Electromagnetic Navigation Linear Displacement Transducer Based on Magnetic Field Gradient Technique

Abstract

A linear displacement transducer (LDT) for electromagnetic navigation is developed based on the sensing of magnetic field gradients in a pair of counter-wound coils. The operation and linear response conditions of the LDT are theoretically described by electromagnetic formulations, numerically analyzed by COMSOL Multiphysics finite element analysis software, and experimentally verified in a 1/10-scaled inspection vehicle-overhead cable model. A high sensitivity of 51 µV/cm and a small nonlinearity of 3.7% are achieved in the LDT prototype by setting an optimal height-to-baseline 𝒉𝒉/𝑳𝑳 ratio of 𝟏𝟏/√𝟖𝟖 in practical linear response condition with the transverse displacement 𝒅𝒅 constraint of ±50% of 𝑳𝑳. The proposed LDT can overcome the discontinuous response and nonlinearity problems intrinsic in traditional magnetic field-based LDTs, thereby providing a continuous displacement (movement) feedback with an accuracy of within several millimeters.

Study on fiber Fabry–Perot displacement sensor for vibration monitoring of fuel pin

“…Electric displacement sensors have developed as a mature and widely used technology, 6–8 but they are inapplicable to a nuclear power plant due to the harsh working condition and the large volume 3,9 . Optical fiber sensors are one of the promising sensing devices for vibration monitoring of fuel pins due to their high compactness, anti‐electromagnetic interference, remote detection, and resistance to hazardous environments such as high temperature and humidity 10,11 .…”