Air Vehicle Flight Mechanism and Control Method

Abstract

Heavier-than-air, aircraft having flapping wings, e.g., ornithopters, where angular orientation control is effected by variable differential sweep angles of deflection of the flappable wings in the course of sweep angles of travel and/or the control of variable wing membrane tension.

What is claimed is: 
     
         1 . An air vehicle, comprising:
 a support structure comprising a flapping drive element, the flapping drive element comprising:
 a rotating element having a center of rotation and a plane of rotation; 
 a first capstan mounted about a shaft, the shaft attached to the rotating element distal from the center of rotation and substantially perpendicular to the plane of rotation; 
 a first rocker member rotatably attached to a support structure; 
 a first drive link rotatably attached to the first capstan and the first rocker member; 
 a first arm rotatably attached to the support structure and rotatably attached to the first rocker member via a first rocker link; 
 a second capstan mounted about the shaft; 
 a second rocker member rotatably attached to the support structure; 
 a second drive link rotatably attached to the second capstan and the second rocker member; and 
 a second arm rotatably attached to the support structure and rotatably attached to the second rocker member via a second rocker link; and 
   a first airfoil rotatably attached to the support structure and a second airfoil rotatably attached to the support structure, the first airfoil comprising a first root spar and a first membrane attached to the first root spar, the first airfoil configured to be driven to flap via the flapping drive element, and the second airfoil comprising a second root spar and a second membrane attached to the second root spar, and the second airfoil configured to be driven to flap via the flapping drive element, wherein air vehicle control about at least one axis of the vehicle is effected by at least one of: a variable membrane luffing; variable root spar rotation travel limitation; and variable flapping angular velocity of the flapping drive element.   
     
     
         2 . The air vehicle of  claim 1  wherein the rotating element is rotatably attached to the support structure. 
     
     
         3 . An air vehicle, comprising:
 a support structure comprising a flapping drive element, the flapping drive element comprising:
 a rotating element having a center of rotation and a plane of rotation; 
 a first capstan mounted about a shaft, the shaft attached to the rotating element distal from the center of rotation and substantially perpendicular to the plane of rotation; 
 a second capstan mounted about the shaft; 
 a first arm mounted to a third capstan, a first linking member connecting the third capstan with the first capstan; 
 a second arm mounted to a fourth capstan, a second linking member connecting the fourth capstan with the second capstan; and 
 a third linking member connecting the third capstan with the fourth capstan; and 
   a first airfoil rotatably attached to the support structure and a second airfoil rotatably attached to the support structure, the first airfoil comprising a first root spar and a first membrane attached to the first root spar, the first airfoil configured to be driven to flap via the flapping drive element, and the second airfoil comprising a second root spar and a second membrane attached to the second root spar, and the second airfoil configured to be driven to flap via the flapping drive element, wherein air vehicle control about at least one axis of the vehicle is effected by at least one of: a variable membrane luffing; variable root spar rotation travel limitation; and variable flapping angular velocity of the flapping drive element.   
     
     
         4 . The air vehicle of  claim 3  wherein the third capstan has a center of rotation, the fourth capstan has a center of rotation, and the center of rotation of the rotating element is collinear with the center of rotation of the third capstan and the center of rotation of the fourth capstan. 
     
     
         5 . The air vehicle of  claim 4  wherein the first linking member comprises a cord, the second linking member comprises a cord, and the third linking member comprises a cord. 
     
     
         6 . An air vehicle, comprising:
 a support structure comprising a flapping drive element, the flapping drive element comprising:
 a first motor driving a first rotating element, the first rotating element having a center of rotation and a plane of rotation; 
 a first capstan mounted about a shaft, the shaft attached to the rotating element distal from the center of rotation and substantially perpendicular to the plane of rotation; 
 a second capstan mounted about the shaft; 
 a first arm mounted to a third capstan, a first linking member connecting the third capstan with the first capstan; 
 a second linking member connecting the fourth capstan with the second capstan; and 
 a third linking member connecting the third capstan with the fourth capstan; 
 a second motor driving a second rotating element, the second rotating element having a center of rotation and a plane of rotation; 
 a fifth capstan mounted about a second shaft, the second shaft attached to the second rotating element distal from the center of rotation and substantially perpendicular to the plane of rotation of the second rotating element; 
 a sixth capstan mounted about the second shaft; 
 a fourth linking member connecting the seventh capstan with the fifth capstan; 
 a second arm mounted to an eighth capstan, a fifth linking member connecting the eighth capstan with the sixth capstan; 
 a sixth linking member connecting the seventh capstan with the eighth capstan; and 
 circuitry controlling a flapping rate of the first motor and the second motor; and 
   a first airfoil rotatably attached to the support structure and a second airfoil rotatably attached to the support structure, the first airfoil comprising a first root spar and a first membrane attached to the first root spar, the first airfoil configured to be driven to flap via the flapping drive element, and the second airfoil comprising a second root spar and a second membrane attached to the second root spar, and the second airfoil configured to be driven to flap via the flapping drive element, wherein air vehicle control about at least one axis of the vehicle is effected by at least one of: a variable membrane luffing; variable root spar rotation travel limitation; and variable flapping angular velocity of the flapping drive element.   
     
     
         7 . An air vehicle, comprising:
 a first airfoil rotatably attached to a support structure and a second airfoil rotatably attached to the support structure, the first airfoil comprising a first root spar and a first membrane attached to the first root spar, the first airfoil configured to be driven to flap via a flapping drive element, and the second airfoil comprising a second root spar and a second membrane attached to the second root spar, and the second airfoil configured to be driven to flap via the flapping drive element, wherein air vehicle control about at least one axis of the vehicle is effected by at least one of: a variable membrane luffing; variable root spar rotation travel limitation; and variable flapping angular velocity of the flapping drive element;   wherein the vehicle is configured to effect air vehicle control via a vehicle control assembly comprising:
 a first flappable wing having a sweep angle of travel, wherein the first flappable wing comprises a membrane attached to a root spar and a mast, the root spar rotatably coupled to the mast to selectively decrease an angle of the root spar relative to the mast to provide increased luffing of the membrane; 
 a second flappable wing having a sweep angle of travel, wherein the second flappable wing comprises a second membrane attached to a second root spar and a second mast, the membrane having surface tension adjustable via rotation of the second root spar relative to the second mast; 
 wherein the first flappable wing extends in a radial direction from the air vehicle and the second flappable wing extends in a radial direction from a side of the air vehicle substantially opposite the first flappable wing; and 
   wherein the vehicle control assembly is configured to generate at least one of: a pitching torque, a rolling torque and a yawing torque, by generating a difference between the luffing of the first flappable wing and the luffing of the second flappable wing.   
     
     
         8 . The air vehicle of  claim 7  wherein the first flappable wing further comprises a sweep angle of deflection comprising a forward sweep angle of deflection and a backward sweep angle of deflection; wherein a second flappable wing further comprising a sweep angle of deflection comprising a forward sweep angle of deflection and a backward sweep angle of deflection; and wherein the vehicle control assembly is further configured to generate a yawing torque, by at least one of: a difference between the forward sweep angle of deflection of the first flappable wing and the forward sweep angle of deflection of the second flappable wing, and a difference between the backward sweep angle of deflection of the first flappable wing and the backward sweep angle of deflection of the second flappable wing. 
     
     
         9 . An air vehicle comprising:
 a first airfoil rotatably attached to a support structure and a second airfoil rotatably attached to the support structure, the first airfoil comprising a first root spar and a first membrane attached to the first root spar, the first airfoil configured to be driven to flap via a flapping drive element, and the second airfoil comprising a second root spar and a second membrane attached to the second root spar, and the second airfoil configured to be driven to flap via the flapping drive element, wherein air vehicle control about at least one axis of the vehicle is effected by at least one of: a variable membrane luffing; variable root spar rotation travel limitation; and variable flapping angular velocity of the flapping drive element; and   wherein the vehicle is configured to effect air vehicle control via a vehicle control assembly comprising a luffing control assembly wherein the first root spar is attached to the luffing control assembly; and the second root spar is attached to the luffing control assembly, and the first root spar is rotatably coupled to a mast to selectively decrease an angle of the first root spar relative to the mast to provide increased luffing of the first membrane.   
     
     
         10 . The air vehicle of  claim 9  wherein the luff control assembly comprises a first yang attached to the first root spar, a second yang attached to the second root spar, a yang yoke repositionable in at least one of a fore/aft tilt position or side tilt position and configured to receive the first yang and the second yang. 
     
     
         11 . The air vehicle of  claim 10  wherein the first yang further comprises a first repositionable stop and a second repositionable stop together defining a rotation angle of the first wing root spar about the first wing mast; and wherein the second yang further comprises a third repositionable stop and a fourth repositionable stop, the third repositionable stop and a fourth repositionable stop together defining a second rotation angle of the second wing root spar about the second wing mast. 
     
     
         12 . The assembly of  claim 11  wherein the first stop is disposed on a first pulley and the second stop is disposed on a second pulley, the first pulley and the second pulley each rotatably repositionable via an actuated linking member and the third stop and fourth stop each rotatably repositionable via a second actuated linking member. 
     
     
         13 . The assembly of  claim 11  wherein the first stop is disposed on a first pulley and the second stop disposed on a second pulley, the first pulley and the second pulley each rotatably repositionable via an actuated linking member to increase a first angle subtended by the first stop and the second stop, and the third stop and fourth stop each rotatably repositionable via a second actuated linking member to increase a second angle subtended by the third stop and the fourth stop. 
     
     
         14 . A wing comprising
 a mast engaging a fitment;   a spar engaging a fitment substantially perpendicular to the mast, the spar rotatably coupled to the mast to selectively decrease an angle of the spar relative to the mast;   a mast tube disposed about a portion of the mast;   a spar tube disposed about a portion of the spar;   a scrim attached to the spar tube and the mast tube; and   a first batten disposed on the scrim and extending in a direction radially from the intersection of the spar and the mast, the first batten having a distal end proximate to an edge of the airfoil;   wherein increased luffing of the scrim results from decreasing the angle of the spare relative to the mast.   
     
     
         15 . The wing of  claim 14  further comprising a second batten disposed on the scrim and extending in a direction radially from the intersection of the spar and the mast, the second batten having a distal end proximate to an edge of the airfoil. 
     
     
         16 . The wing of  claim 14  further comprising a root socket configured to fixedly receive the spar and configured to rotatably receive the mast. 
     
     
         17 . The wing of  claim 14  wherein a planform of the wing is defined by perimeter points comprising: the distal end of the first batten, a distal end portion of the mast, a distal end portion of the spar, a proximal end portion of the mast, and a proximal end portion of the spar. 
     
     
         18 . The wing of  claim 14  wherein the scrim comprises a polyvinyl fluoride film. 
     
     
         19 . The wing of  claim 14  wherein the scrim comprises a polyvinyl fluoride film further comprising a fiber mesh. 
     
     
         20 . The wing of  claim 14  wherein the scrim comprising fiber mesh comprises intersecting lines of fiber mesh, the lines of fiber mesh oriented at oblique angles relative to the spar tube and relative to the mast tube. 
     
     
         21 . The wing of  claim 14  wherein the mast comprises a carbon rod and the first batten comprises a carbon rod. 
     
     
         22 . A method of air vehicle control comprising:
 providing a control assembly comprising:
 a first flappable wing having a sweep angle of travel, and having a sweep angle of deflection comprising a forward sweep angle of deflection and a backward sweep angle of deflection; 
 a second flappable wing having a sweep angle of travel, and having a sweep angle of deflection comprising a forward sweep angle of deflection and a backward sweep angle of deflection; 
 wherein the first flappable wing extends in a radial direction from the air vehicle and the second flappable wing extends in a radial direction from a side of the air vehicle substantially opposite the first flappable wing; and 
   generating at least one of: a rolling torque and a yawing torque, by generating at least one of: a difference between the forward sweep angle of deflection of the first flappable wing and the forward sweep angle of deflection of the second flappable wing, a difference between the backward sweep angle of deflection of the first flappable wing and the backward sweep angle of deflection of the second flappable wing, and a difference between an angle of a root spar of the first flappable wing relative to a mast of the first flappable wing.   
     
     
         23 . The method of air vehicle control of  claim 22  further comprising:
 generating a pitching torque by changing the forward angle of deflection of the first flappable wing based on its sweep angle and by changing the forward angle of deflection of the second flappable wing based on its sweep angle. 
 
     
     
         24 . The method of air vehicle control of  claim 22  further comprising:
 generating a pitching torque by changing the backward angle of deflection of the first flappable wing based on its sweep angle and by changing the backward angle of deflection of the second flappable wing based on its sweep angle. 
 
     
     
         25 . A method of air vehicle control comprising:
 providing a control assembly comprising:
 a first flappable wing having a sweep angle of travel, wherein the first flappable wing comprises a membrane attached to a root spar and a mast, the membrane having surface tension adjustable via rotation of the root spar relative to the mast; 
 a second flappable wing having a sweep angle of travel, wherein the second flappable wing comprises a second membrane attached to a second root spar and a second mast; 
 the membrane having surface tension adjustable via rotation of the second root spar relative to the second mast; 
 wherein the first flappable wing extends in a radial direction from the air vehicle and the second flappable wing extends in a radial direction from a side of the air vehicle substantially opposite the first flappable wing; and 
   generating at least one of: a pitching torque, a rolling torque and a yawing torque, by generating a difference between the luffing of the first flappable wing and the luffing of the second flappable wing by at least one of: i) variably limiting the angular travel of the root spar about the mast; and ii) varying an angle of the root spar of the first flappable wing relative to the mast of the first flappable wing.   
     
     
         26 . A method of air vehicle control of  claim 25 :
 wherein the first flappable wing further comprises a sweep angle of deflection comprising a forward sweep angle of deflection and a backward sweep angle of deflection; and   wherein a second flappable wing further comprising a sweep angle of deflection comprising a forward sweep angle of deflection and a backward sweep angle of deflection; and, the method further comprises:   generating a yawing torque, by generating at least one of: a difference between the forward sweep angle of deflection of the first flappable wing and the forward sweep angle of deflection of the second flappable wing, and a difference between the backward sweep angle of deflection of the first flappable wing and the backward sweep angle of deflection of the second flappable wing.   
     
     
         27 . A method of air vehicle control, comprising:
 flapping a first flappable wing in a forward direction of an aircraft, said first flappable wing having a leading portion and a boom extending from said leading portion;   flapping a second flappable wing in the forward direction of the aircraft; and   selectively varying an angle of the boom relative to the leading portion during said flapping to establish varying luffing of the first flappable wing to generate one of a pitching torque, a rolling torque and a yawing torque.   
     
     
         28 . The method of  claim 27 , further comprising:
 selectively swinging the leading portion of the first flappable wing about a pivot point and in a plane orthogonal to the boom to change an angle of deflection of the airfoil.   
     
     
         29 . The method of  claim 28 , further comprising:
 limiting travel of a distal end of the boom during the flapping to a predetermined sweep angle of deflection.   
     
     
         30 . A method of air vehicle control comprising:
 selectively swinging a leading portion of a first flappable wing about a pivot point and in a plane orthogonal to a root spar of the first flappable wing, the first flappable wing having a trailing edge on a side opposite from the leading portion and the first flappable wing having a boom with a distal end adjacent said trailing edge;   flapping said first flappable wing alternately in the forward and rearward directions of an aircraft; and   wherein at least one of a pitching torque, a rolling torque and a yawing torque is generated by said selectively swinging the leading portion.   
     
     
         31 . The method of  claim 30 , further comprising:
 selectively varying an angle of the boom relative to the leading portion to generate varying luffing of the first flappable wing.   
     
     
         32 . The method of  claim 30 , further comprising:
 limiting travel of the distal end of the boom during the flapping to a predetermined sweep angle of deflection;   wherein expanding travel of the distal end of the boom during the flapping generates relatively low thrust and limiting travel of the distal end of the boom during flapping generates relatively high thrust.