An adaptive bionic three-finger gripper

Abstract

This invention belongs to the field of robot end effector technology. It discloses an adaptive bionic three-finger gripper, comprising a palm, three fingers, two rotary servos, a connecting rod, three bending servos, and three drive lines. Each finger consists of a finger root, a finger root joint, a finger middle joint, and a finger tip joint, hinged sequentially. One finger root is fixed to the palm via the connecting rod, while the other two finger roots are independently driven by two rotary servos to change finger orientation. The bending of each finger is achieved by the corresponding bending servo pulling the finger tip joint via a servo disc and drive lines, forming a tendon-like driven bending. This invention achieves adaptive adjustment of the three-finger layout using only two rotary servos, with a simple drive structure and low control complexity. Simultaneously, each finger joint passively follows the bending motion, resulting in a smooth and conforming gripping action that can adapt to irregular object contours, significantly improving gripping stability and adaptability.

Description

Technical Field

[0001] This invention relates to the field of robot end effector technology, and in particular to an adaptive bionic three-finger gripper. Background Technology

[0002] With the widespread application of robotics in industrial automation, service robots, and logistics sorting, higher demands are being placed on the grasping capabilities and adaptability of end effectors. Biomimetic multi-fingered grippers have become a research hotspot due to their advantages such as flexible grasping and strong envelope adaptability. Existing biomimetic multi-fingered grippers typically consist of multiple fingers, each comprising several sequentially hinged phalanges. The bending and grasping movements of the fingers are achieved through servo motors in conjunction with drive lines or linkage mechanisms.

[0003] However, in most current bionic grippers, the width of the finger joints remains essentially unchanged during bending, relying solely on the simple bending of the joints to envelop and grip objects. This limits the contact area between the fingers and objects, especially for irregularly shaped, smooth-surfaced, or large objects, easily leading to problems such as unstable gripping and insufficient grasping force. To improve gripping stability, some grippers have attempted to add deployable winglets or finger plates to the joints to increase the contact area. However, these deployment mechanisms typically require independent drive sources (such as additional servos or cylinders), resulting in complex gripper structures, increased weight, greater control difficulty, and hindering miniaturization and lightweight design.

[0004] Therefore, how to enable the gripper fingers to simultaneously change the shape of the knuckles during the bending and grasping process without adding an additional driving source, so as to obtain a larger gripping contact area and thus improve the gripping ability and stability of the adaptive bionic three-finger gripper, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This invention provides an adaptive bionic three-finger gripper, which solves the technical problems of existing bionic grippers, such as fixed finger joint shape and small gripping contact area when bending and grasping, and the need for an additional driving source to add an unfolding structure, resulting in complex structure and high control difficulty.

[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: An adaptive bionic three-finger gripper includes: a palm, three fingers, two rotary servos, a connecting rod, three bending servos, and three drive lines. Each finger includes a finger root, a finger root joint, a finger middle joint, and a finger tip joint. The three finger roots are distributed circumferentially around the outside of the palm. The finger root, finger root joint, finger middle joint, and finger tip joint of each finger are sequentially hinged together. The two rotary servos and the connecting rod are respectively arranged opposite to the three finger roots and are all fixed on the palm. The output of the two rotary servos... Both the shaft and the connecting rod are arranged vertically along the palm; the bases of two fingers are respectively fixed on the output shafts of the two rotary servos and the base of the third finger is fixed on the connecting rod to change the orientation of the bases of the two fingers; the three bending servos are respectively fixed on the bases of the three fingers and their output shafts are arranged horizontally along the corresponding bases of the fingers, and each of the three bending servos has a servo disk fixed on its output shaft; one end of each of the three drive lines is fixed on the three servo disks and the other end is fixed on the three finger joints to drive the three fingers to bend respectively.

[0007] The beneficial effects of this invention are as follows: By combining a hand, three fingers, two rotary servos, a connecting rod, three bending servos, and three drive lines, one finger is fixed to the connecting rod as a fixed finger, while the other two fingers are driven independently by two rotary servos. This allows the relative positions of the two finger roots to be changed using only two rotary servos, enabling the three-finger layout to adaptively adjust to the shape and size of different grasping objects. While ensuring the flexibility of the grasping envelope, the drive structure is simplified and the control complexity is reduced. Simultaneously, the bending motion of each finger is achieved by an independent bending servo in conjunction with a servo disk and drive lines. One end of the drive line is fixed to the servo disk of the finger root servo, and the other end is directly fixed to the finger tip joint. This allows the traction force during finger bending to be transmitted sequentially from the tip joint to each finger root joint, with each joint passively following the bending motion, forming a biomimetic bending motion similar to tendon-driven motion. The grasping action is smooth and conforms well, adapting to the shape and contour of irregular objects, significantly improving grasping stability and adaptability.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, each of the three fingers also includes a folding assembly, and each folding assembly includes two pairs of first folding members and second folding members that are hinged to each other; the root joints, middle joints, and tip joints of the three fingers have the same structure and each includes two finger joint plates that are hinged to each other in parallel; the three drive lines are respectively fixed to any one of the first folding members of the three folding assemblies; the two first folding members of each folding assembly are symmetrically fixed to the corresponding root of the finger, and the two second folding members of each folding assembly are symmetrically fixed to the two finger joint plates of the root joints of the three fingers, so that the root joints, middle joints, and tip joints of the three fingers can be simultaneously unfolded while the three fingers are bent.

[0010] The further beneficial effects of adopting the above are as follows: by setting a folding component on each finger, and designing each finger root joint, middle joint, and tip joint as consisting of two parallel hinged finger joint plates, the drive line drives the first folding component fixed on the finger root to rotate while pulling the finger to bend. The second folding component, which is hinged to the finger root joint, transmits the motion to the finger joint plate of the finger root joint, causing the two finger joint plates to unfold outward from their close folded state. This drives each finger joint to unfold synchronously during the bending process, increasing the contact area between the finger and the grasping object, and improving the clamping stability and adaptability.

[0011] Furthermore, the two finger joint plates of the three root joints, the three middle joints, and the three tip joints are all made of aluminum alloy or carbon fiber.

[0012] Furthermore, each of the three folding components also includes a spring, with the two ends of the three springs respectively fixed to a first folding member and a second folding member that are hinged to each other on the three folding components.

[0013] The further beneficial effect of the above is that by setting a spring between the first and second folding parts that are hinged to each other in the folding assembly, when the bending servo releases the drive line in the opposite direction, the spring can use its elastic restoring force to drive the first and second folding parts to rotate relative to each other and reset, thereby causing the finger joint plates of the root joint, middle joint and tip joint of the finger to automatically return from the unfolded state to the folded state. At the same time, in conjunction with the hinge relationship of each joint, the finger can be automatically straightened and reset.

[0014] Furthermore, each of the folding components also includes a positive magnet and a negative magnet, the positive magnet and the negative magnet being fixed to the first folding member and the second folding member that are hinged to each other, respectively.

[0015] The further beneficial effects of the above-mentioned approach are as follows: By fixing positive and negative magnets respectively on the first and second folding components that are hinged to each other in the folding assembly, when the fingers are in the folded state, the positive and negative magnets attract each other, which can stably keep the two finger joint plates in a folded position close to each other, and prevent the finger joints from accidentally unfolding when not performing a grasping action due to factors such as gravity, vibration or inertia. This improves the structural stability and reliability of the gripper in the non-working state and during the movement process. At the same time, during the grasping and unfolding process, the tension of the drive line can overcome the magnetic attraction to unfold the folding assembly. After the grasping and releasing, the magnetic attraction can assist the spring to quickly pull each finger joint back and lock it in the folded state, realizing the dual functions of passive locking and reset. No additional power is required, the structure is simple and compact, and the stability and response consistency of the gripper during continuous operation are improved. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 The attached figure is a schematic diagram of the structure of an adaptive bionic three-finger gripper of the present invention.

[0018] Figure 2 The attached figure is a schematic diagram of the structure of an adaptive bionic three-finger grasper with one finger spread out, according to the present invention.

[0019] Figure 3 The attached figure is a schematic diagram of the adaptive bionic three-finger gripper curling structure of the present invention;

[0020] Figure 4 The attached figure is a schematic diagram of the curling structure of a single finger in an adaptive bionic three-finger grasping hand according to the present invention;

[0021] Figure 5 The attached figure is a structural schematic diagram of the middle finger root, finger root joint, bending servo, first folding component, second folding component and spring of the adaptive bionic three-finger gripper of the present invention;

[0022] Figure 6 The attached figure is a schematic diagram of the structure of the first folding component, the second folding component, and the spring in an adaptive bionic three-finger gripper of the present invention.

[0023] The attached diagram lists the components represented by each number as follows:

[0024] 1. Palm, 2. Fingers, 21. Finger base, 22. Finger root joint, 23. Finger middle joint, 24. Finger tip joint, 25. Finger joint plate, 3. Rotary servo, 4. Connecting rod, 5. Bending servo, 6. Servo disc, 7. First folding piece, 8. Second folding piece, 9. Spring, 10. Positive magnet. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This invention discloses an adaptive bionic three-finger gripper, comprising: a palm 1, three fingers 2, two rotary servos 3, a connecting rod 4, three bending servos 5, and three drive lines. Each finger 2 includes a finger root 21, a finger root joint 22, a finger middle joint 23, and a finger tip joint 24. The three finger roots 21 are circumferentially spaced outside the palm 1. The finger root 21, finger root joint 22, finger middle joint 23, and finger tip joint 24 of each finger 2 are sequentially hinged together. The two rotary servos 3 and the connecting rod 4 are respectively arranged opposite to the three finger roots 21 and are all fixed on the palm 1. The output shaft of the rotary servo 3 and the connecting rod 4 are both arranged vertically along the palm 1; the bases 21 of two fingers are respectively fixed on the output shafts of the two rotary servos 3 and the base 21 of the third finger is fixed on the connecting rod 4 to change the orientation of the bases 21 of the two fingers; the three bending servos 5 are respectively fixed on the bases 21 of the three fingers and their output shafts are arranged horizontally along the corresponding bases 21 of the fingers, and a servo disc 6 is fixed on the output shaft of each of the three bending servos 5; one end of the three drive lines is respectively fixed on the three servo discs 6 and the other end is respectively fixed on the tip joints 24 of the three fingers to drive the three fingers 2 to bend respectively.

[0027] In some specific embodiments, each of the three fingers 2 may further include a folding assembly, each folding assembly including two pairs of first folding members 7 and second folding members 8 that are hinged to each other; the root joints 22, middle joints 23, and tip joints 24 of the three fingers have the same structure and each includes two finger joint plates 25 that are hinged to each other in parallel; three drive lines are respectively fixed on any of the first folding members 7 of the three folding assemblies; the two first folding members 7 of each folding assembly are symmetrically fixed on the corresponding finger root 21, and the two second folding members 8 of each folding assembly are symmetrically fixed on the two finger joint plates 25 of the root joints 22 of the three fingers, so that the root joints 22, middle joints 23, and tip joints 24 of the three fingers are simultaneously unfolded while the three fingers 2 are bent.

[0028] In some specific embodiments, the two finger joint plates 25 of the three finger root joints 22, the three finger middle joints 23, and the three finger tip joints 24 can all be made of aluminum alloy plates or carbon fiber plates.

[0029] In some specific embodiments, each of the three folding components also includes a spring 9, with the two ends of the three springs 9 respectively fixed to the first folding member 7 and the second folding member 8 that are hinged to each other on the three folding components.

[0030] In some specific embodiments, each folding assembly further includes a positive magnet 10 and a negative magnet, which are respectively fixed to the first folding member 7 and the second folding member 8 that are hinged to each other in the corresponding folding assembly.

[0031] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0032] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An adaptive bionic three-finger gripper, characterized in that, include: Palm (1) Three fingers (2), each of the fingers (2) includes a finger root (21), a finger root joint (22), a finger middle joint (23) and a finger tip joint (24), the three finger roots (21) are distributed circumferentially outside the palm (1); the finger root (21), finger root joint (22), finger middle joint (23) and finger tip joint (24) of each finger (2) are hinged together in sequence; Two rotary servos (3) and a connecting rod (4) are arranged opposite to the three finger roots (21) and fixed to the palm (1). The output shafts of the two rotary servos (3) and the connecting rod (4) are arranged vertically along the palm (1). The two finger roots (21) are fixed to the output shafts of the two rotary servos (3) and the third finger root (21) is fixed to the connecting rod (4) to change the orientation of the two finger roots (21). Three bending servos (5) and three drive lines are provided. The three bending servos (5) are respectively fixed on the base (21) of the three fingers and their output shafts are arranged in the horizontal direction along the corresponding base (21) of the fingers. A servo disk (6) is fixed on the output shaft of each of the three bending servos (5). One end of each of the three drive lines is fixed on the three servo disks (6) and the other end is fixed on the finger joints (24) of the three fingers respectively, so as to drive the three fingers (2) to bend respectively.

2. The adaptive bionic three-finger gripper according to claim 1, characterized in that, Each of the three fingers (2) further includes a folding assembly, each of the folding assemblies including two pairs of first folding pieces (7) and second folding pieces (8) that are hinged to each other; the root joints (22), middle joints (23), and tip joints (24) of the three fingers have the same structure and each includes two parallel hinged finger joint plates (25); the three drive lines are respectively fixed on any of the first folding pieces (7) of the three folding assemblies; the two first folding pieces (7) of each folding assembly are respectively symmetrically fixed on the corresponding root of the finger (21) and the two second folding pieces (8) of each folding assembly are respectively symmetrically fixed on the two finger joint plates (25) of the root joints (22) of the three fingers, so that while bending the three fingers (2), the root joints (22), middle joints (23), and tip joints (24) of the three fingers are simultaneously unfolded.

3. The adaptive bionic three-finger gripper according to claim 2, characterized in that, The two finger joint plates (25) of the three root joints (22), the three middle joints (23), and the three tip joints (24) of the fingers are all made of aluminum alloy or carbon fiber.

4. The adaptive bionic three-finger gripper according to claim 2, characterized in that, Each of the three folding components also includes a spring (9), with the two ends of the three springs (9) respectively fixed to the first folding member (7) and the second folding member (8) that are hinged to each other on the three folding components.

5. An adaptive bionic three-finger gripper according to claim 2, characterized in that, Each of the folding components further includes a positive magnet (10) and a negative magnet, the positive magnet (10) and the negative magnet being fixed to the first folding member (7) and the second folding member (8) that are hinged to each other, respectively.

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