Comparison of hybrid systems and fluid stochastic Petri nets

Hybrid Systems are models of interacting digital and continuous devices with applications in the control of aircraft, computers, or modern cars for instance. Concurrently, Fluid Stochastic Petri Nets (FSPNs) have been introduced as an extension of stochastic Petri nets to model physical systems that contain continuous fluid quantities controlled by discrete logic, as well as a means to deal with the possible state explosion of discrete models. Of course, an FSPN is by definition a hybrid system but in this paper, we compare a general hybrid systems formalism with FSPN formalism. The conclusion of this paper, suplemented by some examples, is that fluid stochastic Petri nets and hybrid system formalism can be converted from one to the other. Although there is a price to pay for such a conversion, the conversion can transfer the solution methods from one to the other and thus help the development of both formalisms.