Application of temporal constrained predicate nets to production systems

This paper discusses the advantage of using a hybrid model to express the discrete aspects (events) as well as continuous aspects (time) of production systems. We propose an extension of the Petri Net model to take these two information types into account. Finally we use this new model to describe, to simulate and to check the properties of a production system in a simple example. The proposed model is close to the predicate transition one. However it is more general because it is not limited to finite domains. So, it allows continuous temporal properties to be explicitly defined. Moreover, we show how the constraints intervening in the behaviour modelling can be handled to demonstrate safety properties depending on time