Apparatus and method for controlling twist of a wing of an airborne mobile platform

An airborne mobile platform may have a wing having a length and a chord wise dimension, and a plurality of elongated structural components extending span-wise along the length of the wing. The elongated structural components may each have a localized hinge area. A device may be used for manipulating the elongated structural component to position the localized hinge area to selectively change a hinge line of the wing in response to an airflow over the wing.

FIELD

The present disclosure generally relates to airborne mobile platforms, and more particularly to controlling the cord-wise stiffness of the wings on a mobile platform in a manner that allows the natural aerodynamic bending forces experienced by the wings during flight to twist the wings as needed in a controlled fashion, to assist in controlling flight of the mobile platform.

BACKGROUND

Aircraft designers are tasked with developing efficient technologies for controlling an aircraft flight path. In the earliest years of aviation, the Wright brothers used mechanical wires to twist the wing for aircraft roll control. Traditionally, aircraft have used moveable flap-like control surfaces (ailerons) to roll the aircraft or adjust the aircraft attitude. Recently, aircraft designers have started to devise ways of controlling and using aircraft aero-elastic wing twisting for roll control. This has involved using such components as a torque tube disposed in each wing, and running substantially the full span-wise length of the wings, to assist in twisting the wings to help provide flight control maneuvering for the aircraft. Such systems, however, have often required large, heavy and expensive motors to provide the necessary twisting force to the torque tube.

Accordingly, it would be highly advantageous to provide some means for controllably twisting a wing to assist in controlling flight of an aircraft, but without the large, heavy and expensive wing twisting structures that have previously been attempted.

SUMMARY

The present disclosure relates to an airborne mobile platform that may comprise a wing having a length and a chord wise dimension, and a plurality of elongated structural components extending span-wise along the length of the wing. Each elongated structural component may have a localized hinge area. A device may be used for manipulating the elongated structural components to position the localized hinge area to selectively change a hinge line of the wing in response to an airflow over the wing.

In another aspect the present disclosure may comprise a wing, where the wing includes a plurality of elongated structural components extending span-wise along the wing. The elongated structural components may each have a localized hinge area. A subsystem may be used for manipulating the elongated structural components to selectively position the localized hinge area to controllably position a hinge line of the wing, and without imparting a twisting force to the wing.

In still another aspect the present disclosure may comprise a method for controllably positioning a hinge line on a wing of a mobile platform that includes providing a plurality of structural components extending span-wise within the wing. A localized hinge area may be formed in each structural component. Each structural component may be controlled to position the localized hinge area within the wing so as to controllably vary the position of a hinge line of the wing.

DETAILED DESCRIPTION

The following description of the various preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the present disclosure, its application, or uses.

Referring toFIG. 1, there is shown an exemplary airborne mobile platform, in this example an aircraft10, including a pair of wings12aand12b, and a body or fuselage portion14. While an aircraft is illustrated, it will be appreciated that the present disclosure is applicable to any airborne mobile platform, manned or unmanned, that makes use of wings to control its flight.

Wing12bof the aircraft10includes a dashed line16that illustrates a “neutral” sweep hinge line. The neutral sweep hinge line can be viewed as representing the natural bending line of the wing as the wing experiences aerodynamic forces during flight. Dashed line18represents a “pseudo” wing hinge orientated to provide a negative sweep hinge line. Dashed line20represents another pseudo hinge line that is orientated to provide a positive sweep hinge line. Wing12ais illustrated with a structural component or assembly22represented by dashed lines disposed inside the wing. It will be appreciated, however, that wing12bsimilarly includes structural component22, but the dashed lines indicating its presence have been deleted for clarity. Thus, each of the wings12aand12binclude structural component22, and each are preferably independently controlled by a suitable flight control computer or other subsystem carried on the aircraft10. Each wing (12aand12b) includes hinge sweeps16,18and20as well.

In brief, the structural components22in the wings12aand12bserve to modify the orientation of the hinge line in each wing to provide either a negative hinge sweep, as indicated by dashed line18, or a positive hinge sweep, as indicated by dashed line20, or possibly any intermediate degree of hinge sweep between hinge lines18and20. Controlling the orientation of the hinge line in each wing12aand12ballows the natural aerodynamic forces experienced by the wings during flight to assist in twisting the wings as needed to achieve the desired flight control characteristics. For example, during landing operations, a negative hinge sweep is desirable, while at cruise altitudes a neutral hinge sweep is most desirable. A particular advantage of the system and method described herein is that since the natural aerodynamic forces experienced by the wings provide a significant degree of the force needed to twist the wings12a,12b, that heavy, large and expensive motors and other like devices, that would otherwise be needed to twist the wings, are not needed with the present system and method.

Referring toFIGS. 2-2C, one embodiment of the structural component22is illustrated in wing12b. The structural component22, in this embodiment, includes three independent, elongated tubes26a,26band26c. The tubes26may be formed from aluminum, from composites, or any other suitable material. Tubes26aand26care each coupled at an end near a root of the wing12bto a driving implement28. Driving implement28may comprise an electric motor, an hydraulic actuator, or any other suitable form of implement for rotating the tubes26aand26c. Tube26acan be seen to have a first cutout26a1near a tip of the wing12b, and a second cutout26a2near the root of the wing. In this embodiment the center tube26bincludes only a single cutout26b1and is not coupled to the driving implement28. Tube26c, however, includes a pair of cutouts26c1and26c2. Tube26ais also illustrated inFIG. 2C. It will be noted that cutouts26a1and26a2are angularly displaced from one another by about 90°. The same is true for cutouts26c1,26c2in tube26c.

Referring toFIG. 2A, when the tubes26a,26band26care orientated as illustrated inFIG. 2, the hinge line formed has a negative sweep, as shown inFIG. 2A. During flight, the natural aerodynamic bending force on the wing12b, with the hinge line18as orientated as shown inFIG. 2A, will cause the leading edge24cof the wing12bto twist upwardly, as shown inFIG. 2B. The degree of twisting is at a maximum at the wing tip24b.

To change the sweep of the hinge line, the driving implement28is used to rotate the tubes26aand26capproximately 90°. This places the cutouts26a1and26c2in upright facing orientations which changes the positions of localized hinge areas in the tubes26aand26c. With tubes26a-26cpositioned as shown inFIG. 3, the hinge line produced has a positive sweep, as illustrated inFIG. 3A. This enables the tip24bof the wing12bto be twisted by aerodynamic forces being experienced by the wing12bsuch that the tip24b(as well as the leading edge24c) is twisted downwardly in accordance with arrow32inFIG. 3B. Thus, by simply rotating each of the tubes26aand26cby 90°, the hinge line on the wing12bcan be significantly and controllably changed. The natural aerodynamic forces acting on the wing12bcontribute significantly to twisting of the wing tip24b.

It will be appreciated that while only two cutouts have been illustrated in each of the tubes26aand26c, that more or less than two cutouts could be employed. Additionally, the dimensions and shape of each cutout could be altered to tailor the localized hinge areas in each tube26as needed to form the desired hinge line or hinge lines. A greater or lesser number of tubes26could be employed to suit the needs of specific applications, and the lengths of the tubes26can be tailored to the length and shape of the wing12b.

Referring toFIG. 4, an elongated structural component50in accordance with an alternative embodiment of the present system and method is illustrated. The structural component50includes a plurality of elongated structural members52a,52band52c. Each of the structural members52a-52cincludes generally perpendicularly extending panels or walls54a1-54a4. Panel54a3has a cutout56while panel54a4has a cutout58arranged approximately 90 degrees from cutout56. Structural member52bincludes only a single cutout60, while structural member52cincludes cutouts62and64disposed angularly about 90° from one another and at opposite ends thereof. Each of the cutouts56-64form a localized hinge area in their respective structural members52a,52band52c. When the cutouts56-64are arranged as shown inFIG. 4A, then negative sweep hinge line18is formed on the wing12b, as shown inFIG. 4A. When the driving implement28is used to rotate the structural members52aand52capproximately 90°, such that cutouts56and64are facing upwardly, as shown inFIG. 5, then the positive sweep hinge line20is produced as shown inFIG. 5A. Again, the number and precise location of each of the cutouts used on the structural members52a,52band52ccan be varied to control the localized hinge areas in the wing12bto produce a hinge line having a desired orientation on the wing12b. The structural members52a,52band52ccould be formed from aluminum, from composites, or any other suitably strong, lightweight material.

Referring toFIGS. 6 and 6A, still another structural component70representing another alternative embodiment of the present system and method is illustrated. Structural component70comprises a plurality of sleeved structural members72a,72band72cthat may be of identical construction. A portion of member72ais shown inFIG. 6A. InFIG. 6A, member72acan be seen to include an outer tubular member74and an inner tubular member76having a plurality of opposing cutout portions78and80. Thus, when portion74is slid relative to portion76, the cutout areas78and80form a localized hinge area in the overall support member72a. Preferably, portion74has a wall thickness which is substantially less than the wall thickness of portion76, so that the majority of stiffness of each structural member72is significantly influenced by the position of its associated inner tubular member76. Thus, by controllably positioning the outer tubular member74relative to inner tubular member76, one can change the longitudinal hinge point in the support member72a.

With further reference toFIG. 6, each of the sleeved support members72acan be controlled by the driving implement28such that the inner member76associated with each is longitudinally moved to a desired position to produce a localized hinge line in the wing12b. The positions of the inner members76can thus be aligned to produce a hinge line having a negative sweep, a positive sweep, or virtually any intermediate sweep angle that may be desired.

InFIG. 7, an alternative structural component90is illustrated. Structural component90forms a tube having a spiral cutout92extending over an angular orientation of about 90°. By rotating the tube90, the precise location of the hinge area that it forms can be infinitely adjusted along the 90° arc defined by the spiral cut-out92. For example, in the drawing ofFIG. 7, rotating the structural component90counterclockwise according to arc line94will cause the localized hinge area to move in the direction of arrow96. Rotating the structural component90clockwise would cause the localized hinge area to move in a direction opposite to line96.

From the foregoing, the various embodiments of the structural component, taken together with the driving implement, can be used to create localized hinge areas in the wing that form a hinge line having a desired sweep. It is a particular advantage of the present system that the natural aerodynamic forces acting on the wings12a,12bcan be used to twist the tips of the wings12a,12b. Controlling the sweep of the hinge line on each wing12a,12bcan contribute to producing highly maneuverable aircraft. The ability to controllably change the hinge line on each wing, using the natural aerodynamic forces experienced by the wing, rather than large, expensive and heavy motors or actuators, further enables the present system to be implemented on smaller, lighter aircraft where conventional wing twisting systems might not be possible, practical or cost effective.