New Direction Finding Equation of Navigation by Magnetic Sensors

Abstract

In this paper, we propose a new algorithm of an automotive direction finding method by using the fluxgate magnetometer. Conventionally known an automotive direction finding methods make use of two pickup sensors, x and y, are arranged to make their reference lines perpendicular to each other. All sensor data are converted into DC voltage Vx and Vy respectively which are proportional to each component of the geomagnetic field which is parallel to each reference line. The direction of the geomagnetic field with respect to the reference line of the sensor x is θ=tan-1 (Vy/Vx). However, because of the disparity of the mutual sensitivity of these two sensors, there is a limit in the improvement of the sensitivity of the automotive direction finding system.In this new algorithm, an automotive direction angle θ can be determined with at least one sensor for measuring the horizontal component of the geomagnetic field with good accuracy. In some conditions, it is demonstrated that the equation which is derived from the new algorithm is equal to the conventional automotive direction finding equation.