Method for operating a feed extruder and feed extruder

Abstract

A method is described for the operation of a feed extruder (3) arranged to move along a longitudinal axis (5) of a feeding table (1) at a distance (x) from a feeding table edge (7) and to extrude animal feed placed on the feeding table (1) transversely to the longitudinal axis (5) towards the feeding table edge (7) by rotational movement of a rotatable screw (9) driven by an electric motor (11). The method comprises obtaining values ​​of parameters associated with the electric motor (11) during operation of the feed extruder (3); and estimating the amount of animal feed extruded during that period based on the obtained values ​​of the parameters.A feed extruder (3) for animal feed is also described.

Description

[Background technology]

[0001] The present invention relates to the processing of animal feed on a feeding table.

[0002] In farms, such as livestock farms and / or dairy farms, animals are fed by distributing animal feed on a feeding table in front of the feed fence. As the animals eat, the amount of animal feed decreases. At some point, the remaining animal feed is out of reach of the animals and needs to be moved, e.g. pushed, towards the fence within reach of the animals, and at some point new animal feed needs to be prepared. The animal feed therefore needs to be attended to several times a day, which is time consuming. In recent years, especially in large livestock farms, it has been found preferable to use an automatic feed displacer to bring the animal feed closer to the animals. The use of an automatic feed displacer saves a lot of time for the farmer, who can then concentrate on other tasks on the farm while the automatic feed displacer is processing the animal feed on the feeding table.

[0003] While automatic feeding systems have been in use, efforts have been made to improve feeding systems, especially with regard to the operation of the system. WO2014 / 033275A1 is an example of a system for moving animal feed by a screw action type feed extruder. Although the system and feed extruder described in WO2014 / 033275A1 work well, it is desirable to provide an improved method related to the operation of the feed extruder. There is also a desire to provide an improved feed extruder for animal feed. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide an improved method relating to the operation of a feed extruder, taking into account, inter alia, the reliability of the process of estimating the amount of animal feed on the feeding table, and also to provide an improved feed extruder for animal feed. [Means for solving the problem]

[0005] This object is achieved by a method as defined in claim 1 and a feed extruder as defined in claim 13.

[0006] The above object is therefore achieved by a method relating to the operation of a feed pusher arranged to move along a longitudinal axis of the feeding table at a distance from an end of the feeding table and to push animal feed placed on the feeding table transversely to the longitudinal axis towards the end of the feeding table by rotational movement of a rotatable screw driven by an electric motor, the method comprising the steps of obtaining values ​​of a parameter related to the electric motor during a period of operation of the feed pusher and estimating an amount of animal feed pushed during that period based on the obtained values.

[0007] The operation of the electric motor can be described by parameters related to the electric motor. Thus, by obtaining values ​​of the parameters related to the electric motor, the condition of the electric motor can be monitored. The rotatable screw driven by the electric motor generates some braking force on the electric motor. However, the braking force is mainly related to the amount of animal feed extruded by the rotatable screw. The braking force increases when the extrusion rate of the animal feed increases, and the braking force decreases when the extrusion rate of the animal feed decreases. Thereby, the value of the parameter related to the electric motor correlates with the amount of animal feed extruded by the rotatable screw. Thus, the amount of animal feed extruded during a period of time can be estimated based on the obtained values ​​of the parameters during that period of time.

[0008] Obtaining the value of the parameter related to the electric motor can be achieved in a simple manner by using a measuring or sensing device configured to measure or sense the parameter. Thus, the amount of animal feed extruded during the period can be estimated in a simple and reliable manner without the need for complex equipment.

[0009] This achieves the above objective.

[0010] According to one embodiment, the method includes predicting a remaining amount of animal feed on the feeding table along at least a portion of the length of the feeding table based on the estimated amount of animal feed extruded during the period, such that information about the estimated amount of animal feed extruded during the period can be used to predict, i.e., forecast, the amount of animal feed ahead of the feed extruder along at least a portion of the length of the feeding table.

[0011] The prediction can be based on a predefined algorithm using the estimated amount of animal feed extruded during that period. For example, it can be predicted that along a predefined portion of the feeding table in front of the feed extruder there will be an amount of animal feed equal to the estimated amount of animal feed extruded during that period. The prediction can also be based on further information, for example, on the type and / or size of the animals along the feeding table. Thus, by knowing the amount of animal feed extruded during that period and by knowing the type and / or size of the animals along a portion of the feeding table, it can be predicted how much animal feed will remain in that portion of the feeding table. For example, the amount of animal feed along a portion of the feeding table where the same type of animals are eating and / or where animals of approximately the same size are eating will correspond to the amount of animal feed extruded during that period.

[0012] According to one embodiment, the method includes predicting a total amount of animal feed remaining across the feeding table based on the estimated amount of animal feed and based on the distance from the feeding table edge.

[0013] The feed table edge defines the side of the feed table from the feed table on which the animals eat.

[0014] The estimated amount of animal feed pushed out during that time period at a predetermined distance from the feeding table edge compared to a predetermined amount of animal feed at that predetermined distance from the feeding table edge can indicate the total amount of animal feed remaining on the entire feeding table. A prediction about the total amount of animal feed remaining on the entire feeding table can be made, for example, when the predetermined distance is the outermost distance or when the predetermined distance is the distance closest to the feeding table edge.

[0015] Thereby, an estimated amount of animal feed pushed out during the period that is equal to or greater than the first predetermined amount of animal feed at the first predetermined distance from the feeding table edge can indicate a first total amount of animal feed remaining on the entire feeding table. For example, if the first predetermined distance is the outermost distance from the feeding table edge and the first predetermined amount of animal feed is set to a relatively large amount of animal feed, it can be concluded that the first total amount of animal feed on the entire feeding table is the relatively large amount of animal feed remaining on the entire feeding table. The relatively large amount of animal feed can mean that there is enough animal feed on the entire feeding table to feed the animals.

[0016] Similarly, an estimated amount of animal feed pushed out during the period that is equal to or less than the second predetermined amount of animal feed at a second predetermined distance from the feeding table end indicates a second total amount of animal feed remaining on the entire feeding table. Thus, if the second predetermined distance is the closest distance to the feeding table end and the second predetermined amount of animal feed is set to a relatively small amount of animal feed, it is concluded that the second total amount of animal feed remaining on the entire feeding table is a relatively small amount of animal feed on the entire feeding table. A small amount of animal feed detected near the feeding table end means that most of the animal feed on the entire feeding table has been eaten, and may be advantageously used as a trigger to prepare and / or serve new feed.

[0017] According to one embodiment, the parameter is correlated with the load of the electric motor, which can be monitored by a sensor that can be placed on the electric motor. Thus, the value of the parameter can be obtained in a reliable and efficient way without the need for equipment protruding from the feed extruder.

[0018] According to one embodiment, the parameter is correlated to the current through the electric motor. Measuring the current through the electric motor provides information about how much energy the electric motor uses during the operation of the feed extruder. Thus, the value of the parameter can be obtained in a reliable and efficient way by simply monitoring the current through the electric motor.

[0019] According to one embodiment, the method includes measuring the distance traveled by the feed pusher along the longitudinal axis of the feeding table, whereby the distance traveled can also be used as a variable in estimating the amount of animal feed on the feeding table, thereby providing an improved method for estimating the amount of animal feed on the feeding table.

[0020] According to one embodiment, the method includes calculating a fractional amount of animal feed present along the measured travel distance based on the estimated amount of animal feed pushed during the period and the measured travel distance. Thus, a fractional amount of the total amount of animal feed along the feeding table can be calculated based on the estimated amount of animal feed and based on the measured travel distance, i.e. the amount present along the measured travel distance.

[0021] According to one embodiment, the method includes predicting a remaining amount of animal feed present in a remaining length of the feed table ahead of the measured travel distance based on the calculated portion amount of animal feed. The calculated portion amount of animal feed may be used to predict a remaining amount of animal feed ahead of the measured travel distance. For example, the remaining amount of animal feed ahead of the measured travel distance may be predicted to be the same as the calculated portion amount of animal feed. As a result, a further improved method related to the operation of a feed extruder may be provided, in which a remaining amount of animal feed present in a remaining length of the feed table ahead of the measured travel distance may also be predicted.

[0022] According to one embodiment, the method includes generating or updating a function representative of the current amount of animal feed present on the feeding table based on at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed, the predicted total amount of animal feed, or the calculated partial amount of animal feed. The function representative of the current amount of animal feed present on the feeding table may be used to visualize the current amount of animal feed and / or to make feeding decisions. Further processing and analysis may mean, for example, generating a map or chart of the current amount of animal feed. Thus, with the benefit of the generated function, feeding decisions may be easily made.

[0023] According to one embodiment, the method includes triggering the provision of information about the function to an entity. Thus, the information about the generated function can be provided to the entity, for example the information about the function can be sent to the entity for further processing. The information can be sent wired or wirelessly. Thereby, the entity can be located at the feed extruder or the entity can be located at a distance from the feed extruder.

[0024] According to one embodiment, the method includes triggering the display on a user interface of a visual representation of the function, which facilitates the user's understanding of the information. Displaying the visual representation of the function on the user interface makes it easier for the user to interpret the information and improves the process of drawing conclusions regarding the amount of animal feed on the feeding table and therefore regarding possible actions, if any, to be taken.

[0025] According to one embodiment, the method includes triggering transmission of a message to an animal feed preparation and / or dispensing device if at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed, the predicted total amount of animal feed, or the calculated partial amount of animal feed is below a predetermined value of animal feed and if the distance is less than or equal to a predetermined distance from the feeding table edge.

[0026] For example, the predetermined distance can be the distance closest to the end of the feeding table, such that if the predicted total amount of animal feed is below the predetermined amount of animal feed and if the distance is the distance closest to the end of the feeding table, it can be concluded that the entire feeding table has been eaten and replenishment of the animal feed along the entire feeding table is required.

[0027] Similarly, a conclusion about replenishing animal feed at a location along the feeding table is drawn if at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed, or the calculated portion amount of animal feed is less than a predetermined amount of animal feed at that location along the feeding table.

[0028] The above object is also achieved by a feed extruder for animal feed, comprising a rotatable screw and an electric motor arranged to drive the rotatable screw, the feed extruder operatively arranged to move along a longitudinal axis of the feeding table at a distance from an end of the feeding table and to extrude animal feed transversely to the longitudinal axis towards the end of the feeding table by rotational movement of the rotatable screw, the feed extruder comprising a sensor configured to obtain a value of a parameter related to the electric motor during a period of operation of the feed extruder, the sensor being arranged to communicate with a processing unit configured to estimate an amount of animal feed extruded during that period based on the obtained value of the parameter.

[0029] The operation of the electric motor can be described by parameters related to the electric motor. Thus, by obtaining values ​​of the parameters related to the electric motor, the condition of the electric motor can be monitored. The rotatable screw driven by the electric motor generates some braking force on the electric motor. However, the braking force is mainly related to the amount of animal feed extruded by the rotatable screw. The braking force increases when the extrusion rate of the animal feed increases, and the braking force decreases when the extrusion rate of the animal feed decreases. Thereby, the value of the parameter related to the electric motor correlates with the amount of animal feed extruded by the rotatable screw. Thus, the amount of animal feed extruded in a period of time can be estimated based on the obtained values ​​of the parameters during that period of time.

[0030] Obtaining the value of the parameter related to the electric motor can be achieved in a simple manner by using a measuring device configured to measure the parameter. Thus, the amount of animal feed extruded during the period can be estimated in a simple and reliable manner without the need for complex equipment. This achieves the above-mentioned objective.

[0031] The feed extruder offers advantages corresponding to those of the method described above.

[0032] According to one embodiment, the processing unit is configured to predict the remaining amount of animal feed on the feeding table along at least a portion of the length of the feeding table based on the estimated amount of animal feed extruded during that period, whereby information about the estimated amount of animal feed extruded during that period can be used to predict, i.e. forecast, the amount of animal feed ahead of the feed extruder along at least a portion of the length of the feeding table.

[0033] According to one embodiment, the processing unit is configured to predict a total amount of animal feed across the feeding table based on the estimated amount of animal feed and based on the distance from the feeding table edge.

[0034] The estimated amount of animal feed pushed out during that period at a given distance from the feeding table edge compared to a given amount of animal feed at that given distance from the feeding table edge can indicate the total amount of animal feed remaining on the entire feeding table. Predictions about the total amount of animal feed remaining on the entire feeding table can be made when the given distance is the outermost distance or when the given distance is the closest distance to the feeding table edge.

[0035] The estimated amount of animal feed pushed out during the period that is equal to or greater than the first predetermined amount of animal feed at the first predetermined distance from the feeding table edge can indicate a first total amount of animal feed remaining on the entire feeding table. For example, if the first predetermined distance is the outermost distance from the feeding table edge and the first predetermined amount of animal feed is set to a relatively large amount of animal feed, it can be concluded that the first total amount of animal feed on the entire feeding table is the relatively large amount of animal feed remaining on the entire feeding table. The relatively large amount of animal feed can mean that there is enough animal feed on the entire feeding table to feed the animals.

[0036] Similarly, an estimated amount of animal feed pushed out during the period that is equal to or less than the second predetermined amount of animal feed at a second predetermined distance from the feeding table end indicates a second total amount of animal feed remaining on the entire feeding table. Thus, if the second predetermined distance is the closest distance to the feeding table end and the second predetermined amount of animal feed is set to a relatively small amount of animal feed, it may be concluded that the second total amount of animal feed remaining on the entire feeding table is a relatively small amount of animal feed on the entire feeding table. A small amount of animal feed detected near the feeding table end means that most of the animal feed has been eaten and may be advantageously used as a trigger to prepare and / or serve new feed.

[0037] According to one embodiment, the parameter is correlated with the load of the electric motor, which can be monitored by a sensor that can be placed on the electric motor. Thus, the value of the parameter can be obtained in a reliable and efficient way without the need for equipment protruding from the feed extruder.

[0038] According to one embodiment, the parameter is correlated to the current through the electric motor. Measuring the current through the electric motor provides information about how much energy the electric motor uses during the operation of the feed extruder. Thus, the value of the parameter can be obtained in a reliable and efficient way by simply monitoring the current through the electric motor.

[0039] According to one embodiment, the feed extruder comprises a measuring unit configured to measure the distance travelled by the feed extruder along the longitudinal axis of the feeding table, whereby the distance travelled can also be used as a variable when estimating the amount of animal feed on the feeding table, whereby an improved method for estimating the amount of animal feed on the feeding table can be provided.

[0040] According to one embodiment, the processing unit is configured to calculate a fractional amount of animal feed present along the measured travel distance based on the estimated amount of animal feed pushed during that period and based on the measured travel distance. Thus, a fractional amount of the total amount of animal feed along the feeding table can be calculated based on the estimated amount of animal feed and based on the measured travel distance, i.e. the amount present along the measured travel distance.

[0041] According to one embodiment, the processing unit is configured to predict a remaining amount of animal feed present in a remaining length of the feeding table ahead of the measured travel distance based on the calculated portion amount of the animal feed. The calculated portion amount of the animal feed may be used to predict a remaining amount of animal feed ahead of the measured travel distance. For example, the remaining amount of animal feed ahead of the measured travel distance may be predicted to be the same as the calculated portion amount of the animal feed. As a result, a further improved method relating to the operation of the feed extruder may be provided, in which a remaining amount of animal feed present in a remaining length of the feeding table ahead of the measured travel distance may also be predicted.

[0042] According to one embodiment, the processing unit is configured to generate or update a function representative of the current amount of animal feed present on the feeding table based on at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed, the predicted total amount of animal feed, or the calculated partial amount of animal feed. The function representative of the current amount of animal feed present on the feeding table may be used to visualize the current amount of animal feed and / or to make feeding decisions. Further processing and analysis may mean, for example, generating a map or chart of the current amount of animal feed. Thus, with the benefit of the generated function, feeding decisions may be easily made.

[0043] According to one embodiment, the feed extruder is configured to provide information about the function to the entity. Thus, the information about the generated function can be provided to the entity, for example, the information about the function can be sent to the entity for further processing. The information can be sent wired or wirelessly. Thereby, the entity can be located at the feed extruder or the entity can be located at a distance from the feed extruder.

[0044] According to one embodiment, the processing unit is configured to trigger the display on the user interface of a visual representation of the function. The visual representation of the function facilitates the user's understanding of the information. Displaying the visual representation of the function on the user interface makes it easier for the user to interpret the information and improves the process of drawing conclusions regarding the amount of animal feed on the feeding table and therefore regarding possible actions, if any, to be taken.

[0045] According to one embodiment, the feed extruder is configured to trigger sending of a message to the animal feed preparation and / or dispensing device if at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed, the predicted total amount of animal feed, or the calculated partial amount of animal feed is below a predetermined value of animal feed and if the distance is less than or equal to a predetermined distance from the feeding table edge.

[0046] For example, the predetermined distance can be the distance closest to the feeding table edge. Thus, if the predicted total amount of animal feed is below the predetermined value of animal feed and if the distance is the distance closest to the feeding table edge, it is concluded that the animal feed is being consumed across the feeding table and replenishment of the animal feed along the entire feeding table is required.

[0047] Similarly, a conclusion about replenishing animal feed at a location along the feeding table is drawn if at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed, or the calculated portion amount of animal feed is less than a predetermined amount of animal feed at that location along the feeding table.

[0048] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0049] [Figure 1] FIG. 2 is a schematic diagram of a feeding table and a feed extruder operating on the feeding table. [Diagram 2] FIG. 1 is a perspective view of a feed extruder. [Figure 3.1] 1 is an example of a function that represents the current amount of animal feed on the feeding table. [Figure 3.2] 1 is an example of a function that represents the current amount of animal feed on the feeding table. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] In FIG. 1 a feeding table 1 and a feed extruder 3 operating on the feeding table 1 are shown diagrammatically. The feeding table 1 may be part of the floor of the barn. The feeding table 1 may have different shapes, for example a rectangular or square or an "L" or "T" shape. The feed extruder 3 is arranged to move along the longitudinal axis 5 of the feeding table 1 at a distance x from the feeding table edge 7, which defines the end and side of the feeding table 1 where the animals are eating. The positions of the animals on the feeding table 1 are indicated by a row of rectangles 2, each rectangle representing the position of one animal on the feeding table 1.

[0051] The feeding table 1 comprises a conductive wire 4 arranged so that the feed extruder 3 can move along the feeding table 1. The conductive wire 4 can be arranged as a loop integrated into the feeding table 1, this embodiment being shown in figure 1. As an alternative, part of the wire 4 can be arranged in the feeding table 1 and the remaining part can be suspended above the feeding table 1.

[0052] According to the embodiment of Fig. 1, the portion 4.1 of the wire 4 is arranged along the longitudinal axis 5 to enable the feed extruder 3 to move / operate on the feeding table 1 along a path parallel to the longitudinal axis 5 and parallel to the feeding table edge 7. The wire 4 may be moulded in the feeding table 1. The wire 4 is powered by a control unit 6, which also serves as a charging station for the feed extruder 3. It is noted, however, that other means for guiding the feed extruder 3 along the feed table 1 are possible other than a continuous conductor.

[0053] The feed extruder 3 comprises a positioning unit 8 configured to position the feed extruder relative to the feeding table edge 7. In the disclosed embodiment, the positioning unit 8 has four nodes, a, b, c, and d. The nodes a, b, c, and d may be positioned along a straight line at a distance dn from each other. For simplicity, only the distance dn between node a and node b is shown. However, the distance between the other nodes may be equal to the distance dn between node a and node b. The distance between the nodes may also be different. Thus, for example, the distance between node a and node b may be different from the distance between node b and node c. The distances between the nodes a, b, c, and d define a distance x between the feed extruder 3 and the feeding table edge 7. The distance x to the feeding table edge 7 may be, for example, 111 cm, 99 cm, 87 cm, and 75 cm, corresponding to nodes a, b, c, and d, respectively.

[0054] The positioning unit 8 is configured to communicate with or sense the wire 4 and guide the feed extruder 3 along the wire 4 through the nodes a, b, c or d. As mentioned above, the distance x to the feed table edge 7 is controlled by the nodes a, b, c or d, which are activated one at a time to determine the distance x to the feed table edge 7. The activated node communicates with the wire 4 such that the activated node follows the wire 4. Thus, by activating one of the nodes a, b, c or d, the feed extruder can change its position and thereby the distance x to the feed table edge 7. Thus, in this example, the activation of node d requires the feed extruder 3 to run along the wire 4.1 at the position closest to the feed table edge 7 and the activation of node a requires the feed extruder 3 to run along the wire 4.1 at the position furthest from the feed table edge 7. The node may be implemented by a sensor which, when activated, senses wire 4, thereby navigating the feed extruder to position the activated sensor directly above wire 4 (e.g., sensing wire 4 as strongly as possible).

[0055] In Fig. 1 the feed extruder 3 is shown moving a distance x defined by node b. According to the embodiment of Fig. 1, node d defines the shortest possible distance x to the feed table edge 7 and node a defines the longest possible distance x to the feed table edge 7. The feed extruder 3 can shift between nodes a, b, c and d during its operation, i.e. while moving along the longitudinal axis 5. Which node is activated can depend for example on the amount of animal feed 10 in front of the feed extruder 3.

[0056] The activation and deactivation of the nodes and thereby the change of the distance x to the feeding table edge may be performed automatically using software installed in the feed extruder 3, which may select an appropriate distance x based on, for example, the load of the motor running the feed extruder 3.

[0057] The feed extruder 3 is configured to extrude the animal feed 10 transversely to the longitudinal axis 5 towards the feeding table end 7 by the rotary movement of a rotatable screw 9 driven by an electric motor. The electric motor is shown in FIG. 2. From the point of view of the feed extruder, the animal feed 10 is therefore extruded to the right in FIG. 2. The rotatable screw 9 used to extrude the animal feed 10 has the advantage of eliminating compaction of the animal feed, as is the case with other automated systems on the market. Also, by means of the rotatable screw 9, extrusion and mixing of the animal feed is achieved, which makes the feed more attractive to the animals.

[0058] The rotatable screw 9 driven by the electric motor generates a braking force on the electric motor due to the inertia of the rotatable screw 9. However, the braking force is mainly related to the amount of animal feed 10 extruded by the rotatable screw 9. Thus, the braking force increases when the animal feed amount 10 increases, and decreases when the animal feed amount decreases. Thereby, by acquiring values ​​of a parameter related to the electric motor during an operation period of the feed extruder 3, the amount of animal feed extruded during that period at a distance x can be estimated based on the acquired values ​​of the parameter. The period can be, for example, 3, 5 or 9 seconds. The values ​​of the parameter related to the electric motor can be acquired during one period or multiple periods. Thus, the amount of animal feed extruded during that period can be estimated based on the acquired values ​​of the parameter from one or multiple periods.

[0059] The feeding table 1 has a length l. The amount of animal feed 10 can also be estimated along at least a portion of the length l of the feeding table 1 based on the estimated amount of animal feed extruded during that period. The estimated amount of animal feed extruded during that period can therefore be used to estimate, i.e. predict, the amount of animal feed ahead of the feed extruder along at least a portion of the length of the feeding table. The simplest algorithm is to estimate the estimated amount of feed along all or a portion of the length l of the feed table 1, e.g. assume the distance traveled during that period. Another possibility is to place indicators, e.g. beacons, transceivers or magnets at the beginning and end of at least one feeding station (box 2 in FIG. 1), to estimate the amount of feed extruded from the reception of a signal from the first beacon to the reception of a signal from the second beacon, and to extrapolate this estimated amount to any number of feeding stations for animals.

[0060] The parameter may be correlated to the load of the electric motor, or the parameter may be correlated to the current flowing through the electric motor. Thus, for example, a Hall effect based linear current sensor (not shown) may be used to measure the ampere level through the electric motor. The measured ampere level is then compared to the nominal ampere level of the electric motor. The load of the electric motor may be calculated based on the ampere level. The nominal ampere level means that the load of the electric motor is not increased, which may mean that the amount of animal feed on the feeding table is zero or a relatively small amount of animal feed. An increase in the ampere level means an increase in the amount of animal feed pushed out. The amount of animal feed may be proportional to the correlated ampere level, for example, 100 kg of animal feed corresponds to an increase in the ampere level of 5 A. The correlation between the amount of animal feed in kilograms and the ampere level may depend on the type of animal feed. Thus, animal feed with a higher moisture level causes a larger increase in friction force on the electric motor compared to animal feed with a lower moisture level.

[0061] The total amount of animal feed in the entire feeding table 1 can also be predicted based on the estimated amount of animal feed pushed out during that period and based on the distance x from the feeding table edge 7. As mentioned above, the distance x depends on which node a, b, c, or d is activated. Thus, if the feed extruder 3 operates at a distance x defined by node a and the estimated amount of animal feed pushed out during that period is equal to or greater than the first predetermined amount of animal feed, it is concluded that there is enough animal feed 10 in the entire feeding table 1. The first predetermined amount of animal feed may be set slightly less than the amount of fresh and new animal feed dispensed on the feeding table before the animals start eating.

[0062] Similarly, if the feed extruder 3 operates at a distance x defined by node d and the estimated amount of animal feed extruded during that period is less than or equal to the second predetermined amount of animal feed, it can be concluded that there is very little animal feed 10 remaining in the entire feed table 1. The second predetermined amount of animal feed may be set to be slightly above zero.

[0063] As shown in Figure 1, the feed extruder 3 has travelled a travel distance td. The travel distance td can be measured from the side edge 1.1 of the feeding table 1 or from a position at the feeding table along the beginning of the animal's feeding area (indicated by box 2). The travel distance td can be obtained for example by means of Hall sensors attached to the wheels of the feed extruder 3. Knowing the width of the animal's feeding area 2 makes it possible to use an estimated travel distance corresponding to this width of the animal's feeding area, rather than relying on beacons etc. as mentioned before.

[0064] The feed extruder 3 extrudes the animal feed 10 while moving along the longitudinal axis 5. As shown in Figure 1, the animal feed 10 is extruded towards the feeding table end 7 along a travel distance td.

[0065] By knowing the travel distance td, the partial amount of animal feed on the feeding table 1 along the measured travel distance td can also be calculated based on the estimated amount of animal feed pushed out during that period and based on the measured travel distance td. The partial amount of animal feed can be calculated by multiplying the estimated amount by the measured travel distance.

[0066] Also shown in Fig. 1 is an entity 13 and a feed preparation and / or distribution device 15. The entity 13 may be configured to receive information regarding a function shown in Fig. 3, which represents a current amount of animal feed present along at least a portion of the feeding table 1. The function may be based on a calculated portion amount of animal feed as described above. The function may also be based on a predicted remaining amount of animal feed present in a remaining length of the feeding table ahead of a measured travel distance, which predicted remaining amount of animal feed may be based on a calculated portion amount of animal feed.

[0067] The animal feed preparation and / or distribution device 15, e.g., an autonomous mixer wagon, or a feed distribution vehicle, may be configured to receive a message indicating, for example, that the estimated total amount of animal feed is below a predetermined value of the animal feed, in such a case, the message may indicate that a new set of animal feed needs to be prepared and / or distributed on the feeding table 1.

[0068] In figure 2 the feed extruder 3 shown in figure 1 is shown in a perspective view. The feed extruder 3 comprises an electric motor 11 arranged to drive a rotatable screw 9. The feed extruder 3 comprises a sensor 17 arranged to obtain a value of a parameter related to the electric motor 11. The parameter may be correlated to a load on the electric motor 11 or the parameter may be correlated to a current through the electric motor 11. As an example a Hall effect based linear current sensor may be used.

[0069] The sensor 17 may be located on the electric motor 11 or the sensor 17 may be located on a power cable (not shown) that supplies current to the electric motor 11. The sensor 17 is arranged to communicate with a processing unit 19 configured to estimate, based on the obtained values ​​of the parameters, the amount of animal feed pushed over a period of time at a distance from the feeding table end.

[0070] According to one embodiment, the processing unit 19 may be arranged in the feed extruder 3, i.e. the processing unit 19 may be integrated with the feed extruder 3 by being mounted in a casing of the feed extruder 3. As an alternative, the processing unit 19 may also be arranged at a distance from the feed extruder 3. In such a case the processing unit 19 is arranged to receive signals from the sensor 17, for example via a wireless communication system.

[0071] The processing unit 19 is configured to estimate the amount of animal feed pushed out during a period of time at a distance from the feeding table edge, as described in relation to FIG.

[0072] In FIG. 3.1, the current amount of animal feed according to the function F1 is shown. The function F1 is an example of the distribution of animal feed on the feeding table 1. The function F1 may also be called a map. The function F1 may include a first sub-function f11, a second sub-function f12, and a third sub-function f13. The sub-functions f11, f12, and f13 represent the amount of animal feed along the first travel distance td1, the second travel distance td2, and the third travel distance td3, respectively. The travel distances td1, td2, and td3 represent the travel distances of the feed pusher along the longitudinal axis of the feeding table, as described in connection with FIG. 1. The travel distances td1, td2, and td3 represent the travel distances of the feed pusher along the longitudinal axis of the feeding table, where the presence of animal feed was detected and the amount of animal feed was estimated. At an initial travel distance td0 measured from the side edge 1.1 of the feeding table 1, the amount of animal feed is estimated to be zero.

[0073] The first sub-function f11 is provided based on the obtained values ​​of the parameters related to the electric motor of the feed extruder during an initial period of operation of the feed extruder on the feeding table 1. When the first sub-function f11 is obtained, the feed extruder switches its position to the outer node, i.e., the distance to the feeding table end is increased. The feed extruder then continues to move along the feeding table 1 along the path defined by the outer node until a new amount of animal feed is estimated or until a predefined period of time has elapsed. The new amount of animal feed is greater than the amount of animal feed described in the first sub-function f11. When the predefined period of time has elapsed, the feed extruder returns to the previous node and thereby to the previous path defined by the previous node, which is closer to the feeding table end. The feed extruder returns to the previous node in order to control whether the amount of animal feed is less compared to the amount of animal feed described in the first sub-function f11. If the amount of animal feed remains substantially unchanged, the feed extruder switches again to the outer node. The feed extruder then continues to move along the feeding table 1 along the path defined by the outer nodes until a new amount of animal feed is estimated or a new predetermined period has elapsed and the procedure is repeated. The second sub-function f12 describes the case when a new amount of animal feed is estimated. The new amount of animal feed described by the second sub-function f12 is higher compared to the amount of animal feed described by the first sub-function f11.

[0074] The procedure of estimating the new amount of animal feed is repeated as above. As shown in Figure 3.1, the amount of animal feed described by the third sub-function f13 has been estimated along the third travel distance td3. The amount of animal feed described by the third sub-function f13 is less than the amount of animal feed described by the second sub-function f12.

[0075] As a result, a map of the current amount of animal feed present along at least a portion of the feeding table can be achieved by estimating the amount of animal feed and by generating respective sub-functions that represent the estimated amounts of animal feed.

[0076] A map of the current amount of animal feed indicates how much animal feed is present in different parts of the feeding table. A visual representation of function F1 may be displayed on a user interface, which may be a computer or a phone. Sub-functions f11, f12, and f13 may be indicated using different colors for each sub-function. This makes the animal feed preparation task easier for the farmer, who gets information about the current amount of animal feed on the feeding table.

[0077] FIG. 3.2 shows the current amount of animal feed according to another embodiment, which can be represented by another function F2. The another function F2 can be achieved in a similar manner to the above function F1, and therefore the process of generating the another function F2 will not be described in detail herein. As can be seen, the another function F2 includes a fourth sub-function f21 and a fifth sub-function f22. The sub-functions f21 and f22 are estimated along the fourth moving distance td4 and the fifth moving distance td5, respectively.

[0078] Similar to Fig. 3.1, the travel distances td4 and td5 represent the travel distance of the feed extruder along the longitudinal axis of the feeding table where the presence of animal feed was detected and the amount of animal feed was estimated. At an initial travel distance td0 measured from the side edge 1.1 of the feeding table 1, the amount of animal feed is estimated to be zero.

[0079] The feed extruder may be controlled to move, for example, along the contour of the animal feed 10 placed on the feeding table 1, by switching between the above nodes a, b, c, and d based on the value of the parameter, such that the parameter is within a predefined range. Thereby, the function or map shown in Figure 3.1 and Figure 3.2 may be achieved by the feed extruder following the contour of the animal feed present on the feeding table 1.

[0080] The invention is not limited to the disclosed embodiments but can be varied and modified within the scope of the following claims.

Claims

1. 1. A method relating to the operation of a feed pusher (3) arranged to move along a longitudinal axis (5) of a feeding table (1) at a distance (x) from a feeding table end (7) and to push animal feed placed on said feeding table (1) transversely to said longitudinal axis (5) towards said feeding table end (7) by the rotational movement of a rotatable screw (9) driven by an electric motor (11), comprising: - obtaining values ​​of parameters related to said electric motor (11) during a period of said operation of said feed extruder (3); - estimating the amount of animal feed extruded during said period based on said obtained values ​​of said parameters.

2. - predicting the remaining amount of animal feed on the feeding table along at least a portion of the length (l) of the feeding table (1) based on the estimated amount of animal feed pushed out during said period.

3. 3. The method according to claim 1 or 2, comprising predicting the total amount of animal feed remaining on the entire feeding table (1) based on the estimated amount of animal feed and based on the distance (x) from the feeding table edge (7).

4. The method according to any one of claims 1 to 3, wherein the parameter is correlated with the load of the electric motor (11).

5. The method according to any one of claims 1 to 3, wherein the parameter is correlated with the current through the electric motor (11).

6. The method according to claim 3, comprising measuring the distance (td) travelled by the feed extruder (3) along the longitudinal axis (5) of the feeding table (1).

7. - calculating a fractional amount of animal feed present along the measured travel distance (td) based on the estimated amount of animal feed pushed during the period and the measured travel distance (td).

8. The method according to claim 7, comprising predicting the remaining amount of animal feed present in the remaining length of the feeding table ahead of the measured travel distance based on the calculated portion amount of animal feed.

9. The method of claim 8, comprising generating or updating a function (F1, F2) representing a current amount of animal feed present on the feeding table based on at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed present in the remaining length of the feeding table, the predicted total amount of animal feed, or the calculated partial amount of animal feed.

10. The method according to claim 9, comprising: - triggering the provision of information about said function to an entity (13).

11. A method according to claim 9 or 10, comprising - triggering the display on a user interface of a visual representation of said functions (F1, F2).

12. The method according to any one of claims 8 to 11, comprising triggering the sending of a message to an animal feed preparation and / or distribution device (15) if at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed present in the remaining length of the feeding table, the predicted total amount of animal feed or the calculated partial amount of animal feed is below a predetermined value of animal feed and if the distance (x) is less than or equal to a predetermined distance from the feeding table end (7).

13. 1. A feed extruder (3) for animal feed, comprising a rotatable screw (9) and an electric motor (11) arranged to drive the rotatable screw (9), the feed extruder (3) being operatively arranged to move along a longitudinal axis (5) of a feeding table (1) at a distance (x) from a feeding table end (7) of the feeding table and to extrude animal feed transversely to the longitudinal axis (5) towards the feeding table end (7) by the rotational movement of the rotatable screw (9), the feed extruder (3) comprising a sensor (17) configured to obtain values ​​of a parameter related to the electric motor (11) during a period of operation of the feed extruder (3), the sensor (17) being arranged to communicate with a processing unit (19) configured to estimate an amount of animal feed extruded during said period based on the obtained values ​​of the parameter.

14. 14. The feed extruder (3) according to claim 13, wherein the processing unit (19) is configured to predict a remaining amount of animal feed on the feeding table (1) along at least a portion of a length of the feeding table (1) based on the estimated amount of animal feed extruded during the period.

15. 15. The feed extruder (3) according to claim 13 or 14, wherein the processing unit (19) is configured to predict a total amount of animal feed for the entire feeding table (1) based on the estimated amount of animal feed and based on the distance (x) from the feeding table edge (7).

16. The feed extruder (3) according to any one of claims 13 to 15, wherein said parameter is correlated with the load of said electric motor (11).

17. The feed extruder (3) according to any one of claims 13 to 15, wherein said parameter is correlated with the current through said electric motor (11).

18. 16. The feed extruder (3) according to claim 15, comprising a measuring unit (21) configured to measure a travel distance (td) traveled along the longitudinal axis (5) of the feeding table (1).

19. 19. The feed extruder (3) according to claim 18, wherein the processing unit (19) is configured to calculate a partial amount of animal feed present along the measured travel distance (td) based on the estimated amount of animal feed extruded during the period and the measured travel distance (td).

20. The feed extruder (3) according to claim 19, wherein the processing unit (19) is configured to predict a remaining amount of animal feed present in a remaining length of the feeding table (1) ahead of the measured travel distance based on the calculated partial amount of animal feed.

21. The feed extruder (3) of claim 20, wherein the processing unit (19) is configured to generate or update a function (F1, F2) representative of a current amount of animal feed present on the feeding table (1) based on at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed present in the remaining length of the feeding table (1), the predicted total amount of animal feed, or the calculated partial amount of animal feed.

22. 22. The feed extruder (3) according to claim 21, wherein the feed extruder (3) is configured to provide information about the functions (F1, F2) to an entity (13).

23. 23. The feed extruder (3) according to claim 21 or 22, wherein the processing unit (19) is configured to trigger the display of a visual representation of the functions (F1, F2) on a user interface.

24. The feed extruder (3) according to any one of claims 20 to 23, configured to trigger the sending of a message to an animal feed preparation and / or distribution device (15) if at least one of the estimated amount of animal feed, the predicted remaining amount of animal feed present in the remaining length of the feeding table (1), the predicted total amount of animal feed or the calculated partial amount of animal feed is below a predetermined value of animal feed and if the distance (x) is equal to or less than a predetermined distance from the feeding table end (7).

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