Patent ID: 6286221
Filing Date: 2001-09-11
Classification: G01C

Abstract:
An electronic compass system using magnetic signatures to detect a vehicle event comprising:a vehicle accessory having at least one electrical state, said vehicle accessory generating a known, consistent, magnetic field of an intensity sufficient to cause a static magnetic offset in said electronic compass, said known, consistent, magnetic field having a magnetic signature;a magnetic field sensor located in proximity to said vehicle accessory, said magnetic field sensor detecting a combination of Earth's magnetic field and said known, consistent, magnetic field and generating a magnetic field signal wherein said Earth's magnetic field is modified by said static magnetic offset;a controller coupled to said magnetic field sensor and receiving said magnetic field signal, said controller having control logic operative to search said magnetic field signal for said magnetic signature, lookup a correction factor for said magnetic signature stored in a memory location, and apply said correction factor to said magnetic field signal; anda display coupled to said controller, said display displaying a heading unaffected by said static magnetic offset.