| 摘要 |
<p>PURPOSE:To prevent deterioration of steering performance by fixing the transmission ratio of the wheel steering angle to a set value when failure in a speed sensor is detected, and performing the conversion to the set value at different timings in a high speed area and low speed area. CONSTITUTION:Control means F causes transmission ratio changing means D to perform a predetermined operation, when failure detecting means E detects a failure in a speed sensor C. In the concrete, the control means F transmits a signal to the transmission ratio changing means D to fix the transmission ratio to a set value when such a failure occurs. At this time, if failure in the speed sensor C occurs in a high speed area, conversion to the set value is performed at a timing, and if in a low speed area, it is performed at another timing. For example, conversion is gradually performed in the high speed area, while it is rapidly performed in the low speed area. This prevents unexpected increase of the amount of steering change which would be caused by abruptly increasing change of the transmission ratio on occurance of the sensor failure in the high speed area.</p> |
