CONTROL FLOWS AND FORCES IN VTOL VEHICLES

• US 20110049306A1
• Filed: 04/30/2008
• Published: 03/03/2011
• Est. Priority Date: 05/02/2007
• Status: Active Grant

• Current Assignee: Urban Aeronautics Ltd.
• Original Assignee: Urban Aeronautics Ltd.
• Inventors: Yoeli, Raphael
• Granted Patent: US 8,496,200 B2
• Time in Patent Office: Days
• US Class Current: 244/23.A
• CPC Class Codes: B64C 29/0025 the propellers being fixed relative to the fuselage

Abstract

The present application relates to VTOL vehicles with multi-function capabilities and, specifically to ducted fan arrangements that facilitate the control of forces and flows of air to control movement of the vehicle in six degrees of freedom in both primary and secondary modes of operation. Also disclosed are pitch control mechanisms for the lift propellers of VTOL vehicles: drive and transmission arrangements; a specially configured exhaust duct for directing exhaust gases from such vehicles along an upper surface of the vehicle; and shock absorbing components for the landing gear of such vehicles.

Claims

1. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, said fuselage supporting at least one forward duct and one aft duct having respective fore and aft mounted propellers arranged to force surrounding air into said ducts, and out of said ducts through respective outlets at lower ends of said ducts thereby creating a lift force;

wherein said fore and aft mounted propellers have a pitch control mechanisms with a mechanical connection between said pitch control mechanisms configured such that when said mechanical connection is shortened or lengthened, blade pitch angles of said fore and aft propellers are caused to increase or decrease in a substantially similar direction and magnitude to thereby control up and down (heave) motion of said vehicle; and

when said mechanical connection is externally acted upon substantially longitudinally so as to cause it to translate in a fore-aft direction without being shortened or lengthened, the blade pitch angles of said propellers are caused to change differentially and in opposite directions to thereby control the pitch of said vehicle.

2. The ducted air flow vehicle of claim 1 wherein said mechanical connection comprises a cable operatively connected between said fore and aft pitch control mechanisms, respectively, and wherein said mechanical connection is shortened or lengthened by a first vertically extendable actuator connected at one end to said cable, and wherein said mechanical connection is caused to move in said fore and aft direction by a second horizontally extendable actuator connected at one end to said cable and at an opposite end to said first actuator.

3. The ducted air flow vehicle of claim 1 wherein said mechanical connection comprises a cable operatively connected between fore and aft pitch control mechanisms, respectively, and wherein said mechanical connection is shortened by a first horizontally extendable actuator connected at one end of a vertically-oriented control shaft mounted for pivoting movement about a horizontal axis, said control shaft supporting a pulley assembly through which said cable passes, wherein pivoting movement of said control shaft causes said pulley assembly to rotate, thereby effectively shortening a length dimension of said cable and thereby shortening said mechanical connection.

4. The ducted air flow vehicle of claim 2 wherein said first and second actuators comprise respective piston and cylinder assemblies.

5. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, said fuselage supporting at least one forward duct and one aft duct having respective forward and aft mounted propellers arranged to force surrounding air into said ducts, and out of said ducts through respective outlets at lower ends of said ducts thereby creating a lift force;

wherein said forward and aft mounted propellers have a pitch control mechanisms with a mechanical connection between said pitch control mechanisms, said mechanical connection comprising a first dual action actuator for controlling heave of the vehicle connected at one end to a push pull rod operatively connected to the forward propeller and at an opposite end to another push pull rod operatively connected to the aft propeller; and

a second actuator for controlling pitch of the vehicle connected at one end to said first actuator and at an opposite end to said fuselage.

6. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, supporting at least one forward duct and one aft duct, said ducts having respective lift producing propellers arranged to force surrounding air through said ducts thereby creating a lift force, said respective lift producing propellers lying in a common plane; and

a substantially airfoil-shaped compartment located between said forward and aft ducts, said forward duct having an opening adjacent said compartment, and said compartment oriented upward such that a gap is created between the forward end of said compartment and the tips of the blades of the forward propeller.

7. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, supporting at least one forward duct and one aft duct, said ducts having respective lift producing propellers arranged to force surrounding air through said ducts thereby creating a lift force;

a central area formed in the fuselage between said forward and aft ducts housing a propulsion unit powering said lift-producing propellers, said propulsion unit having an exhaust pipe opening through an upper surface of said fuselage in said central area, wherein said exhaust pipe is formed with an outlet oriented to flow exhaust gases in a rearward direction, substantially parallel to and along said upper surface.

8. The vehicle of claim 7 wherein said exhaust pipe is formed with an exhaust chamber having a relatively narrow inlet end and a relatively wide outlet end configured to distribute said exhaust substantially as a film along said upper surface.

9. The vehicle of claim 8 wherein a plurality of vortex generators are mounted on top of said outlet end of said exhaust chamber.

10. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, supporting at least one forward duct and one aft duct, said ducts having respective lift producing propellers arranged to force surrounding air through said ducts thereby creating a lift force;

a central area formed in the fuselage between said forward and aft ducts, said central area having a substantially airfoil shape; and

means for achieving a wing-in-ground (WIG) effect between the fuselage and ground or other surface over which the vehicle is flying.

11. The ducted air flow vehicle of claim 10 wherein said means comprises a plurality of barrier members attached to opposite sides of said fuselage.

12. The ducted air flow vehicle of claim 10 wherein said means comprises downward and forward air flows to seal incomplete bottom surfaces of the vehicle.

13. The ducted air flow vehicle of claim 11 wherein said barrier members are substantially hollow, thereby serving as floats, enabling the vehicle to land in water.

14. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, supporting at least one forward duct and one aft duct, said ducts having respective lift producing propellers arranged to force surrounding air through said ducts thereby creating a lift force;

landing gear comprising at least two ground-engageable components, each rotatably mounted on a strut secured to said fuselage for pivoting movement, and each having a shock absorber including a piston and a cylinder, said cylinder connected at one end to said fuselage and said piston connected at a free end thereof to said strut, said shock absorber adapted to absorb landing impact; and

means for operating each said shock absorber to delay substantial shock absorption until both of said ground-engageable components contact the ground.

15. The ducted air flow vehicle of claim 14 wherein said means comprises a fluid circuit controlling flow of fluid to opposite sides of said piston including means for delaying substantial shock absorption at upon initial contact of one of said ground-engageable components with the ground, and for enabling shock absorption at said one ground-engageable component and the other ground-engageable component upon subsequent contact with the ground of said other ground-engageable component.

16. The ducted air flow vehicle of claim 15 wherein said at least two ground-engaging components comprise a pair of forward wheels and a pair of aft wheels, and wherein said means delays substantial shock absorption at a first wheel upon initial ground contact, and enables substantial shock absorption at said first wheel upon further ground contact by another wheel, at which time, substantial shock absorption is developed in all wheels substantially evenly.

17. The ducted flow vehicle of claim 16 wherein said means further enables said piston at said first wheel to be extended toward the ground, thereby allowing said first wheel to contact the ground and thus cause said substantial shock absorption at all wheels to be commenced earlier than if said piston had not been extended.

18. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, supporting at least one forward duct and one aft duct, said ducts having respective lifting fans arranged to force surrounding air into said ducts, and out of an outlet at a lower end of each of said ducts thereby creating a lift force;

a pair of thrusters supported at a rearward end of the vehicle, on opposite sides of said longitudinal axis, driven by respective first and second engines; and

a drive unit including first and second transmissions connected between said first and second engines, respectively, and a first gear box operatively connected to said aft lifting fan; and

a three-segment drive shaft extending between said first gear box and a second gear box operatively connected to said forward lifting fan, said three-segment drive shaft comprised of forward, middle and rearward segments, at least two of which lie in a different plane.

19. The vehicle of claim 18 wherein said middle segment is connected to said forward and rearward segments by third and fourth gear boxes, respectively.

20. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, supporting at least one forward duct and one aft duct, said ducts having respective lift producing propellers arranged to force surrounding air through said ducts thereby creating a lift force, said ducts each having front, rear and side openings selectively movable between open and closed positions;

a plurality of adjustable control vanes extending across inlets to said ducts, in a direction substantially parallel to said longitudinal axis;

a pair of thrusters supported in an aft location on said fuselage; and

control means for;

a. effecting motion in a first horizontal direction in a first longitudinal degree of freedom (X) of the vehicle in a primary mode of operation through varying of thrust output of said thrusters, and in a secondary mode of operation through tilting of the vehicle in Pitch (Θ

), thereby creating a horizontal and longitudinal vector component of said lift force in said first direction;

b. effecting motion in a second horizontal direction substantially perpendicular to said first direction, in a second lateral degree of freedom (Y) of the vehicle in a primary mode through deflecting said control vanes, and in a secondary mode of operation through tilting of the vehicle in Roll (Φ

), thereby creating a horizontal and lateral vector component of said lift force in said second direction; and

c. effecting motion in a third vertical direction substantially perpendicular to said first and second directions in a third vertical degree of freedom (Z) of the vehicle in a primary mode through direct variation of said lift force generated by said lift-producing propellers, and in a secondary mode through adjusting said control vanes, or adjusting said openings, to thereby affecting flow of air through said ducts and the vertical lift force in said third direction.

21. The ducted air flow vehicle of claim 20, wherein said control means is also configured for:

a. effecting yaw motion of the vehicle in a fourth degree of freedom (Ψ

) in a primary mode of operation through adjustment of said control vanes, and in a secondary mode of operation through asymmetric operation of said thrusters;

b. effecting roll motion of the vehicle in a fifth degree of freedom (Φ

) in a primary mode through similar symmetric adjustment of said control vanes in each of said fore and aft ducts, and in a secondary mode through asymmetric adjustment of said control vanes;

through moving openings on one side of said ducts to an open position;

or by adjustment of openings in the front and rear openings of said forward and aft ducts differentially on one side relative to the other side;

c. effecting pitch motion of the vehicle in a sixth degree of freedom (Θ

) in a primary mode through control of the lift-producing propellers and in a secondary mode through adjusting said control vanes differentially between said forward and aft ducts;

opening or closing of said side openings uniformly in one of said forward and aft ducts;

or through opening or closing of said front and rear openings uniformly in one of said forward and aft ducts.

22. A ducted air flow vehicle comprising:

a fuselage having a longitudinal axis, supporting at least one forward duct and one aft duct, said ducts having respective lift producing propellers arranged to force surrounding air through said ducts thereby creating a lift force;

a plurality of adjustable control vanes extending across inlets to said ducts, in a direction substantially parallel to said longitudinal axis;

a pair of thrusters supported in an aft location on said fuselage; and

control means for producing movement of the vehicle in each of six degrees of freedom by a first group of primary control elements, and alternatively, by a second group of secondary control elements.

23. The ducted air flow vehicle of claim 22 wherein said second group of secondary control elements comprises plural alternative means for producing movement in at least some of said six degrees of freedom.

24. The ducted air flow vehicle of claim 23 wherein said at least some of said six degrees of freedom include vertical movement, roll and pitch.

25. The ducted air flow of claim 24 wherein said alternative means for producing movement in a vertical direction in said secondary mode include means for effecting one or more of:

a) tilting of said control vanes in said forward and aft ducts toward or away from each other; and

/or

b) adjustment of openings in said duct walls in a substantially uniform manner.

26. The ducted air flow vehicle of claim 24 wherein said alternative means for producing roll movement in said secondary mode include means for effecting one or more of:

a) asymmetric change of control vane angles;

b) adjustment of side openings in said ducts on one side of the vehicle asymmetrically with respect to side openings on the other side of the vehicle; and

c) adjustment of louvers in front and rear openings of said forward and aft ducts differentially on one side of said front and rear openings relative to the other side of said front and rear openings.

27. The ducted air flow vehicle of claim 24 wherein said alternative means for producing pitch movement on said secondary mode include means for effecting one or more of:

a) adjustment of said control vanes in one of said forward and aft ducts relative to the other;

b) opening or closing of said side openings substantially uniformly in one of the forward and aft ducts; and

c) opening or closing of said front or rear openings substantially uniformly in said forward and aft ducts.

28. The ducted flow vehicle of claim 22 wherein said control means selectively creates symmetric and asymmetric flows of air in one or both of said forward and aft ducts.