Bruno Dehez | UCLouvain (University of Louvain) (original) (raw)

Papers by Bruno Dehez

IEEE Transactions on Magnetics, 2015

Proceedings 2002 IEEE International Conference on Robotics and Automation (Cat. No.02CH37292), 2002

... They nevertheless show that some points still have to be investigated hrther, particularly th... more ... They nevertheless show that some points still have to be investigated hrther, particularly the problem of the bearing supporting the rotor (the friction torque is still too much high), the choice of the material for the rotor ... K. Lee, C. Kwan, Design Concept Development of a ...

2008 18th International Conference on Electrical Machines, 2008

... de Louvain Place du Levant, 3 B-1348 Louvain-la-Neuve, Belgique E-mail : bruno.dehez@ uclouva... more ... de Louvain Place du Levant, 3 B-1348 Louvain-la-Neuve, Belgique E-mail : bruno.dehez@ uclouvain.be, jonathan.denies@uclouvain.be 2 SATIE laboratory, Ecole Normale Supérieur de Cachan, Campus de Ker Lann, 35170, Bruz, France E-mail : benahmed@bretagne.ens ...

2012 4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob), 2012

ABSTRACT Instrumentation able to estimate upper limbs kinematics has a lot of relevance in the co... more ABSTRACT Instrumentation able to estimate upper limbs kinematics has a lot of relevance in the context of rehabilitation of stroke patients. The systems based on inertial systems seem to be well suited for clinical environment and numerous authors have presented wearable systems interesting in terms of accuracy and easiness of implementation. These systems always require an initialization procedure and the authors do not justify clearly why they are using one method rather than another. In this paper two common initialization methods are presented and they are evaluated and compared on the basis of the kinematics tracking of upper limbs daily living activities. The experimental results show that an initialization based on functional axes is less sensitive to the respect of initialization conditions than a static initialization.

2014 17th International Conference on Electrical Machines and Systems (ICEMS), 2014

Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, 2010

ABSTRACT Purpose – The purpose of this paper is to propose a mechanism avoiding the topology opti... more ABSTRACT Purpose – The purpose of this paper is to propose a mechanism avoiding the topology optimization methods, and particularly those using gradient-based algorithms, to be trapped in local minimizers when applied to the design of electromagnetic devices made of iron and permanent magnet. Design/methodology/approach – Topology optimization methods aim at finding the optimal distribution of some materials in cells subdividing a design space, regarding a specific objective function. This paper suggests to consider that each cell contains an oriented microstructure of iron whose direction and shape are optimized by the method. Findings – Coupled with convexity and sensitivity mappings quite common in the field of topology optimization, the use of the microstructure allows the optimization algorithm to converge systematically toward the same design. This achievement is illustrated on a practical case, i.e. the optimization of the rotor of a permanent magnet synchronous motor regarding its mean torque and under mass constraint. Also, this paper shows that intermediate iron materials can either be penalized or interpreted, thanks to the realistic physical relations derived from the iron microstructures. Originality/value – This paper proposes a mechanism based on an iron microstructure for avoiding the topology optimization methods and the trap of local minimizers when applied to the design of electromagnetic devices made of iron and permanent magnet.

The XIX International Conference on Electrical Machines - ICEM 2010, 2010

This paper focuses on the maximization of the torque-to-weight ratio of permanent magnet synchron... more This paper focuses on the maximization of the torque-to-weight ratio of permanent magnet synchronous motors (PMSM) using a topology optimization method. It aims at finding the optimal design that either maximizes the torque for a given weight or minimizes the weight for a required torque. The analysis presented in this paper besides considers radial and tangential permanent magnets. The paper

2009 8th International Symposium on Advanced Electromechanical Motion Systems & Electric Drives Joint Symposium, 2009

To perform parameter and shape optimization, an initial topology is required which affects the fi... more To perform parameter and shape optimization, an initial topology is required which affects the final solution. Topology optimization methods have the advantage to release this constraint. They are based on a splitting of the design space into cells, in which they attempt to distribute optimally some given materials. In this paper, the optimization is based on a discrete formulation of

Recent Advances in Optimization and its Applications in Engineering, 2010

We consider an evolutionary method applied to a topology optimization problem. We compare two mat... more We consider an evolutionary method applied to a topology optimization problem. We compare two material distribution formalisms (static vs. Voronoibased dynamic), and two sets of reproduction mechanisms (standard vs. topologyadapted). We test those four variants on both theoretical and practical test cases, to show that the Voronoi-based formalism combined with adapted reproduction mechanisms performs better and is less sensitive to its parameters.

International Symposium on Power Electronics Power Electronics, Electrical Drives, Automation and Motion, 2012

2007 International Conference on Power Engineering, Energy and Electrical Drives, 2007

The purpose of this study is to develop a suspension system for a low-cost flywheel energy storag... more The purpose of this study is to develop a suspension system for a low-cost flywheel energy storage system. This suspension system is composed of two identical magnetic bearings mounted at the end of the flywheel. Due to a specific design of these magnetic bearings, it has the particularity to have only one active axis (sustentation). The others (centering) are passively

IFIP International Federation for Information Processing, 2006

ABSTRACT The main difficulties encountered in the development of microscale fluidic pumping syste... more ABSTRACT The main difficulties encountered in the development of microscale fluidic pumping systems stem from the fact that these systems tend to comprise highly three-dimensional parts, which are incompatible with traditional microproduction technologies. Regardless of the type of pumping principle, most of the hydraulic systems contain valves and in particular a one-way valve. This paper presents the design and modelling of an ortho-planar one-way microvalve. The main advantages of such a valve are that it is very compact and can be made from a single flat piece of material. An analytical model of the spring deflection has been developed and compared to FEM. A prototype with a bore of 1.5 mm has been build using a micro EDM (electro discharge machining) machine and also tested. Full Text at Springer, may require registration or fee

2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, 2014

ABSTRACT Microfluidics or the ability to manipulate micro volumes of a fluid is a field in expans... more ABSTRACT Microfluidics or the ability to manipulate micro volumes of a fluid is a field in expansion. As some examples of potential applications are cited drug delivery systems, electronic cooling devices, micro lab on a chip or dosage systems. Driving fluid from one point to another in those systems is a major challenge. In order to achieve this goal various micropump designs have been proposed. In this paper the design of an electromagnetic peristaltic valveless micropump is proposed. The peristaltic motion is created by inducing body forces in a membrane. Those body forces are due to the interaction of the current circulating in the membrane and a magnetic field created by Halbach arrays. An analytical model for the membrane displacement is proposed and validated using a finite element model. The model is based on the assumption that the effect of the currents on the magnetic field can be neglected. This decouples the problem in a magnetic problem independant of the membrane displacement and a mechanical problem where an external load caused by the currents and the magnetic field is applied. The aim of the proposed model is to provide a tool to evaluate the pumping rate at low computational cost which will be used in optimization algorithm.

2013 International Conference on Electrical Machines and Systems (ICEMS), 2013

ABSTRACT Microfluidics has high potential applications in medical devices for drug delivery, dosi... more ABSTRACT Microfluidics has high potential applications in medical devices for drug delivery, dosing, in micro lab on a chip, microelectronic cooling systems and others. Driving fluid from one point to an other in those systems is a major challenge. To achieve this goal various micropumps have been proposed. In this paper a valveless pump actuated by piezoelectric benders put in series is studied. The benders are activated one after the other to create a peristaltic movement of the driving membrane. The design is presented and in order to optimize the structure an analytical model is proposed. The model is used to evaluate quickly the pumped volume as well as the stresses in the benders. FEM is then used to confirm approximations which have been made.

2014 15th International Conference on Electronic Packaging Technology, 2014

ABSTRACT Piezoelectric materials show interesting properties for developing actuators and sensors... more ABSTRACT Piezoelectric materials show interesting properties for developing actuators and sensors but those materials have strict constraints on the maximum stress and electric field which must be taken into account in the design. In most cases the electric field is supposed constant but this assumption is clearly inappropriate in bending actuators where the electric field vary across piezoelectric layer thickness. This paper presents an analytical model which takes into account the variation of the electric field and its impact on the stress in laminated structures under bending loads allowing an optimal design of laminated structure using piezoelectric materials.

2012 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2012

ABSTRACT Series elastic actuators are very popular in rehabilitation robotics. Among other advant... more ABSTRACT Series elastic actuators are very popular in rehabilitation robotics. Among other advantages, elastic elements between the actuator and the load permit to store and release energy during the task completion, such that the energy balance is improved and the motor power peak is decreased. In rhythmic tasks like walking, this reduces to design the spring stiffness such that it works at resonance. To comply with different gaits and cadences, it is therefore necessary to design Variable Stiffness Actuators (VSA). This paper proposes three contributions: (i) we apply a particular concept of VSA to an active ankle prosthesis; (ii) we discuss the relevance of using VSA to change the stiffness also within the gait cycle; and (iii) we elaborate some control strategies for this device. Our guideline is to track a mechanical design and a controller maximizing energy efficiency. We establish that a promising approach is simply to control the amount of energy stored in the elastic element.

Journal of Micro-Nano Mechatronics, 2008

This paper presents the design, the realization and the modelling of an ortho-planar one-way micr... more This paper presents the design, the realization and the modelling of an ortho-planar one-way microvalve that can be used in a micropump. The main advantages of such valves are that they are very compact and can be made from a single flat piece of material. An analytical model of the spring deflection has been developed and tested, and results are

SPEEDAM 2010, 2010

Page 1. Optimal sinusoidal currents for avoiding torque pulsations after the loss of one phase in... more Page 1. Optimal sinusoidal currents for avoiding torque pulsations after the loss of one phase in polyphase SMPM synchronous motor F. Baudart, B. Dehez, F. Labrique, E. Matagne Université catholique de Louvain (UCL) Centre ...