WO2020189506A1 - Drone, drone control method, and drone control program - Google Patents

Abstract

[Problem] To ensure accurate imaging and chemical dispersal even when a strong wind is blowing around the drone. [Solution] A drone 100 provided with: a first operation unit 22 for flying in a work area 403 and performing a prescribed action on the work area; a detection unit 23 for detecting wind that meets prescribed conditions during the flight in the work area; a storage part 234 for storing a detection point where wind is detected; and a second operation unit 24 for performing, on the detection point, an action that differs from an action performed on undetected points where wind is not detected.

Description

Drone, drone control method, and drone control program

The present invention relates to a drone, a drone control method, and a drone control program.

The application of small helicopters (multicopters) generally called drones is advancing. One of the important application fields is spraying chemicals such as pesticides and liquid fertilizers on farmland (fields) (for example, Patent Document 1). In relatively small farmlands, drones are often more appropriate than manned planes and helicopters.

With technologies such as the Quasi-Zenith Satellite System and RTK-GPS (Real Time Kinematic-Global Positioning System), it has become possible for drones to accurately know the absolute position of their aircraft in centimeters during flight. Even in the typical narrow and complicated terrain of farmland, it is possible to fly autonomously with minimal manual maneuvering and to spray chemicals efficiently and accurately.

When a drone flies, if a strong wind blows on the drone or its surroundings, the aircraft will be blown by the wind and the attitude angle will change, which may shift the shooting field of view and the direction of drug discharge. In addition, the drug may be blown away by the wind. Therefore, there is a need for a drone that can ensure accurate shooting and chemical spraying even when a strong wind blows around the drone.

Patent Document 2 discloses a flying robot control system that determines the wind speed around the flying robot and regenerates the route of the flying robot according to the wind speed and the remaining battery level. Patent Document 3 discloses a flying robot control system that sets a threshold value for the remaining battery level according to the wind speed around the flying robot and shifts to the feedback mode when the remaining battery level is less than the threshold value. Patent Document 4 discloses a flight control method for adjusting the flight position of an air vehicle based on wind information and the standard deviation of the spray area in the spray work.

Patent Publication Japanese Patent Application Laid-Open No. 2001-120151 Patent Publication Gazette 2018-052341 Patent Publication Japanese Patent Application Laid-Open No. 2018-055463 Patent Publication Japanese Patent Application Laid-Open No. 2019-008409

We will provide a drone that can ensure accurate shooting and chemical spraying even when a strong wind blows around the drone.

In order to achieve the above object, the drone according to one aspect of the present invention flies in the work area and performs a predetermined operation with respect to the work area, and during the flight in the work area. A detection unit that detects a strong wind satisfying a predetermined condition, a storage unit that stores a detection point where the wind is detected, and an operation different from the undetected point that does not detect the wind with respect to the detection point. It includes two moving parts.

The detection unit may detect the strong wind when the wind speed exceeds the threshold value.

The detection unit may detect the strong wind when the wind direction is a direction other than the tail wind.

The second operating unit may re-flight the detection point and photograph the detection point.

The second moving unit may re-fly at the detection point and spray the drug.

The first operating unit performs an operation of spraying the drug to the working area, and the storage unit stores the drug dropping point at which the drug reaches at the detection point of the strong wind, and the first operating unit and the second operating unit. The operating unit may not spray the drug at the drug dropping point, or may reduce the spraying concentration at the drug dropping point.

The first operation unit acquires an image in the work area and performs a first analysis to analyze the image, and the second operation unit detects the detection of the images acquired by the first operation unit. The image acquired at the point may be subjected to a second analysis different from the first analysis.

The first analysis may be an operation of analyzing an image of the middle to upper part of a crop growing in the work area, and the second analysis may be an operation of analyzing an image of the stock of the crop.

The second analysis may be an operation of performing at least one of the pathological diagnosis of the crop and the determination of the number of tillers based on the image of the stock origin of the crop.

The flight mode setting unit for setting the flight mode in the work area may be further provided, and the flight mode setting unit may change the flight mode based on the result of the second analysis.

The flight mode includes at least a chemical spraying mode for spraying a chemical on the work area, an upper shooting mode for photographing the middle to upper part of the crop in the working area, and a stock shooting mode for photographing the root of the crop. May be.

The flight altitude of the stock source shooting mode may be lower than that of the upper shooting mode.

The flight speed of the stock source shooting mode may be slower than that of the upper shooting mode.

The flight mode setting unit further includes a stock photography unit for flying in the work area in the stock photography mode, and the flight mode setting unit sets the flight mode to the stock photography mode when a pathological point is found by the second analysis. The stock photography unit may fly in the work area over a wider area than the pathological point.

The stock photography unit flies around the pathological point in the stock photography mode, and when it is determined that the pathological point is further expanded to the outside of the periphery of the pathological point, the outer region. May be determined to fly in the stock photography mode.

The stock photography unit may fly on the outer edge of the work area in the stock photography mode.

A flight path changing unit for changing the flight path of the work area may be further provided, and the flight path changing unit may change the flight path according to the direction of the wind detected by the detection unit.

The flight route changing unit may change the flight route to a route that includes more routes along the wind direction of the detected wind.

In order to achieve the above object, the drone control method according to another aspect of the present invention includes a step of flying in a work area and performing a predetermined operation with respect to the work area, and during the flight in the work area. A step of detecting a strong wind satisfying a predetermined condition, a step of storing a detection point where the wind is detected, and a step of performing an operation different from the undetected point where the wind is not detected with respect to the detection point. including.

In order to achieve the above object, the drone control program according to still another aspect of the present invention is instructed to fly in a work area and perform a predetermined operation on the work area, and during the flight in the work area. , A command to detect a strong wind satisfying a predetermined condition, a command to store a detection point where the wind is detected, and a command to perform an operation different from the undetected point where the wind is not detected with respect to the detection point. Let the computer execute.
The computer program can be provided by downloading via a network such as the Internet, or can be recorded and provided on various computer-readable recording media such as a CD-ROM.

Even if a strong wind blows around the drone, accurate shooting and chemical spraying can be guaranteed.

It is a top view of the drone which concerns on this invention. It is a front view of the said drone. It is a right side view of the above drone. It is a rear view of the said drone. It is a perspective view of the said drone. It is the whole conceptual diagram of the drug spraying system which the said drone has. It is a whole conceptual diagram which shows another example of the drug spraying system which the said drone has. It is a whole conceptual diagram which shows still another example of the drug spraying system which the drone has. It is a conceptual diagram which shows the state of the field where the said drone works. It is a schematic diagram which showed the control function of the said drone. It is a functional block diagram which the said drone has. It is a flowchart which the said drone detects a strong wind and re-flights. It is a flowchart which the said drone detects a strong wind and performs a second analysis. It is a flowchart in which the said drone acquires the distribution of pathological points in the stock origin photographing mode.

Hereinafter, a mode for carrying out the present invention will be described with reference to the drawings. All figures are illustrations. In the following detailed description, certain details are given for illustration purposes and to facilitate a complete understanding of the disclosed embodiments. However, embodiments are not limited to these particular details. Also, for simplification of drawings, well-known structures and devices are outlined.

First, the configuration of the drone according to the present invention will be described. In the specification of the present application, the drone is regardless of the power means (electric power, prime mover, etc.) and the maneuvering method (wireless or wired, autonomous flight type, manual maneuvering type, etc.). It refers to all air vehicles with multiple rotor blades.

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 for flying the Drone 100, and is equipped with eight aircraft (four sets of two-stage rotor blades) in consideration of the balance of flight stability, aircraft size, and power consumption. Each rotor 101 is arranged on all sides of the main body 110 by an arm protruding from the main body 110 of the drone 100. That is, the rotors 101-1a and 101-1b are left rearward in the direction of travel, the rotors 101-2a and 101-2b are forward left, the rotors 101-3a and 101-3b are rearward right, and the rotor 101- 4a and 101-4b are arranged respectively. In addition, the drone 100 has the traveling direction facing downward on the paper in FIG. Rod-shaped legs 107-1, 107-2, 107-3, 107-4 extend downward from the rotation axis of the rotary blade 101, respectively.

Motors 102-1a, 102-1b, 102-2a, 102-2b, 102-3a, 102-3b, 102-4a, 102-4b are rotary blades 101-1a, 101-1b, 101-2a, 101- It is a means to rotate 2b, 101-3a, 101-3b, 101-4a, 101-4b (typically, it is an electric motor, but it may be a motor, etc.), and one is provided for one rotor. Has been done. The motor 102 is an example of a propulsion device. The upper and lower rotors (eg, 101-1a and 101-1b) in one set, and the corresponding motors (eg, 102-1a and 102-1b), are used for drone flight stability, etc. The axes are on the same straight line and rotate in opposite directions. As shown in FIGS. 2 and 3, the radial member for supporting the propeller guard provided so that the rotor does not interfere with foreign matter has a rather wobbling structure instead of horizontal. This is to encourage the member to buckle outside the rotor in the event of a collision and prevent it 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 “drug” generally refers to a liquid or powder sprayed in a field such as a pesticide, a herbicide, a liquid fertilizer, an insecticide, a seed, and 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 at a position lower than the center of gravity from the viewpoint of weight balance. The drug hoses 105-1, 105-2, 1053, 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. It may be made of the above material and also serve to support the drug nozzle. The pump 106 is a means for discharging the drug from the nozzle.

FIG. 6 shows an overall conceptual diagram of a system using an embodiment of the drone 100 for chemical spraying according to the present invention. This figure is a schematic diagram, and the scale is not accurate. In the figure, the drone 100, the actuator 401, the small mobile terminal 401a, and the base station 404 are connected to the farming cloud 405, respectively. These connections may be wireless communication by Wi-Fi, mobile communication system, or the like, or may be partially or wholly connected by wire.

The actuator 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, amount of medicine, remaining battery level, camera image, etc.). Yes, it may be realized by a portable information device such as a general tablet terminal that runs a computer program. The drone 100 according to the present invention is controlled to perform autonomous flight, but may be capable of manual operation during basic operations such as takeoff and return, and in an emergency. In addition to the portable information device, an emergency operation device (not shown) having a function dedicated to emergency stop may be used. The emergency manipulator may be a dedicated device provided with a large emergency stop button or the like so that an emergency response can be taken quickly. Further, apart from the actuator 401, the system may include a small mobile terminal 401a capable of displaying a part or all of the information displayed on the actuator 401, for example, a smart phone. Further, it may have a function of changing the operation of the drone 100 based on the information input from the small mobile terminal 401a. The small mobile terminal 401a is connected to, for example, the base station 404, and can receive information and the like from the farming cloud 405 via the base station 404.

Field 403 is a rice field or field that is the target of chemical spraying by the drone 100. In reality, the terrain of field 403 is complicated, and the topographic map may not be available in advance, or the topographic map and the situation at the site may differ. Field 403 is usually adjacent to houses, hospitals, schools, other crop fields, roads, railroads, etc. In addition, intruders such as buildings and electric wires may exist in the field 403.

The base station 404 is a device that provides a master unit function for Wi-Fi communication, etc., and may also function as an RTK-GPS base station so that it can provide an accurate position of the drone 100 (Wi-). The base unit function of Fi communication and the RTK-GPS base station may be independent devices). In addition, the base station 404 may be able to communicate with the farming cloud 405 using mobile communication systems such as 3G, 4G, and LTE.

The farming cloud 405 is typically a group of computers operated on a cloud service and related software, and may be wirelessly connected to the actuator 401 by a mobile phone line or the like. The farming cloud 405 may analyze the image of the field 403 taken by the drone 100, grasp the growing condition of the crop, and perform a process for determining the flight route. In addition, the topographical information of the stored field 403 may be provided to the drone 100. In addition, the history of the flight and captured images of the drone 100 may be accumulated and various analysis processes may be performed.

The small mobile terminal 401a is, for example, a smart phone or the like. On the display of the small mobile terminal 401a, information on expected operations regarding the operation of the drone 100, more specifically, the scheduled time when the drone 100 will return to the departure / arrival point 406, and the work to be performed by the user 402 at the time of return Information such as contents is displayed as appropriate. Further, the operation of the drone 100 and the mobile body 406a may be changed based on the input from the small mobile terminal 401a. The small mobile terminal 401a can receive information from either the drone 100 or the mobile body 406a. Further, the information from the drone 100 may be transmitted to the small mobile terminal 401a via the mobile body 406a.

Normally, the drone 100 takes off from the departure / arrival point 406 outside the field 403 and returns to the departure / arrival point 406 after spraying the chemicals on the field 403 or when it becomes necessary to replenish or charge the chemicals. The flight route (invasion route) from the departure / arrival point 406 to the target field 403 may be stored in advance in the farming cloud 405 or the like, or may be input by the user 402 before the start of takeoff. The departure / arrival point 406 may be a virtual point defined by the coordinates stored in the drone 100, or may have a physical departure / arrival platform.

Note that, as shown in the example shown in FIG. 7, the drone 100, the actuator 401, the small mobile terminal 401a, and the farming cloud 405 may each be connected to the base station 404.

Further, as shown in the example shown in FIG. 8, the drone 100, the actuator 401, and the small mobile terminal 401a are each connected to the base station 404, and only the actuator 401 is connected to the farming cloud 405. You may.

As shown in Fig. 9, the drone 100 flies over the field 403 and carries out the work in the field. In the present embodiment, one field 403 (example of work area), one drone 100 flies and works, but a plurality of drones may fly and work in one field 403. The drone 100 sprays chemicals and photographs the inside of the field 403a while flying along the operation route 51 planned in advance in the field 403. The driving route 51 is, for example, a route that reciprocates in the field 403 and flies so as to scan, but any route may be used. The imaging and chemical spraying performed in the flight along the driving path 51, and the operation of analyzing the data obtained based on the flight are examples of the first operation.

The operation route 51 includes a start point 51s, a work route 51a, an unworked route 51b, and an end point 51e. Drone 100 starts flying from the start point 51s and flies to the end point 51e. The route that the drone 100 has already flown is the worked route 51a, and the route that the drone 100 plans to fly is the unworked route 51b.

FIG. 10 shows a block diagram showing a control function of an embodiment of the drug spraying drone according to the present invention. The flight controller 501 is a component that controls the entire drone, and may be an embedded computer including a CPU, memory, related software, and the like. The flight controller 501 uses the input information received from the controller 401 and the input information obtained from various sensors described later, and the motors 102-1a and 102-1b via a control means such as ESC (Electronic Speed Control). , 102-2a, 102-2b, 102-3a, 102-3b, 104-a, 104-b to control the flight of the drone 100. The actual rotation speeds of the motors 102-1a, 102-1b, 102-2a, 102-2b, 102-3a, 102-3b, 104-a, 104-b are fed back to the flight controller 501, and normal rotation is performed. 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 software used by the flight controller 501 can be rewritten through a storage medium for function expansion / change, problem correction, etc., or through communication means such as Wi-Fi communication or USB. In this case, protection is performed by encryption, checksum, electronic signature, virus check software, etc. so that rewriting by unauthorized software is not performed. In addition, a part of the calculation process used by the flight controller 501 for control may be executed by another computer located on the controller 401, the farming cloud 405, or somewhere else. Due to the high importance of the flight controller 501, some or all of its components may be duplicated.

The flight controller 501 communicates with the actuator 401 via the Wi-Fi slave unit function 503 and further via the base station 404, receives necessary commands from the actuator 401, and receives necessary information from the actuator 401. Can be sent to 401. In this case, the communication may be encrypted so as to prevent fraudulent acts such as interception, spoofing, and device hijacking. The base station 404 has the function of an RTK-GPS base station in addition to the communication function by Wi-Fi. By combining the signal from the RTK base station and the signal from the GPS positioning satellite, the flight controller 501 can measure the absolute position of the drone 100 with an accuracy of about several centimeters. Since the flight controller 501 is so important, it may be duplicated / multiplexed, and each redundant flight controller 501 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 the acceleration of the drone aircraft in three directions orthogonal to each other, and further, a means for calculating the velocity by integrating the acceleration. The 6-axis gyro sensor 505 is a means for measuring the change in the attitude angle of the drone aircraft in the above-mentioned three directions, 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 barometric pressure sensor 507 is a means for measuring barometric pressure, and can also 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 the laser light, and may be an IR (infrared) laser. The sonar 509 is a means for measuring the distance between the drone aircraft and the ground surface by utilizing the reflection of sound waves such as ultrasonic waves. These sensors may be selected according to the cost target and performance requirements of the drone. In addition, a gyro sensor (angular velocity sensor) for measuring the inclination of the aircraft, a wind power sensor for measuring wind power, and the like may be added. Moreover, 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 an alternative 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 drug, and is provided at a plurality of locations on the route from the drug tank 104 to the drug nozzle 103. The liquid drain sensor 511 is a sensor that detects that the amount of the drug has fallen below a predetermined amount. The multispectral camera 512 is a means of photographing the field 403 and acquiring data for image analysis. The intruder detection camera 513 is a camera for detecting a drone intruder, and is a device different from the multispectral camera 512 because the image characteristics and the orientation of the lens 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 intruder contact sensor 515 is a sensor for detecting that the drone 100, in particular, its rotor or propeller guard part, has come into contact with an intruder such as an electric wire, a building, a human body, a tree, a bird, or another drone. .. The intruder contact sensor 515 may be replaced by a 6-axis gyro sensor 505. The cover sensor 516 is a sensor that detects that the operation panel of the drone 100 and the cover for internal maintenance are in the open state. The drug inlet sensor 517 is a sensor that detects that the inlet of the drug tank 104 is in an open state. These sensors may be selected according to the cost target and performance requirements of the drone, and may be duplicated or multiplexed. Further, a sensor may be provided at the base station 404, the actuator 401, or some other place outside the drone 100, and the read information may be transmitted to the drone. For example, a wind power sensor may be provided in the base station 404 to transmit information on the wind power and the wind direction 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 revolutions, etc.) is fed back to the flight controller 501.

LED107 is a display means for notifying the drone operator of the drone status. Display means such as a liquid crystal display may be used in place of or in addition to the LED. The buzzer 518 is an output means for notifying the state of the drone (particularly the error state) by an audio signal. The Wi-Fi slave unit function 519 is an optional component for communicating with an external computer or the like for transferring software, for example, in addition to the actuator 401. In place of or in addition to the Wi-Fi slave function, other wireless communication means such as infrared communication, Bluetooth (registered trademark), ZigBee (registered trademark), NFC, or wired communication means such as USB connection You may use it. Further, instead of the Wi-Fi slave unit function, it may be possible to communicate with each other by a mobile communication system such as 3G, 4G, and LTE. The speaker 520 is an output means for notifying the state of the drone (particularly the error state) by means of recorded human voice, synthetic voice, or the like. Depending on the weather conditions, it may be difficult to see the visual display of the drone 100 in flight. In such cases, voice communication is effective. The warning light 521 is a display means such as a strobe light for notifying the state of the drone (particularly the error state). These input / output means may be selected according to the cost target and performance requirements of the drone, and may be duplicated / multiplexed.

The drone 100 has a flight control unit 21, a first operation unit 22, a strong wind detection unit 23, a second operation unit 24, a flight mode setting unit 25, a stock photography unit 26, and a flight route change unit 27.

The flight control unit 21 is a functional unit that operates the motor 102 of the drone 100 and controls the flight and takeoff and landing of the drone 100. The flight control unit 21 is realized by, for example, the function of the flight controller 501.

The first operation unit 22 is a functional unit that controls the first operation performed by the drone 100. The first operation includes an operation of flying the field 403, taking an image of the field 403, analyzing the image, and an operation of spraying a drug on the field 403. In the first operation, shooting or chemical spraying may be performed while flying along the planned driving route 51, or the route may be determined based on an external factor.

The first operation unit 22 includes a photographing unit 221, a spraying unit 222, and a first analysis unit 223.

The photographing unit 221 is a functional unit that photographs the field 403 with the drone 100, and is realized by a camera such as a multispectral camera 512. The photographing unit 221 acquires an image of the crop of the field 403. The photographing unit 221 acquires an image capable of analyzing the growth condition of the crop in particular. The photographing unit 221 may further include an irradiation unit that irradiates the field 403 with light rays having a specific wavelength, and may be capable of receiving the reflected light of the light rays from the field 403. The light rays having a specific wavelength may be, for example, red light (wavelength of about 650 nm) and near-infrared light (wavelength of about 774 nm). By analyzing the reflected light of the light beam, the nitrogen absorption amount of the crop can be estimated, and thus the growth state of the crop can be analyzed.

The spraying section 222 is a functional section that sprays the drug stored in the drug tank 104 to the field 403. The spraying unit 222 can control the discharge amount according to the flight altitude, speed, acceleration, etc. of the drone 100 so that the drug is sprayed on the field 403 at an accurate density.

The photographing unit 221 and the spraying unit 222 may shoot and spray at the same time, or may only shoot during one flight and only spray during another flight. For example, the flight mode of the drone 100 may be different between the time of shooting and the time of spraying, the shooting may be performed when the drone 100 flies in the shooting mode, and the chemical spraying may be performed when the drone 100 flies in the chemical spraying mode.

The first analysis unit 223 is a functional unit that analyzes the image acquired by the photographing unit 221 and performs the first analysis. The first analysis unit 223 acquires, for example, an image of reflected light of red light (wavelength of about 650 nm) and near-infrared light (wavelength of about 774 nm) and calculates NDVI (Normalized Difference Vegetation Index). According to NDVI, it is possible to analyze the growth status of crops and, by extension, predict the yield of crops. NDVI is calculated by the formula (IR-R) / (IR + R) (where IR is the reflectance of near-infrared light and R is the reflectance of red light).

In the case of no wind or weak wind, the crops growing in the field are almost upright and dense, so the middle to upper part of the crop is mainly photographed. Therefore, the first analysis analyzes images of the middle to upper part of the crop.

The strong wind detection unit 23 is a functional unit that detects wind that satisfies a predetermined condition. The strong wind detection unit 23 detects, in particular, a temporary strong wind blowing on the drone 100 and its surroundings. The drone 100 is usually controlled so that the posture angle of the drone 100, particularly the pitch angle and the roll angle, is constant in order to secure the planned shooting field of view and the spraying point of the drug. However, if a temporary strong wind blows, the attitude of the drone 100 may collapse and it may not be possible to shoot and spray as planned. In addition, when a crop falls down due to a temporary strong wind, it becomes difficult to compare it with the previous diagnosis, and the diagnosis accuracy decreases depending on the direction of the fall. Even when the drug is scattered by the wind, it is difficult to shoot and spray as planned. Therefore, the strong wind detection unit 23 detects a wind that cannot be photographed and sprayed as planned, and stores the detection point.
The strong wind detection unit 23 may detect a wind blowing strongly on average in place of or in addition to the temporary strong wind.

Also, when shooting under a wind speed higher than the specified value, the crops will fall down due to the wind, and images different from those when there is no wind and when there is a weak wind will be acquired. More specifically, the root of the crop is photographed. By performing an analysis different from the first analysis on this strain source image, it is possible to determine the pathology of the strain source and count the number of tillers. The strong wind detection unit 23 detects the wind in which the stock is photographed and stores the detection point.

The strong wind detection unit 23 includes a wind speed measurement unit 231, a wind direction measurement unit 232, a strong wind determination unit 233, and a detection point storage unit 234.

The wind speed measuring unit 231 is a measuring unit that calculates the wind speed by measuring the stress generated by the wind with, for example, a contact detector. Further, the wind speed measuring unit 231 may have an anemometer such as a wind cup type or a wind turbine type. The wind speed measuring unit 231 may have a separate sensor that directly detects the wind speed. The wind speed measuring unit 231 may calculate the wind speed based on the difference between the current attitude angle and the attitude angle in the windless state.

The wind speed measuring unit 231 is configured to be able to measure the wind speed of the wind blowing on the drone 100 from all directions. Further, the wind speed measuring unit 231 may be configured to be capable of measuring the wind speed in the front-rear direction and the left-right direction in the normal flight state of the drone 100.

The wind speed measuring unit 231 may obtain the wind speed in the traveling direction to be blown on the drone 100 by subtracting the ground speed from the airspeed. Ground speed is the speed of the drone 100 that is actually achieved relative to the ground. The airspeed is the speed at which the propeller of the drone 100 converts the operating force exerted in consideration of the influence of the wind into the speed in a windless state in order to achieve a predetermined ground speed. Since the airspeed in the direction orthogonal to the traveling direction of the drone 100 is 0, the wind speed of the wind orthogonal to the traveling direction can be obtained by obtaining the ground speed. The wind speed measuring unit 231 can obtain the direction of the wind blowing on the drone 100 by calculating the ground speed and the airspeed as a vector in consideration of the direction.

The wind speed measurement unit 231 includes a weight estimation unit 231-1, a ground speed calculation unit 231-2 for calculating the ground speed, and an airspeed calculation unit 231-3 for calculating the airspeed.

The weight estimation unit 231-1 is a functional unit that estimates the total weight m of the drone 100. The weight estimation unit 231-1 may estimate the total weight m of the drone 100 including the load weight of the load, or after estimating the load weight of the load that can change, the weight does not change, for example. The total weight m of the drone 100 including the load may be estimated by adding the weights of the flight controller 501, the rotor blade 101, the motor 102 and other accessories of the drone 100. The load of variable weight is a drug in this embodiment.

Even if the weight estimation unit 231-1 estimates the total weight m of the drone 100 including the load weight of the load based on the thrust T in the height direction exerted by the propulsion unit when the altitude of the drone 100 does not change. Good. This is because the thrust T in the height direction exerted by the propeller of the drone 100 is in balance with the gravitational acceleration g received by the drone 100 when the altitude of the drone 100 does not change.

The weight estimation unit 231-1 integrates the discharge flow rate from the drug tank 104 measured by the flow rate sensor 510 to obtain the drug discharge amount, and subtracts the drug discharge amount from the initially loaded drug amount to obtain the drug discharge amount. The weight of 104 may be estimated. According to this configuration, the weight of the drug tank 104 can be estimated regardless of the flight state of the drone 100. Further, the weight estimation unit 231-1 may have a function of estimating the liquid level in the medicine tank 104, for example. The weight estimation unit 231-1 may estimate the weight by using a liquid level gauge, a water pressure sensor, or the like arranged in the medicine tank 104.

The ground speed calculation unit 231-2 can calculate the ground speed by obtaining the absolute speed of space from the GPS module 504. Further, the ground speed measuring unit 242-1 can be obtained by the GPS modules RTK504-1,504-2 of the drone 100. Furthermore, the ground speed measuring unit 244-2 can also be obtained by integrating the acceleration of the drone 100 acquired by the 6-axis gyro sensor 505. That is, according to this configuration, it is possible to obtain the wind speed of the wind blown on the drone 100 with a simple configuration without mounting a separate wind speed measuring means on the drone 100.

The airspeed calculation unit 231-3 can obtain the airspeed based on the attitude angle θ and the weight of the drone 100. The displacement D between the drug drop point when the drone 100 is flying at an altitude L from the ground and an attitude angle of 0 degrees and the drug drop point when the drone 100 is flying at an attitude angle θ is as shown in the following formula. Desired.
D = L × tan θ (1)
While the drone 100 is moving at a constant speed or hovering, the drag force Fd due to air resistance and the airspeed v _a hold the following equations.
Fd = (1/2) × ρv _a ² S × Cd (2)
The air density ρ and the air resistance coefficient Cd. The representative area S such as the front projected area is a value obtained in advance based on the size and shape of the drone 100.
Further, the posture angle θ holds the following equation with the drag force Fd.
Fd = mg tan θ (3)
In addition, m is the weight of the drone 100. While the drone 100 is moving at a constant velocity or hovering, the airspeed v _a can be obtained by the following equation by solving equations (1) and (2).

(4)
g is the gravitational acceleration. In this way, the airspeed v _a of the drone 100 can be obtained based on the attitude angle θ and the weight m of the drone 100.

The wind direction measuring unit 232 is a functional unit that measures the wind direction of the wind blowing in and around the drone 100. The wind direction measuring unit 232 may record the measured wind direction over time.

The strong wind determination unit 233 is a functional unit that determines strong winds based on the wind speed and direction. The strong wind determination unit 233 may determine a temporary strong wind in real time or may determine it after the fact. The strong wind determination unit 233 determines that the wind is strong when the measured instantaneous wind speed is equal to or higher than a predetermined first threshold value. Further, the strong wind determination unit 233 may determine that the wind is strong when the wind speed of the predetermined value or higher is continued for less than the predetermined time. If strong winds continue, the drone 100 will perform attitude control and discharge control, so there is a high possibility that shooting and spraying will resume as planned, but control cannot catch up with temporary strong winds. There is. Therefore, by detecting a temporary strong wind for a short period of time, it is possible to appropriately perform unusual processing such as rephotographing and respraying. The strong wind determination unit 233 may determine that the wind is strong when the displacement amount of the wind speed within a certain period of time, that is, the acceleration of the wind is equal to or higher than a predetermined value. According to this configuration, it is possible to detect a point where the attitude control and the discharge amount control are not in time.

Note that the strong wind determination unit 233 may detect that the wind is such that the second operation unit 24 operates when the average wind speed is equal to or higher than the second threshold value. The second threshold may be different from the first threshold. According to this configuration, even when the attitude control and the discharge amount control are not sufficient, it is possible to appropriately perform unusual processing such as reimaging and respraying.

The strong wind determination unit 233 may change the conditions for determining strong wind depending on the type of operation performed by the drone 100 as the first operation. For example, the threshold value of the wind speed at the time of spraying the chemicals may be smaller than the threshold value of the wind speed at the time of photographing. This is because the chemicals to be sprayed are easily scattered by the wind, so they are more affected by the wind than when shooting.

Further, the strong wind determination unit 233 may hold a plurality of wind determination conditions stepwise. At the time of shooting, the strong wind determination unit 233 may distinguish between a wind that can be normally photographed, a wind that can be photographed by the stock owner, and a wind that requires re-imaging. Further, the strong wind determination unit 233 may determine that the wind can be photographed when the wind speed is equal to or higher than a predetermined value and the measured wind direction is along the traveling direction, that is, a tail wind. When the wind direction is a direction other than the tail wind, the strong wind determination unit 233 may detect the wind as a strong wind and determine that the wind needs to be re-photographed.

The detection point storage unit 234 is a functional unit that stores the detection point where a strong wind is detected. The detection point storage unit 234 stores the coordinates in which the drone 100 exists when a strong wind is detected, for example, in three-dimensional coordinates. The detection point storage unit 234 distinguishes between winds that need to be re-sprayed, winds that can be photographed at the stock source, and winds that need to be re-photographed, and stores them together with information on the detection points.

The detection point storage unit 234 may calculate and store the drop point of the drug to be sprayed at the detection point. The drug sprayed at the detection point reaches a point different from the intended position. The spraying unit 222 or the complementary spraying unit 242 refers to the coordinates of the drug dropping point at the time of strong wind to prevent further spraying of the drug at the drug dropping point, or the drug dropping point at the drug dropping point. Reduce the density. Here, as a means for lowering the drug drop density at the drug drop point, it is possible to reduce the drug discharge amount, increase the flight speed of the drone 100, increase the flight altitude of the drone 100, or implement a combination thereof. it can. According to this configuration, it is possible to ensure the drug concentration as planned even at a point where the drug is unintentionally sprayed in a strong wind.

The second operation unit 24 is a function unit that controls the operation performed at the detection point where a strong wind is detected. The second operation unit 24 operates the detection point differently from the undetected point where strong wind is not detected. The second operation unit 24 includes a complementary imaging unit 241, a complementary spraying unit 242, and a second analysis unit 243.

Complementary shooting unit 241 is a functional unit that re-flys at the point where a wind that requires re-shooting is detected by the strong wind determination unit 233 and re-shoots. Each configuration of the complementary photographing unit 241 is the same as that of the photographing unit 221. The complementary photographing unit 241 performs re-imaging when the strong wind determination unit 233 detects a wind that can be normally photographed.

The complementary spraying unit 242 is a functional unit that re-flies at a point where a wind that requires re-spraying is detected by the strong wind determination unit 233 and re-sprays. Each configuration of the complementary spraying portion 242 is the same as that of the spraying portion 222. The complementary spraying unit 242 re-photographs when the strong wind determination unit 233 detects a wind on which the chemical can be sprayed.

The complementary shooting unit 241 and the complementary spraying unit 242 generate a flight path for flying at the detection point. When there are a plurality of detection points and the detection points have a predetermined range, the complementary photographing unit 241 and the complementary spraying unit 242 may generate the shortest path for efficiently flying over the detection points. The start point and end point of the flight path for flying at the detection point may be the same or different.

The second analysis unit 243 analyzes the image of the point where the wind that can be photographed by the strong wind determination unit 233 is detected among the images acquired by the photographing unit 221, that is, the image of the stock origin of the crop. It is a functional part to perform. The second analysis makes at least one of the pathological diagnosis of the crop and the determination of the number of tillers based on the image of the root of the crop. In the pathological diagnosis of a crop, for example, it is analyzed whether or not the chlorophyll of the plant origin is destroyed, and the presence or absence of a crop having a disease such as blast is determined. According to this configuration, it is possible to make a pathological diagnosis of a crop by utilizing a strong wind generated by chance during a flight in which the upper part is photographed.

The flight mode setting unit 25 is a functional unit that sets the flight mode of the drone 100 in the field 403. The flight mode defines the control characteristics of flight altitude, velocity and acceleration. The flight mode includes at least a chemical spraying mode for spraying chemicals, an upper shooting mode for photographing the middle to upper part of the crop, and a stock shooting mode for photographing the root of the crop. The upper shooting mode flies at an altitude that does not invade crops. The stock root shooting mode is a mode in which the crop is laid down using the downwash of the rotary blade 101 and the root of the crop is photographed. The flight altitude in the stock shooting mode is lower than that in the upper shooting mode. The flight speed in the stock shooting mode is slower than in the upper shooting mode, and the attitude angle of the drone 100 is closer to horizontal. This is because the stock photography mode requires sufficient downwash to be sprayed on the crop.

The flight mode setting unit 25 changes the flight mode of the drone 100 based on the result of the second analysis. When the pathological diagnosis in the second analysis reveals a diseased crop, the flight mode setting unit 25 sets the drone 100 to the stock photography mode, flies the field 403 again, and causes the crop to fly again. The root of the plant is photographed over a wide area from the detection point where the disease was found, that is, the pathological point, and the second analysis is performed. If a disease is found in a part of the field 403, it is highly probable that the pathological site has expanded to a predetermined range in the field 403. According to the stock photography mode, the distribution of pathological points in the field 403 can be acquired. In addition, according to the configuration of flying in the stock source shooting mode when a disease is found in the upper shooting mode, the second analysis is performed only when flying in the stock source shooting mode on a regular basis in addition to the upper shooting mode. In comparison, since pathological diagnosis can be performed more frequently, the presence or absence and range of pathological sites can be identified earlier.

The stock source shooting unit 26 is a functional unit that flies in the field 403 in the stock source shooting mode and shoots. The stock photography unit 26 may fly the drone 100 over the entire field 403 or may fly around the pathological site. Since the stock source shooting mode flies at a lower speed than the upper shooting mode, if the entire field 403 is to be flown, a very long flight is required. Therefore, the pathological site can be found more efficiently by photographing the area around the found pathological site, which has a high probability of spreading the disease. In addition, as a result of flying and analyzing the area around the pathological point in the stock photography mode, if it is determined that the pathological point is further expanded to the outside of the area around the initially discovered pathological point, the stock photography unit 26 may decide to fly in the outer region in stock photography mode. For example, when a disease is found in all of the acquired data around the pathological point, it is determined that the disease has spread to the outer region because the outer edge of the pathological point is not specified. The stock photography unit 26 flies outside the pathological point while gradually widening the orbiting radius until the outer edge of the pathological point is identified. According to this configuration, the distribution of pathological points can be efficiently obtained.

In addition to the vicinity of the pathological site, the outer edge of the field 403 may be flown in the stock photography mode. If the disease has occurred on the outer edge of the field 403, it may be determined that the disease has spread from the found pathological site to the outer edge of the field 403, and the treatment may be terminated. According to the configuration in which the outer edge of the field 403 is flown in the stock photography mode, it is possible to determine whether or not the disease has spread throughout the field 403, and it is possible to efficiently grasp the state of the spread of the disease. it can.

The flight route changing unit 27 is a functional unit that changes the flight route in the field 403. The flight path changing unit 27 changes the flight path according to the direction of the wind detected by the wind direction measuring unit 232. More specifically, the flight path changing unit 27 changes the flight path to a path that includes many paths along the wind direction of the detected wind. For example, the flight route changing unit 27 determines a route for scanning the field 403 by reciprocating between a route along the detected wind direction and a route opposite to the route. According to this configuration, in the upper shooting mode in the first operation, the stock can be photographed by using the wind. Since the flight speed in the upper shooting mode is faster than that in the stock shooting mode, it is possible to shoot the stock in a shorter time according to this configuration.

● Flow chart for detecting strong winds and re-flying As shown in Fig. 12, the drone 100 first flies the field 403 in the upper shooting mode or the chemical spraying mode, and performs the first operation (S11). When a strong wind is detected during the flight of the field 403 (S12), the detection point of the strong wind is memorized (S13). The strong wind detection unit 23 continuously or periodically detects the presence or absence of a strong wind, and determines that the strong wind has stopped (S14). When it is determined that the strong wind has stopped, the detection point is re-flighted and re-photographed or re-sprayed (S15). Step S14 may be performed at any time during the flight in the field 403, or may be performed after the flight in the field 403 is completed.

● Flow chart for detecting strong winds and performing the second analysis As shown in FIG. 13, the drone 100 first flies the field 403 in the upper shooting mode and shoots as the first motion (S21). When a strong wind is detected during the flight of the field 403 (S22), the detection point of the strong wind is memorized (S23). Next, a second analysis is performed on the image acquired at the detection point (S24). When the pathological point is found in the second analysis (S25), the flight is performed in the stock photography mode (S26).

● Flow chart for acquiring the distribution of pathological points in the stock photography mode As shown in Fig. 14, the stock photography unit 26 first sets the flight path for the stock photography based on the pathological points found in the strong wind. Specifically, a flight path is set around the field 403 and outside the pathological site found by strong wind (S31). Next, the flight route is flown in the stock photography mode (S32). A second analysis is performed on the image data obtained in step S32 (S33). When the outer edge of the pathological site is identified by step S33 (S34), the process ends. When the outer edge of the pathological point is not specified by step S33, a new flight path that goes around the outer edge of the flight path around the pathological point that flew in step S32 is newly set (S35), and the process returns to step S32. Steps S32 to S35 are repeated until the outer edge of the pathological site is identified.

In this description, an agricultural chemical 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 drones for other purposes such as photography and surveillance. .. In particular, it is applicable to machines that operate autonomously.

(Technically remarkable effect of the present invention)
In the drone according to the present invention, accurate imaging and chemical spraying can be ensured even when a strong wind blows around the drone.

Claims (21)

1. A first moving unit that flies through a work area and performs a predetermined operation on the work area,
   A detector that detects wind that meets certain conditions during flight within the work area, and
   A storage unit that stores the detection point where the wind is detected,
   A second moving unit that performs an operation different from that of the undetected point that does not detect the wind with respect to the detected point.
   To prepare
   Drone.
2. The detection unit detects the wind when the instantaneous wind speed becomes equal to or higher than the first threshold value.
   The drone according to claim 1.
3. The detection unit detects the wind when the average wind speed is equal to or higher than the second threshold value.
   The drone according to claim 1 or 2.
4. The detection unit detects the wind when the wind direction is a direction other than the tail wind.
   The drone according to claim 2 or 3.
5. The second operating unit re-flies at the detection point and photographs the detection point.
   The drone according to any one of claims 1 to 4.
6. The second moving unit re-flies at the detection point and sprays the drug.
   The drone according to any one of claims 1 to 5.
7. The first operating unit performs an operation of spraying a chemical on the work area.
   The storage unit stores the drug drop point at which the drug reaches at the detection point of the wind.
   The first operating unit and the second operating unit do not spray the drug at the drug dropping point, or lower the drug dropping density at the drug dropping point.
   The drone according to claim 6.
8. The first operation unit acquires an image in the work area and performs a first analysis to analyze the image.
   The second operating unit performs a second analysis different from the first analysis on the image acquired at the detection point among the images acquired by the first operating unit.
   The drone according to any one of claims 1 to 7.
9. The first analysis is an operation of analyzing an image of the middle to upper part of a crop growing in the work area.
   The second analysis is an operation of analyzing an image of the stock of the crop.
   The drone according to claim 8.
10. The second analysis is an operation of performing at least one of the pathological diagnosis of the crop and the determination of the number of tillers based on the image of the stock origin of the crop.
    The drone according to claim 9.
11. A flight mode setting unit for setting a flight mode in the work area is further provided.
    The flight mode setting unit changes the flight mode based on the result of the second analysis.
    The drone according to any one of claims 8 to 10.
12. The flight mode includes at least a chemical spraying mode for spraying a chemical on the work area, an upper shooting mode for photographing the middle to upper part of the crop in the working area, and a stock shooting mode for photographing the root of the crop.
    The drone according to claim 11.
13. The flight altitude of the stock source shooting mode is lower than that of the upper shooting mode.
    The drone according to claim 12.
14. The flight speed of the stock source shooting mode is slower than that of the upper shooting mode.
    The drone according to claim 12 or 13.
15. Further equipped with a stock photography unit for flying in the work area in the stock photography mode,
    When the pathological point is found by the second analysis, the flight mode setting unit changes the flight mode to the stock source photographing mode, and the stock source photographing unit covers the working area over a wider area than the pathological point. Fly inside,
    The drone according to any one of claims 12 to 14.
16. The stock photography unit flies around the pathological point in the stock photography mode, and when it is determined that the pathological point is further expanded to the outside of the periphery of the pathological point, the outer region. Decides to fly in the stock photography mode,
    The drone according to claim 15.
17. The stock photography unit flies over the outer edge of the work area in the stock photography mode.
    The drone according to claim 15 or 16.
18. Further provided with a flight path changing section for changing the flight path of the work area.
    The flight path changing unit changes the flight path according to the direction of the wind detected by the detecting unit.
    The drone according to any one of claims 1 to 17.
19. The flight path changing unit changes the flight path to a path including more paths along the wind direction of the detected wind.
    The drone according to claim 18.
20. A step of flying in a work area and performing a predetermined operation on the work area,
    A step of detecting a wind satisfying a predetermined condition during flight in the work area, and
    The step of memorizing the detection point where the wind is detected and
    A step of performing an operation different from that of the undetected point where the wind is not detected with respect to the detected point.
    including,
    How to control the drone.
21. A command to fly a work area and perform a predetermined operation on the work area,
    A command to detect wind that meets certain conditions during flight in the work area,
    A command to memorize the detection point where the wind is detected, and
    A command to the detection point to perform an operation different from that of the undetected point that does not detect the wind,
    Let the computer run
    Drone control program.
    
    

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