CN113386165A

CN113386165A - Novel grabbing integrated three-finger rigid-flexible mixed dexterous hand

Info

Publication number: CN113386165A
Application number: CN202110769945.XA
Authority: CN
Inventors: 陈殿生; 王禹辰; 万际海; 丁铭烨; 李傲杰; 刘哲
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-07-05
Filing date: 2021-07-05
Publication date: 2021-09-14

Abstract

The invention provides a novel dexterous hand structure capable of realizing integrated gripping action, which is characterized in that the integrated gripping and holding actions are realized under the coordination operation of a mechanical structure at the tail end of a finger, rope driving and belt driving. The dexterous hand is structurally provided with three knuckles which are connected by using a flexible material, the tail knuckle is in a wedge shape suitable for gripping and working integrally, under-actuation driven by a rope and a belt is adopted, and restoring force is provided by an elastic element with similar principles, such as a torsion spring, an extension spring and the like. The dexterous hand structure has stronger batch processing advantage and meets the condition of mass production. The gripping action is continuous and rapid, and the gripping moment is stable and stable.

Description

Novel grabbing integrated three-finger rigid-flexible mixed dexterous hand

Technical Field

The invention belongs to the field of manipulators and provides a novel grabbing mode

Background of the study

The function is single to commodity circulation manipulator clamp on the current market: when the size of the article is too large or too small and the article is easy to deform, the problem that the irregular object is difficult to grab only the mechanical arm with the clamping function exists; the logistics manipulator only provided with the sucking disc has the problem that the logistics manipulator can not adsorb net-shaped objects with unsmooth surfaces.

In conclusion, the manipulator adopts a grabbing mode of switching the high-low friction grabbing state, the advantage of accurate grabbing of the manipulator is kept, meanwhile, the nylon belt with the low friction coefficient is introduced, and strong grabbing can be performed, so that the grabbing mode of grabbing integration is realized.

Disclosure of Invention

The invention aims to design a novel manipulator with a grabbing mode, which can basically solve the problems mentioned in the research background.

In order to achieve the purpose, the invention provides the following technical scheme:

(1) designing a flexible joint;

(2) designing a rope drive;

(3) a torsion spring is designed to be reset;

(4) designing a low-friction coefficient coating belt;

(5) the speed of the motor can be controlled independently;

as a further scheme of the invention: the flexible joint is characterized in that: the anti-skid rubber has the advantages of low cost, good anti-skid property, better anti-fatigue strength and energy absorption capacity due to the fact that the anti-skid rubber is made of elastic materials, and great flexibility and strength.

As a further scheme of the invention: the rope drive design, its characterized in that: is consistent with the transmission principle of human muscle tendons, and conforms to bionics. The motor with larger mass can be far away from the end-effector, the inertia of the end-effector can be reduced, the dynamic performance is improved, the rope driving geometric space occupies less space, and the rope driving mechanism is very suitable for complex logistics environments.

As a further scheme of the invention: the torsion spring reset design is characterized in that: the manipulator fingers can be better reset after grabbing.

As a further scheme of the invention: the low friction coefficient cladding area design, its characterized in that: the advantage of the smart hand of keeping commodity circulation snatching accurately is simultaneously, introduces the nylon belt of low coefficient of friction, can carry out the powerful and snatch and carry out the cladding, improves and snatchs the success rate.

This manipulator has guaranteed the high efficiency of snatching the letter sorting through the mode that high low friction combined together, can accomplish the letter sorting work of picking up of the unable absorbent article of sucking disc simultaneously. The mechanical finger part of the actuator adopts an underactuated design, the finger has high self-adaptability, and the requirement of a logistics sorting system on a 3D depth vision algorithm is reduced. Each finger can independently control the speed of the motor to rotate forward and backward, so that different grabbing postures are put out. Due to the fact that the flexible belt structures are adopted inside the fingers, the hand grips can grip different articles under the control of no external sensor, and meanwhile switching of the gripping state of the hand grips in the pinching direction can be achieved.

Description of the drawings:

FIG. 1 is an overall view of a robot

Wherein: 1. wedge structure

2. Flexible rubber material

3. With torsion spring therein

4. Rope and belt driven motor

FIG. 2 is a schematic view of a low coefficient of friction clad belt

FIG. 3 is a schematic view of a flexible joint structure

FIG. 4 is a schematic view of a drive line

FIG. 5 is a schematic view of the torsion spring required for return

Detailed Description

A novel grabbing integrated three-finger rigid-flexible mixed dexterous hand mainly structurally comprises a flexible joint, a low-friction-coefficient coating belt, a driving rope and a control system, and the manufacturing method comprises the following steps:

modeling by using solidworks software, and manufacturing parts by adopting a 3D printing mode.

The flexible joint is made and assembled with the finger knuckle portion. The flexible joint manufacturing method comprises the following steps:

(1) modeling is carried out by using solidworks software, the wall thickness of a die is about 1mm, and parts are manufactured by adopting a 3D printing mode.

(2) Mixing rubber a, b liquid 1: 1 and poured into a mold.

(3) And after the liquid is completely filled in the mold, putting the mold into an oven, heating the mold at 200 ℃ for 5 minutes, and taking the mold out.

(4) And breaking the shell of the die, and polishing each contact surface.

The rope and the belt are connected through the reserved hole and are fixed with the motor wheel retracting part. The rope adopts a high-strength thread (a silk thread nylon thread) 150D 3-0.15 mm; the belt is made of polyester silk ribbon and has a belt width of 1 cm.

In order to complete the reset action, a torsion spring is pressed in the base and the root of the finger and is fixed by a pin.

The control system adopts a single chip microcomputer STM32F429ZI, can realize movement after inputting codes, and each motor drives one finger independently, so that each finger can move to different positions, thereby better coating an object.

Claims

1. A mechanical arm for grabbing by changing the friction coefficient is designed, and the picking and sorting work of accurately grabbing and powerfully grabbing in two states is realized. The device is characterized in that the device realizes the integration of two actions of grabbing and gripping through the mechanical structure at the tail end of a finger and the coordination operation of rope driving and belt driving. The adaptive end gripper comprises a base, a wrapping belt, a driving rope, a motor and a torsion spring. Adopt above-mentioned design, this product can realize the crooked and the extension motion of mechanical finger to it is supplementary with the cladding to carry out snatching of object.

2. A dexterous hand structure as claimed in claim 1, wherein a three-knuckle finger structure is used and the connection is made using a flexible material.

3. The structure of the distal knuckles of dexterous hand of claim 1, wherein the configuration is wedge-shaped for gripping and working as a unit.

4. The dexterous hand-actuated version of claim 1, wherein an under-actuated design is used, driven by two flexible structures, a cord and a belt.

The restoring force for restoring the finger to the original position is provided by a torsion spring, a tension spring, or the like.