Method and system for using database and GPS data to linearize VOR and ILS navigation data

• US 7,337,063 B1
• Filed: 12/16/2003
• Issued: 02/26/2008
• Est. Priority Date: 12/16/2003
• Status: Active Grant

• Current Assignee: Garmin International, Inc. (Garmin Limited)
• Original Assignee: Garmin International, Inc. (Garmin Limited)
• Inventors: Lin, Zhe, Oberg, Michael
• Primary Examiner(s): Nguyen; Cuong
• Application Number:
  US10/736,969
• Time in Patent Office: 1,533 Days
• Field of Search: 701/213, 701/117, 701/120, 701/17, 701/4, 701/208, 342/36, 342/407, 244/183
• US Class Current: 701/213
• CPC Class Codes: G01S 1/14 using amplitude comparison of signals transmitted simultaneously from antennas or antenna systems having differently oriented overlapping directivity-characteristics
• CPC Class Codes: G01S 1/50 wherein the phase angle of the direction-dependent envelope signal is compared with a non-direction-dependent reference signal, e.g. VOR
• CPC Class Codes: G01S 19/15 Aircraft landing systems
• CPC Class Codes: G01S 19/39 the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 3/28 using amplitude comparison of signals derived simultaneously from receiving antennas or antenna systems having differently-oriented directivity characteristics

Abstract

A method and system for determining a deviation of a vehicle from a desired course are described. The method includes receiving bearing signals from a transmitter, accessing a database, on the vehicle, to obtain transmitter position information identifying a position of the transmitter, obtaining vehicle position information using GPS identifying a current position of the vehicle, and determining a deviation of the vehicle from the desired course utilizing the transmitter position information, the vehicle position information, and the bearing signal. The system includes a receiver receiving a bearing signal from a transmitter, a database storing transmitter position information identifying a position of the transmitter, a GPS receiver obtaining vehicle position information identifying a current position of the vehicle based on a GPS signal, and a controller determining a deviation of the vehicle from the desired course utilizing the transmitter position information, the vehicle position information, and the bearing signal.

Claims

1. A method for determining a deviation of a vehicle from a desired course, said method comprising:

receiving a bearing signal from a transmitter;

accessing a database to obtain transmitter position information and operating characteristics of the transmitter;

obtaining vehicle position information based on a GPS signal; and

determining a deviation of the vehicle from the desired course utilizing the transmitter information, the vehicle position information, and the bearing signal.

2. The method according to claim 1 wherein said receiving step comprises receiving a bearing signal from at least one of a VOR transmitter, a localizer transmitter of an instrument landing system (ILS), and a glide slope transmitter of the ILS.

3. The method according to claim 1 wherein said determining step comprises determining a linear VOR deviation based on said transmitter position information, said transmitter position information identifying latitude and longitude for a VOR transmitter.

4. The method according to claim 1 wherein said determining step comprises determining a lateral deviation of the vehicle from a desired approach to a runway based on said transmitter position information, said transmitter information identifying latitude, longitude, and runway length of a localizer transmitter.

5. The method according to claim 1 wherein said determining step comprises determining an altitude deviation from a desired altitude approach to a runway based on said transmitter position information, said transmitter position information identifying latitude, longitude, elevation and glide path angle of a glide slope transmitter.

6. The method according to claim 1 wherein said accessing step comprises obtaining from the database a glidepath angle, an elevation and a length for the runway being approached by the vehicle and said determining step determines an altitude deviation from a desired altitude approach to the runway based on a latitude and a longitude of a localizer transmitter and the elevation and length of the runway.

7. The method according to claim 1 further comprising calculating a flight director roll command utilizing the deviation.

8. The method according to claim 1 further comprising initiating a flight director roll command to an auto-pilot function utilizing the deviation.

9. The method according to claim 1 wherein said determining step partitions processing among multiple processors to calculate the deviation and resulting flight director commands.

10. The method according to claim 1 further comprising identifying a VOR cone of confusion extending from the transmitter based on the transmitter position information and vehicle position information.

11. The method according to claim 1 further comprising:

identifying when the vehicle is in a VOR cone of confusion extending from the transmitter based on the transmitter position information and vehicle position information;

initiating a flight director roll command utilizing the deviation when the vehicle is not within the cone of confusion extending from the transmitter; and

initiating a flight director roll command based on a previous heading when the vehicle is within the cone of confusion.

12. The method according to claim 1 wherein said accessing step obtains a latitude, a longitude, and an elevation for the transmitter.

13. The method according to claim 1 wherein said obtaining step obtains a latitude, a longitude, and an elevation for the vehicle.

14. The method according to claim 1 wherein the transmitter is a VOR transmitter and wherein said determining step comprises determining a distance between the VOR transmitter and the vehicle based on a latitude and longitude of the VOR transmitter and a latitude and longitude of the vehicle.

15. The method according to claim 1 wherein the transmitter is a localizer transmitter and wherein said determining step comprises determining a distance between the localizer transmitter and the vehicle based on a latitude and longitude of the localizer transmitter and a latitude and longitude of the vehicle.

16. The method according to claim 1 wherein the transmitter is a glide slope transmitter and wherein said determining step comprises determining a distance between the glide slope transmitter and the vehicle based on a latitude and longitude of the glide slope transmitter and a latitude and longitude of the vehicle.

17. The method according to claim 1 wherein the deviation is a lateral deviation from a desired approach to a runway, wherein said determining step comprises:

determining a distance, D, between the transmitter and the vehicle;

obtaining an end of runway deviation, y, through normalization of localizer deviation ε

, according to

18. The method according to claim 1 wherein the deviation is a lateral deviation from a desired back course approach to a runway, wherein said determining step comprises:

determining a distance, D, between the transmitter and the vehicle;

obtaining an end of runway deviation, y, through normalization of localizer deviation ε

, according to

19. The method according to claim 1 wherein the transmitter is a glide slope transmitter and the deviation is an altitude deviation from a desired approach to a runway, wherein said determining step comprises:

determining a distance, D, between the transmitter and the vehicle;

accessing the database to obtain a glide path angle, GPA;

determining a glide slope deviation error angle in radians according to

20. The method according to claim 1 wherein the transmitter is a VOR transmitter and wherein said determining step comprises:

determining a distance, D, between the transmitter and the vehicle;

obtaining a linear VOR deviation, d, according to d=D×

Sin(ε

), where is a VOR angular deviation.

21. The method according to claim 1 wherein the transmitter is a VOR transmitter and wherein said determining step comprises:

determining a distance, D, between the transmitter and the vehicle;

determining a height above the VOR transmitter, H, from the transmitter position information and a present vehicle altitude from an air data system; and

determining when the vehicle is in a cone of confusion, the vehicle being in the cone if H>

D×

tan(cone angle) is true, where cone angle has a nominal value of 60 degrees.

26. The method according to claim 1 wherein said determining step calculates a linear deviation.

27. The method according to claim 1 wherein said determining step calculates a lateral deviation.

22. A system for determining a deviation of a vehicle from a desired course, the system comprising:

a receiver receiving a bearing signal from a transmitter;

a database storing transmitter position information identifying a position of the transmitter;

a GPS receiver obtaining vehicle position information identifying a current position of the vehicle based on a GPS signal; and

a controller determining a deviation of the vehicle from the desired course utilizing the transmitter position information, the vehicle position information, and the bearing signal.

23. The system according to claim 22 wherein said controller determines a height of the vehicle above a transmitter based on an elevation of the transmitter and an altitude of the vehicle.

24. The system according to claim 22 wherein said controller determines a horizontal distance between a transmitter and the vehicle based on latitude and longitude of the transmitter and latitude and longitude of the vehicle.

25. The system according to claim 22 wherein said controller determines a horizontal distance, D, between a glide slope transmitter and a vehicle based on one or more of a latitude and longitude of a localizer transmitter, a latitude and longitude of the glide slope transmitter, an elevation of the runway, a length of the runway and a glide path angle (GPA) for the runway, and the vehicle position information, including latitude, longitude, and an altitude.

28. The system according to claim 22 wherein said controller determines a linear deviation.

29. The system according to claim 22 wherein said controller determines a lateral deviation.