Sound Source Localization Sensor of Robot for TDOA Method

TDOA (Time Difference of Arrival) is an important passive location method which is widely used in modern localization and navigation system. This design use three microphones to collect the sound signal sent by robot, and process the signal with the filtering circuit which designed to produce an accurate rising edge for microcontroller to capture and calculate the time difference of sound arriving at three microphones. Consequently, we can get three semi-hyperbolic equations at most, combining with the known spatial location of the microphones, the location of the robot can be determined. Even if the noise and reverberation are serious, the sound also can be well captured and the differences are accurate with timing error less than 10^-5 s. Moreover, this design makes less than 1.5 centimeter to locate the position of sound source for each pulse quickly and effectively in the experimental environment.