PROTECTION DEVICE, PROTECTION METHOD, AND UNMANNED AERIAL VEHICLE

Provided is a protection device for protecting a sensor mounted on an unmanned aerial vehicle. The protection device includes a housing and a nozzle provided in the housing and connected to a container, and protects the sensor by discharging a content of the container from the nozzle. The protection device may further include an information acquisition unit for acquiring information from an outside, and discharge the content from the nozzle based on the information acquired by the information acquisition unit. The protection device may further include an environment detection unit configured to detect a change in environment, and discharge the content from the nozzle based on the change detected by the environment detection unit. The protection device may further include a foreign object detection unit configured to detect a foreign object, and discharge the content from the nozzle in response to the foreign object detection unit detecting the foreign object.

BACKGROUND

1. Technical Field

The present invention relates to a protection device, a protection method, and an unmanned aerial vehicle.

2. Related Art

Patent Documents 1 and 2 describe a device that generates an air flow in a housing so that dust or the like does not adhere to a sensor mounted on an unmanned aerial vehicle. In addition, Patent Document 3 describes a device that sprays a cleaning liquid to a sensor mounted on an unmanned aerial vehicle to clean a sensor surface.Patent Document 1: International Publication No. 2018165937Patent Document 2: International Publication No. 2019100316Patent Document 3: Japanese translation publication of PCT route patent application No. 2019-526206

TECHNICAL PROBLEM

With the expansion of the application range of the unmanned aerial vehicle, it is required to effectively protect the sensor in various environments.

GENERAL DISCLOSURE

According to a first aspect of the present invention, there is provided a protection device for protecting a sensor mounted on an unmanned aerial vehicle. The protection device includes a housing and a nozzle provided in the housing and connected to a container. The sensor is protected by discharging a content of the container from the nozzle.

The protection device may further include an information acquisition unit configured to acquire information from an outside. The content may be discharged from the nozzle based on the information acquired by the information acquisition unit.

The information acquisition unit may acquire operation information from an operator.

The information acquisition unit may acquire information from the unmanned aerial vehicle.

The protection device may further include an environment detection unit configured to detect a change in environment. The content may be discharged from the nozzle based on the change detected by the environment detection unit.

The protection device may further include a foreign object detection unit configured to detect a foreign object, and may discharge the content from the nozzle in response to the foreign object detection unit detecting the foreign object.

The foreign object detection unit may be provided closer to an inlet of the housing than the sensor, and the nozzle may be provided between the sensor and the foreign object detection unit.

The foreign object detection unit may include a light receiving portion, and may detect a change in an amount of received light when the foreign object approaches the light receiving portion.

The foreign object detection unit may include an energization portion, and may detect a change in resistance when the foreign object comes into contact with the energization portion.

The nozzle may be provided between the sensor and the inlet of the housing, and the foreign object detection unit may operate as the sensor.

The housing may have a concave portion having a cylindrical or substantially tapered shape from an inlet of the housing toward a bottom portion, the sensor may be attached to the bottom portion, and the nozzle may be provided on a side surface of the concave portion.

The protection device may further include a container.

The content may be discharged from the nozzle in a direction different from the direction toward the sensor.

The discharged content may contain a liquid.

The discharged content may contain a repellent for a living body.

A second aspect of the present invention provides a protection method for protecting a sensor mounted on an unmanned aerial vehicle. The protection method includes protecting the sensor by discharging a content of a container from a nozzle connected to the container.

The protection method may further include acquiring information from an outside, and discharging the content from the nozzle based on the acquired information.

The protection method may further include detecting a change in environment and discharging the content from the nozzle based on the detected change.

The protection method may further include detecting an object and discharging the content from the nozzle in response to detecting the foreign object.

In a third aspect of the present invention, there is provided an unmanned aerial vehicle including a protection device according to the first aspect of the present invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of features described in the embodiments are essential to the solution of the invention.

FIG.1is a diagram illustrating an example of the configuration of an unmanned aerial vehicle100.

The unmanned aerial vehicle100is a flying body that flies in the air. The unmanned aerial vehicle100of the present example includes a main body10, a propulsion unit20, a movable camera30, and a GPS information reception unit40. Note that, in the present specification, a direction in which the movable camera30is directed inFIG.1is referred to as a front direction of the unmanned aerial vehicle100, but the flight direction is not limited to the front direction.

The main body10stores various control circuits, a power supply, and the like of the unmanned aerial vehicle100. In addition, the main body10may function as a structure body that couples the configurations of the unmanned aerial vehicle100. The main body10in the present example is coupled to the propulsion unit20.

The main body10is coupled to a leg portion15. The leg portion15holds the posture of the unmanned aerial vehicle100at the time of landing. The leg portion15holds the posture of the unmanned aerial vehicle100in a state where the propulsion unit20is stopped. The unmanned aerial vehicle100of the present example has two leg portions15. The movable camera30and the protection device400may be attached to the leg portion15.

The propulsion unit20propels the unmanned aerial vehicle100. The propulsion unit20includes rotation blades21and a rotation drive unit22. The unmanned aerial vehicle100of the present example includes four propulsion units20. The propulsion unit20is attached to the main body10via an arm portion24. Note that the unmanned aerial vehicle100may be a flying body including fixed wings.

The propulsion unit20obtains a propulsive force by rotating the rotation blades21. Four rotation blades21are provided around the main body10, but the method of disposing the rotation blades21is not limited to the present example. The rotation blade21is provided at the edge of the arm portion24via the rotation drive unit22.

The rotation drive unit22has a power source such as a motor and drives the rotation blade21. The rotation drive unit22may have a brake mechanism of the rotation blade21. The rotation blade21and the rotation drive unit22may be directly attached to the main body10without the arm portion24.

The arm portion24is provided radially extending from the main body10. The unmanned aerial vehicle100of the present example includes four arm portions24provided corresponding to the four propulsion units20. The arm portion24may be fixed or movable. Another configuration such as a camera may be fixed to the arm portion24.

The movable camera30captures an image around the unmanned aerial vehicle100. The movable camera30of the present example is provided on the lower side of the main body10. In one example, the lower side refers to the side opposite to the side on which the rotation blades21are provided with respect to the main body10.

Although not illustrated inFIG.1, the unmanned aerial vehicle100includes a fixed camera provided on a side surface of the main body10in addition to the movable camera30. The movable camera30and the fixed camera capture videos of different regions. For example, the fixed camera acquires a video of the front of the unmanned aerial vehicle100, and the movable camera30acquires a video of a region narrower than that of the fixed camera. In addition, when the fixed camera is capturing a video in the traveling direction, the movable camera30may capture a video in the discharge direction in which the protection device400described later discharges a content465of the container.

In one example, the videos captured by the movable camera30and the fixed camera are transmitted to the terminal device300described later. The pilot of the unmanned aerial vehicle100may pilot the unmanned aerial vehicle100based on the video captured by the fixed camera. In addition, the pilot of the unmanned aerial vehicle100may directly view and pilot the unmanned aerial vehicle100.

The unmanned aerial vehicle100of the present example includes the fixed camera for piloting and the movable camera30for discharge control, whereby the operation by the operator is facilitated. Since it is not necessary to switch between the operation screen for piloting and the operation screen for discharge control, it is possible to prevent confusion of the pilot. In addition, it is possible to easily grasp the surroundings of the unmanned aerial vehicle100while performing the discharge control.

A coupling portion32couples the main body10and the movable camera30. The coupling portion32may be fixed or movable. The coupling portion32may be a gimbal for controlling the position of the movable camera30in three axial directions.

The GPS information reception unit40is an antenna provided on a side surface of the main body10. The GPS information reception unit40receives position information of the unmanned aerial vehicle100from a GPS satellite.

The protection device400that protects a sensor mounted on the unmanned aerial vehicle100is coupled to the unmanned aerial vehicle100. The protection device400includes the housing410, an extending portion430, and the discharge device450. The sensor may be a camera, an ultrasonic sensor, an optical sensor, or the like. The protection device400may be included as a component of the unmanned aerial vehicle100.

The housing410is coupled to the main body10. The housing410may be coupled to a member other than the main body10such as the arm portion24or the leg portion15. In one example, the housing410has a concave portion420for accommodating a sensor.

The extending portion430is a tube for discharging the content465of a container460. The extending portion430is provided to extend from the container460of the discharge device450to the housing410, and couples the housing410and the discharge device450. The extending portion430branches in the housing410and is connected to each nozzle414described later. The number of extending portions430may correspond to the number of the housings410.

The discharge device450holds the container460to be described later filled with the content465. The discharge device450is coupled to the main body10. The discharge device450may be coupled to a member other than the main body10such as the arm portion24or the leg portion15. In one example, the discharge device450is a cylindrical sleeve that accommodates the container460.

The material of the discharge device450is not particularly limited as long as it can hold the shape of the accommodation portion for accommodating the container460. For example, the material of the discharge device450includes a high strength and lightweight material such as metal such as aluminum, plastic, or carbon fiber. In addition, the material of the discharge device450is not limited to a hard material, and may include a soft material, for example, a rubber material such as silicone rubber or urethane foam. Note that the discharge device450may include a heating mechanism for heating or keeping the container460warm.

FIG.2is a diagram illustrating an example of the configuration of the pilot device200. The pilot device200includes an antenna210, a pilot stick220, and a discharge button230.

The pilot device200is communicably connected to the unmanned aerial vehicle100via the antenna210. The pilot stick220is a device for a pilot of the unmanned aerial vehicle100to input a flight instruction of the unmanned aerial vehicle100. The pilot device200transmits the flight instruction input by the pilot of the unmanned aerial vehicle100by operating the pilot stick220to the unmanned aerial vehicle100, and controls the flight of the unmanned aerial vehicle100.

The discharge button230is a device for the pilot of the unmanned aerial vehicle100to input a discharge instruction for discharging the content465of the container460. The pilot device200transmits the discharge instruction input by the pilot of the unmanned aerial vehicle100by pressing the discharge button230to the protection device400, and controls the discharge of the content465of the container460.

The discharge button230may have a form other than a button such as a stick. The discharge button230may be integral with the pilot stick220.

The pilot device200may be connected to the terminal device300in a wired or wireless manner. A plurality of pilot devices200may be provided and used for piloting the unmanned aerial vehicle100and for controlling the discharge of the protection device400.

Note that the pilot in the present example manually pilots the unmanned aerial vehicle100using the pilot device200. However, the pilot may pilot the unmanned aerial vehicle100automatically by a program instead of manually. In addition, the piloting of the unmanned aerial vehicle100may be automatically controlled, and the discharge of the protection device400may be manually operated.

FIG.3is a diagram illustrating an example of the configuration of the terminal device300. The terminal device300includes a display unit310. In one example, the terminal device300is a mobile terminal such as a smartphone and a tablet.

In one example, the display unit310displays map information of an area where the unmanned aerial vehicle100flies. The display unit310may display the position information of the unmanned aerial vehicle100acquired from the GPS information reception unit40while displaying the position information to be superimposed on the map information. In addition, as will be described later, the display unit310may indicate a preset operation area320of the protection device400on the map information.

Alternatively, the display unit310may display an image captured by each of the fixed camera and the movable camera30mounted on the unmanned aerial vehicle100. For example, the display unit310displays images of the fixed camera and the movable camera30on divided screens. The terminal device300may directly communicate with the unmanned aerial vehicle100, or may indirectly communicate with the unmanned aerial vehicle100via the pilot device200. The terminal device300may be connected to an external server.

The terminal device300may further include an input device for the pilot to input discharge control information for controlling the discharge of the content465. In one example, the discharge control information is information such as a discharge time, an interval, and the number of times.

FIG.4Ais a perspective view illustrating an example of the configuration of the housing410. The housing410has the concave portion420in which the sensor50is attached at the bottom portion424. The sensor50may be a camera or a distance measuring sensor such as an ultrasonic sensor. The housing410may be provided with a temperature sensor443or a humidity sensor444(not illustrated).

The nozzle414is provided between an inlet411of the housing410and a sensor50attached to the bottom portion424of the concave portion420. Although the number of nozzles414is not limited, in one example, a plurality of nozzles414are regularly disposed radially from the sensor50attached to the bottom portion424.

FIG.4Bis a cross-sectional view of the housing410illustrated inFIG.4A. The concave portion420illustrated in (a) ofFIG.4Bhas a substantially tapered shape from the inlet411toward the bottom portion424of housing410. The concave portion420illustrated in (b) ofFIG.4Bhas a cylindrical shape with a constant inner diameter from the inlet411to the bottom portion424of the housing410. The shape of the concave portion420is not limited to these, and may be any shape as long as it does not block the path between the sensor50attached to the bottom portion424and the external detection object.

The nozzle414is provided on the side surface426of the concave portion420. Each nozzle414is connected to the extending portion430coupled to the housing410, and discharges the content465of the container460from each nozzle414.

InFIG.4B, the orientation of each nozzle414is perpendicular to the side surface426, but is not limited thereto. Each nozzle414may be disposed toward a direction different from the direction from the nozzle414to the sensor50. That is, each nozzle414discharges the content465in a direction different from the direction toward the sensor50.

In this way, since the content465discharged from the nozzle414by the protection device400does not directly hit the sensor50, it is possible to avoid a detection error of the sensor50due to adhesion to the surface of the sensor50, damage to the surface of the sensor50, or the like.

FIG.5is a diagram illustrating an example of the configuration of the discharge device450.FIG.5illustrates a cross-sectional view of the discharge device450. The discharge device450holds the container460. The container460may be included as a component of the protection device400.

The discharge device450of the present example includes a main body451, a first end cover portion453, and a second end cover portion455. The discharge device450further includes a discharge drive unit480for controlling the discharge from the container460.

The container460may be an aerosol container that discharges the content465filled therein by gas pressure. For example, the container460discharges the content465by the gas pressure of the liquefied gas or compressed gas filled therein. The container460of the present example is a metal aerosol can. The container460may be a plastic container having pressure resistance. The container460is mounted in a state of being accommodated in the discharge device450. The container460is not limited to the aerosol container, and may be a resin tank.

The contents465may be selected according to a flight area of the unmanned aerial vehicle100. In other words, the content465may be selected according to the intended use of the protection device400. The content465may be a gas or a liquid. In addition, the content465discharged from the nozzle414may contain a liquid, may be a dry gas, or may be heated. The discharged content465may be water or may contain a chemical agent such as a repellent for a living body. The discharged content465may be air, N2or CO2.

Alternatively, the content465may be selected according to characteristics of the sensor50mounted on the unmanned aerial vehicle100. In a case where the ultrasonic sensor is mounted as the sensor50, the content465may be a gas because sensitivity of the ultrasonic sensor decreases when the ultrasonic sensor is wetted with water.

Note that, as a propellant, a liquefied gas such as hydrocarbon (liquefied petroleum gas) (LPG), dimethyl ether (DME), or fluorinated hydrocarbon (HFO-1234ze), or a compressed gas such as carbon dioxide (CO2), nitrogen (N2), or nitrous oxide (N2O) may be used.

The main body451has a cylindrical shape having a larger diameter than the container460. The main body451of the present example is sandwiched between the first end cover portion453and the second end cover portion455.

The first end cover portion453covers one end portion of the main body451. The first end cover portion453of the present example covers the end portion on the injection side of the container460. The first end cover portion453is detachably screwed and fixed to the main body451via a screw portion452. The first end cover portion453of the present example has a dome-shaped cover main body. The diameter of the first end cover portion453is reduced so as to gradually decrease toward the edge in consideration of aerodynamic characteristics. The first end cover portion453has a conical or dome-shaped curved surface with a rounded edge. By having such a shape with favorable aerodynamic characteristics, the influence of the cross wind is reduced, and the flight can be stabilized.

The second end cover portion455covers the other end portion of the end portion covered by the first end cover portion453in the main body451. The second end cover portion455of the present example covers the end portion of the container460on the side opposite to the injection side. The second end cover portion455is formed integrally with the main body451. In addition, the second end cover portion455may be detachably provided with the main body451.

The discharge drive unit480causes the content465to be discharged from the container460in response to a discharge signal received from the foreign object detection unit412described later, or an information acquisition unit440or an environment detection unit442described later. The discharge drive unit480is accommodated in the second end cover portion455located on the bottom side of the container460. The second end cover portion455functions as a housing of the discharge drive unit480. The discharge drive unit480includes a cam481, a cam follower482, and a movable plate483. Since the discharge drive unit480is provided in the discharge device450, it is not necessary to replace the discharge drive unit480when replacing the container460.

The cam481is rotationally driven by a drive source. In one example, a motor is used as a drive source. The cam481has a structure in which the distance from the rotation center to the outer periphery is different. Note that, in the illustrated example, the shape of the cam481is exaggerated. The cam481is in contact with the cam follower482on the outer periphery.

The cam follower482is provided between the cam481and the movable plate483. The cam follower482is connected to the cam481and the movable plate483, and transmits the rotational motion of the cam481to the movable plate483as a linear motion.

The movable plate483is provided in contact with the bottom surface of the container460, and controls opening and closing of the valve of the container460. The movable plate483moves back and forth by the cam follower482. For example, when the distance between the rotation center of the cam481and the contact region of the cam481with which the cam follower482abuts is short, the movable plate483retracts with respect to the container460, and the valve of the container460is closed. On the other hand, when the distance between the rotation center of the cam481and the contact region of the cam481with which the cam follower482abuts is long, the movable plate483moves forward with respect to the container460, and the valve of the container460opens.

Note that the discharge drive unit480is configured to convert rotational motion of the motor into linear motion by a cam mechanism, but is not limited to the cam mechanism. For example, the mechanism of the discharge drive unit480may be a mechanism that converts rotational motion of the motor into linear motion, such as a screw feed mechanism or a rack and pinion. In addition, as a drive source, a linear motor for linear drive, an electromagnetic solenoid, or the like may be provided instead of the rotary motor.

A stem462is provided on the container460. When the stem462is pressed by an actuator454, the content465is discharged from the container460. The content465discharged from the container460is discharged from the nozzle414of the housing410via the extending portion430.

Since the container460of the present example is an aerosol container, even when the container460becomes empty, it can be easily replaced only by mounting a new container460. In addition, the content465is less likely to adhere to a human body, and the safety at the time of replacement is high.

A protection device according to Example 1 will be described.FIG.6is a diagram illustrating an example of functional blocks of the protection device400according to Example 1.FIG.6illustrates an example of functional blocks of the unmanned aerial vehicle100in conjunction with functional blocks of the protection device400.

An unmanned aerial vehicle control unit110is connected to the movable camera30, the GPS information reception unit40, an altitude information reception unit42, the sensor50, and a communication unit60in a wired or wireless manner. In one example, the unmanned aerial vehicle control unit110, the movable camera30, the GPS information reception unit40, the altitude information reception unit42, and the communication unit60are provided in the main body10of the unmanned aerial vehicle100, and the sensor50is provided in the housing410. The altitude information reception unit42acquires altitude information of the unmanned aerial vehicle100from an altimeter. The unmanned aerial vehicle control unit110acquires pilot information from the pilot device200via the communication unit60.

The unmanned aerial vehicle control unit110acquires information from the movable camera30, the GPS information reception unit40, the altitude information reception unit42, the sensor50, and the communication unit60at a preset cycle, and controls the flight of the unmanned aerial vehicle100on the basis of the acquired information.

The protection device400of the present example includes the information acquisition unit440, a communication unit441, and the discharge device450. The information acquisition unit440and the communication unit441may be respectively provided in the main body10of the unmanned aerial vehicle100, and the unmanned aerial vehicle control unit110and the communication unit60may have these functions, respectively. The information acquisition unit440and the communication unit441are connected to each other in a wired or wireless manner. In addition, the information acquisition unit440is connected to the discharge device450in a wired or wireless manner. The information acquisition unit440is wirelessly connected to the pilot device200via the communication unit441. In addition, the information acquisition unit440is connected to the unmanned aerial vehicle control unit110of the unmanned aerial vehicle100in a wired or wireless manner.

Alternatively, the information acquisition unit440and the communication unit441may be provided in the housing410. In this case, the information acquisition unit440and the communication unit441are connected to each other in a wired or wireless manner. In addition, the information acquisition unit440is connected to the discharge device450in a wired or wireless manner. The information acquisition unit440is wirelessly connected to the pilot device200via the communication unit441. In addition, the information acquisition unit440is connected to the unmanned aerial vehicle control unit110of the unmanned aerial vehicle100in a wired or wireless manner.

The information acquisition unit440acquires information from the outside, and transmits a discharge signal to the discharge device450based on the acquired information. In one example, the information acquisition unit440acquires information from the pilot device200via the communication unit441. When the pilot device200transmits the discharge instruction of the pilot input by the discharge button230to the protection device400, the information acquisition unit440transmits a discharge signal generated based on the acquired discharge instruction to the discharge device450. The discharge drive unit480of the discharge device450opens and closes the valve of the container460based on the received discharge signal to discharge the content465, and the content465is discharged from the nozzle414of the housing410via the extending portion430.

Alternatively, the information acquisition unit440and the communication unit441may be provided in the discharge device450. In this case, the information acquisition unit440and the communication unit441are connected to each other in a wired or wireless manner. The information acquisition unit440acquires information from the pilot device200via the communication unit441. When the pilot device200transmits the discharge instruction of the pilot input by the discharge button230to the protection device400, the information acquisition unit440outputs a discharge signal generated based on the acquired discharge instruction to the discharge drive unit480. The discharge drive unit480opens and closes the valve of the container460based on the input discharge signal to discharge the content465, and the content465is discharged from the nozzle414of the housing410via the extending portion430.

FIG.7Ais a diagram illustrating an example of an operation state of the protection device400. Here, the operation of the protection device400will be described by taking a case where the unmanned aerial vehicle100enters the operation area320as an example.

The pilot of the unmanned aerial vehicle100inputs position information of the operation area320of the protection device400to the terminal device300. The operation area320is an area set in advance such that the protection device400discharges the content465of the container460when the unmanned aerial vehicle100enters. In one example, the operation area320is an area such as a forest where the foreign objects500splatter. The terminal device300may indicate the operation area320on the map information displayed on the display unit310.

The terminal device300transmits position information of the operation area320to the unmanned aerial vehicle control unit110in advance. The unmanned aerial vehicle control unit110stores the acquired position information of the operation area320in a memory or the like.

The terminal device300may transmit discharge control information such as a discharge time, an interval, and the number of times set by the pilot to the information acquisition unit440in advance. The information acquisition unit440stores the acquired discharge control information in a memory or the like.

During the flight of the unmanned aerial vehicle100, the unmanned aerial vehicle control unit110compares the position information of the unmanned aerial vehicle100acquired from the GPS information reception unit40with the stored position information of the operation area320. When the position information of the unmanned aerial vehicle100matches the position information of the operation area320, the unmanned aerial vehicle control unit110transmits entry information indicating that the unmanned aerial vehicle100has entered the operation area320to the information acquisition unit440of the protection device400. The information acquisition unit440transmits a discharge signal to the discharge device450based on the acquired entry information and the stored discharge control information.

In response to the discharge signal acquired by the discharge device450, the content465of the container460is discharged from the nozzle414. In one example, the discharged content465comprises a repellent for a living body. The discharged content465floats in the atmosphere in the vicinity of the inlet411of the housing410and obstructs the approach of the foreign object500to the sensor50. As described above, the protection device400protects the sensor50by prophylactically discharging the content465of the container460from the nozzle414in the area where there are many foreign objects500.

Alternatively, the protection device400may discharge the content465of the container460from the nozzle414in response to a discharge instruction of the pilot input from the pilot device200. The pilot device200transmits the discharge instruction of the pilot input by the discharge button230to the protection device400via the antenna210. The information acquisition unit440receives the discharge instruction via the communication unit441, and transmits the discharge signal to the discharge device450based on the acquired discharge instruction.

As described above, the protection device400also protects the sensor50by discharging the content465of the container460from the nozzle414in response to an instruction from the pilot who has confirmed the situation of the flight area of the unmanned aerial vehicle100from the captured image of the movable camera30displayed on the display unit310of the terminal device300.

FIG.7Bis a diagram illustrating an example of a cross section of the housing410inFIG.7A.

The protection device400discharges the content465of the container460from the nozzle414based on the information acquired by the information acquisition unit440. In one example, the discharged content465includes a nebulized biological repellent. The contents465discharged from the plurality of nozzles414are combined from the inside of the concave portion420of the housing410in the vicinity of the inlet411to form an air curtain, and block the approach of the foreign objects500to the sensor50.

Next, a protection device according to Example 2 will be described.FIG.8is a diagram illustrating an example of functional blocks of the protection device400according to Example 2.

The protection device400of the present example includes the environment detection unit442that detects a change in environment, the temperature sensor443and the humidity sensor444, and the discharge device450. The temperature sensor443and the humidity sensor444are provided in the housing410. The environment detection unit442may be provided in the main body10of the unmanned aerial vehicle100, and the unmanned aerial vehicle control unit110may have the function thereof. Alternatively, the environment detection unit442may be provided in the housing410. The environment detection unit442is connected to the temperature sensor443and the humidity sensor444in a wired or wireless manner. In addition, the environment detection unit442is connected to the discharge device450in a wired or wireless manner.

The temperature sensor443and the humidity sensor444measure the temperature and humidity in the housing410, respectively, and transmit the temperature and humidity to the environment detection unit442at a preset cycle. The environment detection unit442detects a change in environment from the acquired temperature and humidity.

In one example, the environment detection unit442transmits the discharge signal to the discharge device450when detecting that the change amount of the temperature and the humidity exceeds a predefined threshold. The discharge drive unit480of the discharge device450opens and closes the valve of the container460based on the received discharge signal to discharge the content465, and the content465is discharged from the nozzle414of the housing410via the extending portion430.

Alternatively, the environment detection unit442may be provided in the discharge device450. In this case, the environment detection unit442is connected to the temperature sensor443and the humidity sensor444in a wired or wireless manner. The environment detection unit442detects a change in environment from the acquired temperature and humidity. The environment detection unit442outputs a discharge signal to the discharge drive unit480when detecting that the change amount of the temperature and the humidity exceeds a predefined threshold. The discharge drive unit480opens and closes the valve of the container460based on the input discharge signal to discharge the content465, and the content465is discharged from the nozzle414of the housing410via the extending portion430.

FIG.9Ais a diagram illustrating an example of an operation state of the protection device400. Here, the operation of the protection device400will be described by taking a case where the unmanned aerial vehicle100enters a fire extinguishing activity site as an example.

Generally, the fire extinguishing activity site has a higher temperature and humidity than other areas. When the unmanned aerial vehicle100flies in the fire extinguishing activity site, the discharge device450accommodates the container460filled with a dry gas such as N2or CO2not containing moisture as the content465.

When the unmanned aerial vehicle100enters the fire extinguishing activity site, the environment detection unit442detects that the temperature and the humidity have increased beyond predefined thresholds. The environment detection unit442transmits the generated discharge signal to the discharge device450.

In response to the discharge signal acquired by the discharge device450, the content465of the container460is discharged from the nozzle414. The discharged content465reduces the moisture content in the atmosphere in the concave portion420of the housing410.

FIG.9Bis a diagram illustrating an example of a cross section of the housing410inFIG.9A.

The protection device400discharges the content465of the container460from the nozzle414based on the change detected by the environment detection unit442. The contents465discharged from the plurality of nozzles414reduce the moisture content in the atmosphere in the concave portion420of the housing410and prevents dew condensation on the surface of the sensor50.

Alternatively, when the unmanned aerial vehicle100flies in a cold district, the discharge device450may heat or keep temperature of the container460by a heating mechanism such that the discharged contents465become hot air. When detecting that the temperature has decreased to exceed a predefined threshold, the environment detection unit442transmits the generated discharge signal to the discharge device450. In response to the discharge signal acquired by the discharge device450, the content465of the container460is discharged from the nozzle414. The discharged contents465increase the temperature in the concave portion420of the housing410to prevent freezing of the surface of the sensor50.

Next, a protection device according to Example 3 will be described.FIG.10is a diagram illustrating an example of functional blocks of the protection device400according to Example 3.

The protection device400of the present example includes the foreign object detection unit412that detects a foreign object and the discharge device450. The foreign object detection unit412is provided in the housing410. The foreign object detection unit412is connected to the discharge device450in a wired or wireless manner.

When detecting the foreign object500, the foreign object detection unit412transmits the generated discharge signal to the discharge device450. In response to the discharge signal acquired by the discharge device450, the content465of the container460is discharged from the nozzle414.

In this case, the content465may be a gas or may include a liquid. The protection device400may hit the detected foreign object500with the content465discharged from the nozzle414, and remove the foreign object500by the impact. Alternatively, the content465may contain a repellent for a living body.

FIG.11Ais a cross-sectional view of the housing410illustrating an example of the foreign object detection unit412. InFIG.11, the foreign object detection unit412includes a pair of a light emitting portion and a light receiving portion provided in the vicinity of the inlet411of the housing410. In one example, a camera and a sensor cover52as the sensor50are attached to the bottom portion424of the concave portion420.

The light emitting portion of the foreign object detection unit412emits light toward the light receiving portion. When detecting the change in an amount of the received light of the light receiving portion, the foreign object detection unit412transmits the generated discharge signal to the discharge device450. The discharge drive unit480of the discharge device450opens and closes the valve of the container460based on the received discharge signal to discharge the content465, and the content465is discharged from the nozzle414of the housing410via the extending portion430.

Note that, in a case where the unmanned aerial vehicle100flies in an area where the amount of ambient light is sufficiently strong, the foreign object detection unit412may have only the light receiving portion without having the light emitting portion.

FIG.11Bis a diagram illustrating an example in which the foreign object500approaches the foreign object detection unit412illustrated inFIG.11A.

When the foreign object500passes through the path of the light from the light emitting portion toward the light receiving portion of the foreign object detection unit412, the foreign object detection unit412detects a change in the amount of the received light of the light receiving portion and transmits the generated discharge signal to the discharge device450.

In response to the discharge signal acquired by the discharge device450, the content465of the container460is discharged from the nozzle414. The discharged content465hits the foreign object500approaching the sensor50and removes the foreign object500.

As described above, when the foreign object detection unit412detects the change in the amount of the received light of the light receiving portion, the protection device400determines that the foreign object500has approached the light receiving portion, discharges the content465of the container460from the nozzle414, and protects the sensor50from the foreign object500.

FIG.12Ais a perspective view of the housing410illustrating another example of the foreign object detection unit412. In addition,FIG.12Bis a cross-sectional view of the housing410inFIG.12A. The foreign object detection unit412includes an energization portion such as a wire provided in the vicinity of the inlet411of the housing410. In one example, an ultrasonic sensor or the like is attached as the sensor50to the bottom portion424of the concave portion420.

When detecting a change in electric resistance in the energization portion, the foreign object detection unit412transmits the generated discharge signal to the discharge device450.

In response to the discharge signal acquired by the discharge device450, the content465of the container460is discharged from the nozzle414. The discharged content465hits the foreign object500approaching the sensor50and removes the foreign object500.

As described above, when the foreign object detection unit412detects a change in electric resistance in the energization portion, the protection device400determines that the foreign object500, which is a conductor, has come into contact with the energization portion, and discharges the content465of the container460from the nozzle414to protect the sensor50from the foreign object500.

Note that the protection devices400according to Examples 1 to 3 may be combined. That is, the protection device400may include at least one of the information acquisition unit440, the environment detection unit442, and the foreign object detection unit412.

FIG.13is a cross-sectional view of the housing410illustrating another example of the foreign object detection unit412. The foreign object detection unit412is attached to the bottom portion424of the concave portion420and operates as the sensor50. In one example, the foreign object detection unit412is a distance measuring sensor such as an ultrasonic sensor or LiDAR. In one example, the foreign object detection unit412functions as the sensor50to monitor a distance to an obstacle around the unmanned aerial vehicle100.

When the foreign object500is located in a path of an ultrasonic wave, a laser beam, or the like emitted by the foreign object detection unit412, the foreign object detection unit412detects a steep change in the distance measurement value and transmits the generated discharge signal to the discharge device450.

In response to the discharge signal acquired by the discharge device450, the content465of the container460is discharged from the nozzle414. The discharged content465hits the foreign object500approaching the sensor50and removes the foreign object500.

As described above, when the foreign object detection unit412detects a steep change in the distance measurement value, the protection device400determines that the foreign object500has approached the sensor50(that is, the foreign object detection unit412), and discharges the content465of the container460from the nozzle414to protect the sensor50from the foreign object500.

FIG.14is a flowchart illustrating an example of a protection method. The protection method of the present example may be applied to the protection device400described above.

In Step S1402, the protection device400acquires information from the outside.

In Step S1404, the protection device400discharges the content465of the container460from the nozzle414connected to the container460based on the acquired information.

FIG.15is a flowchart illustrating another example of the protection method.

In Step S1502, the protection device400detects a change in environment.

In Step S1504, the protection device400discharges the content465from the nozzle414based on the detected change.

FIG.16is a flowchart illustrating another example of the protection method.

In Step S1602, the protection device400detects the foreign object500.

In Step S1604, in response to detecting the foreign object500, the protection device400discharges the content465from the nozzle414.

As described above, the protection method of the present example protects the sensor50mounted on the unmanned aerial vehicle100.

EXPLANATION OF REFERENCES

10: main body

15: leg portion

22: rotation drive unit

24: arm portion

30: movable camera

40: GPS information reception unit

42: altitude information reception unit

52: sensor cover

60: communication unit

100: unmanned aerial vehicle

110: unmanned aerial vehicle control unit

200: pilot device

220: pilot stick

230: discharge button

300: terminal device

310: display unit

320: operation area

400: protection device

412: foreign object detection unit

424: bottom portion

426: side surface

440: information acquisition unit

441: communication unit

442: environment detection unit

443: temperature sensor

450: discharge device

451: main body

453: first end cover portion

455: second end cover portion

480: discharge drive unit

500: foreign object