Automatic differentiation for electromagnetic models used in optimization

• Published in: Compel Vol. 28; no. 5; pp. 1313 - 1326
• Main Authors: Enciu, P., Wurtz, F., Gerbaud, L., Delinchant, B.
• Format: Journal Article
• Language: English
• Published: Bradford Emerald Group Publishing Limited 11.09.2009
• Subjects: Computer architecture; Computer software; Constraint handling; Electromagnetism; Gradient methods; Modelling; Optimization; Optimization techniques; Software; Studies; Constraint handling; Optimization techniques; Gradient methods; Modelling; Electromagnetism; Computer software
• ISSN: 0332-1649; 2054-5606
• DOI: 10.1108/03321640910969557

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 program complexity, or gradients accuracy, in the context of constrained optimization of an electromagnetic actuator.Originality value - AD is employed for a large and complex numerical code computing multidimensional integrals of functions. Thus, the paper intends to prove the AD capabilities in the context of electromagnetic device sizing by means of gradient optimization. The code complexity as also as the implications of AD usage may stand as a good reference for the researchers in this field area.