Fuzzy linguistic modeling and control of manufacturing systems

Manufacturing processes are characterized by both discrete and continuous variable dynamics. The design of innovative and effective control strategies for these processes requires the development of new modeling techniques that not only capture the hybrid continuous/discrete dynamic nature of the process, but also address the performance objectives in a systematic way. It is also desirable that the modeling techniques address the controller design issue from a system-theoretic perspective. This paper introduces a new hierarchical approach for modeling of manufacturing systems in which the manufacturing plant is explicitly differentiated from the controller. A key feature of the proposed approach is the use of system-theoretic control concepts that capitalize upon tools from the area of fuzzy logic. An equivalence of this modeling approach with fuzzy Petri nets is described. An example is given that illustrates the design techniques.