Acoustic source localization and navigation robot

Abstract

There are many areas of using acoustic localization technique. This technique is not only to locate a person, who is talking, but also could find them when they are in need. This can also be implemented in wild life photography, to locate the animals. In this technique, three microphones have been employed in the form of equilateral triangular pattern,in which all these microphones detects the same sound.Using this information and trigonometric formula, the direction of sound has been calculated.The main objective of this project is calculate how precisely the position of sound source can be calculated using the technique mentioned above, while varying the distance and angle of the source.In order to explore the capabilities of TDOA and test the obtainable accuracy, a demonstrator was built. On a complete car chassis, three microphones were mounted and used to determine the direction towards the sound source. Thereafter, the robot rotated towards the sound source with an accelerator, keeping track of how much it had rotated. After this movement a comparison was made between the robot’s direction and the actual direction of the sound source. Finally an ultrasonic sensor was placed on the robot for obstacle detection whilst tracking the sound. The vehicle travelled straight forward until the ultrasonic sensor deemed that an object was too close. The results show that an increased distance yields a more accurate sound localization and that there are some angles in which the sound localization functioned better.