| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device capable of determining, with a simple method, whether or not the gears of a speed reduction mechanism is in a state of backlash, while preventing occurrence of abnormal sounds or vibration, with excellent steering feeling.SOLUTION: A backlash region judgement part of gears is constituted of a motor rotational angular velocity &thetas;m and a motor current value Im. When the backlash region judgement part of gears has determined that gears are in the backlash region, it is so constituted that an integral gain Ki of a current feedback means is made zero. As a result, whether or not the gears are in the backlash region can be easily determined by the motor rotational angular velocity &thetas;m and the motor current value Im, whereas, if gears are determined to be in the backlash region, a load acting on the motor comes to be small, so that making an integral gain Ki zero brings the motor actual current value Im to be small, preventing the occurrence of abnormal sounds or vibration, thus improvement of steering feeling can be achieved. |
