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Automatic Teaching of Storage Racks in an Automated Tape Library

IP.com Disclosure Number: IPCOM000105191D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 4 page(s) / 83K

Publishing Venue

IBM

Related People

Greco, M: AUTHOR [+3]

Abstract

The IBM 3495 Tape Library Dataserver (an automated tape library) uses a multiple axis robot mounted on a sled to handle cartridges. Grippers are mounted on the end of the robot arm to pick cartridges. At lease one camera is mounted adjacent to the grippers at the end of the robot arm. The entire sled, robot, gripper and camera assembly is referred to as the "accessor".

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Automatic Teaching of Storage Racks in an Automated Tape Library

      The IBM 3495 Tape Library Dataserver (an automated tape
library) uses a multiple axis robot mounted on a sled to handle
cartridges.  Grippers are mounted on the end of the robot arm to pick
cartridges.  At lease one camera is mounted adjacent to the grippers
at the end of the robot arm.  The entire sled, robot, gripper and
camera assembly is referred to as the "accessor".

      IBM 3480 Cartridge System Tapes and IBM Enhanced Capacity
Cartridge System Tapes are stored in racks, and the accessor moves
tapes between the racks and IBM 3490 tape drives attached to the
library.

      The camera is attached to a vision system which digitizes the
camera image, and is programmed to analyze the digitized images.  The
camera is used to determine physical gripper positions in the library
by finding fiducial targets mounted in the library, a process
referred to as "teaching" the library.

      Each rack consists of a two thirteen row columns of storage
magazines.  Each magazine holds ten cartridges and has a vision
target molded into it.

      In Fig. 1, the vision target when viewed appears as a series of
three 5mm white squares separated by 5mm.  Because in the design of
our automated tape library the cameras and lamps must be colinear,
excessive glare would occur if the vision target was normal to the
camera viewing angle.

      In order to eliminate parallax errors during the teach process,
the camera is pointed along a vector normal to the storage rack.  A
twenty degree angle was determined experimentally to be adequate to
eliminate glare, so the vision target is molded at a twenty degree
angle away from the plane defined by the front of the storage rack.

      The white targets are raised abov...