# US 8,190,294 B2 · Detection of condition changes in an industrial robot system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,190,294 B2 - Document ID: US8190294B2 - Status: Granted - Kind: B2 - Application number: 12/071,894 - Filed: 2008-02-27 - Published: 2009-05-21 - Granted: 2012-05-29 - Earliest claimed: 2007-03-09 - Assignees: ABB Research Ltd. - Inventors: Niclas Sjöstrand; Ivan Lundberg; Johan Gunnar; Shiva Sander-Tavallaey - Web page: https://patentgrep.com/patent/US8190294B2 ## CPC - G05B 19/4063: Monitoring general control system (G05B19/4062 takes precedence) - G05B 2219/32226: Computer assisted repair, maintenance of system components - G05B 2219/32234: Maintenance planning - G05B 2219/32371: Predict failure time by analysing history fault logs of same machines in databases - G05B 2219/42311: Store working torque profiles as function of time, position, compare with real torque - Y02P 90/02: Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS] - Y02P 90/80: Management or planning - Y10T 74/20329: Joint between elements - 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) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method and an apparatus for detecting condition changes in a robot system. The method includes logging a work cycle representative signal at a first and a second occasion, logging, synchronously with the logging of the work cycle representative signal, a reference signal associated with work cycles at the first and second occasions, selecting the reference signal from signals having the following characteristics: a signal influenced by the path performed by the robot, a signal calculated by the robot system, and a signal that is identical at both the occasions if a manipulator of the robot performs a movement along exactly the same path at the first and second occasions, synchronizing the representative signals utilizing the logged reference signals, and comparing the synchronized signals to determine if any condition changes have occurred between the first and second occasions. ## Claims ### Claim 1 A method for detecting condition changes in a robot system, the method being carried out in a processor, the method comprising: logging a signal representative of a work cycle of the robot system at a first and a second occasion, logging, synchronously with said representative signal representative of a work cycle of the robot system, a reference signal associated with work cycles at said first and second occasions, selecting said reference signal from: a signal calculated by the robot system, a signal influenced by a path performed by the robot system, and a signal that is identical at both said occasions if a manipulator of the robot system performs a movement along exactly a same path at the first and second occasions, synchronizing said representative signals utilizing said logged reference signals, and comparing said synchronized representative signals to determine if any condition changes in the robot system have occurred between said first and second occasions. ### Claim 2 (depends on 1) The method according to claim 1, further comprising: generating a robot path, and said reference signal is a signal calculated by a path generator or based on one or more signals calculated by the path generator. ### Claim 3 (depends on 1) The method according to claim 1, further comprising: performing said logging of said representative and said reference signals as a logging of data sets achieved by sampling of said signals, and performing said logging of said signals during a predetermined time period. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: analyzing all logged data sets of said reference signal to find batches of the reference signal of at least a part of said time period being substantially identical in two or more data sets. ### Claim 5 (depends on 4) The method according to claim 4, further comprising: synchronizing said representative signal in the data sets containing substantially identical batches of the reference signal by extracting corresponding found substantially identical batches of said reference signal. ### Claim 6 (depends on 5) The method according to claim 5, further comprising: comparing said synchronized batches of the representative signal to detect any kind of deviations of the batches of the representative signal between the first and the second occasions. ### Claim 7 (depends on 1) The method according to claim 1, wherein said work cycle represents a cycle wherein a part or a group of parts of a manipulator of the robot system moves along a path from a position A to a position B. ### Claim 8 (depends on 1) The method according to claim 1, wherein said work cycle is a production work cycle or a test cycle. ### Claim 9 A computer program product, comprising: a computer readable medium; and computer program instructions recorded on the computer readable medium and executable by a processor for carrying out a method for detecting condition changes in a robot system, the method comprising logging a signal representative of a work cycle of the robot system at a first and a second occasion, logging, synchronously with said representative signal representative of a work cycle of the robot system, a reference signal associated with work cycles at said first and second occasions, selecting said reference signal from: a signal calculated by the robot system, a signal influenced by a path performed by the robot system, and a signal that is identical at both said occasions if a manipulator of the robot system performs a movement along exactly a same path at the first and second occasions, synchronizing said representative signals utilizing said logged reference signals, and comparing said synchronized representative signals to determine if any condition changes in the robot system have occurred between said first and second occasions. ### Claim 10 An apparatus for detecting condition changes in a robot system, the apparatus comprising: a processor configured to receive and store logged data regarding a work cycle representative signal for the robot at a first and a second occasion, receive and store data regarding a reference signal associated with work cycles at said first and second occasions, the data being logged synchronously with said logging of the work cycle representative signal, wherein said reference signal is a signal calculated by the robot system and influenced by a path performed by the robot, and a signal that is identical at both said occasions if a manipulator of the robot performs a movement along exactly a same path at the first and second occasions, to synchronize said representative signals utilizing said logged reference signals, and to compare said synchronized signals to determine if any condition changes have occurred between said first and second occasions. ### Claim 11 (depends on 10) The apparatus according to claim 10, wherein the robot system includes a path generator for generating a robot path, and said reference signal is a signal calculated by the path generator or based on one or more signals calculated by the path generator. ### Claim 12 (depends on 10) The apparatus according to claim 10, wherein the processor is part of a controller of the robot system. ### Claim 13 (depends on 10) The apparatus according to claim 10, wherein the processor is part of a device external to the robot system. ### Claim 14 (depends on 1) The method according to claim 1, wherein the processor is part of a controller of the robot system. ### Claim 15 (depends on 1) The method according to claim 1, wherein the processor is part of a device external to the robot system.