Partially-decoupled two-freedom-degree parallel mechanism

Abstract

The invention discloses a partially-decoupled two-freedom-degree parallel mechanism. The partially-decoupled two-freedom-degree parallel mechanism comprises a stationary platform, a movable platform,a first moving branch chain and a second moving branch chain; the first moving branch chain comprises a first revolute pair; the stationary platform is rotationally connected with one end of a first arc-shaped connecting rod through the first revolute pair; the second moving branch chain comprises a second revolute pair; the stationary platform is provided with a bracket; the bracket is rotationally connected with one end of a second arc-shaped connecting rod through the second revolute pair; the other end of the second arc-shaped connecting rod is rotationally connected with one end of a third arc-shaped connecting rod; a first pin shaft and a second pin shaft which are arranged in a manner of forming an included angle of 90 degrees with each other are installed at the side surface of themovable platform; the other end of the first arc-shaped connecting rod is rotationally connected with the first pin shaft; and the other end of the third arc-shaped connecting rod is rotationally connected with the second pin shaft. The partially-decoupled two-freedom-degree parallel mechanism disclosed by the invention is simple in structure and high in flexibility, runs stably, realizes partialdecoupling of two rotation freedom degrees and can be applied to the fields of virtual machine tools, aviation simulation equipment, industrial robots, medical surgical equipment and the like.

Description

technical field [0001] The invention relates to a parallel mechanism, in particular to a partially decoupled two-degree-of-freedom parallel mechanism. Background technique [0002] Since the parallel mechanism was first proposed in 1938, it has been widely used in heavy-duty simulations due to its characteristics of large rigidity, strong bearing capacity, small error, high precision, small self-weight-to-load ratio, good dynamic performance, and easy control. Equipment, robots, CNC machine tools, sensors and micro-manipulation and other fields. [0003] At present, there are 2 degrees of freedom, 3 degrees of freedom, 4 degrees of freedom, 5 degrees of freedom, and 6 degrees of freedom parallel mechanisms. The drive units of these parallel mechanisms are coupled, that is, the movement of the overall output platform of the parallel robot in any direction is the synthesis of the movements of all drive units, and the movement of each drive unit is incompatible with the overal...

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Problems solved by technology

[0014] Patent document CN102126212A proposes a type of motion decoupling two-rotation mechanism, but the Hooke hinge contained inside the branch chain limits the rotation range of the mechanism;

[0015] The two-degree-of-freedom decoupling spherical parallel mechanism proposed in the patent document CN1803410A can realize two-degree-of-freedom unconditional decoupling. The working space of the moving platform is defined; although two bias methods are proposed to realize the expansion of the working space, it still cannot make the moving platform have a global working space;

[0016] Patent document CN106426109A proposes a decoupled two-degree-of-freedom parallel mechanism that can realize a spherical working space, which can realize decoupling of rotational degrees of freedom under two degrees of freedom. The rotation in one direction of the parallel mechanism uses a connecting rod pin In the process of rotating the moving platform in this direction, the radius of gyration of the relevant connecting rod is relatively large, and the center of gyration of the moving platform is not the intersection of the two axes of rotation, which limits its precision positioning. applications in

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