RU2746770C1 - Vertical take-off and landing aircraft and its flight control method - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to the field of aviation, in particular to the designs of vertical take-off and landing aircraft. The vertical take-off and landing aircraft contains at least four separate power units for creating thrust in the vertical plane, of which at least two are used as marching units for horizontal flight in airplane mode. The remaining power units are used as heel and tilt controllers during horizontal flight in airplane mode. These power units can freely rotate relatively to the bearing planes in such a way that when the tilt angle of the aircraft changes, the vector of their thrust coincides in the direction with the vector of acceleration of free fall. An even number of power units used as marching units for horizontal flight in airplane mode are fixed on both sides of at least one rocker arm that can be freely rotated in a plane that coincides or is parallel to the plane of symmetry of the aircraft.

EFFECT: invention reduces the transition time from hanging mode to horizontal flight mode and back, improves stability and manageability characteristics in transition mode.

3 cl, 4 dwg

Description

The invention relates to aviation technology, in particular to aircraft (LA) vertical and short takeoff and landing.

Known unmanned aerial vehicle vertical takeoff and landing DeltaQuad [1]. DeltaQuad is an aircraft that contains a propulsion system for level flight, two pairs of lifting propulsion systems for creating vertical thrust in hovering mode, where one pair of lifting screws is located at the rear of the wing and the other pair of lifting screws is located in the front of the wing. ...

The presence of lifting power plants makes an aircraft of a hybrid vertical take-off and landing scheme out of an ordinary aircraft, but at the same time the planes of the lifting rotor circle have the same angle that does not change in flight as the bearing areas (in this case, the wing). As a result, the resulting hybrid aircraft is unstable and ineffective in transient conditions. He cannot accelerate due to the lifting screws without reaching negative angles of attack. Acceleration to the desired speed due to only one sustainer motor in this scheme is difficult, since the operating lifting screws will create resistance as they accelerate and introduce destabilization in the pitch channel due to a significant displacement of the center of pressure forward relative to the center of mass of the aircraft.

Known patent [2]. The known aircraft for vertical take-off and landing contains a cruise power plant for horizontal flight in an airplane mode, from at least three separate lifting power plants to create thrust in a vertical plane. The propellers of the lifting power plants are installed in such a way that the plane of their rotation is located at an angle of 2 to 35 degrees to the bearing planes of the wing or wings. The method for controlling the flight of an aircraft is characterized by the fact that at the time of takeoff, the aircraft in hovering mode is located with a positive pitch angle from 2 to 3 5 degrees, to gain sufficient speed on lifting engines, the entire aircraft is tilted forward to the pitch angle, providing horizontal flight in airplane mode, after reaching the required speed (1.1-1.5 stall speed), the lifting motors are turned off. In fact, the described aircraft in airplane mode bears excess weight in the form of non-working lifting power units, which significantly reduces its energy efficiency. Also, the disadvantages of such an apparatus and the method of controlling its flight include additional aerodynamic resistance of fixed propellers of lifting power plants.

Known aircraft vertical take-off and landing [3], which contains a fuselage, keel, landing gear, articulated wing, two lift-sustainer fans, each of which consists of a propeller in a profiled ring with an independently controlled rotation drive, a power plant with one or more engines , a unit for transmitting torque from the engine to the drive shafts of lift-sustainer fans and a pitch control device. In this case, lift-sustainer fans are fixed near the center of mass, symmetrically relative to the axis of the aircraft on a power beam rigidly connected to the fuselage. An engine with a fenestron located in the aft fuselage is used as a pitch control device. The main disadvantage of the analogue is the presence of rotary drives for lift-sustainer fans, which reduces the reliability of its control system, complicates the design and increases the weight of an empty aircraft. In addition, the transition from vertical take-off to horizontal flight is carried out through a mode in which the same lift-sustainer fans are used both to create lift and to accelerate the vehicle, which significantly reduces its maneuverability in this mode, and also imposes a restriction on the minimum transition time from vertical take-off to level flight.

The closest analogue chosen for the prototype is a vertical take-off aircraft [4], shown in FIG. 1. A vertical takeoff aircraft (1) with a wing (3) contains a first engine block (4) and a second engine block (5) mounted on this wing (3) with the ability to rotate using a lever (7). The first engine block (4) and the second engine block (5) are located on the wing (3) at a distance from its tip (12). The distance from the first engine block (4) to the longitudinal axis (10) of the aircraft (1) is approximately equal to the distance from the second engine block (5) to the longitudinal axis (10) of the aircraft (1). In the horizontal flight position, the first engine block (4) is on the wing above the wing surface, and the second engine block (5) is on the wing under the wing plane. In the vertical flight position, the first engine block (4) and the second engine block (5) are located in the same substantially horizontal plane.

According to the author of the invention, this ensures stable flight characteristics during vertical takeoff and landing. However, it is obvious from the above diagram that in the transition mode from vertical takeoff to horizontal flight, when the steering aerodynamic surfaces are not yet effective, the longitudinal stability and controllability of the analogue is mainly determined by the length of the lever (7) and the speed (rate) of creating a thrust difference between the first (4 ) and the second (5) engine blocks. To obtain a given moment in the longitudinal channel (pitching, diving), it is necessary either to increase the length of the lever (7), which leads to a heavier structure of the apparatus, or, with a small value of the lever (7), to be able to quickly create the required thrust difference between the engine blocks, which is also problematic , taking into account the natural inertia of the engine. Also, the disadvantage of the analogue is the presence of a device for turning the engine blocks (4) and (5), which reduces the reliability of its control system, complicates the design and increases the weight of an empty aircraft.

The objective of the invention is to solve the problem of imperfections in the layouts of vertical take-off and landing aircraft available on the market, as a result of which, firstly, they cannot make high-quality transitions from hover mode to horizontal flight mode along an aircraft and vice versa, and secondly, they are significantly inferior in terms of energy efficiency of horizontal flight for airplanes of conventional schemes and, thirdly, they have a more complex and less reliable control system (when using rotary engines) than airplanes of conventional schemes.

The technical result of the claimed invention is to reduce the time of transition from the hover mode to the horizontal flight mode and vice versa, improve the stability and controllability characteristics in the transient mode, increase the energy efficiency of horizontal flight, simplify the control system and increase its reliability.

The specified technical result is achieved due to the fact that the claimed vertical take-off and landing apparatus contains at least four separate power plants to create thrust in the vertical plane, of which at least two are used as sustainer for horizontal flight in airplane mode. In this case, an even number of power plants used as sustainer for horizontal flight in airplane mode are fixed on both sides of at least one rocker arm, which rotates in a plane that coincides or parallel to the plane of symmetry of the aircraft, solely due to the difference in thrust of the power plants installed on it in order to increase the horizontal component of their total thrust. Power plants that are not used as sustainer for horizontal flight in airplane mode are used as roll and pitch controls and can be rotated relative to the bearing planes in such a way that when the pitch angle of the aircraft changes, their thrust vector coincides in direction with the free acceleration vector. falling.

The claimed method for controlling the flight of an aircraft is characterized by the fact that at the time of takeoff of the aircraft in hovering mode, the rocker is positioned horizontally, and after takeoff to gain horizontal speed, the rocker arm with power plants is gradually rotated due to the difference in thrust, while the power plants outside the rocker arm ensure the inclination of the entire of the aircraft in the vertical plane up to the pitch angle, which ensures the horizontal flight in the airplane mode. After reaching the required speed, the rocker turns to the vertical position. EFFECT: reduced transition time from hover mode to horizontal flight mode and vice versa, improved stability and controllability characteristics in transient mode, increased energy efficiency of horizontal flight, simplified control system and increased its reliability.

Brief description of the drawings.

FIG. 2 shows the device of the aircraft, side view, where:

1 - Aircraft vertical takeoff and landing;

2 - Lifting and cruising power plants,

3 - Lifting power plants used as roll and pitch controls in level flight;

4 - rocker;

FIG. 3 - the device of the aircraft, top view, where:

1 - Aircraft vertical takeoff and landing;

2 - Lifting and cruising power plants,

3 - Lifting power plants used as roll and pitch controls in level flight;

4 - rocker;

5 - the axis of rotation of the rocker arm;

6 - Axis of free rotation of power plants used as roll and pitch controls in level flight;

FIG. 4 shows the device of the aircraft in level flight, side view (designations are similar to those in FIG. 2). Implementation of the invention.

The invention is implemented on the basis of a vertical take-off and landing aircraft 1, for example, a flying wing scheme (see Fig. 2 - Fig. 4), on which a pair of lifting and cruising power plants 2 and a pair of lifting power plants 3 used to create a vertical hover thrust. A pair of lifting and cruising power plants 2 is directly placed at the ends of the rocker arm 4, which can rotate about the axis 5 (see Fig. 3). In turn, the pair of power plants 3 can independently rotate freely about the axis 6 (see Fig. 3).

The indicated design features of the aircraft make it possible to solve the problem of the invention and achieve the claimed technical result. Vertical take-off of the aircraft is carried out due to the thrust of pairs of power plants 2 and 3 (see Fig. 2 - Fig. 3). Moreover, the center of mass of each power plant in pair 3 is located below the axis of rotation 6, which ensures that the thrust of these units is oriented strictly vertically downward, regardless of the orientation of the aircraft itself in the vertical plane (see Fig. 4). The rotation of the rocker arm 4 can ensure the orientation of the pair of power plants 2 in a position practically perpendicular to the direction of flight, which allows them to be used as sustainer in horizontal flight (see Fig. 4). A design feature that implements the invention is the rotation of the rocker arm 4 with power plants 2 after takeoff to gain horizontal speed is carried out only due to the difference in thrust, without using any additional swing drives. The very angle of rotation of the rocker arm 4 can be limited to prevent the consequences of emergencies in the event of failure of one of the pair of lifting and cruising power plants 2. The location of the pair of power plants 3 in front of the center of mass of the apparatus eliminates the loss of lift for its longitudinal balancing.

The proposed layout allows the apparatus to take off vertically (see Fig. 2), and then, having set the required angle of attack of the bearing surfaces, as the rocker arm 4 turns, gains sufficient speed for flight in airplane mode due to the thrust of lift-sustainer engines 2 (see Fig. . four). In other words, after takeoff, the aircraft 1 is switched to hover mode with a positive angle of attack and, accordingly, pitch, accelerates in the horizontal plane, and after reaching the required speed (1.1-1.5 stall speed), the rocker arm 4 becomes almost perpendicular to the flight and the engines 2, only horizontal thrust is created on it.

The proposed arrangement of the apparatus, as well as the control method, allow realizing not only vertical take-off with subsequent transition to horizontal flight, but also take-off at a certain angle to the surface, then also passing to horizontal flight.

Information sources

1.https: //www.deltaquad.com/, publ .: 2016

2. RF patent for the invention "Vertical take-off and landing aircraft and a method of controlling its flight" No. 2638221 dated 12.12.2017

3. RF patent for a useful model "Vertical take-off and landing aircraft" No. 141669 dated 06/10/2014

4. RF patent for the invention "Vertical take-off aircraft" No. 2627261 dated 04.08.2017

Claims (3)

1. An aircraft with vertical take-off and landing, containing at least four separate power plants for creating thrust in the vertical plane, of which at least two are used as sustainer for level flight in airplane mode, characterized in that an even number of power plants used as sustainer for horizontal flight in airplane mode, fixed on both sides of at least one rocker arm with the ability to rotate it in a plane coinciding or parallel to the plane of symmetry of the aircraft, solely due to the difference in thrust, installed on it power plants. 2. The aircraft according to claim 1, characterized in that the power plants, which are not used as sustainer for level flight in airplane mode, are designed to be used as roll and pitch controls and can be rotated relative to the bearing planes in such a way that when the pitch angle of the aircraft changes, their thrust vector coincides in direction with the gravitational acceleration vector. 3. A method of controlling the flight of the claimed aircraft, characterized by the fact that at the time of takeoff of the aircraft in hovering mode, the rocker with power plants is placed horizontally, after takeoff to gain horizontal speed, it gradually rotates due to the difference in thrust of the power plants installed on it, up to to a vertical position, while the power plants outside the rocker arm ensure the inclination of the entire aircraft in the vertical plane to the pitch angle, which ensures horizontal flight in aircraft mode.

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