In chemical batch control applications the specification of how to produce a batch is called a recipe. When several recipes execute concurrently within a plant there is a possibility for circular wait between recipes utilizing shared resources. A circular wait might lead to the loss of an entire batch; this is costly and should therefore be avoided. This work describes the implementation of a discrete-event supervisor aimed to prevent a batch processing system from running into circular waits by restricting resource allocations. The supervisor interacts with SattLine, a commercial control system for flexible production systems, which in turn executes the batch recipes. The supervisor consists of two parts: (1) generation of a circular wait free specification, and (2) an execution part that restricts the behavior of the control system such that the specification is fulfilled.
[1]
W. M. Wonham,et al.
The control of discrete event systems
,
1989
.
[2]
Knut Åkesson,et al.
Petri Net Models in Batch Control
,
1999
.
[3]
B.A. Brandin,et al.
The real-time supervisory control of an experimental manufacturing cell
,
1996,
IEEE Trans. Robotics Autom..
[4]
James Lyle Peterson,et al.
Petri net theory and the modeling of systems
,
1981
.
[5]
Arie Shoshani,et al.
System Deadlocks
,
1971,
CSUR.
[6]
Tadao Murata,et al.
Petri nets: Properties, analysis and applications
,
1989,
Proc. IEEE.
[7]
Torbjörn Liljenvall.
Scheduling for production systems
,
1998
.
[8]
Martin Fabian.
On Object Oriented Nondeterministic Supervisory Control
,
1995
.