Accession Number : ADA195886

Title :   Laser Sensing for Identification and Control of Distributed Parameter Systems.

Descriptive Note : Final rept. 1 Dec 86-30 Nov 87,

Corporate Author : STATE UNIV OF NEW YORK AT ALBANY RESEARCH FOUNDATION

Personal Author(s) : Inman, Daniel J

PDF Url : ADA195886

Report Date : 01 May 1988

Pagination or Media Count : 17

Abstract : This instrumentation award funded the purchase of a laser vibrometer system, mass computer data storage and data acquisition equipment. This equipment used in conjunction with existing vibration testing and control facilities provides a sophisticated low frequency velocity measurement system for use in identifying the coefficients in partial differential equation models of distributed mass structures. In addition, the vibrometer system provides straightforward and direct velocity feedback for such systems. These flexible structures characteristically have very low natural frequencies which cannot be detected by accelerometers. This system has and is being used to perform tests on models and sub-assemblies of large space structures for the purpose of evaluating existing identification and control strategies as well as to stimulate new research in the area of control, observers (estimators) and identification. Several intense experiments using the laser vibrometer were performed to measure the response of a quasi isotropic cantilevered beam with a removable tip mass excited by an impulse at various locations. This data was collected, stored, and sent to AFOSR researchers at Brown University transmitted using BITNET. The data was analyzed using a spline based estimation procedure, starting with a partial differential equation model of the structure. A clear advantage over modal methods based on a finite dimensional model of the same system was observed. (JHD)

Descriptors :   *VIBRATION, *LASER APPLICATIONS, *REMOTE DETECTORS, ACCELEROMETERS, CANTILEVER BEAMS, COEFFICIENTS, COMPUTERS, CONTROL, CONTROL CENTERS, DATA ACQUISITION, DATA PROCESSING EQUIPMENT, DATA STORAGE SYSTEMS, DETECTION, DISTRIBUTION, ESTIMATES, FEEDBACK, FLEXIBLE STRUCTURES, INTENSITY, ISOTROPISM, LASERS, MASS, MASS STORAGE, MODELS, PARAMETERS, PARTIAL DIFFERENTIAL EQUATIONS, RESONANT FREQUENCY, SIZES(DIMENSIONS), SPACECRAFT, SPLINES, STRATEGY, STRUCTURES, TEST AND EVALUATION, VELOCITY, VERY LOW FREQUENCY

Subject Categories : Test Facilities, Equipment and Methods
      Lasers and Masers
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE