摘要 |
PROBLEM TO BE SOLVED: To prevent a sudden change of behavior at a system fail time, in a condition highly holding steering responsiveness of a rear wheel also ensuring a large steering angle. SOLUTION: A device has the first motor 14 operating a rear wheel steering mechanism 9 and the second motor 15 operating the rear wheel steering mechanism 9 independently of the first motor 14. In the case that a steering angular speed or a steering angle absolute value of a rear wheel 6, calculated by an ECU 11, is increased to a prescribed value or more, and when high responsiveness and a large steering angle and required, the rear wheel steering mechanism 9 is operated by the first/second motor 14, 15, also at system fail time, the first/second motor 14, 15 is individually returned, so as to hold steering of the rear wheel 6 in a neutral condition, a sudden change of behavior at system fail time is prevented in a condition highly holding responsiveness of steering of the rear wheel 6 also ensuring a large steering angle. |