.

The system vacuum pressure P_smay be for example somewhere between about 45-55 kPa (arbitrary, non-limiting examples), such as for example about 49 kPa. The system vacuum pressure P_smay be maintained substantially constant over time in the receiver 220 during a majority time of the milking session.

The expressions “vacuum pressure”, “fluid pressure”, “milking vacuum” and/or “system vacuum pressure” respectively, refers to under-pressure/lower pressure in comparison with the environmental atmospheric pressure. A vacuum pressure level of 10 kPa thus means a vacuum pressure level which is 10 kPa lower than the environmental atmospheric pressure.

The receiver 220 may collect milk extracted from the animals during the milking session, which may be forwarded via a pump arrangement, tubing and possibly an optional filter, to a connected cooling tank where the milk may be collected and maintained at chilled temperature until being emptied when the milk truck arrives to the farm.

Each milking unit 140, 140a, 140b of the milking system 100 is also associated with a respective pressure sensor 270, 270a, 270b, or vacuum pressure sensor. The pressure sensor 270, 270a, 270b may be associated with the milk conduit 260, 260a, 260b of the milking unit 140, 140a, 140b and arranged to measure the fluid pressure level in the milk conduit 260, 260a, 260b in relatively close vicinity of the milking unit 140, 140a, 140b. The fluid pressure measured by the pressure sensor 270, 270a, 270b upstream of the controllable valve arrangement 250, 250a, 250b, 250c in a liquid flow path is thereby representative of (although due to possible pressure drop not identical with) the fluid pressure that is prevailing in the teat cups 241, 241a, 241b, 241c under the animal teats.

The pressure sensor 270, 270a, 270b may be arranged in a passage of the milk conduit 160 having substantially the same diameter as the milk conduit 260, 260a, 260b. Thereby a pressure drop over the pressure sensor 270, 270a, 270b is avoided, or at least reduced.

The pressure sensor may for example measure the fluid pressure in the milk conduit at a frequency about 10-1000 Hz in some embodiments, preferably about 100-1000 measurements per second.

The sampling frequency of the pressure sensor may be predetermined or adjustable in different embodiments.

The more frequently the vacuum pressure level is measured by the respective pressure sensor 270, 270a, 270b, the more precise fine tuning of the applied vacuum pressure level could be made.

Each milking unit 140, 140a, 140b of the milking system 100 is also associated with a respective controllable valve arrangement 250, 250a, 250b. The controllable valve arrangement 250, 250a, 250b is arranged in the milk conduit 160 between the milking unit 140, 140a, 140b and the common milk line 130.

The controllable valve arrangement 250, 250a, 250b comprises an adjustable passage wherein fluid pressure of the common milk line 130 is provided to the milk conduit 260, 260a, 260b via the adjustable passage. An adjustment of the adjustable passage thereby results in an adjustment of the fluid pressure upstream the controllable valve arrangement 250, 250a, 250b in a liquid flow path.

The expression “upstream” and/or “downstream” in the current context refers to the liquid flow path, i.e. the milk flow during milk extraction in the milking session, or cleaning liquid flow during Cleaning In Place (CIP) cleaning; from the teat cups 241, 241a, 241b, 241c, via the milk conduit 260, 260a, 260b to the common milk line 130 and the receiver 220.

The controllable valve arrangement 250, 250a, 250b may be implemented in various distinct versions in different embodiments, for example as illustrated in Figured 2A-2B.

By regulating the adjustable passage in a controlled manner, the vacuum pressure level supplied to the milk conduit 260, 260a, 260b upstream the controllable valve arrangement 250, 250a, 250b is correspondingly adjusted.

Each milking unit 140, 140a, 140b of the milking system 100, and thereby also each milking point 120, 120a, 120b, 120c, 120d, 120e, 120f, is associated with a respective controller 280, 280a, 280b, or processing device. The controller 280, 280a, 280b is communicatively connected to the pressure sensor 270, 270a, 270b and to the controllable valve arrangement 250, 250a, 250b, for instance via a wireless connection based on radio or optical technique, or a wired connection implemented by electric cable or optic fiber.

The controller 280, 280a, 280b may comprise one or more instances of a processing circuit/circuitry, i.e. a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a microprocessor, a Graphics Processing Unit (GPU), an Electronic Control Unit (ECU), or other processing logic that may interpret and execute instructions. The herein utilized expression “processing circuitry” may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones enumerated above.

The controller 280, 280a, 280b is configured to, repeatedly during the milking session, obtain pressure level measurements from the pressure sensor 270, 270a, 270b, and, based on the obtained pressure level measurement, generate and provide a control signal to the controllable valve arrangement 250, 250a, 250b, to adjust the adjustable passage. The control signal may for example comprise an electrical control signal.

The controller 280, 280a, 280b may obtain pressure level measurements from the pressure sensor 270, 270a, 270b for example 500-1000 times per second, in some implementations.

By adjusting the adjustable passage, the fluid pressure upstream the controllable valve arrangement 250, 250a, 250b in the liquid flow path is correspondingly adjusted.

The controller 280 may be configured to generate and provide the control signal to the controllable valve arrangement 250, 250a, 250b, 250c in order to maintain the fluid pressure upstream of the controllable valve arrangement 250, 250a, 250b, 250c in the liquid flow path substantially constant during the milking session, in some embodiments.

In other embodiments, controller 280 may be configured to generate and provide the control signal to the controllable valve arrangement 250, 250a, 250b, 250c in order to maintain the fluid pressure upstream of the controllable valve arrangement 250, 250a, 250b, 250c in the liquid flow path at distinct plurality of fluid pressure levels during the milking session, based on the obtained pressure level measurements.

The direction and/or size of the adjustment of the adjustable passage, i.e. increasing or decreasing/closing the passage may be determined by the controller 280, 280a, 280b in several distinct ways in different embodiments. For example, the controller 280, 280a, 280b may compare the obtained respective pressure level measurement with a desired vacuum pressure level; or alternatively a desired vacuum pressure interval.

Alternatively, the controller 280, 280a, 280b may compare the latest obtained respective pressure level measurement with one or several previously obtained pressure level measurements and calculate the size of the adjustment of the adjustable passage based on the size of the difference between the respective pressure level measurements, and/or the change rate of the difference between the pressure level measurements.

When the obtained pressure level measurement is lower (for example 38 kPa below atmospheric pressure) than the desired vacuum pressure level (for example 35 kPa below atmospheric pressure), the controller 280, 280a, 280b may generate and provide a control signal to the controllable valve arrangement 250, 250a, 250b to decrease the adjustable passage in order to provide an increased fluid pressure, i.e. less under-pressure, upstream the controllable valve arrangement 250, 250a, 250b in the liquid flow path.

Alternatively, when the obtained pressure level measurement is higher (for example 32 kPa below atmospheric pressure) than the desired vacuum pressure level (for example kPa below atmospheric pressure), the controller 280, 280a, 280b may generate and provide a control signal to the controllable valve arrangement 250, 250a, 250b to increase the adjustable passage in order to provide a decreased fluid pressure, i.e. more under-pressure, upstream the controllable valve arrangement 250, 250a, 250b in the liquid flow path.

Hereby, a substantially constant fluid pressure may be maintained in the milking unit 140, 140a, 140b, regardless of the current milk flow rate. It is thereby possible to apply a relatively high milking vacuum, i.e. relatively high under-pressure, yet assuring teat integrity by not exposing the animal teats for a too high under pressure.

In some embodiments, the controller 280, 280a, 280b may generate the control signal to the controllable valve arrangement 250, 250a, 250b based on a difference between the obtained pressure level measurement and one or several previously obtained pressure level measurements. In case the difference in pressure level measurements is large, the control signal may cause the controllable valve arrangement 250, 250a, 250b to adjust the adjustable passage with a larger step than in the opposite case.

Thus, the size of the adjustable passage may be proportional to a difference between the latest obtained pressure level measurement and the previously obtained pressure level measurement.

In the embodiment illustrated in FIG. 2A, the milking units 140, 140a, 140b of the milking system 100 comprises a claw 242, connected to each of the teat cups 241, 241a, 241b, 241c. One single milk conduit 260, 260a, 260b, 260c may be connected to the claw 242, for extracting milk from the teats of the animal to the common milk line 130. The single milk conduit 260, 260a, 260b, 260c comprises one pressure sensor 270, 270a, 270b and one controllable valve arrangement 250, 250a, 250b, controlled by one controller 280, 280a, 280b.

In the alternative embodiment illustrated in FIG. 2B, one milk conduit 260, 260a, 260b, 260c may be connected directly to each teat cup 241, 241a, 241b, 241c. Each milk conduit 260, 260a, 260b, 260c may comprise one pressure sensor 270, 270a, 270b, 270c, and one controllable valve arrangement 250, 250a, 250b, 250c. All controllable valve arrangements 250, 250a, 250b, 250c comprised in the respective milking unit 140, 140a, 140b may be controlled by one dedicated controller 280, 280a, 280b.

The controller 280, 280a, 280b may in some embodiments generate the control signal to the controllable valve arrangement 250, 250a, 250b, 250c based on a calculated rolling average of a number of obtained pressure level measurements. Hereby, random fluctuations of measurement values may be evened out.

The controller 280, 280a, 280b may also be configured to, when all pressure level measurements performed during a predetermined time period exceeds a maximum pressure threshold limit, to generate a command to output an alert on an output device, related to the milking unit 140, 140a, 140b, for example a computer or telephone device of the farmer, and/or to completely shut off vacuum supply of the milking unit 140, 140a, 140b. The reason may be a malfunction of the controllable valve arrangement 250, 250a, 250b, 250c or other component of the milking system 100. Thanks to this security measure, harm caused to the animal teats is avoided or reduced.

The alert may for example be output on a mobile telephone, computer, and/or a wearable electronic device of the farmer, such as an intelligent watch and/or intelligent glasses or similar device. The alert may also, or alternatively, be output on a loudspeaker and/or display arranged at the farm.

In embodiments of the milking system 100, the controller 280, 280a, 280b may be configured to apply a latency period before making any changes in the control signal provided to the controllable valve arrangement 250, 250a, 250b, 250c.

By applying the latency period, for example about some few seconds, a sudden spike in milk flow, or some singular/isolated fluid pressure measurements does not trigger an unnecessary adjustment of the controllable valve arrangement 250, 250a, 250b, 250c, unless a consistently increased/decreased milk flow is performed. Teat integrity is thereby additionally enhanced.

The controller 280, 280a, 280b is with general advantage configured to perform the above-described procedure in an automatic manner by executing a computer program. Therefore, according to some embodiment, the controller 280, 280a, 280b may comprise a memory unit, i.e., non-volatile data carrier, storing the computer program, which, in turn, may contain software for making a processing circuitry in the form of at least one processor in the controller 280, 280a, 280b to execute the above-described actions when the computer program is run on the processing circuitry.

The milking system 100 may in addition also comprise a database or data storage memory in some embodiments, communicatively connected to the controller 280, 280a, 280b. The optional database may be configured to store data, for example related to various desired fluid pressure levels, such as for example the desired fluid pressure level, the desired fluid pressure interval, previously obtained fluid pressure level measurements etc.

The database may in some embodiments comprise individual milk flow data, or vacuum profile, stored associated with a respective animal identity reference.

It hereby becomes possible to generate and provide the control signals adapted to the applied vacuum profile/milk flow rate of the individual animal 110, 110a, 110b, 110c, 110d, 110e, 110f during the milking session.

The controller 280, 280a, 280b may thereby be configured to obtain an identity reference of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f at the milking point 120, 120a, 120b, 120c, 120d, 120e, 120f, before or at the beginning of the milking session. Based on the obtained identity reference, vacuum profile of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f may be obtained from the database. The controller 280, 280a, 280b may then generate and provide the control signal to the controllable valve arrangement 250, 250a, 250b, 250c in order to follow the obtained vacuum profile during the milking session of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f.

The identification of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f may be made by an animal identification sensor such as for example a camera that in conjunction with an image recognition program of the controller 280, 280a, 280b may identify the animal 110, 110a, 110b, 110c, 110d, 110e, 110f, based on an animal-unique skin pattern and/or visual markings made on the animal 110, 110a, 110b, 110c, 110d, 110e, 110f such as an animal-unique ID number on an ear tag, an ID number (or other animal-unique marking) on the hide, a bar code comprising the ID number.

Alternatively, in other embodiments, the animal identifying sensor may be based on a short distance radio wave communication. The identification of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f may then be made by the animal identifying sensor in form of a reader or transceiver, obtaining a signal from a Radio-Frequency Identification (RFID) tag associated with the animal 110, 110a, 110b, 110c, 110d, 110e, 110f, for example attached to an ear of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f, carried in a neck lace around the neck of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f, injected under the skin of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f, etc. Instead of RFID, the signaling may be based on Bluetooth, Wi-Fi, Near-Field Communication (NFC), etc.

The signal emitting tag may comprise electronically stored information for uniquely (at least uniquely within the farm) identifying the animal 110, 110a, 110b, 110c, 110d, 110e, 110f.

The animal identifying sensor may then provide the sensor detection data of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f, to the controller 280, over a wired or wireless communication interface.

The optional database/memory may comprise a physical device of integrated circuits comprising silicon-based transistors.

The milking session of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f may be regarded as beginning when the first teat cup 241, 241a, 241b, 241c is attached to the first teat, and/or when milk flow of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f is firstly detected; and/or when pre-treatment is performed on the first teat of the animal 110, 110a, 110b, 110c, 110d, 110e, 110f.

FIG. 3A schematically illustrates an embodiment of a controllable valve arrangement 250.

The controllable valve arrangement 250 comprises an actuator 310 arranged to receive the control signal from the controller 280. The actuator 310 may comprise a cylinder driven by an electrical motor or similar device and a first and a second plate. The milk conduit 260 is comprised between the first plate and the second plate. The cylinder acts on one of the first plate, or the second plate, thereby adjusting the adjustable passage 300 of the milk conduit 260 based on the received control signals of the controller 280 by adjusting the position of the plate in relation to the other plate.

In the illustration of FIG. 3A, the adjustable passage 300 is opened up to a maximum. The actuator 310 may reduce the adjustable passage 300 by pressing on the outside of the milk conduit