Embedded terrain awareness warning system for aircraft

• US 6,484,072 B1
• Filed: 09/28/2001
• Issued: 11/19/2002
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Anderson, Thomas E., Shultz, John William, Hanrahan, Thomas J., Shaffer, Charles W.
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US09/965,251
• Time in Patent Office: 417 Days
• Field of Search: 701/1, 701/3, 701/4, 701/6, 701/9, 701/13, 701/14, 701/16, 244/75.R, 244/158.R, 340/945
• US Class Current: 701/9
• CPC Class Codes: G01C 23/005 Flight directors indicating arrangements specially adapted for rotary gyroscopes G01C19/32
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence

Abstract

An embedded terrain awareness warning system for aircraft being flown by a pilot includes a signal processing component, a protection component and a pilot vehicle interface. A method for providing an embedded terrain awareness warning system for aircraft being flown by a pilot includes providing a signal processing component, a protection component and a pilot vehicle interface. The signal processing component communicates with three-dimensional digital terrain elevation data and is able to take input data from aircraft sensors, aircraft computers or navigation systems and determine aircraft position and velocity. The protection component is in communication with the signal processing unit such that the protection component is able to determine if a potential controlled flight into terrain exists and is able to predict a recovery flight path to avoid terrain. The pilot vehicle interface communicates with the protection component such that the pilot vehicle interface can issue a warning to the pilot of the aircraft of impending flight into terrain, and issue a directive solution to prevent the impending flight into terrain.

Claims

1. An embedded terrain awareness warning system for aircraft, the aircraft being flown by a pilot, the system comprising:

(a) a signal processing component, the signal processing component being in communication with three-dimensional digital terrain elevation data, the three-dimensional digital terrain elevation data containing digital terrain, the signal processing component being able to take input data from aircraft sensors and determine aircraft velocity and aircraft position on the three-dimensional digital terrain elevation data;

(b) a protection component, the protection component being in communication with the signal processing component such that the protection component being able to predict a flight path of the aircraft and overlay the flight path on the digital terrain elevation data and being able to determine if a potential controlled flight into terrain situation exists, the protection component further being able to determine a recovery flight path to avoid terrain; and

(c) a pilot vehicle interface, the pilot vehicle interface communicating with the protection component such that the pilot vehicle interface can issue to the pilot of the aircraft a warning if there exists a potential impending flight into terrain, and issue to the pilot directions for a recovery flight path solution to prevent flight into terrain, the directions for a recovery flight path solution being based on the recovery flight path to avoid terrain.

2. The embedded terrain awareness warning system for aircraft of claim 1, wherein the pilot vehicle interface issues a visual and an aural warning to the pilot indicating direction and maneuver for recovery.

3. The embedded terrain awareness warning system for aircraft of claim 2, wherein the protection component predicts two flight paths, the two flight paths being a vertical recovery trajectory and an oblique recovery trajectory, the protection component setting a warning if both the vertical recovery trajectory and the oblique recovery trajectory intersect digital terrain, the warning being issued to the pilot by the pilot vehicle interface.

4. The embedded terrain awareness warning system for aircraft of claim 3, wherein the flight paths are broken down into five components, the five components include a pilot response phase, a roll response phase, a G-delay phase, a G-onset phase and a dive recovery phase.

5. The embedded terrain awareness warning system for aircraft of claim 4, wherein the warning to the pilot is issued only when both the vertical recovery trajectory and the oblique recovery trajectory intersect digital terrain for four consecutive iterations.

6. The embedded terrain awareness warning system for aircraft of claim 5, wherein the warning is cleared when either of the recovery trajectories no longer intersect the digital terrain for four consecutive iterations.

7. An embedded terrain awareness warning system for aircraft, the aircraft being flown by a pilot, the system comprising:

(a) a signal processing component, the signal processing component communicating with three-dimensional digital terrain elevation data, the three-dimensional digital terrain elevation data containing digital terrain, the signal processing component being able to take input data from aircraft sensors and determine aircraft velocity and aircraft position on the three-dimensional digital terrain elevation data;

(b) a protection component, the protection component being in communication with the signal processing component such that the protection component being able to predict flight paths of the aircraft and overlay the flight paths on the digital terrain elevation data and the protection component being able to determine if a potential controlled flight into terrain exists, the protection component further being able to determine a recovery flight path to avoid terrain, the protection component being able to predict two flight paths, the two flight paths being a vertical recovery trajectory and an oblique recovery trajectory, the vertical recovery trajectory being broken down into five components, the five components include a pilot response phase, a roll response phase, a G-delay phase, a G-onset phase and a dive recovery phase, the oblique recovery trajectory being broken down into four components, the four components include a pilot response phase, a G-delay phase, a G-onset phase and a dive recovery phase; and

(c) a pilot vehicle interface, the pilot vehicle interface communicating with the protection component such that the pilot vehicle interface being able to issue to the pilot of the aircraft a warning of impending flight into terrain, the warning is issued only when both the vertical recovery trajectory and oblique recovery trajectory intersect digital terrain on the three dimensional digital terrain elevation data for four consecutive iterations, the pilot vehicle interface also being able to issue to the pilot a flight path solution to prevent the impending flight into terrain, the flight path solution being based on the recovery flight path, the flight path solution and the warning may be visual and aural.

8. The embedded terrain awareness warning system for aircraft of claim 7, wherein the flight paths are computed based upon average accelerations using the average sines and cosines of attitude angles of the aircraft.

9. The embedded terrain awareness warning system for aircraft of claim 8, wherein the flight paths are sliced into numerous segments which are compared against the digital terrain elevation data for intersection.

10. The embedded terrain awareness warning system for aircraft of claim 9, wherein when the vertical recovery trajectory intersects the digital terrain, terrain on either side of, and perpendicular to the vertical recovery trajectory, the vertical recovery trajectory at the potential intersection point is checked for trajectory intercept.

11. The embedded terrain awareness warning system for aircraft of claim 10, wherein the warning is cleared when either of the recovery trajectories no longer intersect the digital terrain for four consecutive iterations.

12. The embedded terrain awareness warning system for aircraft of claim 11, wherein the three dimensional digital terrain elevation data is stored in a digital terrain elevation database.

13. The embedded terrain awareness warning system for aircraft of claim 12, wherein the digital terrain elevation database is contained in the signal processing component.

14. The embedded terrain awareness warning system for aircraft of claim 13, wherein the visual warning is displayed on a head-up display of the aircraft.

15. The embedded terrain awareness warning system for aircraft of claim 14, wherein the aural warnings are directive and convey the sense of urgency required by the situation.

16. A method for providing an embedded terrain awareness warning system to aircraft, the aircraft being flown by a pilot, the method comprising:

(a) providing three-dimensional digital terrain elevation data;

(b) providing a signal processing component, the signal processing component being able to take input data from aircraft sensors and the three-dimensional digital terrain elevation data, the signal processing component also being able to determine aircraft velocity and position on the three-dimensional digital terrain elevation data;

(c) providing a protection component, the protection component being in communication with the signal processing component such that the protection component being able to predict flight paths of the aircraft and overlay the flight paths on the digital terrain elevation data and being able to determine if a potential controlled flight into terrain situation exists, the protection component being able determine a recovery flight path to avoid terrain; and

(d) providing a pilot vehicle interface, the pilot vehicle interface communicating with the protection component such that the pilot vehicle interface can issue to the pilot of the aircraft a warning if there exists a potential impending flight into terrain, and issue to the pilot directions for a recovery flight path solution to prevent flight into terrain, the recovery flight path solution being based on the recovery flight path to avoid terrain.

17. The method of claim 16, wherein the pilot vehicle interface provides a visual and aural warning to the pilot indicating the direction and maneuver for recovery.

18. The method of claim 17, wherein the protection component being able to predict two flight paths, a vertical recovery trajectory and an oblique recovery trajectory, the vertical recovery trajectory being broken down into five components, the five components include a pilot response phase, a roll response phase, a G-delay phase, a G-onset phase and a dive recovery phase, the oblique recovery trajectory being broken down into four components, the four components include a pilot response phase, a G-delay phase, a G-onset phase and a dive recovery phase.

19. The method of claim 18, wherein the warning is issued only when both the vertical recovery trajectory and oblique recovery trajectory intersect digital terrain on the three dimensional digital terrain elevation data for four consecutive iterations, the pilot vehicle interface also being able to issue to the pilot a flight path solution to prevent the impending flight into terrain, the flight path solution being based on the recovery flight path, the flight path solution and the warning may be visual and aural.

20. An embedded terrain awareness warning system for aircraft, the aircraft being flown by a pilot, the system comprising:

(a) a signal processing component, the signal processing component being in communication with three-dimensional digital terrain elevation data, the three-dimensional digital terrain elevation data containing digital terrain, the signal processing component having a determination means for taking input data from aircraft sensors and determining aircraft velocity and aircraft position on the three-dimensional digital terrain elevation data;

(b) a protection component, the protection component being in communication with the signal processing component, the protection component having a prediction means for predicting a flight path of the aircraft and overlaying the flight path on the digital terrain elevation data and determining if a potential controlled flight into terrain situation exists, the protection component further having a recovery flight path determination means for determining a recovery flight path to avoid terrain; and

(c) a pilot vehicle interface, the pilot vehicle interface communicating with the protection component, the pilot vehicle interface having an issuance means for issuing to the pilot of the aircraft a warning if there exists a potential impending flight into terrain, and issuing to the pilot directions for a recovery flight path solution to prevent flight into terrain, the directions for a recovery flight path solution being based on the recovery flight path to avoid terrain.

21. A computer software system aboard an aircraft being flown by a pilot, the system having a set of instructions for controlling a general purpose digital computer in performing a desired function, the functions comprising:

(a) taking input data from aircraft sensors and three-dimensional digital terrain elevation data and determining aircraft velocity and position on the three-dimensional digital terrain elevation data;

(b) predicting flight paths of the aircraft and overlaying the flight paths on the digital terrain elevation data and determining if a potential controlled flight into terrain situation exists;

(c) determining a recovery flight path to avoid terrain;

(d) issuing to the pilot of the aircraft a warning if there exists a potential impending flight into terrain; and

(e) issuing to the pilot directions for a recovery flight path solution to prevent flight into terrain, the recovery flight path solution being based on the recovery flight path to avoid terrain.