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Tracking of Mechanical System Parameters by Phase‐Locked Loops
Author(s) -
Kern Dominik,
Seemann Wolfgang
Publication year - 2010
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201010299
Subject(s) - cantilever , excitation , phase locked loop , beam (structure) , stiffness , control theory (sociology) , physics , phase (matter) , frequency response , boundary value problem , tracking (education) , loop (graph theory) , acoustics , mathematics , engineering , optics , structural engineering , computer science , electrical engineering , combinatorics , control (management) , quantum mechanics , artificial intelligence , psychology , pedagogy , thermodynamics
The eigenfrequencies of a mechanical system depend on several parameters such as mass‐, damping‐, stiffness‐distribution and boundary conditions. Variation of these parameters results in variation of the Frequency Response Function (FRF). An eigenfrequency can be tracked by resonant excitation with a Phase‐Locked Loop (PLL) in order to monitor a certain parameter. As an example, a cantilever beam with a time‐variant mass at its end is analyzed. In this contribution, the FRF of this beam will be derived, which is the prerequisite for the following resonant excitation. The modified PLL‐design for the resonant excitation of higher modes will be explained and finally tested at the state‐space model of the beam. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)