摘要近年来，现在研究少自由度并联机构的人也越来越多，少自由度相对六自由度的结构简单，价格也低，工作空间比较大，在工业生产领域的应用前景也很好。相对于六自由度并联机构来说，少自由度并联机构的驱动件和构件都减少了，而且运动耦合较弱，容易解耦,控制起来也简单方便。本次设计选择三自由度并联机构平台，该三自由度并联机构重力平台平衡平台的三个支撑点采用等边三角形分布，和其它三支撑的并联驱动平台相比，该三自由度并联机构重力平台平衡平台只产生沿Z轴的平动和绕X轴和Y轴的转动，具有结构简单，易实现的优点。论文中设计一种三自由度并联机构重力平台平衡平台的机械结构，并对平台进行了承载能力的计算；最后对平台进行了基于PLC的控制系统的设计，设计中采用了伺服电动缸，因为它更环保、更节能、更干净，很容易与PLC等控制系统连接，实现对运动的高精度的控制。50793

毕业论文关键词：三自由度；承载能力；伺服电动缸；PLC；

Abstract

Recently the three degrees of freedom Lower-mobility parallel mechanism has become a new hospot. Compared with robot with the six degrees of freedom of the foot, lower-mobility parallel mechanism has the advantages of simple structure, cost less than the six degrees of freedom, has a large working space, and has a more board prospects in industrial production and other fields. three supporting points of the three degree of freedom parallel mechanism of gravity and balance platform adopts the distribution of equilateral triangle, and compared with the parallel of other three supporting driving platform, gravity and balance platform of the three degree of freedom parallel mechanism move only along the Z axis and rotate around the X axis and Y axis, and has the advantages of simple structure and it is easy to achieve. The article introduce a frame of a kind of three degree of freedom parallel mechanism of gravity and balance platform, and calculation of bearing capacity, finally design the control system of the platform based on PLC. The servo electric cylinder is better than the hydraulic cylinder and the cylinder, and has the advantages of environmental protection, save more energy; make the environment cleaner, it can also connect with the PLC control system easily.

Keywords: Three degrees of freedom; Bearing capacity; The servo electric cylinder ;PLC

目  录

第一章 绪论 1

1.1选题背景和意义 1

1.2并联机构简介 1

1.3并联机构国内外研究现状 2

1.4并联平台的现状和发展 4

第二章 并联平台的总体设计 6

2.1并联平台的研究内容..

2.2并联平台的支撑结构和自由度 6

2.3 并联平台空间的反解计算 9

   2.4并联平台驱动系统的选择

   2.5本章小结 14

第三章 伺服电动缸的设计与计算

3.1 伺服电动缸的组成 14

3.2 伺服电动缸的结构 14

3.3 主要部件的计算与选型 15

3.3.1 滚珠丝杠的设计与计算 15

3.3.3 电动机的选型 20

3.4本章小结 18

第四章 基于PLC的并联平台的控制系统的设计