Picking apparatus

Abstract

Embodiments relate to an apparatus for picking. The apparatus comprises a plurality of tangle elements configured to be entangled with a target to be picked. The apparatus further comprises means for selectively picking up the plurality of tangle elements. When the plurality of tangle elements are entangled with the target, the plurality of tangle elements are configured when picked up to engage the target such that the plurality of tangle elements and the target are picked up together.

Description

[0001] PICKING APPARATUS

[0002] FIELD OF THE INVENTION

[0003] The field of the invention relates to an apparatus and a method for picking.

[0004] BACKGROUND

[0005] Robotic picking apparatuses are becoming increasingly popular and are often found in manufacturing lines, packaging assembly lines and automated warehouses. Conventional picking apparatuses may grip a target to be picked up using parallel finger grippers or a vacuum / suction cup gripper. Once gripped, the target can be manoeuvred and subsequently released by the picking apparatus. However, these conventional gripping mechanisms may struggle to pick up certain targets in a consistent and controlled manner. For example, vacuum cups cannot be used to pick up loose targets such as wires, threads, and herbs because no seal can be formed on the target. Moreover, parallel finger grippers may struggle to grip these targets securely and in a consistent amount. Another often difficult to pick target includes objects in a net bag, for example, a net bag of oranges. Net bags are flexible which allows the weight distribution of the objects held within to shift when picked up. This may lead to a lack of control over the picking and manoeuvring process.

[0006] It would be desirable to address at least one of the drawbacks associated with conventional picking apparatuses.

[0007] SUMMARY

[0008] According to an aspect, there is provided an apparatus for picking, comprising: a plurality of tangle elements configured to be entangled with a target to be picked; and means for selectively picking up the plurality of tangle elements, wherein, when the plurality of tangle elements are entangled with the target, the plurality of tangle elements are configured when picked up to engage the target such that the plurality of tangle elements and the target are picked up together.

[0009] Certain targets, such as wires, threads and herbs, may be difficult to pick up using conventional picking robots using parallel finger grippers or vacuum cup grippers because a secure grasp of the target cannot be obtained. It may also be difficult to pick up a consistent amount of the target. By using a plurality of tangle elements (sometimes referred to as tangling agents) which are spread throughout the target, a secure grasp of these typically difficult to pick up targets may be obtained. Once the tangle elements are interspersed within and entangled with the target, the means for selectively picking up the tangle elements can be used to pick up the tangle elements. Each tangle element hooks, interlocks or otherwise engages with a portion of the target such that the target is lifted with the tangle elements. As multiple tangle elements are being used, there are more engagement points between the picking apparatus and the target compared to finger grippers or vacuum cup grippers. This allows the apparatus to pick up loose target items with ease. Furthermore, when the plurality of tangle elements are spread throughout the target, a more secure grip of the target can be achieved which restricts the ability of the target to sway or move whilst it is being manipulated. As a result, control of the target may be improved. The apparatus further enables calibration of the amount of target being picked up based on the number of tangle elements used, their geometry or other physical properties, thereby enabling improved consistency of the amount of target being picked up.

[0010] In this context, the term “entangled” refers to the state in which the tangle elements are mixed with, interspersed across, supported by, twisted with, and / or caught in the target. The tangle elements are designed such that, when they are picked up in the entangled state, the tangle elements hook, interlock with, support or otherwise engage the target such that it is lifted together with the tangle elements.

[0011] In some embodiments, the plurality of tangle elements each comprise a ferromagnetic material, and wherein the means for selectively picking up comprises a magnet for picking up the magnetic material. In some embodiments, the means for selectively picking up comprises an electromagnet. In some embodiments, the plurality of tangle elements each comprise a permanent magnet, and wherein the means for selectively picking up comprises a ferromagnetic material or a second permanent magnet for picking up the permanent magnet.

[0012] A simple yet effective way to selectively pick up the tangle elements and the target is to use magnetism. For example, the tangling elements may comprise or may be formed from a ferromagnetic material and the means for picking up the tangle elements may comprise a magnet, such as an electromagnet, which can be used to attract and pick up the tangle elements. A ferromagnetic material, in this context, may be understood to be a material that is attracted to a magnet. Examples include, but are not limited to, iron, iron oxide, cobalt and nickel. The magnetic force between the tangle elements and the magnet is strong enough to lift, move or hold the weight of the tangle elements and the desired target.

[0013] In some embodiments, the means for selectively picking up comprises a liquid, the plurality of tangle elements being buoyant in the liquid. In some embodiments, the target sinks in the liquid. In this way, when the mixture of tangle elements and target is submerged in a liquid, such as water, the tangle elements float upwards lifting the target with them.

[0014] In some embodiments, the apparatus comprises means for untangling the plurality of tangle elements from the target. In this context, the term ‘untangling’ is used to refer to a state in which the tangle elements are no longer capable of entangling with the target or picking up the target. For example, in some embodiments, when the tangle elements are untangled from the target, they are configured to disengage the target such that they fall out of or separate from the target. In some embodiments, when the tangle elements are untangled from the target, they remain interspersed throughout the target but they can no longer interlock with the target to pick up the target. In this case, the tangle elements may be removed from the target using the means for picking up the target or an additional separation mechanism.

[0015] In some embodiments, the plurality of tangle elements each comprise a decomposable element, and wherein the means for untangling comprises means for decomposing the decomposable element. In some embodiments, the means for untangling is configured to change the plurality of tangle elements from a first state for picking up the target in which the decomposable element is not decomposed to a second state for untangling from the target in which the decomposable element is decomposed. Separation of the tangle elements from the target may be desired once the target has been picked up and manoeuvred. By decomposing at least a portion of the tangle elements, their structure may be changed to enable a transition from the first state in which they are able to pick up the target to the second state in which they are not able to pick up the target. In some embodiments, when the tangle elements have been decomposed and are in the second state, the plurality of tangle elements are configured to disengage the target such that they fall out of or separate from the target. In some embodiments, in the second state, the tangle elements remain interspersed throughout the target but are no longer able to engage the target to pick up the target.

[0016] In some embodiments, the decomposable element comprises a dissolvable element and the means for decomposing comprises a liquid for dissolving the dissolvable element. Dissolving a portion of the tangle elements in an appropriately chosen liquid is one mechanism that can be used for decomposing a tangle element. When desired, the target and tangle element mixture may be rinsed or submerged in the liquid to disentangle the tangle elements from the target. The liquid may be captured and recycled for use in future rinsing.

[0017] In some embodiments, the liquid comprises water. In some embodiments, the dissolvable element comprises Butenediol vinyl alcohol co-polymer, BVOH. Advantageously, water is readily available in most manufacturing facilities and warehouses. It is also a food-safe material making it suitable for use when picking food stuff. Similarly, BVOH is a food safe material and is dissolvable in water.

[0018] In some embodiments, the plurality of tangle elements each comprise a crossbar and at least one leg extending from the crossbar, wherein the dissolvable element detachably mounts the at least one leg to the crossbar. In some embodiments, the dissolvable element comprises a frame for mounting the at least one leg to the crossbar. In some embodiments, the dissolvable element comprises a glue for mounting the at least one leg to the crossbar. The cross bar (or base section) and the at least one leg (or arm) extending from the cross bar creates a “spiky” 2 or 3 dimensional object that is prone to tangling. In this way, the tangle element may be prone to hooking or interlocking with a target. By breaking the at least one leg away from the cross bar, only linear or bar-shaped fragments remain. In this state, the tangle elements are less prone to tangling and may fall out of the target or are at least easier to separate from the target. Additional processes may be used to help remove the tangle elements including shaking or vibrating the target, brushing the tangle elements off the target or by picking up the fragments using the means for selectively picking up the tangle elements. Note that the tangle element fragments would leave the target behind when they are picked up because they no longer form a shape suitable for interlocking with the target.

[0019] In some embodiments, the crossbar and / or the at least one leg is formed from the ferromagnetic material. In some embodiments, the crossbar and / or the at least one leg is formed from the magnetic material. In some embodiments, the crossbar and / or the at least one leg is formed from stainless steel. In this way, the tangle element may be suitable for use with the apparatus when the means for picking up the tangle elements comprises a magnet whilst still being decomposable in a way which aids separation of the tangle elements from the target. In addition, stainless steel is food safe meaning that it can be used for picking food stuff where hygiene is important. Stainless steel can also be ferromagnetic.

[0020] In some embodiments, the decomposable element comprises a solid and the means for decomposing comprises at least one of the following: means for melting the solid; and means for dissolving the solid. Another mechanism for providing a decomposable tangle element uses the phase change between a solid and a liquid to remove the tangle elements. The tangle element may be formed from material configured to be melted once the picking process is complete, thereby removing the tangle elements from the target. Another decomposable tangle element may be provided by using a solid which dissolves when contacted by certain solvents. In this way, when the tangle elements are submerged or sprayed with a suitable solvent, the tangle elements dissolve leaving just the target.

[0021] In some embodiments, the solid comprises at least one of the following: ice; wax; and sugar. In some embodiments, the means for melting comprises a medium surrounding the tangle elements having a temperature above 0°C, preferably between 0°C and 4°C. In some embodiments, the medium is air at room temperature. Ice may be used to provide a temporary tangle element which will melt away after prolonged exposure to a room temperature environment. In this way, the tangle elements will naturally disentangle from the target without any external stimulus. Once melted, a water residue may be left on the target. In some example embodiments, the tangle elements are composed of a material with a melting point closer to room temperature (e.g., wax). In some embodiments, the wax is combined with a magnetic material (e.g., ferromagnetic powder). In some embodiments, the solid or wax is edible, for example, beeswax. This may ensure the tangle elements are food safe. When heat is applied, the wax melts, causing the grains to detach (untangle) from the target.

[0022] In some embodiments, the tangle elements are made of sugar (e.g., glucose). Sugars are food safe. For untangling, sugars may be dissolved in a solvent. For example, sugars may be soluble in water. Alternatively or additionally, the sugar may be melted using electromagnetic waves as discussed below.

[0023] In some embodiments, when the means for decomposing comprises means for melting the solid, the means for melting comprises electromagnetic waves.

[0024] In some embodiments, the tangle elements are designed such that they can be melted with electromagnetic waves (e.g., microwaves). This may allow the tangle elements to be melted / disintegrated by irradiating them with the appropriate frequency electromagnetic wave, thereby causing them to disengage with the target. For example, sugars have a resonance frequency different from water's (2.45 GHz) (e.g., the resonant frequency of glucose is 24.9 GHz). This may allow specific microwave frequencies to melt the sugar without affecting the picked targets.

[0025] In some embodiments, the ferromagnetic material comprises a magnetic powder interspersed within the solid. In this way, the tangle element may be suitable for use in embodiments in which the means for picking up the tangle element comprises a magnet. In some embodiments, the magnetic powder comprises iron oxide, preferably black iron oxide (FesO4). Advantageously, iron oxide may be a food safe material that is also ferromagnetic. When picking food stuff, leaving an iron oxide residue may be desirable because it can improve the quantity of minerals in the food.

[0026] In some embodiments, the solid comprises wax. In some embodiments, the wax is interspersed with iron filings.

[0027] In some embodiments, the plurality of tangling elements each comprise a crossbar and at least one leg extending from the crossbar, the crossbar and / or the at least one leg being formed from the solid. In this way, the spiky tangle elements may be melted away such that they are no longer entangled with the target.

[0028] In some embodiments, the means for untangling comprises an inclined surface and one or more magnets configured to hold the plurality of tangle elements to the inclined surface. In this way, when the mixture of target and tangle elements is positioned on the inclined surface, the target falls down the incline surface whilst the tangle elements are held to the incline surface by the magnets. In some embodiments, the target may be configured to fall under gravity. In some embodiments, mechanical brushes are configured to sweep the target down the incline surface. In some embodiments, the surface is level and the brushes are configured to sweep the target along the surface whilst the magnets hold the tangle elements in place. In some embodiments, the surface or inclined surface comprises a conveyor belt, the target being configured to drop off the end of the conveyor belt and the tangle elements being configured to be held to the conveyor belt by the magnets.

[0029] In some embodiments, the means for untangling comprises a centrifuge configured to separate heavier objects from lighter objects. The tangle elements may be the heavier objects and the target may be the lighter object(s) or vice versa.

[0030] In some embodiments, the means for untangling comprises a liquid, the plurality of tangling elements and the target being configured to separate when in the liquid. In some embodiments, the plurality of tangle elements are configured to float in the liquid and the target is configured to sink in the liquid, or vice versa.

[0031] In some embodiments, the means for untangling comprises means for vibrating the target to separate the plurality of tangle elements from the target. In some embodiments, the means for untangling comprises a sieve configured to allow one of the tangle elements or the target to pass through but not the other. The sieve may be used in combination with the means for vibrating the target. In some embodiments, the means for untangling comprises a brush configured to brush the tangle elements off the target. In this way, the brush helps to separate the tangle elements from the target. The separation mechanisms may be used on their own or in combination with another means for disentangling the tangle elements. For example, in some scenarios, when the tangle elements are dissolved, they may not be completely separated from the target. Therefore, one or more mechanical separation mechanisms, such as vibration, sieving and / or sweeping, may be used to separate the remaining tangle element fragments from the target.

[0032] In some embodiments, the means for untangling comprises means for blowing gas through the target to separate the plurality of tangle elements from the target. In some embodiments, the means for untangling comprises means for rinsing the target with liquid to separate the plurality of tangle elements from the target. A liquid or gas may be able to access difficult to reach areas within a target or between target items. As a result, a more complete removal of the tangle elements may be achieved.

[0033] In some embodiments, the decomposable element comprises a compacted powder and the means for decomposing comprises means for disintegrating the compacted powder. In some embodiments, the entirety of a tangle element of the tangle elements is made from the compacted powder. In some embodiments, a portion of a tangle element of the tangle elements is made from the compacted powder. For example, where the tangling element is made from a crossbar and at least one leg extending from the crossbar, the crossbar and / or the at least one leg may be formed from the compacted powder. The compaction is designed so that on treatment (e.g., washing or shaking) the tangling elements disintegrate or decompose such that their separation from the target is facilitated. In some embodiments, the tangle elements are composed of a compacted ferromagnetic powder or powder mix. The magnetic powder or powder mix may comprise iron oxide.

[0034] In some embodiments, the means for untangling comprises a pulsing magnetic field. To separate the tangle elements from the picked target, a pulsing magnetic field may be applied to encourage the tangle elements to separate from the target. In some embodiments, the tangle elements (entangled with the target) are dropped onto a surface (e.g., conveyor belt) equipped with electromagnets arranged at the sides. Electromagnets pulse to pull the tangle elements away while the targets remain on the belt as they may not be magnetic and / or due to high surface friction with the conveyor belt. It will be appreciated that the pulsing magnetic field may be used in conjunction with other means for untangling such as a decomposable element.

[0035] In some embodiments, the means for untangling comprises at least one magnet and the plurality of tangle elements are configured such that, when the plurality of tangle elements is within a magnetic field of the at least one magnet, a major axis of the tangle elements is caused to align with the magnetic field of the magnet. The major axis of the tangle element is the longest dimension of the tangle element. Therefore, when the tangle elements align with the magnetic field, they are arranged lengthways and may be more likely to separate from the target.

[0036] In some embodiments, wherein the at least one magnet comprises a plurality of magnets, the plurality of magnets being arranged such that at least two of the plurality of magnets have different magnetic fields. In some embodiments, the tangle elements are dropped onto a surface (e.g., conveyor belt) with a structured magnetic surface comprising a plurality of different magnetic fields (e.g., as found in magnetic encoders). Each magnetic field causes the tangle elements to be aligned with that particular magnetic field. The tangle elements may be passed through the magnetic field of each of the plurality of magnets to help disentangle them.

[0037] In some embodiments, the means for untangling comprises a source of low pressure. The source of low pressure may be arranged to suck the plurality of tangle elements out of the target. In this way, the tangle elements can be separated from the target by using the suction provided by a vacuum or low- pressure source, for example, a vacuum pump. In some embodiments, the tangle elements (entangled with the target) are placed on a vacuum platform which sucks the target down while the ferromagnetic tangle elements are pulled up by the electromagnet. In other embodiments, the tangle elements are sucked down and out of the target. It will be appreciated that the low pressure may be arranged to apply suction at any angle. However, a downwards direction may provide a stronger force due to gravity.

[0038] In some embodiments, the plurality of tangle elements are dimensioned to pass through gaps in the target. To entangle with a target, at least a portion of the tangle elements should be dimensioned to pass through holes, gaps or spaces defined by the target such that the tangle elements may interlock with the target. Note that the target may be a single item having gaps or passages defined therein to allow the tangle elements to tangle with the item. Alternatively or additionally, the target may comprise a plurality of items having gaps or passages defined between each item. In some embodiments, the tangle elements are dimensioned such that the legs of the tangle element may extend into the gaps. It will be appreciated that the size of the tangle elements must be selected such that the tangle elements are suitable for tangling with the target.

[0039] In some embodiments, the plurality of tangle elements comprises two or more types of tangle element. For example, the plurality of tangle elements may include tangle elements of differing size and / or shape. This may improve the plurality of tangle elements’ ability to pick up a variety of targets or different parts of a target.

[0040] In some embodiments, the plurality of tangle elements are formed from one or more food-safe materials. In this way, the picking apparatus may be used in hygiene-controlled environments. It will be appreciated that where hygiene is not a concern, the tangle elements may be formed from one or more non-food safe materials.

[0041] In some embodiments, the plurality of tangle elements are configured when picked up to interlock with the target.

[0042] In some embodiments, the means for selectively picking up the plurality of tangle elements comprises a robotic arm. Many existing picking apparatuses employ a robotic arm to pick up and manoeuvre targets, albeit with a different gripping mechanism to the proposed apparatus. As a result, the proposed picking apparatus may be implemented in place of or in conjunction with an existing robotic arm to reduce the number of changes required to existing picking environments to implement the proposed apparatus. In some embodiments, the apparatus may be retrofitted for use with an existing robotic arm. For example, in some embodiments, the magnet, such as an electromagnet, is mounted to an end effector of an existing robotic arm. A plurality of tangle elements may be made accessible to the robotic arm for use in picking up targets.

[0043] In some embodiments, the apparatus further comprises means for entangling the plurality of tangle elements with the target. In other words, the apparatus is capable of entangling the tangle elements with the target. In some cases, entangling comprises dropping, scattering or dispersing the tangle elements over or into the target. In other cases, entangling may include actively mixing the tangle elements with the target. In some embodiments, the means for entangling comprises the robotic arm. In some embodiments, the robotic arm is equipped with a dispenser for dispensing the tangle elements onto or into the target. In some embodiments, the means for entangling comprises means for mixing, shaking, stirring or vibrating the plurality of target elements with the target.

[0044] In some embodiments, the means for entangling comprises a dispenser for dispensing the tangle elements over the target. For example, the dispenser may comprise a container or hopper which can be filled with tangle elements. When it is placed over the target, a hole of controllable size may be opened to dispense the tangle elements over the target. In some embodiments, the dispenser may comprise a means for vibrating such that the tangle elements can be encouraged to leave the dispenser and fall onto the target. A specific number of tangle elements can be dispensed onto the target each time by controlling the size of the hole and how long it is open for. In some embodiments, the distribution of tangle elements on or in the target may be controlled by selectively dispensing elements at different locations or in different patterns.

[0045] In some embodiments, the dispenser comprises means for forcing the tangle elements onto the target. In this way, the dispenser applies a force to the tangle elements when they leave the dispenser. For example, the dispenser may comprise a pneumatic source configured to shoot the tangle elements onto / into the target using air pressure.

[0046] In some embodiments, the dispenser comprises at least one cartridge for each of the two or more types of tangle element. In this way, the dispenser includes cartridges filled with different types of tangle elements. When a particular cartridge is opened, a desired amount of tangle elements of a particular type are dispensed onto the target. According to another aspect, there is provided a method for picking, comprising: entangling a plurality of tangle elements with a target to be picked; picking up the plurality of tangle elements using a means for selectively picking up the plurality of tangle elements, the plurality of tangle elements being configured to engage the target such that the target is picked up with the plurality of tangle elements.

[0047] Conventional picking methods comprise a gripping mechanism which is colocated with the robotic arm, so the whole picking process needs to be completed whilst the target is positioned within reach of the robotic arm. By comparison, the steps of the present method may be temporally and spatially separated, i.e. , the tangle elements may be mixed with the target in advance of the picking up action which may occur at any time later and in a different location. Similarly, removal of the tangle elements from the target may occur at any time after that. In this way, the timing of the picking process may be more flexible. Furthermore, a gripping mechanism comprising a plurality of tangle elements may provide a more robust and consistent grip for certain targets because the plurality of tangle elements engage or “grip” the target in multiple places compared to conventional parallel finger grippers which have only one point of contact on the target and may find it difficult to reach into the target. Moreover, the gripping force may be distributed over a wider area of the target, thereby limiting the maximum fore any location experiences from the gripper. This can make the picking apparatus more suitable for gripping delicate objects.

[0048] In some embodiments, the entangling comprises dropping the plurality of tangle elements onto the target. In some embodiments, the entangling comprises mixing the plurality of tangle elements with the target.

[0049] In some embodiments, the method further comprises selecting a type of tangle element that is appropriate for the target. In some embodiments, selecting a type of tangle element comprises selecting multiple types of tangle element. In some embodiments, selecting the type of tangle element comprises accessing a data store containing test results indicating an association between the target and types of tangle element. In some embodiments, the method further comprises performing the step of calibrating to determine a number of tangle elements for picking up an amount of the target. In some embodiments, the method further comprises selecting a number of tangle elements to entangle with the target to pick up a desired amount of the target based on the calibration. In some embodiments, selecting the number of tangle elements comprises accessing a data store containing results of the calibration. The target may be a certain amount of a particular item. In this situation, the amount of target being picked up depends on the number of tangle elements being entangled with the target. If more tangle elements are used, more target items are engaged and picked up. Therefore, where picking a consistent amount of a target is desirable, a calibration process may be undertaken in which different numbers of tangle elements are used and the number of target items picked is recorded. Once calibrated, a desired amount of a target may be picked up by dropping an appropriate number of tangle elements. It will be appreciated that the number of tangle elements required will differ between target types and tangle element types. In some embodiments, the step of calibrating comprises adaptive calibration in which the number of tangle elements is altered based on an indication of the discrepancy between the actual and the desired amount picked. In some embodiments, the indication is received from means for providing feedback on the discrepancy between the actual and the desired amount picked.

[0050] According to a further aspect, there is provided a tangle element for a picking apparatus according to the aspect, the tangle element being configured to change from a first state for picking up the target to a second state for untangling from the target.

[0051] In this way, the properties of the tangle element may be changed depending on the stage of the picking process. Initially, the tangle elements are required to engage the target, to pick it up and to manoeuvre the target. Subsequently, the tangle elements may be required to be separated from the target which may be helped by changing to a second state. In some embodiments, the tangle element comprises a cross bar and at least one leg extending from the cross bar. The at least one leg extending from the cross bar forms at least one spike which may improve the ability of the tangle element to tangle both with itself and with targets.

[0052] In some embodiments, the cross bar and / or the at least one leg comprises a ferromagnetic material. In this way, the tangle element is suitable for use with an apparatus in which the means for picking up the tangle element comprises a magnet.

[0053] In some embodiments, the cross bar and / or the at least one leg comprises a magnetic material such as a permanent magnet. In this way, the tangle element is suitable for use with an apparatus in which the means for picking up the tangle element comprises another magnet or a ferromagnetic material.

[0054] In some embodiments, the tangle element comprises a decomposable element, the tangle element being configured to change from the first state in which the decomposable element is not decomposed to the second state in which the decomposable element is decomposed. One mechanism for changing from the first state to the second state includes use of a decomposable element such that the physical properties of the tangle element change between the two states. When the tangle element is decomposed into the second state, the broken-down form of the tangle element can facilitate untangling of the tangle element from the target.

[0055] In some embodiments, the decomposable element comprises wax or sugar. In some embodiments, the decomposable element comprises a compacted powder.

[0056] In some embodiments, the at least one leg is detachably mounted to the cross bar by the decomposable element, optionally wherein the decomposable element comprises a dissolvable element. In this way, the at least one leg may detach from the cross bar in the second state. As a result, the remaining fragments of the tangle element are less prone to tangling with the target. The decomposable element may be a frame or a glue which mounts the at least one leg to the cross bar. The decomposable element may be dissolvable in a liquid, the liquid being used to induce the change in the tangle element from the first state into the second state.

[0057] In some embodiments, the cross bar and / or the at least one leg is formed from stainless steel. Stainless steel can be ferromagnetic and so may be used in an apparatus where the means for picking up the tangle element comprises a magnet. However, other ferromagnetic materials may be used. Stainless steel is also a food safe material and so can be used for picking food stuff. In some embodiments, the dissolvable element comprises butenediol vinyl alcohol copolymer, BVOH. BVOH is dissolvable in water which is often readily available in a manufacturing or warehouse facility. BVOH is also a food safe material.

[0058] In some embodiments, the cross bar and / or the at least one leg is formed from the decomposable element, preferably wherein the decomposable element comprises ice. In this way, the tangle element might decompose until it is no longer capable of tangling with the target. For example, when the tangle element is made from ice, it can melt away in the second state.

[0059] In some embodiments, the decomposable element comprises ice interspersed with magnetic powder. In this way, the tangle element can be used with the apparatus when the means for picking up the tangle element comprises a magnet.

[0060] In some embodiments, the magnetic powder comprises iron oxide, optionally black iron oxide (Fe30a4). Iron oxide can be a food safe magnetic powder that can be mixed into water and frozen to form a ferromagnetic ice.

[0061] In some embodiments, the decomposable element comprises wax. Wax may be preferable to ice when the tangle elements are required for extended use at room temperature. However, the wax may need an additional heat source to melt it which may not be the case for a tangle element made from ice. In some embodiments, the wax is interspersed with iron filings such that it can be used with an apparatus when the means for picking up the tangle element comprises a magnet.

[0062] In some embodiments, the at least one leg comprises a first leg extending from a first end of the cross bar and a second leg extending from a second end of the cross bar or an approximate centre of the cross bar. In this way, the tangle element may have a second leg such that it forms substantially a U-shape or an F-shape.

[0063] In some embodiments, the tangle element is substantially L-shaped, U-shaped, F-shaped, X-shaped or H-shaped. In some embodiments, the tangle element is substantially C-shaped. Each of these shapes comprises spikes which can improve the ability of the tangle element to tangle with certain targets. It will be appreciated that too many spikes might distance the tangle element from the target, thereby inhibiting entanglement. Therefore, there is a balance between the number (and size) of legs and the ability of the tangle element to tangle with a target.

[0064] In some embodiments, the at least one leg extends substantially perpendicularly from the cross bar. In this context, substantially means within 10 degrees from perpendicular. In other embodiments, the at least one leg extends at an angle other than 90 degrees from the cross bar. For example, the leg may extend at an angle of between 0 and 180 degrees, the angle being defined between the cross bar and the leg. In some embodiments, the angle is between 10 and 80 degrees. In some embodiments, the angle is between 20 and 70 degrees. In some embodiments, the angle is between 30 and 50 degrees. In some embodiments, the angle is 45 degrees. In some embodiments, the angle is between 120 and 160 degrees. In some embodiments, the angle is 135 degrees. In some embodiments, when the tangle element comprises multiple legs, each leg extends at a same angle or at different angles.

[0065] In some embodiments, the tangle element comprises two or more legs extending from the cross bar. In some embodiments, the at least two legs and the cross bar extend substantially perpendicularly to one another. In this way, the tangle element may extend in 3 dimensions, i.e. , it is not confined to one plane. Such a shape may tangle well with certain target types.

[0066] In some embodiments, the tangle element comprises a plurality of tangle elements.

[0067] In some embodiments, the tangle element is dimensioned to fit between gaps defined in the target.

[0068] In some embodiments, the cross bar and / or the at least one leg is between 0.5 and 1 mm thick, preferably 0.8mm thick.

[0069] In some embodiments, the cross bar is between 5 and 20mm long, in some embodiments between 10 and 15mm long, in some embodiments 12mm in length.

[0070] In some embodiments, the at least one leg is between 5 and 20mm long, in some embodiments between 10 and 15mm long, in some embodiments 12mm in length.

[0071] In some embodiments, the tangle element is configured to change from a zeroth state for dispersal within the target into the first state for picking up the target. In the zeroth state, for example, the tangle element may be less prone to tangling with the target than in the first state to facilitate distribution of the tangle elements. Once the tangle elements have been spread or mixed with the target, the tangle elements can be changed to the first state in which they are more inclined to interlock and entangle with the target. In some embodiments, the tangle element is formed from a shape-memory alloy (SMA). SMAs may be deformed when cooled but return to their original shape when reheated. Therefore, tangle elements made from an SMA may be undeformed in the first state for picking up the target and deformed in the zeroth state for dispersal within the target and the second state for untangling from the target. Further particular and preferred aspects are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as appropriate, and in combinations other than those explicitly set out in the claims.

[0072] Where an apparatus feature is described as being operable to provide a function, it will be appreciated that this includes an apparatus feature which provides that function or which is adapted or configured to provide that function.

[0073] BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Embodiments of the present invention will now be described further, with reference to the accompanying drawings, in which:

[0075] Figure 1 illustrates an apparatus for picking according to an embodiment;

[0076] Figure 2 shows an exemplary target and a plurality of tangling elements according to an embodiment;

[0077] Figure 3 shows the life cycle of a tangle element according to an embodiment;

[0078] Figure 4 illustrates a method of manufacturing a tangle element according to an embodiment;

[0079] Figure 5 shows a means for untangling according to an embodiment;

[0080] Figure 6 shows a plurality of types of tangle elements according to embodiments;

[0081] Figure 7 shows an apparatus for picking according to an embodiment;

[0082] Figure 8 shows a dispenser according to an embodiment; and

[0083] Figure 9 illustrates steps in a method according to an embodiment.

[0084] DESCRIPTION OF THE EMBODIMENTS

[0085] Before discussing the embodiments in any more detail, first an overview will be provided.

[0086] Embodiments relate to an apparatus and a method for gripping and manipulating objects and materials (referred to as targets) for which conventional robotic grippers struggle (a) to grip the targets in a controlled and robust manner, and (b) to manipulate and release them on command.

[0087] Embodiments exploit the propensity of the targets to tangle and proposes to use a plurality of tangle elements, which preferably form a granular disordered mechanical metamaterial, specifically designed to tangle with the targets. Embodiments enable the picking of highly deformable, hard-to-model objects and materials such as wires, cotton threads, woollen yams, hair, herbs and salads, spaghetti and noodles, and netting (including net-bags). These kinds of objects and materials can be challenging to pick with conventional fingered robotic grippers (e.g., parallel, 3-finger or anthropomorphic hands), suction devices, scoops, electromagnets, or so-called “universal grippers” (i.e. , those that use granular-jamming). Embodiments may achieve improved picking consistency for such types of targets.

[0088] The plurality of tangle elements, which may form a granular disordered mechanical metamaterial, possess unique properties due to their specific geometric architecture. It was observed that one behaviour associated with a granular disordered mechanical metamaterial is interlocking or entanglement, a trait that is often shared with the types of target that are difficult to pick up using conventional picking apparatuses. Entanglement occurs in a cluster of interactive objects with peculiar shapes. Spiky objects are inherently prone to tangle, yet longer spikes reinforce separation. This results in having two properties working against each other to determine a material’s overall ability to entangle.

[0089] Embodiments apply the physical phenomenon of “tangling” between the tangle elements (the composed metamaterial) and the target such that embodiments may grip, pick up and release the target. The tangle elements used are designed to have a natural inclination to become entangled, particularly with the desired target. The design and control of the tangle elements can be tailored to the properties of the target to optimise gripping. For instance, some of the geometric parameters of the target that affect entanglement are the thickness, the length, the number of spikes on the targets.

[0090] The apparatus for picking may comprise a plurality of tangle elements configured to be entangled with a target to be picked. The apparatus may comprise means for selectively picking up the plurality of tangle elements. When the plurality of tangle elements are entangled with the target, the plurality of tangle elements may be configured when picked up to engage the target such that the plurality of tangle elements and the target are picked up together.

[0091] In embodiments, the picking process comprises entangling the tangle elements with the target. This may include dropping the tangle elements over the target and / or actively mixing the tangle elements with the target. Once the tangle elements have been entangled with the target, due to the interlocking between the tangle elements and the target, the means for picking up the tangle elements may pick up both the tangle elements and the target. In some embodiments, when the tangle elements comprise a ferromagnetic material, the means for picking up the tangle elements may comprise a magnetic field used as a stimulus for the ferromagnetic tangle elements to construct an entangled disordered metamaterial for picking up the target. The mechanical metamaterial in a first state or structure comprises the individual elements (unit cells or agents) which, when deployed onto the target, penetrate and interlock with the target such that they are entangled with the target. Upon the activation of a magnetic field, the ferromagnetic tangle elements may be lifted by the magnetic field and, in the process, engage the target to secure the target in part or in whole such that the fastened parts of the target may be jointly picked with the tangle elements.

[0092] Once the desired manipulation of the target is achieved, multiple methods for untangling the tangle elements from the target are proposed. In some embodiments, to release the target, the tangle elements may be configured to change state, for example, by decomposing. Once decomposed, the remains of the tangle elements cease to tangle with the target. In some embodiments, a mixture of dissolvable and non-dissolvable components is combined such that, when water or other suitable liquid is introduced, the previously spiky tangle elements are reduced to non-tangling bars. In this way, the interlocking with the target may be lost releasing the target.

[0093] In some embodiments, the tangle elements are constructed by mixing, then freezing water with a food safe ferromagnetic powder such as “black iron oxide’ with the chemical composition of Fe3O4. The liquid mixture may be poured into a moulding case and placed inside a freezer to produce tangle elements formed from ferromagnetic ice. Such tangle elements may be used with a robotic device operating in a temperature below 4°C as is commonly found in packing facilities of commercial food producers. The tangle elements made of ice will decompose by melting, thereby untangling from the target. Melting may occur naturally over time due to the ambient temperature or induced by actively heating the tangle elements when it is desired to melt them.

[0094] The advantages of the proposed gripping approach include, but are not limited to:

[0095] • reduced unnecessary control parameters compared to existing robots which require precise positioning and orientation;

[0096] • the ability to pick objects from tight spots and compact places where there is limited space for conventional robots to manoeuvre;

[0097] • reconfigurable tangle elements (metamaterial) for achieving consistent picking for a variety of target types;

[0098] • significantly reduced applied force for picking delicate targets compared to conventional picking apparatuses (because the engagement between the apparatus and the target is spread over the many contact points between the tangle elements and the target compared to the singular point of contact of conventional finger grippers); and

[0099] • the ability to pick complex and chaotic clusters (tangled matter).

[0100] Apparatus For Picking

[0101] Figure 1 shows an apparatus according to an embodiment for picking and manoeuvring a target 10. The apparatus comprises a plurality of tangle elements 12 configured to be entangled with the target 10 and means for selectively picking up the plurality of tangle elements 12. The apparatus is configured such that, when the tangle elements 12 are picked up whilst the tangle elements 12 are entangled with the target 10, the tangle elements are configured to engage the target such that the target 10 is picked up together with the tangle elements 12. In this embodiment, the means for selectively picking up the plurality of tangle elements 12 comprises a robotic arm 14 having a selectively activatable electromagnet 16 mounted to its end effector. The tangle elements 12 each comprise a ferromagnetic material such that, when the electromagnet 16 is activated, the tangle elements 12 are attracted to and can be picked up by the electromagnet 16.

[0102] The target 10 may be a single item which has gaps or passages defined therein which allow the tangle elements to engage and entangle with the item. In some cases, the target may be a plurality of items having gaps or passages defined between each item and / or within each item to allow the tangle elements to engage and entangle with the items. The target may be a certain amount or number of the plurality of items.

[0103] The tangle elements 12 are dimensioned to pass through or at least partially extend into the gaps or passages defined by the target 10. In this way, the tangle elements 12 may become tangled with the target 10. Specifically, the plurality of tangle elements 12 are configured when picked up to interlock with the target 10 such that the target 12 is lifted together with the tangle elements 12. Each tangle element 12 is formed by a ferromagnetic staple-shaped unit. However, other shapes and types of tangle elements may be used as discussed in more detail below.

[0104] Figure 1 further illustrates the steps performed by the apparatus to pick up the target. In stage 1 , the target 10 and the tangle elements 12 are separate from each other and the electromagnet 16 is switched off. In stage 2, the robotic arm 14 is actuated to pick up the ferromagnetic tangle elements 12 by activating the electromagnet 16. The robot arm 14 manoeuvres the held tangle elements 12 above the target. In the first step of stage 3, the electromagnet 16 is switched off and the tangle elements 12 are dropped onto the target 10 such that they tangle with the target 10. In this way, the robotic arm 14 acts as a means for entangling the plurality of tangle elements with the target 10. It will be appreciated that other means for entangling the plurality of tangle elements may be used. Furthermore, the means for entangling the plurality of tangle element may comprise means for mixing the tangle elements with the target to improve the engagement between the tangle elements and the target. In the second step of stage 3, the electromagnet 16 is switched back on to pick up the tangle elements 12. However, this time, the tangle elements 12 interlock, hook or otherwise engage with the target 10 such that the target 10 is lifted with the tangle elements 12. Once the target 10 is picked up, it can be manoeuvred as desired by the robotic arm 14. In stage 4, once the desired manipulation of the target 10 is completed, the target 10 and the tangle elements 12 are dropped by the robotic arm 14 by switching off the electromagnet 16. In some embodiments, the apparatus may further comprise means for untangling the plurality of tangle elements 12 from the target 10. Exemplary separation mechanisms are discussed in more detail below.

[0105] It will be appreciated that the apparatus may comprise means suitable for selectively picking up the tangle elements different to the robotic arm 14. For example, a magnet on the end of a cable which can be raised and lowered to pick up the target may be used. The means for picking up, whether it be the robotic arm 14 or otherwise, may be manually controlled or automated.

[0106] In some embodiments, a permanent magnet is used instead of the electromagnet 16. In other embodiments, the tangle elements comprise a magnetic material such that the presence of another permanent magnet or a ferromagnetic material may be used to pick up the tangle elements.

[0107] Figure 2 shows the tangle elements 12 and the target 10 in more detail. The left-hand image shows the plurality of tangle elements 12 made from a ferromagnetic material, for example, ferromagnetic stainless steel. The tangle elements 12 have been picked up by the electromagnet 16. The tangle elements 12 each comprise a cross bar and two legs extending from either end of the cross bar such that they are substantially U-shaped. The middle image shows the plurality of tangle elements 12 having been dropped into the target 10 such that they have become entangled with the target 10. In this example, the target 10 is represented by plastic strands. However, it will be appreciated that many different types of targets may be picked using the apparatus. In the right-hand image, the electromagnet 16 has been activated to pick up the tangle elements 12 together with the target 10.

[0108] Separation Mechanisms

[0109] In some embodiments, the apparatus comprises means for untangling the tangle elements from the target. In some embodiments, the plurality of tangle elements each comprise a decomposable element and the means for untangling comprises means for decomposing the decomposable element. In this way, the means for untangling is configured to change the plurality of tangle elements from a first state for picking up the target in which the decomposable element is not decomposed to a second state for untangling from the target in which the decomposable element is decomposed. In some embodiments, in the second state, the plurality of tangle elements are configured to naturally separate and fall out of the target. In other embodiments, in the second state, the plurality of tangle elements remain within the target but are more susceptible to being separated. In this case, the means for untangling may comprise an additional mechanism for separating the tangle elements from the target. For example, the mixture of tangle elements and target may be vibrated, sieved or otherwise mechanically separated. Alternatively, the means for picking up the tangle element and the target may subsequently be used to separate the tangle elements. Once decomposed, the tangle elements are not in a state suitable for interlocking with the target. Therefore, if the electromagnet was to pass over the mixture of target and decomposed tangle elements, the remains of the tangle elements may be picked up but not the target.

[0110] Figure 3 shows the life cycle of a tangle element 12a according to an embodiment. In this embodiment, the decomposable element comprises a dissolvable element and the means for decomposing comprises a liquid. The tangle element 12a comprises a cross bar 18 and legs 20 extending substantially perpendicularly to the cross bar 18. The legs 20 are detachably mounted to the cross bar 18 by the dissolvable element, in this case, a frame 24 configured to hold the legs 20 and the cross bar 18 together. When the tangle element 12a is placed in or is exposed to the liquid 26, the frame 24 dissolves allowing the legs 20 to separate from the cross bar 18. The remaining fragments of the tangle element 12a are bar-shaped rather than spiky, so they have a greatly reduced ability to tangle with the target. As a result, separation of the tangle elements 12a from the target may occur or may be helped. It will be appreciated that the dissolvable element may take the form of other types of mounting mechanism. For example, the legs 20 may be mounted to the cross bar 18 by a glue dissolvable in the liquid.

[0111] In this embodiment, the cross bar 18 and the legs 20 are made from a ferromagnetic stainless steel such that it may be used with the magnetic means for picking up the tangle elements shown in Figure 1 . The frame 24 is made from butenediol vinyl alcohol co-polymer, BVOH, and the liquid 26 is water. These are all food safe materials so may be used for picking food stuff. It will however be appreciated that the decomposable element and the liquid are not limited to these materials and that any suitable combination of liquid and dissolvable material may be selected providing it is suitable for the picking the intended target.

[0112] In stage 1 of Figure 3, the frame 24 is manufactured by additive manufacturing. In stage 2, the tangle element is assembled by inserting the cross bar 18 and the legs 20 into the frame 24 such that the legs 20 are mounted to the cross bar 18. The assembled tangle element is shown in stage 3. Once the picking process, such as the one illustrated in Figure 1 , has been completed, the plurality of tangle elements 12a may be separated from the target. In stage 4, to separate the tangle elements 12a from the target, the mixture of target and tangle elements 12a is submerged in the liquid 26, in this case water. Note that the target has been omitted from Figure 3 for clarity. The frame 24 dissolves in the water allowing the legs 20 to break away from the cross bar 18. In this new state, the remaining elements of the tangle element 12a are straight bars which may not tangle as well with the target in contrast to the original U-shaped tangle elements 12a. Thus, the remaining fragments may simply fall out of the target. Alternatively or additionally, a further mechanism may be required to remove the broken down tangle elements 12a. For example, the electromagnet may be used to pick up the bar-shaped fragments of the tangle elements 12a. Since the cross bar 18 and the legs 20 are now separate, they may not hook or interlock with the target, so they can be picked up without picking up the target. Alternatively, the target may be vibrated to expel any remaining tangle element fragments stuck within the target. A sieve may be used to separate the target from the tangle element fragments.

[0113] Whilst the tangle element 12a in this embodiment comprises a cross bar 18 and two legs 20, it will be appreciated that any shape of tangle element including any number of legs may comprise a dissolvable element configured to breakdown the tangle element such that its ability to tangle is reduced.

[0114] Figure 4 shows a process for manufacturing a tangle element 12b according to another embodiment. In this embodiment, the decomposable element comprises a solid and the means for decomposing comprises means for melting the solid. In particular, the entire tangle element is made from the solid configured to melt.

[0115] The tangle element 12b is made by mixing a magnetic powder, such as black iron oxide (FesO4), with water to form a liquid mixture. The mixture is poured into a mould and frozen. Once frozen, the ferromagnetic ice tangle element 12b can be removed from the mould and used in a pick process such as the one shown in Figure 1 . By interspersing black iron oxide powder in the ice, the tangle element 12b can be used with the electromagnet 16 of the apparatus of Figure 1 . Once the picking process is complete, the tangle element 12b may be melted using any appropriate means. For example, the ice may melt naturally over time due to the ambient temperature. Alternatively, an active heat source may apply heat to melt the tangle elements 12b.

[0116] Using ice to form the tangle elements may be advantageous when picking food stuff because, when melted, an innocuous residue of water is left on the food. The black iron oxide left behind is also food safe and may additionally be purposefully used to enhance the mineral properties of the food stuff. Note that the picking process should occur in temperatures below 4°C when using a tangle element formed from ice. It will also be appreciated that the tangle element 12b may have a shape other than the U-shaped tangle element shown. It will be appreciated that any appropriate combination of solid material and means for melting the solid material may be used. For example, the ferromagnetic decomposable tangle element may be formed from wax having iron filings interspersed throughout the wax. In some embodiments, only a portion of the tangle element may be configured to melt. For example, the cross bar may be made from a material which is not configured to melt whilst the legs are made from the solid configured to melt. In this way, the legs may melt leaving only the cross-bar portion of the tangle element.

[0117] In some embodiments, the decomposable element comprises a solid and the means for decomposing comprises at least one of the following: means for melting the solid; and means for dissolving the solid. Another decomposable tangle element may be provided by using a solid which dissolves when contacted by certain solvents. In this way, when the tangle elements are submerged or sprayed with a suitable solvent, the tangle elements dissolve leaving just the target.

[0118] In some embodiments, the solid comprises at least one of the following: ice; wax; and sugar. In some example embodiments, the tangle elements are composed of a material with a melting point closer to room temperature (e.g., wax). In some embodiments, the wax is combined with a magnetic material (e.g., ferromagnetic powder). In some embodiments, the solid or wax is edible, for example, beeswax. This may ensure the tangle elements are food safe. When heat is applied, the wax melts, causing the grains to detach (untangle) from the target.

[0119] In some embodiments, the tangle elements are made of sugar (e.g., glucose). Sugars are food safe. For untangling, sugars may be dissolved in a solvent. For example, sugars may be soluble in water. Alternatively or additionally, the sugar may be melted using electromagnetic waves as discussed below. In some embodiments, when the means for decomposing comprises means for melting the solid, the means for melting comprises electromagnetic waves.

[0120] In some embodiments, the tangle elements are designed such that they can be melted with electromagnetic waves (e.g., microwaves). This may allow the tangle elements to be melted / disintegrated by irradiating them with the appropriate frequency electromagnetic wave, thereby causing them to disengage with the target. For example, sugars have a resonance frequency different from water's (2.45 GHz) (e.g., the resonant frequency of glucose is 24.9 GHz). This may allow specific microwave frequencies to melt the sugar without affecting the picked targets.

[0121] In some embodiments, the decomposable element comprises a compacted powder and the means for decomposing comprises means for disintegrating the compacted powder. In some embodiments, the entirety of a tangle element of the tangle elements is made from the compacted powder. In some embodiments, a portion of a tangle element of the tangle elements is made from the compacted powder. For example, where the tangling element is made from a crossbar and at least one leg extending from the crossbar, the crossbar and / or the at least one leg may be formed from the compacted powder. The compaction is designed so that on treatment (e.g., washing or shaking) the tangling elements disintegrate or decompose such that their separation from the target is facilitated. In some embodiments, the tangle elements are composed of a compacted ferromagnetic powder or powder mix. The magnetic powder or powder mix may comprise iron oxide.

[0122] In some embodiments, additional or alternative separations mechanisms may be implemented to help untangle and separate the tangle elements.

[0123] In some embodiments, the means for untangling comprises an inclined surface and one or more magnets positioned underneath the surface such that they are configured to attract the plurality of tangle elements to the inclined surface. When the mixture of target and tangle elements is positioned on the inclined surface, the target moves down the incline surface whilst the tangle elements are held in place by the one or more magnets. In some embodiments, the target falls under gravity down the incline surface. In some embodiments, it is encouraged down the slope by any suitable means, for example, mechanical brushes configured to sweep the target down the incline surface. In some embodiments, the surface may be level and the brushes are configured to sweep the target along the surface whilst the magnets hold the tangle elements in place. In some embodiments, the surface or inclined surface comprises a conveyor belt, the target being configured to drop off the end of the conveyor belt whilst the tangle elements are held to the conveyor belt by a magnetic field generated by one or more appropriately positioned magnets.

[0124] In some embodiments, the means for untangling comprises a brush configured to brush the tangle elements to help separate them from the target. In this case, the target may stay still whilst the brush acts to remove the tangle elements from the target.

[0125] In some embodiments, the means for untangling comprises a centrifuge configured to separate heavier objects from lighter objects. The tangle elements may be the heavier objects and the target may be the lighter object(s) or vice versa.

[0126] In some embodiments, the means for untangling comprises a liquid, the plurality of tangling elements and the target being configured to separate when in the liquid. For example, the plurality of tangle elements may be configured to float in the liquid and the target is configured to sink in the liquid, or vice versa.

[0127] In some embodiments, the means for untangling comprises means for vibrating or means for shaking the target to separate the plurality of tangle elements from the target. In some embodiments, the means for untangling comprises a sieve configured to allow one of the tangle elements and the target to pass through but not the other. The sieve may be used in combination with the means for vibrating or the means for shaking the target. In some embodiments, the means for untangling comprises means for blowing gas through the target to separate the plurality of tangle elements from the target. In some embodiments, the means for untangling comprises means for rinsing the target with a liquid to separate the plurality of tangle elements from the target. Compared to the mechanical means for untangling, a flowing liquid or gas may be able to reach into difficult to access areas of the passages defined by the target. As a result, a more complete removal of the tangle elements may be achieved.

[0128] Figure 5 shows an embodiment in which the means for untangling comprises a pulsing magnetic field generated by electromagnets 40. The magnetic field is shown by the arrows in box A. As shown in box B, the tangle elements entangled with the target may be positioned on the conveyor belt 42 between the electromagnets 42 arranged at the side of the conveyor belt. Box C shows that when the electromagnetic field is switched on or is pulsed, the tangle elements can be pulled out of the target by the electromagnets 40. The target is not attracted to the electromagnets 40 and is carried away by the conveyor belt 42.

[0129] A pulsing magnetic field may be applied to encourage the tangle elements to separate from the target. Electromagnets 40 pulse to pull the tangle elements away while the targets remain on the belt due to high surface friction with the conveyor belt 42 and / or due to the target not being attracted to the electromagnets 40. It will be appreciated that the pulsing magnetic field may be used in conjunction with other means for untangling such as a decomposable element.

[0130] In some embodiments, the means for untangling comprises at least one magnet and the plurality of tangle elements are configured such that, when the plurality of tangle elements is within a magnetic field of the at least one magnet, a major axis of the tangle elements is caused to align with the magnetic field of the magnet. The major axis of the tangle element is the longest dimension of the tangle element. Therefore, when the tangle elements align with the magnetic field, they are arranged lengthways and may be more likely to separate from the target.

[0131] In some embodiments, wherein the at least one magnet comprises a plurality of magnets, the plurality of magnets being arranged such that at least two of the plurality of magnets have different magnetic fields. In some embodiments, the tangle elements are dropped onto a surface (e.g., conveyor belt) with a structured magnetic surface comprising a plurality of different magnetic fields (e.g., as found in magnetic encoders). Each magnetic field causes the tangle elements to be aligned with that particular magnetic field. The tangle elements may be passed through the magnetic field of each of the plurality of magnets to help disentangle them.

[0132] In some embodiments, the means for untangling comprises a source of low pressure. The source of low pressure may be arranged to suck the plurality of tangle elements out of the target. In this way, the tangle elements can be separated from the target by using the suction provided by a vacuum or low- pressure source, for example, a vacuum pump. In some embodiments, the tangle elements (entangled with the target) are placed on a vacuum platform which sucks the target down while the ferromagnetic tangle elements are pulled up by the electromagnet. In other embodiments, the tangle elements are sucked down and out of the target. It will be appreciated that the low pressure may be arranged to apply suction at any angle. However, a downwards direction may provide a stronger force due to gravity.

[0133] It will be appreciated that one means for untangling may be used or a combination of the above-described means for untangling. For example, in some embodiments, the dissolvable element may not be able to completely separate the tangle elements from the target. Therefore, once the dissolvable element has been dissolved, one or more mechanical separation mechanisms, such as vibration, sieving and / or sweeping, may be used to separate the remaining fragments of the tangle elements from the target. In some scenarios, the tangle elements are not required to be separated from the target and thus no means for untangling is required. For example, where the picking apparatus is used for packaging items, the tangle elements may be left within the target when the target is packaged. In this way, the picking process may be simplified and be more cost effective.

[0134] Tangle Elements

[0135] Figure 6 shows a non-limiting set of examples of the types of tangle elements 12 according to some embodiments. As discussed above, the primary purpose of the tangle elements 12 is to entangle with a target. Therefore, the type, shape and dimensions of the tangle elements may be selected appropriately for a particular type of target.

[0136] As shown in Figure 6, tangle element 1 is bar-shaped and may be suitable for tangling with certain types of target. However, the ability of the tangle element to tangle may be greatly improved by making it “spiky”. Tangle elements 2, 11 and 20 have at least one leg which extends along an axis that is perpendicular to the axis defined by the length of the original bar-shaped tangle element (sometimes referred to as a cross bar). As a result, these tangle elements extend in two dimensions and comprise some form of spike. The leg may be straight as in tangle elements 2 and 11 or it may be curved as in tangle element 20. The branches of the diagram extending from examples 2 and 11 all comprise a cross bar with at least one leg extending therefrom. The branch extending from the L-shaped tangle element 2 comprises legs extending from either end of the original cross-bar. Examples include the II- or C-shaped tangle element 4 and the H-shaped tangle element 6. The examples branching out from tangle element 11 all include a leg extending from the centre of the original cross bar. One example is the F-shaped tangle element 13. In some embodiments, the tangle element is three dimensional such as tangle elements 7, 10 and 14. In each of these examples, the tangle element comprises at least one leg that is perpendicular to at least one other leg, both legs being substantially perpendicular to the original cross bar. Having more legs may help the tangle element engage and interlock with a target. However, too many legs or having too large legs may reinforce separation of the tangle elements and the target such that tangling is inhibited. Accordingly, there is a balance between the number and the length of the legs. Moreover, the type and shape of tangle element should be selected or designed appropriately for each target. The example embodiments branching out from curved tangle element 20 all comprise a curved or hooked portion / leg. Some of the curved tangle elements do not comprise any straight portion at all such as the helical tangle element 23. It will be appreciated that the cross section of the tangle elements may be any suitable shape, for example, circular, oval, square, or rectangular.

[0137] The size and dimensions of the tangle elements 12 should be selected such that at least a portion of the tangle elements fit between the passages defined by the target such that the tangle elements can engage and interlock with the target. In some embodiments, the plurality of tangle elements are dimensioned to pass through the gaps in the target. In some embodiments, the cross bar and / or the at least one leg is between 0.5 and 1 ,2mm thick and in some embodiments 0.8mm thick. In some embodiments, the cross bar is between 5 and 20mm long, in some embodiments between 10 and 15mm long, and in some embodiments 12mm long. In some embodiments, the at least one leg is between 5 and 20mm long, in some embodiments between 10 and 15mm long, in some embodiments 12mm in length. It will be appreciated that the legs may be shorter than, the same length as or longer than the cross bar. In some embodiments, when there are two or more legs, the two or more legs may comprise legs of different sizes. This may improve the ability of the tangle element to be used with multiple target types. In some embodiments, the curved tangle element has a total height of 18mm and comprises a curved arc of diameter 12mm.

[0138] In the embodiments branching out from tangle elements 2 and 11 , the legs extend substantially perpendicularly from the cross bar. In other words, as shown on tangle element 2, the angle, 0, defined between the cross bar and the at least one leg is 90 degrees. However, it will be appreciated that this need not be the case. In other embodiments (not shown), the at least one leg extends at an angle other than 90 degrees from the cross bar. For example, the leg may extend at an angle of between 0 and 180 degrees, the angle being defined between the cross bar and the leg. In some embodiments, the angle is between 10 and 80 degrees. In some embodiments, the angle is between 20 and 70 degrees. In some embodiments, the angle is between 30 and 50 degrees. In some embodiments, the angle is 45 degrees. In some embodiments, the angle is between 120 and 160 degrees. In some embodiments, the angle is 135 degrees. It will be appreciated that, when the tangle element comprises multiple legs, each leg may extend at a same angle or at different angles.

[0139] It will be appreciated that the tangle elements may be made from any suitable material. For example, when picking food stuff, a food safe material such as stainless steel may be used. However, if the apparatus is not for picking food stuff, other non-food safe materials may be used. When the means for picking up the tangle elements comprises a magnet, such as an electromagnet, the tangle elements may comprise a ferromagnetic material or a magnetic material. In the embodiments in which the tangle element is configured to change from a first state for picking up the target to a second state for untangling from the target, a combination of appropriate materials will need to be selected. In some embodiments, the tangle element comprises a decomposable element, the decomposable element not being decomposed in the first state and decomposed in the second state. For example, the at least one leg may be detachably mounted to the cross bar by the decomposable element, which may be a dissolvable frame. The cross bar and the legs may be made from stainless steel and the frame for holding them together made from BVOH such that the legs may break away from the cross bar when exposed to water. In another example, the cross bar and / or the at least one leg is formed from the decomposable element, which may be a material such as ice that can be melted to decompose it.

[0140] In some embodiments, the plurality of tangle elements comprises two or more types of tangle element. For example, the plurality of tangle elements may include tangle elements of differing size and / or shape. This may improve the plurality of tangle elements’ ability to grip various target types or different parts of a target. In some embodiments, the stiffness of the tangle elements is non-uniform. This means that one or more portions of the tangle element can flex more than other portions. This may allow the tangle elements to bend and reach into more areas within the target. For example, the at least one leg of the tangle element may be mounted to the cross bar such that it can flex away from being perpendicular to the cross bar. It will be appreciated that sufficient stiffness in the tangle element is still required to interlock with and support the weight of the target.

[0141] Figure 7 shows an alternative apparatus for picking up a target 10 using a plurality of tangle elements 12. In this embodiment, the apparatus comprises a floatation vessel 30 and a liquid supply 32 for supplying a liquid 34 to the floatation vessel 30.

[0142] The left-hand diagram of Figure 7 shows the target 10 positioned within the floatation vessel 30. In the middle diagram, the plurality of tangle elements 12 are dropped onto the target 10 and become entangled with the target 10. It will be appreciated that the tangle elements 12 may be entangled with the target 10 inside or outside of the floatation vessel 30. When entanglement occurs inside the vessel 30, entanglement may be performed outside of the liquid 34 or when the target 10 is at the surface of the liquid as shown. The right-hand diagram shows how liquid 34 may be introduced into the floatation vessel 30 by the liquid supply 32. The tangle elements 12 are configured to float within the liquid 34 and so the target 10 (which does not float in the liquid) may be picked up by the liquid 34.

[0143] Figure 8 shows an embodiment in which the means for entangling comprises a dispenser 44 for dispensing the tangle elements 12 over the target 10. Box A shows that the dispenser 44 comprises two containers / hoppers / cartridges 46 which can be filled with tangle elements 12. As shown in box B, when the dispenser 44 is placed over the target, a hole of controllable size may be opened to dispense the tangle elements 12 over the target 10. In some embodiments, the dispenser 44 may comprise a means for vibrating such that the tangle elements can be encouraged to leave the dispenser and fall onto the target. A specific number of tangle elements can be dispensed onto the target each time by controlling the size of the hole and how long it is open for.

[0144] In some embodiments, the distribution of tangle elements on or in the target may be controlled by selectively dispensing elements at different locations or in different patterns.

[0145] In some embodiments, the dispenser comprises means for forcing the tangle elements onto the target. In this way, the dispenser applies a force to the tangle elements when they leave the dispenser. For example, the dispenser may comprise a pneumatic source configured to shoot the tangle elements onto / into the target using air pressure.

[0146] In some embodiments, the dispenser comprises at least one cartridge for each of the two or more types of tangle element. In this way, the dispenser includes cartridges filled with different types of tangle elements. When a particular cartridge is opened, a desired amount of tangle elements of a particular type are dispensed onto the target.

[0147] Figure 9 shows the steps in a method according to an embodiment. In step S1 , the plurality of tangle elements are entangled with a target to be picked. In step S2, the plurality of tangle elements are picked up by the means for selectively picking up the plurality of tangle elements. When the tangle elements are picked up, the plurality of tangle elements engage the target such that the target is also picked up.

[0148] Step S1 may comprise dispersing the tangle elements onto or into the target. In this step, the tangle elements may be in an initial (or zeroth) state designed to facilitate distribution of the tangle elements onto or into the target. Prior to step S2, the tangle elements may be changed from the initial state into an engagement (or first) state in which the tangle elements are configured for picking up the target. For example, once the tangle elements have been spread or mixed with the target, the tangle elements can be changed to the engagement state in which they are more inclined to interlock and entangle with the target. In some embodiments, the tangle elements are formed from a shape-memory alloy (SMA). SMAs may be deformed when cooled but return to their original shape when reheated. Therefore, tangle elements made from an SMA may be deformed in the initial state for dispersal within the target and undeformed in the engagement state for picking up the target. In some embodiments, in the deformed state, the tangle element is less spiky than in the undeformed state. For example, the at least one leg of the tangle element may deform such that the tangle element becomes substantially bar shaped.

[0149] In some embodiments, once the target has been picked up and manipulated in step S2, the method further comprises the optional step S3 of separating the tangle elements from the target. In some embodiments, one or more of the separation mechanisms detailed above is performed. In some embodiments, step 3 comprises changing the tangle elements from the engagement state to a separation (or second state) for untangling from the target. In some embodiments, the initial and the separation state may be the same. For example, a tangle element made from an SMA may be deformed in both the initial and the separation states to facilitate entry into and separation from the target.

[0150] In some embodiments, the step of entangling comprises dropping the plurality of tangle elements onto the target. In some embodiments, the step of entangling comprises mixing the plurality of tangle elements with the target.

[0151] In some embodiments, the method further comprises selecting a type of tangle element that is appropriate for the target. In some embodiments, the step of selecting the type of tangle element comprises accessing a data store containing test results indicating an association between the target and types of tangle element.

[0152] In some embodiments, the method further comprises performing the step of calibrating to determine a number of tangle elements for picking up a certain amount of the target. In some embodiments, the method further comprises selecting a number of tangle elements to entangle with the target to pick up a desired amount of the target based on the calibration step. In some embodiments, the step of selecting the number of tangle elements comprises accessing a data store containing results of the calibration. Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiment and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

Claims

CLAIMS1. An apparatus for picking, comprising: a plurality of tangle elements configured to be entangled with a target to be picked; and means for selectively picking up the plurality of tangle elements, wherein, when the plurality of tangle elements are entangled with the target, the plurality of tangle elements are configured when picked up to engage the target such that the plurality of tangle elements and the target are picked up together.

2. An apparatus according to claim 1 , wherein the plurality of tangle elements each comprise a ferromagnetic material, and wherein the means for selectively picking up comprises a magnet for picking up the magnetic material.

3. An apparatus according to any preceding claim, further comprising means for untangling the plurality of tangle elements from the target.

4. An apparatus according to claim 3, wherein the plurality of tangle elements each comprise a decomposable element, and wherein the means for untangling comprises means for decomposing the decomposable element.

5. An apparatus according to claim 4, wherein the means for untangling is configured to change the plurality of tangle elements from a first state for picking up the target in which the decomposable element is not decomposed to a second state for untangling from the target in which the decomposable element is decomposed.

6. An apparatus according to claim 4 or claim 5, wherein the decomposable element comprises a dissolvable element and the means for decomposing comprises a liquid for dissolving the dissolvable element.

7. An apparatus according to claim 6, wherein the liquid comprises water.

8. An apparatus according to claim 6 or claim 7, wherein the dissolvable element comprises butenediol vinyl alcohol co-polymer, BVOH.

9. An apparatus according to any one of claims 6 to 8, wherein the plurality of tangle elements each comprise a crossbar and at least one leg extending from the crossbar, wherein the dissolvable element detachably mounts the at least one leg to the crossbar.

10. An apparatus according to claim 4 or claim 5, wherein the decomposable element comprises a solid and the means for decomposing comprises at least one of the following: means for melting the solid; and means for dissolving the solid.

11. An apparatus according to claim 10, wherein the solid comprises at least one of the following: ice; wax; and sugar.

12. An apparatus according to claim 10 or claim 11 , wherein, when the means for decomposing comprises means for melting the solid, the means for melting comprises electromagnetic waves.

13. An apparatus according to any one of claims 10 to 12 when dependent on claim 2, wherein the ferromagnetic material comprises a magnetic powder interspersed within the solid.

14. An apparatus according to claim 13, wherein the magnetic powder comprises iron oxide.

15. An apparatus according to any one of claims 10 to 14, wherein the plurality of tangling elements each comprise a crossbar and at least one legextending from the crossbar, the crossbar and / or the at least one leg being formed from the solid.

16. An apparatus according to claim 4 or claim 5, wherein the decomposable element comprises a compacted powder and the means for decomposing comprises means for disintegrating the compacted powder.

17. An apparatus according to any one of claims 3 to 16 when dependent on claim 2, wherein the means for untangling comprises a pulsing magnetic field.

18. An apparatus according to any one of claims 3 to 16 when dependent on claim 2, wherein the means for untangling comprises at least one magnet and the plurality of tangle elements are configured such that, when the plurality of tangle elements is within a magnetic field of the at least one magnet, a major axis of the tangle elements is caused to align with the magnetic field of the magnet.

19. An apparatus according to claim 18, wherein the at least one magnet comprises a plurality of magnets, the plurality of magnets being arranged such that at least two of the plurality of magnets have different magnetic fields.

20. An apparatus according to any one of claims 3 to 19, wherein the means for untangling comprises a source of low pressure.21 . An apparatus according to any preceding claim, wherein the plurality of tangle elements are dimensioned to pass through gaps in the target.

22. An apparatus according to any preceding claim, wherein the plurality of tangle elements comprises two or more types of tangle element.

23. An apparatus according to any preceding claim, wherein the apparatus further comprises means for entangling the plurality of tangle elements with the target.

24. An apparatus according to claim 23, wherein the means for entangling comprises a dispenser for dispensing the tangle elements over the target.

25. An apparatus according to claim 24, wherein the dispenser comprises means for forcing the tangle elements onto the target.

26. An apparatus according to claim 24 or claim 25 when dependent on claim 22, wherein the dispenser comprises at least one cartridge for each of the two or more types of tangle element.

27. A method for picking, comprising: entangling a plurality of tangle elements with a target to be picked; picking up the plurality of tangle elements using a means for selectively picking up the plurality of tangle elements, the plurality of tangle elements being configured to engage the target such that the target is picked up with the plurality of tangle elements.

28. A tangle element for a picking apparatus according to any one of claims 1 to 26, the tangle element being configured to change from a first state for picking up the target to a second state for untangling from the target.

29. A tangle element according to claim 28, wherein the tangle element comprises a cross bar and at least one leg extending from the cross bar.

30. A tangle element according to claim 29, wherein the cross bar and / or the at least one leg comprises a ferromagnetic material.31 . A tangle element according to any one of claims 28 to 30, wherein the tangle element comprises a decomposable element, the tangle element being configured to change from the first state in which the decomposable element is not decomposed to the second state in which the decomposable element is decomposed.

32. A tangle element according to claim 31 when dependent on claim 29, wherein the at least one leg is detachably mounted to the cross bar by the decomposable element.

33. A tangle element according to claim 32, wherein the decomposable element comprises a dissolvable element.

34. A tangle element according to claim 31 , wherein the cross bar and / or the at least one leg is formed from the decomposable element, optionally wherein the decomposable element comprises ice.

35. A tangle element according to claim 34 when dependent on claim 30, wherein the decomposable element comprises ice interspersed with magnetic powder.

36. A tangle element according to claim 29 or any one of claims 30 to 35 when dependent on claim 29, wherein the at least one leg comprises a first leg extending from a first end of the cross bar and a second leg extending from a second end of the cross bar or an approximate centre of the cross bar.

37. A tangle element according to claim 31 , wherein the decomposable element comprises wax or sugar.

38. A tangle element according to claim 31 , wherein the decomposable element comprises a compacted powder.

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