CN114378793B

CN114378793B - Passive rod hinge space three-degree-of-freedom parallel robot with analytic positive solution

Info

Publication number: CN114378793B
Application number: CN202210073208.0A
Authority: CN
Inventors: 梁栋; 李林; 刘军; 李世友
Original assignee: Tianjin Polytechnic University
Current assignee: Tianjin Polytechnic University
Priority date: 2022-01-21
Filing date: 2022-01-21
Publication date: 2024-03-01
Anticipated expiration: 2042-01-21
Also published as: CN114378793A

Abstract

The invention discloses a passive rod hinged space three-degree-of-freedom parallel robot with analytic solutions, which comprises a static platform, an end effector and three branched chains arranged between the static platform and the end effector, wherein the three branched chains are uniformly distributed with 120 degrees around the circumference of the static platform, each branched chain comprises a driving arm, a hook hinge and a driven arm, the upper end of the driving arm is rotationally connected with a mounting seat fixed on the static platform, the lower end of the driving arm is rotationally connected with the upper end of the hook hinge, the lower end of the hook hinge is rotationally connected with the front end of the driven arm, and the tail end of the driven arm is rotationally connected with the end effector. The mechanism is composed of revolute pairs, each branched chain contains a closed-loop subchain, and has the advantages of small number of driving elements, compact structure, high rigidity and bearing capacity, low design, manufacture and control cost, convenient control and the like.

Description

Passive rod hinge space three-degree-of-freedom parallel robot with analytic positive solution

Technical Field

The invention relates to a parallel robot, in particular to a passive rod hinge space three-degree-of-freedom parallel robot with analytic positive solutions.

Background

The three-degree-of-freedom translational parallel robot is a relatively common robot in the current industrial scene application, is mainly formed by rotationally connecting three branched chains with the same structure, has three translational degrees of freedom, can perform the actions of grabbing, sorting, packaging and the like on materials by matching with a machine vision and grabbing mechanism, and has wide market application scenes.

The three-degree-of-freedom translational parallel mechanism has recently obtained extensive attention and intensive study by a plurality of scholars at home and abroad by virtue of the advantages of small number of driving elements, low design and manufacturing cost and the like. The Chinese patent with the patent number 201410158835.X discloses a space three-translation parallel robot mechanism only comprising a revolute pair, wherein a driving arm and a driven arm of three branched chains of the mechanism are formed by adopting one rod piece, so that the whole bearing capacity and rigidity of the mechanism are not large, the stability is poor, and the mechanism is not suitable for operating heavy objects in the field of industrial production.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the three-degree-of-freedom parallel robot with the passive rod hinge space, which has the advantages of less number of driving elements, compact structure, high rigidity and bearing capacity, low design, manufacture and control cost and convenient control and is provided with an analytic solution.

The invention discloses a three-degree-of-freedom parallel robot with a positive solution analysis passive rod hinge space, which comprises a static platform, an end effector arranged below the static platform and three branched chains arranged between the static platform and the end effector, wherein three mounting seats are uniformly distributed and connected with each other around the circumference of the outer wall of the static platform at 120 degrees, a driving motor and a speed reducer fixedly connected with an output shaft of the driving motor are fixed on each mounting seat, the three branched chains are uniformly distributed around the circumference of the static platform at 120 degrees, each branched chain comprises a main movable arm, the upper end of the main movable arm is rigidly connected with the output shaft of the speed reducer, the lower end of the main movable arm is rotatably connected with the front end of a hook hinge through a rotating pair in the horizontal direction, each of the sub movable arms is a closed loop formed by an upper straight connecting rod, a front end 'T' type rod, a lower straight connecting rod and a tail end 'T' type rod, each sub-rod is sequentially connected with each other in a head-to-tail mode through a rotating pair in turn, the upper end of the three branched chains are sequentially connected with the front end of the third branched chain in the horizontal direction through a rotating pair in the horizontal direction, and the third branched chain is sequentially arranged in the vertical pair and the vertical pair is rotatably connected with the front end of the third branched chain through the third rotating pair and the third branched chain in the horizontal direction and the vertical pair is sequentially arranged in the vertical pair along the direction.

The invention has the advantages that:

the parallel robot has three degrees of freedom of movement, can realize the actions of grabbing, sorting, packaging and the like of materials, has a closed-loop sub-chain (parallelogram structure) formed by four coaxial revolute pairs on each branched chain, and has the advantages of small number of driving elements, compact structure, high rigidity and bearing capacity, low design, manufacture and control cost, convenient control and the like.

Drawings

FIG. 1 is a front view of a passive rod articulated space three degree of freedom parallel robot with analytic solution of the present invention;

FIG. 2 is a top view of the parallel robot shown in FIG. 1;

FIG. 3 is a schematic perspective view of the parallel robot of FIG. 1 at an angle;

FIG. 4 is a perspective view of another angle of the parallel robot of FIG. 1;

fig. 5 is a perspective view illustrating another angle of the parallel robot shown in fig. 1.

Detailed Description

The invention is described in detail below with reference to the attached drawings:

the invention discloses a passive rod articulated space three-degree-of-freedom parallel robot with an analytic positive solution, which is shown in the attached drawing, and comprises a static platform 1, an end effector 8 arranged below the static platform 1 and three branched chains arranged between the static platform 1 and the end effector 8. Three mounting seats 4 are uniformly distributed and connected with 120 degrees around the circumference of the outer wall of the static platform 1, a driving motor 3 and a speed reducer 2 fixedly connected with an output shaft of the driving motor 3 are fixed on each mounting seat 4, and three branched chains are uniformly distributed with 120 degrees around the circumference of the static platform 1 and are sequentially a first branched chain IV, a second branched chain V and a third branched chain VI.

Each branched chain comprises a driving arm 5, the upper end of the driving arm 5 is rigidly connected with an output shaft of the speed reducer 2, the lower end of the driving arm 5 is rotationally connected with a hook joint 6 through a revolute pair in the horizontal direction, the lower end of the hook joint 6 is connected with the front end of a driven arm 7, and each driven arm 7 is a closed-loop sub-chain formed by sequentially rotationally connecting an upper straight connecting rod 10, a front end T-shaped rod 9, a lower straight connecting rod 11 and a tail end T-shaped rod 12 with each other in a head-to-tail mode through the revolute pair. The horizontal rod of the front end T-shaped rod 9 arranged in the horizontal direction in each closed-loop sub-chain is rotationally connected with the lower end of the Hooke joint 6 through a revolute pair arranged in the vertical direction, the horizontal rods of the tail end T-shaped rods 12 arranged in the vertical direction in the three closed-loop sub-chains are respectively rotationally connected with the vertical rods of the end effector 8 through revolute pairs (such as bearings) and are sequentially arranged on the vertical rods from top to bottom through revolute pairs of the second branched chain V, the revolute pair of the first branched chain IV and the revolute pair of the third branched chain VI which are connected with the end effector 8.

As shown in the figure, the lower end "T" shaped rod 12 of the first branched chain iv comprises a first horizontal connecting rod 19 and a first vertical connecting rod 18, wherein the connecting point of the first horizontal connecting rod 19 and the first vertical connecting rod 18 is positioned at the center of the first vertical connecting rod 18; the lower end 'T' shaped rod 12 of the second branched chain V comprises a second horizontal connecting rod 17 and a second vertical connecting rod 16, the connecting point of the second horizontal connecting rod 17 and the second vertical connecting rod 16 moves upwards from the center of the second vertical connecting rod 16 for a small distance, the lower end 'T' shaped rod 12 of the third branched chain VI comprises a third horizontal connecting rod 15 and a third vertical connecting rod 14, and the connecting point of the third horizontal connecting rod 15 and the third vertical connecting rod 14 moves downwards from the center of the third vertical connecting rod 14 for a small distance, so that symmetry of movement of each branched chain is ensured.

The three driving motors 3 respectively control the three driving arms 5 to rotate around the static platform 1 through the speed reducer 2, the driving arms 5 move to drive the hook joints 6 to move along the vertical direction, the hook joints move to drive the driven arms 7 to move, and therefore the parallel robot end effector 8 is driven to translate in three dimensions along the x, y and z directions.

The above embodiments are merely illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.

Claims

1. The utility model provides a three degree of freedom parallel robots in passive pole articulated space with analyze positive solution, includes quiet platform, establishes the end effector of quiet platform below and sets up three branch chains between quiet platform and end effector, around the circumference 120 degrees evenly distributed each other of the outer wall of quiet platform be connected with three mount pad, be fixed with a driving motor and the reduction gear that links firmly with driving motor's output shaft on every mount pad, three branch chains wind 120 degrees evenly distributed each other of quiet platform circumference, its characterized in that: each branched chain comprises a driving arm, the upper end of the driving arm is rigidly connected with an output shaft of a speed reducer, the lower end of the driving arm is rotationally connected with a hook joint through a revolute pair in the horizontal direction, the lower end of the hook joint is connected with the front end of a driven arm, each driven arm is a closed-loop sub-chain formed by sequentially rotationally connecting an upper straight connecting rod, a front end 'T' -shaped rod, a lower straight connecting rod and a tail end 'T' -shaped rod head and tail through the revolute pair, the horizontal rod of the front end 'T' -shaped rod and the lower end of the hook joint, which are arranged in the horizontal direction, are rotationally connected through the revolute pair, and the horizontal rods of the tail end 'T' -shaped rods, which are arranged in the vertical direction, of three closed-loop sub-chains are respectively rotationally connected with a vertical rod of an end effector, and the revolute pair of a second branched chain, the revolute pair of a first branched chain and the revolute pair of a third branched chain are sequentially arranged on the vertical rod from top to bottom.