Automatic guidance system for flight vehicle having parafoil and navigation guidance apparatus for the system

• US 6,343,244 B1
• Filed: 11/22/1999
• Issued: 01/29/2002
• Est. Priority Date: 11/24/1998
• Status: Expired due to Term

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Inventors: Amito, Atsushi, Yoneda, Hiroshi
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US09/444,834
• Time in Patent Office: 799 Days
• Field of Search: 701/1, 701/3, 701/5, 701/200, 701/207, 701/213
• US Class Current: 701/3
• CPC Class Codes: G05D 1/105 specially adapted for unpowered flight, e.g. glider, parachuting, forced landing parachutes per se B64D17/00

Abstract

An automatic guidance system guides a flight vehicle having a para foil to a target grounding point. The system opens the para foil of the flight vehicle dropped in a predetermined area above the target grounding point. The system estimates wind velocity and wind direction after the para foil of the flight vehicle is opened. Then, the system determines the landing flight path of the flight vehicle based on the estimated wind velocity and wind direction, guides the flight of the flight vehicle to the determined landing flight path and descends the flight vehicle according to the landing flight path.

Claims

1. An automatic guidance system for guiding a flight vehicle having a parafoil to a target grounding point, comprising the steps of:

opening the parafoil of said flight vehicle dropped in a predetermined area above a target grounding point;

estimating wind velocity and wind direction after the parafoil of said flight vehicle is opened;

determining a landing flight path of said flight vehicle based on said estimated wind velocity and wind direction;

guiding the flight of said flight vehicle to a position close to said determined landing flight path; and

descending said flight vehicle according to said landing flight path.

2. An automatic guidance system according to claim 1, wherein, when the parafoil of said flight vehicle is dropped in a predetermined area on the windward of and above the target grounding point, said determining step determines the landing flight path so that said flight vehicle descends from the windward to the leeward, and said descending step descends from the windward to the leeward according to the said landing flight path.

3. An automatic guidance system according to claim 2, further comprising the step of:

changing an attitude of said flight vehicle so as to direct said flight vehicle to the leeward in the position close to said landing flight path.

4. An automatic guidance system according to claim 2, wherein said guiding step guides the flight of the flight vehicle in a direction perpendicular to the estimated wind direction.

5. An automatic guidance system according to claim 2, further comprising the step of:

landing said flight vehicle by changing the attitude of said flight vehicle so as to direct said flight vehicle windward on the leeward of said target grounding point.

6. An automatic guidance system according to claim 4, further comprising the step of:

adjusting the altitude of said flight vehicle before said descending step.

7. An automatic guidance system according to claim 6, wherein, in said adjusting step, said altitude adjustment of said flight vehicle is performed by a continuous turn of said flight vehicle.

8. An automatic guidance system according to claim 6, wherein, in said adjusting step, said altitude adjustment of said flight vehicle is performed by a race track turn of said flight vehicle.

9. An automatic guidance system according to claim 1, wherein, in said estimating step, said estimation of said wind velocity and wind direction is calculated by the ground speed of said flight vehicle obtained by GPS or DGPS.

10. An automatic guidance system according to claim 1, wherein, in said estimating step, said estimation of said wind velocity and wind direction is calculated by the ground speed of said flight vehicle obtained by GPS or DGPS, the azimuth of said flight vehicle and the airspeed of said flight vehicle.

11. A navigation guidance apparatus for guiding a flight vehicle having a parafoil to a target grounding point, comprising:

a wind-velocity and wind-direction estimating unit estimating wind velocity and wind direction after the parafoil of said flight vehicle is opened;

a land flight path determining unit determining a landing flight path of said flight vehicle based on the wind velocity and wind direction estimated by said wind-velocity and wind-direction estimating unit; and

a flight control unit controlling said parafoil so that said flight vehicle descends according to the landing flight path determined by said flight path determining unit.

12. A navigation guidance apparatus according to claim 11, wherein said wind-velocity and wind-direction estimating unit includes:

a GPS receiver; and

a flight computer estimating the wind velocity and wind direction based on ground speed vectors obtained by said GPS receiver.

13. A navigation guidance apparatus according to claim 12, wherein said wind-velocity and wind-direction estimating unit further includes a DGPS beacon receiver.

14. A navigation guidance apparatus according to claim 12, wherein said flight path determining unit is the flight computer determining the flight path based on the estimated wind velocity and wind direction, and

wherein said flight control unit is an actuator for tugging control lines of said parafoil under the control of said flight computer.

15. A navigation guidance apparatus according to claim 11, wherein said wind-velocity and wind-direction estimating unit includes:

a GPS receiver;

a magnetic direction sensor detecting the azimuth of said flight vehicle; and

a flight computer estimating the wind velocity and wind direction based on ground speed vectors obtained by said GPS receiver, the azimuth of said flight vehicle obtained by said magnetic direction sensor and the airspeed of said flight vehicle.

16. A navigation guidance apparatus according to claim 15, wherein said flight path determining unit is the flight computer determining the flight path based on the estimated wind velocity and wind direction, and

wherein said flight control unit is an actuator for tugging control lines of said parafoil under the control of said flight computer.

17. A navigation guidance apparatus according to claim 11, wherein said wind-velocity and wind-direction estimating unit further includes a DGPS beacon receiver.