tailieunhanh - Báo cáo hóa học: "Analysis of Effort Constraint Algorithm in Active Noise Control Systems"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Analysis of Effort Constraint Algorithm in Active Noise Control Systems | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 54649 Pages 1-9 DOI ASP 2006 54649 Analysis of Effort Constraint Algorithm in Active Noise Control Systems F. Taringoo J. Poshtan and M. H. Kahaei Faculty of Electrical Engineering Iran University of Science and Technology Tehran 16846 Iran Received 11 February 2005 Revised 25 November 2005 Accepted 30 January 2006 Recommended for Publication by Shoji Makino In ANC systems in case of loudspeakers saturation the adaptive algorithm may diverge due to nonlinearity. The most common algorithm used in ANC systems is the FXLMS which is especially used for feed-forward ANC systems. According to its mathematical representation its cost function is conventionally chosen independent of control signal magnitude and hence the control signal may increase unlimitedly. In this paper a modified cost function is proposed that takes into account the control signal power. Choosing an appropriate weight can prevent the system from becoming nonlinear. A region for this weight is obtained and the mean weight behavior of the algorithm using this cost function is achieved. In addition to the previous paper results the linear range for the effort coefficient variation is obtained. Simulation and experimental results follow for confirmation. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION Adaptive algorithms are widely used for feed-forward control systems in which the mean-square error is minimized using the method of steepest descent with no constraint on the magnitude of the control signals. In recent years adaptive signal processing has been developed and applied to the expanding field of active noise control ANC 1 . ANC is achieved by introducing a canceling antinoise wave through an appropriate secondary source as shown in Figure 1. These secondary sources are interconnected through an electric system using a specific signal processing algorithm