| 摘要 |
<p>HIGH DENSITY STACKER CRANE STORAGE SYSTEM A stacker crane storage and retrieval system comprises a storage rack comprising a plurality of positions defined by vertically and horizontally addressed storage areas, a stacker crane, and a track extending horizontally along the rack on which the stacker crane is adapted to be moved. A table is mounted for vertical movement on a vertical track on the stacker. A sensing scale extends along each track. Each scale includes a Gray code array including alternately dark and light increments, each increment defining a bit. An optical source provided on the crane and the table, respectively, includes a source of radiant energy adapted to direct radiant energy against its respective scale, and includes infrared sensor means for sensing the area being illuminated by its respective optical source. A comparator comprises the reading of said infrared sensors with a master position corresponding to the desired position of the crane and table, and provides a signal for driving the respective drives of the crane and the table to position the crane and table at the desired position. -i-</p> |
