Observer-Based 3-D Control Enhancement for Topographic Imaging--Validation With an STM Prototype
Résumé
This article proposes a control method using online state estimation techniques in order to enhance the capabilities of classical PI controllers as well as to improve the topographic imaging for an experimental scanning tunneling microscope-like device. In particular, a set of robust observers are designed following a recently proposed technique that takes advantage of control strategies in order to build such estimators. All three directional axes of such a subnanometric imaging device are controlled using the proposed method in order to obtain better images of a scanned surface. Real-time results for topographic imaging of a graphite sample are presented in order to illustrate the performances of the proposed method.