Automatic compass calibration system and corresponding method

Abstract

Techniques are disclosed for systems and methods to provide automatic and substantially continuous calibration for compasses mounted to moving structures. A compass calibration system may include a logic device configured to receive one or more sensor signals and determine a corrected magnetic field based, at least in part, on a measured local magnetic field. The logic device may be adapted to receive an angular velocity, an acceleration, the measured local magnetic field, and / or a speed of a mobile structure; generate stabilized roll and pitch components of an orientation of the mobile structure based, at least in part, on the acceleration and angular velocity; and determine the corrected magnetic field based, at least in part, on the speed, the local magnetic field, the stabilized roll and pitch components, and / or the angular velocity.

Description

[0001] Cross References to Related Applications [0002] This application asserts U.S. Provisional Patent Application No. 61 / 823,903, filed May 15, 2013, entitled "AUTOMATIC COMPASSCALIBRATION SYSTEMSANDMETHODS" and U.S. Provisional Patent Application No. 61, filed May 15, 2013, entitled "AUTOMATIC COMPASSCALIBRATION SYSTEMSANDMETHODS" / 823,906 priority, which is hereby incorporated by reference in its entirety. technical field [0003] One or more embodiments of the invention relate generally to compass calibration, and more particularly, to systems and methods, for example, for automating compass calibration and providing accurate heading. Background technique [0004] Earth's magnetic field has long been used to provide a reference for estimating heading and planning routes. Typically, a compass is used to measure the local magnetic field, and the Earth's magnetic field is also assumed to be equal to the local magnetic field, or estimated by using local measurements rela...

AI Technical Summary

Problems solved by technology

[0005] These conventional calibration methods require time and / or expensive equipment to implement, and during periods of relatively uncontrolled motion and other short- and long-term changing environmental conditions, in particular, when the Earth's magnetic field includes a relatively large vertical component , calibrations achieved using these methods can quickly become inaccurate or produce inaccurate headings

GPS-based systems have been developed that estimate heading from varying position data, however these types of systems are often very inaccurate over short straight-line distances or with rapid heading changes

Images