Active noise control system with detouring sound apparatus

An active noise control system for actively eliminating noise generated by a blower at an exhaust port of a duct comprising:

• a first reception device disposed in proximity to said blower for receiving noise generated by said blower and a detouring sound, and outputting an analog noise signal in response thereto;
• a sound generation device for generating a noise canceling sound in response to a noise canceling sound generation signal;
• first conversion means for converting the analog noise signal output by said first reception device into a digital noise signal;
• a first digital filter, having a first filter coefficient, for receiving a subtraction result and outputting a digital noise simulating signal simulating the noise generated by said blower in response thereto;
• second conversion means for converting the digital noise simulating signal output by said first digital filter into said noise canceling sound generation signal and for outputting the noise canceling sound generation signal to said sound generation device;
• a second digital filter, having a second filter coefficient, for receiving as input the digital noise simulating signal output by said first digital filter and outputting a detouring sound simulating signal in response thereto to simulate the detouring sound, wherein the detouring sound is the noise canceling sound generated from said sound generation device when received by said first sound reception device through said duct;
• subtraction means for subtracting the detouring sound simulating signal output by said second digital filter from the digital noise signal output by said first conversion means and for outputting the subtraction result in response thereto;
• second updating means, receiving as input the subtraction result output by said subtraction means, for updating the second filter coefficient of said second digital filter in response thereto during active noise elimination;
• a second reception device disposed in proximity to said exhaust port of said duct for receiving residual noise and outputting an analog residual noise signal in response thereto;
• third conversion means for converting the analog residual noise signal output by said second reception device into a digital residual noise signal;
• and
• first updating means, receiving as input the digital residual noise signal output by said third conversion means, for updating the first filter coefficient of said first digital filter in response thereto during active noise elimination.

An active noise control system comprising:

• a sensor transducer for receiving noise and outputting an electrical noise signal in response thereto;
• an error transducer for receiving error noise and outputting an electrical error noise signal in response thereto;
• a first simulation processor for outputting a first simulation signal during a first predetermined period in response to a received subtraction signal;
• first means for updating the first simulation processor to update the first simulation signal in response to the subtraction signal;
• an output transducer electrically connected to the first simulation processor for producing an acoustic vibration in response to the first simulation signal;
• a second simulation processor electrically connected in parallel with the first simulation processor and receiving the first simulation signal therefrom, for outputting a second simulation signal during a second predetermined period in response to the subtraction signal and the first simulation signal;
• second means for controlling the second simulation processor to update the second simulating signal in response to the subtraction signal;
• and
• subtraction means electrically connected to and communicating with the sensor transducer for subtracting the second simulation signal from the electrical noise signal and outputting the subtraction signal in response thereto.