Abstract
Feedforward active electronic mufflers based on adaptive H 2 and H ∞ model matching algorithms have been developed in this study. The performance of the fixed H 2 and H ∞ controllers have been further enhanced by the NLMS algorithm to cope with system uncertainties and perturbations commonly encountered in practical applications. Extensive experimental investigations indicate the proposed methods have potential in suppressing not only stationary noises but also transient noises. The developed methods preserve the advantages of the fixed controllers as well as the adaptive LMS-based compensator.