Gripper devices

Systems are provided for gripping or otherwise manipulating lettuce, sliced foodstuffs (e.g., sliced cheese, sliced tomato or other sliced vegetables), or other foodstuffs or other irregular objects or substances. These systems can facilitate the manipulation of groups of irregular objects, including distributing small amounts (e.g., individual instances) of such groups of objects. These systems operate to manipulate such objects by extending and retracting rods, wires, or otherwise-configured pins to contact and/or penetrate the object(s) to be manipulated. In some examples, the pins are retracted to individually dispense objects (e.g., slices of cheese) from a stack of objects. In some examples, the separation and angle of the pins can be controlled to, e.g., grip one or more irregular objects and subsequently to dispense some or all of the gripped object(s).

BACKGROUND

A variety of grippers are available to facilitate the manipulation of a variety of objects or substances, e.g., mechanical components, electronic components, sheets or metal or other material, planks of wood or lumber, textiles, or other substances. Such grippers may be adapted to the material/object to be manipulated. For example, where the objects to be manipulated have smooth, non-permeable surfaces, a gripper may employ suction to manipulate the objects. Where the object is a manufactured object, the gripper may include elements configured to interface with a particular feature(s) of the manufactured object (e.g., a hard point, handle, or other feature formed to facilitate gripping).

SUMMARY

Some embodiments of the present disclosure provide a gripper apparatus including: (i) a first iris, wherein the first iris includes a first static plate having a first plurality of openings therein and a first rotatable plate having a second plurality of openings therein, wherein the first rotatable plate has a first axis of rotation, and wherein the first rotatable plate is rotatable, relative to the first static plate, about the first axis of rotation; (ii) a second static plate having a third plurality of openings therein; (iii) a push plate that is slidably movable relative to first iris and the second static plate; and (iv) a plurality of flexible wires. Each respective wire of the plurality of wires (e.g., flexible wires, rigid wire) is disposed within a respective opening of the first plurality of openings, a respective opening of the second plurality of openings, and a respective opening of the third plurality of openings such that rotation of the first rotatable plate relative to the first static plate results in a change in a distance between the respective wire and the first axis of rotation of the first rotatable plate. Each wire of the plurality of flexible wires is mechanically coupled to the push plate such that motion of the push plate, relative to the first iris and the second static plate, results in longitudinal motion of the plurality of wires through the first, second, and third pluralities of openings.

Some embodiments of the present disclosure provide a gripper apparatus including: (i) a first push plate, wherein a first plurality of pins are coupled to the first push plate, and wherein the pins of the plurality of first pins are substantially parallel to each other; (ii) a second push plate, wherein a second plurality of pins are coupled to the second push plate, wherein the pins of the plurality of second pins are substantially parallel to each other, and wherein pins of the first plurality of pins are substantially non-parallel to pins of the second plurality of pins; and (iii) a guide plate having a contact surface. The guide plate has formed therein a first plurality of channels extending from the contact surface and a second plurality of channels extending from the contact surface. The first push plate is disposed relative to the guide plate such that the pins of the first plurality of pins are disposed within respective channels of the first plurality of channels. The second push plate is disposed relative to the guide plate such that the pins of the second plurality of pins are disposed within respective channels of the second plurality of channels. The first push plate and the second push plate are slidably movable relative to the guide plate such that the first push plate and the second push plate can be moved relative to the guide plate to result in the first plurality of pins and second plurality of pins, respectively, protruding from the contact surface.

Some embodiments of the present disclosure provide a method for gripping individual items in a stack of items, the method that includes positioning a gripper apparatus proximate to a stack comprising a plurality of items in a stacked arrangement. The gripper apparatus includes: (i) a first push plate, wherein a first plurality of pins are coupled to the first push plate, and wherein the pins of the plurality of first pins are substantially parallel to each other; (ii) a second push plate, wherein a second plurality of pins are coupled to the second push plate, wherein the pins of the plurality of second pins are substantially parallel to each other, and wherein pins of the first plurality of pins are substantially non-parallel to pins of the second plurality of pins; and (iii) a guide plate having a contact surface. The guide plate has formed therein a first plurality of channels extending from the contact surface and a second plurality of channels extending from the contact surface. The first push plate is disposed relative to the guide plate such that the pins of the first plurality of pins are disposed within respective channels of the first plurality of channels. The second push plate is disposed relative to the guide plate such that the pins of the second plurality of pins are disposed within respective channels of the second plurality of channels. The first push plate and the second push plate are slidably movable relative to the guide plate such that the first push plate and the second push plate can be moved relative to the guide plate to result in the first plurality of pins and second plurality of pins, respectively, protruding from the contact surface. The method additionally includes: actuating the first push plate and the second push plate of the gripper apparatus such that the first plurality of pins and the second plurality of pins protrude from the contact surface and penetrate at least a portion of the stack; moving the gripper apparatus to a first location; actuating the first push plate and the second push plate of the gripper apparatus to partially retract the first plurality of pins and the second plurality of pins into the guide plate such that a first item in the stack is dispensed at the first location; moving the gripper apparatus to a second location; and actuating the first push plate and the second push plate of the gripper apparatus to further retract the first plurality of pins and the second plurality of pins into the guide plate such that a second item in the stack is dispensed at the second location.

DETAILED DESCRIPTION

A variety of materials can be difficult to manipulate by artificial means due to slipperiness, stickiness, frangibility, being composed of individual slices or sheets (e.g., sliced cheese, leaves of lettuce or other vegetables, slices of meat, slices of tomato), being composed of a plurality of irregularly-shaped objects (e.g., nuts, berries, small tomatoes, cubed meats or cheeses), being irregularly shaped, being especially compliant and/or being susceptible to plastic deformation, or other reasons. Such materials can include a variety of foodstuffs, making automation of food processing or food preparation difficult.

The present disclosure provides a variety of mechanical grippers or other apparatus adapted to effectively manipulate such materials. These embodiments include sets of pins or wires configured to penetrate, enclose, or otherwise manipulate materials. In some embodiments, sets of parallel pins extend from a contact surface to penetrate material to be manipulated. Subsequently, the pins can be retracted to release or otherwise dispense the material. In examples wherein the penetrated material is a stack of slices of material (e.g., a stack of slices of cheese), the degree of retraction can be controlled to dispense individual slices of the material at a time.

In some embodiments, a gripper includes an enclosing arrangement of wires. The extension of the wires from the gripper, the distance from a center point from which the wires protrude from the gripper, and the angle of the wires relative to a surface of the gripper, a central axis of the array of wires, or to some other structure(s) of the gripper can all be controlled in order to manipulate materials. In some examples, the wires can be extended to penetrate the materials and/or retracted to release or eject such materials. Additionally or alternatively, the gripper can be operated to grasp the material (e.g., to grasp a plurality of irregularly-shaped objects) by, e.g., changing an angle of the wires and/or reducing an effective radius at which the wires protrude from the gripper, thus enclosing and gripping the material. The material can then be dispensed in a controlled manner, e.g., by changing the angle of the wires, by increasing the effective radius at which the wires protrude from the gripper, and/or by retracting the wires into the gripper. In some examples, the gripper includes one or more actuated irises through which the wires protrude such that rotation of the iris changes an effective radius at which the wires protrude through the iris.

In some embodiments, a gripper may be configured to control the orientation and position of a set of wires or rods in order to grip, pierce, scoop, pinch, dispense, release, compactify, or otherwise manipulate foodstuffs or other materials of interest. The ability to control the angle of such wires and/or the effective radius at which the wires protrude from a gripper allows for foodstuffs or other irregular objects to be manipulated in a wide variety of ways, facilitating flexible strategies for the manipulation of the materials of interest.

An example of such a gripper is illustrated inFIG. 1. The gripper100includes a number of wires110(including example wire115). The gripper100is configured to manipulate materials (e.g., foodstuffs, other irregular objects) by controlling the angle of the wires110, the length of the wires110that protrudes from the gripper, and/or an effective radius at which the wires110protrude from the gripper100. The gripper100includes a first iris120, a second iris130, and a push plate140that are configured to facilitate control of the orientation and position of the wires110. The wires110can include tips (including an example tip117that is coupled to the end of the example wire115) that may be pointed (e.g., sharpened), rounded, scoop-shaped, formed to have an edge or blade, or shaped in some other manner to facilitate manipulation of a foodstuff or other material of interest. For example, the tips could be pointed in order to facilitate the gripper100penetrating the material (e.g., slices of tomato) with the wires110.

In order to control the location and angle of the wires110, the first iris120, second iris130, and push plate140may be actuated. The push plate140can control the distance that the wires110protrude from the gripper100(by moving along a sliding direction141) and the irises120,130can control the angle of the wires110and the locations at which the wires110protrude from the gripper100.

FIGS. 2A and 2Billustrate how the irises120,130can be operated to effect this control.FIGS. 2A and 2Bshow a static plate126and a rotatable plate122of an iris120at respective first and second points in time. The rotatable plate122is able to rotate, relative to the static plate126, about an axis of rotation (indicated by the “+” symbol). A plurality of wires (including an example wire115), shown in cross-section, pass through the iris120. The static plate126and rotatable plate122include respective sets of openings (including first example opening127in the static plate126and second example opening123in the rotatable plate122) through which the wires pass (e.g., the example wire115is disposed within the first127and second123openings).

The regions where the openings in the static plate126overlap with the openings in the rotatable plate122define regions where the wires can pass through the iris120. Accordingly, rotation of the rotatable plate122relative to the static plate126can cause the location of the wires to change by changing the locations at which the sets of openings overlap. For example, the location of the rotatable plate122relative to the static plate126at the first point in time (illustrated inFIG. 2A) results in the first127and second123example openings overlapping at a first location such that the example wire115is separated from the axis of rotation of the rotatable plate122by a first distance “D1.” Subsequently, the rotatable plate122may be rotated relative to the static plate126such that the location of the wires is changed. For example, the rotatable plate122could be rotated counter-clockwise, as shown inFIG. 2B, such that the example wire115moves in a radial direction and becomes separated from the axis of rotation of the rotatable plate122by a second distance, “D2,” that is less than “D1.”

As shown inFIGS. 2A and 2B, the openings in the static plate126take the form of linear slots and the openings in the rotatable plate122take the form of spiral slots. However, this is intended as a non-limiting example embodiment, and other configurations of openings are anticipated. For example, the static plate could have spiral openings and the rotatable plate could have linear slot openings. Both plates could have spiral openings, or openings having some other geometry (e.g., an asymmetric geometry), in order to allow the location of the wires to be controlled both radially and circumferentially, to reduce the likelihood that the wires become jammed between the plates126,122, to reduce a torque needed to rotate the rotatable plate122relative to the static plate126, to balance the amount of torque needed to rotate the rotatable plate122relative to the static plate126across a range of relative positions of the plates126,122, or to provide some other benefit.

Additionally, while the irises disclosed herein are described as including “static” plates and “rotatable” plates, these descriptors are only intended for ease of description. While the rotatable plates are rotatable relative to respective static plates, the static plates may also be capable of rotation. For example, the “static plate” and the “rotatable plate” may each be independently rotatable, e.g., to permit both the radial distance and the angle, relative to the axes of rotation of the plates, at which the wires pass through the iris to be independently controlled.

The first120and second130irises contain respective first122and second132rotatable plates and respective first126and second136static plates, with the rotatable plates being rotatable about a central, common axis of rotation relative to the static plates. The first122and second132rotatable plates are coupled to respective first121and second131drive members, allowing motors or other actuators (not shown) to drive the rotation of the first122and second132rotatable plates. As shown, the first drive member121has the form of a tube and the second drive member131has the form of a rod that is disposed within the first drive member121. This allows the irises120,130to be driven coaxially, potentially reducing the size and complexity of the gripper100. The irises120,130could be driven via alternative means, e.g., by motors disposed proximate to the rotatable plates132,122and coupled thereto by, e.g., respective spur gears.

The first122and second132rotatable plates can be rotated in order to control the distance, from the common axis of rotation, at which the wires110pass through the first120and second130irises. The push plate140can increase or decrease the length of the portion of the wires that extends beyond the static plate136. The combination of the rotation of the first and second rotatable plates122and123and the axial movement of the wires110allows the distance of the wires from the central axis of rotation to be controlled at two different planes along the length of the gripper100(i.e., at planes corresponding to the locations of the irises120,130along the length of the gripper), thus facilitating independent control of the angle of the wires110as well as the distance, from the axis of rotation, at which the wires110protrude from the gripper110(e.g., from the static plate136of the second iris130or from some other element of the gripper100(not shown).

The wires110are coupled to the push plate140such that motion of the push plate140, along the axis of the gripper100(the direction indicated by arrow141), results in a change in the distance by which the wires110protrude from the gripper100. In the example illustrated inFIG. 1, the wires110are coupled to the push plate140by being coupled to respective spheres (including an example sphere119that is coupled to the example wire117) that are kept captive within respective channels within the push plate140. This is illustrated by the example wire117being coupled to the example sphere119by passing through a linear slot144formed in a forward plate142of the push plate140. The example sphere119is kept between the forward plate142and a reverse plate146of the push plate140in a channel148that is formed within the push plate140. Thus, the end of the example wire117that is coupled to the example sphere119is maintained at a specified distance along the axis of the gripper100, the specified distance corresponding to the location of the push plate140along the length of the gripper100, while being able to move freely along a radial direction relative to the axis of the gripper100. Alternative methods of coupling wires to a push plate are also contemplated, e.g., direct coupling of an end of a wire to the push plate (relying on flexibility of the wire to permit the wire to deform along its length to pass through one or more irises), coupling via a hinge or pin, or some other form of coupling.

The use of two irises and a push plate to control wires of a gripper is illustrated inFIGS. 3A-D.FIGS. 3A-Dillustrate, in cross-section, elements of a gripper300as described herein (e.g., gripper100) at respective different points in time. The gripper300includes a first iris that includes a first static plate310band a first rotatable plate310a, a second iris that includes a second static plate320band a second rotatable plate320a, and a push plate340. The wire passes through respective openings in the plates of the first and second irises and is coupled to the push plate340via a sphere335that is held captive within a channel of the push plate340. The first rotatable plate310ais driven by a rod315that is disposed within a tube325used to drive the second rotatable plate320a.

FIG. 3Aillustrates the configuration of the gripper300at a first point in time, when the wires330are substantially parallel and at angle “A1” relative to the gripper300, protrude from the gripper by a first length “L1,” and protrude from the gripper300at a first radial distance “R1” from the common axis of rotation of the rotatable plates310a,320a. The irises310,320and push plate340can be operated to control each of these degrees of freedom (i.e., the angle, length of protrusion, and radius of protrusion) individually and/or in combination.

For example, the first rotatable plate310aof the first iris could be rotated to reduce the radial distance at which the wires330protrude from the gripper300as well as to change the angle of protrusion. This is illustrated inFIG. 3B, where the radial distance of protrusion of the wires330has been reduced to “R3” and the angle of the wires330has increased to “A2” while the wires330protrude from the gripper by the same distance “L1” as inFIG. 3A. In another example, multiple aspects of the gripper300could be controlled at the same time, e.g., to enable independent control of one of the degrees of freedom of the wires while keeping the other degrees of freedom substantially static. This is illustrated inFIG. 3C, where the radial distance of protrusion of the wires330has been further reduced (not indicated) while the angle of the wires330is the same angle “A2” and the wires330protrude from the gripper by the same distance “L1” as inFIG. 3B. The push plate340can be moved in order to control the distance by which the wires330protrude from the gripper300. This is illustrated inFIG. 3D, where the push plate340has been moved upward, retracting the wires330into the gripper300.

Note that the example operations shown inFIGS. 3A-3Dare intended as an example sequence that could be used according to an application and additional or alternative operations of a gripper as described herein are anticipated. The example operations shown inFIGS. 3A-3Dcould be used, e.g., to scoop an amount of material (e.g., a number of irregular objects composed of a foodstuff or other material) and then to dispense the material (e.g., after having moved the gripper from a region that contains a source of the material to a region where the material is needed).

Additionally, a gripper could include more or fewer irises than the two irises depicted inFIGS. 1 and 3A-D. For example, a gripper could include only a single iris. In such examples, the number of degrees of freedom of orientation and location of wires of the gripper that can be independently controlled may be reduced. For example, where only a single iris is included, rotation of the rotatable plate of the single iris could result in both a change in angle of the wires and a change in the radius at which the wires protrude from the gripper. In another example, a gripper could include a single iris and an additional static plate through openings of which the wires protrude from the gripper. Rotation of the rotatable plate of the single iris could result in a change in the angle of the wires while the radius at which the wires protrude from the gripper is maintained substantially constant by the location of the openings in the additional static plate.

Yet further, a gripper as described herein could lack a push plate. Such a gripper could operate to grip, dispense, or otherwise manipulate material without the ability to independently extend/retract wires of the gripper, e.g., by grasping/releasing the material by increasing/decreasing the angle of the wires and/or by increasing/decreasing the radius at which the wires protrude from the gripper. Omission of the push plate and/or including only a single iris could allow for a gripper that is lower-cost, that has fewer parts, that is easier to clean and/or service, or that is otherwise improved for applications in which the increased degrees of freedom of control provided by the push plate/additional iris are not needed and/or do not provide sufficient benefits.

One or more of the wires of a gripper described herein (e.g.,100,300) could have a channel formed therein. Such a channel could be used to apply gas and/or liquid (e.g., water) to one or more apertures formed proximate the end of the wire(s). Such a gas and/or liquid could be applied, via the channel of the wire, to eject a material that has been penetrated by the wire and/or to eject a sheet of material, from a stack of such sheets that have been penetrated by the wire, from the wire (e.g., to dispense a slice of cheese or other material that is sticky, wet, or that is otherwise adherent to the wire and/or to other slices of the material that are penetrated by the wire). In some examples, such a channel could additionally or alternatively be used to detect whether the wire is penetrating an object (e.g., by applying a pressure to gas or liquid in the channel and detecting whether the applied pressure is able to escape via the channel or is contained by a material that is penetrated by the wire).

A gripper as described herein (e.g.,100,300) could be disposed on the end of a robotic arm or other means for orienting and positioning the gripper within a space. The gripper could then be used to manipulate materials within the space, e.g., to collect foodstuffs and to manipulate the foodstuffs in order to assemble a sandwich, assemble a salad, assemble a pizza, or perform some other food preparation task or to manipulate some other irregular material(s). In such applications, computer vision could be used in order to determine whether the gripper is interacting with a material, to determine how much of the material is penetrated, held, or otherwise gripped by the gripper, or to determine some other information about the operation of the gripper and/or about materials in the environment of the gripper. Additionally or alternatively, the gripper could include one or more sensors configured to provide such information.

In some examples, a sensor could be coupled to one or more of the wires of the gripper. Such a sensor could include a force sensor configured to detect forces transmitted along the length of the wire, e.g., to detect how much force is being applied along a longitudinal direction of the wire, to determine whether the wire is penetrating at least one object, etc. Such a sensor could include one or more piezoelectric actuators configured to inject mechanical vibrations into the wire. The effects of these vibrations could then be detected (e.g., by the piezo actuators themselves, or by some additional components) and used to determine whether the wire is penetrating one or more objects, whether the wire is in contact with an object, a direction of such an object relative to an end of the wire, etc. In some examples, this could include the sensor having piezoelectric actuators configured to generate at least one of an axial vibration in the wire or a transverse vibration in the wire in one or more directions (e.g., two different transverse vibrations in the wire along orthogonal directions within the wire). Such vibration may additionally or alternatively be employed to dislodge or otherwise eject materials that have been penetrated or otherwise picked up by the wires.

A gripper as described herein (e.g.,100,300) could be configured to facilitate cleaning and/or to comply with food safety standards or other standards of cleanliness. This could include the gripper being able to be disassembled wholly or partially such that the wires and/or other elements of the gripper (e.g., elements that come into contact with foodstuffs) may be removed and cleaned. Additionally or alternatively, the gripper may include disposable elements that may be removed and replaced after use in order to facilitate cleanliness. For example, the wires and/or tips thereof could be disposable. In some examples, the gripper could include a disposable drape that could be fitted over an end of the gripper that comes into contact with foodstuffs. In such examples, the wires could be configured to penetrate the drape, such that foodstuffs are prevented from entering the gripper.

In some embodiments, a gripper may be configured to control the a distance by which two or more sets of penetrating pins protrude from the gripper in order to penetrate, release, or otherwise manipulate foodstuffs or other materials of interest. The ability to control the extent to which such multiple sets of pins protrude from a gripper allows for foodstuffs or other irregular objects to be manipulated in a wide variety of ways, facilitating flexible strategies for the manipulation of the materials of interest. By penetrating the material with the pins, a variety of irregular objects can be gripped. Additionally or alternatively, a stacked arrangement of individual pieces of a material (e.g., stacked slices of cheese) can be stacked and subsequently individual slices of the stack can be dispensed by retracting the pins by specified amounts (e.g., by amounts corresponding to the thickness of the sheets of material).

An example of such a gripper is illustrated inFIGS. 4A and 4B, which provide side and perspective views, respectively, of a gripper400. The gripper400includes first410and second420push plates to which are coupled pins of respective first415and second425pluralities of pins. The pins of the first plurality of pins415are substantially parallel to each other and the pins of the second plurality of pins425are substantially parallel to each other. Pins of the first plurality of pins415are substantially non-parallel to pins of the second plurality of pins425. The gripper400additionally includes a guide plate405having a contact surface407that may be placed in contact with foodstuffs or other material to be manipulated. A first plurality of channels and a second plurality of channels (illustrated by example inFIG. 5Aas512and514) extending from the contact surface407are formed through the guide plate405such that the first plurality of pins415can be disposed within the first plurality of channels and the second plurality of pins425can be disposed within the second plurality of channels.

A gripper (e.g., gripper400) could be configured in a variety of ways to drive such multiple pluralities of pins into a material and then to retract the pins from the material by moving the pins through respective pluralities of channels in a guide plate. The gripper400includes an actuator (e.g., a pneumatic or hydraulic cylinder, a motor with a drive screw, an electromechanical linear actuator) that is operable to slidably move the first push plate410and the second push plate420relative to the guide plate405to result in the first plurality of pins415and the second plurality of pins425moving within respective pluralities of channels within the guide plate405. The actuator is coupled to a drive member430. The drive member430is coupled to the first push plate410via a first linking rod417that is mechanically coupled to the drive plate430via a first pin419aand to the first push plate410via a second pin419b. The drive member430is coupled to the second push plate420via a first linking rod427that is mechanically coupled to the drive plate430via the first pin419aand to the second push plate420via a third pin429b. Additionally or alternatively, the first linking rod427could be mechanically coupled to the drive plate430via a different pin than the first pin419a.

A gripper as described herein (e.g., gripper400) could be operated to penetrate and grip a stacked arrangement of items (e.g., a stack of sheets or slices of cheese, tomato, or some other foodstuff or other material of interest) using the two or more pluralities of pins and subsequently to dispense some (e.g., one or more individual items from the stack) or all of the stack by fully or partially retracting the pins. This is illustrated by way of example inFIGS. 5A-Dwhich show, in cross-section, a gripper500at a number of different points in time as the gripper500is operated to pick up and the dispense items from a stack of items550(e.g., a stack of slices of cheese).

FIG. 5Ashows the gripper500prior to picking up the stack550. The gripper500includes a guide plate510that has a contact surface511. The gripper500additionally includes a first push plate520that is coupled to a first plurality of pins525. Each pin of the first plurality of pins525is disposed within a respective channel of a first plurality of channels512that is formed through the guide plate510from the contact surface511. The gripper500also includes a second push plate530that is coupled to a second plurality of pins535. Each pin of the second plurality of pins535is disposed within a respective channel of a second plurality of channels514that is formed through the guide plate510from the contact surface511. As shown inFIG. 5A, the first525and second535pluralities of pins are fully retracted into the guide plate510.

At a second time point, illustrated inFIG. 5B, the gripper500has been positioned proximate to (e.g., in contact with) a plurality of items551,553,555,557,559arranged in a stacked arrangement (as stack550) and the first510and second520push plates have been actuated such that the first525and second535pluralities of pins have protruded from the contact surface511to penetrate all of the items551,553,555,557,559of the stack.

The gripper can then be used to dispense some or all of the stack at another location (e.g., by using a robot arm or other means to control the position and/or orientation of the gripper500). This is illustrated inFIG. 5C, which shows the gripper500at a third time point. At the third time point, the first510and second520push plates have been actuated such that the first525and second535pluralities of pins have been partially retracted into the guide plate510, dispensing a first item551from the stack. The gripper500could be operated to dispense additional items, e.g., at further locations. This is illustrated inFIG. 5D, which shows the gripper500at a fourth time point. At the fourth time point, the first510and second520push plates have been actuated such that the first525and second535pluralities of pins have been further retracted into the guide plate510, dispensing a second item553from the stack.

A gripper as described herein (e.g.,400,500) could be disposed on the end of a robotic arm or other means for orienting and positioning the gripper within a space. The gripper could then be used to manipulate materials within the space, e.g., to collect foodstuffs and to manipulate the foodstuffs in order to assemble a sandwich, assemble a salad, assemble a pizza, or perform some other food preparation task or to manipulate some other material(s). In such applications, computer vision could be used in order to determine whether the gripper is interacting with a material, to determine how much of the material is penetrated, held, or otherwise gripped by the gripper, or to determine some other information about the operation of the gripper and/or about materials in the environment of the gripper. Additionally or alternatively, the gripper could include one or more sensors configured to provide such information.

In some examples, a sensor could be coupled to one or more of the pins of the gripper (e.g., to a push plate to which such pins are coupled). Such a sensor could include a force sensor configured to detect forces transmitted along the length of the pin(s), e.g., to detect how much force is being applied along a longitudinal direction of the pins(s), to determine whether the pin(s) are penetrating at least one object, etc. The gripper could be operated based on the output of such a sensor, e.g., to detect how many objects are penetrated by the gripper or to detect that an item from a stack has been dispensed and to responsively cease retracting the pins.

In some applications, the items in a stack of items to be dispensed may have a tendency to stick together (e.g., due to a stickiness of the material, due to capillary forces, due to adhesion, due to other attractive forces between the items in a stack). In such applications, simply retracting the pins of a gripper that has penetrated the stack may not result in dispensation of one or more items from the stack, or may result in dispensation of a random or otherwise uncontrolled number of items from the stack. For such applications, a gripper as described herein (e.g.,400,500) could include one or more a channels formed within respective pins of the gripper. Such a channel could be used to apply gas and/or liquid (e.g., water) via one or more apertures to separate an item (e.g., a slice of cheese) from a stack of such items that have been penetrated by the wire in order to dispense the item. In some examples, such a channel could additionally or alternatively be used to detect whether the pin is penetrating an item (e.g., by applying a pressure to gas or liquid in the channel and detecting whether the applied pressure is able to escape via the channel or is contained by a material that is penetrated by the wire) and/or whether an item has been successfully dispensed (e.g., by detecting a reduction in pressure within the channel and/or an increase in gas or liquid flow through the channel following dispensation of an item).

An example of a gripper that includes such channels is shown inFIG. 6A.FIG. 6Aincludes a gripper600athat has gripped a stack650aof items651a,653a,655a,657a. The gripper600aincludes a first push plate620acoupled to a first plurality of pins625aand a second push plate (not shown) coupled to a second plurality of pins (not shown). Channels627aare formed in pins of the first plurality of pins625a. The channels627aterminate in apertures629aformed at the end of respective pins625a. The pins625aare positioned relative to the stack650asuch that gas or liquid (e.g., water, oil) that is applied through the channels627acan act to separate a first item651afrom the remainder of the stack650a. The gas or liquid could be applied as the pins625aare retracted, facilitating dispensation of items of the stack650a.

WhileFIG. 6Ashows the channels of gripper600aterminated in single apertures at the end of respective pins, other arrangements are possible. For example, the channels could terminate in multiple apertures (e.g., to permit multiple sheets, slices, or other items in a stack to be separated from each other at a time) and/or could terminate in apertures formed through a lateral surface of respective pins (e.g., to permit a sheet, slice, or other item to be separated from the remainder of the stack while still being penetrated by pins of the gripper).

An example of a gripper that includes such channels is shown inFIG. 6B.FIG. 6Bincludes a gripper600bthat has gripped a stack650bof items651b,653b,655b,657b. The gripper600bincludes a first push plate620bcoupled to a first plurality of pins625band a second push plate (not shown) coupled to a second plurality of pins (not shown). Channels627bare formed in pins of the first plurality of pins625b. The channels627bterminate in apertures629bformed through a lateral surface of respective pins625b. The pins625bare positioned relative to the stack650bsuch that gas or liquid (e.g., water, oil) that is applied through the channels627bcan act to separate a first item651bfrom the remainder of the stack650bwhile still being penetrated by the pins625b. The gas or liquid could be applied as the pins625bare retracted, facilitating dispensation of items of the stack650b. A gripper as described herein may include multiple sets of pins configured as illustrated inFIGS. 6A and 6B, respective, or according to some other configuration of aperture(s).

A gripper as described herein (e.g.,400,500,600a,600b) could be configured to facilitate cleaning and/or to comply with food safety standards or other standards of cleanliness. This could include the gripper being able to be disassembled wholly or partially such that the guide plate, contact surface, push plates, pins, and/or other elements of the gripper (e.g., elements that come into contact with foodstuffs) may be removed and cleaned. For example, a gripper could include a housing to which a guide plate, push plate with pins coupled thereto, or other elements are removably mounted (e.g., via latches, bolts, clips, snaps, or other features or elements). Additionally or alternatively, the gripper may include disposable elements that may be removed and replaced after use in order to facilitate cleanliness. For example, the guide plate and/or push plate and pins coupled thereto could be disposable. In some examples, the gripper could be cleaned by applying a cleaning fluid (e.g., detergent, bleach, sterilizing fluid) through the channels of the guide plate and/or through channels formed in the pins.

IV. Example Methods

FIG. 7is a flowchart of a method700for slices of material (e.g., slices of cheese, meat, tomato, or some other sliced foodstuff) from a stack of slices of the material (e.g., to construct a sandwich or to perform some other food processing or preparation task). The method700includes positioning a gripper apparatus proximate to a stack that includes a plurality of items in a stacked arrangement (710). The gripper apparatus includes: (i) a first push plate, wherein a first plurality of pins are coupled to the first push plate, and wherein the pins of the plurality of first pins are substantially parallel to each other; (ii) a second push plate, wherein a second plurality of pins are coupled to the second push plate, wherein the pins of the plurality of second pins are substantially parallel to each other, and wherein pins of the first plurality of pins are substantially non-parallel to pins of the second plurality of pins; and (iii) a guide plate having a contact surface and having formed therein a first plurality of channels extending from the contact surface and a second plurality of channels extending from the contact surface. The first push plate is disposed relative to the guide plate such that the pins of the first plurality of pins are disposed within respective channels of the first plurality of channels; the second push plate is disposed relative to the guide plate such that the pins of the second plurality of pins are disposed within respective channels of the second plurality of channels; and the first push plate and the second push plate are slidably movable relative to the guide plate such that the first push plate and the second push plate can be moved relative to the guide plate to result in the first plurality of pins and second plurality of pins, respectively, protruding from the contact surface.

The method700additionally includes actuating the first push plate and the second push plate of the gripper apparatus such that the first plurality of pins and the second plurality of pins protrude from the contact surface and penetrate at least a portion of the stack (720); moving the gripper apparatus to a first location (730); actuating the first push plate and the second push plate of the gripper apparatus to partially retract the first plurality of pins and the second plurality of pins into the guide plate such that a first item in the stack is dispensed at the first location (740); moving the gripper apparatus to a second location (750); and actuating the first push plate and the second push plate of the gripper apparatus to further retract the first plurality of pins and the second plurality of pins into the guide plate such that a second item in the stack is dispensed at the second location (760). In some examples, the first and second location could be the same location, e.g., such that multiple items (e.g., the first and second items) may be dispensed at the same location. The method700could include additional elements or features.

Additionally, while various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are contemplated herein.