| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an electric power steering device that can set a dead zone in which a motor current does not flow when steering torque is in the vicinity of zero, and is simple in constitution and low in cost. <P>SOLUTION: The electric power steering device includes a control circuit 2 which open-loop controls a motor 3 on the basis of the steering torque which is detected by a steering torque sensor 1. The control circuit 2 includes a voltage command value generation circuit 21, a triangle wave generation circuit 22, a PWM circuit 23 and a drive circuit 24. The PWM circuit 23 generates a PWM signal having a duty ratio corresponding to a voltage command value on the basis of a triangle wave generated by the triangle wave generation circuit 22 and a voltage command value generated by the voltage command value generation circuit 21. A frequency (frequency of a triangle wave) of the PWM signal is set so that the motor current reaches almost zero when the duty ratio of the PWM signal is lower than a prescribed threshold A. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
