# US 6,931,302 B1 · Method for a robot > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,931,302 B1 - Document ID: US6931302B1 - Status: Granted - Kind: B1 - Application number: 09/889,171 - Filed: 2000-01-13 - Granted: 2005-08-16 - Earliest claimed: 1999-01-15 - Assignees: ABB AB - Inventors: Igor Potucek; Staffan Ellqvist - Web page: https://patentgrep.com/patent/US6931302B1 ## CPC - B25J 9/1692: {Calibration of manipulator} - B25J 9/101: {using limit-switches, -stops} - G05B 2219/39023: Shut off, disable motor and rotate arm to reference pin - G05B 2219/39024: Calibration of manipulator - G05B 2219/50036: Find center of circular mark, groove - B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50}) - 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 Method for synchronizing a robot where a target is arranged on the movable part of the robot at the respective robot axles. The movable part rotates back and forth and at the same time a sensor reads at least two distinct detectable changes on the target. The center-point for the target is calculated and introduced into the control system. ## Claims ### Claim 1 A device for synchronizing a robot that includes a control system, a first robot part and a second robot part movably attached to the first robot part, the device comprising: a target arranged on the first robot part; and a sensor arranged on the second robot part, wherein the target includes several distinct detectable changes comprising height transitions, said height transitions being defined by sharp level differences in surfaces of said first robot part and comprising walls or sides, said height transitions comprising instantaneous level differences in the form of shoulder parts, said sensor sensing at least two of said distinct detectable changes at said respective height transitions to thereby enable the synchronizing of said robot by calculating a position of the target by calculating a center-point of adjacent height transitions. ### Claim 2 (depends on 1) The device according to claim 1, wherein the sensor comprises a non-contact sensor. ### Claim 3 (depends on 1) The device according to claim 1, wherein the sensor comprises a contact sensor. ### Claim 4 A device for synchronizing a robot that includes a control system, a first robot part and a second robot part movably attached to the first robot part, the device comprising: a target arranged on the first robot part; and a sensor arranged on the second robot part, wherein the target includes several distinct detectable changes comprising height transitions, said height transitions being defined by sharp level differences in surfaces of said first robot part and comprising a groove with walls, said sensor sensing at least two of said distinct detectable changes at said respective height transitions to thereby enable the synchronizing of said robot by calculating a position of the target by calculating a center-point of adjacent height transitions. ### Claim 5 (depends on 4) The device according to claim 4, wherein the sensor comprises a non-contact sensor. ### Claim 6 (depends on 4) The device according to claim 4, wherein the sensor comprises a contact sensor. ### Claim 7 A device for synchronizing a robot that includes a control system, a first robot part and a second robot part movably attached to the first robot part, the device comprising: a target arranged on the first robot part; and a sensor arranged on the second robot part, wherein the target includes several distinct detectable changes comprising height transitions, said height transitions being defined by sharp level differences in surfaces of said first robot part and comprising an elevation with sides, said sensor sensing at least two of said distinct detectable changes at said respective height transitions to thereby enable the synchronizing of said robot by calculating a position of the target by calculating a center-point of adjacent height transitions. ### Claim 8 (depends on 7) The device according to claim 7, wherein the sensor comprises a non-contact sensor. ### Claim 9 (depends on 7) The device according to claim 7, wherein the sensor comprises a contact sensor. ### Claim 10 A device for synchronizing a robot that includes a control system, a first robot part and a second robot part movably attached to the first robot part, the device comprising: a target arranged on the first robot part; and a sensor arranged on the second robot part, wherein the target includes height transitions comprising at least one of sides and walls, level differences in respective surfaces of said sides or walls defining distinct detectable structural changes in surfaces of said first robot part, the structural changes comprising instantaneous level differences in the form of shoulder parts, said sensor sensing at least two of said distinct detectable changes at said respective structural changes to thereby enable the synchronizing of said robot by calculating a position of the target by calculating a center-point of adjacent structural changes. ### Claim 11 (depends on 10) The device according to claim 10, wherein the sensor comprises a non-contact sensor. ### Claim 12 (depends on 10) The device according to claim 10, wherein the sensor comprises a contact sensor. ### Claim 13 A device for synchronizing a robot that includes a control system, a first robot part and a second robot part movably attached to the first robot part, the device comprising: a target arranged on the first robot part; and a sensor arranged on the second robot part, wherein the target includes height transitions comprising an elevation with sides, level differences in respective surfaces of said sides or walls defining distinct detectable structural changes in surfaces of said first robot part, said sensor sensing at least two of said distinct detectable changes at said respective structural changes to thereby enable the synchronizing of said robot by calculating a position of the target by calculating a center-point of adjacent structural changes. ### Claim 14 (depends on 13) The device according to claim 13, wherein the sensor comprises a non-contact sensor. ### Claim 15 (depends on 13) The device according to claim 13, wherein the sensor comprises a contact sensor.