The road surface reaction force torque detector which detects the road surface reaction force torque which it occurs

摘要

PROBLEM TO BE SOLVED: To overcome a problem not enabling any accurate estimation to be carried out whether or not a driver's steering is in a turning state or a returning state when either a motor speed or a steering torque is low in an electric power steering system.;SOLUTION: This device comprises a first state discriminator 27 for comparing an absolute value of a steering shaft reaction torque and an absolute value of a frictional torque of a steering shaft mechanism, a second state discriminator 28 for comparing an absolute value of a steering shaft reaction torque and an absolute value of a road surface reaction torque, and a steering state discriminator 29 for estimating a driver's steering state in reference to a result of first state discrimination and a result of second state discrimination. A driver's steering state estimating unit 17 comprising these discriminators is constituted.;COPYRIGHT: (C)2005,JPO&NCIPI