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Silva-Magalhaes, A., Cederqvist, L., De Backer, J., Hakansson, E., Ossiansson, B. & Bolmsjö, G. (2019). A Friction Stir Welding case study using Temperature Controlled Robotics with a HPDC Cylinder Block and dissimilar materials joining. Journal of Manufacturing Processes, 46, 177-184
Open this publication in new window or tab >>A Friction Stir Welding case study using Temperature Controlled Robotics with a HPDC Cylinder Block and dissimilar materials joining
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2019 (English)In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 46, p. 177-184Article in journal (Refereed) Published
Abstract [en]

The automotive industry is going through a radical transformation from combustion engines to fully electric propulsion, aiming at improving key performance indicators related to efficiency, environmental sustainability and economic competitiveness. In this transition period, it is important to continue the innovation of combustion engines for e.g. plug-in hybrid vehicles. This led Volvo Cars to pursue radically new manufacturing processes such as Friction Stir Welding (FSW). The work presented in this paper is a case study whereby feasibility of using FSW to join a reinforcement element into the aluminium casted Cylinder Block was studied. The complex geometry of the joint required a flexible five-axis manipulator, i.e. an industrial robot, as well as advanced process control, i.e. temperature feedback control, in order to maintain a consistent weld quality throughout the whole component. The process was successfully demonstrated in a lab environment and offers a cost-efficient solution while maintaining the durability and higher efficiency. The outcome of this study shows the great potential of implementing the FSW process in combination with High Pressure Die Casted components, such a Cylinder Block.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Friction stir welding, Automotive, Aluminium, Casting, Robot, Temperature control
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
Technology (byts ev till Engineering), Mechanical Engineering
Identifiers
urn:nbn:se:lnu:diva-90207 (URN)10.1016/j.jmapro.2019.08.012 (DOI)000493221100017 ()
Available from: 2019-11-21 Created: 2019-11-21 Last updated: 2019-11-21Bibliographically approved
Silva-Magalhães, A., De Backer, J., Martin, J. & Bolmsjö, G. (2019). In-situ temperature measurement in friction stir welding of thick section aluminium alloys. Journal of Manufacturing processes, 39, 12-17
Open this publication in new window or tab >>In-situ temperature measurement in friction stir welding of thick section aluminium alloys
2019 (English)In: Journal of Manufacturing processes, ISSN 1526-6125, Vol. 39, p. 12-17Article in journal (Refereed) Published
Abstract [en]

Friction stir welding (FSW) is a reliable joining technology with a wide industrial uptake. However, several fundamentals of the process such as the temperature inside the stirred zone of the weld and its influence on mechanical properties, are not yet fully understood. This paper shows a method for accurate temperature measurements in multiple locations around the tool, to identify the location of the peak temperature, the temperature variations between the advancing and the retreating side of the tool and its relation to the tool geometry. Both standardised thermocouples in the FSW tool and the novel “tool-workpiece thermocouple” method were used to record temperatures.

Bead-on-plate welds in 20 mm thickness AA6082-T6 were produced while the temperatures were measured in three locations on the FSW tool: at the shoulder outer diameter, at the transition from shoulder to probe and at the probe tip. It was found that the hottest point in the stirred zone was 607 °C and was located at the transition between the shoulder and probe, on the retreating-trailing side of the tool. The lowest temperature was found at the probe tip on the retreating-leading side of the tool.

The results offer a better understanding of the temperature distribution around a FSW tool. The method presented can be applied to verification of thermal simulation models, tool design optimization, quality assurance and temperature feedback control.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Friction stir welding, Temperature measurement, Aluminium alloys, Thick section, Thermocouple, TWT
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Applied Mechanics
Research subject
Technology (byts ev till Engineering), Mechanical Engineering
Identifiers
urn:nbn:se:lnu:diva-80638 (URN)10.1016/j.jmapro.2019.02.001 (DOI)000464296700002 ()2-s2.0-85061529967 (Scopus ID)
Available from: 2019-02-18 Created: 2019-02-18 Last updated: 2019-08-30Bibliographically approved
Bolmsjö, G. (2019). Smart Industri och Akademien. In: Presenterades på Regiondagarna 2019: Kosta Boda Art Hotell, 17-18 januari 2019. Paper presented at Regiondagarna 2019. Kosta Boda Art Hotell, 17-18 januari 2019.
Open this publication in new window or tab >>Smart Industri och Akademien
2019 (Swedish)In: Presenterades på Regiondagarna 2019: Kosta Boda Art Hotell, 17-18 januari 2019, 2019, , p. 23Conference paper, Oral presentation only (Other (popular science, discussion, etc.))
Publisher
p. 23
Keywords
robotteknik, innovation
National Category
Robotics
Research subject
Technology (byts ev till Engineering)
Identifiers
urn:nbn:se:lnu:diva-80122 (URN)
Conference
Regiondagarna 2019. Kosta Boda Art Hotell, 17-18 januari 2019
Note

Presentation om smart industri och akademiens vid Regiondagarna 2019. Hölls på Kosta Boda Art Hotell, 17-18 januari 2019. Presentationen ger en överblick över robotik och pågående forskning, dess inverkan på samhället och industrin, samt innovationssystem. Samhällelig Drivkraft

Available from: 2019-02-01 Created: 2019-02-01 Last updated: 2019-08-30Bibliographically approved
Bolmsjö, G., Ferreira Magalhaes, A. C., Cederqvist, L. & De Backer, J. (2018). Robotic Friction Stir Welding of complex geometry and mixed materials. In: ISR 2018: 50th International Symposium on Robotics June, 20-21, 2018, Messe München, Munich, Germany. Paper presented at 50th International Symposium on Robotics June, 20-21, 2018, Messe München, Munich, Germany (pp. 35-41). VDE Verlag GmbH
Open this publication in new window or tab >>Robotic Friction Stir Welding of complex geometry and mixed materials
2018 (English)In: ISR 2018: 50th International Symposium on Robotics June, 20-21, 2018, Messe München, Munich, Germany, VDE Verlag GmbH, 2018, p. 35-41Conference paper, Published paper (Refereed)
Abstract [en]

Friction stir welding (FSW) is a solid state process for joining materials which has demonstrated advantages compares with other methods which include joining of mixed materials, hard to weld alloys and consistent and high quality. This paper presents a study of robotic FSW initiated by Volvo Skoevde plant to join an insert workpiece of extruded aluminium with a cylinder block of aluminium casting. A three-stage procedure was decided to determine the feasibility to apply robotic FSW. The stages included study of welding the mixed materials, weld along the complex joint line with holes and channels close to the joint, and finally welding the cylinder block. The results based on preliminary analysis indicate that the final tests were successful and the process is feasible for the challenging case study. However, further studies are recommended in order to identify the operating parameters window, tool design, and control of the process in order to optimize productivity and quality.

Place, publisher, year, edition, pages
VDE Verlag GmbH, 2018
Keywords
friction stir welding, fsw, robotic, welding, mixed materials
National Category
Applied Mechanics
Research subject
Technology (byts ev till Engineering), Mechanical Engineering
Identifiers
urn:nbn:se:lnu:diva-79441 (URN)2-s2.0-85059384869 (Scopus ID)978-3-8007-4699-6 (ISBN)9781510870314 (ISBN)
Conference
50th International Symposium on Robotics June, 20-21, 2018, Messe München, Munich, Germany
Available from: 2019-01-11 Created: 2019-01-11 Last updated: 2019-08-30Bibliographically approved
Ferreira Silva, A. C., De Backer, J. & Bolmsjö, G. (2017). Temperature measurements during friction stir welding. The International Journal of Advanced Manufacturing Technology, 88(9-12), 2899-2908
Open this publication in new window or tab >>Temperature measurements during friction stir welding
2017 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 88, no 9-12, p. 2899-2908Article in journal (Refereed) Published
Abstract [en]

The increasing industrial demand for lighter, more complex and multi-material components supports the devel-opment of novel joining processes with increased automationand process control. Friction stir welding (FSW) is such aprocess and has seen a fast development in several industries. This welding technique gives the opportunity of automationand online feedback control, allowing automatic adaptation to environmental and geometrical variations of the component. Weld temperature is related to the weld quality and therefore proposed to be used for feedback control. For this purpose, accurate temperature measurements are required. This paper presents an overview of temperature measurement methods applied to the FSW process. Three methods were evaluated in this work: thermocouples embedded in the tool, thermocouples embedded in the workpiece and the tool-workpiece thermocouple (TWT) method. The results show that TWT is anaccurate and fast method suitable for feedback control of FSW.

Place, publisher, year, edition, pages
Springer, 2017
Keywords
friction stir welding, fsw, robotic, temperature measurement, TWT, process control, aluminium, thermocouples, temperature
National Category
Mechanical Engineering
Research subject
Technology (byts ev till Engineering), Mechanical Engineering
Identifiers
urn:nbn:se:lnu:diva-79443 (URN)10.1007/s00170-016-9007-4 (DOI)
Available from: 2019-01-11 Created: 2019-01-11 Last updated: 2019-08-30Bibliographically approved
Silva, A., De Backer, J. & Bolmsjö, G. (2016). Analysis of Plunge and Dwell Parameters of Robotic FSW Using TWT Temperature Feedback Control. In: Proceedings of 11th International Symposium on Friction Stir Welding: . Paper presented at 11th International Symposium on Friction Stir Welding, Cambridge, UK, 17-19 May, 2016 (pp. 1-11). Cambridge: TWI Ltd
Open this publication in new window or tab >>Analysis of Plunge and Dwell Parameters of Robotic FSW Using TWT Temperature Feedback Control
2016 (English)In: Proceedings of 11th International Symposium on Friction Stir Welding, Cambridge: TWI Ltd , 2016, p. 1-11Conference paper, Published paper (Other academic)
Abstract [en]

Friction stir welding (FSW) and variants of the process have generated high interest in many industries due to its several advantages such as low distortion, superior mechanical properties over arc welding and the possibility of joining dissimilar materials. Increased complexity of industrial applications require a better control of the welding process in order to guarantee a consistent weld quality. This can be achieved by implementing feedback control based on sensor measurements. Previous studies have demonstrated a direct effect of weld temperature on the mechanical properties of FSW joints, [1], and therefore, temperature is chosen as primary process variable in this study.A new method for temperature measurement in FSW referred to as the Tool-WorkpieceThermocouple (TWT) method has recently been developed by De Backer. The TWT method is based on thermoelectric effect and allows accurate, fast and industrially suitable temperature monitoring during welding, without the need for thermocouples inside the tool [2]. This paper presents an application of the TWT method for optimisation of the initial weld phases, plunge and dwell, operation in conventional FSW, which can also be applied to friction stir spot welding (FSSW). An analysis of the operation parameters by using feedback temperature control is presented aiming to better control of the initial weld phases through temperature feedback.

The introduction of the TWT temperature sensor provides additional process information during welding. Fast data acquisition gives opportunity to differentiate different process phases: contact of probe tip with workpiece surface; plunge phase; dwell phase. This would be followed by tool retraction for FSSW or tool traverse phase for FSW.The effect of the plunge parameters on weld temperature and duration of each phase were studied for the purpose of optimising the process with respect to process (i) robustness, (ii)time, (iii) robot deflection and (iv) quality. By using temperature feedback, it is possible to control the plunge phase to reach a predefined weld temperature, avoiding overheating of the material, which is known to have a detrimental influence on mechanical properties. The work presented in this paper is an important step in the optimization of robotic FSSW and FSW.

Place, publisher, year, edition, pages
Cambridge: TWI Ltd, 2016
Keywords
Plunging, Friction Stir Spot Welding, Temperature, TWT, Robot
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:lnu:diva-80694 (URN)
Conference
11th International Symposium on Friction Stir Welding, Cambridge, UK, 17-19 May, 2016
Note

Ej belagd 190516

Available from: 2019-02-19 Created: 2019-02-19 Last updated: 2019-08-30Bibliographically approved
Bolmsjö, G., Bennulf, M. & Zhang, X. (2016). Safety System for Industrial Robots to Support Collaboration. In: Schlick C., Trzcieliński S. (Ed.), Advances in Ergonomics of Manufacturing: Managing the Enterprise of the Future.: Proceedings of the AHFE 2016 International Conference on Human Aspects of Advanced Manufacturing, July 27-31, 2016, Walt Disney World®, Florida, USA. Paper presented at 7th International Conference on Applied Human Factors and Ergonomics (AHFE 2016) (pp. 253-265). Springer, 490
Open this publication in new window or tab >>Safety System for Industrial Robots to Support Collaboration
2016 (English)In: Advances in Ergonomics of Manufacturing: Managing the Enterprise of the Future.: Proceedings of the AHFE 2016 International Conference on Human Aspects of Advanced Manufacturing, July 27-31, 2016, Walt Disney World®, Florida, USA / [ed] Schlick C., Trzcieliński S., Springer, 2016, Vol. 490, p. 253-265Conference paper, Published paper (Refereed)
Abstract [en]

The ongoing trend towards manufacturing of customized products generates an increased demand on highly efficient work methods to manage product variants through flexible automation. Adopting robots for automation is not always feasible in low batch production. However, the combination of humans together with robots performing tasks in collaboration provides a complementary mix of skill and creativity of humans, and precision and strength of robots which support flexible production in small series down to one-off production. Through this, collaboration can be used with implications on reconfiguration and production. In this paper, the focus and study is on designing safety for efficient collaboration operator—robot in selected work task scenarios. The recently published ISO/TS 15066:2016 describing collaboration between operator and robot is in this context an important document for development and implementation of robotic systems designed for collaboration between operator and robot.

Place, publisher, year, edition, pages
Springer, 2016
Series
Advances in Intelligent Systems and Computing, ISSN 2194-5357 ; 490
Keywords
human-robot interaction, collaboration, robot safety
National Category
Mechanical Engineering
Research subject
Technology (byts ev till Engineering), Mechanical Engineering
Identifiers
urn:nbn:se:lnu:diva-80123 (URN)10.1007/978-3-319-41697-7_23 (DOI)978-3-319-41697-7 (ISBN)978-3-319-41696-0 (ISBN)
Conference
7th International Conference on Applied Human Factors and Ergonomics (AHFE 2016)
Available from: 2019-02-01 Created: 2019-02-01 Last updated: 2019-08-30Bibliographically approved
Bolmsjö, G. (2015). Supporting Tools for Operator in Robot Collaborative Mode. In: Tareq Ahram, Waldemar Karwowski and Dylan Schmorrow (Ed.), 6th International Conference on Applied Human Factors and Ergonomics (AHFE 2015) and the Affiliated Conferences, AHFE 2015: . Paper presented at 6th International Conference on Applied Human Factors and Ergonomics (AHFE 2015) and the Affiliated Conferences, AHFE 2015 (pp. 409-416). Elsevier, 3
Open this publication in new window or tab >>Supporting Tools for Operator in Robot Collaborative Mode
2015 (English)In: 6th International Conference on Applied Human Factors and Ergonomics (AHFE 2015) and the Affiliated Conferences, AHFE 2015 / [ed] Tareq Ahram, Waldemar Karwowski and Dylan Schmorrow, Elsevier, 2015, Vol. 3, p. 409-416Conference paper, Published paper (Refereed)
Abstract [en]

Making use of robot automation for customized products put high demand not only on the robot but on the efficiency, simplicity and flexibility to actually deploy and use robots in manufacturing stations and production lines in short batches and low volume production. Hence, market oriented product development and production requires more products to be developed and offered in less time than before, and produced for the market with more customizable options. The role of the operator is in this context an important factor and tools are needed to support the operator for highly efficient and flexible production. In this paper, the development and study of supporting tools for operators is presented. A demonstrator has been built for robotic nailing, screwing and manipulation operation in producing scaled down gable wall elements in wood for a family house. Issues raised to support the operator included automatic programming and generating relevant information for the operator for the deployment procedure to prepare for production. During production, different concepts of safety system to support collaboration mode between the operator and the robot was developed and studied. Wearable devices was used for the operator to access the information generated and different safety configurations were developed and evaluated. The baseline for this work has been to identify industrial use cases which has a clear need for automation as well as collaboration between operator(s) and robot(s). Work scenarios were discussed and analyzed with industrial partners and it was concluded that, in addition to the deployment tools, a smart safety system which is able to detect and react on humans entering the robot system work area is needed. This should support for efficient production and less downtime for both automatic mode and collaboration mode. The benefit of operator – robot collaboration is clearly shown as well as the need for supporting tools.

Place, publisher, year, edition, pages
Elsevier, 2015
Series
Procedia Manufacturing, ISSN 2351-9789
Keywords
collaboration, operator, safety, deployment
National Category
Robotics
Research subject
Technology (byts ev till Engineering)
Identifiers
urn:nbn:se:lnu:diva-80273 (URN)10.1016/j.promfg.2015.07.190 (DOI)
Conference
6th International Conference on Applied Human Factors and Ergonomics (AHFE 2015) and the Affiliated Conferences, AHFE 2015
Available from: 2019-02-07 Created: 2019-02-07 Last updated: 2019-08-30Bibliographically approved
Silva, A., De Backer, J. & Bolmsjö, G. (2015). TWT method for temperature measurement during FSW process. In: The 4th international Conference on scientific and technical advances on friction stir welding & processing: . Paper presented at The 4th international Conference on scientific and technical advances on friction stir welding & processing October 1-2, 2015, San Sebastian (pp. 95-98).
Open this publication in new window or tab >>TWT method for temperature measurement during FSW process
2015 (English)In: The 4th international Conference on scientific and technical advances on friction stir welding & processing, 2015, p. 95-98Conference paper, Published paper (Refereed)
Abstract [en]

Friction stir weld (FSW) has generated a high interest in many industry segments in the past 20 years. Along with new industrial challenges, more complex geometries and high quality demands, a better control of the welding process is required. New approaches using temperature controlled welding have been proposed and revealed good results. However, few temperature measurement methods exist which are accurate, fast and industrially suitable. A new and simple sensor solution, the Tool-Workpiece Thermocouple (TWT) method, based on the thermoelectric effect was recently developed.This paper presents a calibration solution for the TWT method where the TWT temperature is compared to calibrated thermocouples inside the tool. The correspondence between both methods is shown. Furthermore, a calibration strategy in different aluminium alloys is proposed, which is based on plunge iterations. This allows accurate temperature monitoring during welding, without the need for thermocouples inside the tool.

Keywords
Friction stir welding, TWT method, Temperature measurements, Aluminium alloys
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:lnu:diva-80696 (URN)
Conference
The 4th international Conference on scientific and technical advances on friction stir welding & processing October 1-2, 2015, San Sebastian
Available from: 2019-02-19 Created: 2019-02-19 Last updated: 2019-08-30Bibliographically approved
De Backer, J. & Bolmsjö, G. (2014). Deflection model for robotic friction stir welding. Industrial robot, 41(4), 365-372
Open this publication in new window or tab >>Deflection model for robotic friction stir welding
2014 (English)In: Industrial robot, ISSN 0143-991X, E-ISSN 1758-5791, Vol. 41, no 4, p. 365-372Article in journal (Refereed) Published
Abstract [en]

This paper aims to present a deflection model to improve positional accuracy of industrial robots. Earlier studies have demonstrated the lack of accuracy of heavy-duty robots when exposed to high external forces. One application where the robot is pushed to its limits in terms of forces is friction stir welding (FSW). This process requires the robot to deliver forces of several kilonewtons causing deflections in the robot joints. Especially for robots with serial kinematics, these deflections will result in significant tool deviations, leading to inferior weld quality.

This paper presents a kinematic deflection model, assuming a rigid link and flexible joint serial kinematics robot. As robotic FSW is a process which involves high external loads and a constant welding speed of usually below 50 mm/s, many of the dynamic effects are negligible. The model uses force feedback from a force sensor, embedded on the robot, and predicts the tool deviation, based on the measured external forces. The deviation is fed back to the robot controller and used for online path compensation.

The model is verified by subjecting an FSW tool to an external load and moving it along a path, with and without deviation compensation. The measured tool deviation with compensation was within the allowable tolerance for FSW.

The model can be applied to other robots with a force sensor.

The presented deflection model is based on force feedback and can predict and compensate tool deviations online.

Place, publisher, year, edition, pages
Bingley: Emerald Group Publishing Limited, 2014
Keywords
Force control, Deflection model, Friction Stir Welding, Path compensation, Robot welding
National Category
Robotics
Research subject
Technology (byts ev till Engineering)
Identifiers
urn:nbn:se:lnu:diva-80371 (URN)10.1108/IR-01-2014-0301 (DOI)2-s2.0-85006320129 (Scopus ID)
Available from: 2019-02-11 Created: 2019-02-11 Last updated: 2019-08-30Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1869-232X

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