| 1. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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AI-Based Quality Control of Wood Surfaces with Autonomous Material Handling
- 2021
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 11:21, s. 9965-9965
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Tidskriftsartikel (refereegranskat)abstract
- The theory and applications of Smart Factories and Industry 4.0 are increasing the entry into the industry. It is common in industry to start converting exclusive parts, of their production, into this new paradigm rather than converting whole production lines all at once. In Europe and Sweden, recent political decisions are taken to reach the target of greenhouse gas emission reduction. One possible solution is to replace concrete in buildings with Cross Laminated Timber. In the last years, equipment and software that have been custom made for a certain task, are now cheaper and can be adapted to fit more processes than earlier possible. This in combination, with lessons learned from the automotive industry, makes it possible to take the necessary steps and start redesigning and building tomorrows automated and flexible production systems in the wood industry. This paper presents a proof of concept of an automated inspection system, for wood surfaces, where concepts found in Industry 4.0, such as industrial Internet of things (IIoT), smart factory, flexible automation, artificial intelligence (AI), and cyber physical systems, are utilized. The inspection system encompasses, among other things, of the shelf software and hardware, open source software, and standardized, modular, and mobile process modules. The design of the system is conducted with future expansion in mind, where new parts and functions can be added as well as removed.
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| 2. |
- Eriksson, Kristina M., 1976-, et al.
(författare)
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Experiences in Running a Professional Course on Digitally-Enabled Production in Collaboration Between Three Swedish Universities
- 2022
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Ingår i: Advances in Transdisciplinary Engineering. - : IOS Press. - 2352-751X .- 2352-7528. ; 21, s. 653-664
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. Needs for new competences and knowledge arise as industry 4.0 evolvesin increasingly digitalized production. This development entails that jobtransformations and future skills need attention from the perspective of industry 5.0,where human and machine find ways of working together to improve productionperformance. Facing this perspective, one challenge is a growing need for novellifelong learning initiatives, to meet emerging and altering occupations for thefulfilment of future skill requirements. This challenge is addressed here byportraying a case where three Swedish universities have formed a distinctivecollaboration to develop a flexible (i.e. blended) course for professionals, in thesubject of Digitally-enabled production. The purpose is to develop a sustainablecollaboration between the universities and create a course format on master leveladdressing lifelong learning for the increasingly digitalized production. Theambition is to increase the impact of the universities respective efforts by sharingresources and utilizing individual specialized expertise to develop a practical andrelevant course that can reach a larger target group. The course encompassesindustry 4.0 readiness on three levels of production systems; plant-, production cell-,and component level; to adopt a holistic view of digitalization in production. Wefollowed an action research approach for continuously collecting and documentingour experiences during the course development, implementation, and disseminationof the course. Within the frame of action research, an explorative case studydescribes and analyzes the initiative. The results highlight challenges andopportunities for succeeding with this form of co-produced course. The joint coursegives professionals possibilities to work on cases from their own companies withexpert supervision from three manufacturing levels to address complex challengesin industry 4.0 implementation. To conclude, the importance of lifelong learning inrelation to the human-centric approach of industry 5.0 is emphasized as a futuredirection.
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| 3. |
- Geijer, Cecilia, 1980, et al.
(författare)
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Initiation of the transcriptional response to hyperosmotic shock correlates with the potential for volume recovery.
- 2013
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Ingår i: The FEBS journal. - : Wiley. - 1742-4658 .- 1742-464X. ; 280:16, s. 3854-67
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Tidskriftsartikel (refereegranskat)abstract
- The control of activity and localization of transcription factors is critical for appropriate transcriptional responses. In eukaryotes, signal transduction components such as mitogen-activated protein kinase (MAPK) shuttle into the nucleus to activate transcription. It is not known in detail how different amounts of nuclear MAPK over time affect the transcriptional response. In the present study, we aimed to address this issue by studying the high osmolarity glycerol (HOG) system in Saccharomyces cerevisiae. We employed a conditional osmotic system, which changes the period of the MAPK Hog1 signal independent of the initial stress level. We determined the dynamics of the Hog1 nuclear localization and cell volume by single-cell analysis in well-controlled microfluidics systems and compared the responses with the global transcriptional output of cell populations. We discovered that the onset of the initial transcriptional response correlates with the potential of cells for rapid adaptation; cells that are capable of recovering quickly initiate the transcriptional responses immediately, whereas cells that require longer time to adapt also respond later. This is reflected by Hog1 nuclear localization, Hog1 promoter association and the transcriptional response, but not Hog1 phosphorylation, suggesting that a presently uncharacterized rapid adaptive mechanism precedes the Hog1 nuclear response. Furthermore, we found that the period of Hog1 nuclear residence affects the amplitude of the transcriptional response rather than the spectrum of responsive genes.
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| 4. |
- Ramanathan, Prabhu K., 1975-, et al.
(författare)
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Development of an Intelligent Robotized Machine Vision Automated System for Bacterial Growth Monitoring
- 2023
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Ingår i: Proceedings of 2023 International Conference on Signal Processing, Computation, Electronics, Power and Telecommunication. - : IEEE. - 9798350312126 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- Pathogenic bacterial growth detection and monitoring is an important scientific process in the field of quality control in the food, water, and medical industries. Very-large-scale process of such bacteria growth monitoring is possible only with an automated process. The mechanism must make sure that the sample is continuously monitored, and detected, data is communicated to supervisors and managers, and data is stored historically retrievable for quality control and analysis. A manual bacteria inspection among the Petri dishes incubated of such bacterial growth in food processing was attempted for automation. The manual inspection in a microbiological industry involves; an operator inspecting the input petri discs to check if there are bacteria, writing down the barcode of the corresponding petri dish, and then sorting the Petri discs depending on the bacterial growth. In this automation attempt of automatizing this petri-disc inspection, the project was split into two phases. 1. Building a vision system to detect bacteria, developing of an algorithm to quantify the growth, and registering the barcode in a registry. 2. The second phase is to design a robot system with programming and define the layout of the station. The development of an intelligent robotized machine vision automated system proves the concept of a major industrial practice that has the potential to significantly increase the quality and productivity of bacterial growth, with increased throughput.
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| 5. |
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| 6. |
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| 7. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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A look at the optimization of robot welding speed based on process modelling
- 2007
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Ingår i: Welding Journal. - 0043-2296. ; 86:8, s. 238-244
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Tidskriftsartikel (refereegranskat)abstract
- Simulation tools to search for optimal process parameters are of great interest to reduce the number of experiments and thereby reduce cost and production time. In this paper, robot simulation has been used in combination with finite element simulations to optimize robot speed in order to minimize distortion while keeping complete joint penetration. In an earlier work performed by the authors, a finite element model was developed to predict heat transfer and residual stresses of parts with complex shapes. An interface between a robot simulation model and a finite element analysis model was also constructed. In this paper, an iterative method for robot speed optimization has been developed using MATLAB. The algorithm is designed to maintain complete joint penetration while maximizing productivity by utilizing the fastest weld speed. The method makes it possible to optimize the heat input to the component and thereby minimize component deformation for parts with complex shapes. The system was evaluated on stainless steel plates with varying thicknesses. Robot weld paths were defined off line and automatically downloaded to the finite element software where the optimization was performed. Simulations and experimental validations are presented.
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| 8. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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Non-contact Temperature Measurements using an Infrared Camera in Aerospace Welding Applications
- 2002
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Ingår i: 6th International Conference on Trends in Welding Research. - Materials Park : ASM International. ; , s. 930-935
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Konferensbidrag (refereegranskat)abstract
- This paper describes the application of infrared (IR) thermal imaging and temperature measurements in welding applications, both on single plane plates and on an aero engine turbine component with complex geometry. Temperature profiles were measured on the plates using thermocouples (T/C) in combination with an IR camera system, and the results were compared. The IR camera was used both in line scan mode (270 Hz scan frequency) and in full frame mode (1 Hz frame rate). Different methods of surface treatments have been tested to handle the problem of the surface emissivity variations due to oxidation during welding. Results from measurements using thermocouples and IR camera is presented in the paper as well as temperature measurements using the IR camera on an turbine exhaust case (TEC) engine component.
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| 9. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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Off-line programming of robots for metal deposition
- 2005
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Ingår i: Trends in welding research. - 0871708426 ; , s. 629-634
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Metal Deposition (MD) is a rapid prototyping technique to build parts by depositing metal in a required fashion. When a complex-shaped part is to be built, a simulation tool is needed to define robot trajectories. Three different simulation-based methods for robot trajectory generation are introduced and compared in this study. The methods are; reversed milling, adapted rapid prototyping and application programming in a computer aided robotics software. All methods were shown capable of creating robot paths for complex shapes, with the CAR software approach being the most flexible. Using this method, the geometry to be built is automatically sliced into layers and a robot path is automatically generated. The method was tentatively evaluated and appears to provide a powerful technique in the design and optimisation of robot paths for MD. Experiments showed that it is possible to manufacture fully dense parts using an Nd-Yag laser.
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| 10. |
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| 11. |
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| 12. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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Three-dimensional simulation of robot path and heat transfer of a TIG-welded part with complex geometry
- 2002
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Ingår i: 11th International Conferences on Computer Technology in Welding. - : Society of Manufacturing Engineers, North American Manufacturing Research Institution. ; , s. 309-316
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The application of commercial software (OLP) packages for robot simulation, and programming, use interactive computer graphics, provide powerful tools for creating welding paths off-line. By the use of such software, problems of robot reach, accessibility, collision and timing can be eliminated during the planning stage. This paper describes how such software can be integrated with a numerical model that predicts temperature-time histories in the solid material. The objective of this integration is to develop a tool for the engineer where robot trajectories and process parameters can be optimized on parts with complex geometry. Such a tool would decrease the number of weld trials, increase productivity and reduce costs. Assumptions and principles behind the modeling techniques are presented together with experimental evaluation of the correlation between modeled and measured temperatures.
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| 13. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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Three Dimensional Simulation of Robot path, Heat Transfer and Residual Stresses of a TIG-welded Part with Complex Geometry
- 2002
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Ingår i: Trends in Welding Research: Proceedings of the 6th International Conference. ; , s. 973-978
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper a system is presented that combines a robot off-line programming software with a finite element model that predicts temperature-time histories and residual stress distributions. The objective is to develop a tool for the engineer where robot trajectories and welding process parameters can be optimized on parts with complex geometry. The system was evaluated on a stainless steel gas turbine component. Robot weld paths were defined off-line and automatically downloaded to the finite element program, where transient temperatures and residual stresses were predicted. Temperature dependent properties and phase change, were included in the analysis. Assumptions and principles behind the modeling techniques are presented together with predicted temperature histories, residual stresses, and fixture forces.
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| 14. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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Three dimensional simulation of robot path, heat transfer and residual stresses of a welded part with complex geometry
- 2005
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Ingår i: International jourrnal for the joining of materials. - 0905-6866. ; 17:2, s. 42-51
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Tidskriftsartikel (refereegranskat)abstract
- In this article a simulation system is presented that combines computer aided robotics software used to define the welding operation, with a finite element model that predicts temperature-time histories and residual stress distributions for welding applications. The objective is to develop a tool for engineering processes in which robot trajectories and welding process parameters can be optimized off-line on parts with complex geometries. The system was evaluated on a stainless steel gas turbine component. Temperature dependent properties and phase change were included in the analysis. The turbine component was welded using an in-house TIG welding cell. The assumptions and principles that underpin the modeling techniques are presented together with predicted temperature histories, residual stresses, and fixture forces. Predicted residual stresses were compared with neutron diffraction measurements.
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| 15. |
- Ericsson, Mikael, 1975-, et al.
(författare)
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Virtual Commissioning of Machine Vision Applications in Aero Engine Manufacturing
- 2018
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Ingår i: Proceedings of The 15th International Conference on Control,Automation, Robotics and Vision, November 18-21, 2018. - 9781538695814 ; , s. 1947-1952
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Konferensbidrag (refereegranskat)abstract
- New aero engine design puts new demands on the manufacturing methods with increased automation level. Therefore, the use of vision sensors for control and guiding of industrial robots is being increasingly used. In such system, it is need to customise the machine vision system with real components in the real environment which is normally done close to the start-up of the production. This paper addresses a new concept for designing, programming, analysing, testing and verifying a machine vision application early in the design phase, called Virtual Machine Vision. It is based on a robot simulation software where the real machine vision application is simulated before the implementation in the production line. To verify the Virtual Machine Vision concept an advanced stereo vision application was used. Using two captured images from the robot simulated environment, camera calibration, image analysis and stereo vision algorithms are applied to determine a desired welding joint. The information of the weld joint, i.e. robot position and orientation for the weld path, are sent from the machine vision system to the robot control system in the simulation environment and the weld path is updated. The validation of the Virtual Machine Vision concept using the stereo vision application is promising for industrial use, and it is emphasised that the same programs are used in the virtual and real word.
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| 16. |
- Eriksson, Kristina M., 1976-, et al.
(författare)
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A novel blended learning course developed jointly between three universities to address competence development of professionals in digitalized manufacturing
- 2019
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Ingår i: VILÄR 5-6 december 2019, University West, Trollhättan. - Trollhättan : University West. - 9789188847430 - 9789188847447 ; , s. 6-7
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- New competences and knowledge needs arises as manufacturing industry evolves and becomes increasingly digitalized. Facing this transformation, one of the challenges is the continuous and growing need for novel initiatives for competence development.The case portrayed here stems from a Swedish cross-university project aiming to jointly develop and offer courses for competence development of professionals in the manufacturing and IT sectors. The ambition is to increase the impact of the universities' respective efforts of meeting industry competence needs, where the continuous digital transformation entails that employees must develop or even change their qualifications.The case outlined focus co-production of a joint course package, at master level, between three universities and their respective company networks. Participating universities have long traditions in working closely with companies in research and education, where approaches for co-production have evolved over time. We make use of our joint understanding of the manufacturing industry's specific competence needs and our experiences of sustainable course formats for participants working full time.The joint course covers aspects of a manufacturing company on three levels: plant level i.e. material and production flows, cell level e.g. robotic simulation and visualisation, and system level i.e. data acquisition and monitoring through sensors. Each university is developing a course module of 2.5 ECTS, addressing a level respectively of their specialist competence. Participants are to complete assignments for each course module, i.e. for all three manufacturing levels, where the previous assignment provides an input to the next level, enabling the participants to encompass a holistic view of a manufacturing system. Participants need to combine study and work and at the same time they wish to extend their network, hence we are adopting a blended learning approach, where virtual labs and web conferences are mixed with physical meetings.A variety of challenges arise when designing such novel approaches: combining company networks, course design including online learning, planning of physical course meetings,joint promotion, common admission and validation process, financial models and more. However, engaging in partnerships with industry for knowledge transformation and development has the potential to become rewarding for all parties.
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| 17. |
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| 18. |
- Keyvani, Ali, 1978-, et al.
(författare)
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Motion synthesizer platform for moving manikins
- 2012
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Ingår i: 2012 AHFE International Conference 21-25 July 2012 Hilton San Francisco, Union Square, California. - : AHFE. - 9780979643552 ; , s. 545-554
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Konferensbidrag (refereegranskat)
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| 19. |
- Keyvani, Ali, 1978-, et al.
(författare)
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Schema for Motion Capture Data Management
- 2011
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Ingår i: Lecture Notes in Computer Science. 3rd International Conference on Digital Human Modeling, ICDHM 2011. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1611-3349 .- 0302-9743. - 9783642217982 ; , s. 99-108
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 20. |
- Muniz, Jorge, et al.
(författare)
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Challenges of Engineering Education 5.0 based on I4.0 Policies in Brazil, India, Japan, and Sweden
- 2022
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Ingår i: International Conference on Work Integrated Learning. - Trollhättan : University West. - 9789189325302 ; , s. 95-96
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Industry and academia have placed increasing attention on implementing Industry 4.0 (I4.0) in the production ofgoods and services. Named as Industry 4.0 in Brazil, Made in India in India, Society 5.0 in Japan, andProduktion2030 in Sweden (Ribeiro et al., 2022). Hereafter, we apply I4.0 to simplify, which promises customizedproducts produced in smaller lots, and that repetitive manufacturing tasks can be automated very soon (Karre etal., 2017).Country policies play an important role in pushing different sectors of the economy, aligned as new with theregulatory framework of national and international trade, especially industrial (Aguinis et al., 2020). The implementation of I4.0 literature indicates different specificities in each country, including culture, R&D targets,education and vocational training, and their research opportunities related to how I4.0 affects workers (Jerman etal., 2020). The research-question is: How do different countries approach the opportunities and challenges of Engineering Education 4.0 through similar or different country policies?This study aims to discuss engineering education related to I4.0 policies. This discussion is based on policies fromBrazil, India, Japan, and Sweden related to education and workers 5.0, which include students and employees.Investigating how these countries are adjusting to I4.0 is relevant for national industrial sectors to wish to actefficiently in this new technological context. Industry 4.0 demands new professional skills and will impactemployment. It is noteworthy that this research is in line with the Sustainable Development Goals (SDGs) proposedby the United Nations (UN): Quality Education (SDG-4); o Decent Work and Economic Growth (SDG-8); andIndustry, Innovation, and Infrastructure (ODS-9) which seeks to promote inclusive and sustainableindustrialization and foster innovation. This research aims to contribute to sustainable o rganizational practices;formulation of public policies that alleviate social problems; guidance of professional curricula affected by I 4.0.Papers and Data Selection: A literature search was conducted in the Scopus database, which gathers some of the most important journalsrelated to manufacturing technologies with high impact factors, based on the PRISMA method, which refers to aminimum set of evidence-based items to report studies in systematic reviews and meta -analyses (MOHER et al.,2009). The paper set was assembled from the Scopus core collection, using the following search string: “industry4.0” OR “industry 5.0” AND “policies” AND ". The results were narrowed to texts in English, which yielded 1496papers. All titles and abstracts were read, which resulted in a set composed of 14 papers. We also use official documents relating to I4.0 raised from official government websites.Comparison of Countries’ Education policies and Industry 4.0: The literature addresses difficulties associated with the implementation of I4.0 in emerging economies (Dalagnore,2018; Hong and Muniz Jr., 2022). Not surprisingly, current literature I4.0 related to technology adoption is themost prevalent theme discussed from a hard, technology-oriented perspective rather than a people-oriented.Production systems are sociotechnical systems, with an explicit understanding that all systems involve ongoinginteractions between people and technology, and they are rapidly transforming virtually all areas of human life,work, and interaction.The European Commission’s (Breque et al., 2021) vision for ‘Industry 5.0’ proposes moves past a narrow andtraditional focus on technology-or economic enabled growth of the existing extractive, production andconsumption driven economic model to a more transformative view of growth that is focused on human progressand well-being based on reducing and shifting consumption to new forms of sustainable, circular and regenerativeeconomic value creation and equitable prosperity. This Human-centric production system design and managementapproach (Industry 5.0) is necessary to support skill development, learning, continuous improvement andcollaboration in the organization (Ribeiro et al., 2022).Conclusion: Brazil, India, Japan and Sweden create policies to support their own technological independence. All countriesindicate concern about education and development of skills related to I4.0.It can be concluded that the four countries studied from the perspective of Industry 4.0 an d Engineering Education4.0 are all embarking on their journeys towards increased digitalization in industry and society as a whole. Therealization of the human-centered Society 5.0 was realized and highlighted comparatively early for Japan, whereasin the Europe Union and thus in Sweden the focus of the importance of Industry 5.0 development in parallelIndustry 4.0 has risen up since year 2021.The results indicate that although there are many initiatives of meeting the needs for new competence andknowledge in the era of I4.0 to accommodate Engineering Education 4.0 there are still challenges for futureresearch to move forward in the nexus between I4.0 and I5.0. The result, of studying different countries'policies, highlights that it is imperative, when approaching novel technologies in I4.0 and designing Engineering Education 4.0, to in parallel consider technological implementations with the inclusion of I5.0 aspects and humancentric perspectives.
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| 21. |
- Ramasamy, Sudha, 1974-, et al.
(författare)
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Sampling-Based Path Planning Algorithm for a Plug & Produce Environment
- 2023
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 13:22, s. 12114-12114
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this article is to investigate a suitable path planning algorithm for a multi-agent-based Plug & Produce system that can run online during manufacturing. This is needed since in such systems, resources can move around frequently, making it hard to manually create robot paths. To find a suitable algorithm and verify that it can be used online in a Plug & Produce system, a comparative study between various existing sampling-based path planning algorithms was conducted. Much research exists on path planning carried out offline; however, not so much is performed in online path planning. The specific requirements for Plug & Produce are to generate a path fast enough to eliminate manufacturing delays, to make the path energy efficient, and that it run fast enough to complete the task. The paths are generated in a simulation environment and the generated paths are tested for robot configuration errors and errors due to the target being out of reach. The error-free generated paths are then tested on an industrial test bed environment, and the energy consumed by each path was measured and validated with an energy meter. The results show that all the implemented optimal sampling-based algorithms can be used for some scenarios, but that adaptive RRT and adaptive RRT* are more suitable for online applications in multi-agent systems (MAS) due to a faster generation of paths, even though the environment has more constraints. For each generated path the computational time of the algorithm, move-along time and energy consumed are measured, evaluated, compared, and presented in the article.
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| 22. |
- Ryberg, Anders, 1973-, et al.
(författare)
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Analysis and evaluation of a general camera model
- 2011
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Ingår i: Computer Vision and Image Understanding. - : Elsevier. - 1077-3142 .- 1090-235X. ; 115:11, s. 1503-1515
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 23. |
- Ryberg, Anders, 1973-, et al.
(författare)
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Stereo vision for path correction in off-line programmed robot welding
- 2010
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Ingår i: Proceedings of the IEEE International Conference on Industrial Technology. ; , s. 1700-1705
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 24. |
- Sikström, Fredrik, 1971-, et al.
(författare)
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3D-Scanning for Weld Distortion Measuring
- 2006
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Ingår i: Instrumentation and Measurement Technology Conference, 2006. IMTC 2006. Proceedings of the IEEE. - : IEEE conference proceedings. - 0780393600 - 0780393597 ; , s. 2132-2137
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Konferensbidrag (refereegranskat)abstract
- Optical three dimensional scanning for weld distortion measurements have been performed for validation, inspection, general visualization and documentation of a robotized welding process. The planning, preparing and processing of the weld is done in a simulation-based concept where computer aided robotics software simulations are integrated with finite element analysis simulations with the objective to reduce global geometrical deformation during welding. The off-line programmed robot paths were used as an input for finite element calculations of temperature fields and distortion in the work piece. In order to validate the finite element model 3D-scannings have been performed before and after every single welding sequence. This paper describes a validation experiment with non-contact measurements of weld distortion and discusses limitations in optical 3D-scanning techniques used for this purpose
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| 25. |
- Sikström, Fredrik, 1971-, et al.
(författare)
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Integration of finite element analysis and computer aided robotics for advanced programming of robotized welding
- 2009
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Ingår i: ASM Proceedings of the International Conference: Trends in Welding Research. - : ASM International. - 9781615030026 ; , s. 454-460
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 26. |
- Sikström, Fredrik, 1971-, et al.
(författare)
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Tools for simulation based fixture design to reduce deformation in advanced fusion welding
- 2008
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Ingår i: Intelligent Robotics and ApplicationsLecture Notes in Computer Science Volume 5315, 2008. - Berlin, Heidelberg : Springer. ; , s. 398-407
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Konferensbidrag (refereegranskat)abstract
- The traditional fusion welding and fixture simulations are performed using advanced finite element simulation tools, commonly used are e.g. MSC.Marc, ANSYS, ABACUS and COMSOL Multiphysics. These simulations are made one at a time and separately due to heavy calculation load for each case. Such an approach does not give a full description of the integrated work piece and fixture behaviour. We propose a strategy to decrease the computational time and solve the problem accurately enough for industrial needs. Focus of the simulation result is on residual deformation. The work piece is a simplified component composed by metal sheets, and rigid and loose clamping was investigated. Simulation results give the size of forces and deformations in the clamped edge. Deformation measurements are performed using 3D-scanning of the work piece after cooling and released from fixture, same situation as in the FE-simulations. The proposed strategy has shown to be useful and is industrially competitive due to reduced engineering manpower, computation time, and need for practical experiments. The strategy is to use full off-line programming where computer aided robotics for weld sequencies is integrated with finite element modelling in order to obtain weld parameters and fixture design.
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