Robust estimation of sound direction for robot interface

This paper proposes a robust method to estimate sound direction for mobile robot interface. In contrast to other methods, the proposed method estimates sound direction at intervals of short time to deal with deterioration by movement of sound source or robot. The two methods, discrete Kalman filter and time delay of arrival (TDOA) using generalized cross-correlation (GCC), are combined by quantifying reliability of TDOA. The combination prevents the deterioration by low power of signals, noise, and reverberation because discrete Kalman filter efficiently filters out such effects. The result of experiments, in which mobile robot estimates azimuth angle with three microphones, shows that the proposed method provides robustness on estimating sound direction even if the sound source or robot is moving during estimation procedure.