An underactuated coupled adaptive robotic finger

Abstract

The present invention provides an underactuated coupled adaptive robotic finger, comprising a base joint, a proximal phalanx, a middle phalanx, and a distal phalanx, wherein the base joint comprises a first base and a second base connected to the proximal phalanx; a fixed-axis transmission rod, one end of which is connected to the proximal phalanx connecting rod and the other end is connected to the fifth rotating part, the fifth rotating part being connected to the first base via a fourth rotating part; a coupling transmission rod, one end of which is connected to the distal phalanx transmission rod and the other end is connected to the fifth rotating part, the distal phalanx transmission rod being rotatable around the proximal phalanx connecting rod; when the second base rotates around the X-axis, the middle phalanx and the distal phalanx are coupled for grasping; an elastic moving component is included between the fourth rotating part and the first base, and when the proximal phalanx contacts the grasped object, the elastic moving component is subjected to force to cause the fourth rotating part to move relative to the first base, and the middle phalanx and the distal phalanx are adaptively grasped. The above-mentioned robotic finger has the functions of both coupled grasping and adaptive grasping, is easy to implement structurally, and has good motion accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of manipulators, and in particular relates to an under-actuated coupled adaptive manipulator finger. Background Art

[0002] According to the relationship between the degrees of freedom of the robotic finger and the number of drive units, the robotic finger can be divided into two types: fully driven and under-driven. Among them, each joint of the fully driven robotic finger is actively moving. Although it has high dexterity and adaptability, the number of drive units is large, resulting in complex structure and control and high cost. Under-driven robotic fingers use under-driven mechanisms to achieve adaptive movement of multiple joints driven by a small number of drive units. It has high adaptability and simplifies the structure and control complexity.

[0003] Underactuated manipulators usually use coupled transmission mechanisms and adaptive transmission mechanisms. The coupled mechanism realizes the cage-type envelope grasping function through the linkage of multiple joints. The movement trajectory of the fingers is fixed, which makes it difficult to adapt to the sizes and shapes of different objects. In the adaptive mechanism, all joints are in a straight or fixed angle state at the initial stage for flexion and extension rotation. When the proximal knuckle contacts the object to be grasped, the subsequent knuckles can rotate in sequence until they contact the object. It can adapt to the size and shape of different objects, but it is difficult to couple pinching and grasping.

[0004] Object grasping by robotic fingers can be categorized into pinching and holding. For small objects, multiple knuckles usually need to be bent for coupled pinching; for larger objects, multiple knuckles usually need to contact the object for enveloping gripping. Traditional robotic fingers are usually only capable of a single function of pinching or holding, and are poorly adaptable to grasping objects of different shapes and sizes. Some robotic fingers that can combine pinching and holding functions have complex structures, large sizes, and use a large number of flexible parts, resulting in inaccurate transmission. Furthermore, the robotic fingers cannot actively swing sideways, resulting in insufficient dexterity. Summary of the Invention

[0005] The purpose of the present invention is to provide an under-actuated coupled adaptive robotic finger to solve the problems of complex structure, insufficient dexterity and adaptability of robotic fingers in the prior art. The robotic finger provided by the present invention has both coupled pinching and adaptive gripping functions, and can realize active side swing, with the characteristics of compact structure, high dexterity and adaptability.

[0006] To solve the above problems, the present invention can adopt the following technical solutions: an underactuated coupled adaptive mechanical finger, comprising: a base joint, a proximal phalanx, a middle phalanx and a distal phalanx; the base joint comprises a first base extending along the Z axis, and a second base rotatably connected to the first base through a first rotating part; the proximal phalanx comprises a proximal phalanx connecting rod and a middle phalanx transmission rod, the proximal phalanx connecting rod and the middle phalanx transmission rod are connected to the second base at intervals along the Z axis; a fixed axis transmission rod, one end of which is connected to the proximal phalanx connecting rod, and the other end is connected to the fifth rotating part, the fifth rotating part is connected to the proximal phalanx connecting rod. The fourth rotating part is connected to the first base; a coupling transmission rod, one end of which is connected to the distal knuckle transmission rod, and the other end is connected to the fifth rotating part, and the distal knuckle transmission rod can rotate around the proximal knuckle connecting rod; when the second base rotates around the X-axis to perform flexion and extension movement, the middle knuckle and the distal knuckle perform coupled flexion and extension movement; an elastic moving component is included between the fourth rotating part and the first base, and when the proximal knuckle contacts the grasped object, the elastic moving component is subjected to force to cause the fourth rotating part to move along the Z-axis direction of the first base, and the middle knuckle and the distal knuckle adapt to the shape and size of the grasped object.

[0007] Furthermore, the elastic moving component includes a slide groove provided on the first base, and an elastic member connected between the fourth rotating part and the first base, and the elastic member is deformed by force so that the fourth rotating part moves along the slide groove.

[0008] Furthermore, the robotic finger includes a driving part arranged on a first base, and the driving part includes a first actuator and a second actuator, the first actuator is used to move a second rotating part arranged on the second base, and the second actuator is used to move a third rotating part arranged on the second base. When the first actuator and the second actuator are driven synchronously to move the second rotating part and the third rotating part, the second base rotates around the X-axis of the first rotating part to perform flexion and extension movement; when the second actuator is driven alone to move the third rotating part, the second base rotates around the Y-axis of the first rotating part to perform side swing movement.

[0009] Furthermore, the X axes of the first rotating part, the second rotating part and the fourth rotating part are parallel and the Y axes are collinear, and the X axes of the second rotating part and the third rotating part are collinear.

[0010] Furthermore, the second base, the proximal knuckle connecting rod, the middle knuckle transmission rod, the middle knuckle connecting rod, the distal knuckle transmission rod and the distal knuckle connecting rod form a two-degree-of-freedom five-bar mechanism.

[0011] Furthermore, the distal knuckle transmission rod is formed as an "L"-shaped connecting rod, the turning angle of the "L"-shaped connecting rod limits the rotation range of the distal knuckle transmission rod, and the turning point of the "L"-shaped connecting rod is connected to the proximal knuckle connecting rod so that the distal knuckle transmission rod can rotate around the proximal knuckle connecting rod.

[0012] Compared with the prior art, the beneficial effects of the specific embodiments of the present invention are at least the following: 1. The robotic finger has both coupled grasping and adaptive grasping functions. In the early stage of grasping, it quickly envelops the grasped object through coupled grasping. After the proximal knuckle contacts the grasped object, it fits the grasped object more accurately through adaptive grasping; 2. The coupling mechanism and the adaptive mechanism are combined, and the structure is easy to implement; 3. The robotic finger adopts a rigid connecting rod to improve the movement speed of the robotic finger. At the same time, fewer elastic components are used to improve the movement accuracy of the robotic finger; 4. The under-actuated robotic finger design has a base joint with active freedom of flexion and extension and lateral swing movement, and the movement flexibility of the robotic finger is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a mechanical finger according to an embodiment of the present invention;

[0014] Figure 2 yes Figure 1 A cross-sectional view of the robotic finger shown;

[0015] Figure 3 is a schematic diagram of coupled flexion and extension motion of a robotic finger according to an embodiment of the present invention;

[0016] Figure 4 is a schematic diagram of the sideways swing motion of a robotic finger according to an embodiment of the present invention;

[0017] Figure 5a is a schematic diagram of a robotic finger not grasping an object according to an embodiment of the present invention;

[0018] Figure 5b is a schematic diagram of a coupled grasping motion of a robotic finger according to an embodiment of the present invention;

[0019] Figure 5c is a schematic diagram of a robotic finger according to an embodiment of the present invention contacting a grasped object with its proximal knuckle;

[0020] Figure 5d is a schematic diagram of adaptive grasping by a robotic finger according to an embodiment of the present invention;

[0021] Figure 6a is a schematic diagram of a fourth rotating portion in an initial position according to an embodiment of the present invention;

[0022] Figure 6b It is a schematic diagram of relative movement between the fourth rotating portion and the first base according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the technical solution of the present invention clearer, the embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the specific description of the implementation mode is only used to teach those skilled in the art how to implement the present invention, rather than to exhaustively list all feasible ways of the present invention, nor to limit the specific scope of implementation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0024] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They 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, or be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0025] Those skilled in the art will understand that when we refer to an element as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intervening elements. In addition, "connected" or "coupled" as used herein can include wireless connections or couplings. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0027] The specific embodiment of the present invention protects an under-actuated coupled adaptive mechanical finger, Figure 1-2 The robotic finger 100 includes a base joint, a proximal phalanx 61, a middle phalanx 62 and a distal phalanx 63. The proximal phalanx 61 is connected to the base joint. The base joint includes a first base 10 extending along the Z axis, and a second base 20 rotatably connected to the first base 10 through a first rotating part 51. The second base 20 can rotate around the X axis and Y axis of the first rotating part 51. The proximal phalanx 61 is connected to the second base 20 and can move with the second base 20.

[0028] The proximal knuckle 61 includes a proximal knuckle connecting rod 611 and a middle knuckle transmission rod 621. Figure 1 In the orientation shown, the robotic finger 100 is described horizontally, and the proximal knuckle connecting rod 611 and the middle knuckle transmission rod 621 are connected to the second base at intervals along the Y-axis direction (vertical direction). Specifically, the proximal knuckle connecting rod and the middle knuckle transmission rod are respectively connected to the upper and lower ends of the second base 20. Preferably, the middle knuckle transmission rod 621 is connected to the upper end of the second base 20, and the proximal knuckle connecting rod 611 is connected to the lower end of the second base 20, so that the driving unit 30 provided on the second base 20 can transmit power to the middle knuckle transmission rod 621. That is, the second base 20 connects the ends of the proximal knuckle connecting rod 611 and the middle knuckle transmission rod 621; the middle knuckle 62 includes the distal knuckle transmission rod 631 and the middle knuckle connecting rod 622, and the distal knuckle 63 includes the distal knuckle connecting rod 632. The second base 20, the proximal knuckle connecting rod 611, the middle knuckle transmission rod 621 and the distal knuckle transmission rod 631 form a two-degree-of-freedom five-link transmission mechanism, and the proximal knuckle 61 and the second base 20 each have one degree of freedom of flexion and extension.

[0029] The proximal knuckle link 611 is connected to the second base 20 , and the second base 20 is rotatably connected to the first base 10 via the first rotating portion 51 , that is, the proximal knuckle link 611 is indirectly connected to the first base 10 via the second base 20 and the first rotating portion 51 .

[0030] The robotic finger 100 includes a fixed-axis transmission rod 432, one end of which is connected to the proximal knuckle link 611, and the other end is connected to the fifth rotating part 55. The fifth rotating part 55 is connected to the first base 10 through the fourth rotating part 54. The fixed-axis transmission rod 432 can rotate around the connection between the fifth rotating part 55 and the proximal knuckle link 611. Exemplarily, the fifth rotating part 55 is formed as a ball joint transmission rod, and the fifth rotating part 55 is used to provide three degrees of freedom of movement, so that the fifth rotating part 55 can provide the degrees of freedom required for spatial movement.

[0031] The middle knuckle comprises a middle knuckle connecting rod and a distal knuckle transmission rod, and the distal knuckle comprises a distal knuckle connecting rod. The middle knuckle transmission rod is connected to the middle knuckle connecting rod, and the distal knuckle transmission rod is connected to the distal knuckle connecting rod.

[0032] The first base 10 is a fixed structural component, while the second base 20 is a movable structural component. The second base 20 performs flexion and extension when it rotates about the X-axis of the first rotating portion 51. The fourth rotating portion 54 is connected to the first base 10. The proximal knuckle connecting rod 611, the fixed-axis transmission rod 432, the fifth rotating portion 55, and the first base 10 form a first coupling transmission mechanism. When the proximal knuckle connecting rod 611 rotates along with the second base 20 about the X-axis, the ends of the fixed-axis transmission rod 432 rotate around the proximal knuckle connecting rod 611 and the fifth rotating portion 55, respectively.

[0033] The robot finger 100 includes a coupling transmission rod 433, one end of which is connected to the distal knuckle transmission rod 631, and the other end is connected to the fifth rotating part 55. The distal knuckle transmission rod 631 can rotate around the proximal knuckle connecting rod 611, that is, the coupling transmission rod 433 and the fixed axis transmission rod 432 are both connected to the fifth rotating part 55, wherein the proximal knuckle connecting rod 611, the distal knuckle transmission rod 631, the coupling transmission rod 433 and the fixed axis transmission rod 432 form a second coupling transmission mechanism. Figure 3 When the proximal knuckle 61 rotates along with the second base 20 about the X-axis, both ends of the coupling transmission rod 433 rotate about the fifth rotating portion 55 and the distal knuckle transmission rod 631, respectively. Exemplarily, the fixed-axis transmission rod 432, the proximal knuckle connecting rod 611, the coupling transmission rod 433, and the distal knuckle transmission rod 631 form an antiparallelogram mechanism. When the fixed-axis transmission rod 432 rotates clockwise about the fifth rotating portion 55, the distal knuckle transmission rod 631 rotates counterclockwise.

[0034] The proximal knuckle link 611, the middle knuckle link 622 and the distal knuckle link 632 are connected in sequence, and the distal knuckle transmission rod 631 is connected to the distal knuckle link 632. The proximal knuckle link 611, the middle knuckle link 622, the distal knuckle link 632 and the distal knuckle transmission rod 631 form a third coupling transmission mechanism.

[0035] As mentioned above, Figure 3 The robotic finger 100 includes a first coupling transmission mechanism, a second coupling transmission mechanism and a third coupling transmission mechanism. When the second base 20 rotates around the X-axis of the first rotating part 51 to perform flexion movement, coupled flexion and extension movement of the three finger joints is generated through the first coupling transmission mechanism, the second coupling transmission mechanism and the third coupling transmission mechanism.

[0036] Through the above solution, the robotic finger 100 has the function of coupled pinching. When the robotic finger 100 grasps a larger object, in the early stage of grasping, the grasped object 300 is quickly enclosed by coupled grasping.

[0037] Furthermore, the fourth rotating portion 54 is connected to the first base 10, and the fourth rotating portion 54 is arranged below the second base 20. Specifically, the fourth rotating portion 54 is arranged below the first rotating portion 51. When the second base 20 rotates around the X-axis of the first rotating portion 51, the fourth rotating portion 54 adaptively provides corresponding degrees of freedom of movement.

[0038] Ginseng Figure 6a-6b The fourth rotating part 54 and the first base 10 include an elastic moving component. When the mechanical finger 100 starts to grasp, Figure 5a-5b The middle phalanx 62 and the distal phalanx 63 can be coupled to flex and extend through the aforementioned first coupling transmission mechanism, the second coupling transmission mechanism and the third coupling transmission mechanism, and the robotic finger quickly envelops the grasped object 300 in a coupled grasping manner; Figures 5c-5d When the proximal knuckle 61 of the manipulator finger 100 contacts the grasped object 300, the movement of the proximal knuckle 61 is blocked, and the driving part 30 of the manipulator finger 100 continues to rotate so that the elastic moving component provided between the fourth rotating part 54 and the first base 10 overcomes the restraining force. Figure 6a-6b The fourth rotating part 54 moves along the Z-axis direction of the first base 10, more specifically, moves along the fingertip direction of the robotic finger 100, so that the coupled motion is released and switched to adaptive motion, and the middle finger joint 62 and the distal finger joint 63 adapt to the shape and size of the grasped object 300, so that the robotic finger 100 can adaptively grasp the grasped object 300.

[0039] Exemplarily, the second base 20, the proximal knuckle link 611, the middle knuckle transmission rod 621, the middle knuckle link 622, the distal knuckle transmission rod 631 and the distal knuckle link 632 form a two-degree-of-freedom five-link transmission mechanism and a third coupling transmission mechanism, and the proximal knuckle 61 and the second base 20 each have one degree of freedom of flexion and extension movement. Figures 5c-5d When the movement of the proximal phalanx 61 is blocked, the driving unit 30 continues to maintain the driving state, the second base 20 continues to perform flexion and extension, and the middle phalanx 62 and distal phalanx 63 adapt to the shape and size of the grasped object 300. The above-mentioned two-degree-of-freedom five-bar mechanism and the third coupling transmission mechanism constitute an adaptive transmission mechanism.

[0040] Through the above technical solution, the robotic finger 100 possesses the dual functions of coupled grasping and adaptive grasping, and is structurally simple to implement. Furthermore, each transmission rod and connecting rod utilizes a rigid connecting rod design. The elastic movable assembly indirectly changes the length of the coupled transmission rod 433, enabling the robotic finger 100 to achieve adaptive grasping, thus avoiding the problem of inaccurate motion caused by the use of elastic connecting rods in the prior art. Furthermore, the reduced number of elastic members 13 employed further improves the problem of inaccurate motion control.

[0041] Specifically, Figure 6a-6b The elastic moving component includes a slide groove 12 provided on the first base 10, and an elastic member 13 connected between the fourth rotating part 54 and the first base 10. The fourth rotating part 54 can move along the slide groove 12 when a force is applied. When the proximal phalanx 61 contacts the grasped object 300, the driving part 30 of the robotic finger 100 continues to drive, and the coupling transmission rod 433 pulls the fifth rotating part 55, thereby pulling the fourth rotating part 54 to move along the slide groove 12. Exemplarily, when the fourth rotating part 54 is not subjected to a force, the fourth rotating part 54 is in an initial position under the action of the elastic member 13; when the fourth rotating part 54 is subjected to a force, the elastic member 13 is stretched, the fourth rotating part 54 moves along the slide groove 12, and the middle phalanx 62 and the distal phalanx 63 continue to flex and extend and adapt to the shape and size of the grasped object 300.

[0042] Further, refer to Figure 2 The distal knuckle transmission rod 631 is formed into an "L"-shaped structure, with one end of the distal knuckle transmission rod 631 connected to the coupling transmission rod 433 and the other end connected to the distal knuckle connecting rod 632. The turning point of the "L"-shaped structure of the distal knuckle transmission rod 631 is connected to the proximal knuckle connecting rod 611, allowing the distal knuckle transmission rod 631 to rotate around the proximal knuckle connecting rod 611. The connecting pin between the proximal knuckle connecting rod 611 and the middle knuckle connecting rod 622 limits the rotational range of the "L"-shaped structure, thereby limiting the rotational range of the flexion and extension movement of the middle knuckle 62 and the distal knuckle 63.

[0043] Further, refer to Figure 1-4 The driving unit 30 of the robotic finger 100 is disposed on the first base 10. The driving unit 30 includes a first actuator 31 and a second actuator 32. The robotic finger 100 also includes a transmission unit for transmitting power from the driving unit 30. The first actuator 31 and the second actuator 32 are distributed in parallel on the first base 10. The first actuator 31 is used to move the second rotating unit 52 disposed on the second base 20, and the second actuator 32 is used to move the third rotating unit 53 disposed on the second base 20. The second base 20 is rotatably connected to the first base 10 via the first rotating unit 51.

[0044] Ginseng Figure 3 When the first actuator 31 and the second actuator 32 are driven synchronously, the second rotating part 52 and the third rotating part 53 move synchronously, the second base 20 rotates around the X-axis of the first rotating part 51, and the finger performs flexion and extension movement; Figure 4 When the second actuator 32 is driven independently relative to the first actuator 31 , the third rotating portion 53 moves so that the second base 20 rotates around the Y-axis of the first rotating portion 51 , and the finger performs a sideways swing motion.

[0045] It can be understood that when the first actuator 31 and the second actuator 32 are driven asynchronously, the second base 20 rotates around the X-axis and the Y-axis simultaneously.

[0046] That is, when the finger performs flexion and extension movement, power is provided by both the first actuator 31 and the second actuator 32, thereby providing a relatively large driving force, thereby reducing the volume of a single actuator; when the finger performs adduction / abduction movement, power is only provided by the second actuator 32, which improves the utilization rate of the actuator by providing a larger driving force to meet the flexion and extension movement requirements and a relatively small driving force to meet the lateral swing movement requirements.

[0047] Specifically, the transmission part includes a first transmission component 41 for transmitting power to the first actuator 31, and a second transmission component 42 for transmitting power to the second actuator 32. The first transmission component 41 is connected to the X-axis of the second rotating part 52, and the second transmission component 42 is connected to the Y-axis of the third rotating part 53.

[0048] The first kinematic branch of the base joint includes a first actuator 31, a first transmission assembly 41, and a second rotating portion 52. The second kinematic branch includes a second actuator 32, a second transmission assembly 42, and a third rotating portion 53. The first kinematic branch and the second kinematic branch are arranged in parallel. The first kinematic branch is a planar branch, and the second kinematic branch is a spatial branch. When the second base 20 simultaneously performs motion around the X-axis and around the Y-axis, the second kinematic branch can generate spatial motion. Compared to the prior art method of coupling two actuators of a symmetrical branch parallel mechanism to drive flexion / extension and adduction / abduction motion, the asymmetric branch parallel mechanism adopted in this solution can effectively avoid kinematic coupling, reduce the difficulty of mechanism assembly and motion control, and solve the problem of insufficient load-bearing capacity and stiffness of the kinematically decoupled asymmetric branch parallel mechanism compared to the strongly coupled symmetric branch parallel mechanism.

[0049] Among them, the first rotating part 51, the second rotating part 52, and the third rotating part 53 are connected to the second base 20, the second base 20 rotates around the first rotating part 51 to move relative to the base, the driving part 30 moves the second rotating part 52 and the third rotating part 53 to make the second base 20 produce corresponding movement, the fourth rotating part 54 is connected to the first base 10 and the fifth rotating part 55, and the first base 10 is a fixed structural part.

[0050] Specifically, the X-axes of the first rotating part 51, the second rotating part 52 and the fourth rotating part 54 are parallel and the Y-axes are collinear. When the second base 20 rotates around the X-axis of the first rotating part 51, the second base 20 rotates around the X-axes of the second rotating part 52 and the fourth rotating part 54 at the same time; the X-axes of the second rotating part 52 and the third rotating part 53 are collinear. When the second base 20 rotates around the Y-axis of the first rotating part 51, the second base 20 rotates around the Y-axes of the second rotating part 52 and the fourth rotating part 54 at the same time. The above design makes the rotation of the second base 20 around the X-axis and the rotation around the Y-axis relatively independent and decoupled from each other.

[0051] It is understood that the first rotating portion 51, the second rotating portion 52, the third rotating portion 53, and the fourth rotating portion 54 can rotate in at least two directions, so that the base joint can achieve two degrees of freedom of movement. For example, the first rotating portion 51, the second rotating portion 52, the third rotating portion 53, and the fourth rotating portion 54 can use connecting components such as universal joints and cross shafts to achieve vertical axis rotation.

[0052] The beneficial effects of the above preferred embodiments are: providing a robotic finger that has both adaptive grasping and coupled grasping functions, and is structurally easy to implement; the transmission rod and connecting rod of the robotic finger both use rigid connecting rods, which is beneficial to improving the movement accuracy of the robotic finger compared to the method of using elastic connecting rods with variable rod lengths; the base joint has two active degrees of freedom of flexion and extension and lateral swing movement, the flexibility of the robotic finger is good, and the flexion and extension movement and lateral swing movement are uncoupled, reducing the difficulty of mechanism assembly and motion control.

[0053] Finally, it should be noted that due to the limitations of textual expression, the above description is merely illustrative and not exhaustive. The present invention is not limited to the disclosed embodiments. Without departing from the scope and spirit of the above examples, improvements and modifications may be made by those skilled in the art, and such improvements and modifications should also be considered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. An underactuated coupled adaptive robotic finger, characterized in that: include: base joint, proximal phalanx, middle phalanx, and distal phalanx; The base joint includes a first base extending along the Z axis, and a second base rotatably connected to the first base via a first rotating portion; The proximal knuckle includes a proximal knuckle connecting rod and a middle knuckle transmission rod, wherein the proximal knuckle connecting rod and the middle knuckle transmission rod are connected to the second base at intervals along the Y-axis direction; a fixed-axis transmission rod, one end of which is connected to the proximal knuckle connecting rod, and the other end of which is connected to the fifth rotating part, wherein the fifth rotating part is connected to the first base via the fourth rotating part; A coupling transmission rod, one end of which is connected to the distal knuckle transmission rod and the other end of which is connected to the fifth rotating part, wherein the distal knuckle transmission rod can rotate around the proximal knuckle connecting rod; the fixed-axis transmission rod, the proximal knuckle connecting rod, the coupling transmission rod and the distal knuckle transmission rod form an antiparallelogram mechanism; When the second base rotates around the X-axis to perform flexion and extension, the middle phalanx and the distal phalanx perform coupled flexion and extension; An elastic moving component is included between the fourth rotating part and the first base. When the proximal knuckle contacts the grasped object, the elastic moving component is subjected to force to cause the fourth rotating part to move along the Z-axis direction of the first base. The middle knuckle and distal knuckle adapt to the shape and size of the grasped object.

2. The underactuated coupled adaptive robotic finger according to claim 1, characterized in that: The elastic moving component includes a sliding groove arranged on the first base, and an elastic member connected between the fourth rotating part and the first base, and the elastic member is deformed by force to enable the fourth rotating part to move along the sliding groove.

3. The underactuated coupled adaptive robotic finger according to claim 1, characterized in that: The robotic finger includes a driving part arranged on a first base, and the driving part includes a first actuator and a second actuator, the first actuator is used to move a second rotating part arranged on the second base, and the second actuator is used to move a third rotating part arranged on the second base. When the first actuator and the second actuator are driven synchronously to move the second rotating part and the third rotating part, the second base rotates around the X-axis of the first rotating part to perform flexion and extension movement; when the second actuator is driven alone to move the third rotating part, the second base rotates around the Y-axis of the first rotating part to perform lateral swing movement.

4. The underactuated coupled adaptive robotic finger according to claim 3, characterized in that: The X axes of the first rotating part, the second rotating part and the fourth rotating part are parallel and their Y axes are collinear. The X axes of the second rotating part and the third rotating part are collinear.

5. The underactuated coupled adaptive robotic finger according to claim 1, characterized in that: The proximal knuckle connecting rod, the middle knuckle transmission rod, the middle knuckle connecting rod, the distal knuckle transmission rod and the distal knuckle connecting rod form a two-degree-of-freedom five-bar mechanism.

6. The underactuated coupled adaptive robotic finger according to claim 1, characterized in that: The distal knuckle transmission rod is formed as an "L"-shaped connecting rod, the turning angle of the "L"-shaped connecting rod limits the rotation range of the distal knuckle transmission rod, and the turning point of the "L"-shaped connecting rod is connected to the proximal knuckle connecting rod so that the distal knuckle transmission rod can rotate around the proximal knuckle connecting rod.

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