摘要 |
Closed loop control for a stepper motor or other synchronous motor. A digital/frequency interface provides drive current to the motor at a frequency determined by output of speed limiter. Required rate-of-change of speed is calculated and applied via rate-of-change limiter to adder which sums rate-of-change signal with existing speed signal. The required rate-of-change is calculated by a calculator in accordance with existing speed, remaining distance to run, and the predetermined rate-of-change signal, to ensure that motor is brought to rest in controlled fashion without overshoot which normally occurs in closed loop control with rate-of-change limitation. |