Micro-Opto-Electro-Mechanical System Accelerometer Based on Coarse-Fine Processing of Fabry–Perot Interferometer Signals

Abstract

The use of micro-electro-mechanical system (MEMS) accelerometers in aircraft control and navigation systems is of great interest. In this paper, a MEMS accelerometer with optical reader based on a two-channel Fabry–Perot interferometer is considered. To improve the accelerometer accuracy, it is proposed to analyze the fractional part of the interference band. The authors have studied the linear acceleration effect on the variation of output signal of the optical reader at various beam sensor parameters, as well as the variation of interferometer transmittance at different mirror reflectivity. Based on the interferometer transmittance vs. displacement relationships, the channel switching conditions were established to enable bypassing low-sensitivity zones. A method of optical signal processing has been developed, which generates the output value by concatenating the coarse measurement results and calculating a fine component. The proposed processing method makes it possible to increase the accuracy of the acceleration measurement results without changing the conversion range.