Biomimetic robotic gripper

Abstract

A kind of bionic robot gripper, including shell module I, drive module II, flexible gripper module III, flexible gripper module III includes single spherical gripper and spherical gripper group respectively installed in the two sides of the shell module;Single spherical gripper includes a single gripping ball, and spherical gripper group includes at least two flexible gripping balls, and two telescopic parts respectively arranged on two flexible gripping balls and oppositely arranged;The single spherical gripper and spherical gripper group both include fixed part, and movable part for fixing the single gripping ball or flexible gripping ball is hingedly connected with the fixed part;The drive module II includes a four-bar linkage unit and a secondary pull rope unit.The present application realizes the switching of different gripping modes by three-claw structure combined with air bag structure, overcomes the shortcoming that flexible gripper cannot grip large mass target object without changing the gripping force of gripping ball itself, and has the advantages of practicality and flexibility.

Description

Technical Field

[0001] This invention belongs to the field of robot gripper technology, specifically relating to a biomimetic robot gripper. Background Technology

[0002] Currently, due to the continuous development of the robotics industry, a considerable number of jobs in the industrial sector have been replaced by automated robots, greatly improving industrial production efficiency and freeing humans from heavy and complex labor. However, most of the robotic arms used in current industrial production are rigid robotic arms. Using rigid robotic arms for gripping operations places significant demands on the surface stiffness and geometry of the target object, which limits their application in many production fields. In contrast, bionic robotic grippers have a greater advantage when dealing with fragile or irregularly shaped objects such as eggs and small electronic components, and offer higher tolerance for deviations in the target object's position compared to rigid robotic arms.

[0003] In recent years, advancements in soft robotics, materials science, and ductile metals have significantly propelled the development of biomimetic robotic grippers. Currently, biomimetic robotic grippers under research can be broadly categorized into three types based on their working principles: driven gripping, surface-adhesive gripping, and variable-stiffness shaping gripping. Driven gripping utilizes traditional direct actuation methods such as motor drive, wire drive, or pneumatic drive to perform gripping tasks. Surface-adhesive gripping relies on the adhesion between the soft manipulator and the target object's surface to achieve gripping. Variable-stiffness shaping gripping is a passive gripping method that enhances gripping or release performance by increasing or decreasing the stiffness of the support or gripping structure during operation.

[0004] Traditional pneumatically driven gripping bionic robotic grippers, such as the pneumatic soft gripper proposed in Chinese patent CN104959992A, directly inflate or depress the air bladder of the gripping device via an external air source, thereby achieving the purpose of gripping the target object by bending or deforming the soft pneumatic gripper inward or outward. Similar examples include Chinese patents CN109048980A and CN106003131A. These soft grippers all employ direct pneumatic operation. The driving mechanism of these soft robotic hands is relatively simple, easy to control, and does not have strict requirements on the geometry of the target object.

[0005] However, due to the inherent stiffness limitations of flexible materials, these flexible mechanical grippers cannot grip heavy objects. Summary of the Invention

[0006] To address the aforementioned problems, the purpose of this invention is to provide a biomimetic robot gripper that achieves switching between different gripping modes through a three-claw structure combined with an airbag structure. Without changing the gripping force of the gripping ball itself, it overcomes the shortcomings of flexible grippers that cannot grasp large-mass target objects, effectively improving the gripping ability of complex-shaped target objects. It has the advantages of practicality and high flexibility, and also has economic benefits and broad industrial application prospects.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: A biomimetic robot gripper includes a housing module I, a drive module II, and a flexible gripper module III. The flexible gripper module III includes a single spherical gripper and a spherical gripping group respectively mounted on both sides of the housing module. The single spherical gripper includes a single gripping ball, and the spherical gripping group includes at least two flexible gripping balls and two telescopic portions respectively disposed on the two flexible gripping balls and arranged opposite to each other. The maximum distance between the two telescopic portions is greater than the diameter of the single gripping ball, and the minimum distance between the two telescopic portions is less than the diameter of the single gripping ball. Both the single spherical gripper and the spherical gripping group include a fixed portion and a movable portion hinged to the fixed portion for fixing the single gripping ball or the flexible gripping ball. The drive module II includes a primary four-bar linkage unit for connecting with the fixed part to drive the single spherical clamp and the spherical clamp group to move closer to or further away from each other, and a secondary pull rope unit for connecting with the movable part to drive the movable part of the single spherical clamp and the two movable parts of the spherical clamp group to interlock to form a staggered structure.

[0008] As a further preferred embodiment of the present invention, the telescopic part includes a closed membrane fixedly installed on the flexible clamping ball, an opening provided on the closed membrane, an air pipe connected to the opening, and a pump body provided on the movable part and connected to the air pipe for supplying or evacuating air into the closed membrane.

[0009] As a further preferred embodiment of the present invention, the first-stage four-bar linkage unit includes a first base disposed on the housing module I, a fixed clamping block disposed on the first base, a movable hole disposed on the first base, a connecting wrist passing through the movable hole and slidably connected to the first base, and a mounting seat for mounting the fixed part; one end of the mounting seat is hinged to the end of the fixed clamping block via a first connecting rod, and the other end is hinged to the end of the connecting wrist via a second connecting rod; a cylinder acting on the connecting wrist is disposed on the housing module I.

[0010] As a further preferred embodiment of the present invention, the secondary pull rope unit includes a second base disposed on the housing module I, a fixed pulley disposed on the second base, a winding wheel disposed on the base, a pull rope having one end connected to the movable part and the other end passing through the fixed pulley and fixed on the winding wheel, and a drive motor disposed on the second base for driving the winding wheel to rotate, wherein all the winding wheels maintain synchronous tightening / slack states of the pull rope.

[0011] As a further preferred embodiment of the present invention, the first-stage four-bar linkage unit further includes a fixed plate connected to the end of the cylinder, and a column disposed on the fixed plate and driving the linkage wrist to move by lifting the end of the linkage wrist.

[0012] As a further preferred embodiment of the present invention, the drive module II further includes a switching unit for enabling the first-stage four-bar linkage unit to drive the spherical clamping group closer to / away from the single spherical clamping member independently; The switching unit includes a stepper motor mounted on the housing module I, a rotating plate connected to the output end of the stepper motor and located between the fixed plate and the first base, two first through holes symmetrically arranged on the rotating plate, and two second through holes symmetrically arranged on both sides of the first through holes; all the second through holes are connected in sequence to form a square and the single rotation angle of the stepper motor is 90 degrees, and the size of the first through holes and the second through holes is larger than the diameter of the column.

[0013] As a further preferred embodiment of the present invention, the column is made of a compression-rebound material or the end of the column is provided with a protrusion made of a compression-rebound material, wherein the maximum compression distance of the compression-rebound material is greater than the maximum vertical movement distance of the connecting wrist.

[0014] As a further preferred embodiment of the present invention, the secondary rope pulling unit further includes a drive gear connected to the output end of a single drive motor, two driven gears meshing with both sides of the drive gear, and a rotating rod disposed on the second base and rotating coaxially with the driven gears. The rotating rod is used to fix and install the winding wheel acting on the movable part of the spherical clamping assembly.

[0015] As a further preferred embodiment of the present invention, the first base is provided with a wire hole for the pull rope to pass through.

[0016] As a further preferred embodiment of the present invention, the housing module I includes a control board that is electrically connected to the cylinder, stepper motor, drive motor and pump body respectively to control the individual opening or closing of the above components.

[0017] In summary, the present invention has the following beneficial effects: This invention achieves switching between different gripping modes by combining a three-claw structure with an airbag structure. Without changing the gripping force of the gripping ball itself, it overcomes the shortcomings of flexible grippers that cannot grip large-mass target objects, effectively improving the gripping ability of complex-shaped target objects, and is highly practical and flexible.

[0018] The structure of this invention is relatively easy to implement, and the switching between different modes is simple and quick, making it economical and with broad prospects for industrial applications. Attached Figure Description

[0019] Appendix Figure 1 This is a schematic diagram of the structure of the present invention from the main viewing angle.

[0020] Appendix Figure 2 This is a schematic diagram of one structure of the telescopic part of the present invention.

[0021] Appendix Figure 3 This is a schematic diagram of the structure of the present invention from a side view.

[0022] Appendix Figure 4 This is a partial structural schematic diagram of the present invention from the main viewing angle.

[0023] Appendix Figure 5 This is a schematic diagram of one structure of the two-stage rope pulling unit of the present invention.

[0024] Appendix Figure 6 This is a schematic diagram of one mode of the switching unit of the present invention.

[0025] Appendix Figure 7 This is a schematic diagram of another mode of the switching unit of the present invention.

[0026] Appendix Figure 8 This is a schematic diagram of the structure of the present invention from a top-down perspective.

[0027] Appendix Figure 9 This is a schematic diagram of one clamping mode of the present invention.

[0028] Appendix Figure 10 This is a schematic diagram of another clamping mode of the present invention.

[0029] Appendix Figure 11 This is a schematic diagram of another clamping mode of the present invention.

[0030] Appendix Figure 12 This is a partial schematic diagram of one clamping mode of the clamping device of the present invention.

[0031] Appendix Figure 13 This is a partial schematic diagram of another clamping mode of the clamping device of the present invention.

[0032] Appendix Figure 14 This is a partial schematic diagram of another clamping mode of the clamping device of the present invention.

[0033] Appendix Figure 15 This is a partial schematic diagram of another clamping mode of the clamping device of the present invention.

[0034] Figure descriptions: Housing module I, drive module II, flexible gripper module III; Control board 11; First-level four-bar linkage unit 21, second-level rope linkage unit 22, switching unit 23; First base 211, fixed clamp 212, movable hole 213, connecting wrist 214, mounting base 215, first connecting rod 216, second connecting rod 217, cylinder 218, fixing plate 219, column 2110, wire hole 2111; Second base 221, fixed pulley 222, winding wheel 223, pull rope 224, drive gear 225, driven gear 226, rotating rod 227, third through hole 228; Stepper motor 231, rotating plate 232, first through hole 233, second through hole 234; Single clamping ball 31, flexible clamping ball 32, telescopic part 33, fixed part 34, movable part 35; 331. Sealing membrane 332. Opening 332. Air tube 333. Pump body 334. Detailed Implementation

[0035] Example 1 As attached Figure 1 As shown, the present invention provides a biomimetic robot gripper, including a housing module I, a drive module II, and a flexible gripper module III. The flexible gripper module III includes a single spherical gripper and a spherical gripper assembly respectively mounted on both sides of the housing module. The single spherical gripper includes a single gripping ball 31, and the spherical gripper assembly includes at least two flexible gripping balls 32 and two telescopic portions 33 respectively disposed on the two flexible gripping balls and disposed opposite to each other. The maximum distance between the two telescopic portions is greater than the diameter of the single gripping ball, and the maximum distance between the two telescopic portions is greater than the diameter of the single gripping ball. The distance is less than the diameter of the single clamping ball; both the single spherical clamping member and the spherical clamping group include a fixed part 34 and a movable part 35 hinged to the fixed part for fixing the single clamping ball or the flexible clamping ball; the drive module II includes a primary four-bar unit 21 connected to the fixed part 34 to drive the single spherical clamping member and the spherical clamping group to move closer / away from each other, and a secondary pull rope unit 22 connected to the movable part 35 to drive the movable part of the single spherical clamping member and the two movable parts of the spherical clamping group to interlock to form a staggered structure.

[0036] The single clamping ball 31 and flexible clamping ball 32 described in this embodiment refer to structures that can bend and deform inward or outward according to the shape of the object being clamped under pressure, thereby achieving the purpose of conforming to and clamping the object. The clamping ball can be made by directly inflating an air bladder, or by filling the inside of an elastic membrane with highly fluid particles. By using a combination of positive and negative pressure and the hardening function under vacuum, objects of different shapes can be grasped and released. The theory of this method is based on relevant papers (University of Chicago, Eric I. et al., Nature, 2005, 23:1075). The specific structure can be referred to the spherical flexible clamping device disclosed in the publicly available technology (a bionic robot clamping device based on particle shaping disclosed in the document with authorization announcement number CN112091996B), so it will not be described in detail here.

[0037] One structure of the telescopic part 33 described in this embodiment is a pneumatic structure, as shown in the attached figure. Figure 2 As shown, the device includes a closed membrane 331 fixedly mounted on the flexible clamping ball 32, an opening 332 provided on the closed membrane 331, an air pipe 333 connected to the opening 332, and a pump body 334 provided on the movable part 35 and connected to the air pipe 333 for supplying or evacuating air into the closed membrane 331. The closed membrane 331 is an elastic membrane, and its bottom end is fixed to two opposite sides of the two flexible clamping balls 32 by adhesive or snap-fit ​​connection. The telescopic part 33 is generally used when the flexible ball is in a fully inflated state. Its functions are twofold: first, to shorten the clamping distance, allowing for the gripping of smaller objects; and second, to provide sufficient clamping force, enabling the gripping of heavier objects.

[0038] As attached Figure 3 and attached Figure 4 As shown, the first-stage four-bar linkage 21 includes a first base 211 disposed on the housing module I, a fixing block 212 disposed on the first base 211, a movable hole 213 disposed on the first base 211, a connecting wrist 214 passing through the movable hole 213 and slidably connected to the first base 211, and a mounting seat 215 for mounting the fixing part 34; one end of the mounting seat 215 is hinged to the end of the fixing block 212 via a first connecting rod 216, and the other end is hinged to the end of the connecting wrist 214 via a second connecting rod 217; a cylinder 218 acting on the connecting wrist 214 is disposed on the housing module I.

[0039] As attached Figure 5As shown, the secondary pull rope unit 22 includes a second base 221 disposed on the housing module I, a fixed pulley 222 disposed on the second base 211, a winding wheel 223 disposed on the base 221, a pull rope 224 with one end connected to the movable part 35 and the other end passing through the fixed pulley 222 and fixed to the winding wheel 223, and a drive motor disposed on the second base 221 for driving the winding wheel 223 to rotate. All the winding wheels 223 maintain synchronized tightening / slack states of the pull rope 224. As a further preferred embodiment, the secondary pull rope unit 22 also includes a drive gear 225 connected to the output end of a single drive motor, two driven gears 226 meshing with both sides of the drive gear 225, and a rotating rod 227 disposed on the second base 221 and coaxially rotating with the driven gears 226. The rotating rod 227 is used to fix and install the winding wheel 223 acting on the movable part 35 of the spherical clamping assembly. In this embodiment, the secondary pull rope unit 22 can employ a pulley structure for the winding wheel 223 acting on the fixing part 34 of the single clamping ball 31; alternatively, a separate drive motor can be connected to the winding wheel 223 to achieve independent driving of the single clamping ball 31. Both the pulley structure and the independent drive motor structure described above are based on existing technologies and will not be elaborated further.

[0040] In this embodiment, the first base 211 is provided with a wire hole 2111 for the pull rope 224 to pass through.

[0041] In this embodiment, as shown in the appendix Figure 8 As shown, the housing module I includes a control board 11 that is electrically connected to the cylinder 218, stepper motor 231, drive motor, and pump body 334 to control the individual opening or closing of the aforementioned components. The control board 11 can achieve individual control of the drive components by using existing technologies such as connecting multiple relay modules to the aforementioned drive components and controlling the relay switches through multiple controllers integrated on the control board 11; alternatively, it can rely on existing technologies such as motor control schemes based on PLC control systems, achieving individual control through programming. Specific control structures and circuits will not be elaborated further.

[0042] This embodiment consists of a three-claw structure combined with an airbag structure, and further refines the function of the drive module to achieve gripping modes adaptable to different shapes, lengths, sizes, and masses, including at least the following: 1. Gripping objects with relatively small mass (below 10kg) and relatively long length (length greater than the distance between the two flexible gripping balls 32) (attached) Figure 9 and attached Figure 12As shown), the object to be clamped is placed between the single clamping ball 31 and the two flexible clamping balls 32. The first-stage four-bar linkage unit 21 drives the fixing part 34 to move closer together until the object is clamped, thus achieving clamping. 2. For objects with relatively small mass (below 10kg) and slightly shorter length (length less than the distance between the two flexible clamping balls 32) (see attached diagram). Figure 13 As shown), first, the telescopic part 33 is fully inflated. Then, the object to be clamped is placed between the single clamping ball 31 and the two flexible clamping balls 32. The extended telescopic part 33 and the single clamping ball 31 clamp the object under the action of the fixing part 34. 3. For objects with a large mass (over 10 kg) and a long length (length greater than the distance between the two flexible clamping balls 32) (see attached diagram). Figure 10 and attached Figure 14 As shown), firstly, the object to be clamped is placed between the single clamping ball 31 and the two flexible clamping balls 32. The first-stage four-bar linkage unit 21 drives the fixing part 34 to move closer together until the object is clamped. Then, the pull rope unit 22 drives the movable part 35 to rotate until the lower end of the object is lifted by the movable part 35 or the clamping ball, and the upper end is pressed by the connecting wrist 214, the mounting base 215, or the fixing part 34. The entire object is clamped at both ends, thus achieving clamping. At this time, since the clamping function of the clamping ball is transformed into a supporting function, it can support objects with greater mass under the same structure. 4. Small mass (below 3kg) and short length (length less than 1 / 5 of the diameter of the single clamping ball) clamping objects (with attached) Figure 15 As shown), the fixed part 34 is driven to a suitable operating position by the first-level four-bar linkage unit 21, and then the clamped object is placed between the two uninflated telescopic parts 33. The two telescopic parts 33 are then inflated by the air pump to clamp the object.

[0043] Compared to existing technologies, this device has at least the following advantages: First, the invention achieves switching between different gripping modes through a three-claw structure combined with an airbag structure. Without altering the gripping force of the gripping ball itself, it overcomes the limitation of flexible grippers in gripping large-mass targets, effectively improving the gripping ability for complex-shaped targets, and demonstrating strong practicality and flexibility. Second, the invention has a relatively simple structure to implement, and the switching between different modes is quick and easy, making it economical and promising for industrial applications.

[0044] Example 2 This embodiment optimizes the structure of Embodiment 1 to overcome interference caused by the simultaneous approach of the single clamping ball 31 when the first-stage four-bar linkage unit 21 drives the flexible clamping ball 32 towards the object being clamped, especially when clamping small target objects (less than 3 kg and less than 1 / 5 of the diameter of a single clamping ball). The specific structure is as follows: As attached Figure 3 and attached Figure 6As shown, the first-stage four-bar linkage 21 also includes a fixed plate 219 connected to the end of the cylinder 218, and a column 2110 disposed on the fixed plate 219 and driving the link wrist 214 to move by lifting the end of the link wrist 214.

[0045] The drive module II further includes a switching unit 23 for enabling the first-level four-bar linkage unit 21 to independently drive the spherical clamping assembly closer to / away from the single spherical clamping member; the switching unit 23 includes a stepper motor 231 disposed on the housing module I, a rotating plate 232 connected to the output end of the stepper motor 231 and located between the fixed plate 219 and the first base 211, two first through holes 233 symmetrically disposed on the rotating plate 232, and two second through holes 234 symmetrically disposed on both sides of the first through holes 233; all the second through holes 234 are connected in sequence to form a square and the single rotation angle of the stepper motor 231 is 90 degrees, and the size of the first through holes 233 and the second through holes 234 is larger than the diameter of the column 2110. The column 2110 is made of a compression-rebound material or the end of the column 2110 is provided with a protrusion made of compression-rebound material, and the maximum compression distance of the compression-rebound material is greater than the maximum vertical movement distance of the connecting wrist 214.

[0046] In this embodiment, the first base 211 is provided with a third through hole 228 for the column 2110 to pass through.

[0047] This embodiment can be implemented in the following scenarios: without moving the position of the device, when dealing with objects that are small in mass (less than 3 kg) and short in length (less than 1 / 5 of the diameter of a single clamping ball), the device can be used to hold objects (with attachments). Figure 11 and attached Figure 15 As shown), the single clamping ball 31 does not work. The first-level four-bar unit 21 coarsely adjusts the fixed part 34 to a suitable operating position, and then the second-level pull rope unit 22 finely adjusts the movable part 35 to the final operating position. At this time, the clamped object is placed between the two uninflated telescopic parts 33. The air pump inflates the two telescopic parts 33 to complete the clamping of the object.

[0048] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A biomimetic robot gripper, comprising a housing module I, a drive module II, and a flexible gripper module III, characterized in that, The flexible clamping module III includes a single spherical clamping member and a spherical clamping group respectively installed on both sides of the housing module; the single spherical clamping member includes a single clamping ball (31), and the spherical clamping group includes at least two flexible clamping balls (32) and two telescopic parts (33) respectively disposed on the two flexible clamping balls and disposed opposite to each other. The maximum distance between the two telescopic parts is greater than the diameter of the single clamping ball, and the minimum distance between the two telescopic parts is less than the diameter of the single clamping ball; both the single spherical clamping member and the spherical clamping group include a fixed part (34) and a movable part (35) hinged to the fixed part and used to fix the single clamping ball or the flexible clamping ball. The drive module II includes a primary four-bar linkage (21) for connecting with the fixed part (34) to drive the single spherical clamp and the spherical clamp group to move closer to or further away from each other, and a secondary pull rope unit (22) for connecting with the movable part (35) to drive the movable part of the single spherical clamp and the two movable parts of the spherical clamp group to interlock to form a staggered structure. The telescopic part (33) includes a closed membrane (331) fixedly installed on the flexible clamping ball (32), an opening (332) provided on the closed membrane (331), an air pipe (333) connected to the opening (332), and a pump body (334) provided on the movable part (35) and connected to the air pipe (333) for supplying or evacuating air into the closed membrane (331). The first-stage four-bar linkage unit (21) includes a first base (211) disposed on the housing module I, a fixing block (212) disposed on the first base (211), a movable hole (213) disposed on the first base (211), a link wrist (214) passing through the movable hole (213) and slidably connected to the first base (211), and a mounting seat (215) for mounting the fixing part (34); one end of the mounting seat (215) is hinged to the end of the fixing block (212) via a first connecting rod (216), and the other end is hinged to the end of the link wrist (214) via a second connecting rod (217); a cylinder (218) acting on the link wrist (214) is disposed on the housing module I. The secondary pull rope unit (22) includes a second base (221) mounted on the housing module I, a fixed pulley (222) mounted on the second base (211), a winding wheel (223) mounted on the base (221), a pull rope (224) with one end connected to the movable part (35) and the other end passing through the fixed pulley (222) and fixed on the winding wheel (223), and a drive motor mounted on the second base (221) for driving the winding wheel (223) to rotate. The first-level four-bar linkage unit (21) also includes a fixed plate (219) connected to the end of the cylinder (218) and a column (2110) disposed on the fixed plate (219) and driving the link wrist (214) to move by pushing up the end of the link wrist (214). The drive module II also includes a switching unit (23) for enabling the first-level four-bar linkage unit (21) to drive the spherical clamping group closer to / away from the single spherical clamping member independently. The switching unit (23) includes a stepper motor (231) mounted on the housing module I, a rotating plate (232) connected to the output end of the stepper motor (231) and located between the fixed plate (219) and the first base (211), two first through holes (233) symmetrically arranged on the rotating plate (232), and two second through holes (234) symmetrically arranged on both sides of the first through holes (233); all the second through holes (234) are connected in sequence to form a square and the single rotation angle of the stepper motor (231) is 90 degrees, and the size of the first through holes (233) and the second through holes (234) is larger than the diameter of the column (2110).

2. The bionic robot gripper according to claim 1, characterized in that, The column (2110) is made of a compression-rebound material or the end of the column (2110) is provided with a protrusion made of compression-rebound material.

3. The bionic robot gripper according to claim 1, characterized in that, The secondary rope unit (22) further includes a drive gear (225) connected to the output end of a single drive motor, two driven gears (226) meshing with both sides of the drive gear (225), and a rotating rod (227) mounted on the second base (221) and rotating coaxially with the driven gears (226). The rotating rod (227) is used to fix and install the winding wheel (223) acting on the movable part (35) of the spherical clamping assembly.

4. The bionic robot gripper according to claim 1, characterized in that, The first base (211) is provided with a wire hole (2111) for the pull rope (224) to pass through.

5. A bionic robot gripper according to claim 1, characterized in that, The housing module I includes a control board (11) that is electrically connected to the cylinder (218), stepper motor (231), drive motor and pump body (334) respectively to control the individual opening or closing of the above components.

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