Evaluating output signal of vehicle revolution rate sensor - involves sensing markings and evaluating pulse signal separations to detect reference marker

摘要

The method involves using a rotating element (10) with a number of similar markings (11) and at least one distinguishable marking. The markings are sensed and an output signal produced from which a revolution rate dependent pulse sequence is produced. The quotients of times between pulses or identical pulse edges are compared (16) with at least one threshold to identify the distinguishable marking. The larger time is always the numerator and the smaller the denominator. ADVANTAGE - Reliable reference mark detection, even from large number of markings e.g. on incremental disc.