Unmanned Aerial Vehicle Drag Augmentation by Reverse Propeller Rotation

• US 20120181388A1
• Filed: 01/14/2011
• Published: 07/19/2012
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: Aerovironment
• Original Assignee: Aerovironment
• Inventors: Cowley, Martyn
• Granted Patent: US 8,800,936 B2
• Time in Patent Office: Days
• US Class Current: 244/175
• CPC Class Codes: B64C 11/002 Braking propellers, e.g. for measuring the power output of an engine
• CPC Class Codes: B64C 11/04 Blade mountings
• CPC Class Codes: B64C 11/08 for non-adjustable blades
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/25 Fixed-wing aircraft VTOL aircraft B64U10/20
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: B64U 30/10 Wings
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: B64U 70/60 Take-off or landing of UAVs from a runway using their own power
• CPC Class Codes: G05D 1/0676 specially adapted for landing

Abstract

An air vehicle configured to augment effective drag to change the rate of descent of the air vehicle in flight via propeller shaft rotation direction reversal, i.e., thrust reversal.

Claims

1. An air vehicle comprising:

at least one propeller, each propeller comprising at lease one blade having a constant pitch angle;

at least one propeller motor configured to reverse propeller rotation rate of the at least one propeller while the air vehicle is in flight; and

an autopilot configured to maintain airspeed of the air vehicle above stall conditions while the air vehicle is in flight.

2. The air vehicle of claim 1 wherein the motor is configured to drive the propeller via a propeller shaft, and wherein the motor is an electrical motor configured to drive the propeller shaft in either of two angular directions.

3. The air vehicle of claim 1 wherein the at least one propeller is at least one forward-mounted tractor propeller.

4. The air vehicle of claim 1 wherein the at least one propeller is at least one aft-mounted pusher propeller.

5. A method of in-flight augmentation of an air vehicle descent rate comprising:

regulating, via an autopilot, an airspeed value of the air vehicle; and

generating an input to effect a change in the in-flight descent rate of the air vehicle via rotation rate reversal of at least one propeller of the air vehicle, each propeller comprising at lease one blade having a constant pitch angle; and

rotating, via a motor and responsive to the input, the propeller shaft in a direction of rotation for generating forward air vehicle thrust.

7. The method of claim 5 wherein the motor driving the at least one propeller is an electrical motor configured to drive the at least one propeller in two angular directions.

8. The air vehicle of claim 5 wherein the at least one propeller is at least one forward-mounted tractor propeller.

9. The air vehicle of claim 5 wherein the at least one propeller is at least one aft-mounted pusher propeller.

6. (canceled)