Active dihedral control system for a torsionally flexible wing

Patent metadata

Field	Value
Publication number	US-9764819-B2
Application number	US-201514838297-A
Country	US
Kind code	B2
Filing date	Aug 27, 2015
Priority date	Feb 14, 2000
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A span-loaded, highly flexible flying wing, having horizontal control surfaces mounted aft of the wing on extended beams to form local pitch-control devices. Each of five spanwise wing segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other wing segments, to minimize inter-segment loads. Wing dihedral is controlled by separately controlling the local pitch-control devices consisting of a control surface on a boom, such that inboard and outboard wing segment pitch changes relative to each other, and thus relative inboard and outboard lift is varied.

First claim

We claim:

1. An aircraft characterized by a flight envelope, comprising:
a laterally extending wing;
a plurality of pitch-control devices, each pitch-control device being mounted at a separate lateral location along the wing, and each pitch-control device being configured to apply pitch-control torque at its lateral location, wherein the wing is characterized by a torsional flexibility high enough to allow the plurality of pitch control devices to control localized pitch at their lateral wing locations to a degree substantial enough to be significant for flight control throughout the flight envelope;
sensors determining the relative localized pitches at the plurality of lateral locations along the wing; and
a control system programmed to control the plurality of pitch-control devices based upon the sensed relative localized pitches at the plurality of lateral locations.

2. The aircraft of claim 1 , wherein each pitch-control device includes a boom connecting the wing to a control surface aft of the trailing edge of the wing at a distance adequate to cause a control surface pitch effect to dominate a control surface flap effect.

3. The aircraft of claim 1 , and further comprising sensors determining the dihedral of the wing;
wherein the control system is programmed to operate the pitch-control devices under a protocol that controls and alters wing dihedral based upon the sensed dihedral of the wing.

4. The aircraft of claim 3 , and further comprising sensors determining the wing bending stresses;
wherein the protocol actively provides for dihedral control and alteration that maintains the wing bending stresses within safety limits.

5. The aircraft of claim 4 , wherein there are both inboard and outboard pitch control devices, and wherein the protocol directs outboard pitch-control devices with more downward pitching pitch-control torques than pitch-control torques of inboard pitch-control devices.

6. The aircraft of claim 1 , and further comprising:
a plurality of motors; and
sensors determining fore-and-aft wing loads between motors;
wherein the control system is programmed to separably control the thrust from the plurality of motors based upon fore-and-aft wing loads between the motors.

7. The aircraft of claim 1 , wherein the pitch-control devices include both fixed and controllable horizontal surfaces.

8. The aircraft of claim 1 , wherein the aircraft does not comprise elevators mounted on an empennage.

9. An aircraft characterized by a flight envelope, comprising:
a laterally extending wing;
a means for separately actuating the pitch of the wing at a plurality of lateral locations along the wing, wherein the wing is characterized by a torsional flexibility high enough to allow the means for separately actuating to actuate localized pitch at the plurality of lateral locations to a degree substantial enough to be significant for flight control throughout the flight envelope;
sensors determining the relative localized pitches at the plurality of lateral locations along the wing; and
a means for controlling the means for separately actuating based upon the sensed relative localized pitches at the plurality of lateral locations.

10. A method of controlling an aircraft characterized by a flight envelope, comprising:
separately actuating the pitch of a laterally extending wing at a plurality of lateral locations along the wing, wherein the wing is characterized by a torsional flexibility high enough to allow the means for separately actuating to actuate localized pitch at the plurality of lateral locations to a degree substantial enough to be significant for flight control throughout the flight envelope;
sensing the relative localized pitches at the plurality of lateral locations along the wing; and
controlling the means for separately actuating based upon the sensed relative localized pitches at the plurality of lateral locations.

11. The method of claim 10 , and further comprising sensing the dihedral of the wing, wherein the step of controlling includes directing a plurality of pitch-control devices under a protocol that controls and alters wing dihedral based upon the dihedral of the wing.

Assignees

• Aerovironment Inc
• Aerovironment Inc

Inventors

• Kendall Greg T
• Lisoski Derek L
• Morgan Walter R
• Griecci John A

Classifications

• B64U2201/20

  Remote controls · CPC title

• B64U2101/20

  for use as communications relays, e.g. high-altitude platforms · CPC title

• B64D27/353

  using solar cells · CPC title

• B64D31/06

  actuated automatically · CPC title

• B64C3/38 Primary

  Adjustment of complete wings or parts thereof · CPC title