Binaural room distribution pattern for nonstationary sound source localization
|關鍵字:||聲源定位;雙耳聽覺;非靜態聲源;sound source localization;doa;nonstationary sound source;HRTF;IPD;ILD|
Nature sound sources are usually nonstationary and the real environment contains complex reverberations. Therefore, nonstationary sound source localization in a reverberant environment is an important research topic. This dissertation discusses the relationships between the nonstationarity of sound sources and the distribution patterns of interaural phase differences (IPDs) and interaural level differences (ILDs) based on short-term frequency analysis. The level fluctuation of nonstationary sound sources is modeled by the exponent of polynomials from the concept of moving pole model. According to this model, the sufficient condition for utilizing the distribution patterns of IPDs and ILDs to localize a nonstationary sound source is suggested and the phenomena of multiple peaks in the distribution pattern can be explained. Simulation is performed to verify the proposed analysis. Furthermore, a Gaussian-mixture binaural room distribution model (GMBRDM) is proposed to model distribution patterns of IPDs and ILDs for nonstationary sound source localization. The effectiveness and performance of the proposed GMBRDM are demonstrated by experimental results. The proposed nonstationary sound source localization algorithm is adopted for robot localization application. A novel and robust robot location and orientation detection method based on sound field features is proposed. Unlike conventional methods, the proposed method does not explicitly utilize the information of direct sound propagation path from sound source to microphones, nor attempt to suppress the reverberation and noise signals. Instead, the proposed method utilizes the sound field features obtained when the robot is at different location and orientation in an indoor environment. The experimental results show that the proposed method using only two microphones can detect robot’s location and orientation under both line-of-sight and non-line-of-sight cases and can be applied to both near-field and far-field conditions. Since this method can provide global location and orientation detection, it is suitable to fuse with other localization methods to provide initial conditions for reduction of the search effort, or to provide the compensation for localizing certain locations that cannot be detected using other localization methods.
|Appears in Collections:||Thesis|
Files in This Item: