\babel@toc {english}{}\relax 
\contentsline {figure}{\numberline {1}{\ignorespaces Principle of the friction disk mechanism used in the tridigital prosthesis \textit {Myoelectric hand A+} by Danyang Reborn, presented {with forces acting on the friction disk} in one direction of operation\relax }}{2}{figure.1}%
\contentsline {figure}{\numberline {2}{\ignorespaces Roller non-backdrivable mechanism at rest (a), during unlocking (b), and in the rotating mode (c) \cite {controzzi2017_UnifiedApproachBidirectional}\relax }}{3}{figure.2}%
\contentsline {figure}{\numberline {3}{\ignorespaces Non-backdrivable mechanism used by Ottobock in the \textit {VariPlus Speed}. On the left, the mechanism is shown alone; in the middle, the mechanism is mounted on the gearmotor; on the right, the gearmotor is shown alone. The wrap spring is placed between the black crowns and the yellow chassis and is not visible.\relax }}{3}{figure.3}%
\contentsline {figure}{\numberline {4}{\ignorespaces Principle of the proposed mechanism, composed of three rotating parts (input shaft, output shaft, and spring) and the ring fixed to the chassis\relax }}{4}{figure.4}%
\contentsline {figure}{\numberline {5}{\ignorespaces Functioning of the mechanism according to the direction (CW=clockwise, CCW=counterclockwise) and origin of movement. When the input shaft is driven in motion, it, in turn, drives the spring and then the output shaft in rotation. When the output shaft is driven, it pushes the spring, which locks against the fixed ring, and the input shaft remains free.\relax }}{4}{figure.5}%
\contentsline {figure}{\numberline {6}{\ignorespaces Geometric parameters of the used wrap spring\relax }}{5}{figure.6}%
\contentsline {figure}{\numberline {7}{\ignorespaces Geometric parameterization of the modeled spring branch as a simply supported beam\relax }}{5}{figure.7}%
\contentsline {figure}{\numberline {8}{\ignorespaces Modeling of the simply supported beam subjected to two forces, composed of a first section formed by a quarter of a circle denoted as 1, and a second straight section denoted as 2\relax }}{6}{figure.8}%
\contentsline {figure}{\numberline {9}{\ignorespaces Definition of angles when the spring is in the ring and when the spring is at rest before the assembly\relax }}{7}{figure.9}%
\contentsline {figure}{\numberline {10}{\ignorespaces Friction torque in the rotating mode $\tau ^f$ as a function of $\delta r$ and $r_s$ for $R_a=$10~mm\relax }}{8}{figure.10}%
\contentsline {figure}{\numberline {11}{\ignorespaces Stresses $\sigma _{int}$, $\sigma _{ext}$, and $\sigma _A$ as a function of $r_e$ for $\tau _{out}^{max}$ = 600~N.mm, $R_a$ = 10~mm, $R$ = 3~mm, and $r_s$ = 0.5~mm\relax }}{8}{figure.11}%
\contentsline {figure}{\numberline {12}{\ignorespaces Set of curves presenting the maximum stress $\sigma _{max}$ as a function of $r_e$, plotted for $\tau _{out}^{max}$ = 600~N.mm, $R_a$ = 10~mm, and all pairs ($R$; $r_s$) such that $R \in $\{1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5.0\}~mm and $r_s \in $\{0.4, 0.45, 0.5, 0.55, 0.6\}~mm\relax }}{8}{figure.12}%
\contentsline {figure}{\numberline {13}{\ignorespaces Stress $\sigma _{max}$ as a function of $R$ and $r_s$ for $\tau _{out}^{max}$ = 600~N.mm, $R_a$ = 10~mm, and $L_A$ = 0.5~mm\relax }}{8}{figure.13}%
\contentsline {figure}{\numberline {14}{\ignorespaces Stress $\sigma _{max}$ as a function of $r_s$ for $\tau _{out}^{max}$ = 600~N.mm, $R$ = 3~mm, $R_a$ = 10~mm, and $L_A$ = 0.5~mm, compared to the material's yield strength $R_e$ provided by a manufacturer\relax }}{9}{figure.14}%
\contentsline {figure}{\numberline {15}{\ignorespaces Von Mises equivalent stress [MPa] obtained through finite element simulation of the spring branch in Fusion360 (deformation not to scale)\relax }}{9}{figure.15}%
\contentsline {figure}{\numberline {16}{\ignorespaces Cross-sectional view of the non-backdrivable prototype (CAD)\relax }}{10}{figure.16}%
\contentsline {figure}{\numberline {17}{\ignorespaces Photo of the non-backdrivable prototype, fully assembled on the top, and partially assembled on the bottom\relax }}{10}{figure.17}%
\contentsline {figure}{\numberline {18}{\ignorespaces Test bench for measuring friction torque in rotating mode\relax }}{12}{figure.18}%
\contentsline {figure}{\numberline {19}{\ignorespaces Measurement of static and dynamic torque sensors and calculation of filtered torques in the nominal configuration with zero output load and a rotational speed of 5 rad/s\relax }}{12}{figure.19}%
\contentsline {figure}{\numberline {20}{\ignorespaces Measurement of static and dynamic torque sensors and calculation of filtered torques in the nominal configuration with a variable output load and a rotational speed of 5 rad/s\relax }}{12}{figure.20}%
\contentsline {figure}{\numberline {21}{\ignorespaces Diagram of the spring misalignment effect during its rotation. On the left, the spring is mounted in its desired position. On the right, the spring misaligns.\relax }}{13}{figure.21}%
