Mechanical finger and manipulator
By setting a bionic joint device with self-winding function at the end of the phalangeal assembly of the robot finger, combining active and passive freedom, the problem of the lack of passive freedom of the robot finger is solved, and more realistic finger simulation actions are achieved.
Patent Information
- Application Number
- CN202510083911.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-04-22
AI Technical Summary
Existing mechanical fingers only have active freedom and lack passive freedom, and cannot effectively simulate the flexibility and passive functions of human hands.
A mechanical finger is designed to achieve a combination of active and passive degrees of freedom by providing a bionic joint device with a self-winding function at the ends of the distal phalangeal phalangeal assembly and the proximal phalangeal assembly. The bionic joint device drives the phalanx assembly to bending and straighten the movement under the drive device, and adaptively undergoes flexible deformation when contacting the object, realizing passive self-winding action.
With the cooperation of active and passive degrees of freedom of the robot, it realizes that various movements of the fingers are more comprehensive and realistic, enriches and perfects the movement model of the robotic fingers, and increases the number of degrees of freedom of the robotic fingers.
Smart Images
Figure CN119858181A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of intelligent robots, and in particular to a mechanical finger and a mechanical hand. Background Art
[0002] As the human hand has evolved to this day, it can perform a wide range of operations, from delicate to rough, from gentle to strong, from steady to fast, from follow-up to active; each of its fingers, phalanges, metacarpals and other functions have their own strengths, from the agility of the fingertips to the huge pulling force in the middle of the fingers, from the coordinated actions of the five fingers to the overall deformation of the palm. The human hand demonstrates various capabilities when performing various operations, including the ability to interact with both rigidity and flexibility, and the ability to highly adapt to various complex shapes, masses and weights, surface characteristics and volume characteristics.
[0003] From the perspective of human hand kinematics and mechanism, the above capabilities are the result of the organic combination of many active and passive degrees of freedom. The design of traditional robotic fingers focuses on precision and strength, which is far from the ability of human hands to combine rigidity and flexibility. The difficulty in designing robotic fingers comes from the need to realize a system with extremely strong comprehensive capabilities in a very limited space, including sensing, motion, drive, and transmission subsystems. Therefore, the pursuit of simplified design is often a last resort.
[0004] In the field of intelligent robots, existing manipulators are some kind of simplification and reconstruction of human fingers. With the continuous advancement of technology, this reconstruction strives to better imitate the functions of human fingers, thereby realizing the functions of hands. At present, the latest manipulators such as Tesla's latest dexterous hand and Optimus Gen 3's dexterous hand have 21 active degrees of freedom in the five fingers plus 1 active degree of freedom in the palm of the little finger. It is a typical 21+1 degree of freedom manipulator design that is actively driven by human muscles. Figure 1 The model of the existing manipulator and the active degrees of freedom of the finger joints are shown. The manipulator thumb has one joint for bending active freedom, two joints for bending and swinging active freedom, and a manipulator thumb has a total of 5 active degrees of freedom; the other four manipulator fingers, namely the index finger, middle finger, ring finger and little finger, respectively have two joints for bending active freedom, and one joint for bending and swinging active freedom, and these four manipulator fingers have a total of 4 active degrees of freedom. All five fingers of the manipulator have a total of 21 (4×4+5) active degrees of freedom.
[0005] When a finger touches other fingers or objects, the force acting on the finger naturally drives the finger to rotate adaptively. This ability to rotate and recover is called passivity. In addition to the thumb, the index finger, middle finger, ring finger and little finger require passivity for many actions, such as pinching the thumb, index finger and middle finger to make the number "7" shape, and pinching the thumb and index finger to make " " type, all require multiple joints of the relevant fingers to make passive rotations of moving angles. To more accurately reflect the movement of the human hand, we need to modify the finger motion model to reflect the flexibility or passive function of the finger. At present, the mechanical finger does not have this passive degree of freedom. When simulating fingers, it is necessary to realize its positive and negative self-winding. Taking the right hand as an example, facing the palm of the right hand, with the fingertips facing up, the positive self-winding is the clockwise rotation of the distal phalanx around its own axis, and the negative self-winding is the counterclockwise rotation of the distal phalanx around its own axis. The positive and negative self-winding directions of the left hand are opposite.
[0006] At present, robotic fingers only have active degrees of freedom but not passive degrees of freedom. It is urgent to develop robotic fingers with passive degrees of freedom to better realize the simulation functions of robotic fingers and manipulators. Summary of the invention
[0007] The embodiment of the present invention provides a mechanical finger and a mechanical hand, which are used to simulate the index finger, middle finger, ring finger and little finger. While realizing the active degree of freedom, it is also used to realize the passive degree of freedom of the mechanical finger, thereby achieving flexible or passive functions in the application of the mechanical hand and more comprehensively realizing the simulation function of the human hand.
[0008] An embodiment of the present invention provides a mechanical finger, comprising: comprising a distal phalanx component and a proximal phalanx component; A first bionic joint device with a self-winding function is provided at the end of the distal phalanx component. The first bionic joint device drives the distal phalanx component to bend and straighten under the drive of the driving device. When the distal phalanx component contacts an object, the first bionic joint device adaptively undergoes flexible deformation, so that the distal phalanx component passively undergoes a self-winding action. A second bionic joint device with a self-winding function is provided at the end of the proximal phalanx assembly. The second bionic joint device drives the proximal phalanx assembly to bend, straighten and swing when driven by the driving device. When the mechanical finger contacts an object, the second bionic joint device adaptively undergoes flexible deformation, causing the proximal phalanx assembly to passively undergo a self-winding action.
[0009] In a preferred embodiment, the second bionic joint device and the first bionic joint device are provided with elastic elements in the radial direction, the elastic elements have elastic preload force to keep the joint in place, and provide restoring torque after the joint device rotates around the phalanx axis under external action.
[0010] In a preferred embodiment, elastic bearings are respectively arranged at the ends of the distal phalanx component and the proximal phalanx component, and are connected to a bionic joint device, so that the distal phalanx component and the proximal phalanx component can adaptively undergo flexible deformation, and the distal phalanx component and the proximal phalanx component can passively undergo self-revolving motion.
[0011] In a preferred embodiment, the joints in the second bionic joint device and the first bionic joint device are spherical contact bearings, so that the second bionic joint device and the first bionic joint device can adaptively undergo flexible deformation.
[0012] In a preferred embodiment, the joints in the second bionic joint device and the first bionic joint device are fisheye bearings or spherical bearings.
[0013] In a preferred embodiment, the positive self-winding angle of the first bionic joint device is 0-30 degrees; the negative self-winding angle is 0 to 45 degrees.
[0014] In a preferred embodiment, the positive self-winding angle of the second bionic joint device is 0 to 20 degrees; and the negative self-winding angle is 0 to 20 degrees.
[0015] A preferred embodiment also includes a middle phalanx component connected to the distal phalanx component and the proximal phalanx component respectively, and a flexion and extension joint device is provided at the end of the middle phalanx component, which drives the middle phalanx component to bend and straighten under the drive of the driving device.
[0016] An elastic bearing may also be provided at the end of the middle phalanx component, which has a self-winding passive degree of freedom, with a positive self-winding angle of 0 to 20 degrees and a negative self-winding angle of 0 to 20 degrees.
[0017] In actual situations, when the five fingers contact each other and external objects, the distal and proximal knuckles are most likely to undergo passive rotation first. Therefore, the rotation of the middle joint can be ignored, which can also simplify the mechanical finger system and reduce costs.
[0018] In a preferred embodiment, the first bionic joint device and the flexion-extension joint device are driven by the same driving device.
[0019] An embodiment of the present invention further provides a robot arm, comprising the robot fingers of any of the aforementioned embodiments, wherein the number of the robot fingers is 1 to 4.
[0020] The robotic fingers and robotic arm formed by the embodiments of the present invention can realize the active degrees of freedom of bending / straightening and swinging of the robotic finger joints while also realizing the passive degrees of freedom of self-rotation of the robotic finger joints, thereby more comprehensively and richly realizing the degrees of freedom of the robotic finger joints; in addition, a functional model of a robotic finger with both active / passive degrees of freedom is realized, thereby increasing the number of degrees of freedom of the robotic arm and realizing the simulation function of the robotic arm more realistically and comprehensively. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 The figure is a schematic diagram of the model of the existing manipulator and the active degrees of freedom of the finger joints; Figure 2A schematic diagram of a model of a manipulator and mechanical fingers of an embodiment of the present invention; Figure 3a is a schematic diagram of a second bionic joint device according to an embodiment of the present invention; Figure 3b Schematic diagram of the self-winding angle of the second bionic joint device according to an embodiment of the present invention; Figure 4a is a schematic diagram of a first bionic joint device according to an embodiment of the present invention; Figure 4b Schematic diagram of the self-winding angle of the first bionic joint device according to an embodiment of the present invention; Figure 5 Schematic diagram of the elastic self-winding of each joint of the robotic finger according to an embodiment of the present invention. DETAILED DESCRIPTION
[0022] The following is combined with Figure 2 , a specific implementation of a mechanical finger provided by an embodiment of the present invention is described in detail. The figure has a mechanical thumb 7 that simulates a thumb, and a mechanical finger 6 that simulates an index finger, middle finger, ring finger and little finger. The two types of fingers are different, and the embodiment of the present invention is described with respect to the mechanical finger 6.
[0023] A mechanical finger 6 provided in an embodiment of the present invention includes: Distal phalanx component 1 and proximal phalanx component 3; A first bionic joint device 51 with a self-winding function is provided at the end of the distal phalanx component 1. The first bionic joint device 51 drives the distal phalanx component 1 to bend and straighten under the drive of the driving device. When the distal phalanx component 1 contacts an object, the first bionic joint device 51 adaptively undergoes flexible deformation, so that the distal phalanx component 1 passively undergoes a self-winding action. A second bionic joint device 52 with a self-winding function is provided at the end of the proximal phalanx component 3. The second bionic joint device 52 is connected to the metacarpal component 4. The second bionic joint device 52 drives the proximal phalanx component 3 to bend, straighten and swing under the drive device. When the mechanical finger 6 contacts an object, the second bionic joint device 52 adaptively undergoes flexible deformation, so that the proximal phalanx component 3 passively undergoes a self-winding action.
[0024] A mechanical finger 6 provided in an embodiment of the present invention may also include a middle phalanx component 2 connected to the distal phalanx component 1 and the proximal phalanx component 3, respectively. A flexion and extension joint device 53 is provided at the end of the middle phalanx component 2, which drives the middle phalanx component 2 to bend and straighten under the drive of the driving device. In some applications that do not require too much joint bending, the middle phalanx component 2 may also be omitted, which can better reduce costs.
[0025] Because the movement of human hands has certain habits and rules, for example, the two joints at the distal end of the fingers often bend at a certain angle ratio at the same time, that is, the movement of the two joints is not independent. When the robot simulation is realized, one drive device can be used to drive them simultaneously. In this way, the first bionic joint device 51 and the flexion and extension joint device 53 are driven by the same drive device, which saves one motor.
[0026] The robotic finger of the embodiment of the present invention realizes a finger motion model of active and passive degrees of freedom. On the basis of the original 4 active degrees of freedom of bending / extension and swinging, various rotation angles with obvious passive motion are added at 2 joints, that is, the robotic finger adds 2 passive self-rotations around the phalanx axis. The robotic finger of the embodiment of the present invention has a total of 6 degrees of freedom (4 active degrees of freedom + 2 passive degrees of freedom). With the coordination of active degrees of freedom and passive degrees of freedom, the robotic finger can simulate various finger movements more comprehensively and realistically, enriching and improving the motion model of the robotic finger.
[0027] Figure 3a and Figure 3b An embodiment of a second bionic joint device 52 and its self-winding angle is provided, and elastic elements 521 are arranged on both sides of the second bionic joint device 52 in the radial direction. The elastic elements 521 have elastic preload force to keep the joint in place and provide restoring torque after the joint device self-winds around the phalanx axis under external action. The elastic element can be a spring, a spring, a rubber or other elastic element.
[0028] The rotation of the three joints of the phalanx around the axis of the phalanx itself is passive, and the specific rotation angle is determined by the force location, force direction and magnitude. For example, when the tip of the index finger contacts the thumb, there will be a very large passive rotation, trying to maintain the maximum contact area or reduce pressure. Different jobs or occupations have different usage habits, which will affect the growth of the soft tissues of each joint and adapt to the outside. In the long run, it will change or train to form the optimal angle range.
[0029] The joint between the proximal phalanx and the metacarpal bone of the finger requires a relatively large self-rotation angle of passive movement to support the movement of the middle and distal phalanx when exerting force to grasp an object of a certain shape, such as a tennis racket, or an irregular object. Therefore, the second bionic joint device 52 between the proximal phalanx component 3 and the metacarpal component 4 is required to have a certain passive degree of freedom. The positive self-rotation angle a of the second bionic joint device 52 here is 0 to 20 degrees, and the negative self-rotation angle a is 0 to 20 degrees, which is used to support the relatively large self-rotation movement of the proximal phalanx component 3.
[0030] Figure 4a and Figure 4bAn implementation of the first bionic joint device 51 and its self-winding angle is provided, and elastic elements 511 are arranged on both sides of the radial direction thereof, and the elastic elements 511 have elastic preload force to keep the joint in place, and provide restoring torque after the joint device self-winds around the phalanx axis under external action. The elastic element can specifically be other elastic elements such as shrapnel, spring, rubber, etc. The movement mode of the distal phalanx of the finger is mainly contact, and its passive phalanx self-winding angle should be in contact with the surface of the object as much as possible. When the force is not large, there will be a large rotation, which is relatively sensitive, such as the contact process between the index finger and the thumb tip. Therefore, the positive self-winding angle c of the first bionic joint device 51 of the mechanical finger is 0 to 30 degrees, and the negative self-winding angle d is 0 to 45 degrees. That is, the elastic stiffness is small and it is easy to turn.
[0031] The structures of the first bionic joint device 51 and the second bionic joint device 52 are relatively similar. The first bionic joint device 51 does not have a mechanism to support swinging, and the other parts are similar. In industrial applications, the joints in the second bionic joint device 52 and the first bionic joint device 51 are spherical contact bearings, so that the joint devices can adaptively deform flexibly, and can specifically be fisheye bearings or spherical bearings. In actual production, in order to reduce the defects of numerous parts model management, the second bionic joint device 52 and the first bionic joint device 51 can use the same spherical contact bearing, which has three degrees of freedom: bending, swinging and self-winding. When used as the first bionic joint device 51, its freedom of swinging can be limited, that is, the freedom of swinging is zero, so that it has only two degrees of freedom, which can reduce the types of parts.
[0032] In order to reduce the cumbersome management of parts, the elastic element can also be built into the bearing, and the elastic element can be made into a part of the spherical bearing, thereby realizing integrated manufacturing.
[0033] Figure 5 An implementation method of elastic self-winding of each phalanx of a mechanical finger is demonstrated. Elastic bearings 8 are respectively arranged at the ends of the distal phalanx component 1 and the proximal phalanx component 3, and are connected to the bionic joint device to realize the adaptive flexible deformation of each corresponding phalanx of the mechanical finger, so that each corresponding phalanx can passively self-wind. Because the self-winding action is mainly realized at the joint or near the joint, the self-winding of the phalanx is mainly passively initiated under the action of external force or torque, making the contact surface between the finger and the object closer, so the elastic bearing 8 can support this function at a certain self-winding angle, and the preferred positive and negative self-winding angles are both 0 to 20 degrees.
[0034] Of course, an elastic bearing may also be provided at the end of the middle phalanx component 2 to allow it to have a passive degree of freedom of self-winding, with the positive and negative self-winding angles both being 0 to 20 degrees.
[0035] In actual situations, when the five fingers are in contact with each other and with external objects, the distal and proximal knuckles are most likely to undergo passive rotation first, so the rotation of the middle phalanx assembly 2 can be ignored, which can also simplify the mechanical finger system and reduce costs.
[0036] The embodiment of the present invention further provides a robot arm, which integrates the robot fingers 6 of any of the aforementioned embodiments. The number of the robot fingers 6 is set according to actual needs, and can be 1 to 4.
[0037] The robotic finger of the embodiment of the present invention realizes a finger motion model of active and passive degrees of freedom. On the basis of the original four active degrees of freedom of bending / extension and swinging, various angles with obvious passive motion are added at two joints. The robotic finger of the embodiment of the present invention has a total of six degrees of freedom. At the same time, it also realizes passive self-winding of two phalanges with passive freedom requirements at small angles. With the coordination of active and passive degrees of freedom, the robotic finger can simulate various finger movements more comprehensively and realistically, thereby enriching and improving the motion model of the robotic hand and realizing a more dexterous intelligent robotic hand.
[0038] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A mechanical finger, characterized in that: It includes a distal phalanx component and a proximal phalanx component. A first bionic joint device with a self-winding function is provided at the end of the distal phalanx component. The first bionic joint device drives the distal phalanx component to bend and straighten under the drive of the driving device. When the distal phalanx component contacts an object, the first bionic joint device adaptively undergoes flexible deformation, so that the distal phalanx component passively undergoes a self-winding action. A second bionic joint device with a self-winding function is provided at the end of the proximal phalanx assembly. The second bionic joint device drives the proximal phalanx assembly to bend, straighten and swing when driven by a driving device. When the mechanical finger contacts an object, the second bionic joint device adaptively undergoes flexible deformation, so that the proximal phalanx assembly passively undergoes a self-winding action.
2. The mechanical finger according to claim 1, characterized in that: The second bionic joint device and the first bionic joint device are provided with elastic elements in the radial direction, and the elastic elements have elastic preload force to keep the joint in place and provide restoring torque after the joint device rotates around the phalanx axis under external action.
3. The mechanical finger according to claim 1, characterized in that: Elastic bearings are respectively arranged at the ends of the distal phalanx component and the proximal phalanx component and are connected to a bionic joint device, so that the distal phalanx component and the proximal phalanx component can adaptively undergo flexible deformation, and the distal phalanx component and the proximal phalanx component can passively undergo self-revolving motion.
4. The mechanical finger according to claim 1, characterized in that: The joints in the second bionic joint device and the first bionic joint device are spherical contact bearings, so as to realize the adaptive flexible deformation of the second bionic joint device and the first bionic joint device.
5. The mechanical finger according to claim 4, characterized in that: The joints in the second bionic joint device and the first bionic joint device are fisheye bearings or spherical bearings.
6. The mechanical finger according to claim 1 or 2, characterized in that: The positive self-winding angle of the first bionic joint device is 0 to 30 degrees, and the negative self-winding angle is 0 to 45 degrees.
7. The mechanical finger according to claim 1 or 2, characterized in that: The positive self-winding angle of the second bionic joint device is 0 to 20 degrees, and the negative self-winding angle is 0 to 20 degrees.
8. The mechanical finger according to claim 1, characterized in that: It also includes a middle phalanx component connected to the distal phalanx component and the proximal phalanx component respectively. A flexion and extension joint device is arranged at the end of the middle phalanx component, which drives the middle phalanx component to bend and straighten under the drive of a driving device.
9. The mechanical finger according to claim 8, characterized in that: The first bionic joint device and the flexion-extension joint device are driven by the same driving device.
10. A robot, characterized in that: It comprises 1 to 4 mechanical fingers as described in any one of claims 1 to 9.