Modular hierarchical models of hybrid systems

Hybrid or continuous/discrete systems have attracted increased scientific attention. In fact, most technical systems consist of physical (sub)systems which are governed by continuous dynamics, continuous or discrete-time controllers, and logical systems which react to and trigger events in the continuous parts. Hybrid systems also arise from modeling of physical phenomena alone, e.g. in evaporation and other processes with phase transitions or in mechanical systems with stiction/friction, hysteresis and backlash. We present a unified and general modeling paradigm which allows modularity and hierarchies of subsystems. These two features are essential for effective modeling of real systems because they allow the modeller to compose a large systems of basic blocks which represent physical subsystems or modules of the control software and can be reused in the same model as well as in other models