| 摘要 |
PURPOSE:To detect a generated abnormality within a short period of time by a method wherein an excessive error alarm is generated when a difference between a positional error, obtained by simulation, and an actual positional error, obtained by servo control, has become larger than a predetermined value. CONSTITUTION:A simulation unit 14 obtains an estimated positional error Ers by subtracting an estimated position PAS from a moving command Mc in an operating unit 21 in parallel to a digital servo control. An estimated speed command Vcs is obtained by multiplying the positional error Ers by a position gain while the estimated position PAS is obtained by integrating the estimated speed command Vcs. An excessive error detecting unit 15 obtains a difference (Er-Ers) between a positional error Er, obtained in a digital servo circuit 1, and the estimated positional error Ers, obtained by the simulation unit 14. The difference (Er-Ers) is compared with a set value As in a comparator 15b and an excessive error alarm SALM is outputted when the difference (Er-Ers) is larger than the set value As. |
