Hybrid Modelling Focused on Hybrid Petri Nets
Stefan Pettersson, Bengt Lennartson · 1995
In the present paper, a general hybrid model is proposed, including vector-field switching and/or state jumps. We clearly separate the open-loop hybrid plant from the closed-loop hybrid system in order to support the construction of a hybrid controller. A unified mathematical description where all changes are expressed as state jumps is presented. The total hybrid system can be described by hybrid Petri nets. It is shown that these can be used for quite general continuous systems. However, for a graphically attractive description, only a certain class of systems are suitable. We also compare hybrid Petri net and switched Bond graph modelling. A process example is used throughout the paper to illustrate different modelling aspects. Keywords: Hybrid phenomena, Hybrid modelling, Hybrid Petri nets, Switched Bond graphs. 1 Introduction Hybrid systems consist of a mixture of a continuous time system and a discrete event system (DES) that influence each others behaviour. For the continuous t...