| 摘要 |
<p>PURPOSE:To increase the selectivity and freeness by determining if a vehicle is stopped as a follower vehicle or a vehicle at the top when it is stopped based on a distance between vehicles, and branching into separate programs corresponding to a result. CONSTITUTION:An ultrasonic wave outputted from a ceramic transmitter/receiver 7 is reflected at a back surface 8 of a preceding vehicle, received 7 after completion of transmission, and it is returned to a computer as a binary signal LR through amplification, wave detection and trigger circuits in an ultrasonic wave receiver 9. An incremental encoder 10 is inserted in true middle of a speedometer cable, and two-line pulses of different phases (so-called phase A and phase B) are sent to the computer corresponding to the run of a vehicle. A stop detector 11 receives a phase B signal, and at the time of complete stoppage of the vehicle, or only a little later than that, a stoppage signal ST0 to the computer is lowered from H to a law level L, and it is set at H without delay for starting running. When the preceding vehicle starts running and an alarm is given, the alarm is stopped by information ST1 temporarily because the running starting action is delayed a little compared to vehicles around it which have been monitoring the preceding vehicle manually. The alarm is given again if keeps stopping without starting.</p> |
