Publications de Yves Perriard | EPFL Graph Search

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Facial paralysis is a highly burdening condition, resulting in a patient's inability to move his musculature on one or both sides of the mouth. The restoration of facial movement is crucial for enhancing the overall patients' quality of life. The use of DE ...

This paper describes a low cost sensorless position detection scheme for a brushless DC motor. This method is based on interruption of the 3 phase-currents and reading the back-EMF. The hardware for measuring the back-EMF is very simple. The method is possible thanks to the flexibility of the modern DSP. The proposed scheme shows how it is possible to get rotor position information with a good accuracy (5°). This precision allows a sinusoidal alimentation. The method takes information about the rotor in

Dielectric Elastomer Actuators (DEAs) are deformable materials frequently employed in soft robotics, distinguished by high energy density. Often referred to artificial muscles, they deform based on the electrostatic principle, where the application of high voltage induces thickness reduction which will lead to an increase of surface in the other directions. This project aims to apply an advanced control algorithm for soft robots to enable small and fast displacements. DEAs are non-linear systems and traditi

This paper presents an analytical formula for the permanent magnet (PM) magnetomotive force (MMF) in a slotted PM rotating motor. To derive this formula, an analytical 2D solution of Poisson's equation for the equivalent slotless configuration using the Fourier series is applied. The formula comprises the case when the PM poles are not symmetrical. The obtained PM MMF can be used to determine the magnetic field using the slot modulation

Electrostatic discharge in quartz watches is becoming more and more important due to the use of plastic materials and tactile sensors. The discharge can lead to different type of dysfunction such as a simple reset, a latch-up, or the destruction of the ele ...

Due to increased demand for compact grippers in applications such as drone deliveries or cleanroom pick and place robots, bistable grippers powered by shape memory alloys (SMAs) are an elegant solution for replacing the traditional pneumatic grippers. But due to their complex behaviour, they are difficult to size and are, thus, rarely used in industrial applications. In this paper, a bistable flexure-based SMA-driven parallel gripper is presented that is lightweight, compact and resistance to friction and w

The paper presents an original method to determine the 2D magnetic field in a square magnetic circuit. To do it, the method of Schwarz-Christoffel mapping is used. This mapping is a special kind of the conformal mappings, applicable to polygonal 2D configu ...

The DC-DC flyback converter is one of the most suitable topologies to generate the voltages necessary to operate Dielectric Elastomer Actuators. Voltages which can range from 5 to 20 kV. Previous works demonstrated through experiments the flyback’s ability ...

In some applications, contacts between two devices are the first cause of dysfunctions. The aim of this paper is to transfer contactless power energy to add new functions to a tool (e.g., drill machine). A bidirectional communication is also needed. This is realized with an ironless high-frequency transformer for both power and information transmission. Different coil geometries have been studied to reduce mutual inductance between power and information coils. This new solution enables to build low-cost and

In some applications, contacts between two devices are the first cause of dysfunctions. The aim of this study is to transfer contactless power energy to add new functions to a tool (drill machine for example). A bi-directional communication is also needed. This is realized with an ironless high frequency transformer for both power and information transmission. Different coil geometries have been studied to reduce mutual inductance between power and information coils. This new solution enables to build low c

The recent development of Dielectric Elastomer Actuators (DEA) requires a new approach to the description of hyperelastic material when the architectures are more complex than a film of material. In this paper, we propose a new technique of identification ...

The Ironless Inductive Position Sensor (I2PS) is an air-cored displacement sensor which has been conceived to be totally immune to external DC/slowly-varying magnetic fields. It can thus be used as a valid alternative to Linear Variable Differential Transf ...

This paper addresses the design of a new hybrid MEMS micromotor. It is a small 3-phases axial flux BLDC motor. The stator is realized following the almost CMOS technology rules used for MEMS manufacture and the coils have two copper layers. The rotor is ma ...

We will present a method allowing to evaluate the mechanical performances (torque, speed, mechanical power, dissipated losses in the surface of contact between stator and rotor) of the travelling wave ultrasonic motors. The visualization of the motor characteristics will make it possible to the manufacturer to optimize the operation point of the motor compared to these proper used criteria. The method was developed based only on the two-dimensional equivalent mechanical model of the motor.

A dielectric elastomer actuator (1) comprising: a plurality of polymer layer (2);a plurality of stretchable electrode layers (3), each polymer layer (2) being sandwiched between two electrode layers (3) so as to control the electric field within the polyme ...

Purpose - The purpose of this paper is to develop a contactless torque measurement methods. The need for low-weight, high-efficiency and high-power density motors has led to an increased research and development activity in the field of very high speed (VHS) motors or generators. Torque measurement methods are inherently linked with the target speed and power of the motor. Therefore, new torque measurement methods compatible with VHS need to be designed in order to apprehend this new area of electrical mach

In large cities, due to expensive land price, high-rise buildings are built, in which the space dedicated to the elevators is considerable and reduces the rented surfaces. To decrease these lost surfaces, a Multi Mobile System is proposed: it consists of several moving cabins in the same shafts permitting also horizontal motions. In this case, the use of direct linear motor drives without counterweight is requested. But it implies high mechanical power and energy consumption. A system design optimization pe

Coreless electric motors are gaining interest from the community as they have a larger power-to-weight ratio and a larger efficiency. The absence of iron slots leaves the winding space unobstructed. This enables the geometry of the coils to be skewed to ov ...

Shape Memory Alloys (SMAs) have gained significant attention due to their high work density in order to fabricate compact and lightweight actuators. However, the major drawback of thermally activated SMAs is the time that takes for these materials to cool ...

Artificial muscles powered by shape memory alloys (SMAs) or highly twisted artificial muscles offer promising alternatives to conventional actuators, particularly in applications requiring lightweight, compliant or biomimetic motion. However, these high-force actuators suffer from reduced actuation frequency due to passive cooling constraints limiting their widespread adoption. This paper presents the design, modeling, and experimental evaluation of a novel twisted and coiled SMA (TCAM) actuator. This actua

Yves Perriard

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DEMO: Dielectric elastomer actuators (DEAs) for the restoration of facial movements

Low cost sensorless position detection for brushless DC motor

Advanced Control of Dielectric Elastomer Actuators

Analytical formula for rotating motor permanent magnet MMF in a general case

Analysis and modeling of electrostatic discharge in a tactile glass featured watch

Design and modelling of a flexure-based bistable gripper powered by shape memory alloys

A square magnetic circuit analysis using Schwarz-Christoffel mapping

An Analytical Model for the Prediction of the Maximum Output Voltage Reachable with an Ultra-high Voltage Flyback Converter Driving Capacitive Actuators

Contactless power and information transmission

Contactless power and information transmission

Identification of material parameters of a tubular dielectric elastomer actuator for a cardiac assist device

Design optimization of an ironless inductive position sensor for the LHC collimators

Development of a Hybrid MEMS BLDC Micromotor

Performance analysis and optimization of the travelling wave ultrasonic motor

Dielectric elastomer actuator

Torque measurement methods for very high-speed motors

Linear motors for Multi Mobile Systems

2.5D Topology Optimization to Design Overlapping Winding in Multi-Phase Coreless Electrical Machine

Improve the Time Response of Shape Memory NiTi Sheets Using Highly Conductive Elastomer Layers

Enhanced actuation frequency in actuators using twisted and coiled SMA artificial muscles