Abstract
This paper proposes a subdivision interpolation technique for
an optical accelerometer based
on diffraction grating interferometry. The diffraction light intensity
curve presents a sine shape with the increase of
the acceleration. To address
the issues of linearization signal processing across the entire range,
a subdivision interpolation circuit is employed, in conjunction with a
90° phase shift and high-precision DC bias-voltage techniques,
converting an analog signal with sinusoidal characteristics from the
photodetector into standard incremental digital signals that vary
linearly over the full range. The novel methodology, to the best of
our knowledge, ensures that its performance is least affected by the
phase imbalance, offset error, and amplitude mismatch induced by
fabrication and alignment errors of the grating, achieving
high-resolution digital signal output. The experiment results reveal
that the optical accelerometer based on grating interferometry
achieved a sensitivity of 85.2 V/g, a resolution of
137.6 µg, as well as a subdivision interpolation factor of 45.
This work provides a significant guide for the development of
high-resolution MOEMS accelerometers in practical applications.
Funder
National Natural Science Foundation of China