Process Networks in Ptolemy II

The Synchronous Reactive (SR) domain in Ptolemy II models systems as components with both infinite processing resources and infinite communication bandwidth. Computation within components and data transfer between components are considered to happen instantaneously. Therefore, a given system is simulated as if all of its components execute and produce outputs at the same time. This raises inter...

The Ptolemy project studies modeling, simulation, and design of concurrent, real-time, embedded systems. The focus is on assembly of concurrent components. The key underlying principle in the project is the use of well-defined models of computation that govern the interaction between components. A major problem area being addressed is the use of heterogeneous mixtures of models of computation. ...

We present Viptos (Visual Ptolemy and TinyOS), a joint modeling and design environment for wireless networks and sensor node software. Viptos is built on Ptolemy II, a graphical modeling and simulation environment for embedded systems, and TOSSIM, an interrupt-level discrete event simulator for homogeneous TinyOS networks. Viptos includes the full capabilities of VisualSense, a Ptolemy II envir...

In Ptolemy II, the widths of the relations between actors have an important role in specifying the semantics of a model. In some situations, however, explicit relation widths break the modularity of a model. In these cases, we would like to infer the widths of relations from the widths of neighboring relations. There is an existing implementation in Ptolemy, but it has some severe limitations. ...

Complex control systems integrate a variety of functions and capabilities, which will in general rely on different computational mechanisms. The plant model may be represented as a set of ordinary differential equations, the mode switching logic may be expressed as a finite state machine, and dataflow models may be used to capture the architecture of a sensor processing subsystem, for example. ...

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