An adaptive control scheme based on fuzzy logic and its application to smart structures

This paper presents an adaptive control scheme based on a fuzzy-logic algorithm and its application in vibration suppression of smart structures. Here, a fuzzy-based adaptive controller is considered due to its simplicity and the fact that it does not require expression of the controller in terms of the system parameters, as is necessary in the case of self-tuning regulators. The objective is to attain an adaptive controller that retains the performance of the closed-loop system under large parameter perturbations. This controller is based on a functional fuzzy model where the consequents are crisp functions of the states and inputs and possibly their past values; these functions represent controllers designed for different operating regimes. The premise is constituted by the fuzzy subsets corresponding to the process parameters estimated in real time. The effectiveness of this new scheme is verified on a clamp-free beam instrumented with piezoceramic sensors and actuators.