Method of positioning perspective terrain on SVS primary flight displays using terrain database and radio altitude

• US 7,715,978 B1
• Filed: 01/31/2007
• Issued: 05/11/2010
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: Postnikov, Alex, Barber, Sarah, Pelzer, Andrew M., Wenger, Jason C.
• Primary Examiner(s): Zanelli; Michael J.
• Application Number:
  US11/700,530
• Time in Patent Office: 1,196 Days
• Field of Search: None
• US Class Current: 701/200
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G08G 5/0052 for cruising combined instruments indicating more than one navigational value G01C23/00
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935

Abstract

The present invention is directed to a method of positioning perspective terrain on a SVS (Synthetic Vision System) based on a navigation solution, the vertical component of which is calculated utilizing a terrain database and sensing unit (which provides height above terrain). The terrain database provides elevation of terrain above MSL. A sensor, such as a GNSS sensor, may be utilized to calculate the navigation solution. In alternative embodiments, the navigation solution is calculated differently based upon the phase of flight. In one, the vertical component calculation utilizes the sensing unit at or below the sensing unit'"'"'s rated altitude. In another, vertical component calculation blends the sensing unit with the sensor. The blending may be based upon percentages based upon altitude or utilize filtering such as Kalman filtering. The present invention is particularly advantageous for close to ground operations, insuring perspective terrain will stay consistent with the real world.

Claims

1. A display assembly, comprising:

a processing unit for calculating a perspective terrain and calculating a navigation solution, the navigation solution including a vertical component;

a display for displaying the perspective terrain, the perspective terrain positioned on the display based upon the navigation solution;

a sensing unit, which provides height above terrain; and

a terrain database;

wherein the processing unit is coupled to the display, the sensing unit is coupled to the processing unit, the terrain database is coupled to the processing unit, and the processing unit calculates the vertical component of the navigation solution utilizing at least the sensing unit and the terrain database.

2. The display assembly as claimed in claim 1, wherein the display assembly is incorporated into a SVS(Synthetic Vision System).

3. The display assembly as claimed in claim 1, wherein the sensing unit is selected from a radio altimeter and a laser rangefinder.

4. The display assembly as claimed in claim 1, wherein the display assembly further comprises at least one sensor selected from a GNSS (Global Navigation Satellite System) sensor, a barometric altitude sensor, an ADC (Air Data Computer) sensor, and an IRS (Inertial Reference System) sensor, the sensor is coupled to the processing unit, and the processing unit calculates the navigation solution utilizing the sensor.

5. The display assembly as claimed in claim 4, wherein the sensing unit includes a rated altitude and the processing unit utilizes at least the sensing unit to calculate the vertical component of the navigation solution when the sensing unit is approximately at or below the rated altitude.

6. The display assembly as claimed in claim 5, wherein the rated altitude is less than or equal to approximately twenty-five hundred feet.

7. The display assembly as claimed in claim 5, wherein the processing unit blends the sensing unit and the sensor in calculating the vertical component of the navigation solution.

8. A method of displaying perspective terrain on a display, comprising the steps of:

providing a display;

providing a sensing unit, which provides height above terrain;

providing a terrain database;

calculating a navigation solution which includes a vertical component, comprising the steps of;

determining current geographic location;

receiving altitude information from the sensing unit and the terrain database; and

calculating the vertical component of the navigation solution utilizing at least the sensing unit and the terrain database;

calculating perspective terrain utilizing navigation solution and terrain database;

displaying a perspective terrain on the display; and

positioning the perspective terrain on the display based upon the navigation solution.

9. The method of claim 8, wherein the display is incorporated into a SVS (Synthetic Vision System).

10. The method of claim 8, wherein the sensing unit is selected from a radio altimeter and a laser rangefinder.

11. The method of claim 8, wherein the navigation solution is calculated utilizing at least one sensor selected from a GNSS (Global Navigation Satellite System) sensor, a barometric altitude sensor, an ADC (Air Data Computer) sensor, and an IRS (Inertial Reference System) sensor.

12. The method of claim 11, wherein the sensing unit includes a rated altitude and the vertical component of the navigation solution is calculated utilizing the sensing unit when the sensing unit is approximately at or below the rated altitude.

13. The method of claim 12, wherein the rated altitude is less than or equal to approximately twenty-five hundred feet.

14. The method as claimed in claim 12, wherein sensing unit and sensor are blended in the calculation of the vertical component of the navigation solution.

15. An SVS (Synthetic Vision System), comprising:

a sensing unit, which provides height above terrain;

a terrain database;

a processing unit, coupled to the sensing unit and to the terrain database, which calculates a perspective terrain and calculates a navigation solution including a vertical component utilizing at least the sensing unit and terrain database; and

a display, coupled to the processing unit, which displays a perspective terrain positioned based upon the navigation solution.

16. The SVS as claimed in claim 15, wherein the sensing unit is selected from a radio altimeter and a laser rangefinder.

17. The SVS as claimed in claim 15, wherein the SVS further comprises at least one sensor selected from a GNSS (Global Navigation Satellite System) sensor, a barometric altitude sensor, an ADC (Air Data Computer) sensor, and an IRS (Inertial Reference System) sensor, the sensor is coupled to the processing unit, and the processing unit calculates the navigation solution utilizing the sensor.

18. The SVS as claimed in claim 17, wherein the sensing unit includes a rated altitude and the processing unit calculates the vertical component of the navigation solution utilizing the sensing unit when the sensing unit is approximately at or below the rated altitude.

19. The SVS as claimed in claim 18, wherein the rated altitude is less than or equal to approximately twenty-five hundred feet.

20. The SVS as claimed in claim 18, wherein the processing unit blends the sensing unit and the sensor in calculating the vertical component of the navigation solution.