Acoustic Vector Sensing

Undergraduate Research by Ian Beil and Evan Nixon

Abstract

This site documents the undergraduate research done by Evan Nixon (BSSSE, 2012) and Ian Beil (BSEE, 2011) during the Fall of 2009. The work focused on a linear array of acoustic vector sensors (AVS) – devices which have a pressure sensor like a microphone, but also include particle velocity sensors in three orthogonal directions. A single AVS can be used to detect the angle of arrival of a sound source, while an array can estimate the location of a source in three dimensions.

 

In order to determine the angle of arrival of a sound source, Capon spectrum beamforming, a spatial filtering process, was used to determine the direction of highest energy density. Work done by previous students in the ESE department involved creating a MATLAB program which used the beamforming process on the data from a single AVS. Our work focused on creating a user friendly interface in LabView, which implements the previously written MATLAB code. Using the angle of arrival estimates from several sensors, as well as the location of each AVS, the LabView Virtual Instrument calculates the two-dimensional position of a sound source.

Top: Signal Conditioners and Data Acquisition box

 

Bottom: Close-up of probe tip (from microflown.com)