| 摘要 |
<p>PURPOSE:To promptly and accurately detect abnormality of an electric motor and to promote the prevention of abnormal steering, by detecting terminal voltage of an electric motor and its supply current in an electrically operated power steering (PS) while measuring input impedance of the electric motor being based on each detection value and cutting off the supply current of the electric motor when it is out of the normal range. CONSTITUTION:Predetermined operation of an electrically operated power steering (PS) is performed by calculation in CPU being based on steering torque T, car speed V and a steering angle theta and changing duty ratio of driving transistors Tr1-4 of an electric motor 9 by driving units 4, 5. A device, detecting terminal voltage of the electric motor 9 and its supply current by each detector 6, 7 and measuring input impedance to the electric motor 9 to be compared with a normal value, cuts off the supply current to the electric motor 9, when it is out of the predetermined range, setting the PS action unable. In this way, the device, promptly and accurately detecting abnormality of the electric motor in its short-circuit trouble, abnormal temperature rise, wire breaking trouble, etc., in no relation to a level of applied feed voltage, prevents abnormal steering.</p> |
