The Optimization Design Research On Pantograph And Pantograph Spring System Based On Genetic Algorithms

It is presented in this thesis the description of optimization design and simulation analysis for a certain single-arm pantograph mechanism of the underground in Shanghai and the study about the pantograph-catenary system using multi-objective optimization design based on Genetic Algorithms, virtual prototype technology and finite element analysis. The optimized geometric parameters of the pantograph and analysis result for collector head spring system are obtained and the results have been applied in actual product development.Optimization model of the pantograph is constituted and Genetic Algorithms and multi-objective optimization design method are studied, and then the geometric parameters of the pantograph are optimized using global optimization method based on Genetic Algorithms, and the best parameters of the pantograph are obtained and the realization of the key technology target of the collector head trajectory and the raising torque, etc. is met. The 3-D model of the pantograph is built in UG which is imported in multi-body dynamics simulation analysis software ADAMS and then the virtual prototype model of the pantograph is established by defining the mass of the components of the model, constrains, motion relations between each of them, on basis of which, the performance of the pantograph is mechanical system dynamic simulated using virtual prototype technology and the correctness of the optimization results are validated. The whole process of designing pantograph by means of combing optimization techniques based on Genetic Algorithms and virtual prototype technology is accomplished. Furthermore, the finite element model of the catenay-pantograph system is built in finite element analysis software Marc, and the influence which the collector head spring system's parameters on dynamic contact pantograph and catenary is simulated , by which , the relation between the stiffness of the collector head spring system and running speed of the pantograph is obtained as well as correlative conclusions which has instructive significance on design of the collector head spring system of pantograph. At last, this thesis investigate how to design pantograph/catenary test, and a good method for validating the performance of pantograph/catenary is provided.