US 5,622,470 A · Method and apparatus for adaptive cartridge retrieval and insertion in a storage library subsystem

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. If the robot is blocked from moving to a desired position, then the methods and apparatus of the present invention retries the insert operation with horizontal and/or vertical offsets of the robotic mechanisms to adjust for the mechanical misalignment. When retraction or insertion adjustments result in a successful operation, the adjustments are recorded in a memory for use in future insert or retraction operations.

Claims21

Dependent claims

In a storage library subsystem having a rotary carousel with removable magazines with slots for storing media cartridges and having a robotic gripper hand for controllably moving media cartridges within said storage library subsystem, a method for adapting the alignment of said robotic gripper hand with one of said slots to adjust for mechanical misalignments between said gripper hand and said one of said slots comprising the steps of:

(a) receiving a request to insert a media cartridge into a slot of a magazine;
(b) retrieving said media cartridge into said gripper hand;
(c) aligning said gripper hand with said slot responsive to receipt of said request to insert;
(d) extending said gripper hand to insert said media cartridge into said slot;
(e) detecting a failure of the extension of said gripper hand;
(f) retracting said gripper hand responsive to detection of said failure;
(g) incrementally adjusting the alignment between said gripper hand and said slot by a predetermined relative movement of said gripper hand with respect to said slot responsive to detection of said failure;
(h) repeating steps (d) through (g) responsive to detection of said failure until the extension of said gripper hand succeeds by inserting said media cartridge into said slot;
and
(l) storing adjustment values indicative of adjustments performed by the last repetition of step (g), the stored adjustment values usable to compensate subsequent movement of said gripper hand.

7 more elements

(a) receiving a request to retract a media cartridge from a slot of a magazine;
(b) aligning said gripper hand with said slot responsive to receipt of said request to retract;
(c) extending said gripper hand to grasp said media cartridge;
(d) retracting said gripper hand from said slot with said media cartridge;
(e) detecting a loss of contact between said gripper hand and said media cartridge;
(f) incrementally adjusting the alignment between said gripper hand and said slot by a predetermined relative movement of said gripper hand with respect to said slot responsive to detection of said loss of contact;
(g) repeating steps (c) through (f) responsive to detection of said loss of contact until the retraction of said gripper hand with said media cartridge succeeds by retracting said media cartridge from said slot;
and
(h) storing adjustment values indicative of adjustments performed by the last repetition of step (f), the stored adjustment values usable to compensate subsequent movement of said gripper hand.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for adaptive cartridge retrieval and insertion in a storage library subsystem

Life of this patent

Method and apparatus for adaptive cartridge retrieval and insertion in a storage library subsystem

Life of this patent

Abstract

Claims21