DOPPLER RADAR TYPE ALARMING DEVICE

摘要

PURPOSE:To discriminate the approach or separation between a preceding car or other preceding cars and own car and to alarm these approach and separation, by varying the contents of alarm according to whether or not the changing factor of the amplitude level or the frequency changing factor of the Doppler signal is beyond a certain level. CONSTITUTION:It is decided at a deciding part of amplitude level changing factor comprising a differentiating circuit 9 and a comparator 10 that the amplitude levelchanging factor of the Doppler signal is larger than a certain level. Otherwise it is decided at a frequency changing factor deciding part comprising a differentating circuit 11 and a comparator 12 that the frequency changing factor is larger than a certain level. Either one or both of the above-mentioned two facts is/are detected simultaneously. In such case, it is decided that a car started precedently. Thus an alarm 8B is actuated. Otherwise an alarm 8A is catuated to warn the possiblity of a collision between the preceding and following cars.