The invention discloses an absolute linear time
grating displacement sensor based on an alternating
electric field. The absolute linear time
grating displacement sensor comprises a probe body and a rule body. A coarse measuring
electrode I, a fine measuring
electrode and a coarse measuring
electrode II are successively disposed on the lower surface of the probe body from left to right. Excitation electrodes A, B, C and D are arranged on the upper surface of the rule body. Envelope lines formed by the vertex connection lines of the excitation electrodes A, B, C and D are sine curves which successively have 90 degree phase differences and periods not more than 2[pi]. A
coupling electric field formed between the left and right parts of the rectangle electrode of the rule body and the square coarse measuring electrodes of the probe
body senses an electric traveling wave
signal to carry out opposite pole positioning and realize a coarse measurement function. A
coupling electric field formed between the middle part of the rectangle electrode of the rule body and the dual sine fine measuring electrode of the probe
body senses an electric traveling wave
signal to carry out precision measurement and achieve a precise measurement function. A symmetrical differential structure is used to improve the stability of measurement, suppress
common mode interference, and increase
signal amplitude. The absolute linear time
grating displacement sensor has the advantages of low
power consumption, high precision, simple structure, low requirement for mechanical installation precision, and high-precision absolute displacement measurement in a
large range.