ARCHITECTURES FOR HIGH INTEGRITY MULTI-CONSTELLATION SOLUTION SEPARATION

• US 20150145724A1
• Filed: 11/27/2013
• Published: 05/28/2015
• Est. Priority Date: 11/27/2013
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Kana, Zdenek, Dunik, Jindrich, Orejas, Martin
• Granted Patent: US 9,784,844 B2
• Time in Patent Office: Days
• US Class Current: 342/357.58
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/421 by combining or switching between position solutions or signals derived from different satellite radio beacon positioning systems; by combining or switching between position solutions or signals derived from different modes of operation in a single system

Abstract

A method comprises receiving a plurality of signals from a plurality of space-based satellites, wherein the plurality of space-based satellites comprises at least one space-based satellite from each of a plurality of Navigation Satellite System (NSS) constellations. The method also comprises determining, in a first domain, a first plurality of sub-solutions based on a respective sub-set of the plurality of signals, each respective sub-set in the first domain chosen according to a characteristic defining the first domain; and determining, in a second domain, a second plurality of sub-solutions based on a respective sub-set of the plurality of signals, each respective sub-set in the second domain chosen according to a characteristic defining the second domain. The method further comprises determining if an error is present in the navigation system based on the first plurality of sub-solutions and on the second plurality of sub-solutions.

Claims

1. A method of integrity monitoring for errors in a navigation system, the method comprising:

receiving a plurality of signals, each signal transmitted from a respective one of a plurality of space-based satellites, wherein the plurality of space-based satellites comprises at least one space-based satellite from each of a plurality of Navigation Satellite System (NSS) constellations;

determining, in a first domain, a first plurality of sub-solutions for the navigation system, wherein each sub-solution in the first plurality of sub-solutions is determined based on a respective sub-set of the plurality of signals, each respective sub-set in the first domain chosen according to a characteristic defining the first domain;

determining, in a second domain, a second plurality of sub-solutions for the navigation system, wherein each sub-solution in the second plurality of sub-solutions is determined based on a respective sub-set of the plurality of signals, each respective sub-set in the second domain chosen according to a characteristic defining the second domain; and

determining if an error is present in the navigation system based, at least in part, on the first plurality of sub-solutions in the first domain and on the second plurality of sub-solutions in the second domain.

2. The method of claim 1, further comprising:

determining a full-solution for the navigation system based on all of the plurality of signals;

wherein each respective sub-set in the first domain comprises only signals from space-based satellites from all constellations except at least one constellation corresponding to the respective sub-set;

wherein each respective sub-set in the second domain comprises signals from all of the plurality of space-based satellites except at least one space-based satellite corresponding to the respective sub-set; and

wherein determining if an error is present comprises determining if an error is present in the navigation system based on a comparison of the first plurality of sub-solutions with the full-solution and on a comparison of the full-solution with the second plurality of sub-solutions;

the method further comprising;

determining a protection level for each sub-solution in the first plurality of sub-solutions and in the second plurality of sub-solutions; and

selecting one of the determined protection levels as a total protection level.

3. The method of claim 1, further comprising:

determining a full-solution for the navigation system based on all of the plurality of signals;

wherein each respective sub-set in the first domain comprises only signals from space-based satellites from all constellations except at least one constellation corresponding to the respective sub-set;

wherein each respective sub-set in the second domain comprises signals from all of the plurality of space-based satellites except at least one space-based satellite corresponding to the respective sub-set; and

wherein determining if an error is present comprises determining if an error is present in the navigation system based on a comparison of one or more sub-solution in the first plurality of sub-solutions with the full-solution and on a comparison of each sub-solution in the second plurality of sub-solutions with a corresponding one of the first plurality of sub-solutions;

the method further comprising;

determining a protection level for each sub-solution in the first plurality of sub-solutions and in the second plurality of sub-solutions; and

combining one of the protection levels for the first plurality of sub-solutions with a corresponding protection level for the second plurality of sub-solutions.

4. The method of claim 1, wherein a first constellation of the plurality of NSS constellations defines the first domain and a second constellation of the plurality of NSS constellations defines the second domain;

wherein each respective sub-set in the first domain corresponds to the first constellation and comprises signals from all but one or more of the space-based satellites that correspond to the first constellation;

wherein each respective sub-set in the second domain corresponds to the second constellation and comprises signals from all but one or more of the space-based satellites that correspond to the second constellation;

wherein determining if an error is present in the navigation system comprises;

determining if an error is present in the navigation system based on comparison of each sub-solution in the first plurality of sub-solutions with a first domain full-solution for the first domain; and

determining if an error is present in the navigation system based on a comparison of each sub-solution in the second plurality of sub-solutions with a second domain full-solution for the second domain;

the method further comprising determining a total protection level, wherein determining a total protection level comprises;

determining a protection level for the first constellation based on the sub-solutions in the first plurality of sub-solutions;

determining a protection level for the second constellation based on the sub-solutions in the second plurality of sub-solutions; and

combining the respective protection levels for the first and second constellations to obtain the total protection level.

5. The method of claim 4, wherein the plurality of NSS constellations further comprises a third constellation which defines a third domain comprising a third plurality of sub-solutions for the navigation system, each sub-solution in the third plurality of sub-solutions determined based on a respective sub-set of the plurality of signals;

wherein each respective sub-set in the third domain corresponds to the third constellation and comprises signals from all but one or more of the space-based satellites that correspond to the third constellation; and

wherein determining if an error is present in the navigation system further comprises determining if an error is present in the navigation system based on comparison of each sub-solution in the third plurality of sub-solutions with a third domain full-solution for the third domain;

wherein determining the total protection level further comprises;

determining a protection level for the third constellation based on the sub-solutions in the third plurality of sub-solutions; and

combining the respective protection levels for the first, second, and third constellations to obtain the total protection level.

6. The method of claim 1, further comprising:

isolating and excluding signals from one or more of the plurality of space-based satellites based on determination of an error in the navigation system.

7. The method of claim 1, wherein the plurality of NSS constellations comprises two or more of a Global Positioning System (GPS) constellation, a Galileo constellation, a GLObalnaya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) constellation, and a Compass constellation.

8. A navigation device comprising:

a receiver configured to receive a plurality of signals transmitted from a plurality of space-based satellites in each of a plurality of Navigation Satellite System (NSS) constellations; and

a processing unit operatively coupled to the receiver and configured to calculate a respective sub-solution for each of a first plurality of sub-sets of the plurality of signals in a first domain;

wherein the processing unit is further configured to calculate a respective sub-solution for each of a second plurality of sub-sets of the plurality of signals in a second domain; and

wherein the processing unit is further configured to identify an error in a navigation system based, at least in part, on the sub-solutions in the first domain and on the sub-solutions in the second domain.

9. The navigation device of claim 8, wherein the processing unit is configured to calculate a full-solution for the navigation system based on all of the plurality of signals from all of the NSS constellations;

wherein the processing unit is further configured to calculate each respective sub-solution in the first domain based only on signals from all NSS constellations except at least one NSS constellation corresponding to the respective sub-solution;

wherein the processing unit is further configured to calculate each respective sub-solution in the second domain based on all of the plurality of signals from all of the plurality of NSS constellations except signals from at least one space-based satellite corresponding to the respective sub-solution;

wherein the processing unit is further configured to identify an error in the navigation system based on a comparison of the full-solution with each respective sub-solution in the first domain and on a comparison of the full-solution with each respective sub-solution in the second domain; and

wherein the processing unit is further configured to determine a protection level for each sub-solution in the first domain and for each sub-solution in the second domain, the processing unit further configured to select one of the determined protection levels as a total protection level.

10. The navigation device of claim 8, wherein the processing unit is further configured to calculate a full-solution for the navigation system based on all of the plurality of signals from all of the NSS constellations;

wherein the processing unit is configured to calculate each sub-solution in the first domain based on all of the received signals from the space-based satellites in all of the NSS constellations except at least one NSS constellation corresponding to the respective sub-solution; and

wherein each respective sub-solution in the second domain corresponds to one of the NSS constellations and the processing unit is configured to calculate each respective sub-solution in the second domain based on signals from all but one or more of the space-based satellites in the NSS constellation that corresponds to the respective sub-solution;

wherein the processing unit is configured to identify an error in the navigation system based on a comparison of one or more respective sub-solutions in the first domain with the full-solution and on a comparison of each respective sub-solution in the second domain with a corresponding sub-solution in the first domain;

wherein the processing unit is further configured to determine a protection level for each sub-solution in the first plurality of sub-solutions and in the second plurality of sub-solutions and to combine one of the protection levels for the first plurality of sub-solutions with a corresponding protection level for the second plurality of sub-solutions.

11. The navigation device of claim 8, wherein a first constellation of the plurality of NSS constellations defines the first domain and a second constellation of the plurality of NSS constellations defines the second domain;

wherein the processing unit is configured to calculate each sub-solution in the first domain based on signals from all but one or more of the space-based satellites that correspond to the first constellation;

wherein the processing unit is configured to calculate each sub-solution in the second domain based on signals from all but one or more of the space-based satellites that correspond to the second constellation;

wherein processing unit is configured to determining if an error is present in the navigation system by comparing each sub-solution in the first domain with a first domain full-solution for the first domain and comparing each sub-solution in the second domain with a second domain full-solution for the second domain;

wherein the processing unit is further configured to determine a total protection level by;

determining a protection level for the first constellation based on the sub-solutions in the first domain;

determining a protection level for the second constellation based on the sub-solutions in the second domain; and

combining the respective protection levels for the first and second constellations to obtain the total protection level.

12. The navigation device of claim 8, further comprising an inertial measurement unit (IMU) configured to provide inertial measurements to the processing unit;

wherein the processing unit is further configured to calculate a respective constellation full-solution for each NSS constellation based on the inertial measurements and on the signals from each respective NSS constellation;

wherein the processing unit is further configured to use the respective constellation full-solutions in tracking loops of the receiver for the respective NSS constellations.

13. The navigation device of claim 8, wherein the processing unit is further configured to isolate and exclude signals from one or more of the plurality of space-based satellites based on an identified error in the navigation system.

14. The navigation device of claim 8, wherein the plurality of NSS constellations comprises two or more of a Global Positioning System (GPS) constellation, a Galileo constellation, a GLObalnaya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) constellation, and a Compass constellation.

15. A program product comprising a non-transitory processor-readable medium on which program instructions are embodied, wherein the program instructions are configured, when executed by at least one programmable processor, to cause the at least one programmable processor to:

calculate a respective sub-solution in a first domain for each of a first plurality of sub-sets of signals received from a plurality of space-based satellites in each of a plurality of Navigation Satellite System (NSS) constellations;

calculate a respective sub-solution in a second domain for each of a second plurality of sub-sets of the signals received from the plurality of space-based satellites; and

identify an error in a navigation system based, at least in part, on the respective sub-solutions in the first domain and on the respective sub-solutions in the second domain.

16. The program product of claim 15, wherein the program instructions are further configured to cause the at least one programmable processor to:

calculate a full-solution for the navigation system based on all of the plurality of signals from all of the NSS constellations;

calculate each respective sub-solution in the first domain based only on signals from all NSS constellations except at least one NSS constellation corresponding to the respective sub-solution;

calculate each respective sub-solution in the second domain based on all of the plurality of signals from all of the plurality of NSS constellations except signals from at least one space-based satellite corresponding to the respective sub-solution in the second domain;

identify an error in the navigation system based on a comparison of the full-solution with each respective sub-solution in the first domain and on a comparison of the full-solution with each respective sub-solution in the second domain;

determine a protection level for each sub-solution in the first domain and for each sub-solution in the second domain; and

select one of the determined protection levels as a total protection level.

17. The program product of claim 15, wherein the program instructions are further configured to cause the at least one programmable processor to:

calculate a full-solution for the navigation system based on all of the plurality of signals from all of the NSS constellations;

calculate each sub-solution in the first domain based on all of the received signals from the space-based satellites in all of the NSS constellations except at least one NSS constellation corresponding to the respective sub-solution;

calculate each respective sub-solution in the second domain based on signals from all but one or more of the space-based satellites in the NSS constellation that corresponds to the respective sub-solution in the second domain;

identify the error in the navigation system based on a comparison of one or more respective sub-solutions in the first domain with the full-solution and a comparison of each respective sub-solution in the second domain with a corresponding sub-solution in the first domain;

determine a protection level for each sub-solution in the first plurality of sub-solutions and in the second plurality of sub-solutions; and

combine one of the protection levels for the first plurality of sub-solutions with a corresponding protection level for the second plurality of sub-solutions.

18. The program product of claim 15, wherein a first constellation of the plurality of NSS constellations defines the first domain and a second constellation of the plurality of NSS constellations defines the second domain;

wherein the program instructions are further configured to cause the at least one programmable processor to;

calculate each sub-solution in the first domain based on signals from all but one or more of the space-based satellites that correspond to the first constellation;

calculate each sub-solution in the second domain based on signals from all but one or more of the space-based satellites that correspond to the second constellation;

determine if an error is present in the navigation system by comparing each sub-solution in the first domain with a first domain full-solution for the first domain and comparing each sub-solution in the second domain with a second domain full-solution for the second domain;

determine a protection level for the first constellation based on the sub-solutions in the first domain;

determine a protection level for the second constellation based on the sub-solutions in the second domain; and

combine the respective protection levels for the first and second constellations to obtain a total protection level.

19. The program product of claim 15, wherein the program instructions are further configured to cause the at least one programmable processor to:

calculate a respective constellation full-solution for each NSS constellation based on inertial measurements from an inertial measurement unit and on the signals from each respective NSS constellation; and

output the respective constellation full-solutions for use in tracking loops of a receiver for the respective NSS constellations.

20. The program product of claim 15, wherein the program instructions are further configured to cause the at least one programmable processor to isolate and exclude signals from one or more of the plurality of space-based satellites based on an identified error in the navigation system.