Design of the All-Wheel Drive Control System for Electric Vehicles

This paper presents an all-wheel drive two-motor control system in which each motor independently controls one axle of the vehicle. An associated torque limiting and control unit is also introduced. The system is designed to optimise torque distribution based on various inputs (including brake, throttle, gear selection and mode selection sensor data, etc.) and thus calculating vehicle speed. Meanwhile the traction control command generation unit calculates the slip rate of each wheel on the drive axle by calculating the slip rate of the axle, and then, the higher of the two wheel slip rates is used to calculate the slip rate of the axle. This paper proposes a drive force control algorithm based on vertical load distribution. The system also uses a continuous running algorithm with multiple parameters to improve performance and stability by reading the relevant parameters, calculating the slip error and optimising the torque. If the temporary torque value is greater than the maximum available torque value, the maximum available torque value will be output and the flux commands for both the main and auxiliary motors will be output. This setup offers advantages in terms of efficiency, control and overall driving experience. Finally, the stability of all-wheel drive was verified by simulation analysis.