| 摘要 |
PURPOSE:To prevent the lowering in magnetization correcting accuracy, by setting the center point of an advance azimuth vector corresponding to a non- magnetized state to a temporary center point and allowing the coordinates center point at the time of the calculation of a magnetization error to approach the center point of an advance direction vector to be calculated at this time. CONSTITUTION:The center point of a vehicle fixing coordinates system corresponding to a non-magnetized state is stored in a reference coordinates memory means 15. When the magnetized state of a car body largely changes by a strong magnetic field and the center point of an advance azimuth vector 10 largely moves with the change of the magnetized state, reference coordinates data is read from the reference coordinates memory means 15 by the output of a control means and the center point of the advance azimuth vector 10 is rewritten to reference coordinates data to set a temporary center point 14. New magnetization correction is started on the basis of the temporary center point 14 by a magnetization error calculating means 13. By this method, even when the center point of the advance azimuth vector 10 largely moves with the change of the magnetized state, the lowering in operation accuracy is prevented. |
