Improving Atomic Force Microscopy Imaging by a Direct Inverse Asymmetric PI Hysteresis Model

Sensors

Dong Wang²  Peng Yu²  Feifei Wang²  Ho-Yin Chan¹  Lei Zhou²  Zaili Dong²  Lianqing Liu² 

[1] Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong, China; E-Mail:;State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, China; E-Mails:

关键词: atomic force microscope;    hysteresis;    piezoelectric actuator;    direct inverse asymmetric PI model;    feedforward control;   

DOI  :  10.3390/s150203409

来源: mdpi

【 摘 要 】

A modified Prandtl–Ishlinskii (PI) model, referred to as a direct inverse asymmetric PI (DIAPI) model in this paper, was implemented to reduce the displacement error between a predicted model and the actual trajectory of a piezoelectric actuator which is commonly found in AFM systems. Due to the nonlinearity of the piezoelectric actuator, the standard symmetric PI model cannot precisely describe the asymmetric motion of the actuator. In order to improve the accuracy of AFM scans, two series of slope parameters were introduced in the PI model to describe both the voltage-increase-loop (trace) and voltage-decrease-loop (retrace). A feedforward controller based on the DIAPI model was implemented to compensate hysteresis. Performance of the DIAPI model and the feedforward controller were validated by scanning micro-lenses and standard silicon grating using a custom-built AFM.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.