Johnson Controls Technology Company

Johnson Controls Gmbh

David J Slater

Thomas R Olson

Jeffrey N Parks

The compass system of the present invention utilizes an improved calibration route in which a processing circuit of the compass recalibrates the compass each time three data points are obtained from a magnetic field sensor that meet predetermined criteria. One such criterion is that the three data points define corners of a triangle that is substantially non-obtuse. When three data points have been obtained that define a triangle meeting this criterion, the processing circuit calculates a center point for a circle upon which all three data points lie by solving the equation x+y+Ax+By+C=0 for A, B, and C, using the coordinate values (x,y) for the three data points and defining the center point as (&#x2212;A/2, &#x2212;B/2).

Vehicle compass system with continuous automatic calibration

The compass system of the present invention utilizes an improved calibration routine in which a processing circuit of the compass recalibrates the compass each time three data points are obtained from a magnetic field sensor that meet predetermined criteria. One such criterion is that the three data points define corners of a triangle that is substantially non-obtuse. When three data points have been obtained that define a triangle meeting this criterion, the processing circuit calculates a center point for a circle upon which all three data points lie by solving the equation x+y+Ax+By+C=0 for A, B, and C, using the coordinate values (x,y) for the three data points and defining the center point as (&#x2212;A/2, &#x2212;B/2).

The compass system of the present invention utilizes an improved calibration routine in which a processing circuit of the compass recalibrates the compass each time three data points are obtained from a magnetic field sensor that meet predetermined criteria. One such criterion is that the three data points define corners of a triangle that is substantially non-obtuse. When three data points have been obtained that define a triangle meeting this criterion, the processing circuit calculates a center point for a circle upon which all three data points lie by solving the equation x+y+Ax+By+C=for A, B, and C, using the coordinate values (x,y) for the three data points and defining the center point as (&#x2212;A/2, &#x2212;B/2).

The compass system of the present invention utilizes an improved calibration routine in which a processing circuit of the compass recalibrates the compass each time three data points are obtained from a magnetic field sensor that meet predetermined criteria. One such criterion is that the three data points define corners of a triangle that is substantially non-obtuse. When three data points have been obtained that define a triangle meeting this criterion, the processing circuit calculates a center point for a circle upon which all three data points lie by solving the equation x+y+Ax+By+C=0 for A, B, and C, using the coordinate values (x,y) for the three data points and defining the center point as (&#x2212;A/, &#x2212;B/).

The compass system of the present invention utilizes an improved calibration routine in which a processing circuit of the compass recalibrates the compass each time three data points are obtained from a magnetic field sensor that meet predetermined criteria. One such criterion is that the three data points define corners of a triangle that is substantially non-obtuse. When three data points have been obtained that define a triangle meeting this criterion, the processing circuit calculates a center point for a circle upon which all three data points lie by solving the equation &plus;y &plus;Ax&plus;By&plus;C&equals;0 for A, B, and C, using the coordinate values (x,y) for the three data points and defining the center point as (&minus;A/2, &minus;B/2).

The compass system of the present invention utilizes an improved calibration routine in which a processing circuit of the compass recalibrates the compass each time three data points are obtained from a magnetic field sensor that meet predetermined criteria. One such criterion is that the three data points define corners of a triangle that is substantially non-obtuse. When three data points have been obtained that define a triangle meeting this criterion, the processing circuit calculates a center point for a circle upon which all three data points lie by solving the equation x,&plus;y,&plus;Ax&plus;By&plus;C&equals;0 for A, B, and C, using the coordinate values (x,y) for the three data points and defining the center point as (&minus;A/2, &minus;B/2).

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Holland, MI, United States of America

David J Slater