The Research On The Simple Method For Function Synthesis Of Planar Six-Bar Mechanism

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-â…¢ six-bar mechanism using different dismantling ways and generating different functions are given to validate the method studied in this dissertation.