A three-degree-of-freedom parallel mechanism with two rotations and one displacement with few joints

Abstract

The invention relates to a few-joint two-turning-one-moving three-freedom-degree parallel mechanism which comprises a fixed platform, a movable platform and three branch chains for connecting the two platforms. One end of a first upper connecting rod of the first branch chain is connected with the movable platform through a second rotation pair, the other end of the first upper connecting rod of the first branch chain is connected with one end of a first lower connecting rod through a first movement pair, and the other end of the first lower connecting rod is connected with the fixed platform through a first rotation pair; one end of a second upper connecting rod of the second branch chain is connected with the movable platform through a first hooke joint, the other end of the second upper connecting rod of the second branch chain is connected with one end of a second lower connecting rod through a second movement pair, and the other end of the second lower connecting rod is connected with the fixed platform through a third rotation pair; and one end of a third upper connecting rod of the third branch chain is connected with the movable platform through a fourth rotation pair, the other end of the third upper connecting rod of the third branch chain is connected with one end of a third lower connecting rod through a third movement pair, and the other end of the third lower connecting rod is connected with the fixed platform through a second hooke joint. According to the few-joint two-turning-one-moving three-freedom-degree parallel mechanism, the number of mechanism joints is small, and the structural stiffness is high; motion is completely decoupled, one-to-one correspondence relationship exists between input and output, a control model is simple, and the practicability is high.

Description

technical field [0001] The invention belongs to the field of robots, in particular to a parallel mechanism. Background technique [0002] The parallel mechanism with few degrees of freedom has the advantages of simple structure, low manufacturing cost and easy control. In recent years, it has become one of the research hotspots in the field of robotics and mechanisms. Among all kinds of parallel mechanisms with few degrees of freedom, the two-rotation-one-transfer three-degree-of-freedom (2R1T) parallel mechanism is an important type of parallel mechanism with few degrees of freedom, which can be applied to motion simulators, coordinate measuring machines, spindle heads of machining centers, etc. , the most typical application of which is as the spindle head of a parallel machine tool. Adding a two-degree-of-freedom rotary head to the spindle head can realize the processing of complex parts in aerospace, automotive industry and other fields. The 3-RPS parallel mechanism doe...

AI Technical Summary

Problems solved by technology

The 3-RPS parallel mechanism does not have two continuous shafts, and its kinematic equations are complex, making it difficult to control

The above-mentioned two-rotation-one-shift parallel mechanism with two continuous shafts also has problems such as a large number of single-degree-of-freedom joints.

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