Benoit Caillaud | Institut National de Recherche en Informatique et Automatique (INRIA) (original) (raw)

Papers by Benoit Caillaud

Nurse Education Today, 2019

Proceedings of the 23rd International Conference on Hybrid Systems: Computation and Control

MDPI Electronics, 2022

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Since its version 3.3, the Modelica language offers the possibility to model multimode systems ha... more Since its version 3.3, the Modelica language offers the possibility to model multimode systems having different DAE-based dynamics in each mode, thanks to the introduction of state machines. When the differentiation index and structure varies with mode changes, compilers generate erroneous simulation code, often resulting in runtime exceptions. We propose in this paper a multimode structural analysis for both multiple modes and mode change events and we show how correct code for restarts can be generated. Our approach is illustrated on two simple but representative mechanical systems.

Electronics

Since its 3.3 release, Modelica offers the possibility to specify models of dynamical systems wit... more Since its 3.3 release, Modelica offers the possibility to specify models of dynamical systems with multiple modes having different DAE-based dynamics. However, the handling of such models by the current Modelica tools is not satisfactory, with mathematically sound models yielding exceptions at runtime. In this article, we propose several contributions to this multifaceted issue, namely: an efficient and scalable multimode extension of the structural analysis of Modelica models; a systematic way of rewriting a multimode Modelica model, based on this analysis, so that the rewritten model is guaranteed to be correctly compiled by state-of-the-art Modelica tools; a proposal for the handling of the consistent initialization of multimode models; multimode structural analysis algorithms that handle both multiple modes and mode change events in a unified framework, coupled with a compile-time algorithm for identifying and quantifying impulsive behaviors at mode changes. Our approach is illu...

2020 Forum for Specification and Design Languages (FDL)

The 16th SYNCHRON workshop has been organized as Dagstuhl seminar 09481 from November 22-27, 2009... more The 16th SYNCHRON workshop has been organized as Dagstuhl seminar 09481 from November 22-27, 2009. Online material of the seminar is available at the following web page:

2016 IEEE Intl Conference on Computational Science and Engineering (CSE) and IEEE Intl Conference on Embedded and Ubiquitous Computing (EUC) and 15th Intl Symposium on Distributed Computing and Applications for Business Engineering (DCABES), 2016

ArXiv, 2021

Fifth International Conference on Application of Concurrency to System Design (ACSD'05)

Lecture Notes in Computer Science, 2008

Proceedings of the 5th ACM international conference on Embedded software - EMSOFT '05, 2005

Electronic Notes in Theoretical Computer Science, 2005

Discrete Event Dynamic Systems, 2007

Annual Reviews in Control, 2020

Modern modeling languages for general physical systems, such as Modelica, Amesim, or Simscape, re... more Modern modeling languages for general physical systems, such as Modelica, Amesim, or Simscape, rely on Differential Algebraic Equations (DAEs), i.e., constraints of the form f (x , x, u) = 0. This drastically facilitates modeling from first principles of the physics, as well as the reuse of models. In this paper, we develop the mathematical theory needed to establish the development of compilers and tools for DAE-based physical modeling languages on solid mathematical bases. Unlike Ordinary Differential Equations (ODEs, of the form x = g(x, u)), DAEs exhibit subtle issues because of the notion of differentiation index and related latent equations-ODEs are DAEs of index zero, for which no latent equation needs to be considered. Prior to generating execution code and calling solvers, the compilation of such languages requires a nontrivial structural analysis step that reduces the differentiation index to a level acceptable by DAE solvers. The models supported by tools of the Modelica class involve multiple modes, with mode-dependent DAE-based dynamics and state-dependent mode switching. However, multimode DAEs are much more difficult to handle than DAEs, especially because of the events of mode change. Unfortunately, the large literature devoted to the mathematical analysis of DAEs does not cover the multimode case, typically saying nothing about mode changes. This lack of foundations causes numerous difficulties to the existing modeling tools. Some models are well handled, others are not, with no clear boundary between the two classes. In this paper, we develop a comprehensive mathematical approach supporting compilation and code generation for this class of languages. Its core is the structural analysis of multimode DAE systems. As a byproduct of this structural analysis, we propose sound criteria for accepting or rejecting multimode models. Our mathematical development relies on nonstandard analysis, which allows us to cast hybrid system dynamics to discrete-time dynamics with infinitesimal step size, thus providing a uniform framework for handling both continuous dynamics and mode change events.