phd-thesis/phd-thesis.org

Glossary and Acronyms - Tables

label	name	description
ms	\ensuremath{m_s}	Mass of the sample
mn	\ensuremath{m_n}	Mass of the nano-hexapod
mh	\ensuremath{m_h}	Mass of the micro-hexapod
mt	\ensuremath{m_t}	Mass of the micro-station stages
mg	\ensuremath{m_g}	Mass of the granite
xf	\ensuremath{x_f}	Floor motion
ft	\ensuremath{f_t}	Disturbance force of the micro-station
fs	\ensuremath{f_s}	Direct forces applied on the sample
d	\ensuremath{d}	Measured motion between the nano-hexapod and the granite
fn	\ensuremath{f_n}	Force sensor on the nano-hexapod
psdx	\ensuremath{Φx}	Power spectral density of signal $x$
asdx	\ensuremath{Γx}	Amplitude spectral density of signal $x$
cpsx	\ensuremath{Φx}	Cumulative Power Spectrum of signal $x$
casx	\ensuremath{Γx}	Cumulative Amplitude Spectrum of signal $x$

key	abbreviation	full form
haclac	HAC-LAC	High Authority Control - Low Authority Control
hac	HAC	High Authority Control
lac	LAC	Low Authority Control
nass	NASS	Nano Active Stabilization System
asd	ASD	Amplitude Spectral Density
psd	PSD	Power Spectral Density
cps	CPS	Cumulative Power Spectrum
cas	CAS	Cumulative Amplitude Spectrum
frf	FRF	Frequency Response Function
iff	IFF	Integral Force Feedback
rdc	RDC	Relative Damping Control
drga	DRGA	Dynamical Relative Gain Array
rga	RGA	Relative Gain Array
hpf	HPF	high-pass filter
lpf	LPF	low-pass filter
dof	DoF	Degree of freedom
svd	SVD	Singular Value Decomposition
mif	MIF	Mode Indicator Functions
dac	DAC	Digital to Analog Converter
fem	FEM	Finite Element Model
apa	APA	Amplified Piezoelectric Actuator

Title Page

Members of the Examination Committee

Prof. Loïc Salles (President of the Committee)≠wline University of Liège (Liège, Belgium)

Prof. Christophe Collette (Supervisor)≠wline University of Liège (Liège, Belgium)

Prof. Olivier Bruls≠wline University of Liège (Liège, Belgium)

Dr. Jonathan Kelly≠wline Diamond Light Source (Oxfordshire, United Kingdom)

Prof. Gérard Scorletti≠wline École Centrale de Lyon, Laboratoire Ampère (Écully, France)

Dr. Olivier Mathon≠wline European Synchrotron Radiation Facility (Grenoble, France)

Abstract

The $4^{\text{th}}$ generation synchrotron light sources has yielded X-ray beams with a 100-fold increase in brightness and sub-micron focusing capabilities, offering unprecedented scientific opportunities while requiring end-stations with enhanced sample positioning accuracy. At the European Synchrotron (ESRF), the ID31 beamline features an end-station for positioning samples along complex trajectories. However, its micrometer-range accuracy, limited by thermal drifts and mechanical vibrations, prevents maintaining the point of interest on the focused beam during experiments.

To address this limitation, this thesis aims to develop a system for actively stabilizing the sample's position down to the nanometer range while the end-station moves the sample through the beam. The developed system integrates an external metrology for sample position measurement, an active stabilization stage mounted between the end-station and the sample, and a dedicated control architecture. The design of this system presented key challenges, first of which involved the design process. To effectively predict how this complex mechatronic system would perform, a series of dynamical models with increasing accuracy were employed. These models allowed simulation of the system's behavior at different design stages, identifying potential weaknesses early on before physical construction, ultimately leading to a design that fully satisfies the requirements. The second challenge stems from control requirements, specifically the need to stabilize samples with masses from $1$ to $50\,\text{kg}$, which required the development of specialized robust control architectures. Finally, the developed Nano Active Stabilization System underwent thorough experimental validation on the ID31 beamline, validating both its performance and the underlying concept.

\vspace{-1em} \begingroup ≤t\clearpage\relax \chapter*{Résumé} \endgroup

L'avènement des sources de lumière synchrotron de $4^{\text{ème}}$ génération a produit des faisceaux de rayons X avec une luminosité multipliée par 100 et des capacités de focalisation sub-microniques, offrant des opportunités scientifiques sans précédent tout en nécessitant des stations expérimentales avec une précision de positionnement d'échantillons améliorée. À l'Installation Européenne de Rayonnement Synchrotron (ESRF), la ligne de lumière ID31 dispose d'une station expérimentale conçue pour positionner des échantillons le long de trajectoires complexes. Cependant, sa précision de l'ordre du micromètre, limitée par des effets tels que les dérives thermiques et les vibrations mécaniques, empêche de maintenir le point d'intérêt sur le faisceau focalisé durant les expériences.

Pour remédier à cette limitation, cette thèse vise à développer un système permettant de stabiliser activement la position de l'échantillon pendant que la station expérimentale déplace l'échantillon à travers le faisceau. Le système développé intègre une métrologie externe pour la mesure de la position de l'échantillon, une platine de stabilisation active montée entre la station expérimentale et l'échantillon, et une architecture de contrôle dédiée. La conception de ce système présente des défis majeurs, dont le premier concerne le processus de conception lui-même. Pour prédire efficacement les performances, une série de modèles dynamiques ont été utilisés. Ces modèles ont permis de simuler le comportement du système aux différentes étapes de conception, identifiant ainsi les limitations potentielles, pour aboutir à une conception répondant aux spécifications. Le deuxième défi provient des exigences de contrôle, notamment la nécessité de stabiliser des échantillons dont la masse peut varier de $1$ à $50\,\text{kg}$, ce qui a nécessité le développement d'architectures de contrôle robustes. Enfin, le Système de Stabilisation Active développé a fait l'objet d'une validation expérimentale sur la ligne de lumière ID31, validant à la fois ses performances et le concept sous-jacent.

Acknowledgments

First and foremost, I would like to express my deepest gratitude to my advisor, Professor Christophe Collette, for his constant support throughout this journey. His ability to challenge my thinking and dedication to mentoring my growth as a researcher has been invaluable. His door was always open, and he generously shared his time and expertise, providing feedback and guidance at every stage of the research process. Our discussions during the regular journeys between Liege and Brussels laboratories transformed routine travel into moments of scientific inspiration. His passion and dedication for research were truly inspiring, and I could not have wished for a better advisor.

I am honored that Professor Loïc Salles accepted the role of president of the jury for this thesis. My sincere appreciation goes to my thesis committee members, Professor Olivier Bruls and Professor Jean-Claude Golinval, for following my work and providing insightful advice through the years.

I extend my gratitude to the jury members: Dr. Jonathan Kelly, Professor Gérard Scorletti, Dr. Olivier Mathon and Professor Olivier Bruls for their willingness to participate in the examination committee of this doctoral thesis. Their time, expertise, and careful consideration of my work are greatly appreciated.

My time at the Precision Mechatronics Laboratory during the first two years of this project was enriched by interesting discussions and collaborations with Ahmad, Mohit, Jennifer, Vicente, Guoying, and Haidar. I am particularly grateful for the opportunity to have worked alongside such talented and dedicated individuals. Thank you, my friends, for making my stay in Belgium such a wonderful souvenir.

The subsequent five years at the ESRF were made possible by several key individuals: Veijo Honkimaki (ID31's Scientist), Michael Krish (Head of the Instrumentation Division), Philippe Marion (Head of the Mechanical Engineering Group), Yves Dabin (Head of the Analysis and Modelling group), and Muriel Magnin-Mattenet (Mechanical Engineer in charge of ID31). I especially want to acknowledge their efforts in providing me with the resources, facilities, and technical expertise necessary to conduct my research at the ESRF.

The technical aspects of this work benefited greatly from various collaborations. I am grateful for the fruitful collaboration on mechanical design with Julien Bonnefoy and Damien Coulon. Special thanks to Philipp Brumund for his invaluable Finite Element Analysis expertise and constant encouragement to complete my PhD thesis. I am especially thankful to Marc Lesourd for introducing me to the world of vibration measurements and modal analysis, and Noel Levet for our interesting discussions about dimensional metrology and his tremendous support with the alignment of the developed instrument. The remarkable technical support from Pierrick Got and Kader Amraoui in electronics allowed smooth implementation of the developed system on the ID31 beamline. I also thank Hans Peter and Ludovic for granting me access to the outstanding mechatronics laboratory at the ESRF.

I am grateful to the master thesis students I had the chance to supervise: Adrien Jublan for his work on multi-body modelling, Youness Benyaklhef for his contribution to the metrology system and Caio Belle for his research on multi-variable control.

Finally, my profound thanks go to my family and close friends. To my father, who inspired me to pursue research, and my mother, whose unwavering support has been precious beyond words. And to Juliette, for being incredibly supportive through the inevitable tough times that are part of the PhD journey.

Reproducible Research

The foundation of this PhD thesis is built upon the principles of reproducible research. Reproducible research is the practice of ensuring that the results of a study can be independently verified by others using the original data, code, and documentation.

This approach was adopted to increase transparency and trust in the presented research findings. Furthermore, it is anticipated that the methods and data shared will facilitate knowledge transfer and reuse within the scientific community, thereby reducing research redundancy and increasing overall efficiency. It is hoped that some aspects of this work may be reused by the synchrotron community.

The fundamental objective has been to ensure that anyone should be capable of reproducing precisely the same results and figures as presented in this manuscript. To achieve this goal of reproducibility, comprehensive sharing of all elements has been implemented. This includes the mathematical models developed, raw experimental data collected, and scripts used to generate the figures.

For those wishing to engage with the reproducible aspects of this work, all data and code are freely accessible in add zenodo link. The organization of the code mirrors that of the manuscript, with corresponding chapters and sections. All materials have been made available under the MIT License, permitting free reuse.

This approach represents a modest contribution towards a more open, reliable, and collaborative scientific ecosystem.

Grants

Table of Contents

Introduction

<<chap:introduction>>

Conclusion and Future Work

<<chap:conclusion>>

Alternative Architecture

/tdehaeze/phd-thesis/src/commit/e3417f65996657bf06488be6c984b40175b31a7b/~/Cloud/work-projects/ID31-NASS/matlab/nass-simscape/org/alternative-micro-station-architecture.org

Bibliography

List of Publications

Glossary

printglossaries:

Footnotes

¹DLPVA-100-B from Femto with a voltage input noise is $2.4\,nV/\sqrt{\text{Hz}}$ ²Mark Product L-22D geophones are used with a sensitivity of $88\,\frac{V}{m/s}$ and a natural frequency of $\approx 2\,\text{Hz}$ ³Mark Product L4-C geophones are used with a sensitivity of $171\,\frac{V}{m/s}$ and a natural frequency of $\approx 1\,\text{Hz}$

⁴As this matrix is in general non-square, the Moore–Penrose inverse can be used instead. ⁵NVGate software from OROS company. ⁶OROS OR36. 24bits signal-delta ADC. ⁷Kistler 9722A2000. Sensitivity of $2.3\,mV/N$ and measurement range of $2\,kN$ ⁸PCB 356B18. Sensitivity is $1\,V/g$, measurement range is $\pm 5\,g$ and bandwidth is $0.5$ to $5\,\text{kHz}$.

⁹It was probably caused by rust of the linear guides along its stroke. ¹⁰Laser source is manufactured by Agilent (5519b). ¹¹The special optics (straightness interferometer and reflector) are manufactured by Agilent (10774A). ¹²C8 capacitive sensors and CPL290 capacitive driver electronics from Lion Precision. ¹³The Spindle Error Analyzer is made by Lion Precision. ¹⁴The tools presented here are largely taken from cite:&taghirad13_paral. ¹⁵Rotations are non commutative in 3D. ¹⁶Ball cage (N501) and guide bush (N550) from Mahr are used. ¹⁷Modified Zonda Hexapod by Symetrie. ¹⁸Made by LAB Motion Systems. ¹⁹HCR 35 A C1, from THK.

²⁰Such equation is called the velocity loop closure ²¹The pose represents the position and orientation of an object ²²Different architecture exists, typically referred as "6-SPS" (Spherical, Prismatic, Spherical) or "6-UPS" (Universal, Prismatic, Spherical)

²³Cedrat technologies ²⁴The manufacturer of the APA95ML was not willing to share the piezoelectric material properties of the stack.

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