| 摘要 |
PURPOSE:To integrate an exact running distance by correcting an error caused by an increase of the outside diameter of a tire at the time of running at a high speed. CONSTITUTION:A rotation sensor 1 for detecting the number of revolutions of a wheel outputs 160 pulse signals Pa per second at the time of a reference car speed (for instance, 80km/h). At the time of the refernce car speed or below, an FF circuit 4 is in a reset state, an output of a 32-scale counter 6 is H, and a distance counter 12 integrates a pulse signal Pb obtained by frequency-dividing a pulse signal Pa to 1/2 through an AND circuit 8. When exceeding the reference car speed, the FF circuit 4 is set by an overflow signal Pc of an 80- scale coutner 3, therefore, the 32-scale counter 6 starts counting. As a result, a distance counter 12 integrates the signal Pa through an AND circuit 7 whenever the signal Pb generates 32 pulses, therefore, at every 32 pulses of the signal Pb, the counter 12 integrates 33 pulses. Accordingly, a running distance integration error caused by an increase of the outside diameter of a tire generated in case of the reference car speed or above is corrected. |
