TIME GRATING LINEAR DISPLACEMENT SENSOR BASED ON ALTERNATING LIGHT FIELD

摘要

A time grating linear displacement sensor based on an alternating light field, comprising a fixed pole plate (2) and a movable pole plate (3), wherein the upper part and the lower part of the fixed pole plate (2) are respectively provided with a row of square fixed pole plate light-transmitting surfaces (21) which are uniformly distributed; the upper part and the lower part at the rear of the fixed pole plate (2) are respectively provided with one group of light-emitting devices; the upper part and the lower part of the movable pole plate (3) are respectively provided with two semi-sinusoidal movable pole plate light-transmitting surfaces; and four light-sensitive receiving units (4) are fixed on the movable pole plate (3), the photoelectric receiving surfaces of the light-sensitive receiving units (4) covering the movable pole plate light-transmitting surfaces. The two groups of light-emitting devices respectively provide an alternating light field. The movable pole plate (3) moves relative to the fixed pole plate (2). The four light-sensitive receiving units (4) output electrical signals. Coupling signals of the two light fields are obtained after difference calculation and then are synthesized into one-path travelling wave signal Uo via an add circuit, and a linear displacement value of the movable pole plate (3) relative to the fixed pole plate (2) is obtained via clock interpolation and scale transformation after shaping and phase comparison are conducted on the travelling wave signal Uo and one-path reference signal Ur. The present invention is high in accuracy, low in power consumption, low in costs and easy in installation and manufacturing.