| 摘要 |
PROBLEM TO BE SOLVED: To detect step-out and a sign thereof in a stepping motor by a simple system without monitoring the absolute rotational angle of the stepping motor. SOLUTION: A stepping motor drive unit A comprises a pulse signal input portion 90 which inputs a pulse signal b outputted from an encoder 200; a synchronization determination portion 50 which determines as the presence/absence of step-out in a stepping motor B whether the pulse signal b is synchronized with a rotation command pulse a; a determination portion 70 which, if there is an increase or periodical increase and a decrease in the ratio K of the pulse width T1 of the rotation command pulse a and the pulse width T2 of the pulse signal b, determine that there is a sign of overload step-out or overvibration step-out; and a motor control portion 40 provided with a function of stopping the stepping motor B in the case of step-out and, if there is a sign of overload step-out overvibration step-out, correcting a current control value or a rotational speed command value for the stepping motor B so as to prevent overload step- out or overvibration step-out from occurring. COPYRIGHT: (C)2004,JPO |
