An Advanced Lateral Control System Based on Multi-Machine Control for a Four-Wheel-Drive Electric Vehicle

Abstract

Introduction: Traditional mechanical differentials in four-wheel-drive (4WD) vehicles distribute torque passively and symmetrically, which limits their ability to adapt to varying road conditions. This limitation negatively affects lateral stability and vehicle maneuverability, especially during high-speed cornering and low-traction scenarios.

Objectives: This study aims to develop an advanced lateral control strategy for 4WD electric vehicles by replacing the conventional mechanical differential with a controllable electric differential, in order to enhance vehicle stability, handling, and safety.

Methods: The proposed approach is based on multi-machine control, where each wheel is driven by an independent electric motor supplied by two synchronized three-level Neutral Point Clamped (NPC) inverters. This configuration enables precise and real-time torque distribution among the wheels. An electric differential control algorithm is implemented to actively regulate wheel torques, ensuring proper yaw rate and lateral force control under varying driving conditions.

Results: The effectiveness of the proposed system is validated through numerical simulations under critical driving conditions, including sudden steering inputs and low-adhesion surfaces. The results demonstrate improved lateral stability, reduced trajectory deviation, and strong robustness of the control strategy.

Conclusions: The study confirms that electric differential-based control is a promising solution for next-generation electric vehicles. It significantly enhances vehicle handling, agility, and safety by enabling adaptive and intelligent torque distribution.