| 摘要 |
PURPOSE:To easily correct an earth magnetism sensor by storing the difference from a traveling direction detected by the earth magnetism sensor is stored as a correcting quantity when a traveling direction is set by a direction input means. CONSTITUTION:A distance sensor 2 detects the traveling distance of a vehicle. The earth magnetism sensor 1 detects the traveling direction of the vehicle. A vehicle position arithmetic unit 4 finds the position of the vehicle according to the outputs of the sensors 1 and 2 and stores the position. When the real traveling direction of the vehicle is set by the direction input means 5, a direction correcting means 3 corrects the detected direction of the sensor 1 according to the difference between the traveling direction detected by the sensor 1 and the set traveling direction. Consequently, the earth magnetism sensor can easily be corrected without making one turn of the vehicle nor preparing map data at all times. |
