| 摘要 |
PURPOSE:To accurately detect the traveling azimuth of a vehicle by calculating the traveling direction of the vehicle from received data from a roadside transmission station and intersection information which is stored previously. CONSTITUTION:The center position of an earth magnetism azimuth sensor is set under the control of a CPU 201, the current traveling position of the vehicle is set from a key input part 205, and a guide map and a reference position are displayed on a CRT 20. Then when the movement of the vehicle is confirmed, integral calculation interruption processing is started to read the traveling azimuth of the vehicle out of a sensor 203, and X- and Y- directional components of distance data are found every time the vehicle travels by a specific distance and added to each directional integral distances. Further, the current value is rewritten with the received data from an antenna 210, information on principal intersections is read out of an external storage device 206, and the distance between a last coordinate value to each intersection is calculated to find the road azimuth. Then the center of a new output circle is obtained from the radius of the output circle of earth magnetism intensity and the road azimuth. |
