This paper describes the study of wavelet-based methods employed to de-noise a force transducer signal. This signal was extracted during the extensional deformation of a non-Newtonian polymer fluid. The non-Newtonian polymeric fluid was extensionally deformed with an exponentially increasing velocity profile. This velocity profile corresponded to a specific strain rate. Since the motion was stopped quickly (deceleration time was below 50ms for a complete stop), a serious problem of ringing occurred for approximately one second after the motion has ceased. The ringing manifested itself as a damped harmonic oscillation, which overrides the relaxation characteristics of the molecular structure within the boger fluid. In this paper, our goal was to suppress the damped harmonic oscillatory signal while preserving the relaxation characteristics (decaying exponential signal) of the force data. Several wavelet-based techniques provided acceptable noise suppression while preserving the signal of interest.

Date Published: 22 February 2002
PDF: 9 pages
Proc. SPIE 4576, Advanced Environmental Sensing Technology II, (22 February 2002); doi: 10.1117/12.456945

Published in SPIE Proceedings Vol. 4576:
Advanced Environmental Sensing Technology II
Tuan Vo-Dinh; Stephanus Buettgenbach, Editor(s)