Patent Application
20140238304
1. Field of the Invention
The invention relates generally to a method and apparatus for monitoring a milking process, and more particularly, to monitoring a milking process by measuring at least one property of a vibrational signal within an airline.
2. Description of the Related Art
In any milking system, it is important to ensure that teatcups are properly connected to the teats of animals being milked. Improper connection may result in inefficient milking—if any milk at all may be extracted—and cause damage to the udder. If a teatcup becomes completely disconnected, there is also a risk that extraneous material within the milking environment will be sucked into the milk delivery system, which is highly undesirable.
The ability to detect these problems is especially important in an automated milking system, such as those controlled by a robot, where operators are not always present to observe an improper connection and readjust the teatcup.
One method for doing so measures sound within the milking line and compares these measurements with predetermined reference values to determine whether present conditions within the line indicate that the teatcup is correctly connected to the teat. Document EP-0953829A provides an example of one such method based on this principle.
Such methods suffer limitations due to the nature of the environment within the milking line. In particular, the passage of liquid within the line creates significant levels of interference which makes obtaining consistent and accurate measurements difficult. Connection of the milking line to other elements within the milking plant also introduces other sources of noise.
Furthermore, such methods require placement of the sensor for measuring sound within the milking line between the teatcups and milk receiver. The environment surrounding the teatcups is harsh, for example due to exposure to liquid (including cleaning chemicals), impact, and variation in temperature. Positioning of the sensor at this point is also not conducive to the generally desirable objective of minimising bulk and weight to the milking implement.
It is an object of the invention to address the foregoing problems or at least to provide the public with a useful choice.
All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the reference states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms parts of the common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word “comprise”, or variations thereof such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
According to one aspect of the present invention there is provided a method of monitoring a milking process, the milking process performed by a milking apparatus including at least one teatcup with a pulsation space and at least one pulsation airline configured to deliver varying levels of pressure to the pulsation space, the method characterised by the steps of:
According to another aspect of the present invention there is provided a control device for monitoring a milking process, the milking process performed by a milking apparatus including at least one teatcup with a pulsation space and at least one pulsation airline configured to deliver varying levels of pressure to the pulsation space, the device including:
According to another aspect of the present invention there is provided a robotic automatic milking implement configured to perform a milking process, the implement including:
It is envisaged that the vibrational signal may be an acoustic signal within the airline.
The airline may provide a much cleaner source of sound within the teatcup than the milking line. Variation in noise levels, particularly during certain phases of the pulsation cycle, may be attributed to variation in airflow through the teatcup with a greater level of confidence than in previously known systems.
It is envisaged that the pulsation space may be the space between a teatcup shell and teatcup liner, as known in the art. The pulsation space may also act as a “sounding” diaphragm in order to provide a large signal to noise ratio within the airline.
By measuring vibrations in the airline the sensor may also be positioned away from the point of milk extraction, minimising sensor requirements with regard to withstanding environmental effects and reducing clutter. Furthermore, activity within the airline is not as constrained by hygiene regulations as the milking line.
In a preferred embodiment the condition is one of the teatcup being disconnected from a teat of the milking animal, or the teatcup being incorrectly fitted to a teat of a milking animal.
It should be appreciated that determining the condition may be achieved in a number of ways.
Preferably determining the condition includes comparing an amplitude of the measured property with the reference value.
However, in another embodiment determining the condition may include comparing deviation of the value of the measured property over time with the reference value.
Alternatively, determining the condition may include comparing the rate of change of the measured property over time with the reference value.
The varying levels of pressure delivered to the pulsation space are commonly known as a pulsation cycle in which the pulsation space is alternately exposed to atmospheric pressure and a negative pressure commonly referred to as “vacuum”. Within this cycle, there are a number of phases characterised by the level of pressure and direction of airflow. It is envisaged that in a preferred embodiment the invention includes determining a phase of one of the milking process or a pulsation phase.
It is envisaged that the phase may be determined by comparing the value of the measured property with a predetermined threshold.
Alternatively, or in combination with other methods, the phase may be determined using a signal associated with a pulsator configured to control the level of pressure within the airline.
Preferably the property may be measured during at least one selected phase.
Specifically, it is envisaged that the property may be measured during a phase in which the airline is exposed to atmosphere.
Further, the expected characteristics of the vibrational signal may vary between phases. As such, the phase in which the property is measured may be used to determine the reference value to be used in the comparison.
In a preferred embodiment the vibration sensor is at least one of a piezoelectric transducer and a microphone.
Preferably, the property of the vibrational signal is an average sound pressure level or a peak sound pressure level. In particular, it is envisaged that this may be measured during a resting phase and/or a milking phase of a pulsation cycle of the milking process. In an embodiment, an average sound pressure level or a peak sound pressure level may be measured during at least one of a resting phase and a milking phase of a pulsation cycle of the milking process. The inventor has determined that measurement of sound properties provides a avenue for checking the quality of the teatcup attachment.
It should be appreciated that this is not intended to be limiting, and that any suitable means of measuring properties of vibrational signals known to a person skilled in the art may be used to implement the present invention.
Preferably, the positioning of the teatcup is adjusted in response to the determined condition.
For example, if the present invention is implemented in a robotic milking machine and it is determined that the teatcup has fallen off, the teatcup applicator of the robot may be controlled to reapply the teatcup. Similarly, if it has been determined that the teatcup is incorrectly fitted to a teat, such a teatcup applicator may be controlled to reapply the teatcup.
In an embodiment of the present invention, an alarm may be issued in response to the determined condition. This may be by way of an alarm device such as a siren or light in order to alert an operator that action needs to be taken—particularly in milking systems without automated means for applying the teatcups. Alternatively (or additionally), the alarm may be a virtual notification or record within software monitoring or managing the milking process.
For a firmware and/or software (also known as a computer program) implementation, the techniques of the present invention may be implemented as instructions (for example, procedures, functions, and so on) that perform the functions described. It should be appreciated that the present invention is not described with reference to any particular programming languages, and that a variety of programming languages could be used to implement the present invention. The firmware and/or software codes may be stored in a memory, or embodied in any other processor readable medium, and executed by a processor or processors. The memory may be implemented within the processor or external to the processor.
A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a digital signal processor (DSP) and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The processors may function in conjunction with servers and network connections as known in the art.
The steps of a method, process, or algorithm described in connection with the present invention may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The various steps or acts in a method or process may be performed in the order shown, or may be performed in another order. Additionally, one or more process or method steps may be omitted or one or more process or method steps may be added to the methods and processes. An additional step, block, or action may be added in the beginning, end, or intervening existing elements of the methods and processes.
The present invention may provide at least the following advantages:
The features and advantages of the invention will be appreciated upon reference to the following drawings, in which:
a-c illustrate extraction of milk using a milking device according to an embodiment of the present invention;
a-c are examples of measurements of a vibrational signal according to an embodiment of the present invention.
The following is a description of certain embodiments of the invention, given by way of example only and with reference to the drawings.
Each teatcup 2, 3, 4, 5 may be automatically connected and disconnected from a teat of a cow by means of a milking robot (as described with reference to
A position-determining device 25 detects the positions of the respective teats 22, 24 and teatcups 21, 23, and guides the teatcups 21, 23 to the teats 22, 24 such that vacuum attaches them.
Returning to
The milk extracted by each teatcup 2, 3, 4, 5 is supplied via separate milk lines, exemplified by milk line 9 which is associated with teatcup 2, to a milk jar 10 and ultimately a milk tank (not illustrated).
Each teatcup 2, 3, 4, 5 is provided with a vibration sensor, exemplified by vibration sensor 11, within their respective airlines—for example airline 7 of teatcup 2—configured to measure at least one property of a vibrational signal within the airline.
The value of the measured property is sent from the sensor 11 to a processor 12. The processor 12 is also in communication with the pulsator system 6. It should be appreciated that the signals communicated from the sensor 11 and pulsator system 6 may include data identifying the respective sensor 11, pulsator within the pulsator system 6, and/or the teatcup 2,3,4,5.
Data transmitted to the processor 12 may be stored in memory 13, together with other data used in calculations performed by the processor 12, as described hereinafter.
a, 3b and 3c illustrate interaction of a dairy animal's udder 30 with a teatcup—for example, teatcup 2.
The teatcup 2 includes a shell 31 and a liner 32, between which a pulsation space 33 is formed. The liner 32 is connected to the milking line 9, while the pulsation space 33 is connected by the airline 7 to a pulsator 34, which forms part of the pulsator system 6 of
The pulsator 34 acts as a valve, controlling connection of the airline 7 to vacuum 9 and atmospheric pressure 35.
Turning to
In
As illustrated by
In each case, the vibration sensor 11 is positioned in the airline 7.
A piezo element 51 is mounted within the tubing 50, exposed to the airline 7. A co-axial cable 52 connects the piezo element 51 to the processor 12 of
a, 6b and 6c illustrate measurements of a vibrational signal made by the vibration sensor 11.
a illustrates the amplitude of acoustic signals in the airline 7 under normal milking conditions versus time. The phases of the pulsation cycle illustrated by
It may be seen that the amplitude of the signal is greater during the A and B phases than during C and D.
b illustrates a scenario in which the teatcup 2 falls off during the second phase A of the series.
In doing so, the milking line 9 is exposed to atmospheric pressure, causing an inrush of air. This is particularly noticeable during phases C and D, when the amplitude of the signal would be expected to drop significantly due to the teatcup liner 32 collapsing about the teat 36 and preventing airflow.
The processor 12 may therefore determine the condition of a teatcup falling off by comparing the amplitude of the signal during at least phase D of the cycle with a reference value. The reference value may be, for example:
It should be appreciated that the measurement for comparison with the reference value may be instantaneous amplitude, an average, deviation over a predetermined period, rate of change, or any other quantifiable means by which a comparison may be made with the reference value.
Further, the processor 12 may use measurements from phases other than D—although it is envisaged that phase D will provide the most reliable comparison.
If the processor 12 determines that the teatcup 2 has fallen off, it may control the robot arm 20 to reapply the teatcup 2 to the teat 36.
c illustrates a scenario in which the teatcup 2 is incorrectly connected to the teat 36, allowing air to flow past the teat 36 during phases A and B.
This accounts for the large spike in amplitude during phase B in particular, as compared with the normal milking conditions of
The processor 12 may compare measurements from phase B with reference values to determine whether the teatcup 2 is connected, albeit incorrectly. In doing so, the processor 12 may control the robot arm 20 to adjust the position of the teatcup 2 rather than attempting to relocate the teat 36 again.
It should be appreciated that there are multiple means for determining the phase of the milking process. The large transient signals at the start of phases A and C are due to the switching between vacuum and atmospheric pressure, and this together with amplitude of the acoustic signals in the airline 7 during the following phases may be used to determine phase. Alternatively, the processor 12 may be in communication with the pulsator system 6 and receive signals indicative of same.
In addition to, or in place of, adjusting the position of the teatcups, the processor 12 may be configured to issue an alarm regarding the detected condition. This may be by way of display of text or lights at the milking device or control module thereof, an audible alarm, a flag in software or any other suitable means known to a person skilled in the art.
In manually operated systems, this will enable the timely reapplication of the teatcup 2. In an automatic milking device, recordal of such alarms may allow for identification of ongoing faults requiring either recalibration of equipment, or repair or replacement of faulty components.
Further modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007732 | Nov 2011 | NL | national |
This application is a continuation of PCT application number PCT/NL2012/050640 filed on 13 Sep. 2012, which claims priority from Netherlands application number 2007732 filed on 7 Nov. 2011. Both applications are hereby incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/NL2012/050640 | Sep 2012 | US |
| Child | 14271482 | US |
