摘要 |
A turning-characteristic estimating unit of an ECU estimates a stability factor and a steering-response time constant coefficient that are parameter values related to turning characteristics of a vehicle. A standard yaw rate of the vehicle is calculated using the estimation values of the stability factor and the steering-response time constant coefficient estimated by the turning-characteristic estimating unit. A validity determining unit of the ECU determines the validity of the estimation values based on the standard yaw rate and an actual yaw rate of the vehicle. This allows improving the estimation accuracy of the stability factor and the steering-response time constant coefficient. |