Publications associées à Zero Parasitic Shift Pivoting Kinematic Structures Based On Coupled N-RRR Planar Parallel Mechanisms For Flexure Pivot Design

Near-Zero Parasitic Shift Flexure Pivots Based on Coupled n-RRR Planar Parallel Mechanisms

Simon Nessim Henein, Florent Cosandier, Etienne Frédéric Gabriel Thalmann, Loïc Benoît Tissot-Daguette

Flexure pivots, which are widely used for precision mechanisms, generally have the drawback of presenting parasitic shifts accompanying their rotation. The known solutions for canceling these undesirable parasitic translations usually induce a loss in radi ...

2024

Pivot, process for manufacturing such a pivot, oscillator comprising such a pivot, watch movement and timepiece comprising such an oscillator

Simon Nessim Henein, Loïc Benoît Tissot-Daguette

The present invention concerns a pivot comprising two assemblies, namely a central assembly (401) and a peripheral assembly (400). These two assemblies are mobile in rotation relative to each other around an axis of rotation (A). The pivot is characterized ...

2024

The General Crack Component Model for reversed cyclic shear

David Michael Volpe Ruggiero

A growing body of research has shown that reversed cyclic shear loading of reinforced concrete (RC) causes effects that are not accounted for in monotonic behavioral models. Notable among these effects are a reduction in shear strength and significant plas ...

2023

Synthesis of Novel Integrated Actuators Powered by Shape Memory Alloys

Sean Thomas

In the modern age of miniaturisation, Smart Materials, a type of material that reacts mechanically to a certain stimulus, have become an integral part of this revolution. Among these materials, Shape Memory Alloys (SMAs), which have the highest volumetric ...

EPFL2022

A 4D printed active compliant hinge for potential space applications using shape memory alloys and polymers

Ralph Spolenak, Jamie Paik, Zhenishbek Zhakypov, Jian-Lin Huang

This paper presents the proof-of-concept for a 4D printed active compliant hinge with a selectively variable stiffness for the deployment and reorientation of satellite appendages. We use 4D printing to create an active compliant hinge capable of bending t ...

IOP PUBLISHING LTD2021

Designing compliant mechanisms composed of shape memory alloy and actuated by induction heating

Paolo Germano, Yves Perriard, Sean Thomas, Adrien Jean-Michel Thabuis, Thomas Guillaume Martinez

Shape Memory Alloys (SMAs) are a type of smart materials that reacts mechanically to heat. Due to their complex behavior, they are often used in a simple geometry such as wires. This constrains the output displacement of the alloy to a simple linear contra ...

2021

Sensor system

Simon Nessim Henein, Charles Baur, Thomas Jean Julien Fussinger, Hubert Pierre-Marie Benoît Schneegans, Lisa Anaïs Jeanne Bonnefoy

Sensor system (1) comprising a frame (306) supporting a force-sensing tip (310) arranged to generate a signal based upon a force applied by said force-sensing tip (310) to a material to be tested,characterised in that said system (1) further comprises:- an ...

2020

An inverse optimization approach to understand human acquisition of kinematic coordination in bimanual fine manipulation tasks

Aude Billard, Kunpeng Yao

Tasks that require the cooperation of both hands and arms are common in human everyday life. Coordination helps to synchronize in space and temporally motion of the upper limbs. In fine bimanual tasks, coordination enables also to achieve higher degrees of ...

2020

Postural transitions detection and characterization in healthy and patient populations using a single waist sensor

Kamiar Aminian, Benoît Mariani, Farzin Dadashi, Arash Atrsaei

Background: Sit-to-stand and stand-to-sit transitions are frequent daily functional tasks indicative of muscle power and balance performance. Monitoring these postural transitions with inertial sensors provides an objective tool to assess mobility in both ...

BioMed Central2020

Rigid foldability and mountain-valley crease assignments of square-twist origami pattern

Huijuan Feng

Rigid foldability allows an origami pattern to fold about crease lines without twisting or stretching component panels. It enables folding of rigid materials, facilitating the design of foldable structures. Recent study shows that rigid foldability is affe ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Bipedal walking and push recovery with a stepping strategy based on time-projection control

Auke Ijspeert, Seyed Hamed Razavi, Salman Faraji

In this paper, we present a simple control framework for online push recovery on biped robots with dynamic stepping properties. Owing to relatively heavy legs in our humanoid robot COMAN, we use a linear model called 3LP, which is composed of three pendulu ...

SAGE PUBLICATIONS LTD2019

Gravity-Insensitive Flexure Pivot Oscillators

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

Classical mechanical watch plain bearing pivots have frictional losses limiting the quality factor of the hairspring-balance wheel oscillator. Replacement by flexure pivots leads to a drastic reduction in friction and an order of magnitude increase in qual ...

2018

Theory and design of spherical oscillator mechanisms

Simon Nessim Henein, Nicolas Ferrier, Roland Andreas Bitterli, Billy Nussbaumer, Mohammad Hussein Kahrobaiyan, Ilan Vardi, Lennart Rubbert

In previous work, we showed that two degree of freedom oscillators can be advantageously applied to horological time bases since they can be used to eliminate the escapement mechanism. We subsequently examined planar two degree of freedom oscillators based ...

2018

Priority coordination of fiber positioners in multi-objects spectrographs

Denis Gillet, Mohamed Bouri, Laleh Makarem, Jean-Paul Richard Kneib

Projects such as "The Dark Energy Spectroscopic Instrument" (DESI) [1] or "The Multi Object Optical and Near-infrared Spectrograph" (MOONS) [5] are developing spectrographs, composed of more than thousand of optical fibers in a confined hexagonal focal pla ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Range-based underwater target localization using an autonomous surface vehicle: Observability analysis

In the field of marine robotics, the problem of range based underwater target localization can be defined as that of localizing an unknown - fixed or moving - target from a surface vehicle called the tracker, using range information available about the tar ...

2018

Higher-order continuation method for the rigid-body kinematic design of compliant mechanisms

Simon Nessim Henein, Lennart Rubbert

Compliant mechanisms are of great interest in precision engineering. In this paper we propose a higher order continuation method to help their rigid-body kinematic design. The method helps to investigate the choice of a mechanism configuration through the ...

2017

The Design of A New Rotary Hexapod with A Single Active Degree of Freedom

Jamie Paik, Alexey Fomin

This study provides a novel approach for designing a rotary hexapod with a single actuator and definable motion of a platform. Hexapod is a parallel structure mechanism with six legs and six degrees of freedom (DoF) of an end-effector. It is not an underac ...

2017

Spine Controller for a Sprawling Posture Robot

Auke Ijspeert, Tomislav Horvat, Kamilo Andres Melo Becerra

More and more biologically inspired robots present spines with multiples degrees of freedom to resemble their biological counterparts. The function of the spine on both animal and robot can play an important role in locomotion. If it has enough degrees of ...

2017

Étude des engrenages de microtechnique

Quentin Theurillat-Bonjour

The research presented in this thesis addresses the design of gear drives for micro engineering applications, and was performed in collaboration with a watch manufacturer. Gears have long been found in many fields of mechanical engineering. Their use in wa ...

EPFL2016

Three-Parameter Kinematic Theory for Shear-Dominated Reinforced Concrete Walls

Katrin Beyer, Pia Hannewald, Boyan Iliev Mihaylov

This paper is aimed at addressing the need for physically accurate and computationally effective models for predicting the response of shear-dominated reinforced concrete walls. The presented theory is based on a three-degree-of-freedom kinematic model for ...

Asce-Amer Soc Civil Engineers2016