| 摘要 |
PROBLEM TO BE SOLVED: To restrict the peak torque to be transmitted to a torque transmitting member when an electric power steering device reaches a steering limit position. SOLUTION: This electric power steering device comprises: an electric motor 12 for transmitting the steering auxiliary torque to a steering mechanism; and a controller 15 for controlling drive of the electric motor 12 with a pulse amplitude modulating signal in response to a current command value based on the steering torque. The controller 15 has a steering limit position detecting section for determining whether the steering device reaches the steering limit position, based on a motor torque change ratioΔTma of the electric motor 12. When the motor torque change ratioΔTma is a threshold valueΔTth for determining steering limit or more, the controller 15 limits a post-compensation torque command value I<SB>M</SB><SP>*'</SP>by the limit amountΔi<SB>L</SB>corresponding to the steering speed dδcomputed based on turning angleθof the motor or the steering torque T for a limit time t<SB>L</SB>. COPYRIGHT: (C)2009,JPO&INPIT |
