| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress the quick change of steering torque caused by the inertia of a drive source by controlling the drive of a transmission ratio changing means so that the transmission ratio is decreased as the steering quantity is increased in a steering angle terminal region. SOLUTION: An electronic control unit(ECU) 200 sets the transmission ratio of a transmission ratio changing mechanism 100 so that the target transmission ratio is gradually decreased as the stroke quantity is increased in a steering angle terminal region. When a rack shaft 4 is stroked to the terminal position, the target transmission ratio is set to a reference transmission ratio for the stopped state of a drive motor 114. Even if the rack shaft 4 reaches the terminal position, such a phenomenon can be suppressed that steering torque is quickly changed due to the inertia of the drive motor 114, and the steering sense of incompatibility given to a driver can be reduced.</p> |
