| 摘要 |
PROBLEM TO BE SOLVED: To reduce cost by measuring a pitching angle from the height of a sensor from the road surface when electromagnetic field indicators installed at specified spaces are in first and second specified positions from the sensor of a vehicle, and also from a space between the specified positions. SOLUTION: Which of sensors 2a-2e is closest to a magnet 4 is judged, and a signal of each Hall element of the closest sensor is used for operation. Whether the magnet 4 came into a position 15cm in front of the sensor is judged. The signals of the respective longitudinal and lateral Hall elements at the time of the magnet 4 being positioned 15cm ahead in a proceeding direction from the discriminated sensor closest to the magnet 4 are projected on a map so as to obtain the vertical distance between the sensor and the upper end part of the magnet 4, that is, the road surface, at that time. In the same way, a state of the magnet 4 being positioned 15cm backward is detected, and the distance at that time, that is, the vertical distance between the sensor and the road surface, is obtained. The pitching angle of a vehicle can be obtained by operation using both vertical distance and a space (30cm) between two longitudinal points. |
