Research On Power Transmission System Parameters Matching And Optimization Of Mini Car

Vehicle power, fuel economy and emissions are the important indicators of evaluatingautomobile performance, and the merits of vehicle performance is restricted by the powertransmission system parameters, Therefore, a reasonable match parameters for improvingautomotive drive train power, fuel economy and reducing emissions of pollutants is of greatsignificance.Based on a mini-car as the research object, established a double objective optimizationmathematical models to improve the vehicle power, fuel economy and emissions targets, andaround the car’s transmission system parameters matching optimization, specific researchwork carried out the following:Firstly, this paper determined the power performance, fuel economy and emissions ofmini car evaluation index. Based on the engine mathematical model of the external and theuniversal characteristics, applying MATLAB software to deal with the engine bench test data,and fitting the external characteristic curve and characteristic performance curve.Secondly, with mini-car’s power transmission line, its vehicle simulation model wasestablished. The mini car’s power performance, fuel economy and emissions were simulated,and the results were compared and analyzed to verify the accuracy of the simulation model.What’s more, based on the theory of multiple target optimal design, established themini-car mathematical optimization model, which transmission gear ratio and the mainreduction gear ratio regard as design variables, standing start acceleration time continuousshifting regard as dynamic sub-objectives, UDC driving cycle fuel consumption for economicsub-goals, and using linear weighted combination method to convert them into a singleobjective function optimization mathematical model of vehicle drive train, and selecting the appropriate optimization algorithms to solve it.Last, the AVL CRUISE software was applied to simulate mini-car’s power performance,fuel economy and emissions of optimized, and the simulation results contrasted analysis. Theresults show that the optimized mini-car met the requirements of the power performance, thefuel economy and emissions has improved than the original model, which indicates that themethod is feasible and has certain reference significance for future vehicle development.