Two-degree-of-freedom finger mechanism of five-finger manipulator

Abstract

The two-degree-of-freedom finger mechanism of the five-finger manipulator is suitable for five-finger manipulator equipment of a humanoid robot and serves as a ring finger and little finger module. The robot consists of two parts, namely a finger bending assembly and a finger swinging assembly. The finger bending assembly drives a ball screw nut pair through a driving motor to convert rotary motion into linear motion, and then a ball nut drives an elastic connecting rod and finger joints to achieve bending motion of fingers. The finger swinging assembly drives a bevel gear set through a driving motor, and after the direction of rotating motion is changed, a connecting rod and finger joints are driven through a universal joint to achieve the swinging action of fingers. According to the two-degree-of-freedom mechanical finger, the two assemblies are ingeniously combined to one finger, and the overall size of the mechanical finger is reduced while two-degree-of-freedom movement is achieved. And in combination with the use of the elastic connecting rod, the driving motor is protected, and the action area of the manipulator and the grabbed object is increased.

Description

Technical Field

[0001] The present invention is applied to a five-finger manipulator mechanism of a humanoid robot and relates to a two-degree-of-freedom finger mechanism design of the five-finger manipulator, which is suitable for finger modules of the ring finger and the little finger. Background Art

[0002] One of the core functions of humanoid robots is to grasp and manipulate various objects and tools. Five-finger manipulators, which simulate the movements of the human hand, are an ideal solution for achieving this function. In addition to the bending and grasping function, some existing five-finger manipulator designs also achieve independent side-swing of the fingers. However, while rope-driven manipulators have a certain degree of flexibility, they are heavy and difficult to integrate the transmission structure into the hand. They also perform poorly in terms of durability and reliability. In addition, using a single motor to directly drive each finger to achieve independent side-swing movement results in an excessive number of motors, which takes up a lot of space and is not conducive to improving the compactness of the hand structure. Therefore, a highly integrated finger mechanical structure is urgently needed to overcome the above-mentioned shortcomings. Summary of the Invention

[0003] The technical problem solved by the present application is: to overcome the deficiencies of the existing technology and provide a two-degree-of-freedom finger mechanism of a five-finger manipulator, which comprehensively considers factors such as volume, load, flexible interaction, and impact change, and can simultaneously realize two degrees of freedom on one finger, namely finger bending movement and finger swinging movement, thereby improving the mobility of the robot manipulator and improving the degree of freedom of the manipulator.

[0004] The technical solutions provided in this application are as follows:

[0005] A two-degree-of-freedom finger mechanism of a five-finger manipulator includes a finger base, a finger assembly, a finger bending assembly and a finger swing assembly; the finger swing assembly includes a universal joint and a swing drive assembly, the universal joint is rotatably connected to the finger base, and the swing drive assembly is used to drive the universal joint to rotate; the finger bending assembly includes a ball nut and a bending drive assembly, the ball nut is slidably connected to the finger base, the sliding direction of the ball nut is perpendicular to the rotation axis of the universal joint, and the bending drive assembly is used to drive the ball nut to move; the finger assembly includes a lower finger joint, a middle finger, an upper finger joint, an upper elastic connecting rod and a lower elastic connecting rod, one end of the lower finger joint is rotatably connected to the universal joint and connected to the ball nut through the universal connecting rod, the other end of the lower finger joint is hinged to one end of the middle finger through a first rotating rod, and the other end of the middle finger is hinged to the upper finger joint through a second rotating rod, one end of the lower elastic connecting rod is rotatably connected to the universal joint, and the other end is slidably connected to the lower finger joint, one end of the upper elastic connecting rod is rotatably connected to the lower finger joint, and the other end is rotatably connected to the upper finger joint.

[0006] The lower finger joint, middle finger joint and upper finger joint that are hinged to each other form a group of connecting parts. There are two groups of connecting parts in total, and the two groups of connecting parts share the first rotating rod and the second rotating rod.

[0007] The upper elastic link and the lower elastic link are elastic.

[0008] The upper elastic connecting rod and the lower elastic connecting rod both have a serpentine bending structure.

[0009] An arc-shaped groove with the axis of the first rotating rod as the axis is opened on one side of the lower finger joint, and a protrusion is provided at one end of the lower elastic connecting rod connected to the lower finger joint. The protrusion is located in the arc-shaped groove so that the protrusion slides along the arc-shaped groove and rotates in the arc-shaped groove.

[0010] A guide groove with the axis of the first rotating rod as the axis is provided on the side of the lower finger joint away from the lower elastic connecting rod, and a guide block is provided at the end of the middle finger. The guide block is located in the guide groove so that the guide block slides along the guide groove and rotates in the guide groove.

[0011] The swing drive assembly includes a swing drive motor and a direction-changing bevel gear set, the direction-changing bevel gear set includes a first bevel gear and a second bevel gear, the swing drive motor is fixedly connected to the finger base, the output shaft of the swing drive motor is connected to the second bevel gear, the end of the universal joint is connected to the first bevel gear, and the first bevel gear is matched with the second bevel gear.

[0012] The bending drive assembly includes a bending drive motor, a spur gear set and a ball screw. The spur gear set includes a first spur gear and a second spur gear. The ball screw is rotatably connected to the finger base, and the end of the ball screw is connected to the first spur gear. The bending drive motor is fixedly connected to the finger base, and the output shaft of the bending drive motor is connected to the second spur gear, and the second spur gear cooperates with the first spur gear.

[0013] The universal connecting rod includes an upper rod and a lower rod, one end of the upper rod and the lower rod are rotatably connected, the other end of the lower rod is hinged to the ball nut, the other end of the upper rod is rotatably connected to the lower finger joint, the rotation axis between the upper rod and the lower finger joint is perpendicular to the rotation axis of the universal joint and the ball screw, and the rotation axis between the upper rod and the lower finger joint is perpendicular to the rotation axis between the upper rod and the lower finger joint.

[0014] The finger base includes a vertical base, a horizontal upper base, a horizontal lower base and a horizontal mounting plate, the horizontal upper base and the horizontal lower base are fixedly connected to one side of the vertical base, the horizontal mounting plate is fixedly connected to the other side of the vertical base, and the horizontal upper base and the horizontal lower base are parallel to each other, the ball screw is rotatably connected between the horizontal upper base and the horizontal lower base, one end of the ball screw extends out of the horizontal lower base away from the side of the horizontal upper base, and the end of the ball screw extending out of the horizontal lower base is connected to the first spur gear, the bending drive motor is fixedly connected to the vertical base and is located between the horizontal upper base and the horizontal lower base, the output shaft of the bending drive motor extends out of the horizontal lower base, and the end of the output shaft of the bending drive motor extending out of the horizontal lower base is connected to the second spur gear; the universal joint is rotatably connected to the vertical base, and the universal joint is located on the side of the horizontal upper base away from the horizontal lower base, one end of the universal joint extending out of the vertical base and connected to the horizontal mounting plate is connected to the first bevel gear, the swing drive motor is fixedly connected to the side of the horizontal mounting plate away from the universal joint, and the output shaft of the swing drive motor extends out of the horizontal mounting plate, and the end of the output shaft of the swing drive motor extending out of the horizontal mounting plate is connected to the second bevel gear.

[0015] In summary, this application has at least the following beneficial technical effects:

[0016] 1. The present invention discloses a two-degree-of-freedom finger mechanism design for a five-finger manipulator, which realizes the ability of independent single fingers to have two degrees of freedom to move independently in a smaller size by combining a finger bending component with a finger swing component.

[0017] 2. This invention discloses a two-degree-of-freedom finger mechanism design for a five-finger manipulator, replacing traditional inelastic links with elastic ones. This design reduces the rigid impact on the motor when grasping an object, minimizing the possibility of damage to the drive motor. It also makes the movement of the manipulator's fingers more like biological fingers, increasing the gripping area when grasping irregular objects and allowing the gripping surface to more closely conform to the object being grasped. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of finger bending action;

[0019] Figure 2 Schematic diagram of finger swinging action;

[0020] Figure 3 This is a schematic diagram of the finger structure of the present invention;

[0021] Figure 4 Schematic diagram of the structure of the upper elastic link and the lower elastic link.

[0022] Description of reference numerals:

[0023] 1-bending drive motor, 2-spur gear set, 3-ball screw, 4-ball nut, 5-universal connecting rod, 6-lower finger joint, 7-middle finger, 8-upper finger joint, 9-upper elastic connecting rod, 10-lower elastic connecting rod, 11-universal joint, 12-direction-changing bevel gear set, 13-swing drive motor. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] The embodiment of the present application discloses a two-degree-of-freedom finger mechanism of a five-finger manipulator, such as Figure 1 As shown, it includes a finger base, a finger assembly, a finger bending assembly and a finger swing assembly.

[0026] like Figure 3 As shown, the finger assembly includes a lower finger joint 6, a middle finger 7, an upper finger joint 8, an upper elastic link 9 and a lower elastic link 10. One end of the lower finger joint 6 is connected to the finger swing assembly and the finger bending assembly. The other end of the lower finger joint 6 is hinged to one end of the middle finger 7 through a first rotating rod. The other end of the middle finger 7 is hinged to the upper finger joint 8 through a second rotating rod. The mutually hinged lower finger joint 6, middle finger 7 and upper finger joint 8 form a group of connecting parts. There are two groups of connecting parts in total, and the two groups of connecting parts share the first rotating rod and the second rotating rod. One end of the lower elastic link 10 is rotatably connected to the finger swing assembly, and the other end is connected to the lower finger joint 6. One end of the upper elastic link 9 is rotatably connected to the lower finger joint 6, and the other end is rotatably connected to the upper finger joint 8. The upper elastic link 9 and the lower elastic link 10 are elastic. In this embodiment, the upper elastic link 9 and the lower elastic link 10 include a serpentine bending structure, such as Figure 4 As shown, the upper and lower elastic links 9 and 10 can absorb rigid impacts from the fingertips, minimizing mechanical damage to the finger assembly. This reduces pressure on the manipulator's electrical control, algorithms, and visuals, and the accuracy of system commands. The amount of interference in the system's output commands is converted into elastic potential energy absorbed by the elastic links, while the maximum gripping force of the fingertips is influenced by the elastic limits of the upper and lower elastic links 9 and 10. The inner side of the lower finger joint 6 is defined by an arcuate groove centered on the axis of the first rotating rod. The end of the lower elastic link 10 connected to the lower finger joint 6 is provided with a protrusion that is located within the arcuate groove and can slide and rotate along the groove. The outer side of the lower finger joint 6 is defined by a guide groove centered on the axis of the first rotating rod. A guide block is provided at the end of the middle finger 7. The guide block is located within the guide groove and can slide and rotate along the groove.

[0027] The finger swing assembly consists of a swing drive motor 13, a bevel gear set 12, and a universal joint 11. Universal joint 11 is rotationally connected to the finger base, to which the swing drive motor 13 is attached. One end of universal joint 11 is connected to a first bevel gear, and the output shaft of the swing drive motor 13 is connected to a second bevel gear. The first and second bevel gears cooperate to enable the swing drive motor 13 to drive the universal joint 11 in rotation. The first and second bevel gears form the bevel gear set 12. The lower finger joint 6 is rotationally connected to the universal joint 11, and the lower elastic link 10 is rotationally connected to the universal joint 11.

[0028] The change in rotational direction is achieved through the structure of universal joint 11. The rotation axis of universal joint 11 (referred to as axis 1) is perpendicular to the rotation axis of ball screw 3; the rotation axis between universal joint 11 and lower finger joint 6 (referred to as axis 2); and the rotation axis between universal joint 11 and lower elastic link 10 (referred to as axis 3). Axis 1 and axis 2 intersect perpendicularly, axis 1 and axis 3 do not intersect perpendicularly, and axis 2 and axis 3 are parallel.

[0029] The finger bending assembly consists of a bending drive motor 1, a spur gear set 2, a ball screw 3, a ball nut 4, and a universal joint 5. The ball screw 3 is rotatably connected to the finger base, with its rotation axis perpendicular to the rotation axis of the universal joint 11. The ball nut 4 is threaded onto the outside of the ball screw 3 and slides along the axis of the ball screw 3 with the finger base. The bending drive motor 1 is connected to the finger base, and a first spur gear is connected to the end of the ball screw 3. The output shaft of the bending drive motor 1 is connected to a second spur gear. The first and second spur gears cooperate to enable the bending drive motor 1 to rotate the ball screw 3, which in turn drives the ball nut 4. The first and second spur gears form the spur gear set 2. One end of the universal joint 5 is ball-jointed to the ball nut 4, and the other end is rotatably connected to the lower finger joint 6. The rotation axis between the universal joint 5 and the lower finger joint 6 is perpendicular to both the rotation axis of the universal joint 11 and the rotation axis of the ball screw 3. The rotation axis between the universal link 5 and the lower finger joint 6 is parallel to the rotation axis between the lower finger joint 6 and the universal joint 11 , and the rotation axis between the universal link 5 and the lower finger joint 6 is parallel to the rotation axis between the lower elastic link 10 and the universal joint 11 .

[0030] The universal connecting rod 5 includes an upper rod and a lower rod, one end of the upper rod and the lower rod are rotatably connected, the other end of the lower rod is ball-hinged with the ball nut 4, and the other end of the upper rod is rotatably connected with the lower finger joint 6. The rotation axis between the upper rod and the lower finger joint 6 is perpendicular to the rotation axis of the universal joint 11 and the ball screw 3, and the rotation axis between the upper rod and the lower finger joint 6 is perpendicular to the rotation axis between the upper rod and the lower rod.

[0031] The finger base includes a vertical substrate, a horizontal upper substrate, a horizontal lower substrate and a horizontal mounting plate. The horizontal upper substrate and the horizontal lower substrate are fixedly connected to one side of the vertical substrate, the horizontal mounting plate is fixedly connected to the other side of the vertical substrate, and the horizontal upper substrate and the horizontal lower substrate are parallel to each other. The ball screw 3 is rotatably connected between the horizontal upper substrate and the horizontal lower substrate. One end of the ball screw 3 extends out of the horizontal lower substrate away from the side of the horizontal upper substrate, and the end of the ball screw 3 extending out of the horizontal lower substrate is connected to the first spur gear. The bending drive motor 1 is fixedly connected to the vertical substrate and is located between the horizontal upper substrate and the horizontal lower substrate. The output shaft of the bending drive motor 1 extends out of the horizontal lower substrate, and the end of the output shaft of the bending drive motor 1 extends out of the horizontal lower substrate is connected to the second spur gear. Universal joint 11 is rotatably connected to the vertical baseplate and is located on the side of the horizontal upper baseplate facing away from the horizontal lower baseplate. The end of universal joint 11 that extends from the vertical baseplate to the horizontal mounting plate is connected to a first bevel gear. A swing drive motor 13 is fixedly connected to the side of the horizontal mounting plate facing away from universal joint 11, with its output shaft extending from the horizontal mounting plate. The end of the output shaft extending from the horizontal mounting plate is connected to a second bevel gear. The structural design of the finger base cleverly combines these two components into a single finger, achieving two degrees of freedom while reducing the overall size of the robotic finger.

[0032] The finger bending assembly is driven by a bending drive motor 1, which provides rotational power. This power is transmitted via meshing spur gears 2 to one end of a ball screw 3. The ball screw nut assembly then converts this rotational motion into linear motion for ball nut 4. Finally, ball nut 4 drives universal joint 5, which in turn drives the finger assembly to bend.

[0033] The finger swing assembly is powered by a swing drive motor 13. This power is converted to rotational direction by the meshing bevel gear set 12. The motor's output is rotational about the Y axis, but after passing through the bevel gear set, it is converted to rotational direction about the X axis. The driven gears in the bevel gear set then drive the finger joints to rotate slightly, achieving the finger swing motion.

[0034] Finger bending movement exercise instructions: Figure 1 、 3 As shown, the structures involved in the action include a bending drive motor 1, a spur gear set 2, a ball screw 3, a ball nut 4, a universal joint 5, finger joints 6, 7, 8, elastic connecting rods 9, 10, a universal joint 11, a bevel gear set 12, and a swing drive motor 13.

[0035] Explanation of the specific operation: When in operation, the bending drive motor 1 generates rotational motion, which is transmitted to the ball screw 3 via the spur gear set 2. The ball screw 3 and ball nut 4 together form a ball screw-nut pair. Therefore, the rotational motion transmitted to the ball screw 3 is converted into linear motion by the kinematic characteristics of the ball screw-nut pair, which is then output by the ball nut 4. The transmission power is decoupled by the universal joint 5, driving the elastic links 9 and 10 to move the finger joints 6, 7, and 8, thereby achieving finger bending.

[0036] Finger wiggling motion exercise instructions: Figure 2 、 3 As shown, the structures involved in the action include a bending drive motor 1, a spur gear set 2, a ball screw 3, a ball nut 4, a universal joint 5, finger joints 6, 7, 8, elastic connecting rods 9, 10, a universal joint 11, a bevel gear set 12, and a swing drive motor 13.

[0037] Specific operation explanation: When in operation, the swing drive motor 13 generates rotational motion. This rotational motion is converted by the bevel gear set 12 from rotational motion about the "Y" axis to rotational motion about the "X" axis. This rotational motion is transmitted to the lower elastic link 10 and the lower finger joint 6 via the universal joint 11. The lower elastic link 10 and the lower finger joint 6 then drive the finger portion to swing, thereby achieving the swing of the entire finger.

[0038] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

[0039] The present application has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present application. Those skilled in the art will appreciate that, without departing from the spirit and scope of the present application, various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present application, all of which fall within the scope of the present application. The scope of protection of the present application shall be determined by the appended claims.

Claims

1. A two-degree-of-freedom finger mechanism of a five-finger manipulator, characterized by: It includes a finger base, a finger assembly, a finger bending assembly and a finger swing assembly; The finger swing assembly includes a universal joint (11) and a swing drive assembly, wherein the universal joint (11) is rotatably connected to the finger base, and the swing drive assembly is used to drive the universal joint (11) to rotate; The finger bending assembly comprises a ball nut (4) and a bending drive assembly, wherein the ball nut (4) is slidably connected to the finger base, the sliding direction of the ball nut (4) is perpendicular to the rotation axis of the universal joint (11), and the bending drive assembly is used to drive the ball nut (4) to move; The finger assembly comprises a lower finger joint (6), a middle finger (7), an upper finger joint (8), an upper elastic link (9) and a lower elastic link (10); one end of the lower finger joint (6) is rotatably connected to a universal joint (11) and is connected to a ball nut (4) through a universal link (5); the other end of the lower finger joint (6) is hinged to one end of the middle finger (7) through a first rotating rod, and the other end of the middle finger (7) is hinged to the upper finger joint (8) through a second rotating rod; one end of the lower elastic link (10) is rotatably connected to the universal joint (11), and the other end of the lower elastic link (10) is slidably connected to the lower finger joint (6); one end of the upper elastic link (9) is rotatably connected to the lower finger joint (6), and the other end of the upper elastic link (9) is rotatably connected to the upper finger joint (8).

2. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 1, characterized in that: The lower finger joint (6), the middle finger joint (7) and the upper finger joint (8) which are hinged to each other form a group of connecting parts. There are two groups of connecting parts in total. The two groups of connecting parts share the first rotating rod and the second rotating rod.

3. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 1, characterized in that: The upper elastic connecting rod (9) and the lower elastic connecting rod (10) are elastic.

4. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 3, characterized in that: The upper elastic connecting rod (9) and the lower elastic connecting rod (10) both have a serpentine curved structure.

5. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 1, characterized in that: An arc groove with the axis of the first rotating rod as the axis is opened on one side of the lower finger joint (6), and a protrusion is provided on one end of the lower elastic connecting rod (10) connected to the lower finger joint (6). The protrusion is located in the arc groove so that the protrusion slides along the arc groove and rotates in the arc groove.

6. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 4, characterized in that: A guide groove with the axis of the first rotating rod as the axis is provided on the side of the lower finger joint (6) away from the lower elastic connecting rod (10), and a guide block is provided at the end of the middle finger (7). The guide block is located in the guide groove so that the guide block slides along the guide groove and rotates in the guide groove.

7. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 1, characterized in that: The swing drive assembly comprises a swing drive motor (13) and a direction-changing bevel gear set (12), wherein the direction-changing bevel gear set (12) comprises a first bevel gear and a second bevel gear, the swing drive motor (13) is fixedly connected to the finger base, the output shaft of the swing drive motor (13) is connected to the second bevel gear, the end of the universal joint (11) is connected to the first bevel gear, and the first bevel gear is matched with the second bevel gear.

8. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 7, characterized in that: The bending drive assembly comprises a bending drive motor (1), a spur gear set (2) and a ball screw (3); the spur gear set (2) comprises a first spur gear and a second spur gear; the ball screw (3) is rotatably connected to the finger base; the end of the ball screw (3) is connected to the first spur gear; the bending drive motor (1) is fixedly connected to the finger base; the output shaft of the bending drive motor (1) is connected to the second spur gear; and the second spur gear cooperates with the first spur gear.

9. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 8, characterized in that: The universal connecting rod (5) comprises an upper rod and a lower rod, one end of the upper rod and the lower rod are rotatably connected, the other end of the lower rod is spherically hinged with the ball nut (4), the other end of the upper rod is rotatably connected with the lower finger joint (6), the rotation axis between the upper rod and the lower finger joint (6) is perpendicular to the rotation axis of the universal joint (11) and the ball screw (3), and the rotation axis between the upper rod and the lower finger joint (6) is perpendicular to the rotation axis between the upper rod and the lower rod.

10. The two-degree-of-freedom finger mechanism of a five-finger manipulator according to claim 8, characterized in that: The finger base comprises a vertical base plate, a horizontal upper base plate, a horizontal lower base plate and a horizontal mounting plate, wherein the horizontal upper base plate and the horizontal lower base plate are fixedly connected to one side of the vertical base plate, the horizontal mounting plate is fixedly connected to the other side of the vertical base plate, and the horizontal upper base plate and the horizontal lower base plate are parallel to each other, a ball screw (3) is rotatably connected between the horizontal upper base plate and the horizontal lower base plate, one end of the ball screw (3) extends out of the horizontal lower base plate away from the side of the horizontal upper base plate, and the end of the ball screw (3) extending out of the horizontal lower base plate is connected to the first straight gear, the bending drive motor (1) is fixedly connected to the vertical base plate and is located between the horizontal upper base plate and the horizontal lower base plate, and the bending drive The output shaft of the motor (1) extends out of the horizontal lower base plate, and the end of the output shaft of the bending drive motor (1) extending out of the horizontal lower base plate is connected to the second spur gear; the universal joint (11) is rotatably connected to the vertical base plate, and the universal joint (11) is located on the side of the horizontal upper base plate away from the horizontal lower base plate, and one end of the universal joint (11) extending out of the vertical base plate and connected to the horizontal mounting plate is connected to the first bevel gear; the swing drive motor (13) is fixedly connected to the side of the horizontal mounting plate away from the universal joint (11), and the output shaft of the swing drive motor (13) extends out of the horizontal mounting plate, and the end of the output shaft of the swing drive motor (13) extending out of the horizontal mounting plate is connected to the second bevel gear.

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