A time
grating linear displacement sensor based on an alternating
electric field comprises two parts, namely a head measuring base body and a
sizing base body, wherein a left
electrode and a right
electrode are coated on the lower surface of the head measuring base body; a left row of electrodes and a right row of electrodes are coated on the upper surface of the
sizing base body; the distance between the start position of the left row of electrodes and the start position of the right row of electrodes of the
sizing base body is 1 / 2
electrode width; the lower surface of the head measuring base body is relatively parallel to the upper surface of the sizing base body; a fixed clearance theta is formed between the lower surface of the head measuring base body and the upper surface of the sizing base body; a left group of differential capacitors and a right group of differential capacitors are formed; the head measuring base body and the sizing base body are relatively moved; the left rowof electrodes and the right row of electrodes of the sizing base body are respectively connected with
sinusoidal excitation voltages with equal amplitude and equal frequency, wherein the difference between the phases of the
sinusoidal excitation voltages is 90 degrees; two routes of
electric field coupling signals respectively generated by the left electrode and the right electrode of the head measuring base body are combined into one
route of travelling wave signals Uo through an adding circuit; after the
route of travelling wave signals Uo is shaped with one
route of common-frequency reference signals Ur with fixed phase, phase comparison is performed; and the
phase difference between the two routes of signals is represented by an interpolated
clock pulse and is transformed to generate a
linear displacement value. The time
grating linear displacement sensor based on the alternating
electric field has the advantages of low
power consumption, light weight,
high resolution and low cost.