Aerial vehicles, cooperative flying systems, and methods of operating the same

Abstract

An aerial vehicle includes a wing body. The aerial vehicle includes a plurality of rotors coupled to the wing body. Each one of the rotors includes a plurality of rotor blades. The aerial vehicle includes a drive assembly configured to rotate the rotors. The aerial vehicle includes a controller configured to selectively control thrust produced by each one of the rotors. Selective control of the thrust produced by each one of the rotors induces a pitch motion of the aerial vehicle to transition the aerial vehicle between a horizontal flight state and a vertical flight state. In the horizontal flight state, the wing body is approximately horizontal and a collective thrust from the rotors is directed forward. In the vertical flight state, the wing body is approximately vertical and the collective thrust from the plurality rotors is directed upward.

What is claimed is: 
     
         1 . An aerial vehicle having a first vehicle axis and a second vehicle axis, perpendicular to the first vehicle axis, the aerial vehicle comprising:
 a wing body having an airfoil shape and comprising:
 a first wingtip and a second wingtip, located opposite the first wingtip along the first vehicle axis; and 
 a first edge and a second edge, located opposite the first edge along the second vehicle axis; 
   a plurality of rotors coupled to the wing body, each one of the plurality of rotors comprising a plurality of rotor blades;   a drive assembly configured to rotate the plurality of rotors; and   a controller configured to selectively control thrust produced by each one of the plurality of rotors,   wherein:
 selective control of the thrust produced by each one of the plurality of rotors induces a pitch motion of the aerial vehicle to transition the aerial vehicle between a horizontal flight state and a vertical flight state; 
 in the horizontal flight state, the second vehicle axis is approximately horizontal and a collective thrust from the plurality of rotors is directed forward; and 
 in the vertical flight state, the second vehicle axis is approximately vertical and the collective thrust from the plurality of rotors is directed upward. 
   
     
     
         2 . The aerial vehicle of  claim 1 , further comprising a variable pitch mechanism configured to selectively manipulate blade pitch of the plurality of rotor blades,
 wherein the controller is configured to selectively adjust the blade pitch of the plurality of rotor blades corresponding to each one of the plurality of rotors to selectively vary at least one of the thrust and torque produced by each one of the plurality of rotors and to induce at least one of the pitch motion, a yaw motion, and a rolling motion of the aerial vehicle.   
     
     
         3 . The aerial vehicle of  claim 2 , wherein:
 the plurality of rotors further comprises:
 a first rotor and a second rotor, located opposite the first rotor along a third vehicle axis that is perpendicular to the first vehicle axis and the second vehicle axis; and 
 a third rotor and a fourth rotor, located opposite the third rotor along a fourth vehicle axis that is perpendicular to the first vehicle axis and the second vehicle axis; 
   the first rotor and the fourth rotor are configured to rotate in a first rotational direction and form a rotationally correlated first pair of the plurality of rotors; and   the second rotor and the third rotor are configured to rotate in a second rotational direction that is opposite to the first rotational direction and form a rotationally correlated second pair of the plurality of rotors.   
     
     
         4 . The aerial vehicle of  claim 3 , wherein:
 the variable pitch mechanism is configured to collectively manipulate the blade pitch of the plurality of rotor blades; and   the controller is configured to selectively vary the blade pitch of the plurality of rotor blades corresponding to the rotationally correlated first pair and the blade pitch of the plurality of rotor blades corresponding to the rotationally correlated second pair to create a torque imbalance, which generates a rotational moment about a roll axis of the aerial vehicle that induces the rolling motion of the aerial vehicle.   
     
     
         5 . The aerial vehicle of  claim 3 , wherein:
 the drive assembly is configured to manipulate a rotational speed of each one of the plurality of rotors; and   the controller is configured to selectively vary the rotational speed of the plurality of rotors corresponding to the rotationally correlated first pair and the blade pitch of the plurality of rotor blades corresponding to the rotationally correlated second pair to create an additional torque, which generates a rotational moment about a roll axis of the aerial vehicle that induces the rolling motion of the aerial vehicle.   
     
     
         6 . The aerial vehicle of  claim 3 , wherein:
 the wing body further comprises:
 a wing first section; and 
 a wing second section coupled to the wing first section along the first vehicle axis; and 
   the wing first section and the wing second section are rotatable about the first vehicle axis relative to each other in response to a variation in the thrust produced by the plurality of rotors corresponding to the rotationally correlated first pair and the thrust produced by the plurality of rotors corresponding to the rotationally correlated second pair to vary an angle of attack between the wing first section and the wing second section that induces the rolling motion of the aerial vehicle.   
     
     
         7 . The aerial vehicle of  claim 2 , wherein:
 the plurality of rotors further comprises:
 a first coaxial rotor configured to rotate in a first rotational direction; and 
 a second coaxial rotor configured to rotate in a second rotational direction that is opposite to the first rotational direction. 
   
     
     
         8 . The aerial vehicle of  claim 7 , wherein:
 the variable pitch mechanism is configured to collectively manipulate the blade pitch of the plurality of rotor blades; and   the controller is configured to collectively vary the blade pitch of the plurality of rotor blades corresponding to the first coaxial rotor and the blade pitch of the plurality of rotor blades corresponding to of the second coaxial rotor to create a torque imbalance, which generates a rotational moment about a roll axis of the aerial vehicle that induces the rolling motion of the aerial vehicle.   
     
     
         9 . The aerial vehicle of  claim 7 , wherein:
 the variable pitch mechanism is configured to independently manipulate the blade pitch of each one of the plurality of rotor blades; and   the controller is configured to cyclically vary the blade pitch of each one of the plurality of rotor blades corresponding to at least one of the first coaxial rotor and the second coaxial rotor through different sectors of a rotation cycle to induce at least one of the pitch motion and the yaw motion of the aerial vehicle.   
     
     
         10 . The aerial vehicle of  claim 7 , wherein:
 the drive assembly comprises a motor; and   the wing body further comprises:
 a wing first section coupled to the motor; and 
 a wing second section coupled to the motor opposite to the wing first section along the first vehicle axis. 
   
     
     
         11 . The aerial vehicle of  claim 7 , further comprising a duct that is concentric to the first coaxial rotor and the second coaxial rotor,
 wherein the wing body further comprises:
 a wing first section coupled to the duct; and 
 a wing second section coupled to the duct opposite to the wing first section along the first vehicle axis. 
   
     
     
         12 . The aerial vehicle of  claim 11 , wherein:
 the duct comprises:
 a leading end; and 
 a plurality of slats located at the leading end and configured to extend and retract; and 
   the controller is configured to selectively extend or retract each one of the plurality of slats to produce a thrust differential between the first coaxial rotor and the second coaxial rotor adjacent to the plurality of slats at different sectors of a rotation cycle to induce at least one of the pitch motion and the yaw motion of the aerial vehicle.   
     
     
         13 . A method of controlling an aerial vehicle comprising a wing body having an airfoil shape, a plurality of rotors coupled to the wing body, and a drive assembly configured to rotate the plurality of rotors, the method comprising:
 selectively controlling at least one of thrust and torque produced by each one of the plurality of rotors to induce at least one of a pitch motion, a yaw motion, and a rolling motion of the aerial vehicle; and   in response to the pitch motion, transitioning the aerial vehicle between a horizontal flight state in which the wing body is oriented horizontally and a collective thrust from the plurality of rotors is directed forward, and a vertical flight state in which the wing body is oriented vertically and the collective thrust from the plurality of rotors is directed upward.   
     
     
         14 . The method of  claim 13 , wherein selectively controlling at least one of the thrust and the torque produced by each one of the plurality of rotors comprises selectively adjusting blade pitch of a plurality of rotor blades corresponding to each one of the plurality of rotors. 
     
     
         15 . The method of  claim 14 , wherein:
 the plurality of rotors comprises:
 a rotationally correlated first pair configured to rotate in a first rotational direction; and 
 a rotationally correlated second pair configured to rotate in a second rotational direction that is opposite to the first rotational direction; and 
   selectively adjusting the blade pitch of the plurality of rotor blades corresponding to each one of the plurality of rotors comprises collectively varying the blade pitch of the plurality of rotor blades corresponding to at least one of the rotationally correlated first pair and the rotationally correlated second pair to create a torque imbalance, which generates a rotational moment about a roll axis of the aerial vehicle that induces the rolling motion of the aerial vehicle.   
     
     
         16 . The method of  claim 14 , wherein:
 the plurality of rotors comprises:
 a first coaxial rotor configured to rotate in a first rotational direction; and 
 a second coaxial rotor configured to rotate in a second rotational direction that is opposite to the first rotational direction; and 
   selectively adjusting the blade pitch of the plurality of rotor blades corresponding to each one of the plurality of rotors comprises collectively varying the blade pitch of the plurality of rotor blades corresponding to at least one of the first coaxial rotor and the second coaxial rotor to create a torque imbalance, which generates a rotational moment about a roll axis of the aerial vehicle that induces the rolling motion of the aerial vehicle.   
     
     
         17 . The method of  claim 16 , wherein selectively adjusting the blade pitch of the plurality of rotor blades corresponding to each one of the plurality of rotors comprises cyclically varying the blade pitch of each one of the plurality of rotor blades corresponding to at least one of the first coaxial rotor and the second coaxial rotor through different sectors of a rotation cycle to create the torque imbalance, which generates at least one of a rotational moment about a pitch axis of the aerial vehicle that induces the pitch motion of the aerial vehicle and a rotational moment about a yaw axis of the aerial vehicle that induces the yaw motion of the aerial vehicle. 
     
     
         18 . The method of  claim 13 , further comprising selectively varying at least one the thrust and the torque produced by at least one of the plurality of rotors to control at least one of the pitch motion, the yaw motion, and the rolling motion of the aerial vehicle while the aerial vehicle is in the horizontal flight state or the vertical flight state. 
     
     
         19 . A cooperative flying system comprising:
 a plurality of aerial vehicles configured to be coupled together in flight, wherein each one of the plurality of aerial vehicles comprises a wing body having a first vehicle axis and comprising a first wingtip and a second wingtip, located opposite to the first wingtip along the first vehicle axis, and a plurality of rotors coupled to the wing body;   an alignment apparatus configured to align the first wingtip of each one of the plurality of aerial vehicles with the second wingtip of a directly adjacent one of the plurality of aerial vehicles;   a coupling apparatus configured to couple the first wingtip of each one of the plurality of aerial vehicles to the second wingtip of the directly adjacent one of the plurality of aerial vehicles; and   a set of vehicle controllers configured to coordinate thrust produced by the plurality of rotors of each one of the plurality of aerial vehicles to alter at least one of a pitch angle, a yaw angle, and a roll angle of the cooperative flying system and a velocity of the cooperative flying system.   
     
     
         20 . The cooperative flying system of  claim 19 , further comprising a first formation-end, formed by the first wingtip of one of the plurality of aerial vehicles, and a second formation-end, formed by the second wingtip of another one of the plurality of aerial vehicles, wherein the plurality of aerial vehicles is arranged in one of:
 an open formation in which the first vehicle axis of each one of the plurality of aerial vehicles is coincident with the first vehicle axis of the directly adjacent one of the plurality of aerial vehicles and the first formation-end is axially opposed to the second formation-end; or   a closed formation in which the first vehicle axis of each one of the plurality of aerial vehicles intersects the first vehicle axis of the directly adjacent one of the plurality of aerial vehicles and the first formation-end is connected to the second formation-end.