Research On The Theory And Approach Of Function Synthesis For Planar Six-Bar Dwell Mechanism

A new approach of approximate dwell function synthesis for planar six-bar mechanism is presented in the dissertation, which transforms the synthesis of planar six-bar mechanism to the synthesis of two-bar linkage, reduces the variables to four ,by selecting all dimensions of the four-bar mechanism in advance. Then, based on constraint curves of characteristic points of mechanisms, the characteristic points on the float link can be certained. As a result, unified model of dwell function synthesis of planar six-bar mechanism is set up.The model of dwell function synthesis of planar six-bar mechanism in the dissertation is decomposed into two relatively independent sub-questions. The first one is to evaluate the characteristic of points on moving rigid body, whose mathematics model is a kind of special non-differential max-mini optimal problem with inequality constraints. By the method of Saddle-point Programming and maximum entropy, the problem can be transformed as a differential optimal problem with single objective. The second one is to search approximative character points on fixed rigid body within design space, whose mathematic model is nonlinear and non-differential problem with multiple constraints. By genetic algorithm method, the problem can be resolved.For a general optimal approach, the results depend on the initial point. In this dissertation, a series of good initial points can be produced automatically by genetic algorithm.Finally, Results of different synthesis examples are given to illustrate the effectiveness of the approach. In each case, the optimization algorithm was run automatically with several initial parameters.