Adaptive Key Technology Research, Engineering Implementation Of Active Headsets

With the development of electronic techniques and control theories, active noise control has become a hot point in the field of noise control in recent decades. Active headset, which can control low frequency by using active noise control approach, has obtained many achievements in past two decades. Active headset is a more important direction as active noise control technique application. Analogue active headset has been applied successfully in engineering.Firstly, the key techniques involving in engineering implementation for adaptive active headset consist of the secondary path modeling, the software programming and the experimental system construction, have been studied in this thesis.Secondly, the history and state of art of active noise control has been reviewed, the Filtered LMS algorithm is derived and its performances are analyzed. The characteristics of the secondary path are examined and its influences on noise control are studied by computer simulations.Finally, an experimental system for adaptive active headset is established. DSP based assembling program for adaptive active control and error path modeling off-line are written. The experimental results by the DLMS and FLMS algorithm are compared. It is shown that the FLMS algorithm is better than the DLMS algorithm.