ALTERNATING ELECTRIC FIELD-BASED PLANAR TWO-DIMENSIONAL TIME GRATING DISPLACEMENT SENSOR

摘要

Disclosed is an alternating electric field based plane 2D time-grating displacement sensor which includes two parts: the base of fixed ruler (1) and the base of moving ruler, and the two parts are installed in parallel and facing to each other with a gap therebetween. The base of fixed ruler (1) is arranged with square excitation electrodes (11) that are respectively staggered coded along axis X and Y, and the base of moving ruler (2) is arranged with induction electrodes (a, b, c, d) arranged adjacently along X-axis and Y-axis, sinusoidal excitation signals with the same frequency and same amplitude with a phase difference of 90° are respectively applied to four excitation phases, and the four induction groups respectively output four traveling wave signals through electric field coupling, and summation of adjacent output signals with an adder can simultaneously decouple two traveling wave signals with opposite phases and only containing X-axis displacement and two traveling wave signals with opposite phases and only containing Y-axis displacement; two traveling wave signals in either direction are differenced by a subtractor to eliminate common mode interference. The sensor has a simple structure and decouples completely, which can realize high precision plane 2D displacement measurement over a large range.