NEAR-RANGE PROXIMITY SENSOR HAVING A FAST-TRACKING ANALOG OUTPUT

摘要

A proximity sensor having a generator providing a signal of which a small portion is used as a reference signal and the remaining portion is radiated out towards a target. The radiation reflected from the target is equalized and/or normalized relative to the reference signal. The signals are compared in terms of relative phase relationship. This relationship implies the distance of the target from an antenna. An example target may be a rail wheel. A certain part of the wheel is measured in terms of distance from the sensor. This distance may determine wheel wear. Such wear is gauged relative to a threshold signal or reference distance. Also, speed and direction of the rail wheel can be determined from the signal reflected back to the proximity sensor.