273 lines
11 KiB
TeX
273 lines
11 KiB
TeX
% Created 2025-04-21 Mon 16:49
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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-design.bib}
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\author{Dehaeze Thomas}
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\date{\today}
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\title{Nano Hexapod - Obtained Design}
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\hypersetup{
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pdfauthor={Dehaeze Thomas},
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pdftitle={Nano Hexapod - Obtained Design},
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pdfkeywords={},
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pdfsubject={},
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pdfcreator={Emacs 30.1 (Org mode 9.7.26)},
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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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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1,width=0.95\linewidth]{figs/detail_design_nano_hexapod_elements.png}
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\caption{\label{fig:detail_design_nano_hexapod_elements}Obtained mechanical design of the Active platform, the ``nano-hexapod''}
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\end{figure}
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\textbf{Design goals}:
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\begin{itemize}
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\item Position \texttt{bi} and \texttt{si}
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\item Maximum height of 95mm
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\item As close as possible to ``perfect'' stewart platform: flexible modes at high frequency
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\item Easy mounting, easy change of strut in case of failure
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\end{itemize}
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Presentation of the obtained design:
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\begin{itemize}
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\item Fixation
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\item Section on: Complete strut
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\item Cable management
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\item Plates design
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\item FEM results
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\item Explain again the different specifications in terms of space, payload, etc..
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\item CAD view of the nano-hexapod
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\item Chosen geometry, materials, ease of mounting, cabling, \ldots{}
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\item Validation on Simscape with accurate model?
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\end{itemize}
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\chapter{Mechanical Design}
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\label{sec:detail_design_mechanics}
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\section{Struts}
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\begin{figure}[htbp]
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.95\linewidth]{figs/detail_design_strut_without_enc.jpg}
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\end{center}
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\subcaption{\label{fig:detail_design_strut_without_enc}Before encoder integration}
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\end{subfigure}
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.95\linewidth]{figs/detail_design_strut_with_enc.jpg}
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\end{center}
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\subcaption{\label{fig:detail_design_strut_with_enc}With the mounted encoder}
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\end{subfigure}
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\caption{\label{fig:detail_design_strut}Design of the Nano-Hexapod struts. Before (\subref{fig:detail_design_strut_without_enc}) and after (\subref{fig:detail_design_strut_with_enc}) encoder integration.}
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\end{figure}
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\subsubsection{Flexible joints}
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Flexible joints: X5CrNiCuNb16-4 (F16Ph)
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\begin{itemize}
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\item high yield strength: specified >1GPa using heat treatment
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\item high fatigue resistance
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\end{itemize}
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\begin{figure}[htbp]
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,scale=1]{figs/detail_design_apa.png}
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\end{center}
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\subcaption{\label{fig:detail_design_apa}Amplified Piezoelectric Actuator}
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\end{subfigure}
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,scale=1]{figs/detail_design_flexible_joint.png}
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\end{center}
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\subcaption{\label{fig:detail_design_flexible_joint}Flexible joint}
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\end{subfigure}
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\caption{\label{fig:detail_design_apa_joints}Two main components of the struts: the amplified piezoelectric actuator (\subref{fig:detail_design_apa}) and the flexible joint (\subref{fig:detail_design_flexible_joint}).}
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\end{figure}
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\subsubsection{Piezoelectric Amplified Actuators}
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APA: modification for better mounting
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\subsubsection{Encoder support}
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All other parts are made of aluminum.
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\section{Plates}
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Plates: X30Cr13
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\begin{itemize}
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\item high hardness to not deform
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\end{itemize}
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\begin{itemize}
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\item Maximize frequency of flexible modes (show FEM)
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\item Good tolerances for interfaces with flexible joints
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Positioning of \texttt{bi} and orientation \texttt{si}
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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,scale=1]{figs/detail_design_top_plate.png}
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\caption{\label{fig:detail_design_top_plate}The mechanical design for the top platform incorporates precisely positioned V-grooves for the joint interfaces (displayed in red). The purpose of the encoder interface (shown in green) is detailed later.}
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\end{figure}
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The cylindrical component is located (or constrained) within the V-groove via two distinct line contacts.
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\begin{figure}
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\begin{subfigure}{0.33\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.99\linewidth]{figs/detail_design_fixation_flexible_joints.png}
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\end{center}
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\subcaption{\label{fig:detail_design_fixation_flexible_joints}Flexible Joint Clamping}
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\end{subfigure}
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\begin{subfigure}{0.33\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.99\linewidth]{figs/detail_design_location_top_flexible_joints.png}
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\end{center}
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\subcaption{\label{fig:detail_design_location_top_flexible_joints}Top positioning}
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\end{subfigure}
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\begin{subfigure}{0.33\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.99\linewidth]{figs/detail_design_location_bot_flex.png}
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\end{center}
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\subcaption{\label{fig:detail_design_location_bot_flex}Bottom Positioning}
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\end{subfigure}
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\caption{\label{fig:detail_design_fixation_flexible_joints}Fixation of the flexible points to the nano-hexapod plates. Both top and bottom flexible joints are clamped to the plates as shown in (\subref{fig:detail_design_fixation_flexible_joints}). While the top flexible joint is in contact with the top plate for precise positioning of its center of rotation (\subref{fig:detail_design_location_top_flexible_joints}), the bottom joint is just oriented (\subref{fig:detail_design_location_bot_flex}).}
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\end{figure}
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\section{Finite Element Analysis}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1,width=0.9\linewidth]{figs/detail_design_enc_struts.jpg}
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\caption{\label{fig:detail_design_enc_struts}Obtained Nano-Hexapod design}
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\end{figure}
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\begin{itemize}
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\item FEM of complete system
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\item Show modes of the struts
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\end{itemize}
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\begin{figure}[htbp]
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\begin{subfigure}{0.33\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.9\linewidth]{figs/detail_design_fem_rigid_body_mode.jpg}
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\end{center}
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\subcaption{\label{fig:detail_design_fem_rigid_body_mode}Suspension modes}
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\end{subfigure}
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\begin{subfigure}{0.33\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.9\linewidth]{figs/detail_design_fem_strut_mode.jpg}
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\end{center}
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\subcaption{\label{fig:detail_design_fem_strut_mode}Strut - Local modes}
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\end{subfigure}
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\begin{subfigure}{0.33\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.9\linewidth]{figs/detail_design_fem_plate_mode.jpg}
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\end{center}
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\subcaption{\label{fig:detail_design_fem_plate_mode}Top plate modes}
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\end{subfigure}
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\caption{\label{fig:detail_design_fem_nano_hexapod}Measurement of strut flexible modes. First six modes are ``suspension'' modes in which the top plate behaves as a rigid body (\subref{fig:detail_design_fem_rigid_body_mode}). Then modes of the struts have natural frequencies from \(205\,\text{Hz}\) to \(420\,\text{Hz}\) (\subref{fig:detail_design_fem_strut_mode}). Finally, the first flexible mode of the top plate is at \(650\,\text{Hz}\) (\subref{fig:detail_design_fem_plate_mode})}
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\end{figure}
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\section{Obtained Design}
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\begin{itemize}
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\item Alternative encoder position: on the plates
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\item Support made of aluminum
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\end{itemize}
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\begin{figure}[htbp]
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\begin{subfigure}{0.59\textwidth}
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\begin{center}
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\includegraphics[scale=1,height=5cm]{figs/detail_design_enc_plates.jpg}
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\end{center}
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\subcaption{\label{fig:detail_design_enc_plates}Nano-Hexapod with encoders fixed to the plates}
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\end{subfigure}
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\begin{subfigure}{0.39\textwidth}
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\begin{center}
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\includegraphics[scale=1,height=5cm]{figs/detail_design_encoders_plates.jpg}
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\end{center}
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\subcaption{\label{fig:detail_design_encoders_plates}Zoom on encoder fixation}
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\end{subfigure}
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\caption{\label{fig:detail_design_enc_plates_design}Alternative way of using the encoders: they are fixed directly to the plates.}
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\end{figure}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1]{figs/detail_design_fem_encoder_fix.png}
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\caption{\label{fig:detail_design_fem_encoder_fix}Finite Element Analysis of the encoder supports. Encoder inertia was taken into account.}
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\end{figure}
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\chapter{Multi-Body Model}
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\label{sec:detail_design_model}
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\textbf{Multi body Model}:
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\begin{itemize}
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\item Complete model: two plates, 6 joints, 6 actuators, 6 encoders
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\item Joint Model
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\item APA Model
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\item Encoder model
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\item Say that obtained dynamics was considered good + possible to perform simulations of tomography experiments with same performance as during the conceptual design
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\end{itemize}
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Two configurations:
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\begin{itemize}
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\item Encoders fixed to the struts
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\item Encoders fixed to the plates
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\end{itemize}
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\begin{figure}[htbp]
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.95\linewidth]{figs/detail_design_simscape_encoder_struts.png}
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\end{center}
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\subcaption{\label{fig:detail_design_simscape_encoder_struts}Encoders fixed to the struts}
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\end{subfigure}
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,width=0.95\linewidth]{figs/detail_design_simscape_encoder_plates.png}
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\end{center}
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\subcaption{\label{fig:detail_design_simscape_encoder_plates}Encoders fixed to the plates}
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\end{subfigure}
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\caption{\label{fig:detail_design_simscape_encoder}3D representation of the multi-body model. There are two configurations: encoders fixed to the struts (\subref{fig:detail_design_simscape_encoder_struts}) and encoders fixed to the plates (\subref{fig:detail_design_simscape_encoder_plates}).}
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\end{figure}
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\section{Flexible Joints}
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\begin{figure}[htbp]
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\centering
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\includegraphics[scale=1,scale=1]{figs/detail_design_simscape_model_flexible_joint.png}
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\caption{\label{fig:detail_design_simscape_model_flexible_joint}Multi-Body (using the Simscape software) model of the flexible joints. A 4-DoFs model is shown.}
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\end{figure}
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\section{Amplified Piezoelectric Actuators}
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\section{Encoders}
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\begin{figure}[htbp]
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,scale=1]{figs/detail_design_simscape_encoder.png}
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\end{center}
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\subcaption{\label{fig:detail_design_simscape_encoder}Aligned encoder and ruler}
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\end{subfigure}
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\begin{subfigure}{0.49\textwidth}
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\begin{center}
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\includegraphics[scale=1,scale=1]{figs/detail_design_simscape_encoder_disp.png}
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\end{center}
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\subcaption{\label{fig:detail_design_simscape_encoder_disp}Rotation of the encoder head}
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\end{subfigure}
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\caption{\label{fig:detail_design_simscape_encoder_model}Representation of the encoder model in the multi-body model. Measurement \(d_i\) corresponds to the \(x\) position of the encoder frame \(\{E\}\) expresssed in the ruller frame \(\{R\}\) (\subref{fig:detail_design_simscape_encoder}). A rotation of the encoder therefore induces a measured displacement (\subref{fig:detail_design_simscape_encoder_disp}).}
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\end{figure}
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\chapter{Conclusion}
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\label{sec:detail_design_conclusion}
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\printbibliography[heading=bibintoc,title={Bibliography}]
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\end{document}
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