| 摘要 |
PURPOSE:To provide a method for controlling a stepper motor by which the rapid control of the motor is available and a step-out phenomenon can be effectively prevented. CONSTITUTION:Coil current of a stepper motor is detected (step S1) and it is judged whether the detected value is smaller than a specified value or not (step S2). When the detected value is the same as or smaller than the specified value, the driving of the stepper motor is stopped (step S4) since there is the possibility that the step motor cannot fully operate and shows a step-out. When the detected value is the same as or larger than the specified value, the upper limit of a driving frequency is so set as to secure the output torque of the stepper motor in correspondence with the coil current (step S3). By detecting the coil current of the stepper motor, actual output torque can be detected regardless of coil temperatures of the stepper motor, etc., and the stoppage of supply of a driving signal to the stepper motor can be controlled according to the actual output torque and the upper limit of the driving frequency of the stepper motor can be set based on the actual output torque. |
