Method of and a device for acoustically monitoring the course of a process, such as a milking process

Abstract

A method and apparatus which acoustically monitors a process, specifically an automated milking process. In the process the amplitude differences or the intensity values or both of the sound are measured during the process by a sound sensor comprising a piezoelectric transducer. These measurements which are taken during the entire process either continuously or at least continually at frequent intervals are compared with predetermined threshold values or other reference values or a reference pattern or patterns for the purpose of detecting whether the process is proceeding as it should or there are irregularities such as the presence of disturbances or deviations or both in the course of the process. The piezoelectric transducer is mounted in a housing of sound absorbent material on a good sound conductivity material so that it receives, with minimal attenuation, sounds which emanate from a conduit connected to a teat cup of the milking apparatus when a fluid is flowing through the conduit, which fluid is usually milk during the milking process and air when the teat cup is disconnected from the animal's teat.

1 . A method of acoustically monitoring the course of a process, in which method the amplitude difference and/or the intensity value of sound are/is measured during the process, and the amplitudes and/or the intensity values of the sound and/or the vibrations are measured continuously or with an adjustable frequency by means of a sound and/or vibration sensor ( 4 ), such as a piezoelectric transducer ( 12 ), during the entire process or part of the process and are compared mutually and/or with a predetermined threshold value and/or reference value and/or reference pattern for the purpose of drawing, on the basis thereof, conclusions in relation to the progress and/or the course of the process and/or the presence of disturbances and/or deviations in the course of the process.  
     
     
         2 . A method as claimed in  claim 1 , characterized in that the threshold value is adjusted depending on what process has been started up and/or depending on the stage of the process.  
     
     
         3 . A method as claimed in  claim 1  or  2 , characterized in that, if the process is a milking process, in part of the milk line system and/or in a teat cup ( 1 ), by means of the piezoelectric transducer ( 12 ) the amplitude and/or the intensity value are/is measured of the sound that is produced by the air flow in the teat cup ( 1 ) and/or in the milk line system when said teat cup ( 1 ) is not connected and a milk vacuum has been applied in the milk line system, which amplitude and/or intensity value are/is recorded as a reference value and/or reference pattern for the purpose of deducing therefrom whether or not a teat cup ( 1 ) has been correctly connected to a teat.  
     
     
         4 . A sensor ( 4 ) for measuring the amplitude difference and/or the intensity value of sound, said sensor being provided with a piezoelectric transducer ( 12 ) that is adapted to the application of the method as claimed in any one of claims  1 - 3 .  
     
     
         5 . A sensor for measuring the amplitude difference and/or the intensity value of sound, said sensor being provided with a piezo-sensor ( 4 ), such as a piezoelectric transducer ( 12 ), characterized in that the sensor ( 4 ) comprises a housing ( 5 ) which is made of a material having a strongly absorbing capacity for sound and/or vibrations, such as silicones, for example, while at least one piezoelectric sensor ( 12 ) is embedded in said housing ( 5 ).  
     
     
         6 . A sensor as claimed in  claim 5 , characterized in that the piezo-sensor ( 10 ) is disposed relatively closely to a wall of the housing ( 5 ).  
     
     
         7 . A sensor as claimed in  claim 5  or  6 , characterized in that the piezo-sensor ( 10 ) comprises a guide element extending as far as near a wall of the housing ( 5 ) or extending through said wall.  
     
     
         8 . A sensor as claimed in any one of claims  4 - 5 , characterized in that the piezo-sensor ( 10 ) is disposed in a chamber or closable cavity ( 8 ) in the housing ( 5 ).  
     
     
         9 . A sensor as claimed in  claim 8 , characterized in that the chamber or closable cavity ( 8 ) is dimensioned in such a manner that it also comprises an air chamber ( 14 ).  
     
     
         10 . A sensor as claimed in any one of claims  5 - 9 , characterized in that the piezo-sensor ( 10 ) bears on a liquid or viscous layer ( 9 ) such as vaseline or gel, for example, having a relatively good conductivity for vibrations and/or sound.  
     
     
         11 . A sensor as claimed in any one of claims  8 - 10 , characterized in that the closable cavity ( 8 ) can be closed by means of a closing element ( 13 ), such as a cap, for example.  
     
     
         12 . A sensor as claimed in  claim 11 , characterized in that the closing element ( 13 ) as well as the housing ( 5 ) are made of a strongly absorbing material.  
     
     
         13 . A sensor as claimed in  claim 11  or  12 , characterized in that the closing element ( 13 ) is designed as a pressure cap for the piezo-sensor ( 10 ).  
     
     
         14 . A sensor as claimed in  claim 13 , characterized in that the pressure cap comprises a pressure portion ( 15 ) acting on an other part of the sensor ( 10 ) than the measuring element ( 12 ) thereof.  
     
     
         15 . A sensor as claimed in any one of claims  5 - 14 , characterized in that the housing ( 5 ) is provided with at least one duct ( 7 ) through which a liquid and/or a gas can flow.  
     
     
         16 . A sensor as claimed in  claim 15 , characterized in that in or near the duct ( 7 ) there is provided a flow disturbing element ( 16 ) affecting the liquid and/or gas flow in at least part of the duct ( 7 ).  
     
     
         17 . A sensor as claimed in  claim 16 , characterized in that the flow disturbing element ( 16 ) comprises a sensor, such as a temperature or conductivity sensor, for example.  
     
     
         18 . A milking implement comprising a milk line system and teat cups, characterized in that the milking implement is suitable for the application of the method as claimed in any one of claims  1 - 3  and/or is provided with a sensor as claimed in any one of claims  4 - 17 .  
     
     
         19 . A milking implement as claimed in  claim 18 , characterized in that said milking implement is provided with a milking robot for automatically connecting teat cups to an animal to be milked.