Abstract
A front and rear wheel independent drive type electric vehicle (FRID EV) developed as a next generation EV is focused on here. The FRID EV has ideal characteristics which are compatible with good driving performance and safety and it has propulsion systems which can control the driving and braking torques of the front and rear wheels independently to produce various indispensable functions. The first is the failsafe function under which vehicles continue running without any unexpected sudden stops, even if one of the propulsion systems fails. The second is the function for performing efficient acceleration and deceleration on all roads by suitably distributing the driving or braking torques to the front and rear wheels, taking into consideration load movement. The third is the function for ensuring safe running on low friction coefficient roads like frozen roads so that slip ratios of the front and rear wheels are maintained within the stable domain. These functions are unique to the FRID EV and they have not been realized previously in any gasoline engine-powered car, hybrid car or conventional EV.
KEYWORDS: Front-and-rear-wheel-independent-drive, FRID EV, in-wheel motor drive, load movenet, failsafe, slip ratio.