Research On Multiple Objective Optimization Of Dynamic Characteristics Of A Type Metro Vehicle

In recent years,in order to alleviate the traffic congestion,large and mediumsized cities have higher requirements to improve the transport capacity of urban subway.Metro car a has more carrying capacity and running speed than B type metro vehicle.However,the curve negotiation performance of metro is worse than that of B type metro vehicle.At the same time,it is contradictory to improve the snake running stability and curve negotiation ability of metro.Therefore,it is necessary to balance and optimize the snake running stability and curving performance of vehicles.In this paper,taking A type metro vehicle as the research object,based on Simapck software,the dynamic model of snake running stability and curvilinear trafficability of A type metro vehicle is established,and based on the method of radial basis function,the surrogate model of each dynamic index of A type metro vehicle is established.Based on NSGA-II multi-objective genetic algorithm,the multi-objective optimization is carried out with the nonlinear critical speed and wheel rail wear index as the optimization objectives.The research results are as follows.Based on python programming environment and integrating Simpack dynamics software,a multi process Python batch command flow is established,which improves the simulation efficiency of Simpack.By means of parameter test,the sensitivity of each dynamic index of a type metro vehicle to key suspension parameters is studied.The sensitivity is used as the basis for the initial optimization space selection of vehicle suspension parameters to avoid the blindness of parameter optimization space selection.Based on the approximate model of each dynamic index of A type metro vehicle established by radial basis function method,the contribution rate of suspension parameters of a type metro vehicle to serpentine running stability and wheel rail wear index is obtained by Monte Carlo simulation.According to the contribution rate of suspension parameters,the optimization space of multi-objective optimization suspension parameters is determined.The research content of this paper can provide an optimization method to improve the vehicle dynamics index by changing the suspension parameters of A type metro vehicles.At the same time,batch processing is used to improve the efficiency of simulation.The Monte Carlo simulation method also provides a reference for the identification of key suspension of rail vehicles.There are 64 pictures,14 tables and 50 references.