| 摘要 |
PURPOSE:To obtain the active noise controller which makes a system hard to become abnormal and stable for a long period. CONSTITUTION:Sensor microphones M1 and M2 are arranged in a propagation passage 1 across a speaker S as an additional sound source. Then 30 and 32 are microphone amplifiers which amplify the output signals of microphones M1 and M2 and 34 is a power amplifier which amplifies a driving signal outputted to the speaker S up to a specific level. Further, 50 and 52 are A/D converters, 54 a D/A converter, 60 a display part, and 70 a digital signal processor. They are mutually connected through a bus line 200. The digital signal processor 70 serves for control processor processing for total control over the whole system such as data FIR digital filter, FIR adaptive digital filter, and LMS algorithm processing, data transfer from the A/D converters 50 and 52 to the D/A converter 54, and processing for data output to a display part. |
