| 摘要 |
<p>PURPOSE:To ensure safety in running by providing two speed sensors cutting out a motor current and voltage applicable to an electromagnetic clutch via the judgement that the speed sensors are abnormal when a deviation operated with output therefrom has exceeded the predetermined value, and causing a condition free from an auxiliary load. CONSTITUTION:When a vehicle is running, the speed thereof is measured with first and second speed measurement means 9b and 9c on the basis of output signals from speed sensors 10 and 11, and steering torque is measured with a steering torque measurement means 9a on the basis of output from a torque sensor 3. And when a difference between measurement values available from said means 9a and 9b has exceeded the predetermined value, a speed sensor abnormality judgement means 9d judges that the speed sensors 10 and 11 are abnormal. In this case, a motor current determination means 9f controls a molor current control means 9g and an electromagnetic clutch control means 9h, thereby de-energizing a DC motor 14 for assisting steering and an electromagnetic clutch 15 for transmitting the power of the DC motor 14 to a rack shaft 6.</p> |
