Publications de Philippe Müllhaupt

Feasibility of an alternative method to estimate glenohumeral joint center from videogrammetry measurements and CT/MRI of patients

Dominique Pioletti, Philippe Müllhaupt, Alexandre Terrier, Alain Farron, Matteo Mancuso, Ehsan Sarshari

Videogrammetry is commonly used to record upper limb motions. However, it cannot track the glenohumeral joint center (GH). GH is required to reconstruct upper limb motions. Therefore, it is often estimated by separately measuring scapular motions using sca ...

2021

A Matlab toolbox for scaled-generic modeling of shoulder and elbow

Dominique Pioletti, Philippe Müllhaupt, Alexandre Terrier, Ehsan Sarshari, Yasmine Boulanaache

There still remains a barrier ahead of widespread clinical applications of upper extremity musculoskeletal models. This study is a step toward lifting this barrier for a shoulder musculoskeletal model by enhancing its realism and facilitating its applicati ...

Nature Research2021

Muscle co-contraction in an upper limb musculoskeletal model: EMG-assisted vs. standard load-sharing

Dominique Pioletti, Philippe Müllhaupt, Alexandre Terrier, Alain Farron, Matteo Mancuso, Ehsan Sarshari

Estimation of muscle forces in over-actuated musculoskeletal models involves optimal distributions of net joint moments among muscles by a standard load-sharing scheme (SLS). Given that co-contractions of antagonistic muscles are counterproductive in the n ...

2021

On two isomorphic Lie algebroids associated with feedback linearization

Philippe Müllhaupt

We present two Lie algebroids linked to the construction of the linearizing output of an input affine nonlinear system. The algorithmic development of the linearizing output proceeds inductively, and each stage has two structures, namely a codimension one ...

ELSEVIER2019

On two isomorphic Lie algebroids for Feedback Linearization

Philippe Müllhaupt

Two Lie algebroids are presented that are linked to the construction of the linearizing output of an affine in the input nonlinear system.\ The algorithmic construction of the linearizing output proceeds inductively, and each stage has two structures, name ...

2019

Imprecise dynamic walking with time-projection control

Philippe Müllhaupt, Auke Ijspeert, Salman Faraji

We present a new walking foot-placement controller based on 3LP, a 3D model of bipedal walking that is composed of three pendulums to simulate falling, swing and torso dynamics. Taking advantage of linear equations and closed-form solutions of the 3LP mode ...

2018

A simulation framework for humeral head translations

Dominique Pioletti, Philippe Müllhaupt, Alexandre Terrier, Alain Farron, Ehsan Sarshari

Humeral head translations (HHT) play a crucial role in the glenohumeral (GH) joint function. The available shoulder musculoskeletal models developed based on inverse dynamics however fall short of predicting the HHT. This study aims at developing a simulat ...

2017

A framework for forward-dynamics simulation of the human shoulder

Dominique Pioletti, Philippe Müllhaupt, Alexandre Terrier, Alain Farron, Ehsan Sarshari

A vast majority of the available biomechanical models of the human shoulder has been developed based on inverse dynamics, e.g. [1,2]. This imposes a number of limitations on their application. For instance, the glenohumeral joint is approximated as an idea ...

2016

Modelling of the human shoulder as a parallel mechanism without constraints

Philippe Müllhaupt, Alexandre Terrier, Alain Farron, David Ingram, Christoph Anselm Engelhardt

The synthesis of shoulder kinematics, either for simulation in a model or imitation in a robot, is a challenging task because of the contact between shoulder blade and ribcage. As the shoulder moves, the shoulder blade glides over the ribcage. In kinematic ...

Elsevier2016

Application of Artificial Neural Networks in Assessing the Equilibrium Depth of Local Scour Around Bridge Piers

Philippe Müllhaupt, Ehsan Sarshari

Scour can have the effect of subsidence of the piers in bridges, which can ultimately lead to the total collapse of these systems. Effective bridge design needs appropriate information on the equilibrium depth of local scour. The flow field around bridge p ...

2015

Comparison of an EMG-based and a stress-based method to predict shoulder muscle forces

Dominique Pioletti, Philippe Müllhaupt, Alexandre Terrier, Alain Farron, David Ingram, Valérie Hélène Emilie Malfroy Camine, Christoph Anselm Engelhardt

The estimation of muscle forces in musculoskeletal shoulder models is still controversial. Two different methods are widely used to solve the indeterminacy of the system: electromyography (EMG)-based methods and stress-based methods. The goal of this work ...

Taylor & Francis2015

Modeling and Compensating Friction in Power Steering

Robert Fuchs, Philippe Müllhaupt

2015

A Friction Compensation Control for Power Steering

Robert Fuchs, Philippe Müllhaupt

The effects of friction are critical to the dynamics of electric power steering (EPS). On the one hand, friction contributes to the stability of the system and filters some of the disturbances (road vibration, etc.). On the other hand, it affects negativel ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Muscle Moment-Arms: A Key Element in Muscle-Force Estimation

Philippe Müllhaupt, Alexandre Terrier, Alain Farron, David Ingram, Christoph Anselm Engelhardt

A clear and rigorous definition of muscle moment-arms in the context of musculoskeletal systems modelling is presented, using classical mechanics and screw theory. The definition provides an alternative to the tendon excursion method, which can lead to inc ...

Taylor & Francis2015

A Quotient Method for Designing Nonlinear Controllers

Dominique Bonvin, Philippe Müllhaupt

An algorithmic method is proposed to design stabilizing control laws for a class of nonlinear systems that comprises single-input feedback-linearizable systems and a particular set of single-input non feedback-linearizable systems. The method proceeds iter ...

Wiley-Blackwell2013

Quotient method for stabilising a ball-on-a-wheel system – Experimental results

Dominique Bonvin, Philippe Müllhaupt, Killian Mark Daly

This paper extends the quotient method proposed in [1] and applies it to stabilize a “ball-on-a-wheel” system. The quotient method requires a diffeomorphism to obtain the normal form of the input vector field and uses canonical pro- jection to obtain the q ...

2012

Bilinear Control Systems with Forced Integrable Filtration

Philippe Müllhaupt, Basile Graf

A class of nonlinear systems and a filtration of the corresponding codistributions are presented. The filtration enjoys some strong integrability property which allows an easy computation of a linearizing normal form whenever the algorithm terminates with ...

American Institute of Physics2012

Avoiding Feedback-Linearization Singularity Using a Quotient Method -- The Field-Controlled DC Motor Case

Dominique Bonvin, Philippe Müllhaupt

Feedback linearization requires a unique feedback law and a unique diffeomorphism to bring a system to Brunovsk´y normal form. Unfortunately, singularities might arise both in the feedback law and in the diffeomorphism. This paper demonstrates the ability ...

2012

Numerical algorithm for feedback linearizable systems

Dominique Bonvin, Philippe Müllhaupt

A numerical algorithm that achieves asymptotic stability for feedback linearizable systems is presented. The nonlinear systems can be represented in various forms that include differential equations, simulated physical models or lookup tables. The proposed ...

American Institute of Physics2012

Minimal State Representation for Open Fluid-Fluid Reaction Systems

Michael Amrhein, Dominique Bonvin, Philippe Müllhaupt, Nirav Pravinbhai Bhatt

Reaction systems are typically represented by first-principles models that describe the evolution of the states (typically concentrations, volume and temperature) by means of conservation equations of differential nature and constitutive equations of algeb ...

Ieee Computer Soc2012