The Transmission System Parameter Optimization Of Combination Vehicle Based On Fuel Economy

The dynamic performance and fuel economy of vehicle are important evaluationindexes for vehicle, it’s good or bad mainly concerned with the matching of powertransmission system parameters. In this paper, taking a combination vehicle of adomestic auto company as research object, to improve the dynamic performance andfuel economy as the goal, around the matching optimization for the power transmissionsystem parameters, launched the following research work:1) According to the data of engine test-bed experiment, and the theory of leastsquare method, fitted the engine’s full load characteristics and universal characteristicsthrough the software of Matlab.2) Taking the power transmission of the combination vehicle as core, establishedthe vehicle simulation model by GT-DRIVE, simulated the index of the car’s dynamicperformance and fuel economy, laid a foundation for the following optimizationdesign.3) Taking the transmission ratio and final drive ratio of the combination vehicle asdesign variable, standing start acceleration time as dynamic target, comprehensive fuelconsumption of C-WTVC circulation as economic target, relevant dynamic andeconomy optimization model as constraints, established multi-objective optimizationmodel by the software modeFRONTIER.4) By using the optimization strategy of combining design of experiments (DOE)and multi-objective optimization genetic algorithm, through GT-DRIVER andmodeFRONTIER joint simulation, we received many optimizing design schemeswhich meeting the constraint conditions. Then according to the driving conditions andrequirements of combination vehicle，found out the best power transmission systemparameters matching scheme based on pateto theory, and found out correspondingtransmission and final drive finally.5)Through Experimental Verification, the fuel economy of the optimized vehicle3.6%lower than the original scheme, it shows that “the transmission system parameteroptimization of combination vehicle based on fuel economy” of this paper is effectiveand feasible for combination vehicle.