Project Leader: Karin Forslund (Research group: Geometry Assurance & Robust Design)
RG: Geometry and Motion Planning (GMP)
RG: Geometry Assurance and Robust Design (GA)
Karin Forslund, PhD Student
RG: Flexible Automation (FA)
Kristofer Bengtsson, PhD Student
Volvo Cars AB
Ola Wagersten, Industrial PhD Student
Lennart Malmsköld, Industrial PhD Student
Early concept studies and evaluations involve a number of decisions that have to be taken on the basis of uncertain or incomplete information, which constitutes a great risk for a company. Visualization of future products and processes with high level of realism and with respect to real manufacturing conditions, before they are built, has the potential to highly improve decisionmaking in early design stages.
Visually sensitive design concepts often lead to production problems with scrap, rework and delays as a consequence. Therefore, new methods and tools for visualizing and evaluating design concepts with respect to form language and split-line solutions, including the effects of manufacturing variation, are needed.
The Perceived Quality of a product is highly related to the customer’s final perception of the product. In a complex assembled product like an automobile, a number of plastic, rubber and sheet metal parts are assembled together under over-constrained assembly conditions which deform the parts and affect the appearance of the product in a negative way.
The purpose of the project was to develop new knowledge about visualization techniques and Perceived Quality, i.e. how form and split-lines influence perceived quality and how manufacturing variation may be amplified by the design concept itself. The project aimed at finding a process for Perceived Quality evaluation, based on non-nominal visualization of assemblies. This approach takes digital prototypes from nominal to non-nominal and generates an IT solution that links industrial design, engineering design and production. Hereby, product realization time and cost can be reduced with maintained or improved quality. The project addressed the following research questions (slightly modified from Operational Plan Stage 2):
- RQ 4: 1
How does manufacturing variation affect perceived quality of a product?
- RQ 4: 2
How do the form language and split line solutions for a product affect its visual sensitivity to manufacturing variation?
- RQ 4: 3
How can the visual sensitivity of a product be evaluated in early design stages?
- RQ 4: 4
How can non-nominal variation simulation and visualization of split-lines on non-rigid components be performed when complete engineering CAD data is not available?
- RQ 4: 5
How can such a method support the process of evaluating Perceived Quality?
- RQ 4: 6
Is there a non-FEA-based deformation model that can be used for variation visualization to support requirement definition in early design stages?
- RQ 4: 7
How can station logic be visualized?
The project results will support early concept evaluations and have the potential to highly improve decision- making in early design stages. The project was carried out in close cooperation with our industrial partners and also involved people from these companies. Case studies were carried out on the basis of problems from the industrial partners.
Summary of results
The project has resulted in a number of methods and tools that help visualize and evaluate Perceived Quality (PQ) in early product development phases. In a proposed framework [4:11], the aims and scopes of the different methods and tools are defined. Thereby a standardized procedure for early PQ evaluation is proposed.
The procedure consists of four main phases. In the initial stage, concept evaluation, the overall concept sensitivity is focused. Here, alternative design concepts can be evaluated through the proposed Visual Sensitivity Analysis [4:8]. The subsequent step is requirement evaluation, where aesthetic requirement levels are investigated and judged. In the variation prediction (styling) phase, more comprehensive analyses can be performed.
A method has been proposed that aids non-rigid behavior prediction based on styling data [4:14]. Critical vehicle areas for non-rigid simulations based on styling data have been identified [4:12]. In the final step, variation prediction (engineering), variation can be simulated and visualized on the basis of more mature geometrical models. The previous implementation of such methods at one of the automotive companies has been validated in a retrospective analysis [4:16].
To attain even more realistic predictions, studies addressing variation simulation of injection-molded components have also been performed [4:9 and 4:10]. To further support PQ evaluations and decision-making, studies have been undertaken to increase knowledge of the customers’ perceptions of geometrical quality.
The visual sensitivity of different design concepts has been thoroughly studied [4:4, 4:6, 4:18 and 4:17]. Parameters influencing the perception of geometrical deviations in a virtual environment have been explored in a user experiment [4:7]. The importance of navigational methods in virtual environments has been investigated [4:15]. In addition, the project addressed visualization of station logic, and a tool for visualizing various sequence projections has been developed in collaboration with a participating company. Research question RQ4:1 is addressed in 4:18.
Research question RQ4:2 is addressed in 4:8. The results are under implementation at VCC. Research question RQ4:3 is addressed in 4:7. Research question RQ4:4 is addressed in 4:14 and 4:12. Research question RQ4:5 is addressed in 4:11 and 4:19. Research question RQ4:6 is partly addressed in 4:11 and 4:19. Further results are available but not yet presented. Research question RQ4:7 is addressed in 4:2 and 4:1.
Visual sensitivity analysis
Image: Visual Sensitivity Evaluation
A method for comparing automotive exteriors regarding the visual sensitivity of their split-line concepts has been presented. The method supports preparation of technical input to industrial design, enables comparison between car projects, and aids competitor benchmarking [4:8].
The method has been introduced at Volvo Cars and is under implementation and evaluation in an ongoing vehicle program. The method has been introduced and tested at Saab Automotive.
Publication and Presentation Activity
4:1 Bengtsson, K., Magnusson, P., Thorstensson, C., Lennartson, B., Åkesson, K., Yuan, C., Miremadi, S., Falkman, P., 2012, “Sequence Planning using Multiple and Coordinated Sequences of Operations”. Accepted for publication in IEEE Transactions on Automation Science and Engineering.
4:2 Bengtsson, K., Thorstensson, C., Lennartson, B., Åkesson, K., Yuan, C., Miremadi, S., Falkman, P., 2010, “Relations Identification and Visualization for Sequence Planning and Automation Design”, Proc. of the 6th IEEE International Conference on Automation Science and Engineering (CASE 2010), Toronto, Canada.
4:3 Forslund, K., Kero, T., Söderberg, R., 2009, “Appearance FMEA - a Method for Appearance Quality Evaluation of Early Design Concepts”, Proc. of the ASME 2009 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, San Diego, California.
4:4 Forslund, K., Söderberg, R., 2009, “The Effects of Geometrical Variation on Perceived Quality - A Close Look at the Concept of Visual Robustness”, Proc. of the 11th International Conference on Computer Aided Tolerancing, Annecy, France.
4:5 Forslund, K., Söderberg, R., 2010, “Aesthetic consequences of making car exteriors visually robust to geometrical variation”, J. of Design Research, 8 (3), pp. 252-271.
4:6 Forslund, K., Söderberg, R., 2010, “Effects of Variation on Perceived Quality”, Product Life-Cycle Management: Geometric Variations, Giordano, M., Mathieu, L. and Villeneuve, F. (eds.), pp. 505- 521, Wiley-ISTE, London-Hoboken, ISBN/ISSN: 978-1848212763.
4:7 Forslund, K., Wagersten, O., Tafuri, S., Segerdahl, D., Carlsson, J.S., Lindkvist, L., Söderberg, R., 2011, “Parameters Influencing the Perception of Geometrical Deviations in a Virtual Environment”, Proc. of the ASME 2011 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Washington, D.C., USA.
4:8 Forslund, K., Wickman, C., Söderberg, R., 2012, “Evaluating Relative Complexity of Industrial Design Concepts Regarding Visual Sensitivity to Geometrical Variation”. Accepted for publication in Journal of Engineering Design.
4:9 Lorin, S., Forslund, K., Söderberg, R., 2010, “Investigating the Role of Simulation for Robust Plastic Design”. Proc. of NordDesign2010 International Conference on Methods and Tools for Product and Production Development, Gothenburg, Sweden.
4:10 Lorin, S., Söderberg, R., Carlson, J.S., Edelvik, F., 2010, “Simulating Geometrical Variation in Injection Molding”, Proc. of NordDesign2010 International Conference on Methods and Tools for Product and Production Development, Gothenburg, Sweden.
4:11 Wagersten, O., Forslund, K., Wickman, C., Söderberg, R., 2011, “A Framework for non-nominal visualization and perceived quality evaluation”, Proc. of the ASME 2011 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Washington, D.C., USA.
4:12 Wagersten, O., Söderberg, R., 2010 “Identifying Critical Areas for Styling Data Based Simulation to Evaluate Perceived Quality Related to Non-Rigidity”, Proc. of NordDesign2010 International Conference on Methods and Tools for Product and Production Development, Gothenburg, Sweden.
4:13 Wagersten, O., Wickman, C., Söderberg, R., 2009,”Non-Nominal Physical Representation for Evaluation of Perceived Quality”, Proc. of the 11th International Conference on Computer Aided Tolerancing, Annecy, France.
4:14 Wagersten, O., Wickman, C., Söderberg, R., 2009,”Non-Rigid Behaviour Prediction Based on Styling Data for Evaluation of Perceived Quality”, Proc. of the 14th International Mechanical Engineering Congress and Exposition, IMECE2009, Lake Buena Vista, Florida, USA.
4:15 Wickman, C., Söderberg, R., 2009, “Importance of navigation method in virtual environments during non-nominal evaluation of Perceived Quality”, Proc. of the 11th International Conference on Computer Aided Tolerancing, Annecy, France.
4:16 Wickman, C., Söderberg, R., 2010, “Retrospective Analysis and Evaluation of Non-Nominal Visualization as Means for Evaluation of Perceived Quality in the Automotive Industry”, Proc. of Nord- Design2010 International Conference on Methods and Tools for Product and Production Development, Gothenburg, Sweden.
4:17 Forslund, K., 2009, “Visual Robustness – Effects of Variation on Product Appearance and Perceived Quality”, Licentiate thesis, Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
4:18 Forslund, K., 2011, “Evaluating the Effects of Variation on Product Appearance through Visual Robustness”, Doctoral Thesis, Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
4:19 Wagersten, O., 2011, “Towards Efficient Evaluation of Impacts of Geometrical Variation on Perceived Quality in Early Phases”, Licentiate thesis, Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.