Real-time tracking of a flying object by using 3D acoustic intensimetry

Abstract

A 3D sound intensity probe configured in a tetrahedron is used for the localization of a flying drone in real-time. Two important bias errors are compensated in the measurement and calculation of the sound intensity vectors along with the conventional bias errors of the p-p instrumentation method: spectral bias and spatial bias errors.Adrone with 4 propellers is tested in an anechoic chamber and a reverberant room. The reference position of the flying drone is measured by applying an object tracking algorithm and depth sensors. The spacing between two adjacent microphones in the probe is 30 mm. The effective frequency band of the intensity measurement includes the blade passing frequency and its major harmonics related to the speed and number of blades of the rotating propellers. The test is conducted with changing the update rate of the sampling and reverberation conditions. The localization error is calculated by the position vector from the vision system and the intensity vector from the acoustic center. The results show that the flying object such as a drone can be tracked in real-time at any field at indoors or outdoors with good precision.