Vehicular traveling direction measuring system with automatic center coordinate position correction

摘要

A ststem measures a traveling direction of a vehicle based on a direction toward a coordinate position defined by output data from a geomagnetic direction sensor from a first coordinate position of a center of a corresponding output circle. The system utilizes a preliminary coordinate position as a preliminary corrected value of the first center coordinate position and a correction value indicative of reliability of the preliminary center coordinate position for deriving a finally corrected value of the first center coordinate position. The reliability of the preliminary center coordinate position is derived from previously stored data in terms of a derived variation in a vehicular traveling direction. The system derives the finally corrected value of the first center coordinate position based on the preliminary center coordinate position and the correction value such that the finally corrected value is derived closer to the preliminary center coordinate position when the correction value is derived larger.