| 1. |
- Andersson, Alf, et al.
(författare)
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Inline Process Control – a concept study of efficient in-line process control and process adjustment with respect to product geometry
- 2016
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Ingår i: Swedish Production Symposium 2016 SPS 2016. - Lund, Sweden.
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Konferensbidrag (refereegranskat)abstract
- All manufacturing processes have variation which may violate the fulfillment of assembly, functional, geometrical or esthetical requirements and difficulties to reach desired form in all areas. The cost for geometry defects rises downstream in the process chain. Therefore, it is vital to discover these defects as soon as they appear. Then adjustments can be done in the process without losing products or time. In order to find a solution for this, a project with the overall scope “development of an intelligent process control system” has been initiated. This project consists of five different work packages: Inline measurement, Process Evaluation, Corrective actions, Flexible tooling and demonstrator cell. These work packages address different areas which are necessary to fulfill the overall scope of the project. The system shall both be able to detect geometrical defects, propose adjustments and adjust simple process parameters. The results are demonstrated in a demo cell located at Chalmers University of Technology. In the demonstrator all the different areas have been verified in an industrial case study – assembly of GOR Volvo S80. Efficient offline programming for robot based measurement, efficient process evaluation based on case base reasoning (CBR) methodology, flexible fixtures and process adjustments based on corrective actions regarding in going part positioning.
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| 2. |
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| 3. |
- Erdem, Ilker, 1987, et al.
(författare)
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A novel comparative design procedure for reconfigurable assembly fixtures
- 2017
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Ingår i: CIRP Journal of Manufacturing Science and Technology. - : Elsevier BV. - 1755-5817 .- 1878-0016. ; 19, s. 93-105
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Tidskriftsartikel (refereegranskat)abstract
- While market requirements demand that manufacturing systems increase their responsiveness, assembly fixtures remain limited in corresponding to the same demand. Fixture designers as practitioners are left without guidance to design reconfigurable fixtures. This study proposes a comparative design procedure for reconfigurable assembly fixtures that can adapt to manufacturing system characteristics by using efficiency metrics. In this study, a theoretical analysis based on manufacturing systems is presented to establish efficiency metrics. Later, these metrics are utilized in a design procedure that offers guidance and determines the efficiency of fixtures in conceptual and detailed design stages. Finally, an experimental verification is presented.
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| 4. |
- Erdem, Ilker, 1987, et al.
(författare)
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Development of Affordable Reconfigurable Tooling in Car Manufacturing Cells – A Case Study
- 2015
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Ingår i: 23rd International Conference for Production Research, ICPR 2015, Manila, Philippines, 2-6 August 2015.
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Konferensbidrag (refereegranskat)abstract
- Assembly fixtures are one of the cost driving factors in automotive industry. Previous research have shown that the utilization of affordable reconfigurable tooling (ART) can be a key-enabling technology to reduce the cost and lead times. Inspired by the research results, Volvo Cars Corporation initiated an automated process control project, the aim of which is the automatic inspection and correction of the defects in Body in White (BIW). The project comprises of three stages – the first of which is the in-line measurement of BIW. Then, the results of measurements are transferred to a common database where process evaluation through case-based reasoning suggests corrective actions on the fixture. The last stage involves the development of flexible tooling to meet these changes in a cost and time effective way. Hence, the aim of this paper is to present preliminary results on the development and implementation of ART as flexible tooling.
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| 5. |
- Erdem, Ilker, 1987, et al.
(författare)
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Development of Automated Flexible Tooling as Enabler in Wing Box Assembly
- 2016
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Ingår i: Procedia CIRP. - : Elsevier BV. - 2212-8271. ; 44, s. 233-238
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Konferensbidrag (refereegranskat)abstract
- Flexible tooling has been a focal point of investigation for various industries with an emphasis on cost and time effectiveness. Previous research has shown that when combined with the general requirements of tooling such as rigidness and repeatability, the implementation of flexibility can be a very daunting task. Therefore, LOCOMACHS (Low Cost Manufacturing and Assembly of Composite and Hybrid Structures) project has dedicated a work package for the creation of an automated flexible tooling to meet the demands of future aerospace production. The work package focuses on a creation of a tooling technology that can facilitate the process requirements of an automated wing-assembly by using flexible tooling and intelligence support from a force sensor. Hence, this paper aims to present the framework for automated flexible tooling development and results on a hexapod fixture as a case study.
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| 6. |
- Erdem, Ilker, 1987, et al.
(författare)
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Feedforward control for oscillatory signal tracking using Hilbert transform
- 2019
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Ingår i: European Journal of Control. - : Elsevier BV. - 0947-3580. ; 50, s. 41-50
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents feedforward control for oscillatory signal tracking using Hilbert transform. The proposed controller utilizes Hilbert transform and analysis techniques to determine the signal's amplitude, frequency, and phase. By using the frequency response of the linear time-invariant process model, an amplified and phase-shifted feedforward signal is reconstructed. The proposed controller also analyzes the system response to determine the differences from the model to modify the feedforward signal. Simulation experiments with multicomponent stationary, amplitude-, and frequency-modulated signals are also conducted. The results show that using an amplified and phase-shifted signal determined by Hilbert analysis can enable an effective tracking performance.
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| 7. |
- Erdem, Ilker, 1987, et al.
(författare)
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Workpiece force and position control for active and flexible fixtures in assembly
- 2021
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Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 112:1-2, s. 333-346
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Tidskriftsartikel (refereegranskat)abstract
- With strengthening focus on digitalization and flexibility, active and flexible fixtures can provide the right tools for manufacturing systems. However, fixturing solutions are often too individualized for processes and need a universal approach. Firstly, a system formulation of multiple workpieces interacting with each other is presented. Secondly, strategies for direct and indirect force control along with their characteristics have been developed. The stability of assembly of force-controlled components has been analyzed, and certain key characteristics have been presented. The position control under different signal types, including oscillatory, have been discussed. Finally, a set of experiments have been conducted for performance evaluation.
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| 8. |
- Herbertsson, Jonas, et al.
(författare)
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Reconfigurable aircraft assembly : using industrial robots and new tooling to meet future production scenarios
- 2002
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Ingår i: Proceedings of the 33rd ISR (International Symposium on Robotics).
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Konferensbidrag (refereegranskat)abstract
- This paper presents the development of a new concept for aircraft airframe assembly tooling. While conventional aircraft assembly tooling relics on rigid steel frames this novel approach can be re-con figured for different products by the help of an accurate laser tracker guided industrial robot. Through this, aircraft manufacturers can better cope with an increased number of variants and smaller volumes which will increase the already high tooling costs. So far in the project a tooling concept has been conceptually designed and economically evaluated. The early technical results of the concepntal work indicate that the concept will work provided that enough mechanical stiffness can be obtained. The economical analysis shows that despite a much higher investment cost, a reconfigurable tool can be economical if it will replace 4-5 conventional tools. In certain future production scenarios reconfigurable tooling can play a very important role to keep the tooling costs down.
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| 9. |
- Jonsson, Marie, 1979-, et al.
(författare)
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Development of an automated reconfigurable device for affordable fixturing
- 2011
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Ingår i: Proceedings of the 21st International Conference on Production Research (ICPR2011), 31st July - 4th August, Stuttgart, Germany. - 3839602939 - 9783839602935
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Fixtures are used in manufacturing to hold and position products or workpieces. Linköping University has over a period of several years developed an approach to flexible fixturing that relies on an outer measuring system to ensure accuracy rather than the more common approaches of high internal accuracy or a built-in chain of tolerances. The Linköping system fuses modularity, a rebuildable framework, with reconfigurability, through the means of adjustable devices. To address the need for speed in reconfiguration an automated approach has been developed as a proof-ofconcept. The system consists of electrical motors attached to the legs of the Flexapod 6, a PC, controller cards and an external measuring system. The measuring system feeds information to the PC that is utilized to calculate desired leg length using a Visual Basic program that communicates with CATIA V5. This program then sets signals to the motor controller cards which run the actuators. Due to the motors used the accuracy achieved are in the range of +/-0.15 mm but this may be enhanced with other types of motors developed for higher strengthrather than speed. The system can be further developed by having the actuators as the actual legs of the Flexapod, making it a cheaper Hexapod robot. The paper presents the automated Flexapod 6 in the current system along with possible further development.
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| 10. |
- Jonsson, Marie, 1979-, et al.
(författare)
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Fixture design using Configurators
- 2008
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Ingår i: Proceedings of the 2008 Swedish Production Symposium.
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Konferensbidrag (refereegranskat)abstract
- Design and manufacture of fixtures are among one of the major cost drivers in product industrialization. Modular or reconfigurable fixture solutions that may be adapted to encompass a large variety of parts or products have been researched and employed in applications ranging from machining to assembly. These solutions have not only the potential to reduce fixture manufacturing cost, but they also render it possible for different solutions to facilitate and speed up actual design work. The process of designing fixtures today is complicated, time consuming and require long experience by the tool designer. In this paper we present the Configurator approach - add on programs to the CAD-software which aids the designer in the design process. The Configurators are semi-automated and interactive, designed to use in compliance with the ART-concept, a reconfigurable fixture concept for assembly applications. The Configurator approach has been tested on industrial cases and parts of the results are presented in this paper.
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