High-adaptability variable-rigidity flexible manipulator and grabbing method thereof

Abstract

The invention discloses a high-adaptability variable-rigidity flexible manipulator and a grabbing method thereof, and relates to the technical field of robot end execution. Comprising a plurality of rope-driven flexible grabbing fingers connected to the high-adaptability attaching transmission structure. The rope-driven flexible grabbing finger comprises a multi-joint movable rigid phalanx, a flexible adaptive contact layer and a special-shaped channel air bag. The high-adaptability attaching transmission structure comprises a transmission cavity formed by connecting a flexible attaching silicon rubber sleeve and a fixed bottom plate seat, and a plurality of connecting rods and a plurality of soft springs are arranged in the transmission cavity. The contact face of the mechanical arm and an object is made of a flexible material, flexible contact can be achieved, the high-adaptability attaching transmission structure can be well attached to the grabbed object, the grabbing attaching degree is increased, the grabbing adaptability is improved, meanwhile, under the influence of the air bag and the variable-rigidity structure, rigidity change can be achieved in the bearing process, and the mechanical arm is more flexible. And the bearing capacity of the manipulator is improved.

Description

Technical Field

[0001] The present invention relates to the field of robot end execution technology, and in particular to a highly adaptable variable-rigidity flexible manipulator and a grasping method thereof. Background Art

[0002] At present, traditional rigid manipulators have high strength and high precision when grasping objects. They are structurally stable and can maintain precise positioning and motion control during repeated operations, which is particularly suitable for repetitive tasks on industrial production lines. However, they generally lack flexibility and adaptability. For irregularly shaped or fragile objects, rigid manipulators cannot grasp them gently, and there is a risk of damaging the object or failing to grasp it effectively. In addition, they may pose a safety hazard in an environment where they work with humans, because hard materials may cause harm to people when they collide.

[0003] With the development of robot technology, soft robots have shown different advantages in grasping operations due to the use of flexible materials. Soft robots can gently wrap and grasp irregular or fragile objects, reducing damage to the objects. Their adaptability makes them perform well when handling irregular shapes and fragile objects.

[0004] The invention patent application with publication number CN 111791247 A proposes a variable stiffness wire-driven flexible gripper based on layer interference technology and a variable stiffness control method thereof. The flexible gripper is driven by a tendon rope driven by a motor to bend the fingers, and the gripper stiffness change is controlled by an external negative pressure pump. However, since most of the overall structure is made of flexible materials and the grasping part has no rigid structure support, the stiffness change is limited and cannot provide greater load capacity and grasping stability. The utility model patent with publication number CN 218082707 U proposes a driving device for a flexible variable stiffness manipulator. The manipulator changes the overall grasping stiffness of the manipulator by extending the tendon rope driver, and adjusts the grasping force of the manipulator by bending the tendon rope driver to complete the grasping of the manipulator. However, due to its complex driving, too many driving motors are required, resulting in difficulty in control. The invention patent application with publication number CN 110788881 A proposes a pneumatic soft gripper with a vacuum adsorption locking joint. The pneumatic soft gripper adds a flexible suction cup spine inside the soft fingers to achieve a variable stiffness fully flexible gripper. Although the load-bearing capacity is improved, there are still problems of insufficient stability in grasping objects and weak load-bearing capacity, especially for objects with complex shapes. Summary of the invention

[0005] The purpose of the present invention is to provide a highly adaptable variable-rigidity flexible manipulator and a grasping method thereof, which can perform highly adaptable wrapping grasping and has the advantages of simple driving, good adaptability, strong load-bearing capacity and high grasping stability.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is: a highly adaptable variable-rigidity flexible manipulator, comprising a plurality of rope-driven flexible grasping fingers connected to a highly adaptable attachment transmission structure; The rope-driven flexible grasping finger comprises a multi-jointed movable rigid phalanx, a flexible and adaptable contact layer and a special-shaped channel airbag, wherein the flexible and adaptable contact layer is fixed to the inner side of the multi-jointed movable rigid phalanx, and the special-shaped channel airbag is fixed to the outer side of the multi-jointed movable rigid phalanx; The highly adaptable attachment transmission structure includes a transmission cavity formed by connecting a flexible attachment silicone sleeve and a fixed base plate seat. A plurality of connecting rods and a plurality of soft springs are arranged in the transmission cavity. The connecting rod passes through the flexible attachment silicone sleeve and is connected to the upper part of the spherical sleeve. The spherical sleeve is nested and connected to the suction cup. The upper end of the soft spring is fixed in the reserved hole of the fixed base plate seat, and the lower end of the soft spring is nested in the hollow groove of the connecting rod.

[0007] As a preferred solution of the present invention, a follower rod is provided in the transmission cavity, the upper end of the follower rod passes through the fixed base plate seat and the hollow fixed seat to be connected to the pulley assembly, a rope is wound around the pulley assembly, the rope passes through the fixed base plate seat and is connected to the rope-driven flexible grasping finger, and the hollow fixed seat is connected to the fixed base plate; the lower end of the follower rod is nested in the hollow groove of the connecting rod.

[0008] As a preferred solution of the present invention, gears are provided between the joints of the multi-joint movable rigid phalanges, and the gears are fixed to the multi-joint movable rigid phalanges through gear shafts. A rope passes around the gears to connect the rope-driven flexible grasping fingers and the highly adaptable attachment transmission structure together, thereby providing drive for the rope-driven flexible grasping fingers.

[0009] As a preferred solution of the present invention, the interlayer of the flexible silicone sleeve is filled with spherical particles, and the flexible silicone sleeve is connected to an external air source.

[0010] As a preferred solution of the present invention, a plurality of lower extension plates are provided on the fixed base plate seat, and each lower extension plate is rotationally connected to a corresponding rope-driven flexible grasping finger.

[0011] As a preferred solution of the present invention, a groove for limiting the connection rod is formed on the flexible attached silicone sleeve.

[0012] As a preferred solution of the present invention, a positioning plate extending upward is provided on the top of the flexible attached silicone sleeve, and the positioning plate is placed in the fixed base seat.

[0013] As a preferred solution of the present invention, the hemispherical part of the spherical sleeve is embedded in the upper part of the suction cup to achieve rotational and sliding connection.

[0014] As a preferred solution of the present invention, the central axis of the follower rod is collinear with the central axis of the central reserved hole of the fixed base plate seat.

[0015] The present invention also provides a grasping method of a highly adaptable variable-rigidity flexible manipulator, comprising the following steps: S1. The highly adaptable attachment transmission structure and multiple ropes drive the flexible grasping fingers to move longitudinally. When the suction cup contacts the grasped object, the soft spring provides pressure, which is transmitted to the spherical sleeve through the connecting rod. The suction cup rotates on the hemispherical part of the spherical sleeve to adjust the adsorption angle to ensure that the suction cup is closely attached to the surface of the grasped object; S2. When grasping, after the highly adaptable attachment transmission structure is closely attached to the grasped object, the special-shaped channel airbag is inflated to make it gradually expand, and the flexible attachment silicone sleeve is evacuated to make the interlayer shrink, and the spherical particles in the interlayer have interference stiffness increase; S3. After the special-shaped channel airbag is fully inflated, the interlayer of the flexible attached silicone sleeve is completely contracted, and the highly adaptable attached transmission structure and multiple rope-driven flexible grasping fingers continue to move longitudinally. The suction cup is close to the grasped object, and the force of the object on the suction cup is transmitted to the follower rod through the spherical sleeve and the connecting rod. The follower rod rises, driving the rope to contract, and then driving the rope-driven flexible grasping fingers to bend inward at the same time to complete the grasping and covering action.

[0016] The present invention adopts the above technical solution, and can achieve the following technical effects: 1. The highly adaptable variable-rigidity flexible manipulator provided by the present invention connects the rope-driven flexible grasping fingers with the highly adaptable attachment transmission structure by passing a wire rope around a gear assembly, thereby providing drive for the rope-driven flexible grasping fingers. This design method can simplify the drive and realize the synchronous movement of the highly adaptable attachment transmission structure and the rope-driven flexible grasping fingers. At the same time, multiple fingers move together, which can make the grasping more stable and improve the load-bearing capacity.

[0017] 2. The highly adaptable variable-rigidity flexible manipulator provided by the present invention designs a highly adaptable attachment transmission structure and rationally arranges the flexible attachment silicone sleeve, suction cup, connecting rod, spherical sleeve, soft spring, etc. Under the pressure provided by the soft spring, the suction cup is tightly attached to the surface of the grasped object. At the same time, the spherical sleeve enables the suction cup to adapt to the slight fluctuations on the surface of the object, thereby improving the adaptability of the manipulator.

[0018] 3. The highly adaptable variable-rigidity flexible manipulator provided by the present invention fills spherical particles in the interlayer of the flexible attached silicone sleeve and draws air to form negative pressure during grasping, thereby improving the rigidity and increasing the grasping stability and carrying capacity.

[0019] 4. The highly adaptable variable-rigidity flexible manipulator provided by the present invention ensures that the particles and other structures do not interfere with each other during operation by designing a flexible attached silicone sleeve, while concentrating the distribution of particles to facilitate the change of rigidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the structure of a highly adaptable variable stiffness flexible manipulator; Figure 2 Schematic diagram of the rope-driven flexible grasping finger structure; Figure 3 A half-section view of the transmission structure for high adaptability attachment; Figure 4 This is a schematic diagram of the structure of the flexible attached silicone sleeve; Figure 5 It is a schematic diagram of the spherical sleeve structure; Figure 6 Schematic diagram of the grasping state of the highly adaptable variable stiffness flexible manipulator; Figure 7 Schematic diagram of the multi-jointed movable rigid phalanx structure.

[0022] Explanation of the serial numbers in the figure: 1. Rope-driven flexible grasping fingers; 2. Highly adaptable attached transmission structure; 3. Wire rope; 11. Multi-jointed movable rigid phalanges; 12. Flexible and adaptable contact layer; 13. Special-shaped channel airbag; 141. Gear shaft; 142. Gear; 211. Flexible attached silicone sleeve; 212. Spherical particles; 22. Suction cup; 23. Connecting rod; 24. Spherical sleeve; 25. Soft spring; 26. Fixed base seat; 27. Follow-up rod; 28. Hollow fixed seat; 291. Pulley assembly; 292 Pulley shaft. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. 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.

[0024] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0025] In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0026] In the description of the present application, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application 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 on the present application.

[0027] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. Example 1

[0028] like Figure 1 As shown, this embodiment provides a highly adaptable variable-rigidity flexible manipulator, which includes rope-driven flexible grasping fingers 1 (four are shown in the figure, and can also be adjusted according to actual conditions), a highly adaptable attachment transmission structure 2, and a wire rope 3, wherein the wire rope 3 provides drive for the rope-driven flexible grasping fingers.

[0029] like Figure 2As shown, the rope-driven flexible grasping finger 1 includes a multi-joint movable rigid phalanx 11, a flexible and adaptable contact layer 12, and a special-shaped channel airbag 13, wherein the flexible and adaptable contact layer 12 is fixed to the inner side of the multi-joint movable rigid phalanx 11 by gluing, and the special-shaped channel airbag 13 is fixed to the outer side of the multi-joint movable rigid phalanx 11 by gluing, and gears 142 are arranged between the joints of the multi-joint movable rigid phalanx 11, and the gears 142 are fixed to the multi-joint movable rigid phalanx 11 by gear shafts 141, and the rope 3 is fixed to the limiting column of the tail arc joint after passing through all the gears 14, and one end of the special-shaped channel airbag 13 is connected to an external air source through a universal interface; like Figure 3 As shown, the highly adaptable attachment transmission structure 2 includes a flexible attachment silicone sleeve 211, a suction cup 22, a connecting rod 23, a spherical sleeve 24, a soft spring 25, a fixed base seat 26, a follower rod 27, a hollow fixed seat 28, a pulley assembly 291 and a pulley shaft 292. The positioning plate extending upward from the flexible attachment silicone sleeve 211 is placed in the fixed base seat 26, and the flexible attachment silicone sleeve 211 and the fixed base seat 26 are connected and fixed by fastening bolts around them. The connecting rod 23 is connected to the upper part of the spherical sleeve 24 by threads, the suction cup 22 is nested and connected with the hemispherical part of the spherical sleeve 24, the connecting rod 23 is fixed by the groove body on the flexible silicone sleeve 211, the upper end of the soft spring 25 is fixed in the reserved hole of the fixed base plate seat 26, the lower end of the soft spring 25 is nested in the hollow groove of the central connecting rod 23, the upper end of the follower rod 27 passes through the central reserved hole of the fixed base plate seat 26 and the hollow fixed seat 28 and is connected to the pulley assembly 291, and the lower end of the follower rod 27 is nested in the connecting rod 23 In the hollow groove, the hollow fixed seat 28 is threadedly connected to the fixed base seat 26, and the limiting part of the follower rod 27 is above the fixed base seat 26; the pulley assembly 291 includes symmetrically arranged transverse pulleys and symmetrically arranged longitudinal pulleys, and the transverse pulleys and longitudinal pulleys are both installed on the follower rod through the pulley shaft 292; a rope 3 is wound around the pulley 291, one end of the rope is fixed to the fixed column in the fixed base seat, and the other end passes through the fixed base seat 26 and is connected to the rope-driven flexible grasping finger 1.

[0030] like Figure 4 As shown, the flexible attached silicone sleeve 211 is a sandwich structure, which is connected to an external air source through a universal interface. Spherical particles 212 are arranged inside the sandwich. The spherical particles 212 interfere with each other through vacuum negative pressure to improve the overall stiffness. At the same time, the flexible attached silicone sleeve 211 separates the spherical particles 212 from the soft spring 25 to prevent the two from interfering with each other and affecting the working effect of the soft spring 25, and increases the aggregation degree of the spherical particles 212.

[0031] like Figure 5 As shown, the hemispherical part of the spherical sleeve 24 is embedded in the upper part of the suction cup 22 to achieve rotational and sliding connection.

[0032] In a preferred embodiment, the soft spring 25 is stably connected to the fixed base plate 26 and the connecting rod 23, the central axes of the three are collinear, and the stiffness of the soft spring 25 is appropriate.

[0033] In a preferred embodiment, the central axis of the follower rod 27 is collinear with the central axis of the central reserved hole of the fixed base plate seat 26 .

[0034] In a preferred embodiment, a plurality of rope-driven flexible grasping fingers are symmetrically arranged. Example 2

[0035] like Figure 6 As shown, this embodiment provides a grasping method of a highly adaptable variable stiffness flexible manipulator, which includes the following steps: S1. In the initial state of the grasping task, the highly adaptable variable stiffness flexible manipulator is controlled to move longitudinally to contact the grasped object. The soft spring provides a slight pressure, which is transmitted to the spherical sleeve through the connecting rod. The suction cup rotates on the hemispherical part of the spherical sleeve to adjust the adsorption angle to ensure that the suction cup can be closely attached to the surface of the grasped object. S2. When grasping, after the highly adaptable attachment transmission structure is closely attached to the grasped object, the external air source inflates the special-shaped channel airbag through the universal interface to make it gradually expand, and the flexible attachment silicone sleeve is evacuated through the universal interface to shrink the interlayer, so that the spherical particles in the interlayer are disturbed, the rigidity is increased, the fixing ability of the grasped object is improved, and the stability and carrying capacity of the grasping are improved; S3. After the special-shaped channel airbag is fully inflated and the flexible attached silicone sleeve interlayer is completely contracted, the highly adaptable variable-rigidity flexible manipulator continues to move longitudinally, and the suction cup is close to the grasped object. The force of the object on the suction cup is transmitted to the follower rod through the spherical sleeve and the connecting rod. The follower rod rises, driving the wire rope to contract, and then driving the wire rope to drive the flexible grasping fingers to bend inward at the same time, completing the grasping and covering action. The transfer action can be completed by controlling the longitudinal lifting and horizontal movement of the highly adaptable variable-rigidity flexible manipulator.

[0036] After reaching the designated position, the external air source stops working, the inside of the special-shaped channel airbag and the flexible attached silicone sleeve interlayer are restored to atmospheric pressure, the special-shaped channel airbag returns to its initial state before grasping, the spherical particles inside the flexible attached silicone sleeve interlayer return to their initial state, the stiffness returns to its initial stiffness, the follower rod descends, and the rope drives the flexible grasping fingers to open to place the object.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. Highly adaptable variable stiffness flexible manipulator, characterized in that: It includes a plurality of rope-driven flexible grasping fingers connected to a highly adaptable attachment transmission structure; The rope-driven flexible grasping finger comprises a multi-jointed movable rigid phalanx, a flexible and adaptable contact layer and a special-shaped channel airbag, wherein the flexible and adaptable contact layer is fixed to the inner side of the multi-jointed movable rigid phalanx, and the special-shaped channel airbag is fixed to the outer side of the multi-jointed movable rigid phalanx; The highly adaptable attachment transmission structure includes a transmission cavity formed by connecting a flexible attachment silicone sleeve and a fixed base plate seat. A plurality of connecting rods and a plurality of soft springs are arranged in the transmission cavity. The connecting rod passes through the flexible attachment silicone sleeve and is connected to the upper part of the spherical sleeve. The spherical sleeve is nested and connected to the suction cup. The upper end of the soft spring is fixed in the reserved hole of the fixed base plate seat, and the lower end of the soft spring is nested in the hollow groove of the connecting rod.

2. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: A follower rod is provided in the transmission cavity, the upper end of which passes through the fixed base plate seat and the hollow fixed seat to be connected to the pulley assembly, a rope is wound around the pulley assembly, the rope passes through the fixed base plate seat and is connected to the rope-driven flexible grasping finger, and the hollow fixed seat is connected to the fixed base plate; the lower end of the follower rod is nested in the hollow groove of the connecting rod.

3. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: Gears are provided between the joints of the multi-joint movable rigid phalanges, and the gears are fixed to the multi-joint movable rigid phalanges through gear shafts. A rope passes around the gears to connect the rope-driven flexible grasping fingers and the highly adaptable attachment transmission structure together, providing drive for the rope-driven flexible grasping fingers.

4. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: The interlayer of the flexible silicone sleeve is filled with spherical particles, and the flexible silicone sleeve is connected to an external air source.

5. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: The fixed base plate seat is provided with a plurality of lower extension plates, and each lower extension plate is rotationally connected with a corresponding rope-driven flexible grasping finger.

6. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: The flexible silicone sleeve is provided with a groove for limiting the position of the connecting rod.

7. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: A positioning plate extending upward is provided on the top of the flexible attached silicone sleeve, and the positioning plate is placed in the fixed bottom plate seat.

8. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: The hemispherical part of the spherical sleeve is embedded in the upper part of the suction cup to achieve rotational and sliding connection.

9. The highly adaptable variable stiffness flexible manipulator according to claim 1, characterized in that: The central axis of the follower rod is collinear with the central axis of the central reserved hole of the fixed base plate seat.

10. A grasping method of a highly adaptable variable stiffness flexible manipulator, characterized in that: The following steps are involved: S1. The highly adaptable attachment transmission structure and multiple ropes drive the flexible grasping fingers to move longitudinally. When the suction cup contacts the grasped object, the soft spring provides pressure, which is transmitted to the spherical sleeve through the connecting rod. The suction cup rotates on the hemispherical part of the spherical sleeve to adjust the adsorption angle to ensure that the suction cup is closely attached to the surface of the grasped object; S2. After the highly adaptable attachment transmission structure is closely attached to the grasped object, the special-shaped channel airbag is inflated to make it gradually expand, and the flexible attachment silicone sleeve is evacuated to make the interlayer shrink, so that the spherical particles in the interlayer have interference stiffness increase; S3. After the special-shaped channel airbag is fully inflated, the interlayer of the flexible attached silicone sleeve is completely contracted, and the highly adaptable attached transmission structure and multiple rope-driven flexible grasping fingers continue to move longitudinally. The suction cup is close to the grasped object, and the force of the object on the suction cup is transmitted to the follower rod through the spherical sleeve and the connecting rod. The follower rod rises, driving the rope to contract, and then driving the rope-driven flexible grasping fingers to bend inward at the same time to complete the grasping and covering action.

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