shifting each main portion in a direction opposite to the wind direction by the determined offset amount.

[0102] [Item 7] A flight path generation system as described in Item 2 or 3, wherein the unmanned aerial vehicle can be connected to a sprayer for spraying granular or liquid agricultural materials on the ground, and the processing device determines an offset amount for shifting at least one of the plurality of main parts in a direction opposite to the wind direction, taking into account at least one of the type, size, and weight of the agricultural material.

[0103] [Item 8] The flight path generation system described in Item 7 further includes a sensing device that senses the spraying status of the agricultural materials by the sprayer, the sensing device acquires the sensing data indicating the spraying status after the unmanned aerial vehicle has flown along the updated flight path, and the processing device estimates, based on the sensing data, incomplete areas where spraying has not been completed out of the entire area on the ground to be sprayed with the agricultural materials.

[0104] [Item 9] The flight path generation system described in Item 8, wherein the processing device generates a further flight path for spraying the agricultural material in the estimated uncompleted area and flies the unmanned aerial vehicle along the further flight path.

[0105] [Item 10] An unmanned aerial vehicle comprising: a plurality of rotors; and a flight path generation system according to any one of items 1 to 9.

[0106] The unmanned aerial vehicle disclosed herein can be widely used not only for aerial photography, surveying, logistics, and pesticide spraying, but also for ground work related to agricultural work, transporting harvested products and agricultural materials, and the like.

[0107] 2: Rotor (propeller), 3: Rotation drive device, 4: Airframe body, 4a: Control device, 4b: Sensor group, 4c: Communication device, 5: Airframe frame, 6: Ground station, 7a: Internal combustion engine, 7b: Fuel tank, 8: Power generation device, 9: Power buffer, 10: Multicopter, 12, 22: Rotor, 14: Motor, 16: ESC, 76: Power supply device, 200: Work machine

Claims

1. A flight path generation system mounted on an unmanned aerial vehicle, an acquisition device that acquires data of a predetermined flight path; a sensor that measures wind direction and outputs sensor data indicating the wind direction; a processing device that updates the flight path in response to the wind direction indicated by the sensor data; A flight path generation system comprising:

2. the flight path includes a plurality of main segments and a plurality of sub-segments, each sub-segment connecting the main segments; The flight path generation system according to claim 1 , wherein the processing device updates the flight path by shifting at least one of the plurality of main portions in a direction opposite to the wind direction according to the wind direction indicated by the sensor data.

3. The flight path generation system of claim 2 , wherein each of the plurality of main segments includes a straight segment.

4. the flight path includes a starting point that causes the unmanned aerial vehicle to begin flight along the flight path; the sensor measures the wind direction before the unmanned aerial vehicle passes the starting point; The flight path generation system according to claim 2 or 3, wherein the processing device updates the flight path by shifting all of the plurality of main segments in a direction opposite to the measured wind direction, in accordance with the measured wind direction.

5. the sensor is configured to further measure wind speed; The flight path generation system according to claim 2 or 3, wherein the processing device determines an offset amount for shifting at least one of the plurality of main portions in a direction opposite to the wind direction in accordance with the wind speed.

6. Before the unmanned aerial vehicle starts flying along each of the plurality of main portions, the sensor measures the wind speed for each main portion; 6. The flight path generation system according to claim 5, wherein the processing device determines the offset amount for each main segment according to the measured wind speed, and updates the flight path by shifting each main segment in a direction opposite to the wind direction by the determined offset amount.

7. A sprayer for spraying granular or liquid agricultural materials on the ground can be connected to the unmanned aerial vehicle; 4. The flight path generation system of claim 2, wherein the processing device determines an offset amount for shifting at least one of the plurality of main portions in a direction opposite to the wind direction, taking into account at least one of the type, size, and weight of the agricultural material.

8. The agricultural material spraying method further includes a sensing device that senses the spraying status of the agricultural material by the sprayer, the sensing device acquires the sensing data indicating a spraying situation after the unmanned aerial vehicle has flown along the updated flight path; The flight path generation system according to claim 7 , wherein the processing device estimates, based on the sensing data, an incomplete area where spraying has not been completed out of the entire area on the ground to which the agricultural material is to be sprayed.

9. The flight path generation system of claim 8 , wherein the processing device generates a further flight path for spraying the agricultural material in the estimated uncompleted area and flies the unmanned aerial vehicle along the further flight path.

10. A plurality of rotors; A flight path generation system according to any one of claims 1 to 3; An unmanned aerial vehicle comprising: