Modeling and analysis of industrial hybrid systems based on first order and second order FSPN

Many industrial systems are governed by discrete state digital controllers, whose internal states interact mutually with the value of some continuous physical quantities. We model, continuous quantities of industrial systems and their mutual interaction with the systems´ discrete part by using two formalisms of Petri nets: first order and second order fluid stochastic Petri net (FO-FSPN and SO-FSPN). Simulative and numerical methods are used to analyze these models. As an example, an industrial mixing tank with digital controllers is modeled. The continuous physical quantities (fluid level) in the tank are calculated for both FO-FSPN and SO-FSPN models. Lastly, the benefits and limitations of each approach are discussed.