SYSTEMS AND METHODS FOR GYROCOMPASS ALIGNMENT USING DYNAMICALLY CALIBRATED SENSOR DATA AND AN ITERATED EXTENDED KALMAN FILTER WITHIN A NAVIGATION SYSTEM

• US 20090048779A1
• Filed: 08/14/2007
• Published: 02/19/2009
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Zeng, Yueping, Northcutt, Scott T.
• Granted Patent: US 8,024,119 B2
• Time in Patent Office: Days
• US Class Current: 701/214
• CPC Class Codes: G01C 21/1654 with electromagnetic compass
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices

Abstract

A navigation system and method for gyrocompass alignment in a mobile object. The system includes an inertial measurement device configured to provide a first set of sensor data and a positioning unit configured to provide a second set of data. In an example embodiment, the navigation system includes a processing device configured to receive the data sets provided by the inertial measurement device and the positioning device, and the processing device is configured to dynamically calibrate the received first data set the processing device includes a Kalman filter, and the processing device is further configured to generate a gyrocompass alignment using the first dynamically calibrated first data set, the second data set, and the Kalman filter. The method includes receiving sensor data from a plurality of sensors, dynamically calibrating at least a portion of the sensor data, and generating gyrocompass alignment information based on the dynamically calibrated sensor data.

Claims

1. A navigation system for a mobile object comprising:

an inertial measurement device configured to provide a first set of sensor data relating to operation of the mobile object;

a positioning unit configured to provide a second set of data relating to position of the mobile object; and

a processing device configured to receive the first and second data sets, the processing device configured to dynamically calibrate the received first data set, the processing device comprising a Kalman filter and further configured to generate a gyrocompass alignment using the first dynamically calibrated first data set, the second data set, and the Kalman filter.

2. The navigation system of claim 1, wherein the inertial measurement device includes accelerometers and gyros.

3. The navigation system of claim 2, wherein the accelerometers and gyros are MEMS based.

4. The navigation system of claim 1, wherein the positioning unit includes a GPS device.

5. The navigation system of claim 1, wherein the processing device is configured to real-time average the first set of sensor data.

6. The navigation system of claim 5, wherein the processing device is configured to estimate a heading based on the dynamically calibrated first set of sensor data and wherein the processing device is further configured to generate a gyrocompass alignment using the estimated heading.

7. The navigation system of claim 6, wherein the processing device is configured to initialize a conversion matrix using at least a portion of the estimated heading and wherein the processing device is further configured to initialize the Kalman filter using the initialized conversion matrix.

8. The navigation system of claim 7, wherein the processing device is configured to estimate sensor error using the real-time averaged first set of sensor data, and wherein the processing device is further configured to correct the estimated sensor error with known gravitational acceleration and earth rate values to generate the dynamically calibrated first set of sensor data.

9. The navigation system of claim 1, further comprising a navigation display device configured to display navigation information using the generated gyrocompass alignment.

10. The navigation system of claim 1, wherein the mobile object is an aircraft.

11. A method for gyrocompass alignment, the method comprising:

receiving sensor data from a plurality of sensors;

dynamically calibrating at least a portion of the sensor data; and

generating gyrocompass alignment information based on the dynamically calibrated sensor data.

12. The method of claim 11, further comprising displaying a navigation output based on the generated gyrocompass alignment information.

13. The method of claim 11, wherein generating gyrocompass alignment information includes estimating a heading based on the dynamically calibrated sensor data.

14. The method of claim 13, wherein generating gyrocompass alignment information further includes initializing a conversion matrix using at least a portion of the estimated heading.

15. The method of claim 14, wherein generating gyrocompass alignment information further comprises initializing an iterated extended Kalman filter using the initialized conversion matrix.

16. The method of claim 14, wherein dynamically calibrating comprises processing the sensor data using real-time averaging to generate averaged sensor data with reduced noise.

17. The method of claim 16, wherein dynamically calibrating further comprises estimating sensor error using the averaged sensor data and correcting the estimated sensor error with known gravitational acceleration and earth rate values.

18. The method of claim 17, wherein estimating heading comprises calibrating gyro component data, calculating a standard component based on a known earth rate value, and generating an estimated heading using the calibrated gryo component data, standard component, and dynamically calibrated sensor data.