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Tyan, C.-Y., P.P. Wang, and D. Bahler,
The Design of an Adaptive Multiple-Agent Fuzzy Constraint-Based
Controller (MAFCC) for a Complex Hydraulic System,
Intl. Journal of Uncertainty, Fuzziness, and Knowledge-Based
Systems 8(6), 1996, 537-551.
In this paper, a complete design framework for an adaptive multiple agent fuzzy
constraint-based controller based on fuzzy penumbra constraint processing
in each fuzzy constraint subnetwork collaborated by a connected constraint
network and its corresponding semantic modeling in a first-order predicate
calculus (FOPC) language applied in a complex hydraulic system are presented.
The concept of ``multiple agent'' and ``fuzzy constraint subnetwork''
in a complex control system is introduced and some basic
definitions of penumbra fuzzy constraint processing in a constraint subnetwork
and the collaboration with an overall connected constraint network and its
semantic modeling are addressed. The partitioning of a complex problem into
subproblems is performed by employing a ``multiple agent'' concept. In this
concept, the decomposition of a complex system is based on assigning each
agent specific objects subjected to the constraints to act on. This idea
contribute significantly to the domain of problem with great complexity due
to the fact of collaboration of each agent and the assertion and deletion of
its constraints that occur in the world model. As the result, a human
agent interacts with system agents and allows the constraints to be
added or deleted on-line according to the constraints imposed from outside
environment. An optimal system performance is accomplished by restricting all
the penumbra constraints to be satisfied in each constraint subnetwork
simultaneously which are interconnected as a results of constraints
that exist between each of them. Following the principle of constraint
satisfaction and fuzzy local propagation reasoning, each individual
system agent is now constrained to behave in a certain fashion
as dictated by the overall constraint network. In addition, the constraint
network in MAFCC system provides an update strategy which makes a real time
adaptive hydraulic control for all 20 cities possible.
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