Novel parallel mechanism with three incompletely symmetric transition branches

Abstract

A novel parallel mechanism with three incompletely symmetric transition branches comprises a movable platform, a fixed platform and three kinematic chains, wherein the three kinematic chains are usedfor connecting the movable platform with the fixed platform; each of the three kinematic chains comprises four connecting rods, wherein the first connecting rod is hinged with the fixed platform through a rotating pair, the second connecting rod is hinged with the first rotating rod through a moving pair and hinged with the third connecting rod through a rotating pair, and the fourth connecting rod is connected with the third connecting rod through a rotating pair and connected with the movable platform through a rotating pair; the three kinematic chains are uniformly distributed in an angle of 120 degrees relative to the center of the fixed platform; axes of the first and second rotating pairs of the first, second and third kinematic chains are parallel to each other, and axes of the third and fourth rotating pairs of the first, second and third kinematic chains are parallel to each other; axes of the fourth rotating pairs of the first and second kinematic chains are perpendicularly intersected with the movable platform, and axes of the second and third rotating pairs of the first and second kinematic chains are spatially orthogonal to each other; the axis of the fourth rotating pair of the third kinematic chain is obliquely crossed with the movable platform, and spatial different planes of axes of the second and third rotating pairs of the kinematic chain have an included angle of 45 degrees. The novel parallel mechanism with the three incompletely symmetric transition branches has the advantages of compact structure, easy manufacturing and assembling, larger working space and so on.

Description

technical field [0001] The invention belongs to the field of robots and relates to a parallel mechanism. technical background [0002] The parallel mechanism has the advantages of high rigidity, high precision, and high load-bearing capacity. Among them, the three-degree-of-freedom translational parallel mechanism is one of the important branches of the research on the few-degree-of-freedom parallel mechanism. The kinematic inverse solution of the three-degree-of-freedom parallel mechanism is simple, and it is easy to plan and control the trajectory. It is widely used in precision machining, medicine, microelectronics, and precision engineering. And other fields, such as 3D coordinate measuring machine, aviation 3D shockproof shooting platform, 3D assembly robot, etc. The operator of the parallel mechanism has been applied in industry, especially the operator that realizes the three-translation function in space, and has played a very good role in high-speed pick-and-place,...

AI Technical Summary

Problems solved by technology

In the document "A New Type of Three-DOF 3-RPRRR Parallel Platform Mechanism and Its Position Analysis", in the 3-RPRRR parallel mechanism, the axes of the 4th and 5th rotation pairs of the branches are parallel to each other and have an angle with the upper platform, and the 4th rotation The axes of the pair and the third revolving pair intersect at one point in space and form a certain angle. Such a structure makes it difficult to manufacture and assemble the mechanism; the three branches of the 3-RPRRR parallel mechanism in the document "Kinematic Analysis of a Novel 3-DOF Translational Parallel Mechanism" All are the same; in the document "Research on Position Reverse Solution and Singular Configuration of 3-PRRU Parallel Robot", in the 3-PRRU parallel mechanism, the moving pair is directly fixed to the fixed platform and there are Hooke hinges in the branches. There are many such structures. Large constraints, so less workspace

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