阅读说明：本技术 控制系统、旋转挤奶厅、用于控制旋转挤奶厅的方法及计算机程序 (Control system, rotary milking parlor, method for controlling a rotary milking parlor and computer program ) 是由 A.乌梅加德 于 2018-12-14 设计创作，主要内容包括：传感器装置测量表示旋转厅(100)的可移动平台(110)相对于静态基准点(P<Sub>ref</Sub>)的位置的参数(P)。继而基于参数(P),控制单元(150)影响可移动平台(110)的运动。具有第一发射器天线的第一发射器单元(210)放置在可移动平台(110)上,因此与可移动平台(110)一起移动。从发射器天线发射的第一无线电信号(S<Sub>ID</Sub>)包含定时基准并且唯一地标识第一发射器单元(210)。至少三个接收器站(221、222、223；224、225、226)放置成静态,其相应的接收器天线位于使得经由视线传播接收第一无线电信号(S<Sub>ID</Sub>)。基于第一无线电信号(S<Sub>ID</Sub>)和从第一无线电信号(S<Sub>ID</Sub>)中的定时基准导出的相应传播时间,接收器站生成参数(P)。(The sensor device measures a movable platform (110) representing the rotating hall (100) relative to a static reference point (P) ref ) Parameter (P) of the position of (a). The control unit (150) then influences the movement of the movable platform (110) based on the parameter (P). A first transmitter unit (210) having a first transmitter antenna is placed on the movable platform (110) and thus moves together with the movable platform (110). A first radio signal (S) transmitted from a transmitter antenna ID ) Contains a timing reference and uniquely identifies the first transmitter unit (210). At least three receiver stations (221, 222, 223; 224, 225, 226) are placed in a static state with their respective receiver antennas located so as to be passed throughLine-of-sight propagation receives a first radio signal (S) ID ). Based on a first radio signal (S) ID ) And from the first radio signal (S) ID ) The receiver station generates a parameter (P) based on the respective propagation times derived from the timing references in (1).)

1. A control system for a rotary milking parlor (100), the control system comprising:

a sensor device configured to measure a movable platform (110) representing the rotating hall (100) relative to a static reference point (bP_ref) A parameter (P) of the position of, and

a control unit (150) configured to receive the parameter (P) and to generate a control signal (Ctrl) affecting the movement of the movable platform (110) based thereon,

characterized in that the sensor device comprises:

a first transmitter unit (210) having a first transmitter antenna, the first transmitter unit (210) being configured to:

is placed on the movable platform (110) so as to move together with any movement of the movable platform (110), and

transmitting a first radio signal (S) from a transmitter antenna_ID) The first radio signal (S)_ID) Contains a timing reference and uniquely identifies a first transmitter unit (210),

at least three receiver stations (221, 222, 223; 224, 225, 226), each of which is configured to:

placed in a stationary state with its receiver antenna positioned such that during operation of the rotary milking parlor (100) the first radio signal (S)_ID) May propagate along a line of sight from a first transmitter antenna to a receiver antenna,

receiving a first radio signal (S)_ID) And on the basis thereof,

generating corresponding sensor signals (R1, R2, R3), an

A processing unit (230) configured to:

receiving sensor signals (R1, R2, R3) from at least three receiver stations and based on the first radio signals (S) contained in the signals_ID) The corresponding propagation time derived from the timing reference in (1),

parameters (P) are generated.

2. Control system according to claim 1, wherein said static reference point (P)_ref) Is a fixed point in space, whose position:

by the coordinates stored in the memory of the processing unit (230) being known,

via the at least three receiver stations (221, 222, 223; 224, 225, 22)6) And by having a reference point (P) at a static position_ref) A second transmitter unit of a second transmitter antenna is repeatedly measured, the second transmitter antenna transmits a second radio signal which contains the timing reference and uniquely identifies the second transmitter unit, and/or

Is repeatedly measured by means of at least one sensor not associated with the sensor device.

3. Control system according to any of the preceding claims, wherein the first radio signal (S)_ID) Is an ultra wideband signal.

4. A rotary milking parlor (100) comprising:

the control system according to any one of claims 1 to 3,

a movable platform (110), and

a drive unit (140) configured to control the movement of the movable platform (110) in response to the control signal (Ctrl).

5. A rotary milking parlor (100) according to claim 4 when dependent on any of claims 2 or 3, wherein:

the first detector member is arranged at a static reference point (P)_ref) At the position of the air compressor, the air compressor is started,

the second detector member is arranged at a well-defined position on the movable platform (110), and

the control unit (150) is configured to receive a detector signal from at least one of the first and second detector members and to determine based thereon when a well-defined position on the movable platform (110) passes a static reference point (Pref).

6. A rotary milking parlor (100) according to any of claims 4 or 5, wherein at least one receiver station (221, 222, 223) of said at least three receiver stations is placed with its receiver antenna in a central Area (AC) of the rotary milking parlor (100) around which the movable platform (110) Rotates (RF) during operation of the rotary milking parlor (100).

7. The rotary milking parlor (100) according to any of claims 4 to 6, wherein at least one receiver station (224, 225, 226) of the at least three receiver stations is placed with its receiver antenna in a peripheral area outside the outer periphery of the movable platform (110).

8. The rotary milking parlor (100) according to any of claims 4 to 7, wherein the first transmitter unit (210) is arranged on a piece of equipment on a movable platform (110), and the first transmitter unit (210) is further configured to transmit a first radio signal (S)_ID) To enable positioning of the apparatus on a movable platform (110) during operation of the rotary milking parlor (100).

9. The rotary milking parlor (100) according to any of claims 4 to 8, wherein the first transmitter unit (210) comprises a motion sensor configured to detect a micromotion of the first transmitter unit (210) with respect to the orientation of the first transmitter unit (210) with respect to a fixed reference frame, and the first transmitter unit (210) is configured to:

checking whether the amount of micro-movement exceeds a threshold value, and if so, checking whether the amount of micro-movement exceeds the threshold value

An alarm signal is generated.

10. A rotary milking parlor (100) according to claim 9, wherein:

if the amount of micro-motion exceeds a threshold value, the first transmitter unit (210) is configured to repeatedly transmit a first radio signal (S) at a first repetition frequency_ID) And an

If the amount of micro-motion is less than or equal to the threshold value, the first transmitter unit (210) is configured to repeatedly transmit a first radio signal (S) at a second repetition frequency lower than the first repetition frequency_ID)。

11. A rotary milking parlor (100) according to any of claims 9 or 10, wherein the motion sensor is configured to register at least one of:

displacement in three dimensions, and

acceleration in three dimensions.

12. The rotary milking parlor (100) according to any of claims 4 to 11, wherein the physical configuration of the movable platform (110) is described in a computer model accessible to a processing unit (230), and the processing unit (230) is configured to determine a set of positions on the movable platform (110) based on the parameter (P) and the computer model.

13. A method of controlling a rotary milking parlor (100), the method comprising:

measuring, via a sensor device, a movable platform (110) representing a rotating hall (100) relative to a static reference point (P)_ref) A parameter (P) of the position of, and

generating a control signal (Ctrl) based on the parameter (P), the control signal (Ctrl) being configured to influence the motion of the movable platform (110),

characterized in that the sensor device comprises a first transmitter unit (210) with a first transmitter antenna, and the method further comprises:

placing the first emitter unit (210) on the movable platform (110) such that the first emitter unit (210) moves with any movement of the movable platform (110), and

transmitting a first radio signal (S) from a transmitter antenna_ID) The first radio signal (S)_ID) Contains a timing reference and uniquely identifies a first transmitter unit (210),

receiving first radio signals (S) in at least three receiver stations (221, 222, 223; 224, 225, 226)_ID) Each of which is placed in a stationary state, the receiver antennas of which are positioned such that during operation of the rotary milking parlor (100) the first radio signals (S)_ID) May propagate along a line of sight from a first transmitter antenna to a receiver antenna,

generating a respective sensor signal (R1, R2, R3) in each of at least three receiver stations (221, 222, 223; 224, 225, 226), and

based on the first radio signal (S) contained in the signal_ID) The parameter (P) is generated from the respective propagation times derived from the timing references in (a).

14. The method according to claim 13, wherein the static reference point (P)_ref) Is a fixed point in space, and the method further comprises at least one of:

reading out static reference points (P) from a memory_ref) Coordinates of the location of (a);

via the at least three receiver stations (221, 222, 223; 224, 225, 226) and by means of the at least one reference point (P)_ref) A second transmitter unit of a second transmitter antenna repeatedly measures a static reference point (P)_ref) A second transmitter antenna transmitting a second radio signal containing a timing reference and uniquely identifying the second transmitter unit; and

repeatedly measuring a static reference point (P) via at least one sensor not related to the sensor device_ref) The position of (a).

15. The method of any of claims 13 or 14, further comprising:

at a static reference point (P)_ref) Is arranged with the first detector member,

arranging a second detector member at a well-defined position on the movable platform (110), an

Determining when a well-defined position on the movable platform (110) passes a static reference point (P) based on a detector signal received from at least one of the first and second detector members_ref)。

16. The method of any of claims 13 to 15, comprising:

at least one receiver station (221, 222, 223) of the at least three receiver stations is placed with its receiver antenna in a central Area (AC) of the rotary milking parlor (100), around which central Area (AC) the movable platform (110) Rotates (RF) during operation of the rotary milking parlor (100).

17. The method of any of claims 13 to 16, comprising:

at least one receiver station (224, 225, 226) of the at least three receiver stations is positioned with its receiver antenna in a peripheral region outside the outer periphery of the movable stage (110).

18. The method of any of claims 13 to 17, comprising:

the parameter (P) is measured a number of times repeatedly, and on the basis thereof,

an estimated velocity of the movable platform (110) is determined.

19. The method of claim 18, comprising:

the parameter (P) is further generated based on an estimated velocity of the movable platform (110).

20. The method of any of claims 13 to 19, wherein the first transmitter unit (210) comprises a motion sensor configured to detect a micro-motion of the first transmitter unit (210) relative to an orientation of the first transmitter unit (210) relative to a fixed reference frame, and the method comprises:

checking whether the amount of micromotion of the first transmitter unit (210) is below a threshold value, and if so, then

An alarm signal is generated.

21. The method of claim 20, wherein:

if the amount of micro-motion exceeds the threshold, the method further comprises repeating at a first repetition frequency (f)₁) Repeatedly transmitting a first radio signal (S)_ID) And an

If the amount of micro-movement is less than or equal to the threshold value, the method includes increasing the first repetition frequency (f)₁) Is heavyComplex frequency (f)₂，f₃) Repeatedly transmitting a first radio signal (S)_ID)。

22. The method according to any one of claims 20 or 21, wherein the method further comprises:

checking whether the amount of micromotion of the first transmitter unit (210) transitions from below to above a threshold value, and if so, then

At a second repetition frequency (f)₂) Repeatedly transmitting a first radio signal (S) from a first transmitter unit (210)_ID) And that within a predetermined interval (T) thereafter, the first transmitter unit (210) has a fine movement above a threshold,

continuing to repeatedly transmit the first radio signal (S) from the first transmitter unit (210) at the second repetition frequency_ID) Until the predetermined interval (T) expires, thereafter

As long as the amount of micromovement of the first transmitter unit (210) remains above a threshold value, at the first and second repetition frequencies (f)₁，f₂) Third repetition frequency (f) in between₃) Repeatedly transmitting a first radio signal (S) from a first transmitter unit (210)_ID) And if the amount of micromotion of the first transmitter unit (210) transitions from above the threshold to below the threshold, then

At a first repetition frequency (f)₁) Repeatedly transmitting a first radio signal (S) from a first transmitter unit (210)_ID)。

23. The method of any one of claims 20 to 22, comprising detecting the micromotion via at least one of:

displacement in three dimensions, and

acceleration in three dimensions.

24. A computer program (237) loadable into a non-volatile data carrier (235) communicatively connected to a processing unit (230), the computer program (237) comprising software for performing the method according to any of claims 13 to 23 when the computer program (237) is run on the processing unit (157).

25. A non-volatile data carrier (235) containing the computer program (237) of claim 24.

Technical Field

The present invention generally relates to rotary milking parlors. More particularly, the invention relates to a control system for a rotary milking parlor, a rotary milking parlor and a method of controlling a rotary milking parlor. The invention also relates to a computer program and a non-volatile data carrier.

Background

Rotary milking parlors (also known as rotary positioners) enable efficient milking of larger animals. The first rotary milking parlor was put into operation in 1930. Since then, the basic technical concept has been gradually perfected. Tracking the position of the movable platform of the device is important, among other things, for safety reasons and to ensure consistent operation.

US2010/0147221 describes an apparatus and a method for operating a rotary milking installation having a plurality of milking stations arranged on a movable platform. The movement of the platform is determined relative to a reference point and the position of the at least one milking station may be calculated using the position detection means. It is proposed here to arrange a visual and/or magnetic periodic pattern on the periphery of the turntable, wherein the local height of the line and the angle on the turntable can be unambiguously determined by determining the height of the line by means of optical and/or magnetic sensors.

However, due to its sensitivity to soling, this design risks providing unreliable results in a farm environment, especially if the positioning is based on optical registration only.

Disclosure of Invention

It is therefore an object of the present invention to alleviate the above problems and to provide a more reliable system for controlling a rotary milking parlor.

According to an aspect of the invention, the object is achieved by a control system for a rotary milking parlor. The control system comprises a sensor device, a control unit, a first transmitter unit, at least three receiver stations and a processing unit. The sensor device is configured to measure a parameter indicative of a position of a movable platform of the rotating hall relative to a static reference point. The control unit is configured to receive the parameters and to generate control signals based thereon that affect the motion of the movable platform. The first transmitter unit has a first transmitter antenna and is configured to be placed on the movable platform so as to move with any movement of the movable platform. The first transmitter unit is further configured to transmit a first radio signal, preferably in the ultra-wideband spectrum, from the transmitter antenna, the first radio signal containing a timing reference and uniquely identifying the first transmitter unit. Each of the at least three receiver stations is configured to be placed in a stationary state with its receiver antenna located such that during operation of the rotary milking parlor, a first radio signal may propagate along the line of sight from the first transmitter antenna to the respective receiver antenna. Each of the at least three receiver stations is further configured to receive the first radio signal and, based thereon, to generate a respective sensor signal. The processing unit is configured to receive sensor signals from at least three receiver stations and to generate a parameter based on respective propagation times derived from timing references contained in the first radio signal.

This control system is advantageous because it is not sensitive to soliton. The proposed radio positioning is further advantageous as it can be easily extended to include additional transmitter units to improve accuracy. Furthermore, it is straightforward to gradually improve the quality of the positioning by collecting a plurality of measurements over time. This improvement is particularly significant if two or more transmitter units are employed.

According to one embodiment of this aspect of the invention, the static reference point is a fixed point in space whose position: known by coordinates stored in a memory of the processing unit; repeatedly measured via at least three receiver stations and by means of a second transmitter unit having a second transmitter antenna located at a static reference point, wherein the second transmitter antenna transmits a second radio signal containing a timing reference and uniquely identifying the second transmitter unit; and/or repeatedly measured by means of at least one sensor not associated with the sensor device. Thus, there are many alternative ways of determining the actual physical location of the movable platform.

According to another aspect of the invention, the object is achieved by a rotary hall comprising the above-mentioned control system, a movable platform and a drive unit configured to control the movement of the movable platform in response to a control signal. The advantages of this rotating hall are apparent from the above discussion with reference to the proposed control system.

According to one embodiment of this aspect of the invention, the first detector member is arranged at a static reference point, the second detector member is arranged at a well-defined position on the movable platform, and the control unit is configured to receive the detector signal from at least one of the first and second detector members. Based on this, the control unit is configured to determine when a well-defined position on the movable platform passes a static reference point. This means that when the first milking station is located in front of the entrance gate, it is not complicated to register the exact point in time, for example.

According to another embodiment of this aspect of the invention, at least one of the at least three receiver stations is positioned with its receiver antenna in a central region of the rotary milking parlor about which the movable platform rotates during operation of the rotary milking parlor. Such an arrangement is advantageous because it saves space and reduces the likelihood that other equipment in the barn will affect the transmission of the radio signal.

According to a further embodiment of this aspect of the invention, at least one of the at least three receiver stations is positioned with its receiver antenna in a peripheral region outside the outer periphery of the movable platform. This arrangement may be beneficial if the interior region of the platform is used for other purposes and/or if the barn provides an alternative location for the receiver station.

According to a further embodiment of this aspect of the invention, the first transmitter unit is arranged on a specific device on the movable platform. The first transmitter unit is further configured to transmit a first radio signal to enable positioning of the device on the movable platform during operation of the rotary milking parlor. Thus, such a device and the movable platform may be co-located.

According to another embodiment of this aspect of the invention, the first transmitter unit further has a motion sensor configured to detect a micro-motion of the first transmitter unit relative to an orientation of the first transmitter unit relative to the fixed reference frame. Furthermore, the first transmitter unit is configured to check whether the amount of micro-motion exceeds a threshold value; if so, the first transmitter unit generates an alarm signal. Thereby, for example, undesired and/or harmful vibrations in the movable platform may be noticed at an early stage and appropriate corrective measures may be taken before the movable platform is damaged.

Preferably, the first transmitter unit is configured to repeatedly transmit the first radio signal at a first repetition frequency, e.g. 5 to 10Hz, if the amount of micro-motion exceeds the threshold value. Conversely, if the amount of micro-motion is less than or equal to the threshold value, the first transmitter unit is configured to repeatedly transmit the first radio signal at a second repetition frequency, e.g., 1Hz, which is lower than the first repetition frequency. In practice, the second repetition frequency may even be zero in order to save energy. In other words, the first radio signal is not transmitted at all. This may be particularly advantageous if it can reasonably be expected that a small amount of micromovement is caused by the movable platform being stationary.

According to an embodiment of this aspect of the invention, the motion sensor is configured to register displacements in three dimensions and/or accelerations in three dimensions. Thus, highly accurate movement patterns can be recorded and analyzed.

According to another aspect of the invention, the object is achieved by a method of controlling a rotary milking parlor. The method involves the following: a parameter indicative of a position of a movable platform of the rotating hall relative to a static reference point is measured via a sensor device. More precisely, the first emitter unit is placed on the movable platform such that the first emitter unit moves with any movement of the movable platform. The first transmitter has a transmitter antenna from which a first radio signal is transmitted. The first radio signal contains a timing reference and uniquely identifies the first transmitter unit. The first radio signals are received in at least three receiver stations, each of which is placed in a stationary state, the receiver antennas of which are located such that during operation of the rotary milking parlor the first radio signals can propagate along a line of sight from the first transmitter antenna to the receiver antennas. Generating a respective sensor signal in each of at least three receiver stations; and further based on the sensor signal, the generated parameter reflects a corresponding propagation time derived from a timing reference contained in the first radio signal. Finally, a control signal is generated based on the parameter, the control signal configured to affect motion of the movable platform. The advantages of the method and its preferred embodiments are apparent from the discussion above with reference to the proposed control system and rotary milking parlour.

According to another aspect of the invention the object is achieved by a computer program, which is loadable into a non-volatile data carrier communicatively connected to a processing unit. The computer program comprises software for performing the above-described method when the program is run on a processing unit.

According to another aspect of the invention the object is achieved by a non-volatile data carrier containing the computer program described above.

Further advantages, advantageous features and applications of the invention will become apparent from the following description and the dependent claims.

Drawings

The invention will now be explained in more detail by means of preferred embodiments disclosed as examples and with reference to the accompanying drawings.

1-2 illustrate examples of a rotary milking parlor and a control system therefor according to embodiments of the present invention;

FIG. 3 shows a graph illustrating how the repetition frequency of the transmitted radio signal varies over time in response to the amount of registration of the jog on the moveable platform; and

fig. 4 shows a general method of controlling a rotary milking parlor according to the invention by means of a flow chart.

Detailed Description

Fig. 1 shows a first example of a rotary milking parlor 100 and a control system thereof according to an embodiment of the invention. The proposed control system comprises a sensor arrangement and a control unit 150.

The sensor device is configured to measure the representative rotationThe moveable platform 110 of the hall 100 is relative to a static reference point P_refThe parameter P of the position of (a). The control unit 150 is configured to receive the parameter P and generate a control signal Ctrl on the basis thereof that affects the movement of the movable platform 110, e.g. its rotational speed.

The sensor device in turn comprises a first transmitter unit 210, at least three receiver stations 221, 222 and 223, respectively, and a processing unit 230.

The first transmitter unit 210 has a first transmitter antenna and is configured to be placed on the movable platform 110 so as to move with any movement of the movable platform 110. The first transmitter unit 210 is further configured to transmit a first radio signal S from the transmitter antenna_ID. A first radio signal S_IDContains a timing reference and uniquely identifies the first transmitter unit 210, for example by a signature code.

Each of the at least three receiver stations 221, 222 and 223 is configured to be placed statically, with its receiver antenna located such that the first radio signal S is during operation of the rotary milking parlor 100_IDMay propagate along a line of sight from the first transmitter antenna to the receiver antenna. Thus, the first radio signal S_IDPreferably of relatively high frequency, for example in the ultra-wideband spectrum, with propagation characteristics similar to visible light.

Each of the at least three receiver stations 221, 222 and 223 is further configured to receive a first radio signal S_IDAnd based thereon generate corresponding sensor signals R1, R2, and R3, respectively. The sensor signals R1, R2 and R3 reflect the first radio signal S_IDThe corresponding propagation delay experienced when travelling from the transmitter antenna to the receiver station in question, i.e. the receiver antennas 221, 222 and 223 respectively. Due to the first radio signal S_IDContaining a timing reference, so that the first radio signal S can be transmitted by_IDAnd the first radio signal S in the receiver station_IDThe local timing references of the timing reference synchronization are compared to determine the propagation delay.

The processing unit 230 is configured to receive sensor signals R1, R2 and R3 from at least three receiver stations. Based on slaveA first radio signal S_IDThe processing unit 230 is further configured to generate a parameter P, i.e. the movable platform 110 of the rotating hall 100 relative to a static reference point P_refThe position of (a).

Thus, the parameter P may represent the angle of rotation relative to a central axis through the movable platform 110. Given that the configuration of the movable platform 110 is known and properly described, different individual positions of all elements on the movable platform 110 can be established based on the parameter P. Preferably, the physical configuration of the movable platform 110 is described in a computer model accessible to the processing unit 230. For example, to obtain information about the respective locations of all booths, the first transmitter unit 210 may be associated with a particular location in a given booth. Assuming that the movable platform 110 has, for example, 60 identical and evenly distributed booths, the parameter P also reveals the respective positions of all other booths and their respective equipment. After recording the parameter P over a period of time, and assuming a linear movement, all these positions can be determined very accurately. This is especially true if more than one transmitter unit is disposed on the mobile platform 110.

Static reference point P_refCan be known by: coordinates stored in the memory of the processing unit 230; measurements repeated by using at least three receiver stations 221, 222 and 223; and by means of a second transmitter unit having a reference point P at the static level_refA second transmitter antenna. Here, the second transmitter antenna transmits a second radio signal containing the timing reference and uniquely identifying the second transmitter unit. Thus, the receiver stations 221, 222 and 223 may determine the static reference point P similarly to how the parameter P is determined_ref. Furthermore, if the measurements are repeated, the static reference point P can be determined very accurately_refFor example by an averaging process.

Of course, the static reference point P_refMay also be repeatedly measured by means of at least one sensor not associated with the sensor device, such as an optical and/or magnetic sensor device.

The control system is arranged to control the movable platform 110 of the rotary milking parlor 100 according to an embodiment of the invention. To this end, the parameter P is fed to a control unit 150, which is configured to generate a control signal Ctrl that is based on the parameter P. The drive unit 140 is configured to receive the control signal Ctrl and control the motion of the movable platform 110 in response thereto.

For reference and orientation purposes, the control system must know the static reference point P_refThe position of (a). Thus, the first detector member may be arranged at a static reference point P_refHere, the second detector member may be arranged at a well-defined position on the movable platform 110.

Usually, a static reference point P_refCo-located with an important location of the rotating milking parlor 100, such as where an animal steps onto the entry area 120 on the movable platform 110, an exit area 130 where an animal steps off the movable platform 110, or a robot for washing the animal's teats is located.

Furthermore, it may be advantageous to arrange the first transmitter unit 210 on a specific device fixedly positioned on the movable platform 110. That is, as a result, during operation of the rotary milking parlor 100, the position of the device is immediately known.

In any case, the control unit 150 is configured to receive the detector signal from at least one of the first and second detector members and determine based thereon when a well-defined position on the movable platform 110 passes a static reference point P_ref. Thus, it may be accurately determined when the movable platform 110 has a predetermined orientation. Similar to the above, the quality of this information also improves over time, i.e. after multiple registrations have been recorded.

It can be seen that in the embodiment shown in fig. 1, the receiver stations 221, 222 and 223 are all placed with their receiver antennas in the central area AC of the rotary milking parlor 100, around which the movable platform 110 rotates the RF during operation of the rotary milking parlor 100. Preferably, in order to save space, at least one of the at least three receiver stations is placed with its receiver antenna in the central area AC.

Fig. 2 shows another example of a rotary milking parlor and a control system thereof according to an embodiment of the invention. Here, all three receiver stations 224, 225 and 226 are instead placed with their receiver antennas in a peripheral region outside the outer perimeter of the movable platform 110. For improved accuracy and reliability it is advantageous to separate the receiver antennas at a distance from each other. Thus, according to an embodiment of the present invention, at least one of the at least three receiver stations is positioned with its receiver antenna in a peripheral region outside the outer periphery of the movable stage 110.

Further, in general, position accuracy can be improved by repeated registration by increasing the number of transmitters and recording multiple registrations over time based on one or more identical transmitters and receivers. For example, if the position registration is updated at a frequency of 5Hz, the global positioning is done five times per second for one transmitter; for two transmitters, ten total fixes were made per second; for ten emitters, 50 total fixes per second and so on. Thus, as the number of transmitters increases, the measurement error decreases.

In addition, assuming that the movable platform 110 is rotatable, i.e., performs a rotational motion about an axis, each emitter unit on the movable platform 110 moves along a circular path. Thus, over time, not only will the angular position of the transmitter unit be determined with increased accuracy, but the size of the radius of the circular path will also be determined more accurately. Of course, if a series of measurements are recorded, the velocity of the movable platform 110 may also be determined relatively accurately. Given a relatively constant velocity, the positioning can be further enhanced.

Even if the accuracy of each registration is relatively low (e.g., ± 10cm), using multiple transmitter units may reduce the resulting uncertainty Δ x, as follows:

where Δ i is the uncertainty of each measurement and N is the number of measurements. For example, N is 5 and Δ i is 10cm, yielding Δ x of 4.5 cm; n is 10 and Δ i is 10cm, yielding Δ x of 1.4 cm.

The uncertainty can be reduced even further if an adaptive filter (e.g. of kalman type) is applied.

According to an embodiment of the invention, the first transmitter unit 210 further comprises a motion sensor configured to detect a micro-motion of the first transmitter unit 210 relative to a fixed reference frame, e.g. thus the orientation of the earth.

Thus, the motion sensor in the first transmitter unit 210 (or any other transmitter unit included in the system) is configured to register displacements in three dimensions and/or accelerations in three dimensions. Thereby, the start and/or stop pattern of the movable platform 110 can be recorded very accurately. This in turn provides a valuable basis for diagnosing the operation of the rotary milking parlor 100 and its movable platform 110.

In particular, according to an embodiment of the invention, the first transmitter unit 210 is further configured to check whether the micro-momentum exceeds a threshold value. If the first transmitter unit 210 finds that the threshold is exceeded, the first transmitter unit 210 is configured to generate an alarm signal. Thereby, undesired and/or harmful vibrations in the movable platform 110 may be noticed at an early stage and appropriate corrective measures may be taken before the rotary milking parlor 100 breaks down.

According to an embodiment of the invention, the repetition frequency of the transmissions of the first transmitter unit 210 depends on the amount of micromovement. More precisely, if the amount of micro-motion exceeds the threshold value, the first transmitter unit 210 is configured to repeatedly transmit the first radio signal S at a first repetition frequency_ID。

On the other hand, if the amount of fluctuation is less than or equal to the threshold value, the first transmitter unit 210 is configured to repeatedly transmit the first radio signal S at a second repetition frequency lower than the first repetition frequency_ID。

Fig. 3 shows an exemplary transmitted radio signal S_IDIs a graph of how the repetition frequency f varies with time t in response to the registration amount of micromovements on the movable platform 110.

Here, we assume to be mobileThe movable platform 110 is in a static state until a first time point t when the movable platform 110 starts to rotate₁And as a result the amount of inching increases above a threshold. Thus, up to a first point in time t₁The first transmitter unit 210 has a relatively low first repetition frequency f₁Transmitting a first radio signal S, e.g. 0-3Hz_ID. Then, from a first point in time t₁Initially, the first transmitter unit 210 is at a second repetition frequency f₂Transmitting a first radio signal S_IDThe second repetition frequency f₂Higher than the first repetition frequency f₁E.g. f₂Equal to 10-15 Hz.

Then, assuming that the amount of micromovement of the first transmitter unit 210 remains above the threshold value within a predetermined interval T thereafter, the first transmitter unit 210 continues at the second repetition frequency f₂Repeatedly transmitting a first radio signal S_IDUntil the expiration of a predetermined interval T. In the example shown in fig. 3, the predetermined interval T is at a second point in time T₂Expiration; and here the first transmitter unit 210 starts at the third repetition frequency f₃Repeatedly transmitting a first radio signal S_IDThe third repetition frequency f₃Are respectively at a first repetition frequency f₁And a second repetition frequency f₂In between, e.g. f₃Equal to 5-8 Hz. Thereafter, i.e. from a third point in time t₃Initially, the first transmitter unit 210 continues at the third repetition frequency f as long as the amount of micro-motion exceeds the threshold value₃Transmitting a first radio signal S_ID. This process is advantageous because it provides relatively accurate position data associated with activating the movable platform 110. At the same time, energy is saved during continuous operation.

It is often advantageous to configure the processing unit 230 described above to implement the processes described above in an automated manner, for example by executing a computer program 237. Thus, the processing unit 230 may be communicatively connected to a storage unit, i.e. a non-volatile data carrier 235, storing a computer program 237, the computer program 237 in turn comprising software for causing at least one processor in the processing unit 230 to perform the above-mentioned actions when the computer program 237 is run in the processing unit 230.

To summarize, and with reference to the flow chart in fig. 4, we will now describe a general method of controlling a rotary milking parlor according to the invention.

In a first step 410, a first transmitter unit is placed on the movable platform such that the first transmitter unit and its transmitting antenna move with any motion of the movable platform. Then, in step 420, a first radio signal is transmitted from the transmitter antenna. The first radio signal contains a timing reference. The first radio signal also uniquely identifies the first transmitter unit.

In a step 430, which is parallel to step 420, first radio signals are received in at least three receiver stations. Each of these stations is placed in a stationary state with its receiver antenna located such that during operation of the rotary milking parlor, a first radio signal may propagate along the line of sight from the first transmitter antenna to the receiver antenna. Thereby, the first transmitter antenna may be triangulated. Specifically, in step 440 following step 430, a respective sensor signal is generated in each of the at least three receiver stations.

Subsequently, in step 450 following steps 420 and 440, parameters are generated based on the respective propagation times, which in turn are derived from the timing references contained in the first radio signal. Since the propagation speed is the same for each receiver station (i.e. the speed of light), the propagation time corresponds to the respective distance between the transmitter antenna and the receiver antenna. Furthermore, the parameters are used to influence the movement of the movable platform, such as its rotational speed and/or the start and stop sequence.

After step 450, the process loops back to steps 420 and 430.

Preferably, although shown as discrete steps in fig. 4, all steps 420 to 450 are performed sequentially and simultaneously, such that, for example, when a radio signal is transmitted at a specific point in time in step 420, in step 450, the parameter is generated based on the radio signal transmitted at a slightly earlier point in time.

All of the process steps and any sub-sequence of steps described with reference to fig. 4 may be controlled by a programmed processor. Furthermore, although the embodiments of the invention described above with reference to the drawings comprise processors and processes performed in at least one processor, the invention thus also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other form suitable for use in the implementation of the process according to the invention. The program may be part of the operating system or may be a separate application program. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a flash memory, a ROM (read only memory), e.g. a DVD (digital video/universal disk), a CD (compact disc) or a semiconductor ROM, an EPROM (erasable programmable read only memory), an EEPROM (electrically erasable programmable read only memory) or a magnetic recording medium, e.g. a floppy disk or a hard disk. Further, the carrier may be a transmissible carrier such as an electrical or optical signal which may be conveyed via electrical or optical cable or by radio or by other means. When the program is embodied in a signal which may be conveyed directly by a cable or other device or means, the carrier may be constituted by such cable or device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being adapted for performing, or for use in the performance of, the relevant processing.

The term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components. However, the term does not preclude the presence or addition of one or more additional features, integers, steps or components or groups thereof.

The invention is not limited to the embodiments described in the drawings, but may be varied freely within the scope of the claims.