Research On Environment Sound Event Localization System And Algorithm Based On WASN

The technology of sound source localization has been widely used in various fields.Common technologies of sound source localization usually use the maximum-likelihood method,the least-squares,the Taylor series expansion and other methods for position estimation.These methods have shortcomings such as high computational complexity,requiring an initial guess position,and slow speed of search.In order to solve these shortcomings,this paper proposes a localization algorithm of sound source using trichotomy method for multiple circle linkage's search.The algorithm first calculates the initial value of the search radius based on the positional relationship of the microphone in the localization system of sound source,and then converts the non-linear problem into a linear problem according to the geometric relationship constructed by measured values of TDOA,which reduces the computational complexity.What's more,the trichotomy method was introduced to speed up the search.Traditional localization systems of sound source usually use microphone arrays to achieve localization.Such systems have shortcomings such as small coverage,relying on the characteristics of the microphone arrays and low positioning accuracy.With the rapid development of wireless acoustic sensor network technology,the localization technology based on wireless acoustic sensor networks has become a focus in the research field of source localization due to its large coverage,strong environmental adaptability and high positioning accuracy.In addition,people are more and more concerned about the safety of people's livelihood.The localization and recognition of environmental sound events is an effective measure to improve people's quality of life.Based on the above two aspects,this paper designs and construct a localization system of environmental sound events based on WASN,which uses a variety of technologies such as sound signal processing,time synchronization,wireless communication to achieve localization of environmental sound events.The research contents are summarized as follows:(1)The research on the current status and developing trends of sound source localization technology in both applications and algorithms,and the research on common key technologies for sound source localization,including the localization technology of sound source based on microphone arrays and WASNs,the delay estimation algorithms and the comparison of various algorithms.(2)Aiming at the shortcomings of common localization algorithms,research the localization algorithm of sound source based on searching and the trichotomy method for searching.A localization algorithm of sound source for multi circle linkage's search using the trichotomy method was proposed.The theoretical and experimental results show that compared with traditional search algorithms,the localization algorithm proposed in this paper has superiority in computational complexity,search speed,and localization accuracy.(3)Aiming at the limitation of weather and area in the outdoor environment,an acquisition and localization system of environmental sound event based on wireless acoustic sensor network was proposed.The hardware composition and key technologies of the localization system were introduced in detail,and a suitable method of packing for sensor nodes in the outdoor environment was proposed.(4)The proposed localization algorithm was applied to the proposed localization system,which means the theoretical research was combined with practical applications.Several experiments were implemented to verify the integral performance,including reliability of transmission,practicability of system and accuracy of localization.