Equivalent monopole modeling using a modified Dual-LP beamforming method and evaluation of Raspberry Pi usage in place of laptops at MWL

Abstract: This seminar presents the results of two projects conducted during the summer. The first project evaluated the Dual-Linear Programming (Dual-LP) beamforming method for identifying equivalent monopole sources. The method uses the squared acoustic pressure fields, resulting in a loss of phase information, to identify sources. Thus a modified two-step approach was developed: the Dual-LP algorithm first identifies viable monopole candidate points and a least-squares solution recovers the phase and amplitude. COMSOL-generated data was used for testing three source configurations: simple line, complex, and asymmetric. Results show low mean deviation from simulated data even with relatively few probe points but with a strong dependency on parameter selection. Despite low errors, visual sound field agreement was limited for some configurations. Overall, the approach offers a sufficiently effective method for equivalent monopole source identification in the simple cases evaluated.

The second project examined the feasibility of replacing aging laboratory laptops with Raspberry Pi:s. Results showed much lower CPU usage compared to the laptops during data collection and allowed synched multi-channel recordings of more than 2 channels. Stress testing the system showed no negative impacts during multiple 8 second long 192 kHz recordings across 4 sound cards and 10 total channels.