X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/dmems12.git/blobdiff_plain/5bd43a57b7e5c885d77aac6dceea8cc19f2cfaea..099b94e08988d44f4f22b13a2da77f029c6ec29a:/dmems12.tex diff --git a/dmems12.tex b/dmems12.tex index 423b0f7..6a7f646 100644 --- a/dmems12.tex +++ b/dmems12.tex @@ -71,7 +71,35 @@ \section{Introduction} -%% blabla + +Cantilevers are used inside atomic force microscope which provides high +resolution images of surfaces. Several technics have been used to measure the +displacement of cantilevers in litterature. For example, it is possible to +determine accurately the deflection with optic +interferometer~\cite{CantiOptic89}, pizeoresistor~\cite{CantiPiezzo01} or +capacitive sensing~\cite{CantiCapacitive03}. In this paper our attention is +focused on a method based on interferometry to measure cantilevers' +displacements. In this method cantilevers are illiminated by an optic +source. The interferometry produces fringes on each cantilevers which enables to +compute the cantilever displacement. In order to analyze the fringes a high +speed camera is used. Images need to be processed quickly and then a estimation +method is required to determine the displacement of each cantilever. +In~\cite{AFMCSEM11} {\bf verifier ref}, the authors have used an algorithm based +on spline to estimate the cantilevers' positions. The overall process gives +accurate results but all the computation are performed on a standard computer +using labview. Consequently, the main drawback of this implementation is that +the computer is a bootleneck in the overall process. In this paper we propose to +use a method based on least square and to implement all the computation on a +FGPA. + +The remainder of the paper is organized as follows. Section~\ref{sec:measure} +describes more precisely the measurement process. Our solution based on the +least square method and the implementation on FPGA is presented in +Section~\ref{sec:solus}. Experimentations are described in +Section~\ref{sec:results}. Finally a conclusion and some perspectives are +presented. + + + %% quelques ref commentées sur les calculs basés sur l'interférométrie \section{Measurement principles} @@ -328,9 +356,9 @@ Finally, the whole summarizes in an algorithm (called LSQ in the following) in t \subsubsection{Comparison} -\subsection{VDHL design paradigms} +\subsection{VHDL design paradigms} -\subsection{VDHL implementation} +\subsection{VHDL implementation} \section{Experimental results} \label{sec:results}