Output-Boundary Regulation: High-Speed AFM Imaging Application

This article addresses output-boundary regulation for high-scan-frequency Atomic Force Microscope (AFM) imaging of soft samples. The main contribution of this article is to use the causal inverse for nonminimum phase systems to rapidly transition an output away from a specified boundary whenever the output approaches the boundary due to unknown disturbances. The proposed feedforward-based control technique overcomes both: (i) lack of preview information of the disturbances; and (ii) performance limitations of feedback-based control methods for non-minimum phase systems. Simulation results for an example AFM are presented to illustrate the approach.