690 lines
29 KiB
TeX
690 lines
29 KiB
TeX
% Created 2024-05-06 Mon 14:50
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% Intended LaTeX compiler: pdflatex
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\documentclass[a4paper, 10pt, DIV=12, parskip=full, bibliography=totoc]{scrreprt}
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\input{preamble.tex}
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\input{preamble_extra.tex}
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\bibliography{nass-introduction.bib}
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\author{Dehaeze Thomas}
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\date{\today}
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\title{Nano Active Stabilization System - Introduction}
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\hypersetup{
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pdfauthor={Dehaeze Thomas},
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pdftitle={Nano Active Stabilization System - Introduction},
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pdfkeywords={},
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pdfsubject={},
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pdfcreator={Emacs 29.3 (Org mode 9.6)},
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pdflang={English}}
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\usepackage{biblatex}
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\begin{document}
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\maketitle
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\tableofcontents
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\clearpage
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\chapter{Context of this thesis}
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\section{Synchrotron Radiation Facilities}
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\paragraph{Accelerating electrons to produce intense X-ray}
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\begin{itemize}
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\item Explain what is a Synchrotron: light source
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\item Say how many there are in the world (\textasciitilde{}50)
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\item Electron part: LINAC, Booster, Storage Ring \ref{fig:introduction_esrf_schematic}
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\item Synchrotron radiation: Insertion device / Bending magnet
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\item Many beamlines (large diversity in terms of instrumentation and science)
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\item Science that can be performed:
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\begin{itemize}
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\item structural biology, structure of materials, matter at extreme, \ldots{}
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\end{itemize}
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\end{itemize}
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\paragraph{The European Synchrotron Radiation Facility}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1,width=0.7\linewidth]{figs/introduction_esrf_picture.jpg}
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\caption{\label{fig:introduction_esrf_picture}European Synchrotron Radiation Facility}
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\end{figure}
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\begin{figure}[htbp]
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\centering
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\includesvg[scale=1,width=0.7\linewidth]{figs/introduction_esrf_schematic}
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\caption{\label{fig:introduction_esrf_schematic}Schematic of the ESRF - Over 40 beamlines. Booster, Linac, storage ring}
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\end{figure}
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\paragraph{3rd and 4th generation Synchrotrons}
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\begin{itemize}
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\item 4th generation light sources
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\begin{itemize}
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\item \cite{raimondi21_commis_hybrid_multib_achrom_lattic}
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\item[{$\square$}] Picture of 3rd generation ``beam source'' vs 4th generation?
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\end{itemize}
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\item[{$\square$}] Picture showing Synchrotron ``moore's law''
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\end{itemize}
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\section{The ID31 ESRF Beamline}
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\paragraph{Beamline Layout}
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\begin{itemize}
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\item[{$\square$}] Beamline layout (OH, EH)
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\item ID31 and Micro Station (Figure \ref{fig:introduction_id31_microstation_picture})
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Check \url{https://www.esrf.fr/UsersAndScience/Experiments/StructMaterials/ID31}
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\url{https://www.wayforlight.eu/beamline/23244}
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\item X-ray beam + detectors + sample stage (Figure \ref{fig:introduction_id31_beamline_schematic})
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\item Focusing optics
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\item Optical schematic with: source, lens, sample and detector.
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Explain that what is the most important is the relative position between the sample and the lens.
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\item Explain the XYZ frame for all the thesis (ESRF convention: X: x-ray, Z gravity up)
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\begin{itemize}
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\item[{$\square$}] Add XYZ on figure \ref{fig:introduction_id31_cad}
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\end{itemize}
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\end{itemize}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1,width=0.8\linewidth]{figs/introduction_id31_cad.jpg}
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\caption{\label{fig:introduction_id31_cad}CAD view of the optical hutch with the nano-focusing optics, the micro-station}
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\end{figure}
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\paragraph{Positioning End Station: The Micro-Station}
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Micro-Station:
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\begin{itemize}
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\item DoF with strokes: Ty, Ry, Rz, Hexapod
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\item Experiments: tomography, reflectivity, truncation rod, \ldots{}
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Make a table to explain the different ``experiments''
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\item Explain how it is used (positioning, scans), what it does. But not about the performances
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\item Different sample environments
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\item Alternative: \texttt{id31\_microstation\_cad\_view.png} (CAD view)
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\end{itemize}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1,width=0.49\linewidth]{figs/introduction_id31_microstation_picture.png}
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\caption{\label{fig:introduction_id31_microstation_picture}Picture of the ID31 Micro-Station with annotations}
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\end{figure}
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\paragraph{Science performed on ID31}
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\begin{itemize}
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\item Few words about science made on ID31 and why nano-meter accuracy is required
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\item Typical experiments (tomography, \ldots{}), various samples (up to 50kg), sample environments (high temp, cryo, etc..)
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\begin{itemize}
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\item Alignment of the sample, then
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\item Reflectivity
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\item Tomography
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\item Diffraction tomography: most critical
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\end{itemize}
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\item Example of picture obtained (Figure \ref{fig:introduction_id31_tomography_result}) with resolution
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\end{itemize}
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\texttt{introduction\_exp\_scanning} and \texttt{introduction\_exp\_scanning\_image}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1,width=0.49\linewidth]{example-image-c.png}
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\caption{\label{fig:introduction_id31_tomography_result}Image obtained on the ID31 beamline}
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\end{figure}
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\section{Need of accurate positioning end stations with high dynamics}
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\paragraph{A push towards brighter and smaller beams\ldots{}}
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Improvement of both the light source and the instrumentation:
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\begin{itemize}
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\item EBS: smaller source + higher flux
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\item Better focusing optic (add some links): beam size in the order of 10 to 20nm FWHM (reference)
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\begin{itemize}
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\item[{$\square$}] Show picture or measurement of the beam size
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\end{itemize}
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crossed silicon compound refractive lenses, KB mirrors [17], zone plates [18], or multilayer Laue lenses [19]
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\cite{barrett16_reflec_optic_hard_x_ray}
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\end{itemize}
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Higher flux density (+high energy of the ID31 beamline) => Radiation damage: needs to scan the sample quite fast with respect to the focused beam
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\begin{itemize}
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\item Allowed by better detectors: higher sampling rates and lower noise => possible to scan fast
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\cite{hatsui15_x_ray_imagin_detec_synch_xfel_sourc}
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\end{itemize}
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\paragraph{\ldots{}Requires the use of dynamical positioning}
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``from traditional step by step scans to \emph{fly-scan}''
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Fast scans + needs of high accuracy and stability => need mechatronics system with:
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\begin{itemize}
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\item accurate metrology
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\item multi degree of freedom positioning systems
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\item fast feedback loops
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\end{itemize}
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Shift from step by step scan to \emph{fly-scan} \cite{huang15_fly_scan_ptych}
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\begin{itemize}
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\item Much lower pixel size + large image => takes of lot of time if captured step by step.
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Explain what is step by step scanning: move motors from point A to point B, stops, start detector acquisition, open shutter , close the shutter, move to point C, \ldots{}
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\end{itemize}
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\cite{xu23_high_nsls_ii}
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\begin{quote}
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In traditional step scan mode, each exposure position requires the system to stop prior to data acquisition, which may become a limiting factor when fast data collection is required.
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Fly-scanning is chosen as a preferred solution that helps overcome such speed limitations [5, 6].
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In fly-scan mode, the sample keeps moving and a triggering system generates trigger signals based on the position of the sample or the time elapsed.
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The trigger signals are used to control detector exposure.
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\end{quote}
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\begin{itemize}
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\item[{$\square$}] Make picture representing a typical experiment (maybe YZ scan?) with:
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Probably already shown earlier \texttt{introduction\_exp\_scanning}
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\begin{itemize}
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\item nano focusing optics (see the beam focused)
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\item positioning stage with displayed YZ motion (pixel by pixel in the YZ plane)
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\item detector
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\end{itemize}
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\end{itemize}
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Subject of this thesis: design of high performance positioning station with high dynamics and nanometer accuracy
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\chapter{Challenge definition}
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\section{Multi DoF, Highly accurate, and Long stroke positioning end station?}
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\paragraph{Performance limitation of ``stacked stages'' end-stations}
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Typical positioning end station:
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\begin{itemize}
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\item stacked stages
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\item ballscrew, linear guides, rotary motor
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\end{itemize}
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Explain the limitation of performances:
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\begin{itemize}
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\item Backlash, play, thermal expansion, guiding imperfections, \ldots{}
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\item Give some numbers: straightness of the Ty stage for instance, change of \(0.1^oC\) with steel gives x nm of motion
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\item Vibrations
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\item Explain that this micro-station can only have \textasciitilde{}10um of accuracy due to physical limitation
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\item Possibility to have linear/rotary encoders that correct the motion in the considered DoF, but does not change anything to the other 5DoF
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\end{itemize}
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Talk about flexure based positioning stations?
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Advantages: no backlash, etc\ldots{}
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But: limited to short stroke
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Picture of schematic of one positioning station based on flexure
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\paragraph{The ID31 Micro-Station}
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Presentation of the Micro-Station in details \ref{fig:introduction_id31_microstation_cad}:
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\begin{itemize}
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\item Goal of each stage (e.g. micro-hexapod: static positioning, Ty and Rz: scans, \ldots{})
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\item Stroke
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\item Initial design objectives: as stiff as possible, smallest errors as possible
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\end{itemize}
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\paragraph{New positioning requirements}
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\begin{itemize}
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\item To benefits from nano-focusing optics, new source, etc\ldots{} new positioning requirements
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\item Positioning requirements on ID31:
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\begin{itemize}
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\item Maybe make a table with the requirements and the associated performances of the micro-station
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\item Make tables with the wanted motion, stroke, accuracy in different DoF, etc..
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\end{itemize}
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\item Sample masses
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\end{itemize}
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The goal in this thesis is to increase the positioning accuracy of the micro-station to fulfil the initial positioning requirements.
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\textbf{Goal}: Improve accuracy of 6DoF long stroke position platform
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\section{The Nano Active Stabilization System}
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\paragraph{NASS Concept}
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Briefly describe the NASS concept.
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4 parts:
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\begin{itemize}
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\item Micro Station
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\item multi-DoF positioning system with good dynamics
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\item 5DoF metrology system
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\item Control system and associated instrumentation
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\end{itemize}
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6DoF vibration control platform on top of a complex positioning platform that correct positioning errors based on an external metrology
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\begin{itemize}
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\item[{$\square$}] Add the control system in the schematic
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\end{itemize}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1]{figs/introduction_nass_concept_schematic.png}
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\caption{\label{fig:introduction_nass_concept_schematic}Nass Concept. 1: micro-station, 2: nano-hexapod, 3: sample, 4: 5DoF metrology}
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\end{figure}
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\paragraph{Metrology system}
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Requirements:
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\begin{itemize}
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\item 5 DoF
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\item long stroke
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\item nano-meter accurate
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\item high bandwidth
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\end{itemize}
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The accuracy of the NASS will only depend on the accuracy of the metrology system.
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Concept:
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\begin{itemize}
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\item Fiber interferometers
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\item Spherical reflector with flat bottom
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\item Tracking system
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\end{itemize}
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Complex mechatronics system on its own.
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This metrology system is not further discussed in this thesis as it is still under active development.
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In the following of this thesis, it is supposed that the metrology system is accurate, etc..
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\begin{itemize}
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\item Say that there are several high precision sensors, but only interferometers for long stroke / high accuracy?
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\end{itemize}
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\paragraph{Multi-DoF Positioning stage for error compensation}
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\begin{itemize}
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\item 5 DoF
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\item High dynamics
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\item nano-meter capable (no backlash,)
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\item Accept payloads up to 50kg
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\end{itemize}
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\paragraph{MIMO robust control strategies}
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Explain the robustness need?
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\begin{itemize}
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\item 24 7/7 \ldots{}
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\item That is why most of end-stations are based on well-proven design (stepper motors, linear guides, ball bearing, \ldots{})
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\item Plant uncertainty: many different samples, use cases, rotating velocities, etc\ldots{}
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\end{itemize}
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Trade-off between robustness and performance in the design of feedback system.
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\section{Predictive Design}
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\begin{itemize}
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\item The performances of the system will depend on many factors:
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\begin{itemize}
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\item sensors
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\item actuators
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\item mechanical design
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\item achievable bandwidth
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\item \ldots{}
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\end{itemize}
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\item Need to evaluate the different concepts, and predict the performances to guide the design
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\item The goal is to design, built and test this system such that it work as expected the first time.
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Very costly system, so much be correct.
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\end{itemize}
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\section{Control Challenge}
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High bandwidth, 6 DoF system for vibration control, fixed on top of a complex multi DoF positioning station, robust, \ldots{}
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\begin{itemize}
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\item Many different configurations (tomography, Ty scans, slow fast, \ldots{})
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\item Complex MIMO system. Dynamics of the system could be coupled to the complex dynamics of the micro station
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\item Rotation aspect, gyroscopic effects, actuators are rotating with respect to the sensors
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\item Robustness to payload change: very critical.
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Say that high performance systems (lithography machines, etc\ldots{}) works with calibrated payloads.
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Being robust to change of payload inertia means large stability margins and therefore less performance.
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\end{itemize}
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\chapter{Literature Review}
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\section{Nano Positioning end-stations}
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\paragraph{End Station with Stacked Stages}
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Stacked stages:
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\begin{itemize}
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\item errors are combined
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\end{itemize}
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To have acceptable performances / stability:
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\begin{itemize}
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\item limited number of stages
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\item high performances stages (air bearing etc\ldots{})
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\end{itemize}
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Examples:
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\begin{itemize}
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\item ID16b \cite{martinez-criado16_id16b}
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\item ID13 \cite{riekel10_progr_micro_nano_diffr_at}
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\item ID11 \cite{wright20_new_oppor_at_mater_scien}
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\item ID01 \cite{leake19_nanod_beaml_id01}
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\item[{$\square$}] Maybe make a table to compare stations
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\end{itemize}
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Explain limitations => Thermal drifts, run-out errors of spindles (improved by using air bearing), straightness of translation stages, \ldots{}
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\paragraph{Online Metrology and Active Control of Positioning Errors}
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The idea of having an external metrology to correct for errors is not new.
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\begin{itemize}
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\item To have even better performances: online metrology are required.
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\item Several strategies:
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\begin{itemize}
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\item only used for measurements (post processing)
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\item for calibration
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\item for triggering detectors
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\item for real time positioning control
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\end{itemize}
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\end{itemize}
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\begin{itemize}
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\item[{$\square$}] HXN \cite{xu23_high_nsls_ii}
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Laser interferometers on reference ring (on top of rotary stage).
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Used to trigger the detectors (ptychography, microscope)
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Similar to \cite{wang12_autom_marker_full_field_hard}
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\end{itemize}
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\begin{table}[htbp]
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\caption{\label{tab:introduction_sample_stages}Table caption}
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\centering
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\begin{tabularx}{\linewidth}{lllllllX}
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\toprule
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Architecture & Sensors and measured DoFs & Actuators and controlled DoFs & Institute, BL & OL/CL (bandwidth) & Stroke, DoF & Samples & Ref\\
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\midrule
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XYZ, Spherical retroreflector, Sample & 3 interferometers\footnotemark, Y,Z & YZ piezo stages & PETRA III, P06 & OL & 100um & light & \cite{schroer17_ptynam,schropp20_ptynam}\\
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Spindle / Metrology Ring / XYZ Stage / Sample & 3 Capacitive, Y,Z,Rx & & NSLS, X8C & OL, post processing & & micron scale & \cite{wang12_autom_marker_full_field_hard}\\
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\textbf{Hexapod} / Spindle / Metrology Ring / Sample & 12 Capacitive\footnotemark, X,Y,Z,Rx,Ry & Piezo (Hexapod) & ESRF, ID16a & CL, 10Hz bandwidth & 50um, 500urad & light & \cite{villar18_nanop_esrf_id16a_nano_imagin_beaml}\\
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XYZ, Rz, XY, Cylindrical reference & 5 interferometers\footnotemark, X,Y,Z,Rx,Ry & XYZ linear motors & Soleil & CL & & light & \cite{engblom18_nanop_resul,stankevic17_inter_charac_rotat_stages_x_ray_nanot}\\
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XYZ, Rz, XYZ Spherical reference & 3 Interferometers\footnotemark, Y,Z,Rx & XYZ parallel piezo stage & PSI, OMNY & CL & 400um & light & \cite{holler18_omny_tomog_nano_cryo_stage,holler17_omny_pin_versat_sampl_holder}\\
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XYZ, mirrors/sample & 3 interferometers\textsuperscript{\ref{org12e9b3b}}, XYZ & XYZ piezo stage & APS & CL, 3 PID & 3mm & light & \cite{nazaretski15_pushin_limit}\\
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Rz, Parallel XYZ stage & 3 interferometers\textsuperscript{\ref{orgd8c7548}} & 3xVCM parallel stage & LNLS, CARNAUBA & CL, 100Hz bandwidth & YZ: 3mm, Rz: +-110deg & light & \cite{geraldes23_sapot_carnaub_sirius_lnls}\\
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Parallel XYZ stage & 3 interferometers\textsuperscript{\ref{org65d59ad}}, XYZ & 3xVCM parallel stage & Diamond, I14 & CL, 100Hz bandwidth & XYZ: 3mm & up to 350g & \cite{kelly22_delta_robot_long_travel_nano}\\
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\bottomrule
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\end{tabularx}
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\end{table}\footnotetext[1]{\label{orgd8c7548}PicoScale SmarAct Michelson interferometers}\footnotetext[2]{\label{orgcd87c48}Capacitive sensors from Fogale Sensors}\footnotetext[3]{\label{org12e9b3b}Attocube FPS3010 Fabry-Pérot interferometers}\footnotetext[4]{\label{org65d59ad}Attocube IDS3010 Fabry-Pérot interferometers}
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\begin{itemize}
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\item[{$\square$}] Figure with different stages
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\item[{$\square$}] Compared to the existing stages (see table), what are the challenges here? Rotation, large stroke, light to heavy payloads, lots of DoF (5 to be controlled)
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\item[{$\square$}] Comparison with NASS?
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\end{itemize}
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\begin{center}
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\begin{tabular}{llllllll}
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Architecture & Sensors & Actuators & Institute, BL & OL/CL (bandwidth) & Stroke, DoF & Samples & Ref\\
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\hline
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Ty,Ry,Rz,Hexapod,Sample & 6+ Interferometers & & ESRF, ID31 & CL & Ty, Ry, Rz, Hexa & up to 50kg & \\
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\end{tabular}
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\end{center}
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\paragraph{Long Stroke - Short Stroke architecture}
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Speak about two stage control?
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\begin{itemize}
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\item Long stroke + short stroke
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\item Usually applied to 1dof, 3dof (show some examples: disk drive, wafer scanner)
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\item Any application in 6DoF? Maybe new!
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\item In the table, say which ones are long stroke / short stroke. Some new stages are just long stroke (voice coil)
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\end{itemize}
|
||
|
||
\section{Multi-DoF dynamical positioning stations}
|
||
\paragraph{Serial and Parallel Kinematics}
|
||
|
||
Example of several dynamical stations:
|
||
\begin{itemize}
|
||
\item XYZ piezo stages
|
||
\item Delta robot? Octoglide?
|
||
\item Stewart platform
|
||
\end{itemize}
|
||
|
||
Serial vs parallel kinematics (table?)
|
||
|
||
\paragraph{Stewart platforms}
|
||
|
||
\begin{itemize}
|
||
\item[{$\square$}] Explain the normal stewart platform architecture
|
||
\item[{$\square$}] Make a table that compares the different stewart platforms for vibration control.
|
||
Geometry (cubic), Actuator (soft, stiff), Sensor, Flexible joints, etc.
|
||
\end{itemize}
|
||
|
||
\begin{figure}
|
||
\begin{subfigure}{0.49\textwidth}
|
||
\begin{center}
|
||
\includegraphics[scale=1,width=0.8\linewidth]{example-image-a.png}
|
||
\end{center}
|
||
\subcaption{Stewart platform based on voice coil actuators}
|
||
\end{subfigure}
|
||
\begin{subfigure}{0.49\textwidth}
|
||
\begin{center}
|
||
\includegraphics[scale=1,width=0.8\linewidth]{example-image-b.png}
|
||
\end{center}
|
||
\subcaption{Stewart platform based on piezoelectric actuators}
|
||
\end{subfigure}
|
||
\caption{\label{fig:introduction_stewart_platform_examples}Examples of Stewart Platforms}
|
||
\end{figure}
|
||
|
||
\section{Mechatronics approach}
|
||
\paragraph{Predicting performances using models}
|
||
|
||
\begin{itemize}
|
||
\item \cite{monkhorst04_dynam_error_budget}
|
||
\begin{quote}
|
||
high costs of the design process: the designed system must be \textbf{first time right}.
|
||
When the system is finally build, its performance level should satisfy the specifications.
|
||
No significant changes are allowed in the post design phase.
|
||
Because of this, the designer wants to be able to predict the performance of the system a-priori and gain insight in the performance limiting factors of the system.
|
||
\end{quote}
|
||
\end{itemize}
|
||
|
||
|
||
Can use several models:
|
||
\begin{itemize}
|
||
\item Lumped mass-spring-damper models
|
||
\cite{rankers98_machin}
|
||
\item Multi-Body Models
|
||
\item Finite element models
|
||
Sub structuring?
|
||
\end{itemize}
|
||
|
||
\paragraph{Closed-Loop Simulations}
|
||
|
||
\cite{schmidt20_desig_high_perfor_mechat_third_revis_edition}
|
||
|
||
Say what can limit the performances for a complex mechatronics systems as this one:
|
||
\begin{itemize}
|
||
\item disturbances
|
||
\item measurement noise
|
||
\item DAC / amplifier noise (actuator)
|
||
\item feedback system / bandwidth
|
||
\end{itemize}
|
||
|
||
Simulations can help evaluate the behavior of the system.
|
||
|
||
\paragraph{Dynamic Error Budgeting}
|
||
|
||
\begin{itemize}
|
||
\item \cite{monkhorst04_dynam_error_budget}
|
||
\begin{quote}
|
||
high costs of the design process: the designed system must be \textbf{first time right}.
|
||
When the system is finally build, its performance level should satisfy the specifications.
|
||
No significant changes are allowed in the post design phase.
|
||
Because of this, the designer wants to be able to predict the performance of the system a-priori and gain insight in the performance limiting factors of the system.
|
||
\end{quote}
|
||
\item \cite{jabben07_mechat}
|
||
\item \cite{okyay16_mechat_desig_dynam_contr_metrol}
|
||
\begin{quote}
|
||
Error budgets [23] are frequently used in the design of precision machines, in order to assess the
|
||
contributions of different factors such as parasitic motions, thermal expansion, and servo accuracy, on
|
||
the positioning accuracy of a machine. Dynamic Error Budgeting (DEB) or ‘Spectral Analysis’
|
||
extends this concept to the realm of feedback control. Recognizing that the controller can provide
|
||
only a finite attenuation of disturbance signals interfering with the servo, DEB provides a
|
||
methodology for predicting the cumulative effect of such signals on the control error as a function of
|
||
their spectral (frequency) content. The method can be used to predict the control accuracy of a system
|
||
implemented using a set of certain devices under certain conditions before it is realized. Furthermore,
|
||
as it is formulated in the frequency domain, it can be used to optimize the controller design as well,
|
||
typically leading to an H2 - optimal control framework. In DEB, the disturbance signals are modeled
|
||
with their power spectral density (PSD), assuming that they are stationary stochastic processes which
|
||
are not correlated with each other. Then, these PSD’s are transmitted to the performance goal, most
|
||
often the positioning error, using linear time invariant (LTI) system theory. The transmitted PSD’s are
|
||
summed up into the variance of the performance goal, which constitutes a comparative measure of
|
||
performance. Most importantly, the influence of different dynamic factors and disturbance sources,
|
||
which have the greatest impact on the achievable performance (e.g., accuracy) can be easily spotted
|
||
and improved, through this kind of analysis. An approach similar to DEB was followed to decompose
|
||
the contribution of different noise sources on the hard disk position error in [1], [2], [45]. DEB has
|
||
been used to assess the performance of a geophone and a vibration isolation system in [75]. Jabben
|
||
[49] has used DEB in the mechatronic design of a magnetically suspended rotating platform. Aguirre
|
||
et al. [3] have analyzed the performance of active aerostatic thrust bearings using DEB.
|
||
\end{quote}
|
||
\end{itemize}
|
||
|
||
\section{Control architecture}
|
||
|
||
Maybe make a simple review of control strategies for Stewart platform control.
|
||
Based on \url{file:///home/thomas/Cloud/work-projects/ID31-NASS/matlab/stewart-simscape/org/bibliography.org}
|
||
|
||
Broad subject (MIMO control), maybe talk only about vibration control based on external metrology.
|
||
|
||
\begin{itemize}
|
||
\item Active Damping
|
||
\item Decentralized
|
||
\item Centralized
|
||
\item Manually tuned: PID, lead lag, etc\ldots{}
|
||
\item Automatic / Optimal: LQG, H-Infinity
|
||
\end{itemize}
|
||
|
||
\chapter{Original Contributions}
|
||
This thesis proposes several contributions in the fields of Control, Mechatronics Design and Experimental validation.
|
||
|
||
\paragraph{Active Damping of rotating mechanical systems using Integral Force Feedback}
|
||
|
||
\cite{dehaeze20_activ_dampin_rotat_platf_integ_force_feedb,dehaeze21_activ_dampin_rotat_platf_using}
|
||
\begin{quote}
|
||
This paper investigates the use of Integral Force Feedback (IFF) for the active damping of rotating mechanical systems.
|
||
Guaranteed stability, typical benefit of IFF, is lost as soon as the system is rotating due to gyroscopic effects.
|
||
To overcome this issue, two modifications of the classical IFF control scheme are proposed.
|
||
The first consists of slightly modifying the control law while the second consists of adding springs in parallel with the force sensors.
|
||
Conditions for stability and optimal parameters are derived.
|
||
The results reveal that, despite their different implementations, both modified IFF control scheme have almost identical damping authority on the suspension modes.
|
||
\end{quote}
|
||
|
||
\paragraph{Design of complementary filters using \(\mathcal{H}_\infty\) Synthesis and sensor fusion}
|
||
|
||
\cite{dehaeze19_compl_filter_shapin_using_synth}
|
||
\cite{verma20_virtual_sensor_fusion_high_precis_contr}
|
||
\cite{tsang22_optim_sensor_fusion_method_activ}
|
||
|
||
\begin{itemize}
|
||
\item Several uses (link to some papers).
|
||
\item For the NASS, they could be use to further improve the robustness of the system.
|
||
\end{itemize}
|
||
|
||
\paragraph{Multi-body simulations with reduced order flexible bodies obtained by FEA}
|
||
|
||
\cite{brumund21_multib_simul_reduc_order_flexib_bodies_fea}
|
||
|
||
Combined multi-body / FEA techniques and experimental validation on a Stewart platform containing amplified piezoelectric actuators
|
||
Super-element of amplified piezoelectric actuator / combined multibody-FEA technique, experimental validation on an amplified piezoelectric actuator and further validated on a complete stewart platform
|
||
|
||
\begin{quote}
|
||
We considered sub-components in the multi-body model as \emph{reduced order flexible bodies} representing the component’s modal behaviour with reduced mass and stiffness matrices obtained from finite element analysis (FEA) models.
|
||
These matrices were created from FEA models via modal reduction techniques, more specifically the \emph{component mode synthesis} (CMS).
|
||
This makes this design approach a combined multibody-FEA technique.
|
||
We validated the technique with a test bench that confirmed the good modelling capabilities using reduced order flexible body models obtained from FEA for an amplified piezoelectric actuator (APA).
|
||
\end{quote}
|
||
|
||
\paragraph{Robustness by design}
|
||
|
||
\begin{itemize}
|
||
\item Design of a Stewart platform and associated control architecture that is robust to large plant uncertainties due to large variety of payload and experimental conditions.
|
||
\item Instead of relying on complex controller synthesis (such as \(\mathcal{H}_\infty\) synthesis or \(\mu\text{-synthesis}\)) to guarantee the robustness and performance.
|
||
\item The approach here is to choose an adequate architecture (mechanics, sensors, actuators) such that controllers are robust by nature.
|
||
\item Example: collocated actuator/sensor pair => controller can easily be made robust
|
||
\item This is done by using models and using HAC-LAC architecture
|
||
\end{itemize}
|
||
|
||
\paragraph{Mechatronics design}
|
||
|
||
Conduct a rigorous mechatronics design approach for a nano active stabilization system
|
||
\cite{dehaeze18_sampl_stabil_for_tomog_exper,dehaeze21_mechat_approac_devel_nano_activ_stabil_system}
|
||
|
||
Approach from start to finish:
|
||
\begin{itemize}
|
||
\item From first concepts using basic models, to concept validation
|
||
\item Detailed design phase
|
||
\item Experimental phase
|
||
\end{itemize}
|
||
|
||
Complete design with clear choices based on models.
|
||
Such approach, while not new, is here applied
|
||
This can be used for the design of future end-stations.
|
||
|
||
\begin{figure}[htbp]
|
||
\centering
|
||
\includegraphics[scale=1,width=\linewidth]{figs/nass_mechatronics_approach.png}
|
||
\caption{\label{fig:introduction_nass_mechatronics_approach}Overview of the mechatronic approach used for the Nano-Active-Stabilization-System}
|
||
\end{figure}
|
||
|
||
\paragraph{6DoF vibration control of a rotating platform}
|
||
|
||
Vibration control in 5DoF of a rotating stage
|
||
To the author's knowledge, the use of a continuously rotating stewart platform for vibration control has not been proved in the literature.
|
||
|
||
\paragraph{Experimental validation of the Nano Active Stabilization System}
|
||
|
||
Demonstration of the improvement of the the positioning accuracy of a complex multi DoF (the micro-station) by several orders of magnitude (Section \ldots{}) using \ldots{}
|
||
|
||
\chapter{Thesis Outline - Mechatronics Design Approach}
|
||
\begin{figure}[htbp]
|
||
\centering
|
||
\includegraphics[scale=1,width=\linewidth]{figs/introduction_overview_chapters.png}
|
||
\caption{\label{fig:introduction_overview_chapters}Overview of the sections}
|
||
\end{figure}
|
||
|
||
This thesis
|
||
\begin{itemize}
|
||
\item has a structure that follows the mechatronics design approach
|
||
\end{itemize}
|
||
|
||
Is structured in three chapters that corresponds to the three mains parts of the proposed mechatronics approach.
|
||
|
||
A brief overview of these three chapters is given bellow.
|
||
|
||
\paragraph{Conceptual design development}
|
||
|
||
\begin{itemize}
|
||
\item Start with simple models for witch trade offs can be easily understood (uniaxial)
|
||
\item Increase the model complexity if important physical phenomenon are to be modelled (cf the rotating model)
|
||
\item Only when better understanding of the physical effects in play, and only if required, go for higher model complexity (here multi-body model)
|
||
\item The system concept and main characteristics should be extracted from the different models and validated with closed-loop simulations with the most accurate model
|
||
\item Once the concept is validated, the chosen concept can be design in mode details
|
||
\end{itemize}
|
||
|
||
\paragraph{Detailed design}
|
||
|
||
\begin{itemize}
|
||
\item During this detailed design phase, models are refined from the obtained CAD and using FEM
|
||
\item The models are used to assists the design and to optimize each element based on dynamical analysis and closed-loop simulations
|
||
\item The requirements for all the associated instrumentation can be determined from a dynamical noise budgeting
|
||
\item After converging to a detailed design that give acceptable performance based on the models, the different parts can be ordered and the experimental phase begins
|
||
\end{itemize}
|
||
|
||
\paragraph{Experimental validation}
|
||
|
||
\begin{itemize}
|
||
\item It is advised that the important characteristics of the different elements are evaluated individually
|
||
Systematic validation/refinement of models with experimental measurements
|
||
\item The obtained characteristics can be used to refine the models
|
||
\item Then, an accurate model of the system is obtained which can be used during experimental tests (for control synthesis for instance)
|
||
\end{itemize}
|
||
|
||
|
||
\printbibliography[heading=bibintoc,title={Bibliography}]
|
||
\end{document}
|