Talker Tracking Display On Autonomous Mobile Robot With A Moving Microphone Array

Abstract

A microphone array is the most effective technique for hands-free speech communication with a robot. However, it is known that the estimation accuracy of the sound source direction degrades under reverberant conditions. The estimation of the source direction is difficult under highly reverberant conditions even if the CSP (Cross-power Spectrum Phase analysis)-based method, which is one of the conventional methods for the estimation of source directions, is used. Therefore, it is necessary to use a method for source-direction estimation which is robust against reverberation when the microphone array is carried on an autonomous mobile robot.In this paper, we propose a new reverberation-robust method for the estimation of sound-source directions based on the synchronous addition of CSP coefficients obtained by a circular microphone array. Also, we propose a sound-source localization method that improves the localization accuracy by using the moving microphone array on an autonomous mobile robot. To evaluate the proposed method, the source-localization accuracy of the moving microphone array was quantified by computer simulation. We also carried out an experiment in which a mobile robot approached a talker by using only information on the source localization.The results show that the proposed method can estimate the sound-source location accurately and that the robot can approach the talker even under the condition that the reverberation time is 0.85 sec.