Application of multilateration for microphone localization using audio samples at room scale

Autor: Christoph Reichl, Peter Wimberger
Rok vydání: 2021
Předmět:
Zdroj: e & i Elektrotechnik und Informationstechnik. 138:244-249
ISSN: 1613-7620
0932-383X
Popis: To capture sound emissions of industrial machines (e.g., heat pumps) that are resolved in terms of frequency, time and space, an acoustic dome geometry with up to 64 microphones is used. Exact coordinates of all microphones are needed to ensure reproducibility of measurements as foundation for other algorithms (e.g., sound power level analysis) and for visualization purposes (plots and augmented reality applications). As the coordinates are difficult and imprecise to produce by hand, an acoustic solution independent of hardware and software using multilateration and Time Difference of Arrival is being developed to automatically and efficiently determine their position. The calculation procedure starts with playing predetermined audio samples (based on a sequence of non-repeatable numbers) on speakers with known coordinates and recording the microphone data. By cross-correlating the sent data with the recorded data, it is possible to extract the signal travel times. These propagation times, the precisely known coordinates of the speakers and the temperature-dependent speed of sound are used as input for the multilateration algorithm, which returns the coordinates of the microphones. Within the accuracy required for the application, the system works for measurements in line of sight. Performance degrades in settings with too many multipath effects (reflection and diffraction), which may cause unrecoverable loss of information. Several validation measurements and simulations were conducted. Various error sources with possible fixes are identified and discussed.
Databáze: OpenAIRE
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