Simultaneous Structural and Control Optimization of Large Space Structures

Abstract

This paper focuses on the simultaneous structural/control optimization of a large space structure (LSS) subject to the gravity-gradient. The finite element method is used in conjunction with the Lagrangian formulation to derive the mathematical model for the structure. It is assumed to be a long unidimensional orbiting beam. In deriving the model vibrational and rotational planar motion and circular orbit are assumed. The NEWSUMT-A and the ORACLS computer programs are integrated to perform the simultaneous structural/control optimization problem. MATLAB software package is used for the transient phase simulation of the optimal integrated system. The simultaneous structural/control optimization is performed by the combined and the sequential integrated approaches (approach definitions are presented in this paper) with constraints on the structural weight, first natural frequency of vibration (bending), and on the damping (control). The results about the vibrational-rotational control for the optimal integrated system are presented through graphics. Comparison between those approaches shows some gains for the performance and control efforts for the sequential integrated approach.