Mobile structure heading and piloting systems and methods

Patent metadata

Field	Value
Publication number	US-10837780-B2
Application number	US-201715785319-A
Country	US
Kind code	B2
Filing date	Oct 16, 2017
Priority date	Oct 17, 2016
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

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.

First claim

What is claimed is:

1. An apparatus comprising: a gyroscope; an attitude and heading reference system (AHRS); a controller configured to communicate with a plurality of navigational sensors comprising at least the gyroscope and the AHRS, wherein each navigational sensor is configured to provide navigational data associated with a mobile structure, and the controller is configured to: receive first attitude and/or heading data from the AHRS over a network comprising a network latency; receive first angular velocity data from the gyroscope, wherein the first angular velocity data is received according to no latency or lower latency than the network latency; determine a first orientation of the mobile structure from the first attitude and/or heading data from the AHRS; determine a first slave orientation of the mobile structure based, at least in part, on the first angular velocity data from the gyroscope; receive updated attitude and/or heading data from the AHRS over the network; determine a time delay indicative of the network latency, wherein the determining the time delay is based, at least in part, on comparing the first slave orientation and the updated attitude and/or heading data from the AHRS; and determine a second orientation of the mobile structure based, at least in part, on the first slave orientation and the time delay.

2. The apparatus of claim 1 , wherein:
the determining the first slave orientation is based, at least in part, on the first angular velocity data from the gyroscope and the first attitude and/or heading data from the AHRS; and
the determining the second orientation of the mobile structure is based, at least in part, on the first slave orientation, the time delay, and the updated attitude and/or heading data from the AHRS.

3. The apparatus of claim 1 , wherein the controller is further configured to:
determine a first true orientation based, at least in part, on a comparison of the first slave orientation and the first AHRS orientation.

4. The apparatus of claim 1 , wherein determining the time delay comprises:
determining a mean delay indicative of a latency associated with the ARHS communicating the first attitude and/or heading data and the controller receiving the first attitude and/or heading data; and
determining a fine-tune term for use within an integration portion of a Kalman filter arrangement, wherein the fine-tune term comprises a difference between the first attitude and/or heading data and the first slave orientation after time shifting the first slave orientation by the mean delay.

5. 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.

6. The apparatus of claim 5 , wherein a difference between the first time period and the second time period comprises a latency between the AHRS sensing the first attitude and/or heading and the controller receiving the first attitude and/or heading data.

7. The apparatus of claim 1 , wherein the controller is communicatively coupled to and remote from the AHRS.

8. The apparatus of claim 1 , wherein the controller is further configured to:
calibrate a coordinate frame of the gyroscope to a coordinate frame of the AHRS.

9. The apparatus of claim 1 , wherein the mobile structure comprises a watercraft.

10. The apparatus of claim 1 , wherein the controller is further configured to:
determine a wind speed and/or direction experienced by the mobile structure based, at least in part, on the second slave orientation.

11. The apparatus of claim 10 , wherein determining the wind speed and/or direction further comprises:
determining a mobile structure control input; and
correcting the second slave orientation based, at least in part, on the mobile structure control input.

12. The apparatus of claim 1 , further comprising an actuator for changing an orientation of the mobile structure and/or of at least one said sensor in response to the determining the second orientation.

13. A method comprising: receiving by a controller, over a network comprising a network latency, first attitude and/or heading data from an attitude and heading reference system (AHRS) coupled by the network to the controller; receiving, by the controller, first angular velocity data from a gyroscope, wherein the first angular velocity data is received according to no latency or lower latency than the network latency; determining by the controller a first orientation of a mobile structure from the first attitude and/or heading data from the AHRS; determining by the controller a first slave orientation of the mobile structure based, at least in part, on the first angular velocity data from the gyroscope; receiving, by the controller, updated attitude and/or heading data from the AHRS over the network; determining by the controller a time delay indicative of the network latency, wherein the determining the time delay is based, at least in part, on comparing the first slave orientation and the updated attitude and/or heading data from the AHRS; and determining by the controller a second orientation of the mobile structure based, at least in part, on the first slave orientation and the time delay.

14. The method of claim 13 , wherein:
the determining the second orientation of the mobile structure is based, at least in part, on the first slave orientation, the time delay, and the updated attitude and/or heading data from the AHRS.

15. The method of claim 13 , further comprising:
determining a first true orientation based, at least in part, on a comparison of the first slave orientation and the first AHRS orientation.

16. The method of claim 13 , wherein determining the time delay comprises:
determining a mean delay indicative of a latency associated with the ARHS communicating the first attitude and/or heading data and the controller receiving the first attitude and/or heading data; and
determining a fine-tune term for use within an integration portion of a Kalman filter arrangement, wherein the fine-tune term comprises a difference between the first attitude and/or heading data and the first slave orientation after time shifting the first slave orientation by the mean delay.

17. The method of claim 13 , 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 comprises a latency between the AHRS sensing the first attitude and/or heading and the controller receiving the first attitude and/or heading data.

18. The method of claim 13 , further comprising:
determining a wind speed and/or direction experienced by the mobile structure based, at least in part, on the second slave orientation.

19. The method of claim 13 , further comprising changing an orientation of the mobile structure and/or of at least one said sensor in response to the determining the second orientation.

Assignees

• FLIR Belgium BVBA

Inventors

• Johnson Mark
• Hodgson Chris
• Yeomans Christopher

Classifications

• G01C21/183

  Compensation of inertial measurements, e.g. for temperature effects · CPC title

• G01C25/005 Primary

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

• G01C21/18 Primary

  Stabilised platforms, e.g. by gyroscope · CPC title

• G01C21/16

  by integrating acceleration or speed, i.e. inertial navigation · CPC title