Modeling of Discrete-Time Systems Using Petri Nets

A basic requirement in modeling of hybrid systems is deployment of a uniform framework, such as petri net, in such a way that the model can represent both continuous and discrete dynamics. This paper deals with modeling the continuous part of a hybrid system by a special Petri net called Continuous Time-Delay Petri Net (CTDPN). According to the theorem presented in this paper, an exact correspondence between discrete- time state space equations and fundamental equations of the CTDPN can be established. Based on this theorem, a systematic method is presented for realization of a continuous system represented by a discrete-time state space model. By integrating the concept of state space models and Petri Nets in this paper, new and effective methods can be proposed for analyzing and modeling of hybrid systems. Finally, the performance of the proposed method is investigated for a DC motor.