| 摘要 |
<p>PROBLEM TO BE SOLVED: To eliminate the abnormality in controlling the steering force by an electric power steering unit caused by the current flow in a motor which occurs independent of the driver's steering condition due to failure in the motor terminal voltage detection circuit which prevents the motor angle speed estimated value from being calculated correctly. SOLUTION: The first target current for the motor is determined based on the detected value of the driver's steering force. The second target current for the motor is determined based on the counter electromotive force voltage for the motor. The third target current for the motor is determined based on these first and second target currents for the motor, allowing the current to flow to the motor assisting the driver's steering force. The upper limit is set for the second or third target current. Furthermore, the unit detects failures in circuits required for calculating the counter electromotive force voltage for the motor.</p> |
