| 摘要 |
PURPOSE:To obtain the detecting device which grasps an invariably accurate position by integrating the angular velocity voltage obtained by subtracting a voltage stored in a zero-voltage storage means from the output voltage of an angular velocity sensor when a radio wave from an artificial satellite cannot be received. CONSTITUTION:This system normally calculates the latitude, longitude, and altitude of the current position of a vehicle with signals received from three satellites, reads map data on the neighboring position out of a CD-ROM 3, and displays the data on a CRT 4. When, however, the vehicle moves to a place where a radio wave is not received from an artificial satellite, a data processor 5 performs switching to a method which calculates the position from the position which is found last by using the artificial satellites with signals from a tuning-fork vibration type angular velocity sensor 6 and a vehicle speed sensor 8. Then the angular velocity voltage obtained by subtracting the voltage stored in the zero-voltage storage means from the output voltage of the sensor 6 is integrated to calculate the variation angle of the current travel direction of the vehicle and also calculate the travel direction of the vehicle, and the current coordinates of the vehicle in a travel on the map are calculated from said calculated value and the movement quantity of the vehicle detected by the vehicle speed sensor 8. |
