On observer-based estimation enhancement by parametric amplification in a weak force measurement device

This paper focuses on the problem of force estimation performances in some EFM-like device (Electric Force Microscope). In this context it is shown how those performances can be significantly improved w.r.t. noise measurement by combining techniques in the spirit of the so-called ¿parametric amplification¿ in particular investigated in physics, with observer techniques as they are developed in the control community. The minimal force which can be estimated in this way is expressed in terms of estimation rate and measurement noise variance.