Journal ArticleDOI
A theory of discontinuities in physical system models
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TLDR
An algorithm for inferring the correct new mode and state variable values in the hybrid modeling framework, and a verification scheme that ensures hybrid models conform to physical system principles based on the principles of divergence of time and temporal evolution in behavior transitions are developed.Abstract:
Physical systems are by nature continuous, but often display nonlinear behaviors that make them hard to analyze. Typically, these nonlinearities occur at a time scale that is much smaller than the time scale at which gross system behavior needs to be described. In other situations, nonlinear effects are small and of a parasitic nature. To achieve efficiency and clarity in building complex system models, and to reduce computational complexity in the analysis of system behavior, modelers often abstract away any parasitic component parameter effects, and analyze the system at more abstract time scales. However, these abstractions often introduce abrupt, instantaneous changes in system behavior. To accommodate mixed continuous and discrete behavior, this paper develops a hybrid modeling formalism that dynamically constructs bond graph model fragments that govern system behavior during continuous operation. When threshold values are crossed, a meta-level control model invokes discontinuous state and model configuration changes. Discontinuities violate physical principles of conservation of energy and continuity of power , but the principle of invariance of state governs model behavior when the control module is active. Conservation of energy and continuity of power again govern behavior generation as soon as a new model configuration is established. This allows for maximally constrained continuous model fragments. The two primary contributions of this paper are an algorithm for inferring the correct new mode and state variable values in the hybrid modeling framework, and a verification scheme that ensures hybrid models conform to physical system principles based on the principles of divergence of time and temporal evolution in behavior transitions . These principles are employed in energy phase space analysis to verify physical consistency of models.read more
Citations
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Journal ArticleDOI
Causality Assignment and Model Approximation for Hybrid Bond Graph: Fault Diagnosis Perspectives
TL;DR: In this work, a comprehensive study on the HBG from FDI viewpoints is presented and a causality assignment procedure and a model approximation technique are developed to achieve a HBG with a desirable causality assignments that leads a unified description of system's behavior.
Journal ArticleDOI
A Comprehensive Diagnosis Methodology for Complex Hybrid Systems: A Case Study on Spacecraft Power Distribution Systems
Matthew Daigle,Indranil Roychoudhury,Gautam Biswas,Xenofon Koutsoukos,Ann Patterson-Hine,Scott Poll +5 more
TL;DR: Hybrid Transcend is a comprehensive model-based diagnosis scheme that uses the hybrid bond graph modeling language to systematically develop computational models and algorithms for hybrid state estimation, robust fault detection, and efficient fault isolation.
Journal ArticleDOI
Quantitative Hybrid Bond Graph-Based Fault Detection and Isolation
TL;DR: The DHBG is exploited to analyze the hybrid system's fault detectability and fault isolability and a quantitative FDI framework for effective fault diagnosis for hybrid systems is proposed.
Journal ArticleDOI
Robust Trajectory Tracking for a Class of Hybrid Systems: An Internal Model Principle Approach
TL;DR: A feedback control law based on a discontinuous version of the classical internal model principle is proposed for asymptotic tracking of periodic trajectories for hybrid systems having linear dynamics in each operating mode and isolated discrete switching events.
Journal ArticleDOI
Analysis of the Bond Graph Model of Hybrid Physical Systems with Ideal Switches
TL;DR: In this article, the authors used the bond graph technique to establish their knowledge model, based upon an ideal representation of the switches, and applied it to power converters, where switches only commutate by pairs.
References
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Journal ArticleDOI
The algorithmic analysis of hybrid systems
Rajeev Alur,Costas Courcoubetis,Nicolas Halbwachs,Thomas A. Henzinger,Pei Ho,Xavier Nicollin,Alfredo Olivero,Joseph Sifakis,Sergio Yovine +8 more
TL;DR: A general framework for the formal specification and algorithmic analysis of hybrid systems is presented, which considers symbolic model-checking and minimization procedures that are based on the reachability analysis of an infinite state space.
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A qualitative physics based on confluences
Johan de Kleer,John Seely Brown +1 more
TL;DR: A fairly encompassing account of qualitative physics, which introduces causality as an ontological commitment for explaining how devices behave, and presents algorithms for determining the behavior of a composite device from the generic behavior of its components.