To precisely estimate a gripping degree expressing a lateral gripping degree for a wheel, and to properly control motion of a vehicle, based on the gripping degree.
Self-aligning torque for front wheels is estimated based on steering torque and steering force by a self-aligning torque estimating means 6, and side force for the front wheels is estimated based on a vehicular state quantity by a side force estimating means 9 (or a slip angle for the front wheel is estimated). The gripping degree for the front wheels is estimated based on a change of the self-aligning torque with respect to the side force (or the front wheel slip angle), in a gripping degree estimating means M12. When the change of the self-aligning torque is judged, a reference self-aligning torque is preferably set, and the gripping degree is preferably estimated based on a comparison result of the self-aligning torque with the reference self-aligning torque.
TANAKA WATARU
ONO HIDEKAZU
MURAKISHI YUJI
ASANO KATSUHIRO
MOMIYAMA MINEICHI
OGAWA SEIJI
ASANO KENJI
IMOTO YUZO
TOYOTA CENTRAL RES & DEV
TOYODA MACHINE WORKS LTD
ADVICS KK