Adaptive Fuzzy Logic Controller Synthesis Via Sliding Mode Approach

The VSC (Variable Structure Control) with SM (Sliding Mode) dynamics is a well known theory used to dene a robust controller for a plant in the presence of model uncertainty and disturbance input. In this paper a method for de ning a Sugeno type of Fuzzy Logic Controller (FLC) parameters, derived from VSC design considerations, is proposed. The idea is to generate a set of VSC controllers, related to di erent bounds on model uncertainties and disturbances, and use the interpolatory capability of the fuzzy paradigm to merge the VSC behavior in only one structure. Moreover a heuristic algorithm for the on-line FC parameter tuning is given. The global stability of the proposed controller is also demonstrated. Simulations show that the FC obtained performs better than the basic VSC counterpart in the presence of unmodeled dynamics and disturbances.