Recalibrated contactless FPGA-based optical-MEMS hybrid vibration sensing architecture with self-compensation for high-fidelity measurement applications

This study elucidates the ingenuity of a contactless self-vibration compensated vibration sensing architecture employing a 2D position sensitive detector (PSD) integrated with a micro-electro mechanical systems (MEMS) digital accelerometer. The proposed instrumentation framework was experimentally implemented using an NI-CompactRIO platform and was initially calibrated with a single-axis Brüel & Kjær piezoelectric accelerometer and linear piezo positioning system. In the present work, the earlier calibration is further refined employing a unified calibration configuration to enhance measurement performance. For this purpose, the system is recalibrated using a Piezotronics Model 353B03 ICP Quartz Shear Accelerometer, combined with a K2004E0 1 Smart Shaker excitation arrangement and EDM software for controlled testing. Experimental evaluation reveals that the developed arrangement achieves 0.08 Hz frequency error across the vibration range of 1 Hz to 1 kHz, while the relative error in displacement estimation reaches 1.548%. The device successfully measures vibration displacement from 3.5 µm to 3.8 mm, exhibiting a maximum deviation of 1.337% for different gain configurations at the examined frequencies. With a maximum standard deviation of only 0.38 µm, the system demonstrates high repeatability. This autonomous photonic instrumentation paradigm offers precise, resilient, and economical non-contact vibration sensing in mechanically challenging vibration measurement conditions.