Audio servo for robotic systems with pinnae

Sound localization is one of important abilities for robots which utilize auditory information. Binaural information such as interaural time difference (ITD) or interaural intensity difference(IID) is effective for horizontal sound localization. In order to extend this ability to vertical sound localization, spectral cues were utilized in this paper instead of increasing number of microphones. Spectral cues were the information about the vertical position of the sound source on frequency domain. Since spectral cues strongly depended on the shape of pinnae, artificial pinnae for auditory robots were designed based on diffraction-reflection model. A method to detect spectral cues was also developed. By utilizing them, a controller which made the robot orient to the sound source was proposed. Results of an experiment showed the validity of the proposed method.