Position estimation of sound source on ground by multirotor helicopter with microphone array

Multirotor helicopters are expected to be utilized various tasks including rescue missions and surveillance. For those missions, sensors are equipped with helicopters in order to recognize the environment, and auditory information is one of such information that can be utilized to find the target sound source even if it is occluded by objects. One of the difficulty comes from the fact that the noise generated by rotating rotors distorts the target signal significantly, which leads inaccurate estimate of the target source direction. Besides, the estimate of the attitude and the position of the helicopter is inaccurate, which is another technical issue. This paper proposes a robust sound source position estimation taking such uncertainty into account, and experiment with real flight tests showed that the helicopter was able to estimate the target position within about 2m accuracy.