Browsing by Author "Lin, Z"

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Active noise cancellation for a three-dimensional enclosure by using multiple-channel adaptive control and H infinity control
(1998-10-01)
Bai, MR
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Lin, Z
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機械工程學系
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Department of Mechanical Engineering
Active noise control (;WC) techniques for a three-dimensional enclosure are compared in terms of two control structures and two control algorithms. The multiple-channel filtered-x least-mean-square (FXLMS) algorithm and the H-infinity robust control algorithm are employed for controller synthesis. Both feedforward and feedback control structures are compared. The Youla's parameterization is employed in the formulation of the multiple-channel feedback FXLMS algorithm. The algorithms are implemented using a floating-point digital signal processor (DSP), Experiments are carried out to validate the ANC approaches for, attenuation of the internal field in a rectangular wooden box Position and number of actuators and sensors are also investigated. A broadband random noise and an engine noise are chosen as the primary noises in the experiments. The experimental results indicate that the feedforward structure yields a broader band of attenuation than the feedback structure. The FXLMS control and H-infinity control achieve comparable performance.
Development and implementation of a semi-adaptive H-infinity active control algorithm for duct noise
(1999-01-01)
Bai, MR
;
Lin, H
;
Lin, Z
;
機械工程學系
;
Department of Mechanical Engineering
A hybrid active noise control (ANC) scheme for suppressing duct noise based on the H-infinity control synthesis is proposed. The controllers are designed in terms of performance, and robustness using a general framework of the H-infinity robust control theory. In addition to the fixed controller, the system is further enhanced by introducing an adaptive compensator based on the least-mean-square (LMS) algorithm. Youla parameterization is employed in designing the adaptive compensator so that the resulting system is stable. Experimental investigations demonstrate that the proposed methods are effective in suppressing broadband random noise in finite-length duct.