Mechanical thumb with passive degree of freedom and manipulator
By setting up a bionic joint device with self-winding function between the phalange components of the mechanical thumb, the problem of lack of passive freedom of the mechanical fingers is solved, and a more realistic simulation function and richer motion model are achieved.
Patent Information
- Application Number
- CN202510083870.8
- 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 lack passive freedom and cannot effectively mimic the flexibility and adaptability of human hands, especially when they come into contact with other fingers or objects.
A mechanical thumb with passive freedom is designed, and bending, straightening, swinging and self-winding actions are achieved by setting a bionic joint device with a self-winding function between the distal phalangeal assembly, the proximal phalangeal assembly and the metacarpal assembly. These bionic joint devices drive the phalanx assembly to actively move under the drive device, and passive self-winding action is achieved through flexible or elastic deformation when contacting the object.
With the cooperation of active and passive degrees of freedom, the mechanical thumb can more comprehensively and realistically simulate various movements of the human thumb, increasing the number of degrees of freedom of the robot, and improving the authenticity of its simulation function.
Smart Images
Figure CN119858180A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of intelligent robots, and in particular to a mechanical thumb and a mechanical hand with passive degrees of freedom. 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 simple 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, both require the thumb and other fingers to make passive rotations of multiple joints with different moving angles. To more accurately reflect the movement of the human hand, we need to modify the finger motion model to reflect the flexible 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, the mechanical thumb only has active degrees of freedom but not passive degrees of freedom. It is urgent to develop a mechanical thumb with passive degrees of freedom to better realize the simulation functions of the mechanical thumb and the manipulator. Summary of the invention
[0007] The embodiments of the present invention provide a mechanical thumb and a manipulator with passive degrees of freedom, which are used to realize the passive degrees of freedom of the mechanical thumb while realizing the active degrees of freedom, thereby achieving the flexible or passive functions in the application of the manipulator and more comprehensively realizing the simulation function of the human hand.
[0008] The embodiment of the present invention provides a mechanical thumb with passive degrees of freedom, comprising: a distal phalanx component, a proximal phalanx component and a metacarpal component; The distal phalanx component and the proximal phalanx component are connected via a first bionic joint device with a self-winding function. 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 or elastic deformation, so that the distal phalanx component passively winds around the phalanx axis. A second bionic joint device with a self-winding function is provided between the proximal phalanx component and the metacarpal component. The second bionic joint device drives the proximal phalanx component to bend, straighten and swing under the drive of the driving device. When the distal phalanx component or the proximal phalanx component contacts an object, the second bionic joint device adaptively undergoes flexible or elastic deformation, so that the proximal phalanx component passively undergoes a self-winding action around the phalanx axis. A second bionic joint device with a self-winding function is arranged between the connection between the metacarpal component and the wrist component. The second bionic joint device drives the metacarpal component to bend, straighten and swing under the drive of the driving device. When the distal phalanx component, the proximal phalanx component or the metacarpal component contacts an object, the second bionic joint device adaptively undergoes flexible or elastic deformation, so that the metacarpal component passively winds itself around the phalanx axis.
[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 provided at the ends of the distal phalanx component, the proximal phalanx component and the metacarpal component, and are connected to a bionic joint device to achieve adaptive flexible deformation of the corresponding phalanges or metacarpals of the mechanical thumb, so that the corresponding phalanges or metacarpals 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 to 20 degrees, and the negative self-winding angle is 0 to 20 degrees.
[0014] In a preferred embodiment, the positive self-winding angle of the second bionic joint device between the proximal phalanx component and the metacarpal component is 0 to 20 degrees, and the negative self-winding angle is 0 to 20 degrees.
[0015] In a preferred embodiment, the second bionic joint device at the connection between the metacarpal component and the wrist component has a positive self-winding angle of 0 to 10 degrees and a negative self-winding angle of 0 to 10 degrees.
[0016] In a preferred embodiment, the elastic element is built into the bearing.
[0017] An embodiment of the present invention further provides a mechanical hand, comprising the mechanical thumb of any of the aforementioned embodiments.
[0018] The mechanical thumb and manipulator with passive degrees of freedom formed by the embodiments of the present invention can realize the active degrees of freedom of bending / straightening and swinging of the mechanical thumb joint while also realizing the passive degrees of freedom of self-rotation of the mechanical thumb joint, thereby realizing the degrees of freedom of the mechanical thumb joint more comprehensively and richly; in addition, a mechanical thumb functional model with both active and passive degrees of freedom is realized, thereby increasing the number of degrees of freedom of the manipulator and realizing the simulation function of the manipulator more realistically and comprehensively. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] 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 2 A schematic diagram of a model of a manipulator and a mechanical thumb according to 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 mechanical thumb according to an embodiment of the present invention. DETAILED DESCRIPTION
[0020] The following is combined with Figure 2 , a specific implementation manner of a mechanical thumb with passive freedom provided by an embodiment of the present invention is described in detail.
[0021] A mechanical thumb with passive degrees of freedom provided by an embodiment of the present invention comprises: a distal phalanx component 1, a proximal phalanx component 2 and a metacarpal component 3; The distal phalanx component 1 is connected to the proximal phalanx component 2 via a first bionic joint device 4 with a self-winding function. The first bionic joint device 4 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 4 adaptively deforms flexibly, so that the distal phalanx component 1 passively winds around the phalanx axis. A second bionic joint device 5 with a self-winding function is provided between the proximal phalanx component 2 and the metacarpal component 3. The second bionic joint device 5 drives the proximal phalanx component 2 to bend and straighten as well as swing under the drive of the driving device. When the distal phalanx component 1 or the proximal phalanx component 2 contacts an object, the second bionic joint device 5 adaptively undergoes flexible deformation, so that the proximal phalanx component 2 passively undergoes a self-winding action around the phalanx axis. A second bionic joint device 5 with a self-winding function is arranged between the connection between the metacarpal component 3 and the wrist component. The second bionic joint device 5 drives the metacarpal component 3 to bend, straighten and swing under the drive of the driving device, and when the distal phalanx component 1 or the proximal phalanx component 2 or the metacarpal component 3 contacts an object, the second bionic joint device 5 adaptively undergoes flexible deformation, so that the metacarpal component 3 passively winds itself around the phalanx axis.
[0022] The mechanical thumb with passive degrees of freedom in the embodiment of the present invention realizes the thumb motion model of active and passive degrees of freedom. On the basis of the original 5 active degrees of freedom of bending / extension and swinging, various angles with obvious passive motion are added at 3 joints, that is, the mechanical thumb adds 3 passive self-rotations around the phalangeal axis. The mechanical thumb of the embodiment of the present invention has a total of 8 degrees of freedom (5 active degrees of freedom + 3 passive degrees of freedom). With the cooperation of active degrees of freedom and passive degrees of freedom, the mechanical thumb can simulate various movements of the thumb more comprehensively and realistically, enriching and improving the motion model of the mechanical thumb.
[0023] Since the thumb has five active degrees of freedom and is in a relatively stable and dependent position when cooperating with the other four fingers, its passive range of motion is not large. However, it is also needed when exerting great force in order to adapt to the external environment. Therefore, the spring stiffness of the passive degree of freedom is large compared to the other four fingers.
[0024] Figure 3a and Figure 3b An embodiment of a second bionic joint device 5 and its self-winding angle is provided, and elastic elements 51 are arranged on both sides of the second bionic joint device 5 in the radial direction. The elastic elements 51 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 shrapnel, a spring, rubber or other elastic element. The joint between the proximal phalanx and the metacarpal bone of the thumb can realize three rotational movements, two active degrees of freedom and one passive degree of freedom. The passive degree of freedom required by the second bionic joint device 5 between the proximal phalanx component 2 and the metacarpal component 3 is that the positive self-winding angle a is 0 to 20 degrees, and the negative self-winding angle b is 0 to 20 degrees, which is used to support the rich and diverse movement modes of the proximal phalanx component 2. The movement mode realized by the joint between the metacarpal bone of the thumb and the wrist is mainly to support the joint movement between the proximal phalanx and the metacarpal bone, and to provide stability. Therefore, the passive degree of freedom required by the second bionic joint device 5 at the connection between the metacarpal component 3 and the wrist component is lower than the passive degree of freedom required by the second bionic joint device 5 between the proximal phalanx component 2 and the metacarpal component 3. The positive self-winding angle a of the second bionic joint device 5 there is 0 to 10 degrees, and the negative self-winding angle b is 0 to 10 degrees.
[0025] Figure 4a and Figure 4bAn embodiment of a first bionic joint device 4 and its self-winding angle is provided, and elastic elements 41 are arranged on both sides of the first bionic joint device 4 in the radial direction. The elastic element 41 has an elastic preload force to keep the joint in place and provide a restoring torque after the joint device self-winds around the phalanx axis under external action. The elastic element can be a shrapnel, a spring, rubber or other elastic element. The distal phalanx of the thumb mainly moves in a gripping manner, and its passive phalanx self-winding angle is not required to be high. Therefore, the positive self-winding angle c of the first bionic joint device 4 of the mechanical thumb is 0 to 10 degrees, and the negative self-winding angle d is 0 to 10 degrees.
[0026] The structures of the first bionic joint device 4 and the second bionic joint device 5 are relatively similar. The first bionic joint device 4 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 5 and the first bionic joint device 4 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 5 and the first bionic joint device 4 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 4, its freedom of swinging can be limited, that is, the freedom of swinging is zero, so that it has only two degrees of freedom.
[0027] 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.
[0028] Figure 5 An implementation method of elastic self-winding of each joint of the mechanical thumb is demonstrated. Each joint of the mechanical thumb: the ends of the distal phalanx component, the proximal phalanx component and the metacarpal component are respectively provided with elastic bearings 6, and are connected to the bionic joint device, so as to realize the adaptive flexible deformation of each corresponding joint of the mechanical thumb, so that each corresponding joint can passively self-wind. Because the self-winding action is mainly realized at the joint, the self-winding of the joint is mainly to passively support the self-winding function of the joint contact surface, making the contact surface tighter, so the self-winding angle of the elastic bearing 6 is small to support this function, preferably, the positive and negative self-winding angles are both 20 degrees. The elastic stiffness can be selected according to the needs and the situation of frequently grasping objects.
[0029] An embodiment of the present invention further provides a mechanical hand with passive degrees of freedom, integrating the mechanical thumb of any of the aforementioned embodiments.
[0030] The mechanical thumb with passive degrees of freedom in the embodiment of the present invention realizes the thumb motion model of active and passive degrees of freedom. On the basis of the original 5 active degrees of freedom of bending / extension and swinging, various angles with obvious passive motion are added at 3 joints. The mechanical thumb of the embodiment of the present invention has a total of 8 degrees of freedom, which realizes passive self-winding of each joint at a small angle. With the coordination of active degrees of freedom and passive degrees of freedom, the mechanical thumb can more comprehensively and realistically imitate various movements of the human thumb, thereby enriching and improving the motion model of the robot hand and realizing a more dexterous intelligent robot hand.
[0031] 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 thumb with passive degrees of freedom, characterized in that: It includes a distal phalanx component, a proximal phalanx component and a metacarpal component; The distal phalanx component and the proximal phalanx component are connected via a first bionic joint device with a self-winding function. The first bionic joint device drives the distal phalanx component to bend and straighten under the drive of a 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 between the proximal phalanx component and the metacarpal component. The second bionic joint device drives the proximal phalanx component to bend, straighten and swing when driven by a driving device. When the distal phalanx component or the proximal phalanx component contacts an object, the second bionic joint device adaptively undergoes flexible deformation, so that the proximal phalanx component passively undergoes a self-winding action. A second bionic joint device with a self-winding function is arranged between the connection between the metacarpal component and the wrist component. The second bionic joint device drives the metacarpal component to bend, straighten and swing when driven by a driving device. When the distal phalanx component, the proximal phalanx component or the metacarpal component contacts an object, the second bionic joint device adaptively undergoes flexible deformation, so that the metacarpal component passively undergoes a self-winding motion.
2. The mechanical thumb 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 thumb according to claim 1, characterized in that: The ends of the distal phalanx component, the proximal phalanx component and the metacarpal component are respectively provided with elastic bearings and connected to the bionic joint device, so as to realize the adaptive flexible deformation of the corresponding phalanges or metacarpals of the mechanical thumb, so that the corresponding phalanges or metacarpals passively undergo self-revolving motion.
4. The mechanical thumb 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 thumb 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 thumb according to claim 1 or 2, characterized in that: The first bionic joint device has a positive self-winding angle of 0 to 20 degrees, and a negative self-winding angle of 0 to 20 degrees.
7. The mechanical thumb according to claim 1 or 2, characterized in that: The positive self-winding angle of the second bionic joint device between the proximal phalanx component and the metacarpal component is 0 to 20 degrees, and the negative self-winding angle is 0 to 20 degrees.
8. The mechanical thumb according to claim 1 or 2, characterized in that: The second bionic joint device at the connection between the metacarpal component and the wrist component has a positive self-winding angle of 0 to 10 degrees and a negative self-winding angle of 0 to 10 degrees.
9. The mechanical thumb according to claims 2 and 4, characterized in that: The elastic element is built into the bearing.
10. A robot, characterized in that: It comprises the mechanical thumb as claimed in any one of claims 1 to 9.