A method of measuring moving element displacements in micro-hydraulic valves with the use of optical fibers

This work presents a fiberoptic technique used to measure displacements of moving elements in micro-hydraulic valves. Fiberoptic sensors coupled with a reflection method have proven to be perfect for touchless measurement of movement for elements hard to measure by other methods due to their small size and presence of a hydraulic oil. The article presents results of experiments revealing correlation between the measurement signal and element movement as well as sample displacement changes in time of the moving element in non-equilibrium states – for both, a stable action and self-exciting vibrations of the element.