An Ontology for Transitions in Physical Dynamic Systems

Physical systems often exhibit complex nonlinear behaviors in continuous time at multiple temporal and spatial scales. Abstractions simplify behavioral analysis and help focus on dominant system behaviors by defining sets of equivalent behavior types called modes. System behavior evolves in continuous modes with discrete transitions between modes. Subtle interactions between the continuous behaviors and discrete transitions need to be captured by well-defined hybrid modeling and analysis semantics. This paper presents a taxonomy of transition modes, and develops a formal semantics for transition conditions that lead to efficient and physically consistent simulation algorithms for physical systems.