Research On Sound Source Orientation For Mobile Robot

There are great many difficulties to search survivors in the disaster site. With the development of computer technology, robotics technology has been widely used. How to help robots search and rescue disaster victims is not only an important research but also a significance issue. This paper describes how to get the sound source orientation while searching disaster victims. The main process is getting the sound information when survivors seek help, then determining the direction of sound to help the robots to find the survivors.The current technologies of sound source orientation are mostly worked out by a microphone array. The paper mainly study the topic of sound source orientation based on time delay estimation. Firstly, the author has taken a lot of experiments to prove the theorem of sound source orientation based on directional microphone, and proposes a way to correct the difference of channels based on divided frequency. Secondly, it takes a study of two kinds of spatial orientation algorithm:four-cross array and three-rectangular array, and the fusion. Thirdly, the method of time delay estimation based on the cross-correlation algorithm is described in the paper. Several basic pretreatment methods are discussed in view of the importance of pretreatment in signal processing. What's more, the impact caused by filtering and spectral subtraction on Cross-correlation algorithm is focused on, and is verified by several experiments. The paper combines the Cross-correlation algorithm with the filtering and spectral subtraction which is successfully to estimate time delay in the noise environment. Considering that there are a large number of errors in the results of the cross-correlation algorithm, it summarizes two algorithms to choose the right results from the results. Discuss three interpolation algorithms which can improve the precision of time delay estimation. Finally the author designs and implements a six-channel audio acquisition system and the program of audio acquisition system. Pretreatment the sound and estimate the time delay base on the cross-correlation algorithm, the author compiles two sets of sound source orientation programs based on the differ rent choose algorithm of time delay, and verifies the results.