An underactuated rigid-flexible coupling manipulator

Abstract

The present invention relates to the field of manipulator technology, and in particular to an under-actuated rigid-flexible coupling manipulator. The under-actuated rigid finger comprises a plurality of movable knuckles connected in series, each of the knuckles having a porous mounting portion; the flexible contact portion has a plurality of flexible microstructures, and each flexible contact portion is embedded in the porous mounting portion of each knuckle through the flexible microstructure. The present invention arranges an adjustable flexible structure on the under-actuated rigid finger, and during the grasping process, adjusts the flexible structure to improve the flexibility during the grasping process, making it suitable for grasping relatively fragile or soft objects, thereby improving the adaptability of the rigid-flexible coupling manipulator. The flexible microstructure is embedded in the porous mounting portion of the knuckle to ensure the toughness of the rigid-flexible coupling connection between the knuckle and the flexible contact portion, thereby improving the compliance of the manipulator, and in conjunction with the cooperative drive of the under-actuated structure and the pneumatic structure, the manipulator has load capacity, controllability and flexibility.

Description

Technical Field

[0001] The invention relates to the technical field of manipulators, and in particular to an under-actuated rigid-flexible coupling manipulator. Background Art

[0002] As an important functional component in the robot system, the manipulator can replace human hands to perform a variety of work tasks, reducing labor costs while improving work efficiency. It plays an important role in the manufacturing, service, transportation and medical fields.

[0003] Traditional rigid manipulators have high rigidity and stability and are widely used. However, when faced with unstructured environments such as human-machine interaction, rigid manipulators have weak environmental adaptability and low compliance. Flexible manipulators are developing rapidly due to their good flexibility and high safety. However, they still have problems with weak output force and load capacity, which limits the scope of application of flexible manipulators. In order to solve the above problems, a rigid-flexible coupling manipulator is proposed, which combines the characteristics of rigid and flexible materials and has both load capacity, compliance and flexibility. It is an important development direction of manipulators.

[0004] Existing rigid-flexible coupling manipulators, because the flexible material is less rigid than the rigid material, will cause damage to the interface of the rigid-flexible coupling structure when the flexible structure becomes larger, making it difficult to have both flexibility and large-load grasping capabilities. Summary of the invention

[0005] The present invention aims to at least improve one of the technical problems existing in the prior art. To this end, the present invention proposes an underactuated rigid-flexible coupling manipulator.

[0006] According to an underactuated rigid-flexible coupling manipulator according to an embodiment of the first aspect of the present invention, the underactuated rigid-flexible coupling manipulator comprises:

[0007] At least two underactuated rigid fingers, at least two of the underactuated rigid fingers having a gripping space therebetween, wherein each of the underactuated rigid fingers comprises a plurality of movable knuckles connected in series, each of the knuckles having a porous mounting portion facing the gripping space;

[0008] Multiple flexible contact parts are arranged one by one corresponding to the multiple finger joints, each of the flexible contact parts has multiple flexible microstructures, and each flexible contact part is embedded in the porous mounting part of each finger joint through the flexible microstructure so that the flexible contact part is flexibly connected to the finger joint, so as to realize rigid-flexible coupling between the two and improve the toughness of the connection interface.

[0009] In a possible implementation of the technical solution, a plurality of the flexible microstructures are distributed in an array, and each of the flexible microstructures includes:

[0010] A first connecting portion, wherein the first connecting portion is an inverted boss;

[0011] The second connection portion is fixedly connected to the inverted boss and can improve the toughness of the rigid-flexible coupling connection through elastic stress dissipation.

[0012] In a possible implementation of the technical solution, it also includes:

[0013] Each flexible contact portion has a cavity therein, and the flexible contact portion has a gripping surface facing away from the porous mounting portion;

[0014] A plurality of airbags are correspondingly arranged in the cavity, wherein the airbags in the same finger joint are interconnected, and when inflated, the airbags expand toward the gripping surface, and the contact force between the gripping surface and the object to be gripped is adjusted by regulating the expansion behavior of the airbags.

[0015] In a possible implementation of the present technical solution, the gripping surface is serrated, which is used to increase the roughness of the gripping surface, increase the contact friction, and ensure the safety of the object to be grasped.

[0016] In a possible implementation of the present technical solution, in each finger joint, the porous mounting portion, the flexible microstructure and the airbag are cast and solidified as a whole to obtain an integrated connection structure for realizing rigid-flexible coupling.

[0017] In a possible implementation of the present technical solution, the flexible contact portion is provided with an air path connected to the airbag to ensure that the internal air pressure of each knuckle airbag is consistent, thereby achieving synchronous driving of each knuckle airbag and increasing the load capacity and controllability of the rigid-flexible coupling manipulator.

[0018] In a possible implementation of the present technical solution, the gripping surface has a plurality of protrusions that are away from the flexible microstructure, so as to increase the roughness of the gripping surface, increase the contact friction, and ensure the safety of the object to be grasped.

[0019] In a possible implementation of the technical solution, the plurality of movable knuckles connected in series specifically include:

[0020] A fingertip triangle, the fingertip triangle having a fingertip tip, a first fingertip connecting portion and a second fingertip connecting portion, wherein a first multi-hole mounting portion is fixedly mounted on a side adjacent to the fingertip tip close to the second fingertip connecting portion;

[0021] a first knuckle connecting plate, the first knuckle connecting plate being movably connected to the second connecting portion of the fingertip, and a second multi-hole mounting portion being fixedly mounted on the side of the first knuckle connecting plate facing the grasping space;

[0022] A second finger joint connecting plate, a third multi-hole mounting portion being fixedly mounted on the second finger joint connecting plate side facing the gripping space;

[0023] The driving rod, the fingertip triangle plate, the first finger joint connecting plate, the second finger joint connecting plate and the driving rod are connected in series through a connecting component.

[0024] The connection component comprises:

[0025] A first connecting rod, movably connected to the first connecting portion of the fingertip;

[0026] A triangular plate, the triangular plate having a third knuckle connection portion, a fourth knuckle connection portion and a fifth knuckle connection portion, the third knuckle connection portion being movably connected to the first knuckle connection plate away from the end of the triangular plate at the fingertip, and the fourth knuckle connection portion being movably connected to the first connecting rod away from the end of the triangular plate at the fingertip;

[0027] a second connecting rod, movably connected to the fifth connecting portion of the finger joint;

[0028] The underactuated rigid fingers of this structure can achieve balanced contact forces at each knuckle, thereby further maximizing the total gripping force of the manipulator.

[0029] In a possible implementation of the technical solution, the underactuated rigid-flexible coupling manipulator further includes:

[0030] A base, movably connected to the driving rod;

[0031] A transmission rod, movably connected to the driving rod away from the base;

[0032] a support frame fixedly connected to a surface of the base away from the finger joint;

[0033] A screw mechanism, the screw mechanism includes a screw motor, a screw and a movable disk, the movable disk is screwed on the screw, a transmission rod is movably connected to the side of the movable disk, the screw is connected to the output shaft of the screw motor, the screw end away from the screw motor is movably connected to the base through a bearing, and the screw can be driven by the screw motor to drive the movable disk to move up and down, thereby controlling the movement of the transmission rod to realize the grasping operation of the manipulator;

[0034] A flange is fixedly connected to the support frame, and a lead screw motor is fixedly mounted on the flange.

[0035] In a possible implementation of the present technical solution, the base includes three mounting holes evenly distributed around the circumference, the driving rod of the under-actuated rigid finger is installed on the mounting hole, and the grasping surfaces of the under-actuated rigid fingers are all facing the center of the evenly distributed circumference of the mounting hole, so that the under-actuated rigid-flexible coupling manipulator is suitable for grasping spherical objects, such as eggs, balls, apples, etc.

[0036] According to the underactuated rigid-flexible coupling manipulator of the embodiment of the present invention, the grasping operation of multiple fingers can be realized only by a single driving source, thus avoiding the problem of complex structure. By setting the adjustable flexible structure on the underactuated rigid finger, the flexibility in the grasping process is improved by adjusting the flexible structure during the grasping process, making it suitable for grasping relatively fragile or soft objects, thereby improving the adaptability of the rigid-flexible coupling manipulator. The flexible microstructure is embedded in the porous mounting part of the finger joint to ensure the toughness of the rigid-flexible coupling connection between the finger joint and the flexible contact part, and the compliance of the manipulator is improved by the flexible contact part. With the cooperative drive of the underactuated structure and the pneumatic structure, the manipulator has load capacity, controllability and flexibility.

[0037] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 is a schematic structural diagram of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of the structure of an underactuated rigid finger of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0041] Figure 3 is a schematic diagram of a knuckle explosion of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0042] Figure 4 is a cross-sectional view of a finger joint connection of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0043] Figure 5 is a cross-sectional view of a flexible contact portion including an airbag of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0044] Figure 6 is a schematic diagram of a flexible contact portion including a serrated gripping surface of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0045] Figure 7 is a simulation diagram of the grasping force of each knuckle of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0046] Figure 8is a diagram of interface stress simulation results of tensile deformation of a flexible microstructure of an underactuated rigid-flexible coupling manipulator according to an embodiment of the present invention;

[0047] Fig. 9 is a contact force simulation diagram of an underactuated rigid-flexible coupling manipulator contacting a rigid material according to an embodiment of the present invention;

[0048] Fig.10 4 is a contact force simulation diagram of an underactuated rigid-flexible coupling manipulator contacting a flexible material according to an embodiment of the present invention.

[0049] Reference numerals:

[0050] Underactuated rigid finger 1, fingertip triangle plate 11, fingertip tip 110, fingertip first connection portion 111, fingertip second connection portion 112, first porous mounting portion 113, first knuckle connecting plate 12, second porous mounting portion 120, first connecting rod 13, triangle plate 14, knuckle third connection portion 140, knuckle fourth connection portion 141, knuckle fifth connection portion 142, second knuckle connecting plate 15, third porous mounting portion 150, second connecting rod 16, driving rod 17;

[0051] Flexible contact part 2, flexible microstructure 21, first connecting part 210, second connecting part 220, cavity 22, airbag 23;

[0052] Base 3;

[0053] Transmission rod 4;

[0054] Support frame 5;

[0055] Screw mechanism 6, screw motor 61, screw 62, movable plate 63;

[0056] Flange 7. DETAILED DESCRIPTION

[0057] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0058] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0060] The terms "first", "second", "third", etc. in the specification and claims of the present application and the drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a series of steps or units are included, or optionally, steps or units not listed are included, or optionally, other steps or units inherent to these processes, methods, products or devices are included.

[0061] Only the part relevant to the present application is shown in the accompanying drawings, but not all of the content. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processing or methods depicted as flow charts. Although the flow chart describes each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of each operation can be rearranged. When its operation is completed, the process can be terminated, but it can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0062] The terms "component", "module", "system", "unit", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a unit can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or distributed between two or more computers. In addition, these units can be executed from various computer-readable media having various data structures stored thereon. Units can communicate through local and / or remote processes, for example, based on signals having one or more data packets (e.g., data from a second unit interacting with another unit in a local system, a distributed system, and / or a network. For example, the Internet interacts with other systems via signals).

[0063] Example 1

[0064] This embodiment provides an underactuated rigid-flexible coupling manipulator, such as Figures 1 to 4 As shown, including:

[0065] At least two underactuated rigid fingers 1, with a gripping space between at least two of the underactuated rigid fingers 1, wherein each of the underactuated rigid fingers 1 comprises a plurality of movable knuckles connected in series, and each of the knuckles has a porous mounting portion facing the gripping space;

[0066] Multiple flexible contact parts 2 are arranged one by one corresponding to the multiple finger joints, each of the flexible contact parts 2 has multiple flexible microstructures 21 and a gripping surface facing away from the flexible microstructures 21, and each flexible contact part 2 is embedded in the porous mounting part of each finger joint through the flexible microstructure 21, so that the flexible contact part 2 is flexibly connected to the finger joints, so as to realize rigid-flexible coupling between the two and improve the toughness of the connection interface.

[0067] It should be noted that the plurality of flexible microstructures 21 are distributed in an array, and each of the flexible microstructures 21 includes:

[0068] A first connecting portion 210, wherein the first connecting portion 210 is an inverted boss;

[0069] The second connecting portion 220 is fixedly connected to the inverted boss.

[0070] It should be noted that the inverted boss is an inverted frustum or an inverted trapezoidal table, which can improve the toughness of the rigid-flexible coupling connection through elastic stress dissipation.

[0071] In this embodiment, the inverted boss is an inverted frustum, the second connecting part 220 is a cylindrical rod, the outer diameter of the second connecting part 220 is smaller than the outer diameter of the first connecting part 210, and the second connecting part 220 is completely embedded in the porous mounting parts corresponding to each finger joint, thereby realizing the rigid-flexible coupling of the under-actuated manipulator.

[0072] Furthermore, the toughness of the rigid-flexible coupling connection can be controlled by adjusting the geometric parameters of the first connecting portion 210 and the second connecting portion 220 in the flexible microstructure 21, wherein the geometric parameters include radius, height, shape and arrangement thereof.

[0073] It should be noted that the flexible microstructure 21 and the flexible contact part 2 are made of the same flexible material and after molding, form an integral structure with the flexible contact part 2. Based on the flexible microstructure 21, the toughness of the rigid-flexible coupling connection interface can be improved by elastic stress dissipation.

[0074] It should be noted that the flexible contact portion 2 is made of a stretchable flexible material, and the grasping performance of the manipulator is regulated by changing its material properties, shape and size as well as an external drive.

[0075] Furthermore, the material properties of the flexible contact part 2 are changed, and different flexible materials are selected for manufacturing, so as to change the rigidity of the flexible contact part 2 and adjust the compliance of the flexible contact part 2.

[0076] It should be noted that the underactuated rigid finger 1 is an underactuated multi-link structure, which is connected by connecting rods, triangular plates and connecting plates, and can achieve adaptive envelope grasping through the coordinated actions between them. It includes:

[0077] A fingertip triangle plate 11, wherein the fingertip triangle plate 11 comprises a fingertip tip 110, a fingertip first connecting portion 111 and a fingertip second connecting portion 112, wherein a first multi-hole mounting portion 113 is fixedly mounted on a side adjacent to the fingertip tip 110 close to the fingertip second connecting portion 112;

[0078] A first knuckle connecting plate 12, wherein the first knuckle connecting plate 12 is movably connected to the fingertip second connecting portion 112, and a second multi-hole mounting portion 120 is fixedly mounted on the side of the first knuckle connecting plate 12 facing the grasping space;

[0079] A first connecting rod 13, movably connected to the fingertip first connecting portion 111;

[0080] The triangular plate 14 comprises a third knuckle connection portion 140, a fourth knuckle connection portion 141 and a fifth knuckle connection portion 142, wherein the third knuckle connection portion 140 is movably connected to the first knuckle connection plate 12 away from the end of the fingertip triangular plate 11, and the fourth knuckle connection portion 141 is movably connected to the first connecting rod 13 away from the end of the fingertip triangular plate 11;

[0081] A second finger joint connecting plate 15, wherein the second finger joint connecting plate 15 is movably connected to the third finger joint connecting portion 140, and a third multi-hole mounting portion 150 is fixedly mounted on the side of the second finger joint connecting plate 15 facing the gripping space;

[0082] A second connecting rod 16, movably connected to the fifth connecting portion 142 of the finger joint;

[0083] The driving rod 17 is respectively connected to the second finger joint connecting plate 15 and the second connecting rod 16 away from the end of the triangle plate 14; the under-actuated rigid finger 1 through this structure can achieve balanced contact force of each finger joint, thereby further realizing the maximum total gripping force of the manipulator.

[0084] It should be noted that the respective porous shapes of the first porous mounting part 113, the second porous mounting part 120 and the third porous mounting part 150 are consistent with the corresponding flexible microstructure 21. The flexible microstructure 21 is embedded in each porous part to improve the flexibility of the gripping surface of the flexible contact part 2 and improve the toughness and strength of the rigid-flexible structure coupling interface.

[0085] It should be noted that, in the present embodiment, the under-actuated rigid finger 1 is a three-joint structure, namely, a proximal joint, a middle joint and a distal joint, but is not limited to a three-joint structure, and may also be a two-joint structure, a four-joint structure, a five-joint structure or even more joint structures, wherein the correspondence between the joints is as follows: the proximal joint corresponds to the second joint connecting plate 15, the middle joint corresponds to the first joint connecting plate 12, and the distal joint corresponds to the fingertip triangle plate 11.

[0086] Furthermore, the under-actuated rigid finger 1 adopts a human-like length configuration of each section, that is, the length pattern of each knuckle is: the length of the second knuckle connecting plate 15 > the length of the first knuckle connecting plate 12 > the length of the fingertip triangle plate 11, which can ensure that the under-actuated rigid finger 1 has greater driving force and stability.

[0087] This embodiment provides a three-joint underactuated rigid-flexible coupling manipulator with specific structural dimensions:

[0088] The length of the second finger joint connecting plate 15 is 45 mm;

[0089] The length of the first finger joint connecting plate 12 is 30 mm;

[0090] The length of the fingertip triangle 11 is 24 mm.

[0091] In order to ensure the consistent gripping force of each knuckle, the specific geometric dimensions of each component in the underactuated rigid finger 1 are:

[0092] The fingertip triangle plate 11 is a right-angle triangle plate, and the two right-angle sides are 13mm and 24mm respectively;

[0093] The length of the first connecting rod 13 is 35 mm.

[0094] The lengths of the two sides of the triangle plate 14 are 32 mm and 20 mm respectively, and the angle between the two sides is 30 degrees;

[0095] The length of the second connecting rod 16 is 38 mm;

[0096] The length of the driving rod 17 is 30 mm.

[0097] It should be noted that all rigid components of the under-actuated rigid-flexible coupling manipulator can be made by 3D printing with photosensitive resin.

[0098] Furthermore, the three-joint under-actuated rigid finger 1 has a driving source and three degrees of freedom, and can provide constraints by installing springs between each connecting rod and the triangular plate to maintain the posture of the mechanical finger.

[0099] In this embodiment, the dimensions of the flexible microstructure include:

[0100] The outer diameter of the first connecting portion 210 is 4 mm;

[0101] The outer diameter of the second connection portion 220 is 2 mm.

[0102] Furthermore, the 3D printed first knuckle connecting plate 12 and the second knuckle connecting plate 15 can be used as a mold for the flexible microstructure 21, and a ring-shaped mold with the same size as the first knuckle connecting plate 12 and the second knuckle connecting plate 15 can be used to cover the outer circle of the connecting plate, and the A and B components of the liquid Ecoflex 00-30 silicone (platinum silicone) are mixed in a 1:1 ratio and poured into the first knuckle connecting plate 12 and the second knuckle connecting plate 15. After curing, the flexible contact part 2 with the embedded flexible microstructure 21 can be obtained, and rigid-flexible coupling can be achieved.

[0103] Furthermore, the control of multiple finger joints is achieved through the under-actuated structure, the adaptability of the grip is improved through the flexible contact part 2, and the elastic stress dissipation of the flexible microstructure 21 ensures the toughness of the rigid-flexible connection.

[0104] Furthermore, the underactuated rigid-flexible coupling manipulator with the above structure was simulated and tested. Figure 7 As shown in the figure, the gripping forces of the distal phalanx, proximal phalanx, and middle phalanx during the enveloping grasping are 10N, 13N, and 14N, respectively. The flexible microstructure 21 with a second connecting portion 220 having a diameter of 10mm is stretched. According to the deformation and restoration process test of the flexible microstructure, through the elastic stress dissipation and the restoration process after unloading, its strain energy is 0.17J. By increasing the diameter of the second connecting portion 220, as Figure 8 As shown, the maximum strain energy of the flexible microstructure 21 is 0.76 J, so it has good rigidity and flexibility.

[0105] Example 2

[0106] This embodiment makes further improvements on the basis of the embodiment 1, and provides an underactuated rigid-flexible coupling manipulator, which includes:

[0107] At least two underactuated rigid fingers 1, with a gripping space between at least two of the underactuated rigid fingers 1, wherein each of the underactuated rigid fingers 1 comprises three movable knuckles connected in series, and each of the knuckles has a porous mounting portion facing the gripping space;

[0108] A plurality of flexible contact parts 2 are arranged one by one corresponding to the plurality of finger joints, each of the flexible contact parts 2 has a plurality of flexible microstructures 21 and a gripping surface away from the flexible microstructures 21, and each flexible contact part 2 is embedded in the porous mounting part of each finger joint through the flexible microstructure 21, so that the flexible contact part 2 is flexibly connected to the finger joint, so as to realize rigid-flexible coupling between the two and improve the toughness of the connection interface; and further comprising:

[0109] Each flexible contact portion 2 is provided with a cavity 22;

[0110] A plurality of airbags 23 are correspondingly arranged in the cavity 22, wherein the airbags 23 of the same knuckle are interconnected, and when inflated, the airbags 23 expand toward the gripping surface, and the contact force between the gripping surface and the object to be gripped is adjusted by regulating the expansion behavior of the airbags 23, such as Figure 5 shown.

[0111] It should be noted that the airbag 23 is made of the flexible material Ecoflex 00-30 silicone. First, the corresponding mold is prepared by 3D printing, and then the A and B components of the liquid Ecoflex 00-30 silicone are mixed in a 1:1 ratio and poured into the corresponding mold. The airbag 23 can be obtained after curing and demolding.

[0112] Furthermore, the airbag 23 has a cavity and air holes inside, and can expand toward the gripping surface after air pressure is applied.

[0113] Furthermore, since the airbag 23 and the flexible microstructure 21 are made of the same material, the airbag 23 can be made first, and then the embedded flexible microstructure 21 can be cast after the airbag 23 is solidified. When the liquid silicone is not solidified, the surface of the airbag 23 with the cavity is bonded to the liquid Ecoflex 00-30 silicone. After it is solidified, an integrated structure of porous mounting part-flexible microstructure-airbag is obtained, and rigid-flexible coupling is achieved.

[0114] Furthermore, each rigid-flexible coupling finger structure includes three airbags 23, which are interconnected. The internal air pressure of the airbags 23 of each knuckle is consistent, so that the airbag structures of each knuckle can be driven synchronously.

[0115] It should be noted that the flexible contact portion 2 is provided with a pipeline connected to the airbag 23 to ensure that the internal air pressure of each knuckle airbag 23 is consistent, to achieve synchronous driving of each knuckle airbag 23, and to increase the load capacity and controllability of the rigid-flexible coupling manipulator.

[0116] Furthermore, the connecting pipeline is integrated on the air hole of the airbag 23 through a bonding process. During the bonding process, mixed liquid Ecoflex 00-30 silicone is applied to the outside of the connecting air pipe and the inside of the reserved air hole respectively, and the bonding process is completed after natural curing.

[0117] The shape or size of the flexible contact portion 2 is changed, and the gripping surface of the flexible contact portion 2 is made into a multi-convex structure, so as to change the stiffness of the contact surface, increase the roughness of the contact surface, and improve the gripping stability.

[0118] Furthermore, by changing the flexible contact part 2 from a solid body to an internal cavity structure, and applying an external drive including but not limited to gas drive or fluid drive, the gripping force and compliance of the flexible contact part 2 during contact can be regulated.

[0119] like Fig. 9 As shown, by regulating the expansion behavior of the airbag 23, the maximum contact force with the rigid object is close to 0.135N, and the maximum contact force with the flexible object is close to 0.046N, as shown in FIG. Fig.10 As shown, as the contact force increases, the contact area also increases, avoiding stress concentration and showing good interaction safety.

[0120] Example 3

[0121] This embodiment makes further improvements on the basis of the embodiment 1, and provides an underactuated rigid-flexible coupling manipulator, which includes:

[0122] An underactuated rigid finger 1, the underactuated rigid finger 1 comprising a plurality of movable knuckles, the knuckles having a porous mounting portion facing a gripping space;

[0123] A plurality of flexible contact parts 2, each of which has a flexible microstructure 21 and a gripping surface facing away from the flexible microstructure 21, and each flexible contact part 2 is embedded in the porous mounting part of each finger joint through the flexible microstructure 21, so as to achieve rigid-flexible coupling between the two and improve the toughness of the connection interface;

[0124] The gripping surface is serrated to increase the roughness of the gripping surface, increase the contact friction, and ensure the safety of the object to be gripped. Figure 6 shown.

[0125] It should be noted that the flexible contact portion 2 is made of the flexible material Ecoflex 00-30 silicone. First, the corresponding mold is prepared by 3D printing, and then the A and B components of the liquid Ecoflex 00-30 silicone are mixed in a 1:1 ratio and poured into the corresponding mold. After curing and demolding, a flexible contact portion 2 with a serrated gripping surface can be obtained.

[0126] Furthermore, since the serrated gripping surface and the flexible microstructure 21 are made of the same material, the serrated gripping surface can be made first, and after it is solidified and formed, the embedded flexible microstructure 21 can be cast. When the silicone is not solidified, the connecting surface of the flexible contact part 2 is bonded to the liquid Ecoflex 00-30 silicone. After it is solidified, the flexible contact part 2 with the embedded flexible microstructure 21 is obtained, and rigid-flexible coupling is achieved.

[0127] Furthermore, the control of multiple finger joints is achieved through the under-actuated structure, the roughness of the contact surface during grasping is increased through the serrated gripping surface, the stability of the grip is improved, and the elastic stress dissipation of the microstructure ensures the toughness of the rigid-flexible connection.

[0128] Example 4

[0129] In this embodiment, based on the first embodiment, the underactuated rigid-flexible coupling manipulator further includes:

[0130] A base 3, movably connected to the driving rod 17;

[0131] The transmission rod 4 is movably connected to the driving rod 17 away from the base 3;

[0132] A support frame 5 is fixedly connected to a surface of the base 3 away from the finger joint;

[0133] The screw mechanism 6 includes a screw motor 61, a screw rod 62 and a movable disk 63. The movable disk 63 is screwed on the screw rod 62. The movable disk 63 is movably connected to the transmission rod 4 on the side. The screw rod 62 is connected to the output shaft of the screw motor 61. The end of the screw rod 62 away from the screw motor 61 is movably connected to the base 3 through a bearing. The screw motor 61 can drive the screw rod 62 to drive the movable disk 63 to move up and down, thereby controlling the movement of the transmission rod 4 to realize the envelope grabbing operation of the manipulator;

[0134] The flange 7 is fixedly connected to the support frame 5, and a lead screw motor 61 is fixedly installed on the flange 7 for connecting the under-actuated rigid-flexible coupling manipulator to a robot arm and a mobile platform, such as a motion platform or a robot arm, so as to increase the working space of the manipulator.

[0135] It should be noted that the base 3 includes three mounting holes evenly distributed around the circumference, the driving rod 17 of the under-actuated rigid finger 1 is installed on the mounting hole, and the grasping surfaces of the under-actuated rigid fingers 1 are all facing the center of the mounting hole evenly distributed around the circumference, so that the under-actuated rigid-flexible coupling manipulator is suitable for grasping spherical objects, such as eggs, balls, apples, etc.

[0136] It should be noted that holes are provided on the flange 7 and the base 3 to fix the pipelines of the airbag 23 to prevent the pipelines from getting entangled during the movement of the manipulator.

[0137] It should be noted that when the under-actuated rigid-flexible coupling manipulator is working, the gripping force and compliance of the under-actuated rigid-flexible coupling manipulator can be regulated by respectively controlling the driving ratio of the screw mechanism 6 and the pneumatic drive device.

[0138] Furthermore, the rigid-flexible coupling manipulator adopts a control strategy of a screw mechanism 6 and pneumatic cooperative drive. When grasping heavy objects such as a kettle, stable grasping can be achieved through the drive of the screw mechanism 6. When grasping fragile or soft objects, the manipulator can achieve an enveloping action through the screw mechanism 6, and then the airbag 23 is inflated by pneumatic drive to control the grasping force and improve the safety of grasping objects.

[0139] The process of the under-actuated rigid hand's enveloping grasping of the sphere is as follows: the screw motor 61 drives the movable disk 63 to move downward, and then the transmission rod 4 moves downward. When there is no contact, the three knuckles remain relatively still, and the transmission rod 4 pushes the under-actuated rigid finger 1 to rotate as a whole around the base connecting hole; after the proximal knuckle first contacts, the second knuckle connecting plate 15 stops rotating, and the driving rod 17 starts to rotate under the action of the transmission rod 4, and pushes the triangle plate 14 to rotate through the second connecting rod 16, but the middle knuckle and the distal knuckle remain relatively still, and the whole rotates with the triangle plate 14; after the middle knuckle contacts, the first knuckle connecting plate 12 stops rotating, and the triangle plate 14 still keeps rotating, and pushes the fingertip triangle plate 11 to rotate through the first connecting rod 13 until the fingertip triangle plate 11 contacts, thereby achieving enveloping grasping.

[0140] According to the underactuated rigid-flexible coupling manipulator of the embodiment of the present invention, the grasping operation of multiple fingers can be realized only by a single driving source, thus avoiding the problem of complex structure. By setting the adjustable flexible structure on the underactuated rigid finger, the flexibility in the grasping process is improved by adjusting the flexible structure during the grasping process, making it suitable for grasping relatively fragile or soft objects, thereby improving the adaptability of the rigid-flexible coupling manipulator. The flexible microstructure is embedded in the porous mounting part of the finger joint to ensure the toughness of the rigid-flexible coupling connection between the finger joint and the flexible contact part, and the compliance of the manipulator is improved by the flexible contact part. With the cooperative drive of the underactuated structure and the pneumatic structure, the manipulator has load capacity, controllability and flexibility.

[0141] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the invention.

[0142] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0143] Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Mentioning "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present embodiment application. The appearance of this phrase in various positions in the specification is not necessarily the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0144] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An underactuated rigid-flexible coupling manipulator, characterized in that: include: At least two underactuated rigid fingers (1), with a gripping space between at least two of the underactuated rigid fingers (1), wherein each of the underactuated rigid fingers (1) comprises a plurality of movable finger joints connected in series, and each of the finger joints has a porous mounting portion facing the gripping space; A plurality of flexible contact portions (2) are arranged one-to-one corresponding to the plurality of finger joints, each of the flexible contact portions (2) has a plurality of flexible microstructures (21), the flexible microstructures (21) are embedded in the porous mounting portion, so that the flexible contact portion (2) is flexibly connected to the finger joint, and in each of the finger joints, the porous mounting portion, the flexible microstructures (21) and the airbag (23) are integrally cast and solidified, wherein the plurality of flexible microstructures (21) are distributed in an array, and each of the flexible microstructures (21) comprises: A first connecting portion (210), wherein the first connecting portion (210) is an inverted boss; A second connection portion (220) is fixedly connected to the inverted boss, and the toughness of the rigid-flexible coupling connection can be regulated by adjusting geometric parameters of the first connection portion (210) and the second connection portion (220) in the flexible microstructure (21); A cavity (22) is provided in each flexible contact portion (2), and the flexible contact portion (2) has a gripping surface facing away from the porous mounting portion; A plurality of airbags (23) are correspondingly arranged in the cavity (22), wherein the airbags (23) of the same finger joint are interconnected.

2. The underactuated rigid-flexible coupling manipulator according to claim 1, characterized in that: The gripping surface is serrated.

3. The underactuated rigid-flexible coupling manipulator according to claim 1, characterized in that: The gripping surface has a plurality of protrusions facing away from the flexible microstructure (21).

4. The underactuated rigid-flexible coupling manipulator according to claim 1, characterized in that: The plurality of movable knuckles connected in series specifically include: A fingertip triangle plate (11), the fingertip triangle plate (11) comprising a fingertip tip (110), a first fingertip connecting portion (111) and a second fingertip connecting portion (112), a first multi-hole mounting portion (113) being fixedly mounted on the adjacent side of the fingertip tip (110) close to the second fingertip connecting portion (112); A first finger joint connecting plate (12), the first finger joint connecting plate (12) being movably connected to the fingertip second connecting portion (112), and a second multi-hole mounting portion (120) being fixedly mounted on the side of the first finger joint connecting plate (12) facing the grasping space; A second finger joint connecting plate (15), a third multi-hole mounting portion (150) being fixedly mounted on the side of the second finger joint connecting plate (15) facing the gripping space; A driving rod (17), wherein the fingertip triangle plate (11), the first finger joint connecting plate (12), the second finger joint connecting plate (15), and the driving rod (17) are connected in series via a connecting assembly.

5. The underactuated rigid-flexible coupling manipulator according to claim 4, characterized in that: The connection component comprises: A first connecting rod (13) movably connected to the fingertip first connecting portion (111); A triangular plate (14), the triangular plate (14) comprising a third knuckle connection portion (140), a fourth knuckle connection portion (141) and a fifth knuckle connection portion (142), the third knuckle connection portion (140) being movably connected to the first knuckle connection plate (12) at an end away from the fingertip triangular plate (11), and the fourth knuckle connection portion (141) being movably connected to the first connecting rod (13) at an end away from the fingertip triangular plate (11); The second connecting rod (16) is movably connected to the fifth connecting portion (142) of the finger joint.

6. The underactuated rigid-flexible coupling manipulator according to claim 5, characterized in that: The underactuated rigid-flexible coupling manipulator further comprises: A base (3) movably connected to the driving rod (17); A transmission rod (4) movably connected to the driving rod (17) away from the base (3); A support frame (5) fixedly connected to a surface of the base (3) away from the finger joint; The screw mechanism (6) is used to drive the transmission rod (4) to move, thereby realizing the grasping operation of the manipulator; The flange (7) is fixedly connected to the support frame (5), and a screw motor (61) is fixedly mounted on the flange (7).

7. The underactuated rigid-flexible coupling manipulator according to claim 6, characterized in that: The base (3) comprises three mounting holes evenly distributed around the circumference, the driving rod (17) of the under-actuated rigid finger (1) is mounted on the mounting hole, and the gripping surfaces of the under-actuated rigid finger (1) all face the center of the evenly distributed mounting hole.

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