Accession Number : ADP003397

Title :   A Decentralized Active Control System for a Large Flexible Structure in Space,

Corporate Author : ROME UNIV (ITALY) SCUOLA DI INGEGNERIA AEROSPAZIALE

Personal Author(s) : Danesi,A.

Report Date : JAN 1984

Pagination or Media Count : 15

Abstract : A new strategy in controlling the modal shapes of large structure in space is presented in this study. An active low authority modal control system, consisting of a discrete number of servo system units (M.C.U.) distributed along flexible masts supporting RF radiators, is provided to measure and control the local structural deformations in order to obtain a modal shapes resulting in acceptable pointing error for the RF radiators. Each servo unit is conceived as a model following control system implementing a strategy based on FFT(Fast Fourier Transforms) pairs computations. The control efforts applied by the M.C.U.s to the mast control points are made proportional to the spectral error function generated by a real time F.F.T dedicated microprocessor as the difference between the measured and desidered modal spectra relative to the antenna angular deflections in respect to a fixed set point. The decentralized control system organized by a central controller residing in the master M.C.U., will force the antenna to match the model dynamical behaviour which is expected to improve the antenna pointing accuracy within the L.S.S. design requirements. (Author)

Descriptors :   *Attitude control systems, *Satellite attitude, *Space systems, Spacecraft components, Space technology, Decentralization, Flexible structures, Mathematical models, Fast fourier transforms, Computer aided design, Algorithms

Distribution Statement : APPROVED FOR PUBLIC RELEASE