Audio noise cancellation system for a sensor in an automotive vehicle

Abstract

A compensation circuit ( 12 ) for a sensor ( 22 ) generating electrical sensor output near a speaker ( 18 ) of an audio system ( 16 ) comprises an inverting circuit ( 26 ) coupled to the electrical output ( 16 ) of the audio system. The inverting circuit ( 26 ) generates an inverted electrical signal corresponding to a speaker audio output. A sensor controller ( 24 ) coupled to the inverting circuit ( 26 ) and the sensor ( 22 ) generates a compensated electrical output in response to the electrical sensor output and the inverted electrical signal.

1 . A compensation circuit for a sensor generating an electrical sensor output positioned near a speaker of an audio system comprising; 
 an inverting circuit electrically coupled to the electrical output of the audio system, said inverting circuit generating an inverted electrical signal corresponding to a speaker audio output; and    a sensor controller coupled to the inverting circuit and said sensor, said controller generating a compensated electrical output in response to said electrical sensor output and said inverted electrical signal.    
     
     
         2 . A compensation circuit as recited in  claim 1  wherein said inverting circuit comprises an operational amplifier.  
     
     
         3 . A compensation circuit as recited in  claim 1  wherein said sensor comprises a pressure sensor.  
     
     
         4 . A compensation circuit as recited in  claim 1  wherein said speaker comprises a subwoofer.  
     
     
         5 . A compensation circuit as recited in  claim 1  wherein said inverting circuit comprises a delay circuit generating a time delay in said inverted electrical signal.  
     
     
         6 . A compensation circuit as recited in  claim 1  wherein said sensor controller adds the compensated electrical output and said electrical sensor output.  
     
     
         7 . A compensation circuit as recited in  claim 6  wherein said operational amplifier comprises a resistor coupled to an inverting input and an output.  
     
     
         8 . A compensation circuit comprising: 
 a sensor generating an electrical sensor output;    a speaker of an audio system acoustically coupled to said sensor;    an inverting circuit coupled to the electrical output of the speaker, said inverting circuit generating an inverted electrical signal corresponding to a speaker audio output, and    a sensor controller coupled to the inverting circuit and said sensor, said controller generating a compensated electrical output in response to said electrical sensor output and said inverted electrical signal.    
     
     
         9 . A compensation circuit as recited in  claim 8  wherein said sensor comprises a pressure sensor.  
     
     
         10 . A compensation circuit as recited in  claim 8  wherein said speaker comprises a subwoofer.  
     
     
         11 . A compensation circuit as recited in  claim 8  wherein said inverting circuit comprises a delay circuit generating a delay in said inverted electrical signal.  
     
     
         12 . A compensation circuit as recited in  claim 8  wherein said inverting circuit comprises an operational amplifier.  
     
     
         13 . A compensation circuit as recited in  claim 12  wherein said operational amplifier comprises a resistor coupled to an inverting input and an output.  
     
     
         14 . A compensation circuit as recited in  claim 8  wherein said sensor controller adds the inverted electrical output and said electrical sensor output.  
     
     
         15 . A method for compensating for an electrical output of a sensor comprising: 
 generating an electrical signal at an audio system output and electrical input to a speaker;    inverting the electrical signal to form an inverted electrical signal;    generating an electrical sensor output signal altered by the acoustics of the speaker; and    combining the inverted electrical signal and sensor output signal to form a compensated electrical output.    
     
     
         16 . A method as recited in  claim 15  wherein the speaker comprises a subwoofer.  
     
     
         17 . A method as recited in  claim 15  further comprising generating a delay signal, wherein said inverted signal is formed in response to said delay signal.  
     
     
         18 . A method as recited in  claim 15  wherein combining comprises adding the inverted electrical output and said electrical sensor output.  
     
     
         19 . A method as recited in  claim 15  wherein the sensor comprises a pressure sensor.  
     
     
         20 . A method as recited in  claim 15  wherein generating an electrical signal comprises generating an electrical signal corresponding to the acoustic signal of the speaker.