Benoit Delinchant

An optimizer using the software component paradigm for the optimization of engineering systems

Purpose – This paper is a synthesis paper which seeks to discuss an optimisation framework using software components, which is a new emerging paradigm in computer science.Design/methodology/approach – The goal of this paper is to show the efficiency of the software component approach for the implementation of optimisation frameworks for engineering systems in general, and electromagnetic systems in particular.Findings – This paper highlights the component standard, a generator based on analytical expressions of the system, and an optimization service. References and examples show application in the area of electromagnetic components and systems.Practical implications – This paper presents CADES, a framework dedicated to system design, based on optimization needs. The framework is defined with a standard implementing the software component paradigm and a pattern to use it. Indeed, this pattern details how to create and use a component (the model of the device to design).Originality/value – This paper shows...

Using Coulombian approach for Modeling Scalar Potential and Magnetic Field of a Permanent Magnet with Radial Polarization

New compact semianalytical expressions of the scalar potential and magnetic fields produced by a radially polarized permanent magnet are described in this paper by using Coulombian approach. It uses fictitious magnetic charge to model the magnetic field intensity. With this fast model, we can compute the demagnetization field in each point inside the permanent magnet and the magnetic fields outside it

A Component-Based Framework for the Composition of Simulation Software Modeling Electrical Systems

This article deals with a component-based approach to design electrical systems modeled by several simulation software. The component paradigm can be applied to simulation software, thus taking advantage of composition facilities. To do so, a visual composition tool has been developed and is presented in this article. It produces recursively a global simulation component from several pieces of simulation software. It also deals with uncertainty by taking into account different kinds of components as well as different kinds of coupling methods. A specific coupling method for components dedicated to optimization is detailed. The sizing process of a home system filter is then presented to illustrate the use of the visual composer tool and this specific coupling method.

Automatic differentiation for electromagnetic models used in optimization

Purpose – The purpose of this paper is to illustrate automatic differentiation (AD) as a new technology for the device sizing in electromagnetism by using gradient constrained optimization. Component architecture for the design of engineering systems (CADES) framework, previously described, is presented here with extended features.Design/methodology/approach – The paper is subject to further usage for optimization of AD (also named algorithmic differentiation) which is a powerful technique that computes derivatives of functions described as computer programs in a programming language like C/C++, FORTRAN.Findings – Indeed, analytical modeling is well suited regarding optimization procedure, but the modeling of complex devices needs sometimes numerical formulations. This paper then reviews the concepts implemented in CADES which aim to manage the interactions of analytical and numerical modeling inside of gradient‐based optimization procedure. Finally, the paper shows that AD has no limit for the input prog...

Two Levels Modeling for the Optimization of Electromagnetic Actuators

In this paper, a two-stage modelling, to ensure a good and fast optimization procedure for microdevices, is presented. This methodology is supported by three noncommercial software. The first one is dedicated to analytical modelling of non ferromagnetic electromagnetic devices, the second one is dedicated to numerical modelling of electromagnetic devices, and the last is dedicated to constrained-based optimization. Issues and solutions of such a methodology are highlighted, and illustrated by designing a matrix of actuators for an adaptive optic.

Formal Sensitivity Computation of Magnetic Moment Method

This paper presents a methodology for computing formally sensitivities of the magnetic moment method. This numerical method is known to be very accurate and light to compute force and torque acting on an open field problem. We propose an approach which computes formal derivatives with respect to the geometrical parameters of the device. Once the sensitivities are obtained, gradient based optimization algorithm can be used.

Reducing sensitivity analysis time-cost of compound model

This paper deals with the sensitivity analysis of compound models in the case of gradient based optimization. Multidisciplinary optimization (MDO) may use time-consuming analysis such as the finite-element method (FEM) resolution, their sensitivity analysis must then be managed efficiently in order to limit their evaluations. A composition model implementation based on differential propagation mechanism has been used. Different solutions of sensitivity analysis based on forward finite difference are proposed at the level of each inner model. These solutions have been implemented for the design of a transformer, using mixed modeling (FEM + analytic). It has led to a reduction by a factor of two then three of an optimization iteration time cost.

Interaction between ring-shaped permanent magnets with symbolic gradients: application to magnetic bearing system optimization

This paper presents a semi-analytical calculation of the interaction between magnetic bodies with ring shapes. It leads to fast and accurate evaluation of forces and torques but also to the symbolic expression of their gradients. Our method can be used to compute partial derivatives to address optimization needs. It has been implemented into CADES environment in order to be automatically available for end users. A very efficient optimization of a magnetic bearing system is demonstrated.

Analytical Calculation of Magnet Systems: Magnetic Field Created by Charged Triangles and Polyhedra

An analytical method for the calculation of the magnetostatic scalar potential and the magnetic field created by a polyhedron-shaped permanent magnet is presented in this paper. The magnet is supposed to be uniformly magnetized. The magnetization is equivalent to distributions of magnetic charges: it is the coulombian approach. The analytical calculation is made by a surface integration on all the polygons that composes the polyhedron. For each polygonal surface, we have shown that it can be decomposed in a series of right triangles. An analytical solution in the particular case of the right triangle has been developed. By this way, the magnetostatic potential and the magnetic field of any polyhedral-shaped magnet can be analytically calculated.

Java Automatic Differentiation Tool Using Virtual Operator Overloading

AD tools are available and mature for several languages such as C or Fortran, but are just emerging in object oriented language such as Java. In this paper, a Java automatic differentiation tool called JAP is presented which has been defined and developed with specific requirements for the design of engineering systems using optimization. This paper presents JAP requirements and the implementation architecture. It also compares JAP performance to ADOL-C in forward mode on a magnetic MEMS model. JAP has been successfully used on several system optimizations in the field of electromagnetic MEMS.