Vehicle Transmission System Ratio Optimization Based Standard Cyclic Operation

Automobile can significantly reduce fuel consumption and obtain better dynamicproperty by reasonable matching of engine and transmission system. In connection withthe transmission speed ratio using the status quo bias geometric sequence, we used thecar’s dynamic property as the constraint condition and the car’s minimum fuelconsumption based four ECE and EUDC as the optimization target to optimize afive-speed manual vehicle transmission system ratio and did the simulation analysis ofdynamic and economic performance in this paper. This essay mainly did the followingmain points:(1) On the basis of the existing automobile theory and the characteristic of fourECE and EUDC, researched and analyzed evaluation and simulation method of car’sdynamic and economic performance.(2) Using MATLAB\simulink software to build the simuliation models ofcalculating gasoline consumption and dynamic property. The models of calculatinggasoline consumption included the following modules: simulation model of four ECEand EUDC, simulation model of vehicle driving resistance, simulation model oftransmission, simulation model of engine and simulation model of calculating thevehicle’s gasoline consumption; The simuliation models of dynamic property includedthe following modules: simulation model of vehicle maximum speed, simulation modelof vehicle accelerating time and simulation model of vehicle gradeability.(3) Based on the above models, chose the appropriate optimizing method asfoundation for optimizing a five-speed manual vehicle transmission system ratio usingthe car’s dynamic property as the constraint condition and the car’s minimum fuelconsumption based twenty-eight cyclic operating mode as the optimization target.(4) Used complex method to optimizing a five-speed manual vehicle transmissionsystem ratio by using the original vehicle dynamic property and the following conditionof twenty-eight cyclic operating mode as constraint condition respectively and we gotthe optimization results. The optimization results are remarkable after we compared thesimulating analysis of dynamic and economic performance before and afteroptimization.