| To improve the fuel consumption of a satellite, maintain the position and orientation and eliminate the unwanted thruster vibration, intelligent composite structure technology was proposed in the ADPICAS (Adaptive Damping and Positioning using Intelligent Composite Active Structures) project funded by the ONR (Office of Naval Research) in collaboration with the NRL (Naval Research Laboratory) in 2000. This dissertation introduces the author's research achievements in developing smart composite panels for the ADPICAS project, including modeling, actuator optimization, and vibration control.;The method of separation of variables is presented to derive the analytical shape functions for complex composite structures with asymmetric constraints, i.e., the 2-D Adaptive Composite Circular Plate (ACCP) in cylindrical coordinates and the 3-D Adaptive Composite Satellite Dish (ACSD) in spherical coordinates. Following these solutions, two modeling approaches are developed to obtain the models of adaptive composite panels including an adaptive composite beam, the ACCP, and the ACSD. One model approach is to employ the Lagrange-Rayleigh-Ritz method based on the developed analytical shape functions. Meanwhile, the transfer function estimation technique, combining the finite element analyses, is applied to obtain the numerical model of the composite panels.;Aiming at improving the actuation efficiency, a Genetic Algorithm is presented to optimize the piezoelectric actuator placement on the composite panels. Taking the inertia and stiffness characteristics of the piezoelectric actuators into account, this algorithm defines the performance index as a weighted summation of control error and control energy consumption, and obtained the optimal solution that minimizes the performance index.;Furthermore, an adaptive disturbance observer/feed-forward (ADOB/FF) controller is proposed to achieve simultaneous precision positioning and vibration suppression of the adaptive composite panels. Numerical simulations and experiments are conducted. The optimal piezoelectric actuator configuration saves the control energy and reduces vibration of the composite panels substantially. The simulations and experiments show that the ADOB/FF provides a robust performance against the system parameter perturbations and environmental disturbances. |
