Control of hierarchical systems with fuzzy system models

In this paper, we use fuzzy systems to model higher levels of hierarchical systems and design a controller for the hierarchical model. Specifically, we consider three-level hierarchical systems where the lowest level comprises the plant and convertional feedback controllers, the middle level performs supervisory operations to guarantee the stability of the whole system, and the top level is a planning level which provides control targets for the lower levels. The plant is modeled by differential equations, and the supervision and planning levels are modeled by fuzzy systems. A control strategy for the three levels of the model is developed which guarantees that: 1) the states of the system are bounded, and 2) the tracking error converges to zero exponentially