Hearing based relative localization for mobile robots in outdoor environments

We present a relative localization method based on sound source localization for mobile robots in outdoor environments. One robot estimates the relative position of nearby robots by receiving the sound signals they generate. In our work, a device including a buzzer and an array of four microphones is designed and installed on each mobile robot. We describe a technique for calculating the relative directions and distances of nearby sound sources based on the microphone array. Then we characterize the accuracy of the relative localization through some tests. Finally, the usefulness of the proposed method is demonstrated in a simple formation experiment with three small mobile robots in outdoor environments.