DE102016014309A1 - Throw-catch device for unmanned fixed-wing aircraft - Google Patents

Abstract

The invention relates to a throw-catch device (10) for take-off and landing of a complete and operational unmanned fixed-wing aircraft (6), wherein the throw-catch device (10) an electrically driven multicopter (11) with several in Direction of the vertical axis acting carrier rotors (1) additionally with at least one electrically driven propulsion rotor (2) with a thrust vector in the direction of the longitudinal axis of the multi-opter (11).

Description

The invention relates to a throw-catch device as an aid for the take-off and landing of unmanned fixed-wing aircraft according to the preamble of patent claim 1.

Unmanned aerial vehicles are generally divided into fixed-wing aircraft, such as aircraft, and rotorcraft, such as helicopters, also called "helicopters". Depending on the purpose of one or the other design is more advantageous.

Thus, the fixed-wing aircraft has the advantage of lower energy consumption in flight. Airplanes for long flight durations are therefore always fixed-wing aircraft. But these have the disadvantage that they are carried only by aerodynamic buoyancy of their wings, so at start and landing for the lift generation must have a horizontal speed through the air. In this respect, they either need a runway and a corresponding rollability, or they have to be started and landed with special aids. Common launchers are catapults or booster, landing parachutes with floor-mounted dampers, such as deformable elements, airbags, or trapping systems, such as net or rope systems. Practical main meaning have the launch catapult and the landing net, with a parachute as an emergency landing system.

Launch catapult and landing net but have relatively large sizes, so that usually at least the landing net, but often also the launch catapult is tied to a vehicle. As a result, the total cost of using such an unmanned aerial vehicle consists of several vehicles. For use, equipment must be built or deployed with a time overhead that limits the responsiveness of the system.

In contrast, the rotorcraft for takeoff and landing without bottom-side infrastructure, such as a runway, and thus without tools in a position. Its disadvantage, however, is compared to the fixed-wing aircraft higher energy consumption in flight, so that the flight time is reduced.

On the basis of this fundamental difference between the two types of aircraft, there has been a difference in the operational techniques for the mission flight. Basically, all of these propulsion techniques are based on the recoil of moving gas masses, either air in propellers and rotors, or combustion exhaust gas in jet engines, or a combination of both forms in so-called turbofan engines. The basic design of the drive unit is thus a thruster.

In principle, a single thruster with a thrust direction parallel to the longitudinal axis of the aircraft corresponding to a single-engine aircraft is sufficient for a fixed-wing aircraft. For reasons of reliability, at least two such thrusters are also common. In the case of unmanned fixed-wing aircraft in the weight class below those of manned aircraft, propulsion engines driven by thrust engines have become commonplace. The energy source is usually a hydrocarbon liquid fuel, e.g. Gasoline.

Basically, a rotorcraft with a single acting in the vertical axis thruster (support thrust) and smaller auxiliary thrusters for the application of torque (control thrust) is sufficient. In this case, the combination of support thrust and control thrust is common, in the form of rotors whose propeller blades are rotated periodically controlled during their rotation; However, the required so-called rotor heads are mechanically complex arrangements. Alternatively, thrusters can be pivoted as so-called tilt rotors as a whole, but again with the consequence of mechanical complexity.

Technological advances in the field of power density of electric motors and the energy density of batteries have led to the development of so-called multicopters, derived from the compound word helicopters, which use only electrically driven rotors, usually in a rigid arrangement and without adjustable rotor blades. Common arrangements of 4, 6 and 8 rotors, according to the notation as quadro-, hexa- and octocopter. These rotors are usually coplanar, d. H. the axes of rotation of the rotors are parallel. The power supply of the rotors is made of batteries. The trajectory control of the multicopper is carried out by the same direction increase or decrease in the thrust forces of the individual electric motors to control the thrust and by increasing or decreasing the thrust forces of the individual electric motors to generate control moments about the three spatial axes.

In practice, electric multicopters with payloads up to a weight of people with flying endurance have been built up to about half an hour.

Combinations of fixed-wing aircraft and rotary-wing aircraft have been proposed in many different ways in order to combine the advantages of fixed-wing aircraft with those of rotary-wing aircraft.

From the DE 10 2015 000 703 is an electrically driven, additive (removable) vertical take-off and landing aid (Vertical Take-Off and Landing - VTOL) described for fixed-wing aircraft, supplemented by an equally additive (removable) electrically driven horizontal thrust assembly, thus avoiding tilt rotor thrust units in the vertical take-off and landing assistance, ie all thrust units are rigidly mounted on fixed-wing aircraft , Such that only their propeller rotors about their axes of rotation in pivot bearings, z. B. ball bearings, are movable, all other components are firmly connected to the aircraft.

The consequence of all these measures, however, is that the electrical VTOL equipment of the internal combustion-powered fixed-wing aircraft must be "dragged along" during the entire flight, ie the flight duration or operational range of such aircraft is limited.

From the Article "Quadcopter Performs ScanEagle Mid-Air Launch and Recovery", UAS Vision, November 2015 is a quadcopter-assisted launch aid for fixed-wing aircraft is known, which transports the suspended fixed-wing aircraft from the ground to a height above ground, in which the fixed-wing aircraft can be unlatched without risk of contact with the ground, so that it goes under its own drive thrust in the horizontal flight. The same quadrocopter is used in the alternative for the landing of the fixed-wing aircraft, wherein this landing is carried out regularly by means of a safety rope, which is mounted vertically on the ground by a bottom-fixed crane arm. The fixed wing aircraft flies during landing targeted to the safety rope, which slides during the collision along an airfoil edge to trigger a squeegee at the tip of the wing, so that the fixed-wing aircraft claws to the safety rope. This method is modified so that the quadrocopter replaces the crane arm, that is to say the safety cable is tensioned approximately vertically between a base-side fixing and the quadrocopter.

Disadvantages of the aforementioned starting method is that a minimum height for the notching of the fixed-wing aircraft is required and that structural modifications must be made to the fixed-wing aircraft in order to enable the detachable suspension on the quadrocopter. Disadvantages of the landing method described are the high structural dynamic tensile loads of the effective wing at the rope capture and the need for precise positional position of the quadrocopter in the rope tension and the precise guidance of the fixed wing to the safety rope. Furthermore, it is disadvantageous that the quadrocopter must be retrofitted on the bottom side after the start until the landing of the fixed-wing aircraft on the holder of the fishing line.

• (a) die einem unbemannten Starrflügler-Fluggerät, nachfolgend Starrflügler genannt, VTOL-Eigenschaften verleiht, ohne dass die entsprechenden Gerätschaften im Einsatzflug von dem Starrflügler mitgeführt werden müssen,
• (b) die dennoch bodenseitige Großgeräte wie Startkatapult und Landenetz vermeidet,
• (c) und die im Betrieb keine weiteren bodenseitigen Gerätschaften benötigt, letztlich also eine Anordnung zu schaffen, die ein Starten und Landen eines Starrflüglers besonders effizient durchführen kann.

The present invention has for its object to provide an arrangement,

• (a) imparts VTOL characteristics to an unmanned fixed wing aircraft, hereafter referred to as fixed wing aircraft, without having to carry the corresponding equipment in the mission flight of the fixed wing aircraft;
• (b) which nevertheless avoids large-scale ground equipment such as launch catapult and landing net,
• (c) and in operation requires no further bottom-side equipment, so ultimately to provide an arrangement that can perform a start and landing a fixed-wing aircraft particularly efficient.

The stated object is solved by the subject matter of patent claim 1. Advantageous embodiments of the throw-catch device according to the invention are the subject of the dependent claims and will become apparent from the following description of the invention.

According to the invention designed as a throw-catch device arrangement in the design of an electrically driven multicopper with multiple support rotors in the direction of the vertical axis acting and equipped with at least one additional electrically driven propulsion rotor with the thrust in the direction of the longitudinal axis.

• – nach dem Start von einem vorgegebenen Startplatz und der Beschleunigung in den Horizontalflug zum eigenständigen Flug freizugeben, d. h. zu starten, und
• – im Streckenflug nahe einem vorgesehenen Landeplatz in der Luft im Fluge aufzugreifen, als Nutzlast zu fixieren und an dem Landeplatz zu landen.

This throw-catch device is able to carry a complete fixed-wing aircraft as a payload and this

• - to release after the start of a given starting position and the acceleration in the level flight for autonomous flight, ie to start, and
• - to catch in the air near a designated landing site in the air, fix it as a payload and land it at the landing site.

In addition to the aforementioned advantages of the invention, it is advantageous that the two maneuvers for takeoff and landing of the fixed-wing aircraft can be carried out in practice within a short time of a maximum of a few minutes, thus with time reserve to the flight duration capacity of electric multicopters specified by the prior art (currently about half an hour).

This reserve means a usable technical power reserve, which allows to optimize the throw-catch device constructive in terms of the reception of fixed-wing aircraft, without at the same time having to make special demands on the aerodynamic drag of the overall arrangement; the aerodynamic aspect is secondary here. As a result, the throw-catch device can be designed so that it can start and land not just one, but alternatively several different types and types of fixed-wing aircraft without structural change. This possibility is particularly advantageous if technically developed versions of fixed-wing aircraft are to be operated without a technical change to the throw-catch device.

The feature of the additional propulsion rotors has the advantage that in horizontal flight, the spatial position of the throw-catch device may be horizontal despite high airspeed, while a multicopter without such additional horizontal thrust drive for horizontal flight tilt its position in the direction of flight (assume a pitch angle nonzero ) to provide the thrust vector component required for forward flight to overcome the aerodynamic drag; the application of this thrust is according to the invention the horizontal shear drive.

Conveniently, the electric horizontal thrust drive of the throw-catch device is designed with a thrust reserve, which allows the throw-catch device to have a speed reserve against this when capturing the fixed-wing aircraft and thus speed differences in all three coordinate directions during the maneuver and to be able to compensate for the effects of local air turbulence, so that the trapping and fixing of the fixed-wing aircraft with a low relative speed, i. H. done without damage.

Of course, the capture of the fixed-wing aircraft is easiest when it is in a straight-line flight. His cooperation with the throw-catch device is not required.

Advantageously, the multicopter of the throw-catch device with at least one additional electrically driven pushing rotor, with the thrust force acting in the direction of the transverse axis, equipped, namely to the right or left, d. H. with positive or negative thrust direction sign. This lateral drive allows lateral movements of the Multikopter without having to change its spatial position; without such a lateral drive lateral movements would require the change of the spatial position about the longitudinal axis (roll axis), so that a component of the along the vertical axis upward support thrust can be effective laterally; however, this can be undesirable because it causes rotational side shifts of components of the capture system.

According to another development of the multicopter is designed so that this is the fixed-wing aircraft in the essay from the upper half-space, d. H. Carries "piggyback". This feature has the advantage that the fixed-wing aircraft can be lifted off the multicopter after landing or maintained in its regular operating position on the multicopter as an auxiliary "bearing block" and possibly prepared for a new mission flight.

According to an advantageous development, the multicopter has a funnel-like, preferably realized by oblique guide rods guide device by means of which the seated fixed-wing aircraft from the upper half-space coming passive in the holding position and -raumlage is mechanically passable. When starting the accelerated to sufficient aerodynamic wing lift fixed wing aircraft is released for independent onward flight that existing fixations of the fixed-wing aircraft are released and then actively the speed of the multi-opter is changed so that the fixed-wing due to its inertia peel passively from the multicopter.

Advantageously, the multicopter is alternatively designed so that this the fixed wing aircraft in picking up from the lower half space, d. H. as a suspended, so attached below load. This feature has the advantage that the fixed-wing aircraft can be deposited after landing, for example, on a bearing block, maintained and possibly prepared for a new mission flight.

When landing for landing the throw-catch device flies, for example with a speed surplus and precise track guidance of the fixed wing aircraft from behind or from below, so that the fixed-wing aircraft is guided by the guide device in its holding position on the throw-catch device. After being locked, the fixed-wing aircraft is transported to the landing area as a payload of the multi-copter. Alternatively, the multicopter can sit in front of the fixed-wing aircraft and brake easily, so that the fixed-wing aircraft flies from behind into the multicopter and can be fixed and locked there. This fixation and locking takes place as soon as the fixed-wing aircraft is in its capture position in the catch volume of the multicopter.

Advantageously, the multicopter has an electronic maneuver control unit, with which the trajectory maneuver of the multi-copter for capturing the fixed-wing aircraft via a trajectory control. This device evaluates the location and speed differences of both the multicopter and the fixed-wing aircraft, and executes the capture maneuver either automatically or with the assistance of a ground-based remote operator. With regard to the information technology and tax technical effort, the capture maneuver (capture) is technically more demanding than the starting maneuver (litter); in the former case of capture, the local and speed difference must be in a closed loop be brought to zero between the two flying objects to allow the capture and the fixation and locking of the fixed-wing aircraft; in the second case of the throw for the start, on the other hand, a simple control procedure without a closed loop is sufficient: If the speed relative to the air and the height above ground are sufficient, the fixed-wing aircraft can be released for autonomous onward flight.

An analogy to the operation of the throw-catch device is the throw of a light model aircraft with the hand and the capture of such an approaching aircraft by hand.

The differences in the technical complexity of throwing and trapping can be found in unmanned fixed wing aircraft in the net or Fangseillandung against the catapult start again: the catapult start is a simple throwing process without control loop; the net or Fangseillandung, however, requires a control circuit for compliance with a predetermined nominal trajectory, which leads into the middle of the safety net or to a safety rope, so that the net or safety rope purely passive can cause the deceleration of the flown fixed wing aircraft.

According to a development of the multicopter for transport and storage is zerleg- or einfaltbar. This saves space in handling, in particular during transport, without restricting the size of the multicopter in the unfolded operating state.

Advantageously, the multicopter has landing legs on which preferably landing gear wheels are located. In this way, a movement on the ground in a simple manner possible, either by hand or by driving and steering wheels.

Embodiments of the invention will be explained in more detail with reference to the drawing. Show it:

1 a schematic plan view of an inventive arrangement of a throw-catch device in the form of a multi-copter with attached fixed-wing aircraft;

2 a schematic side view of the arrangement according to 1 ;

3 a schematic front view of the arrangement according to 1 ;

4 a schematic perspective view of the arrangement according to 1 ; and

5 a schematic side view of an alternative arrangement for the horizontal throw and catch, shown here in the operating state of the catch.

A throw-catch device 10 is in the in the 1 to 5 shown embodiment in the form of a multi-opter 11 , as a left-right symmetric octocopter, with eight vertically acting electrically driven carrier rotors 1 educated. The carrier rotors 1 each have a propeller 12 and an electric motor 13 on. As far as applicable, the propeller circuits are shown, otherwise the propellers. Furthermore, on the multicopter 11 two horizontally acting propulsion rotors 2 and four laterally acting electric thrust drives in the form of thrust rotors 3 intended. Also the propulsion and the thrust rotors 2 . 3 each have a propeller and an electric motor.

The eight carrying rotors 1 , the two propulsion rotors 2 and the four side-acting push rotors 3 are on a support frame 4 attached. Four on the rack 4 fortified landing legs 5 provide the floorstand for the distance to the ground 14 and for stability. The bottom ends of the landing legs 5 are shown here as disc-shaped structures. According to another embodiment, the landing legs are located at the bottom ends 5 Chassis wheels (not shown).

A fixed wing aircraft 6 is according to the illustrated embodiment on the multicopter 11 , in particular on its support frame 4 held and fastened. The guide rods 7 are flexurally elastic in their upper part and provided with a lubricious coating.

This is on the throw-catch device before take-off 10 mounted fixed-wing aircraft 6 by a funnel-like, in this embodiment by four oblique guide rods 7 realized guide device coming from the upper half-space passively mechanically conductive in the illustrated holding position and -raumlage. This holding position is defined by the four angle corners resulting from the connection of the wings to the fuselage and also by damping cushions 8th and 9 for the wings and stern of the fixed-wing aircraft 6 , The cushioning pads 8th . 9 Serve not only as position stops but also to dampen a possible collision impact when inserting or when capturing the fixed wing aircraft 6 ,

At take-off, the fixed-wing aircraft becomes 6 with already started combustion engine through the throw-catch device 10 transported vertically upwards and simultaneously accelerated horizontally, namely to a safe height above ground obstacles and to a horizontal speed, wherein the aerodynamic lift of its wings the fixed wing aircraft 6 independently carries; the Support function of the throw-catch device 10 So it will not be needed anymore. That's why it gets off the fixed wing aircraft 6 separated. This is done in such a way that while maintaining the horizontal speed and the spatial position of the throw-catch device 10 the thrust of its carrying rotors 1 is lowered. As a result, the throw-catch device sinks 10 under his weight. Subsequently, the fixed-wing aircraft comes 6 passively from the guide device of the guide rods 7 free and is henceforth in independent flight. The launch of the fixed-wing aircraft 6 is finished. The throw-catch device 10 returns to its initial ground position and lands there.

To land the fixed wing aircraft 6 the throw-catch device rises 10 from the ground up and on a trajectory, which is approximately the same as the trajectory of the fixed-wing aircraft 6 with the difference according to a first embodiment that the throw-catch device 10 at a small safety distance directly under the fixed wing aircraft 6 flies.

By operating at high cut-off frequency controllers (controllers) of the electrical carrying rotors 1 , the propulsion rotor 2 and the laterally acting thrust rotors 3 the leadership of this parallel trajectory of the throw-catch device takes place 10 with high precision, through in the 1 to 4 not shown optical or electromagnetic sensors for the relative position to the fixed-wing aircraft 6 , The goal is the guiding device with its guide rods 7 exactly below the four angle corners of the fixed-wing aircraft resulting from the connection of the wings to the fuselage 6 bring to. Once the relative position to the fixed-wing aircraft 6 within a given fault tolerance, capture takes place: the throw-catch device 10 automatically increases the thrust of the carrier rotors 1 under exact retention of space and speed. This increases the throw-catch device 10 and brings the fixed-wing aircraft from below 6 in the area of the guide rods 7 , so the fixed-wing aircraft 6 passively guided to its holding position. This capture process is smooth by the active control of the throw-catch device 10 and by the passive mutual force effects between the throw-catch device 10 and the fixed-wing aircraft 6 that have comparable masses. A cooperation on the part of the fixed-wing aircraft 6 not done. This is how the fixed-wing aircraft becomes 6 in the guide device consisting of the guide rods 7 taken, centered by this and finally locked in the stop position. The trapping process is completed as soon as the fixed-wing aircraft 6 the cushioning pads 7 and 8th touched. At this time, the drive motor of the aircraft 6 shut off and the speed of the throw-catch device 10 by reducing the thrust of the propulsion rotors 2 lowered. With the thus captured fixed wing aircraft 6 flies the throw-catch device 10 now to the landing site and lands there.

Not shown are movably designed locking elements that the fixed wing aircraft 6 During the take-off maneuver, hold onto the independent flight and after the landing gear has been caught, fix the fixed-wing aircraft that has reached the stop position.

5 schematically shows an alternative two-part spreader fork-shaped guide device 15 (right / left) into which the fixed wing aircraft 6 with the wings centered around the fuselage, slid in horizontally from behind.

At the start, the throw-catch device rises 10 with the fixed-wing aircraft 6 and tempered combustion engine at safe altitude over ground obstacles and accelerates at the same time for the aerodynamic Eigentragfähigkeit the fixed-wing aircraft 6 required speed. Now the fixed wing aircraft becomes 6 from his lock on the throw-catch device 10 solved. Then the throw-catch device accelerates 10 , The no longer locked fixed wing aircraft 6 can in the guide device 15 horizontal slide and thus performs the lack of traction acceleration of the throw-catch device 10 not with. So it slides backwards out of the guide device 15 out and is then in self-contained flight. The throw-catch device 10 returns to its initial ground position and lands there.

To catch the throw-catch device goes 10 on a trajectory that is approximately the same as the trajectory of the fixed-wing aircraft 6 , with the difference according to a second embodiment, that the throw-catch device 10 at a small safety distance directly in front of the fixed-wing aircraft 6 flies. Once a precise relative position is achieved, the throw-catch device automatically reduces the thrust of the propulsion rotors 1 under exact retention of the spatial position and altitude. This slows down the throw-catch device 10 and brings, coming from the front, the fixed-wing aircraft 6 in the area of the guide forks 16 the guide device 15 , so the fixed-wing aircraft 6 passive mechanically slides into its holding position and is locked there. The trapping process is finished. Now the drive engine of the fixed-wing aircraft 6 off. With the captured fixed wing aircraft 6 flies the throw-catch device 10 to the landing field and lands there.

Also in 5 are movably designed locking elements not shown, the fixed wing aircraft 6 at the start maneuver until the release for to hold the flight on its own and after catching the fixed-wing aircraft 6 for landing, fix the fixed-wing aircraft that has arrived at the stopping position.

Thus, a throw-catch device is created that can very efficiently start and capture a fixed-wing aircraft and land with it.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015000703 [0012]

Cited non-patent literature

• Article "Quadcopter Performs ScanEagle Mid-Air Launch and Recovery", UAS Vision, November 2015 [0014]

Claims (8)

Throw-catch device for take-off and landing of a complete and operational unmanned fixed-wing aircraft ( 6 ), characterized by an electrically driven multicopter ( 11 ) with several acting in the direction of the vertical axis support rotors ( 1 ) and additionally at least one electrically driven propulsion rotor ( 2 ) with a thrust vector in the direction of the longitudinal axis of the multi-opter ( 11 ). Throw-catch device according to claim 1, characterized in that the multicopter ( 11 ) additionally at least one electrically driven thrust rotor ( 3 ) with the thrust force acting in the direction of the transverse axis and although optionally to the right or left acting ie having a positive or negative thrust direction sign. Throw-catch device according to claim 1 or 2, characterized in that the multicopter ( 11 ) the fixed-wing aircraft ( 6 ) in the essay, ie "piggyback" carries. Throw-catch device according to claim 3, characterized in that the multicopter ( 11 ) a funnel-like, preferably by oblique guide rods ( 7 ) realized by means of the subsequently seated fixed-wing aircraft ( 6 ) coming from the upper half-space passive in the holding position and space position is mechanically conductive. Throw-catch device according to claim 1 or 2, characterized in that the multicopter ( 11 ) the fixed-wing aircraft ( 6 ) carries as below attached load. Throw-catch device according to one of the preceding claims, characterized in that the multicopter ( 11 ) has an electronic maneuver control unit, which by evaluating the location and speed differences of both those of the multi-opter ( 11 ) as well as the fixed-wing aircraft ( 6 ) the trajectory maneuver for capturing the fixed-wing aircraft ( 6 ) controls. Throw-catch device according to one of the preceding claims, characterized in that the multicopter ( 11 ) is dismantled or foldable for transport and storage. Throw-catch device according to one of the preceding claims, characterized in that the multicopter ( 11 ) Landing legs ( 5 ), on which are preferably suspension wheels.

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