Verification of Stiff Hybrid Systems by Modeling the Approximations of Computational Semantics

Abstract:

With the seemingly unbounded proliferation of computing power into most any engineered artifact, ever more 'smart' systems are being created. This increase of available smarts in engineered systems has given rise to a new field of innovation where unique value is derived from having intelligent systems interact in novel and unforeseen manners. With the physical world an intrinsic part of the interaction and the smarts being implemented in a networked information modality, also called cyber space, these innovative systems are referred to as Cyber-Physical Systems. Modeling cyber aspects, physics, and their nexus then plays a crucial role in the design of Cyber-Physical Systems. A pick-and-place machine is presented as a paradigmatic example of such Cyber-Physical Systems to illustrates the intricate interplay between cyber space and physics, which serves to motivate the importance of integrated heterogeneous modeling paradigms that support modeling, simulation, and analysis of combined physics, geometry, signal processing, and control aspects. At a macroscopic level, physics models often comprise differential and algebraic equations and these equations typically require computational approaches to derive solutions. Approximations introduced by the solvers that derive these solutions to a large extent determine the meaning of the models, in particular when continuous-time behavior interacts with discontinuities such as in so-called hybrid dynamic systems. In reasoning about models that are solved computationally it is therefore imperative to also model the solvers. This presentation outlines an approach to modeling numerical solver approximations to help reason about approximations and to enable verification of stiff hybrid dynamic systems.

Slides from the presentation

Biography:

Pieter J. Mosterman is a Senior Research Scientist at MathWorks in Natick, MA where he works on computational design automation technologies. He also holds an Adjunct Professor position at the School of Computer Science of McGill University. Before, he was a Research Associate at the German Aerospace Center (DLR) in Oberpfaffenhofen. He has a Ph.D. degree in Electrical and Computer Engineering from Vanderbilt University in Nashville, TN, and a M.Sc. degree in Electrical Engineering from the University of Twente, Netherlands. His primary research interests are in Computer Automated Multiparadigm Modeling (CAMPaM) with principal applications in design automation, training systems, and fault detection, isolation, and reconfiguration. Dr. Mosterman designed the Electronics Laboratory Simulator that was nominated for The Computerworld Smithsonian Award by Microsoft Corporation in 1994. In 2003, he was awarded the IMechE Donald Julius Groen Prize for his paper on the hybrid bond graph modeling and simulation environment HYBRSIM. In 2009, he received the Distinguished Service Award of The Society for Modeling and Simulation International (SCS) for his services as Editor-in-Chief of SIMULATION: Transactions of SCS. Dr. Mosterman was Guest Editor for special issues on CAMPaM of SIMULATION, IEEE Transactions on Control Systems Technology, and ACM Transactions on Modeling and Computer Simulation. He has chaired over thirty scientific events, served on over eighty International Program Committees, published over a hundred peer reviewed papers, and is inventor on over thirty awarded patents.