# US 6,438,448 B1 · Self aligning robotic arm calibration apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,438,448 B1 - Document ID: US6438448B1 - Status: Granted - Kind: B1 - Application number: 09/499,925 - Filed: 2000-02-08 - Granted: 2002-08-20 - Earliest claimed: 2000-02-08 - Assignees: Storage Technology Corporation - Inventors: Joseph Paul Manes; David Black; Dan Plutt - Web page: https://patentgrep.com/patent/US6438448B1 ## CPC - G11B 15/682: {with fixed magazines having fixed cassette storage cells, e.g. in racks} - G11B 17/225: {wherein the disks are transferred from a fixed magazine to a fixed playing unit using a moving carriage} - G05B 2219/37572: Camera, tv, vision - G05B 2219/39012: Calibrate arm during scanning operation for identification of object - G05B 2219/39024: Calibration of manipulator - G05B 2219/45057: Storage handling for disks or material - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A calibration apparatus for use with a storage system for storing a plurality of objects in an array of object storage locations. In a preferred embodiment, the calibration apparatus includes a target affixed in a predetermined location to the storage system, an object retrieval mechanism, and an imaging system. The object retrieval mechanism is used for retrieving objects from the object storage locations and has a principal direction of movement which is perpendicular to a plane in which an exposed surface of each of the plurality of objects lie. The imaging system is attached to the object retrieval mechanism for imaging the target. The imaging system is positioned such that the direction from the target to the imaging system is parallel to the principal direction. ## Claims ### Claim 1 A calibration apparatus for use with a storage system for storing a plurality of objects in an array of object storage locations, comprising: an object retrieval mechanism for retrieving objects from said object storage locations; a calibration block moveably attached to said storage system, having at least one nesting feature for engaging a portion of said object retrieval mechanism and having a target; and an imaging system attached to said object retrieval mechanism for capturing an image of a portion of said target for use in calibrating said object retrieval mechanism. ### Claim 2 (depends on 1) The calibration apparatus as recited in claim 1, wherein said object retrieval mechanism has a principal direction of movement, said calibration block is free to move in any of two orthogonal directions, and the two orthogonal directions are both substantially perpendicular to the principal direction of movement. ### Claim 3 (depends on 1) The calibration apparatus as recited in claim 1, wherein said calibration block is moveably attached to said storage system with a plurality of springs. ### Claim 4 (depends on 1) The calibration apparatus as recited in claim 1, wherein a direction from said target to said imaging system is substantially parallel to said principal direction. ### Claim 5 (depends on 1) The calibration apparatus as recited in claim 1, wherein an offset by which said retrieval component needs to be adjusted for proper calibration is obtained based the position of the target relative to a scan line generated by the camera as compared to a nominal position of the target. ### Claim 6 (depends on 1) The calibration apparatus as recited in claim 1, wherein the imaging system comprises a camera. ### Claim 7 (depends on 1) The calibration apparatus as recited in claim 1, wherein the imaging system comprises a line scan camera. ### Claim 8 (depends on 1) The calibration apparatus as recited in claim 1, wherein said target is an “N”-shaped target having a first stripe, a second stripe parallel to said first stripe, and a middle stripe positioned diagonally between said first stripe and said second stripe, said first, middle and second stripes being aligned in a horizontal direction. ### Claim 9 (depends on 1) The calibration apparatus as recited in claim 1, wherein said target is a triangular shaped target. ### Claim 10 (depends on 1) The calibration apparatus as recited in claim 1, wherein said imaging said target produces an imaged target, which is analyzed to determine a vertical offset of said object retrieval mechanism with respect to a given one of said plurality of object storage locations. ### Claim 11 (depends on 1) The calibration apparatus as recited in claim 1, wherein said imaging said target produces an imaged target which is analyzed to determine a vertical offset of said object retrieval mechanism with respect to a given one of said objects. ### Claim 12 (depends on 1) The calibration apparatus as recited in claim 1, wherein each of said plurality of object storage locations is configured to hold a tape cartridge for use in a data processing system. ### Claim 13 A method of calibrating a object retrieval mechanism for use in a object storage library, comprising the steps of: inserting at least a portion of the object retrieval mechanism into a moveable calibration block; obtaining an image of the target after said inserting step; and using the position of the target in the image as compared to a nominal position to calculate an offset by which the object retrieval mechanism must be adjusted when retrieving an object from the object storage library. ### Claim 14 (depends on 13) The method as recited in claim 13, wherein the target is an “N”-shaped target having a first stripe, a second stripe parallel to said first stripe, and a middle stripe positioned diagonally between said first stripe and said second stripe, said first, middle and second stripes being aligned in a horizontal direction. ### Claim 15 (depends on 13) The method as recited in claim 13, wherein the objects are tape cassettes for use in a data processing system. ### Claim 16 (depends on 13) The method as recited in claim 13, wherein the object retrieval mechanism is a robotic arm. ### Claim 17 (depends on 13) The method as recited in claim 13, wherein the obtaining an image step is performed using a camera. ### Claim 18 (depends on 17) The method as recited in claim 17, wherein the camera is a line scan camera. ### Claim 19 (depends on 18) The method as recited in claim 18, wherein the images are line scans.