KR20200080825A - Veryical takeoff and landing fixed wing unmanned aerial vehicle - Google Patents

Abstract

The present invention relates to a vertical takeoff and landing unmanned aerial vehicle with fixed wings, which includes: a fuselage having the fixed wings; rotor support parts arranged across the fixed wings along a progress direction of the fuselage and installed on both sides of the fixed wings in parallel; a plurality of rotors which are arranged on the rotor support parts to be symmetrical to each other and of which a part is arranged at the front of the most front end of the fuselage; and a tilt part respectively coupled to the plurality of rotors and tilting the plurality of rotors at a specific angle. Accordingly, the vertical takeoff and landing unmanned aerial vehicle with the fixed wings performs leap and flight mechanism at the same time to be quickly moved in an atypical environment such as obstacles and rough places and a disaster environment such as a collapsed wall.

Description

VERYICAL TAKEOFF AND LANDING FIXED WING UNMANNED AERIAL VEHICLE}

The present invention relates to a vertical takeoff and landing fixed wing drone, and more specifically, to a vertical takeoff and landing fixed wing drone capable of performing a mission through vertical takeoff and landing and long flight without being constrained by the takeoff and landing system by fusion of the shape of the fixed wing and the rotorcraft. .

The drone is a generic term for an unmanned aerial vehicle (UAV) in the form of an airplane or helicopter that can fly and steer by induction of radio waves without a pilot. Recently, it is used in various civilian fields besides military use.

The types of drones that can be commonly encountered are fixed wing type with flat wings on the left and right sides of the aircraft, such as airplanes, and rotary wings with a plurality of rotors installed around the aircraft, such as helicopters. It is divided into forms.

The fixed-wing drone has the wings fixed in the shape of a regular airplane, and it can obtain thrust through the power of engines, props, etc., and it can fly by generating lift through the flat-shaped wings provided on the left and right sides, and tilt at the rear of each wing. By applying a mechanism, a control surface that can be rotated up and down is provided to control the attitude of the aircraft during flight.

A drone in the form of a rotorcraft generates lift through a plurality of rotors (propellers) that are disposed and rotated around the aircraft, and can control flight by partially controlling the plurality of rotors (propellers).

In the case of a fixed-wing drone, there is an advantage in that high-speed flight and long-time flight are possible through wings provided on the left and right sides of the aircraft, but a vertical takeoff and landing is impossible, so a separate takeoff and landing system is required.

On the other hand, in the case of a rotary wing drone, vertical lift take-off and landing is possible by generating lift through a plurality of rotors provided around the aircraft, and there is an advantage in that a separate take-off and landing system is not necessary due to the easy control of the aircraft's posture. The disadvantages are that the flight speed is very slow and the flight time is short.

Korean Registered Patent No. 10-1636170 relates to a drone and a rotorcraft structure of a drone, in a drone having a plurality of arms and propellers respectively provided in the arms, the propellers respectively provided in the arms The number of is a plurality, the number of arms is 4, 6 or 8, the number of propellers is 4, 6 or 8, the plurality of propellers are formed at equal intervals radially, the plurality of propellers The rotational directions are the same, and the plurality of arms are formed at equal intervals radially around the central axis of the drone's rotorcraft structure, and the first and third groups and the second and fourth groups symmetrically opposite each other are located. It is divided into 4 groups, and the rotational directions of the first and third groups and the rotational directions of the second and fourth groups are opposite to each other.

Korean Patent Publication No. 10-2018-0089086 relates to a vertical take-off and landing quad-rotor drone having a fixed wing shape, and a flying body formed long before and after, and an upper portion to generate lift to support the weight in the air when flying from both sides of the flying body In the drone, the left and right main wings provided on both side surfaces of the body of the flight body, and a streamlined flight body formed of a head portion, a body portion and a tail portion of the drone including the left and right main wings greater than the lower curve of the Right main wing, left propeller provided on the left main wing and installed in the same direction as the head, and right propeller provided on the right main wing and installed in the same direction as the head, the flying body The upper vertical tail wing and the lower vertical tail wing, which are vertically provided at the upper and lower sides of the tail, and the upper propeller provided at the upper end of the upper vertical tail wing and installed in a direction parallel to the body part, and the lower vertical tail wing It is provided at the lower end of the body portion is configured to include a lower propeller installed in a direction parallel to the body.

Korean Registered Patent No. 10-1636170 (Registration on June 28, 2016) Korean Patent Publication No. 10-2018-0089086 (published August 08, 2018)

One embodiment of the present invention is to provide a vertical takeoff and landing fixed wing drone that can perform missions through vertical takeoff and landing and long flight without constraining the takeoff and landing system by fusion of the shape of the fixed wing and the rotary wing.

An embodiment of the present invention is to provide a vertical takeoff and landing fixed-wing drone that can perform a simple and fast flight transition between the fixed and rotating rotor by including a tilt structure and tilting the rotor.

Among the embodiments, the vertical takeoff and landing fixed wing drone is a gas having a fixed wing, a rotor blade support portion disposed across the fixed blade along the traveling direction of the aircraft, and installed parallel to both sides of the fixed blade, disposed symmetrically on the rotor blade support portion Some parts include a plurality of rotor blades disposed in front of the front end of the aircraft, and a tilt unit coupled to each of the plurality of rotor blades and capable of tilting the plurality of rotor blades at a specific angle.

The rotor blade support includes a reinforcing member of the I-beam and a rear anchor blade interconnecting the rear ends of the reinforcement members at a higher position than the plurality of rotor blades.

The tilt unit is coupled to the plurality of rotor blades and a plurality of rotary stages for rotationally controlling the plurality of rotor blades to be tilted, and a driving member for independently controlling the rotation angle of each of the plurality of rotary stages Includes.

Each of the plurality of rotary stages detects over-rotation or over-tilt of the corresponding rotor blade through a rotation sensor measuring the rotational speed of the rotor blade and a tilt sensor measuring the tilt of the rotor blade.

The driving member includes a plurality of tilt motors connected to each of the plurality of rotating stages to rotate the corresponding rotating stage, and a control unit controlling the plurality of tilt motors based on the rotation speed and the tilt. . In one embodiment, the driving member checks the instantaneous change amounts of the rotational speed and the tilt to decelerate the instantaneous change amounts when a specific criterion is exceeded. In one embodiment, the drive member is connected to the front and rear rotating stages on one side of the rotor support in both directions of the tilt motor to rotate vertically relative to the tilt motor. In one embodiment, the driving member controls the plurality of rotational stages in an erected state to vertically take off and land by rotating the plurality of rotors perpendicular to the ground during the takeoff and landing process of the aircraft. In one embodiment, the driving member tilts the angles of the plurality of rotor blades toward the front in the course of the flight of the aircraft to control the plurality of rotating stages to be inclined forward so that the aircraft flies forward.

The aircraft further includes a rear rotor blade disposed at the rear end and vertically disposed with the plurality of rotor blades to provide forward thrust of the aircraft.

Among embodiments, a gas having a stator blade, a rotor blade support that is disposed across the stator blade along a direction of travel of the gas and is installed parallel to both sides of the stator blade, is disposed symmetrically to each other on the rotor blade support and some of the gas A plurality of rotor blades disposed in front of the front end, and a rotary stage coupled to each of the plurality of rotor blades and configured to rotate by tilting the plurality of rotor blades at a specific angle, the rotary stage being axially coupled to the rotary stage It includes a tilt motor for rotating and a tilt unit including a control unit for controlling the tilt motor.

The disclosed technology can have the following effects. However, since a specific embodiment does not mean that all of the following effects should be included or only the following effects are included, the scope of rights of the disclosed technology should not be understood as being limited thereby.

One embodiment of the present invention can provide a fast and stable vertical take-off and fixed-wing drone by combining the advantages of the rotorcraft and fixed-wing methods. Through this, it is possible to fly at high speeds and long distances, so it can be used for missions such as spatial information creation beyond the use of a rotorcraft drone, while vertical takeoff and landing function of the risk of a fall that can occur during a conventional takeoff or landing of a mapping drone This can be greatly eased.

One embodiment of the present invention is to add a tilt structure to the front motor of a plurality of rotors disposed in front of the front end of the aircraft to generate propulsion during the aircraft's forward flight, to take off the vertical takeoff and landing fixed-wing unmanned aircraft to provide.

One embodiment of the present invention is a simple structure without significantly increasing the volume and weight not only for a small drone but also a medium-large-sized drone as well as a small drone by constructing a tilt structure that performs a tilt function including a rotating stage and a tilt motor and a control unit as one component. It provides a fixed-wing drone that can be mounted and used vertically.

1 is a perspective view showing a vertical takeoff and landing fixed-wing drone according to an embodiment of the present invention.
FIG. 2 is a plan view showing a vertical takeoff and landing fixed-wing drone according to FIG. 1.
3 is a side view showing the vertical takeoff and landing fixed-wing drone according to FIG. 1.
4 is a front view showing the vertical takeoff and landing fixed-wing drone according to FIG. 1.
5 is a perspective view showing the tilt portion of the vertical take-off and landing fixed-wing UAV according to FIG. 1.
6 is a photograph showing the tilt unit according to FIG. 5.
7 is a photograph showing a rotating state of the rotating stage in FIG. 6.
8 is a view showing a vertical tilt state of the vertical take-off and landing fixed-wing UAV according to FIG. 1.
FIG. 9 is a view showing a horizontal tilt state of a vertical takeoff and landing drone according to FIG. 1.
10A-10C are graphs showing the flight performance of a vertical takeoff and landing fixed-wing drone according to FIG. 1.

Since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be interpreted as being limited by the embodiments described in the text. That is, since the embodiments can be variously changed and have various forms, it should be understood that the scope of the present invention includes equivalents capable of realizing technical ideas. In addition, the purpose or effect presented in the present invention does not mean that a specific embodiment should include all of them or only such an effect, and the scope of the present invention should not be understood as being limited thereby.

Meanwhile, the meaning of terms described in the present application should be understood as follows.

Terms such as “first” and “second” are for distinguishing one component from other components, and the scope of rights should not be limited by these terms. For example, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

Singular expressions are to be understood as including plural expressions unless the context clearly indicates otherwise, and terms such as “comprises” or “have” are used features, numbers, steps, actions, elements, parts or the like. It is to be understood that a combination is intended to indicate the existence, and does not preclude the existence or addition possibility of one or more other features or numbers, steps, operations, components, parts or combinations thereof.

All terms used herein have the same meaning as generally understood by a person skilled in the art to which the present invention pertains, unless otherwise defined. The terms defined in the commonly used dictionary should be interpreted as being consistent with meanings in the context of the related art, and cannot be interpreted as having ideal or excessively formal meanings unless explicitly defined in the present application.

1 to 4 are a perspective view, a plan view, a side view, and a front view showing a vertical takeoff and landing drone according to an embodiment of the present invention.

1 to 4, the vertical take-off and landing fixed-wing drone 100 includes an aircraft 110, a plurality of fixed wings 120, a rotor wing support 130, a plurality of rotor blades 140 and a tilt unit 150. Includes.

The base 110 is a basic skeleton of the unmanned aerial vehicle 100, and may be a general streamlined shape, but is not limited thereto, and it can be formed in various shapes such as a cylindrical shape such as a drone and an octahedron shape. .

The plurality of stator blades 120 includes two front stator blades 121 symmetrically disposed on the left and right sides of the aircraft 110 and a rear stator blade 123 disposed at a rear end of the rotor wing support 130.

The rotor blade support 130 is disposed across the front stator blade 121 along the traveling direction of the body 110, and is installed parallel to both sides of the front stator blade 120, and the body 110 and the plurality of rotor blades 140 ). In one embodiment, the rotor blade support 130 is a portion in which a plurality of rotor blades 140 is mounted, and is configured to cross the front fixed blade 121 and both sides of the front fixed blade 121 along the traveling direction of the body 110 It is composed of a reinforcing material of the I-beam installed in parallel to the aircraft 110 may be disposed on the left and right sides of the front and rear left and right 140.

The plurality of rotor blades 140 are disposed symmetrically to each other on the rotor blade support 130, and some of the rotor blades 141 are disposed at the foremost front of the aircraft 110 and at the rear of the aircraft 110. The rear rotor blade 143 may be implemented, and the rear rotor blade 143 may be vertically disposed with the front rotor blade 141 to provide the forward thrust of the aircraft 110. The plurality of rotor blades 140 includes a propeller 210 and a driving motor 220 that rotates each corresponding propeller 210 in correspondence with the propeller 210, respectively. The propeller 210 and the driving motor 220 connected to each propeller 210 are tilted by the tilt unit 150 as one combination.

The tilt unit 150 may be coupled to each of the plurality of rotor blades 140 and tilt the plurality of rotor blades 140 at a specific angle. In one embodiment, the tilt unit 150 tilts the two rotor blades 141 disposed in front of the plurality of rotor blades 140.

5 and 6 is a perspective view and a photograph showing the tilt portion 150 of the vertical takeoff and landing fixed-wing drone 100 according to FIG. 1, and FIG. 7 is a photograph showing the rotational state of the rotating stage 310 in FIG.

5 to 7, the tilt unit 150 includes a rotating stage 310 and a driving member 320.

The rotating stage 310 may be coupled to the front rotor blade 141 and rotated to rotate the rotor blade 141. The rotating stage 310 is axially connected to the driving member 320 so that the rotating stage 310 and the driving member 320 may form a tilt structure as one assembly. The rotatable stage 310 is manufactured by injection molding in an approximately “c” shape and is connected to the front rotor blade 141 and can tilt the front rotor blade 141 by rotation.

The rotating stage 310 is combined with a rotation sensor that measures the rotational speed of the combined front rotor blade 141 and an inclination sensor that measures the tilt of the front rotor blade 141, so that the rotation or over-tilt of the front rotor blade 141 is combined. Can be detected.

The driving member 320 is connected to the rotary stage 310 and a tilt motor 321 for rotating the rotary stage 310 and a control unit 323 for controlling the tilt motor 321 based on rotation speed and tilt. It can contain.

In the tilt motor 321, the rotating stage 310 is axially connected in both directions to vertically rotate the rotating stage 310 based on the tilt motor 321.

The control unit 323 may be implemented on the PCB stage 330 by arranging the PCB stage 330 on one side of the rotating stage 310 and may be electrically connected to the tilt motor 321, and may be controlled by a plurality of control algorithms. Among the rotor blades 140, the tilt of the two front rotor blades 141 can be controlled. In one embodiment, the control unit 323 enters the rotating stage 310 to vertically take off and land by rotating the front rotor 141 so that the angle of the front rotor 141 is perpendicular to the ground during the takeoff and landing process of the aircraft 110 Can be controlled by. In one embodiment, the control unit 323 controls the rotating stage 310 to be inclined forward so that the aircraft 110 is flying forward by tilting the angle of the front rotor blade 141 toward the front during the flight of the aircraft 110. Can.

The control unit 323 may check the instantaneous change amounts of the rotational speed and tilt of the front rotor blade 141 measured by the rotation sensor and the tilt sensor to reduce the instantaneous change amounts when a specific criterion is exceeded. In one embodiment, the control unit 323 may be controlled by a flight control device provided in the aircraft 110, and the flight control device may receive a user command from a user remote controller (not shown) and perform flight control. . The control unit 323 drives the tilt motor 321 to control the rotation of the rotary stage 310 that is axially connected to the tilt motor 321, and at this time, the rotary stage connected to the tilt motor 321 by adjusting the rotation direction and speed The rotation direction and speed of 310 are controlled. The rotating stage 310 rotates within a range of 90 degrees to tilt the two front rotor blades 141 connected to the rotating stage 310 among the plurality of rotor blades 140. That is, when taking off, the rotational stage 310 controls the standing state so that it is perpendicular to the ground, and a plurality of rotor blades 140 generate thrust in the sky direction, and after takeoff, the rotating stage 310 is gradually forwarded. By tilting and controlling the posture to be horizontal with the ground, the plurality of stator blades 120 generates lift, and the plurality of rotor blades 140 generate only thrust forward. And when landing, the rotating stage 310 is rotated again in the sky direction to perform vertical landing.

The tilt unit 150 further includes a safety pin that secures the rotating stage 310 so as to prevent the rotational stage 310 from being pushed by the torque of the tilting motor 321 to exceed the rotational range or shake the posture. Can be implemented.

In one embodiment, the tilt unit 150 can be configured as a single component of the tilt structure that performs the tilt function, so it is light and reliable, and can also be used for medium to large-sized drones of 20 to 25 kg.

8 and 9 are views showing the vertical tilt and horizontal tilt states in the vertical takeoff and landing drone 100 according to FIG. 1, respectively.

8 and 9, the vertical takeoff and landing fixed-wing drone 100 is in a plurality of rotor blades 140, while maintaining the ground and the horizontal direction by the tilt portion 150 coupled to each of the front rotor blades 141 while flying And the remaining rear rotor 143 may control the flight posture to maintain a vertical direction with the ground.

The two front rotor blades 141 disposed at the front of the front end of the aircraft 110 are respectively connected to the tilt unit 150, which is connected to the front rotor blades 141 and the rotating stage ( The front rotor blades 141 may be tilted by the rotation of 310). At this time, the tilt motor 321 controls the rotation of the rotating stage 310.

Referring to FIG. 8, the tilt unit 150 keeps the front rotor blades 141 perpendicular to the ground, and the tilt motor 321 controls the posture so that the rotating stage 310 is perpendicular to the ground. In this way, when the rotating stage 310 maintains the vertical posture in the standing state, the motor output works in a direction that helps the aircraft 110 to take off and land quickly and stably.

Referring to FIG. 9, the tilt unit 150 keeps the front rotor blades 141 in a horizontal direction on the ground, and the tilt motor 321 controls the posture so that the rotating stage 310 is horizontal with the ground. In this way, if the rotating stage 310 maintains a horizontal posture in an inclined state toward the front, the motor output operates in a direction that matches the traveling direction of the aircraft 110.

As a result, the vertical takeoff and landing fixed-wing drone 100 vertically takes off and lands by rotating the plurality of rotor blades 140 during the takeoff and landing process of the aircraft 110 through tilting of the plurality of rotor blades 140 and the flight process of the aircraft 110 In a plurality of fixed wings 120 will fly forward. In the course of the flight of the aircraft 110, the rotational stage 310, which was fixed vertically, is rotationally controlled to be fixed in a horizontal direction to the ground. At this time, the motor output is applied in a direction that matches the flight direction of the aircraft 110 to improve the acceleration capability.

10A-10C is a graph of performance analysis of the vertical takeoff and landing drone 100 according to FIG. 1, wherein FIG. 10A is a voltage vs. flight speed, FIG. 10B is a flight time vs. flight speed, and FIG. 10C is a flight distance vs. flight speed. Performance.

Referring to Figures 10a to 10c, first, the vertical takeoff and landing fixed drone 100 is 2.9m wide, 2.18m long, 0.25m high (excluding landing gear), and a total weight of 21kg. By taking off vertically, securing the determination altitude and flying forward, the power supply of the vertical motor is stopped at a standby speed equal to or higher than the stall speed, and the horizontal thrust motor is operated to transition to a fixed-wing flight state. In a fixed-wing flight, the speed is reduced to shift power from a horizontal thrust motor to a vertical motor near the stall speed to land vertically.

In the flight test for performance measurement, the flight weight, center of gravity position, temperature, atmospheric pressure, angle of attack, and air velocity are measured while maintaining the horizontal constant velocity flight condition so that the horizontal acceleration or ascent rate becomes zero. It is divided into 20 speed sections and tested.

The required power in horizontal flight (P _req ), as shown in Equation 1 below, adds thrust to overcome drag (D) multiplied by flight speed (V), power for horizontal acceleration, and power according to the rate of rise.

[Equation 1]

으로, 비행속도에 따라 달라지므로 비행시험 결과에서 무차원 항력계수(C_D)로 추출되어야 한다. Here, drag

As, as it depends on the flight speed, it should be extracted as a dimensionless drag coefficient (C _D ) from the flight test results.

The drag coefficient (C _D ) is affected by the lift coefficient as shown in Equation 2 below.

[Equation 2]

The required power in Equation (1) is the required power in the fixed-wing forward flight, and when the stall speed of the fixed-wing flight is obtained, it can be expressed by the following Equation (3).

[Equation 3]

The unit of wing load (W/S) is N/m ² , σ is the density ratio and C _Lmax is the maximum lift coefficient.

In one embodiment, since the vertical takeoff and landing fixed-wing drone 100 has four upward propellers for vertical take-off and landing, the drag coefficient may be very large compared to a general fixed-wing drone.

The vertical takeoff and landing fixed-wing drone 100 having the shape of an embodiment has a battery power consumption during high-speed flight, as shown in the voltage vs. flight speed graph of FIG. You can check the good, so you can fly at high speed and fly for a long time. In addition, the flight time according to the flight speed is shown as shown in FIG. 10B, and the flight distance according to the flight speed is shown as shown in FIG. 10C.

In one embodiment, the vertical take-off and landing fixed-wing drone 100 can simply transition from a rotor blade to a stationary blade, and from a stationary blade to a rotor blade through tilting, and achieve maximum acceleration performance.

Although described above with reference to preferred embodiments of the present application, those skilled in the art variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. And can be changed.

100: vertical takeoff and landing fixed-wing drone
110: aircraft 120: a plurality of fixed wings
121: front fixed wing 123: rear fixed wing
130: rotor blade support 140: a plurality of rotor blades
141: front rotors 143: rear rotors
150: tilt part 210: propeller
220: drive motor 310: rotary stage
320: drive member 321: tilt motor
323: control unit 330: PCB stage

Claims (11)

A gas having a fixed wing;
A rotor blade support part disposed across the stator blades along the traveling direction of the gas and installed parallel to both sides of the stator blades;
A plurality of rotor blades disposed symmetrically on the rotor blade support portion and partially disposed in front of the foremost end of the aircraft; And
A vertical takeoff and landing fixed-wing drone including a tilt portion coupled to each of the plurality of rotor blades and capable of tilting the plurality of rotor blades at a specific angle.
According to claim 1, The rotor blade support
A vertical takeoff and landing fixed wing drone comprising an I-beam reinforcement and a rear fixed wing interconnecting a rear end of the reinforcement at a higher position than the plurality of rotor blades.
The method of claim 1, wherein the tilt portion
A plurality of rotating stages coupled to the plurality of rotor blades and rotatingly controlled to tilt the plurality of rotor blades; And
Vertical takeoff and landing fixed-wing drone, characterized in that it comprises a drive member for independently controlling the rotation angle of each of the plurality of rotating stages.
The method of claim 3, wherein each of the plurality of rotating stages
A vertical takeoff and landing fixed wing drone characterized by detecting an over-rotation or excessive tilt of the corresponding rotor blade through a rotation sensor measuring the rotation speed of the corresponding rotor blade and a tilt sensor measuring the tilt of the corresponding rotor blade.
The method of claim 4, wherein the drive member
A plurality of tilt motors connected to each of the plurality of rotating stages to rotate the corresponding rotating stage; And
And a control unit for controlling the plurality of tilt motors based on the rotational speed and the inclination.
The method of claim 5, wherein the driving member
A vertical takeoff and landing fixed-wing UAV, characterized in that the instantaneous changes in the rotational speed and the tilt are checked to decelerate the instantaneous changes when a specific criterion is exceeded.
The method of claim 5, wherein the driving member
A vertical takeoff and landing fixed wing drone, characterized in that the front and rear rotating stages on one side of the rotor support are axially connected in both directions of the tilt motor to vertically rotate based on the tilt motor.
The method of claim 7, wherein the drive member
In the process of take-off and landing of the aircraft, the vertical take-off and landing fixed-wing UAV is characterized in that the plurality of rotating stages are vertically controlled by rotating the plurality of rotors perpendicular to the ground to take off and land vertically.
The method of claim 8, wherein the drive member
A vertical takeoff and landing fixed wing drone characterized by controlling the plurality of rotating stages to be inclined forward so that the aircraft is flying forward by inclining the angles of the plurality of rotor blades in the course of the flight of the aircraft.
The method of claim 7, wherein the gas
A vertical takeoff and landing fixed wing drone further comprising a rear rotor blade disposed at the rear end and vertically disposed with the plurality of rotor blades to provide forward thrust of the aircraft.
A gas having a fixed wing;
A rotor blade support part disposed across the stator blades along the traveling direction of the gas and installed parallel to both sides of the stator blades;
A plurality of rotor blades disposed symmetrically on the rotor blade support portion and partially disposed in front of the foremost end of the aircraft; And
A rotary stage coupled to each of the plurality of rotor blades and configured to rotate by tilting the plurality of rotor blades at a specific angle, a tilt motor axially coupled to the rotary stage, and a control unit controlling the tilt motor to rotate the rotary stage A vertical takeoff and landing fixed-wing drone including a tilt portion including a.

Images