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Publications (10 of 21) Show all publications
Wärmefjord, K., Söderberg, R., Ericsson, M., Appelgren, A., Lundbäck, A., Lööf, J., . . . Svensson, H.-O. (2016). Welding of non-nominal geometries: physical tests. Paper presented at 14th CIRP Conference on Computer Aided Tolerancing, May 18-20th 2016, Gothenburg, Sweden.. Procedia CIRP, 43, 136-141
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2016 (English)In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 43, p. 136-141Article in journal (Refereed) Published
Abstract [en]

The geometrical quality of a welded assembly is to some extent depending part positions before welding. Here, a design of experiment is set up in order to investigate this relation using physical tests in a controlled environment. Based on the experimental results it can be concluded that the influence of part position before welding is significant for geometrical deviation after welding. Furthermore, a working procedure for a completely virtual geometry assurance process for welded assemblies is outlined. In this process, part variations, assembly fixture variations and welding induced variations are important inputs when predicting the capability of the final assembly.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Welding, deviation, fixturing, clamping
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-9353 (URN)10.1016/j.procir.2016.02.046 (DOI)2-s2.0-84978481247 (Scopus ID)
Conference
14th CIRP Conference on Computer Aided Tolerancing, May 18-20th 2016, Gothenburg, Sweden.
Available from: 2016-05-30 Created: 2016-05-30 Last updated: 2018-09-06Bibliographically approved
Batungwanayo, G., Runnemalm, A. & Ericsson, M. (2014). Weld Joint Tracking System in an Automatic Inspection Cell by Using Emissivity Variation. In: Stahre, Johan, Johansson, Björn & Björkman, Mats (Ed.), Proceedings of the 6th International Swedish Production Symposium 2014: . Paper presented at 6th Swedish Production Symposium 2014 (pp. 1-7).
Open this publication in new window or tab >>Weld Joint Tracking System in an Automatic Inspection Cell by Using Emissivity Variation
2014 (English)In: Proceedings of the 6th International Swedish Production Symposium 2014 / [ed] Stahre, Johan, Johansson, Björn & Björkman, Mats, 2014, p. 1-7Conference paper, Published paper (Refereed)
Abstract [en]

Thermography has proven to be a suitable nondestructive testing method for automatic crack inspection of welds. However automatic weld inspection raises challenges. E.g. the position of the weld might not be exactly as the predefined weld seam, and a weld joint tracking system is needed. To reduce the number of equipment used, a solution is presented in this papers. The infrared camera in the thermography system is a carrier of information of the weld path. This is used for the weld joint tracking system. It is shown that the weld joint tracker is fast enough for an on-line automatic inspection.

Keywords
Weld joint tracking, emissivity variation, IR camera, automatic nondestructive testing.
National Category
Engineering and Technology Mechanical Engineering
Research subject
ENGINEERING, Mechatronics; Production Technology
Identifiers
urn:nbn:se:hv:diva-6989 (URN)978-91-980974-1-2 (ISBN)
Conference
6th Swedish Production Symposium 2014
Available from: 2014-11-14 Created: 2014-11-14 Last updated: 2018-08-12Bibliographically approved
Runnemalm, A., Liu, T., Ericsson, M. & Appelgren, A. (2013). Influence of Vibration Induced Disturbances in an Automatic Inspection Cell. In: Pedro Neto,António Paulo Moreira (Ed.), Robotics in Smart Manufacturing: . Paper presented at FAIM 2013 (pp. 191-202).
Open this publication in new window or tab >>Influence of Vibration Induced Disturbances in an Automatic Inspection Cell
2013 (English)In: Robotics in Smart Manufacturing / [ed] Pedro Neto,António Paulo Moreira, 2013, p. 191-202Conference paper, Published paper (Refereed)
Abstract [en]

In the modern manufacturing industry, quality assurance is important. Over the last few years, the interest in automatic inspection has increased and automatic non-destructive testing (NDT) has been introduced. A general automated inspection cell consists of a mechanized system for scanning and a computer system for automatic analysis of the data. In the manufacturing industry, it is preferable to use industrial robots as the scanning equipment since they offer great flexibility, excellent support organization and the in-house know-how is normally high. Another benefit is that a robot can carry different inspection equipment and an inspection cell can therefore include more than one NDT method. For an automatic analysis, high quality of the resulting data is essential. However, a non-stable condition of the NDT sensor mounted on the robotic arm may influence the results. This paper focuses on the influence of the vibration induced disturbances on the results from an NDT system. Vibration amplitude of a point to point robot movement on the robotic arm is measured. The influence of vibration disturbances on the inspection results are evaluated on the thermal images from a thermography system mounted on a six axis industrial robot. The thermal images taken by the system during the movement and after the stop of the robot are evaluated, and the influence of the vibration in these two situations is considered.

Series
Communications in Computer and Information Science, ISSN 1865-0929 ; 371
Keywords
Automatic non-destructive testing, NDT, Vibration, Thermography, SpotWeld, Work-integrated learning, WIL, AIL
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
ENGINEERING, Manufacturing and materials engineering; Work Integrated Learning
Identifiers
urn:nbn:se:hv:diva-5564 (URN)2-s2.0-84888395272 (Scopus ID)978-3-642-39222-1 (ISBN)978-3-642-39223-8 (ISBN)
Conference
FAIM 2013
Available from: 2013-08-12 Created: 2013-08-12 Last updated: 2016-02-08Bibliographically approved
Keyvani, A., Johansson, H. & Ericsson, M. (2012). Motion synthesizer platform for moving manikins. In: 2012 AHFE International Conference 21-25 July 2012 Hilton San Francisco, Union Square, California: Conference proceedings. Paper presented at AHFE 2012. Held as a part of 4th international conference on applied human factors and ergonomics, AHFE 2012 (pp. 545-554). AHFE
Open this publication in new window or tab >>Motion synthesizer platform for moving manikins
2012 (English)In: 2012 AHFE International Conference 21-25 July 2012 Hilton San Francisco, Union Square, California: Conference proceedings, AHFE , 2012, p. 545-554Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
AHFE, 2012
Keywords
Digital human models, Human motion analysis, Motion synthesizing
National Category
Robotics
Research subject
ENGINEERING, Mechatronics; Production Technology
Identifiers
urn:nbn:se:hv:diva-4457 (URN)978-0-9796435-5-2 (ISBN)
Conference
AHFE 2012. Held as a part of 4th international conference on applied human factors and ergonomics, AHFE 2012
Available from: 2012-06-28 Created: 2012-06-26 Last updated: 2018-08-09Bibliographically approved
Ryberg, A., Lennartson, B., Christiansson, A.-K., Asplund, L. & Ericsson, M. (2011). Analysis and evaluation of a general camera model. Computer Vision and Image Understanding, 115(11), 1503-1515
Open this publication in new window or tab >>Analysis and evaluation of a general camera model
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2011 (English)In: Computer Vision and Image Understanding, ISSN 1077-3142, E-ISSN 1090-235X, Vol. 115, no 11, p. 1503-1515Article in journal (Refereed) Published
Abstract [en]

A versatile General Camera Model, GCM, has been developed, and is described in detail. The model is general in the sense that it can capture both fisheye and conventional as well as catadioptric cameras in a unified framework. The camera model includes efficient handling of non-central cameras as well as compensations for decentring distortion. A novel way of analysing radial distortion functions of camera models leads to a straightforward improvement of conventional models with respect to generality, accuracy and simplicity. Different camera models are experimentally compared for two cameras with conventional and fisheye lenses, and the results show that the overall performance is favourable for the GCM.

Place, publisher, year, edition, pages
Elsevier, 2011
Keywords
Camera models, Fisheye, Catadioptric camera, Central camera, Non-central camera, Radial distortion, Decentring distortion, Stereo vision
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-2380 (URN)10.1016/j.cviu.2011.06.009 (DOI)
Projects
AFFIX, EU FP6
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2017-12-12Bibliographically approved
Ericsson, M., Holmblad, L., Almhage, L. & Brochmann, J. (2011). Co-op-modellen – ökad motivation, genomströmning och anställningsbarhet hos studenterna. In: Svante Gunnarsson (Ed.), 3:e UTVECKLINGSKONFERENSEN FÖR SVERIGES INGENJÖRSUTBILDNINGAR 30 NOVEMBER – 1 DECEMBER 2011 PÅ TEKNISKA HÖGSKOLAN VID LINKÖPINGS UNIVERSITET: . Paper presented at 3:e Utvecklingskonferensen för Sveriges ingenjörsutbildningar (pp. 90-93). Linköping: Linköpings Universitet
Open this publication in new window or tab >>Co-op-modellen – ökad motivation, genomströmning och anställningsbarhet hos studenterna
2011 (Swedish)In: 3:e UTVECKLINGSKONFERENSEN FÖR SVERIGES INGENJÖRSUTBILDNINGAR 30 NOVEMBER – 1 DECEMBER 2011 PÅ TEKNISKA HÖGSKOLAN VID LINKÖPINGS UNIVERSITET / [ed] Svante Gunnarsson, Linköping: Linköpings Universitet , 2011, p. 90-93Conference paper, Published paper (Refereed)
Abstract [sv]

Den här artikeln beskriver ett mycket framgångsrikt utbildningskoncept som genomförs på Högskolan Väst, främst på ingenjörsutbildningarna maskin och elkraft, som ger en ökad samverkan mellan högskola och omkringliggande samhälle. Konceptet bygger på en amerikansk modell som heter ”Cooperative Education” (Co-op). I Co-oputbildningen varvas teoriperioder med betalda arbetsperioder ute på olika företag och organisationer. Genom en väl planerad integration mellan teoriperioderna och arbetsperioderna förlängs utbildningen i genomsnitt med ca 6 månader men studenten har efter erlagd examen ca 1 års arbetslivserfarenhet. För att sköta kontakterna med de olika företagen finns Co-opkoordinatorer anställda på högskolan. Dessa har till uppgift att sköter den grundläggande kontakten med respektive företag. Studenterna anställs av företagen via ett normalt anställningsförfarande och de har lön enligt företagets kollektivavtal. Företagens organisation och arbetssätt integreras naturligt i utbildningen genom Co-opmodellen då studenten deltar i företagets verksamhet. Detta ger studenten en direkt inblick i arbetslivets villkor och en för Co-opmodellen karaktäristisk självgående förmåga hos studenterna utvecklas.

Under arbetsperioden besöks studenten och företaget av Co-opkoordinatorn. Under detta besök diskuteras bl.a. arbetsinnehåll, utbildning och framtida kunskapsbehov i företaget. Företagens önskemål fångas upp och integreras på ett bra sätt i utbildningen. Exempel på bra samverkan är gästlärare från företagen. Gästlärare har funnits med sen starten av högskolans ingenjörsutbildningar 1990 och andelen kurser med en eller flera gästföreläsare har ökat genom åren. Den främsta samarbetspartnern på elkraftprogrammet är Vattenfall, men också Preemraff och Trollhättan Energi finns representerade.

Konkreta resultat av utbildningskonceptet är att studenterna blir mer studiemotiverade vilket ger en ökad genomströmning av godkända studenter på programmen jämfört med studenter som inte följer Co-opmodellen. Ett annat resultat är att Co-opstudenterna har en mycket högre anställningsbarhet jämfört med en vanlig student som har läst samma utbildning.

Place, publisher, year, edition, pages
Linköping: Linköpings Universitet, 2011
Keywords
Co-oputbildning, Arbetsintegrerat lärande, samverkan, ökad genomströmning
National Category
Pedagogical Work
Research subject
Work Integrated Learning
Identifiers
urn:nbn:se:hv:diva-4003 (URN)
Conference
3:e Utvecklingskonferensen för Sveriges ingenjörsutbildningar
Available from: 2012-01-13 Created: 2012-01-12 Last updated: 2014-11-14Bibliographically approved
Keyvani, A., Johansson, H., Ericsson, M., Lämkull, D. & Örtengren, R. (2011). Schema for Motion Capture Data Management. In: Lecture Notes in Computer Science. 3rd International Conference on Digital Human Modeling, ICDHM 2011: Orlando, 9-14 July 2011. Paper presented at 3rd International Conference on Digital Human Modeling, ICDHM 2011 (pp. 99-108).
Open this publication in new window or tab >>Schema for Motion Capture Data Management
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2011 (English)In: Lecture Notes in Computer Science. 3rd International Conference on Digital Human Modeling, ICDHM 2011: Orlando, 9-14 July 2011, 2011, p. 99-108Conference paper, Published paper (Refereed)
Abstract [en]

A unified database platform capable of storing both motion captured data and information about these motions (metadata) is described. The platform stores large motion captured data in order to be used by different applications for searching, comparing, analyzing and updating existing motions. The platform is intended to be used to choose a realistic motion in simulation of production lines. It is capable of supporting and handling different motion formats, various skeleton types and distinctive body regions in a uniform data model. Extended annotating system is also introduced to mark the captured data not only in the time domain (temporal) but also on different body regions (spatial). To utilize the platform, sample tests are performed to prove the functionality. Several motion captured data is uploaded to the database while MATLAB is used to access the data, ergonomically analyze the motions based on OWAS standard, and add the results to the database by automatic tagging of the postures.

Series
Lecture Notes in Computer Science, ISSN 0302-9743 ; 6777
Keywords
motion capture database, virtual production systems, digital human modeling, computerized ergonomic analysis
National Category
Robotics
Research subject
ENGINEERING, Mechatronics
Identifiers
urn:nbn:se:hv:diva-4472 (URN)10.1007/978-3-642-21799-9_11 (DOI)978-3-642-21798-2 (ISBN)
Conference
3rd International Conference on Digital Human Modeling, ICDHM 2011
Available from: 2012-06-28 Created: 2012-06-28 Last updated: 2018-07-25Bibliographically approved
Ericsson, M., Ryberg, A., Nilsson, J., Christiansson, A.-K. & Lennartson, B. (2010). Off-Line Simulation of Advanced Stereo Vision Welding Applications. Machine Vision and Applications
Open this publication in new window or tab >>Off-Line Simulation of Advanced Stereo Vision Welding Applications
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2010 (English)In: Machine Vision and Applications, ISSN 0932-8092, E-ISSN 1432-1769Article in journal (Refereed) Submitted
National Category
Other Engineering and Technologies not elsewhere specified
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-2379 (URN)
Note

Ingår i avhandling

Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2018-07-25Bibliographically approved
Ryberg, A., Ericsson, M., Christiansson, A.-K., Eriksson, K., Nilsson, J. & Larsson, M. (2010). Stereo vision for path correction in off-line programmed robot welding. In: Proceedings of the IEEE International Conference on Industrial Technology: . Paper presented at IEEE-ICIT 2010 International Conference on Industrial Technology, ICIT 2010 (pp. 1700-1705).
Open this publication in new window or tab >>Stereo vision for path correction in off-line programmed robot welding
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2010 (English)In: Proceedings of the IEEE International Conference on Industrial Technology, 2010, p. 1700-1705Conference paper, Published paper (Refereed)
Abstract [en]

The paper describes a versatile machine vision system for correcting off-line programmed nominal robot trajectories for advanced welding. Weld trajectory corrections are needed due to slight variations in weld joints. Such variations occur naturally because of varying tolerances in parts and to heat induced deformations during earlier weld sequences. The developed system uses one camera and a weld tool mounted on the robot hand. As a first step, the whole system, including the camera, is calibrated. Then the system takes images of the weld joint from different positions and orientations, and determines the weld joint geometry in 3D using a stereo vision algorithm and a novel camera model. The weld trajectory is then updated in the robot control system, and weld operation is performed. These steps are repeated for all weld sequences of the work piece. The strategy has successfully been demonstrated for a standard industrial welding robot and a standard FireWire CMOS camera. The maximum deviation of the trajectory found by the system compared to a reference (coordinate measuring machine) is 0.7 mm and the mean deviation is 0.23 mm. Thus, the system shows high potential for industrial implementation. ©2010 IEEE.

Keywords
Camera model; CMOS camera; Firewires; Heat-induced deformation; High potential; Industrial implementation; Machine vision systems; Mean deviation; One camera; Robot control systems; Robot hand; Robot trajectory; Robot welding; Stereo vision algorithms; System use; Trajectory correction; Weld joints; Welding robots; Whole systems; Work pieces
National Category
Other Engineering and Technologies not elsewhere specified
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-2637 (URN)10.1109/ICIT.2010.5472442 (DOI)
Conference
IEEE-ICIT 2010 International Conference on Industrial Technology, ICIT 2010
Available from: 2010-08-31 Created: 2010-08-31 Last updated: 2018-07-25Bibliographically approved
Sikström, F. & Ericsson, M. (2009). Integration of finite element analysis and computer aided robotics for advanced programming of robotized welding. In: S.A. David, T. DebRoy, J.N. DuPont, T. Koseki, and H.B. Smartt (Ed.), ASM Proceedings of the International Conference: Trends in Welding Research: . Paper presented at 1-6 june 2008, Pine Mountain, Georgia (pp. 454-460). ASM International
Open this publication in new window or tab >>Integration of finite element analysis and computer aided robotics for advanced programming of robotized welding
2009 (English)In: ASM Proceedings of the International Conference: Trends in Welding Research / [ed] S.A. David, T. DebRoy, J.N. DuPont, T. Koseki, and H.B. Smartt, ASM International, 2009, p. 454-460Conference paper, Published paper (Refereed)
Abstract [en]

This paper describes a promising approach where finite element analysis is combined with computer aided robotics in off-line programming of advanced robotized welding. Finite element analysis is used to find an optimized weld power signal based on weld trajectories obtained from computer aided robotic simulations. The weld power signal is calculated by applying feedback control in the finite element simulation. This optimization ensures a full penetration weld while the total specific thermal energy input is minimized in order to mitigate unwanted residual stress and distortion. The objective with this approach is to support the design of robotized welding and significantly reduce the number of costly trials in physical implementations. The relevance of this paper is a useful method for off-line optimization of robot trajectories and varying process parameters.

Place, publisher, year, edition, pages
ASM International, 2009
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Mechatronics
Identifiers
urn:nbn:se:hv:diva-2232 (URN)978-1-61503-002-6 (ISBN)
Conference
1-6 june 2008, Pine Mountain, Georgia
Available from: 2010-02-22 Created: 2010-02-22 Last updated: 2016-02-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4329-418X

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