A new self-tuning fuzzy controller for vibration of a flexible structure subjected to multi-frequency excitations

Abstract

This work proposes a new self-tuning fuzzy controller for vibration control of a flexible structure subjected to both single-frequency and multi-frequency excitations. A piezoelectric stack actuator is used to generate control force to attenuate vibrations in the resonant and non-resonant frequency ranges. As a first step, modal frequencies and modal shapes of the flexible beam structure are obtained via the finite element method, and these are verified through comparison with the measured values. Second, in order to attenuate multi-frequency vibration of the beam, a new fuzzy controller with self-tuning factors is proposed. This controller is independent of the structure model and very adaptive to variable excitations. Then, vibration control performances of the self-tuning fuzzy controller are experimentally investigated under two different excitation conditions: single-frequency and multi-frequency excitations. It is shown that vibration control capability of the proposed controller outperforms conventional fuzzy controller under two different excitation conditions. In addition, it is demonstrated by experimentally implementing the proposed self-tuning fuzzy controller that high performances of multi-frequency vibration control are successfully achieved in which both amplitude and frequency of sinusoidal excitations are varied.