Research on Easy Turn Control of Single-motor Front-wheel Drive Electric Vehicles

doi:10.3901/JME.260281

Abstract

Abstract: The easy turn(EZT) function of electric vehicles is designed for scenarios with low speed and large steering wheel angles. Based on the normal driving of the vehicle, it reduces the steering radius of the vehicle and improves its maneuverability by applying braking torque to the inner steering wheel and controlling the torque increase of the drive motor simultaneously without affecting the original acceleration and deceleration characteristics of the vehicle. This paper conducts principle analysis, control strategy development, simulation and real vehicle verification of the EZT function of the single-motor front-wheel drive electric vehicle. Firstly, based on the single-track vehicle model, analyze the principle by which the EZT function reduces the steering radius of the vehicle. Secondly, with the goal of not affecting the acceleration and deceleration characteristics of the original vehicle, a matching strategy for the braking torque of the inner wheels of the EZT and the increment of the motor torque is designed, and the differences in the effect of reducing the steering radius of the vehicle between the braking of the inner rear wheel and the braking of the inner front wheel are analyzed. Secondly, a Carsim-Simulink joint simulation platform was established to simulate and verify the EZT control strategy. The results show that when the EZT function is activated, the steering radius of the vehicle can be reduced without affecting the original vehicle's acceleration and deceleration characteristics. In addition, when the same braking torque is applied, the reduction in the steering radius is greater when braking the inner rear wheel than when braking the inner front wheel. Finally, a real vehicle test platform was built, the steering radius estimation algorithm was designed, and the real vehicle verification of the EZT control strategy was carried out. The results show that the error of the steering radius estimation method is 0.4%, and the reduction of the steering radius increases approximately linearly with the increase of the braking torque of the inner rear wheel. The minimum steering radius can be reduced by 0.18 m without the wheels locking up.

Key words: single-motor front-wheel drive electric vehicles, easy turn, control strategy, steering radius

CLC Number:

U461

SHI Biaofei, LIU Zhongtao, MENG Xianfu, WEI Zhongkang, ZHANG Weidong, WEI Heng. Research on Easy Turn Control of Single-motor Front-wheel Drive Electric Vehicles[J]. Journal of Mechanical Engineering, 2026, 62(8): 125-138.

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URL: http://www.cjmenet.com.cn/EN/10.3901/JME.260281

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