News Column

Patent Application Titled "Air Vehicle Flight Mechanism and Control Method for Non-Sinusoidal Wing Flapping" Published Online

July 2, 2014



By a News Reporter-Staff News Editor at Defense & Aerospace Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors Keennon, Matthew Todd (Simi Valley, CA); Andryukov, Alexander (Simi Valley, CA); Klingebiel, Karl Robert (Simi Valley, CA); Won, Henry Thome (Sherman Oaks, CA), filed on August 16, 2013, was made available online on June 19, 2014.

The assignee for this patent application is AeroVironment, Inc.

Reporters obtained the following quote from the background information supplied by the inventors: "Radio-controlled, heavier-than-air aircraft having sustainable beating wings, i.e., ornithopters."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "Embodiments of the invention include a flapping wing driving apparatus that comprises at least one crank gear capstan rotatably coupled to a crank gear, the at least one crank gear capstan disposed radially offset from a center of rotation of the crank gear, a first wing capstan coupled to a first wing, the first wing capstan having a first variable-radius drive pulley portion, and a first drive linking member configured to drive the first capstan, the first drive linking member windably coupled between the first variable-radius drive pulley portion and one of the at least one crank gear capstan so that the first wing capstan is configured to non-constantly, angularly rotate responsive to a constant angular rotation of the crank gear. The invention may also comprise a second wing capstan coupled to a second wing, the second wing capstan having a second variable-radius drive pulley portion, a second drive linking member windably coupled between the second variable-radius drive pulley portion and one of the at least one crank gear capstan, a first synchronization pulley and a second synchronization pulley disposed on the first wing capstan and the second wing capstans, respectively, and a first crossing synchronization linking member and a second crossing synchronization linking member each windably coupled between the first synchronization pulley and the second synchronization pulley, the first crossing synchronization linking member and the second crossing synchronization linking member, so that the first wing capstan is configured to non-constantly, angularly rotate responsive to a constant angular rotation of the crank gear. In such an embodiment, the first drive linking member may be received by the first variable-radius drive pulley portion at a maximum radius of the first variable-radius drive pulley portion as the first wing capstan changes rotational direction. The first synchronization drive pulley and second synchronization drive pulley may be configured with a constant radius and, in such an embodiment, the first synchronization drive pulley and the second synchronization drive pulley may each be configured to windably receive the first synchronization linking member and the second synchronization linking member at non-constant radius drive pulley portions. A first drive linking member winding peg may be configured to rotatably take up the first drive linking member so that slack in the first drive linking member between the first variable-radius drive pulley portion and one of the at least one crank gear capstan is reduced. Embodiments may include means for reducing slack in the first drive linking member between the first variable-radius drive pulley portion and one of the at least one crank gear capstan. The first drive linking member and the second drive linking member may each comprise a plurality of cables and the plurality of cables may be elastic.

"Embodiments of the invention include a flapping wing driving apparatus that may comprise a motor and a plurality of reduction gears coupled between the motor and the crank gear so that at least one of the plurality of reduction gears is configured to drive the at least one crank gear capstan in an orbital path about a center of rotation of the crank shaft. The first and second drive linking members may each be a plurality of cables.

"Embodiments of the invention include a flapping wing driving apparatus that may comprise a first wing and a second wing, a first wing capstan and a second wing capstan respectively coupled to the first wing and the second wing, each of the first wing capstan and the second wing capstan having respective variable radius drive pulley portions, at least one rotatable crank gear capstan coupled to a crank arm at a location offset from the axis of rotation of the crank arm, a first drive linking cable and second drive linking cable wherein each drive linking cable is respectively coupled to one of the at least one crank gear capstan, the first drive linking cable windably coupled to the variable-radius drive pulley portion of the first wing drive capstan and the second drive linking cable windably coupled to the variable-radius drive pulley portion of the second wing drive capstan, a first synchronization pulley and a second synchronization pulley each respectively coupled to the first wing capstan and the second wing capstan, and a first crossing synchronization linking member and a second crossing synchronization linking member each windably coupled between the first synchronization pulley and the second synchronization pulley, the first crossing synchronization linking member and the second crossing synchronization linking member wherein the second wing capstan is configured to rotate in a direction counter to a rotation of the first wing capstan, wherein constant angular rotation of the crank arm alternately pulls the first and second drive linking cables to drive the first and second wing capstans with a return force for each of the first and second wing capstans provided respectively by the second and first crossing synchronization linking members so that the first and second wings move in a non-sinusoidal back-and-forth flapping motion. In one embodiment, coupling of the first drive linking cable and second drive linking cable to the first variable-radius drive pulley portion and the second variable-radius drive pulley portion, respectively, is configured so that the first and second drive linking cables are received at respective maximum radii of the first and second variable-radius drive pulley portions as the first and second wings, respectively, are configured to change direction of travel so that the speed and the acceleration of the first and second wings about the end of the wing travel is reduced. The respective variable-radius drive pulley portions of the first wing capstan and the second wing capstan may also each be lob-shaped, oval-shaped, or each of the first second synchronization pulley and second synchronization pulley may be variable-radius synchronization pulleys. In one embodiment, the first variable-radius synchronization pulley and the second variable-radius synchronization pulley are lob-shaped. The invention may also include a motor configured to rotatably drive the crank arm, and the at least one rotatable crank gear capstan may comprise two co-axial, rotatable, crank gear capstans. Each of the first drive linking cable and the second drive linking cable may be elastic.

"In a further embodiment, a flapping wing method comprises orbiting a crank capstan about an axis of rotation, pulling a first drive cable with the crank capstan, the first drive cable windably coupled to a variable-radius drive pulley portion fixed on a rotatable first wing capstan to cause the rotatable first wing capstan to rotate, the rotatable first wing capstan coupled to a first wing, winding up a first synchronization cable about a synchronization pulley on the first wing capstan in response to the rotating of the rotatable first wing capstan, and synchronizably rotating a rotatable second wing capstan windably coupled to the first synchronization cable in response to the winding up the first synchronization cable about the synchronization pulley, the rotatable second wing capstan coupled to a second wing, so that the first wing is configured to rotate with a non-sinusoidal angular velocity about a rotation axis of the rotatable first wing capstan as the crank capstan orbits about the axis of rotation at a constant angular velocity and the second wing rotates with about a rotation axis of the rotatable second wing capstan. The method may also comprise pulling a second drive cable with the crank capstan after pulling the first drive cable, the second drive cable windably coupled to a variable-radius drive pulley portion fixed on a rotatable second wing capstan to cause the rotatable second wing capstan to rotate, the rotatable second wing capstan coupled to a second wing, winding up a second synchronization cable about a synchronization pulley on the second wing capstan in response to the rotating of the rotatable second wing capstan, and synchronizably rotating the rotatable first wing capstan windably coupled to the second synchronization cable in response to the winding up the second synchronization cable about the synchronization pulley on the second wing capstan so that the second wing is configured to rotate with a non-sinusoidal angular velocity about a rotation axis of the rotatable second wing capstan as the crank capstan orbits about the axis of rotation at a constant angular velocity and the first wing rotates about a rotation axis of the rotatable first wing capstan. The pulling of the second drive cable may begin when the first drive cable is received at a maximum radius of the variable-radius drive pulley portion on the first wing capstan. Pulling the second drive cable may begin as the first wing changes rotational direction. The synchronization pulley on the second wing capstan may be non-circular. The second drive cable may also be elastic. Pulling of the first drive cable may begin when the second drive cable is received at a maximum radius of the variable-radius drive pulley portion on the second wing capstan. The synchronization pulley on the first wing capstan may be non-circular.

"Embodiments of the invention may also include a flapping wing driving apparatus that comprises means for orbiting at least one crank gear capstan about a center of rotation and at a constant velocity, a first wing capstan coupled to a first wing, the first wing capstan having a first variable-radius drive pulley portion, and a first drive linking member configured to drive the first wing capstan, the first drive linking member windably coupled between the first variable-radius drive pulley portion and one of the at least one crank gear capstan so that the first wing capstan is configured to non-constantly, angularly rotate responsive to a constant velocity of the means for orbiting. The invention may also comprise a second wing capstan coupled to a second wing, the second wing capstan having a second variable-radius drive pulley portion, a second drive linking member windably coupled between the second variable-radius drive pulley portion and one of the at least one crank gear capstan, a first synchronization pulley and a second synchronization pulley coupled to the first wing capstan and the second wing capstans, respectively, and a first crossing synchronization linking member and a second crossing synchronization linking member each windably coupled between the first synchronization pulley and the second synchronization pulley, the first crossing synchronization linking member and the second crossing synchronization linking member, so that the first wing capstan is configured to non-constantly, angularly rotate responsive to a constant angular rotation of the crank gear.

"Another embodiment of the invention includes a flapping wing driving apparatus that comprises a first wing and a second wing, a first wing capstan and a second wing capstan respectively coupled to the first wing and the second wing, means for rotating the first wing capstan and the second wing capstan in a predetermined non-sinusoidal acceleration from a first sweep angle position to a second sweep angle position of the first wing and the second wing, means for returning the first wing capstan and the second wing capstan to their respective first sweep angle positions after the respective first sweep angle position to second sweep angle position predetermined non-sinusoidal acceleration, so that the means for rotating and the means for returning are configured so that the first wing and second wing move in a non-sinusoidal back-and-forth flapping motion. The means for returning may further comprise means for returning the first wing capstan and the second wing capstan to their respective original angular positions in a predetermined non-sinusoidal acceleration from the second sweep angle position to the first sweep angle position.

BRIEF DESCRIPTION OF THE DRAWINGS

"Embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawing, and in which:

"FIG. 1 is a perspective view of one embodiment of an air vehicle that has two flappable wings that flap in a horizontal plane about the air vehicle;

"FIG. 2 is a perspective view of an air vehicle that has a flapping mechanism mid-body, vehicle components located above the flapping mechanism, and batteries on a tail post;

"FIGS. 3A, 3B, and 3C are front plan, front perspective and side views, respectively, illustrating components placement, flapping mechanism placement, and battery placement on a lower body gimbal frame system of an air vehicle;

"FIGS. 4A, 4B, and 4C are front plan, front perspective and side views, respectively, illustrating vehicle components placement, flapping mechanism placement, and battery placement on a lower body gimbal frame system of an air vehicle;

"FIGS. 5A and 5B are perspective views of an air vehicle frame having one embodiment of an integrated boom yang system;

"FIGS. 6A and 6B are perspective views of an air vehicle frame having a lower body gimbal system;

"FIGS. 7A, 7B, and 7C are perspective views of three embodiments of a crank arm to drive a flapping mechanism;

"FIG. 8 is a front perspective view of one embodiment of a crank arm and pulley assembly of a flapping mechanism;

"FIG. 9 is a perspective view of one embodiment of a wing capstan having pulley portions and string winding pegs to windably couple a plurality of cables to the wing capstan;

"FIG. 10 is a rear perspective view of the embodiment of the crank arm and pulley assembly first illustrated in FIG. 8;

"FIG. 11 is an exploded view of the device show in FIGS. 8 and 10;

"FIGS. 12A-12F show an embodiment of the flapping mechanism having wing capstans each driven by a crank gear in a first rotational direction by drive linking cables and in an opposite rotational direction by crossing synchronization linking members;

"FIGS. 13A, 13B and 13C are exemplary graphs of flap angle (degrees) and tip accelerations (g) verses flap cycle to illustrate the effects of the variable-radius drive pulley portions on wing position and acceleration;

"FIGS. 14A and 14B illustrate one embodiment of a coupling configuration for coupling wing masts to respective wing root spars and boom vangs to enable yaw control of a flapping mechanism;

"FIGS. 15A and 15B illustrate one embodiment of a pitch-tiltable camera coupled to the top of an air vehicle frame that has a lower body gimbal system configuration;

"FIGS. 16A, 16B, and 16C illustrate one embodiment of a yaw control arrangement and structure thereof for an air vehicle that includes a yaw servo driving push-pull cables through respective cable guides;

"FIGS. 17A, 17B, and 17C illustrate an embodiment for providing yaw control of an air vehicle frame using lever arms coupled to respective pushrods to drive respective drive wing root spars;

"FIGS. 18A and 18B are front and rear perspective views, respectively, illustrating one embodiment of an integrated boom yang system driven by a yaw servo through pushrods to provide yaw control of a flapping mechanism;

"FIGS. 19A and 19B are front and rear perspective views of an air vehicle frame having a yaw control system driving a lower body gimbal system and supporting a plurality of batteries;

"FIGS. 20A and 20B are front and rear perspective views of another embodiment of an air vehicle frame having a yaw control system driving an integrated boom yang system;

"FIGS. 21A-21D are perspective views of one embodiment of a plurality of tail elements that may fold toward a center axis of an air vehicle after taking off from a surface;

"FIGS. 22A, 22B, and 22C are rear perspective views of a lower body gimbal system having a root spar coupled to an attitude control arm through a universal joint to provide yaw control of an air vehicle; and

"FIG. 23 illustrates one embodiment of an air vehicle that has wings configured to fold against a body of the air vehicle."

For more information, see this patent application: Keennon, Matthew Todd; Andryukov, Alexander; Klingebiel, Karl Robert; Won, Henry Thome. Air Vehicle Flight Mechanism and Control Method for Non-Sinusoidal Wing Flapping. Filed August 16, 2013 and posted June 19, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=6429&p=129&f=G&l=50&d=PG01&S1=20140612.PD.&OS=PD/20140612&RS=PD/20140612

Keywords for this news article include: Aerospace and Defense Companies.

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Source: Defense & Aerospace Week


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