| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a steering system of a vehicle, which steering system can apply a steering assist force suitable for the steering operation of a steering wheel even when a steering angle detecting means is in trouble. <P>SOLUTION: When the steering angleθof the steering wheel has exceeded a reference steering angleθa (S103: No), a basic assist current value Ias* is compared with an end current limiting value Iend. If Ias* is larger than Iend, the current limitation is carried out by Iend (S106). If Ias* is smaller than Iend, the current limitation is not carried out (S104). By this method, the current limitation of an electric motor by a small current value can be prevented. In determining Iend, a limitation current lower limit value Ilimit_low is compared with the electric motor actual current I when the steering angleθhas exceeded the reference steering angleθa. If ¾I¾>¾Ilimit_low¾, limit_low is used as Iend. If ¾I¾≤¾Ilimit_low¾, I is used as Iend. The most appropriate end current limitation value Iend can be determined by determining Iend as described above. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
