Mobile Structure Heading and Piloting Systems and Methods

• US 20180106619A1
• Filed: 10/16/2017
• Published: 04/19/2018
• Est. Priority Date: 10/17/2016
• Status: Active Grant

• Current Assignee: Flir Belgium BVBA (Teledyne Technologies Incorporated)
• Original Assignee: Flir Belgium BVBA (Teledyne Technologies Incorporated)
• Inventors: Johnson, Mark, Hodgson, Chris, Yeomans, Christopher
• Granted Patent: US 10,837,780 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 21/18 Stabilised platforms, e.g. by gyroscope
• CPC Class Codes: G01C 21/183 Compensation of inertial measurements, e.g. for temperature effects
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices

Abstract

Techniques are disclosed for systems and methods for navigating mobile structures. The mobile structure may include a main attitude & heading reference system (AHRS) and one or more devices. The one or more devices may include a slave AHRS such as a gyroscope. Data may be transmitted from the main AHRS to the one or more devices through a network. Latency may be present in the transmission of data. As such, data from the slave AHRS may be used to determine changes in heading and/or attitude of the mobile structure to compensate for such latency. In addition, such data may be used to determine changes in wind direction and/or heading experienced by the mobile structure.

Claims

1. An apparatus comprising:

a logic device configured to communicate with a plurality of navigational sensors, wherein each navigational sensor is configured to provide navigational data associated with a mobile structure, the plurality of navigational sensors comprises at least a gyroscope and an attitude &

heading reference system (AHRS), and the logic device is configured to;

receive first attitude and/or heading data from the AHRS and first angular velocity data from the gyroscope;

determine a first AHRS orientation of the mobile structure from the first attitude and/or heading data, wherein the first AHRS orientation is associated with an orientation of the mobile structure at a first timeframe;

determine a first slave orientation of the mobile structure with the first angular velocity data, wherein the first slave orientation is associated with the orientation of the mobile structure at the first timeframe;

determine, by, at least, comparing the first slave orientation and the first AHRS orientation, an error bias;

receive second angular velocity data from the gyroscope; and

determine a second slave orientation of the mobile structure with the second angular velocity data and the error bias, wherein the second slave orientation is associated with the orientation of the mobile structure at a second timeframe.

2. The apparatus of claim 1, wherein the logic device is further configured to:

receive second attitude and/or heading data from the AHRS;

determine a second AHRS orientation of the mobile structure from the second attitude and/or heading data, wherein the second AHRS orientation is associated with an orientation of the mobile structure at the second timeframe; and

determine, by, at least, comparing the second slave orientation and the second AHRS orientation, an updated error bias.

3. The apparatus of claim 1, wherein the logic device is further configured to:

determine a first true orientation responsive to a comparison of the first slave orientation and the first AHRS orientation.

4. The apparatus of claim 1, wherein the error bias is determined responsive to, at least, a time delay estimate.

5. The apparatus of claim 1, wherein determining the error bias comprises:

determining a mean delay indicative of a latency associated with the ARHS communicating the first attitude and/or heading data and the logic device receiving the first attitude and/or heading data; and

determining a residual comprising an error between the first attitude and/or heading data and the first attitude and/or heading data after time shifting the first slave orientation by the mean delay.

6. The apparatus of claim 1, wherein the first attitude and/or heading data is received at a first time period and the first angular velocity data is received at a second time period.

7. The apparatus of claim 6, wherein a difference between the first time period and the second time period is, at least, a latency between the AHRS sensing a first attitude and/or heading and the logic device receiving the first attitude and/or heading data.

8. The apparatus of claim 1, wherein the logic device is communicatively coupled to and remote from the AHRS.

9. The apparatus of claim 1, wherein the logic device is further configured to:

calibrate a coordinate frame of the gyroscope to a coordinate frame of the AHRS.

10. The apparatus of claim 1, further comprising the gyroscope and/or the AHRS.

11. The apparatus of claim 1, further comprising the mobile structure, wherein the mobile structure is a watercraft and comprises:

the AHRS; and

the gyroscope.

12. The apparatus of claim 1, wherein the logic device is further configured to:

determine a wind speed and/or direction experienced by the mobile structure responsive to, at least, the second slave orientation.

13. The apparatus of claim 12, wherein determining the wind speed and/or direction further comprises:

determining a mobile structure control input; and

correcting the second slave orientation responsive to the mobile structure control input.

14. A method comprising:

receiving first attitude and/or heading data from an attitude &

heading reference system (AHRS) and first angular velocity data from a gyroscope;

determining a first AHRS orientation of a mobile structure from the first attitude and/or heading data, wherein the first AHRS orientation is associated with an orientation of the mobile structure at a first timeframe;

determining a first slave orientation of the mobile structure with the first angular velocity data, wherein the first slave orientation is associated with the orientation of the mobile structure at the first timeframe;

determining, by, at least, comparing the first slave orientation and the first AHRS orientation, an error bias;

receiving second angular velocity data from the gyroscope; and

determining a second slave orientation of the mobile structure with the second angular velocity data and the error bias, wherein the second slave orientation is associated with the orientation of the mobile structure at a second timeframe.

15. The method of claim 14, further comprising:

receiving second attitude and/or heading data from the AHRS;

determining a second AHRS orientation of the mobile structure from the second attitude and/or heading data, wherein the second AHRS orientation is associated with an orientation of the mobile structure at the second timeframe; and

determining, by, at least, comparing the second slave orientation and the second AHRS orientation, an updated error bias.

16. The method of claim 14, further comprising:

determining a first true orientation responsive to a comparison of the first slave orientation and the first AHRS orientation.

17. The method of claim 14, wherein the error bias is determined responsive to, at least, a time delay estimate.

18. The method of claim 14, wherein determining the error bias comprises:

determining a mean delay indicative of a latency associated with the ARHS communicating the first attitude and/or heading data and the logic device receiving the first attitude and/or heading data; and

determining a residual comprising an error between the first attitude and/or heading data and the first attitude and/or heading data after time shifting the first slave orientation by the mean delay.

19. The method of claim 14, wherein the first attitude and/or heading data is received at a first time period and the first angular velocity data is received at a second time period, and wherein a difference between the first time period and the second time period is, at least, a latency between the AHRS sensing a first attitude and/or heading and the logic device receiving the first attitude and/or heading data.

20. The method of claim 14, further comprising:

determining a wind speed and/or direction experienced by the mobile structure responsive to, at least, the second slave orientation.