Precision Approach Control

• US 20080071431A1
• Filed: 09/19/2006
• Published: 03/20/2008
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Dockter, Gregory E., Graham, Jason, Caldwell, Donald G.
• Granted Patent: US 7,693,617 B2
• Time in Patent Office: Days
• US Class Current: 701/3
• CPC Class Codes: B63B 35/50 Vessels or floating structures for aircraft aircraft carriers B63G11/00; flying-boat hulls, other flotation means for aircraft B64
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G05D 1/0684 on a moving platform, e.g. aircraft carrier

Abstract

An aircraft control system for operations close to the ground includes a camera having a rangefinder for measuring the azimuth, elevation and slant range from a fixed point on the aircraft relative to a selected target point on a surface below the aircraft, a navigation system for measuring the latitude and longitude of the aircraft on the surface, a computer for computing the position of the fixed point on the aircraft relative to the target point from the respective measurements of the camera and the navigation system, and a controller for controlling the movement of the aircraft such that the fixed point is positioned at a selected position above the selected target point on the surface. The controller may also include an automatic tracking mechanism for maintaining the position of the fixed point on the aircraft at the selected position above a moving object.

Claims

1. An aircraft command and control system, comprising:

a camera, including a rangefinder, disposed aboard the aircraft for measuring an azimuth angle, an elevation angle and a slant range from a fixed point on the aircraft relative to a selected target point on a surface located below the aircraft;

a navigation system disposed aboard the aircraft for measuring a latitude and a longitude of a point on the surface that is disposed perpendicularly below the fixed point on the aircraft;

a computer for computing the position of the fixed point on the aircraft relative to the target point on the surface from the respective measurements of the camera and the navigation system; and

,

a controller for controlling the movement of the aircraft such that the fixed point on the aircraft is positioned at a selected azimuth angle, elevation angle and slant range above the selected target point on the surface.

2. The system of claim 1, wherein the rangefinder of the camera comprises a laser rangefinder.

4. The system of claim 1, wherein the navigation system comprises a Global Positioning Satellite (GPS) system, an Inertial Navigation System (INS), or both a GPS and an INS.

5. The system of claim 1, wherein the aircraft comprises a helicopter or an aerial vehicle.

6. The system of claim 1, wherein the aircraft is unmanned.

7. The system of claim 6, wherein the aircraft is controlled from a ground control station remote from the aircraft.

8. The system of claim 7, further comprising a Graphical User Interface (GUI) useable by an operator of the aircraft for controlling the position of the aircraft relative to the target point.

11. The system of claim 1, wherein the target point comprises an object moving on the surface, and further comprising a tracking mechanism for automatically maintaining the position of the fixed point on the aircraft at the selected azimuth angle, elevation angle and slant range above the moving object.

12. A method for controlling the position of a fixed point on an aircraft at a selected azimuth angle, elevation angle and slant range above a selected target point on a surface located below the aircraft, the method comprising:

providing the aircraft with the command and control system of claim 1; and

,

controlling the position of the fixed point on the aircraft relative to the target point with the command and control system.

13. A method for maintaining an aircraft at a selected slant range above an object moving over a surface, the method comprising:

providing the aircraft with the command and control system of claim 1;

controlling the aircraft with the command and control system such that the fixed point on the aircraft is disposed at the selected slant range above the moving object; and

,

controlling the movement of the aircraft with the command and control system such that the aircraft remains at the selected slant range above the moving object.

14. A method for picking up a cargo load disposed on a surface with a helicopter, the method comprising:

providing the helicopter with the command and control system of claim 1;

positioning a cargo hook on the helicopter immediately above the load using the command and control system;

attaching the load to the cargo hook; and

,

lifting the load off of the surface with the helicopter.

15. A method for dropping off a cargo load carried on a cargo hook below a helicopter at a selected target point on a surface, the method comprising:

providing the helicopter with the command and control system of claim 1;

positioning the load immediately above the selected target point using the command and control system; and

, detaching the load from the hook such that the load is disposed at the selected target point on the surface.

16. A method for landing a helicopter at a selected target point on a surface, the method comprising:

providing the aircraft with the command and control system of claim 1; and

,

positioning landing gear of the helicopter immediately above the target point with the command and control system; and

,

decreasing the altitude of the helicopter until the landing gear engages the surface.

3. The system of clam 1, wherein the camera is supported on gimbals, and wherein the gimbals are used to measure the azimuth and elevation angles to the target point.

9. The system of clam 6, wherein the surface comprises a surface of a marine vessel.

10. The system of claim 9, wherein the marine vessel is moving.

17. A method for controlling the position of a fixed point on an aircraft at a selected azimuth angle, elevation angle and slant range above a selected target point on a surface located below the aircraft, the method comprising:

measuring an azimuth angle, an elevation angle and a slant range from the fixed point on the aircraft relative to a selected target point on a surface located below the aircraft with a camera having a rangefinder;

measuring a latitude and a longitude of a point on the surface that is disposed perpendicularly below the fixed point on the aircraft with a navigation system;

computing the position of the fixed point on the aircraft relative to the target point on the surface from the respective measurements of the camera and the navigation system with a computer; and

,

controlling the movement of the aircraft such that the fixed point on the aircraft is positioned at the selected azimuth angle, elevation angle and slant range above the selected target point on the surface with a controller.

18. The method of claim 17, wherein the camera is supported on gimbals, and wherein measuring the azimuth and elevation angles to the target point comprises:

aiming the camera at the target point; and

,

measuring the azimuth and elevation angles using the gimbals of the camera.

19. The method of claim 17, wherein the aircraft comprises a helicopter and the fixed point comprises a cargo hook on the helicopter, and further comprising:

positioning the cargo hook immediately above a cargo load disposed on the surface;

attaching the load to the cargo hook; and

,

lifting the load off of the surface with the helicopter.

20. The method of claim 17, wherein the aircraft comprises a helicopter and the fixed point comprises a load carried below the helicopter, and further comprising:

positioning the load immediately above the selected target point on the surface; and

,

detaching the load from the helicopter such that the load is disposed on the surface at the selected target point on the surface.

21. The method of claim 17, wherein the selected target point is an object moving over the surface, and further comprising:

maintaining the position of the fixed point on the aircraft at the selected azimuth angle, elevation angle and slant range above the moving object.

22. The method of claim 17, wherein the aircraft is a helicopter and the fixed point comprises a landing gear of the helicopter, and further comprising:

positioning the landing gear immediately above the selected target point; and

,

decreasing the altitude of the helicopter until the landing gear engages the surface at the selected target point.

23. An improved precision approach control system for an aircraft of a type incorporating a navigation system comprising at least one of a Global Positioning Satellite (GPS) system and an Inertial Navigation System (INS), wherein the improvement comprises:

a camera, including a rangefinder, disposed aboard the aircraft for measuring an azimuth angle, an elevation angle and a slant range from a fixed point on the aircraft relative to a selected target point on a surface located below the aircraft; and

,

a computer for computing the position of the fixed point on the aircraft relative to the target point on the surface from the respective measurements of the camera and the navigation system.

24. The system of claim 23, wherein the improvement further comprises a controller for controlling the movement of the aircraft such that the fixed point on the aircraft is positioned at a selected azimuth angle, elevation angle and slant range above the selected target point on the surface.

25. The system of claim 24, wherein the controller includes a tracking mechanism for automatically maintaining the position of the fixed point on the aircraft at the selected azimuth angle, elevation angle and slant range above the moving object.