Active control of large amplitude nonlinear free vibrations and nonlinear supersonic panel flutter of beams and composite plates using piezoelectric self-sensing actuators.

摘要

This thesis employs a coupled structural-electrical finite element modal formulation for the control of nonlinear free vibrations, and supersonic panel flutter of beams and composite plates with and without thermal environment. Multiple modes of the nonlinear free vibration and supersonic panel flutter are considered in the closed loop simulations. Two different controllers are designed and investigated. The first one is the output feedback controller comprised of a Linear Quadratic Regulator (LQR) and an Extended Kalman Filter (EKF). EKF considers the nonlinear state space matrix and has a gain sequence evaluated on-line. Thus the LQR/EKF nonlinear controller has more accurate state estimation over Linear Quadratic Gaussian (LQG) controller for the nonlinear dynamics. The second controller is the output feedback adaptive LQR/EKF controller. This adaptive controller includes a modal frequency identification and state estimation algorithm. (Abstract shortened by UMI.)