Front and rear wheel independent drive type electric vehicle (FRID EV) providing efficient running performance on various road surfaces

This paper describes the drive performance of a FRID EV (front and rear wheel independent drive type electric vehicle) that is safe and has good running performance, and is specifically focused on a driving method that can deliver efficient running performance on various road surfaces. The driving performance is obtained via a traction control method that uses the structural features of the FRID EV in which longitudinal forces on the front and rear wheels can be adjusted flexibly according to the road and the driving conditions. For performing the traction control, which is also beneficial for energy saving during running, a slip ratio control, based on slip ratio-of-friction coefficient (μ)-curve and compensation for load movement produced by acceleration, is needed. When running on high-μ roads, compensation for load movement is effective; however, while running on lowμ roads, both compensation for load movement and slip ratio control are performed simultaneously. The effectiveness of the proposed traction control was verified using simulations; experiments also contributed to the validation.