公开(公告)号：US20040123475A1

公开(公告)日：2004-07-01

申请号：US10663954

申请日：2003-09-16

Applicant: Johnson Controls Technology Company

Inventor： Jeffrey N. Parks ,  Thomas R. Olson ,  David J. Slater

IPC: G01C017/38

CPC classification number: G01C17/38

Abstract: 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 x2nully2nullAxnullBynullCnull0 for A, B, and C, using the coordinate values (x,y) for the three data points and defining the center point as (nullA/2, nullB/2).

Abstract translation: 本发明的罗盘系统利用改进的校准程序，其中每当从满足预定标准的磁场传感器获得三个数据点时，罗盘的处理电路重新校准指南针。 一个这样的标准是三个数据点定义基本上不钝的三角形的角。 当获得三个满足该标准的三角数据点时，处理电路通过求解方程x 2 + y 2 + Ax + By +计算所有三个数据点所在的圆的中心点， 对于A，B和C，C = 0，使用三个数据点的坐标值（x，y）并将中心点定义为（-A / 2，-B / 2）。