Driving Torque Distribution Method for Front-and- Rear- Wheel-Independent-Drive-Type Electric Vehicles (FRID EVs) at the Time of Cornering

This paper describes a driving torque distribution method for front–and-rear-wheel-independent-drivetype electric vehicles (FRID EVs) in which it is possible to get stable steering on a low friction coefficient road surface. This method is characterized by distributing driving torque to the left and right wheels of the front and rear wheels, considering not only load movement of the longitudinal direction but also load movement of the lateral direction which is generated at cornering. The load movements are estimated by detecting components of the 3-axis directions, i.e., longitudinal and lateral accelerations and yaw rate, and the steering angle and friction coefficient μ of the road surface. The effectiveness of the proposed driving torque distribution method was verified using simulators equivalent to the prototype FRID EV simulated with Matlab/Simulink and CarSim software. This method is expected to be indispensable to improving running performance of FRID EVs.