DE102015218473A1 - Separable airfoil for an aircraft, aircraft with separable airfoil and method of landing such an aircraft - Google Patents

Abstract

There is disclosed an airfoil (110) for an aircraft (100) comprising at least two airfoil components (111-113) arranged in the longitudinal direction of the airfoil (110) and connected together. Further, the support surface (110) each includes a connection unit (301, 302) between two adjacent wing components (111-113) for releasably connecting the two adjacent wing components (111-113) and a control system (150) adapted to be in front of Landing of the aircraft (100) to at least one connection unit (301, 302) to send a release signal. The at least one connection unit (310, 302) is set up to release the connection of the two adjacent wing components (111-113) upon receipt of a release signal.

Description

The invention relates to a wing for an aircraft, an aircraft with such a wing and a method for landing such an aircraft. In particular, the invention relates to a wing with distributed mass, which find use in large, extremely light aircraft.

Aircraft capable of operating at very high altitudes, for example above 15,000 m, must have very large wings to generate enough lift. For efficient flying in the stratosphere, the wing must also have a large extension. On the other hand, the entire aircraft should be very light and still be able to carry a sufficient payload. These diverging conditions are met by so-called HALE (High Altitude Long Endurance) aircraft, such as HAPS (High Altitude Pseudo Satellite) aircraft. These aircraft have spans of 25 m and more at very low weight. However, landing such filigree aircraft involves the risk of destroying the wing, especially when the wing first touches the ground.

To ensure a safe landing, a very level runway is necessary. This should ideally be oriented so that it lies downwind while landing. Only so is a uniform landing, the aircraft is simultaneously on the entire width of the main wing, feasible. However, this limits the possible span of the aircraft and also places very high demands on the weather conditions and selection of the runway.

The invention is directed to the object of providing a support surface for such aircraft, with which a safe landing of the aircraft is made possible.

This object is achieved by a wing with the features of claim 1, an aircraft according to claim 8 and a method for landing an aircraft with the features of claim 9.

An aircraft airfoil comprises at least two airfoil components arranged one behind the other in the longitudinal direction of the airfoil and interconnected. In this case, in each case a connection unit between two adjacent wing components for releasably connecting the two adjacent wing components may be arranged. Furthermore, the support surface comprises a control system which is set up to send a release signal to at least one connection unit prior to a landing of the aircraft, wherein the at least one connection unit is arranged to release the connection of the two adjacent wing components upon receipt of a release signal.

The longitudinal direction of the support surface is substantially perpendicular to the direction of flight. The two adjacent wing components connected by the connecting unit meet at two opposite abutment surfaces - preferably end faces - of the respective wing components. The abutment surfaces can be perpendicular to the longitudinal direction, ie parallel to the direction of flight, whereby any edges on the collapsed abutment surfaces produce the lowest air resistance.

The subdivision of the wing can be done on existing structural joints. For example, portions of the wing may be disposed at an angle to other portions of the wing. At the locations where the wing is bent or angled, a corresponding connection unit can connect the two adjacent wing components together.

Furthermore, the subdivision of the wing does not have to cause a symmetrical division of the wing. Rather, depending on the aircraft structure, the subdivision can be effected as often as desired and at any desired points symmetrically or asymmetrically. In a preferred embodiment, the support surface consists of at least three wing components, wherein a wing component is arranged centrally above the fuselage of the aircraft. This central wing component also remains on the fuselage of the aircraft after the other wing components have been released. Thus, only the "ends" of the wing are released before a landing. Of course, two adjacent wing components may also butt against each other on the fuselage of the aircraft and be detachably connected to a connection unit. In this case, the fuselage of the aircraft may also be detached from the two wing components prior to landing and land separately from all wing components. Since the payload is mainly attached to the wings, so the protection of the payloads can be increased.

By loosening the wing components, the overall span is reduced such that landing of a wing portion (on the runway or runway) has less leverage on the overall structure of the aircraft or on the detached wing portion. This will cause an uncontrolled breakup or other destruction the wing avoided - but at least greatly reduced.

Further, the control system may be configured to transmit the release signal in response to an altitude over ground or as a result of manual triggering of an operator of the aircraft. For example, the release signal can be triggered and transmitted at a height of 2 m or a height of 1 m. When the wing components are released at such low altitude, there is a high probability that the individual wing components can land safely. Alternatively, the aircraft can also be separated at a greater height, so that the items can be flown separately to the same landing site or to different landing sites.

The altitude can be measured by at least one corresponding sensor and transmitted to the control system for further processing. Such a sensor may be a radar sensor, lidar sensor, ladar sensor, camera or other sensor. Furthermore, a satellite-based system, such as a GPS sensor, find use. However, the exact height of the runway in the GPS coordinate system must be known. If the aircraft is already equipped with at least one such sensor, for example for monitoring the earth's surface, this sensor can be used to measure the distance between the aircraft and the ground (runway, runway).

In a preferred embodiment of the support surface, the at least one connection unit comprises a holding device, which causes the connection of the two adjacent airfoil components, and a release device, which releases the connection of the two adjacent airfoil components upon receipt of the release signal.

The holding device may comprise at least one rope. For example, a rope may hold together two adjacent wing components in which it is attached to respective fixations on each of the two wing components. Advantageously, matching, interlocking shapes are provided on two wing components to be joined together. For example, pins or bolts and corresponding receiving openings can be arranged on the two wing components. These intermeshing shapes may be disposed on the abutting end surfaces of the two adjacent airfoil components. Thus, the two wing components are secured against displacement (perpendicular to the longitudinal direction of the wing components). The at least one cable is attached to each of the two adjacent airfoil components and is preferably under tension so that the abutting surfaces of the two airfoil components are pressed together.

Alternatively or additionally, the holding device may comprise at least one connecting bolt and / or a detonating bolt. Each bolt is guided through at least one bracket on a first of the adjacent wing components and at least one bracket on a second of the adjacent wing components. The bolt is preferably arranged parallel to the abutting surfaces of the wing components or perpendicular to the longitudinal direction of the wing components.

The release device may comprise a cutting device. This is particularly advantageous if the holding device consists of a rope and the cutting device severed the rope. The cutting device can be mechanically operated. But it can also be a pyrotechnic cutting device. Such encapsulated blasting mechanisms are also used, for example, in a "Cypress Cutter ™".

In the event that the holding device comprises a (stronger) connecting bolt, the release device may comprise an actuator which is adapted to move the connecting bolt from a holding position to a release position. The actuator can exert a tensile or compressive force on the connecting bolt, so that it is pulled or pushed from at least one holder on a wing component. As a result, at least one mount belonging to one of the adjacent wing components can become free, so that this wing component separates from the other adjacent wing component.

Alternatively, the release device may comprise a pyrotechnic cutting charge or explosive charge that cuts through the connecting bolt. By severing the connecting bolt also a holder of the adjacent wing components is free. A cutting charge or explosive charge is particularly advantageous when space or weight reasons an actuator can not be installed to release the connecting bolt.

There may also exist a connecting element between the wing components, which is destroyed, for example, by a blast / cutting charge and thus the wing components are separated from each other. The connecting element can thereby releasably, for. B. by screws, be attached to both wing components. The connecting element is then a wearing part, which is replaced after each landing.

Furthermore, the connection unit may comprise a spring element. The spring element is designed so that it exerts a compressive force on the adjacent wing components. For example, the spring element can push apart the abutting surfaces of the adjacent wing components. As soon as the holding device is released (removed) by the release device, the adjacent wing components can be forced apart by the spring element and thus be better detached from one another. Alternatively, a pyrotechnic release device may be designed so that it also repels one of the adjacent wing components from the other during release of the connection.

The connection unit may be attached to one of the two adjacent airfoil components so that it remains on one airfoil component after the release of the two adjacent airfoil components. Thus, the connection unit can be reused and / or restored. In the event that a spring element is present, this may be attached as part of the connection unit to a wing component. Alternatively, the spring element may be arranged on the second of the adjacent wing components, so that the wing component without connecting unit repels the wing component with connecting unit. Advantageously, this is an outboard wing component that is farther from a main structure of the aircraft.

Optionally, the airfoil may include a stabilizer on each of the at least two airfoil components, each airfoil configured to stabilize a pitch angle of the associated airfoil component. This allows a sliding of a detached (separated) wing component. For weight reasons, such a tail can be made very small. Furthermore, the tail can be folded out of the wing or moved out. An associated mechanism can be triggered with the release signal. By way of example, an actuator of a connecting bolt and / or a spring element can be used to provide the necessary force for folding out or retracting the tail.

The wing may also be designed so that each wing component includes its own tail, which also contributes to the stabilization of the entire aircraft during normal flight operations. Thus, an aircraft of the type described above may include a plurality of small tail units rather than a large main tail unit. Alternatively or additionally, a main stabilizer can be designed controllable, so that the aircraft can be controlled. The tail of the other wing components can be controllable but also rigid (non-controllable) configured.

Also optionally, the support surface may further comprise a drive unit on at least one or each of the at least two airfoil components, each drive unit being configured to propellably fly the associated airfoil component in the disconnected state. The propulsion unit (s) may provide propulsion of the aircraft during normal flight operations. Due to the presence of a drive unit on each wing component each separated wing component can be kept airworthy at least for a safe landing.

In another aspect, an aircraft may include a wing as described above. This is suitable for so-called HALF aircraft (High Altitude Long Endurance aircraft), such as HAPS (High Altitude Pseudo Satellite) aircraft. These are characterized by the fact that the mass of the aircraft is concentrated mainly in the wing and evenly distributed along the span.

The concentrated along the wing spar mass distribution requires that occur in normal flight almost no bending and torsional moments on the main spar of the wing. This special weight distribution along the wing makes it possible to separate individual wing components without the aircraft getting into an unstable attitude. Furthermore, the individual components of the aircraft and in particular the dissolved wing components can be landed safely separated. The divided into several components bearing surface has just at the joints on or only very small bending and torsional moments, whereby after disengagement of the wing components each wing component is in balance. The wing components detached from each other can thus each land safely. This can be done in controlled or uncontrolled gliding flight or partially supported by a drive unit on at least one wing component. An airfoil component alone may also form an unstable configuration and fall (in autorotation) to the ground. Due to the low weight with suitable substrate, no damage occurs. Optionally, gliding or powered flies are enhanced by a stabilizer on each wing component.

Due to the separate landing of the wing components is the construction of even larger aircraft (with even larger spans) of the type mentioned above possible. The selection of certain landing fields for these aircraft is no longer limited. For example, now also (slightly uneven) runways, grassy runways, runways with a similar natural or artificial surface or water can be used. Also, landing on floating platforms is made possible because on these platforms a flat runway (in the long run) can not be guaranteed mostly.

In accordance with another aspect of the present disclosure, a method of landing an aircraft includes the steps of: outputting a release signal to at least one connection unit provided between two adjacent wing components; and releasing a connection between the two adjacent airfoil components caused by the at least one connection unit.

In this case, the issuing of a release signal may include determining an altitude of the aircraft over ground, comparing the determined altitude with a threshold value and outputting the release signal if the determined altitude coincides with the threshold value.

The release of a connection can be done by severing a rope, moving a connecting element from a holding position to a release position or pyrotechnic severing a connecting element. Also, the severing of the rope can be done by a pyrotechnic cutting device.

The method may further include controlling each of the disengaged airfoil components to land each of the airfoil components separately. The controlling of each individual wing component may include stabilizing a pitch angle and / or a roll angle of the wing component and / or a driving of the wing component.

Preferred embodiments of the invention will now be described with reference to the accompanying schematic drawings, which are given in FIG

1 a schematic representation of an aircraft with a support surface of at least two wing components shows, and

2 a schematic representation of various connection units on a collision surface of a wing component shows.

1 schematically shows a plan view of an aircraft 100 with a wing 110 consisting of at least two wing components 111 . 112 . 113 and a landing operation of such an aircraft 100 , The wing 110 puts on this aircraft 100 the relevant supporting structure. In this type of aircraft, the wing 110 at a span of about 25 m just come to a weight of 20 kg. A payload (energy system, avionics, propulsion and payload) of a maximum of approximately 25 kg (total mass approx. 50 kg) is distributed evenly over the span. Of course, you can also use aircraft 100 are made with larger (and smaller) spans according to the principle of the present disclosure.

Next to the wing 110 includes the aircraft 100 another hull or body 120 , perpendicular to the wing 110 is arranged. In flight direction at the rear end of the body 120 there is a tail unit 121 , causing the aircraft 100 is controllable. An alternative is also an education of the aircraft 100 conceivable in a Nurflügelkonfiguration.

The wing 110 exists in the in 1 illustrated embodiment of a total of three wing components. A first wing component 111 is centered on or on the trunk / body 120 arranged. A second 112 and third 113 Wing components are arranged in the longitudinal direction of the wing and in each case with the first wing component 111 connected. Of course, the wing can 110 consist of more or less than the illustrated wing components. For example, the wing tips at the outer ends of the wing 110 be designed as independent wing components. Thus, a non-payload wing section may also constitute a wing component in accordance with the present disclosure.

The second and third wing component 112 . 113 is in each case with the first wing component 111 via a connection unit ( 2 ; 301 . 302 ) connected. The connection unit described in more detail below 310 . 302 may be respectively adjacent wing components 111 . 112 . 113 releasably connect.

This includes the aircraft 100 a control system 150 which is prior to a landing of the aircraft 100 to at least one connection unit sends a release signal. The control system 150 can be on / in the hull 120 or on / in the wing 110 to be appropriate. Furthermore, the control system 150 emit a release signal as a function of altitude above ground. Alternatively, the release signal can also be triggered manually. The control system can, for. B. be transmitted via radio a corresponding trigger command. The altitude over ground can be determined by means of one or more sensors (not shown) that can measure a distance to the ground. If an altitude of, for example, 1 or 2 m above ground is determined during the landing process, the control system transmits 150 a release signal to the at least one connection unit.

In addition to the tail unit 121 on the trunk / body 120 of the aircraft 100 For example, further tail units or other devices may be used to stabilize the pitch angle on the aircraft 100 be provided. For example, at least one wing component 112 . 113 which, after releasing, no longer interfere with the trunk / body 120 are connected, their own tail 130 include.

The aircraft 100 may also include one or more drive units 140 include. A drive unit 140 can be configured for example as a motor-driven propeller. The associated motor drive may be an electric motor. Furthermore, the aircraft can 100 comprise at least one solar cell (solar panel) (not shown), for example, on an upper surface of the wing 110 is mounted / during the flight operation sufficient electrical energy for the drive units 140 provide.

In 1 are the drive units 140 as at the central wing component 111 arranged shown. Alternatively or additionally, the drive units 140 also on the outer wing components 112 . 113 to be appropriate. Also alternatively or additionally, further drive units 141 on the aircraft 100 be provided so that each wing component 111 . 112 . 113 with at least one drive unit 140 . 141 Is provided.

As in 1 is further shown, the outer, adjacent airfoil components 112 . 113 from the middle wing component 111 resolved shortly before landing ( 200 ) and optionally from the middle wing component 111 repelled ( 200 ). Subsequently, the two outer wing components 112 . 113 in gliding or powered and uncontrolled or controlled next to the rest of the aircraft 100 land safely. To control all wing components 111 . 112 . 113 can both a drive unit 140 . 141 as well as a tail unit 121 . 130 be used. The tail units 130 need not necessarily be controllable, so include moving parts. By its own drive device 141 can be the corresponding wing component 112 . 113 be brought into a safe descent.

Thus, each wing component 111 . 112 . 113 as well as the remaining parts of the aircraft 100 a corresponding different trajectory 211 . 212 . 213 to land. Out 1 It can be seen that the outer, adjacent wing components 112 . 113 can be designed to fly in uncontrolled or controlled descent to the center of the aircraft 100 fly when viewed from the middle wing component 111 were solved. This allows the entire aircraft 100 land on a narrower runway than conventional aircraft of this type. In addition, the weight of each component to be landed is much lower. This allows a landing on less level ground. Thus, landings on grassy runways or on runways with similar natural or artificial surface are possible. Furthermore, the aircraft can 100 also landed specifically in the water or on floating platforms.

Further shows 2 a schematic representation of various connection units on a collision surface of a wing component.

Upon receipt of a release signal, the connection unit releases the connection of the two adjacent wing components associated with the connection unit.

This can be done for example by severing a rope (as a holding device) by means of the release device. By way of example, a pyrotechnic cutting device and a knife or similar device equipped with a blade are mentioned here. Alternatively, a holding device in the form of a bolt can be moved by means of an actuator (as a release device) from a holding position into a release position. In this case, at least one holder on one of the two adjacent airfoil components 111 . 112 . 113 be released from the bolt. The release operation can be further assisted by a spring element, whereby the two adjacent wing components 111 . 112 . 113 be pressed apart.

Claims (13)

Wing ( 110 ) for an aircraft ( 100 ) comprising: at least two wing components ( 111 - 113 ), which are arranged in the longitudinal direction of the support surface and connected to each other; each one connection unit ( 301 . 302 ) between two adjacent wing components ( 111 - 113 ) for detachably connecting the two adjacent wing components ( 111 - 113 ); a control system ( 150 ), which is set up before landing the aircraft ( 100 ) at at least one connection unit ( 301 . 302 ) to send a release signal, wherein the at least one connection unit ( 301 . 302 ) is arranged, upon receipt of a release signal, the connection of the two adjacent wing components ( 111 - 113 ) to solve. Wing ( 110 ) according to claim 1, wherein the control system ( 150 ) is adapted to send the release signal in response to an altitude over ground. Wing ( 110 ) according to claim 1 or 2, wherein the at least one connecting unit ( 301 . 302 ) comprises: a holding device ( 310 . 320 ) connecting the two adjacent wing components ( 111 - 113 ) causes; and a release device ( 315 . 325 ), which upon receipt of the release signal, the connection of the two adjacent wing components ( 111 - 113 ) releases. Wing ( 110 ) according to claim 3, wherein the holding device comprises at least one cable ( 320 ) and the release device comprises a pyrotechnic cutting device ( 325 ) that the at least one rope ( 320 ), or wherein the holding device ( 310 ) a connecting bolt ( 311 ) and the release device comprises an actuator ( 315 ), which is adapted to the connecting bolt ( 311 ) to move from a holding position to a release position, or wherein the holding device ( 310 ) a connecting bolt ( 311 ) and the release device comprises a pyrotechnic cutting charge or explosive charge, which the connecting bolt ( 311 ) is severed. Wing ( 110 ) according to one of claims 1 to 4, wherein the at least one connecting unit ( 301 . 302 ) further comprises: a spring element ( 330 ), which exerts a compressive force on the two adjacent wing components ( 111 - 113 ) exercises. Wing ( 110 ) according to one of claims 1 to 5, further comprising: a tail ( 121 . 130 ) on each of the at least two wing components ( 111 - 113 ), with each tail ( 121 . 130 ) is adapted to a pitch angle of the associated wing component ( 111 - 113 ) to stabilize. Wing ( 110 ) according to one of claims 1 to 6, further comprising: a drive unit ( 140 . 141 ) on each of the at least two wing components ( 111 - 113 ), each drive unit ( 140 . 141 ) is adapted to the associated wing component ( 111 - 113 ) in the separated state capable of flying. Aircraft ( 100 ), which has a wing ( 110 ) according to one of claims 1 to 7. A method of landing an aircraft, the method comprising: Outputting a release signal to at least one connection unit provided between two adjacent wing components; and Releasing a connection between the two corresponding adjacent wing components caused by the at least one connection unit. The method of claim 9, wherein issuing a release signal comprises determining a flight altitude of the aircraft over ground, comparing the determined altitude with a threshold, and outputting the release signal when the detected altitude matches the threshold. The method of claim 9 or 10, wherein releasing a connection comprises severing a rope, moving a connecting bolt from a holding position to a release position, or pyrotechnic severing a connecting bolt. The method of any one of claims 9 to 11, further comprising: Controlling each of the disengaged airfoil components to land each of the airfoil components separately. The method of claim 12, wherein controlling each individual wing component comprises stabilizing a pitch angle and / or a roll angle of the wing component and / or driving the wing component.

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