Intelligent sensor design for audio source localization implementing digital beamforming

摘要

Paper deals with design of compact intelligent sensor for audio source localization based on delay and sum type digital beamformer with focus on security, teleconferencing and robotics systems application area. Hardware design of the device presumes utilization of microphone array with 16 omnidirectional microphone units with geometrical setup optimized for audio source frequencies in the range of 1500 Hz to 2000 Hz. Output signal is processed in evaluation system consisting of five Freescale Coldfire VI microcontrollers with 32bit central processing unit where first four perform data acquisition tasks and digital filtering while fifth microcontroller coordinates their operation and performs final stage of localization algorithm. Master microcontroller also provides USB and RS232 interfaces allowing connection to supervision system and simple information alphanumerical LCD display which is used in case when device works in autonomous mode.