Modelagem e controle ativo de vibrações de painéis flexíveis de satélites artificiais empregando transdutores piezelétricos

Abstract

In this dissertation, modeling procedures were developed to characterize de dynamic behavior of artificial satellites containing flexible panels, aiming the active control of these panels through the combined use of a reaction wheel and piezoelectric actuators bonded their surfaces. First, some basic concepts regarding the technology of artificial satellites, smart material systems and vibration active control are presented, as those aspects are addressed in the study. Then, three variants of analytical models of hybrid rigid-flexible satellites are developed. In the first, the panels are modeled as a one-degree-of-freedom spring-mass system; in the second, the Assumed-Modes Method (AMM) is used for space discretization of the panels which are modeled as continuous beams; in the third, the AMMbased model is adapted to include piezoelectric transducers, which can be set either as sensors or as actuators. For each model, the differential equations of motion are derived and adapted for the design of active control algorithms. The more complete model is implemented in MATLAB® programming environment and various numerical simulations are made aiming at validating the modeling procedures and characterizing the static and dynamic behavior of a particular configuration of satellite having flexible panels and piezoelectric sensor and actuators. The results of some of those simulations are compared to those obtained by using the commercial finite element package ANSYS®. The behavior of the satellite subjected to feedback control is also simulated demonstrating the possibility of achieving a significant increase of damping of the panels vibrations by means of piezoelectric actuators. Conclusions of the research study and perspectives are presented in the last part of the dissertation.