| 摘要 |
PURPOSE:To prevent the reception of the disturbance due to the external magnetic field, by calculating new correction data on the basis of the output data at two points and correcting the output data of an earth magnetism sensor on the basis of said correction data. CONSTITUTION:An earth magnetism sensor 1 is mounted on a vehicle at a predetermined angle with respect to the fore-and-aft or left-and-right direction of the vehicle and operation is performed on the basis of the output data from the detection elements in both of the north and east directions to detect the azimuth of the vehicle. In this case, the sampling of data is performed with respect to the output data of the earth magnetism sensor 1 within a predetermined time and, when the variation of said data is within a tolerable range and the data at least at two points separated by a predetermined angle or more from each other are obtained, correction data is calculated on the basis of the data at two points and used for correcting the output of the sensor 1. By this method, without receiving the disturbance due to the external magnetic field, highly reliable azimuth data can be obtained. |
