| 摘要 |
PURPOSE:To highly precisely detect the direction azimuth of a vehicle because an offset can be frequently and exactly renewed even if the direction azimuth of the vehicle may be frequently and an error component in an absolute azimuth may be included at the time when the vehicle is running on a mountain pass and the like. CONSTITUTION:When a sensor azimuth indicates the azimuth of a vehicle is detected with a sensor azimuth detection part 26, a difference between the sensor azimuth and an absolute azimuth including an error component may be calculated by an azimuth difference operation part 27 and the error component included in its azimuth difference may be removed by LPF 29. Thereafter a drift estimation value per unit time can be calculated on the basis of the output of LPF 29 with an offset change part estimation value operation part 30, an offset estimation value can be computed on the basis thereof by an offset renewal part 31 and an offset value stored in an offset memory 5 is rewritten into the offset estimation value. |
