MULTIPLE REFERENCE FEEDFORWARD ACTIVE NOISE CONTROL PART I: ANALYSIS AND SIMULATION OF BEHAVIOR

In this work, two forms of frequency domain optimum solutions for multiple reference active noise control (MRANC) in a feedforward arrangement are given in terms of signal spectra and system frequency response functions (FRF). It is particularly noted that the optimum solutions are uncoupled if the reference signals are uncorrelated or the noise sources are directly available as reference signals. Other than the traditional control configuration which feed each reference signal into a different filter, another control configuration which combines multiple reference signals into a single input is also investigated. Although this configuration generally delivers a compromised control effect, the payoff is a simplified control structure and significant computational savings. In addition, under some circumstances, the desired performance which is comparable to other complex configurations can be achieved. Simulations based on sound transmission through a vibrating plate have been conducted and the results presented are consistent with the theoretical analysis.