Publications associées à Pendule simple

Design of a Flexure-Based Flywheel for the Storage of Angular Momentum and Kinetic Energy

Simon Nessim Henein, Florent Cosandier, Hubert Pierre-Marie Benoît Schneegans, Patrick Robert Flückiger

The flywheel is a widespread mechanical component used for the storage of kinetic energy and angular momentum. It typically consists of cylindrical inertia rotating about its axis on rolling bearings, which involves undesired friction, lubrication, and wea ...

2024

Rapid motion estimation and correction using self-encoded FID navigators in 3D radial MRI

Tobias Kober, Davide Piccini

Purpose: To develop a self-navigated motion compensation strategy for 3D radial MRI that can compensate for continuous head motion by measuring rigid body motion parameters with high temporal resolution from the central k-space acquisition point (self-enco ...

Wiley2023

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

Nonlinear evolution of the centrifugal instability using a semilinear model

François Gallaire, Eunok Yim

We study the nonlinear evolution of the axisymmetric centrifugal instability developing on a columnar anticyclone with a Gaussian angular velocity using a semilinear approach. The model consists of two coupled equations: one for the linear evolution of the ...

Cambridge University Press2020

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

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 Restoring Torque Nonlinearity and Isochronism Defect

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

Flexure pivot based oscillators can advantageously replace the hairspring and balance wheel, the time base used in mechanical watches, by drastically reducing friction. However, flexure pivots have drawbacks including gravity sensitivity and restoring torq ...

AMER SOC MECHANICAL ENGINEERS2018

Pushing amplitude equations far from threshold: application to the supercritical Hopf bifurcation in the cylinder wake

François Gallaire, Edouard Boujo, Philippe Meliga, Cristobal Manuel Arratia Martinez, Vladislav Mantic Lugo

The purpose of this review article is to push amplitude equations as far as possible from threshold. We focus on the Stuart-Landau amplitude equation describing the supercritical Hopf bifurcation of the flow in the wake of a cylinder for critical Reynolds ...

Iop Publishing Ltd2016

Self-consistent model for the saturation mechanism of the response to harmonic forcing in the backward-facing step flow

François Gallaire, Vladislav Mantic Lugo

Certain flows denominated as amplifiers arc characterized by their global linear stability while showing large linear amplifications to sustained perturbations. As the forcing amplitude increases, a strong saturation of the response appears when compared t ...

Cambridge University Press2016

Robust and Agile 3D Biped Walking With Steering Capability Using a Footstep Predictive Approach

Auke Ijspeert, Salman Faraji, Soha Pouya

In this paper, we formulate a novel hierarchical controller for walking of torque controlled humanoid robots. Our method uses a whole body optimization approach which generates joint torques, given Cartesian accelerations of different points on the robot. ...

2014

Stabilization of the cart-pendulum system through approximate manifold decomposition

Dominique Bonvin, Philippe Müllhaupt, David Ingram

This paper proposes a feedback law capable of swinging up and stabilizing the cartpendulum system. The approach uses an iterative algorithm that is typically used to construct a locally linearizing output for nonlinear control-affine systems. However, rath ...

2011

Fluid-structure coupling for an oscillating hydrofoil

François Avellan, Mohamed Farhat, Philippe Ausoni, Cécile Münch-Alligné, Olivier Braun

Fluid-structure investigations in hydraulic machines using coupled simulations are particularly time-consuming. In this study, an alternative method is presented that linearizes the hydrodynamic load of a rigid, oscillating hydrofoil. The hydrofoil, which ...

Elsevier2010

Dynamics and Control of 2D SpiderCrane: A Lie-Bäcklund Approach

Dominique Bonvin, Philippe Müllhaupt

In this paper we present modeling and control of a multicable suspended mechanism called the ‘2D SpiderCrane’. The use of cables, and thus avoiding conventional heavy components, makes such a mechanism suitable for working at high transfer speeds. The init ...

2009