Multifunctional unmanned aerial vehicle

Abstract

FIELD: aviation technology.SUBSTANCE: invention can be used in unmanned aircraft designed to perform functions that require flight in the range of speeds from zero to subsonic, as well as requiring repeated vertical takeoffs and landings in unprepared places, for example, for the protection and patrol of borders and objects in duty mode, for surveillance, collection and transmission of information, for rescue operations in emergency situations, for counter-terrorism operations, as well as reconnaissance and strike operations, for example, for the interception of ground and air targets, in particular for combating a massive drone attack. An unmanned aerial vehicle (UAV) is proposed, comprising a fuselage, in the nose of which a propeller is located, equipped with a swash plate, which serves to control the heading and pitch moments. The UAV also comprises a wing with ailerons, comprising at least three consoles, evenly distributed around the circumference of the fuselage. The warhead, in particular, may be a centrifugal throwing device that uses propeller blades to accelerate bullets.EFFECT: ability to re-take off from any position after a rollover landing, including nose-down; high load-bearing capacity of the aerodynamic system in the speed range from zero to subsonic; and a high rate of fire of the warhead with inertia-free retargeting across the entire azimuth.6 cl, 13 dwg

Description

[0001] The invention relates to the design and takeoff method of an aerodynamic unmanned aerial vehicle (UAV) capable of performing various functions requiring flight at speeds ranging from zero to subsonic, as well as multiple vertical takeoffs and landings in unprepared locations. It can be used, for example, to guard and patrol borders and facilities in standby mode, for surveillance, information collection, and transmission, for rescue operations in emergency situations, for counter-terrorism operations, as well as reconnaissance and strike operations, such as intercepting ground and air targets, in particular to counter a massive drone attack.

[0002] The development of microelectronics and cybernetics has led to the widespread use of inexpensive small UAVs, also known as "drones," which can be used not only for peaceful purposes but also by terrorists, posing a threat to civilian life in virtually any country. This requires the development of adequate defenses against this threat. Traditional air defense systems are primarily designed to counter large aircraft. They are too expensive and have high-powered warheads. Their use against a massive attack by a swarm of small UAVs is costly and poses a danger to civilians. At the same time, the terrorist threat posed by small UAVs in many cases exceeds that posed by traditional weapons, due to their high mobility.This danger is comparable to that of chemical and biological weapons, which are currently banned but are being secretly developed in some countries. Moreover, while the development of chemical and biological weapons is hampered by the scientific and technological complexity of their development, the technology for mass-producing dual-use drones has already been mastered, requiring an immediate response.

[0003] The problem is that a drone swarm is an aerial target, consisting either of a large number of small elements (a swarm) or of larger elements distributed over a large area (a flock). In both cases, intercepting them is a challenging task. Currently, electronic warfare (EW) systems that jam or cause thermal damage to the drone's onboard equipment are partially effective. However, this capability is likely to soon be exhausted due to the development of jam-resistant drone communication and navigation systems based on the use of non-sinusoidal, particularly noise-like, carrier waves. Drones equipped with such communication and navigation systems will therefore be able to operate virtually unimpeded.

[0004] This raises the question: how to combat a drone swarm? A possible answer seems to be a "symmetrical response." That is, counter the drone swarm with a group of small UAVs capable of engaging the swarm. This combat technique is well-known in biological systems and is also used in combat involving classical weapons between groups of similar weapons: aircraft, ships, tanks, artillery, and infantry. Success is determined by the slightest advantage in the tactical and technical parameters of one side, with inevitably heavy losses on both sides. In the case of a fight between swarms of small UAVs, these losses will be less severe, which is already a merit of scientific and technological progress, which is replacing the confrontation of physical manpower with a confrontation of intellects.

[0005] Thus, the problem is transferred to the area of ​​engineering and technical solutions concerning the design of small-sized UAVs and their weapons systems.

[0006] Formally, two types of devices can be classified as UAVs: rockets, which can fly in two environments, and aerodynamic aircraft, which can fly almost exclusively within the troposphere. A rocket, which uses a stored propellant as support, necessarily expends a significant amount of its structural components, such as fuel tanks and heat shields, during flight. Therefore, a rocket can be considered a consumable item. An aerodynamic aircraft, on the other hand, expends virtually no structural components during flight, making it practical to return to its base for refueling, i.e., be reusable. Moreover, the design of an aerodynamic UAV is often more complex than that of a rocket. It contains an engine, complex aerodynamic elements, and instruments. Furthermore, missiles generally fly at excessively high speeds, making it difficult to accurately target small targets.Using rockets is also problematic when landing and then taking off again is necessary. Therefore, in this review of the state of the art, we will focus only on aerodynamic UAVs.

[0007] Aerodynamic aircraft can be divided into two broad classes: a) those with a fixed-wing configuration, using a wing as the primary lift system, and b) those with a rotary-wing configuration, using a propeller as the primary lift system. However, there are also numerous hybrid aircraft that utilize both types of lift systems, as well as convertible aircraft, also known as tiltrotors, in which the aerodynamic configuration changes during flight. UAVs utilize all types of aerodynamic configurations.

[0008] Since the problem solved by the proposed invention concerns the design of a UAV that is effective, in particular, in combating swarms of other small UAVs, we exclude designs that are inherently unsuitable for drone interception, namely multicopters and helicopters, which have limited flight speeds (approximately 1 / 4 of the rotor blade tip speed), as well as convertiplanes, which cannot effectively perform their primary functions in transient speed conditions. The only exception is the design of the aircraft according to patent No. 2746025. In this design, the rotor system is a drum with multiple wings oriented with their spans along the cylinder's generatrices, and the drum's axis of rotation is oriented primarily along the direction of flight. This enables flight in a range of speeds from zero to subsonic. However, the feasibility of using this design for combating swarms has not yet been studied.We also exclude from consideration classical aircraft configurations, as they have a severely limited lower speed (approximately 1 / 2 the cruising speed), which is inadequate for ensuring precise guidance against small targets, especially low-speed ones. This leaves vertical takeoff and landing (VTOL) aircraft, which maintain their aerodynamic configuration at all flight speeds from zero to maximum, and which, in principle, can reach subsonic speeds if equipped with an engine of suitable power per unit mass. However, effective operation of the UAV is required across the entire speed range from zero to 700-800 km / h, while maintaining the same aerodynamic configuration at all speeds. Most known VTOL aerodynamic configurations cannot satisfy this requirement.

[0009] At least two known UAV aircraft designs satisfy these conditions. They utilize a swashplate, which is mounted on the aircraft's forward-facing propeller, for control in all modes. One of these designs is described in Russian Federation patents No. 2742496 and No. 2742495, and the other in patent No. 2805888. These designs fundamentally provide the ability to ensure stable flight control across the entire speed range from 0 to 700-800 km / h, due to the fact that yaw and pitch control are performed by torques generated by the swashplate, rather than by the empennage, as in conventional aircraft, or by auxiliary jet engines, as in military VTOL aircraft. This allows for primary flight operations to be performed at any speed from zero to maximum without flow stalls around the rotor system components.

[0010] A disadvantage of the above-mentioned VTOL designs when used to create a multifunctional UAV is the difficulty of landing and re-takeoff on unprepared, random sites, where the aircraft could capsize, especially in strong winds. However, landing can be extremely necessary, for example, for waiting, fuel conservation, covert surveillance, or logistical coordination with other vehicles.

[0011] In military applications of UAVs, the design of their warheads is also a challenge. For example, to combat a swarm of drones, the "komikaze" principle—that is, ramming—or a high-explosive fragmentation warhead can certainly be used. However, this would make the interceptor expendable. A warhead that does not damage its carrier is required. For example, dropping ammunition from a height, particularly in the form of a glide grenade, or a throwing device (firing device). A throwing device, which increases the number of shots per flight, is more suitable for counter-drone operations. A disadvantage of traditional firearms when deployed on small aircraft is the large mass of the structure due to the high pressure of the propellant gases. Jet-propelled launchers, on the other hand, consume too much fuel. Furthermore, the automatic reloading mechanism for the cartridge ammunition is too complex and cumbersome.Mounting firearms on the aircraft worsens aerodynamics, reducing maximum speed and range, and increases engine weight and the required fuel supply.

[0012] The most acceptable technical solution is one that allows for the placement of weapons without degrading flight performance or increasing the weight of the UAV structure. This solution is the use of a centrifugal propelling device, in which the aircraft's propeller serves as the rotor accelerating the projectiles. A variant of the VTOL aircraft design, harmoniously combined with a centrifugal propelling device, is described in Russian Federation Patent Application No. 2022106793, "Remotely Controlled Combat Device," author and applicant A.A. Gorshkov, published September 15, 1923, Bulletin No. 26. This device uses disc-shaped bullets. The disc-shaped bullets are stored, like a stack of coins, in a magazine located in the propeller's nose cone. Under the action of centrifugal forces, disc bullets enter the entrance to an open channel made inside the corresponding propeller blade, in which the bullet is held by a controlled stop valve.At the moment of time corresponding to the circumferential position of the blade at which the bullet, according to the known ballistics of acceleration and flight, will hit the target, the stop valve opens. The remaining bullets behind it in the specified channel and in the magazine are held by a second valve, which, together with the first, forms a locking mechanism. Uniformity of the centrifugal acceleration of the bullets is ensured by eliminating slippage of the bullet disk relative to the guides due to a toothed knurling along the edge of the bullet disk, which interacts with a toothed rack mounted on one of the guides in the blade channel. Rotation of the disk stabilizes the bullet in flight, converting aerodynamic moments arising from random angles of attack during atmospheric flight into a roll rotation of the bullet around the direction of flight, limiting deviation from the original flight direction and improving accuracy.The bullet's velocity is determined by the blade's tip rotation speed and, taking into account the peripheral velocity and acceleration speed, can be approximately 1.5 times the tip velocity, i.e., approximately 500 m / sec. The corresponding kinetic energy is approximately 600 joules per 5 grams of mass, which is close to the energy of a small arms bullet. Targeting is accomplished by a remote operator by aligning the crosshairs on a television monitor with the current target image or with a lead point. The actual bullet release is accomplished by a cam or electromagnet during the next propeller revolution. During targeting, the disc on which the aforementioned cam or collector lamella is located is adjusted to an angular position that corresponds to the desired bullet exit direction from the propeller blade's guide channel. The bullet is released by applying voltage to the lamella.The shutter opens automatically at the moment when, in its continuous, rapid rotation with the propeller blade, the current-collecting brush of the corresponding blade reaches the position corresponding to the bullet's release from the guides toward the target. This means that the bullet's release occurs with an automatic delay relative to the trigger signal, rather than immediately, as occurs in firearms. The loss of time before the release is compensated for by the calculated aiming point lead.

[0013] A disadvantage of the device described in application No. 2022106793 is the potential for the disk projectile to become stuck in the transition pipe located between the magazine and the barrel due to the variable blade pitch. This limits the range of blade pitch variation during propeller pitch control, thereby limiting dynamic flight capabilities. Another disadvantage is the difficulty of landing on uneven surfaces and in strong winds, which can cause the UAV to capsize, making it impossible to take off again. This limits the range of operations that can be performed using the UAV. Another disadvantage of this UAV is its limited load-bearing capacity at low and medium flight speeds.

[0014] The purpose of the invention is to solve the above-mentioned problems, namely: to ensure the possibility of repeated takeoff and landing of UAVs in unprepared places and in strong winds, to increase the reliability of the centrifugal throwing device combined with the design of the aircraft propeller, and to eliminate the deficiency of load-bearing capacity in the low and medium flight speed mode.

[0015] A multifunctional UAV designed as a VTOL aircraft is proposed. The nose of the fuselage houses a tractor propeller equipped with a collective and cyclic pitch control mechanism, i.e., a swashplate used to generate control moments for the yaw and pitch angles. The VTOL aircraft wing is equipped with ailerons used to control roll moments, and also used as flaps to control the wing's lift at low speeds. The invention's objective is partially achieved by the wing comprising at least three wing panels, uniformly distributed around the fuselage. The wing tips are positioned as close as possible to the propeller's rotation plane and are adapted for use as ground support during landing. This enables a normal landing and subsequent takeoff of the aircraft using any pair of adjacent wing panels as ground support. That is,The UAV may tip over and roll along the ground when landing with a strong crosswind or on an uneven surface.

[0016] In one embodiment, the said tips are provided with protrusions that protect the propeller from touching the ground when it tips over onto its nose.

[0017] Considering that a multifunctional UAV must be capable of performing its primary functions over a wide range of speeds, including medium and low speeds, it is advisable to control lift not by deflecting hinged flaps, as in a conventional aircraft, but by controlling the wing's camber. This reduces the likelihood of flow separation at the upper edge of the wing and increases the maximum achievable lift coefficient. To achieve this, in a specific embodiment, the wing console airfoil consists of a leading edge and trailing edge connected along the upper edge by a flexible shell. The lower portion of the wing airfoil is partially filled with a compression-elastic material that slightly expands laterally under compression, such as open-cell foam rubber.The elastic material is constructed in layers alternating with flexurally rigid spacers attached to the flexible shell located along the upper edge of the profile. To control the profile curvature, the console contains a cable routed through openings in the elastic package, connected to a servo drive that controls compression of the elastic package by varying the cable's length.

[0018] In a specific embodiment, a multifunctional UAV comprises a warhead in the form of a centrifugal propelling device, using propeller blades as a rotor, containing longitudinal open channels for propelling projectiles by centrifugal force. The projectiles are shaped like small balls and are housed in a hopper mounted in the propeller hub fairing and connected to the propeller blades via curved circular tubes pivotally mated with an opening in the blade root, coaxial with the blade pitch control hinge and communicating with the aforementioned longitudinal channel in the blade. This embodiment of the centrifugal propelling device removes restrictions on the range of propeller blade pitch adjustment during swashplate operation, which is necessary for performing the primary function over a wide range of flight speeds, particularly for takeoff from any position.

[0019] In a specific embodiment, the control of the stop valves, which fire the projectile by releasing it within the centrifugal force field, is accomplished by a high-speed electronic device comprising a control unit whose input is connected to a target designation unit and a sensor for the current angular position of the propeller relative to the fuselage, and whose output is connected, via a wireless (contactless) communications system, to the stop valves rotating with the blades, which control the release of the projectile. This enables rapid (inertia-free) retargeting of the launcher to different target elements scattered in various azimuthal directions without the need for mechanical movement of significant masses. That is,It is possible to ensure circular targeted firing at a multi-element target scattered in space, for example a flock of drones, with a frequency that is two or more times greater than the rotation frequency of the UAV propeller.

[0020] To ensure engine starting from a low-power source, which is necessary for repeated takeoffs, it is advisable to use a piston internal combustion engine operating on an isobaric cycle, i.e., with combustion occurring at a constant pressure, as the propeller drive engine. This ensures engine starting with gentle shaft rotation, since there is no need to perform work during the compression cycle when starting an isobaric engine. Starting occurs at zero initial pressure of the combustible mixture. At the same time, the spark plug located in the intake manifold immediately fires, i.e., combustion occurs as the combustible mixture is drawn into the cylinder. Once a small pressure is generated, a positive work balance is established, sinceAn already burnt combustible mixture, the volume of which is many times greater than the volume of the supplied combustible mixture, enters the inlet of the working cylinder of an isobaric engine (for more information on a piston internal combustion engine with an isobaric working cycle, see the patent for invention of the Russian Federation No. 2746820).

[0021] The problem of re-launching the proposed multifunctional UAV in the event of a nose-over landing remains. Although the propeller is protected from ground contact by the aforementioned wingtip protrusions, simply reversing the propeller thrust direction does not solve the problem. This prevents the wing ailerons from compensating for the engine's reaction torque, as the required directional airflow over the wing consoles ceases. A method for re-launching the multifunctional UAV in the event of a nose-over landing is proposed, consisting of the following sequential steps:

[0022] a) - propeller spinning by the engine;

[0023] b) - reorientation of the plane of rotation of the propeller to a horizontal position while overcoming the gyroscopic moments of the propeller using moments created by the swash plate;

[0024] c) - reversing the propeller thrust and performing takeoff and climb in a mode in which the reactive torque applied by the engine to the fuselage is compensated by the aerodynamic forces acting on the wing console during the rotation of the fuselage under the action of the specified reactive forces of the engine;

[0025] г) - turning off the engine thrust by moving the propeller to the feathering position and tilting the fuselage axis by 180 degrees during the free fall of the UAV while controlling the heading and pitch moments using the swash plate;

[0026] d) - upon completion of the rollover process - rapid introduction of propeller thrust, damping of the falling speeds and rotation of the fuselage, accumulated during the fall, and transition to the normal flight mode using the wing ailerons.

[0027] The invention is explained by the following detailed description of implementation examples and thirteen figures.

[0028] Fig. 1 shows a general view of the proposed UAV with a section of the propeller location area along plane A - A, shown in Fig. 2.

[0029] Fig. 2 shows a view along arrow B shown in Fig. 1.

[0030] Fig. 3 shows a close-up sectional view of the propeller hub with a swash plate, the propeller drive mechanism, and the propeller blade feed unit.

[0031] Fig. 4 shows a block diagram of the shot control system of a centrifugal throwing device, which provides the possibility of inertia-free circular retargeting.

[0032] Fig. 5 shows the proposed UAV in one of four possible parking positions.

[0033] Figure 6 shows the proposed UAV performing a nose-up landing.

[0034] Fig. 7 shows the design of the wing console, which ensures the ability to perform the main functions of a multifunctional UAV in the range of low and medium speeds without a significant reduction in aerodynamic quality.

[0035] In Fig. 8-11, the proposed method of takeoff from the UAV position with the aircraft tilted onto its nose is illustrated.

[0036] Fig. 12 illustrates the process of aiming a centrifugal throwing device at elements of a drone flock.

[0037] Fig. 13 shows the placement on board the UAV of non-directional antennas of the radar system for monitoring the surrounding space using multi-position radar, which are also used in the UAV navigation system for tracking the current angular orientation of the UAV.

[0038] The proposed UAV comprises a short fuselage 1 (see Figs. 1 and 2), in the front part of which a propeller is located, consisting of a hub 2 (Fig. 3) and blades 3. Hub 2 is mounted on rollers 4 (see Fig. 3). The propeller blades have a constant twist (approximately 45 degrees), which ensures propeller operation in a wide range of UAV flight speeds - from zero to 700-800 km / h. At maximum (subsonic) flight speed, the tip sections of the blades are located at approximately 45 degrees, and the roots are close to the feathering position and create thrust similar to a flapping wing. At zero flight speed, when the fuselage axis is located almost vertical, the tip sections of the blades are located at small angles relative to the plane of rotation, and the roots are located at approximately 45 degrees, because the air flow velocity through the propeller is approximately equal to the peripheral velocity of the blade in the root sections.

[0039] The front part 5 of the propeller hub fairing does not rotate and is connected to the fuselage 1 by means of a stand 6. A video camera 7, communication devices, navigation devices, etc. can be located in the nose part.

[0040] The wing of the proposed UAV has several wing panels 8, evenly distributed around the fuselage 1. The minimum possible number of wing panels is three. However, to reduce the likelihood of the propeller touching the ground during landing without significantly increasing the length of the wing panels, it is advisable to make four wing panels (see Fig. 2). This will be optimal from both an aerodynamic and weight standpoint. All wing panels are equipped with wingtips 9, designed to support the apparatus on the ground during landing on any pair of adjacent wing panels. Moreover, each wingtip 9 has a protrusion "f" covering the axial direction of the entire propeller rotation zone and designed to protect the propeller blades from impact with the ground if the apparatus tips over on its nose during landing. To soften the impact, the wingtips 9 can be made of an elastic material.Each of the consoles 8 is equipped with an aileron 10, which is also used as a flap to increase lift at low flight speeds.

[0041] Propeller blades 3 are mounted in bearings 11 (see Fig. 3), providing the ability to control the overall and cyclic pitch of the propeller, which is accomplished using a swashplate, the plate 12 of which is connected to levers 13, secured to the roots of all the blades. The movement of the plate 12 along three degrees of freedom (along two tilts and along axial movement) is accomplished using three servo-electric motors 14. Flapping movements of the blades are not provided in the depicted embodiment. (They are provided, for example, in the design described in Russian Federation Patent for Invention No. 2746024, which is also suitable for use in the proposed UAV).

[0042] In the embodiment shown in Figs. 1, 2, and 3, the UAV is equipped with a warhead in the form of a centrifugal propelling device, the design of which is integrated with the design of the propeller. Each propeller blade 3 has a through channel 15, each of which has two controllable stop valves installed in the root zone—an inlet 16 and an outlet 17—between which one or more bullets 18 made in the form of steel (or heavier) balls can fit. The bullet supply is located in a hopper 19, which can be the propeller nose cone, which rotates with the propeller. The hopper 19 is connected to the entrance to the channel 15 of each blade by means of a curved tube 20 inserted into the opening of the blade, coaxial with the bearing 11. The bullets enter the tube 20 and then into the channel 15 under the action of centrifugal forces.

[0043] Control of flaps 16 and 17 is performed by high-speed electronic unit 21 (see Fig. 4). It is connected to flaps 16 and 17 via a wireless multi-channel communication system. This can be implemented, for example, in the form of buses with capacitive "brushes" located on the dielectric body of the fuselage, or in the form of a high-frequency multi-channel communication system. In both cases, power is required to power the drive of the flaps located on a rotating base, which in this particular case can be supplied in the same way as information - contactlessly. However, in this case, contact current collection - by brushes - is also permitted. There is also a propeller angular position sensor 22. The moment of sending the signal for opening is calculated automatically based on the signal from the target designation unit 23.

[0044] In particular, target designation can be performed by a remote operator using a wireless communication system and onboard video camera 7. By aiming the crosshairs at the target, the operator thereby transmits the target coordinates to the UAV, and control unit 21, also guided by the signal from sensor 22 of the current angular position of the propeller, sends a signal to open the output stop valve 17 of one of the blades 3 at the moment when the blade reaches the position corresponding to the bullet release moment calculated by unit 21, at which it leaves the blade guides in the direction of the target. Unit 21 also calculates the required lead time of the targeting point if the target is moving rapidly.To simplify this process and increase the probability of hitting the target, it is desirable to engage the target at close range and with a small difference in speed between the interceptor and the target, which should be ensured by the required speed and dynamic design parameters of the multifunctional UAV. Specifically, the ability to close in on the target allows for reduced requirements for firing range and projectile dispersion, and the replacement of the disk projectiles used in the prototype with ball projectiles, which expands the range of blade pitch and improves the aircraft's dynamic performance.

[0045] Engine 24 drives the propeller via two (or more) idler gears 25 (see Fig. 3), transmitting (multi-threaded) rotation to a toothed rim 26 fixed to the propeller hub. To ensure ease of starting and a low specific weight of the structure, it is desirable to use a piston internal combustion engine with an isobaric working cycle (see, for example, Russian patent for invention No. 2746820). The advantage of such an engine, especially for the proposed UAV, is its ease of starting, which makes it possible to use a low-power starter. This is due to the absence of compression during start-up, since the excess pressure in the receiver of an isobaric engine is zero during start-up. A positive power balance occurs even with a slight increase in pressure. As is known, an isobaric internal combustion engine operates without flashes or sharp pressure peaks – smoothly, like a steam engine.But at the same time, it has the same high efficiency as a conventional automobile engine with compression operating on an isochoric cycle, i.e. with combustion at a constant volume.

[0046] The standard takeoff, landing, and parking position of the proposed UAV is shown in Fig. 5. The UAV rests on the ground with the tips 9 of two adjacent consoles 8, using any of the four adjacent pairs. The fuselage serves as the third support point. Before takeoff, the control system automatically reconfigures itself according to the direction of the gravity vector measured by the G-force sensor.

[0047] If the aircraft tips over onto its nose (see Figs. 6 and 8), as detected by the g-force sensor, the UAV rests on the ground with the "f" protrusions of the wingtips 9, preventing the propeller from touching the ground. In this case, takeoff is performed as follows:

[0048] A) - the propeller 3 is spun by the engine (see Fig. 8);

[0049] B) - reorient the plane of rotation of the propeller 3 to a horizontal position (see Fig. 9) while overcoming the gyroscopic moments of the propeller with the help of moments created by the swash plate; in this case, the UAV maintains its balance like a top;

[0050] B) - reverse the direction of the propeller thrust and perform vertical takeoff and climb in a mode in which the reactive torque applied by the engine to the fuselage is compensated by the aerodynamic forces acting on the wing consoles during the rotation of the fuselage under the action of the said reactive forces of the engine (see Fig. 10); in this case, the consoles are located at 90° to the air flow;

[0051] G) - after reaching a sufficient altitude (about 15-20 meters), the engine thrust is turned off by moving the propeller to the feathering position and the fuselage axis is tilted by 180 degrees during the free fall of the UAV while controlling the heading and pitch moments using the swash plate (see Fig. 11);

[0052] D) - upon completion of the rollover process, the propeller thrust is quickly introduced, the speed of fall and rotation of the fuselage, accumulated during the free fall, is dampened, and the aircraft switches to the normal flight mode along the trajectory “E” (Fig. 11) using the wing ailerons.

[0053] Let's consider the aerodynamic features of the proposed UAV as a whole. The absence of a tailplane, which serves as a stabilizer for the aircraft's attitude during flight in a conventional aircraft, eliminates the positive feedback on pitching moments that occurs at high wing angles of attack, where stalling causes the derivative of the lift-angle-of-attack function to change sign. Consequently, the aircraft is prevented from being pulled into a steep dive or a spin. Pitch and yaw control at all speeds is performed by a swashplate, the moment generated by which is independent of the aircraft's actual attitude angles, but depends solely on the inclination of the swashplate 12. In the early stages of aviation development, characterized by manual aircraft control, preference was given to an automatically operating aerodynamic stabilizer.However, this was accompanied by drawbacks, such as the occurrence of a stall phenomenon, which automatically increases due to positive feedback. However, today, with the almost universal use of autopilots, the use of aerodynamic stabilization, which is stable only over a limited range of wing angles of attack, is impractical. An autopilot will not be significantly hindered if it lacks the convenience of piloting in the "dropped stick" mode. This mode is tiring only for humans. But in a UAV, only the autopilot operates, and it has no use for the "dropped stick" mode. This is achieved in the proposed UAV control system using a swashplate on the main propeller. This also eliminates excess aerodynamic drag created by the tail, improving lift-to-drag ratio. It is also possible to reduce the length of the tail cone, which makes it difficult to land a VTOL aircraft on its tail and reduces wind stability during landing.

[0054] But most importantly, the swashplate enables stable control of the VTOL aircraft in transition modes, when the lift function is redistributed between the propeller and the wing. This eliminates modes typical of helicopters, such as flight with a high flow downwash on the main propeller, which limits the flight speed to the lift capacity of the retreating blade. In all transition modes in the proposed UAV, both rotor systems, the propeller and the wing, operate in their characteristic flow modes – the propeller operates with a slight flow downwash, and the wing with a small angle of attack. And they combine their lift capacities, each not exceeding its "professional" capabilities. Specifically, without the propeller entering a high flow downwash mode, and the wing entering a high angle of attack mode. Moreover, the wing's angle of attack is adjusted largely not by using flaps (in this case, they are also called ailerons), but by reorienting the longitudinal axis of the fuselage.

[0055] However, one of the opposite wing panel pairs can be adapted to operate in a transitional mode with a high lift coefficient. In conventional aircraft, this mode is achieved by using a large flap deflection angle. However, this sharply reduces lift-to-drag ratio due to flow separation from the upper edge of the wing profile, where, due to the curvature concentrating on a small radius in the flap hinge area, flow separation occurs around the upper section of the wing profile. The steep flow bend requires a high vacuum in the small-radius flow turning zone, but this vacuum is disrupted by airflow along the boundary layer in the diffuser section of the profile.

[0056] However, it is possible to design a wing in which, instead of a hinged flap, an increase in the lift coefficient is achieved by changing the curvature of the wing profile, distributed over most of the wing profile chord.

[0057] A design variant of a wing with a variable profile camber, which makes it possible to significantly increase the operating efficiency of a multifunctional UAV in transient modes, is shown in Fig. 7. In this version, the profile of the wing console consists of a nose section 27 and an end section 28, connected along the upper edge by a flexible shell 29. Along the lower edge, the profile is partially filled with a material that is elastic in compression and has a Poisson's ratio close to zero (i.e., does not expand in the transverse direction under compression), for example, porous rubber with open pores. Moreover, the elastic material is made in the form of layers 30, alternating with plates 31, rigidly attached to the flexible shell 29. In this case, the curvature is controlled by tensioning a cable 32, passed along the lower edge of the profile through openings in the said layers and gaskets. The curvature is controlled using a winch 33 with a worm drive from a servo motor 34.

[0058] This device operates as follows. When the porous rubber layers 30 are not stressed, i.e. the cable 32 is relaxed, the airfoil is curved upward (line "M" in Fig. 7). When the cable is shortened by winding it onto the winch 33, the wing airfoil first straightens (line "H"), and then bends in the other direction (line "O"). In any configuration, the airfoil can be loaded with excess pressure from below, which corresponds to all operating modes of one of the opposite pairs of consoles used as a load-bearing element. At the same time, the configuration remains rigid in perceiving the lift force, which is ensured by the rigidity of the cable 32, the self-braking properties of the worm winch 33, and the constancy of the angle of the plates 31 to the shell 29, rigidly attached to it. In this case, another pair of opposite wing consoles, located orthogonally, can be used for roll control.

[0059] Thus, the airfoil camber is distributed along the airfoil chord. Consequently, the radius of curvature, even with a strong deflection of the airfoil's trailing edge, is many times smaller than at the flap-wing junction. This significantly reduces the vacuum generated in the diffuser section of the wing airfoil and increases the boundary layer length. Consequently, the vacuum is maintained within the boundary layer, and flow separation is shifted to larger flow deflection angles (see lines "K" in Fig. 7). Accordingly, the achievable lift coefficient of the wing increases, allowing for increased lift capacity at low and medium flight speeds, which are particularly important for performing many of the primary functions listed above for the proposed multifunctional UAV.

[0060] Let us consider examples of the main functions performed by the proposed UAV, which are not available for other types of equipment.

[0061] Firstly, it intercepts a swarm of drones with a fast, virtually inertia-free retargeting of the firing direction to individual drones dispersed in all azimuth directions over 360 degrees. In this case, the frequency of aimed fire can be up to two or more times higher than the frequency of rotation of the aircraft propeller (i.e. up to 200 or more shots per second). This is ensured by the fact that two or more shots (according to the number of blades) can be fired during one revolution of the propeller* (* shots in which the calculated bullet descent coincides with the protrusion "ф" of the wingtip 9 are blocked by block 21). By scanning the plane P of rotation of the propeller in space by swinging the fuselage over the entire sphere S (see Fig. 12), it is possible to sequentially attack all targets that alternately fall into the plane of rotation of the propeller. For example, target C1 is currently in plane P. Then, with further rotation of plane P along arrow "C", target C2 will fall into plane P. Then - target C3, C4, etc.In principle, a single pass of plane P across the entire sphere S can eliminate an entire swarm if the viewing angles of individual targets exceed the scattering field of the ball bullets. Misses are compensated for by repeated passes of the specified scanning across the entire swarm. Plane P can be rotated. The impact of individual targets on plane P is predicted by target designation unit 23, which continuously monitors the dynamics of changes in the observed target locations in the space surrounding the UAV. When engaging a large swarm, the high maximum speed and acceleration of the UAV is essential, allowing it to engage the swarm by sequentially moving across its volume, thereby reducing the distances to individual elements to aimed fire ranges. In any case, the effectiveness of swarm combat, estimated by the ratio of the number of swarm elements destroyed to the number of UAV interceptors expended, should be significantly greater than one for the proposed design versus existing designs.

[0062] Monitoring of the surrounding environment can be performed by a multi-positional radar (MPRL). Interception is carried out by a group of similar UAVs. Each UAV is equipped with a non-directional dipole antenna 35 (see Fig. 13).

[0063] In this case, inter-positional identification of signals from individual targets hitting all of the system's omnidirectional antennas is achieved by using a redundant number of MBSR positions based on the principle that the calculated coordinates remain unchanged regardless of changes in the MBSR system configuration. This method is described in more detail in Russian Patent No. 2814291, "Anti-Missile Guidance Method," author and patent holder A.A. Gorshkov.

[0064] This patent also describes a method for monitoring the current angular position of a UAV, consisting of direction-finding radio signals from external sources with known coordinates. Such signals can include signals from the UAV group itself, which is intercepting targets. This direction-finding requires the use of a vector antenna consisting of three mutually orthogonal dipoles. In the proposed UAV, the conductors of two dipoles 35 and 36 of such an antenna can be placed in mutually orthogonal wing consoles 8, and the third dipole 37 can be placed along the fuselage 1 (see Fig. 13).

[0065] Another example of the proposed UAV's application could be reconnaissance and strike missions, requiring covertly awaiting the appearance of a target on the ground. The proposed UAV can reach the expected target area by overcoming air defense lines at high speed, gliding with the engines off, and landing in autorotation mode (note that the UAV also has a small radar cross-section). After making a low-noise landing in an area susceptible to television surveillance, for example, on the roof of a suitable building, the UAV switches to covert alert mode with remote television surveillance. When a target visually identified by the remote operator appears, the UAV takes off and, closing in on the target to a distance sufficient for accurate fire, engages the target. The entire operation is carried out without risk to the operator.

Claims

1. A multifunctional unmanned aerial vehicle (hereinafter referred to as UAV), designed as a vertical takeoff and landing aircraft, in the nose of the fuselage of which is located a propeller equipped with a mechanism for controlling the general and cyclic pitch, and the wing is equipped with ailerons used to control roll moments, and also used as flaps, characterized in that the wing contains at least three consoles, uniformly distributed along the circumference around the fuselage, and the tips of all wing consoles are located as close as possible to the plane of rotation of the propeller and are adapted to touch the ground upon landing.

2. A multifunctional UAV according to paragraph 1, characterized in that the said wing tips are extended to the intersection with the plane of rotation of the propeller blades and prevent the blades from touching the ground when landing in an inverted position.

3. A multifunctional UAV according to claim 1, characterized in that it contains a warhead made in the form of a centrifugal throwing device that uses, as a rotor, propeller blades in which through channels for throwing bullets are located, wherein the bullets are made in the form of balls located in a hopper installed in the fairing of the propeller hub, connected to the said channel of each blade by means of a curved tube pivotally entering an opening located coaxially with the blade pitch control hinge and communicating with the said through channel of the blade.

4. A multifunctional UAV according to paragraph 3, characterized in that it contains a control unit, the inputs of which are connected to a target designation source, as well as to a propeller rotation angle sensor, and the outputs are connected via a wireless communication system to stop flaps located on the propeller blades that control the release of bullets.

5. A multifunctional UAV according to paragraph 1, characterized in that the propeller is driven by a piston internal combustion engine with an isobaric working cycle.

6. A multifunctional UAV according to paragraph 1, characterized in that the profile of the wing console consists of a nose and end portion connected to each other along the upper edge by a flexible shell, and the lower edge of the profile is formed by a material elastic under compression in the form of layers alternating with rigid gaskets attached to the said flexible shell located on the upper edge of the profile, and control of the curvature of the profile is carried out by means of a cable passed along the lower edge of the profile through an opening made in the said alternating layers and connected to a servo drive that controls the length of the cable.

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