| 摘要 |
PURPOSE:To accurately grasp the present position by inhibiting a detection in the forward direction based on a signal from a wheel speed sensor at the time when the wheel runs idle. CONSTITUTION:Right and left wheel speed detecting values are inputted to an idling wheel detecting means 4 from a wheel speed sensor 1. Differential values are obtained on the detected values of the right and left wheel speeds by this means 4 and compared with a preset reference value. Now, for example, when the differential value of the right wheel is larger than the reference value, an idling signal is outputted to an inhibiting means 5. Then, when the idling signal from the means 4 is received, the means 5 outputs an inhibiting signal. Subsequently, when the inhibiting signal is inputted from the means 5 to a selecting means 7, a distance detecting means 2 and a forward direction detecting means 3 are inhibited from detecting respectively, and a moving distance and a forward direction are detected by a speedometer and a geomagnetic sensor of a detecting means 6, and these data are outputted to a control unit 8. Then, in the unit 8, the present position of the vehicle is detected based on the data from the means 7, and this present position is called from a compact disk to be displayed via a display 9. |
