Abstract: A method and associated apparatus within a storage library subsystem for simply adapting the motion of a robotic mechanism for moving media cartridges to allow for mechanical misalignments. When retracting a cartridge from a slot in the library subsystem, the present invention monitors a sensor in the gripper hand to verify that the cartridge is not being pulled from the gripper due to "snagging" caused by mechanical misalignment of the had with the slot. When a snag is sensed, the methods and apparatus of the present invention stop the motion, initiate robotic actions to regroup the cartridge securely, and retry the retraction with adjustments to the robotic movements and positions to avoid the snag. When inserting a cartridge into a slot in the library subsystem, the present invention monitors the progress of the servo motor controlling the robot to determine whether the motion is blocked due to mechanical misalignment of the robotic mechanism with the slot.

Abstract: An automated magnetic tape cartridge library system includes a cabinet (24) having a door (26) removably and pivotally connected thereto. The cabinet (24) houses a plurality of tape drives (56A-56E) and a plurality of racks (70) wherein magnetic tape cartridges are stored. A cartridge transport assembly (100) serves to retrieve a cartridge from a rack (70) and to load the cartridge into a target tape drive (56), and vice versa. Movement of the cartridge transport assembly (100) along X, Y, and Z rectangular coordinate axes is effected by X, Y, and Z displacement systems (104, 106, 108). The cartridge transport assembly (100) and the X, Y, and Z displacement systems (104, 106, 108) are all mounted on the removable, pivotal door (26). The cartridge transport assembly (100) includes a pair of engagement fingers (402A, 402B) which engage a selected cartridge upon contact with the cartridge.