Application of multivariable methods for control and estimation of satellite flexible parameters
by
Luiz Carlos Gadelha DeSouza
National Institute for Space Research - INPE - Brasil

This work applies multivariable methods to control and estimate flexible parameter at the same time that the flexibility influences in the attitude control system performance is evaluated. The satellite model consists of one flexible appendice connected to a rigid central hub. The control law is designed applying a sequence of three multivariable methods, the Linear Quadratic Regulator (LQR), the Linear Quadratic Gaussian (LQG) and the Linear Quadratic Gaussian with Loop Transfer Recovery (LQG/LTR). The control law based on LQR method has good performance when all states are considered in feedback, but this is not possible in the practice, once there are no sensors in the flexible appendices. Therefore, it is used the LQG technique to estimate the flexible displacements from rigid body measures (angle and angular velocity). However, when the LQG filter is introduced, the performance of the control law is degraded. To recovery the LQR control law good performance degraded by the filter, it is employed the LQG/LTR technique. The novelty of that study is the utilization of the LQG/LTR method to estimates the satellite flexible parameters.

Date received: March 12, 2008

Copyright © 2008 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cawz-20.