Time-of-flight measurement techniques for airborne ultrasonic ranging.
Airborne ultrasonic ranging is used in a variety of different engineering applications for which other positional metrology techniques cannot be used, for example in closed-cell locations, when optical line of sight is limited, and when multipath effects preclude electromagnetic-based wireless systems. Although subject to fundamental physical limitations, e.g., because of the temperature dependence of acoustic velocity in air, these acoustic techniques often provide a cost-effective solution for applications in mobile robotics, structural inspection, and biomedical imaging. In this article, the different techniques and limitations of a range of airborne ultrasonic ranging approaches are reviewed, with an emphasis on the accuracy and repeatability of the measurements. Simple time-domain approaches are compared with their frequency-domain equivalents, and the use of hybrid models and biologically inspired approaches are discussed.
Centre for Ultrasonic Engineering, University of Strathclyde, Glasgow, UK. joseph.jackson@strath.ac.uk
Joseph C
JC
Jackson
Rahul
R
Summan
Gordon I
GI
Dobie
Simon M
SM
Whiteley
S G
SG
Pierce
Gordon
G
Hayward