CN114378793A

CN114378793A - Passive rod hinged space three-degree-of-freedom parallel robot with analytic positive solution

Info

Publication number: CN114378793A
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: 2022-04-22
Anticipated expiration: 2042-01-21
Also published as: CN114378793B

Abstract

The invention discloses a passive rod hinged space three-degree-of-freedom parallel robot with analytic positive solution, 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 at 120 degrees around the circumference of the static platform and respectively comprise a driving arm, a hooke hinge and a driven arm, the upper end of the driving arm is rotatably connected with a mounting seat fixed on the static platform, the lower end of the driving arm is rotatably connected with the upper end of the hooke hinge, the lower end of the hooke hinge is rotatably connected with the front end of the driven arm, and the tail end of the driven arm is rotatably 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, convenience in control and the like.

Description

Passive rod hinged 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 hinged space three-degree-of-freedom parallel robot with an analytic positive solution.

Background

The three-degree-of-freedom translational parallel robot is a 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 actions such as grabbing, sorting, packaging and the like on materials by matching with machine vision and a grabbing mechanism, and has a wide market application scene.

The three-degree-of-freedom translation parallel mechanism has the advantages of small number of driving elements, low design and manufacturing cost and the like, and has recently gained wide attention and intensive research of numerous scholars at home and abroad. The chinese patent No. 201410158835.X discloses a spatial three-translation parallel robot mechanism only comprising a revolute pair, and a driving arm and a driven arm of three branched chains of the mechanism are both formed by a 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 a passive rod hinged space three-degree-of-freedom parallel robot with less driving elements, compact structure, high rigidity and bearing capacity, low design, manufacture and control cost and convenient control and having analytic positive solution.

The invention relates to a passive rod hinged space three-degree-of-freedom parallel robot with analytic positive solution, 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 at an interval of 120 degrees around the circumferential direction of the outer wall of the static platform, 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 at an interval of 120 degrees around the circumferential direction of the static platform, each branched chain comprises a driving arm, the upper end of the driving arm is rigidly connected with the output shaft of the speed reducer, the lower end of the driving arm is rotatably connected with a Hooke hinge through a rotating pair in the horizontal direction, the lower end of the Hooke hinge is connected with the front end of a driven arm, and each driven arm is formed by an upper straight connecting rod, The closed-loop sub-chains are formed by mutually and sequentially connecting a front end T-shaped rod, a lower straight connecting rod and a tail end T-shaped rod end to end through revolute pairs in a revolute connection mode, the horizontal rod of the front end T-shaped rod arranged in the horizontal direction in each closed-loop sub-chain is rotatably connected with the lower end of a hook hinge through revolute pairs in the vertical direction, the horizontal rods of the tail end T-shaped rods arranged in the three closed-loop sub-chains in the vertical direction are respectively rotatably connected with a vertical rod of an end actuator through revolute pairs, and the revolute pairs of a second branched chain, the revolute pairs of a first branched chain and the revolute pairs of a third branched chain which are connected with the end actuator are sequentially arranged on the vertical rod from top to bottom.

The invention has the advantages that:

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

Drawings

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

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

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

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

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

Detailed Description

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

the invention discloses a passive rod hinged space three-degree-of-freedom parallel robot with an analytic positive solution, which 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 in a 120-degree-interval mode around the circumferential direction 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 the three branched chains are uniformly distributed in a 120-degree-interval mode around the circumferential direction of the static platform 1 and sequentially comprise 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 rotatably connected with a Hooke hinge 6 through a revolute pair in the horizontal direction, the lower end of the Hooke hinge 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 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 which are sequentially connected end to end through the revolute pair in a rotating mode. The horizontal rod of the front end T-shaped rod 9 arranged in each closed-loop sub-chain along the horizontal direction is rotatably connected with the lower end of the hook hinge 6 through a revolute pair along the vertical direction, the horizontal rod of the tail end T-shaped rod 12 arranged in the three closed-loop sub-chains along the vertical direction is respectively rotatably connected with the vertical rod of the tail end actuator 8 through a revolute pair (if a bearing can be adopted), and the revolute pair 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 connected with the tail end actuator 8 are sequentially arranged on the vertical rod from top to bottom.

As shown in the figure, the lower end T-shaped rod 12 of the first branch chain IV comprises a first horizontal connecting rod 19 and a first vertical connecting rod 18, and the connecting point of the first horizontal connecting rod 19 and the first vertical connecting rod 18 is positioned in 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 a small distance upwards from the center of the second vertical connecting rod 16, 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, the connecting point of the third horizontal connecting rod 15 and the third vertical connecting rod 14 moves a small distance downwards from the center of the third vertical connecting rod 14, and therefore the symmetry of the movement of each branched chain is guaranteed.

Three driving motors 3 respectively control three driving arms 5 to rotate around the static platform 1 through speed reducers 2, the driving arms 5 move to drive the Hooke joints 6 to move along the vertical direction, and the Hooke joints move to drive the driven arms 7 to move, so that the parallel robot end effector 8 is driven to perform spatial three-dimensional translation along the x, y and z directions.

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

Claims

1. The utility model provides a passive pole articulated space three degree of freedom parallel robot with analytic positive solution, includes quiet platform, establishes the end effector and the three branch chains of setting between quiet platform and end effector below quiet platform, wind the circumference of quiet platform the 120 degrees evenly distributed each other of looks of outer wall be connected with three mount pads, be fixed with a driving motor and with the fixed reduction gear that links to each other of driving motor's output shaft on each mount pad, three branch chains wind quiet platform circumference 120 degrees evenly distributed each other of looks, 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 rotatably connected with a Hooke hinge through a revolute pair in the horizontal direction, the lower end of the Hooke hinge is connected with the front end of a driven arm, each driven arm is a closed-loop sub-chain formed by sequentially connecting an upper straight connecting rod, a front end T-shaped rod, a lower straight connecting rod and a tail end T-shaped rod end to end through a revolute pair in a rotating mode, a horizontal rod of the front end T-shaped rod arranged in the horizontal direction in each closed-loop sub-chain is rotatably connected with the lower end of the Hooke hinge through a revolute pair in the vertical direction, horizontal rods of the tail end T-shaped rod arranged in the vertical direction in the three closed-loop sub-chains are respectively rotatably connected with a vertical rod of a tail end actuator through revolute pairs, a revolute pair of a second branched chain connected with the tail end actuator and a revolute pair of a first branched chain, And the revolute pairs of the third branched chain are sequentially arranged on the vertical rod from top to bottom.