Robust acoustic source localization of emergency signals from Micro Air Vehicles

Abstract

Abstract-In search and rescue missions, Micro Air Vehicles (MAV's) can assist rescuers to faster locate victims inside a large search area and to coordinate their efforts. Acoustic signals play an important role in outdoor rescue operations. Emergency whistles, as found on most aircraft life vests, are commonly carried by people engaging in outdoor activities, and are also used by rescue teams, as they allow to signal reliably over long distances and far beyond visibility. For a MAV involved in such missions, the ability to locate the source of a distress sound signal, such as an emergency whistle blown by a person in need of help, is therefore significantly important and would allow the localization of victims and rescuers during night time, through foliage and in adverse conditions such as dust, fog and smoke. In this paper we present a sound source localization system for a MAV to locate narrowband sound sources on the ground, such as the sound of a whistle or personal alarm siren. We propose a method based on a particle filter to combine information from the cross correlation between signals of four spatially separated microphones mounted on the MAV, the dynamics of the aerial platform, and the doppler shift in frequency of the sound due to the motion of the MAV. Furthermore, we evaluate our proposed method in a real world experiment where a flying micro air vehicle is used to locate and track the position of a narrowband sound source on the ground.

On-Board Relative Bearing Estimation for Teams of Drones Using Sound

“…A loud sound wave can be produced if the input signal frequencies are close to the resonance frequency of the piezo element. To generate a loud sound that is needed for achieving a long detection range, particularly suitable for outdoor operations, and to avoid the problem of ambiguous bearing measurements related with localization of narrowband sounds [26], a piezo transducer is used on the robots to generate band limited linear chirp signals.…”

“…Furthermore, since the engine of most flying platforms already produce sound in flight, this sound could be exploited for passively obtaining the relative position of team-mates and of other non-cooperative flying platforms. This could be further exploited to detect and locate many other interesting acoustic targets, such as the sound of a safety whistle in a search and rescue mission [26].…”

Noise correlation matrix estimation for improving sound source localization by multirotor UAV

“…We reduced the weight of the AR.Drone by removing unneeded components because it originally lacked the ability to carry the signal processing unit and microphone array. We used as the recording system the HRI-JP Audition for Robots with Kyoto University (HARK) 3 and the Robot Operating System (ROS) 4 . HARK is a collection of modules for robot audition that enabled us to publish a ROS topic containing a multichannel acoustic signal recorded using the signal processing unit.…”

“…Additionally, auditory sensing is useful for detecting people and animals because they emit vocal sounds to communicate with others. This means that auditory sensing is beneficial in search and rescue tasks and environmental monitoring and surveillance [4]- [7]. An example application is shown in Fig.…”

Real-time sound source localisation for target tracking applications using an asynchronous microphone array

“…Diverse scenarios include museum guidance [1], hospital assistance [7], pedestrian tracking [2] and search and rescue scenario [8]. Among these applications, target tracking based on sound is of increasing interest since the acoustic waves travel in all directions, can be detected at long distances from the sound source, and beyond the line of sight [9]. Moreover, the sound source can be detected in night time, cluttered environments or in fog, dust, smoke and dense forests, which makes it more reliable than visual cues.…”