Publications de Ilan Vardi | EPFL Graph Search

La géométrie du tourbillon

Simon Nessim Henein, Roland Andreas Bitterli, Ilan Vardi, Patrick Robert Flückiger, Quentin Gubler

À l'origine, le but du tourbillon était d'améliorer la chronométrie d'une montre de poche en moyennant ses positions verticales. Avec I'avènement de la montre-bracelet, le tourbillon est prisé plus pour la prouesse technique de sa réalisation que pour sa f ...

Société Suisse de Chronométrie2021

Rocker oscillator time bases

Simon Nessim Henein, Ilan Vardi

Since the invention of the pendulum clock by Christiaan Huygens in 1657, precision timekeepers have been regulated by oscillators. Although the pendulum is not an isochronous oscillator, its introduction as a time basis for clock regulation led to a signif ...

2021

Foucault pendulum properties of spherical oscillators

Simon Nessim Henein, Ilan Vardi, Patrick Robert Flückiger

The Foucault pendulum provides a demonstration of the turning of the Earth. The principle at work is that linear oscillations of a two-degree-of-freedom isotropic harmonic oscillator remain unchanged in an inertial frame of reference, so appear to precess ...

2020

Statically and dynamically balanced oscillator based on Watt's linkage

Simon Nessim Henein, Ilan Vardi, Hubert Pierre-Marie Benoît Schneegans

We present a new mechanical oscillator architecture that can be made insensitive to linear and angular accelerations while keeping constant oscillation frequency. The oscillator has the kinematics of a Watt linkage, so we call it a Watt oscillator. In orde ...

EUSPEN2020

Programmable Logic Gates Based On Tunable Multistable Mechanisms

Simon Nessim Henein, Ilan Vardi, Mohamed Gamal Abdelrahman Ahmed Zanaty, Hubert Pierre-Marie Benoît Schneegans

Binary logic operations are the building blocks of computing machines. In this paper, we present a new programmable binary logic gate based on programmable multistable mechanisms (PMM), which are multistable structures whose stability behavior depends on m ...

AMER SOC MECHANICAL ENGINEERS2020

Reconfigurable Logic Gates Based on Programable Multistable Mechanisms

Simon Nessim Henein, Ilan Vardi, Mohamed Gamal Abdelrahman Ahmed Zanaty, Hubert Pierre-Marie Benoît Schneegans

Binary logic gates are building blocks of computing machines, in particular, electronic computers. One variant is the programable logic gate, also known as the reconfigurable logic gate, in which the logical function implemented can be modified. In this pa ...

2020

Tuning stiffness nonlinearty: theory and applications

Simon Nessim Henein, Ilan Vardi, Mohamed Gamal Abdelrahman Ahmed Zanaty

Perfect elasticity is not achievable in real-life situation, so spring stiffness is not perfectly constant. In this paper, we study the effect of modifying non-linear stiffness terms while keeping the nominal stiffness constant. We introduce three methods ...

ASME2020

Foucault pendulum properties of spherical oscillators

Simon Nessim Henein, Ilan Vardi, Patrick Robert Flückiger

In 1851 Léon Foucault created a sensation with his pendulum providing a direct demonstration of the turning of the Earth. This simple device consists of a pendulum which is launched in a purely planar orbit. Following Mach's principle of inertia, the mass ...

euspen2020

Flexure Pivot Oscillator With Intrinsically Tuned Isochronism

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Etienne Frédéric Gabriel Thalmann, Ilan Vardi

The most important property for accurate mechanical time bases is isochronism: the independence of period from oscillation amplitude. This paper develops a new concept in isochronism adjustment for flexure-based watch oscillators. Flexure pivot oscillators ...

2020

Design of a Flexure Based Low Frequency Foucault Pendulum

Simon Nessim Henein, Ilan Vardi, Patrick Robert Flückiger

The Foucault pendulum is a well-known mechanism used to demonstrate the rotation of the Earth. It consists in a pendulum launched on linear orbits and, following Mach’s Principle, this line of oscillation will remain fixed with respect to absolute space bu ...

2020

A la recherche du temps précis : la découverte de l’oscillateur

Simon Nessim Henein, Ilan Vardi

L'introduction d'un oscillateur comme base de temps a marqué une révolution dans la mesure précise du temps. Cet article décrit comment les chercheurs du 17e siècle ont découvert les oscillateurs qui règlent nos horloges et montres mécaniques. Une lecture ...

2019

Two degree of freedom mechanical oscillator

Simon Nessim Henein, Ilan Vardi

2019

Automatically Starting and Secured Detent Escapement for a Timepiece

Simon Nessim Henein, Ilan Vardi

A horological detent escapement for a horological movement arranged to transmit a torque from said horological movement to an oscillating regulating organ of said horological movement, the regulating organ comprising a first mobile body and the escapement ...

2019

Horological oscillator

Simon Nessim Henein, Billy Nussbaumer, Mohammad Hussein Kahrobaiyan, Etienne Frédéric Gabriel Thalmann, Ilan Vardi

Horological oscillator comprising: - a first inertial body (141; 151; 1305; 1405; 1505; 301; 311; 314; 41; 51; 507; 529; 544; 541; 901; 903) arranged to rotate with respect to a first axis; - a second inertial body (143; 153; 1306; 1406; 1506; 302; 313; 31 ...

2019

General 2 degree of freedom isotropic harmonic oscillator and associated time base without escapement or with simplified escapement

Simon Nessim Henein, Ilan Vardi, Lennart Rubbert

A mechanical isotropic harmonic oscillator including a frame, a mass configured to oscillate, and three flexure rods, each flexure rod connecting the mass to the frame. ...

2019

Programmable Multistable Mechanisms for Safe Surgical Puncturing

Simon Nessim Henein, Charles Baur, David Lambelet, Andrea Lovera, Arno Rogg, Thomas Jean Julien Fussinger, Ilan Vardi, Mohamed Gamal Abdelrahman Ahmed Zanaty

We present novel medical devices for safe surgical puncturing, in particular a cannula for the treatment of retinal vein occlusion (RVO). This passive mechanical device has an adjustable stroke and exerts a puncturing force independent of operator applied ...

2019

Programmable Multistable Mechanisms: Synthesis and Modeling

Simon Nessim Henein, Ilan Vardi, Mohamed Gamal Abdelrahman Ahmed Zanaty

2018

Two degree of freedom mechanical oscillator

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Ilan Vardi

Mechanical oscillator (10) comprising an inertial body (101) joined to a support (100) by means of an elastic system (102, 103, 104, 105, 106, 107) arranged to provide the inertial body (101) with substantially no degrees of freedom in translation and with ...

2018

Le sens de la recherche

Ilan Vardi

2018

Mechanical oscillator

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Ilan Vardi

wherein k1, k3, k5 . . . are constants and θ is an angle of inclination of said third axis (x, P) of said inertial body with respect to a direction of said third axis (xr) when said inertial body is in said resting position. ...

2018