Study Of The Secondy Path Problem Of Active Noise Control In Duct

Ducts are widely used as channels to transfer goods or as medium to carry message in the domain of agricultural and industry production, that followed the duct noise which impacts on the development of agriculture and industry. The study of duct active noise control (ANC) will be an application research. The issue of uncertentity of secondary path is a burning issue in the duct active noise control. At present, the mainstream control algorithm is modeling and identification of secondary path at home and abroad.In allusion to the uncertainty of secondary-path in the duct active noise control, we give a research on the main methods of secondary-path identification. We introduce the theory of on-line and off-line identification in detail, and give a comparatively research on the advantages and disadvantages of the representativeness algorithms.On the basis of the fundamental of secondary-path identification methods, we model the system and give system analogue simulation based on the Simulink platform in MATLAB. Then, we give comparatively research on the influence over the algorithms with different steps, sampling frequency, filter length. And we carry on the qualitative study about the convergence speed, stability of the system and the effect of the noise reduction.With the ground work of theory study and system analogue simulation, the duct active noise control based on Digital Signal Processor (DSP) TMS3205509 is accomplished. We dispose the signal by collecting signal real time and programming, then analyze the ANC algorithm experimentally and compare the characteristic and effect of different algorithms when identify the secondary-path. Paper provides lots of data and figures of several algorithm experiments, reflects the characteristic of cornucopia algorithms distinctly and intuitively. It provides a valuable basis for the research of such projects and has significance for practical research.