System for reading information from an animal tag at a predetermined position

Abstract

It is disclosed a system for reading tags for livestock, including -an animal tag (3), two readers (1, 2) and a radio transmitter (7) installed at an intermediate position (P3) between the two readers (1, 2) and configured to transmit a Long-Range Radio signal. The animal tag (3) receives the Long Range Radio signal when is active and at a distance from the transmitter (7) shorter than a first maximum distance (D1); the readers (1, 2) receives a beaconing signal from the animal tag (4), when the animal tag (5) is at a distance shorter than a second maximum distance (D2); the second maximum distance (D2) is shorter than the first maximum distance (D2).

Description

[0001] Title: System for reading information from an animal tag at a predetermined position.

[0002] Prior art

[0003] Systems for reading information from an animal tag in association with a position of the animal tag are known.

[0004] Known systems adopt the use of active tags, which are tags including an internal battery, an antenna, a radio interface powered by the internal battery, and a memory storing an identification number. The radio interface emits beaconing signals, such as a Bluetooth signal, for position determination at a reading system, and the beaconing signal includes the identification number, so as the reading system attributes the determined position to a certain animal tag, the one identified by the identification number.

[0005] Passive tags are unsuitable for such use. Passive tags include an antenna and a radio interface, but not a battery. They are powered by an electromagnetic signal emitted by the reading system (exciter), received by the antenna. However, the amount of power is not sufficient to enable the radio interface for transmission of a Bluetooth signal for position determination.

[0006] Moreover, the applicant noted other drawbacks in use of passive tags at the stage of reading the identification number in certain environments affected by electromagnetic noises, generated by appliances, such as devices frequently adopted for livestock management. Indeed, passive tags transmits at so called Low Frequency, 125-134 kHz, or so-called High Frequency, 13.56 MHz, and the electromagnetic noises of said appliances at such frequencies cause failures in reading the identification number.

[0007] On the other hand, active tags are subject to other issues when used in a system for position determination.

[0008] Each time the beaconing signal is emitted by the radio interface, energy of the battery is consumed and the lifetime of the battery is reduced. This is a considerable limitation since requires frequent replacements / recharges of the internal battery.

[0009] Prior art systems have tried to reduce this problem by emitting the beaconing signal at predetermined interval, instead of continuously. However, this solution is not completely satisfying when animals are free to move in wide areas, far from the reader where the information has to be read. In other words, power consumption of these systems may be tolerated if the position of the tag has to be monitored continuously (for real time application) but not if information on the animal tag has to be read only at a predetermined position.

[0010] Other prior art systems have tried to overcome the problem of power consumption of active tags by adopting physical fencing within which managing livestock. The fence is however unsuitable in certain application, where the animal must be left free. Virtual fencing, instead, is unsuitable to solve the mentioned problem since it requires continuously tracking animal movement, generally adopting GPS techniques, that are power demanding.

[0011] The problem at the base of the present invention is that of providing a system for reading information from an active tag at a predetermined position, and not at any position of the active tag, wherein both determination of the identification number and determination of the position is based on signals from the active tag, and not from a passive tag, therefore reducing power consumption and enabling the reading in environment with electromagnetic noises, substantially overcoming the drawbacks that currently affects the prior art systems.

[0012] Summary of the invention

[0013] The idea at the base of the present invention is that of reducing as much as possible the energy consumption of an active tag by actively determining, within the active tag, when a radio interface may be switched off and when it has to be switched on with the scope of enabling the active tag for the transmission of a beaconing signal useful for reading information on the tag when it is at a predetermined position. Moreover, the idea of the invention is to find a way to reduce the energy consumption also caused by a processor, a memory or other resources of the active tag for making the active tag identifiable by a reader system. Furthermore, the idea is to find a way to identify almost in real-time the tag when it is at the predetermined position, providing a trade-off between energy efficiency and speed of identification. The speed of identification is fundamental in some applications where other actions have to be promptly taken based on the animal tag identified, for instance when the action is actuation of a gate for guiding the animal along a first path, determined by the gate closure (or opening), rather than another path, which would be available for the animal in case of late actuation of the gate. Since the animal may move potentially at high speed, also quasi real time speed of identification is fundamental for closing (opening) the gate, and therefore properly handling such applications.

[0014] Based on the solution idea given above, the applicant managed to reduce consumption by determining when the radio interface can be switched off, when switching it on for receiving purpose only, when switching it on with the scope of receiving and transmitting an identification number of the tag, and reducing as much as possible energy consumption of the battery onboard the tag for the what strictly necessary to enable reading information from the tag at the predetermined position.

[0015] Based on the solution idea mentioned above, the technical problem is solved by a system according to claim 1. Advantageous embodiments of the system are claimed in dependent claims from 2 to 14.

[0016] Further features and advantages of the system as disclosed are apparent from an embodiment therefore, described hereafter with reference to some drawings, given only for exemplificative and not limiting purpose.

[0017] Brief description of the enclosed drawings

[0018] Fig. 1 is a schematic view of a system according to the present invention.

[0019] Fig. 2 is another schematic view of a method according to the present invention, wherein an animal tag is represented in a first mode of passive sensing (the cow is at the first position from the left hand side of fig. 2), since a Long-Range Radio signal transmitted by a transmitter placed between a main and a secondary node readers is not received by a radio interface of the animal tag, or it is so weak, i.e. with a so low signal to noise ratio, that the radio interface disregards it or cannot process it. In the first mode, the radio interface wakes up (is turned on) at predetermined intervals, for instance after 5 seconds during which it is switched off. The radio interface is switched on for the time strictly necessary to verify the presence of the signal. The signal to noise ratio is schematically represented by a curve “RSSI Candle to AT”, increasing proportionally to the distance of the animal tag (AT) with respect to the transmitter, this has being schematically represented with a Candle. In a second mode of active sensing (the cow is at the second position from the left hand side of fig. 2), when the Long-Range Radio signal is received (and the strength of the signal is not-disregardable) but not still sufficiently strong; the signal to noise ratio is still considered too low to start beaconing; at such distance any signal transmitted by the animal tag could not be reached by the readers or, even if reached, would be unrequired by the system, since scope of the system is keeping track of the animal at a predetermined position, in an area between the readers, close thereto, not at any positions far from the readers. Transmission from the animal tag at such distance is avoided to save energy. In the second mode, the radio interface wakes up (is switched on by a processor of the tag) at predetermined intervals only for receiving the Long-Range Signal, for instance after 500 milliseconds during which it is switched off. In this second mode, the radio interface is switched on for the time strictly necessary to verify the presence of the signal and to allow the processor processing the signal to noise ratio.

[0020] In a third mode of active sensing (the cow is now at the third position from the left-hand side of fig. 2) when the Long-Range Radio signal is received and stronger, the animal tag starts beaconing; at this distance the signal transmitted by the animal tag is reached by the readers. In the third mode, the radio interface wakes up (is turned on) at predetermined intervals, for instance after 500 milliseconds seconds during which it is switched off. In this third mode, the radio interface is switched on for the time strictly necessary to verify the presence of the signal and to allow the processor processing the signal to noise ratio and to transmit the beaconing signal.

[0021] In a fourth mode, optional, still of active sensing (the cow is now at the fourth position from the left-hand side of fig. 2, between the readers) when the Long-Range Radio signal is received and stronger, the animal tag may continuously beaconing (without switching off). As said, the fourth mode is optional and the animal tag may beacon switching on and off, substantially remaining in the third mode, or in case with different duration of switch off than in the second and third modes. From the tag perspective, the third mode and the fourth mode may be the same, as said above. From the readers perspective, however, when the animal is at the fourth position from the left-hand side of fig. 2 (i.e. when the animal tag is closed to the reader, such as between the readers, in particular at the predetermined position between the readers) the Signal to Noise Ratio is so high that the readers may track elevation and azimuth of the signal and determine angular position and tag identification.

[0022] Fig. 3a to 3c schematically represent modes in which a processor of a tag according to the present invention runs.

[0023] Fig. 4a and 4b schematically represent the readers in an X, Y, Z coordinate system.

[0024] Fig. 5 is a top view of the readers of fig. 4a.

[0025] Fig. 6 is a view of the system, with a radio transmitted including a beam antenna.

[0026] Fig. 7 is a view of the system, including sensor(s) for speed determination.

[0027] Fig. 8a and 8b is a view of the system, including landmark detection. Detailed description of the drawings

[0028] With reference to fig. 1 it is herein disclosed a system for reading information from an animal tag at a predetermined position P4.

[0029] “Reading information from the animal at the predetermined position” within the meaning of the present disclosure means that readability of the information from the animal tag at positions different from the predetermined one P4 is not required, or at least not mandatory.

[0030] The predetermined position P4 is a position where activity of the animal must be registered or controlled. Recording or controlling the activity at positions different from the predetermined one P4 is not required. To cite two examples: a) the predetermined position P4 is a position where an animal feeder is placed, and scope of the system is to record time when the animal eats from the feeder at position P4 and the identification number of the animal tag; b) the predetermined position P4 is a position where a gate has to be opened or closed, and scope of the system is to control movement of the animal at the gate, based on a unique identification number of the animal tag at the position P4. Readability of the information from the animal tag when the animal tag is at positions different from the predetermined one P4 has to be reduced as much as possible, to reduce also energy consumption of a battery on board the animal tag. Indeed, such readability depends on emission of a signal from the animal tag, and such emission is energy consuming for the animal tag.

[0031] The animal tag 3 is an active tag including the battery, a processor, a memory storing the unique identification number, and a radio interface 4. To make the information readable, particularly the unique identification number, the radio interface must be active.

[0032] According to the present disclosure, the signal emitted by the radio interface cannot be at Low Frequency, such as 125-134 kHz, or at High Frequency, such as 13.56 MHz, which are those frequencies emitted by passive tags, since those frequencies are affected by electromagnetic noises introduced in the farm environment by other appliances used by the farmer for livestock management; such noises cause the unreadability of signals emitted by passive tags.

[0033] The signal adopted for transmission in the animal tag according to the present disclosure is at frequencies in the order of GHz, such as 2.400-2.4835 GHz. The signal is a Bluetooth signal. Features of such signal emitted by the active tag is also suitable for position determination, and in particular to check if the signal is emitted from the predetermined position P4, as it will be explained further below.

[0034] The system includes a reading system. The reading system comprises at least two readers 1, 2. Each reader is installed at a respective position P1, P2 and includes a radio interface 5.

[0035] A radio transmitter 7 is installed at an intermediate position P3 between the two readers 1, 2. The intermediate position P3 and the predetermined position P4 may be overlapped, i.e. the radio transmitter 7 may be over the location P4 where the information has to be read, this last being at ground level. In any case, the intermediate position P3 and the predetermined position P4 may be very close. The radio transmitter 7 includes an antenna, mounted separately from the readers 1, 2, suitable to provide a directional beam. A directional beam is used with the aim of activating only animals approaching the predetermined position P4 from a race direction, and to avoid that the tags of those animals lingering around (but not approaching the predetermined position P4) are activated.

[0036] The radio transmitter 7 is configured to transmit a Long-Range Radio signal. “Long-Range Radio signal” means a signal that may be read from the radio interface 4 of the animal tag 3 also at long distances from the predetermined position P4. The radio frequency of the Long-Range Radio signal transmitted from the radio transmitter 7 is for instance 2,4 GHz. This radio frequency is preferred since it allows to equip the animal tag with the (same and only) radio interface for receiving the radio signal from the radio transmitter and for transmitting the beaconing signal. However, in another embodiment, the radio frequency of the Long-Range Radio signal is between 800 and 1000 MHz, preferably between 863 and 873 MHz or between 902 and 928 MHz, in general in the order of MHz; in this case, the animal tag may be equipped with a radio interface for receiving the radio signal from the radio transmitter which is separate and different from the radio interface for transmitting the beaconing signal.

[0037] The radio interface 4 of the animal tag 3 receives the Long-Range Radio signal from the radio transmitter 7 when the radio interface 4 is active and the animal tag 3 is at a distance from the transmitter 7 shorter than a first maximum distance D1. For instance, with reference to fig.

[0038] 1, when the animal is at a distance greater than D1, the radio interface 4, even if active, does not receive the signal or it is in any case uncapable of using it, since the intensity of the signal is too weak.

[0039] The radio interface 5 of the two readers 1, 2, instead, receives a beaconing signal from the radio interface 4 of the animal tag 3, when the animal tag 3 is at a distance shorter than a second maximum distance D2. The second maximum distance D2 is shorter than the first maximum distance D1, as represented in figure 1. If the animal tag 3 is at a distance greater than the second maximum distance D2, the radio interface 5 of the two readers 1, 2 does not receives the beaconing signal from the radio interface 4 of the animal tag 3, i.e. the Bluetooth signal, or in any case it is uncapable of correctly processing the signal and therefore it ignores it.

[0040] The processor of the animal tag 3 is configured to control the operation modes of the radio interface 4, to reduce as much as possible the energy consumption, while guaranteeing an almost real-time identification capability.

[0041] Hereafter, the operative modes are disclosed.

[0042] In a first mode, reception of the Long-Range Radio signal from the transmitter 7 is checked, sporadically. In this mode, the processor in the first mode switches off and on the radio interface 4 of the animal tag 3. Each switch off lasts for a first predetermined time interval Tl. Reception of the Long-Range Radio signal is checked at each switched-on between two switch-off. The first mode is kept by the processor until the Long-Range Radio signal is not received.

[0043] If the Long-Range Radio signal is received, the processor run in a second mode. In the second mode, the processor processes a signal to noise ratio, STN, of the Long-Range Radio signal. The processor is configured to run in the second mode until the signal to noise ratio STN of the Long-Range Radio signal is less than a first predetermined threshold, STN1.

[0044] The logic above is the following.

[0045] The active tag resources in the first mode (processor, radio interface, etc..) are kept at the minimum energy consumption, by keeping the processor active, at low power consumption mode, and not computationally busy, during the first predetermined period Tl and the radio interface 4 fully powered off during such first predetermined period Tl. The processor is active only for switching on the radio interface 4 when the first predetermined period is lapsed; the radio interface 4 switched on only checks the presence (reception) of the Long-Range Radio signal and then is immediately switched off by the processor to stop consumption thereto associated. In case, has been received by the radio interface 4, the processor remains in the first mode. The tag is indeed considered so far from the predetermined position P4 that any other activity, in the processor or in radio interface, is useless. As anticipated above, the processor in the first predetermined period Tl may switch in a low power consumption mode, in which, it only counts the lapse of the predetermined time interval Tl, while stopping any other activity.

[0046] The active tag resources in the second mode are still kept at a low level of energy consumption, by keeping the processor active, but not computationally busy, preferably at low power consumption mode, during a second predetermined period T2; the radio interface 4 is fully powered off during such second predetermined period T2. Again, the radio interface 4 is switched on by the processor when the second predetermined period T2 has lapsed only for checking the presence (reception) of the Long-Range Radio signal and then it is immediately switched off. In the second mode, the processor is computationally busy between two consecutive switches off of the radio interface only for what regards the computation of the signal to noise ratio STN and the comparison between signal to noise ratio ANT and the first predetermined threshold STN1. In case, STN is lower than STN1, the processor remains in the second mode. The processor also in the second predetermined period T2 may switch in the low power consumption mode, in which, it only counts the lapse of the predetermined time interval T2, while stopping any other activity. The tag is indeed considered not so far from the predetermined position P4 as in the first mode, but still too far for making any other activity, in the processor or radio interface, useful for allowing the readers reading information at the predetermined position P4.

[0047] In a third mode, if the signal to noise ratio STN of the Long-Range Radio signal is greater than the first predetermined threshold STN1, the processor activates the radio interface 4 of the animal tag 3 not only for check reception of the Long-Range Radio signal but also for transmission of the beaconing signal. In this mode, the animal tag is indeed considered at a distance quite proximate to the predetermined position P4, and therefore it is considered necessary to start emitting the beaconing signal to let the readers start checking whether the position of the animal tag is corresponding to the predetermined position, and therefore reading information from the animal tag 3, such as the unique identification number, and start recording other information such as time (see example a) above).

[0048] As said, the processor is configured to switch off the radio interface 4 for the second predetermined time intervals T2. The second predetermined time intervals T2 is shorter than the first predetermined time intervals Tl. Also in the third mode, the radio interface may be switched off for the second predetermined time intervals T2.

[0049] The Long-Range Radio signal is therefore received at each switched-on between two switch-off for processing the signal to noise ratio STN.

[0050] When the beaconing signal reaches the readers 1, 2, the systems determines whether the signal has been emitted from the predetermined position P4, in which case it is further processed, or whether it is emitted from a position different from the predetermined one P4, in which case it may be ignored. The two readers 1, 2 are configured to start receiving the beaconing signal when the signal to noise ratio STN is greater than a second predetermined threshold STN2.

[0051] In order to determine the position of the animal tag (actually, in order to determine if the tag is at the predetermined position), the angle of arrival of the beaconing signal at the readers is checked.

[0052] If the processor is in the third mode, the system is configured to:

[0053] -determine the angle of arrival of the beaconing signal transmitted from the radio interface 4 of the animal tag 3 to the radio interface 5 of the two readers 1, 2,

[0054] -determine if the animal tag 3 is at the predetermined position P4, -read at least the identification number of the animal tag 3 and a time when the animal tag 4 is at the predetermined position P4,

[0055] wherein the animal tag is determined to be at the predetermined position if an azimuth of the angle of arrival is 0 or close to 0.

[0056] In this regard, fig. 4a, 4b, and fig 5 are taken in consideration for more details.

[0057] In figure 4a, the two readers 1, 2 are schematically represented in an X, Y, Z coordinate system, having origin at a centre of the reader 1.

[0058] Each reader 1, 2, may have a plurality of antennas, for instance 8 antennas. The size of the readers in fig. 4a has been exaggerated with respect to the distance between the readers 1, 2, for easy of comprehension. Fig. 5 represents the readers 1, 2 in another scale, where the distance between readers 1, 2 is more realistic with respect to their size.

[0059] A vertical plane PL (again with reference to figure 4a) is a plane delimited by an axis X connecting the (centres) of the readers 1, 2 and an axis Z, which is perpendicular to axis X and to the ground, for instance passing through the origin (centre of the reader 1) of the coordinate system X, Y, Z.

[0060] In figure 4b, one of the readers, the reader 1, is represented in more detail, with indication on an azimuth angle and an elevation angle 0. The azimuth angle and the elevation angle 0 are angles delimited by the beaconing signal which is received by the reader 1. The same beaconing signal allows the other reader 2 (not represented in figure 4b) to delimit an azimuth angle ' and an elevation angle O’.

[0061] The animal tag is considered to be at the predetermined position P4 when the azimuth angles Φ, Φ' are 0 or close to 0.

[0062] In particular, the animal tag is determined to be at the predetermined position if the azimuth of the angle of arrival at both the readers 1, 2 is 0 or close to 0.

[0063] “Close to 0” means an angle between 0 and a predetermined angle | fi |. Fig. 5 is a top view of the readers 1, 2 of fig. 4a, for more details.

[0064] ß is the predetermined angle formed between the axis X and a line L1 passing through the center of the reader 1.

[0065] -ß is the angle formed between the axis X and a line L2 passing through the center of the reader 1, the line L2 being symmetrical to L1 with respect to the axis X.

[0066] Same predetermined angles ß and – ß are delimited for the second reader 2.

[0067] ß is the predetermined angle formed between the axis X and a line L3 passing through the center of the reader 2.

[0068] -ß is the angle formed between the axis X and a line L4 passing through the center of the reader 2, the line L4 being symmetrical to L3 with respect to the axis X.

[0069] Advantageously, according to the present invention, it is not required to determine the exact position of the tag.

[0070] The tag is determined to be at the predetermined position P4 if the azimuth of the angle of arrival is 0 or less than the predetermined angle | fi |, i.e. if - fi < azimuth of angle of arrival < fi. |ß| is for instance 15°.

[0071] Preferably |ß| is 10°.

[0072] More preferably, |ß| is 5°.

[0073] In a preferred embodiment, |ß| is less than 5°.

[0074] With reference to example a) mentioned above, for instance, the feeder is placed in the area between the two readers 1, 2, and more particular within the area indicated in fig. 5 with L1-L2-L3-L4. The term “predetermined position” has not to be read as a single point in space, such as a X, Y, Z coordinate, but a set of points.

[0075] In particular, if the predetermined position P4 is controlled with respect to an azimuth of the angle of arrival equal to 0, the set of points is formed by those points included in a (imaginary) vertical plane between the two readers 1, 2. The vertical plane is represented schematically with PL in fig. 4a (embossed line PL).

[0076] If the predetermined position has to be controlled with respect to an azimuth of the angle of arrival minor to | ß |, and not precisely at 0°, the set of points is formed by those points included in a (imaginary) volume between the two readers 1, 2. The volume is that delimited by planes passing through lines L1, L2, 3, L4, and perpendicular to the ground. These planes are represented schematically in figure 4a.

[0077] Advantageously, according to the invention, the precise position of the animal tag has not to be determined. To the contrary, it is only required to determine whether the animal tag is at a position on the vertical plane PL or within the volume PL1-PL2-PL3-Pl4, and this determination may be made based on the azimuth of the angles.

[0078] For instance, the feeder is behind the vertical plane PL and the animal, to eat in the feeder, has to pass with the neck through the vertical plane, so as the animal tag is identified at the vertical plane, i.e. the predetermined position P4. At that position, the time is read and stored together with the unique identification number in a memory of the system.

[0079] According to the present disclosure, switches between the operative modalities are controlled, for instance as follows.

[0080] If the Long-Range Radio signal is no longer received by the radio interface 4 of the animal tag, the processor switched from the second mode to the first mode. This switch allows to reduce power consumption, since in the first mode the processor does not process the signal to noise ratio STN and does not compare it with the first signal to noise ratio threshold STR1.

[0081] If the signal to noise ratio STN becomes less than the first predetermined threshold STN1, the processor switched from the third mode to the second mode. This switch allows to reduce power consumption, since in the second mode the radio interface is activated only for receiving Long Range Radio signal and not for transmitting the beaconing signal. Receiving the Long-Range Radio signal is much less consuming that transmitting the beaconing signal, i.e. the Bluetooth signal.

[0082] If the radio interface starts receiving the Long-Range Radio signal, the processor switched from the first mode to the second mode. This switch involves a minor increase of energy consumption since the radio interface still work in the reception mode, as when the processor is in the first model, but with an increased frequency of check (further details below).

[0083] If the signal to noise ratio STN becomes greater than the first predetermined threshold STN1, the processor switches from the second mode to the third mode.

[0084] Preferably, the predetermined time intervals T2, when the radio interface is switched off in the second and third modalities, includes a second mode time interval T22 and a third mode time interval T23. In particular, the processor is configured to switch off the radio interface 4 for the second mode time interval T22 when it runs in the second mode and to switch off the radio interface 4 for the third mode time interval T22 it is runs in the third mode. The second mode time interval T22 may be longer than the third mode time interval T23 (fig. 3a). Accordingly, the Long Range Radio signal is checked more frequently when the distance from the predetermined position 4 is considered to decrease.

[0085] In an embodiment of the present disclosure, the processor is configured to change a duration of the second mode time interval T22 and a duration of the third mode time interval T23. For instance, the duration (T22, T22’, T23, T23’) is inversely proportional to a value of the signal to noise ratio (STNa, STNb, STNc, STNd) of the Long-Range Radio signal (fig. 3b). The closer the animal tag is considered to the predetermined position, the shorter is the time interval in which the radio interface is kept switched off. The logic here is that the animal tag is considered approaching to the predetermined position if the signal to noise ratio increases and distancing therefrom if the signal to noise ratio decreases. According to a different embodiment of the disclosure, a duration (Ton) of a switch on of the radio interface 4 in the second mode is equal to or less than a duration of a switch on in third mode (fig. 3a, 3b). The duration is constant.

[0086] According to a different embodiment of the disclosure, a duration of a switch on (Ton, Ton’) of the radio interface 4 in the second mode and third mode is proportional to a value (STNe, STNf) of the signal to noise ratio of the Long-Range Radio signal (fig. 3c).

[0087] According to another embodiment of the disclosure, a duration of a switch on (Ton”) of the radio interface 4 in the first mode is shorter than a duration (Ton, Ton’) of the switch on in the second mode and the mode (Fig. 3c).

[0088] In an embodiment, the processor is configured to keep the radio interface 4 switched on in the third mode.

[0089] In a preferred embodiment, the Long-Range Radio signal complies with a LoRaWAN (Long Range Wide Area Network) standard communication protocol of the International Telecommunication Union, ITU-T Y.4480. The Long-Range Radio signal has a radio frequency preferably between 863 and 873 MHz or between 902 and 928 MHz. Hereafter are given some examples of durations, not however limiting the scope of protection of the invention, in the embodiment where constant values are attributed.

[0090] The first predetermined time interval T1 may be between 3 and 20 seconds, preferably between 5 and 10 seconds, more preferably 5 seconds.

[0091] The second predetermined time interval T2 is between 50 milliseconds and 2 second, preferably between 100 and 800 milliseconds, more preferably 500 milliseconds.

[0092] The identification number of the tag at the predetermined position is read almost in real-time. Almost in “real time” means that the identification is made in around 100 milliseconds or less. For instance, the third mode time interval T23 in the third mode (i.e. duration of switch off in third mode) is set to 70 milliseconds; the duration of the switch on of the radio interface 4 in the third mode is set to 30 milliseconds. In this case, a time to read the identification number of the animal tag 3 if the animal tag 3 is at the predetermined position P4 is less than 100 milliseconds from when the tag is switched. The time to receive the beaconing signal from when the tag switches on and starts beaconing is less than the duration of switch on, i.e. less than 30 milliseconds, since the tag is already at the predetermined location. Advantageously, the almost real-time identification allows to manage conditions when two animals are very close. Cows, for instance, tends to move keeping contacts one to the other, such as in a row, with one cow's face close to another cow's butt; thanks to the almost real-time identification, the system is able to drive a gate or barrier between the two cows, separating and delivering them in different directions, even when they move attached. After the animal has been read in the predetermined position P4, depending on the scope of the application, it might be preferred to avoid further reading. For instance, once it is known that the animal has eaten at 3.07 p.m., it is not required to record that it has eaten again at 3.08, 3.09, since this considered part of same activity (“lunch”). To the contrary, for instance, it is useful to record that it has eaten again at short distance, at 4.35 p.m., or after long time, at 5.07 a.m., to analyse its behaviour.

[0093] The processor is therefore configured to include the identification number of the animal tag 4 at the predetermined position P4 in an exclusion list, if the identification number has been already read in a predetermined suspension time interval ta-tb.

[0094] Time of reading and identification number of the animal tag 4 in the exclusion list are not stored in the memory and the identification number of the animal tag 4 is excluded from the exclusion list after the predetermined suspension time interval ta-tb lapses.

[0095] The predetermined suspension time interval ta-tb starts when the identification number of the animal tag 4 is read for the first time in absolute or when the identification number of the animal tag 4 is read for the first time after being extracted from the exclusion list.

[0096] Moreover, according to an embodiment of the present disclosure, the processor of the animal tag may be configured to switch off the radio interface for predetermined time period, for instance in a certain time slot (such as from 2 a.m. to 6 a.m. or “nighttime”, to cite one), during which it is not considered necessary to read information from the tag. Accordingly, energy consumption may further be reduced.

[0097] In a preferred embodiment, the radio transmitter 7 is configured to emit a directional beam. In particular, the radio transmitter includes a directional antenna or beam antenna. The directional antenna or beam antenna is an antenna which radiates greater radio wave power in specific directions. Figure 6 is an example of such radiation. Movements of cows are schematically represented by arrows: after eating in a grazing area, the cows enter a milking area and then from the milking area into a corridor or pathway, longer than wider. Cows are identified at a predetermined position inside the pathway and, based on their “identity” (identification number), separated, for instance for selective artificial insemination: a cow to be inseminated is delivered to a first room, for instance placed immediately after the readers 1, 2, whereas another cow not to be inseminated enters a second room; the system opens a gate to the first room for the first cow and closes it to the second cow, to which it instead opens a gate to the second room. Opening and closures of the gates is controlled based on the identification number read at the predetermined position.

[0098] Advantageously, the beam antenna allows to concentrate the radio wave power along the length of the path, so avoiding that animal tags of cows which are grazing, relatively close to the antenna (see for instance position X), but out of the pathway, are reached by the radio signal. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain direction is desired, for instance along one specific direction, in contrasts with omnidirectional antennas such as dipole antennas which radiate radio waves over a wide angle. The radio signal transmitted by the antenna substantially covers an area of elliptical shape.

[0099] In an embodiment of the invention, the system is configured to determine also a speed of the animal tag 3. The speed as determined is used by the system to estimate when the animal might arrive at a place where an action has to be taken, for instance at a room where closure or opening of a gate has to be controlled. Based on the speed of the animal as determined, indeed, it may be necessary to take the action very fast. Still with reference to the example given above, in may happen that a first cow in the queue (pathway), to be inseminated, is moving slower than a second cow in the pathway. Since the first cow has to enter the first room immediately after the readers 1, 2, and the second cow has not, the system closes the gate of the first room immediately after the first cow enter. Alternatively, the system may actuate an intermediate barrier between the two cows, just for delaying the second cow until the first room is closed; the intermediate barrier may be arranged between the predetermined position P4 and the gate of the first room.

[0100] The speed may be determined by tracking the animal tag. In an embodiment, tracking is made by determining a change of a strength of the beaconing signal over time. The animal moves straight in the pathway, which is an obligatory way; the strength of the beaconing signal is read by one of the readers 1, 2 at a first time te1and at a second time te2. In an embodiment, the second time te2 is the time when the animal tag is at the predetermined position P4. The speed is determined as a function of the change over time of the signal strength of the beaconing signal: the greater is the change over time, the higher is the speed of the animal along the pathway. Advantageously, the speed is determined without knowledge of an absolute position of the animal tag (i.e. without geo-localization). Once the speed has been determined between time te1and time te2, the system assumes that the same speed is kept by the animal between time te2and a time te3(in the future); for instance, after determining the speed based on time te1and time te2, where time te2 is the time when the animal is at the predetermined position P4, it is assumed that same speed is kept by the animal between P4 and a subsequent position, with known distance from P4, for instance the position of a gate to be opened / closed. Also, the animal is assumed to move straight between P4 and the gate, since it moves in the obligatory path. Accordingly, a time te3 when the animal is assumed to arrive at the gate may be estimated. A formula to determine the time te3 is:

[0101] te3- te2= [distance between subsequent position and P4] / speed, where speed is the speed determined between times te3and te2and said distance is known a priori. For the above-mentioned tracking, the animal identification number is read also at time te2and te1, and not only when the animal is at the predetermined position P4.

[0102] In one embodiment, the speed is determined based on sensors, for instance n photocells (n >= 1). Fig. 7 represents three photocells PH1-PH3, installed at predetermined distances along the pathway, where the directional beam is transmitted. In this pathway, cows move only in queue; the cows do not overcome each other in the queue because the queue allows only one cow to pass at a time. The photocell PH3 is at the predetermined position P4, where the identification number of the tag is read. No other readings of the identification number are required according to this embodiment. Indeed, an animal A activates the first to the third cells in sequence; in other words, photocell PH1 is activated at time tPH1-Aby the animal A, then photocell PH2 is activated at time tPH2-Aby the same animal A and finally photocell PH3 is activated at time tPH3-Aby the animal A. These timings tPH1-A, tPH2-A, tPH3-Amay be stored in three different stacks. A fourth stack may be used to store the identification number of the tag, for instance tag A for animal A, as read at the predetermined position P4.

[0103] An animal B following the animal A in the queue also activates the photocells: photocell PH1 is activated at time tPH1-B, where tPH1-Bis subsequent to tPH1-A; then photocell PH2 is activated at time tPH2-band finally photocell PH3 is activated at time tPH3-b, where tPH2-Bis subsequent to tPH2-Aand tPH3-Bis subsequent to tPH3-A, since the animals do not overcome each other in the queue. Also timings tPH1-B, tPH2-B, tPH3-Bare stored in the three different stacks and in the fourth stack is store the identification number of tag B, as read at the predetermined position P4.

[0104] The distance between the photocells PH3 and PH2 is known (the distance between photocells PH2 and PH 1 is also known).

[0105] The times tPH2(i.e. tPH2-Aand tPH2-B) stored in the second stack and the times tPH3(i.e. tPH3-Aand tPH3-B) stored in the third stack are used to determine the speed between photocells PH3 and PH2 of the animal having the tag stored in the fourth stack (space over time).

[0106] Accordingly, a time te3when such animal is assumed to arrive at the gate may be estimated with the formula

[0107] te3 - tpH3 = [distance between subsequent position and P4] / speed, with same hypothesis mentioned above for the case of speed determined by tracking.

[0108] In one embodiment, only one sensor (photocell) is installed before the predetermined position P4; the system reads the time tPH2when the photocell is activated and the time tPH3when the animal tag is identified at the predetermined position P4. The speed is determined based on the distance between the sensor and the intermediate position P4 and the difference in time tPH3- tPH2(space over time). In other words, the system determines the speed based on a distance travelled by the animal between an installation position of the sensor PH2 and the predetermined position (P4), and a difference in time when the animal tag is, respectively, at the sensor and at the predetermined position P4. In a further embodiment, the system is configured to determine the shape of the cows (or other animals to be processed). The shape is determined to distinguish an animal with respect to another animal moving along the pathway (the queue), for further control. Preferably, landmark detection is used. In computer science, landmark detection is the process of finding significant landmarks in an image. The image is the image of the animal and it is taken by a vision system, such as a camera installed over the pathway. The image is preferably a top image of the cow. The system stores and runs an algorithm configured to determine key points of the image, for instance, the neck, the butt and the abdomen of the cow; each of these parts may be associated to three landmarks, i.e. 9 landmarks may be adopted to identify the shape of each cow. Advantageously, knowledge of different parts (neck, the butt and the abdomen) of each animal by means of landmarks improves precision detection and avoids “false positive”; indeed, being the arrangement of landmarks different from cow to cow, it uniquely identifies a cow and allows to separate and distinguish its shape from the one of another cow.

[0109] In this respect, for instance, fig. 8a is an example where a template is used as an image for any animal, i.e. no distinction among different shapes of the animal is made. The same image is used for any cow, i.e. the cow having the animal tag identification number E1135008373B and the cow having animal tag identification number El 135011273B. The cows in fig. 8a are distanced sufficiently to distinguish one from the other. However, it they were very close, the neck (or head) of a cow may be undistinguishable from the butt of the previous cow in the pathway (queue); moreover, in that condition of contacts or overlapping between cows, the photocell is unable to detect a discontinuity (i.e. it is unable to detect that the first cow has passed but not the second one). In that condition, it might happen that the two cows are “read” by the system, for instance for the purpose of speed determination, as one single cow, the one with identification number El 135011273B. This may end in a wrong processing of the cow, since a gate controlled based on the speed of the cow is opened or closed erroneously, misinterpreting the undiscontinued signal from the photocell as a single body moving between the photocell and the predetermined position P4.

[0110] This false positive is avoided with visual sensor fusion and landmark detection. Indeed, using landmarks, the shape of the cow 175 of fig. 8b is clearly distinguishable from the one of cow 176, even if the neck of the second cow overlaps with the butt of the first cow at the passage in front of the photocell. Accordingly, the cows are processed correctly and separately, and their speed may be correctly estimated.

[0111] Moreover, since a shape based on landmarks uniquely identifies a certain cow (animal), shape of each cow (animal) is associated to the animal tag identifier, for instance El 135011273B.

Claims

CLAIMS:

1. System for reading an animal tag for livestock at a predetermined position, the system including-an animal tag (3), the animal tag (3) being an active tag including a processor, a battery, a memory storing a unique identification number, and a radio interface (4),-two readers (1, 2), each installed at a respective position (Pl, P2) and including a radio interface (5),-a radio transmitter (7) installed at an intermediate position (P3) between the two readers (1, 2) and configured to transmit a Long-Range Radio signal, wherein-the radio interface (4) of the animal tag (3) is configured to receive the Long-Range Radio signal from the radio transmitter (7) when the radio interface (4) is active and the animal tag (3) is at a distance from the transmitter (7) shorter than a first maximum distance (DI), and-the radio interface (5) of the two readers (1, 2) is configured to receive a beaconing signal from the radio interface (4) of the animal tag (4), when the animal tag (5) is at a distance shorter than a second maximum distance (D2), the second maximum distance (D2) being shorter than the first maximum distance (D2), and the beaconing signal being a Bluetooth signal;the processor of the animal tag (3) is configured to:-run in a first mode, for checking reception of the Long-Range Radio signal from the transmitter (7), wherein the processor in the first mode switches off and on the radio interface (4) of the animal tag (3), each switch off lasting for a first predetermined time interval (Tl) and reception of said Long-Range Radio signal being checked at each switched-on between two switch-off, the processor running in the first mode until the Long-Range Radio signal is not received;-run in a second mode if the Long-Range Radio signal is received, wherein the processor in the second mode processes a signal to noise ratio (STN) of the Long-Range Radio signal, the processor being configured to run in the second mode until the signal to noise ratio (STN) of the Long-Range Radio signal is less than a first predetermined threshold (STN1);-run in a third mode if the signal to noise ratio (STN) of the Long-Range Radio signal is greater than the first predetermined threshold (STN1), wherein the processor in the third mode activates the radio interface (4) of the animal tag (3) for transmission of the beaconing signal;the processor is further configured to switch off the radio interface (4) for second predetermined time intervals (T2), shorter than said first predetermined time intervals (Tl), in said second mode and third mode, said Long-Range Radio signal being received at each switched-on between two switch-off for processing the signal to noise ratio (STN); wherein, if the processor is in the third mode, the system is configured to:-determine the angle of arrival of the beaconing signal transmitted from the radio interface (4) of the animal tag (3) to the radio interface (5) of the two readers (1, 2),-determine if the animal tag (3) isat the predetermined position (P4),-read at least the identification number of the animal tag (3) and a time when the animal tag (4) is at the predetermined position (P4), if the animal tag (3) is at the predetermined position (P4),wherein the animal tag is determined to be at the predetermined position if an azimuth of the angle of arrival is lower than | fi |, where fi is a predetermined angle.

2. System for reading tags for livestock according to claim 1, wherein the processor is further configured to switch from one to another of said first to third modes as follows:-switch from the second mode to the first mode, if the Long-Range Radio signal is no longer received;-switch from the third mode to the second mode, if the signal to noise ratio (STN) becomes less than the first predetermined threshold (STN1), and switch from the first mode to the second mode if it starts receiving the Long-Range Radio signal;-switching from the second mode to the third mode if the signal to noise ratio (STN) becomes greater than the first predetermined threshold (STN1).

3. System for reading tags for livestock according to claim 1, wherein the two readers (1, 2) are configured to start receiving the beaconing signal when the signal to noise ratio (STN) processed by the processor is greater than a second predetermined threshold (STN2).

4. System for reading tags for livestock according to claim 1, wherein said second predetermined time intervals (T2), shorter than said first predetermined time intervals (Tl), includes a second mode time interval (T22) and a third mode time interval (T23), wherein the processor is configured to switch off the radio interface (4) for the second mode time interval (T22) in said second mode and to switch off the radio interface (4) for the third mode time interval (T23) in said third mode.

5. System for reading tags for livestock according to claim 4, wherein said second mode time interval (T22) is longer that the third mode time interval (T23).

6. System for reading tags for livestock according to claim 5, wherein the processor is configured to change a duration of the second mode time interval (T22) and a duration of the third mode time interval (T23), wherein said duration is inversely proportional to a value of the signal to noise ratio of the Long-Range Radio signal.

7. System for reading tags for livestock according to claim 1, wherein a duration of a switch on of the radio interface (4) in said second mode is equal to or less than a duration of a switch on in said third mode, or a duration of a switch on of the radio interface (4) in said second modeand third mode is proportional to a value of the signal to noise ratio of the Long-Range Radio signal.

8. System for reading tags for livestock according to claim 7, wherein the duration of said switch on of the radio interface (4) in said third mode is 30 milliseconds.

9. System for reading tags for livestock according to claim 7, wherein a duration of a switch on of the radio interface (4) in said first mode is shorter than a duration of the switch on in said second mode and third mode.

10. System for reading tags for livestock according to claim 1, wherein said Long Range Radio signal complies with a LoRaWAN (Long Range Wide Area Network) standard communication protocol of the International Telecommunication Union, ITU-T Y.4480.

11. System for reading tags for livestock according to claim 1, wherein said Long Range Radio signal has a radio frequency between 863 and 873 MHz or between 902 and 928 MHz.

12. System for reading tags for livestock according to claim 1, wherein the processor is configured to keep the radio interface (4) switched on in said third mode.

13. System for reading tags for livestock according to claim 4, wherein said first predetermined time interval (Tl) is between 3 and 20 seconds, preferably between 5 and 10 seconds, more preferably 5 seconds and said second predetermined time interval (T2) is between 50 milliseconds and 2 second, preferably between 100 and 800 milliseconds, more preferably 500 milliseconds.

14. System for reading tags for livestock according to claims 8 and 13, wherein said third mode time interval (T23) in said third mode is 70 milliseconds, the duration of said switch on of the radio interface (4) in said third mode is 30 milliseconds, and a time to read the identification number of the animal tag (3) if the animal tag (3) is at the predetermined position (P4) is less than 100 milliseconds.

15. System for reading tags for livestock according to claim 1, wherein the processor is configured to include the identification number of the animal tag (4) at the position (P4) in an exclusion list, if the identification number has been already read in a predetermined suspension time interval (ta-tb), wherein time of reading and identification number of the animal tag (4) in the exclusion list are not stored in said memory and wherein the identification number of the animal tag (4) is excluded from the list after the predetermined suspension time interval (ta-tb) lapses.

16. System for reading tags for livestock according to claim 15, wherein the predetermined suspension time interval (ta-tb) starts when the identification number of the animal tag (4) is read for the first time or when the identification number of the animal tag (4) is read after extraction from the exclusion list.

17. System for reading tags for livestock according to claim 1, wherein the radio transmitter (7) is configured to emit a directional beam, said directional beam covering an area of elliptical shape.

18. System for reading tags for livestock according to claim 1 configured to further determine a speed of the animal tag (3), wherein the identification number of the animal tag (3) is read also at a time (tei) when the animal tag (4) is at a position different from the predetermined position (P4), and the speed is determined between time (tei) when the animal tag (4) is at the position different from the predetermined position (P4) and the time (tea) when the animal tag (4) is at the predetermined position (P4).

19. System for reading tags for livestock according to claim 18, wherein said speed is determined by tracking the tag.

20. System for reading tags for livestock according to claim 19, wherein said tracking includes determining a change over time of a strength of the beaconing signal at the time (tei) when the animal tag (4) is at a position different from the predetermined position (P4) and a time (tea) when the animal tag (4) is at the predetermined position (P4), the speed being proportional to said change.

21. System for reading tags for livestock according to claim 18, configured to estimate a time (tes) when the animal arrives at a position subsequent the predetermined position (P4), wherein a distance between said subsequent position and the predetermined position (P4) is known, wherein a speed between said subsequent position and the predetermined position (P4) is assumed to be corresponding to the speed determined, and said time (tes) is estimated with the formula te3 - tea = [distance between (subsequent position and predetermined position P4)] / speed determined.

22. System for reading tags for livestock according to claim 18, including at least a video camera configured to take pictures of animals from the top, the system being configured to uniquely identify each animal by means of landmark detections.

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