| 1. |
- Björnsson, Andreas
(författare)
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Automated layup and forming of prepreg laminates
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Composite materials like carbon fiber-reinforced polymers (CFRPs) present highly appealing material properties, as they can combine high strength with low weight. In aerospace applications, these properties help to realize lightweight designs that can reduce fuel consumption. Within the aerospace industry, the use of these types of materials has increased drastically with the introduction of a new generation of commercial aircraft. This increased use of CFRP drives a need to develop more rational manufacturing methods.For aerospace applications, CFRP products are commonly manufactured from a material called prepreg, which consists of carbon fibers impregnated with uncured polymer resin. There are two dominant manufacturing technologies for automated manufacturing using prepreg, automated tape layup and automated fiber placement. These two technologies are not suitable for all types of products, either due to technical limitations or a combination of high investment costs and low productivity. Automation alternatives to the two dominant technologies have been attempted, but have so far had limited impact. Due to the lack of automation alternatives, manual manufacturing methods are commonly employed for the manufacturing of complex-shaped products in low to medium manufacturing volumes.The research presented in this thesis aims to explore how automated manufacturing systems for the manufacturing of complex CFRP products made from prepreg can be designed so that they meet the needs and requirements of the aerospace industry, and are suitable for low to medium production volumes. In order to explore the area, a demonstrator-centered research approach has been employed. A number of demonstrators, in the form of automated manufacturing cells, have been designed and tested with industrial and research partners. The demonstrators have been used to identify key methods and technologies that enable this type of manufacturing, and to analyze some of these methods and technologies in detail. The demonstrators have also been used to map challenges that affect the development of enabling methods and technologies.Automated manufacturing of products with complex shapes can be simplified by dividing the process into two steps. Thin layers of prepreg are laid up on top of each other to form flat laminates that are formed to the desired shape in subsequent forming operations. The key methods and technologies required to automate such a system are methods and technologies for automated prepreg layup, the automated removal of backing paper and the forming of complex shapes. The main challenges are the low structural rigidity and tacky nature of prepreg materials, the extensive quality requirements in the aerospace industry and the need for the systems to handle a wide array of prepreg shapes.The demonstrators show that it is possible to automate the manufacturing of complexshaped products using automated layup and forming of prepreg laminates. Tests using the demonstrators indicate that it is possible to meet the quality requirements that apply to manual manufacturing of similar products.
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| 2. |
- Björnsson, Andreas, 1981-, et al.
(författare)
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Automated material handling in composite manufacturing using pick-and-place systems - a review
- 2018
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Ingår i: Robotics and Computer-Integrated Manufacturing. - : Elsevier BV. - 0736-5845 .- 1879-2537. ; 51, s. 222-229
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Tidskriftsartikel (refereegranskat)abstract
- With increasing use of fiber reinforced polymer composites follows a natural pursuit for more rational and effective manufacturing. Robotic pick-and-place systems can be used to automate handling of a multitude of materials used in the manufacturing of composite parts. There are systems developed for automated layup of prepreg, dry fibers and thermoplastic blanks as well as to handle auxiliary materials used in manufacturing. The aim of this paper is to highlight the challenges associated with automated handling of these materials and to analyze the main design principles that have been employed for pick-and-place systems in terms of handling strategy, reconfigurability, gripping technology and distribution of gripping points etc. The review shows that it is hard to find generic solutions for automated material handling due to the great variety in material properties. Few cases of industrial applications in full-scale manufacturing could be identified.
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| 3. |
- Björnsson, Andreas, 1981-, et al.
(författare)
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Automation of composite manufacturing using off-the-shelf solutions; three cases from the aerospace industry
- 2015
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Ingår i: ICCM International Conferences on Composite Materials. - : International Committee on Composite Materials.
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Konferensbidrag (refereegranskat)abstract
- With an increased use of composite materials follows a need for rational, cost-efficient manufacturing processes. This paper explores how off-the-shelf solutions, developed for other purposes than composite manufacturing, can be used to build systems for automated composite manufacturing. Three demonstrators, each of them dealing with a specific type of material and all of them representing different manufacturing technologies for automated composite manufacturing, are presented and analyzed to find aspects that affect the ability to use off-the-shelf solutions. The three demonstrators target low to medium manufacturing volumes of complex products and they have been developed in collaboration with industrial partners within the aerospace industry. The conclusions drawn from the development of the demonstrators are that it is technically feasible to use off-the-shelf solutions in the three cases while adhering to the high quality standards of the industry. Furthermore three groups of aspects, quality aspects, product aspects and system aspects, which affect the ability to use off-the-shelf solutions for automated composite manufacturing, are identified.
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| 4. |
- Björnsson, Andreas, 1981-, et al.
(författare)
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Robot-forming of prepreg stacks - Development of equipment and methods
- 2016
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Ingår i: ECCM 2016 - Proceeding of the 17th European Conference on Composite Materials. - : European Conference on Composite Materials, ECCM. - 9783000533877
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Konferensbidrag (refereegranskat)abstract
- Within the aerospace industry the manufacturing of composite components with complex shapes, such as spars, ribs and beams are often manufactured using manual layup and forming of prepreg material. Automated processes for prepreg layup and efficient forming techniques like vacuum forming are sometimes difficult to employ to these type of products due to technical limitations. This paper describes the development of tools and the forming sequence needed to automate sequential forming of a complex shape using an industrial robot. Plane prepreg stacks are formed to the final shape using a dual-arm industrial robot equipped with rolling tools. Tests show that the developed tools and the employed sequence can be used to form stacks to the desired shape with acceptable quality.
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| 5. |
- Fredriksson, Anna, 1979-, et al.
(författare)
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What are the differences between related offset and outsourcing? : A case study of a related offset business at Saab
- 2016
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Ingår i: International Journal of Technology Transfer and Commercialisation. - : InderScience Publishers. - 1470-6075 .- 1741-5284. ; 14:2, s. 132-149
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Tidskriftsartikel (refereegranskat)abstract
- Recently, offset contracts have become more complex. For the seller to carry through and review the effects and the demands of an offset contract, they need a framework.The paper identifies five main differences between outsourcing and related offset, which are translated into activities to be included in a suggested related offset framework. The paper is based on an in-depth case study of a related offset business at Saab, a Swedish military aircraft producer. The analysis compared the studied case with an existing outsourcing process identified in literature. The paper contributes by providing an overview of the activities taking place during a related offset process and showing the effect of the different hierarchical levels involved in the process on the efficiency of the fulfilment of the offset business. This paper is based on a single case study, and the suggested differences should be verified through further case studies.
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| 6. |
- Gopinath, Varun, et al.
(författare)
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Collaborative Assembly on a Continuously Moving Line - An Automotive Case Study
- 2018
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Ingår i: 28TH INTERNATIONAL CONFERENCE ON FLEXIBLE AUTOMATION AND INTELLIGENT MANUFACTURING (FAIM2018): GLOBAL INTEGRATION OF INTELLIGENT MANUFACTURING AND SMART INDUSTRY FOR GOOD OF HUMANITY. - : ELSEVIER SCIENCE BV. ; 17, s. 985-992
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Konferensbidrag (refereegranskat)abstract
- Collaborative operation is a state in which a purposely designed robot system and an operator work within a collaborative workspace. To ensure a safe working environment, safety standards suggest conducting a task-based risk assessment followed by risk reduction to reduce the risks to an acceptable level. In this article, an automotive case study will be used to understand safety issues associated with collaborative operations with large industrial robots. Based on this case study, a layout of the collaborative workstation, in terms of workspaces and tasks, which is the outcome of a risk assessment program will be presented. The first critical step in risk assessment is hazard identification, which can allow the risk assessing team to evaluate the hazards and suggest measures to mitigate the risks. Therefore, the hazards identified during the risk assessment program will also be detailed along with measures to mitigate the risks and is expected to complement our understanding of the nature of hazards associated with collaborative operations with large industrial robots. (C) 2018 The Authors. Published by Elsevier B.V.
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| 7. |
- Gopinath, Varun, 1982-, et al.
(författare)
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Demonstrators to support research in Industrial safety - A Methodology
- 2018
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Ingår i: Procedia Manufacturing. - : ELSEVIER SCIENCE BV. - 2351-9789. ; 17, s. 246-253
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Tidskriftsartikel (refereegranskat)abstract
- Activities to support manufacturing research are carried out with the intention to gain knowledge of industrial problems and provide solutions that addresses these issues. In order for solution to be viable to the industry, research activities are carried out in close collaboration with participants from the industry, academia and research institutions. Interactive research approach motivates participants with multi-disciplinary perspective to collaborate and emphasizes joint learning in the change process. This article, presents a methodology, where participants with different expertise can collaborate to develop safety solutions. The concept of a demonstrator, which represents cumulative result of a series of research activities, is presented as a tool to showcase functioning and design intent in a collaborative research environment. The results of a pilot study, where manufacturing professionals evaluated design decisions that resulted in a demonstrator, will be presented. (C) 2018 The Authors. Published by Elsevier B.V.
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| 8. |
- Gopinath, Varun, 1982-
(författare)
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On Safe Collaborative Assembly With Large Industrial Robots
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis pertains to industrial safety in relation to human-robot collaboration. The aim is to enhance understanding of the nature of systems where large industrial robots collaborate with humans to complete assembly tasks. This understanding may support development and safe operations of future collaborative systems.Industrial robots are widely used to automate manufacturing operations across several industries. The automotive industry is the largest user of robots and have identified robot-based automation as a strategy to improve efficiency in manufacturing operations.Recently, a class of machines referred to as collaborative robots have been developed by robot manufacturers to support operators in assembly tasks. The use of these robots to support human workers in an industrial context are referred to as collaborative operations.Presently, collaborative robots have limited reach and load carrying capacity compared to standard industrial robots. Large/standard industrial robots are widely used for applications such as welding or painting. They can, in principle support operators in assembly tasks as well.Two laboratory demonstrators representing the final results from a series of research activities will be presented. They were developed to investigate issues related to personnel and process safety while working with large industrial robots in collaborative operations. The demonstrators were partially based on assembly workstations that are currently operational and they exemplify challenges faced by the automotive industry.Demonstrator-based Research, a methodology for collaborative research that emphasizes development of demonstrators as a research tool, forms the rationale for carrying out research operations presented in this thesis. An evaluation of the laboratory demonstrators by industrial participants suggests an increased interest and confidence in collaborative operations with large robots. The demonstrators have served as a tentative platform for participants to identify and discuss manufacturing and safety challenges in relation to their organization.A main outcome presented in this thesis relates to specifying requirements for introducing robots in a human-populated environment. Introducing robotic systems in new environments requires reconsideration of the nature of the hazards particular to the domain. An analysis of the laboratory demonstrators suggest that, in addition to hazards associated with normal functioning of the system, limitations in human cognition must be considered. These results will be exemplified and discussed in the context of situational and mode awareness. Additionally, a model of a collaborative workstation will be presented in terms of three constituents – workspace, tasks and interaction.This is particularly significant considering the direction of present-day research aimed at introducing robots across various industries and working environments. In response to this trend, this thesis discusses the relevance of Interactive Research and its emphasis on joint learning that goes on between academic researchers and industrial participants as a valuable principle for collaborative research.
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| 9. |
- Gopinath, Varun, 1982-, et al.
(författare)
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Risk Assessment for Collaborative Operation : A Case Study on Hand-Guided Industrial Robots
- 2018
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Ingår i: Risk Assessment. - : InTech. - 9789535137986 - 9789535137993
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Bokkapitel (refereegranskat)abstract
- Risk assessment is a systematic and iterative process, which involves risk analysis, where probable hazards are identified, and then corresponding risks are evaluated along with solutions to mitigate the effect of these risks. In this article, the outcome of a risk assessment process will be detailed, where a large industrial robot is used as an intelligent and flexible lifting tool that can aid operators in assembly tasks. The realization of a collaborative assembly station has several benefits, such as increased productivity and improved ergonomic work environment. The article will detail the design of the layout of a collaborative assembly workstation, which takes into account the safety and productivity concerns of automotive assembly plants. The hazards associated with hand-guided collaborative operations will also be presented.
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| 10. |
- Gopinath, Varun, 1982-, et al.
(författare)
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Risk Assessment for Collaborative Operation : A Case Study on Hand-Guided Industrial Robots
- 2018
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Ingår i: Risk Assessment. - London/Rijeka : InTech. - 9789535137986 - 9789535140634 - 9789535137993 ; , s. 167-187
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Bokkapitel (refereegranskat)abstract
- Risk assessment is a systematic and iterative process, which involves risk analysis, where probable hazards are identified, and then corresponding risks are evaluated along with solutions to mitigate the effect of these risks. In this article, the outcome of a risk assessment process will be detailed, where a large industrial robot is used as an intelligent and flexible lifting tool that can aid operators in assembly tasks. The realization of a collaborative assembly station has several benefits, such as increased productivity and improved ergonomic work environment. The article will detail the design of the layout of a collaborative assembly workstation, which takes into account the safety and productivity concerns of automotive assembly plants. The hazards associated with hand-guided collaborative operations will also be presented.
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