| 摘要 |
PURPOSE:To improve detecting accuracy of the running direction of an earth magnetism sensor by correcting a reference value of the earth magnetism sensor in the direction of a magnetic field of the body magnetization and reducing gradually an detecting error of the running direction due to the body magnetization of the sensor. CONSTITUTION:When the vehicle running is guided to a destination spot by a display screen 5a, since the output of a direction sensor 6 is sampled by a sampling means 22 and the X, Y components are compared with reference values X0, Y0 of a reference value setting part 21 by a comparing means 23 and the reference values X0, Y0 are changed and corrected one by one in the direction of the magnetic field of the body magnetization based on the result, the output differences among the north, south, east and west directions of the sensor 6 are reduced and the influence by the body magnetization is reduced effectively and the detection of the running direction by the sensor 6 is made accurate. Further, since the correction of the reference values X0, Y0 is automatically performed during the running when the magnetic field of the body magnetization is changed, the correction of the running direction detecting error is made effective. |
