Modeling Physical Quantities in Industrial Systems using Fluid Stochastic Petri Nets
Marco Gribaudo, Andrea Bobbio, Matteo Sereno · 2001
Introduction Many industrial and production systems are governed by discrete state digital controllers whose internal state transitions are triggered by the value of some measured continuous physical quantity (e.g. speed, temperature, power consumption, fluid rate ....). Such systems, which are described by both discrete and continuous variables, are usually referred to as hybrid systems and are very complex to be modeled and analyzed. In this area, two main streams of research can be envisaged. The first one originated from the community involved in the study of formal models and model checking, the second one from the performance evaluation community. The first stream has lead to the definition of hybrid automata [4, 2], that are finite state automata where, in each state a number of real variables can be defined whose value can range in a predefined interval. When a continuous variable reaches a boundary, it triggers a state change. In this way, the transition