modeling of continuous systems using modified petri nets

due to the changes which may occur in their parameters, systems are usually demonstrated by some subsystems for different conditions. this paper employs modified petri nets (mpn) to model theses subsystems and makes it simple to analyze them. in this method, first, the continuous transfer function is converted to a discrete transfer function and then, by mpn, system is modeled and analyzed. all subsystems can be modeled and used in state control or cascade control loops. here, the focus is mainly on the conception as well as the definitions of the new unified representation model for continuous control systems. simulation results show that the new method for modeling continuous systems works effectively.