| 1. |
- Björkenstam, Staffan C, 1981, et al.
(författare)
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Assembly path planning by distance field based shrinking
- 2012
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Ingår i: Proceedings of the 4th CIRP Conference on Assembly Technologies and Systems: Technologies and Systems for Assembly Quality, Productivity and Customization, Editor: Professor S. Jack Hu, May 20- 22, 2012, Ann Arbor, Michigan, USA. - 9780615640228 ; 4, s. 179-182
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Konferensbidrag (refereegranskat)abstract
- This paper presents a method to support dynamic packing in cases when no collision-free path can be found. The method, which is primarily based on path planning and shrinking of geometries, suggests a minimal geometry design change that results in a collision-free assembly path. A new method to shrink geometry based on adaptively sampled distance fields is suggested. Compared to previous work, the new method is less sensitive to input mesh quality. The method works directly on the triangle mesh and requires neither tetrahedralization nor calculation of a medial axis. The algorithm paired with a state of the art path planner has been applied to several industrial cases demonstrating that the proposed method can be used effectively for assembly verification during geometry design.
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| 2. |
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| 3. |
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| 4. |
- Segeborn, Johan, 1972, et al.
(författare)
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Geometry Design Supported by Minimizing and Visualizing Collision in Dynamic Packing
- 2007
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Ingår i: International Journal of Mathematical, Physical and Engineering Sciences. - 1307-7465. ; 1:2, s. 101-108
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a method to support dynamic packing in cases when no collision-free path can be found. The method, which is primarily based on path planning and shrinking of geometries, suggests a minimal geometry design change that results in a collision-free assembly path. A supplementing approach to optimize geometry design change with respect to redesign cost is described. Supporting this dynamic packing method, a new method to shrink geometry based on vertex translation, interweaved with retriangulation, is suggested. The shrinking method requires neither tetrahedralization nor calculation of medial axis and it preserves the topology of the geometry, i.e. holes are neither lost nor introduced. The proposed methods are successfully applied on industrial geometries.
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| 5. |
- Carlson, Johan, 1972, et al.
(författare)
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Minimizing Dimensional Variation and Robot Traveling Time in Welding Stations
- 2014
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Ingår i: Procedia CIRP. - : Elsevier BV. - 2212-8271. ; 23:C, s. 77-82
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Konferensbidrag (refereegranskat)abstract
- Complex assembled products as an automotive car body consist of about 300 sheet metal parts joined by up to 4000 spot welds. In the body factory, there are several hundred robots organized into lines of welding stations. The distribution of welds between robots and the welding sequences have a significant influence on both dimensional quality and throughput. Therefore, this paper proposes a novel method for quality and throughput optimization based on a systematic search algorithm which exploits properties of the welding process. It uses approximated lower bounds to speed up the search and to estimate the quality of the solution. The method is successfully tested on reference assemblies, including detailed fixtures, welding robots and guns.
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| 6. |
- Mark, Andreas, 1980, et al.
(författare)
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Optimisation of Robotised Sealing Stations in Paint Shops by Process Simulation and Automatic Path Planning
- 2014
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Ingår i: International Journal of Manufacturing Research. - 1750-0591 .- 1750-0605. ; 9:1, s. 4-26
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Tidskriftsartikel (refereegranskat)abstract
- Application of sealing materials is done in order to prevent water leakage into cavities of the car body, and to reduce noise. The complexity of the sealing spray process is characterised by multi-phase and free surface flows,multi-scale phenomena, and large moving geometries, which poses great challenges for mathematical modelling and simulation. The aim of this paper is to present a novel framework that includes detailed process simulation andautomatic generation of collision free robot paths. To verify the simulations, the resulting width, thickness and shape of applied material on test plates as a function of time and spraying distance have been compared to experiments. The agreement is in general very good. The efficient implementation makes it possible to simulate application of one meter of sealing material in less than anhour on a standard computer, and it is therefore feasible to include such detailed simulations in the production preparation process and off-line programming of the sealing robots.
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| 7. |
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| 8. |
- Segeborn, Johan, 1972, et al.
(författare)
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A Chronological Framework for Virtual Sheet Metal Assembly Design
- 2009
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Ingår i: The 11th CIRP International Conference on Computer Aided Tolerancing, Annecy, France, March 26th-27th 2009..
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Konferensbidrag (refereegranskat)abstract
- In this paper, a chronological framework for virtual sheet metal assembly design is presented. The framework conveys the order, in which design parameters, that influence geometrical quality and equipment utilization, need to be introduced to ensure that each design parameter is analytically determined. The order is significant, as design parameters usually are prerequisital to start analysis of subsequent design parameters. Recent progress within product life cycle management and the advent of efficient analysis tools targeting most of the influencing design parameters makes a holistic approach to sheet metal assembly design feasible. The chronological framework provides a roadmap in this effort.
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| 9. |
- Segeborn, Johan, 1972, et al.
(författare)
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A Chronological Framework for Virtual Sheet Metal Assembly Design
- 2013
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Ingår i: Product Lifecycle Management - Geometric Variations, ISTE Ltd, Wiley, London, 2010. - : Wiley. ; , s. 175-190
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, a chronological framework for virtual sheet metal assembly design is presented. The framework conveys the order, in which design parameters, that influence geometrical quality and equipment utilization, need to be introduced to ensure that each design parameter is analytically determined. The order is significant, as design parameters usually are prerequisital to start analysis of subsequent design parameters. Recent progress within product life cycle management and the advent of efficient analysis tools targeting most of the influencing design parameters makes a holistic approach to sheet metal assembly design feasible. The chronological framework provides a roadmap in this effort.
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| 10. |
- Segeborn, Johan, 1972, et al.
(författare)
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A Generalized method for weld Load balancing in multi station sheet metal assembly lines
- 2011
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Ingår i: Proceedings of the ASME 2011 International Mechanical Engineering Congress & Exposition IMECE2011 November 11-17, 2011, Denver, Colorado, USA.
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Konferensbidrag (refereegranskat)abstract
- Sheet metal assembly is investment intense. Therefore the equipment needs to be efficiently utilized. The balancing of welds has a significant influence on achievable production rate and equipment utilization. Robot line balancing is a complex problem, where each weld is to be assigned to a specific station and robot, such that line cycle time is minimized. Industrial robot line balancing has been manually conducted, based on experience and trial and error rather than mathematical methods. However, recently an automatic method for robot line balancing was proposed by the authors. To reduce robot coordination cycle time losses, this method requires identical reach ability of all line stations. This limits applicability considerably since in most industrial lines, reach ability differs over the stations to further line reach ability and flexibility.Therefore, in this work we propose a novel generalized simulation-based method for automatic robot line balancing that allows any robot positioning. It reduces the need for robot coordination significantly by spatially separating the robot weld work loads. This is furthermore achieved at a cost neglectable to line cycle time. The proposed method is furthermore successfully demonstrated on an automotive stud welding line. Moreover, algorithm CPU-times is a mere fraction of corresponding manual optimization times.
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