Patent ID: 6282803
Filing Date: 2001-09-04
Classification: G01C

Abstract:
A self calibration method of zero compensation for a fluxgate compass, said fluxgate compass having a ferromagnetic core, a drive coil positioned around the core and at least two secondary sensing coils spaced around portions of said core, said method comprising the steps of:generating and passing a drive signal through the drive coil for a first period of time, the drive signal selected to alternately drive the core into saturation in a first direction and drive the core into saturation in a direction opposite the first direction;sensing a first sensor signal using at least one of the secondary sensing coils, where the first sensor signal includes a first portion sensed while the core is saturated in the first direction and a second portion sensed while the core is saturated in the opposite direction;sensing a second sensor signal during a second period of time from at least one of said sensing coils while the drive signal is removed; andusing said second sensor signal to determine a zero reference; anddetermining a magnitude of said first sensor signal using the first and second portions of the first signal and the zero reference.