The laser displacement measurement with feedback control in a magnetic levitation and suspension system

In this study, we used a laser displacement sensor, which the resolution wa s precise over 2 mum and capable of measuring infinitesimal displacement ra pidly for magnetic levitation and suspension equipment. A Feedback control was applied in this system, which required quick response to voltage variat ions. We also derived the equations of motion to determine the stability li mits and compared our calculations with the experimental results. From the experimental results, this mag-lev system, with special optical sensors and feedback circuits, is able to dynamically adjust unstable levitation posit ions. (C) 2000 Elsevier Science S.A. All rights reserved.