Date of Award

3-1991

Document Type

Thesis

Degree Name

Master of Science in Astronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

Howard D. Gans, PhD

Abstract

There has been much interest during the past decade to develop and launch large space structures. The high cost of launching material into orbit will require that these structures be assembled in space using light weight elements which are vulnerable to dynamic excitations. Active control may be necessary to rapidly attenuate large amplitude vibrations. The active vibration control system is usually designed after the structure has been optimized. The integrated design of the control system and the structure may provide additional weight savings. This thesis presents a sensitivity analysis of the structure/ control optimization problem. The structure used is an aluminum rectangular beam with proof mass actuators mounted on the free end and a structural dynamics shaker attached at the midpoint. A finite element model of the structure is developed using MSC/NASTRAN. LQR theory is used as the control law with velocity feedback. Constant and variable values of Q and R for the performance index are used. The variable values of Q and R are selected to minimize total system energy. Optimization methods examined are; first, the minimization of the performance index J and structural weight; second, Onada's formulation, which minimizes control weight and structural weight.

AFIT Designator

AFIT-GA-ENY-91M-2

DTIC Accession Number

ADA238739

Comments

The author's Vita page is omitted.

Download

Share

COinS