Powertrain Sizing for Four-wheel-independent-actuated Electric Vehicles Based on Multi-objective Optimization

doi:10.3901/JME.2021.08.195

Abstract

Abstract: A multi-objective optimization scheme for four-wheel-independent-actuated electric vehicles is proposed to improve ride comfort and reduce energy consumption. Firstly, a generalized efficiency model and a mass model for the permanent magnet synchronous in-wheel motor are constructed based on the bench testing data. Then, the optimal torque allocation strategies for the drive and brake modes are respectively proposed based on the dynamic programming method to optimize overall efficiency and ride comfort. Finally, taking the overall energy consumption and the unsprung mass minimization as optimization objectives, the powertrain sizing is cast as a multi-objective optimization problem, which is solved to obtain the Pareto set for the optimal sizing of the front and rear in-wheel motors. The results show that there is a contradiction between the power and the overall efficiency, and higher power requirement is conducive to higher energy consumption. The optimal powertrain configuration is that high- and low-power in-wheel motors are used for the front- and rear-axles, respectively. Besides, the axial length of the motor should be minimized to improve the handling performance and ride comfort. The energy consumption is strongly related to driving cycles, and a knowledge of driving patterns is helpful to optimize the motor efficiency.

Key words: four-wheel-independent-actuated electric vehicles, multi-objective optimization, in-wheel motors, generalized motor efficiency model, torque allocation strategy

CLC Number:

TG156

DING Xiaolin, WANG Zhenpo, ZHANG Lei. Powertrain Sizing for Four-wheel-independent-actuated Electric Vehicles Based on Multi-objective Optimization[J]. Journal of Mechanical Engineering, 2021, 57(8): 195-204.

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