Introduction of the first chapter

phd-thesis.org

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+The conceptual design of the Nano Active Stabilization System (NASS) follows a methodical progression from simple to more accurate modeling approaches, as illustrated in Figure\nbsp{}ref:fig:chapter1_overview.
+
 #+name: fig:chapter1_overview
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+#+caption: Overview of the conceptual design development. The approach evolves from simplified analytical models to a multi-body model tuned from experimental modal analysis. It is concluded by closed-loop simulations of tomography experiments, validating the conceptual design.
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 [[file:figs/chapter1_overview.png]]
 
+The design process begins with a uniaxial model, presented in Section\nbsp{}ref:sec:uniaxial, which provides initial insights into fundamental challenges associated with this complex system.
+This simplified representation focuses exclusively on the vertical direction—having the most stringent requirements—though similar conclusions were drawn from analyses of other axes.
+Despite its simplicity, this uniaxial model proves valuable for testing initial control strategies and, more importantly, for evaluating how the active platform stiffness affects overall system performance.
+
+Building upon these findings, Section\nbsp{}ref:sec:rotating introduces the rotational aspect through a three-degree-of-freedom model.
+This new model allows to study the gyroscopic effects induced by the spindle's continuous rotation—a distinctive characteristic of the NASS.
+The investigation reveals that these gyroscopic effects have more impact on softer active platforms, creating significant challenges for stability and control.
+
+As the investigation progressed, the need for a more accurate representation of the micro-station dynamics became increasingly evident.
+To construct such a model, a comprehensive modal analysis was conducted, as detailed in Section\nbsp{}ref:sec:modal.
+This experimental modal analysis confirmed the complex nature of the micro-station dynamics while validating that each stage behaves predominantly as a rigid body within the frequency range of interest—thus supporting the subsequent development of a multi-body model.
+
+Section\nbsp{}ref:sec:ustation presents the development of this multi-body model for the micro-station.
+Parameters were meticulously tuned to match measured compliance characteristics, and disturbance sources were carefully modeled based on experimental data.
+This refined model was then validated through simulations of scientific experiments, demonstrating its accuracy in representing the micro-station behavior under typical operating conditions.
+
+For the active stabilization stage, the Stewart platform architecture was selected after careful evaluation of various options.
+Section\nbsp{}ref:sec:nhexa examines the kinematic and dynamic properties of this parallel manipulator, exploring its control challenges and developing appropriate control strategies for implementation within the NASS.
+The multi-body modeling approach facilitated the seamless integration of the nano-hexapod with the micro-station model.
+
+Finally, Section\nbsp{}ref:sec:nass validates the NASS concept through closed-loop simulations of tomography experiments.
+These simulations incorporate realistic disturbance sources, confirming the viability of the proposed design approach and control strategies.
+
+This progressive approach, beginning with easily comprehensible simplified models, proved instrumental in developing a thorough understanding of the physical phenomena at play.
+By methodically increasing model complexity only as needed, the design process converged efficiently toward a concept capable of delivering the required performance levels.
+The confidence gained through this systematic investigation provides a solid foundation for transitioning to the detailed design phase, which will be addressed in the following chapter.
+
 ** Uni-axial Model
 <<sec:uniaxial>>
 *** Introduction                                                        :ignore: