000013678 001__ 13678
000013678 005__ 20161114170127.0
000013678 04107 $$aeng
000013678 046__ $$k2011-05-25
000013678 100__ $$aFeng, Z.
000013678 24500 $$aThe Effect of Non-Synchronous Sensing in Wireless Sensors on Structural Modal Identification

000013678 24630 $$n3.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013678 260__ $$bNational Technical University of Athens, 2011
000013678 506__ $$arestricted
000013678 520__ $$2eng$$aStructural health monitoring (SHM) employing wireless sensor networks (WSN) is becoming increasingly popular in recent years. Accurate synchronized sensing amongst wireless sensors is a key issue enabling the implementation of such smart systems for SHM based on vibration measurements. However, perfect synchronized sensing is unachievable in WSN. The effect of non-synchronous sensing when using wireless sensors on structural modal identification is addressed and a methodology for correcting such errors is proposed herein. This paper first discusses the potential sources causing non-synchronous sensing and estimates their extents based on data samples collected from Imote2 sensors, and then investigates the impact of synchronization errors in the measured output response on modal identification using numerical simulations. The simulation results show that even small synchronization errors in the output response can distort the identified mode shapes. A new methodology is proposed herein for eliminating such errors. This methodology estimates the power spectral densities (PSDs) of output responses using non-synchronous samples directly based on a modified FFT. As long as the corrected PSDs are obtained, the correlation functions can also be easily obtained by IFFT. Then these corrected PSDs or correlation functions can be fed into various output-only modal identification algorithms. The proposed methodology is validated using numerical simulations. It is found that the simulation results closely match the identified parameters based on synchronous data.

000013678 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013678 653__ $$anon-synchronous sensing, wireless sensor network, modal identification.

000013678 7112_ $$aCOMPDYN 2011 - 3rd International Thematic Conference$$cIsland of Corfu (GR)$$d2011-05-25 / 2011-05-28$$gCOMPDYN2011
000013678 720__ $$aFeng, Z.$$iKatafygiotis, L.
000013678 8560_ $$ffischerc@itam.cas.cz
000013678 8564_ $$s183027$$uhttps://invenio.itam.cas.cz/record/13678/files/492.pdf$$yOriginal version of the author's contribution as presented on CD, section: MS 21 Reliability of Structural and Mechanical Systems for Uncertain Operating Conditions.
000013678 962__ $$r13401
000013678 980__ $$aPAPER