GB2617356A

GB2617356A - A foodstuff gripper for gripping food items using a needle

Info

Publication number: GB2617356A
Application number: GB2204992.8A
Authority: GB
Inventors: Rodolfo Cuan Urquizo
Original assignee: Brandenburg Ip Ltd
Current assignee: Brandenburg Ip Ltd
Priority date: 2022-04-05
Filing date: 2022-04-05
Publication date: 2023-10-11
Also published as: GB202204992D0; WO2023194719A1

Abstract

A foodstuff gripper 200 suitable for a food handling robot (102 figure 1), the food handling robot (102 figure 1) comprising a robot arm having a distal mount for engaging with the foodstuff gripper 200, the robot arm (102 figure 1) comprising a plurality of joints whereby the configuration of the arm (102 figure 1) can be altered, the foodstuff gripper 200 comprising a needle 202 for penetrating a food item and a plate 204 comprising an aperture 206 through which the needle 202 is arranged to pass as the needle 202 and the plate 204 move relative to one another between an extended configuration in which the needle 202 extends through the aperture 206 in the plate in a direction substantially normal to the plate 204 permitting the needle 202 to penetrate the food item and a retracted configuration in which the needle 202 is retracted at least partially through the aperture 206 whereby a food item gripped by the needle 202 is removed from the needle 202 by action of the plate 204 on the food item. The plate (506 figure 5A) may be remote from the gripper (502 figure 5A) and provided at a deposition location.

Description

A FOODSTUFF GRIPPER FOR GRIPPING FOOD ITEMS USING A NEEDLE

FIELD OF THE INVENTION

This invention relates to foodstuff grippers for food handling robots for gripping food items from a source location and depositing the food items in a deposition location, and methods of gripping food items, in particular using the foodstuff grippers.

BACKGROUND

It is known to use robots to pick up and place food or food components in an automated food handling system. Conventional approaches employ vacuum gripping or claw-like mechanisms for picking up and moving food components.

Vacuum gripping mechanisms employ vacuum generators and vacuum lines which create suction at suction cups. The suction is used by the vacuum gripping mechanism to hold onto food. This type of mechanism requires relatively bulky vacuum equipment, which can lead to higher costs of such mechanisms. Further, either parts of food gripped by such mechanisms or fat (in meat products like bacon) can be sucked into the vacuum lines, which can damage the food, block the suction cup and reduce the effectiveness of the suction, and/or contaminate the gripping mechanism. Food residue within the gripping mechanism necessitates frequent cleaning, which is laborious and time-consuming. A further shortcoming of this type of gripping mechanism is the difficulty in achieving a good suction seal between the suction cup and a food item. For example, porous foods are difficult to grip since it is challenging to obtain a good vacuum seal on such foods. Typically, custom vacuum cups are required for each ingredient or each type of ingredient, and the cups required will also vary with the size of the ingredient. This means that such vacuum systems cannot readily cope with food containers containing ingredients of different types and/or sizes. It is also necessary to correctly align/orient the suction cup with the food to be gripped to ensure a good vacuum seal. This means that food preparation for the vacuum gripping mechanism can be arduous and labour-intensive, since it is a challenge with systems of this type to pick up ingredients placed randomly (with different locations and orientations) in a food container, or ingredients that might be clustered together.

Claw-like gripping mechanisms typically consist of actuatable fingers which close to grip an object and open to release the object. Such mechanisms suffer from limited precision in the number of objects gripped by the fingers. Claw-like gripping mechanisms also have difficulty in accurately gripping ingredients that are clustered together, because the fingers typically are unable to embrace single ingredients without neighbouring ingredients interfering.

Another type of automated food system comprises slicing machines. These operate by holding a bulk food item, such as a 'log' of cheese or meat, in a receptacle and moving the receptacle over a slicing blade. The sliced food is deposited under gravity on a moving conveyor belt. These systems do not move the food item, but rather just deposit it underneath the slicing blade.

It is therefore desirable to provide a food gripping tool that can pick up a range of food products or ingredients and can reproducibly grip food items even where there is a high degree of variance in such food items (for example bacon slices).

SUMMARY

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

According to an aspect of the present invention, there is provided a foodstuff gripper for a food handling robot, the food handling robot comprising a robot arm having a distal mount for engaging with the foodstuff gripper, the robot arm comprising a plurality of joints whereby the configuration of the arm can be altered, the foodstuff gripper comprising: a needle for penetrating a food item to be gripped by the foodstuff gripper; and a plate comprising an aperture through which the needle is arranged to pass; wherein the foodstuff gripper is configured to move the needle and the plate relative to one another such that the foodstuff gripper has an extended configuration in which the needle extends through the aperture in the plate in a direction substantially normal to the plate permitting the needle to penetrate the food item in a direction along the longitudinal axis of the needle and a retracted configuration in which the needle is retracted at least partially through the aperture whereby a food item gripped by the needle is removed from the needle by action of the plate on the food item.

The needle may comprise one or more of a friction-increasing coating; a roughened surface to increase grip on the food item; a non-smooth cross-section along at least a portion of its length; a polygonal cross-section along at least a portion of its length; a twist along at least a portion of its length; and a decreasing thickness along at least a portion of its length in a direction along the needle from a distal tip of the needle. The needle may comprise one or more surface protrusions to increase grip on the food item. A thickness of the needle may increase in a direction along the needle from a distal tip of the needle.

The plate may comprise a surface feature to aid gripping of the food item held against the plate by the needle.

The foodstuff gripper may comprise a sensor configured to sense a force on the needle. The foodstuff gripper may be configured to, in dependence on an output of the sensor, determine at least one of: whether the food item is gripped by the needle; a weight of the food item gripped by the needle; when the food item is removed from the needle; a force as the needle is inserted through the food item; and an inventory tracking signal.

The foodstuff gripper may comprise a plurality of needles. The plate may comprise a plurality of apertures through which the plurality of needles are arranged to pass. The foodstuff gripper may comprise a plurality of actuators, each actuator being configured to move at least one needle of the plurality of needles relative to the plate such that the at least one needle is moved as the foodstuff gripper transitions between the extended configuration and the retracted configuration. The foodstuff gripper may comprise a plurality of sets of needles, each set of needles of the plurality of sets of needles comprising at least one needle, and each actuator of the plurality of actuators being configured to move a respective set of needles relative to the plate such that the respective set of needles is moved as the foodstuff gripper transitions between the extended configuration and the retracted configuration. At least one needle of a first set of needles may be configured to grip a different food item compared to at least one needle of a second set of needles.

The foodstuff gripper may comprise an actuator configured to move the or each needle and the plate relative to one another such that the or each needle is moved as the foodstuff gripper transitions between the extended configuration and the retracted configuration.

In the extended configuration, the or each needle may be configured to grip a plurality of food items. The foodstuff gripper may be configured to move the or each needle and the plate relative to one another to at least one intermediate configuration between the extended configuration and the retracted configuration, whereby the foodstuff gripper is arranged to grip an additional food item in the intermediate configuration and/or to remove a gripped food item from the needle on transitioning from the extended configuration to the intermediate configuration.

The foodstuff gripper may be configured to at least partially sterilise (i) the or each needle and/or (ii) the plate using UV light. The foodstuff gripper may be configured to at least partially sterilise the or each needle in the retracted configuration.

The foodstuff gripper may comprise a resilient needle mount for mounting the or each needle.

According to another aspect of the present invention, there is provided a food handling system comprising a foodstuff gripper as described herein and an imaging system for imaging at least one of a source location for food items and a deposition location for food items, wherein the foodstuff gripper is controllable in dependence on an output of the imaging system.

According to another aspect of the present invention, there is provided a food handling system comprising a foodstuff gripper as described herein; and a robot arm having a distal mount for engaging with the foodstuff gripper, the robot arm comprising a plurality of joints whereby the configuration of the arm can be altered; wherein the robot arm is configured to sense a force on the foodstuff gripper.

According to another aspect of the present invention, there is provided a food handling system comprising a foodstuff gripper for a food handling robot, the food handling robot comprising a robot arm having a distal mount for engaging with the foodstuff gripper, the robot arm comprising a plurality of joints whereby the configuration of the arm can be altered, the food handling system further comprising a deposition plate; the foodstuff gripper comprising a needle for penetrating a food item to be gripped by the foodstuff gripper; the deposition plate comprising an aperture; and the food handling system being configured to (i) move the foodstuff gripper such that a shaft of the needle proximal to a gripped food item passes along the aperture of the deposition plate and (ii) move the foodstuff gripper such that the needle moves in a direction generally along a longitudinal axis of the needle towards a proximal end of the needle, whereby the gripped food item is removed from the needle by action of the deposition plate on the food item.

The aperture in the deposition plate may comprise a flared opening. The foodstuff gripper may comprise a plurality of needles. The deposition plate may comprise a plurality of apertures.

According to another aspect of the present invention, there is provided a method of gripping a food item for moving the food item from a source location to a deposition location, the method comprising: gripping a food item, from a source location, using a needle inserted into the food item along a longitudinal length of the needle; moving the gripped food item to a deposition location; and removing the gripped food item from the needle by drawing the needle in a proximal direction of the needle through an aperture in a deposition plate in a direction substantially normal to the deposition plate whereby the food item is removed from the needle by action of the deposition plate on the food item.

The method may comprise sensing a force on the needle and using the sensed force to determine one or more of: whether the needle is gripping a food item; a weight of the gripped food item; a change in force as the needle penetrates the food item; and an inventory tracking signal. The method may comprise gripping a plurality of food items using a respective plurality of needles; and removing the plurality of gripped food items from the plurality of needles by drawing the needles in a proximal direction of the needles through one or more apertures in a deposition plate whereby the food items are removed from the needles by action of the deposition plate on the food items. The method may comprise gripping a first food item using a first set of needles, the first set of needles comprising at least one needle; and gripping a second food item using a second set of needles, the second set of needles comprising at least one needle; wherein the at least one needle of the first set of needles has a different configuration to the at least one needle of the second set of needles.

The method may comprise gripping a plurality of food items using the needle; and removing a subset of the plurality of food items from the needle by partially drawing the needle in a proximal direction of the needle through the aperture in the deposition plate. The method may comprise removing an additional food item of the plurality of food items from the needle by further drawing the needle in a proximal direction of the needle through the aperture in the deposition plate.

The method may comprise at least partially sterilising one or both of the needle and the plate using UV light and/or a cleaning solution.

According to another aspect of the present invention, there is provided a food container for holding food items, the food container comprising a weight sensor for sensing a weight of food items held in the food container. The food container may comprise a side wall and a base movable relative to the side wall. The base is arranged to support the food items held in the container. The food container may comprise one or more supporting elements configured to support the base, and to raise and lower the base relative to the side wall. The food container may comprise a position sensor for sensing the position of the base relative to the side wall.

According to another aspect of the present invention, there is provided a food container for holding food items, the food container comprising a side wall and a base movable relative to the side wall, the base being for supporting food items held in the container, the food container comprising a sensor for sensing at least one of a weight of food items held in the container and a position of the base relative to the side wall. The food container may comprise one or more supporting elements for supporting the base. The one or more supporting elements may be configured to raise and lower the base relative to the side wall.

The one or more supporting elements may comprise an active supporting element and/or a passive supporting element. The one or more supporting elements may comprise a piston. The one or more supporting elements may comprise a lead screw. The one or more supporting elements may comprise a resilient element. The resilient element may comprise a spring or a spring-loaded rod.

The active supporting element may be driven in response to a reading of the sensor. The active supporting element may be driven in response to one or both of a weight sensor reading and a position sensor reading.

According to another aspect of the present invention, there is provided a non-transitory computer readable storage medium having stored thereon computer readable instructions that, when executed at a computer system, cause the computer system to perform a method as defined herein.

Any feature of any aspect above can be combined with any one or more other feature of any aspect above. Any method feature may be rewritten as an apparatus feature, and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example with reference to the accompanying drawings.

In the drawings: Figure 1 schematically illustrates an example food handling system; Figure 2A schematically illustrates a foodstuff gripper in an extended configuration; Figure 28 schematically illustrates the foodstuff gripper of figure 2A in a retracted configuration; Figure 3A schematically illustrates another foodstuff gripper in an extended configuration; Figure 38 schematically illustrates the foodstuff gripper of figure 3A in a retracted configuration; Figure 4 schematically illustrates an example of a remote plate; Figures 5A, 5B and 5C schematically illustrate different stages in relative movement between a foodstuff gripper and a remote plate; Figure 6 illustrates an example method; and Figures 7A and 7B schematically illustrate a food container.

DETAILED DESCRIPTION

The following description is presented by way of example to enable a person skilled in the art to make and use the invention. The present invention is not limited to the embodiments described herein and various modifications to the disclosed embodiments will be apparent to those skilled in the art. Embodiments are described by way of example only.

The following description describes the present techniques in the context of food handling systems, though the features described below are not limited to such systems, but may be applied to robotic systems more generally. Robotic systems can include manufacturing systems, such as vehicle manufacturing systems, parts handling systems, laboratory systems, and manipulators such as for hazardous materials.

In the food preparation industry, food products can be assembled manually or by food assembly robots. Such food products can include sandwiches, lunch boxes, pizzas, burgers and fruit pots. This list is not exhaustive. Manual preparation of these and other food products involves repetitive, laborious tasks. Labour for such methods of food preparation is in increasingly short supply, meaning that it can be difficult to satisfy supply chains efficiently.

Attempts have been made to use food assembly robots, for example robots that make use of vacuum gripping techniques and/or claw-like mechanisms. These robots have the drawbacks discussed above, in that they can be inefficient, slow, and/or unable to properly and effectively handle a sufficient range of foodstuffs. For example, these robots may be suitable for gripping a limited range of types of ingredients presented singly, such as one by one in a line on a conveyor belt, but are unsuitable for gripping other types of ingredients presented singly, or for gripping several items presented at the same time, such as one at least partially overlapping another, either on a conveyor belt or in a container. Further, they can be bulky and/or expensive which further limits their applicability in food production lines that require compact operations and which have low profit margins.

The present inventors have identified the need for a compact, cost-effective solution to these problems and have developed the present techniques accordingly. The techniques discussed herein aim to address these, and other, problems.

The present inventors have developed a foodstuff gripper comprising a needle for gripping a food item on penetration of the needle into the food item, and a plate through which the needle is movable and which can effect removal of the food item from the needle as the needle is drawn through the plate. Either or both of the needle and the plate can be movable; what matters is that the needle and the plate are movable relative to one another so that the needle can be extended through the plate in one direction and retracted through the plate in a different (e.g. opposite) direction. The needle can be provided with characteristics that enhance the gripping of the food item. The needle can be arranged to grip several food items. Additionally or alternatively, multiple needles can be provided for gripping one or several food items. That is, each of a plurality of needles can be configured to grip one or more food items.

The foodstuff gripper described herein advantageously makes use of a highly compact mechanism for gripping and depositing food items. The foodstuff gripper described herein can operate with a single actuator or motor, which is suitably electrically driven, thereby avoiding the need to provide additional supply lines to the gripper. The compact mechanism helps ensure that the footprint of the gripper, and/or of a food handling system comprising the gripper, is small. Such a small footprint enables the gripper and/or food handling system to be provided in a smaller space. The compact nature of the gripper enables it to project into small-sized containers for picking food items up from such small containers and for depositing food items into such small containers. The ability to pick up and drop off food items in smaller containers as well as larger containers increases the range of use of the gripper. The gripper can advantageously pick up ingredients of different sizes. The compact nature of the gripper enables it to pick up small objects, for example using a single needle. Larger objects can also be picked up by the same gripper, using one or more needles, as discussed in more detail elsewhere herein. The gripper described herein is useful in applications such as bin-picking and food product assembly.

As will be described in more detail elsewhere herein, the present techniques include measuring the force exerted on the gripper, or on an element of the gripper, whereby a weight of a food item can be obtained. The force measurements are also useful for determining how far a needle of the gripper needs to penetrate into a food item to grip that food item. Measuring the weight of food items enables more accurate food portioning and can be fed back into inventory management systems for more efficient food production systems.

Reference is made to figure 1, which shows an example food handling system 100 comprising a food handling robot 102 having a foodstuff gripper 104 at a distal end of the food handling robot 102. The food handling system comprises an imaging device 106 such as a camera. The camera can be an optical camera. The foodstuff gripper 104 can pick up food items from a source location 108, for example from one or more containers of food items. The foodstuff gripper 104 can deposit food items at a deposition location 110, such as a pot or container for the food product. Whilst the present discussion will refer to depositing food items in containers, it is to be understood that food items may be placed on a piece of bread, for example to form a sandwich or burger. The present techniques are equally applicable to depositing food items on a piece of bread, on other food items, or in a container.

The food handling robot 102 comprises a robot arm having a distal mount for engaging the foodstuff gripper 104. The robot arm comprises a plurality of joints whereby the configuration of the arm can be altered. The food handling robot 102 can therefore manipulate the foodstuff gripper 104 mounted to the distal end of the robot arm in multiple degrees of freedom. This enables the foodstuff gripper 104 to pick food items up from one location and to deposit the food items at a different location.

The imaging device 106 images at least one of the source and deposition locations. This is useful to identify to the food handling system (i) where the food items are to be picked up from, (ii) the number and/or type of food items to be picked up, (iii) where the food items are to be deposited, (iv) which food items have already been deposited, (v) how many food items have already been deposited, and/or (vi) the quality or one or more food items or the quality of an assembled food product. Identifying where the food items are to be deposited is useful in a system such as that illustrated schematically in figure 1, in which containers move past the food handling robot 102.

Identifying the relative position between the food handling robot and the container enables the food item to be deposited in the correct location.

It will be understood that it is not necessary in all embodiments to image the source location(s). For example, where the source location is fixed (or the source locations are fixed), the relative position between the food handling robot and the food item containers may be known. Similarly, it is not necessary in all embodiments to image the deposition location(s). For example, where the deposition location is fixed (or the deposition locations are fixed), the relative position between the food handling robot and the containers may be known.

In some implementations, the food handling robot comprises a base. That is, the arm of the food handling robot is suitably mounted on a base. The food handling robot can be static or mobile. The food handling robot can be moved between different locations. The food handling robot base can comprise wheels to enable the food handling robot to be easily moved between different locations.

The base can comprise one or more food container mounts, to which one or more food containers can be mounted. For example, the base may comprise a platform on which food containers can be placed. The platform can comprise recesses or apertures in which the food container(s) can be seated. The base can comprise the food container(s). In some examples, the food containers are fixed to the base. These arrangements enable the one or more food containers to be located in known relative positions to the arm of the food handling robot 102.

A further advantage of providing the food container(s) nearby the arm, e.g. on or as part of the base, is that the arm can thereby be kept more compact, since the range of travel needed for the foodstuff gripper 104 can be reduced. This is in comparison to a typical setup, in which a food container would be placed to the opposite side of a conveyor belt from a manual operator. Thus, the robot arm need not be configured to reach over the belt to access the food container, but can successfully operate with a range that is more limited. A smaller sized arm can be cheaper to manufacture. The smaller reach needed to access the food containers and the deposition location can reduce the time taken for the arm to move between these locations. Providing the food containers on the base provides increased flexibility in positioning the food handling robot, since there may then be no need to align the food handling robot with remotely located food containers. The further away the food containers are from the food handling robot, the more accurately the positioning may need to be, to ensure that the containers are located within the range of motion of the arm.

Conventional approaches to imaging the source and/or deposition locations, as will be known to the skilled person, can be used with the foodstuff gripper discussed herein, so a detailed description of such imaging approaches and object recognition will not be provided here. It will be appreciated that examples of computer vision techniques that are applicable to the present discussion include the detection and/or identification of ingredients and/or food base layers (e.g. pizza dough, bread).

Applicable computer vision techniques may include detection and/or identification of an orientation of an ingredient (either for picking up, or for depositing) and/or a base layer or a previously-deposited food item. The orientation may be a relative orientation between a food item to be deposited and a previously-deposited food item or a base layer.

The foodstuff gripper 104 comprises a needle and a plate. The needle is configured to penetrate a food item to be gripped by the foodstuff gripper. The plate comprises an aperture through which the needle is arranged to pass. The aperture can be a hole in the plate or it can be a recess such as an elongate recess in the plate. E.g. the aperture in the plate may extend to the side of the plate. The aperture can be of any desired shape and size. Suitably the aperture is larger than the largest width of the needle but smaller than a typical food item to be gripped by the needle, so that the needle may move freely through the aperture, but the food item to be gripped will not pass through the aperture, but will abut against the plate (in particular, against a surface of the place) as a needle carrying the food item is moved through the aperture.

The foodstuff gripper 104 is configured to move the needle and the plate relative to one another. The needle and the plate are movable relative to each other between an extended configuration and a retracted configuration.

In the extended configuration, the needle extends through the aperture in the plate in a direction substantially normal to the plate (i.e. the needle will extend perpendicularly to the plane of the plate). The needle need not extend through the plate exactly along the direction normal to the plate. It is sufficient if the needle extends through the plate within 10 degrees of the normal direction, or preferably within 5 degrees of the normal direction. This configuration enables the needle to protrude by a suitable distance from the plate to be able to grip a food item, without requiring a large movement between the needle and the plate to effect the change between the extended and the retracted configurations. This arrangement can therefore provide a compact foodstuff gripper 104. This extension of the needle through the plate permits the needle to penetrate a food item nearby the plate. The needle is configured to penetrate the food item in a direction along the longitudinal axis of the needle.

In the retracted configuration, the needle is retracted at least partially through the aperture whereby a food item gripped by the needle is removed from the needle by action of the plate on the food item. That is, as the needle is drawn through the aperture in the plate, the food item contacts the plate (in particular, the surface of the plate). Contact between the food item and the plate causes the food item to remain in place as the needle is retracted through the aperture. The action of the plate on the food item therefore causes the food item to be removed from the needle and deposited by the foodstuff gripper.

The foodstuff gripper will now be described with reference to the examples illustrated in figures 2A, 28, 3A and 3B. Figure 2A illustrates an example foodstuff gripper 200. The gripper 200 comprises a needle 202 which can extend through a plate 204. As illustrated, the needle 202 extends through a channel 206 in the plate. Suitably the channel is oriented along the longitudinal axis of the needle.

This arrangement can help guide the needle 202 as the foodstuff gripper 200 moves towards the retracted configuration. In this example, the plate is in a fixed position relative to a housing 208 of the gripper 200. The gripper 200 comprises an actuator 210 for actuating a needle mount 212 in which the needle 202 is mounted. The actuator 210 is configured to cause the needle 202 to move along its longitudinal axis. The actuator 210 is configured to cause the needle to move in a direction substantially normal to the plane of the plate 204. Figure 2A shows the extended configuration, in which the distal portion of the needle 202 extends through the plate 204. In this configuration, the needle is able to penetrate a food item so as to grip the food item. The gripped food item is suitably held against the plate by the needle, although it may be held by the needle in a manner such that it does not contact the plate until the needle is retracted through the plate.

Figure 25 shows the retracted configuration of the gripper 200. In this configuration, the actuator has caused the needle 202 to retract through the aperture or channel 206 in the plate 204. As illustrated in figure 25, in the retracted configuration the needle 202 is contained within the housing 208. In other examples, the needle need not be entirely retracted within the housing in the retracted configuration. It can be sufficient for the needle to retract such that the food item gripped by the needle is removed from the needle. It will be understood that the amount by which the needle can remain protruding from the plate while ensuring that the food item is removed from the needle will depend both on the food item being gripped and characteristics of the needle.

Another example of the foodstuff gripper is illustrated in figures 3A and 3B. The illustrated foodstuff gripper 300 comprises a needle 302 which extends through a plate 304 (in the extended configuration). The needle 302 suitably extends through a channel (not shown) in the plate 304. Suitably the channel 304 is oriented along the longitudinal axis of the needle. This arrangement can help guide the needle 302 as the foodstuff gripper 300 moves towards the retracted configuration.

In this example, the needle 302 is in a fixed position relative to a housing 308 of the gripper 300. The needle 302 is mounted in a needle mount 312 which is in a fixed position relative to the housing 308. The gripper 300 comprises an actuator 310 for actuating the plate 304 relative to the housing 308. The actuator 310 is configured to cause the plate 304 to move in a direction perpendicular to the plane of the plate, i.e. along a direction substantially aligned with the longitudinal axis of the needle 302. Figure 3A shows the extended configuration, in which the distal portion of the needle 302 extends through the plate 304. In this configuration, the needle is able to penetrate a food item so as to grip the food item. The gripped food item is suitably held against the plate by the needle, although it may be held by the needle in a manner such that it does not contact the plate until the needle is retracted through the plate.

Figure 3B shows the retracted configuration of the gripper 300. In this configuration, the actuator has caused the plate 304 to move relative to the needle 302 such that the needle 202 is retracted through the aperture or channel in the plate 304. The needle may be, but need not be, retracted within the housing in the retracted configuration. It can be sufficient for the needle to retract such that the food item gripped by the needle is removed from the needle. The needle may remain partially protruding through the plate in the retracted configuration. It will be understood that the amount by which the needle can remain protruding from the plate while ensuring that the food item is removed from the needle will depend both on the food item being gripped and characteristics of the needle.

The characteristics of the needle 202, 302 suitably affect how the needle will grip one or more food items. The needle can comprise a friction-increasing coating. The coating can help the needle to grip food items. The coating may be designed to increase a grip force between the needle and a predetermined food item, or type of food item, for example fat, meat, fruit and/or vegetable matter. The needle may comprise a coating arranged to improve the ease with which the needle can be cleaned and/or sterilised after use. The needle may comprise a roughened surface. The roughened surface can help to increase grip on the food item gripped by the needle.

The needle 202, 302 can, in some examples, comprise a polygonal cross-section (or more generally, a non-smooth cross section) along at least a portion of its length. For example, the needle may have a square cross section. The needle may have a pentagonal cross-section. The edge profile of such a needle can cause a greater compression of the food item compared to a circular or oval cross-sectional needle. This greater compression can increase the friction between the needle and the food item, improving the gripping ability of the foodstuff gripper 104, 200, 300. The polygonal (or more generally) non-smooth) cross section can be provided along substantially the whole length of the needle. However, the polygonal (or more generally, non-smooth) cross section need not be provided along the whole length of the needle. Suitably the non-smooth cross section is provided along a portion of the needle which is arranged to penetrate the food item as the food item is gripped by the needle, and carried by the foodstuff gripper. Thus, in some examples, the length of the non-smooth cross sectional portion of the needle can correspond to a thickness of a food item to be gripped by the foodstuff gripper.

The needle may comprise a twist along at least a portion of its length. The twist may be provided in the non-smooth cross sectional portion of the needle. The twisted portion of the needle suitably provides additional grip to assist in retaining a food item on the needle during a food gripping operation. Needles comprising a non-smooth cross section and/or a twisted section are useful in gripping relatively heavy food items such as a chunk of meat.

A further characteristic of the needle that can assist in increasing grip between the needle and the food item is the thickness of the needle. The needle may have a constant thickness along its length, or along at least a substantial portion of its length. Suitably, the needle has a decreasing thickness along at least a portion of its length in a direction along the needle from a distal tip of the needle.

This arrangement means that the food item can be retained on the needle above a relatively thicker part of the needle. This arrangement can help with positioning the food item at a desired position on the needle (e.g. just above the thicker part), which may assist with determining how far to retract the needle to ensure that the food item can be removed from the needle. The thickness of the needle can additionally or alternatively increase in a direction along the needle from a distal tip of the needle. Increasing the thickness of the needle can cause a greater amount of compression of the food item as the needle penetrates the food item, which can increase the grip between the needle and the food item. Needles with a relatively thicker distal portion can be useful in lifting thin objects, such as slices of cheese or ham.

Another characteristic of the needle that can assist in increasing grip between the needle and the food item is the provision of one or more surface protrusions on the needle. The surface protrusion(s) may be provided at one or more positions along the length of the needle and/or at the distal tip of the needle. The one or more surface protrusions can comprise a barb. The surface protrusion(s) suitably engage with the food item (e.g. by a barb hooking a portion of the food item) so as to increase the grip between the needle and the food item. Providing surface protrusions on the needle can improve the grip on moist food items or food items with a high liquid content, such as grapes and tomatoes or tomato slices.

Suitably, the characteristics of the needle to be used in the foodstuff gripper can be selected in dependence on the food item, or type of food item, to be gripped by the gripper. This can enable a more effective gripping by the gripper of the food items to be picked up. A needle with a given characteristic may be suitable for picking up a range of food items or types of food items. Providing needles with different characteristics that can be used in the foodstuff gripper can increase the range of food items or types of food items that can be picked up by the gripper and/or can increase the effectiveness with which the foodstuff gripper can pick up a particular food item.

The actuator 210, 310 of the foodstuff gripper 200, 300 suitably comprises an electronic actuator configured to move the foodstuff gripper between the extended and retracted configurations. For picking up a food item, first the actuator will cause the foodstuff gripper to move towards or remain in the extended configuration. In the extended configuration, the needle may be extended as fully as is possible. Alternatively, the needle may not be extended by the full amount. Instead, it may be extended short of this amount, such that there remains some tolerance or play in the system. This arrangement can help reduce damage to the foodstuff gripper if the needle impacts a hard surface, such as the base of a container.

When in the extended configuration, the foodstuff gripper will approach the object to be picked up, e.g. a food item, and the needle will penetrate the object. Friction between the needle and the object creates a force sufficient to grip the object for lifting the object. To place the object at a desired location, the foodstuff gripper approaches the desired location and the actuator will cause the foodstuff gripper to move towards the retracted configuration. That is, the actuator will cause the needle to at least partially retract through the plate. As the needle retracts through the plate, the gripped object will come into contact with the plate (in particular, an outer surface of the plate).

The resistance of the object to movement, or further movement in the retraction direction of the needle, by abutment against the plate, will cause the needle to slide out of the object and the object thereby to be released from the needle.

In the above examples of the foodstuff gripper, the gripper need only comprise a single needle. This provides a simple and compact arrangement for the gripper. The weight of the gripper can thereby be kept low, improving the operating characteristics of the robot arm to which the gripper is mountable. A cheaper robot arm can be used where the gripper is kept lightweight, enabling further cost reductions to be made in the food handling system comprising the gripper.

Suitably, the foodstuff gripper comprises a sensor configured to sense a force on the needle. The sensor can comprise a weight sensor. The sensor is suitably configured to sense the weight of a food item held by the needle. Enabling the sensing of the force on the needle in this way means that the foodstuff gripper is able to determine whether a food item is being gripped or held by the foodstuff gripper (e.g. by the needle), and/or when the food item is removed from the foodstuff gripper (e.g. when the food item is removed from the needle). Sensing when the needle is gripping a food item can be used to determine the success or otherwise of a pickup operation. That is, the sensed force on the needle can provide a measure of whether the food item has successfully been picked up. This can save time in food processing, since the food handling system need not try and deposit items where the gripper has not yet picked up an object. Determining the success of the pickup operation using the force on the needle provides a simple yet accurate way to track the pickup of food items.

Making this determination from the measure of the force on the needle can avoid the need to carry out computationally more complex operations such as visual image analysis. Hence, the processing power required by the foodstuff gripper can also be reduced. This can help reduce the cost of the foodstuff gripper.

Use of the sensor can also avoid reliance on image processing to determine where to pick up a food item. For example, analysis of a visual image can provide a location from which a food item is to be picked up. Obtaining this location involves image analysis and processing, which takes time and computational power. The present inventors have realised that savings can be made by avoiding the need to carry out such intensive image processing algorithms. In an alternative approach, it is possible to perform a 'blind stab': moving the foodstuff gripper to direct the needle into a container of food items without having determined where in that container the food items are located.

A benefit of the present techniques is that the needle is able to grip the food item by penetrating the food item across a range of positions in the food item. The foodstuff gripper as described in examples herein is able to pick up or grip food items by moving the needle in a downward direction. It is not necessary to approach the food item to be picked up in a specific direction. It does not matter how the food item is oriented; a penetration of the needle through the item, e.g. in the downward direction, is able to grip and so pick up the food item across a range of different food items. Thus, the present approach enables successful gripping of food items with a greater tolerance of misalignment of the food items with the foodstuff gripper.

Thus, the 'blind stab' is highly likely to result in a successful pickup of the food item. If the pickup is not successful, e.g. as determined from the sensor, the foodstuff gripper can be moved by a given (or random) amount in a given (or random) direction and the operation attempted again.

The sensor may be a relatively less sophisticated sensor that is able to output a binary determination of whether or not a food item is gripped and lifted by the foodstuff gripper. Suitably, however, the sensor is able to quantify the force on the needle. This enables the foodstuff gripper to be able to quantify the weight of a given food item gripped by the gripper.

The sensor can sense the force on the needle as the gripper is moving from the source location to the deposition location. A change in force during this movement can be indicative of a food item having fallen off the needle. In such cases, the foodstuff gripper can return to the source location to pick up another food item and need not carry on to the deposition location unnecessarily. This configuration can therefore help reduce wasted time in a food processing assembly line. Where the sensor measurement indicates that part of the food item has dropped off the needle, but part of the food item remains gripped by the needle (for example by comparing the weight of food items held by the needle before and after the change in weight), a determination can be made as to whether to carry on to deposit the remaining gripped part of the food item, or whether to return to the source container to pick up more food items. This determination can be made based on the amount of the food item remaining on the needle, and/or how close the gripper is to one or both of the source and deposition locations, so as to optimise the operation of the food handling system.

Measuring the weight of food items gripped by the gripper and moved to the deposition location enables accurate inventory tracking and portion control. Rather than, as in conventional systems, having to make assumptions about the amount of a particular food item that is placed in a pot or in a sandwich, or to average out amounts over a number of pots or sandwiches, the present techniques allow for precise determination of portion sizes in each pot/sandwich. This can enable the calorific content of the pot/sandwich to be identified with a greater accuracy, since rather than making assumptions about the amount of, say, chicken in a sandwich, the present techniques can provide a measure of the precise weight of chicken in the sandwich.

The determination of the weight of food items deposited at the deposition location can avoid the issue with overfilling. In some food production lines, pots are deliberately overfilled to ensure that, on average, the pots contain sufficient food items. This approach uses a greater amount of food items than is necessary in the food production line. The present approach enables pots to be filled with a more precisely-determined amount of food, thus improving the efficiency of the food production line (and/or the supply chain) and offering the possibility to make significant cost savings.

Suitably, the weight of a food item carried by the needle(s) is determined by taking the difference in weight measured at the needle(s) before and after depositing the food item. It is also possible to continuously measure the weight at the needle(s), or to periodically sample the weight, for example every second or every two seconds. This continuous or periodically sampled weight measurement data can then be analysed to determine the weight of food items picked up, and/or the weight of any food items dropped, and/or the weight of food items deposited in one or more deposition operations.

More accurately measuring the portions deposited can aid inventory management since the 'oversupply' of foodstuffs to account for variations in the amounts deposited can be reduced or avoided. Suitably, therefore, the foodstuff gripper is able to determine an inventory tracking signal that is indicative of a measure of the foodstuff used. The signal may comprise a cumulative value, indicating an amount of the foodstuff that has, at that time, been successfully picked up and/or successfully deposited.

Suitably, the sensor is able to determine both a positive force on the needle and a negative force on the needle, i.e. forces in both directions. A force in a downward direction (which may be defined as a positive force) can be indicative of the weight of a food item on the needle. A force in an upward direction (which may be defined as a negative force) can be indicative of the needle coming into contact with an object, such as a food item or the base of a container. As the needle contacts, and penetrates, a food item, the sensor is suitably able to detect the change in force. This enables a determination to be made not only that a food item has been penetrated by the needle, but also of a measure of the distance through which the needle penetrates the food item. The foodstuff gripper can then advantageously be configured to stop advancing towards the food item once it is determined that a minimum penetration distance has been met or exceeded. The minimum penetration distance may differ depending on the food item to be picked up and/or the characteristics of the needle, but suitably gives an indication of the distance through which the needle ought to penetrate the food item to ensure a sufficient grip force to lift that food item is attained. This approach can help save time in a pickup operation. By avoiding penetrating the food item further than is necessary, damage to the food item can be reduced or avoided.

In some configurations, the force on the needle can be determined without needing to provide an additional sensor. For example, a measure of the resistance or torque in the needle actuator or motor can provide an indication of the force on the needle. In another example, joint sensor readings from joint sensors of the robot arm can provide an indication of the force at the distal end of the arm (which can correspond to the force on the needle). This approach can make use of existing systems within the robot arm, to provide additional information. Torque sensors, configured to sense the torque at one or more joints of the robot arm, can provide a determination of the force on the needle. Enabling the force determination without needing to provide a separate sensor at the foodstuff gripper can reduce the complexity and cost of the gripper whilst retaining overall functionality. In some implementations, one or a combination of these approaches can be used. That is, the force on the needle can be determined in dependence on one or any combination of: a force sensor at the gripper, a measure of the resistance or torque in the needle actuator, and joint sensor reading from joint sensors of the robot arm.

In addition to, or instead of, the force sensing on the needle, a weight sensor can be provided at or as part of the food container from which food items are picked up. A weight sensor can be provided at the food deposition location. Reference is made to figures 7A and 7B. Figure 7A schematically illustrates a food container 700. The food container comprises a side wall 702 and an internal base 704 for supporting food items 706 placed in the container. The internal base is supported by one or more supporting elements 708, which can raise or lower the height of the internal base 704 relative to the side wall 702. A sensor 710 is configured to sense the weight of food items 706 on the internal base 704 and/or to sense a position of the internal base 704.

The internal base 704 is suitably configured to be raised and lowered so as to remain horizontal. This can avoid food items clumping together. Alternatively, the internal base 704 can be slanted, to cause food items to move towards one end of the container. This slanted configuration can direct the food items towards the end of the container that is closer to the food handling robot arm. This arrangement can therefore reduce the range of motion needed for the arm.

The supporting elements 708 can be of any suitable number and configuration. The supporting elements can comprise active and/or passive supporting elements. Examples of an active supporting element include a driven piston such as a pneumatic piston and a linear actuator such as a lead screw. Use of an electrically actuated supporting element avoids the need for additional connections or components (such as an air line or air compressor for a pneumatic piston). The active supporting element can be driven in response to the amount of food items remaining in the container. Where the amount of food items decreases, the position of the uppermost food item will become lower, necessitating the foodstuff gripper to drop further within the container 700 to pick up a food item 706. This will increase the length of travel as the food items within the food container 700 are depleted, and thereby also the length of time taken (at a given speed of movement) to pick up food items and return to the deposition location. Hence, as the amount of food items decreases, the active supporting element can be driven to raise the internal base 704. This can mean that the food item picking height remains constant, or at least varies less than if the internal base was fixed. Such an arrangement can avoid increases in food picking time as the food items in the container are depleted.

The amount of food items remaining can be determined based on one or more of visual imaging of the contents of the food container, a number of times the foodstuff gripper has picked up items from the food container, and a weight of items remaining in the food container. The weight of items remaining in the food container can be derived from the sensor 710. The weight of items remaining in the food container can be derived from a known initial weight of food items, and the weight of food items picked up from the container. The weight of food items picked up from the container can be determined from sensing the weight of food items carried by the foodstuff gripper (as described elsewhere) and/or from sensing the weight of deposited food items. The weight of deposited food items can be determined from a weight sensor placed underneath the deposition location. For example, where the food items are being placed in a pot, the pot can be positioned on a weight sensor. Where the food items are being placed on a conveyor belt, the conveyor belt system can comprise a sensor configured to sense the weight of items placed thereon. Similarly, the weight of food items in or remaining in the food container 700 can be determined from a weight sensor placed underneath the food container 700. Such a weight sensor can be provided additionally to or instead of a weight sensor in the food container 700.

The supporting element 708 can comprise a passive supporting element, such as a spring or a spring-loaded rod. The force exerted on the internal base 704 by the passive supporting element can be predetermined to cause food items supported by the internal base 704 to remain at approximately the same height within the food container 700.

As illustrated in figures 7A and 7B, the food container 700 comprises two supporting elements 708.

A single supporting element may be sufficient. In other implementations, additional supporting elements can be provided. Where there are multiple supporting elements 708, they are suitably spaced apart from one another so as better to support the internal base 704 across the whole of the internal base 704. Guide rails may be provided along which the internal base 704 is movable relative to the side wall 702. Such guide rails can assist in keeping the internal base 704 at a desired orientation, e.g. horizontal. Such guide rails can be especially useful where a smaller number of supporting elements is provided, e.g. a single supporting element 708.

As illustrated in figure 7A, the food container 700 comprises a sensor 710. The sensor 710 can comprise a weight sensor configured to sense the weight of food items 706 on the internal base 704. The sensor 710 can comprise a position sensor configured to sense the position of the internal base 704 relative to the side wall 702.

Figure 7B illustrates another sensor comprising a movable sensor 712 and a fixed sensor 714. The movable sensor 712 is arranged at or towards an edge of the internal base 704 and is configured to cooperate with the fixed sensor 714 which is arranged at or just outside the side wall 702. The side wall can comprise the fixed sensor 714. The side wall 702 can enclose the fixed sensor 714 to provide protection to the fixed sensor 714. This is illustrated in figure 7B by the dashed lines at 716. The movable sensor 712 suitably comprises a magnet and the fixed sensor 714 suitably comprises a Hall effect sensor. The sensor 712, 714 of figure 78 can thereby sense the relative position between the internal base 704 and the side wall 702. As illustrated, two such sensor systems are provided in the food container 700 in figure 78. A single such sensor system is sufficient in some examples, but more of such sensor systems can be provided as desired. Where multiple sensor systems are provided, a more accurate sensor result can be obtained by combining readings from the separate sensor systems. For example, the readings can be averaged.

The foodstuff grippers illustrated in figures 2A and 3A comprise a single needle. In other implementations, the foodstuff gripper comprises a plurality of needles. Needles of the plurality of needles are suitably laterally offset from one another. The plurality of needles can be provided in any desired geometrical configuration. One such configuration is to provide the needles in a line.

Another, preferred, configuration is to provide three needles in a triangular configuration. The provision of multiple needles enables larger food items to be picked up, and/or multiple food items to be picked up at once.

Providing a plurality of needles enables a more reproducible pick up of certain food items that may be difficult to pick up, for example tomato slices. When using a single needle, there is a chance that the needle might miss the fleshy part of the tomato slice and thereby be unable to pick up the tomato slice. By providing multiple needles, the chance of penetrating the fleshy part of the tomato increases, thereby increasing the ability of the gripper to grip the tomato slice.

The use of multiple needles of a gripper also enables more effective gripping of larger, heavier and/or floppy or flexible food items, such as a slice of cheese or a slice of ham.

Where multiple needles are provided, the plate can comprise a plurality of apertures through which the plurality of needles passes. Suitably, the plate comprises a number of apertures corresponding to the number of needles such that, for example, each needle is configured to pass through a respective aperture in the plate. The multiple needles are suitably provided so as to generally align with one another. In other words, the longitudinal axes of each of the needles are generally aligned. The needles can be considered to be aligned where the longitudinal axes of the needles are within 10 degrees of one another, or preferably within 5 degrees of one another. Where there is a slight misalignment in the directions of the needles, this can improve the grip effected by the needles.

The use of multiple needles can enable rotation of a gripped food item to be carried out more quickly than where a single needle is used to grip that food item. Suitably, the plate comprises a surface feature (on the surface facing a gripped food item) configured to aid the gripping of the food item held against the plate by the needle or by the plurality of needles. The surface feature can comprise a roughened surface and/or surface protrusions, such as ribs. The surface feature is particularly useful in aiding rotation of a food item gripped by a single needle, but is also effective in aiding rotation of a food item gripped by multiple needles, particularly in the case of a floppy or flexible food item.

Where multiple food items are picked up at once, e.g. with a gripper comprising a plurality of needles, the food items can all be deposited at the same time.

The multiple needles of the gripper can all be caused to retract through the plate at the same time (by movement of all the needles relative to the plate at the same time). This requires only a single actuator for the gripper (although more may be provided as desired). Causing all the needles to retract through the plate at the same time with a single actuator can reduce the complexity, size, weight and/or cost of the gripper. The single actuator may be configured to actuate a needle mount to which all of the needles are mounted (see figures 2A and 2B for an illustration of a needle mount 212 movable by an actuator 210). The single actuator may be configured to actuate a movable plate (see figures 3A and 3B for an illustration of a plate 304 movable by an actuator 310).

Alternatively, the gripper can comprise more than one actuator, with each actuator being configured to actuate a subset of the needles. In one example, each needle can be actuated by a different actuator. The provision of more than one actuator in this way enables the food items gripped by the multiple needles of the gripper to be deposited sequentially, either at the same location or at different locations, for example in different containers. This can improve the efficiency of the system by enabling multiple items of a type of food item to be picked up at once, and then deposited in a number of containers, without requiring the gripper to move back to the source of that type of food item between each deposition process.

Actuating different needles or sets of needles with respective actuators can enable a staggered release of a large food item gripped by the needles. For example, where a slice of ham is held by, say, 5 needles, retracting those needles sequentially can aid in a more reproducible deposition of the slice of ham on a slice of bread. Such sequential retraction of multiple needles can provide more control over the deposition of the food item held by the multiple needles.

The foodstuff gripper may comprise a plurality of sets of needles, with each set of needles of the plurality of sets of needles comprising at least one needle. The gripper suitably comprises a plurality of actuators, with each actuator of the plurality of actuators being configured to move a respective set of needles relative to the plate such that the respective set of needles is moved between the extended configuration and the retracted configuration, under the action of the respective actuator.

At least one needle of a first set of needles may be configured to grip a different food item compared to at least one needle of a second set of needles. The provision of sets of needles in this way, where needles of each of the sets of needles can be provided having differing characteristics, enables a selection to be made of a particular set of needles, for example based on a food item or type(s) of food item to be picked up by the gripper. The gripper can therefore use a set of needles most suited to a particular application. Having multiple sets of such needles in a single gripper can mean that the range of uses of that gripper is expanded, compared to a gripper having needles only of a single type.

The sets of needles of the gripper need not be of different types. Multiple sets of needles in a gripper can be of the same type. This redundancy in the sets of needles can accommodate breakages in the needles or actuators actuating those needles, whilst still permitting the gripper to remain operational. This provided redundancy can reduce the time for which the gripper is non-operational, thus improving efficiencies in the food handling system.

Providing multiple sets of needles in a gripper, whether of the same or different type, means that a given set of needles can remain within the housing of the gripper for longer. This increases the time during which that set of needles may be cleaned or sterilised (as discussed elsewhere herein), which can improve the cleaning or sterilisation process.

In some implementations, each needle (of a single or multiple needle gripper) is configured to grip a plurality of food items. For example, a long needle can be provided that can pass through a food item to pick up that food item, and can also pass through another food item to pick up that other food item as well. In this way, a needle of the foodstuff gripper can be used to stack food items. The extension of the needle (or needles) can be graduated. That is, the foodstuff gripper is suitably configured such that there is at least one configuration between the extended configuration and the retracted configuration. Such a configuration can be considered to be an intermediate configuration, in which the relative positions of the needle(s) and the plate are intermediate their relative positions in the extended configuration and the retracted configuration. The foodstuff gripper is configured to grip a food item when in the intermediate position, by the needle(s) penetrating that food item. The foodstuff gripper can then be transitioned to the extended configuration, exposing a greater length of needle than in the intermediate position. In the extended configuration, the needle(s) are able to penetrate a further food item. Picking up the food items in this way enables each food item to be penetrated by the needle until the food item meets resistance, stopping it from being further penetrated by the needle. For the first food item picked up, the resistance is from the food item abutting against the plate. For the second food item picked up, the resistance is from the second food item abutting against the first food item. More than one intermediate position may be provided, for example two or three intermediate positions. Further intermediate positions can be provided as desired. More than two food items may be picked up by the needle, for example three or four. The gripper may be configured to pick up additional food items at once, as desired.

Where the foodstuff gripper is configured to pick up multiple food items using a particular needle, it is preferably configured to remove the food items from the needle such that not all food items need to be removed in one go. This can enable the gripper to deposit gripped food items across multiple containers. The foodstuff gripper is suitably configured to remove at least one food item from the needle on transitioning from the extended configuration to the intermediate configuration (or on transitioning from one intermediate configuration to another intermediate configuration) e.g. an adjacent intermediate configuration, or on transitioning from an intermediate configuration to the retracted configuration). Of course, it will be appreciated that more than one, and possibly all, of the multiple gripped food items can be removed from the needle in one go if desired, by retracting the needle containing all the food items through the aperture in the plate by a desired amount, for example fully retracting the needle towards the retracted configuration. Such an approach can reduce the time it takes to pick and place multiple food items, as it reduces the need for back and forth motion between the source(s) of the items and the deposition location.

As mentioned briefly above, the needles of the foodstuff gripper can be cleaned or sterilised. One way in which this can be done is by exposing the needles to UV light. For this purpose, the gripper can comprise a UV light source such as one or more LEDs configured to emit UV light. The UV light source need not be provided local to the gripper; the light source may be provided remote from the gripper and the light directed onto the needles of the gripper, preferably onto the needles when within the gripper. However, providing a local light source such as a UV LED enables a more convenient way of sterilising the needles of the gripper. With reference to figures 2A, 2B, 3A and 35, a UV light source 214, 314 such as a UV LED can be provided within the housing 208, 308 of the foodstuff gripper 200, 300 so as to illuminate the one or more needles of the gripper. Suitably the steriliser 214, 314 (e.g. the UV light source) is directed towards the needles when they are retracted within the housing 208, 308. The interior of the housing may be provided with reflecting materials to ensure that all sides of the needle(s) are exposed to the sterilising light. Additionally or alternatively, multiple sources of the sterilising light may be provided to ensure full illumination of the needle(s).

This configuration enables the steriliser to sterilise the needle(s) between each pickup of a food item. Sterilising the needle(s) in this way can reduce the down time of the foodstuff gripper, since the sterilising process can occur after a food item has been deposited and whilst the gripper is being moved to the source location to pick up another food item. The use of sterilising light such as UV light can reduce the amount of washing of the component parts of the gripper, thereby reducing water usage in the cleaning and sterilising process. This can therefore lead to a more sustainable food handling system.

The gripper may comprise replaceable parts, such as the needle(s) and/or the plate. Providing the gripper with replaceable parts, which may be washable or disposable, means that the parts can be quickly and easily replaced, to ensure that high hygiene standards are maintained.

Sanitation with UV light is mentioned above. UV light can be directed onto the one or more needles, and/or the plate (e.g. an upper surface facing into the gripper and/or a lower surface facing outwardly and against which a food item can be held) to sanitise these parts. UV light can be directed more generally onto the gripper as whole. Such UV light can be obtained by locating one or more UV light sources, such as UV LEDs, so as to direct the emitted light as desired. The UV light sources can be located at the gripper and/or remote from the gripper. For example, a UV light source housed internally to the gripper body can be used to direct UV light onto the needle(s) in the retracted configuration and/or onto the upper surface of the plate. A UV light source remote from the gripper can be used to direct UV lights onto the lower surface of the plate and/or onto other exterior parts of the gripper. Other methods for maintaining the sterility of at least a portion of the gripper or for sanitising at least a portion of the gripper (for example one or more needles, and/or the plate), which can be used in place of or in addition to UV exposure, include immersion (e.g. of the needle(s), or of the plate, or of the whole gripper) in a cleaning solution, and enveloping a portion of the food handling system in a protective cover. For example, the robot arm and/or at least a portion of the gripper can be covered with a protective cover.

In some implementations, the plate (which can also be termed a stripper plate, as it strips food items from the needle(s)) is removable from the foodstuff gripper. The plate can be magnetically attachable to the gripper. For example, the plate is formed from or comprises a magnetic material, and a plate mounting portion of the gripper is formed from or comprises a magnetic material of opposite polarity to that of the plate. Suitably, the magnetic attraction between the plate and the plate mounting portion has a higher force than a force that stripping actions will exert on the plate. This helps ensure that the plate remains in place as part of the foodstuff gripper during normal foodstuff moving operations. This configuration enables quick and easy replacement of the plate. The plate replacement can be carried out automatically.

The plate suitably comprises a tab protruding from a profile of the remainder of the foodstuff gripper. The presence of the tab means that the food handling robot can drive the foodstuff gripper towards a plate removing tool which can engage with the tab to remove the plate from the plate mounting portion. The food handling robot can then drive the plate mounting portion of the foodstuff gripper to a replacement plate. The plate mounting portion can pick up the replacement plate by magnetic attraction between the replacement plate and the plate mounting portion.

The plate mounting portion may comprise an electromagnet in place of a permanent magnet. This configuration can make it simpler to remove the plate from the plate mounting portion. Switching off the electromagnet can cause the plate mounting portion to drop the plate, avoiding the need for the plate removing tool.

The plate is suitably mounted so as to be removable from the gripper. The mounting may be magnetic, as described above. The mounting may comprise a retaining clip or any other suitable retaining mechanism. To aid automatic removal and/or remounting of the plate to the rest of the gripper, the retaining mechanism is suitably automatically operable, for example by applying pressure to a tab or operating an engagement mechanism. The plate may be held behind a lip. The plate may comprise a resilient portion for enabling a snap-fit with the lip. The lip may comprise a resilient portion for enabling a snap-fit with the plate. The gripper body may comprise a resilient clip, and the plate can be retained by the resilient clip. The engagement mechanism can comprise the clip, which is suitably movable between an engaged configuration in which the clip retains the plate on the gripper body and a disengaged configuration in which the plate is able to detach from the gripper body.

Removed plates can be taken away for washing. Removed plates can be deposited in a sterilising location, e.g. under UV light or in a bath of sterilising liquid. Replacement plates can be picked up from the sterilising location, for example after a given length of time has been met or exceeded. Replacement plates can be clean plates.

Depositing the plates in the sterilising location, and/or picking up new plates or plates from the sterilising location can mean that the food handling robot can operate for longer without user assistance.

The needle mount 212, 312 suitably comprises a resilient needle mount. The needle(s) can be located in the needle mount 212, 312 by a friction fitting. This arrangement means that the needles can be replaced quickly and easily, helping to reduce down time when the foodstuff gripper is nonoperational. The resilient mount can comprise an elastomeric mounting portion for holding the proximal portion of the needles. The resilient mount can comprise a sprung holder for holding the proximal portion of the needles.

The resilient mount may provide an additional benefit. The resilient mount may provide a tolerance in needle angle when picking up a food item, since the needle may be able to move by a limited amount whilst still being held by the resilient mount. The resilient mount may provide a tolerance in needle position along the longitudinal axis of the needle. Thus, in case of an impact on the needle, for example by the needle coming into contact with a base of a container, the resilience of the needle mount can reduce or avoid damage to the needle and/or to the mount.

As discussed, the foodstuff gripper can comprise a needle and a plate through which the needle is retractable so as to remove gripped food items from the needle. The plate need not be provided at the foodstuff gripper. A plate may instead, or additionally, be provided remote from the gripper. The remote plate may be provided at the deposition location. The remote plate suitably comprises one or more apertures. The one or more apertures of the remote plate can correspond to one or more needles of the gripper. For example, an aperture of the remote plate can correspond to a respective needle of the gripper. The apertures of the remote plate suitably comprise channels in the remote plate, which are open at the edge of the plate. The apertures in the remote plate can conceptually be considered to be like the gaps between the tines or teeth of a comb. The apertures in the remote plate are suitably elongate. An example of a remote plate 402 is illustrated in figure 4. The remote plate 402 comprises elongate apertures 404 that extend to the edge of the remote plate.

Where a remote plate 402 is to be used to remove food items from needles of the gripper, the foodstuff gripper is moved relative to the remote plate in the following manner; reference is made to figures 5A, 5B and 5C. The foodstuff gripper 502 is moved (see the arrow 510 in figure 5A) such that respective shafts of the needles 504 (e.g. proximal to a gripped food item) pass along respective apertures 508 of the remote plate 506. The needles 504 of the foodstuff gripper 502 are then interdigitated with the apertures 508 of the remote plate 506, as illustrated in figure 5B. The foodstuff gripper 502 is moved (see the arrow 512 in figure Sc) such that the needles move in a direction generally along a longitudinal axis of the needles towards a proximal end of the needles, whereby the gripped food item is removed from the needles by action of the remote plate 506 on the food item. With reference to figures 5A to 5C, a food item gripped by the lowermost portion of the needles 504 will pass under the top of the remote plate 506 and on lifting the foodstuff gripper 502, the food item will be deposited below the remote plate 506.

The apertures in the plate (e.g. the remote plate 506) can be flared. That is, the edge of the aperture may have a greater width than the remainder of the aperture. The change in width along the aperture can be linear, or non-linear, such as curved. The flared opening to the aperture (or to each aperture where there is a plurality of apertures) makes it easier for the needle shafts to enter the apertures. The flared arrangement thus increases the tolerance of the foodstuff gripper movement whilst ensuring that the needles pass along the apertures so that removal of the food item from the needles can be effected. The narrowing of the apertures away from the flared ends can mean that the food item is deposited with a greater accuracy since the positioning of the needles is more constrained in the narrower portion of the aperture than in the flared portion of the aperture.

Advantages of the foodstuff gripper described herein include that the actuator or actuators are electrically operable. This decreases cost and complexity compared to systems that use compressed air lines. The mechanism discussed herein can be easily integrated into existing production lines with minimal reconfiguration. Thus the present techniques can be used to retrofit existing production lines at low cost. The low cost of the described foodstuff gripper enables a relatively greater number of such grippers to be provided with minimal impact on overall cost. A greater number of such grippers can improve efficiencies. Enabling multiple needles to be used in the same gripper, with dependent or independent functionality, can help increase the range of use of the gripper and can lower or remove barriers to entry for use of such systems by food producers with low margins. The present techniques can operate with one-point contact grip, e.g. using a single needle. With only one contact point, the gripper can pick and place food products. This configuration enables the picking and placement of food products independently of their surface structure, surface area and shape. Thus, the present techniques are demonstrated to be suitable for bin-picking food and ingredients with unstructured shapes. The approach by the gripper towards an object to be gripped can usefully be done from top to bottom, e.g. along a longitudinal axis of the gripper needle. There is no need to approach the object at a specific angle, e.g. one dependent on the surface normal of the object or on the object position. This increases the flexibility of use of the foodstuff gripper. At least the needles of the gripper are suitably made from a material that is easily cleaned and/or sterilised, for example a metal such as stainless steel. Other parts of the foodstuff gripper may also be made from a material that is easily cleaned and/or sterilised, for example a metal such as stainless steel.

Cleaning and sanitizing is therefore made less complex and can be achieved at low cost and within a shorter timeframe.

A method of gripping a food item for moving the food item from a source location to a deposition location will now be described with reference to figure 6. The method comprises gripping the food item using a needle 602. The food item can be gripped with multiple needles as described herein. The food item is picked up from a source location. The food item is picked up by inserting the needle into the food item along a longitudinal length of the needle. The gripped food item is moved 604, for example to a deposition location. The gripped food item is removed from the needle 606. The removal process occurs by drawing the needle in a proximal direction of the needle through an aperture in a deposition plate in a direction substantially normal to the deposition plate. This enables the food item to be removed from the needle by action of the deposition plate on the food item.

The method may further comprise sensing a force on the needle. The sensed force may be used to determine one or more of: whether the needle is gripping a food item; a weight of the gripped food item; a change in force as the needle penetrates the food item; and an inventory tracking signal. Reference is made to the discussion elsewhere herein in relation to force sensing.

The method may further comprise gripping a plurality of food items using a respective plurality of needles, and removing the plurality of gripped food items from the plurality of needles by drawing the needles in a proximal direction of the needles through one or more apertures in a deposition plate whereby the food items are removed from the needles by action of the deposition plate on the food items. Thus, the picking up and deposition process can be made more efficient.

The method may comprise gripping a first food item using a first set of needles, the first set of needles comprising at least one needle, and gripping a second food item using a second set of needles, the second set of needles comprising at least one needle. The at least one needle of the first set of needles suitably has a different configuration to the at least one needle of the second set of needles. The method may comprise removing the gripped first food item from the first set of needles. This can be achieved by drawing the first set of needles in a proximal direction of the first set of needles through a first aperture (or first plurality of apertures) in a deposition plate. This motion enables the first food item to be removed from the first set of needles by action of the deposition plate on the first food item. The removal of the gripped first food item may occur before the second food item is gripped using the second set of needles. The method may further comprise removing the gripped second food item from the second set of needles. This can be achieved by drawing the second set of needles in a proximal direction of the second set of needles through a second aperture (or second plurality of apertures) in a deposition plate whereby the second food item is removed from the second set of needles by action of the deposition plate on the second food item. The second aperture may be the same as the first aperture. The second plurality of apertures may be the same as the first plurality of apertures.

The method suitably comprises gripping a plurality of food items using the needle and removing a subset of the plurality of food items from the needle by partially drawing the needle in a proximal direction of the needle through the aperture in the deposition plate. The method may comprise removing an additional food item of the plurality of food items from the needle by further drawing the needle in a proximal direction of the needle through the aperture in the deposition plate.

The method may comprise at least partially sterilising the needle using UV light.

Control of the foodstuff gripper can be effected using an exemplary computing-based device which may be implemented as any form of a computing and/or electronic device, and in which embodiments of the methods and foodstuff gripping systems described herein may be implemented. The computing-based device comprises one or more processor which may comprise microprocessors, controllers or any other suitable type of processors for processing computer executable instructions. In some examples, for example where a system on a chip architecture is used, the processors may include one or more fixed function blocks (also referred to as accelerators) which implement a part of the method of gripping a food item in hardware (rather than software or firmware). Platform software comprising an operating system or any other suitable platform software may be provided at the computing-based device to enable application software, such as software implementing the method of figure 6, to be executed on the device.

The computer executable instructions may be provided using any computer-readable media that is accessible by the computing-based device. Computer-readable media may include, for example, computer storage media such as a memory and communications media. Computer storage media (i.e. non-transitory machine-readable media), such as the memory, includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by a computing-based device. In contrast, communication media may embody computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave, or other transport mechanism. As defined herein, computer storage media does not include communication media. Although the computer storage media (i.e. non-transitory machine-readable media, e.g. the memory) is described as being within the computing-based device it will be appreciated that the storage may be distributed or located remotely and accessed via a network or other communication link (e.g. using a communication interface).

In the description above actions taken by the system have been split into functional blocks or modules for ease of explanation. In practice, two or more of these blocks could be architecturally combined. The functions could also be split into different functional blocks.

The present techniques have been described in the context of food handling systems, though at least some features described are not limited to such systems, but may be applied to robotic systems more generally. Robotic systems can include manufacturing systems, such as vehicle manufacturing systems, parts handling systems, laboratory systems, and manipulators such as for hazardous materials.

The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

Claims

Claims 1. A foodstuff gripper for a food handling robot, the food handling robot comprising a robot arm having a distal mount for engaging with the foodstuff gripper, the robot arm comprising a plurality of joints whereby the configuration of the arm can be altered, the foodstuff gripper comprising: a needle for penetrating a food item to be gripped by the foodstuff gripper; and a plate comprising an aperture through which the needle is arranged to pass; wherein the foodstuff gripper is configured to move the needle and the plate relative to one another such that the foodstuff gripper has an extended configuration in which the needle extends through the aperture in the plate in a direction substantially normal to the plate permitting the needle to penetrate the food item in a direction along the longitudinal axis of the needle and a retracted configuration in which the needle is retracted at least partially through the aperture whereby a food item gripped by the needle is removed from the needle by action of the plate on the food item.
2. A foodstuff gripper as claimed in claim 1, in which the needle comprises one or more of: a friction-increasing coating; a roughened surface to increase grip on the food item; a non-smooth cross-section along at least a portion of its length; a polygonal cross-section along at least a portion of its length; a twist along at least a portion of its length; and a decreasing thickness along at least a portion of its length in a direction along the needle from a distal tip of the needle.
3. A foodstuff gripper as claimed in claim 1 or claim 2, in which the needle comprises one or more surface protrusions to increase grip on the food item.
4. A foodstuff gripper as claimed in claim 2 or claim 3, in which a thickness of the needle increases in a direction along the needle from a distal tip of the needle.
5. A foodstuff gripper as claimed in any preceding claim, in which the plate comprises a surface feature to aid gripping of the food item held against the plate by the needle.
6. A foodstuff gripper as claimed in any preceding claim, comprising a sensor configured to sense a force on the needle.
7. A foodstuff gripper as claimed in claim 6, in which the foodstuff gripper is configured to, in dependence on an output of the sensor, determine at least one of: whether the food item is gripped by the needle; a weight of the food item gripped by the needle; when the food item is removed from the needle; a force as the needle is inserted through the food item; and an inventory tracking signal.
8. A foodstuff gripper as claimed in any preceding claim, comprising a plurality of needles.
9. A foodstuff gripper as claimed in claim 8, in which the plate comprises a plurality of apertures through which the plurality of needles are arranged to pass.
10. A foodstuff gripper as claimed in claim 8 or claim 9, comprising a plurality of actuators, each actuator being configured to move at least one needle of the plurality of needles relative to the plate such that the at least one needle is moved as the foodstuff gripper transitions between the extended configuration and the retracted configuration.
11. A foodstuff gripper as claimed in claim 10, in which the foodstuff gripper comprises a plurality of sets of needles, each set of needles of the plurality of sets of needles comprising at least one needle, and each actuator of the plurality of actuators being configured to move a respective set of needles relative to the plate such that the respective set of needles is moved as the foodstuff gripper transitions between the extended configuration and the retracted configuration.
12. A foodstuff gripper as claimed in claim 11, in which at least one needle of a first set of needles is configured to grip a different food item compared to at least one needle of a second set of needles.
13. A foodstuff gripper as claimed in any of claims 1 to 9, comprising an actuator configured to move the or each needle and the plate relative to one another such that the or each needle is moved as the foodstuff gripper transitions between the extended configuration and the retracted configuration.
14. A foodstuff gripper as claimed in any preceding claim, in which, in the extended configuration, the or each needle is configured to grip a plurality of food items.
15. A foodstuff gripper as claimed in claim 14, in which the foodstuff gripper is configured to move the or each needle and the plate relative to one another to at least one intermediate configuration between the extended configuration and the retracted configuration, whereby the foodstuff gripper is arranged to grip an additional food item in the intermediate configuration and/or to remove a gripped food item from the needle on transitioning from the extended configuration to the intermediate configuration.
16. A foodstuff gripper as claimed in any preceding claim, in which the foodstuff gripper is configured to at least partially sterilise (i) the or each needle and/or (ii) the plate using UV light.
17. A foodstuff gripper as claimed in claim 16, in which the foodstuff gripper is configured to at least partially sterilise the or each needle in the retracted configuration.
18. A foodstuff gripper as claimed in any preceding claim, comprising a resilient needle mount for mounting the or each needle.
19. A food handling system comprising a foodstuff gripper as claimed in any preceding claim and an imaging system for imaging at least one of a source location for food items and a deposition location for food items, wherein the foodstuff gripper is controllable in dependence on an output of the imaging system.
20. A food handling system comprising: a foodstuff gripper as claimed in any of claims 1 to 18; and a robot arm having a distal mount for engaging with the foodstuff gripper, the robot arm comprising a plurality of joints whereby the configuration of the arm can be altered; wherein the robot arm is configured to sense a force on the foodstuff gripper.
21. A food handling system comprising a foodstuff gripper for a food handling robot, the food handling robot comprising a robot arm having a distal mount for engaging with the foodstuff gripper, the robot arm comprising a plurality of joints whereby the configuration of the arm can be altered, the food handling system further comprising a deposition plate; the foodstuff gripper comprising a needle for penetrating a food item to be gripped by the foodstuff gripper; the deposition plate comprising an aperture; and the food handling system being configured to (i) move the foodstuff gripper such that a shaft of the needle proximal to a gripped food item passes along the aperture of the deposition plate and (ii) move the foodstuff gripper such that the needle moves in a direction generally along a longitudinal axis of the needle towards a proximal end of the needle, whereby the gripped food item is removed from the needle by action of the deposition plate on the food item.
22. A food handling system as claimed in claim 21, in which the aperture in the deposition plate comprises a flared opening.
23. A food handling system as claimed in claim 21 or 22, in which the foodstuff gripper comprises a plurality of needles, and the deposition plate comprises a plurality of apertures.
24. A method of gripping a food item for moving the food item from a source location to a deposition location, the method comprising: gripping a food item, from a source location, using a needle inserted into the food item along a longitudinal length of the needle; moving the gripped food item to a deposition location; and removing the gripped food item from the needle by drawing the needle in a proximal direction of the needle through an aperture in a deposition plate in a direction substantially normal to the deposition plate whereby the food item is removed from the needle by action of the deposition plate on the food item.
25. A method as claimed in claim 24, further comprising sensing a force on the needle and using the sensed force to determine one or more of: whether the needle is gripping a food item; a weight of the gripped food item; a change in force as the needle penetrates the food item; and an inventory tracking signal.
26. A method as claimed in claim 24 or claim 25, further comprising: gripping a plurality of food items using a respective plurality of needles; and removing the plurality of gripped food items from the plurality of needles by drawing the needles in a proximal direction of the needles through one or more apertures in a deposition plate whereby the food items are removed from the needles by action of the deposition plate on the food items.
27. A method as claimed in any of claims 24 to 26, further comprising: gripping a first food item using a first set of needles, the first set of needles comprising at least one needle; and gripping a second food item using a second set of needles, the second set of needles comprising at least one needle; wherein the at least one needle of the first set of needles has a different configuration to the at least one needle of the second set of needles.
28. A method as claimed in any of claims 24 to 27, further comprising: gripping a plurality of food items using the needle; and removing a subset of the plurality of food items from the needle by partially drawing the needle in a proximal direction of the needle through the aperture in the deposition plate.
29. A method as claimed in claim 28, further comprising: removing an additional food item of the plurality of food items from the needle by further drawing the needle in a proximal direction of the needle through the aperture in the deposition plate.
30. A method as claimed in any of claims 24 to 29, further comprising at least partially sterilising one or both of the needle and the plate using UV light and/or a cleaning solution.