In this paper an application of an active muffler system is presented for reducing exhaust noise of a heavy vehicle. The signal-to-noise ratio associated with the process of estimating the transfer function of a secondary path was improved using conventional inverse modeling combined with an adaptive line enhancer as a control strategy. The simplified passive muffler using two-duct perforated elements was combined with the active muffler system instead of a conventional passive exhaust system to reduce exhaust noise and flow restriction simultaneously. In experiments to estimate the transfer function of a secondary path, the estimates using the inverse modeling method alone show many errors at the dominant frequencies of primary noise. Results obtained using the proposed algorithm correspond well to the actual transfer function as estimated without the primary noise. Control experiments with the proposed active muffler system have been implemented for stationary and driving states, respectively. Compared to the conventional passive muffler, the experimental results showed that the proposed active muffler could reduce the backpressure up to 60% as well as the overall sound pressure level below about 2200 rpm.
Development of an active muffler system for reducing exhaust noise and flow restriction in a heavy vehicle
Noise Control Engineering Journal ; 47 , 2 ; 57-63
1999
7 Seiten, 12 Quellen
Aufsatz (Zeitschrift)
Englisch
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