Method of detecting a flow, detection device, automatic milking device and computer program

Abstract

Milk flow detecting method and device monitors a flow of milk in a milk line which is connected to a teat cup and which has an aeration opening, like in a milking device. For this purpose, the milk filling level is monitored in a measuring section of the line. If the variation therein is too little, the absence of a flow, or at least an inadequate flow, is established. If, additionally, a (sufficient) filling level is detected, it can be concluded that there is an obstructed aeration opening.

What is claimed is: 
     
         1 . A method of detecting a flow of milk in a milk line which is connected to a teat cup, having a pulsator space and which has an aeration opening , wherein the milk defines a filling level in a measuring section of the milk line, wherein the method comprises:
 applying a milking vacuum in the milk line, and a pulsating vacuum in the pulsator space of the teat cup;   measuring the filling level of the milk in the measuring section at least during a first period of time;   determining a variation of the filling level measured at least during the first period of time in the form of an indicator number;   comparing the indicator number and a predetermined threshold value, which threshold value is indicative of the presence or absence of a flow of milk in the milk line.   
     
     
         2 . The method according to  claim 1 , wherein the filling level is a linear level of the milk in the measuring section. 
     
     
         3 . The method according to  claim 1 , wherein the determining of the indicator number comprises the determining of one of the maximum variation, the variance or the standard deviation of the filling level measured at least during the first period of time. 
     
     
         4 . The method according to  claim 3 , wherein the filling level measured at least during the first period of time is divided by the average of the measured filling level. 
     
     
         5 . The method according to  claim 1 , wherein the method comprises the step of milking a dairy animal, during which milking run the filling level is detected. 
     
     
         6 . The method according to  claim 5 , comprising the continuation of the milking according to a predetermined expected milking duration. 
     
     
         7 . The method according to  claim 6 , comprising the continuation of the milking according to a predetermined expected milking duration instead of on the basis of a measured flow of milk through said teat cup. 
     
     
         8 . The method of  claim 1 , wherein the first period of time amounts to at least 20 seconds. 
     
     
         9 . The method according to  claim 1 , wherein the absence of a flow of milk is established if the indicator number is smaller than the threshold value. 
     
     
         10 . The method according to  claim 9 , further comprising the emission of a warning signal, that indicates absence of the flow of milk. 
     
     
         11 . The method according to  claim 1 , wherein an obstruction of the aeration opening is established if the indicator number is smaller than the threshold value, and the filling level measured is above a filling level threshold value. 
     
     
         12 . The method according to  claim 11 , wherein the measured filling level is averaged during the first period of time. 
     
     
         13 . The method according to  claim 11 , comprising the emission of an alarm signal which comprises the message that the aeration opening is obstructed. 
     
     
         14 . The method according to  claim 1 , wherein the measuring of the filling level of the milk in the milk line starts after a second period of time has elapsed, wherein the second period of time precedes the first period of time. 
     
     
         15 . The method according to  claim 14 , comprising:
 measuring of the filling level during the second period of time, and   starting of the measuring of the filling level during the first period of time after the filling level measured in the second period of time exceeds a predetermined threshold value thereof.   
     
     
         16 . A detection device for detecting a flow of milk in a milk line which is connected to a teat cup provided with a pulsator space and which has an aeration opening, wherein the milk defines a filling level in a measuring section of the milk line, wherein the detection device comprises:
 a detector configured to measure, during a first period of time, the filling level in the measuring section of the milk line and to emit a filling level signal, and   a control member with an input for receiving the filling level signal, which control device is configured to determine a variation of the filling level measured at least during the first period of time in the form of an indicator number, and to compare the indicator number with a predetermined threshold value, which threshold value is indicative of the presence or absence of a flow of milk in the milk line.   
     
     
         17 . The detection device according to  claim 16 , wherein the indicator number is one of the maximum variation, the variance or the standard deviation of the filling level measured at least during the first period of time. 
     
     
         18 . The detection device according to  claim 17 , wherein the filling level measured at least during the first period of time is divided by the average of said measured filling level. 
     
     
         19 . The detection device according to  claim 16 , wherein the first period of time amounts to at least 20 seconds. 
     
     
         20 . An automatic milking device for milking dairy animals, provided with at least one teat cup and with a detection device for detecting a flow of milk in a milk line which is connected to a teat cup provided with a pulsator space and which has an aeration opening, wherein the milk defines a filling level in a measuring section of the milk line, wherein the detection device comprises:
 a detector configured to measure, during a first period of time, the filling level in the measuring section of the milk line and to emit a filling level signal, and   a control member with an input for receiving the filling level signal, which control device is configured to determine a variation of the filling level measured at least during the first period of time in the form of an indicator number, and to compare the indicator number with a predetermined threshold value, which threshold value is indicative of the presence or absence of a flow of milk in the milk line.   
     
     
         21 . The automatic milking device according to  claim 20 , wherein the control member of the detection device is configured to emit an alarm signal if the indicator number is smaller than the threshold value and the filling level measured. 
     
     
         22 . The automatic milking device according to  claim 21 , wherein the indicator number is smaller than the threshold value and the filling level averaged during the first period of time is above a filling level threshold value. 
     
     
         23 . A computer implemented method of detecting a flow of milk in a milk line using a detection device, wherein the detection device is connected to a teat cup provided with a pulsator space and an aeration opening, wherein the milk defines a filling level in a measuring section of the milk line, wherein the detection device comprises a control device comprising software for implementing the method, wherein the method comprises:
 applying a milking vacuum in the milk line, and a pulsating vacuum in the pulsator space of the teat cup;   measuring via the detection device the filling level of the milk in the measuring section at least during a first period of time and emitting a filling level signal;   receiving the filling level signal,   determining a variation of the filling level measured at least during the first period of time in the form of an indicator number;   comparing the indicator number and a predetermined threshold value, which threshold value is indicative of the presence or absence of a flow of milk in the milk line, and on the basis of this comparison, transmitting a alarm signal to an alarm device.