Petri net based control of a modular production system

A systematic approach to the design of sequential control is presented. It is illustrated by a case study of a two level hierarchical and distributed control design for a laboratory scale modular production system. The authors´ first goal is to show how Petri net models can be used as a tool for sequential control specification that enables systematic development and analysis of specification model. Secondly, they show how the same specification model can be used as an input data for the design of the second, coordination level employing supervisory control concepts. Finally, an implementation method is presented, which enables Petri net supervisor to be separated from the low level process model and implemented in a distributed environment.