CA2387882A1 - Welding system and methodology providing multiplexed cell control interface - Google Patents

Welding system and methodology providing multiplexed cell control interface Download PDF

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Publication number
CA2387882A1
CA2387882A1 CA002387882A CA2387882A CA2387882A1 CA 2387882 A1 CA2387882 A1 CA 2387882A1 CA 002387882 A CA002387882 A CA 002387882A CA 2387882 A CA2387882 A CA 2387882A CA 2387882 A1 CA2387882 A1 CA 2387882A1
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CA
Canada
Prior art keywords
welders
control
commands
control network
over
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA002387882A
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French (fr)
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CA2387882C (en
Inventor
Edward Dennis Hillen
George Daryl Blankenship
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Lincoln Global Inc
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Lincoln Global Inc
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Publication date
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Publication of CA2387882A1 publication Critical patent/CA2387882A1/en
Application granted granted Critical
Publication of CA2387882C publication Critical patent/CA2387882C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00Programme-control systems
    • G05B19/02Programme-control systems electric
    • G05B19/04Programme control other than numerical control, i.e. in sequence controllers or logic controllers
    • G05B19/042Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/20Pc systems
    • G05B2219/24Pc safety
    • G05B2219/24182Redundancy
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/20Pc systems
    • G05B2219/25Pc structure of the system
    • G05B2219/25208Control message, address and command portion
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/30Nc systems
    • G05B2219/45Nc applications
    • G05B2219/45135Welding

Abstract

The present invention provides a welding system and methodology to facilitate communications and control. The system includes a cell controller to control one or more welders over a control network. An interface module associated with the cell controller and the control network communicates with the welders and employs a communications protocol adapted to the interface module to facilitate communications and control between the cell controller and the one or more welders over the control network.

Claims (26)

1. A welding system, comprising:
a cell controller to control one or more welders over a control network;
an interface module associated with the cell controller and the control network to communicate with the one or more welders; and a communications protocol adapted to the interface module to facilitate communications and control between the cell controller and the one or more welders over the control network.
2. The system of claim 1, the interface module and communications protocol configured according to at least one of Device Net, Control Net, ProfiBus, User Datagram Protocol (UDP), Transmission Control Protocol (TCP), and ArcLink.
3. The system of claim 1, the interface module communicates at least one of command, configuration, set point, status and feedback information between the cell controller and the one or more welders.
4. The system of claim 1, the communications protocol includes at least one of a header, a node address, a control layer, a data layer, an error check layer, and an end packet.
5. The system of claim 1, further comprising fault detection and maintenance routines to diagnose problems within the welding system.
6. The system of claim 1, the interface module configured to transfer data between data stores associated with the one or more welding systems and a data store on the cell controller.
7. The system of claim 6, the interface module configured to transfer data between the one or more welders.
8. The system of claim 1, the one or more welders configured in a redundant configuration having an active welder and a standby welder.
9. The system of claim 8, further comprising a controller to control switching between the active welder and the standby welder.
10. The system of claim 1, the one or more welders configured in a, tandem configuration having coordinated welders.
11. The system of claim 10, further comprising a controller and associated commands to synchronize the coordinated welders over the control network, the commands including at least one of adjustable time delay commands for starting and stopping a trail or lead arc, time commands and settings for a crater fill of the trail and lead arcs, feedback detection status for arc detection and collision sense, safety stop commands for termination of a weld cycle, trigger commands for on or off timing, sending suitable output command levels per respective welder to achieve a desired weld profile, applying suitable procedures per respective welder to achieve a desired weld profile.
12. The system of claim 11, further comprising a universal clock to enable the synchronization.
13. The system of claim 1, further comprising at least one other cell controller having an associated interface module to provide multi-cell communications and coordination.
14. The system of claim 13, the at least one other cell controller enabling transfer of control and data between the one or more welders and one or more other welders.
15. A welding communications method, comprising:
communicating and controlling one or more welders over a control network;
adapting a singular interface to the control network to communicate and control the one or more welders; and providing a protocol with the interface to facilitate communications and control of the one or more welders over the control network.
16. The method of claim 16, further comprising communicating at least one of command, configuration, set point, status and feedback information to the one or more welders.
17. The method of claim 15, further comprising providing a mufti-layered protocol to facilitate communications and control.
18. The method of claim 15, further comprising providing fault detection to diagnose problems within the welding system.
19. The method of claim 15, further comprising transferring information between the one or more welders to coordinate a welding process.
20. The method of claim 15, further comprising adapting the one or. more welders in a redundant configuration.
21. The system of claim 15, further comprising adapting the one or more welders in a tandem configuration utilizing coordinated welders.
22. The method of claim 21, further comprising synchronizing the coordinated welders.
23. The method of claim 15, further comprising utilizing multiple communications channels to enable multi-cell communications and coordination.
24. A welding system, comprising:
means for communicating to one or more welders over a control network;
means for interfacing to the control network to communicate with the one or more welders; and means for adapting a protocol to facilitate communications with the one or more welders over the control network.
25. A tandem welding system, comprising:
a cell controller to control coordinated welders over a control network;
an interface module associated with the cell controller and the control network to communicate with the coordinated welders; and a command protocol adapted to the interface module to facilitate communications and control between the cell controller and the coordinated welders over the control network.
26. The system of claim 25, the command protocol further comprising commands to synchronize the coordinated welders over the control network, the commands including at least one of adjustable time delay commands for starting and stopping a trail or lead arc, time commands and settings for a crater fill of the trail and lead arcs, feedback detection status for arc detection and collision sense, safety stop commands for termination of a weld cycle, trigger commands for on or off timing, and commands to achieve a desired weld profile.
CA2387882A 2001-08-09 2002-05-29 Welding system and methodology providing multiplexed cell control interface Expired - Fee Related CA2387882C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/925,198 2001-08-09
US09/925,198 US6697701B2 (en) 2001-08-09 2001-08-09 Welding system and methodology providing multiplexed cell control interface

Publications (2)

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CA2387882A1 true CA2387882A1 (en) 2003-02-09
CA2387882C CA2387882C (en) 2010-11-09

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CA2387882A Expired - Fee Related CA2387882C (en) 2001-08-09 2002-05-29 Welding system and methodology providing multiplexed cell control interface

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US (2) US6697701B2 (en)
CA (1) CA2387882C (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7687741B2 (en) 2005-02-03 2010-03-30 Lincoln Global, Inc. Triggering events in a welder with a real-time clock

Families Citing this family (91)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8172546B2 (en) * 1998-11-23 2012-05-08 Entegris, Inc. System and method for correcting for pressure variations using a motor
US7375304B2 (en) * 2001-01-25 2008-05-20 Lincoln Global, Inc. System and method providing automated welding notification
US6697701B2 (en) * 2001-08-09 2004-02-24 Lincoln Global, Inc. Welding system and methodology providing multiplexed cell control interface
AU2003229340A1 (en) * 2002-07-04 2004-01-23 Fronius International Gmbh Method for operating a welding device, and one such welding device
US6942139B2 (en) * 2003-04-29 2005-09-13 Lincoln Global, Inc. Robotic cylinder welding
US7159753B2 (en) * 2003-08-19 2007-01-09 Autodesk, Inc. Wire body based welding representation
US7318011B2 (en) * 2003-08-29 2008-01-08 Autodesk, Inc. Facial characteristic based generation of fillet weld bead representation
US7206661B2 (en) * 2003-09-30 2007-04-17 Autodesk, Inc. Persistent naming for sub-paths of intermittent fillet weld beads
US20050194367A1 (en) * 2004-03-02 2005-09-08 Fredrick William G.Jr. System and method for remote controlled actuation of laser processing head
JP2005334945A (en) * 2004-05-27 2005-12-08 Fanuc Ltd Spot welding equipment
CN101155992B (en) * 2004-11-23 2013-02-20 恩特格里公司 System and method for a variable home position dispense system
US7643890B1 (en) 2005-01-13 2010-01-05 Lincoln Global, Inc. Remote management of portable construction devices
US8115138B2 (en) * 2005-03-15 2012-02-14 Lincoln Global, Inc. Comprehensive identification and designation of welding procedures
US8680432B2 (en) * 2005-04-20 2014-03-25 Illinois Tool Works Inc. Cooperative welding system
US7860609B2 (en) * 2005-05-06 2010-12-28 Fanuc Robotics America, Inc. Robot multi-arm control system
AT502326B1 (en) * 2005-09-09 2009-07-15 Fronius Int Gmbh REMOTE ACCESS UNIT AND COMMUNICATION METHOD FOR MANAGING WELDING DEVICES
CN101583796B (en) 2005-11-21 2012-07-04 恩特格里公司 Multistage pump and method for forming the same
US8753097B2 (en) * 2005-11-21 2014-06-17 Entegris, Inc. Method and system for high viscosity pump
US7850431B2 (en) * 2005-12-02 2010-12-14 Entegris, Inc. System and method for control of fluid pressure
CN102705209B (en) * 2005-12-02 2015-09-30 恩特格里公司 For system and method pressure compensated in pump
US7878765B2 (en) * 2005-12-02 2011-02-01 Entegris, Inc. System and method for monitoring operation of a pump
CN101356715B (en) * 2005-12-02 2012-07-18 恩特格里公司 System and method for valve sequencing in a pump
DE602006021614D1 (en) * 2005-12-02 2011-06-09 Entegris Inc I / O SYSTEMS, METHOD AND DEVICE FOR CONNECTING A PUMP CONTROL
US8083498B2 (en) 2005-12-02 2011-12-27 Entegris, Inc. System and method for position control of a mechanical piston in a pump
WO2007067360A2 (en) * 2005-12-05 2007-06-14 Entegris, Inc. Error volume system and method for a pump
TWI402423B (en) * 2006-02-28 2013-07-21 Entegris Inc System and method for operation of a pump
US7494265B2 (en) * 2006-03-01 2009-02-24 Entegris, Inc. System and method for controlled mixing of fluids via temperature
US7684446B2 (en) * 2006-03-01 2010-03-23 Entegris, Inc. System and method for multiplexing setpoints
US8242410B2 (en) 2006-07-14 2012-08-14 Lincoln Global, Inc. Welding methods and systems
US9095929B2 (en) 2006-07-14 2015-08-04 Lincoln Global, Inc. Dual fillet welding methods and systems
US20080011727A1 (en) * 2006-07-14 2008-01-17 Lincoln Global, Inc. Dual fillet welding methods and systems
US10010961B2 (en) * 2006-07-17 2018-07-03 Lincoln Global, Inc. Multiple arc welding system controls and methods
US8963045B2 (en) * 2006-09-19 2015-02-24 Lincoln Global, Inc. Non-linear adaptive control system and method for welding
US9104195B2 (en) 2006-12-20 2015-08-11 Lincoln Global, Inc. Welding job sequencer
US9937577B2 (en) 2006-12-20 2018-04-10 Lincoln Global, Inc. System for a welding sequencer
US10994358B2 (en) 2006-12-20 2021-05-04 Lincoln Global, Inc. System and method for creating or modifying a welding sequence based on non-real world weld data
US9442481B2 (en) * 2008-01-09 2016-09-13 Illinois Tool Works Inc. Automatic weld arc monitoring system
US8747116B2 (en) 2008-08-21 2014-06-10 Lincoln Global, Inc. System and method providing arc welding training in a real-time simulated virtual reality environment using real-time weld puddle feedback
US9483959B2 (en) 2008-08-21 2016-11-01 Lincoln Global, Inc. Welding simulator
US9280913B2 (en) 2009-07-10 2016-03-08 Lincoln Global, Inc. Systems and methods providing enhanced education and training in a virtual reality environment
US9318026B2 (en) 2008-08-21 2016-04-19 Lincoln Global, Inc. Systems and methods providing an enhanced user experience in a real-time simulated virtual reality welding environment
US9330575B2 (en) 2008-08-21 2016-05-03 Lincoln Global, Inc. Tablet-based welding simulator
US8911237B2 (en) 2008-08-21 2014-12-16 Lincoln Global, Inc. Virtual reality pipe welding simulator and setup
US8834168B2 (en) 2008-08-21 2014-09-16 Lincoln Global, Inc. System and method providing combined virtual reality arc welding and three-dimensional (3D) viewing
US8851896B2 (en) 2008-08-21 2014-10-07 Lincoln Global, Inc. Virtual reality GTAW and pipe welding simulator and setup
US8884177B2 (en) 2009-11-13 2014-11-11 Lincoln Global, Inc. Systems, methods, and apparatuses for monitoring weld quality
US9196169B2 (en) 2008-08-21 2015-11-24 Lincoln Global, Inc. Importing and analyzing external data using a virtual reality welding system
US8255497B2 (en) * 2008-11-03 2012-08-28 Lincoln Global, Inc. Method of discovery and communication with industrial equipment
WO2010098030A1 (en) * 2009-02-25 2010-09-02 パナソニック株式会社 Welding method and welding system
US8274013B2 (en) 2009-03-09 2012-09-25 Lincoln Global, Inc. System for tracking and analyzing welding activity
JP4676544B2 (en) * 2009-05-29 2011-04-27 ファナック株式会社 Robot control device for controlling a robot for supplying and taking out workpieces from a machine tool
US9221117B2 (en) 2009-07-08 2015-12-29 Lincoln Global, Inc. System for characterizing manual welding operations
US9230449B2 (en) 2009-07-08 2016-01-05 Lincoln Global, Inc. Welding training system
US9773429B2 (en) 2009-07-08 2017-09-26 Lincoln Global, Inc. System and method for manual welder training
US10748447B2 (en) 2013-05-24 2020-08-18 Lincoln Global, Inc. Systems and methods providing a computerized eyewear device to aid in welding
US9011154B2 (en) 2009-07-10 2015-04-21 Lincoln Global, Inc. Virtual welding system
US8569655B2 (en) 2009-10-13 2013-10-29 Lincoln Global, Inc. Welding helmet with integral user interface
US8569646B2 (en) 2009-11-13 2013-10-29 Lincoln Global, Inc. Systems, methods, and apparatuses for monitoring weld quality
US9468988B2 (en) 2009-11-13 2016-10-18 Lincoln Global, Inc. Systems, methods, and apparatuses for monitoring weld quality
US20110180517A1 (en) * 2010-01-26 2011-07-28 Illinois Tool Works Inc. Methods and systems for binding a wireless control device to a welding power source
US8680431B2 (en) 2010-11-15 2014-03-25 Lincoln Global, Inc. Device and method to control a power source
US9669484B2 (en) * 2012-04-20 2017-06-06 Illinois Tool Works Inc. Systems and methods for detecting welding and cutting parameters
US10507542B2 (en) * 2012-05-31 2019-12-17 Illinois Tool Works Inc. System and method for pairing welding devices
US20160093233A1 (en) 2012-07-06 2016-03-31 Lincoln Global, Inc. System for characterizing manual welding operations on pipe and other curved structures
US9767712B2 (en) 2012-07-10 2017-09-19 Lincoln Global, Inc. Virtual reality pipe welding simulator and setup
US9712947B2 (en) 2012-08-17 2017-07-18 Illinois Tool Works Inc. Wireless communication network improved robustness for control of industrial equipment in harsh environments
US9119023B2 (en) 2012-08-17 2015-08-25 Illinois Tool Works Inc. Wireless communication network association and security for control of industrial equipment in harsh environments
US10286475B2 (en) * 2012-08-17 2019-05-14 Illinois Tool Works Inc. Wireless communication network for control of industrial equipment in harsh environments
US9449498B2 (en) 2012-08-17 2016-09-20 Illinois Tool Works Inc. Wireless communication network power optimization for control of industrial equipment in harsh environments
US9270520B2 (en) 2012-08-17 2016-02-23 Illinois Tool Works Inc. Wireless communication network sensor information for control of industrial equipment in harsh environments
US10052759B2 (en) * 2013-03-29 2018-08-21 Fanuc America Corporation Adaptive control of robotic laser braze/weld operation
US10930174B2 (en) 2013-05-24 2021-02-23 Lincoln Global, Inc. Systems and methods providing a computerized eyewear device to aid in welding
US20150072323A1 (en) 2013-09-11 2015-03-12 Lincoln Global, Inc. Learning management system for a real-time simulated virtual reality welding training environment
US10083627B2 (en) 2013-11-05 2018-09-25 Lincoln Global, Inc. Virtual reality and real welding training system and method
US9836987B2 (en) 2014-02-14 2017-12-05 Lincoln Global, Inc. Virtual reality pipe welding simulator and setup
JP5952330B2 (en) * 2014-03-27 2016-07-13 ファナック株式会社 Machining application robot system with machining condition management function
EP3111440A1 (en) 2014-06-02 2017-01-04 Lincoln Global, Inc. System and method for manual welder training
US11137748B2 (en) * 2014-09-12 2021-10-05 Fronius International Gmbh Welding control system
US10363627B2 (en) 2014-12-16 2019-07-30 Illinois Tool Works Inc. Systems and methods for providing location services for a welding power supply
US10369652B2 (en) 2015-07-24 2019-08-06 Illinois Tool Works Inc. Wireless and powerline communications in a welding-type system
EP3292937A1 (en) * 2016-08-17 2018-03-14 Weber & Scher MFG. Co., Inc. Systems and methods for changing electrodes in continuous welding processes
US20180059648A1 (en) * 2016-08-31 2018-03-01 Esab Ab Techniques for network charting and configuration in a welding or cutting system
EP3319066A1 (en) 2016-11-04 2018-05-09 Lincoln Global, Inc. Magnetic frequency selection for electromagnetic position tracking
US10878591B2 (en) 2016-11-07 2020-12-29 Lincoln Global, Inc. Welding trainer utilizing a head up display to display simulated and real-world objects
US10913125B2 (en) 2016-11-07 2021-02-09 Lincoln Global, Inc. Welding system providing visual and audio cues to a welding helmet with a display
JP6496340B2 (en) * 2017-03-17 2019-04-03 ファナック株式会社 Scanner control device, robot control device, and remote laser welding robot system
US10997872B2 (en) 2017-06-01 2021-05-04 Lincoln Global, Inc. Spring-loaded tip assembly to support simulated shielded metal arc welding
CN108356452A (en) * 2018-01-26 2018-08-03 常州伟泰科技股份有限公司 A kind of Intelligent welding method
US11475792B2 (en) 2018-04-19 2022-10-18 Lincoln Global, Inc. Welding simulator with dual-user configuration
US11557223B2 (en) 2018-04-19 2023-01-17 Lincoln Global, Inc. Modular and reconfigurable chassis for simulated welding training
CN109240075A (en) * 2018-08-15 2019-01-18 南宁学院 A kind of thermal power plant bus redundancy control system

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06309011A (en) * 1993-04-08 1994-11-04 Internatl Business Mach Corp <Ibm> Production-cell controller of fa system
JP3406080B2 (en) * 1994-08-24 2003-05-12 ファナック株式会社 Method of allocating and using welding equipment in welding robot system
JP3327123B2 (en) 1996-06-04 2002-09-24 トヨタ自動車株式会社 Integrated control system for work robots
JP3307886B2 (en) * 1998-10-16 2002-07-24 松下電器産業株式会社 Welding equipment
US6609033B1 (en) * 1999-08-03 2003-08-19 Nadex Co. Ltd Field programmable welding controller
JP2001259839A (en) * 2000-03-22 2001-09-25 Matsushita Electric Ind Co Ltd Arc welding device
US6486439B1 (en) * 2001-01-25 2002-11-26 Lincoln Global, Inc. System and method providing automated welding information exchange and replacement part order generation
US7245875B2 (en) * 2001-04-24 2007-07-17 Lincoln Global, Inc. System and method to facilitate wireless communication in a welding environment
US6697701B2 (en) * 2001-08-09 2004-02-24 Lincoln Global, Inc. Welding system and methodology providing multiplexed cell control interface

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7687741B2 (en) 2005-02-03 2010-03-30 Lincoln Global, Inc. Triggering events in a welder with a real-time clock
AU2006200397B2 (en) * 2005-02-03 2011-11-24 Lincoln Global, Inc. Triggering events in a welder with a real-time clock

Also Published As

Publication number Publication date
CA2387882C (en) 2010-11-09
US6697701B2 (en) 2004-02-24
US6920371B2 (en) 2005-07-19
US20040162630A1 (en) 2004-08-19
US20030033052A1 (en) 2003-02-13

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