Six-freedom-degree parallel platform in driving orthogonal arrangement

Abstract

The invention discloses a six-freedom-degree parallel platform in driving orthogonal arrangement. The six-freedom-degree parallel platform comprises driving motors, a movable platform, a fixed base and connecting rod branch chains, wherein the driving motors are divided into two groups, each group of driving motors is respectively in center symmetrical distribution in the respective fixed plane, the axial lines of output shafts of the first group of driving motors are mutually parallel but not coplanar, the axial lines of output shafts of the second group of driving motors are positioned in the same plane, the axial lines of the output shafts of the two groups of driving motors are mutually orthogonal, the connecting rod branch chains are divided into two groups, and each group of connecting rod branch chains is respectively connected onto the movable platform in a center symmetrical way, but all of the connecting rod branch chains are not crossed in one point; each group of connecting rod branch chains is connected with the driving motors through rotating pairs, and is connected with the movable platform through a ball hinge or a hooke joint, each connecting rod branch chain consists of multiple sections of connecting rods, all sections of connecting rods are connected through the ball hinges or the hooke joints. The six-freedom-degree parallel platform has the advantages that the carrying capability is high, the decoupling calculation is simple, the work space is large, the system rigidity and the dynamic response features can be improved, a transmission system is simple, the driving control is easy, the manufacturing cost and the maintenance cost are low, and the system pollution is little.

Description

technical field [0001] The invention relates to a parallel platform in the field of mechanics, in particular to a six-degree-of-freedom parallel platform with drive orthogonal arrangement. Background technique [0002] Compared with the series mechanism, the parallel mechanism has the advantages of high precision, strong bearing capacity, high rigidity, and stable structure, and is widely used in theory and practical work. Most of the parallel mechanisms that are widely used at present belong to the Stewart platform. For parallel platforms of this type of structure, the drive is usually arranged on the same plane (the connecting branch is located under the moving platform, such as on a fixed base). For the multi-degree-of-freedom Stewart structure, this arrangement makes the driving force highly Coupling and decoupling calculations are more difficult, which also increases the difficulty of platform control; fixing the driver on the motion platform also affects the response ...

AI Technical Summary

Problems solved by technology

For parallel platforms of this type of structure, the drive is usually arranged on the same plane (the connecting branch is located under the moving platform, such as on a fixed base). For the multi-degree-of-freedom Stewart structure, this arrangement makes the driving force highly Coupling and decoupling calculations are more difficult, which also increases the difficulty of platform control; fixing the driver on the motion platform also affects the response characteristics of the system

In addition, due to the limitation of mechanism layout, most of the existing parallel platforms are driven by large servo cylinders and equipped with large energy storage devices. The equipment structure is large, the manufacturing and maintenance costs are high, and the leakage of hydraulic oil is easy to cause environmental pollution; Due to the relatively low stiffness of the hydraulic cylinder itself, the dynamic response delay is relatively large, which affects the overall stiffness of the system

For a parallel platform driven by a linear drive, the transmission system needs to be equipped with ball screws, sliders, guide rails, etc., which undoubtedly increases the assembly difficulty, accuracy requirements and manufacturing costs of the system

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