Analysis and implementation of microvibration measurement techniques using optical interferometry and digital signal processors

• Grant number: 10/13868-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2011
• End date: February 28, 2013
• Field of knowledge: Engineering - Electrical Engineering - Electrical, Magnetic and Electronic Measurements, Instrumentation
• Principal Investigator: Ricardo Tokio Higuti
• Grantee: Paula Lalucci Berton
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil
• Associated scholarship(s): 12/02148-2 - Laser Doppler Vibrometry system for measurement of vibration/velocity, BE.EP.MS

Abstract

Optical interferometry is a well-established method for the measurement of micro- and nanodisplacements and vibrations. The displacement information is contained in the instantaneous phase of the photodetected signal, which can be subject to fading, that makes it difficult its correct detection. In general, optical phase interferometric measurement methods demand expensive optical circuits and hardware. On the other side, digital signal processors (DSPs) systems allow the acquisition and processing of the photodetected signal in real time and with lower cost. In this work the integration of an interferometric system, based on a homodine Michelson interferometer, with a DSP system, is proposed. Important topics to be addressed are: study and evaluate phase demodulation techniques that are more adequate for the proposed implementation, in general based on a spectral analysis of the signals, observing effects such as dynamic range, random and quantization noise, and real time implementation; fixed- and floating-point DSP platforms will be evaluated for the acquisition and signal processing of the photodetected signals. These results will be compared to those obtained with a traditional laboratory setup: oscilloscope for data acquisition, data transfer to computer for post-processing in Matlab. The use of the DSP system will reduce the cost of the interferometric system, and allow faster and more automatic measurements. The realization of several measurements per second will allow the rapid and denser transfer functions and linearity curves tracing, making easier the analysis of hysteresis and saturation effects, for example, even in the presence of fading.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

BERTON, Paula Lalucci. Análise e implementação de técnicas de medição de microvibrações utilizando interferometria óptica e processadores digitais de sinais. 2013. Master's Dissertation - Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira Ilha Solteira.