Active Vibration Control Of Flexible Plate Structure Driven By Piezoelectric Actuators

Flexible structures applied in the aviation and aerospace equipment are usually characterized by their low rigidity, large size and high flexibility. Vibrations produced by any disturbance are difficult to attenuate. The development of smart structures and active control of structure response provides some new solutions for those problems. In this thesis, a hybrid feedforward-feedback control scheme was designed, and implemented in a plate with piezoelectric actuators. Using 4-node rectangular element model, the coupled flexible plate/piezoelectric elements dynamic equation was established based on Hamilton principle. By adopting an energy-based optimal positioning strategy and particle swarm optimization algorithm, the installation locations of piezoelectric actuators/sensors were optimized. Stain analysis on low order modes of the flexible plate was accomplished in order to discuss the effect of the optimization on vibration control and observation. The hybrid control scheme was established by combining a Linear Quadratic Gaussian(LQG) feedback controller and an adaptive feedforward controller. Simulations in steady and transient excitation conditions were carried out by Simulink. Comparing the vibration control effects by utilizing feedforward, feedback and hybrid controllers, hybrid control scheme proves to outperform the others. The functions of feedforward and feedback controllers in vibration control were also analyzed.