Displacement sensing mechanism and measurement model of planar two-dimensional time-grating based on alternating magnetic field
To address the limitations of traditional planar two-dimensional displacement sensors in ultra-precision lithography and large-area sensor manufacturing,a new method using a spatial alternating mag-netic field is proposed.This method involves arranging uniform sine/cosine excitation windings on a fixed ruler and applying time-quadrature electric current to these windings,creating a two-dimensional alternat-ing magnetic field that links spatial displacement with a time reference.The method achieves spatial dis-placement measurement through a model of"dimension judgment+displacement decoupling."Dimension judgment is performed using the binary output signals from a dimension-judgment induction winding array.The alternating magnetic field is detected by a displacement-decoupling induction winding array arranged in two dimensions,producing spatial traveling-wave signals and enabling displacement decoupling via phase comparison.Error analysis of this two-dimensional time-grating displacement measurement model was conducted through electromagnetic simulation.A prototype and experimental platform were devel-oped,demonstrating that within a 120 mm×120 mm range,the maximum measurement errors were±9.4 µm in the X direction and±9.7 µm in the Y direction,with a resolution of 0.15 µm.This method achieves micron-level measurement accuracy using millimeter-sized excitation and induction windings,overcoming the limitations of traditional sensors in ultra-precision lithography and simplifying sensor manu-facturing.The research holds significant theoretical and practical value.
two-dimensional displacement measurementalternating magnetic fieldtime-grating sen-sorscombined measurement