A constraint-based fuzzy logic controller

This paper presents a constraint-based approach to fuzzy logic control based on a theory of fuzzy constraint processing. In modeling, constraints serve not only as description of the system to be modeled, but also as commands to the system telling it that certain conditions must be satisfied. As a result, constraints are suitable to the task of modeling the controller in a dynamic control system so that the output is governed to a desired state as specified by a network of constraints. In this paper, some basic definitions of fuzzy constraint networks and the concept of fuzzy constraint processing in problem solving are introduced. Then, a constraint-based fuzzy logic controller (CFLC) and its design framework are proposed. Finally, to show the utility of this approach, simulation results for a DC motor-positional control system, a cart-and-pole problem, and a track backer-upper control system are also presented in this paper.