Modelling and simulation of manufacturing systems with first-order hybrid Petri nets

First-order hybrid Petri nets are models that consist of continuous places holding fluid, discrete places containing a non-negative integer number of tokens, and transitions, either discrete or continuous. In the first part o f the paper, we provide a framework to describe the overall hybrid net beha viour that combines both time-driven and event-driven dynamics. The resulti ng model is a linear discrete-time, time-varying state variable model that can be directly used by an efficient simulation tool. In the second part of the paper, we focus on manufacturing systems. Manufacturing systems are di screte-event dynamic systems whose number of reachable states is typically very large, hence approximating fluid models have often been used in this c ontext. We describe the net models of the elementary components of a flexib le manufacturing system (machines and buffers) and we show in a final examp le how these modules can be put together in a bottom-up fashion.