3D object localisation with a binaural sonarhead, inspirations from biology

We present a bionic sonarhead consisting of one transmitter and two receivers placed on a headlike, 6 DOF, platform. Both the layout of this sonarhead and the signal processing performed on the received echoes are inspired by biological in-air echolocators, i.e. bats. We then show how interaural amplitude differences (IAD), measured at different frequencies and in different ear configurations, allow the 3D position of an object to be estimated. To combine the measured IADs we propose a classic Bayesian combination rule. Using experimental data gathered with the real sonarhead we show that the accuracy of the system is comparable to that of bats, i.e. elevation and azimuth errors of ≃2°