Three-degree-of-freedom measurement method based on planar two-dimensional time grating sensor

Abstract

The invention discloses a three-degree-of-freedom measurement method based on a planar two-dimensional time grating sensor, and the method comprises the following steps: enabling a movable ruler base body and a fixed ruler base body to be installed in a parallel and opposite manner, and leaving a certain gap between the movable ruler base body and the fixed ruler base body; after same-frequency and equal-amplitude sine excitation signals with the phase difference of pi / 2 are applied to the four-phase excitation electrode groups on the fixed ruler base body respectively, the movable ruler base body moves in the X direction and the Y direction and deflects around the Z axis relative to the fixed ruler base body; the single sensing unit on the movable ruler base body can solve output signals deflecting in the X direction and the Y direction and around the axis, the output signals of all the sensing units are subjected to combined operation, and displacement values of the movable ruler base body in the X direction and the Y direction and the deflection angle theta can be decoupled. According to the method, displacement measurement in the X direction, the Y direction and the deflection angle around the Z axis can be achieved through combined calculation between the induction units on the movable ruler base body, the calculation speed is high, interference can be further eliminated, and the measurement precision is improved.

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