Grabbing and picking component and grabbing and picking system

Abstract

The invention discloses a grabbing and picking member and a grabbing and picking system comprising the grabbing and picking member. The pick-up member includes a pair of support members and a palm portion. Each support member of the pair of support members is a bendable actuator. The palm portion includes a first surface that partially defines a cavity. Opposite sides of the first surface are coupled to the pair of support members along respective lengths of the pair of support members. The first surface extends between the pair of support members. The palm portion includes a filler disposed in the cavity.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Singapore application number 10202251349K filed on October 12, 2022, the contents of which are incorporated herein by reference in their entirety for all purposes. Technical Field

[0002] The invention relates to a grasping component and a grasping system suitable for grasping various objects. Background Art

[0003] Advances in robotics have enabled robots made of soft and compliant materials to accomplish challenging tasks, such as a close gripper for picking up objects. Usually, a close gripper needs to push down on the object before picking it up, and this push force can cause the soft object to deform or break, and this push force can even be greater than the gripping force. Therefore, close grippers are usually set for specific objects with certain characteristics, thus limiting the scope of use / application. Summary of the invention

[0004] In one aspect, the present application discloses a gripping member. The gripping member includes a pair of support members and a palm portion. Each of the pair of support members is a bendable actuator. The palm portion includes a first surface, and the first surface partially defines a cavity. The first surface partially defines a cavity. Opposite sides of the first surface are coupled to the pair of support members along corresponding lengths of the pair of support members. The first surface extends between the pair of support members. The palm portion includes a filler disposed in the cavity.

[0005] The stiffness of the palm portion is variable and changes in response to jamming of the filler within the cavity, and the palm portion can bend in response to bending of the pair of support members. The jamming can be responsive to negative pressure within the cavity. Each support member of the pair of support members can extend along a first axis and can be operated to at least partially bend the first surface about a second axis, wherein the second axis is transverse to the first axis.

[0006] On the other hand, the present application discloses a grasping system. The grasping system includes: a grasping device and a controller in signal communication with the grasping device. The grasping device may include multiple grasping members, such as two or more grasping members. The controller is configured to control the grasping members to collaboratively process an object. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Various embodiments of the present application are described below with reference to the following drawings:

[0008] Figure 1 is a schematic diagram of a grabbing system according to an embodiment of the present application;

[0009] Figure 2 is a perspective view of an embodiment of a gripping device according to one embodiment;

[0010] Figure 3 is an exploded view of a grabbing member according to one embodiment;

[0011] Figure 4 yes Figure 3 A cross-sectional top view showing an AA view;

[0012] Figure 5 yes Figure 3 A front view of the grabbing member shown;

[0013] Figure 6 yes Figure 3 a side view of the grabbing member shown;

[0014] Figure 7 is a front view of a grabbing member according to another embodiment;

[0015] Figure 8 is a front view of a grabbing member according to another embodiment;

[0016] Fig. 9 yes Figure 2 A cross-sectional view showing a BB view;

[0017] Fig.10 yes Fig. 9 , showing a detailed view of view C;

[0018] Fig.11 is a perspective view of a filler according to one embodiment;

[0019] Fig.12 is a perspective view of a filler according to another embodiment;

[0020] Fig.13 is a perspective view of a filler according to another embodiment;

[0021] Fig.14 is a perspective view of a palm portion of a gripping member conforming to an object according to one embodiment;

[0022] Fig.15A is a side view of a gripping device for gripping an object according to one embodiment;

[0023] Fig. 15B is to pick up another object, Fig.15A A side view of the grabbing device shown;

[0024] Fig. 15C is to pick up another object, Fig.15A A side view of the grabbing device shown;

[0025] Fig.15D is to pick up another object, Fig.15A A side view of the grabbing device shown;

[0026] Fig.16 An image showing the gripping device of the present application picking up different objects;

[0027] Fig.17 The following are the settings for measuring the gripping force of different gripping devices of the present application and the corresponding measurement results;

[0028] Fig.18 shows the maximum gripping force applied by different gripping devices to different objects during the gripping process; and

[0029] Fig.19 The clamping force measurement settings of different gripping devices of the present application and the corresponding measurement results are shown. DETAILED DESCRIPTION

[0030] The following detailed description is made with reference to the accompanying drawings, which show details and embodiments of the present application for illustrative purposes. Features described in the context of one embodiment apply accordingly to the same or similar features in other embodiments, even if not explicitly described in these other embodiments. Additions and / or combinations and / or substitutions for feature descriptions in the context of one embodiment may apply accordingly to the same or similar features in other embodiments.

[0031] In the context of various embodiments, the articles “a”, “an”, and “said” used with respect to a feature or element include reference to one or more features or elements.

[0032] In the context of various embodiments, the term "about" or "substantially" applied to a numerical value includes the exact value as well as a reasonable difference commonly understood in the relevant technical field, for example, within 10% of the specified value.

[0033] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0034] For the sake of brevity, the term "handling" may be used interchangeably with terms such as "grabbing", "picking up", "gripping", "holding", "picking up", "transporting", "raising", "transferring", etc., as will be understood from the context. For the sake of brevity, the term "pressure" used herein may be understood with reference to ambient pressure. For example, "positive pressure" may refer to a pressure above ambient pressure, and "negative pressure" may refer to a pressure below ambient pressure. Depending on the context, the term "positive pressure" may refer to an increase in pressure, and "negative pressure" may refer to a decrease in pressure.

[0035] To aid understanding and without limitation, the following will describe specific implementations of different embodiments of the gripping device 100 and the gripping system 50 with reference to the accompanying drawings. The gripping device 100 can also be described as a gripper that can handle one or more objects with different physical characteristics (e.g., size, shape, softness, etc.) without applying excessive force that can damage the one or more objects. For simplicity, different examples will be described below with reference to the processing of one object, but it will be understood that in different examples, multiple objects can be processed simultaneously by one gripping system.

[0036] Figure 1 is a schematic diagram of a gripping system 50 according to different embodiments of the present application. According to some embodiments, the gripping system 50 includes one or more gripping devices 100, which can provide one or more first surfaces 212 individually or in combination to contact the object 60 to be processed. The first surface 212 is characterized by having a variable stiffness. For example, in a lower stiffness state, the first surface 212 is sufficiently flexible or soft to exhibit fabric-like properties. For example, in some states, the first surface 212 may have a shape that is complementary to the shape of the object 60. For example, in some states, the shape of the first surface 212 may be formed or molded by the shape of the object 60. In other words, in some states, the first surface 212 may be compliant. The variable stiffness of the first surface 212 can be controlled by controlling the degree of jamming of the filler in the cavity. For example, if the filler in the cavity is jammed, the first surface 212 is correspondingly rigid, and the shape of the first surface 212 does not change until the filler is released from the jamming state. According to some embodiments, one or more first surfaces provide a relatively large contact area or support area for the exemplary object 60 so that any irregularly shaped object can be firmly grasped and transported. In other examples, the grasping system 50 can be configured to first apply a small contact force or clamping force to the object 60, and then apply a relatively large lifting force to raise the object 60. The first surface 212 and the palm 210 can be rigidified to provide a large lifting force. This beneficially allows vulnerable items such as fruits to be grasped or picked up without damaging the fruits. Beneficially, the grasping system 50 can also be used to grasp or pick up a variety of objects with different characteristics, such as objects of different materials, different geometries, different weight distributions, different surface states, etc.

[0037] In some embodiments, Figure 1 As shown, the picking system 50 includes a picking device 100 in signal communication with a controller 52. The picking device 100 may include a frame 110 coupled to one or more picking members 200. Figure 1An example of a gripping system 50 having two gripping members 200 is shown. Multiple gripping members 200 can be actuated to cooperatively grip an object 60. In some embodiments, the gripping members 200 can be actuated to bend or curve toward the object 60 to pick up the object 60 from the surface 62. Each gripping member 200 includes a pair of support members 220. Each gripping member 200 includes a palm 210 that defines a cavity 214 therein. The palm 210 includes a first surface 212, wherein the first surface 212 partially defines the cavity 214 in the palm 210, for example, the first surface 212 constitutes a portion of the cavity wall 213. The first surface 212 is coupled along respective lengths of the multiple support members. The cavity 214 can be fluidly / pneumatically sealed so that a relative pressure difference between the interior of the cavity 214 and the exterior of the cavity 214 can cause a change in the stiffness of the first surface 212. The bending of the palm 210, such as the bending of the cavity wall 213 or the first surface 212, can be driven by pneumatically actuating the support member 220. The pneumatic actuation of the palm 210 (also interchangeably referred to as the pneumatic actuation of the cavity 214) hardens the cavity wall 213 or the first surface 212, for example, becomes harder and less compliant. As used herein, the stiffness enhancement of the palm 210 can be referred to as a jamming transition. The plurality of gripping members 200 can present one or more first surfaces 212 of each to be oriented to achieve contact and conformance between the plurality of gripping members to the object 60. The first surface 212 can constitute a significant portion of the gripping member area (approximately 83% of the total area). The controller 52 can be configured to control the plurality of gripping members 200 to operatively grip the object 60. In various examples, the gripping members 200 can be pneumatically actuated by a pressure pump 56 in fluid communication with the plurality of gripping members 200, wherein the pressure pump 56 can be controlled by the controller 52.

[0038] In some embodiments, the gripping member 100 is a compacting gripper. Each gripping member 200 may include a cavity 214, wherein a compacting material or one or more fillers 240 are disposed within the cavity. In some examples, the filler 240 within the cavity may include a substantially planar grid member or a planar grid member. In response to a vacuum or negative pressure within the cavity, formed by using, for example, a vacuum pump 58, the filler is "compacted" (e.g., compacted more closely to each other), which causes the first surface 212 that contacts the object 60 to adapt in a manner that conforms to the shape of the object 60. The first surface 212 may be described as forming at least a portion of a palm, because similar to the palm of a hand, the first surface may wrap around the object or form a cup to hold the object. The gripping member 200 may be described as a variable stiffness member. In some embodiments, the gripping device 100 may be coupled to a robotic arm 54 or an end effector of the robotic arm 54. The robotic arm 54 may be configured to move the gripping device 100. In some embodiments, the controller 52 may also be in signal communication with the robotic arm 54 to control the position of the gripping device 100 relative to the surrounding environment.

[0039] In some embodiments, the gripping system 50 may include one or more suction nozzles 59 configured to elevate the object 60. In some embodiments, the suction nozzle 59 may be combined with the gripping device 100, for example, coupled to the gripping device 100 to achieve a compact solution. The suction nozzle 59 may be detachably coupled to the gripping device 100 so that the suction nozzle 59 can be installed or uninstalled according to different types of treatments required. Alternatively, the suction nozzle 59 may be provided independently of the gripping device 100 so that the suction nozzle 59 can be changed or replaced according to operational needs, for example, including but not limited to changing or replacing the suction nozzle 59 according to operational needs involving nozzle size, suction pressure, etc. The provision of the suction nozzle 59 beneficially allows thinner and softer objects, such as a piece of paper or fabric, to be first raised to expose a "lower" surface that can be supported by one or more gripping devices 100. It will be appreciated that only using conventional side gripping operations may cause deformation of softer and thinner sheet-like objects. The suction nozzle 59 may be operated so that the suction nozzle 59 does not need to be in physical contact with the object. In some embodiments, the suction nozzle 59 may also be in fluid communication with a vacuum pump 58 , wherein the vacuum pump 58 provides suction pressure for the suction nozzle 59 .

[0040] Figure 2A gripping device 100 according to various embodiments of the present application is shown. The gripping device 100 includes a frame 110 coupled to a pair of gripping members 200a / 200b. The frame 110 may be formed with a plurality of grooves 112 for slidable engagement between the frame 110 and each of the pair of gripping members 200a / 200b so that the spacing between the pair of gripping members 200a / 200b is adjustable. The spacing between the pair of gripping members 200a / 200b may be adjustable to accommodate the size of the object. The frame 110 may also include a coupling hole 114 for coupling with the robotic arm 54. In some embodiments, the gripping members 200a / 200b may be substantially planar members, each substantially planar member in a default state setting a respective gripping surface 80a / 80b. During the operation of picking up an object, the gripping members 200a / 200b can be actuated to move toward each other and away from the respective gripping surfaces 80a / 80b. In other embodiments, for the purpose of picking up granular objects (e.g., grains, cereals, etc.), one or both of the gripping members 200a / 200b can be bent or curved away from the respective gripping surfaces 80a / 80b to form a scoop for scooping up granular objects.

[0041] Figure 3 A non-limiting embodiment of a gripping member 200 is shown in more detail. The gripping member 200 can be substantially planar in a default state, for example, when in a non-operating state, the gripping member 200 can set a substantially flat or planar gripping surface 80. The gripping member 200 includes a palm 210 characterized by having a variable stiffness. The palm 210 may include a contact surface, such as a first surface 212 that can contact an object. In some embodiments, the palm 210 or at least the first surface 212 is made of an elastic material, such as a silicone elastomer. The first surface 212 can be friction-enhanced to facilitate a secure grip of an object. The first surface 212 can extend between opposing sides 216 of the palm 210.

[0042] Reference again Figure 3 and Figure 4, the gripping member 200 may include a coupling member 230, which is coupled to the palm 210 and the pair of support members 220. The coupling member 230 may be coupled to the frame 110 of the gripping device 100, for example, it may be coupled to a plurality of grooves 112 formed in the frame 110 of the gripping device 100. In addition, the coupling member 230 may be formed with a plurality of channels 232, and the plurality of channels 232 may achieve fluid communication between the cavity 214 and the first nozzle 234. Fluid communication between the vacuum pump and the cavity 214 may be achieved through the first nozzle 234. The coupling member may also provide fluid communication between each actuation cavity 224 and the corresponding second nozzle 236. Fluid communication between the pressure pump and each actuation cavity 224 is achieved through the second nozzle 236.

[0043] like Figure 5 and Figure 6 As shown in the enlarged view of , the first surface 212 may include multiple serrated edges or multiple folds. This provides space for the first surface 212 to expand when the gripping member 200 is deformed. The folds can be arranged differently. In some examples, the folds can be formed with triangular and / or zigzag cross-sections extending along the first axis 82. In some examples, the zigzag cross-sections can form alternating 60° angles (α) with a wall thickness (t) of 1 mm and a pitch length (p) of 2.3 mm.

[0044] In some embodiments, when the first surface 212 contacts the object, the curvature of the first surface 212 can change or deform to conform to the object. For example, each support member of the pair of support members extending along the first axis can be operated to at least partially bend the first surface 212 about a second axis, wherein the second axis is transverse to the first axis. For example, the first surface 212 can be bent about the first axis 82 and about the second axis 84 to conform to the object, wherein the deformation of the first surface 212 can be partially contributed by actuation of at least one support member and can be partially contributed by pneumatic operation of the palm (e.g., changes in relative pressure within the cavity). In some embodiments, the first surface 212 can be deformed to form a topologically complex surface, wherein the topological surface includes at least one three-dimensional valley or at least one notched area relative to the gripping surface 80. The term "topologically complex surface" as used in this application refers to a non-planar surface, for example, can include one or more local peaks and local valleys arranged across the surface.

[0045] Reference again Figure 3According to various embodiments, the palm portion 210 may include a cavity 214 formed within the palm portion 210. In some embodiments, the cavity 214 is at least partially defined by the first surface 212. In some embodiments, the cavity 214 may be disposed adjacent to or proximate to the first surface 212.

[0046] In various embodiments, Fig. 9 and Fig.10 As shown, the filler 240 may be disposed in the cavity 214. The cavity 214 may be configured to be fluid-tight so that when negative pressure is applied to the cavity 214, the cavity 214 is in a compacted state. When the cavity 214 is not in a vacuum state or a compacted state, the cavity 214 is in a compacted release state, wherein the first surface 212 has a weaker rigidity or a higher compliance. In some embodiments, in the compacted release state, multiple portions of the filler 240 may move relative to each other. In the compacted state, multiple portions of the filler 240 are fixed relative to each other when they are more closely compacted with each other. In the compacted state, the filler 240 may be more compact or denser. In some embodiments, in the compacted state, the filler 240 maintains or sets the shape of the cavity 214. In some embodiments, in the compacted state, the first surface 212 may be maintained in a shape at least partially set by the distribution of the filler 240 around the object. It is understood that the elastic modulus (rigidity) of the first surface 212 is lower than the elastic modulus (rigidity) of the material of the filler 240 so that in the compacted state, the filler 240 can operate to maintain the first surface 212 in a curved or deformed shape.

[0047] In various embodiments of the present application, the gripping member 200 includes a pair of support members 220 or actuators, each of which is coupled to a pair of opposing sides 216 of the palm portion 210. The support members 220 may be made of a silicone elastomer such as Smooth-On Mold Star 30. In one example, the support members 220 are secured to the opposing sides 216 of the palm portion 210 by an adhesive. In some embodiments, one or both support members 220 may extend along the respective opposing sides 216 of the palm portion 210, which substantially covers the opposing sides 216 of the palm portion 210. In a default state, each of the pair of support members 220 may be aligned with the gripping surface 80, or in other words, the support members 220 are coplanar with the gripping surface 80. In some embodiments, the support members 220 are coupled to the midplane of the palm portion 210 by, for example, an adhesive. In some examples, the support member 220 need not be in contact with the object 60 in order for the gripping member 200 to handle the object.

[0048] In some embodiments, each of the pair of support members 220 may be a pneumatically operable member, each having a respective actuation chamber 224. The support members 220 may be formed of two elastomeric sheets or shells, which define the actuation chamber 224 therebetween. In addition, the support members 220 may further include a tension limiting layer, such as a paper sheet or nylon cloth disposed between the two elastomeric sheets or shells, for tension limiting the actuation of the support members 220.

[0049] In some embodiments, a plurality of grooves 222 may be formed on at least one surface of each support member 220. Each groove 222 may set a respective groove width (W). Each support member 220 may be actuated to bend or curl in response to a change in pressure in a respective actuation chamber 224, i.e., an increase or decrease in pressure in each actuation chamber 224. In response to an increase in pressure in each actuation chamber, the corresponding support member 220 bends so that the width of each groove in the plurality of grooves increases, in other words, so that each groove width (W) increases. Alternatively, the support member 220 may also be actuated by other means, such as by an electrically driven actuator, a cable driven actuator, a magnetically driven actuator, etc.

[0050] Thus, by coupling a plurality of support members 220 to respective opposing sides 216 of the palm portion 210, the palm portion 210 can be deformed upon actuation of one or both support members 220. In addition to conforming to an object, actuation by the support members 220 can also result in a change in the curvature of the first surface 212, or in other words, bending the first surface 212. In some embodiments, changing the curvature of the first surface 212 can include bending at least a portion of the first surface 212, such as an end 212a of the first surface 212, away from the gripping surface 80 in a direction 90. In some embodiments, referring to Figure 5 and Figure 6 The change in curvature of the first surface 212 may include bending the first surface about the first axis 82 and simultaneously bending the first surface about the second axis 84 .

[0051] In some embodiments, the first surface 212 may be a quadrilateral surface, such as a rectangular surface, which provides a relatively large surface for gripping. Figure 7 and Figure 8 As shown, the first surface 212 may include a narrow end 212b for coupling with the coupling member 230 and an opposite wide end 212c. The narrow end 212b limits the constraining effect of the coupling member 230 on the conformability of the first surface 212 or the palm 210. In other embodiments, the first surface 212 may be a polygonal surface having multiple sides, such as Figure 8The first surface 212 may include a plurality of end portions 212d that are not directly coupled to the coupling member 230. This allows the plurality of end portions 212d to be free from the constraining effect of the coupling member 230, thereby improving the conformability of the first surface 212.

[0052] Further references Fig.10 In addition to the filler material 240 disposed in the cavity 214 of the palm portion 210, one or more polymer sheets 250 may be disposed in the cavity 214 of the palm portion 210. The polymer sheet 250 may be disposed between the first surface 212 and the filler 240 so that when the cavity 214 is in a compacted state, the polymer sheet 250 is in full contact with the filler material 240, which results in a higher bending stiffness than when there is no polymer sheet 250. In one example, the polymer sheet 250 may be a 0.1 mm, relatively thin polyethylene terephthalate sheet.

[0053] Fig.11 A filler 240 according to an embodiment of the present application is shown. The filler 240 may be provided in the form of a flat sheet. In some embodiments, the filler 240 includes a plurality of interconnected truss units 242 or structured fabrics. The filler 240 may be made using a hard material by a stereolithography 3D printer. In some embodiments, each truss unit 242 includes a plurality of truss members 244 that collectively set a hollow interior space 246. It is understood that the interconnection / interlocking between the plurality of truss units 242 enhances the stiffness change of the filler 240. In one example, the truss unit 242 may be an octahedral truss unit. The octahedral truss unit may have a diameter of 0.7 mm and a length of 4.5 mm. The sides of each octahedral truss may be truncated and attached to a flat sheet 248 as a support. The provision of the flat sheet 248 facilitates the 3D printing process and may beneficially avoid potential punctures of the palm 210. In some embodiments, two layers of interconnected truss units 242 may be stacked and disposed in the cavity 214. The sheet 248 may be disposed toward the wall of the cavity 214. In some examples, the filler 240 may occupy a rectangular parallelepiped volume in the cavity 214 of approximately 10 cm x 8 cm x 1 cm.

[0054] refer to Fig.12 In alternative embodiments, the filler 240 may include a plurality of sheets 241 stacked together to form a thickness. Fig.13 As shown, the filler 240 may include a plurality of fibers 243, and the plurality of fibers 243 are arranged parallel to each other to form a thickness.

[0055] Fig.14A single gripping member 200 is shown in operation according to some embodiments of the present application. For simplicity, only one gripping member 200 is described, and the skilled person will appreciate that one or more gripping members 200 may cooperate in a complementary manner during operation. During operation, the palm portion 210 may be actuated by the plurality of support members 220 to move the first surface 212 toward the object 60 until the first surface 212 contacts the exterior of the object 60. Fig.14 In the example shown, the first surface 212 is deformable so as to bend about the first axis 82 in a manner that conforms to the object 60 and bend about the second axis 84. In addition, the first surface 212 can form a notch 216 of the topological surface when conforming to the object 60. As can be understood from the foregoing description, the term "deformation" used in this application generally refers to a change in the shape and / or volume of an object. A "deformed" object can be the result of any one or more of a bent state and / or a soft, flexible, and compliant state of the object. In various examples, the gripping member 200 can be deformed by a combination of bending and / or a change in the degree of rigidity, wherein the bending and the change in rigidity can be achieved independently of each other. In various examples, the palm 210 or the first surface 212 is deformed or bent / unbent by bending / unbending the support member 220. In various examples, the palm 210 or the first surface 212 is deformed or rigidified by a tightening transition of the palm 210.

[0056] In some examples, negative pressure or vacuum can be applied to the cavity 214 and the gripping member 200 is placed in a compacted state, wherein the filler 240 at least partially holds the first surface 212 against the object 60. The application of negative pressure is optional. For example, if the gripping force applied from the gripping member 200 in the de-clamped state is insufficient to grip the object, negative pressure can be applied.

[0057] Optionally, the suction nozzle 59 described above may be configured to provide suction to an object 60, such as a piece of fabric, to lift the object 60 before the palm 210 is actuated to contact the object 60. This advantageously prevents any potential deformation or damage to the piece of fabric during the operation of picking up from the side of the object.

[0058] FIG. 15A to FIG. 15DAn example of the gripping device 100 gripping different objects is shown. It can be understood that different objects 60 can cause different deformations of each palm 210 of the corresponding gripping member 200a / 200b under the simultaneous actuation of the supporting members of the two gripping members 200a / 200b. Subsequently, the deformation can be maintained by tightening the gripping members 200a / 200b, which provides rigidity to each palm 210. The gripping members 200a / 200b can be kept in place to lift the object 60. The gripping force applied to the object 60 may include friction between the object 60 and the first surface 212, and a pinching force or a supporting force provided by the palm 210 on the object 60.

[0059] refer to Fig.15A , if the object 60 is substantially flat along the direction of gravity without any protrusions for gripping, the gripping force may be mainly the friction between the first surface 212 and the object 60. Fig. 15B , if the object 60 includes an inclined (conical) surface along the direction of gravity, the grasping force may include friction force and support force on the object 60. Fig. 15C If the size of the object 60 is relatively small (relative to the palm 210), the grasping force may mainly include the clamping force of the palm on the object 60. Fig.15D If the object is large and has a rounded surface that provides at least one anchor point for support, the gripping force is primarily the support force provided by the first surface 212 to the object 60 . Object picking performance

[0060] By successfully using the gripping device 100 to pick up 12 common and representative objects, the test verified the versatility of the gripping system, such as Fig.16 In this example, a positive pressure of 120 kPa is applied to the support member so that the palm can conform and grasp the object. If necessary, the chamber is provided with a negative pressure of -90 kPa to activate the tightening state. The grasping member is then raised at a constant speed of 0.5 m / min. The test process shows that the grasping device can successfully pick up grape berries (10 g, Fig.16 Image (a)), Chinese cabbage or vegetables (78g, Fig.16 Image (b)), apple (192g, Fig.16 Image (c)), Pitaya (454g, Fig.16 Image (d)), a bag of fried vegetable sticks (55g, Fig.16 Image in (e)), stapler (35g, Fig.16 Image (f)), and hand cream (124g, Fig.16 This demonstrates that the proposed picking system is able to handle objects of various sizes and weights, as well as soft and deformable food packaging.

[0061] For smaller, lightweight objects such as grape berries and staplers, friction may be sufficient to grasp them. For heavier objects such as dragon fruit, it is necessary to gather the palm to rigidify it, thereby applying a stronger geometric constraint to surround the object and passively provide the grasping force. In addition, the grasping device 100 can also pick up fragile objects such as a badminton shuttlecock (4g, Fig.16 The image in (h)) and the ping pong ball (3g, Fig.16 The gripping device 100 can pick up these objects without bending the feathers of a badminton or forming an indentation on a ping-pong ball. In addition, the gripping device 100 can pick up slender or slippery objects, such as a chocolate bar (54 g, Fig.16 Image in (j)), bottle (404g, Fig.16 Image (k)) and wet hydrogel spheres (83 g, Fig.16 Figure 1.2 shows the image in Figure 1. Maximum gripping force

[0062] Use a universal testing machine (Mark-10 F305) to pull the gripping device away from a fixed object (such as Fig.17 The gripping device is mounted on a mobile force sensor of the testing machine and the weight of the gripping device is compensated so that the pulling or pushing force on the gripping device can be measured. Fig.17 The image (b) in Figure 1 shows 12 objects of different shapes and sizes used in the test. The objects tested include spheres, cubes, and cylinders oriented horizontally or vertically. The diameters of the spheres and cylinders are 7 cm and 5 cm, respectively, and the length of the cube is 3 cm.

[0063] For a single run of the test, the gripping device was first lowered to a fixed position and the support member or actuator was pressurized to 120 kPa to grip the object. This position was chosen so that for a sphere and a horizontal cylinder, Fig.17 As shown in Figures (c) to (f) in the figure, the palm of the gripping member completely surrounds the object; and for the cube and vertical cylinder, the palm covers the edge of the object. The vacuum level in the palm cavity is controlled to 0 kPa or negative 90 kPa so that the effect of tightening on the gripping force can be measured. The gripping device is pulled or raised upward at a constant speed of 2 mm / s until the object falls off the gripping device, and the test is repeated 5 times for each object. For spheres (such as Fig.17 ) and for a horizontal cylinder (as shown in Figure (c) in Fig.17), two qualitatively different responses are observed, where the grasping force first reaches a maximum value as the pulling distance increases, and then drops to zero when the grasping device loses contact with the object. Fig.17 Figure (e)) and the vertical cylinder ( Fig.17 (f) of the accompanying drawings), the grasping force is smaller than that for the sphere and cube, and remains relatively constant throughout the pulling process. Without being limited by theory, it should be understood that two main mechanisms contribute to the maximum grasping force, namely: geometric interlocking and frictional contact. For the cube and vertical cylinder, frictional contact substantially contributes to the grasping force. For the sphere and horizontal cylinder, the interlocking effect substantially dominates the grasping force. Due to the additional effort required to break through the geometric constraints provided by the curved or deformed palm, the grasping force for the sphere and horizontal cylinder is greater than that for the cube and vertical cylinder. In addition, when grasping the sphere and horizontal cylinder, the enhanced palm stiffness causes stronger constraints when compacting, and therefore significantly larger grasping forces are measured. For the 7 cm sphere, the maximum grasping force increases by 4.6 times, and for the 7 cm horizontal cylinder, the grasping force increases by 3.5 times. For the cube and vertical cylinder, the grasping force changes slightly before and after compacting. In these cases, the gripping force comes mainly from frictional contact, and the results show that the pinch force, that is, the force of the palm actively gripping the object, remains almost unchanged when pinching. Tests have shown that the gripping device of the present application can pick up a variety of objects.

[0064] Fig.18 The maximum gripping force that can be achieved using different examples of gripping members is shown. Example F1 corresponds to Figure 5 The gripping member shown has a polymer sheet and a filler material (interconnected grid cells or structured fabric), such as Fig.10 and Fig.11 Example F2 corresponds to an example with a structured fabric and no polymer sheet. Example L1 corresponds to Figure 5 The pick-up member shown has a paper for filling material, such as Fig.12 Example T1 corresponds to Figure 7 The gripping member shown has a polymer sheet and a filler material (interconnected grid cells or structured fabric), such as Fig.10 and Fig.11 shown. Clamping force test

[0065] To estimate the gripping force of the gripper, a gripping force test is performed on the palm of the gripper, such as Fig.19 As shown in the image (a). Fig.19Graph (b) of FIG. 1 shows the clamping force as a function of the pressure in the support member or the actuator pressure for three palm designs (F1, F2 and L1), and Fig.19 Figures (c), (d) and (e) show the effect of the bunching, respectively. All gripping forces rise as a function of the pressure of the support member, with the results of the two palms being averaged. When the palm bunching is released, the L1 gripping member has a maximum gripping force of 0.58N at 120kPa; and the F2 gripping member has a gripping force of 0.38N, which is higher than the gripping force of 0.32N of the F1 gripping member at 120kPa. Beneficially, the gripping force of each example is relatively low, making it suitable for gripping soft and fragile objects.

[0066] The ratios of the maximum gripping force (7 cm horizontal cylinder in the compacted state) to the clamping force at 120 kPa in the compacted state are about 42, about 62, and about 33 for the F1 gripping member, about 62 for the F2 gripping member, and about 33 for the L1 gripping member, all of which exceed the current state-of-the-art technology based on compacted, variable stiffness mechanical fingers or membrane grippers. The larger ratios indicate that the present gripping device is capable of applying a smaller force for picking up fragile objects, while being able to passively provide a larger gripping force or support force in the compacted state.

[0067] In one aspect, the present application discloses a gripping member. The gripping member includes a pair of support members and a palm portion. Each of the pair of support members is a bendable actuator. The palm portion includes a first surface that partially sets a cavity. The first surface partially sets the cavity. Opposite sides of the first surface are coupled to the pair of support members along corresponding lengths of the pair of support members. The first surface extends between the pair of support members. The palm portion includes a filler disposed in the cavity.

[0068] The stiffness of the palm portion may be variable and change in response to compaction of the filler within the cavity, and the palm portion may bend in response to bending of the pair of support members.

[0069] The compaction can be responsive to negative pressure within the cavity. Each of the paired support members can extend along a first axis and can be operable to at least partially bend the first surface about a second axis, wherein the second axis is transverse to the first axis. The curvature of the first surface can be responsive to positive pressure within the paired support members. In response to the compaction of the filler by the negative pressure within the cavity, the first surface can maintain deformation. The first surface in a default state can set a gripping surface, wherein the first surface can be deformed away from the first surface. The first surface can be deformed to form a topological complex surface. The elastic modulus of the first surface can be lower than the elastic modulus of the filler material. The first surface may include multiple folds.

[0070] The gripping member may further include a polymer sheet disposed within the cavity, wherein the polymer sheet is disposed between the first surface and the filler. The filler may include a plurality of interconnected truss units, wherein each truss unit defines a hollow interior space. The filler may include a plurality of sheets, wherein the plurality of sheets are stacked together to form a thickness. The filler may include a plurality of fibers, wherein the plurality of fibers are disposed parallel to each other.

[0071] Each support member in the pair of support members may include a corresponding actuation cavity, wherein each support member in the pair of support members may bend in response to a change in pressure in the corresponding actuation cavity. Each support member in the pair of support members may include a plurality of grooves formed on at least one face of each corresponding support member, wherein in response to a change in pressure in the corresponding actuation cavity, the corresponding support member may bend to increase the width of the plurality of grooves.

[0072] On the other hand, the present application discloses a grasping system. The grasping system includes: a grasping device and a controller in signal communication with the grasping device. The grasping device includes two grasping members, each of which is any one of the grasping members described above. The controller is configured to control the two grasping members to collaboratively process an object.

[0073] The picking system may further include a suction nozzle, wherein the suction nozzle is configured to lift the object by suction. The picking system may further include a robotic arm coupled to the picking device, wherein the picking device may be moved by the robotic arm. The picking system may further include a vacuum pump in fluid communication with the corresponding cavity of each of the two picking members.

[0074] All examples described herein, whether apparatus, methods, materials or products, are presented for illustrative purposes and to aid understanding, and are not intended to be limiting or exhaustive. Those skilled in the art may make modifications without departing from the scope of the claims of the present invention.

Claims

1. A grabbing member, comprising: a pair of support members, each support member of the pair of support members being a bendable actuator; as well as A palm portion, the palm portion comprising: a first surface, the first surface partially defining the cavity, opposite sides of the first surface coupled to the pair of support members along respective lengths of the pair of support members, the first surface extending between the pair of support members; as well as A filler is disposed in the cavity.

2. A gripping member according to claim 1, wherein the stiffness of the palm portion is variable and the stiffness changes in response to the packing of the filler within the cavity, and wherein the palm portion is bendable in response to the bending of the pair of support members.

3. A gripping member according to claim 1 or 2, wherein the compaction is responsive to negative pressure within the cavity.

4. A gripping member according to any one of claims 1 to 3, wherein each support member of the pair of support members extends along a first axis and is operable to at least partially bend the first surface about a second axis, the second axis being transverse to the first axis.

5. A gripping member according to any one of claims 1 to 4, wherein the curvature of the first surface is responsive to positive pressure within the pair of support members.

6. A gripping member according to any one of claims 1 to 5, wherein the first surface is responsive to compaction of the filler by negative pressure within the cavity to remain deformed.

7. A gripping member according to any one of claims 1 to 6, wherein the first surface in a default state defines a gripping surface, wherein the first surface is deformable away from the first surface.

8. A gripping member according to any one of claims 1 to 5, wherein the first surface is deformable to form a topologically complex surface.

9. A gripping member according to any one of claims 1 to 6, wherein the elastic modulus of the first surface is lower than the elastic modulus of the material of the filler.

10. A gripping member according to any one of claims 1 to 7, wherein the first surface comprises a plurality of folds.

11. The gripping member of any one of claims 1 to 8, further comprising a polymer sheet disposed in the cavity, the polymer sheet disposed between the first surface and the filler.

12. A gripping member according to any one of claims 1 to 9, wherein the filler comprises a plurality of interconnected truss units, each of the plurality of truss units defining a hollow interior space.

13. A gripping member according to any one of claims 1 to 9, wherein the filler comprises a plurality of sheets stacked together to form a thickness.

14. A picking member according to any one of claims 1 to 9, wherein the filler comprises a plurality of fibres arranged parallel to each other.

15. A gripping member according to any one of claims 1 to 12, wherein each support member of the pair of support members includes a corresponding actuation cavity, and each support member of the pair of support members is bendable in response to a change in pressure in the corresponding actuation cavity.

16. A gripping member according to claim 13, wherein each of the pair of support members includes a plurality of grooves formed on at least one surface of each corresponding support member, and wherein in response to a change in pressure within the corresponding actuation chamber, the corresponding support member can bend to increase the width of the plurality of grooves.

17. Picking system, including: A picking device comprising two picking members, each of the two picking members being a picking member according to any one of claims 1 to 16; as well as A controller, the controller being in signal communication with the picking device, The controller is configured to control the two grasping members to process the object in a coordinated manner.

18. The gripping system according to claim 17, further comprising a suction nozzle, wherein the suction nozzle is configured to lift the object by suction.

19. The gripping system according to claim 17 or 18, further comprising a robot arm coupled to the gripping device, the gripping device being movable by the robot arm.

20. The picking system of claim 18, further comprising a vacuum pump in fluid communication with a corresponding cavity of each of the two picking members.

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