Patent ID: 7295943
Filing Date: 2007-11-13
Classification: G01C

Abstract:
1. A geomagnetic sensor, comprising: a geomagnetism measuring unit, including an X axis fluxgate comprising a first magnetic core and a Y axis fluxgate comprising a second magnetic core, which generates voltage values corresponding to measured geomagnetism when the X axis fluxgate is driven by a first signal and the Y axis fluxgate is driven by a second signal; an acceleration sensor, which measures a pitch angle and a roll angle which indicate a tilting degree of the geomagnetic sensor based on a horizontal state of the geomagnetic sensor; and a control unit, which calibrates an azimuth by compensating the voltage values generated by the geomagnetism measuring unit using the pitch angle and the roll angle measured by the acceleration sensor and which normalizes the compensated voltage values to values within a predetermined range, wherein the control unit compensates actual X-axis and Y-axis voltage values of the X-axis and Y-axis flux gates, respectively, which are generated by the geomagnetic sensor as the geomagnetic sensor takes a predetermined number of turns, by reflecting the pitch angle and the roll angle in the actual measured values in order to provide compensated voltage values, and then calculates normalization factors using maximum and minimum values among the compensated voltage values, and wherein the control unit compensates the X-axis and Y-axis voltage values using the following equations: where X