WO2021166008A1

WO2021166008A1 - Drone and method for controlling drone

Info

Publication number: WO2021166008A1
Application number: PCT/JP2020/005932
Authority: WO
Inventors: 敦規西東; 千大和氣; 宏記加藤
Original assignee: 株式会社ナイルワークス
Priority date: 2020-02-17
Filing date: 2020-02-17
Publication date: 2021-08-26
Also published as: JP7369485B2; JPWO2021166008A1

Abstract

Provided are a drone that is robust with respect to changes in a lower object such as the ground, and a method for controlling said drone. A flight control unit (200) performs flight control of a drone (24) by using a control altitude that is set by selecting one, or combining both, of a first distance up to a lower object as detected by an optical sensor (100) and a second distance up to the lower object as detected by an ultrasonic sensor (102). Further, when the accuracy of the optical sensor is low, the flight control unit may set the control altitude by selecting the second distance or by assigning greater weight to the second distance than to the first distance, and further, may decrease flight velocity.

Description

Drone and drone control method

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

Altitude information may be used for drone flight control. In Patent Document 1, an altimeter 36 is used that emits a laser beam or an ultrasonic signal below the unmanned flying object 1 to generate an output indicating altitude from the reflected wave ([0019]).

Japanese Unexamined Patent Publication No. 2018-192932

As described above, Patent Document 1 uses an altimeter 36 that radiates a laser beam or an ultrasonic signal below the unmanned flying object 1 to generate an output indicating altitude from the reflected wave ([0019]). The altimeter 36 here seems to be supposed to use only one of the laser beam and the ultrasonic signal.

However, in the case of an optical sensor using a laser beam or the like, when the reflected light from a mirror-like object (for example, a water surface having high reflectance) is received, the amount of received light is too large and the measurement range (dynamic range) is saturated and the detection accuracy is high. May go down. Further, even in the case of an optical sensor having a variable measurement range, if the sensor suddenly moves from a dark place (shade or the like) to a bright place (sunlight or the like), the change in the measurement range may be delayed and the detection accuracy may decrease.

Furthermore, since ultrasonic waves are weakly reflected from soft objects that easily absorb sound, the detection accuracy may decrease when such objects exist.

The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a drone that is robust against changes in a downward object such as the ground and a control method thereof.

The drone according to the present invention
It is provided with an optical sensor that detects a first distance to a lower object and an ultrasonic sensor that detects a second distance to the lower object.
It is characterized by further having a flight control unit that controls the flight of the drone by using a control altitude set by selecting one of the first distance and the second distance or a combination of both.

According to the present invention, control is set by selecting one of the first distance to the lower object (ground, etc.) detected by the optical sensor and the second distance to the lower object detected by the ultrasonic sensor, or a combination of both. Control the flight of the drone using the altitude. This makes it possible to fly a drone based on the advantages and disadvantages of optical sensors and ultrasonic sensors. Therefore, it is possible to improve the robustness against changes in the downward object such as the ground. As the optical sensor, for example, a laser type can be used.

As the optical sensor, for example, a time-of-flight type sensor (TOF sensor) may be used. Compared to other types of optical sensors (phase difference detection method, triangular ranging method, etc.), the TOF sensor is often lighter in weight, and the use of the TOF sensor makes it possible to reduce the weight of the drone. ..

The optical sensor and the ultrasonic sensor may be arranged side by side in the lateral direction of the drone. Further, the light irradiation direction by the optical sensor and the ultrasonic irradiation direction by the ultrasonic sensor are at least a part of the light irradiation range by the optical sensor and the ultrasonic irradiation range by the ultrasonic sensor. May be set to overlap. The drone may move forward in a forward leaning position in the direction of travel. If the optical sensor and the ultrasonic sensor are arranged in the lateral direction of the drone, the detected values of both sensors are less likely to deviate from each other even in such a forward leaning posture. Therefore, it is possible to suppress the discrepancy between the first distance by the optical sensor and the second distance by the ultrasonic sensor.

The drone may have a support member that projects downward from the main body of the drone to support the optical sensor and the ultrasonic sensor. As a result, even when a heat generation source (power distribution board, inverter, power supply, image processing unit of a camera, etc.) exists in the main body of the drone, the optical sensor and the ultrasonic sensor can be arranged away from the heat generation source. Therefore, it is possible to suppress the influence of the heat from the heat generation source on the optical sensor and the ultrasonic sensor.

The drone may include a tank for storing the sprayed material and a discharge port (nozzle or the like) for spraying the sprayed material. Further, the optical sensor and the ultrasonic sensor may be arranged above the discharge port. Further, the optical sensor and the ultrasonic sensor may be arranged in front of the discharge port. As a result, it is possible to suppress the influence of the sprayed material sprayed from the discharge port during the flight of the drone on the measurement of the optical sensor or the ultrasonic sensor.

The drone may further include a camera that images the lower object and a lower state determination unit that determines the state of the lower object based on the image of the camera. When the state of the lower object determined by the lower state determination unit is not a state in which the accuracy of the optical sensor is reduced (normal time), the flight control unit detects the first item. The control altitude may be set by selecting one distance or by increasing the weighting of the first distance from the second distance detected by the ultrasonic sensor. Further, when the state of the lower object is the state in which the accuracy of the optical sensor is lowered, the flight control unit selects the second distance or weights the second distance more than the first distance. The control altitude may be set.

As a result, when the detection accuracy of an optical sensor is higher than that of an ultrasonic sensor in normal times, the ultrasonic sensor is preferentially used in situations where the detection accuracy of the optical sensor is low, so that the drone can fly with high accuracy. It becomes possible to control.

The state in which the accuracy of the optical sensor is lowered may include a state in which the lower object is a mirror surface or white, or a state in which the lower object has a boundary between the shade and the sun and the measurement position of the optical sensor straddles the boundary. .. The measurement position referred to here means a position where the light emitted from the optical sensor hits the lower object and is reflected.

In the state where the accuracy of the optical sensor is lowered, when the boundary between the shade and the sun exists in the lower object and the measurement position of the optical sensor straddles the boundary, the flight control unit determines the measurement position of the optical sensor. The flight speed of the drone may be reduced before crossing the boundary between the shade and the sun.

Some optical sensors have a variable dynamic range of the amount of light received in order to improve the detection accuracy. In the case of such an optical sensor, when the measurement position straddles the boundary from the shade to the sun, the dynamic range is temporarily saturated due to a sudden increase in the amount of light received, and then the dynamic range is adjusted to achieve high accuracy even in the sun. Measurement becomes possible. In the present invention, the flight speed of the drone is reduced before the measurement position of the optical sensor crosses the boundary from the shade to the sun. As a result, the distance traveled by the drone can be shortened when the amount of light received by the optical sensor is saturated. Therefore, the applicable range of the optical sensor can be expanded, and the robustness against changes in the downward object such as the ground can be improved.

Also, ultrasonic waves are much slower than light, and the Doppler effect that accompanies the movement of the drone has a large effect. Therefore, when using the detection value (second distance) of an ultrasonic sensor, the detection accuracy is lowered due to the Doppler effect by lowering the flight speed as compared with the case of using the detection value (first distance) of an optical sensor. Can be suppressed.

Furthermore, even when the measurement position straddles the boundary from the sun to the shade, the measurement accuracy may temporarily decrease due to the dynamic range. In the case of the present invention, such a case may be dealt with.

The drone according to the present invention
An optical sensor that detects the first distance to the lower target,
A flight control unit that controls the flight of the drone by using the first distance as a control altitude.
It is provided with a lower state determination unit for determining the surface state of the lower object.
When the surface state of the lower object determined by the lower state determination unit is an optical sensor accuracy reduction state in which the detection accuracy of the optical sensor is reduced, the flight control unit reduces the flight speed of the drone. It is a feature.

Even with the above configuration, the applicable range of the optical sensor can be expanded, and the robustness against changes in the downward object such as the ground can be improved.

The drone control method according to the present invention is
A drone control method including an optical sensor that detects a first distance to a lower object and an ultrasonic sensor that detects a second distance to the lower object.
The flight control unit controls the flight of the drone using a control altitude set by selecting one of the first distance and the second distance or a combination of both.

The drone control method according to the present invention is
An optical sensor that detects the first distance to the lower target,
A flight control unit that controls the flight of the drone by using the first distance as a control altitude.
It is a control method of a drone including a lower state determination unit for determining the surface state of the lower object.
When the surface state of the lower object determined by the lower state determination unit is an optical sensor accuracy reduction state in which the detection accuracy of the optical sensor is reduced, the flight control unit reduces the flight speed of the drone. It is a feature.

According to the present invention, it is possible to improve robustness against changes in downward objects such as the ground.

It is an overall block diagram which shows the outline of the crop growing system including the drone which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the drone which concerns on said embodiment simply. It is an external perspective view of the drone which concerns on the said embodiment. It is a bottom view of the drone which concerns on the said embodiment. It is a top view which simply shows the internal structure of the main body of the drone which concerns on the said embodiment, and the arrangement around it. It is a side view which shows simply the internal structure of the main body of the drone which concerns on the said embodiment, and the arrangement around it. It is a flowchart of the altitude-related control of the said embodiment. It is a side view which shows the internal structure of the main body of the drone which concerns on a modification and the arrangement around it simply. It is a flowchart of altitude-related control which concerns on a modification.

A. One Embodiment <A-1. Configuration>
[A-1-1. overall structure]
FIG. 1 is an overall configuration diagram showing an outline of a crop growing system 10 including a drone 24 according to an embodiment of the present invention. The crop growing system 10 (hereinafter, also referred to as “system 10”) can diagnose the growth of the crop 502 growing in the field 500 and spray the chemicals on the crop 502. The crop 502 of the present embodiment is rice (paddy rice), but other crops (for example, upland rice, wheat, barley) may also be used.

As shown in FIG. 1, the system 10 has a field sensor group 20, a growth diagnosis server 22, and a user terminal 26 in addition to the drone 24. The field sensor group 20, the drone 24, and the user terminal 26 can wirelessly communicate with each other via the communication network 30 (including the wireless base station 32) and can communicate with the growth diagnosis server 22. As the wireless communication, communication that does not go through the wireless base station 32 (for example, LTE (Long Term Evolution), WiFi, etc.) can be used.

[A-1-2. Field sensor group 20]
The field sensor group 20 is installed in the field 500 as a paddy field, detects various data in the field 500, and provides the growth diagnosis server 22 and the like. The field sensor group 20 includes, for example, a water temperature sensor, a temperature sensor, a precipitation sensor, an illuminance meter, an anemometer, a barometer and a hygrometer. The water temperature sensor detects the water temperature of the field 500, which is a paddy field. The temperature sensor detects the air temperature of the field 500. The precipitation sensor detects the amount of precipitation in the field 500. The illuminometer detects the amount of sunshine in the field 500. The anemometer detects the wind speed of the field 500. The barometer detects the barometric pressure in the field 500. The hygrometer detects the humidity of the field 500. Some of the values of these sensors may be acquired from a weather information providing server or the like (not shown).

[A-1-3. Growth diagnosis server 22]
The growth diagnosis server 22 (hereinafter, also referred to as “diagnosis server 22”) performs growth diagnosis using the growth diagnosis model, and gives work instructions to the user 600 and the like based on the diagnosis result. Work instructions include fertilizer application timing, fertilizer type / amount, pesticide application timing, pesticide type / amount, and the like. The diagnostic server 22 has an input / output unit, a communication unit, a calculation unit, and a storage unit (none of which are shown). In addition, the diagnosis server 22 executes growth diagnosis control for performing growth diagnosis using the growth diagnosis model, flight management control for managing the flight (flight timing, flight path, etc.) of the drone 24, and the like.

[A-1--4. Drone 24]
(A-1-4-1. Overview)
FIG. 2 is a configuration diagram simply showing the configuration of the drone 24 according to the present embodiment. FIG. 3 is an external perspective view of the drone 24 according to the present embodiment. FIG. 4 is a bottom view of the drone 24 according to the present embodiment. FIG. 5 is a plan view simply showing the internal configuration of the main body 50 of the drone 24 and the arrangement around the main body 50 according to the present embodiment. FIG. 6 is a side view simply showing the internal configuration of the main body 50 of the drone 24 of the present embodiment and the arrangement around the main body 50. The drone 24 of the present embodiment functions as a means for acquiring an image of the field 500 (crop 502) and also as a means for spraying a chemical solution (including a liquid fertilizer) on the crop 502. The drone 24 takes off and landing at the departure and arrival point 510 (FIG. 1).

As shown in FIG. 2, the drone 24 includes a drone sensor group 60, a communication unit 62, a flight mechanism 64, a photographing mechanism 66, a spraying mechanism 68, a drone control unit 70, and a power supply unit 72.

(A-1-4-2. Drone sensor group 60)
The drone sensor group 60 includes a global positioning system sensor (hereinafter referred to as “GPS sensor”), a gyro sensor, a liquid level sensor (none of which is shown), a speedometer 80, an altimeter 82, and the like. The GPS sensor outputs the current position information of the drone 24. The gyro sensor detects the angular velocity of the drone 24. The liquid amount sensor detects the amount of liquid in the tank 180 (FIG. 4) of the spraying mechanism 68. The speedometer 80 detects the flight speed Vf of the drone 24.

The altimeter 82 detects the distance (so-called ground level) to the object located below the drone 24 (hereinafter referred to as the "downward object Row"). The lower target Row includes the ground 520 (FIG. 1), crop 502 and the like. The altimeter 82 of this embodiment includes a TOF sensor 100 and an ultrasonic sensor 102. The TOF sensor 100 is an optical sensor that detects a distance by a time-of-flight method using a laser. The TOF sensor 100 faces downward from the drone 24, and determines the distance to the lower target Row such as the ground 520 (FIG. 1) and the crop 502 (hereinafter, also referred to as “first distance D1” or “detection value D1”). To detect. The TOF sensor 100 has a variable dynamic range of the amount of received light in order to improve the detection accuracy.

The ultrasonic sensor 102 is a sensor that detects a distance using ultrasonic waves. The ultrasonic sensor 102 faces downward from the drone 24 and detects the distance to the lower target Row such as the ground 520 and the crop 502 (hereinafter, also referred to as “second distance D2” or “detection value D2”). The light irradiation direction by the TOF sensor 100 and the ultrasonic irradiation direction by the ultrasonic sensor 102 are the range of the light irradiation by the TOF sensor 100 and the ultrasonic irradiation range by the ultrasonic sensor 102 in the measurement areas of both sensors. At least part of it is set to overlap. For example, the light irradiation direction of the TOF sensor 100 and the ultrasonic irradiation direction of the ultrasonic sensor 102 are substantially the same (the central axes in the irradiation direction are substantially parallel).

As shown in FIG. 5, the TOF sensor 100 and the ultrasonic sensor 102 are provided on the bottom surface portion 52 constituting the main body 50 of the drone 24. More specifically, the TOF sensor 100 and the ultrasonic sensor 102 are arranged on the left and right sides of the camera 160 (described later) on the front side of the bottom surface portion 52. In other words, the TOF sensor 100 and the ultrasonic sensor 102 are arranged side by side in the lateral direction of the drone 24. The TOF sensor 100 and the ultrasonic sensor 102 are arranged above and in front of the nozzles 186l1, 186l2, 186r1, and 186r2 (see FIGS. 3 and 4).

(A-1--4-3. Communication unit 62)
The communication unit 62 (FIG. 2) is capable of radio wave communication via the communication network 30 (FIG. 1), and includes, for example, a radio wave communication module. The communication unit 62 can communicate with the field sensor group 20, the diagnosis server 22, the user terminal 26, and the like via the communication network 30 (including the wireless base station 32). The radio wave communication module constituting the communication unit 62 is arranged in the control board 110 (FIG. 5).

(A-1--4-4. Flight mechanism 64)
The flight mechanism 64 is a mechanism for flying the drone 24. As shown in FIGS. 3 and 4, the flight mechanism 64 includes a plurality of propellers 130flu, 130fl, 130fru, 130fl, 130rlu, 130rll, 130rru, 130rrl (hereinafter collectively referred to as “propeller 130”) and a plurality of propeller actuators. 132fl, 132fl, 132fru, 132fl, 132rlu, 132rrl, 132rru, 132rrl (hereinafter collectively referred to as "propeller actuator 132") and propeller guard 134fl, 134fr, 134rr, 134rr (hereinafter collectively referred to as "propeller guard 134"). And have.

Further, the flight mechanism 64 has a plurality of inverters 136 (FIG. 5). Arrows A in FIGS. 3 to 6 indicate the traveling direction of the drone 24. As shown in FIG. 3, the propeller 130 of the present embodiment is a so-called counter-rotating type, in which two propellers 130 (for example, propellers 130flu and 130fl) are arranged coaxially, and the upper and lower propellers 130 are oriented in opposite directions. Rotate. In this embodiment, there are four sets of counter-rotating propellers 130.

As shown in FIGS. 3 and 4, each propeller 130 is arranged on four sides of the main body 50 by arms 138u, 138l, 140ru, 140rl, 140ru, 140rl extending from the main body 50 of the drone 24. That is, propellers 132fl and 132fl are arranged on the left front side, propellers 132fru and 132fll are arranged on the right front side, propellers 132rlu and 132rll are arranged on the left rear side, and propellers 132rru and 132rrl are arranged on the right rear side, respectively. Below the axis of rotation of the propeller 130, rod-shaped legs 142fl, 142fr, 142rr, and 142rr (hereinafter collectively referred to as "feet 142") extend.

The propeller actuator 132 is a means for rotating the propeller 130, and is provided for each propeller 130. The propeller actuator 132 of the present embodiment is an electric motor, but may be a motor or the like. A set of upper and lower propellers 130 (eg, propellers 130flu, 130fl) and their corresponding propeller actuators 132 (eg, propeller actuators 132fl, 132fl) are coaxial. A set of upper and lower propeller actuators 132 rotate in opposite directions.

The inverter 136 converts the direct current from the power supply unit 72 into alternating current and supplies it to the propeller actuator 132, and is a so-called ESC (Electric Speed Controller). Eight inverters 136 are provided for each propeller actuator 132. As shown in FIG. 5, the inverter 136 is provided on the bottom surface portion 52 constituting the main body 50 of the drone 24. The inverters 136 are arranged side by side in the front-rear direction on the left and right sides of the control board 110.

(A-1--4-5. Imaging mechanism 66)
The photographing mechanism 66 (FIG. 2) is a mechanism for capturing an image of the field 500 or the crop 502, and has a camera 160 (FIGS. 2, 4 to 6). The camera 160 of the present embodiment is a multispectral camera, and particularly acquires an image capable of analyzing the growth state of the crop 502. The photographing mechanism 66 may further include an irradiation unit that irradiates the field 500 with light rays having a specific wavelength, and may be capable of receiving the reflected light from the field 500 with respect to the light rays. 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 502 can be estimated, and the growth state of the crop 502 can be analyzed based on the estimated nitrogen absorption amount.

As shown in FIG. 5, the camera 160 is provided on the bottom surface portion 52 constituting the main body 50 of the drone 24. More specifically, the camera 160 is arranged between the TOF sensor 100 and the ultrasonic sensor 102 on the front side of the bottom surface portion 52. The camera 160 is arranged downward and images the lower target Row of the ground 520, the crop 502, and the like.

The camera 160 outputs image data related to peripheral images taken around the drone 24. The camera 160 is a video camera that shoots a moving image. Alternatively, the camera 160 may be capable of capturing both moving images and still images, or only still images.

The orientation of the camera 160 (the posture of the camera 160 with respect to the main body 50 of the drone 24) can be adjusted by a camera actuator (not shown). Alternatively, the position of the camera 160 with respect to the main body 50 of the drone 24 may be fixed.

(A-1--4-6. Spraying mechanism 68)
The spraying mechanism 68 (FIG. 2) is a mechanism for spraying a chemical (including liquid fertilizer). As shown in FIG. 4 and the like, the spraying mechanism 68 is collectively referred to as a tank 180, a pump 182, a pipe 184, a flow rate adjusting valve (not shown), and a drug nozzle 186l1, 186l2, 186r1, 186r2 (hereinafter, “nozzle 186”). ).

The tank 180 stores the chemicals (sprayed material) to be sprayed. The pump 182 pushes the medicine in the tank 180 into the pipe 184. The pipe 184 connects the tank 180 and each nozzle 186. The pipe 184 is made of a hard material and may also serve to support the nozzle 186.

Each nozzle 186 is a means (discharge port) for spraying the drug downward. Instead of providing the nozzle 186, the discharge port may be formed by providing one or more through holes in the pipe 184.

(A-1--4-7. Drone control unit 70)
The drone control unit 70 (FIG. 2) controls the entire drone 24, such as flying, photographing, and spraying the drug. As shown in FIG. 2, the drone control unit 70 includes an input / output unit 190, a calculation unit 192, and a storage unit 194. The input / output unit 190, the calculation unit 192, and the storage unit 194 are arranged on the control board 110 (FIG. 5). As shown in FIG. 5, the control board 110 is arranged near the center of the bottom surface portion 52 on the bottom surface portion 52 constituting the main body 50.

The input / output unit 190 inputs / outputs signals to / from each unit of the drone 24. The arithmetic unit 192 includes a central processing unit (CPU) and operates by executing a program stored in the storage unit 194. Some of the functions executed by the arithmetic unit 192 can also be realized by using a logic IC (Integrated Circuit). The arithmetic unit 192 may also configure a part of the program with hardware (circuit components). The same applies to the calculation unit of the diagnostic server 22 described above, the calculation unit of the user terminal 26 described later, and the like.

As shown in FIG. 2, the calculation unit 192 includes a flight control unit 200, an imaging control unit 202, and a spray control unit 204. The flight control unit 200 controls the flight of the drone 24 via the flight mechanism 64. Further, the flight control unit 200 executes a part of the altitude-related control related to the altitude above ground level (hereinafter, also referred to as “altitude H”) of the drone 24. The shooting control unit 202 controls shooting by the drone 24 via the shooting mechanism 66. The shooting control unit 202 also executes a part of altitude-related control. The spraying control unit 204 controls the spraying of the drug by the drone 24 via the spraying mechanism 68.

The storage unit 194 stores programs and data used by the calculation unit 192, and includes a random access memory (hereinafter referred to as "RAM"). As the RAM, a volatile memory such as a register and a non-volatile memory such as a hard disk and a flash memory can be used. Further, the storage unit 194 may have a read-only memory (ROM) in addition to the RAM. The same applies to the storage unit of the diagnostic server 22 described above, the storage unit of the user terminal 26 described later, and the like.

(A-1--4-8. Power supply unit 72)
The power supply unit 72 supplies electric power to each unit of the drone 24. The power supply unit 72 has a power supply 210 (FIG. 6) and a power supply circuit 212 (FIGS. 5 and 6). The power supply 210 is made of a secondary battery such as a lithium ion battery, for example. The power supply circuit 212 includes a converter and the like, and distributes the electric power from the power supply 210 to each part of the drone 24.

As shown in FIGS. 5 and 6, the power supply circuit 212 is provided behind the bottom surface portion 52 constituting the main body 50 of the drone 24. Further, as shown in FIG. 6, the power supply 210 is arranged above the power supply circuit 212. The main body 50 has a removable cover 214. The power supply 210 can be attached / detached or replaced with the cover 214 removed.

[A-1-5. User terminal 26]
The user terminal 26 (FIG. 1) controls the drone 24 by the operation of the user 600 (FIG. 1) as an operator in the field 500, and the information received from the drone 24 (for example, the position, the amount of drug, and the remaining battery level). , Camera image, etc.). In the present embodiment, the flight state (altitude, attitude, etc.) of the drone 24 is not remotely controlled by the user terminal 26, but is autonomously controlled by the drone 24. Therefore, when a flight command is transmitted from the user 600 to the drone 24 via the user terminal 26, the drone 24 performs autonomous flight. However, manual operations may be possible during basic operations such as takeoff and return, and in emergencies. The user terminal 26 includes an input / output unit (including a touch panel and the like), a communication unit, a calculation unit, and a storage unit (not shown), and is composed of, for example, a general tablet terminal.

Further, the user terminal 26 of the present embodiment receives and displays a work instruction or the like from the growth diagnosis server 22. In addition to the user terminal 26 as the controller of the drone 24, another user terminal used by another user other than the operator (user 600) may be provided. The other user terminal receives and displays flight information of the drone 24 (current flight status, scheduled flight end time, etc.), work instructions for the user 602, growth diagnosis information, etc. from the diagnosis server 22 or the drone 24. It can be a mobile information terminal. Alternatively, the other user terminal may be a terminal used by the user 600 or the like in order to use the growth diagnosis by the growth diagnosis server 22 in a place other than the field 500 (for example, the company to which the user 600 belongs).

<A-2. Control of this embodiment>
[A-2-1. Overview]
The diagnosis server 22 of the present embodiment performs growth diagnosis control and flight management control. The growth diagnosis control is a control for performing a growth diagnosis using a growth diagnosis model. The growth diagnosis referred to here includes, for example, an estimated value (estimated yield) of the yield for each field 500. Further, in the growth diagnosis control, work instructions regarding water management, fertilization, chemical spraying, etc. of the field 500 as a paddy field are also given. The work instruction is displayed on, for example, the display unit of the user terminal 26. In the growth diagnosis model, the yield of crop 502 (paddy rice), red light absorption rate, number of paddy, effective light receiving area ratio, amount of accumulated starch in paddy and protein content in paddy can be calculated.

Flight management control is a control that manages the flight of the drone 24. In the flight management control, the flight timing, flight path, target speed, target altitude, imaging method of the imaging mechanism 66, spraying method of the spraying mechanism 68, etc. of the drone 24 are set based on the work instructions in the growth diagnosis control. ..

In the drone 10 of the present embodiment, flight control, imaging control, and chemical spray control are performed. The flight control is a control for flying the drone 24 in the field 500 for photographing, spraying chemicals, and the like. In flight control, the flight control unit 200 controls the flight mechanism 64 based on a command from the diagnostic server 22. In this embodiment, altitude-related control is performed as part of flight control. Details of altitude-related control will be described later with reference to FIG.

The imaging control is a control that acquires an image of the field 500 (or crop 502) by the camera 160 of the drone 24 and transmits it to the diagnostic server 22. In imaging control, the imaging control unit 202 controls the imaging mechanism 66 based on a command from the diagnostic server 22. The field image transmitted to the diagnosis server 22 is image-processed and used for growth diagnosis. The chemical spraying control is a control for spraying a chemical solution (including liquid fertilizer) using the drone 24. In the drug spraying control, the spraying control unit 204 controls the spraying mechanism 68 based on a command from the diagnostic server 22.

[A-2-2. Advanced related control]
(A-2-2-1. Overview)
As mentioned above, the altitude-related control is the control related to the altitude H of the drone 24 and is a part of the flight control. As described above, in the present embodiment, the TOF sensor 100 and the ultrasonic sensor 102 are included as sensors for detecting the altitude H of the drone 24 (FIGS. 2, 4 and 5). In the altitude-related control of the present embodiment, the drone control unit 70 uses a TOF sensor 100 and an ultrasonic sensor for the altitude H (hereinafter, also referred to as “control altitude Hc” or “detection altitude Hc”) used in the flight control of the drone 24. It is set based on the detected values of 102 (first distance D1, second distance D2). In this embodiment, the detection value (first distance D1) of the TOF sensor 100 is basically used as the control altitude Hc. Further, in a special situation, the detected value (second distance D2) of the ultrasonic sensor 102 is used as the control altitude Hc. Further, the drone control unit 70 reduces the flight speed Vf of the drone 24 under special circumstances. The detected altitude Hc is compared with the target altitude and used for altitude control of the drone 24.

(A-2-2-2. Specific flow)
FIG. 7 is a flowchart of the altitude-related control of the present embodiment. The altitude-related control of the present embodiment is basically executed by the drone control unit 70 (FIG. 2) of the drone 24. Note that some of the altitude-related controls shown in FIG. 7 can overlap with other controls in flight control.

In step S11, the drone control unit 70 (shooting control unit 202) acquires the lower image Ilaw (image of the ground 520 or the like) of the camera 160. In step S12, the drone control unit 70 (shooting control unit 202) performs image processing on the lower image Ilaw to determine the state (lower state Slow) of the lower target Row (ground 520 or the like). The downward state Slow here includes, for example, a state in which the lower target Trow is a mirror surface or white, a state in which the lower target Trow has a boundary from the shade to the sun, and a state in which the measurement position of the TOF sensor 100 straddles the boundary. ..

Whether or not the lower target Trow is a mirror surface or white is determined, for example, by pattern determination in a region where the light receiving amount of the light receiving element of the camera 160 is saturated. Similarly, the boundary from the shade to the sun is determined, for example, by pattern determination in a region where the light receiving amount of the light receiving element of the camera 160 is saturated. The determined downward state Slow is notified from the shooting control unit 202 to the flight control unit 200.

In step S13, the drone control unit 70 (flight control unit 200) determines whether or not the detection accuracy of the TOF sensor 100 is in a reduced state (TOF sensor accuracy lowered state) based on the downward state Slow. The TOF sensor accuracy reduction state includes a state in which the lower target Row is a mirror surface or white, and a state in which the drone 24 straddles the boundary from the shade to the sun. In other cases, it is determined that the TOF sensor accuracy is not reduced. When the TOF sensor accuracy is not lowered (S13: true), the drone control unit 70 determines that it is a normal time, and proceeds to step S14.

In step S14, the drone control unit 70 (flight control unit 200) sets the detection value (first distance D1) of the TOF sensor 100 as the control altitude Hc.

If the TOF sensor accuracy is low (S13: false), the process proceeds to step S15. In step S15, the drone control unit 70 (flight control unit 200) determines whether or not the established TOF sensor accuracy reduction state is a state that straddles the boundary from the shade to the sun (in other words, the drone 24 passes through the boundary). Whether or not it is inside) is determined. If the boundary from the shade to the sun is being passed (S15: true), the process proceeds to step S16.

In step S16, the drone control unit 70 (flight control unit 200) executes flight speed reduction control for reducing the flight speed Vf of the drone 24 to a predetermined value (boundary flight speed THvf). As described above, the TOF sensor 100 of the present embodiment has a variable dynamic range of the amount of received light in order to improve the detection accuracy. Therefore, when the measurement position straddles the boundary from the shade to the sun, the dynamic range is temporarily saturated due to a sudden increase in the amount of light received, and then the dynamic range is adjusted to enable highly accurate measurement even in the sun.

Therefore, in the present embodiment, the flight speed Vf of the drone 24 is reduced to the boundary flight speed THvf before the measurement position of the TOF sensor 100 crosses the boundary from the shade to the sun. As a result, the distance traveled by the drone 24 can be shortened when the amount of light received by the TOF sensor 100 is saturated. Therefore, the applicable range of the TOF sensor 100 can be expanded. After the flight speed Vf drops to the boundary flight speed THvf, the flight speed Vf is maintained at the boundary flight speed THvf.

In step S17, the drone control unit 70 (flight control unit 200) sets the detection value (second distance D2) of the ultrasonic sensor 102 as the control altitude Hc. Steps S18 and S19 are the same as steps S11 and S12.

In step S20, the drone control unit 70 (flight control unit 200) determines whether or not the measurement position of the TOF sensor 100 has completed the passage of the boundary from the shade to the sun. The determination is made by determining whether or not the measurement position of the TOF sensor 100 is separated from the boundary line by a predetermined distance after passing the boundary line from the shade to the sun based on the lower image Ilow. Alternatively, after determining that the measurement position of the TOF sensor 100 has passed the boundary line from the shade to the sun based on the lower image Ilow, the detection value D1 of the TOF sensor 100 and the detection value D2 of the ultrasonic sensor 102 are compared. Do it by. More specifically, after determining based on the lower image Ilaw that the measurement position of the TOF sensor 100 has passed the boundary line from the shade to the sun, the absolute value of the difference between the detected values D1 and D2 or the ratio of the difference is determined. It is performed based on whether or not it is below the threshold value of.

If the measurement position has not finished passing through the same boundary (S20: false), the process returns to step S16. When the measurement position finishes passing through the same boundary (S20: true), the process proceeds to step S21. In step S21, the drone control unit 70 (flight control unit 200) sets the detection value (first distance D1) of the TOF sensor 100 as the control altitude Hc.

Returning to step S15, when the established TOF sensor accuracy reduction state is other than passing through the boundary from the shade to the sun (S15: false), the established TOF sensor accuracy reduction state is a mirror surface of the lower target Row. Or it is in a white state. In that case, the process proceeds to step S22. In step S22, the drone control unit 70 (flight control unit 200) sets the detection value (second distance D2) of the ultrasonic sensor 102 as the control altitude Hc.

After steps S14, S21, and S22, the process returns to step S11.

<A-3. Effect of this embodiment>
According to this embodiment, one of the first distance D1 to the lower target Low (ground 520 etc.) detected by the TOF sensor 100 (optical sensor) and the second distance D2 to the lower target Low detected by the ultrasonic sensor 102. The flight control of the drone 24 is performed using the control altitude Hc set by selecting. (FIG. 7). This makes it possible to fly the drone 24 based on the advantages and disadvantages of the TOF sensor 100 and the ultrasonic sensor 102. For example, the TOF sensor 100 does not reduce the detection accuracy even in soil where the ultrasonic sensor 102 is not good at. Further, the ultrasonic sensor 102 does not reduce the detection accuracy even for a mirror-surfaced object, a white object, or the like, which the TOF sensor 100 is not good at. Therefore, it is possible to improve the robustness of the drone 24 as a whole against changes in the downward target Row such as the ground 520.

In this embodiment, the TOF sensor 100 is used as the optical sensor (Fig. 2, etc.). Compared with other types of optical sensors (phase difference detection method, triangular ranging method, etc.), the TOF sensor 100 is often lighter in weight, and the weight of the drone 24 can be reduced by using the TOF sensor 100. It will be possible.

In the present embodiment, the TOF sensor 100 (optical sensor) and the ultrasonic sensor 102 are arranged side by side in the lateral direction of the drone 24 (FIGS. 4 and 5). Further, the light irradiation direction by the TOF sensor 100 and the ultrasonic irradiation direction by the ultrasonic sensor 102 are the light irradiation range by the TOF sensor 100 and the ultrasonic irradiation by the ultrasonic sensor 102 in the measurement areas of both sensors. At least part of the range is set to overlap. The drone 24 may move forward in a forward leaning posture in the direction of travel (arrow A in FIG. 3 and the like). If the TOF sensor 100 and the ultrasonic sensor 102 are arranged in the lateral direction of the drone 24, the detection values of both sensors (first distance D1 and second distance D2) even in such a forward leaning posture. Is less likely to be misaligned with each other. Therefore, it is possible to suppress the dissociation between the first distance D1 by the TOF sensor 100 and the second distance D2 by the ultrasonic sensor 102.

In the present embodiment, the drone 24 includes a tank 180 for storing the sprayed material and a nozzle 186 (discharge port) for spraying the sprayed material (FIGS. 3 and 4). Further, the TOF sensor 100 (optical sensor) and the ultrasonic sensor 102 are arranged above the nozzle 186 (FIGS. 3 and 4). Further, the TOF sensor 100 and the ultrasonic sensor 102 are arranged in front of the nozzle 186 (FIGS. 3 and 4). As a result, it is possible to suppress the influence of the sprayed material sprayed from the nozzle 186 on the measurement of the TOF sensor 100 or the ultrasonic sensor 102.

In the present embodiment, the drone 24 determines the state of the lower target Trow (lower state Slow) based on the images of the camera 160 (FIGS. 2, 4 to 6) that captures the lower target Tlow and the images of the camera 160. It is provided with a shooting control unit 202 (lower state determination unit; FIG. 2). The flight control unit 200 selects the first distance D1 detected by the TOF sensor 100 (optical sensor) and sets the control altitude Hc in the normal state (S13: true in FIG. 7) when the accuracy of the optical sensor is not deteriorated. (S14). Further, when the optical sensor accuracy is lowered (S13: false), the flight control unit 200 selects the second distance D2 detected by the ultrasonic sensor 102 and sets the control altitude Hc (S17, S22). ..

As a result, when the detection accuracy of the TOF sensor 100 is higher than that of the ultrasonic sensor 102 in normal times, the ultrasonic sensor 102 is preferentially used in a situation where the detection accuracy of the TOF sensor 100 is lowered. It is possible to control the flight with high accuracy.

In the present embodiment, the optical sensor accuracy reduction state includes a state in which a boundary from the shade to the sun exists in the lower target Row and the measurement position of the TOF sensor 100 (optical sensor) straddles the boundary (S13, S15 in FIG. 7). ). The flight control unit 200 reduces the flight speed Vf of the drone 24 before the measurement position of the TOF sensor 100 crosses the boundary from the shade to the sun (S16).

The TOF sensor 100 has a variable dynamic range of the amount of received light in order to improve the detection accuracy. Therefore, when the measurement position straddles the boundary from the shade to the sun, the measurement range is temporarily saturated due to a sudden increase in the amount of light received, and then the dynamic range is adjusted to enable highly accurate measurement even in the sun. In the present embodiment, the flight speed Vf of the drone 24 is reduced before the measurement position of the TOF sensor 100 crosses the boundary from the shade to the sun. As a result, the distance traveled by the drone 24 can be shortened when the amount of light received by the TOF sensor 100 is saturated. Therefore, the applicable range of the TOF sensor 100 can be expanded, and the robustness against a change in the downward target Row such as the ground 520 can be improved.

Also, ultrasonic waves are much slower than light, and the Doppler effect that accompanies the movement of the drone 24 has a large effect. Therefore, when using the detected value (second distance D2) of the ultrasonic sensor 102, the Doppler effect is obtained by lowering the flight speed Vf as compared with the case of using the detected value (first distance D1) of the TOF sensor 100. It is possible to suppress a decrease in detection accuracy due to the above.

B. Modifications It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various configurations can be adopted based on the contents described in the present specification. For example, the following configuration can be adopted.

<B-1. Configuration>
The crop growing system 10 of the above embodiment had components as shown in FIG. However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc. For example, the crop growing system 10 may have only the drone 24 and the user terminal 26. In that case, the flight of the drone 24 may be controlled by the user terminal 26.

In the above embodiment, the drone 24 imaged the crop 502 and sprayed the chemical solution (FIG. 1). However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc. For example, the drone 24 may only image the crop 502 and spray the chemical solution. Alternatively, the drone 24 may be used for other purposes (for example, aerial photography other than growth diagnosis).

In the above embodiment, the TOF sensor 100 is used as the optical sensor. However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detection values D1 and D2 of the optical sensor and the ultrasonic sensor 102 as the control altitude Hc. For example, instead of the TOF sensor 100, another type of optical sensor (phase difference detection method, triangular ranging method, etc.) may be used.

In the above embodiment, the TOF sensor 100 and the ultrasonic sensor 102 are arranged side by side in the horizontal direction of the drone 24 (FIGS. 4 and 5). However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc. For example, the TOF sensor 100 and the ultrasonic sensor 102 may be arranged side by side in the front-rear direction of the drone 24.

In the above embodiment, the TOF sensor 100 and the ultrasonic sensor 102 are arranged in the main body 50 of the drone 24 (FIGS. 5 and 6). However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc. For example, the TOF sensor 100 and the ultrasonic sensor 102 may be arranged outside the main body 50 of the drone 24.

FIG. 8 is a side view simply showing the internal configuration of the main body 50 of the drone 24 and the arrangement around the main body 50 according to the modified example. In the example of FIG. 8, the drone 24 has a support member 220 that projects downward from the main body 50 and supports a TOF sensor 100, an ultrasonic sensor 102, and a camera 160. As a result, even if a heat generation source (control board 110, inverter 136, power supply 210, etc.) exists in the main body 50 of the drone 24, the TOF sensor 100, the ultrasonic sensor 102, and the camera 160 can be arranged away from the heat generation source. Can be done. Therefore, it is possible to prevent the TOF sensor 100, the ultrasonic sensor 102, and the camera 160 from being affected by the heat from the heat generation source.

In the above embodiment, the sprayed product sprayed by the drone 24 was a drug as a liquid. However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detected values of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc. For example, the sprayed material may be something other than a drug (water, etc.), or may be a gas or a solid (including powder).

<B-2. Control>
In the above embodiment, the determination of the state of the lower target Tlow (lower state Slow) is performed based on the lower image Ilaw of the camera 160 in real time (S12, S19 in FIG. 7). However, for example, from the viewpoint of determining the downward state Slow, the present invention is not limited to this. For example, the position coordinates and the lower state Slow may be stored in association with each other in advance, and the lower state Slow may be determined based on the position coordinates during the flight of the drone 24 and the stored information. Alternatively, the downward state Slow may be determined using means other than the TOF sensor 100, the ultrasonic sensor 102, and the camera 160 (for example, the position coordinates of the satellite image and the drone 24).

In the above embodiment, as the TOF sensor accuracy reduction state, a state in which the lower target Row is a mirror surface or a white surface and a state in which the drone 24 straddles the boundary from the shade to the sun are used (S13 and S15 in FIG. 7). However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc. For example, a state in which the drone 24 straddles the boundary from the sun to the shade may be used. In this case, the dynamic range of the TOF sensor 100 is not saturated, but the range to be used is narrowed, so that the detection accuracy may be lowered. Therefore, by switching to the ultrasonic sensor 102 and / or reducing the flight speed Vf, it is possible to improve the robustness against a change in the downward target Tlow.

In the above embodiment, the detection value (first distance D1) of the TOF sensor 100 is used as the control altitude Hc in the normal state (when the TOF sensor accuracy is not lowered), and the ultrasonic sensor 102 is used when the TOF sensor accuracy is lowered. (2nd distance D2) was used as the control altitude Hc (FIG. 7). However, the present invention is not limited to this, for example, from the viewpoint of selectively using the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc. For example, in a configuration in which the first distance D1 and the second distance D2 are combined to calculate the control altitude Hc, the first distance D1 and the second distance D2 are weighted (ratio) according to the state of the lower target Tlow (lower state Slow). ) May be changed. For example, in the normal state, the first distance D1 × 0.9 + the second distance D2 × 0.1 is set as the control altitude Hc, and when the TOF sensor accuracy is lowered, the first distance D1 × 0.3 + the second distance D2 × 0.7 may be the control altitude Hc.

Alternatively, the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 may be selectively used as the control altitude Hc without using the lower image Ilaw of the camera 160. For example, normally, the detection value of the TOF sensor 100 (first distance D1) is used as the control altitude Hc, and when an abnormality occurs in the TOF sensor 100, the detection value of the ultrasonic sensor 102 (second distance D2). May be used as the control altitude Hc.

In the above embodiment, when the measurement position of the TOF sensor 100 crosses the boundary from the shade to the sun (S15: true in FIG. 7), the flight speed Vf of the drone 24 is reduced (S16). However, for example, from the viewpoint of selectively using the detection values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 as the control altitude Hc, the measurement position of the TOF sensor 100 is not limited to this, and the measurement position of the TOF sensor 100 is from the shade to the sun. The flight speed Vf may be maintained even when crossing the boundary.

<B-3. Others>
In the above embodiment, the detection value (first distance D1) of the TOF sensor 100 is used as the control altitude Hc in the normal state (when the TOF sensor accuracy is not lowered), and the ultrasonic sensor 102 is used when the TOF sensor accuracy is lowered. (2nd distance D2) was used as the control altitude Hc (FIG. 7). In other words, the detected values D1 and D2 of the TOF sensor 100 and the ultrasonic sensor 102 were selectively used as the control altitude Hc. However, from the viewpoint of reducing the flight speed Vf of the drone 24 when the measurement position of the TOF sensor 100 crosses the boundary from the shade to the sun, the detection value of the TOF sensor 100 (first) without using the ultrasonic sensor 102. It is also possible to use only the distance D1) as the control altitude Hc.

FIG. 9 is a flowchart of altitude-related control according to a modified example. In the altitude-related control of FIG. 9, only the detection value (first distance D1) of the TOF sensor 100 is used as the control altitude Hc without using the ultrasonic sensor 102.

Steps S31 and S32 in FIG. 9 are the same as S11 and S12 in FIG. In step S33, the drone control unit 70 (flight control unit 200) determines whether or not the downward state Slow is normal (whether or not the measurement position of the TOF sensor 100 crosses the boundary from the shade to the sun). To judge. When the downward state Slow is normal (normal time) (S33: true), the process proceeds to step S34. In step S34, the drone control unit 70 (flight control unit 200) sets the detection value D1 of the TOF sensor 100 as the control altitude Hc. When the measurement position of the TOF sensor 100 crosses the boundary from the shade to the sun (S33: false), the process proceeds to step S35.

Step S35 is the same as step S16 in FIG. In the following step S37, the drone control unit 70 (flight control unit 200) sets the detection value D1 of the TOF sensor 100 as the control altitude Hc. That is, the drone control unit 70 (flight control unit 200) continues to use the detected value D1 as the control altitude Hc. Steps S37, S38, and S39 are the same as steps S18, S19, and S20 of FIG.

If the measurement position of the TOF sensor 100 has not completed the passage of the boundary from the shade to the sun (S39: false), the process returns to step S35. When the measurement position finishes passing through the same boundary (S39: true), the process proceeds to step S40. In step S40, the drone control unit 70 (flight control unit 200) sets the detection value D1 of the TOF sensor 100 as the control altitude Hc.

As described above, in the altitude-related control of FIG. 9, the drone control unit 70 (flight control unit 200) continues to use the detected value (first distance D1) of the TOF sensor 100 as the control altitude Hc. When the control of FIG. 9 is regarded as the control of the flight speed Vf of the drone 24, the processing of the control altitude Hc (S34, S36, S40) may be positioned as another control. Further, in the control of FIG. 9, only the time when the boundary from the shade to the sun passed was used as the optical sensor accuracy reduced state (S13), but as described above, the time when the boundary from the sun to the shade passed was the optical sensor accuracy. It may be included in the lowered state.

The flow shown in FIG. 7 was used for the altitude-related control of the above embodiment, and the flow shown in FIG. 9 was used for the altitude-related control of the modification. However, for example, when the effect of the present invention can be obtained, the content of the flow (order of each step) is not limited to this. For example, the order of steps S16 and S17 in FIG. 4 can be exchanged.

24 ... Drone 100 ... TOF sensor (optical sensor)
102 ... Ultrasonic sensor 160 ... Camera 180 ... Tank 186l1, 186l2, 186r1, 186r2 ... Nozzle (discharge port)
200 ... Flight control unit 202 ... Shooting control unit (downward state determination unit)
220 ... Support member D1 ... First distance D2 ... Second distance Hc ... Control altitude Tlow ... Downward target Vf ... Flight speed

Claims

An optical sensor that detects the first distance to the lower object, an ultrasonic sensor that detects the second distance to the lower object, and
A drone equipped with a camera that captures the lower object.
The drone
A lower state determination unit that determines the state of the lower object based on the image of the camera, and a lower state determination unit.
It further has a flight control unit that controls the flight of the drone by using the control altitude set by selecting one of the first distance and the second distance or a combination of both.
The flight control unit
When the state of the lower object determined by the lower state determination unit is not a state in which the accuracy of the optical sensor is reduced, the first distance detected by the optical sensor is selected or the ultrasonic wave is detected. The control altitude is set by increasing the weighting of the first distance from the second distance detected by the sensor.
When the state of the lower object is the state in which the accuracy of the optical sensor is lowered, the control altitude is set by selecting the second distance or by increasing the weighting of the second distance from the first distance. A drone characterized by reducing the flight speed of the drone.
A drone including an optical sensor that detects a first distance to a lower object and an ultrasonic sensor that detects a second distance to the lower object.
A drone further comprising a flight control unit that controls the flight of the drone by using a control altitude set by selecting one of the first distance and the second distance or a combination of both.
In the drone according to claim 1 or 2.
The optical sensor is a drone characterized by being a time-of-flight type sensor.
In the drone according to any one of claims 1 to 3,
The optical sensor and the ultrasonic sensor are arranged side by side in the lateral direction of the drone.
The light irradiation direction by the optical sensor and the ultrasonic irradiation direction by the ultrasonic sensor overlap at least a part of the light irradiation range by the optical sensor and the ultrasonic irradiation range by the ultrasonic sensor. A drone characterized by being set up to.
In the drone according to any one of claims 1 to 4,
A drone characterized by having a support member that projects downward from the main body of the drone and supports the optical sensor and the ultrasonic sensor.
In the drone according to any one of claims 1 to 5,
The drone
A tank to store the spray and
It is provided with a discharge port for spraying the sprayed material.
A drone characterized in that the optical sensor and the ultrasonic sensor are arranged above the discharge port.
In the drone according to claim 6,
A drone characterized in that the optical sensor and the ultrasonic sensor are arranged above and in front of the discharge port.
In the drone according to any one of claims 1 to 5,
The drone
A tank to store the spray and
It is provided with a discharge port for spraying the sprayed material.
A drone characterized in that the optical sensor and the ultrasonic sensor are arranged in front of the discharge port.
In the drone according to claim 2,
The drone
A camera that captures the lower object and
Further, a lower state determination unit for determining the state of the lower object based on the image of the camera is provided.
The flight control unit
When the state of the lower object determined by the lower state determination unit is not a state in which the accuracy of the optical sensor is reduced, the first distance detected by the optical sensor is selected or the ultrasonic wave is detected. The control altitude is set by increasing the weighting of the first distance from the second distance detected by the sensor.
When the state of the lower object is the state in which the accuracy of the optical sensor is lowered, the control altitude is set by selecting the second distance or by increasing the weighting of the second distance from the first distance. Characterized drone.
In the drone according to claim 1 or 9,
The state in which the accuracy of the optical sensor is lowered includes a state in which the lower object is a mirror surface or white, or a state in which the lower object has a boundary between the shade and the sun and the measurement position of the optical sensor straddles the boundary. Characterized drone.
In the drone according to claim 9,
The state in which the accuracy of the optical sensor is lowered is a state in which a boundary between the shade and the sun exists in the lower object, and the measurement position of the optical sensor straddles the boundary.
The flight control unit is a drone characterized in that the flight speed of the drone is reduced before the measurement position of the optical sensor crosses the boundary between the shade and the sun.
An optical sensor that detects the first distance to the lower target,
A flight control unit that controls the flight of the drone by using the first distance as a control altitude.
A drone including a lower state determination unit for determining the surface state of the lower object.
When the surface state of the lower object determined by the lower state determination unit is an optical sensor accuracy reduction state in which the detection accuracy of the optical sensor is reduced, the flight control unit reduces the flight speed of the drone. Characterized drone.
A drone control method including an optical sensor that detects a first distance to a lower object and an ultrasonic sensor that detects a second distance to the lower object.
A method for controlling a drone, wherein the flight control unit controls the flight of the drone by using a control altitude set by selecting one of the first distance and the second distance or a combination of both.
An optical sensor that detects the first distance to the lower target,
A flight control unit that controls the flight of the drone by using the first distance as a control altitude.
It is a control method of a drone including a lower state determination unit for determining the surface state of the lower object.
When the surface state of the lower object determined by the lower state determination unit is an optical sensor accuracy reduction state in which the detection accuracy of the optical sensor is reduced, the flight control unit reduces the flight speed of the drone. The characteristic drone control method.