Unmanned aerial vehicle, unmanned aerial vehicle control system, and unmanned aerial vehicle control method

Abstract

To provide: an unmanned flight vehicle capable of returning to an upright posture and flying again even when the airframe is in contact with the ground in a vertically inverted posture; a control system for the unmanned flight vehicle; and a control method for the unmanned flight vehicle.SOLUTION: The unmanned flight vehicle according to the present disclosure comprises: a plurality of rotary blades provided on an airframe; and a control unit that controls rotation of the rotary blades. The control unit, in a state where the airframe is in contact with the ground in a vertically inverted posture, rotates only some of the plurality of rotary blades in an opposite direction to that during normal flight to raise the airframe into upright posture, meanwhile, in a process until the airframe returns to the upright posture, the control unit reduces rotation speed of the rotary blades rotating in the opposite direction or stops the rotation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an unmanned aerial vehicle, a control system for an unmanned aerial vehicle, and a control method for an unmanned aerial vehicle. [Background technology]

[0002] In recent years, unmanned aerial vehicles such as drones have been used in various fields, such as facility inspection. Unmanned aerial vehicles are equipped with multiple rotors to obtain thrust for lift. For example, Patent Document 1 discloses a method for controlling an aircraft to turn by varying the rotation speed of the rotors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-111181 Summary of the Invention [Problem to be solved by the invention]

[0004] If an unmanned aerial vehicle equipped with such multiple rotors fails to land or crashes and lands upside down (upside down), it may not be able to fly again, and depending on where it falls, it may not be possible to recover the vehicle.

[0005] Therefore, the present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide an unmanned aerial vehicle, a control system for an unmanned aerial vehicle, and a control method for an unmanned aerial vehicle that can return the aircraft to an upright position and fly again even if it has landed in an upside-down position. [Means for solving the problem]

[0006] According to the present disclosure, there is provided an aircraft comprising: a plurality of rotors provided on an airframe; a control unit that controls the rotation of the rotor, The control unit When the aircraft is in an upside-down position on the ground, only a portion of the rotors are rotated in a direction opposite to that during normal flight, thereby raising the aircraft to an upright position; An unmanned aerial vehicle is provided in which the rotational speed of the rotors rotating in the reverse direction is reduced or the rotation is stopped during the process of the aircraft returning to an upright attitude. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an unmanned aerial vehicle, a control system for an unmanned aerial vehicle, and a control method for an unmanned aerial vehicle that can return the aircraft to an upright position and fly again even if the aircraft has landed in an upside-down position. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view schematically showing an unmanned aerial vehicle according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a front view of the unmanned aerial vehicle according to the embodiment. [Figure 3] FIG. 2 is a diagram illustrating an example of the configuration of an unmanned aerial vehicle according to the embodiment. [Figure 4] This is a front view of the unmanned aerial vehicle according to the embodiment in an upside-down position. [Figure 5] A figure showing the process of the unmanned aerial vehicle of the same embodiment rising from an upside-down attitude to an upright attitude. [Figure 6] A figure showing a modified example of control of an unmanned aerial vehicle according to the same embodiment. [Figure 7] 6A to 6C are diagrams illustrating a process of rising from the state of FIG. 5 to an upright posture. [Figure 8] FIG. 10 is a diagram showing the unmanned aerial vehicle when it assumes an upright position. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0010] <Summary> FIG. 1 is a schematic diagram of an unmanned aerial vehicle (drone) in a plan view according to one embodiment of the present disclosure. The unmanned aerial vehicle 1 (hereinafter also referred to simply as "air vehicle") of this example is a rotorcraft that obtains lift and thrust using multiple rotors. Note that although the air vehicle 1 of this example is an unmanned aerial vehicle, it may also be applied to a manned aerial vehicle.

[0011] The flying vehicle 1 can fly in any space, whether indoors or outdoors. The present invention is particularly effective in environments where it would be difficult for a user to directly retrieve the flying vehicle 1 if it crashes, such as small spaces that are difficult for people to enter, closed spaces, dark places, or environments filled with special gases or high-temperature gases.

[0012] As shown in the plan view of Figure 1 and the front view of Figure 2, the aircraft 1 comprises a plurality of rotors 20 provided on a main body 10 (airframe) and a control unit (e.g., a flight controller 23) that controls the rotors 20 (20A, 20B, 20C, 20D).

[0013] The main body 10 is provided with electronic components that constitute a control unit, a memory unit, a communication unit, a sensor unit, an imaging unit (camera), etc., which will be described later, and has a frame that supports these components, a cover that covers the electronic components, etc. The center of gravity of the aircraft 1 is preferably located approximately in the center of the main body 10 in a plan view, but is not limited to this.

[0014] As shown in FIG. 1, the rotors 20 (20A, 20B, 20C, 20D) of this example are arranged at four locations around the main body 10 in a plan view. The number of rotors 20 is not limited to four, and may be three or less, or five or more. The number of blades constituting the rotor 20 is not particularly limited, and any shape and any number of blades may be employed. Furthermore, each rotor may have multiple blades arranged in the axial direction.

[0015] As shown in Figure 2, the rotor 20 is preferably located toward the center in the vertical direction. In other words, it is preferable that the propeller of the rotor 20 does not come into contact with the ground when the aircraft 1 is in an upright or upside-down position. The aircraft 1 has an upper frame 10A that supports the rotor 20 from above, and a lower frame 10B that is positioned below the upper frame 10A. Electronic components that constitute a control unit and the like are provided between the upper frame 10A and the lower frame 10B.

[0016] The aircraft 1 of this example is equipped with a left front rotor 20A located on the left front side of the main body 10, a right front rotor 20B located on the right front side, a left rear rotor 20C located on the left rear side, and a right rear rotor 20D located on the right rear side. In this example, the two rotors 20 adjacent to each other in the circumferential direction of the main body 10 are configured to rotate in opposite directions during flight, but they may also rotate in the same direction.

[0017] In this example, during normal flight, the left front rotor 20A and the right rear rotor 20D are configured to rotate clockwise (CW (Clockwise) direction) in a plan view, and the right front rotor 20B and the left rear rotor 20C are configured to rotate counterclockwise (CCW (Counterclockwise) direction) in a plan view. When the aircraft 1 rises from an upside-down attitude and flips back to an upright attitude, the rotors 20 are rotated in the opposite direction to the above. However, this configuration is not limited to this, and they may each be configured to rotate in the opposite direction.

[0018] Here, a propeller guard 11 is provided on the outside of the rotor (outside when viewed from the center of the fuselage in a plan view) extending from the main body 10 (lower frame 10B in this example) to protect the rotor 20. The propeller guard 11 may be integral with the lower frame 10B, or may be detachable from the lower frame 10B. Each rotor may also be provided with a cylindrical propeller duct that surrounds the periphery of the rotor.

[0019] In this example, the rotor 20 is supported by a rotor support portion (upper frame 10A) that extends outward from the center of the main body 10. The rotor 20 is held below the rotor support portion. In this example, a motor is located above a propeller that constitutes the rotor 20, and the rotor support portion is located above the motor. This prevents the propeller from coming into contact with the ground even when the rotor 20 is landed upside down. The rotor 20 may also be supported from below by the main body 10. In this example, the upper frame 10A is located above the rotor 20 and functions as a protective frame that protects the rotor 20, but protective frames separate from the upper frame 10A may be provided above and below the rotor 20.

[0020] The aircraft 1 of this example includes a base unit 30 detachably attached to the underside of the main body unit 10. The base unit 30 is located at the center of the aircraft in the width direction (left-right direction), but is not limited to this. The base unit 30 is located at the center of the aircraft in the front-rear direction, but is not limited to this.

[0021] The base unit 30 is, for example, a battery pack, and has built-in batteries that can be charged and reused. By preparing and charging multiple battery packs in advance, after a flight, it is possible to replace the charged battery pack and fly immediately. The battery supplies power to the rotors, control unit, etc. The joint between the base unit 30 and the main body unit 10 is provided with a connector (contact point) for power supply or signal communication. The base unit 30 may have components inside that constitute at least part of the memory unit, control unit, etc., which will be described later.

[0022] The aircraft 1 in this example is structured so that the underside of the base 30 touches the ground when landing, but it may also be provided with, for example, four legs at the four corners of the aircraft (front left, front right, rear left and right), or with a pair of legs extending in the front-to-rear direction.

[0023] FIG. 3 is a diagram (plan view) showing an example of the hardware configuration of an aircraft 1 according to this embodiment. As shown in FIG. 3, the aircraft 1 according to this embodiment includes a rotor 20 for generating thrust, a motor 21, and an ESC (Electric Speed ​​Controller) 22. The aircraft 1 also includes a flight controller 23 as a control unit in the main body 10. The flight controller 23 may include one or more processors 23b, such as a central processing unit (CPU) or a programmable processor such as an FPGA (Field-Programmable Gate Array). The flight controller 23 includes a memory 23a accessible to the memory 23a. The memory 23a stores logic, code, and / or program instructions executable by the flight controller 23 to perform one or more steps. The flight controller 23 is an example of a control unit. The aircraft 1 according to this embodiment also includes a camera and / or sensor 24 as an information acquisition unit. The aircraft 1 also includes a transceiver 25. The configuration of the aircraft 1 shown in FIG. 3 is an example, and rotorcraft having a configuration different from that of the main body 10 shown in FIG. 3 may also be included in the scope of the present invention.

[0024] The main body 10 is formed by a frame and other components of the aircraft 1. The material of the main body 10 is not particularly limited and may be, for example, carbon fiber resin, glass fiber resin, magnesium, magnesium alloy, aluminum, aluminum alloy, steel, titanium, or other materials. The rotors 20 are attached to a motor 21. The rotors 20 rotate with the rotation of the motor 21, generating lift (thrust) for the aircraft 1 and, when in an upside-down position, generating a force to raise the aircraft 1 to an upright position. In this embodiment, the rotors 20 are provided at four locations (front, back, left, and right), but the present invention is not limited to this example. For example, the rotors 20 may be provided at six, seven, eight, or other locations around the aircraft. The number, size, and structure of the rotors 20 may be changed as appropriate depending on the structure, shape, equipment, and size of the aircraft 1.

[0025] The memory 23a may include, for example, a separable medium such as an SD card or random access memory (RAM) or an external storage device. Data acquired from the camera / sensor 24 may be directly transmitted to and stored in the memory 23a. For example, still image and video data captured by the camera may be recorded in an internal memory or an external memory. The memory 23a may also store various types of information, such as information acquired from an external information processing device connected via the signal connector 13 or information transmitted from the control terminal 26.

[0026] The flight controller 23 includes a control module configured to control the state of the air vehicle 1. For example, the control module controls the motor 21, which is the propulsion mechanism of the air vehicle 1, via the ESC 22 to adjust the spatial arrangement, speed, and / or acceleration of the air vehicle 1, which has six degrees of freedom (translational motion x, y, and z, and rotational motion θx, θy, and θz). The rotation of the rotor 20 by the motor 21 generates lift for the air vehicle 1, thrust for lifting up from an upside-down attitude, and the like. The flight controller 23 can adjust the force generated by the rotor 20 by controlling the rotation direction and rotation speed (number of rotations) of the motor 21. The number of rotations also means the number of rotations per given time.

[0027] The flight controller 23 can communicate with a transceiver 25 configured to transmit and / or receive data from one or more external devices (e.g., a piloting terminal 26). The transceiver 25 can use any suitable communication means, such as wired or wireless communication. The transceiver 25 can utilize one or more of any communication method, such as a local area network (LAN), a wide area network (WAN), infrared, radio, WiFi, a point-to-point (P2P) network, a telecommunications network, or cloud communication.

[0028] The transceiver 25 can transmit and / or receive one or more of data acquired by the sensors 24, processing results generated by the flight controller 23, predetermined control data, user commands from a terminal or a remote controller, etc., and can store the received information in a storage unit such as the memory 23a. Information acquired by the camera and sensors 24 may be output via the transceiver 25 to the control terminal 26, an external device, etc.

[0029] The control terminal 26 is a device for instructing the flying object 1 to fly, rise (flip), and perform other actions (i.e., to control the flying object). A user can operate the control terminal 26 to instruct the flying object 1 to rise and the direction in which it should rise. For example, by operating a button (or an icon image in the case of a touch panel) on the control terminal 26 to instruct the flying object 1 to rise, a signal instructing the flying object 1 to rise is transmitted to the flying object 1. Furthermore, by operating a directional input operation (such as tilting the stick in the corresponding direction) from the control terminal 26 to instruct the direction in which it should rise, such as forward, backward, left, or right, a signal instructing the direction in which it should rise is transmitted to the flying object 1. The user can use the control terminal 26 to operate the button instructing the flying object 1 to rise and to instruct the direction in which it should rise, thereby causing the flying object 1 to rise in the desired direction. When an input operation to rise forward is performed, the rear rotor rotates in the opposite direction, causing the rear side to rise, and the flying object 1 to rise toward the front of the aircraft.

[0030] The flight and rising of the aircraft 1 may be controlled by an operator on the ground, or may be controlled by automatic or manual control based on an autonomous flight program (e.g., a Ground Control Station (GCS)) using flight path information and sensing. The control terminal 26 may be, for example, a transceiver (radio transmitter), a smartphone, a tablet, or other terminal. The control terminal 26 can send flight control instruction information to the flight controller 23.

[0031] The sensor 24 according to this embodiment can directly acquire various information such as the tilt of the flying object 1 in three axial directions (including at least the angle relative to the horizontal plane), angular velocity, speed, and acceleration, or acquire data for calculating these information. The sensor 24 can include, for example, an inertial sensor (an inertial measurement unit such as an IMU (Inertial Measurement Sensor)), an acceleration sensor, a gyro sensor, a GPS sensor, a wind sensor, a temperature sensor, a humidity sensor, a barometric pressure sensor, an altitude sensor, a proximity sensor such as LiDAR (Laser Imaging Detection and Ranging), or a vision / image sensor other than a camera. The sensor 24 may be mounted on the flight controller 23 or provided externally to the flight controller 23. If a camera is provided, the camera may be any camera. For example, the camera may be a general camera, an infrared camera, a stereo camera, or the like. For example, the flying object 1 may be provided with a camera for self-location estimation and a camera for capturing an image of a subject. When the flying object 1 according to this embodiment is not flying, the battery pack can be detached from the main body 10 and charged. Furthermore, the aircraft 1 may be equipped with multiple batteries or only one battery.

[0032] When the aircraft 1 is hovering in the air, it basically rotates all four rotors 20 at the same rotational speed. The rotational speed of each rotor 20 is controlled appropriately depending on the flight environment. For example, information on the flight environment, such as the temperature, air pressure, wind speed, and wind direction of the flight space, is acquired by various sensors or received from an external device, and the flight controller determines the rotational speed of each rotor 20 based on this information, thereby maintaining an appropriate flight state.

[0033] When the aircraft 1 ascends, the rotational speeds of the four rotors 20 are made evenly larger (faster) than when hovering, and conversely, when descending, the rotational speeds are made evenly smaller (slower) than when hovering. When the aircraft 1 moves forward, the rotational speeds of the rear rotors (left rear rotor 20C and right rear rotor 20D) are made faster than the front rotors (left front rotor 20A and right front rotor 20B), and conversely, when moving backward, they are made slower. When the aircraft 1 moves left, the rotational speeds of the right rotors (right front rotor 20B and right rear rotor 20D) are made faster than the left rotors (left front rotor 20A and left rear rotor 20C), and conversely, when moving right, they are made slower. Note that the aircraft 1 moves while tilting in the direction of movement from the reference attitude when hovering.

[0034] When the aircraft 1 turns left (counterclockwise), the rotational speed of the rotors rotating clockwise (CW (Clockwise) direction) (in this example, the left front rotor 20A and the right rear rotor 20D) is made higher than the rotational speed of the rotors rotating counterclockwise (CCW (Counterclockwise) direction) (in this example, the right front rotor 20B and the left rear rotor 20C), and conversely, when turning right, it is made lower. This takes advantage of the fact that a turning torque is generated in the airframe in the opposite direction to the rotational direction of the rotors 20.

[0035] 4 shows a state in which the aircraft 1 has crashed due to, for example, an operational error by a user using the control terminal 26 or contact with an obstacle, and has landed in an upside-down attitude. When the aircraft has landed in an upside-down attitude, the control unit 23 causes only some of the rotors to rotate in the opposite direction to that during normal flight, thereby raising the aircraft to an upright attitude, and reduces the rotational speed of the rotors rotating in the opposite direction or stops their rotation during the process until the aircraft returns to the upright attitude.

[0036] The user can perform an input operation to instruct the flying object 1 to rise (to flip to an upright position) by, for example, pressing the rise button on the control terminal 26 (or by selecting and inputting a button icon on the input screen), which causes a signal instructing the flying object 1 to rise from the control terminal 26. The control unit of the flying object 1 controls the rotor 20 based on the received instruction signal, and executes the rise operation (flip operation).

[0037] In the example of FIG. 4, because obstacle A is present on one side of aircraft 1 (the right side of the figure: the left side from the perspective of aircraft 1), aircraft 1 is raised and flipped toward the other side (the left side of the figure: the right side from the perspective of aircraft 1) where obstacle A is not present. To achieve this, control unit 23 rotates the right rotors (right front rotor 20B and right rear rotor 20D) in the opposite direction to normal rotation to generate a downward thrust P toward the ground G. In this case, the rotors other than the rotors that are rotated in the opposite direction (left front rotor 20A and left rear rotor 20C) may be stopped or may be rotated in the normal direction.

[0038] As shown in FIG. 5, the right side of the aircraft 1 rises due to thrust P generated by the rotation of the right rotor 20. In the example of FIG. 5, the propeller guard 11, which is the outer end of the aircraft opposite the rotor that is being reverse-rotated, serves as a fulcrum, gradually raising the aircraft 1. At this time, by rotating the rotors (left front rotor 20A and left rear rotor 20C) located opposite the rotor that is being reverse-rotated, i.e., the rotors on the fulcrum side, in the same manner as in normal flight to generate thrust P2 (see FIG. 6), it is possible to prevent the fulcrum from slipping to the left in FIG. 5 (the opposite direction from the rotor that is being reverse-rotated). As a result, unnecessary movement of the aircraft 1 can be suppressed and the aircraft 1 can be efficiently reversed. Note that there may be only one or more rotors 20 that are reverse-rotated. Furthermore, there may be only one or more rotors 20 that are rotated in the same direction as in normal flight to generate thrust P2.

[0039] As shown in FIG. 7, the control unit 10 reduces the rotational speed of the rotor 20 rotating in the reverse direction or stops its rotation during the process of the aircraft returning to an upright attitude. This allows the momentum of the aircraft 1 flipping over to be appropriately suppressed. For example, if the rotational speed of the rotor 20 rotating in the reverse direction is maintained until the aircraft 1 returns to an upright attitude, as shown in FIG. 8, the aircraft 1 may come into strong contact with the ground G as it returns to an upright attitude, which could result in damage to the aircraft. However, by reducing the rotational speed of the rotor 20 rotating in the reverse direction at least during the process of the aircraft returning to an upright attitude as in the present invention, the momentum of the aircraft 1 flipping over to reduce the possibility of damage. In other words, the aircraft 1 can flip over more gently, reducing the load on the underside (base unit 30) of the aircraft 1 when it touches down. Note that the control unit 10 may change the rotational direction of the rotor 20 rotating in the reverse direction to the direction of normal flight during the process of the aircraft returning to an upright attitude.

[0040] As described above, the unmanned aerial vehicle of this embodiment includes a plurality of rotors mounted on the airframe and a control unit that controls the rotation of the rotors. When the airframe is in an upside-down position on the ground, the control unit rotates only some of the rotors in the opposite direction to normal flight, thereby raising the airframe to an upright position, and reduces the rotational speed of the rotors rotating in the opposite direction or stops their rotation during the process of the airframe returning to the upright position. This configuration allows the airframe to return to an upright position and fly again even if it has landed in an upside-down position after a crash or other such event. Damage to the airframe can also be prevented when flipping from an upside-down position to an upright position.

[0041] In this embodiment, the control unit may also reduce the rotational speed of the rotors rotating in the reverse direction or stop their rotation when the angle of the aircraft relative to the horizontal plane (for example, angle θ in FIG. 5) satisfies a predetermined condition. The angle θ of the aircraft 1 can be acquired from an information acquisition unit such as an inertial sensor, and may be compared with a threshold angle stored in advance in a storage unit. If the angle θ is equal to or greater than the threshold, the control unit may reduce the rotational speed of the rotors rotating in the reverse direction or stop their rotation. The threshold angle may be, for example, 90 degrees, or may be greater than or equal to 90 degrees.

[0042] In this embodiment, the control unit may also be configured to reduce the rotational speed of the rotor blades rotating in the reverse direction or stop their rotation if the angular velocity when the aircraft returns from an upside-down attitude to an upright attitude satisfies a predetermined condition. In this case, the angular velocity of the aircraft 1 can be acquired from an information acquisition unit such as an inertial sensor, and compared with a threshold angular velocity stored in advance in a storage unit. If the threshold angular velocity is equal to or greater than the threshold, the control unit may reduce the rotational speed of the rotor blades rotating in the reverse direction or stop their rotation. The threshold angular velocity can be, for example, 360 degrees / second, but is not limited to this and may be a value greater or smaller than this.

[0043] In addition, in this embodiment, the control unit may reduce the rotational speed of the rotor blades rotating in the reverse direction or stop their rotation if the distance from a predetermined surface or point, such as the ground or a wall, to a specific point on the aircraft when the aircraft returns from an upside-down attitude to an upright attitude satisfies a predetermined condition. The distance from the predetermined surface or point to the specific point on the aircraft can be calculated based on length information measured by a distance measurement sensor such as a ToF sensor provided on the aircraft 1, for example, as shown by length d in FIG. 5 . The specific point may be the location where the distance measurement sensor is provided, but is not limited to this. The distance from the predetermined surface or point to the center point of the aircraft may also be calculated using data from the distance measurement sensor. In this case, the control unit may also reduce the rotational speed of the rotor blades rotating in the reverse direction or stop their rotation if the distance from the predetermined surface or point to the specific point on the aircraft is equal to or greater than a threshold distance value stored in advance in the storage unit. The predetermined surface or point is not limited to the ground, but may be any surface or point measurable by a distance measurement sensor, such as a side wall or obstacle A.

[0044] In this embodiment, the control unit may also slow down or stop the rotation of the rotors rotating in the reverse direction if the elapsed time since the rotors began rotating in the reverse direction satisfies a predetermined condition. In this case, the control unit of the aircraft 1 may use a clock function to measure the elapsed time since the rotors began rotating in the reverse direction, compare it with a threshold value stored in the memory unit, and if the measured elapsed time is equal to or greater than the threshold value, slow down or stop the rotation of the rotors rotating in the reverse direction. For example, the control unit may slow down or stop the rotation of the rotors 0.5 seconds, 1 second, 2 seconds, etc. after the rotors began rotating in the reverse direction.

[0045] In this embodiment, the control unit may also rotate at least some of the rotors other than the rotors rotated in the reverse direction in the same forward direction as in normal flight, thereby enabling efficient reversal by suppressing the slippage of the fulcrum during the reversal process.

[0046] In this embodiment, the control unit may control the rotational speed of the rotor blades rotated in the reverse direction from a high speed to an intermediate speed lower than the high speed during the process until the airframe returns to an upright attitude. This allows for an appropriate change (transition) in the thrust P without simply switching the reverse rotation on and off.

[0047] In this embodiment, the rotors may be four or more rotors arranged around the airframe in a plan view, and the rotors that rotate in the opposite direction may be located on the front, rear, left, or right side of the airframe. This allows the airframe 1 to be flipped in four directions: the front, rear, left, or right side.

[0048] In this embodiment, the control unit may determine the rotor to rotate in the reverse direction based on a control signal transmitted from the control device. For example, a plurality of options, each associating a direction in which the aircraft is to be flipped with one or more rotors to be rotated in the reverse direction, may be stored in advance in the storage unit, and the control unit may select an appropriate rotor depending on the direction in which the user wishes to flip the aircraft. That is, if the user instructs the control terminal 26 to flip the aircraft 1 forward, the rear rotor 20 rotates in the reverse direction, and if the user instructs the control terminal 26 to flip the aircraft 1 backward, the front rotor 20 rotates in the reverse direction. In this way, it is preferable that the aircraft 1 can be flipped in multiple directions (e.g., four directions (forward, backward, left, right) and eight directions (including diagonals)).

[0049] It is preferable that the control unit of the flying object 1 be able to detect that the flying object 1 is in an upside-down position. For example, it can detect that the flying object 1 is currently in an upside-down position based on sensor data (data indicating the flying object's position) such as an inertial sensor, or image data from a camera. In this case, the control unit of the flying object 1 notifies the control terminal 26 that the flying object 1 is in an upside-down position.

[0050] Furthermore, when the control unit detects that the drone is in an upside-down attitude, it may automatically switch to a mode (flip mode) for performing a flip function (a function for raising the drone from an upside-down attitude to an upright attitude). In this flip mode, a specific rotor 20 stored in advance or a specific rotor 20 based on information input from the user's control terminal 26 rotates in the direction opposite to that during normal flight.

[0051] The control unit of the flying object 1 may detect obstacles that may hinder the rising motion from sensors or camera images, and notify the user or restrict the rising motion in the direction of the obstacle.

[0052] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the present disclosure can conceive of various modified or altered examples within the scope of the technical idea described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0053] In the above embodiment, the autonomous flight control is described as being executed by the flight controller 23 of the aircraft 1, but the present technology is not limited to this example. That is, the autonomous flight control method is not limited to an example in which processing is performed on an edge device in the aircraft, but may be a method in which the above-described correction processing is performed remotely by another autonomous flight control device, the processing results are transmitted to the aircraft, and the drive unit is controlled based on the results. That is, the main hardware that executes the autonomous flight control method is not particularly limited, and the above-described functional units may be executed by multiple hardware devices.

[0054] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that will be apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0055] The following configurations also fall within the technical scope of the present disclosure. (Item 1) A plurality of rotors provided on the airframe; a control unit that controls the rotation of the rotor, The control unit When the aircraft is in an upside-down position on the ground, only a portion of the rotors are rotated in a direction opposite to that during normal flight, thereby raising the aircraft to an upright position; An unmanned aerial vehicle in which the rotational speed of the rotor blades rotating in the reverse direction is reduced or the rotation is stopped during the process of the aircraft returning to an upright attitude. (Item 2) The unmanned aerial vehicle described in item 1, wherein the control unit reduces the rotational speed of the rotor blades rotating in the opposite direction or stops their rotation when the angle of the aircraft relative to the horizontal plane satisfies a predetermined condition. (Item 3) The control unit of the unmanned aerial vehicle described in item 1 reduces the rotational speed of the rotor blades rotating in the reverse direction or stops their rotation when the angular velocity of the aircraft when returning from an upside-down attitude to an upright attitude satisfies a predetermined condition. (Item 4) The control unit of the unmanned aerial vehicle described in item 1 reduces the rotational speed of the rotor blades rotating in the reverse direction or stops their rotation when the distance from a predetermined plane or point to a specific point on the aircraft when the aircraft returns from an upside-down attitude to an upright attitude satisfies a predetermined condition. (Item 5) The control unit of the unmanned aerial vehicle described in item 1 reduces the rotational speed of the rotor rotating in the reverse direction or stops the rotation when the elapsed time since the rotor started rotating in the reverse direction satisfies a predetermined condition. (Item 6) The unmanned aerial vehicle described in item 1, wherein the control unit rotates at least some of the rotors other than the rotors that rotate in the reverse direction in the same forward direction as during normal flight. (Item 7) The control unit controls the rotational speed of the rotor blades rotating in the reverse direction from a high speed to an intermediate speed lower than the high speed during the process until the aircraft returns to an upright attitude. (Item 8) the plurality of rotors are four or more rotors arranged around the airframe in a plan view, An unmanned aerial vehicle as described in item 1, wherein the rotors that rotate in the opposite direction are multiple rotors located on either the front, rear, left, or right side of the aircraft. (Item 9) The control unit of the unmanned aerial vehicle described in item 1 determines the rotor to rotate in the opposite direction based on a control signal transmitted from a control device. (Item 10) A plurality of rotors provided on the airframe; A control unit that controls the rotation of the rotor blades, The control unit When the aircraft is in an upside-down position on the ground, only a portion of the rotors are rotated in a direction opposite to that during normal flight, thereby raising the aircraft to an upright position; A control system for an unmanned aerial vehicle that reduces the rotational speed of the rotor blades rotating in the reverse direction or stops their rotation during the process of the aircraft returning to an upright attitude. (Item 11) A plurality of rotors provided on the airframe; A control unit that controls the rotation of the rotor blades. The control unit When the aircraft is in an upside-down position on the ground, only a portion of the rotors are rotated in a direction opposite to that during normal flight, thereby raising the aircraft to an upright position; A method for controlling an unmanned aerial vehicle, which reduces the rotational speed of the rotor blades rotating in the reverse direction or stops their rotation during the process until the aircraft returns to an upright attitude. [Explanation of symbols]

[0056] 1. Unmanned aerial vehicles 10 Main body 20 rotor blades 23 Control Unit

Claims

1. A plurality of rotors provided on the airframe; a control unit that controls the rotation of the rotor, The control unit With the airframe on the ground in an upside-down attitude, by rotating only some of the plurality of rotors in a direction opposite to that during normal flight, the airframe is raised to an upright attitude using the outer end of the airframe opposite to the rotor that is rotated in the opposite direction as a fulcrum, and An unmanned aerial vehicle that reduces the impact caused by contact with the ground when the vehicle returns to an upright attitude by slowing down or stopping the rotation of the rotors rotating in the reverse direction in the following cases: the angle of the vehicle with respect to the horizontal plane satisfies a specified condition during the process of the vehicle returning to an upright attitude; the angular velocity of the vehicle when returning from an upside-down attitude to an upright attitude satisfies a specified condition; the distance from a specified plane or point to a specific point on the vehicle when returning from an upside-down attitude to an upright attitude satisfies a specified condition; or the elapsed time since the rotors began rotating in the reverse direction satisfies a specified condition.

2. The unmanned aerial vehicle according to claim 1 , wherein the control unit rotates at least some of the rotors other than the rotors that rotate in the reverse direction in the same forward direction as during normal flight.

3. The unmanned aerial vehicle described in claim 1, wherein the control unit controls the rotational speed of the rotor rotating in the reverse direction from a high speed to an intermediate speed lower than the high speed during the process until the aircraft returns to an upright attitude.

4. the plurality of rotors are four or more rotors arranged around the airframe in a plan view, The unmanned aerial vehicle according to claim 1 , wherein the rotors that rotate in the opposite direction are a plurality of rotors located on either the front, rear, left, or right side of the aircraft.

5. The unmanned aerial vehicle according to claim 1 , wherein the control unit determines the rotor to be rotated in the reverse direction based on a control signal transmitted from a control device.

6. A plurality of rotors provided on the airframe; A control unit that controls the rotation of the rotor blades, The control unit With the airframe on the ground in an upside-down attitude, by rotating only some of the plurality of rotors in a direction opposite to that during normal flight, the airframe is raised to an upright attitude using the outer end of the airframe opposite to the rotor that is rotated in the opposite direction as a fulcrum, and A control system for an unmanned aerial vehicle that reduces the impact caused by contact with the ground when the vehicle returns to an upright attitude by slowing down or stopping the rotation of the rotors rotating in the reverse direction in the following cases: the angle of the vehicle with respect to the horizontal plane satisfies a specified condition during the process of the vehicle returning to an upright attitude; the angular velocity of the vehicle when returning from an upside-down attitude to an upright attitude satisfies a specified condition; the distance from a specified plane or point to a specific point on the vehicle when returning from an upside-down attitude to an upright attitude satisfies a specified condition; or the elapsed time since the rotors began rotating in the reverse direction satisfies a specified condition.

7. A plurality of rotors provided on the airframe; A control unit that controls the rotation of the rotor blades. The control unit With the airframe on the ground in an upside-down attitude, by rotating only some of the plurality of rotors in a direction opposite to that during normal flight, the airframe is raised to an upright attitude using the outer end of the airframe opposite to the rotor that is rotated in the opposite direction as a fulcrum, and A method for controlling an unmanned aerial vehicle, which reduces the impact caused by contact with the ground when the vehicle returns to an upright attitude by slowing down or stopping the rotation of the rotors rotating in the reverse direction in the following cases: the angle of the vehicle with respect to the horizontal plane satisfies a predetermined condition during the process of the vehicle returning to an upright attitude; the angular velocity of the vehicle when returning from an upside-down attitude to an upright attitude satisfies a predetermined condition; the distance from a predetermined plane or point to a specific point on the vehicle when returning from an upside-down attitude to an upright attitude satisfies a predetermined condition; or the elapsed time since the rotors started rotating in the reverse direction satisfies a predetermined condition.

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