Fiber-optic sensors for nanometric displacement and vibration measurement in mechatronics

Fiber-optic sensors are widely used for displacement and vibration measurements in mechatronic systems. Sensors can be of very small size and operate in blast danger conditions and strong electromagnetic interference environment. In this work modeling and experimental investigation of the characteristics U-h of fiber-optic sensor of displacement have been accomplished with a view to obtain the maximal sensitivity in the displacement and vibration measurements. The modeling and experimental results were perfectly coincidental, therefore the limit sensitivity of sensors can be predicted by modeling. Configurations of non-contact fiber optic sensors of the maximal possible sensitivity have been found, the metrological parameters of which do not depend either on the degradation of the light source, intensity or on the elements used in the mechatronics system measurements as well as on the value of the mirror reflection coefficient and changes with the aging process. All that increases the reliability of mechatronics system monitoring, which is of utmost importance for their exploitation.