Flat Magnetic X-Y Alignment sensor

Abstract

We propose a novel flat 2-D inductive position sensor based on stationary coils and moving armature. The geometry was optimized by FEM simulations, the predicted parameters of the final design fit well to the measured values. The position sensitivity of 100 mV/cm for 500 kHz/140 mA excitation achieved with laminated nanocrystalline armature was 5-times higher than with FeSi material. We have also shown by measurements that the influence of the liftoff variations can be effectively suppressed by ratiometric method. The total sensor thickness is only 2.5 mm. The developed sensor is suitable for position alignment in industrial applications.The present design has linear range of ±10 mm for directions up to ±30° from X and Y axes. The minimum linear range of ±5 mm is in the diagonal (45°) direction.