Robust output high-gain feedback controllers for the atomic force microscope under high data sampling rate

This paper proposed a robust output feedback controller of an atomic force microscope (AFM) device for the purpose of high rate data sampling. The AFM device is modeled as a cantilever-sample system in which the interactive forces between the cantilever and the sample consists of a long range attractive force and short range repulsive force. By using the feedback linearization and the singular perturbation technique, an output high-gain feedback controller is designed such that the cantilever tip can track the surface of the sample at a high rate of data sampling even though the topology of the surface is arbitrary and not given a priori. By adopting the controller developed here, the signals to be measured are the deflection of the cantilever. Finally, a computer simulation is provided to demonstrate the effectiveness of the proposed controller