| 摘要 |
<p>PURPOSE:To deal with runaway of a CPU when a motor is driven according to detected steering torque so as to assist steering operation by prohibiting to drive the motor in the reverse direction of the detected torque in the case of the detected torque over a decided value, comparing the detected torque with the decided value. CONSTITUTION:Output of a torque sensor 2 is input to a CPU 1 and a prohibition circuit 7 through an interface 3. At this time in the CPU 1, after A/D conversion 11 and phase compensation 12, the input approaches a target current table 13 and obtains a current target value for driving a motor 5. The current target value is input to an adder 9 through a D/A converter 8. Further the actual driving current of the motor 5 is detected by a detecting circuit 6, and the current detected value is fed back to the adder 9 so as to compute a current deviation value. The current deviation value is input to a PWM circuit 10, and a driving signal to be given to the driving circuit 4 of the motor 5 is made. The prohibition circuit 7 prohibits to drive the motor in the reverse direction of the torque, when the detected torque exceeds a prescribed value.</p> |
