Mukai Honoka, Hasegawa Keisuke, Nara Takaaki
Graduate School of Technology Management for Innovation, The University of Tokyo, Tokyo, 113-8656, Japan.
Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, 113-8656, Japan.
J Acoust Soc Am. 2021 Dec;150(6):4178. doi: 10.1121/10.0007464.
In this article, a structured acoustic holography technique in the self-positioning method of a single microphone from the monaurally recorded signals is proposed. A series of three-dimensional ultrasonic holograms, designed for positioning in a workspace, are sequentially projected. As a result, the microphone receives a position-dependent sequence of amplitude signals encoded with information on the observation position. Subsequently, the microphone position is determined by obtaining the peak position of the cross-correlation function between the received signal and the reference signal. Experiments were conducted using a custom-made phased array of 40-kHz ultrasound transducers to evaluate the positioning accuracy. It is demonstrated that when applied to a 100×100×50 mm workspace, the measurement error was less than 1 mm at all observation points in the numerical experiment, which was maintained for more than 96% of the points in the real-environment experiments. The proposed method is advantageous in that it does not use the phase information of the recorded signals, thus requiring no multiple synchronized recordings as the microphone-array-based methods. In addition, this scheme does not directly use the absolute value of the received amplitude as a positioning clue, which means that no amplitude-to-voltage calibration is required.
