| 摘要 |
PURPOSE:To eliminate the setting of a torque margin by a method V wherein a motor is operated as a normal stepping motor when there is no step-out and when there is a step-out, the motor is operated as a DC motor and a command position is traced with the maximum torque and after that the motor is returned to a normal operation as a stepping motor. CONSTITUTION:A counter 3 takes in a position command pulse and outputs a count command position thetacmd signal. A memory 6 reads out an excitation angle of lag thetalag to correspond to the preliminarily stored rotor speed thetarot from a counter 4. An adder and subtractor 7 calculates a formula I wherein the command position thetacmd, the rotor position thetarot, and the excitation angle of lag thetalag are added or subtracted. A signal from the adder and subtractor 7 is compared with + or -pi/2N by a comparator 10. When there is no step-out as shown by a formula II, an excitation command position thetaex output from a data selector 11 is set the same as the command position thetacmd. When there is a step-out as shown by a formula III, a formula IV is used instead, that is, the command position is traced and returned to the synchronous position and then is reset to the original stepping motor mode. |
