Application of Damped-Oscillation Control Signals for Wide-Band Feedback Active Noise Control in Acoustic Ducts

摘要

Multi-damped-oscillation control signals are applied in this study for active noise control (ANC) in an acoustic duct. Feedback active noise controllers that can generate damped-oscillation control signals are designed by using an internal model based linear quadratic Gaussian (LQG) design technique. The low and upper bounds containing a desired ANC bandwidth is specified by two frequencies of the control signals. To acquire desired ANC performance, sound pressure attenuation ratios within the bandwidth are tuned by control signals of other frequencies and damping ratios. Computer simulation and experimental results show that sound pressure attenuation ratio of ≤0.3 and ≤0.5, respectively, can be achieved in a wide-band of 100 Hz by using 3 damped-oscillation control signals. Experimental results also show effective noise reduction for time varying disturbance and band-limited white noise within the ANC bandwidth. These results support the feasibility of the designed controllers with damped-oscillation control signals for wide-band feedback active noise control in acoustic ducts.