Personal navigation using terrain-correlation and/or signal-of-opportunity information

• US 20050197769A1
• Filed: 02/25/2005
• Published: 09/08/2005
• Est. Priority Date: 03/02/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Hawkinson, Wesley J., Soehren, Wayne A., Bye, Charles T.
• Granted Patent: US 7,305,303 B2
• Time in Patent Office: Days
• US Class Current: 701/220
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments

Abstract

A navigation system includes an inertial navigation unit. The navigation system also includes a Kalman filter that generates corrective feedback for use by the inertial navigation unit. The Kalman filter generates the corrective feedback as a function of at least one of GPS/DGPS information, sensor information, user input, terrain correlation information, signal-of-opportunity information, and/or position information output by a motion classifier.

Claims

1. A navigation system comprising:

a plurality of sensors, wherein each sensor outputs sensor information, wherein the plurality of sensors comprises an altitude sensor, wherein the sensor information output by the altitude sensor comprises altitude information;

an inertial navigation unit communicatively coupled to at least one of the plurality of sensors to generate a navigation solution based on at least a portion of the sensor information;

a motion classifier communicatively coupled to at least one of the plurality of sensors, wherein the motion classifier generates position information based on at least a portion of the sensor information;

a terrain correlator communicatively coupled to the altitude sensor, wherein the terrain correlator generates terrain-correlation information based on the altitude information; and

a Kalman filter communicatively coupled to the inertial navigation unit and the motion classifier, wherein the Kalman filter generates corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information and the position information;

wherein the corrective feedback is used by the inertial navigation unit to generate the navigation solution.

2. The navigation system of claim 1, wherein the altitude information comprises at least one of:

absolute altitude information, relative altitude information, altitude change information, and altitude gradient information.

3. The navigation system of claim 1, wherein the terrain-correlation information comprises position error information.

4. The navigation system of claim 1, wherein the terrain correlator generates the terrain-correlation information based on the navigation solution.

5. The navigation system of claim 1, wherein the terrain correlator implements a minimum absolute differences algorithm to generate the terrain-correlation information.

6. The navigation system of claim 1, further comprising at least one of:

a global positioning satellite receiver to receive at least one global positioning satellite radio frequency signal, wherein the global positioning satellite receiver is communicatively coupled to the Kalman filter;

a differential global positioning satellite receiver to receive at least one global positioning satellite radio frequency signal, wherein the differential global positioning satellite receiver is communicatively coupled to the Kalman filter;

a user interface to receive user input, wherein the user interface is communicatively coupled to the Kalman filter; and

a signal-of-opportunity interface to receive at least one signal of opportunity, wherein the signal-of-opportunity interface is communicatively coupled to the Kalman filter.

7. The navigation system of claim 6, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using loosely coupled integration.

8. The navigation system of claim 6, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using tightly coupled integration.

9. The navigation system of claim 6, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using ultra-tightly coupled integration.

10. The navigation system of claim 1, wherein the plurality of sensors comprises an inertial sensor and a magnetic sensor.

11. The navigation system of claim 1, wherein the inertial navigation unit generates a navigation confidence associated with the navigation solution.

12. The navigation system of claim 1, further comprising a programmable processor to execute software, wherein the software comprises at least one of the inertial navigation unit, the terrain correlator, the motion classifier, and the Kalman filter.

13. A method comprising:

receiving sensor information about a plurality of physical attributes associated with a navigation system, wherein the sensor information comprises altitude information about an altitude attribute associated with the navigation system;

generating an inertial navigation solution based on at least a portion of the sensor information;

classifying a motion based on at least a portion of the sensor information in order to generate position information;

correlating the altitude information with reference terrain information in order to generate terrain-correlation information;

using a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information and the position information; and

using the corrective feedback to generate the navigation solution.

14. Software embodied on a storage medium comprising a plurality of program instructions operable to cause a processor to:

receive sensor information output by a plurality of sensors, wherein the plurality of sensors comprises an altitude sensor, wherein the sensor information output by the altitude sensor comprises altitude information;

generate an inertial navigation solution based on at least a portion of the sensor information;

classify a motion based on at least a portion of the sensor information in order to generate position information;

correlate the altitude information with reference terrain information in order to generate terrain-correlation information;

use a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information and the position information; and

use the corrective feedback to generate the navigation solution.

15. An apparatus comprising:

means for receiving sensor information about a plurality of physical attributes associated with a navigation system, wherein the sensor information comprises altitude information about an altitude attribute associated with the navigation system;

means for generating an inertial navigation solution based on at least a portion of the sensor information;

means for classifying a motion based on at least a portion of the sensor information in order to generate position information;

means for correlating the altitude information with reference terrain information in order to generate terrain-correlation information;

means for using a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information and the position information; and

means for using the corrective feedback to generate the navigation solution.

16. A navigation system comprising:

a plurality of sensors, wherein each sensor outputs sensor information, wherein the plurality of sensors comprises an altitude sensor, wherein the sensor information output by the altitude sensor comprises altitude information;

an inertial navigation unit communicatively coupled to at least one of the plurality of sensors to generate a navigation solution based on at least a portion of the sensor information;

a motion classifier communicatively coupled to at least one of the plurality of sensors, wherein the motion classifier generates position information based on at least a portion of the sensor information;

a terrain correlator communicatively coupled to the altitude sensor, wherein the terrain correlator generates terrain-correlation information based on the altitude information; and

a Kalman filter communicatively coupled to the inertial navigation unit, the motion classifier, and the terrain correlator, wherein the Kalman filter generates corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information, and the terrain-correlation information;

wherein the corrective feedback is used by the inertial navigation unit to generate the navigation solution.

17. The navigation system of claim 16, further comprising at least one of:

a global positioning satellite receiver to receive at least one global positioning satellite radio frequency signal, wherein the global positioning satellite receiver is communicatively coupled to the Kalman filter;

a differential global positioning satellite receiver to receive at least one global positioning satellite radio frequency signal, wherein the differential global positioning satellite receiver is communicatively coupled to the Kalman filter;

a user interface to receive user input, wherein the user interface is communicatively coupled to the Kalman filter; and

a signal-of-opportunity interface to receive at least one signal of opportunity, wherein the signal-of-opportunity interface is communicatively coupled to the Kalman filter.

18. The navigation system of claim 17, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using loosely coupled integration.

19. The navigation system of claim 17, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using tightly coupled integration.

20. The navigation system of claim 17, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using ultra-tightly coupled integration.

21. A method comprising:

receiving sensor information about a plurality of physical attributes associated with a navigation system, wherein the sensor information comprises altitude information about an altitude attribute associated with the navigation system;

generating an inertial navigation solution based on at least a portion of the sensor information;

classifying a motion based on at least a portion of the sensor information in order to generate position information;

correlating the altitude information with reference terrain information in order to generate terrain-correlation information;

using a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information, and the terrain-correlation information; and

using the corrective feedback to generate the navigation solution.

22. Software embodied on a storage medium comprising a plurality of program instructions operable to cause a processor to:

receive sensor information output by a plurality of sensors, wherein the plurality of sensors comprises an altitude sensor, wherein the sensor information output by the altitude sensor comprises altitude information;

receiving sensor information about a plurality of physical attributes associated with a navigation system, wherein the sensor information comprises altitude information about an altitude attribute associated with the navigation system;

generate an inertial navigation solution based on at least a portion of the sensor information;

classify a motion based on at least a portion of the sensor information in order to generate position information;

correlate the altitude information with reference terrain information in order to generate terrain-correlation information;

use a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information, and the terrain-correlation information; and

use the corrective feedback to generate the navigation solution.

23. An apparatus comprising:

means for receiving sensor information about a plurality of physical attributes associated with a navigation system, wherein the sensor information comprises altitude information about an altitude attribute associated with the navigation system;

means for generating an inertial navigation solution based on at least a portion of the sensor information;

means for classifying a motion based on at least a portion of the sensor information in order to generate position information;

means for correlating the altitude information with reference terrain information in order to generate terrain-correlation information;

means for using a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information, and the terrain-correlation information; and

means for using the corrective feedback to generate the navigation solution.

24. A navigation system comprising:

a plurality of sensors, wherein each sensor outputs sensor information, wherein the plurality of sensors comprises an altitude sensor, wherein the sensor information output by the altitude sensor comprises altitude information;

an inertial navigation unit communicatively coupled to at least one of the plurality of sensors to generate a navigation solution based on at least a portion of the sensor information;

a motion classifier communicatively coupled to at least one of the plurality of sensors, wherein the motion classifier generates position information based on at least a portion of the sensor information;

a signal-of-opportunity interface to receive at least one signal of opportunity and to generate signal-of-opportunity information based on the signal of opportunity;

a Kalman filter communicatively coupled to the inertial navigation unit, the motion classifier, and the signal-of-opportunity interface, wherein the Kalman filter generates corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information output, and the signal-of-opportunity information;

wherein the corrective feedback is used by the inertial navigation unit to generate the navigation solution.

25. The navigation system of claim 24, wherein the signal of opportunity comprises at least one of a broadcast television signal, a broadcast radio signal, a data networking signal, and an interference signal.

26. The navigation system of claim 24, further comprising at least one of:

a global positioning satellite receiver to receive at least one global positioning satellite radio frequency signal, wherein the global positioning satellite receiver is communicatively coupled to the Kalman filter;

a differential global positioning satellite receiver to receive at least one global positioning satellite radio frequency signal, wherein the differential global positioning satellite receiver is communicatively coupled to the Kalman filter;

a user interface to receive user input, wherein the user interface is communicatively coupled to the Kalman filter; and

a signal-of-opportunity interface to receive at least one signal of opportunity, wherein the signal-of-opportunity interface is communicatively coupled to the Kalman filter.

27. The navigation system of claim 26, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using loosely coupled integration.

28. The navigation system of claim 26, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using tightly coupled integration.

29. The navigation system of claim 26, wherein at least one of the global positioning satellite receiver and the differential global positioning satellite receiver is integrated with the inertial navigation unit using ultra-tightly coupled integration.

30. A method comprising:

receiving sensor information about a plurality of physical attributes associated with a navigation system, wherein the sensor information comprises altitude information about an altitude attribute associated with the navigation system;

generating an inertial navigation solution based on at least a portion of the sensor information;

classifying a motion based on at least a portion of the sensor information in order to generate position information;

receiving at least one signal of opportunity and generating signal-of-opportunity information based on the signal of opportunity;

using a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information, and the signal-of-opportunity information;

using the corrective feedback to generate the navigation solution.

31. Apparatus comprising:

means for receiving sensor information about a plurality of physical attributes associated with a navigation system, wherein the sensor information comprises altitude information about an altitude attribute associated with the navigation system;

means for generating an inertial navigation solution based on at least a portion of the sensor information;

means for classifying a motion based on at least a portion of the sensor information in order to generate position information;

means for receiving at least one signal of opportunity and generating signal-of-opportunity information based on the signal of opportunity;

means for using a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information, and the signal-of-opportunity information;

means for using the corrective feedback to generate the navigation solution.

32. Software embodied on a storage medium comprising a plurality of program instructions operable to cause a processor to:

receive sensor information output by a plurality of sensors, wherein the plurality of sensors comprises an altitude sensor, wherein the sensor information output by the altitude sensor comprises altitude information;

generate an inertial navigation solution based on at least a portion of the sensor information;

classify a motion based on at least a portion of the sensor information in order to generate position information;

receive signal-of-opportunity information from a signal-of-opportunity information that receives a signal of opportunity;

use a Kalman filter to generate corrective feedback as a function of the navigation solution and, when available, at least one of the following;

at least a portion of the sensor information, the position information, and the signal-of-opportunity information;

use the corrective feedback to generate the navigation solution.