Practical and Numerical Investigation on a Minimal Design Navigation System of Bats

Abstract

In this study, to investigate how the behavioral strategy employed by bats contributed to acoustic navigation based on a minimal design sensing, we conducted vehicle experiments and numerical simulation based on a simple algorithm inspired by bats. Especially, a double-pulse scanning method was proposed as a bat-inspired navigation algorithm in which (1) the direction of pulse emission was alternately shifted between the direction of movement and the direction of the nearest obstacle, and (2) the direction of movement was calculated for every double-pulse emission based on integrated information from all echoes detected by double-pulse sensing. To quantify that method, a conventional scanning method was also developed. The conventional scanning method was that (1) the pulse direction was fixed in the direction of travel of the car body and (2) the moving direction was calculated for every pulse emission. As a result of 100 repeated drives with autonomous vehicle equipped with 1 transmitter and 2 receivers in a practical course, the success rate of an obstacle-avoidance drive on a test course improved from 13% for conventional method to 73% with the proposed method. Furthermore, the numerical simulation demonstrated that the proposed method operate the robust path planning by suppressing the localization ambiguity due to interference of multiple echoes. These practical experiments and numerical simulation suggest that bats employed the simple behavioral solution on the operation of acoustic sensing for various problems occurring in the real world.