Impact Localization Using Nonequidistant T-Shaped Sensor Clusters

In this article, a nonequidistant T-shaped sensor cluster used for localizing the impact on structures is presented. The normal T-shaped sensor cluster configuration, in which all the sensors are equidistantly set, can effectively remove blind areas because it is a combination of two impact-localization techniques: equidistant linear sensor array beamforming and an L-shaped sensor cluster method. The normal T-shaped sensor cluster can reduce the number of sensors while guaranteeing acceptable accuracy. However, equidistant linear sensor array beamforming suffers from the “spatial aliasing” effect, which results in a localization accuracy that is not sufficiently high. Thus, further optimizing the normal T-shaped sensor cluster to increase its accuracy is necessary. As confirmed in various reports, the nonequidistant linear sensor array can reduce the effects of “spatial aliasing,” which is a typically encountered phenomenon in the equidistant linear sensor array. In contrast to the normal T-shaped sensor cluster, the proposed nonequidistant T-shaped sensor cluster uses the nonequidistant linear sensor array beamforming method for impact localization in the regions near vertical directions. Thus, the impact localization accuracy is improved with the same number of sensors.