Near-field source localization method and application using the time reversal mirror technique

Abstract

In order to develop the acoustic keyboard for Personal Computer (PC), it is necessary to seek high-precision near-field source localization algorithm for identifying the keyboard characters. First of all, the focusing property of Time Reversal Mirror (TRM) is introduced, and then a mathematical model of microphone array receiving typing sound is established according to the realization of acoustic keyboard from which the TRM localization algorithm is carried out. The results through computer simulation show that the localization Root Mean Square Error (RMSE) performance of the algorithm can reach 10−3, which demonstrates that the algorithm possesses a high accuracy for the actual near-field acoustic source localization, with potential of developing the computer acoustic keyboard. Furthermore, for the purpose of testing its effect on actual near-field source localization, we organize three experiments for acoustic keyboard characters localization. The experiment results show that the positioning error of TRM algorithm is less than 1 cm within a provided acoustic keyboard region. This will provide theoretical guidance for the further research of computer acoustic keyboard.