EP2855263A1

EP2855263A1 - Aircraft, preferably unmanned

Info

Publication number: EP2855263A1
Application number: EP13725987.5A
Authority: EP
Inventors: Florian SEIBEL; Michael Wohlfahrt; Michael Kriegel
Original assignee: Logo-Team UG (Haftungsbeschrankt)
Current assignee: QUANTUM-SYSTEMS GMBH
Priority date: 2012-06-01
Filing date: 2013-05-31
Publication date: 2015-04-08
Also published as: DE102012104783A1; US20150136897A1; WO2013178776A1; CN104364154A; DE102012104783B4

Abstract

The invention relates to an aircraft (1), preferably an unmanned aircraft (UAV), drone, or unmanned aerial system (UAS), comprising a rigid wing (2), which enables aerodynamic horizontal flight, and at least four rotors (4, 4'), which are driven by means of controllable electric motors (5) and which can be pivoted between a vertical starting position and a horizontal flight position by means of a pivoting mechanism (7), wherein all electric motors (5) and rotors (4) are arranged on the wing (2).

Description

AIRPLANE, PREFERRED UNMANUFACTURED

Technical area

The present invention relates to an aircraft, preferably a UAV (Unmanned Aerial Vehicle), a drone and / or a Unmanned Aerial System (UAS).

State of the art

In the field of unmanned aerial vehicles, drones and / or unmanned aerial systems different concepts are known, which relate to the takeoff and landing of such aircraft. For example, drones are known, which are started by means of a catapult and are designed in the form of a conventional plane aircraft with a rigid wing. The achievable possible flight times of these aircraft are systemically quite high, as these aircraft have a high aerodynamic quality. The preparations for the start, however, are very complex due to the required infrastructure in the form of a catapult or a runway. Also for landing arrangements are necessary here, since these aircraft either need a runway, or landed in a network or on a parachute.

Also known are drones, which operate as rotorcraft. The possible flight times that can be reached here are compared to the high energy input due to the system

Fixed-wing aircraft relatively short. However, the preparations for take-off and landing are completed faster, so that these aircraft are quickly deployable and in particular require neither the construction of a catapult or a runway, nor the construction of safety nets. Unmanned aerial vehicles, and in particular so-called MAVs (Micro Aerial Vehicles), which can be used for surveillance and reconnaissance purposes, are both civilian and military

Use of great benefit.

For example, such unmanned aerial vehicles can be used in civilian use for monitoring and control of gas and oil pipelines in order to detect the occurrence of leaks early and to be able to estimate the maintenance requirements of the pipeline. Other civilian deployment scenarios include, for example, the works protection of port facilities or in the

Large-scale industry, the monitoring and maintenance of offshore installations such as wind farms, drilling and production platforms, supervision of overhead power lines, environmental and nature protection tasks, monitoring of forest and forest condition, damage assessment after natural disasters, surveillance and reconnaissance in the field of species protection for the identification of livestock, the monitoring of compliance with fishing quotas, the preservation of monuments and the review of the structure of buildings, the supervision of major events such as regattas, rallies and other sporting events, the use in the field of aerial photography and aerial filming , as well as for mapping. In the scientific field such unmanned aerial vehicles may continue to be used, for example, to explore oil deposits and other geological formations, to study volcanoes and to predict volcanic eruptions, or to map archaeological sites. In the field of agriculture can be with such

unmanned aerial vehicles, which may be of great importance in the area of precision farming

Planning and monitoring machine usage. In addition, the growth of the respective crop can be measured on the field surface to be monitored, for example by means of infrared cameras. In this way, the overall condition of a crop can be checked and thus determine the optimal harvest time. Furthermore, a possibly occurring pest infestation can be noticed in time, so that appropriate

Countermeasures can be initiated. The monitoring from the air also allows different soil conditions within a field to be determined so that the input of fertilizers can be planned and optimized for certain soil sections. Further application scenarios concern the use in the area of responsibility of the authorities and organizations with security tasks (BOS), such as SAR (search and rescue), civil protection, damage assessment in case of natural disasters (severe weather,

Floods, snow and mud avalanches, large and large-scale fires, earthquakes,

Tsunami, volcanic activity), damage assessment in the case of technical-biological disasters (eg nuclear reactor accidents, chemical or oil spills), support of operational coordination through live images, monitoring of major events and demonstrations, on

Traffic monitoring, as well as a communication relay to increase the range.

In the military sector unmanned aerial vehicles are used for reconnaissance, are used to monitor objects such as base camps, to secure borders, to secure convoys, can be used in civil protection and are used for SAR (Search and Rescue) missions. Other military applications include CSAR (Combat Search and Rescue), use as communication relays (e.g.

Request of CSAR forces to increase the range), the coordination of material supply, as escort (eg convoy protection), for patrol flights and reconnaissance flights, for tactical reconnaissance (eg in urban terrain or even inside buildings, BDA ), for surveillance, targeting, ordnance search (eg mine and IED detection, detection of ABC contamination), for electronic warfare, and for use of munitions (eg light guided missiles).

An example of such an aircraft according to the rotary vane concept is known, for example, from WO 2009/1 15300 A1, wherein this aircraft is suitable for carrying, for example, a surveillance camera pointing to the front.

Another approach is the combination of the rotary wing concept and the fixed wing concept, so that on the one hand a vertical take-off and a vertical landing (VTOL - Vertical Take-off and Landing) can be achieved, and on the other hand carried out a horizontal flight due to the aerodynamically strong rigid wing can be.

This concept has been used for a long time in the field of manned aircraft, with the Beil-Boeing V-22 ("Osprey") being a particularly outstanding example. In the field of unmanned aerial vehicles, for example, from US 201 1/0001020 A1 an aircraft is known, which on the basis of a so-called quad-tilt rotor aircraft (QTR) a corresponding combination of a rotary wing aircraft and a

Fixed wing aircraft disclosed. The four rotors according to this concept are arranged such that two main rotors are arranged at the outermost ends of the main wing and two significantly smaller rotors are arranged at the extreme ends of the horizontal stabilizer.

Furthermore, from the article by Gerardo Ramon Flores et al.: "Quad-Tilting Rotor Convertible MAV: Modeling and Real-Time Hoover Flight Controf, Journal of Intelligent & Robotic Systems (2012) 65: 457-471 an unmanned aerial vehicle known as a fuselage with a

Main wing, vertical and vertical stabilizer, and four rotors includes, which are arranged directly on the fuselage of the aircraft. In this case, two rotors are arranged in front of and two rotors behind the main wing, so that there is an "H" arrangement of the rotors

Based on the cited prior art, it is an object of the present invention to provide an aircraft with VTOL properties, preferably an unmanned aerial vehicle, which offers further improved properties with regard to different possible applications.

This object is achieved by an aircraft with the features of claim 1. Advantageous developments emerge from the dependent claims.

Accordingly, an aircraft, preferably an unmanned aerial vehicle (UAV), proposed, which includes a rigid wing that allows aerodynamic horizontal flight. Furthermore, at least four rotors driven by controllable electric motors are provided, which are pivotable by means of a pivot mechanism between a vertical start position and a horizontal flight position. According to the invention, all electric motors and rotors are arranged on the rigid wing.

The fact that all rotors are arranged on the rigid wing and pivotable, resulting in improved VTOL properties of the aircraft. Accordingly, an aircraft is specified, which is able to both start vertically and land and pass through a transition maneuver in the horizontal flight. This gives greatly improved properties in terms of applications, as a runway or a parachute or network landing no longer needs to be provided, but at the same time a tremendous increase in flight time and range due to the more effective lift generation in horizontal flight through the wing is possible.

The center of gravity of the aircraft coincides both at take-off and landing, as well as in the hover near flight conditions with the lift center of gravity of the four rotors. Depending on the stability design, the center of gravity of the aircraft still coincides with the main lift in dynamic horizontal flight. In other words, the center of gravity of the aircraft can be aligned identically for the dynamic flight as well as for the hover. As a result, the design of the rotors and the electric motors is simplified and it can be used identically sized rotors and electric motors, which provide a substantially identical thrust. Due to the identical design of the four rotors and the control can be simplified. This simplification of the control is particularly clear over concepts that use different sized rotors.

In addition, resulting from the arrangement of the electric motors and the rotors on the wing essential structural advantages in the construction of the aircraft. Characterized in that the masses, which are applied by the electric motors and the rotors on the aircraft, are arranged on the wing, the root bending moment can be reduced at the wing root in the dynamic flight operation. Accordingly, the spar of the wing can be dimensioned with the same design of the aircraft for a given load multiple with a lower strength. This results in a reduction of the mass of the spar, so that either the payload of the aircraft can be increased, or the efficiency of the use of the drive energy is increased. These advantages can not be achieved with conventional attachment of the motors and rotors directly to the fuselage.

Furthermore, it is possible by the arrangement of the four rotors on the rigid wing, the

Maneuverability or to improve the maneuvering properties in hover, so that the aircraft a hovering is possible, which corresponds in principle to the hovering of a conventional floating platform. Thus, the aircraft can be used on the one hand in dynamic flight operation for remote monitoring, and on the other in the identical

Configuration can also be used as a stationary monitoring platform. Especially at This is particularly advantageous for monitoring tasks since, for example, a pipeline can be flown off in dynamic operation over its length, but on the other hand, in critical areas a particularly precise control or monitoring can be achieved with the aid of the operation as a floating platform.

Furthermore, results from the specific design possibility to the effect that for the hover all four rotors are needed for the aerodynamic horizontal flight, however, only a fraction of the hovercraft performance is required, the possibility of two of the four rotors in

Turn off horizontal flight. This means a very efficient use of the existing drive energy, as the two front rotors can be aerodynamically optimized for horizontal flight, but the two rear rotors can be optimized for hovering. In horizontal flight, the two rear rotors can then be turned off, for example, and folded back aerodynamically favorable. This results in the proposed aircraft a combination of a

Floating platform and an aerodynamic aircraft, with a vertical take-off and a vertical landing are possible in any terrain accordingly. Thus, the aircraft is operational in a very short time. In particular, on the complex structure of Startbeziehungsweise landing devices, for example in the form of a catapult, or of

Waste net, completely dispensed with.

The proposed aircraft continues to provide a very wide range of speeds between 0km / h in hover and high dynamic

Flying speeds in the range of, for example, 300 km / h ready, with a large

Range and long flight times can be combined by the dynamic flight characteristics with the simple take-off and landing characteristics.

An advantage of said aircraft is also that the rigid wing aerodynamically can be optimized so that he must provide the full, the aircraft carrying buoyancy only from relatively high speeds, and accordingly can have optimized for cruising very efficient wing profile. Because of the VTOL properties a start

or a landing without the help of the rigid wing can be performed, the wing profile can be optimized accordingly only efficient cruise operation. This results in a very slim and highly efficient wing profile, which is an even more efficient Handling the drive energy allows. In other words, for dynamic flight, a highly efficient aerodynamic design takes place without having to make the compromises that would have to be made for a conventional launch or landing, such as the provision of launch and landing flaps or high lift systems.

Furthermore, by the possibility of the aerodynamic wing on a single

To be able to optimize operating point, the achievement of an unusually high (relative to the size of the aircraft) glide ratio possible, so that a completely silent and vibration-free operation of the proposed aircraft in gliding flight over long distances is possible. In this case, the aircraft can also be operated in a forwardly inclined aerodynamic flight in a "sawtooth trajectory" with short thrust phases and a corresponding altitude gain in combination with a longer sliding phase depending on the drive characteristic be achieved.

The aircraft preferably comprises an automatic control device which stabilizes the aircraft during vertical take-off and vertical landing, in hovering flight as well as in the transition to and from hovering into dynamic flight. For this purpose, the rotors, which are usually driven in opposite directions, are controlled with respect to their thrust or with respect to the torque applied via the electric motors in such a way that a stable attitude is provided during takeoff and landing, during hovering and in transition. The ability to control all four engines in their thrust individually and to be able to pivot all four rotors independently of each other, the transition to the dynamic flight mode can be safely achieved.

The control device is preferably further designed so that a simple maneuvering of the aircraft in hovering is made possible. In particular, a simple rotation about the vertical axis, as well as a movement of the entire aircraft forward, backward and sideways can be achieved by a corresponding control of the rotors. Rotation can be achieved, for example, by varying the distribution of thrust between the four rotors. Since the rotors usually rotate in opposite directions, resulting from a change in the distribution of the thrust at constant total thrust a rotational moment corresponding to the relatively higher-powered rotor whose torque corresponding to the remaining Rotors is no longer caught. This principle of the control of flight platforms or aircraft in hover is known in principle.

In a further preferred embodiment, all the rotors of the aircraft are pivotable in one direction to reach the vertical start position. In this case, for example, all

Rotors for starting and landing swivel upwards, which can be dispensed with a landing gear or a landing gear and accordingly the aerodynamics in horizontal flight is not disturbed by this. This also results in a weight savings. The aircraft is on the hull and the motor gondolas before take-off and after landing.

The rotors together with their electric motors are preferably arranged in a middle region of the rigid wing with respect to its length, particularly preferably in the first third of the

Wing length. The arrangement in the middle third is due to regulatory technical as well as

Reasons of structural design. The masses of the aircraft are thus arranged more central and compact. This results in reduced moments of inertia and correspondingly a better dynamic response and easier maneuvering in hover. In principle, the positioning of the motors / rotors would also be possible further outward in the direction of the end of the wing.

The electric motors with the rotors are in this case preferably arranged on the rigid wing via corresponding motor nacelles, so that there is no collision of the rotors in horizontal flight

or hovering there and also no excessive coverage of the

Vertical thrust share done by the rigid wing. At the same time the rigid wing is flown very efficiently during forward flight. Furthermore, it can be achieved by this embodiment of the motor nacelles that the rotors are so far apart that the characteristic of a floating platform

Leverage ratios are achieved. In particular, here by the "X" shape of the arrangement of the rotors is achieved that a particularly stable flight behavior can be achieved both in hover and in horizontal flight.

The rigid wing is preferably equipped with a profile which allows an aerodynamic flight only from higher ground speeds of at least 50 km / h, preferably from 100 km / h. Accordingly, the rotors are designed and the electric motors dimensioned so that they provide a vertical thrust component as long as in a transition phase until the rigid wing can take the lift from a certain predetermined speed. In this way, it is possible to design the aerodynamic rigid wing optimized for the flight phase and accordingly not take into account take-off and landing phases in the design of the wing.

In comparison, the conventional use of a dynamic lift aircraft with a rigid wing typically comprises at least two

Areas of application: On the one hand the cruising flight, on the other hand also the slow flight, to which also the maneuvers takeoff and landing are assigned. To both

In order to be able to take into account key areas of application, compromises have to be made in the design of the airfoil. Accordingly, the conventional wing profiles are designed so that they allow for both low-speed flight with take-off and landing, as well as cruise flight safe flight characteristics. A conventional one developed in this way

However, wing profile can not be optimized exclusively for the trip flight, since the corresponding aircraft then could neither start nor land.

In the aircraft proposed here, which has VTOL properties and can accomplish both the transition from hovering to dynamic flight, as well as the transition from the dynamic flight to hover independently, the slow-flight characteristics are correspondingly of minor importance. Thus, for an efficient handling of a limited drive energy and for the optimization of the range or the duration of flight, the flight characteristics of the profile of the wing can advantageously be optimized.

Preferably, the wing is optimized exclusively for cruising. This may imply that a slow aerodynamic forward flight with the correspondingly optimized wing is not possible.

The flight time or the range during the cruise are thereby from the

Energy demand determined, which is in addition to the weight centrally dependent on the reciprocal glide ratio. Thus, in the proposed aircraft, the profile polar can be designed specifically so that the smallest profile resistance occurs at the associated c _A value. Other c _A values need not be given much attention in the proposed aircraft. As a result, significantly smaller profile resistances can be achieved than with profile designs that also have to cover other areas (eg take-off and landing). Furthermore, it allows the renunciation of slow flight conditions (with possibly accompanying

Reynolds number problems), to optimize the wing extension in a wide range. A significant increase in the elongation becomes possible and leads to a reduction in the induced resistance and thus to a further improvement in the reciprocal glide ratio.

The aircraft proposed here thus makes possible by its combination of aerodynamic cruise with takeoff and landing in hover an extraordinary aerodynamic quality. This is all the more true because the propellers can be folded in the unpowered gliding flight as a folding propeller aerodynamically favorable to the motor gondolas.

As an energy source for the aircraft are preferably provided in addition to battery cells, a fuel cell or a solar cell. In this way, the flight time can be optimized especially in dynamic flight.

A control device is preferably provided which monitors the state of charge of the on-board accumulators and at the same time monitors the distance for safe return to the starting point. If the state of charge of the accumulators reaches a value which just allows a return to the starting point and a vertical landing, the operator is informed, depending on the operating mode, or the aircraft is returned directly to the starting point and landed there automatically.

In order to further improve the flight characteristics in dynamic flight, at least one pair of rotors is designed as a folding propeller or folding rotor, such that in dynamic flight at least this pair of rotors can be switched off and then folded in order to improve the aerodynamic properties. In a further preferred embodiment, all rotors are designed as Faltrotoren to collapse in a gliding or gliding flight after reaching a predetermined height all rotors can and accordingly further improve the aerodynamic properties in gliding. In this way, a gliding flight can be achieved over very long distances. Due to the above-mentioned optimization of the wing profile, very small sliding angles can be achieved here.

In gliding engine-related or rotor-induced vibrations are no longer transmitted to the aircraft, so here is a monitoring from higher altitudes by means of sensitive optical devices is possible without this with a vibration compensation or a

To equip decoupling. In this way, sensitive optical devices can be relatively inexpensively installed and recorded in the aircraft, since the operation of the aircraft in gliding flight on a vibration compensation can be dispensed with. Thus, the proposed aircraft is particularly well suited for the application for monitoring with sensitive optical devices.

In a further preferred embodiment of the aircraft, a controller is designed so that in dynamic flight after reaching a predetermined altitude above ground, the motors are turned off and automatically a sliding phase is initiated. The control is further preferably designed so that in the gliding flight when a certain minimum height above ground is automatically started the engines and the aircraft is brought into a stable horizontal flight or a climb. The control device is furthermore preferably designed such that, after receiving a corresponding control command, it automatically returns the aircraft to the launch site, carries out the transition there and the aircraft lands vertically.

In a particularly preferred variant, the aircraft is modular. For the modular design, different variants for the equipment of the aircraft and thus also different variants are used. Here, the aircraft can either be used only as a floating platform, in which case the necessary components for the dynamic forward flight can be exchanged, omitted or dismantled.

Accordingly, the takeoff weight when using the aircraft as pure

Suspended platform and accordingly either a longer flight time in the

Hovering be achieved or transported a higher payload. This can be achieved by removing the tail section with the tail units and the disassembly of the outer parts of the rigid wing, so that there is a very compact floating platform. By a corresponding renewed cultivation of the outer wing, for example, the respective outer two-thirds of the wing length, as well as the renewed cultivation of a rear part with vertical and vertical tail, the floating platform can then be rebuilt into the aircraft described above, which is optimized for dynamic horizontal flight , In a further variant, the components mentioned can also be combined to form a conventional surface aircraft, such that the suspension platform module has a

conventional fuselage nose is infected with a single propeller. Furthermore, the four engines are removed together with the left and right engine nacelle. The left and right outer wings are now directly attached to the wing middle part.

In the modular structure can continue by growing different

Outer wing modules are adapted to the floating platform the flight characteristics during dynamic flight operations to the respective task. In particular, here can be different

Wing modules are grown with different wing profiles, which are optimized, for example, for different speed ranges or different altitudes.

Accordingly, slow-flight characteristics can be provided with a correspondingly designed wing profile here, so that monitoring in slow flight is possible. Preferably, the modular aircraft then comprises two different sets of

Outer wings, wherein a first set is optimized exclusively for cruise and a second set also has sufficient slow-flying characteristics, so that a conventional take-off and a conventional slow-speed landing is possible. Due to the modular design can continue to be achieved a small pack size, so that the aircraft can be easily transported to its respective location. Furthermore, an exchange of damaged modules in this way is easily possible.

The use of an electric drive is advantageous for the fast and precise controllability of the rotor speeds. External disturbances can be effectively controlled. For the concept of the rapid control of the thrust or the torque by means of the change in the rotor speeds are accordingly no adjustable propeller necessary. easy

Rigid propellers, which are preferably made foldable for aerodynamic reasons, allow a particularly simple and easy construction of the aircraft.

The electric drive is still compared to conventional reciprocating engines

or turbines, very quiet and is at least at the place of use emission-free. At the same time, brushless electric motors offer extremely high reliability, low complexity and are virtually maintenance-free. Furthermore, brushless electric motors very efficient and light and deliver high performance and high torques over a wide speed range with small dimensions. In this way, on the one hand the

Total mass of the aircraft as well as moments of inertia around the center of gravity are kept small. On the other hand, the very reliable electric motors can be arranged within a motor nacelle with aerodynamically advantageous dimensions.

Brief description of the figures

Preferred further embodiments and aspects of the present invention are explained in more detail by the following description of the figures. Showing:

1 shows an aircraft according to an embodiment of the present invention in a schematic plan view in hover flight;

FIG. 2 shows the aircraft of FIG. 1 in hover in a schematic side view;

Figure 3 shows the aircraft of Figures 1 and 2 in hover in a schematic

Front view;

4 shows the aircraft of the preceding figures in a schematic plan view in aerodynamic horizontal flight;

Figure 5 shows the aircraft of Figure 4 in horizontal flight in a schematic side view;

Figure 6 shows the aircraft of Figures 4 and 5 in horizontal flight in a schematic

Front view;

Figure 7 is a schematic plan view of that shown in the preceding figures

Aircraft during the transition from hover to aerodynamic forward flight;

FIG. 8 shows the aircraft from FIG. 7 in a schematic side view during the FIG

Transition from hover to aerodynamic forward flight; FIG. 9 is a schematic front view of the aircraft of FIGS. 7 and 8 during the transition from hover to aerodynamic forward flight;

Figure 10 is a schematic plan view of that shown in the preceding figures

Aircraft during the transition from aerodynamic forward flight to hover;

Figure 1 1, the aircraft of Figure 10 in a schematic side view during the

Transition from aerodynamic forward flight to hover;

FIG. 12 shows the aircraft of FIGS. 10 and 11 during the transition from aerodynamic

Forward flight in the hover in a schematic front view;

Figure 13 is a schematic representation of an aircraft of modular design showing a floating platform, an aircraft according to an embodiment of the invention and a surface aircraft;

Figure 14 is schematic diagrams of the engine thrust, the carrying capacity of the wing, the

Speed of the aircraft and propulsion of the aircraft during the transition from hover to dynamic forward flight; and

Figure 15 shows schematic diagrams of the engine thrust, the carrying capacity of the wing, the

Speed and propulsion of the aircraft during a transition from dynamic forward flight to hover.

Detailed Description of Preferred Embodiments

In the following, preferred embodiments will be described with reference to the figures. In this case, the same, similar or equivalent elements are denoted by identical reference numerals and a repeated description of these elements will be omitted in the following description in part in order to avoid redundancies.

In the figures 1 to 3 is a schematic plan view, a side view and a

Front view of an aircraft according to an embodiment of the present invention shown. The aircraft 1 comprises a rigid aerodynamic wing 2, which is formed in a manner known in principle. In the illustrated rigid wing 2 is an optimized for aerodynamic flight wing, which provides so much buoyancy from a certain speed, for example, from 50 km / h, that the entire aircraft 1 can be dynamically operated in forward flight.

The wing 2 has an outer wing tip 20 and a connection region 22 to the fuselage 3 of the aircraft 1. Furthermore, ailerons 24 are provided, which serve to control the aircraft in aerodynamic forward flight about the roll axis. Landing flaps 26 are also provided, which act as an air brake.

The wing 2 has a span S, which is formed depending on the application and the desired buoyancy or flight weight. In one example, which corresponds to the schematic exemplary embodiment on which FIG. 1 is based, the aircraft 1 has a span S of approximately 3.4 m.

The hull 3 has a rear part 34 with a tail unit 30, which is formed in the embodiment shown as a V-tail. A design of the tailplane 30 as a T-tail, namely with a separate horizontal stabilizer and rudder is also possible. The nose 32 of the aircraft 1 may include, for example, a camera or other optical and electronic monitoring devices. These monitoring devices can also be arranged in other areas of the fuselage 3, for example between the wings 2. On the wing 2 of the aircraft 1 four rotors 4, 4 'are provided, which are each driven by a separate electric motor 5. The rotors are arranged in pairs, so that there are two forward rotors 4 in the direction of flight and two rotors 4 'in the direction of flight. The electric motors 5 and the rotors 4, 4 'are attached to the wing 2 on corresponding motor nacelles 6. The motor nacelles 6 extend parallel to the hull 3 and provide at their front and rear ends each have a pivot mechanism 7 and thereon recordings for the motors 5 with the rotors 4, 4 'attached thereto. In other words, two electric motors 5 and correspondingly two rotors 4, 4 'are arranged on each motor nacelle 6. The motor nacelle 6 is arranged in the inner third of the wing 2 with respect to its lateral extent and correspondingly with respect to the span S of the aircraft 1. Due to the relatively far-lying arrangement of the engine nacelle 6 on the wing 2, the moment of inertia of the aircraft 1 can be reduced.

In addition, resulting from the arrangement of the motor nacelles 6 on the wing 2 essential structural advantages in the construction of the aircraft 1. The fact that the masses applied by the electric motors 5, the rotors 4, 4 'and the motor nacelles 6 on the aircraft be arranged on the wing 2, the root bending moment can be reduced at the wing root in dynamic flight operation. Accordingly, the spar of the wing 2 can be dimensioned with the same design of the aircraft 1 for a given load multiple with a lower strength. This results in a reduction of the mass of the spar, so that either the payload of the aircraft 1 can be raised, or the efficiency with respect to the use of drive energy is increased.

The rotors 4 together with the electric motors 5, as can be seen particularly well in FIG. 2, can be pivoted upward via a pivoting mechanism 7. The pivoting mechanism 7 can be continuously operated, for example, in each case via servo motors. By using electric motors 5, which have a small dimension, the entire drive can

Electric motor 5 and rotor 4, 4 'are pivoted together, so that can be dispensed with a vulnerable transmission.

In FIGS. 1 to 3, the aircraft 1 is correspondingly shown in a state in which it can perform a hovering flight and accordingly all the rotors 4 are pivoted upwards into a vertical start position, so that the aircraft 1 can start and land vertically as well can perform a hover.

About a not shown here corresponding control of the hover and the start and landing process is automatically checked with respect to the position of the aircraft 1. When applying external disturbances, for example due to wind influences, the aircraft is correspondingly immediately stabilized by the fact that the thrust of the individual rotors compensates for the regulation of their electric motors directly applied the disorder. Since electric motors 5 are used here, very short control rates are possible, for example control rates which are in the range of a few milliseconds. Through the use of 3-axis acceleration sensors, 3-axis Rotation rate sensors, 3-axis magnetic field sensors, a barometric altimeter and GPS can stabilize the automatic control via a fusion of all sensor data

Regulate hover. When landing and starting the thrust of the rotors 4 is adjusted accordingly so that a slow rise or slow sinking of the aircraft 1 is possible with stable attitude.

In hover, the aircraft 1 can be maneuvered by being able to rotate in the air about its vertical axis (yaw axis) by, for example, operating in pairs two of the rotors with an increased thrust and correspondingly reducing the other two rotors by this thrust in total , As a result, the torque applied by the high-thrust rotors is no longer balanced by the other two rotors, so that a corresponding total torque acts on the aircraft 1.

A movement of the aircraft 1 in the hover flight in the forward and backward direction can by appropriate pairwise raising or lowering of the thrust of the front rotors 4 and the rear rotors 4 'and correspondingly complementary lowering

or raising the thrust of the other pair of the rear rotors 4 'and the front rotors 4 can be achieved. As a result, a slight inclination of the aircraft 1 takes place about the transverse axis and it moves due to the applied by the inclination

Horizontal component of the thrust in the direction in which the pair of rotors 4, 4 'is arranged with the reduced thrust. The rotors 4, 4 'are preferably operated in opposite directions, so that the

Torques of the front pair of rotors 4 and the rear pair of rotors 4 cancel accordingly and applied over the rotors on the aircraft 1 total torque in hover equal to zero, so that here a stable hovering position can be assumed. In order to realize the control described above, the rotors are always operated diagonally in opposite directions.

Furthermore, by the arrangement of the four rotors in the example of Figure 1 very well recognizable X-shaped arrangement a good balance of the thrusts with respect to

Mass center of the aircraft 1 reached. The main focus is in In terms of flight mechanics, the area around the center of lift of the wings 2, so that the center of gravity of the lift in dynamic flight coincides with the center of lift in the hover flight to a few millimeters. In this way, the rotors 4, 4 'with the

Electric motors 5 correspondingly dimensioned identically.

The motor nacelle 6 accordingly has an extension in the longitudinal direction which, on the one hand, serves to prevent a collision of the two front and rear rotors 4, 4 'arranged on the motor nacelle 6 with one another. On the other hand, the longitudinal extent of the

Motor nacelle 6, however, also about the corresponding leverage a stable

Suspended platform, which in principle by the between the waves of the

Electric motors 5 registered area corresponds, which allows the most stable flight operation with varying payloads.

In FIGS. 4 to 6, the aircraft 1 known from the preceding figures is now shown in a state in which it is set for forward aerodynamic flight. Accordingly, the front rotors 4 are now folded over the pivot mechanism 7 completely forward and the rear rotors 4 'folded over their pivot mechanism 7 to the rear, so that the thrust is directed so that the aircraft 1 is driven forward. The landing flaps 26, which were extended in the hover position of Figures 1 to 3 in the braking position to ensure a largely undisturbed outflow of the rotor thrust down, are now retracted to optimize the airfoil of the wing 2 for the forward flight.

In the aircraft 1 shown in Figures 4 to 6 is in principle a

Conventional, rigid-wing aircraft with two drive motors, namely the front two rotors 4 with their respective electric motors. 5

The two rear rotors 4 'are folded, since the required power for horizontal flight is significantly lower than for the hover. The required power for the forward flight is only about 5% of the power that is necessary for the hover flight.

The folding in of the rear rotors 4 'improves the aerodynamic properties in forward flight. Preferably, the front rotors 4 may be formed as folding rotors, so that they can also fold in sliding phases. In this way, both the hovering position shown in FIGS. 1 to 3, which results in a stable hovering platform, and a highly efficient dynamic flying in the position shown in FIGS. 4 to 6 can be achieved.

In FIGS. 7 to 9, a specific position of the rotors 4, 4 'of the aircraft 1 during the transition from hover to forward flight is shown. The front rotors 4 are pivoted together with their electric motors 5 via the pivot mechanism 7 gradually forward to apply a forward thrust to the aircraft 1. Thus, the aircraft 1 sets from the hover out in a forward movement in motion and the dynamic buoyancy on the rigid wing 2 takes over from a certain speed the entire lift until the dynamic horizontal flies shown in Figures 4 to 6 due to the aerodynamic buoyancy of rigid wing 2 is achieved. Then the rear rotors 4 'can be switched off and pivoted backwards via the pivot mechanism 7 in an aerodynamically favorable position.

The flaps 26 are both in the hover, as shown in Figures 1 to 3, as well as in parts of the transition still folded in the braking position, inter alia, to the rear rotors 4 'as possible to oppose any turbulence. Accordingly, the thrust generated by the front rotors 4 and rear rotors 4 'in the vertical direction is substantially equal and is not affected by the rigid wing 2.

FIGS. 10 to 12 show a specific position of the rotors 4, 4 'of the aircraft 1 during the transition from the forward flight into the hover flight. The front rotors 4 are pivoted together with their electric motors 5 via the pivot mechanism 7 upwards in order to raise buoyancy can. The rear rotors 4 'are first pivoted in an obliquely rearward facing position so that they can muster both buoyancy, as well as a braking thrust. Thus, the aircraft 1 is braked and the rotors 4, 4 'gradually take over the buoyancy until the aircraft 1 is completely in hover and the hover behavior shown in Figures 1 to 3 is achieved.

FIG. 13 shows a further preferred embodiment of the present invention in that the aircraft 1 has a modular construction. The modular construction of the aircraft 1 is designed so that, as shown for example in Figure 13a, the inner region of the aircraft 1 can be used as a separate floating platform 10. For this purpose, only the four rotors 4, 4 'are then provided with their respective electric motors 5, which are attached via the two motor gondolas 6 to a wing middle part 200. On a rear part of the fuselage 3 is omitted and instead mounted again a nose 32 for more batteries and sensors.

The floating platform 10 shown in Figure 13a corresponds in principle to the X-shaped inner region of the aircraft 1 shown in Figures 1 to 12, which is again shown schematically in Figure 13b, but with the aforementioned modifications. Accordingly, both the drive in the form of the electric motors 5 and the rotors 4, 4 'can be used, as well as the entire control electronics and the power supply, which is used in the aircraft 1. The wings 2 may be at least three parts, so that in each case outer wing 210 can be attached to the wing center part 200, if an aerodynamic forward flight is to be achieved again.

Further components, such as the outer wings 210 and the rear part 34, can furthermore be connected in the embodiment shown in FIG. 13 c to the fuselage module 300, which likewise has the wing center part 200, in order to produce a conventional surface aircraft from the outer wings 210 and the rear part 34 , which then has to be started and landed accordingly in a conventional manner.

Preferably, the modularly constructed aircraft 1 comprises two different sets of outer wings 210, wherein a first set is optimized exclusively for cruising flight and a second set also has sufficient low-speed flight characteristics, so that a conventional take-off and a conventional low-speed landing is also possible.

Due to the modular structure can be achieved with a central element, namely the fuselage module 300 and the wing center part 200, which correspond in principle to the floating platform shown in Figure 13a, and corresponding add-on modules that are provided on the same technological basis both a very flexible floating platform aircraft can, as well as a highly efficient aircraft, which combines the properties of a floating platform with a conventional aircraft surface, as shown in Figure 13b. FIG. 13d shows a variant of the modular aircraft in which the motor gondolas 6 'are not equipped with motors and rotors on their rear side, but merely a sleeve for improving the aerodynamics is attached here. Also, this version of the aircraft shown in Figure 13d must be started and landed conventionally. By the arrangement of

Electric motors 5 and rotors 4 in the motor nacelles 6 ', but a variant can be provided, which allows the trunk module 300 and the nose 32 from a clear view to the front. This may be important in certain applications of cameras or other sensors. Such a clear view to the front is not given in the variant shown in Figure 13c due to the rotor.

FIG. 14 is a schematic diagram of an engine thrust diagram

Carrier wing diagram, a speed diagram and a propulsion diagram shown how the transition from hover to forward flight takes place. At the beginning at time 0, a pivoting of the front rotors 4 begins in the forward direction, such that in addition to the thrust of the rotors, which provide for the lift, simultaneously

Forward component is added. The speed increases slowly, as can be seen from the velocity diagram. The engine thrust must be increased in the short term by about 15%, both to keep the altitude in hover, and to apply the corresponding forward movement, since the buoyancy of the rigid wing 2 is not yet sufficient to take the buoyancy.

As can be seen from the load wing diagram, the lift above the wing only increases significantly after a certain speed after about 2 seconds. Accordingly, the wing profile of the rigid wing 2 is optimized here so that only from a certain

Speed is a sufficient buoyancy. The wing profile is designed accordingly for higher speeds and accordingly a very efficient wing profile with respect to the range of the aircraft. 1

From the propulsion diagram it follows that the aircraft is accelerated in the range of 2 seconds at the strongest, and then this acceleration slowly decreases again.

Figure 15 shows schematically the transition from aerodynamic forward flight in the hover. For this purpose, among other things, the brake flaps are extended to achieve a quick stopping of the aircraft. At the same time, the front rotors 4 of the Horizontal flight position, namely the forward position in which the thrust provides only for forward movement, in the hover position or

Upstroke position pivoted upwards and the rear rotors 4 ', which were turned off in forward flight, are consulted to also provide lift accordingly. The rear rotors 4 'can also provide a brake boost. Accordingly, the aircraft 1 brakes sharply, the carrying capacity of the wing 2 also decreases accordingly, so that the buoyancy is ultimately exclusively on the rotors 4, 4 'is generated.

As far as applicable, all the individual features illustrated in the individual embodiments can be combined and / or exchanged without departing from the scope of the invention.

LIST OF REFERENCES

1 aircraft

10 levitation platform

2 rigid wings

20 wing tip

22 Connection area of the wing

24 ailerons

26 landing flap

200 wing middle part

210 outer wings

3 hull

30 tail unit

32 nose

34 rear section

300 fuselage module

4 front rotor

4 'rear rotor

5 electric motor

6 engine nacelle

7 swivel mechanism

S span

Claims

claims

1. aircraft (1), preferably unmanned aerial vehicle (UAV), drone and / or unmanned aerial vehicle (UAS), comprising a rigid wing (2), which a

aerodynamic horizontal flight, and at least four controllable

Electric motors (5) driven rotors (4, 4 '), which by means of a

Swing mechanism (7) between a vertical start position and a

Horizontal flight position are pivotable, characterized in that all the electric motors (5) and rotors (4) on the wing (2) are arranged.

2. aircraft (1) according to claim 1, characterized in that the electric motors (5) and the rotors (4, 4 ') are provided in an X-shaped arrangement with respect to the longitudinal axis of the aircraft.

3. aircraft (1) according to claim 1 or 2, characterized in that the rotors (4, 4 ') in the vertical start position are all pivotable in the same direction and preferably all the rotors (4, 4') are pivotable upwards.

4. aircraft (1) according to one of the preceding claims, characterized in that a control device for controlling the electric motors (5) is provided so that the aircraft (1) is automatically preserved in a stable hover.

5. Aircraft (1) according to one of the preceding claims, characterized in that a front rotor (4) and a rear rotor (4 ') with the corresponding electric motors (5) via a respective pivot mechanism (7) on one of the wing (2 ) provided motor nacelle (6) are arranged.

6. aircraft (1) according to one of the preceding claims, characterized in that the rotors (4, 4 ') in a region of the wing (2) are arranged with respect to the transverse extent, which between the wing tip (20) and the connection (22 ) of Wing (2) on the hull (3) of the aircraft (1) is arranged, preferably in an inner third between the connection (22) and wing tip (20).

Aircraft (1) according to one of the preceding claims, characterized in that at least the rear rotors (4 ') and preferably also the front rotors (4) are designed as folding rotors.

Aircraft (1) according to any one of the preceding claims, characterized in that the rigid wing (2) has a profile such that it increases the total lift for the aircraft (1) in aerodynamic forward flight from speeds of 50 km / h, preferably at speeds between 70 km / h and 300 km / h, particularly preferably at speeds between 90 km / h and 180 km / h.

Aircraft (1) according to one of the preceding claims, characterized in that the wing (2) is optimized exclusively for cruising.

Aircraft (1) according to one of the preceding claims, characterized in that for the energy supply of the electric motors (5) at least one accumulator, at least one fuel cell and / or at least one photovoltaic solar cell in

or on the aircraft (1) is arranged.

Aircraft (1) according to one of the preceding claims, characterized in that the aircraft (1) has a modular construction and preferably comprises at least one levitation platform (10) comprising the rotors (4) and electric motors (5), to which outer wings (210) and / or a rear part (34) can be attached.

Aircraft (1) according to claim 1 1, characterized in that the modularly constructed aircraft (1) comprises at least two sets of outer wings (210), wherein a first set of outer wings (210) is optimized exclusively for cruising flight and a second set Exterior wings (210) are also suitable for slow flight.