Abstract
For the purpose of developing refined devices for environmental recognition in autonomous mobile robots, a practical method for simultaneous estimation of 3D-position and velocity of a moving random acoustic source in near-field is proposed by using 4 fixed point-detectors. By using 3 pairs of estimated short time auto- and cross-spectra of signals detected simultaneously at 4 fixed point-detectors, information on ratios of relative compression or extension rates of the spectral patterns due to the Doppler effect, ratios of the amplitude attenuation of wave propagation and differences of wave propagation times between signals detected simultaneously are derived in such a manner that they are all independent of the shape of power spectrum of the source radiating random signal so as to be applicable to any moving acoustic source radiating a stationary random signal. Then, with an aid of geometric relations of signal detection, the source position and velocity in 3D-space are estimated by the least mean squared (LMS) method based on the information extracted above.
After the principle of the proposed estimation method and the required conditions being made clear, fundamental experiments are carried out to show the effectiveness of the method and make clear the influence of the detection noises on the final estimates. The results illustrate the effectiveness as well as fundamental characteristics of the proposed method under practical circumstances.
