A bionic mechanical finger

Abstract

The present invention provides a bionic robotic finger, comprising a first base extending along the length of the robotic finger; a finger joint portion rotatably connected to the front side of the first base via a first motion shaft; a first drive unit disposed on the first base, the first drive unit being connected to the finger joint portion via a first transmission assembly to drive the finger joint portion to rotate around the first motion shaft to perform a first rotational motion; a finger base rotatably connected to the rear side of the first base via a second motion shaft; a second drive unit connected to the finger base, the second drive unit being connected to the front side of the first base via a second transmission assembly to drive the first base to rotate around the second motion shaft to perform a second rotational motion. The robotic finger of a specific embodiment of the present invention has three active degrees of freedom and good flexibility. The second drive unit adopts a cross-joint drive method, which effectively reduces the motion inertia of the robotic finger.

Description

Technical Field

[0001] The invention belongs to the technical field of manipulators, and in particular relates to a bionic manipulator finger. Background Art

[0002] To assist or replace human hands in human work environments, robotic arms must achieve flexible and precise movements. Based on the relationship between the manipulator's degrees of freedom and the number of actuators, they are typically categorized as underactuated and fully actuated. Existing underactuated manipulators are primarily divided into coupled arms, flat gripper arms, adaptive arms, coupled adaptive arms, and flat gripper adaptive arms. Underactuated arms can reduce weight and structural complexity by minimizing the number of actuators.

[0003] Current robotic arm design focuses on creating dexterous, humanoid hands, aiming for highly human-like features with minimal weight, compact size, and high flexibility. The thumb, index finger, and middle finger require high flexibility to ensure optimal performance. Existing robotic arms often suffer from insufficient degrees of freedom, large size, and high inertia. Therefore, it is necessary to design compact, lightweight, and highly flexible robotic fingers to enhance overall performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a bionic mechanical finger with three active degrees of freedom and good flexibility. The first and second joints adopt an under-actuated mechanism to reduce the number of drives. In addition, the transmission components are simplified to make the mechanical finger structure simpler and lighter, thereby improving the problems of complex structure, heavy weight and poor flexibility of mechanical fingers in the prior art.

[0005] In order to solve the above technical problems, the present invention may adopt the following technical solutions: a bionic mechanical finger, comprising: a first base, extending along the length direction of the mechanical finger; a finger joint part, rotatably connected to the front side of the first base through a first motion axis; a first drive unit, arranged on the first base, the first drive unit is connected to the finger joint part through a first transmission assembly to drive the finger joint part to rotate around the first motion axis to perform a first rotational motion; a finger base, rotatably connected to the rear side of the first base through a second motion axis; a second drive unit, connected to the finger base, the second drive unit is connected to the front side of the first base through a second transmission assembly to drive the first base to rotate around the second motion axis to perform a second rotational motion.

[0006] Furthermore, the robotic finger includes: a third driving unit connected to the finger base, the finger base includes a third motion shaft arranged along the length direction of the robotic finger, and the third driving unit drives the finger base to rotate around the third motion shaft to perform a third rotational motion.

[0007] Furthermore, the second drive unit is arranged on the rear side of the finger base, and the second drive unit transmits the motion to the second transmission assembly arranged on the front side of the finger base through the base transmission shaft passing through the finger base, and the base transmission shaft and the third motion shaft are coaxially arranged.

[0008] Furthermore, the second drive unit is placed horizontally on the rear side of the finger base, and the second drive unit transmits the rotational motion to the base transmission shaft through the second gear set, and the second gear set is used to change the rotational motion direction of the second drive unit.

[0009] Furthermore, the first drive unit and the first transmission assembly are arranged on the first base along the height direction, and the movement of the first drive unit is transmitted to the first transmission assembly through the first gear set arranged at the end of the first base.

[0010] Furthermore, the first transmission assembly includes a first linear motion member and a first screw transmission rod, the first linear motion member converts the rotational motion of the first drive unit into linear motion, the first linear motion member includes a first screw and a first nut that cooperate with each other, and the first screw transmission rod is fixedly connected to the first nut; the second transmission assembly includes a second linear motion member and a second screw transmission rod, the second linear motion member converts the rotational motion of the second drive unit into linear motion, the second linear motion member includes a second screw and a second nut that cooperate with each other, and the second screw transmission rod is fixedly connected to the second nut.

[0011] Furthermore, the knuckle portion includes a first knuckle and a second knuckle, the first knuckle includes a second base, the second base is connected to the first base via a first motion shaft, and the first driving unit drives the knuckle portion to rotate around the first motion shaft via the second base.

[0012] Furthermore, the first knuckle includes a first knuckle connecting rod, a first transmission rod, a second transmission rod and a third transmission rod, the second knuckle includes a second knuckle connecting rod, one end of the third transmission rod is rotatably connected to the first base, and the other end is hinged to the first transmission rod and the second transmission rod, the second transmission rod is rotatably connected to the first knuckle connecting rod, and the first transmission rod is connected to the second knuckle connecting rod.

[0013] Furthermore, when the robotic finger is in an initial position where no movement occurs, the knuckle portion deflects by a preset angle relative to the first base. Compared to the prior art, the beneficial effects of the specific embodiments of the present invention are: 1. It provides a highly dexterous bionic robotic finger with three active degrees of freedom, which improves the flexibility of the robotic finger; 2. The flexion / extension movement of the robotic finger adopts a link-coupled under-actuated mechanism, in which a single drive unit drives the movement of two knuckles, reducing the number of drives; 3. The structural design enables the abduction / adduction range of the robotic finger to be large, thereby improving the gripping ability of the robotic hand; 4. The first and second transmission assemblies adopt a linear drive design, eliminating the need for a guide member, thereby simplifying the structure of the robotic finger. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a bionic mechanical finger according to an embodiment of the present invention;

[0015] Figure 2 Schematic diagram of the various motion axes of a bionic mechanical finger according to an embodiment of the present invention;

[0016] Figure 3 is a cross-sectional view of a bionic mechanical finger according to an embodiment of the present invention;

[0017] Figure 4 is a schematic diagram of a bionic mechanical finger performing a first rotational motion according to an embodiment of the present invention;

[0018] Figure 5 is a schematic diagram of a bionic mechanical finger performing a second rotational motion according to an embodiment of the present invention;

[0019] Figure 6 Schematic diagram of a bionic mechanical finger performing a third rotational motion according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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 specific circumstances.

[0024] The specific embodiment of the present invention protects a bionic mechanical finger, Figure 1 The robotic finger 100 includes a first base 10, a finger joint portion 60 connected to the front side of the first base 10, and a finger base 70 connected to the rear side of the first base 10. The first base 10 extends along the length direction of the robotic finger 100. The finger joint portion 60 is rotatably connected to the first base 10 through a first motion shaft 51. A first driving unit 31 is provided on the first base 10. The first driving unit 31 is connected to the finger joint portion 60 through a first transmission assembly 41. The first driving unit 31 drives the finger joint portion 60 to rotate around the first motion shaft 51 to perform a first rotational motion through the first transmission assembly 41. Figure 4 Specifically, the first rotational movement is a flexion / extension movement.

[0025] Among them, the "length direction" referred to in this application, unless otherwise specified, refers to the direction of the longer side of the finger, refer to the length direction of human fingers; the definitions of "front" and "back" in this application, unless otherwise specified, refer to the direction where the fingertip is located as "front".

[0026] Ginseng Figure 2-3 The knuckle portion 60 exemplarily includes a first knuckle 61 and a second knuckle 62, and the first transmission assembly 41 is connected to the first knuckle 61. Specifically, the first knuckle 61 includes a second base 20, and the second base 20 is rotatably connected to the first base 10 through a first motion shaft 51. The first transmission assembly 41 is connected to the second base 20. When the first driving unit 31 is driven, the first transmission assembly 41 applies a force to the second base 20, so that the second base 20 rotates around the first motion shaft 51.

[0027] It is understandable that in this embodiment, the knuckle portion 60 exemplarily includes a first knuckle 61 and a second knuckle 62. In other embodiments, the knuckle portion can be provided with a number of knuckles as needed, for example, the knuckle portion only includes the first knuckle, or a greater number of knuckles can be provided.

[0028] Specifically, Figure 1 and Figure 3 The first finger joint 61 includes a first finger joint link 614, a first transmission rod 611, a second transmission rod 612 and a third transmission rod 613. The first finger joint link 614 is fixed to the second base 20 to follow the movement. One end of the third transmission rod 613 is rotatably connected to the first base 10, and the other end is connected to the first transmission rod 611 and the second transmission rod 612 through a ball joint universal joint. The second transmission rod 612 is rotatably connected to the first finger joint link 614. The first transmission rod 61 1 is connected to the second knuckle link 621. That is, the first base 10, the first knuckle link 614, the second transmission rod 612, and the third transmission rod 613 form a four-bar transmission mechanism. The first knuckle link 614, the second knuckle link 621, the first transmission rod 611, and the second transmission rod 612 form an antiparallelogram transmission mechanism. When the first knuckle 61 rotates around the first motion axis 51 via the second base 20, the second knuckle link 621 and the first knuckle link 614 are coupled and underdriven. That is, when the first knuckle 61 rotates around the first motion axis 51, the second knuckle 62 generates a coupled motion.

[0029] The flexion / extension motion of the robotic finger 100 utilizes a linkage-coupled underactuated mechanism, with the first drive unit 31 driving the motion of both joints, thus reducing the number of drive units. Furthermore, the use of a linkage mechanism in the robotic finger 100 improves the motion precision of the robotic finger 100, overcoming the shortcomings of conventional robotic fingers 100 in terms of degrees of freedom, dexterity, and motion precision.

[0030] Among them, when the robotic finger is in an initial position where no movement is generated, the knuckle portion is deflected relative to the first base by a preset angle. The robotic finger can be used as a thumb, for example. When the thumb cooperates with other fingers to perform a palm-to-palm movement, the contact area when grasping an object during the palm-to-palm movement is increased. For example, the preset angle can be selected as 10°. The preset angle is set comprehensively based on factors such as the size of the robotic finger. It is understandable that when the robotic finger is installed on the palm, the existence of the preset angle causes the robotic finger to face the inside of the palm in the initial position. In this way, the first knuckle 61 of the robotic finger 100 can actively perform flexion / extension movement, and the second knuckle 62 can passively couple movement.

[0031] Specifically, Figure 1 The first drive unit 31 and the first transmission assembly 41 are arranged along the height direction on the first base 10. The first base 10 is provided with a first gear set 416. The first gear set 416 is arranged at the end of the first base 10 to transmit the movement of the first drive unit 31 to the first transmission assembly 41. By arranging the first drive unit 31 and the first transmission assembly 41 along the height direction on the first base 10, the structure of the robot finger 100 is compact and the length occupied by the robot finger is reduced.

[0032] The first transmission assembly 41 includes a first linear motion member and a first screw transmission rod 411 . The first linear motion member can convert the rotational motion of the first driving unit 31 into linear motion.

[0033] Ginseng Figure 1-3 The finger base 70 is rotatably connected to the rear side of the first base 10 through the second motion shaft 52, the second drive unit 32 is connected to the finger base 70, and the second drive unit 32 is connected to the front side of the first base 10 through the second transmission assembly 42 to drive the first base 10 to rotate around the second motion shaft 52 to perform the second rotational motion. Figure 5 Specifically, the second rotation movement is an abduction / adduction movement.

[0034] Specifically, the second drive unit 32 is horizontally connected to the rear side of the finger base 70, and the finger base 70 includes a base transmission shaft 71 along the length direction of the finger. The second drive unit 32 transmits the rotational motion to the second transmission assembly 42 through the base transmission shaft 71. The second transmission assembly 42 is connected to the front side of the first base 10. The second drive unit 32 drives the first base 10 to rotate around the second motion axis 52 to perform the second rotational motion through the base transmission shaft 71 and the second transmission assembly 42. Specifically, the first base 10 drives the knuckle part 60 to rotate around the second motion axis 52 to perform the second rotational motion.

[0035] Exemplarily, the second drive unit 32 transmits rotational motion to the second transmission assembly 42 via the base drive shaft 71 via a second gear set 426. The second gear set 426 exemplarily includes a bevel gear or a face gear to convert the direction of motion. The second transmission assembly 42 includes a second linear motion member and a second lead screw drive rod 421. The second linear motion member is used to convert the rotational motion of the second drive unit 32 into linear motion. When the second drive unit 32 is driven, the second transmission assembly 42 applies a force to the first base 10, causing the first base 10 to rotate about the second motion axis 52.

[0036] In the above method, the second drive unit 32 is set on the rear side of the finger base 70, and the first base 10 is driven to rotate around the second motion axis 52 by cross-joint driving to perform the second rotational motion, which is beneficial to position the center of gravity of the robotic finger backward and reduce the motion inertia of the robotic finger; placing the second drive unit 32 horizontally on the rear side of the finger base 70 can advantageously reduce the length of the robotic finger and make full use of the palm space of the robotic hand.

[0037] Specifically, the first transmission assembly 41 and the second transmission assembly 42 are both formed as linear driving members, and the first transmission assembly 41 and the second transmission assembly 42 are used to generate linear motion.

[0038] Further, refer to Figure 1 The robotic finger 100 further includes a third drive unit 33 connected to the finger base 70. For example, the third drive unit 33 is arranged in parallel with the second drive unit 32, and the third drive unit 33 is placed horizontally on the rear side of the finger base 70. The finger base 70 includes a third motion shaft 53 arranged along the length direction of the finger. The third drive unit 33 is used to drive the finger base 70 to rotate around the third motion shaft 53 to perform a third rotational motion. Specifically, Figure 6 The third rotational motion is an outward / inward swing motion. When the finger base 70 rotates around the third motion axis 53, the first base 10 and the finger joint 60 connected thereto are driven to rotate as a whole around the third motion axis 53.

[0039] Furthermore, the base transmission shaft 71 and the third motion shaft 53 are coaxially arranged, and the structural compactness of the robotic finger 100 is improved through the coaxial transmission mode.

[0040] Understandable, Figure 4 When the first driving unit 31 is driven, the finger joint portion 60 rotates around the first movement shaft 51 to perform the first rotational motion; Figure 5 When the second driving unit 32 is driven, the first base 10 drives the finger joint portion 60 to rotate around the second movement shaft 52 to perform the second rotational motion; Figure 6When the third drive unit 33 is driven, the finger base 70 drives the first base 10 and the finger joint 60 to rotate about the third motion axis 53 to perform a third rotational motion. At this time, the second drive unit 32 can perform a compensating motion so that the third rotational motion does not affect the joint angle of the second rotational motion. It can be understood that each drive unit corresponds to an active degree of freedom. When different drive units are combined, the robotic finger 100 simultaneously exhibits a combined rotational motion. For example, when the first drive unit 31 and the second drive unit 32 are driven simultaneously, the robotic finger 100 simultaneously performs the first rotational motion and the second rotational motion.

[0041] Specifically, the second driving unit 32 provided at the rear side of the finger base 70 is used to drive the first base 10 provided at the front side of the finger base 70 to rotate around the second motion axis 52 , and the second driving unit 32 is a cross-joint drive.

[0042] Specifically, the third driving unit 33 is arranged at the rear side of the finger base 70 and drives the finger base 70 to rotate around the third motion shaft 53 through a worm gear transmission. The worm gear transmission can be used to convert the rotational movement direction of the third driving unit 33.

[0043] The first transmission assembly 41 is used to transmit power from the first drive unit 31 , and the second transmission assembly 42 is used to transmit power from the second drive unit 32 .

[0044] In a specific embodiment, the first transmission assembly 41 includes a first linear motion member and a first screw transmission rod 411, the first linear motion member includes a first screw 413 and a first nut 412, the first screw 413 and the first nut 412 cooperate to convert the rotational motion of the first drive unit 31 into linear motion, the first screw transmission rod 411 is fixedly connected to the first nut 412, the first screw transmission rod 411 receives the rotational motion of the first drive unit 31, that is, the first nut 412 receives the rotation of the first drive unit 31 The first screw 413 generates linear motion, applies a force to the knuckle 60, and then causes the knuckle 60 to rotate around the first motion shaft 51. The first nut 412 rotates and drives the first screw 413 to generate linear motion. In another embodiment, the first screw 413 is used to receive the rotational motion of the first drive unit 31, convert it into linear motion through the first nut 412, and apply a force to the knuckle 60 through the first screw transmission rod 411 fixed to the first nut 412, so that the knuckle 60 rotates around the first motion shaft 51. Exemplarily, the first screw transmission rod 411 is formed as a hollow rod, and the first screw transmission rod 411 is arranged on the outside of the first screw 413. When the first drive unit 31 is driven, the first screw transmission rod 411 and the first screw 413 generate relative motion.

[0045] Furthermore, the second transmission assembly 42 includes a second linear motion member and a second lead screw drive rod 421, which includes a second lead screw 423 and a second nut 422 that cooperate with each other. The second transmission assembly 42 exemplarily employs the same design as the first transmission assembly 41. Therefore, the movement and structure of the various components of the second transmission assembly 42 can be understood with reference to the first transmission assembly 41 and will not be further described here. When the second drive unit 32 is driven, the second transmission assembly 42 is connected to the front side of the first base 10 and applies a force to the first base 10, causing the first base 10 to rotate about the second motion shaft 52 disposed on the rear side to perform the second rotational motion.

[0046] In the above embodiment, the first transmission assembly 41 and the second transmission assembly 42 each transmit power from the first drive unit 31 and the second drive unit 32, and each generates linear motion. The first screw drive rod 411 is fixed to the first nut 412, and the second screw drive rod 421 is fixed to the second nut 422. The first screw drive rod 411 moves along the axis of the first screw 413, and the second screw drive rod 421 moves along the axis of the second screw 423. It is understood that one end of the first transmission assembly 41 is connected to the first base 10 via a cross-axis universal joint, and the other end is connected to the second base 20 via a hinge. One end of the second transmission assembly 42 is connected to the finger base 70 via a cross-axis universal joint, and the other end is connected to the first base 10 via a hinge. This method prevents axial rotation of the first nut 412 and the second nut 422. In addition, the structures of the first transmission assembly 41 and the second transmission assembly 42 do not require guide rods, which helps simplify the structural design of the robotic finger.

[0047] As can be understood, the structural distribution of the aforementioned robotic finger facilitates its reduced length, making it suitable for use as a thumb. The various rotational movements of the robotic finger experience less interference, thus allowing for a wider range of motion. The wide range of outward and inward swing motions facilitates coordination with other fingers in performing palm-op movements, resulting in a more anthropomorphic effect.

[0048] In the preferred embodiment of the above scheme, the robotic finger has three active degrees of freedom and one passive degree of freedom, and the flexibility of the robotic finger is good; the first drive unit drives the first joint and the second joint to move at the same time, and the second joint can be coupled to move, reducing the number of drive units; the first drive unit and the first transmission assembly are arranged on the first base along the height direction, so that the structure of the robotic finger is compact, and the second drive unit is placed behind the robotic finger, driving the first base to move across the joint, which is beneficial to reducing the movement inertia of the robotic finger.

[0049] 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. A bionic mechanical finger, characterized in that: include: A first base extending along the length of the robotic finger; a finger joint portion rotatably connected to the front side of the first base via a first motion shaft; a first drive unit, disposed on the first base, connected to the knuckle portion via a first transmission assembly to drive the knuckle portion to rotate about a first movement axis to perform a first rotational motion; the first rotational motion being a flexion / extension motion; a finger base, wherein the rear side of the first base is rotatably connected to the finger base via a second motion shaft; a second driving unit connected to the finger base, the second driving unit being connected to the front side of the first base via a second transmission assembly to drive the first base to rotate around the second motion axis to perform a second rotational motion; The second rotational movement is the abduction / adduction movement; The mechanical finger comprises: The third driving unit is connected to the finger base, and the finger base includes a third motion shaft arranged along the length direction of the mechanical finger. The third driving unit drives the finger base to rotate around the third motion shaft to perform a third rotational motion; the third rotational motion is an outward swing / inward swing motion.

2. The bionic mechanical finger according to claim 1, characterized in that: The second drive unit is arranged on the rear side of the finger base, and the second drive unit transmits motion to the second transmission assembly arranged on the front side of the finger base through the base transmission shaft passing through the finger base. The base transmission shaft and the third motion shaft are coaxially arranged.

3. The bionic mechanical finger according to claim 2, characterized in that: The second driving unit is vertically arranged at the rear side of the finger base. The second driving unit transmits the rotational motion to the base transmission shaft through the second gear set. The second gear set is used to change the rotational motion direction of the second driving unit.

4. The bionic mechanical finger according to claim 1, characterized in that: The first driving unit and the first transmission assembly are arranged on the first base along the height direction, and the movement of the first driving unit is transmitted to the first transmission assembly through the first gear set arranged at the end of the first base.

5. The bionic mechanical finger according to claim 1, characterized in that: The first transmission assembly includes a first linear motion member and a first screw transmission rod. The first linear motion member converts the rotational motion of the first drive unit into linear motion. The first linear motion member includes a first screw and a first nut that cooperate with each other. The first screw transmission rod is fixedly connected to the first nut. The second transmission assembly includes a second linear motion member and a second screw transmission rod. The second linear motion member converts the rotational motion of the second drive unit into linear motion. The second linear motion member includes a second screw and a second nut that cooperate with each other. The second screw transmission rod is fixedly connected to the second nut.

6. The bionic mechanical finger according to claim 1, characterized in that: The knuckle portion includes a first knuckle and a second knuckle, the first knuckle includes a second base, the second base is connected to the first base via a first motion shaft, and the first driving unit drives the knuckle portion to rotate around the first motion shaft via the second base.

7. The bionic mechanical finger according to claim 6, characterized in that: The first knuckle includes a first knuckle connecting rod, a first transmission rod, a second transmission rod and a third transmission rod. The second knuckle includes a second knuckle connecting rod. One end of the third transmission rod is rotatably connected to the first base, and the other end is hinged to the first transmission rod and the second transmission rod. The second transmission rod is rotatably connected to the first knuckle connecting rod, and the first transmission rod is connected to the second knuckle connecting rod.

8. The bionic mechanical finger according to claim 1, characterized in that: When the robotic finger is in an initial position where no movement is generated, the finger joint portion is deflected by a preset angle relative to the first base.

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