Ptolemy is an open-source and extensible modeling and simulation framework. It offers heterogeneous modeling capabilities by allowing different models of computation to be composed hierarchically in an arbitrary fashion. This paper describes modal models, which allow to hierarchically compose finite-state machines with other models of computation, both untimed and timed. The semantics of modal ...

Event-driven simulators are an eeective way to behaviorally describe a system. Timing constraints are also an important component of a system description. Ptolemy, a powerful graphical simulation framework, provides an event-driven environment. OESIM, a text-based event-driven simulator, provides support for timing constraints. This paper describes a new Ptolemy environment, based on the existi...

This paper presents a hierarchical hybrid system modeling and simulation framework using the Ptolemy I1 environment. Ptolemy I1 is a system-level design tool that supports the integration of multiple models of computation. The modeling of hierarchical hybrid systems is achieved by combining continuous-time models with finite state automata. Breakpoint handling, event detection and invariant mon...

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This is a chapter from the book System Design, Modeling, and Simulation using Ptolemy II This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. To view a copy of this license, visit: http://creativecommons.org/licenses/by-sa/3.0/, or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA. Permissions beyond t...

Complex control systems are heterogeneous from both an implementation and a modeling perspective. Design and simulation environments for such systems need to integrate different component interaction styles, like differential equations, discrete events, state machines, dataflow networks, and real-time scheduling. This paper motivates the use of Ptolemy II software environment for modeling and s...

Ptolemy is a flexible and extensible platform for simulations, rapid prototyping, and other software systems. It is our third generation software environment, building on our experience with Blosim, a signal processing simulation system, and Gabriel, a prototyping environment for real-time signal processing. Unlike its predecessors, Ptolemy does not enforce a single simulation or execution mode...

Triquetrum is an open platform for managing and executing scientific workflows that is under development as an Eclipse project. Both Triquetrum and Kepler use Ptolemy II as their execution engine. Triquetrum presents opportunities and risks for the Kepler community. The opportunities include a possibly larger community for interaction and a path for Kepler to move from Kepler’s one-off ant-base...

Ptolemy is an open-source and extensible modeling and simulation framework. It offers heterogeneous modeling capabilities by allowing different models of computation, both untimed and timed, to be composed hierarchically in an arbitrary fashion. This paper proposes a formal semantics for Ptolemy which is modular, in the sense that atomic actors and their compositions are treated in a unified wa...