Patent Number: 6,301,794

Title: Vehicle compass system with continuous automatic calibration

Abstract: The compass system of the present invention utilizes an improvedcalibration routine in which a processing circuit of the compassrecalibrates the compass each time three data points are obtained from amagnetic field sensor that meet predetermined criteria. One such criterionis that the three data points define corners of a triangle that issubstantially non-obtuse. When three data points have been obtained thatdefine a triangle meeting this criterion, the processing circuitcalculates a center point for a circle upon which all three data pointslie by solving the equation x.sup.2 +y.sup.2 +Ax+By+C=0 for A, B, and C,using the coordinate values (x,y) for the three data points and definingthe center point as (-A/2, -B/2).

Inventors: Parks; Jeffrey N. (Holland, MI), Olson; Thomas R. (Holland, MI), Slater; David J. (Holland, MI)


International Classification:

Expiration Date: 10/16/2013