Indoor self-localization using multipath arrival time measured by a single acoustic ranging sensor

Abstract

The objective of this study is to achieve vehicle self-localization using a single acoustic ranging sensor in a multipath environment. For this purpose, we proposed a measurement method of multiple time-of-flight (ToF) using an acoustic ranging sensor and a self-localization method using the ToFs. The proposed method predicts the ToFs based on the wall position and the predicted self-location and corrects the self-location by comparing it with the actual ToFs. Sound waves radiated indoors are reflected multiple times by every wall, ceiling, and floor. Therefore, the observed signal contains multiple reflected waves. Since the conventional method only considers a single reflection, self-localization becomes challenging in a multiple reflection environment. We showed that the estimation accuracy can be improved by utilizing the multiple reflections of sound waves in three-dimensional space and modeling them. The experiments confirm that the average location error of the proposed method is 0.084 m.