Modelling and Control of Discrete Event Dynamic Systems

Abstract

Discrete event dynamic systems (DEDS) in general are
investigated as to their analytical models most suitable for control
purposes and as to the analytical methods of the control synthesis.
The possibility of utilising both the selected kind of Petri nets
and the oriented graphs on this way is pointed out. Because many
times the control task specifications (like criteria, constraints,
special demands, etc.) are given only verbally or in another form of
non analytical terms, a suitable knowledge representation about
the specifications is needed. Special kinds of Petri nets (logical,
fuzzy) are suitable on this way too. Hence, the knowledge-based
control synthesis of DEDS can also be examined. The developed
graphical tools for model drawing and testing as well as for the
automated knowledge-based control synthesis are described and
illustratively presented.
Two approaches to modelling and control synthesis based on
oriented graphs are developed. They are suitable when the
system model is described by the special kind of Petri nets - state
machines. At the control synthesis the first of them is straightforward
while the second one combines both the straight-lined model
dynamics development (starting from the given initial state
towards the prescribed terminal one) and the backtracking model
dynamics development.