WO2023194719A1

WO2023194719A1 - A foodstuff gripper for gripping food items using a needle

Info

Publication number: WO2023194719A1
Application number: PCT/GB2023/050897
Authority: WO
Inventors: Rodolfo CUAN URQUIZO
Original assignee: Brandenburg Ip Limited
Priority date: 2022-04-05
Filing date: 2023-04-04
Publication date: 2023-10-12
Also published as: GB202204992D0; GB2617356A

Abstract

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.

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 aperture in the plate may comprise a chamfered portion.

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 crosssection 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 plate may comprise a non-planar surface. The plate may comprise a concave surface portion. The plate may comprise a convex surface portion.

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 needle may have a generally rectangular cross-section. 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.

The foodstuff gripper may comprise a needle mounting plate and an actuating plate. The needle mounting plate may be for mounting one or more needles. The actuating plate may be for actuating the needle mounting plate. The actuating plate may be for actuating the needle mounting plate between the retracted configuration and the extended configuration. The needle mounting plate and the actuating plate may be magnetically engageable. The needle mounting plate may comprise a magnetic material. The needle mounting plate may comprise a magnet. The magnet may be embedded within the needle mounting plate. The needle mounting plate may comprise a plurality of magnets. The plurality of magnets may be embedded within the needle mounting plate. The actuating plate may comprise a magnetic material. The actuating plate may comprise a magnet. The magnet may be embedded within the actuating plate. The actuating plate may comprise a plurality of magnets. The plurality of magnets may be embedded within the actuating plate.

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.

The sensor may be configured to sense the force between the foodstuff gripper and the distal mount. The food handling system may be configured to compare a force sensed by the sensor with an expected force or a force profile. The food handling system may be configured to modify control of the foodstuff gripper and/or the robot arm based on the comparison.

The food handling system may be configured to determine the position of one or more needles of the foodstuff gripper. The food handling system may be configured to compare a determined position with an expected position or a position profile. The food handling system may be configured to modify control of the foodstuff gripper and/or the robot arm based on the comparison.

The food handling system may comprise wheels. The wheels may enable the food handling system to be mobile. The food handling system may comprise a locking mechanism for restricting movement of the food handling system.

The food handling system may comprise one or more container storage locations. The food handling system may comprise 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.

The robot arm may be configured to sense a force on the foodstuff gripper.

The food handling system may further comprise a deposition plate; the foodstuff gripper may comprise a needle for penetrating a food item to be gripped by the foodstuff gripper; the deposition plate may comprise an aperture; and the food handling system may be 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.

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.

The robot arm may be 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 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 2B schematically illustrates the foodstuff gripper of figure 2A in a retracted configuration;

Figure 3A schematically illustrates another foodstuff gripper in an extended configuration;

Figure 3B 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;

Figures 7A and 7B schematically illustrate a food container;

Figure 8 schematically illustrates an example food container in cross-section;

Figure 9 schematically illustrates an example of a food handling system in side view;

Figure 10 schematically illustrates a perspective view of a portion of the food handling system of figure 9;

Figure 11 schematically illustrates a perspective view of a portion of another example of a food handling system in side view;

Figure 12 schematically illustrates an example of an aperture comprising a chamfer;

Figure 13 schematically illustrates another example of an aperture comprising a chamfer;

Figure 14 schematically illustrates an example of a plate having apertures for needles;

Figure 15 schematically illustrates another example of a plate having apertures for needles;

Figure 16 schematically illustrates another example of a plate having apertures for needles;

Figure 17 schematically illustrates a portion of an example foodstuff gripper holding a food item;

Figure 18 schematically illustrates a portion of an example needle;

Figure 19 schematically illustrates an example of a needle;

Figure 20 schematically illustrates another example of a needle;

Figure 21 schematically illustrates another example of a needle;

Figure 22 schematically illustrates a partially-constructed example of a needle mounting plate;

Figure 23 schematically illustrates an example of a needle mounting plate;

Figure 24 schematically illustrates a view of an example gripper body;

Figure 25 schematically illustrates another view of an example gripper body; and

Figure 26 schematically illustrates an example of a foodstuff gripper.

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.

Providing a mobile food handling robot enables the food handling robot to be placed next to any assembly line or conveyor belt, and to be movable relative to the conveyor belt to place the food handling robot in a desired location. This approach means that the food handling robot need not be provided as part of a fixed structure relative to the conveyor belt, but can be adjustably located relative to the conveyor belt. This provides more flexibility in where one or more food handling robots are placed relative to one or more conveyor belts. Suitably the food handling robot comprises a locking mechanism to restrict movement of the food handling robot. An example of such a locking mechanism is a mechanism acting on one or more of the wheels of the mobile food handling robot to restrict rotation of the wheels. Thus, it is possible to move the food handling robot to a desired location, and to restrict or prevent movement away from that location during an operation of the food handling robot. The locking mechanism may be provided in any other suitable manner, for example by a support depending from an underside of the food handling robot. The support is suitably movable between a raised state in which the support does not interfere with movement of the food handling robot and a lowered state in which the support restricts movement of the food handling robot, for example by causing the wheels of the food handling robot to be lifted off the floor. In another example, the locking mechanism comprises a connecting member to connect the food handling robot to a fixing which is fixed relative to the conveyor belt and/or to the floor. In one implementation the fixing can take the form of a fixing plate attached to the floor, where the fixing plate has an aperture. The connecting member can take the form of a hook for engaging with the aperture of the fixing plate. Combinations of these examples of locking mechanisms, as well as others, are possible. For example, the locking mechanism can comprise a mechanism configured to act on one or more wheels to restrict their rotation and a support as described above.

The provision of a mobile food handling robot also has advantages for cleaning, maintenance and repair. Where the conveyor belt, the food handling robot, and/or an area around one or both of the conveyor belt and the food handling robot require cleaning, the ability to move the food handling robot away from the conveyor belt enables the cleaning operation to be carried out more easily and more quickly. This helps reduce the downtime of the assembly line.

Moving the food handling robot away from the conveyor belt enables the food handling robot to be cleaned by spraying the food handling robot without such spray contacting the conveyor belt. It also permits the food handling robot to be more easily sprayed from all directions, without the conveyor belt interfering with the spray. Moving the food handling robot away from the conveyor belt enables the conveyor belt and the floor surrounding the belt to be more easily cleaned.

During operation of the food handling robot, the food items contained within a food container will supply the assembly line for a limited period of time, until the food items in the food container are exhausted. Typically this will take a time period in the order of 15 minutes (depending on the nature of the assembly line and the food items within the food container). Once the food items have all been used up, the food container will need to be replaced with a new food container. Conventionally, replacement food containers are provided from a separate store of food containers which are remote from the conveyor belt. This means that replacing the food containers can be a time-consuming process. The present inventors have realised that it is possible to provide food container storage local to the food handling robot. This is particularly useful where the food handling robot is mobile, since multiple food containers can be loaded into the food handling robot before the food handling robot is moved into position at the assembly line or conveyor belt.

Suitably, a mobile food handling robot is provided with multiple food containers, to reduce the need to resupply the food handling robot from a separate location. Reference is now made to figures 8 to 11. Figure 8 illustrates an example food container in cross-section. Figure 9 illustrates an example of a food handling robot in side view. Figure 10 is a perspective view of a portion of the food handling robot of figure 9. Figure 11 is a perspective view of a portion of another example of a food handling robot in side view.

An example of a food container 800 is illustrated in figure 8. The food container 800 comprises a base 802 and a side wall 804. The food container comprises a lip 806. Suitably, the lip 806 is provided along two, opposite, sides of the food container. The lip 806 is, in some examples, provided along all four sides of a square or rectangular food container.

A food handling robot, an example of which is schematically illustrated at 900 in figure 9, comprises a robot arm 902 mounted on a base 904. The base comprises a food container mount 906 for mounting a food container. The base 904 comprises wheels 908 for moving the food handling robot. The food handling robot suitably comprises a locking mechanism, not shown.

The food handling robot 900 comprises one or more container storage locations 910 for storing a food container. In this example, the container storage locations comprise pairs of rails 912 in the base 904 along which lips 806 of a food container 800 are slidable for inserting the food container into and removing the food container from the base. As illustrated, the food handling robot 900 comprises three container storage locations 910. More or fewer container storage locations can be provided in other examples. Suitably, the number of container storage locations will depend on the size of the food containers 800 and the height at which the robot arm 902 is to operate.

The food containers 800 can be moved between the container storage locations 910 and the food container mount 906 under robotic control, by a separate robot, and/or manually.

Suitably, the system will monitor the usage of food items from a food container and will provide an indication of when a food container is to be replaced. The indication may be provided shortly in advance of when the food container needs replacing, so that a manual or robotic operator can be in position to replace the food container when needed. This can reduce the time for which the food handling robot does not have access to food items for use in the assembly line. The indication may comprise a light at the food handling robot to indicate to an operator that the food container in use is nearly empty. The indication can be provided based on one or both of a time for which the food container has been used and a weight of the food container.

The food handling robot may be configured to store food containers in the container storage locations at a different orientation to an orientation in which a food container is mountable in the food container mount. This configuration permits the sizing of the food handling robot (its width and depth) to be selected as desired. In other implementations, the container storage locations need not extend for the whole width of the base 904.

Figure 10 schematically illustrates a perspective view of a portion of the food handling robot of figure 9. In figure 10, the robot arm and food container mount are not shown, but their general locations are indicated on the top of the base 904: the robot arm location is shown at 1002 and the food container mount location is shown at 1004.

The food container storage locations 910 can be formed in a recess to one side of the base 904 of the food handling robot 900. It is possible for the robot arm location 1002 and the food container mount location 1004 to be provided either way round, to suit the use and positioning of the food handling robot. In other examples, the food container storage locations 910 can be accessed from either side of the food handling robot. That is, rather than the food container storage locations being within a recess to one side of the base, the base comprises an opening to either side, where the opening both communicate with a common cavity in the base. In this arrangement, the food handling robot can be oriented as desired.

An alternative food handling robot is schematically illustrated in figure 11 at 1100. The base 1101 is provided with two robot arm locations 1102 and a food container mount location 1104. The food container mount location 1104 is provided in between the two robot arm locations 1102. This arrangement permits each of two robot arms at the robot arm locations 1102 to access a food container at the food container mount location 1104. Thus, the food handling robot of figure 11 is a larger food handling robot than that illustrated in figures 9 and 10. The additional size of the food handling robot 1100 of figure 11 enables two columns of container storage locations 1110 to be provided in the base 1101.

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, 2B, 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 2B 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 2B, 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 apertures in the plate suitably comprise chamfered edges, as illustrated in figure 12. The plate 1202 comprises an aperture 1204 which is wider at the top than the bottom (in the orientation of the figure). The inner edges 1206 of the aperture can be provided with a chamfer 1207 along a portion of their depth through the plate 1202. This chamfer assists the needle to pass through the aperture in a downward direction (the downward direction is the direction in which a needle moves relative to the plate to move towards the extended configuration). The chamfered portion can extend across the whole depth of the plate, as illustrated in figure 13.

Whether or not a chamfer is provided in the plate, and the extent of that chamfer, in some arrangements, in the retracted position, the needle tip 1208 is preferably inserted past the upper edge of the plate (but not past the lower edge). That is, the needle tip is within the aperture. This is illustrated in figures 12 and 13. In one example, the needle tip is, in the retracted position, approximately 1 mm lower than the top edge of the plate, where the plate is thicker than 1 mm.

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 current) 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 current) or torque in the needle actuator, and joint sensor reading from joint sensors of the robot arm.

The motor used to drive the system between the retracted configuration and the extended configuration is suitably an electrical motor such as a servo motor. A hydraulic or pneumatic piston can be used to drive the system between the retracted and extended configuration, but these will require an additional connection in the form of a fluid line. Hence, using an electrical motor will result in a more compact assembly.

A motor used to drive a joint of the robot arm is suitably an electrical motor, such as a servo motor.

The needle can be driven into a food item by placing the foodstuff gripper in the extended configuration, such that a needle extends through the plate, and moving the needle of the foodstuff gripper into a food item by moving one or more joints of the robot arm. Alternatively, the needle can be driven into a food item by placing the foodstuff gripper near a food item by moving one or more joints of the robot arm, and moving the needle into the extended configuration such that the needle pierces the food item. A combination of these approaches may be used.

Thus, movement of the needle into a food item can be effected by one or more servo motors, where a servo motor is provided at the foodstuff gripper and another servo motor is provided at a joint of the robot arm.

The electrical current through a servo motor is typically proportional to a force exerted by that servo motor. Thus, measuring the current through a servo motor can provide an indication of force exerted by that servo motor. Thus, knowledge of the current through the one or more servo motors can provide an indication of a force exerted on the needle. Similarly, a measure of the resistance of the one or more servo motors can also be used to provide an indication of the force on the needle.

In addition to, or instead of, determining the force on a needle via servo motor characteristics, a load cell or pressure sensor can be provided, for example at the foodstuff gripper. The load cell is suitably configured to sense a force on the needle. The load cell is, in some examples, configured to sense force on the foodstuff gripper, relative to the distal end of the robot arm, and thereby to obtain an indication of the force on the needle.

Providing the load cell or pressure sensor between the foodstuff gripper and the distal end of the robot arm enables the load cell to determine the force on the whole foodstuff gripper. The determined force can therefore include the effects (weight) of any food items held by the needle.

The force on the needle can be compared to an expected force or an expected force profile. The comparison is suitably carried out at a processor coupled to the foodstuff gripper. For example, a control system used to control the foodstuff gripper suitably comprises one or more processors which can be configured to obtain the force exerted on the needle and to compare the obtained force with a stored force or a stored force profile. The stored force and/or the stored force profile are suitably stored at a memory accessible to the control system, such as a local memory. The stored force and/or the stored force profile against which the obtained force is compared are suitably selected in dependence on one or more of: a needle or type of needle being used, a type of food item to be picked up from a food container, a type of the assembly line or operation of the foodstuff gripper (whether filling a pot with fruit or placing sandwich filling on a slice of bread, for example).

The position of the needle can be compared to an expected position or an expected position profile. The comparison is suitably carried out at a processor coupled to the foodstuff gripper. For example, a control system used to control the foodstuff gripper suitably comprises one or more processors which can be configured to obtain the position of the needle and to compare the obtained position with a stored position or a stored position profile. The stored position and/or the stored position profile are suitably stored at a memory accessible to the control system, such as a local memory. The stored position and/or the stored position profile against which the obtained position is compared are suitably selected in dependence on one or more of: a needle or type of needle being used, a type of food item to be picked up from a food container, a type of the assembly line or operation of the foodstuff gripper (whether filling a pot with fruit or placing sandwich filling on a slice of bread, for example).

Suitably, the system is configured to obtain one or both of the force on the needle and the position of the needle, and to compare the obtained force and/or position with an expected force/force profile or an expected position/position profile, respectively.

Comparing the obtained force and/or position with an expected force and/or position, respectively, enables the detection of problems or faults. For example, where a needle position is determined to be below the position of a bottom of a food container, it can be determined that the needle has broken, and/or that the needle has penetrated the bottom of the food container. Where the force on a needle is determined to be larger than that expected on piercing a slice of bread, it can be determined that the needle has contacted something other than bread, for example an obstruction such as the bottom of a food container or another part of the system.

Detecting unusual or unexpected forces can be indicative of the foodstuff gripper coming into contact with an obstruction. Obstructions can include the bottom, sides or lip of a food container, another robot arm, the conveyor belt, or an operator. In the case of contacting an operator, it is important that the robot arm does not continue movement, so as to avoid injuring the operator. In other cases, it is important that the robot arm does not move in a way that might damage a part of the system.

Suitably, the robot arm is configured to stop movement before a force on the needle exceeds a breakage force at which the needle may break. The robot arm may be configured to stop movement before a force on the needle exceeds a threshold force which is below the breakage force, to reduce the risk of the needle breaking.

Where the position or force deviates by more than a threshold amount from a position profile or a force profile, the robot arm is suitably configured to stop movement, since the deviation may be indicative of a fault in the system. On detecting a position or force error (e.g. a deviation from an expected profile or a position or force beyond a position limit or a force limit), the control mode of the robot arm and foodstuff gripper is configured to change. In one example, the movement of the robot arm and the foodstuff gripper is stopped until the fault is cleared, for example by a human operator. In another example, the movement of the robot arm and/or foodstuff gripper is restricted such that: (i) the deviation from the position profile or force profile is not increased, and/or (ii) the needle position does not further exceed the position limit, and/or (iii) the force on the needle does not further exceed the force limit.

For example, the needle may contact an obstruction on moving the needle in a first direction. On contacting the obstruction, a force on the needle exceeds a threshold force. The system is configured to restrict movement of the robot arm and/or the foodstuff gripper that might drive the needle further in the first direction. However, the system is suitably still able to move the needle in another direction, such as in a second direction opposite to the first direction. In this case, movement in the second direction will cause the needle to move away from the obstruction. The system may then control the robot arm and/or foodstuff gripper to try moving along the desired path in the first direction again (since the obstruction might have moved out of the way in the intervening time) or the system may control the robot arm and/or foodstuff gripper to move to the desired end location along a different path, so avoiding a static obstruction. These approaches, of moving in the first direction again, and moving along a different path, can be used in combination. For example, one approach may be tried and should another fault occur, a different approach can then be tried. In this way, the system can automatically clear an obstruction following contact with that obstruction.

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 weight sensor placed underneath the food container may comprise a plurality of separate sensors, such as load cells. For example, the weight sensor may comprise two load cells, each placed underneath or near opposite edges of the food container. In another example, four load cells are provided, each being located at or near a corner of a food container, such as a generally rectangular food container. Providing more than one load cell can enable more accurate weight sensing by averaging the weight sensed by each load cell.

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 7B 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 7B. 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 3B, 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 non-operational. 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 mentioned elsewhere herein, the apertures in the plate may extend towards an edge of the plate, thereby forming a channel along the plate, the needle being movable perpendicularly through the plate through the channel. In other examples, the plate may comprise cut-out portions, which can be considered to be apertures, in the sense that the needles are not obstructed by the plate in these locations of the plate. Examples of plates showing different aperture configurations are schematically illustrated in figures 14 to 16. Figure 14 shows a generally square plate 1402 with four apertures 1404 through which needles can pass. As illustrated in figures 12 and 13, one or more of the apertures 1404 can comprise a chamfer. Figure 15 shows a plate as in figure 14, where the corners of the plate 1502 have been cut away to provide spaces through which the needles can pass (the location of the needles is shown at 1504). Figure 16 shows a plate 1602 where more of the plate has been cut away, compared to figure 15, to leave a cross-shaped plate. The cross, in this example, extends between the location of the needles 1604. Conceptually, the plates 1502 and 1602 of figures 15 and 16 comprise apertures, in that the plate has cut-away portions so as not to obstruct the needles.

The plates 1502, 1602 of figures 15 and 16 are able to move relative to the needles in the same manner as the plate 1402 of figure 14 to push food items off the needles, where the food items are large enough, for example where the food items are held by more than one needle. The plate 1502 of figure 15 is advantageously lighter than the plate 1402 of figure 14, and the plate 1602 of figure 16 is advantageously lighter than the plate 1502 of figure 15. Thus, an effective plate can be provided whilst minimising weight of the foodstuff gripper. Using less material for the plate can also result in a cost saving when manufacturing the foodstuff gripper.

Figures 2A, 2B, 3A and 3B show examples of foodstuff grippers in which the surface of the plate against which a food item can be held, and which pushes against the food item as the foodstuff gripper is moved towards the retracted configuration, is generally planar. This need not be the case in all examples. As illustrated in figure 17, which shows a portion of the foodstuff gripper holding a food item, the surface of the plate which can contact the food item may not be planar. In figure 17, needles 1702 pass through a plate 1704. The needles are illustrated as holding a food item 1706. The lowermost surface of the plate 1704, i.e. the surface 1708 facing the food item 1706 held by the needles 1702 is concave. In the illustrated example, the curvature of the plate does not extend to the edges of the plate, but it may do so in other examples. The plate thus comprises a non-planar portion extending across at least some of its surface. In this example the non-planar portion is concave. The non-planar portion may comprise a convex portion instead of or as well as a concave portion. Thus, the curvature may be relatively simple, such as being either concave or convex, or may be more complicated, such as including one or more concave portions and one or more convex portions. The surface of the plate may, in other examples, take other shapes.

The provision of a non-planar surface 1708 of the plate 1704 enables the plate to push on food items unevenly as the foodstuff gripper is moved towards the retracted configuration. In the example illustrated in figure 17, as the needles retract through the plate, the outer edges of the plate 1708 will contact the food item before the central portion of the plate. Thus, the edges of the food item 1706 will be pushed off the needles before the central portion of the food item. Hence, the surface profile of the plate 1708 can be selected to cause food items to be pushed off the needles in a desirable way. Pushing the edges of food items off the needles before the central portion of the food item can aid in the reproducible dropping of the food item. For example, this approach can reduce the chance that the food item is held only by a needle at an extremity of the plate, which might otherwise cause the food item to swing laterally as it is pushed off the needles.

The needle of the foodstuff gripper need not be circular in cross-section. Indeed, it can be advantageous for the needle to have a generally rectangular cross-section, since this shape can increase the contact area with the food item to be gripped without making a hole in the food item that is likely to be visible. A portion of an example of such a needle 1802 is shown in figure 18. To aid in mounting the needle in the foodstuff gripper, the needle can have an inverted 'L-shape' as shown in figure 19. The horizontal part of the needle 1902 can be retained in a needle mount. In an alternative, a pair of needles can be formed unitarily with one another, by joining them at the horizontal part of the needle of figure 19. This is illustrated in figure 20. The needle 2002 has two needle tips 2004, 2006. Forming the needle in this way can aid the relative stability of the needle tips. It may also make manufacture of the foodstuff gripper more convenient, since fewer separate parts need to be assembled. Reference is also made to figure 21, illustrating an example needle 2102 in which four needle tips 2104, 2106, 2108, 2110 are unitarily formed together. This configuration may further stabilise the needle tips relative to one another, and/or may make assembly of the foodstuff gripper more convenient.

In considering the construction of a foodstuff gripper, hygienic considerations can also be taken into account. The present inventors have realised that it is advantageous for the foodstuff gripper to comprise two gripper components: (i) a gripper body comprising an actuating plate, the motor for actuating the actuating plate, and optionally the sensor(s); and (ii) a needle mounting plate holding the needle(s) which is engageable with the actuating plate. This configuration enables the needles to be changed quickly and efficiently between picking up one sort of ingredient and picking up another sort of ingredient, since different needle mounting plates (e.g. with different types and/or configurations of needle(s)) can be used with the actuating plate. Changing the needle mounting plate also means that no food residue from an earlier ingredient will be present when preparing food using a new ingredient.

Further, the needle mounting plate will need to be periodically sterilised. The gripper body, including the motor, is not as easy to sterilise as the needle mounting plate. Thus, it can be helpful to provide these components separately so that the needle mounting plate can be separated from the gripper body for cleaning.

Mounting the needle mounting plate to the actuating plate using screws would give rise to a problem, since the screw threaded recess and screws provide an opportunity for bacterial growth, and are hard to effectively clean. Screw-mounted plates would also be time consuming to replace. The present inventors have realised that these problems can be overcome by mounting the needle mounting plate to the actuating plate magnetically. Magnetic coupling can be achieved without the need of external tooling, this making the attachment and detachment processes easier. Further, the attachment and detachment need not be performed by a skilled engineer.

Further, this configuration enables use of an anti-bacterial sleeve between the actuating plate and the needle mounting plate. The sleeve can be provided around the gripper body to prevent food items from contaminating the gripper body. Similarly, the sleeve can prevent the gripper body from contaminating food prepared using the food handling robot.

Suitably, therefore, the foodstuff gripper comprises an actuating plate comprising a magnetic material and a needle mounting plate comprising a magnetic material. Conveniently, the magnetic material in the needle mounting plate comprises a permanent magnet. The needle mounting plate can comprise a plurality of magnets. The magnetic material in the actuating plate may also comprise a permanent magnet, such as a plurality of magnets. The magnetic material in one or both of the actuating plate and the needle mounting plate may comprise an electromagnet. Suitably, the magnetic material in the actuating plate may comprise an electromagnet. Where an electromagnet is to be provided, it is more convenient to provide the electromagnet at the actuating plate, since this portion of the foodstuff gripper is electrically connected to a power source and control system. Thus, in one example, the actuating plate comprises an electromagnet and the needle mounting plate comprises a magnetic material.

In the examples illustrated in figures 22 to 26, both the actuating plate and the needle mounting plate comprise a plurality of permanent magnets, but it will be appreciated that a different number of permanent magnets and/or an electromagnet could be used instead. It is advantageous for the surface of the actuating plate facing towards the needle mounting plate and for the surface of the needle mounting plate facing towards the actuating plate to be generally planar. A generally planar interface can reduce the risk of bacterial growth in cavities, and/or can make the plates easier to clean. As mentioned, a sleeve can be captured between the actuating plate and the needle mounting plate. A generally planar interface can reduce the chance of the sleeve becoming damaged and thereby allowing contamination of the food assembly line.

Suitably, the magnetic material, such as the one or more magnets, is held within the respective plates so that the surfaces of the plates are planar. For example, a cavity can be provided in the plates in which a magnet can be provided. Where multiple magnets are to be provided, the plate can have a corresponding number of cavities.

By exploiting the advantages of using 3D printing methods instead of conventional manufacturing, one can design a plates with cavities inside the plate. Placing magnets in these cavities, e.g. as part of the manufacturing process, can allow the embedding of the magnet fully into the plate, since additional material can be provided to close the cavity and cover the magnet. As the magnets are fully embedded, the plates can have a generally smooth exterior surface. Such an exterior smooth surface is preferable from a hygiene point of view.

The magnets are suitably strong enough to hold the needle mounting plate against the actuating plate when the needle mounting plate carries a food item. The numbers of magnets provided and/or the number of needles in the needle mounting plate can be selected depending on the weight likely to be carried by that needle mounting plate. This can lead to multiple types of needle mounting plate. Thus, where needle mounting plates need only support a relatively lower weight, a smaller number of magnets can be provided in the needle mounting plate. Where the needle mounting plate needs to support a relatively greater weight, a larger number of magnets can be provided in the needle mounting plate. Thus, magnets are provided only as needed, which can help to reduce manufacturing cost.

The food items picked up by a needle mounting plate may have an uneven weight distribution across the needle mounting plate. Thus, the engagement between the actuating plate and the needle mounting plate ought to be able to cope with such uneven weight distribution. It is therefore advantageous to provide a plurality of magnets in the needle mounting plate. The actuating plate can be provided with a corresponding number of magnets. The plurality of magnets in the actuating plate are suitably provided in locations corresponding to the locations of the magnets in the needle mounting plate, although they need not be in all examples. It is convenient to use flat magnets, since these can be embedded in the plates without causing the plates to become unduly thick. One type of magnet that has been found to be suitable is a round magnet of approximately 10 mm in diameter and approximately 3 mm in thickness. Such a magnet is able to hold 0.8 kg. Another type of magnet that is suitable for use in the foodstuff gripper is a waterproof sewing magnet, for example an 11.5 mm neodymium, plastic-covered, magnet.

Reference is now made to figure 22, which shows a partially-constructed needle mounting plate 2200. The needle mounting plate comprises a cross-shaped channel 2202 and apertures 2204. The needle tip of an inverted L-shaped needle (illustrated in figure 19) is insertable through the aperture 2204 in the needle mounting plate, and the shorter limb of the needle (the horizontal portion, as oriented in figure 19) is locatable in the channel 2202. The needle mounting plate comprises four generally cylindrical recesses 2206 for receiving flat, circular magnets. The recesses are provided towards the corners of the needle mounting plate. Spacing the magnets apart in this manner can provide a more stable engagement than a single magnet towards the centre, or multiple magnets towards the centre.

After placing the magnets in the recesses 2206, the manufacture of the needle mounting plate continues, for example by 3D printing material over the magnet recesses to cover the magnets and seal them within the needle mounting plate. An example of a needle mounting plate 2302 comprising material 2304 covering the magnet recesses, and including four needles 2306, is illustrated in figure 23. The top portion of the needles 2306 can be seen within the cross-shaped channel 2308.

Reference is now made to figures 24 and 25, illustrating different views of a gripper body 2400 comprising an actuating plate 2402. The actuating plate 2402 is coupled to a servo motor 2404 via a hinged connector 2406. A housing 2408 of the gripper body comprises guide channels (one of which is shown at 2410) along which protrusions 2412 of the actuating plate 2402 are guided as the actuating plate is actuated by the servo motor, via the hinged connector. The guide channels 2410 ensure that the actuating plate 2402 moves linearly within the gripper body 2400. The face 2414 of the actuating plate 2402 is smooth.

Figure 26 illustrates a foodstuff gripper comprising the gripper body, including the actuating plate 2402, of figures 24 and 25 and the needle mounting plate 2302 of figure 23. The engagement of the actuating plate 2402 and the needle mounting plate 2302 assists in retaining the needles 2306 in the needle mounting plate, since the actuating plate 2402 covers the channel 2308 and so holds the top portions of the needles 2306 in place. Whilst in the illustrated examples described, the surface of the actuating plate is flat, in some examples the surface of the actuating plate comprises an alignment feature. The alignment feature can comprise a recess or ridge to help with the alignment of the needle mounting plate against the actuating plate. For example, the actuating plate may comprise a ridge for seating within the channel 2308 of the needle mounting plate. The ridge may be in the form of a cross, to aid with alignment between the plates. In some examples, the needle mounting plate comprises a further alignment feature for cooperating with the alignment feature of the actuating plate. For example, the alignment feature may comprise one of a recess and a protrusion and the further alignment feature may comprise one of a protrusion or a recess. The alignment features, and optionally the further alignment feature can restrict lateral movement between the plates, so that they do not slide sideways against one another. It is also noted that the housing 2408 also restricts lateral movement between the plates. In some examples, a lip may be provided towards the edge of one of the actuating plate and the needle mounting plate, to restrict relative lateral movement between the plates.

The location of the magnets can also aid in the alignment between the plates. Providing the magnets off- centre, such as in the corners of the actuating plate and the needle mounting plate, means that the plates will self-align at least to some extent when brought close together, due to the magnetic attraction between the magnets in the corners of the plates.

Where the magnetic attraction is controlled by an electromagnet, the attachment and detachment can be performed automatically. Switching the electromagnet off will mean that the actuating plate and the needle mounting plate can be detached from one another. For example, the needle mounting plate may fall away from the actuating plate under gravity when the electromagnet is switched off.

The needles themselves may also be formed from magnetic material. In this way, attraction of the needles to the actuating plate can supplement (or in some examples replace) the attraction of the embedded magnets. This could be useful in particular for heavier foodstuffs, where the magnetic attraction of the needles supplementing the embedded magnets can mean that a greater weight can be carried by the needles without requiring additional embedded magnets to be provided. For example, one or more needles can be formed from a magnetic material such as ferritic steel, an example of which is steel 430.

A further advantage of a magnetic coupling between the actuating plate and the needle mounting plate is that when put under a high force, the needle mounting plate will separate from the actuating plate rather than break. The present arrangement therefore reduces the potential for damage to the foodstuff gripper. A food production line on which the food handling robot described herein is used will suitably have a metal detector at or towards the end of the production line. The use of magnetic materials, e.g. for the needles and/or for other parts of the foodstuff gripper makes it easier to detect and remove any parts of the needle and/or other parts that might have broken off during food assembly. Thus, the use of magnetic materials can aid in the safety of the food production process.

Safety can also be improved by monitoring the weight of the foodstuff gripper - an unexpected loss in weight can be indicative of a part of the foodstuff gripper having broken or become detached. On occurrence of such an expected loss in weight, the location of the affected foodstuff gripper can be checked for detached or broken parts.

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 5C) 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.

The food handling robot suitably comprises a light emitter configured to indicate the location of at least a part of the food handling robot. For example, the light emitter can indicate the location of the foodstuff gripper. The distal end of the robot arm and/or the foodstuff gripper can comprise a light emitter configured to project light onto a structure such as the conveyor belt underneath the foodstuff gripper. For example, the light emitter can be mounted to the foodstuff gripper and angled downwardly. This can aid the safety of the food handling robot, since an operator can see where the foodstuff gripper is, and know that the needles point towards the projected light. The operator can therefore avoid placing their hand in the beam of light. The light emitter may be configured to indicate the range of motion of the foodstuff gripper, for example by illuminating an arc through which the foodstuff gripper is movable by the robot arm. The light emitter suitably comprises an LED. The light emitter can comprise a laser.

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 non-volatile, 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 nontransmission 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

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; the foodstuff gripper further comprising a sensor configured to sense a force on the needle.

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 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.

4. A foodstuff gripper as claimed in any preceding claim, in which the plate comprises a non-planar surface.

5. A foodstuff gripper as claimed in any preceding claim, 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.

6. A foodstuff gripper as claimed in any preceding claim, comprising a plurality of needles.

7. A foodstuff gripper as claimed in claim 6, 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.

8. A foodstuff gripper as claimed in claim 7, 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.

9. A foodstuff gripper as claimed in claim 8, 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.

10. 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.

11. A foodstuff gripper as claimed in claim 10, 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.

12. 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.

13. A foodstuff gripper as claimed in claim 12, in which the foodstuff gripper is configured to at least partially sterilise the or each needle in the retracted configuration.

14. A foodstuff gripper as claimed in any preceding claim, comprising a needle mounting plate for holding one or more needles and an actuating plate for actuating the needle mounting plate between the retracted configuration and the extended configuration, where the needle mounting plate and the actuating plate are magnetically engageable.

15. A foodstuff gripper as claimed in claim 14, in which one or both of the needle mounting plate and the actuating plate comprises an embedded magnet.

16. A food handling system comprising: a foodstuff gripper as claimed in any of claims 1 to 15; 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 sensor is configured to sense the force between the foodstuff gripper and the distal mount.

17. A food handling system as claimed in claim 16, in which the food handling system is configured to compare a force sensed by the sensor with an expected force or a force profile, and to modify control of the foodstuff gripper and/or the robot arm based on the comparison.

18. A food handling system as claimed in claim 16 or claim 17, in which the food handling system is configured to: determine a position of the needle; compare the determined position with an expected position or a position profile; and modify control of the foodstuff gripper and/or the robot arm based on the comparison.

19. A food handling system comprising a foodstuff gripper as claimed in any of claims 1 to 15 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 15; 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 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; sensing a force on 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.

22. A method as claimed in claim 21, further comprising 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.

23. A method as claimed in any of claims 21 to 22, 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.

24. A method as claimed in any of claims 21 to 23, 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.

25. A method as claimed in any of claims 21 to 24, further comprising at least partially sterilising one or both of the needle and the plate using UV light and/or a cleaning solution.