0
TECHNICAL BRIEFS

Analytic Wavelet-Based Ultrasonic Pulse Differentiation for Injection Mold Cavity Pressure Measurement

[+] Author and Article Information
Li Zhang

Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, MA 01003

Charles B. Theurer

Pervasive Decisioning Systems Lab, GE Global Research Center, Niskayuna, NY 12309

Robert X. Gao1

Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, MA 01003gao@ecs.umass.edu

David O. Kazmer

Department of Plastics Engineering, University of Massachusetts, Lowell, MA 01854

1

To whom correspondence should be addressed.

J. Manuf. Sci. Eng 128(1), 370-374 (Jul 20, 2005) (5 pages) doi:10.1115/1.2123048 History: Received June 15, 2004; Revised July 20, 2005

A new signal-processing technique based on analytic wavelet transform has been developed for detecting and differentiating temporally overlapped ultrasonic pulse trains that carry spatially distributed pressure information across an injection mold cavity. Compared to conventional wavelets that have a constant relative bandwidth at all the scales, the analytic wavelets investigated in this paper feature variable relative bandwidth, making it possible to simultaneously match the frequency characteristics of the ultrasonic pulse trains transmitted from the mold-embedded pressure sensors. As a result, more accurate detection and differentiation of the temporal and spectral information embedded within the ultrasonic pulse trains could be achieved. Theoretical framework for the analytic wavelet transform was established, and a multichannel ultrasonic pulse detector based on the complex Morlet wavelet was designed and experimentally investigated. The results have confirmed the effectiveness of the new signal-processing technique for on-line pressure sensing for injection molding process monitoring.

FIGURES IN THIS ARTICLE
<>
Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 4

Multichannel pulse detector based on the complex Morlet wavelet

Grahic Jump Location
Figure 5

Detection and differentiation of six timely and spectrally adjacent pulse trains

Grahic Jump Location
Figure 6

Detection and differentiation of two pulse trains that are timely overlapped and spectrally adjacent and two pulse trains that are timely adjacent but spectrally identical

Grahic Jump Location
Figure 7

Experimental detection of ultrasonic pulse trains having the same center frequency

Grahic Jump Location
Figure 8

Experimental detection and differentiation of temporally overlapped and spectrally adjacent ultrasonic pulse trains generated by three transmitters

Grahic Jump Location
Figure 3

Analysis windows for STFT, conventional CWT, and wavelet transforms with variable relative bandwidth

Grahic Jump Location
Figure 2

Limitation of a one-dimensional enveloping technique

Grahic Jump Location
Figure 1

Sensing principle and the sensor array arrangement in an injection mold

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In