Spatial three-freedom parallel robot mechanism

Abstract

The present invention belongs to the field of industrial robot. The robot mechanism consists of one frame, one moving stage and three branches to connect the moving stage to the frame to form a parallel closed loop structure. Of the branches, each of two contains two single-freedom motion pairs and one ball articulation, and the third contains one single-freedom motion pair and one Hooke. The ends containing the moving stage and the frame are not collinear. The robot mechanism of the present invention combines the spatial shift and rotation and has the advantages of high rigidity, high accuracy, low motion mass high dynamic performance, very easy kinematics solution, etc.2

Description

Technical field [0001] The invention belongs to the field of industrial robots, and particularly relates to a spatial three-degree-of-freedom parallel robot mechanism with two-dimensional movement and one-dimensional rotation. Background technique [0002] There are two types of mechanisms in existing robots in service with roboticized tasks: series and parallel. The tandem type is an open chain in which the rods are connected in sequence through the motion pair. This type of robot has a large working space and high flexibility. The disadvantages are: ①The accuracy of the end pieces is very low due to the accumulation of errors of the rods; ②Rigidity Low; ③Large inertia and poor dynamic performance. Therefore, tandem robots are not suitable for operations that require high positioning and force control accuracy. In order to avoid such shortcomings, the robot mechanism can be parallel. [0003] The parallel robot mechanism is a closed-loop mechanism, and its moving platform or ter...

AI Technical Summary

Problems solved by technology

The tandem type is an open chain in which the rods are connected sequentially through kinematic pairs. This type of robot has a large working space and high flexibility. The disadvantages are: ①The accuracy of the end piece is very low due to the accumulation of errors of each rod; ②Stiffness Low; ③ large inertia, poor dynamic performance

Among the 40% of the existing three-degree-of-freedom parallel mechanisms, some are planar mechanisms, some are spherical mechanisms, some are three-dimensional purely moving mechanisms, and some are spatial mechanisms whose motion is difficult to determine at different points in space

For example, the 3-RPS robot mechanism, which has been studied for a long time at home and abroad, was proposed in 1983. The kinematic pair connected to each branch and the moving platform is a three-degree-of-freedom ball hinge, and the kinematic pair connected to the frame is a revolving pair. The two rotations and one movement of the motion table relative to the frame are through three The expansion and contraction of the branch is realized, because the reference point on the moving platform of the mechanism is in different positions in space, and the two rotation axes cannot be arbitrarily or difficult to give, so the mechanism is difficult to apply in practice

In the existing three-degree-of-freedom parallel mechanism, there is a lack of spatial three-degree-of-freedom parallel robot mechanism that combines space movement and rotation and has definite motion

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