Mechanical arm

Abstract

The invention discloses a manipulator which is used for realizing the overall passive degree of freedom of the manipulator. Comprising a mechanical thumb and four mechanical fingers, and metacarpal bone assemblies and wrist assemblies of the four mechanical fingers are connected through elastic components; and an elastic element is arranged between the metacarpal bone components of the adjacent mechanical fingers. Therefore, the mechanical arm can integrally coordinate the passive degree of freedom of the mechanical arm, the flexibility or passive function of the overall action in the mechanical arm application is achieved, and the simulation function of the human hand is achieved more comprehensively.

Description

Technical Field

[0001] The invention relates to the technical field of intelligent robots, and in particular to a manipulator 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 finger, phalanx, metacarpal bone 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 movement of the five fingers to the overall deformation of the palm. When performing various operations, the human hand demonstrates various abilities, 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 manipulators focuses on precision and strength, which is far from the ability of human hands to combine rigidity and flexibility. The difficulty in designing a robotic finger stems 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 to move at different angles. To more accurately reflect the movement of the human hand, we need to modify the finger movement 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. In addition, most existing mechanical hands have four fingers. The metacarpal bones of the fingers are designed as a rigid body of the palm, which is convenient for arranging drive devices, such as micro screw motor drives, etc. In order to simplify the design and reduce costs, the metacarpal bones will not produce passivity, sacrificing the performance and flexibility of the manipulator. Not only do individual fingers need to have passivity, but more importantly, when the human hand grasps objects of different shapes with force, under the action of muscle groups, the human hand will work as a whole to fully wrap the object of a specific shape, trying to increase the contact area and stabilize the grasp. In this process, the overall active degree of freedom of the human hand plays a role together with the passive degree of freedom.

[0006] At present, the robot arm only has active degrees of freedom, but not passive degrees of freedom. When performing overall movements, the overall passive degrees of freedom of the robot arm should be especially considered to better realize the function of the robot arm to imitate the overall movements of the human hand. Summary of the invention

[0007] The embodiment of the present invention provides a manipulator, which is used to realize the passive degrees of freedom of the overall coordinated manipulator while realizing the active degrees of freedom, so as to achieve the flexibility or passive function of the overall action in the manipulator application and more comprehensively realize the simulation function of the human hand.

[0008] An embodiment of the present invention provides a manipulator, comprising: Includes 1 mechanical thumb and 4 mechanical fingers; The metacarpal components of the four mechanical fingers are connected to the wrist components through elastic components, so that the metacarpal components can bend passively and self-wind passively; An elastic element is arranged between the metacarpal assemblies of adjacent mechanical fingers, so that the metacarpal assemblies of the four mechanical fingers are passively deformed as a whole, thereby realizing the overall curling of the palm of the mechanical hand; The elastic element connection method is any of the following methods: connected between the ends of the metacarpal components of two adjacent robotic fingers; connected between the distal ends of the metacarpal components of two adjacent robotic fingers; Connections are made between the distal ends and the distal ends of the metacarpal components of two adjacent robotic fingers.

[0009] In a preferred embodiment, the elastic component is any one of an "X"-shaped or "8"-shaped spring, a spring sheet, or a polymer material, and the two ends of the elastic component are respectively connected to the metacarpal component and the wrist component to achieve passive self-winding and recovery, and the cross structure of the elastic component achieves passive bending and recovery.

[0010] In a preferred embodiment, the elastic element is any one of a spring, a spring sheet, a polymer material and an 8-shaped elastic member.

[0011] In a preferred embodiment, elastic bearings are respectively provided at the ends of the distal phalanx assemblies and the proximal phalanx assemblies of the four mechanical fingers, the distal phalanx assemblies and the proximal phalanx assemblies of the mechanical thumb, and the end of the metacarpal assembly, so that the corresponding phalanx assemblies can adaptively undergo flexible deformation and realize passive self-winding action.

[0012] In a preferred embodiment, the forward and reverse self-winding angles of each phalanx component are both 20 degrees.

[0013] In a preferred embodiment, the passive bending degree between the metacarpal bone components of adjacent mechanical fingers toward the palm is 0-20 degrees, and the cumulative curling angle range of the palm of the entire mechanical hand toward the palm is 0-60 degrees.

[0014] A preferred embodiment is that there is a passive small-angle elastic rotation deformation between the metacarpal bone component and the wrist of the robotic finger, the positive self-winding angle around the metacarpal bone component is 0-10 degrees, the reverse self-winding angle around the metacarpal bone component is 0-10 degrees, and the bending angle toward the palm is 0-10 degrees, so that the palm of the robotic hand can be passively curled toward the palm.

[0015] The robot formed by the embodiment of the present invention can realize the overall passive freedom of the robot and fully realize the wrapping action of the robot. At the same time, when performing the overall work, the robot finger joints generate self-winding passive freedom, which more realistically realizes the overall wrapping movement of the robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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 manipulator according to an embodiment of the present invention; Figure 3 Schematic diagrams of different examples of elastic components according to embodiments of the present invention; Figure 4 Schematic diagram of the curling angle of the palm of the robot arm according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following is combined with Figure 2, a specific implementation of a manipulator provided by an embodiment of the present invention is described in detail. The figure has a mechanical thumb 2 that simulates a thumb, and a mechanical finger 1 that simulates an index finger, a middle finger, a ring finger, and a little finger.

[0018] A robot arm provided by an embodiment of the present invention includes: including a mechanical thumb 2 and four mechanical fingers 1; The metacarpal bone components 6 of the four mechanical fingers 1 are connected to the wrist components through an elastic component 8, so that the metacarpal bone components 6 undergo passive bending and passive self-winding movements; An elastic element 7 is provided between the metacarpal bone components 6 of adjacent mechanical fingers 1, so that the metacarpal bone components 6 of the four mechanical fingers 1 are passively deformed as a whole, thereby realizing the overall curling of the palm of the mechanical hand; The connection mode of the elastic element 7 is any one of the following modes: Connected between the ends of the metacarpal components 6 of two adjacent mechanical fingers; Connected between the distal ends of the metacarpal components 6 of two adjacent mechanical fingers; Connections are made between the distal ends and the distal ends of the metacarpal components 6 of two adjacent mechanical fingers.

[0019] The manipulator of the embodiment of the present invention realizes the motion model of the overall passive freedom of the palm, increases the passive bending and self-winding freedom of the metacarpal bones of the palm, and at the same time increases the passive curling movement of the four fingers through the entire metacarpal assembly, thereby better supporting the wrapping movement of the manipulator. Therefore, when the manipulator grasps objects of different shapes with force, the manipulator, under the action of the overall passive freedom, will wrap objects of specific shapes in all directions, increase the contact area, and stabilize the grasping.

[0020] Figure 3 Different implementation examples of the elastic member 8 are provided. The elastic member 8 is any one of an "X"-shaped or "8"-shaped spring, a spring sheet, or a polymer material. The two ends of the elastic member 8 are respectively connected to the metacarpal component 6 and the wrist component to achieve passive self-winding and recovery. The cross structure of the elastic member achieves passive bending and recovery. The elastic member 8 has an elastic preload to keep the metacarpal component 6 in place, and provides a restoring torque after the metacarpal component 6 is self-rotated or bent by an external force. Figure 3 As shown, the thickness, width and length of the spring steel sheet determine the elastic stiffness, that is, the difficulty of passive deformation and the reaction speed of returning to the original shape after the external force is removed. In actual application, different styles can be selected to set the elastic stiffness according to the safety requirements of the application environment. Of course, the two ends of the elastic member 8 can also be deformed into a cylindrical shape to facilitate the installation of the manipulator joints. Other deformations are adaptively changed according to the application, which are not listed here one by one.

[0021] The elastic element 7 is any one of a spring, a spring sheet, a polymer material and an 8-shaped elastic member.

[0022] The overall passive degrees of freedom of the manipulator are set in this way, so that there is a passive small-angle elastic rotation deformation between the metacarpal bone component 6 of the manipulator finger and the wrist, the positive self-winding angle around the metacarpal bone component is 0-10 degrees, the reverse self-winding angle around the metacarpal bone component is 0-10 degrees, and the bending angle toward the palm is 0-10 degrees, so that the palm of the manipulator can be passively curled toward the palm. In addition, the passive bending degree between the metacarpal bone components of every two adjacent manipulator fingers toward the palm is 0-20 degrees, so that the cumulative curling angle range of the palm of the entire manipulator is 0-60 degrees. In this way, the entire manipulator palm can be supported to passively complete various curling angles, such as Figure 4 As shown, various packaging movements of the robot can be realized.

[0023] Elastic bearings 9 are respectively provided at the ends of the distal phalanx components 3 and proximal phalanx components 5 of the four mechanical fingers 1, the distal phalanx components 3 and proximal phalanx components 5 of the mechanical thumb 2, and the ends of the metacarpal components 6, so that the corresponding phalanx components can adaptively undergo flexible deformation and passively self-winding. The positive and negative self-winding angles of each phalanx component are both 20 degrees. When the palm makes an overall wrapping movement, the palm forms a wrapping shape, and the corresponding fingers also undergo passive self-winding, so that each finger can more fully contact the outer surface of the object and grasp it more tightly.

[0024] The manipulator of the embodiment of the present invention realizes the motion model of the overall passive freedom of the palm, increases the passive bending and self-winding freedom of the metacarpal bones of the palm, and increases the overall passive traction movement of the four fingers, better supporting the wrapping movement of the manipulator, so that when the manipulator grasps objects of different shapes with force, under the action of the overall passive freedom of the manipulator, the manipulator will wrap objects of specific shapes in all directions, increase the contact area, and stabilize the grasp. In addition, during the wrapping movement, the corresponding fingers also undergo passive self-winding, so that each section of the finger is more fully in contact with the outer surface of the object and the grasp is tighter.

[0025] 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 robot, characterized in that: Including 1 mechanical thumb and 4 mechanical fingers, The connection between the metacarpal bone components and the wrist component of the four mechanical fingers is connected by an elastic component, so that the metacarpal bone components can be passively bent and passively self-winding; An elastic element is arranged between the metacarpal assemblies of adjacent mechanical fingers, so that the metacarpal assemblies of the four mechanical fingers are passively deformed as a whole, thereby realizing the overall curling of the palm of the mechanical hand; The elastic element connection method is any one of the following methods: connected between the ends of the metacarpal components of two adjacent mechanical fingers; connected between the distal ends of the metacarpal components of two adjacent mechanical fingers; Connections are made between the distal ends and the distal ends of the metacarpal components of two adjacent mechanical fingers.

2. The robot according to claim 1, characterized in that: The elastic component is any one of an "X"-shaped or "8"-shaped spring, a spring sheet, or a polymer material. The two ends of the elastic component are respectively connected to the metacarpal component and the wrist component to achieve passive self-winding and recovery. The cross structure of the elastic component achieves passive bending and recovery.

3. The robot according to claim 1, characterized in that: The elastic element is any one of a spring, a spring sheet, a polymer material and an 8-shaped elastic piece.

4. The robot according to claim 1, characterized in that: The distal phalanx components and the ends of the proximal phalanx components of the four mechanical fingers, the distal phalanx components and the proximal phalanx components of the mechanical thumb, and the end of the metacarpal component are respectively provided with elastic bearings to achieve adaptive flexible deformation of the corresponding phalanx components and realize passive self-winding action.

5. The robot according to claim 4, characterized in that: The forward and reverse self-winding angles of each phalanx component are both 20 degrees.

6. The robot according to claim 1, 2 or 3, characterized in that: The passive bending degree between the metacarpal components of the adjacent mechanical fingers toward the palm is 0-20 degrees, and the cumulative curling angle range of the entire palm of the mechanical hand is 0-60 degrees.

7. The robot according to claim 1, 2 or 3, characterized in that: There is passive small-angle elastic rotation deformation between the metacarpal bone component and the wrist of the robotic finger. The positive self-winding angle around the metacarpal bone component is 0-10 degrees, the reverse self-winding angle around the metacarpal bone component is 0-10 degrees, and the bending angle toward the palm is 0-10 degrees, so that the palm of the robotic hand can be passively curled toward the palm.

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