Fuzzy logic control for design and control of manufacturing systems

In this study, first recent applications of fuzzy logic in design and control of manufacturing systems are briefly reviewed. Fuzzy logic control is presented as a technique to implement real-time control algorithms that can be embedded in workstations in the framework of intelligent hierarchical control of manufacturing systems. Then two applications of fuzzy logic in design and control of manufacturing systems are presented. The first application is a fuzzy decomposition method for performance evaluation of manufacturing systems. A model of a workcell with rework is used to describe the fuzzy decomposition method. Fuzzy logic is used as a gain scheduler in the search algorithm of the decomposition method. It is observed that fuzzy logic improves the convergence rate of the decomposition method substantially. The second application is a fuzzy flow controller that adjusts the production rate of a failure prone manufacturing system in order to minimize total inventory carrying and backorder costs while satisfying uncertain demand. As an extension of this model, adaptive fuzzy flow rate controller is discussed.