Numerical Analysis of Inductive Proximity Sensors for Non-Ferrous Targets

Abstract

Proximity sensors are devices found in many fields of activity from the automotive area to robotics and beyond. Among them, proximity sensors occupy an important place due to their low price and reliable response. They are found in a wide range of sizes and detection distances. In this work, a comparative study was carried out on two constructive solutions - one shielded and one unshielded. The response provided by the sensor was followed through a 2D FEMM analysis varying a series of parameters: the material from which the target is made, the distance between the target and the sensor, as well as its operating frequency. The results highlight the influence of these parameters by changing some quantities of a magnetic nature such as the spectrum of the magnetic flux density, the magnetic energy stored by the target, respectively the inductance of the sensor coil.