Systems and methods for determining inertial navigation system faults

Patent metadata

Field	Value
Publication number	US-9568321-B2
Application number	US-201113029204-A
Country	US
Kind code	B2
Filing date	Feb 17, 2011
Priority date	Apr 19, 2010
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

An inertial navigation system (INS) includes a primary inertial navigation system (INS) unit configured to receive accelerometer measurements from an accelerometer and angular velocity measurements from a gyroscope. The primary INS unit is further configured to receive global navigation satellite system (GNSS) signals from a GNSS sensor and to determine a first set of kinematic state vectors based on the accelerometer measurements, the angular velocity measurements, and the GNSS signals. The INS further includes a secondary INS unit configured to receive the accelerometer measurements and the angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based on the accelerometer measurements and the angular velocity measurements. A health management system is configured to compare the first set of kinematic state vectors and the second set of kinematic state vectors to determine faults associated with the accelerometer or the gyroscope based on the comparison.

First claim

What is claimed is:

1. An inertial navigation system (INS), comprising:
a primary inertial navigation system (INS) unit configured to receive first accelerometer measurements from a first accelerometer and first angular velocity measurements from a first gyroscope,
the primary INS unit further configured to receive global navigation satellite system (GNSS) signals from a GNSS sensor and to determine a first set of kinematic state vectors based on the first accelerometer measurements, the first angular velocity measurements, and the GNSS signals;

a secondary INS unit configured to receive the first accelerometer measurements and the first angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based on the first accelerometer measurements and the first angular velocity measurements; and
a health management system configured to compare the first set of kinematic state vectors and the second set of kinematic state vectors to determine faults associated with at least one of the first accelerometer or the first gyroscope based on the comparison.

2. The INS of claim 1 , wherein the primary INS unit includes primary accelerometer and gyroscope measurement models for determining the first set of kinematic state vectors and the secondary INS unit includes secondary accelerometer and gyroscope measurement models for determining the second set of kinematic state vectors.

3. The INS of claim 2 , wherein the primary accelerometer and gyroscope measurement models and the secondary accelerometer and gyroscope measurement models are the same.

4. The INS of claim 2 , wherein the health management system is further configured to determine faults associated with the primary accelerometer and gyroscope measurement models or the secondary accelerometer and gyroscope measurement models.

5. The INS of claim 1 , wherein the health management system is configured to generate the second set of kinematic state vectors with errors due to accelerometer bias.

6. The INS of claim 1 , wherein the health management system is configured to generate the second set of kinematic state vectors with errors due to gyroscope bias.

7. The INS of claim 1 , further comprising a switch coupled to the secondary INS unit and configured to initialize the secondary INS unit based on a predetermined sampling rate or statistics associated with the first set of kinematic state vectors.

8. The INS of claim 1 , wherein the primary INS unit is further configured to receive additional sensor measurements from at least one additional aiding sensor and to additionally determine the first set of kinematic state vectors based on the additional sensor measurements.

9. The INS of claim 1 , wherein the secondary INS unit is configured to determine the second set of kinematic state vectors independently of the GNSS signals.

10. The INS of claim 1 , wherein the comparison between the first set of kinematic state vectors and the second set of kinematic state vectors generates a first set of health indicators, and wherein the primary INS unit includes a first Kalman filter configured to receive the GNSS signals and to determine a second set of health indicators associated with the first set of kinematic state vectors.

11. The INS of claim 10 , wherein primary INS unit includes an input filter configured to produce a third set of health indicators associated with the first set of kinematic state vectors, and wherein the health management system includes a fusion module configured to determine the faults based on the first set of health indicators, the second set of health indicators, and the third set of health indicators.

12. A vehicle system, comprising:
an inertial measurement unit (IMU) comprising a first accelerometer configured to generate first acceleration measurements and a first gyroscope configured to generate first angular velocity measurements;
a global navigation satellite system (GNSS) configured to generate GNSS signals;
a primary inertial navigation system (INS) unit configured to receive the first accelerometer measurements, the first angular velocity measurements, and the GNSS signals, the primary INS unit further configured to determine a first set of kinematic state vectors based on the first accelerometer measurements, the first angular velocity measurements, and the GNSS signals;
a secondary INS unit configured to receive the first accelerometer measurements and the first angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based on the first accelerometer measurements and the first angular velocity measurements, wherein the secondary INS unit is configured to determine the second set of kinematic state vectors independently of the GNSS signals; and
a health management system coupled to the primary INS unit and the secondary INS unit and configured to compare the first set of kinematic state vectors and the second set of kinematic state vectors to determine faults associated with at least one of the first accelerometer or the first gyroscope based on the comparison,
wherein the primary INS unit includes primary accelerometer and gyroscope measurement models for determining the first set of kinematic state vectors and the secondary INS unit includes secondary accelerometer and gyroscope measurement models for determining the second set of kinematic state vectors,
wherein the primary accelerometer and gyroscope measurement models and the secondary accelerometer and gyroscope measurement models are the same, and
wherein the health management system is further configured to determine faults associated with the primary accelerometer and gyroscope measurement models or the secondary accelerometer and gyroscope measurement models.

13. The vehicle system of claim 12 , wherein the health management system is configured to generate the second set of kinematic state vectors with errors due to accelerometer bias.

14. The vehicle system of claim 12 , wherein the health management system is configured to generate the second set of kinematic state vectors with errors due to gyroscope bias.

15. The vehicle system of claim 12 , further comprising a switch coupled to the secondary INS unit and configured to initialize the secondary INS unit based on a predetermined sampling rate or statistics associated with the first set of kinematic state vectors.

16. A vehicle system, comprising:
a first inertial measurement unit (IMU) comprising a first accelerometer configured to generate first acceleration measurements and a first gyroscope configured to generate first angular velocity measurements;
a global navigation satellite system (GNSS) configured to generate GNSS signals;
a primary inertial navigation system (INS) unit configured to receive the first accelerometer measurements, the first angular velocity measurements, and the GNSS signals, the primary INS unit further configured to determine a first set of kinematic state vectors based on the first accelerometer measurements, the first angular velocity measurements, and the GNSS measurements, the primary INS unit including a first Kalman filter configured to receive the GNSS signals and to determine a first set of health indicators associated with the first set of kinematic state vectors and an input filter configured to produce a second set of health indicators associated with the first set of kinematic state vectors;
a secondary INS unit configured to receive the first accelerometer measurements and the first angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based

Assignees

• Bharadwaj Raj Mohan
• Bageshwar Vibhor L
• Kim Kyusung
• Honeywell Int Inc

Inventors

• Bharadwaj Raj Mohan
• Bageshwar Vibhor L
• Kim Kyusung

Classifications

• G01C25/005

  initial alignment, calibration or starting-up of inertial devices · CPC title

• G01C21/188 Primary

  for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems · CPC title

• G01C21/165 Primary

  combined with non-inertial navigation instruments · CPC title