| 摘要 |
<p>A head positioning system includes a calculating circuit for outputting a signal uk corresponding to an equilibrium of a step motor (10) for driving a head (7) on the basis of a position error of the head detected at each sampling time. The calculating circuit includes a first calcu- lator (1) for calculating a temporary equilibrium u sec k on the basis of a position error, a memory (2) for storing uk-1 to uk-N at respective sampling times, a predictor (3) for calculating a predicted value u min k and an average value u'''k in accordance with outputs from the first calculator (1) and the memory (2), a comparator (4, 5) for comparing u min k with u sec k to check if they satisfy certain conditions, outputting u sec k as uk to a step motor driver (6) when the conditions are satisfied, and outputting u'''k as uk to the step motor driver (6) when the conditions are not satisfied, and a second calculator (9), activated by the comparator (4, 5) when the conditions are not satisfied, for calculating back the position error using the output uk from the comparator (4, 5) so that the first calculator (1) recalculates u sec k.</p> |
