Fiber Bragg Grating Sensors for Micro-displacement Measurement

摘要

Micro-displacement measurement takes a very important role in mechanical manufacturing process, micro-mechanics and other applied systems. A new kind of measurement method for micro- displacement based on fiber Bragg grating (FBQ) sensing technology is presented in this paper. Measurement span of FBG sensor is largely broadened and its resolution is improved through a spring structure. Different sensor structures are designed to meet different application requirements. The resolution of test system for micro- displacement is finer than 0.2 μm with the measurement span being about 700μm. Fundamentals of FBG sensor are discussed in this paper. A novel concept and technique for distinguishing displacement signal from FBG wavelength shift aroused from temperature is proposed using dual FBGs, the measurement precision and accuracy are thus improved. The sensing system shows satisfied repeatability and linearity. The given sensing system can also be useful for measurement of pressure, vibration and Yang's elastic modulus and extension modulus of materials.