Eddy current sensors on Printed Circuit Board for compact mechatronic application

Abstract:
In a context of always smaller and smarter mechatronic devices, the need of more integrated sensors becomes critical. Particularly, small mechanisms using small actuators like piezo actuators require compact sensors, with performances that measure up to the actuators characteristics. Eddy current position sensors (ECPSs) are widely used for non contact position, displacement, and proximity measurement with very good performances (bandwidth resolution, linearity, robustness in dirt environment). Operating on the principle of magnetic induction, these detectors can precisely measure the position of a metallic target. With the performances increase in PCB manufacturing, a specific design of this kind of sensors on Printed Circuit boards allows a compact device which could be coupled with its electronic conditioner. The modeling of the magnetic behavior of the probe and the coupling with a dedicated electronic conditioning are studied in this paper. Tests are involved on a X piezoelectric stage mechanism to verify the final performances. PCB-based eddy current sensors allows less space offering reduced weight with more controllability in integrated mechatronic devices.