Automatic transmission parameter optimization design for electric heavy-duty commercial vehicles considering the actuation frequency
YANG Mengchen
CHENG Zhun
LI Zhenghao
LIN Jiawei
Abstract：[Objective]Electric heavy-duty commercial vehicles should not be shifted frequently.Improper transmission design easily leads to difficulties in the comprehensive optimization of vehicle economy,reliability and durability.Taking shift frequency and accelerator pedal operation frequency to characterize the actuation frequency,an optimization design method of transmission parameters(including the number of gears)considering the comprehensive performance of the whole vehicle was proposed.[Methods]Firstly,a simulation model of multi-gear electric heavy-duty commercial vehicle was established by AVL Cruise software,and simulation tests were carried out with 2-speed,3-speed and 4-speed transmissions respectively to obtain performance data under different transmission parameters.Secondly,a fuzzy evaluation system was constructed,and the index weights were determined by combining analytic hierarchy process and variance analysis method to comprehensively score the test results.Then,a particle swarm optimization-back propagation neural network prediction model was established to analyze the influencing factors and determine the optimal design interval of transmission parameters.Finally,Latin hypercube test was adopted to obtain the optimal design values of transmission parameters.[Results]The results show that the transmission parameters corresponding to the optimal comprehensive performance all appear in the regions with smaller maximum transmission ratio and minimum transmission ratio;the transmission shift frequency increases with the increase of the number of gears and is inversely proportional to the power consumption rate;the 4-speed transmission has the optimal comprehensive performance,and its highest score is 1.5%and 7.9%higher than that of the 3-speed and 2-speed transmissions respectively;the optimal score of the 3-speed transmission is only 1.5%lower than that of the 4-speed transmission,which can be used as an alternative scheme considering manufacturing cost.
Keywords：Electric heavy-duty commercial vehicleShift frequentlyTransmission shift frequencyAccelerator pedal frequencyNumber of gearsTransmission ratio optimization design
Publication Date：2026-06-30
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：10( 87-96 )