A DEVICE AND A METHOD FOR NON-CONTACTUAL SPEED MEASUREMENT ON SURFACES

摘要

A device for non-contactual measurement of the speed of an object (10) moving over a surface (12) comprises a means (20) for radiating a signal of fixed frequency at an angle (a) onto the surface (12) in or against the direction of motion, said angle (a) being variable by the movement of the object (10), and for receiving a Doppler-shifted signal reflected at the surface (12). A means (24) is provided for combining a plurality of reflected Doppler-shifted signals, which are received in temporal succession, so as to produce a combined spectrum (50; 60, 62, 64). The device for non- contactual speed measurement additionally comprises a means (24) for detecting from the combined spectrum the spectral portion having the highest or lowest frequency and exceeding a predetermined signal power, and a means (30) for deducing the speed from the frequency of the detected spectral portion.