JP7679125B2 - Unmanned aerial vehicles - Google Patents

Description

This disclosure relates to unmanned aerial vehicles.

In recent years, unmanned aerial vehicles such as drones have been used in various fields such as facility inspection. The unmanned aerial vehicle has multiple rotors and obtains thrust for lifting. For example, Patent Document 1 discloses a method for controlling an aerial vehicle that turns the vehicle by varying the rotation speed of the rotors.

JP 2020-111181 A

There is a demand for technology that enables unmanned aerial vehicles equipped with multiple rotors to fly more efficiently.

Therefore, the present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide an unmanned aerial vehicle that can efficiently obtain turning force through multiple rotors.

According to the present disclosure, an unmanned aerial vehicle is provided that includes a plurality of rotors for generating thrust, and a shielding portion positioned between any two adjacent rotors in a planar view and blocking the airflow below the two rotors during flight.

According to the present disclosure, an unmanned aerial vehicle can be provided that can efficiently obtain turning force through multiple rotors.

A plan view diagrammatically illustrating an unmanned aerial vehicle according to one embodiment of the present disclosure. 2 is a front view of the unmanned aerial vehicle according to the embodiment. FIG. FIG. 4 is a diagram for explaining torque generated between adjacent rotor blades. FIG. 11 is a plan view of an aircraft shown for comparison. A plan view showing a schematic diagram of the torque generated when the unmanned aerial vehicle according to this embodiment turns. A side view of the unmanned aerial vehicle according to the same embodiment. A diagram showing an example of the configuration of an unmanned aerial vehicle according to the same embodiment.

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 denoted by the same reference numerals and redundant explanations are omitted.

＜Overview＞
1 is a schematic diagram of an unmanned aerial vehicle (drone) according to an embodiment of the present disclosure in a plan view. The unmanned aerial vehicle 1 (hereinafter also simply referred to as an "aerial vehicle") of this example is a rotorcraft that obtains lift and thrust by a plurality of rotors. Note that although the aerial vehicle 1 of this example is an unmanned aerial vehicle, it may also be applied to a manned aerial vehicle on which a person is aboard.

As shown in the plan view of FIG. 1, the aircraft 1 includes a main body 1 located at the center of the aircraft in a plan view.
The aircraft includes a rotor blade 20 (aircraft body) 0 and a plurality of rotor blades 20 (20A, 20B, 20C, 20D) supported by a main body 10 and used to generate thrust for flight. As shown in the front view of Fig. 2, a shielding portion 30 is provided on the main body 10 and is located around the main body 10 between two rotor blades adjacent in the circumferential direction (between the left and right rotor blades in this example). The shielding portion 30 is configured to block the airflow between the two rotor blades below the rotor blades 20.

The main body 10 is provided with electronic components constituting 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 them, a cover that covers the electronic components, etc. The center of gravity of the flying object 1 is preferably located approximately in the center of the main body 10 in a plan view, but is not limited to this.

The shielding part 30 of this example is configured to be detachable from the bottom surface side of the main body part 10. Also, the shielding part 30 of this example constitutes a battery pack with a built-in rechargeable battery, and when the battery runs out, a battery pack with a pre-charged battery is inserted into the shielding part 30.
The battery can be replaced as a whole. The battery can supply power to the rotor. A connector (contact point) for power supply or signal communication is provided at the joint between the shielding part 30 and the main body part 10. The shielding part 30 may have components inside that constitute at least a part of a memory part, a control part, etc., which will be described later.

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 vanes (blades) constituting the rotor 20 is not particularly limited, and any shape and any number of vanes may be adopted. Each rotor may have multiple vanes in the axial direction.

The flying body 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 in the circumferential direction of the main body 10 are configured to rotate in opposite directions to each other during flight, but they may also rotate in the same direction.

In this example, the left front rotor 20A and the right rear rotor 20D rotate clockwise (CW) in a plan view.
The right front rotor 20B and the left rear rotor 20C are configured to rotate in a counterclockwise (CCW) direction in a plan view, and the right front rotor 20B and the left rear rotor 20C are configured to rotate in a counterclockwise (CCW) direction in a plan view. Note that the present invention is not limited to this configuration, and each rotor may be configured to rotate in the opposite direction.

Here, a propeller guard extending from the main body 10 may be provided on the outer side of the rotor (the outer side as seen from the center of the aircraft in a plan view). Also, each rotor may be provided with a cylindrical propeller duct surrounding the periphery of the rotor.

The rotor 20 in this example is supported by a rotor support portion (not shown) that extends outward from the main body portion 10. The rotor 20 is held below the rotor support portion.
A motor is located above a propeller constituting the rotor 20, and a rotor support portion is located above the motor. The rotor 20 may be supported from below by the main body portion 10.

When the flying object 1 is hovering in the air, it basically rotates the four rotors 20 at the same rotation speed. The rotation speed of each rotor 20 is appropriately controlled according to 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 obtained by various sensors or received from an external device, and the flight controller determines the rotation speed of each rotor 20 based on the information, thereby maintaining an appropriate flight state.

When the flying object 1 ascends, the rotation speeds of the four rotors 20 are made evenly larger (faster) than when hovering, and when it descends, the rotation speeds are made evenly smaller (faster) than when hovering.
When the aircraft 1 moves forward, the rotation speed of the rear rotors (left rear rotor 20C and right rear rotor 20D) is made faster than that of the front rotors (left front rotor 20A and right front rotor 20B), and when moving backward, the rotation speed is made slower. When the aircraft 1 moves to the left, the rotation speed of the right rotors (right front rotor 20B and right rear rotor 20D) is made faster than that of the left rotors (left front rotor 20A and left rear rotor 20C), and when moving to the right, the rotation speed is made slower. The aircraft 1 moves while tilting in the direction of movement from the reference attitude during hovering.

When the aircraft 1 turns left (counterclockwise), the rotational speed of the rotors (the left front rotor 20A and the right rear rotor 20D in this example) rotating in the clockwise (CW (Clockwise) direction) is set as follows:
The rotational speed of the rotors 20 is set to be faster than the rotational speed of the rotors (in this example, the right front rotor 20B and the left rear rotor 20C) rotating in a counterclockwise (CCW) direction, and conversely, is set to be slower when turning to the right. This utilizes the fact that a turning torque is generated in the aircraft in the opposite direction to the rotational direction of the rotors 20.

Here, when there is a difference in rotational speed between two adjacent rotors in a planar view, as shown in Figure 3, an airflow (wind) is generated from the rotor with a lower rotational speed (rotor 20A in Figure 3) to the rotor with a higher rotational speed (rotor 20B in Figure 3), and a turning torque in the opposite direction of this airflow is generated on the aircraft.

For comparison, Fig. 4 is a plan view showing an aircraft 100 without a shielding portion. As shown in Fig. 4, when the aircraft 100 turns left (counterclockwise), airflow is generated from the rotors with a relatively low rotation speed (right front rotor 20B and left rear rotor 20C) toward the rotors with a high rotation speed (left front rotor 20A and right rear rotor 20D), and a rotation torque is generated in the opposite direction. In this case, the rotation torque T1 caused by the airflow from the right front rotor 20B to the left front rotor 20A and the rotation torque T2 caused by the airflow from the left rear rotor 20C to the left front rotor 20A act in directions that cancel each other out. Similarly, the rotation torque T in Fig. 4
3 and turning torque T4 also cancel each other out.

Therefore, as in the example shown in Figure 5, a shielding portion 30 is provided between two adjacent rotors (between the left front rotor 20A and the right front rotor 20B, and between the left rear rotor 20C and the right rear rotor 20D) to make it difficult for airflow to occur between the two rotors below the rotors.
This suppresses (or reduces) the generation of the turning torques T1 and T3 in FIG. 4, and suppresses the turning torques in the opposite directions from canceling each other out. As a result, the turning torques T2 and T4
In particular, in the aircraft 1 shown in FIG. 4, the two rotors on the front side adjacent to each other in the left-right direction (width direction) of the aircraft (the left front rotor 2
5. A shielding portion 30 (front portion) is provided between the left front rotor 20A and the right front rotor 20B, and a shielding portion 30 (rear portion) is provided between the two rear rotors (left rear rotor 20C and right rear rotor 20D) adjacent in the left-right direction (width direction) of the aircraft, thereby reducing the turning torque between the left front rotor 20A and the right front rotor 20B, and the turning torque between the left rear rotor 20C and the right rear rotor 20D. As a result, the turning torque T2 caused by the airflow from the left rear rotor 20C to the left front rotor 20A and the turning torque T3 caused by the airflow from the right front rotor 20B to the right rear rotor 20D both act as left turning torques, enabling efficient turning. Note that when turning to the right, turning torques are generated in the opposite direction to the turning torques T2 and T4 in FIG. 5, so efficient turning is possible even in this case. The shielding portion 30 may extend from the front end to the rear end of the aircraft (main body portion 10), or may be provided on only a portion of the aircraft in the fore-and-aft direction.

When the flying object 1 turns clockwise, the rotation speed of the rotors rotating clockwise (the left front rotor 20A and the right rear rotor 20D in this example) is made slower than the rotation speed of the rotors rotating counterclockwise (the right front rotor 20B and the left rear rotor 20C in this example) as shown in Fig. 5. This causes the turning torque T4 due to the airflow from the right rear rotor 20D to the right front rotor 20B and the turning torque T3 due to the airflow from the left front rotor 20A to the left rear rotor 20C to both act as right turning torques, enabling efficient turning.

As described above, the unmanned aerial vehicle 1 of this embodiment is equipped with a plurality of rotors 20 for generating thrust, and a shielding portion 30 that is located between any two adjacent rotors in a plan view and blocks the airflow below the two rotors during flight. This configuration makes it possible to efficiently obtain a turning force from the multiple rotors. The position and size of the shielding portion 30 are as follows:
It is preferable to set it appropriately depending on the rotation direction of the rotors 20, the distance between the rotors 20, etc.

It is preferable that the shielding unit 30 is configured to be able to change the amount of shielding. In this way, the magnitude of the turning torque can be adjusted by changing the amount of shielding. For example, the shielding unit 30 is
The shielding unit 30 may be configured to be partially detachable. The shielding unit 30 is configured by connecting a plurality of parts via detachable connecting parts, and can be attached or removed. The configuration of the connecting parts is not particularly limited, and may be any one or a combination of a hook mechanism for hooking one part onto another, a claw engagement, a connection by magnetic force, a screw, a hook-and-loop fastener, and the like. The shielding unit 30 may also be configured to change the amount of shielding by a sliding structure. Specifically, for example, a part of the shielding unit 30 may slide in the front-rear direction of the aircraft to expand and contract in the front-rear direction, or a part of the shielding unit 30 may slide in the up-down direction to expand and contract in the up-down direction.

6 is a side view of the aircraft 1. The shielding unit 30 may be capable of changing the amount of shielding in the vertical direction (axial direction of the rotor blade). As shown in FIG. 6, the amount of shielding in the vertical direction (height H) of the shielding unit 30 from the lower surface of the rotor blade 20 downward is preferably 1/3 or more of the diameter D.
This is not limited to the above.

The length of the shielding portion 30 may be changeable in a direction perpendicular to a line connecting the centers of the two rotors sandwiching the shielding portion 30 in a plan view (the front-rear direction of the aircraft in the example of FIG. 1). The shielding amount (each length L in FIG. 6) in the horizontal direction (direction perpendicular to the line connecting the centers of the two rotors) of the shielding portion 30 is preferably ½ or more of the area between both ends of the rotor 20 in the radial direction. In other words, it is preferably ½ or more of the diameter D, but is not limited thereto, and it is sufficient if the area below the rotor between the two rotors is partially shielded.

FIG. 7 is a diagram (plan view) showing an example of the hardware configuration of the aircraft 1 according to this embodiment.
As shown in FIG. 7, the aircraft 1 according to this embodiment includes a rotor 20 for generating thrust, a motor 21, and an ESC (Electric Speed Control).
The aircraft 1 also includes a flight controller 23 as a control unit in the main body 10. The flight controller 23 is, for example, a central processing unit (C
PU) and FPGA (Field-Programmable Gate Array)
The flight controller 23 may have one or more processors 23b, such as a programmable processor such as a PLC. The flight controller 23 has a memory 23a and can access the memory 23a. The memory 23a stores logic, code, and/or program instructions that the flight controller 23 can execute to perform one or more steps. The flight controller 23 is an example of a control unit. The flying object 1 of this example also includes a camera and/or a sensor 24 as an information acquisition unit. The flying object 1 also includes a transmission/reception unit 2
7 is merely an example, and rotorcraft having a configuration different from that of the main body 10 shown in FIG.

The main body 10 is formed by a frame that constitutes the flying object 1. The material that constitutes 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 rotor 20 is attached to the motor 21. The rotor 20 generates lift (thrust) in the flying object 1 by rotating itself due to the rotation of the motor 21. In this embodiment, the rotor 20 is provided at four locations, front, rear, left and right, but the present invention is not limited to such an example, and the rotor 20 may be provided at six or eight locations around the airframe. The number of rotors 20 provided may be appropriately changed depending on the structure, shape, equipment, size, etc. of the flying object 1.

The memory 23a may include, for example, a separable medium such as an SD card or a 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 and video data captured by the camera is recorded in the built-in memory or an external memory.
3a can appropriately 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.

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 motors 2, which are the propulsion mechanisms of the air vehicle 1, via the ESC 11c to adjust the spatial arrangement, speed, and/or acceleration of the air vehicle 1, which has six degrees of freedom (translational motions x, y, and z, and rotational motions θx, θy, and θz).
The motor 21 rotates the rotor 20 to generate lift for the aircraft 1. The flight controller 23 can adjust the thrust of the rotor 20 by controlling the rotation speed of the motor 21 (rotation speed also means the number of rotations per given time).

The flight controller 23 may be connected to one or more external devices (e.g., a flight control terminal 26
The transceiver 25 may be in communication with a transceiver 25 configured to transmit and/or receive data from a local area network (LAN), a local area network (LAN), or a network that is connected to a network. The transceiver 25 may use any suitable communication means, such as wired or wireless communication. The transceiver 25 may be, for example, a local area network (LAN), a local area network (LAN), or a network that is connected to a network.
Any communication method may be utilized, such as a wide area network (WAN), infrared, wireless, WiFi, point-to-point (P2P) network, telecommunication network, cloud communication, or any combination thereof.

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

The control terminal 26 is a device for controlling the operation of the flight of the aircraft 1. The flight of the aircraft 1 may be controlled by an operator on the ground or the like, or may be controlled by an autonomous flight program (e.g., a Ground Control System (GCS)) based on flight path information and sensing.
The flight controller 23 may be controlled by automatic piloting or manual piloting based on a remote control (ROC) or a satellite communication station (SMS). The piloting terminal 26 may be, for example, a transceiver (radio transmitter), a smartphone, a tablet, or other terminal. The piloting terminal 26 may send flight control instruction information to the flight controller 23.

The sensor 24 according to the present embodiment is, for example, an inertial sensor (IMU (Inertial Measurement Unit)
Inertial measurement devices such as GPS (Inertial Measurement Sensor), acceleration sensors, gyro sensors, GPS sensors, wind sensors, temperature sensors, humidity sensors, air pressure sensors, altitude sensors,
LiDAR (Laser Imaging Detection and Rangin)
g), or a vision/image sensor other than a camera. The sensor 24 may be mounted on the flight controller 23 or provided outside 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. The camera may include, for example, a camera for use in self-position estimation and a camera for capturing an image of a subject. In the flying object 1 of this example, when in a non-flying state, the battery pack is inserted into the main body 10.
The battery pack may be integrated with the shielding portion 30 or may not be integrated with the shielding portion 30. The aircraft 1 may also include multiple batteries or may include only one battery.
The battery may include only one battery.

Although the preferred embodiment of the present disclosure has been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field of the present disclosure can conceive of various modified or amended examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

In the above embodiment, the autonomous flight control is described as being executed by the flight controller 23 of the flying object 1, but the present technology is not limited to such an example. That is, the autonomous flight control method is not limited to an example in which the autonomous flight control method is processed at an edge in the flying object, and the above-mentioned correction process may be performed remotely by another autonomous flight control device, the processing result may be transmitted to the flying object, and the drive unit may be controlled based on the result. That is, the main hardware that executes the autonomous flight control method is not particularly limited, and the above-mentioned functional unit may be executed by multiple hardware.

In addition, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification, in addition to or in place of the above effects.

Note that the following configurations also fall within the technical scope of the present disclosure.
(Item 1)
a plurality of rotors for generating thrust;
An unmanned aerial vehicle comprising a shielding portion located between any two adjacent rotors in a planar view and blocking the airflow below the two rotors during flight.
(Item 2)
2. The unmanned aerial vehicle described in item 1, wherein any two adjacent rotors rotate in opposite directions to each other.
(Item 3)
The unmanned aerial vehicle described in item 1 or 2, wherein the shielding portion is configured to be able to change the amount of shielding by partially attaching and detaching it.
(Item 4)
The unmanned aerial vehicle described in any one of items 1 to 3, wherein the shielding portion is configured to be able to change the amount of shielding by a partial sliding structure.
(Item 5)
An unmanned aerial vehicle described in any one of items 1 to 4, wherein the shielding section is configured to be able to change the amount of shielding in the vertical direction of the aircraft.
(Item 6)
An unmanned aerial vehicle described in any one of items 1 to 5, wherein the shielding section is configured to be able to change the amount of shielding in the fore-and-aft direction of the aircraft.
(Item 7)
An unmanned aerial vehicle described in any one of items 1 to 6, wherein the shielding portion is located between adjacent rotors in the left-right direction of the aircraft.
(Item 8)
An unmanned aerial vehicle described in any one of items 1 to 7, wherein the rotors are provided at four locations on the front right side, front left side, rear right side, and rear left side of the aircraft.
(Item 9)
An unmanned aerial vehicle described in any of items 1 to 8, wherein the shielding portion has a battery for supplying power to the rotor.
(Item 10)
An unmanned aerial vehicle described in any one of items 1 to 9, wherein the shielding portion extends from the front end to the rear end of the aircraft.

Reference Signs List 1 Aircraft 10 Main body 20 Rotor 30 Shielding part

Claims (9)

a plurality of rotors for generating thrust;
A main body portion located at the center in the left-right direction of the unmanned aerial vehicle and supporting the plurality of rotors;
a shielding portion provided on a lower side of the main body portion and positioned between any two adjacent rotors in a plan view, the shielding portion blocking an airflow between the two rotors that occurs due to a difference in rotation speed between the two rotors under the two rotors during flight;
The shielding portion is provided at least one between the left and right rotors located in front of the unmanned aerial vehicle and between the left and right rotors located in the rear of the unmanned aerial vehicle,
The unmanned aerial vehicle is configured so that the amount of shielding can be changed by a partial sliding structure. The unmanned aerial vehicle according to claim 1, wherein any two of the adjacent rotors rotate in opposite directions. The unmanned aerial vehicle according to claim 1 or 2, wherein the shielding portion is configured so that the amount of shielding can be changed by partially attaching and detaching it. The unmanned aerial vehicle according to claim 1 or 2, wherein the shielding portion is configured to change the amount of shielding in the vertical direction of the aircraft. The unmanned aerial vehicle according to claim 1 or 2, wherein the shielding portion is configured to change the amount of shielding in the fore-aft direction of the vehicle. The unmanned aerial vehicle described in claim 1 or 2, wherein the shielding portion is detachable from the main body portion. The unmanned aerial vehicle according to claim 1 or 2, wherein the rotors are provided at four locations on the front right side, front left side, rear right side, and rear left side of the aircraft. The unmanned aerial vehicle according to claim 1 or 2, wherein the shielding portion has a battery for supplying power to the rotor blades. The unmanned aerial vehicle described in claim 1 or 2, wherein the shielding portion extends from the front end to the rear end of the aircraft body.

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