WO2020095842A1

WO2020095842A1 - Drone

Info

Publication number: WO2020095842A1
Application number: PCT/JP2019/043061
Authority: WO
Inventors: 千大和氣; 洋柳下
Original assignee: 株式会社ナイルワークス
Priority date: 2018-11-06
Filing date: 2019-11-01
Publication date: 2020-05-14
Also published as: JPWO2020095842A1; JP6913979B2

Abstract

[Problem] To generate downwash with a stronger wind force in a drone having rotary wings. [Solution] A drone 100 is provided with a body 110 and a plurality of rotary wings 101 arranged around the body so as to form a plurality of pairs each disposed vertically, and the drone 100 moves through generating thrust with downwash generated downward of lower-side rotary wings 101-1b, 101-2b, 101-3b, 101-4b. Upper-side rotary wings 101-1a, 101-2a, 101-3a, 101-4a and the lower-side rotary wings rotate in directions opposite to each other. The diameters of the lower-side rotary wings are smaller than the diameters of the upper-side rotary wings.

Description

Drone

The present invention relates to drones.

The application of small helicopters (multicopters) commonly called drones is progressing. One of the important fields of application thereof is spraying chemicals such as pesticides and liquid fertilizers on agricultural land (field) (for example, Patent Document 1). In relatively small farmlands, it is often the case that drones are more suitable than manned planes and helicopters.

Technologies such as the Quasi-Zenith Satellite System and RTK-GPS (Real Time Kinematic-Global Positioning System) have made it possible for the drone to accurately know its absolute position in centimeters during flight. Even in a farmland with a narrow and complicated terrain typical of the above, it is possible to autonomously fly with minimal manual operation, and to efficiently and accurately apply a drug.

On the other hand, there were cases where it was difficult to say that safety considerations were sufficient for autonomous flight drones for agricultural drug spraying. A drone loaded with medicines weighs several tens of kilograms, which could have serious consequences in the event of an accident such as falling onto a person. In addition, the drone operator is usually not an expert, so a fool-proof mechanism is necessary, but the consideration for this was insufficient. Until now, there has been a drone safety technology that is premised on human control (for example, Patent Document 2), but in particular, it addresses the safety issues peculiar to an autonomous flight drone for drug spraying for agriculture. There was no technology to do this.

In agricultural drones, a method is known in which the crops in the field are appropriately laid down by downwash (also referred to as "downdraft") to expose the crop stockers, spray the chemicals, and photograph the stock crops. ing. Drones that can generate downdrafts with stronger wind power are needed to expose crop origins.

Patent Literature 3 discloses a counter-rotating propeller device in which two front and rear propellers are provided on the same axis, and thrust is generated by rotating a front propeller and a rear propeller in mutually opposite directions. Are disclosed, each of which is set larger than the diameter and pitch of the rear propeller.

Patent Document 4 discloses that in a gas turbine engine having a contra-rotating propeller array having front and rear propellers, the diameter of the front propeller is larger than the diameter of the rear propeller in order to reduce engine noise.

Patent publication gazette JP 2001-120151 Patent publication gazette JP 2017-163265 Patent publication gazette JP-A-60-226391 Japanese Patent Laid-Open Publication No. 2013-144545

-Provides a drone that can generate a downdraft with stronger wind power in a drone that has rotor blades.

In order to achieve the above object, a drone according to one aspect of the present invention includes a main body, a plurality of rotor blades arranged around the main body, and a plurality of pairs of rotor blades that are arranged in pairs vertically. A drone that moves by generating thrust by downward airflow generated toward the lower part of the lower rotary blade, wherein the upper rotary blade and the lower rotary blade rotate in mutually opposite directions, and the lower rotary blade The diameter of the blade is smaller than the diameter of the upper rotary blade.

The elevation angle of the lower rotor blade may be smaller than the elevation angle of the upper rotor blade.

The diameter of the lower rotor blade may be smaller than 95% of the diameter of the upper rotor blade.

The diameter of the lower rotary blade may be configured to be larger than 80% of the diameter of the upper rotary blade.

The diameter of the lower rotor blade may be configured to be 90% of the diameter of the upper rotor blade.

A flight control unit may be further provided, which controls rotation speeds of each of the plurality of rotor blades, and can control rotation of the upper rotor blade and the lower rotor blade in mutually opposite directions.

The drone may be capable of performing a predetermined work in the target area, and the flight control unit may be configured to reduce the flight speed during the work more than during the work.

The drone can perform a predetermined work in the target area, and the flight control unit may be configured to lower the altitude during the work more than when the work is not performed.

The drone is a drone used for spraying a drug, further including a drug tank for storing a drug and a drug nozzle for discharging the drug, and the object is laid down by a downdraft generated by the plurality of rotor blades. By doing so, the medicine may reach the root of the object.

The drone is a drone that further includes an imaging unit, and may be configured to image the root of the object by laying the object down due to the descending airflow generated by the plurality of rotor blades.

▽ In a drone with rotating blades, it is possible to generate a downdraft with stronger wind force.

1 is a plan view showing an embodiment of a drone according to the present invention. It is a front view of the said drone. It is a right view of the said drone. It is a rear view of the drone. It is a perspective view of the drone. It is the whole conceptual diagram of the medicine spraying system which the drone has. It is a schematic diagram showing the control function of the said drone. (a) A schematic vertical cross-sectional view showing how a one-stage rotor having a related art drone generates a swirl flow, and (b) a two-stage rotor having a drone according to the present invention has a swirl flow. FIG. 4 is a schematic vertical cross-sectional view showing a state in which is generated.

Hereinafter, modes for carrying out the present invention will be described with reference to the drawings. The figures are all examples. In the following detailed description, for purposes of explanation, certain specific details are set forth in order to facilitate a thorough understanding of the disclosed embodiments. However, embodiments are not limited to these particular details. Also, well-known structures and devices are schematically shown in order to simplify the drawing.

In the specification of the present application, the drone, regardless of power means (electric power, prime mover, etc.), control method (whether wireless or wired, and whether it is an autonomous flight type or a manual control type), It refers to all aircraft with multiple rotors.

● Drone ●
As shown in FIGS. 1 to 5, the rotor blades 101-1a, 101-1b, 101-2a, 101-2b, 101-3a, 101-3b, 101-4a, 101-4b (also referred to as rotors) are It is a means to fly the drone 100, and considering the stability of flight, the size of the aircraft, and the balance of battery consumption, 8 aircraft (4 sets of two-stage rotary blades) are provided around the main body 110. ing. Each rotor 101 is arranged on four sides of the main body 110 by an arm 120 extending from the main body 110 of the drone 100. That is, the rotating blades 101-1a, 101-1b on the left rear in the traveling direction, the rotating blades 101-2a, 101-2b on the left front, the rotating blades 101-3a, 101-3b on the right rear, and the rotating blades 101-on the right front. 4a and 101-4b are arranged respectively. Note that the drone 100 has the traveling direction downward in the plane of FIG.

The motors 102-1a, 102-1b, 102-2a, 102-2b, 102-3a, 102-3b, 102-4a, 102-4b are rotor blades 101-1a, 101-1b, 101-2a, 101-. 2b, 101-3a, 101-3b, 101-4a, 101-4b is a means for rotating (typically an electric motor, but may be an engine, etc.), one for each rotor Has been. The motor 102 is an example of a propulsion device. The upper and lower rotor blades (eg 101-1a and 101-1b) and their corresponding motors (eg 102-1a and 102-1b) in one set are for drone flight stability etc. The axes are collinear and rotate in opposite directions. Although some rotor blades 101-3b and the motor 102-3b are not shown, their positions are self-explanatory, and if there is a left side view, they are at the positions shown. As shown in FIGS. 2 and 3, the radial member for supporting the propeller guard, which is provided so that the rotor does not interfere with foreign matter, is not horizontal but has a tower-like structure. This is to promote the buckling of the member to the outside of the rotor blade at the time of collision and prevent the member from interfering with the rotor.

The drug nozzles 103-1, 103-2, 103-3, 103-4 are means for spraying the drug downward, and are equipped with four machines. In the specification of the present application, the term "chemicals" generally refers to pesticides, herbicides, liquid fertilizers, insecticides, seeds, and liquids or powders applied to fields such as water.

The drug tank 104 is a tank for storing the sprayed drug, and is provided at a position close to the center of gravity of the drone 100 and lower than the center of gravity from the viewpoint of weight balance. The drug hoses 105-1, 105-2, 105-3, 105-4 are means for connecting the drug tank 104 and the drug nozzles 103-1, 103-2, 103-3, 103-4, and are rigid. And may also serve to support the chemical nozzle. The pump 106 is a means for discharging the medicine from the nozzle.

FIG. 6 shows an overall conceptual diagram of a system using an example of drug spraying application of the drone 100 according to the present invention. This figure is a schematic diagram and the scale is not accurate. The operation unit 401 is a means for transmitting a command to the drone 100 by the operation of the user 402 and displaying information received from the drone 100 (for example, position, drug amount, battery level, camera image, etc.). Yes, and may be realized by a portable information device such as a general tablet terminal that runs a computer program. Although the drone 100 according to the present invention is controlled to perform autonomous flight, it may be configured so that it can be manually operated during basic operations such as takeoff and return, and during emergencies. In addition to the portable information device, you may use an emergency operating device (not shown) that has a function dedicated to emergency stop (a large emergency stop button, etc. is provided so that the emergency operating device can respond quickly in an emergency). It may be a dedicated device with). The operation unit 401 and the drone 100 perform wireless communication by Wi-Fi or the like.

The field 403 is a rice field, a field, etc. to which the drug is sprayed by the drone 100. Actually, the topography of the farm field 403 is complicated, and there are cases where the topographic map cannot be obtained in advance, or the topographic map and the situation at the site are inconsistent. Normally, the farm field 403 is adjacent to a house, a hospital, a school, another crop farm field, a road, a railroad, and the like. In addition, there may be obstacles such as buildings and electric wires in the field 403.

The base station 404 is a device that provides a master device function of Wi-Fi communication, etc., and may also function as an RTK-GPS base station to provide an accurate position of the drone 100 (Wi- The base unit function of Fi communication and RTK-GPS base station may be independent devices). The farm cloud 405 is typically a group of computers operated on a cloud service and related software, and may be wirelessly connected to the operation unit 401 via a mobile phone line or the like. The farming cloud 405 may analyze the image of the field 403 captured by the drone 100, grasp the growing condition of the crop, and perform a process for determining a flight route. Further, the drone 100 may be provided with the stored topographical information of the field 403 and the like. In addition, the history of the flight of the drone 100 and captured images may be accumulated and various analysis processes may be performed.

Normally, the drone 100 will take off from the landing point 406 outside the field 403 and return to the landing point 406 after spraying the drug on the field 403 or when it becomes necessary to replenish or charge the drug. The flight route (entry route) from the landing point 406 to the target field 403 may be stored in advance in the farm cloud 405 or the like, or may be input by the user 402 before the start of takeoff.

FIG. 7 shows a block diagram showing the control function of the embodiment of the drug spraying drone according to the present invention. The flight controller 501 is a component that controls the entire drone, and specifically may be an embedded computer including a CPU, a memory, related software, and the like. The flight controller 501, based on the input information received from the operation unit 401 and the input information obtained from various sensors described later, via the control means such as ESC (Electronic Speed Control), the motor 102-1a, 102-1b , 102-2a, 102-2b, 102-3a, 102-3b, 104-a, 104-b are controlled to control the flight of the drone 100. The actual rotation speed of the motors 102-1a, 102-1b, 102-2a, 102-2b, 102-3a, 102-3b, 104-a, 104-b is fed back to the flight controller 501 to perform normal rotation. It is configured so that it can be monitored. Alternatively, the rotary blade 101 may be provided with an optical sensor or the like so that the rotation of the rotary blade 101 is fed back to the flight controller 501. The flight controller 501 is an example of a flight controller.

The software used by the flight controller 501 can be rewritten through storage media or the like for function expansion / change, problem correction, etc., or through communication means such as Wi-Fi communication or USB. In this case, encryption, checksum, electronic signature, virus check software, etc. are used to protect the software from being rewritten by unauthorized software. Further, a part of the calculation process used by the flight controller 501 for control may be executed by another computer existing on the operation unit 401, the farm cloud 405, or another place. Since the flight controller 501 is highly important, some or all of its constituent elements may be duplicated.

The battery 502 is a means for supplying electric power to the flight controller 501 and other components of the drone, and may be rechargeable. The battery 502 is connected to the flight controller 501 via a power supply unit including a fuse or a circuit breaker. The battery 502 may be a smart battery having a function of transmitting its internal state (amount of stored electricity, accumulated use time, etc.) to the flight controller 501 in addition to the power supply function.

The flight controller 501 exchanges with the operation unit 401 via the Wi-Fi slave unit 503 and further via the base station 404, receives a necessary command from the operation unit 401, and outputs necessary information to the operation unit 401. Can be sent to. In this case, the communication may be encrypted so as to prevent illegal acts such as interception, spoofing, and hijacking of equipment. The base station 404 has a function of an RTK-GPS base station in addition to a communication function by Wi-Fi. By combining the signal from the RTK base station and the signal from the GPS positioning satellite, the GPS module 504 can measure the absolute position of the drone 100 with an accuracy of about several centimeters. Since the GPS module 504 is highly important, it may be duplicated / multiplexed, and each redundant GPS module 504 should use a different satellite to cope with the failure of a specific GPS satellite. It may be controlled.

The 6-axis gyro sensor 505 is a means for measuring accelerations of the drone aircraft in three directions orthogonal to each other (further, a means for calculating speed by integrating accelerations). The 6-axis gyro sensor 505 is a means for measuring the change in the attitude angle of the drone body in the three directions described above, that is, the angular velocity. The geomagnetic sensor 506 is a means for measuring the direction of the drone body by measuring the geomagnetism. The atmospheric pressure sensor 507 is a means for measuring the atmospheric pressure, and can indirectly measure the altitude of the drone. The laser sensor 508 is a means for measuring the distance between the drone body and the ground surface by utilizing the reflection of laser light, and may be an IR (infrared) laser. The sonar 509 is a means for measuring the distance between the drone body and the ground surface by using the reflection of sound waves such as ultrasonic waves. These sensors may be selected depending on the drone's cost goals and performance requirements. Further, a gyro sensor (angular velocity sensor) for measuring the tilt of the machine body, a wind force sensor for measuring wind force, and the like may be added. Further, these sensors may be duplicated or multiplexed. If there are multiple sensors for the same purpose, the flight controller 501 may use only one of them, and if it fails, it may switch to another sensor for use. Alternatively, a plurality of sensors may be used at the same time, and if the measurement results do not match, it may be considered that a failure has occurred.

The flow rate sensor 510 is a means for measuring the flow rate of the medicine, and is provided at a plurality of places on the path from the medicine tank 104 to the medicine nozzle 103. The liquid shortage sensor 511 is a sensor that detects that the amount of the medicine has become equal to or less than a predetermined amount. The multi-spectral camera 512 is a means for photographing the field 403 and acquiring data for image analysis. The obstacle detection camera 513 is a camera for detecting a drone obstacle and is a device different from the multispectral camera 512 because the image characteristics and the lens orientation are different from those of the multispectral camera 512. The switch 514 is a means for the user 402 of the drone 100 to make various settings. The obstacle contact sensor 515 is a sensor for detecting that the drone 100, in particular, its rotor or propeller guard portion has come into contact with an obstacle such as an electric wire, a building, a human body, a tree, a bird, or another drone. .. The cover sensor 516 is a sensor that detects that the operation panel of the drone 100 and the cover for internal maintenance are open. The drug injection port sensor 517 is a sensor that detects that the injection port of the drug tank 104 is open. These sensors may be selected according to the drone's cost targets and performance requirements, and may be duplicated or multiplexed. Further, a sensor may be provided at the base station 404 outside the drone 100, the operation device 401, or at another place, and the read information may be transmitted to the drone. For example, a wind sensor may be provided in the base station 404, and information regarding wind force / wind direction may be transmitted to the drone 100 via Wi-Fi communication.

The flight controller 501 sends a control signal to the pump 106 to adjust the drug discharge amount and stop the drug discharge. The current status of the pump 106 (for example, the number of rotations) is fed back to the flight controller 501.

LED107 is a display means for notifying the drone operator of the status of the drone. As the display means, a display means such as a liquid crystal display may be used instead of the LED or in addition to the LED. The buzzer 518 is an output means for notifying a drone state (especially an error state) by a voice signal. The Wi-Fi slave device function 503 is an optional component for communicating with an external computer or the like, for example, for software transfer, in addition to the operation unit 401. In addition to or in addition to the Wi-Fi cordless handset function, other wireless communication means such as infrared communication, Bluetooth (registered trademark), ZigBee (registered trademark), NFC, or wired communication means such as USB connection May be used. The speaker 520 is an output means for notifying the drone state (particularly an error state) by the recorded human voice, synthesized voice or the like. Depending on the weather conditions, it may be difficult to see the visual display of the drone 100 in flight, and in such a case, it is effective to communicate the situation by voice. The warning light 521 is a display means such as a strobe light for notifying the state of the drone (in particular, an error state). These input / output means may be selected according to the cost target and performance requirements of the drone, or may be duplicated / multiplexed.

As shown in FIGS. 1 to 5, the diameters of the lower rotary blades 101-1b, 101-2b, 101-3b, 101-4b are the same as those of the upper rotary blades 101-1a, 101-2a, 101-3a, 101. It is smaller than the diameter of -4a, about 90%. The elevation angles of the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b are smaller than the elevation angles of the upper rotor blades 101-1a, 101-2a, 101-3a, 101-4a. By making the configurations of the upper and lower rotary blades different in this way, the swirling flow can be canceled.

Fig. 8 will be used to explain how the counter-rotating blades cancel out the swirling flow. Since the drawing is a longitudinal sectional view, only the front rotor blades 201-2a and 201-4a of the related art drone 200 and the front rotor blades 101-2 and 101-4 of the drone 100 according to the present invention are shown. However, the same applies to the state of the swirling flow in the rear rotor blade. Further, the drone 200 shown in FIG. 8 (a) is a drone 200 in which arms extending from the main body 210 are arranged on the four sides of the main body 210 to form a single-stage rotary blade. It is almost the same as 100.

As shown in FIG. 8 (a), the rotary blades 201-2a and 201-4a of the one-stage configuration in the drone 200 of the related art respectively generate swirling flows 261-2a and 261-4a near the outer circumferences of their respective rotation loci. Occur. Therefore, as shown in FIG. 8 (b), the rotary blades 101 are arranged coaxially to form a two-stage structure in which pairs are vertically arranged, and the upper and lower rotary blades 101 are rotated in opposite directions to each other. Swirl flow 61-2a, 61-4a generated by the rotary blades 101-2a, 101-4a of the above and swirl flow 61-2b, 61-4b generated by the lower rotary blades 101-2b, 101-4b are in opposite directions. To do. With this configuration, the swirling flows generated by the rotary blades 101 can be canceled each other. By canceling the swirling flow, it is possible to further increase the downward airflow downward by the rotor blades.

The diameter of the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b is smaller than the diameter of the upper rotor blades 101-1a, 101-2a, 101-3a, 101-4a. Further speaking, the diameter of the lower rotary blades 101-1b, 101-2b, 101-3b, 101-4b is 95 times the diameter of the upper rotary blades 101-1a, 101-2a, 101-3a, 101-4a. It should be smaller than%. If the diameter of the lower rotary blades 101-1b, 101-2b, 101-3b, 101-4b is larger than 95% of the diameter of the upper rotary blades 101-1a, 101-2a, 101-3a, 101-4a, The upward airflow generated by the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b cancels the downward airflow of the upper rotor blades 101-1a, 101-2a, 101-3a, 101-4a. The total amount of downdraft discharged below the two-stage rotor blade becomes small.

Further, the diameter of the lower rotary blade 101-1b, 101-2b, 101-3b, 101-4b is 80% of the diameter of the upper rotary blade 101-1a, 101-2a, 101-3a, 101-4a. It should be big. If the diameter of the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b is smaller than 80% of the diameter of the upper rotor blades, the upper rotor blades 101-1a, 101-2a, 101-3a The effect of sufficiently canceling the swirling flow by 101-4a becomes small. Therefore, the rotor blades 101-1b, 101-2b, 101-3b, 101-4b in the lower stage generate wind force of downdraft generated by the rotor blades 101-1a, 101-2a, 101-3a, 101-4a in the upper stage. A shape that generates wind force that cancels the swirl flow without impairing it, that is, smaller than 95% and larger than 80% of the diameter of the upper rotor blades 101-1a, 101-2a, 101-3a, 101-4a. It is configured. Further, the weight of the rotor blades 101-1b, 101-2b, 101-3b, 101-4b can be reduced. When the diameter of the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b is 90% of the diameter of the upper rotor blades 101-1a, 101-2a, 101-3a, 101-4a. , The downdraft can be maximized.

By reducing the elevation angle of the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b, the wind force generated by the rotor blades 101-1b, 101-2b, 101-3b, 101-4b is reduced. be able to. Since the swirl flow is generated on the outer circumference of the rotation trajectory of the rotary blade, when the diameter of the rotary blade is reduced, the region where the swirl flow is generated moves inward in the radial direction. Therefore, if the diameter of the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b is too small, the lower rotor blades 101-1b, 101-2b, 101-3b, 101-4b cause There is a large difference between the swirl flow 61-2b, 61-4b region and the swirl flow 61-1 region due to the upper rotor blades 101-1a, 101-2a, 101-3a, 101-4a, and the swirl flow is effective. Cannot cancel each other out. Therefore, to prevent the diameter of the lower rotor blade from becoming too small, the diameter of the upper rotor blade is reduced to about 90% while the elevation angle of the lower rotor blade is reduced to change the region where swirling flow occurs. Without generating a swirl flow.

▽ The downdraft by the rotating blades 101 of the drone 100 flows backward in the traveling direction of the drone 100. This downdraft creates the effect of temporarily overriding the crops in the field. Experiments by the inventor have revealed that the crop most affected by the air flow created by the rotor blades 101 of the drone 100 is behind the traveling direction of the drone 100 and is at a depression angle of about 60 degrees. .. The crop is an example of the object. The target object may have various configurations other than the crop, which is collapsed by the wind from above.

The drone 100 may be a drug spraying drone that flies in the field and sprays a drug on the root or the tip of the crop growing in the field, or may be a growth monitoring drone that monitors the growth of the crop. Good. A field is an example of a target area, and drug spraying and growth monitoring are examples of predetermined work. If the descending airflow from the rotor blades 101 is small, the crop cannot be sufficiently laid down, and in the drug spray drone, the drug may not be able to sufficiently reach the plant base of the crop. Further, in the growth monitoring drone, there is a possibility that the plant origin of the crop may not be properly photographed. According to the drone 100 of the present invention, it is possible to generate a sufficient downdraft of the wind power, and thus it is possible to more effectively carry out drug spraying and growth monitoring.

The flight control unit may reduce the flight speed during work compared to when the work is not in progress. During work, i.e. during drug spraying or growth monitoring, it is necessary to lay down crops in a downdraft. As mentioned above, by reducing the flight speed during work, the wind force of the downdraft that reaches the crop can be increased, and the crop can be laid down.

-The flight control unit may lower the altitude during work as compared to during flight except during work. During work, that is, during spraying of chemicals or monitoring of growth, it is necessary to lay down the crops with the downdraft, so by lowering the flight altitude, it is possible to secure the wind force of the downdraft necessary to lay down the crops. it can.

Note that, in the present description, the drug spray drone has been described as an example, but the technical idea of the present invention is not limited to this, and can be applied to all flying bodies having a rotary wing. This flying body may be capable of autonomous flight or may be capable of manual flight control.

(Technically remarkable effect of the present invention)
In the drone according to the present invention, the drone having the rotor blade can generate the downdraft with stronger wind force.

Claims

Body,
A plurality of rotor blades arranged around the main body, and a plurality of pairs of rotor blades arranged in pairs vertically.
And a drone that moves by generating thrust by descending airflow generated toward the lower side of the lower rotor blade,
The upper rotary blade and the lower rotary blade rotate in mutually opposite directions,
The diameter of the lower rotary blade is smaller than the diameter of the upper rotary blade,
Drone.
The elevation angle of the lower rotor blade is smaller than the elevation angle of the upper rotor blade,
The drone according to claim 1.
The diameter of the lower rotary blade is smaller than 95% of the diameter of the upper rotary blade,
The drone according to claim 1 or 2.
The diameter of the lower rotary blade is greater than 80% of the diameter of the upper rotary blade,
The drone according to claim 3.
The diameter of the lower rotary blade is 90% of the diameter of the upper rotary blade,
The drone according to claim 1 or 2.
Each of the plurality of rotor blades is controlled in rotation speed, further comprising a flight control unit capable of rotating control of the upper rotor blade and the lower rotor blade in mutually opposite directions.
The drone according to any one of claims 1 to 5.
The drone is capable of performing certain tasks within the target area,
The flight control unit lowers the flight speed during the work as compared with during the work,
The drone according to claim 6.
The drone is capable of performing certain tasks within the target area,
The flight control unit lowers the altitude during the work, as compared with when the work is not performed,
The drone according to claim 6 or 7.
The drone
A drug tank that stores the drug,
A drug nozzle for ejecting the drug,
A drone used for drug spraying, further comprising:
By laying down the object by the descending airflow generated by the plurality of rotor blades, the drug reaches the root of the object,
The drone according to any one of claims 1 to 8.
The drone
It is a drone that further has an imaging unit,
An image of the root of the object is obtained by inclining the object by the descending airflow generated by the plurality of rotor blades,
The drone according to any one of claims 1 to 9.