文摘
External feedback control of microcantilevers was previously demonstrated to be one of promising techniques to develop high-performance noncontact atomic force microscopy, but it has a difficulty in reproducing oscillatory waveforms of fast vibrating microcantilevers. Here we propose an approach to overcome this difficulty by using approximate waveforms for vibrations of the cantilevers, instead of the actual ones, as control signals. The approximations are very simple and consist of the lowest frequency and constant components. We call the proposed technique, rough external feedback control, to distinguish it from the original one. The efficiency and validity of our approach are demonstrated by numerical simulations, and numerical bifurcation analyses are carried out.