Architectures for high integrity multi-constellation solution separation

Patent metadata

Field	Value
Publication number	US-9784844-B2
Application number	US-201314092454-A
Country	US
Kind code	B2
Filing date	Nov 27, 2013
Priority date	Nov 27, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

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.

First claim

What is claimed is:

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 a plurality of first sub-solutions for the navigation system in a constellation domain, wherein each respective first sub-solution of the plurality of first sub-solutions in the constellation domain is determined from a first sub-set of signals received from space-based satellites from all constellations except at least one constellation that corresponds to the respective first sub-solution;
determining a plurality of second sub-solutions for the navigation system in a satellite domain, wherein each respective second sub-solution of the plurality of second sub-solutions in the satellite domain is determined from a second sub-set of signals received from all of the plurality of space-based satellites except at least one space-based satellite that corresponds to the respective second sub-solution; and
determining if an error is present in the navigation system based, at least in part, on the plurality of first sub-solutions in the constellation domain and on the plurality of second sub-solutions in the satellite domain.

2. The method of claim 1 , further comprising:
determining a full-solution for the navigation system based on the received signals; 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 plurality of first sub-solutions with the full-solution and on a comparison of the full-solution with the plurality of second sub-solutions;
the method further comprising:
determining a protection level for each sub-solution in the plurality of first sub-solutions and in the plurality of second sub-solutions; and
selecting one of the determined protection levels as a total protection level.

3. The method of claim 1 , wherein the constellation domain is based on a plurality of NSS constellation signals and the satellite domain is based on a distinct plurality of satellites signals related to respective NSS constellations;
wherein each respective first sub-set of signals in the constellation domain comprises only signals from space-based satellites from all constellations except at least one constellation corresponding to the respective first sub-set of signals;
wherein space-based satellite signals from one constellation constitutes a full solution for the satellite domain;
wherein determining if an error is present in the navigation system comprises:
determining if an error is present in the navigation system based on a comparison of each first sub-solution in the plurality of first sub-solutions with a constellation domain full-solution for the constellation domain; and
determining if an error is present in the navigation system based on a comparison of each second sub-solution in the plurality of second sub-solutions with the the satellite domain full-solution;
the method further comprising determining a total protection level, wherein determining a total protection level comprises:
determining a protection level for each first sub-solution in the plurality of first sub-solutions;
determining a protection level for each second sub-solution in the plurality of second sub-solutions; and
combining the respective protection levels for the first and second sub-solutions to obtain the total protection level.

4. 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.

5. 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.

6. 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 first sub-solution for each of a plurality of first sub-sets of the plurality of signals in a constellation domain, the constellation domain including signals received from space-based satellites from all constellations except at least one constellation that corresponds to the respective first sub-solution;
wherein the processing unit is further configured to calculate a respective second sub-solution for each of a plurality of second sub-sets of the plurality of signals in a satellite domain, the satellite domain including signals received from all of the plurality of space-based satellites except at least one space-based satellite that corresponds to the respective second sub-solution; and
wherein the processing unit is further configured to identify an error in a navigation system based, at least in part, on the first sub-solutions in the constellation domain and on the second sub-solutions in the satellite domain.

7. The navigation device of claim 6 , 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 identify an error in the navigation system based on a comparison of the full-solution with each respective first sub-solution in the constellation domain and on a comparison of the full-solution with each respective second sub-solution in the satellite domain; and
wherein the processing unit is further configured to determine a protection level for each first sub-solution in the constellation domain and for each second sub-solution in the satellite domain, the processing unit further configured to select one of the determined protection levels as a total protection level.

8. The navigation device of claim 6 , 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 identify an error in the navigation system based on a comparison of one or more respective first sub-solutions in the constellation domain with the full-solution and on a comparison of each respective second sub-solution in the second satellite domain with a corresponding sub-solution in the constellation domain;
wherein the processing unit is further configured to determine a protection level for each first sub-solution in the plurality of first sub-solutions and in the plurality of second sub-solutions and to combine one of the protection levels for the plurality of first sub-solutions with a corresponding protection level for the plurality of second sub-solutions.

9. The navigation device of claim 6 , 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.

Assignees

• Honeywell Int Inc

Inventors

• Kana Zdenek
• Dunik Jindrich
• Orejas Martin

Classifications

• G01S19/20 Primary

  Integrity monitoring, fault detection or fault isolation of space segment · CPC title

• G01S19/421

  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 · CPC title