Accession Number : ADA289251

Title :   A State-Space Model of a Large, Lightly Damped Space Structure Using the Eigensystem Realization Algorithm.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Woods, Robert D.

PDF Url : ADA289251

Report Date : DEC 1994

Pagination or Media Count : 166

Abstract : Large, lightweight space structures of the future will require state-of-the-art vibration suppression systems. To design such a system, it is necessary to have a mathematical model that adequately describes the motion of the system. Coulomb damping compensation was utilized to remove a known nonlinearity from the frequency response functions obtained from the Passive and Active Control of Space Structures (PACOSS) Dynamic Test Article (DTA). Via the Eigensystem Realization algorithm (ERA), the frequency response functions were then used to generate a mathematical representation of the structure's dynamics. Two models were obtained. The first model, without friction compensation, acted as a baseline. The second was obtained using friction compensation. Comparing the models, it was determined that active friction compensation was worthwhile and resulted in a more accurate mathematical description of the system.

Descriptors :   *VIBRATION, COMPUTER PROGRAMS, MATHEMATICAL MODELS, ALGORITHMS, CONTROL SYSTEMS, SPACECRAFT, DISPLACEMENT, DAMPING, THESES, SOLAR CELLS, LIGHTWEIGHT, ACTUATORS, TRUSSES, SUSPENSION DEVICES, FRICTION, SUPPRESSION, FLEXIBLE STRUCTURES, TRIPODS.

Subject Categories : Unmanned Spacecraft
      Manned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE