Patent ID: 9578433
Date: 2017-02-21
CPC Classifications: H04R

Claim:
1. A method for self-calibration of the position of a set of sensors of acoustic signals, arranged in a region of space, comprising: providing in said region of space a plurality of transducers able to generate acoustic waves; generating acoustic waves by the plurality of transducers; receiving the acoustic waves at a plurality of sensors; measuring times of flight of said acoustic waves between each transducer and each sensor; and determining the positions of the set of sensors and the positions of the transducers through a maximum-likelihood estimation procedure executed on the basis of said measured times of flight, acquiring times of emission of said acoustic waves; obtaining said times of flight as a function of the respective times of emission, among said acquired times of emission; calculating from said times of flight distances between said transducers and said sensors and arranging said distances in a matrix of distances; calculating a matrix of estimated positions of the sensors and a matrix of estimated positions of the transducers via a maximum-likelihood procedure comprising performing a nonlinear least-squares optimization that minimizes a cost function between Euclidean distances of the positions of the sensors and of the transducers and said calculated distances; and processing a set of equations associated to said maximum-likelihood procedure for calculating a reduced matrix of the measured distances as a bilinear form that is a function of a reduced matrix of positions of the sensors and of a reduced matrix of positions of the events; executing a procedure of singular-value decomposition of said reduced matrix of the measured distances in order to reduce the number of the unknowns in said maximum-likelihood procedure, in particular from three times the sum of the number of sensors and of the number of acoustic sources to nine.