Unified hysteresis and creep compensation in AFM tip positioning with an extended PI model

The nonlinearities such as hysteresis and creep are the major factors inherent in PZT actuation that affect the tip positioning precision and manipulation performance of the AFM system. In this study, an extended PI model is generalized by introducing a creep model to the basic hysteretic operator of the PI model at the inflexion point of the hysteresis loop. Unified compensation for hysteresis and creep can be implemented with the extended PI model. Experiment results demonstrate the validity and effectiveness of the extended PI model and it is implied that the inflexion creep compensation not only improves the tip positioning precision at the inflexion points on the hysteresis loops, but also the localization effectiveness during the whole process of PZT actuation.