The Development of Textile Based Acoustic Sensing Arrays for Sound Source Acquisition Acknowledgements

Luthy, Kyle Anthony. The Development of Textile Based Acoustic Sensing Arrays for Sound Source Acquisition. (Under the direction of Dr. Edward Grant.) This research project dealt primarily with the production of an electronic textiles (etextiles) demonstrator. The goal of electronic textiles is to integrate textiles technology and electronics to create large area conformal surfaces with embedded electronics. Here, the etextiles demonstrator serves as an acoustic array for sound source localization and tracking. To create portable acoustic arrays on a flexible textile substrate, an understanding of textile designs and textile processes was obtained. This research resulted in the fabrication of woven substrates with conducting lines and embedded microphone windscreens. Similarly, an understanding of the design and manufacture of flexible substrates for electronics had to be gained in order to produce miniature electronic circuits that will flex when embedded in a textile substrate. The acoustic array technology developed includes microphone arrays with their associated software for data capture and analysis, a multiplexer circuit on a flexible Kapton substrate, and a UC-Berkeley mote-based technology for use with a custom miniature microphone amplification system. Ultimately, these arrays are used to demonstrate sound localization by triangulation as well as via the spatial filtering technique of beamforming. Experiments were performed to compare different array sizes and geometries in both simulation and real world practice for a variety of target frequencies. Mote performance in the role of beamforming is compared to simulation as well as a commercially available system. Although not as ideal as in simulation, the results achieved are comparable to those of the professional system tested against. The Development of Textile Based Acoustic Sensing Arrays for Sound Source Acquisition by Kyle Anthony Luthy A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the Degree of Master of Science COMPUTER ENGINEERING