【作者】 李鹤荣；

【导师】 褚金奎；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2006， 硕士

【摘要】 平面连杆机构尺度综合是连杆机构设计的主要内容,现在尺度综合方法已经相当丰富,但是对六杆机构尺度综合的研究在理论上还不是很完善,目前主要对间歇六杆机构作了分析综合,且已有的全参数求解法存在局限性和求解困难性,因此本文主要针对六杆机构函数综合的简化方法进行了研究。本文从机构组合角度、机构运动学及优化方法等方面对平面六杆机构的拆分方法及综合方法进行了深入的研究。 首先,由于六杆机构实质上是简单机构组成的组合机构,本文以简单机构尺度综合理论和机构组合理论为基础,对六杆机构五种类型的尺度综合过程进行了详细分析,通过比较六杆机构与四杆机构的结构特性,分析出六杆机构实现较四杆机构更复杂的函数关系和复杂轨迹的可行性。 基于以上的基础理论和分析,本文对六杆机构三个类型的拆分方法进行了分析,并针对拆分方法的不同,建立了适当的坐标系。在此基础上给出了六杆机构简化函数综合的步骤,即首先给定部分参数的初始值,并寻找连接组成机构的关键关系或关键点,以此关系建立数学模型,对其余的未知参数进行综合,然后返回修订初始给定参数值,如此循环往复直到综合出的六杆机构满足精度要求,该方法实质上是对多维优化进行了降维。 本文采用极大—极小化方法和序列二次规划法(SQP法),利用MATLAB编写了Stephenson六杆机构的函数简化综合的求解程序。该方法是一种简化的全参数六杆机构函数综合方法,求解迅速且精度高。最后文章给出了Stephenson-Ⅲ型六杆机构的同拆分方法及实现不同函数关系的实例进行了验证。更多还原

【Abstract】 The dimensional synthesis of the planar mechanism is the main content of the linkage mechanism design. A large number of dimensional synthesis methods are presented. But the theory for the dimensional synthesis of six-bar mechanism is still not perfect, furthermore the research mainly focuses on the six-bar dwell mechanism at present, and the existed methods to synthesize all the parameters are limited and difficult to solve, so a simple method for dimension synthesis of six-bar mechanism is deeply researched in this dissertation based on the theory of mechanism combination, mechanism kinematics and optimization.Firstly, as a matter of fact the six-bar mechanism is the combination of the simple linkages, so at the beginning, the synthesis theory of the simple linkages and the theory of the mechanism combination are deeply studied. Based on that, the processes to synthesize the five styles of six-bar linkage are analyzed in detail. By comparing the characteristics of the six-bar linkages with the four-bar linkages, the feasibility to synthesize the six-bar mechanism is found out.Based on the above theory and analysis, the ways to dismantle three styles of six-bar mechanism are analyzed and the most proper reference frames are built according to these different ways. After that, the steps to synthesize the six-bar mechanism with the simple method are given, namely, some parameters are pre-elected, and then find the key connection or the key point which is used to build the mathematic model to synthesize the rest of the unknown parameters, following that, the original parameters are amended. The above steps are cycled in turn until the precision is satisfied. The essence of this simple method is to reduce the dimension.The optimization methods Max-Min and SQP (Sequential Quadratic Programming) are taken to synthesize the Stephenson six-bar mechanism with MATLAB. This is a simple method to synthesize all the parameters of six-bar mechanism for function generation with high speed and precision. At the end of this dissertation, the examples of Stephenson-Ⅲ six-bar mechanism using different dismantling ways and generating different functions are given to validate the method studied in this dissertation.更多还原