Real-time Implementation of Global Active Noise Control with Acoustic Power minimization

Global active noise control system with acoustic power minimization's real time implementation is studied in this paper. Global active noise control system with acoustic power minimization consists of control speakers nearly around noise source and minimization of acoustic power of them. For real-time implementation, we used Wiener filter solution to get causal control filter. We also used open-loop active noise control system that does not need error microphones during active noise control. Configuration and number of control speakers and microphones to measure acoustic power is decided by frequency range of interest and directivity pattern of noise source considering spatial aliasing. For high control performance, the ANC system should be causal, but the above system has non-causality due to the characteristics of global space control inevitably. When the reference signal is measured using reference sensor, this non-causality is greater than when known signal arbitrarily made as reference signal is used. So, we conducted simulations based on experimental data for above two cases and compared two cases to find out the effect of non-causality on control performance. In conclusion, we confirmed that the increase in non-causality caused by the use of reference sensor causes control performance degradation.