Gutting system comprising a force control system

Abstract

A gutting system for fish comprising a servomotor for moving a gutting tool along a predetermined time trajectory towards a predetermined position, a force measurement system for measuring a force exerted by the tool on the fish, a force control system configured to control the force exerted by the tool on the fish, a control system configured to perform steps of obtaining a threshold force value based on fish data indicative of a fish characteristic, and while the tool is moving determining that the force exerted by gutting tool exceeds or is going to exceed the threshold force value, and based said determination, activating the force control system to cause the force exerted by the tool to have a controlled, nonzero value below the threshold force value herewith causing the tool to follow a time trajectory different from the predetermined time trajectory.

Description

[0001] Gutting system comprising a force control system

[0002] FIELD OF THE INVENTION

[0003] This disclosure relates to a gutting system for gutting fish, in particular to such system comprising a force measurement system and a force control system. This disclosure further relates to computer-implemented method for controlling a gutting system, a method for gutting fish, a control system for controlling a gutting system, and a computer program for gutting fish.

[0004] BACKGROUND

[0005] Gutting systems for gutting fish enable automatic gutting offish, which saves time, is safer than manual gutting, and enables a more consistent gutting result. There is a continuous striving in the art to improve the quality of the gutting as performed by a gutting system.

[0006] WO2015 / 169320 discloses a fish processing machine for gutting fish. The machine comprises one or more fish processing means including pressing means for pressing a fish processing tool against or into the fish with a certain contact pressure at least during a part of a fish processing process. The fish processing machine also comprises control means arranged to receive input at least corresponding partly to a rigidity value of the fish, wherein the control means is arranged to adjust the contact pressure in accordance with the input.

[0007] A disadvantage of the fish processing machine disclosed in WO2015 / 169320 is that there is a significant risk that the machine damages the fish if the rigidity of the fish is different from the rigidity as expected based on the input received by the control means.

[0008] SUMMARY

[0009] Hence, a gutting system for gutting fish is disclosed herein. The gutting system comprises a gutting tool, for example a suction nozzle that is configured to remove organs out of the fish using negative pressure. The gutting system also comprises a servomotor for moving the gutting tool along a predetermined time trajectory towards a predetermined position relative to the servomotor herewith moving the gutting tool into an opened abdominal cavity of the fish for gutting the fish. The gutting system also comprises a force measurement system for repeatedly, preferably continuously, measuring a force exerted by the gutting tool on the fish while the gutting tool is moving towards the predetermined position. Further, the gutting system comprises a force control system configured to control the force exerted by the gutting tool on the fish. The gutting system also comprises a control system that is configured to perform steps of:

[0010] -obtaining a threshold force value that has been determined based on fish data that are indicative of one or more characteristics of the fish, and

[0011] -while the gutting tool is moving along the predetermined time trajectory, determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, and

[0012] -based on determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, activating the force control system to cause the force exerted bythe gutting tool on the fish to have a controlled, nonzero value below the threshold force value herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory, preferably still towards the predetermined position.

[0013] A time trajectory referred to herein may be understood as defining a plurality of positions and defining, for each position out of the plurality of positions, an associated time. As referred to herein, an element that is said to follow some time trajectory may be understood as that, at each time defined by that time trajectory, the element is at the position defined for that time. The plurality of positions as defined by time trajectory may be said to define a spatial path. It should be appreciated that an element can deviate from a time trajectory by not following the spatial path as defined by the time trajectory or by following the spatial path yet not being at the defined positions at the times defined for those positions. To illustrate, an element may deviate from a time trajectory in that it follows the defined spatial path but reaches the defined positions later than the times defined forthose positions.

[0014] The gutting system disclosed herein is advantageous in that it enables to ensure that the force that the gutting tool applies to the fish does not exceed a threshold force value. This way, damage to the fish due to the gutting tool exerting too high forces on the fish is prevented. The threshold force value is determined based on fish data that are indicative of one or more characteristics of the fish, so that it has an appropriate value. The gutting system disclosed herein may be said to be configured to switch between position-based control, which would by quite typical for a servomotor, and force-based control. With position-based control, the servomotor may adapt the force that it applies to the gutting tool as needed for the gutting tool to follow the predetermined time trajectory. However, if the force exerted by the gutting tool on the fish becomes too high, the gutting system will switch to force-based control to ensure that the threshold force value is not exceeded.

[0015] The fish processing machine disclosed in WO2015 / 169320 provides for force-based control. However, force-based control can damage the fish, especially if the fish is less rigid than expected based on the rigidity values that are input into the control means of the fish processing machine of WO2015 / 169320. In such case, the contact pressure of the fish processing tool may be far too high which may damage the fish. In contrast, the gutting system disclosed herein can start with positionbased control. If the fish is less rigid than expected, then relatively low forces, which are less likely to cause damage, are already sufficient for the gutting tool to follow the predetermined time trajectory.

[0016] The gutting system disclosed herein is further advantageous in that the movement of the gutting tool relative to the servomotor is not necessarily halted if the force at some point in time exceeds the threshold force value. The gutting system namely comprises the force control system which can then set the force exerted by the gutting tool on the fish to a nonzero value. This nonzero force value may then cause the gutting tool to continue moving relative to the servomotor and into the fish, albeit at a somewhat slower speed than the speed defined by the predetermined time trajectory. As a result, the gutting tool may still reach the bottom of the abdominal cavity, albeit somewhat later than intended. However, the gutting tool arriving at the bottom of the abdominal cavity with a delay is preferred over the gutting tool not reaching the bottom at all. To illustrate, it would be highly undesired if the gutting system would determine, based on the force exceeding the threshold force value, that the gutting tool has reached the bottom of the abdominal cavity and halt the movement of the gutting tool. If thegutting tool operates at some distance above the bottom of the abdominal cavity, then it will not operate effectively and the gutting result will likely not meet the applicable quality standards.

[0017] The fish that is gutted is preferably a salmon.

[0018] Obtaining the threshold force value may be performed by receiving an input, via a user interface, which input is indicative of the threshold force value. A human operator may for example manually measure a rigidity of a fish out of a certain batch, and determine the threshold force value for the entire batch based on the measured rigidity of the fish. The human operator may the input the threshold force value via the user interface into the control system, thus causing the control system to obtain the threshold force value.

[0019] The force measurement system for example comprises a mechanical transducer for measuring the force or torque that the servomotor applies to the gutting tool.

[0020] Determining that the force exerted by the gutting tool exceeds the threshold force value may involve a comparison between the force as measured by the force measurement system and the threshold force value. Determining that the force exerted by the gutting tool is going to exceed the threshold force value may involve predicting an expected force value based on previous measurements of the force exerted by the gutting tool on the fish. Such predicting for example involves extrapolating the previous force measurement. Determining that the force exerted by the gutting tool is going to exceed the threshold force value may additionally or alternatively involve determining, based on position data, a required force value that is required to cause the gutting tool to keep following the predetermined time trajectory, and then determining that this required force value is higher than the threshold force value.

[0021] The force exerted by the gutting tool on the fish having a controlled value may be understood as that the force is actively controlled to have a value within a desired range or to have a specific value. The force control system for example comprises a feedback loop that causes the servomotor to for example adapt the speed with which the gutting tool moves through the fish until the force measurement system measures the force exerted by the gutting tool on the fish to have a desired value or is within a desired range. Activating the force control system may be performed by the control system sending an activation signal to the force control system. This activation signal may be indicative of the nonzero value. It should be appreciated that the controlled, nonzero value may vary while the force control system is in active state.

[0022] In an embodiment, the control system is configured to perform the step of obtaining the threshold force value by

[0023] -receiving the fish data that are indicative of the one or more characteristics of the fish, and -determining the threshold force value based on the one or more characteristics of the fish indicated by the fish data.

[0024] This embodiment is advantageous in that the threshold force value is determined based on one or more characteristics of the fish. This allows to ensure that the threshold force value is appropriate for the to-be-gutted fish. For example, a higher threshold force value would typically be appropriate for fish that are more rigid.

[0025] In an embodiment, the one or more characteristics include at least one of:-a rigidity of the fish,

[0026] -a dimension of the fish, such as a width, height, length of the fish,

[0027] -a ratio between two dimensions of the fish, such as a ratio between length and width of the fish,

[0028] -an age of the fish,

[0029] -one or more farming conditions.

[0030] These characteristics may influence how much force can be applied to the fish without damaging it and are therefore preferably considered when determining the threshold force value.

[0031] In an embodiment, the gutting system comprises a fish measurement system that is configured to measure the one or more characteristics of the fish and output the fish data indicative of the one or more characteristics of the fish to the control system.

[0032] This embodiment is advantageous in that it allows for automatic determination of an appropriate threshold force value for each individual fish.

[0033] In an embodiment, the force control system is configured to control the force exerted by the gutting tool on the fish to have a substantially constant value while the force control system is in activated state.

[0034] This embodiment enables to ensure that the gutting tool keeps moving relative to the servomotor as fast as possible without damaging the fish. Preferably, the controlled, nonzero value is equal to or little bit less than the threshold force value.

[0035] In an embodiment, the predetermined time trajectory defines a spatial path. Then, the time trajectory different from the predetermined time trajectory may have the spatial path as defined by the predetermined time trajectory.

[0036] This embodiment enables for the gutting tool to keep moving along the same spatial path only at a lower speed than defined by the predetermined time trajectory.

[0037] In an embodiment, the servomotor comprises a position measurement system for repeatedly, preferably continuously, measuring a position of the gutting tool. In this embodiment, the control system is configured to perform steps of:

[0038] -while the force control system is in activated state, determining that the gutting tool is back on the predetermined time trajectory again, and

[0039] -based on determining that the gutting tool is back on the predetermined time trajectory again, deactivating the force control system herewith causing the gutting tool to follow the predetermined time trajectory again.

[0040] This embodiment is advantageous in that it allows the gutting system to switch back to positionbased control when appropriate. It may be that the gutting tool, due to the controlled, nonzero value exerted on the gutting tool by the servomotor, has moved at a higher speed than defined by the predetermined time trajectory and has caught up with the predetermined time trajectory. Additionally or alternatively, it may be that the time trajectory defines a particular position in association with a particular time and that the gutting tool happens to be at that particular position at that particular time. This may very well happen if the time trajectory not only defines the movement of the gutting tool for going into the fish, but also the movement of the gutting tool for exiting the fish. Then, the timetrajectory for exiting the fish may pass by very close to the current position of the gutting tool, which allows the gutting tool to catch up with the predetermined time trajectory.

[0041] In an embodiment, the force measurement system comprises the servomotor and the control system. In this embodiment, the servomotor is an electrical motor that is configured to output one or more electrical parameter values of the servomotor. Further, in this embodiment, the control system is configured to perform a step of determining the force exerted by the gutting tool on the fish based on the one or more electrical parameter values as output by the servomotor.

[0042] This embodiment advantageously allows to measure the force exerted by the gutting tool on the fish without having to implement mechanical transducers. Such mechanical transducers are typically vulnerable to wear and tear which may influence the force measurements over time and need to be replaced every now and then.

[0043] In an embodiment, the force control system comprises the servomotor and the control system. In this embodiment, the servomotor is an electrical motor. Further, the control system is configured to perform a step of sending to the servomotor a signal indicative of one or more electrical parameter values to cause the servomotor to operate with the one or more electrical parameter values herewith causing the force exerted by the gutting tool on the fish to have the controlled, nonzero value below the threshold force value.

[0044] This embodiment allows to directly control the force exerted by the gutting tool on the fish without having to rely on a feedback loop, thus without having to continuously measure the force when the force control system is active. Such force control based on measured force values may be less accurate, for example due to measurement errors. Further, controlling the force based on such feedback loop is relatively slow. However, when the gutting system has to change to force-based control because the force exceeds or is going to exceed the threshold force value, then the force is under control and at the desired nonzero value as soon as possible to reduce the risk of damaging the fish.

[0045] In an embodiment, the one or more electrical parameter values comprises a value for an electric current that drives the servomotor.

[0046] In this embodiment, the force measurement system typically comprises a current sensor.

[0047] Further, the force control system typically comprises a current control system that is configured to control the electric current that is provided to the servomotor.

[0048] In an embodiment, the predetermined time trajectory defines a or the spatial path comprising a plurality of path segments. In this embodiment, the control system is configured to perform steps of -obtaining a plurality of respective threshold force values for the plurality of path segments, wherein each threshold force value out of the plurality of threshold force values has been determined based on fish data that are indicative of one or more characteristics of the fish, and

[0049] -for each path segment out of the plurality of path segments, comparing, while the gutting tool is moving along the path segment in question, the force exerted by the gutting tool on the fish with the threshold force value determined for the path segment in question, and

[0050] -upon determining, for a particular path segment out of the plurality of path segments, that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force valueassociated with the particular path segment while the gutting tool is moving along the particular path segment, activating the force control system to cause the force exerted by the gutting tool on the fish to have a controlled, nonzero value below the threshold force value associated with the particular path segment herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory, preferably still towards the predetermined position.

[0051] This embodiment advantageously allows to determine a plurality of threshold force values for the gutting process of a single fish, which allows for even more accurate control of the gutting process. It may for example be that a relatively low threshold force value would be appropriate for a first part of the fish, for example for a part of the fish where the gutting tool enters the abdominal cavity, and that a relatively high threshold force value would be appropriate for a second part of the fish, or example a part of the fish that is closer to the bottom of the abdominal cavity. It may be that second part of the fish can better cope with a high force exerted by the gutting tool than the first part of the fish.

[0052] The step of obtaining the plurality of respective threshold force values may be performed by determining, based on the one or more characteristics of the fish as indicated by the fish data, the plurality of respective threshold force values for the plurality of path segments.

[0053] In this embodiment, if the force control system is in activated state, then the controlled, nonzero value exerted by the gutting tool on the fish may vary. Preferably, the nonzero, controlled value is equal to or just below the applicable threshold force value, so if the threshold force value varies for different path segments then the controlled value may also vary. For example, the controlled, nonzero value fora path segment near the entry point of the gutting tool into the fish may be relatively low, whereas it may be higher for a path segment near the bottom of the abdominal cavity.

[0054] In an embodiment, the plurality of path segments comprises a first path segment and a second path segment. Further, in this embodiment, the predetermined time trajectory defines a first time period for traversal of the first path segment and a second time period for traversal of the second path segment. In this embodiment, the plurality of threshold force values comprises a first threshold force value for the first path segment and a second threshold force value for the second path segment. The first path segment sits in the abdominal cavity above a bottom of the abdominal cavity during the first time period, and the second path segment sits at or under the bottom of the abdominal cavity during the second time period.

[0055] In an embodiment, the second threshold force value is higher than the first threshold force value. If the gutting tool reaches the bottom of the abdominal cavity it is preferably pressed against the bottom quite firmly so that the fish is effectively gutted.

[0056] Note that if the second path segment sits under the bottom of the abdominal cavity, it means that the gutting tool will not, in principle, reach the second path segment. This would namely require a force that causes the gutting tool to breakthrough the bottom of the abdominal cavity. The threshold force value would not allow for this to happen, in principle. As a result, the gutting system will have force-based control during the second time period, which is advantageous as this ensures that the gutting tool is pressed firmly against the bottom of the abdominal cavity.

[0057] One aspect of this disclosure relates to a computer-implemented method comprising the steps of-obtaining a threshold force value that has been determined based on fish data that are indicative of one or more characteristics of a fish, and

[0058] -receiving force data indicative of a force exerted by a gutting tool on the fish while the gutting tool is moving along a predetermined time trajectory, and

[0059] -determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, and

[0060] -based on determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, activating a force control system to cause the force exerted by the gutting tool on the fish to have a controlled, nonzero value below the threshold force value herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory, preferably still towards the predetermined position.

[0061] In this aspect, the computer-implemented method may comprise any of the steps disclosed herein which the control system is configured to perform.

[0062] To illustrate, in an embodiment, the computer-implemented method comprises

[0063] -receiving the fish data that are indicative of the one or more characteristics of the fish, and -determining the threshold force value based on the one or more characteristics of the fish indicated by the fish data.

[0064] In an embodiment, the computer-implemented method comprises

[0065] -while the force control system is in activated state, determining, preferably based on position data received from a position measurement system referred to herein, that the gutting tool is back on the predetermined time trajectory again, and

[0066] -based on determining that the gutting tool is back on the predetermined time trajectory again, deactivating the force control system herewith causing the gutting tool to follow the predetermined time trajectory again.

[0067] In an embodiment, the computer-implemented method comprises determining the force exerted by the gutting tool on the fish based on the one or more electrical parameter values as output by the servomotor.

[0068] In an embodiment, the computer-implemented method comprises sending to the servomotor a signal indicative of one or more electrical parameter values to cause the servomotor to operate with the one or more electrical parameter values herewith causing the force exerted by the gutting tool on the fish to have the controlled, nonzero value below the threshold force value.

[0069] In an embodiment, the computer-implemented method comprises

[0070] -determining, based on the one or more characteristics of the fish as indicated by the fish data, a plurality of respective threshold force values for the plurality of path segments, and

[0071] -for each path segment out of the plurality of path segments, comparing, while the gutting tool is moving along the path segment in question, the force exerted by the gutting tool on the fish with the threshold force value determined for the path segment in question, and

[0072] -upon determining, for a particular path segment out of the plurality of path segments, that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value associated with the particular path segment while the gutting tool is moving along the particular pathsegment, activating the force control system to cause the force exerted by the gutting tool on the fish to have a controlled, nonzero value below the threshold force value associated with the particular path segment herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory, preferably still towards the predetermined position.

[0073] In an embodiment, the computer-implemented method comprises

[0074] -determining a first threshold force value for a first path segment, and

[0075] -determining a second threshold force value for a second path segment, wherein

[0076] the first path segment sits in the abdominal cavity above a bottom of the abdominal cavity during the first time period, and the second path segment sits at or under the bottom of the abdominal cavity during the second time period.

[0077] One aspect of this disclosure relates to a method for gutting fish. The method comprises measuring, e.g. manually measuring, one or more characteristics of a reference fish thus obtaining fish data. The method also comprises inputting the fish data indicative of the measured one or more characteristics into a control system for controlling a gutting system. Additionally or alternatively to inputting the fish data, the method may comprise determining the threshold force value based on the fish data and inputting the threshold force value into the control system for controlling the gutting system. Herein, the step of determining the threshold force value may be performed by a human operator. In this aspect, the method also comprises the control system performing any of the computer-implemented methods described herein. If the method involves inputting the fish data into the control system, then the control system may perform the step of obtaining the threshold force value by determining the threshold force value based on the one or more characteristics as indicated by the fish data.

[0078] The reference fish may be the fish that is going to be gutted. However, the reference fish may also be some representative fish of the fish that is going to be gutted, such as a fish from the same batch.

[0079] One aspect of this disclosure relates to a control system for controlling a gutting system. In this aspect, the control system comprises a computer readable storage medium having computer readable program code embodied therewith, and a processor, preferably a microprocessor, coupled to the computer readable storage medium, wherein responsive to executing the computer readable program code, the processor is configured to perform any of the computer-implemented methods described herein.

[0080] One aspect of this disclosure relates to a computer program or suite of computer programs comprising at least one software code portion or a computer program product storing at least one software code portion, the software code portion, when run on a computer system, being configured for executing the any of the computer-implemented methods described herein.

[0081] A non-transitory computer-readable storage medium storing at least one software code portion, the software code portion, when executed or processed by a computer, is configured to perform any of the computer-implemented methods described herein.One aspect of this disclosure relates to a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out any of the computer-implemented methods described herein.

[0082] One aspect of this disclosure relates to a computer-readable data carrier having stored thereon any of the computer programs described herein.

[0083] The computer-readable data carrier may be hard disk, for example, or a signal.

[0084] One aspect of this disclosure relates to a computer readable storage medium having computer readable program code embodied therewith, and a processor, preferably a microprocessor, coupled to the computer readable storage medium, wherein responsive to executing the computer readable program code, the processor is configured to perform any of the computer-implemented methods described herein.

[0085] One aspect of this disclosure relates to a computer program or suite of computer programs comprising at least one software code portion or a computer program product storing at least one software code portion, the software code portion, when run on a computer system, being configured for executing any of the computer-implemented methods described herein.

[0086] One aspect of this disclosure relates to a non-transitory computer-readable storage medium storing at least one software code portion, the software code portion, when executed or processed by a computer, is configured to perform any of the computer-implemented methods described herein.

[0087] One aspect of this disclosure relates to a data carrier signal carrying any of the computer programs described herein.

[0088] Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise.

[0089] Embodiments of the present invention will be further illustrated with reference to the attached drawings, which schematically will show embodiments according to the invention. It will be understood that the present invention is not in any way restricted to these specific embodiments.

[0090] BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Aspects of the invention will be explained in greater detail by reference to exemplary embodiments shown in the drawings, in which:

[0092] FIG. 1 illustrates a gutting system 2 for gutting fish according to an embodiment;

[0093] FIG. 2 is a diagram illustrating a gutting process of a single fish;

[0094] FIG. 3 is a flow chart illustrating a method according to an embodiment for activating and deactivating the force control system;

[0095] FIG. 4 is a flow chart illustrating a method according to an embodiment for ensuring that the force exerted by the gutting tool on the fish has a controlled value;

[0096] FIG. 5 shows an isometric view of elements of a gutting device according to an embodiment; FIG. 6 shows another isometric view of the gutting device of figure 5;

[0097] FIG. 7 shows a gutting system according to an embodiment;

[0098] FIG. 8 shows a gutting system according to an embodiment comprising two gutting devices; FIG. 9 illustrates a data processing system according to an embodiment.DETAILED DESCRIPTION OF THE DRAWINGS

[0099] In the figures, identical reference numbers indicate identical or similar elements.

[0100] Figure 1 illustrates a gutting system 2 for gutting fish according to an embodiment. The system of figure 1 comprises gutting tool 4. Gutting tool 4 is for example a tool for opening the abdomen of the fish 16a, 16b. Alternatively, gutting tool 4 is suction tool that comprises a suction nozzle configured to remove, using negative pressure, internal organs that are present in the abdominal cavity of the fish 16a, 16b. Typically, the gutting system 2 comprises a plurality of gutting tools, however, for clarity, figure 1 only shows one gutting tool 4. The gutting system 2 typically comprises a conveyer system 18 for conveying fish along a conveying direction 20 so that the fish pass through the gutting system 2 and move past the gutting tool 4. As the fish pass the gutting tool 4, the tool may be moved relative to the gutting system 2 into the abdominal cavity of the fish 16a, 16b so that the tool can perform its gutting function there. To this end, the gutting system 2 comprises a servomotor 6 that is configured to move the gutting tool 4 along a predetermined time trajectory towards a predetermined position relative to the servomotor. (The servomotor is typically static relative to earth.) The servomotor 6 is for example configured to move a rod-like element 9 that is attached to the gutting tool 4. Although figure 1 only indicates (see the double arrow) up-and-down movement of the rod-like member 9 and the gutting tool 4, more complex movements are possible.

[0101] The depicted servomotor 6 comprises a position measurement system 8 that is configured to repeatedly, preferably continuously, measure the position of the gutting tool 4, for example in that it is configured to repeatedly measure a relative position of the rod-like member 9 relative to the servomotor.

[0102] The gutting system 2 of figure 1 also comprises a force measurement system 10 that is configured to repeatedly, preferably continuously, measure the force that is exerted by the gutting tool 4 on the fish 16a, 16b while the gutting tool 4 is moving towards the predetermined position. The force measurement system 10 may be a force sensor, for example a sensor positioned between rod-like element 9 and gutting tool 3 as in figure 1. Additionally or alternatively, the force exerted by the gutting tool 4 on the fish may be determined based on a value of an electrical parameter of the servomotor, such as a value of an electric current that drives the servomotor. This parameter value would then allow to determine the force or torque provided by the servomotor, for example to the rod-like member 9, and this force or torque can be taken as an approximation of the force exerted by the gutting tool 4 on the fish. Thus, the force measurement system may comprise a device for measuring an electrical parameter of the servomotor, such as a current sensor. Also, measuring the force exerted by the gutting tool 4 on the fish 16a, 16b may be performed by measuring the force or torque provided by the servomotor 6.

[0103] The gutting system 2 further comprises a control system 100. The control system 100 is configured to receive signals from the force measurement system 10 indicative of measured force values, and from the position sensor 8 indicative of the position of the gutting tool 4. The control system 100 is further configured to obtain a threshold force value that has been determined based on fish data indicative of one or more characteristics of the fish. To this end, the control system 100 forexample comprises a user interface, such as a keyboard and / or touch screen, that allows a human operator to input the threshold force value.

[0104] Additionally or alternatively, the control system 100 is configured to determine the threshold value based on one or more characteristics of the fish as indicated by fish data. In this case, the fish data may have been input into the control system 100 via a user interface by a human operator. Preferably, however, the control system 100 is configured to receive signals from a fish measurement system 12 that is configured to measure the one or more fish characteristics. This enables to automatically determine a suitable threshold force value for each fish that is going to be gutted. The fish measurement system 12 is for example configured to measure a rigidity of the fish. The rigidity of the fish can be determined using any tool or method available in the art. An example could be to press a probe against the fish meat and monitor the force on the probe when the probe is pushed into the fish meat (i.e. to monitor how the fish meat pushes back on the probe). The one or more characteristics include a rigidity of the fish and / or a dimension of the fish, such as a width, height, length of the fish, and / or a ratio between two dimensions of the fish, such as a ratio between length and width of the fish, and / or an age of the fish and / or one or more farming conditions.

[0105] In the embodiment of figure 1 , the control system 100 is configured to send signals to the servomotor 6 for controlling the servomotor 6. This may allow the control system 100 to control the force exerted by the gutting tool 4 on the fish as will be explained with reference to figure 4. The gutting system 2 namely also comprises a force control system that is configured to control the force exerted by the gutting tool 4 on the fish and in a preferred embodiment the control system 100 is configured to perform at least some of the functions of the force control system.

[0106] Figure 2 is a diagram illustrating a gutting process of a single fish, wherein the horizontal axis indicates x-position relative to the fish and the vertical axis indicates y-position. The solid line represents a predetermined spatial path of the gutting tool. Further, the diagram indicates for a plurality of xy-positions, a time at which the gutting tool should be at that xy-position. The gutting tool should be at (xo,yo) at time to, at (xi,yi) at time ti, et cetera. Hence, the diagram indicates a predetermined time trajectory. It should be appreciated that the time trajectory as represented by the solid line may have been determined for a specific fish. In fact, the gutting system 2 may be configured to determine a suitable time trajectory for the gutting tool for each individual fish, for example based on size measurements of the fish and / or based on a detected location of an anal vent of the fish.

[0107] The dashed line in the diagram represents the spatial path that the gutting tool 4 has actually followed. The dash-dotted line shows the difference between the predetermined spatial path and the actually followed spatial path.

[0108] The spatial path as defined by the predetermined time trajectory, i.e. the solid line in figure 2, comprises a plurality of path segments, namely a first path segment between (xo,yo) and (xi,yi), a second path segment between (xi,yi) and (X2,y2), a third path segment between (X2,y2) and ( j.ys), a fourth path segment between (xa.ya) and (X4,y4), and a fifth path segment between (X4,y4) and (xs.ys).

[0109] In a preferred embodiment, the control system 100 obtains, e.g. determines, a respective threshold force value for each path segment. To illustrate, the threshold value for the first path segment may be relatively high because in this path segment the gutting tool is approaching the fishand has not yet entered the abdominal cavity of the fish. The threshold value for the second path segment may be lower. When the gutting tool traverses this second path segment, which happens between t1 and t2 according to the predetermined time trajectory, it will be moving in the abdominal cavity of the fish towards the bottom of the abdominal cavity but will still be above the bottom of the abdominal cavity. The respective threshold force values for the third and fourth path segment may be somewhat higher again. The third and fourth path segment are to be traversed in a time period between t2 and t4, and sit below the bottom of the abdominal cavity. The fifth path segment represents the retraction of the gutting tool 4 from the abdominal cavity of the fish. In the coordinate system of the gutting system, position (xo,yo) may be the same position as (xs.ys) so that the gutting tool, in the coordinate system of the gutting system, returns to its original position after traversal of the fifth path segment.

[0110] The servomotor 6 is configured to move the gutting tool 4 along the predetermined time trajectory. If the gutting tool 4 experiences a resistant force exerted by the fish on the gutting tool 4, then the servomotor 6 may increase the torque or force that it provides to for example the rod-like member 9, so that the gutting tool 4 remains on the predetermined time trajectory. However, if the gutting tool 4 exerts a very high force on the fish, it may damage the fish which is, of course, undesired.

[0111] The gutting system 2 disclosed herein prevents such damage in that its control system 100 is configured to determine that the force exerted on the fish exceeds or is going to exceed the applicable threshold value and, in response, activate a force control system to cause the force to have a controlled, nonzero value. To this end, the control system 100 may repeatedly receive force measurements from the force measurement system 10 and may compare each measured force value with the applicable threshold force value.

[0112] Figure 3 is a flow chart illustrating a method that may be performed by the control system 100 referred to herein while the gutting tool 4 is following the predetermined time trajectory shown in figure 2. In step 24 the control system 100 receives a force measurement from the force measurement system 10 and the control system 100 subsequently checks in step 26 whether the measured force exceeds the applicable threshold force value. If not, then step 24 is performed again. Steps 24 and 26 may thus be repeated over and over while servomotor moves the gutting tool 4 along the predetermined time trajectory as long as the force exerted by the gutting tool on the fish does not reach the applicable threshold value. In the example of figure 2, for the first path segment between (xo,yo) and (xi ,yi), which has a relatively high threshold force value, the measured force value never reaches the threshold value.

[0113] However, in the second path segment between (xi,yi) and (X2,y2), the force exerted by the gutting tool on the fish does exceed the applicable (relatively low) threshold value. Therefore, the control system 100 will perform step 28 of activating the force control system to cause the force exerted by the gutting tool on the fish to have a controlled, nonzero value below the threshold force value herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory. Figure 2 does not readily show that the actually followed time trajectory differs from the predetermined time trajectory, because the spatial paths of the predetermined time trajectory and theactually followed time trajectory overlap in the diagram. The predetermined time trajectory defined that the gutting tool 4 should have been at position (xA.yA) at time tA, however, in the example of figure 2, the gutting tool was at position (XA^A) at time later than tA.

[0114] As can be seen in figure 3, once the force control system has been activated in step 28, the control system 100 receives in step 30 a position measurement indicating the position of the gutting tool 4. This position measurement would typically be provided by the position measurement system 8 of the servomotor. Then, in step 32, the control system 100 checks whether the gutting tool is on the predetermined time trajectory again. When this is not the case, the force control system remains active and steps 30 and 32 are performed again. These steps are repeated until the control system 100 determines that the gutting tool is on the predetermined time trajectory again. In the present example, the gutting tool 4 is at the predetermined time trajectory again at (x4.y4.t4). As a result, the force control system is deactivated (step 34) and the gutting system switches back to position-based control again. Thereafter, the gutting tool will follow the predetermined time trajectory again.

[0115] Figure 4 is a flow chart illustrating steps that may be performed by the control system 100 for causing the force exerted by the gutting tool on the fish to have a controlled, nonzero value. When the control system 100 is configured to perform these steps it may be understood as the force control system or may be understood as being a part of the force control system. Figure 4 represent a relatively simple feedback loop wherein measured force values, that are received by the control system in step 36, are compared (step 38) with a set force. This set force represents the controlled, nonzero value that is to be exerted by the gutting tool on the fish when the force control system is in activated state. Then, based on the comparison that is performed in step 38, the control system may cause the servomotor to change the speed with which it moves the gutting tool in order to increase or decrease the force exerted by the gutting tool on the fish. In principle, lowering (or increasing) the speed with which the gutting tool moves through the abdominal cavity towards the bottom of the abdominal cavity reduces (or increases) the force exerted by the gutting tool on the fish.

[0116] In a preferred embodiment, however, as also explained above, the force exerted by the gutting tool on the fish is controlled in a more direct manner, for example in that the control system sends to the servomotor a signal indicative of one or more electrical parameter values, such as an electrical current value, to cause the servomotor to operate with the one or more electrical parameter values herewith causing the force exerted by the gutting tool on the fish to have the controlled, nonzero value below the threshold force value.

[0117] Figures 5-8 show working drawings of a gutting system and / or elements thereof. Figure 5 shows an isometric view of elements of a gutting device, more particularly gutting tools arranged along a conveying direction 414, including an abdominal opening device (not shown), a mechanical profiling tool or a non-contact profilometer (not shown) (which could be replaced with a camera, such as a 2D camera), a centering and supporting tool (before the cutting) 404a, a knife to cut open the fish 404b, a suction nozzle 404c, and a fish measuring device 412 in the form of a 3D scanner.

[0118] Figure 6 shows another isometric view of the elements also depicted in figure 5 wherein like reference signs designate like features.Figure 7 shows a gutting device 600 comprising elements also depicted in figures 5-6 wherein like reference signs designate like features. Figure 7 furthermore shows a conveying means 606 for conveying the fish, which is an endless belt conveyor. Figure 7 also shows a frame 624 and a casing 626.

[0119] Figure 8 shows a gutting machine 700 comprising two gutting devices, wherein the first gutting device, closest to a point of view, is similar to the gutting device and the elements shown in FIGs. 4-6, wherein like reference signs designate like features, and a second gutting device, which is identical or similar (yet substantially mirrored with respect to an yx-plane and / or copied and displaced in the z-direction) gutting device (with conveying means 706) is shown further away from the point of view (displaced in antiparallelly with the z-direction with respect to the first gutting device FIG. 7). The two gutting devices in FIG. 7 are arranged in parallel, such as forming dual lane gutting device. The two gutting devices in FIG. 7 are mounted on the same frame 724 and enclosed within a single casing 726.

[0120] Figure 9 schematically illustrates a data processing system 100, also referred to as a computer, according to an embodiment. The data processing system 100 may for example represent a controller system as described herein. Additionally or alternatively, the data processing system 100 can be implemented, for example, as a consumer device such as a smartphone, other mobile phone, tablet computer, wearable computing device (for example, a smart watch, eyeglasses, or a head wearable display), desktop computer, laptop computer, or implemented with distributed computing devices.

[0121] In data processing system 100, a system bus 102 connects the different components of the data processing system 100. In particular, the system bus 102 depicted in figure 9 connects the Central Processing Unit (CPU) 104, memory elements 106, input devices 108, output devices 110 and communication devices 112 with each other so that they can exchange information. The system bus 102 may be understood to serve both as data bus, address bus and control bus known in the art.

[0122] The CPU 104 is configured to perform steps as per the instructions comprised in a computer program. To illustrate, based on such instructions, the CPU may perform any of the computer-implemented methods described herein. Typically, the CPU 104 is embodied as a microprocessor, which can be implemented on a single metal-oxide-semiconductor integrated circuit chip. The CPU 104 comprises a control unit 114, an arithmetic logical unit (ALU) 116 and a plurality of registers 118.

[0123] The control unit 114 is configured to retrieve instructions from a main memory 120. Typically, the control unit 114 comprises a binary decoder to convert the retrieved instructions into timing and control signals that direct the operation of for example the ALU 116. ALU 116 is configured to perform logical operations, such as additions, subtraction, multiplication, division and Boolean operations, that are required for carrying out the instructions. The registers 118 are small memory elements that can be read and written at relatively high speed. A register may for example store an instruction, a storage address, or any other kind of data. In addition, the CPU may contain hardware caches known in the art (not shown). Preferably the CPU has different levels of caches. These hardware caches may be understood as an intermediate state between the faster registers 119 and the slower main memoryMemory elements 106 comprise a main memory 120. The main memory 120, also referred to as primary storage in the art, has stored data that is directly accessible to the CPU 104. The CPU 104 may continuously read instructions, i.e. read computer programs, stored in the main memory 120 and execute these instructions. The main memory 120 is typically a random access memory (RAM).

[0124] Memory elements 106 further comprise so-called secondary storage 122, which may be embodied as one or more hard disk drives and / or as one or more solid state drives. Typically, these secondary storage is non-volatile. Further, the memory elements may comprise other storage devices 124, such as removable storage devices, e.g. CD, DVD, USB flash drives, floppy disks, et cetera.

[0125] Input devices 108 may be understood as devices that are used to provide information to the computer 100, in particular to the CPU 104. In turn, the computer can interpret this information as indicative of particular user requests or information. Non-limiting examples of input devices are a keyboard, a microphone, a joystick, a touch sensitive screen, a keyboard, a touch pad, a touch screen, a mouse or other pointing device, a scroll wheel, a click wheel, a dial, a button, a switch, a keypad, a sensor (for example, a motion sensor or an eye tracking sensor), a force measurement system referred to herein, a position measurement system referred to herein, a device for measuring electrical parameter of the servomotor referred to herein, et cetera.

[0126] Output devices 110 may be understood as devices that output information out of the computer and / or as devices that are controlled by the computer. Non-limiting examples of output devices 110 are a printer, a headphones, loudspeaker, a motor-generator referred to herein, a servomotor referred to herein, et cetera. Another example of an output device is a display to display images generated by or delivered to the computer. The display can incorporate various image generation technologies, for example, a liquid crystal display (LCD), a light-emitting diode (LED), such as an organic light-emitting diode (OLED), a projection system, a cathode ray tube (CRT), or the like, together with supporting electronics (for example, digital-to-analog or analog-to-digital converters, or signal processors). A device such as a touch screen that functions as both input and output device can be used. User output devices 424 can be provided in addition to or instead of a display. Examples include indicator lights, speakers, tactile “display” devices, printers, and so on.

[0127] Communication devices 112 may be understood as devices that allow the computer system to communicate with other computers, such as with a server computer, client computer, or any other type of remote device. Communication devices 112 are for example configured to provide a connection to a wide area network (for example, the Internet) to which a WAN interface of a remote server system is also connected. Communication devices 112 can include a wired interface (for example, ethernet) and / or a wireless interface implementing various RF data communication standards, such as Wi-Fi, Bluetooth, or cellular data network standards (for example, 3G, 4G, 5G, 60 GHz, or LTE). Non-limiting examples of communication devices 112 include modems, cable modems, ethernet cards, Bluetooth modules, et cetera.

[0128] Many of the features described in this specification can be implemented as processes that are specified as a set of program instructions encoded on a computer readable storage medium. When these program instructions are executed by one or more processors, they cause the processors to perform various operations indicated in the program instructions. Examples of program instructions orcomputer code include machine code, such as is produced by a compiler, and files including higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter. Through suitable programming, processor 104 can provide various functionality for computer 100, including any of the functionality described herein as being performed by a server or client, or other functionality associated with message management services.

[0129] It will be appreciated that computer 100 is illustrative and that variations and modifications are possible. Computer systems used in connection with the present disclosure can have other capabilities not specifically described here. Further, while computer 100 is described with reference to particular blocks, it is to be understood that these blocks are defined for convenience of description and are not intended to imply a particular physical arrangement of component parts. For instance, different blocks can be located in the same facility, in the same server rack, or on the same motherboard. Further, the blocks need not correspond to physically distinct components. Blocks can be configured to perform various operations, for example, by programming a processor or providing appropriate control circuitry, and various blocks might or might not be reconfigurable depending on how the initial configuration is obtained. Implementations of the present disclosure can be realized in a variety of apparatus, including electronic devices implemented using any combination of circuitry and software.

[0130] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments.

[0131] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0132] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.

[0133] A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to obtain an advantage.

[0134] A computer program may be stored / distributed on a suitable medium, such as an optical storage medium ora solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

[0135] Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS1. A gutting system for gutting a fish, the gutting system comprisinga gutting tool, anda servomotor for moving the gutting tool along a predetermined time trajectory towards a predetermined position relative to the servomotor herewith moving the gutting tool into an opened abdominal cavity of the fish for gutting the fish, anda force measurement system for repeatedly, preferably continuously, measuring a force exerted by the gutting tool on the fish while the gutting tool is moving towards the predetermined position, and a force control system configured to control the force exerted by the gutting tool on the fish, and a control system that is configured to perform steps of:-obtaining a threshold force value that has been determined based on fish data that are indicative of one or more characteristics of the fish, and-while the gutting tool is moving along the predetermined time trajectory, determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, and-based on determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, activating the force control system to cause the force exerted by the gutting tool on the fish to have a controlled, nonzero value below the threshold force value herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory, preferably still towards the predetermined position.

2. The gutting system according to claim 1 , wherein the control system is configured to perform the step of obtaining the threshold force value by-receiving the fish data that are indicative of the one or more characteristics of the fish, and -determining the threshold force value based on the one or more characteristics of the fish indicated by the fish data.

3. The gutting system according to claim 1 or 2, wherein the one or more characteristics include a rigidity of the fish.

4. The gutting system according to claim 2 or 3, further comprising a fish measurement system that is configured to measure the one or more characteristics of the fish and output the fish data indicative of the one or more characteristics of the fish to the control system.

5. The gutting system according to any of the preceding claims, wherein the force control system is configured to control the force exerted by the gutting tool on the fish to have a substantially constant value while the force control system is in activated state.

6. The gutting system according to any of the preceding claims, whereinthe predetermined time trajectory defines a spatial path, whereinthe time trajectory different from the predetermined time trajectory has the spatial path as defined by the predetermined time trajectory.

7. The gutting system according to any of the preceding claims, whereinthe servomotor comprises a position measurement system for repeatedly, preferably continuously, measuring a position of the gutting tool, wherein the control system is configured to perform steps of:-while the force control system is in activated state, determining that the gutting tool is back on the predetermined time trajectory again, and-based on determining that the gutting tool is back on the predetermined time trajectory again, deactivating the force control system herewith causing the gutting tool to follow the predetermined time trajectory again.

8. The gutting system according to any of the preceding claims, whereinthe force measurement system comprises the servomotor and the control system, wherein the servomotor is an electrical motor that is configured to output one or more electrical parameter values of the servomotor, and wherein the control system is configured to perform a step of -determining the force exerted by the gutting tool on the fish based on the one or more electrical parameter values as output by the servomotor.

9. The gutting system according to any of the preceding claims, whereinthe force control system comprises the servomotor and the control system, whereinthe servomotor is an electrical motor, and wherein the control system is configured to perform a step of-sending to the servomotor a signal indicative of one or more electrical parameter values to cause the servomotor to operate with the one or more electrical parameter values herewith causing the force exerted by the gutting tool on the fish to have the controlled, nonzero value below the threshold force value.

10. The gutting system according to claim 8 or 9, wherein the one or more electrical parameter values comprises a value for an electric current that drives the servomotor.

11. The gutting system according to any of the preceding claims, whereinthe predetermined time trajectory defines a or the spatial path comprising a plurality of path segments, whereinthe control system is configured to perform steps of19-obtaining a plurality of respective threshold force values for the plurality of path segments, wherein each threshold force value out of the plurality of threshold force values has been determined based on fish data that are indicative of one or more characteristics of the fish, and-for each path segment out of the plurality of path segments, comparing, while the gutting tool is moving along the path segment in question, the force exerted by the gutting tool on the fish with the threshold force value determined for the path segment in question, and-upon determining, for a particular path segment out of the plurality of path segments, that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value associated with the particular path segment while the gutting tool is moving along the particular path segment, activating the force control system to cause the force exerted by the gutting tool on the fish to have a controlled, nonzero value below the threshold force value associated with the particular path segment herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory, preferably still towards the predetermined position.

12. The gutting system according to claim 11 , whereinthe plurality of path segments comprises a first path segment and a second path segment, wherein the predetermined time trajectory defines a first time period for traversal of the first path segment and a second time period for traversal of the second path segment, whereinthe plurality of threshold force values comprises a first threshold force value for the first path segment and a second threshold force value for the second path segment, whereinthe first path segment sits in the abdominal cavity above a bottom of the abdominal cavity during the first time period, andthe second path segment sits at or under the bottom of the abdominal cavity during the second time period.

13. The gutting system according to claim 12, wherein the second threshold force value is higher than the first threshold force value.

14. A computer-implemented method comprising the steps of-obtaining a threshold force value that has been determined based on fish data that are indicative of one or more characteristics of a fish, and-receiving force data indicative of a force exerted by a gutting tool on the fish while the gutting tool is moving along a predetermined time trajectory, and-determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, and-based on determining that the force exerted by the gutting tool on the fish exceeds or is going to exceed the threshold force value, activating a force control system to cause the force exerted by the gutting tool on the fish to have a controlled, nonzero value below the threshold force value herewith causing the gutting tool to follow a time trajectory different from the predetermined time trajectory, preferably still towards the predetermined position.2015. A method for gutting fish, comprisingmeasuring one or more characteristics of a reference fish thus obtaining fish data, and inputting the fish data indicative of the measured one or more characteristics into a control system for controlling a gutting system, and / ordetermining the threshold force value based on the fish data and inputting the threshold force value into the control system for controlling the gutting system , andthe control system performing the computer-implemented method according to claim 14.

16. A control system for controlling a gutting system, the control system comprising a computer readable storage medium having computer readable program code embodied therewith, anda processor, preferably a microprocessor, coupled to the computer readable storage medium, wherein responsive to executing the computer readable program code, the processor is configured to perform the method according to claim 14.

17. A computer program or suite of computer programs comprising at least one software code portion or a computer program product storing at least one software code portion, the software code portion, when run on a computer system, being configured for executing the method according to claim 14.

Images