| 摘要 |
<p>PURPOSE:To provide a motor driven power steering device in which a failure in a driving current detection circuit of a steering force assisting motor can be detected in a short time so as to prevent excessive steering assisting force. CONSTITUTION:In a motor driven power steering device, in which a motor current target value of a steering force assisting motor 5 determined based on a detection value of steering torque is adopted as a target value of automatic control and a detection value of a driving current of the motor 5 is adopted as a feedback value of the automatic control to drive-control the motor 5, and when a state wherein the target value and the feedback value are different from each other more than a specified value continues for a specific time, generation of a failure is judged so as to output a fail-safe signal for operation to a safe side, a steering torque comparing means 20 for comparing a steering torque value detected by a steering torque sensor 2 with a specified steering torque value is provided. Further, an abnormality detecting means 21 is provided, which outputs the fail-safe signal when the motor current target value is within a range of the specified motor current target value and a detection value of the driving current of the motor 5 is within a range of the specified driving current, in the case where the steering torque value is not more than the specified steering torque value.</p> |
