Negotiating design specifications: evolving functional constraints in mechanical assembly design

ABSTRACT

Traditionally it has been assumed "Design Specifications" are given a priori, and constitute the primary constraints on the process of search that is design. This view is under challenge in emergentist accounts of design, where it is seen that for well-understood functional needs, experienced designers are able to come up with good designs very quickly. It is hypothesized that this is possible because search is minimized using novel functional constraints that emerge from experience. These emergent aspects are difficult to model in a computational framework, and this work is a preliminary attempt in this direction. "Well-understood functions" are assumed to be quantifiable in terms of some performance metrics, which permits us to identify regions of high functional validity as emergent constraint regions in the design space. In addition, designers often change the design space itself, and negotiate the initial specs in many ways. We show that small changes in the design space may result in large changes in this mapping, which is why such emergent knowledge is limited to a specific embodiment. By introducing such measures into future solid modeling systems, it may reduce the human designer's search to the more ill-posed aspects of the problem.

REFERENCES

• 1: Ahmed, S., Wallace, K. M, and Blessing, L. T. 2003. Understanding the differences between how novice and experienced designers approach design tasks. Research in Engineering Design 14, 1 (February), 1--11.
• 2: Cross, N. 2004. Expertise in design:an overview. Design Studies 25, 5 (September), 427--441.
• 3: Dabbeeru, M. M., and Mukerjee, A. 2007. Functional design for part families of mechanical assemblies. ISCA, San Francisco, G. Hu, Ed., no. ISBN 978-1-880843-65-9, ISCA, 263--268.
• 4: Gero, J. S., and Kannengiesser, U. 2002. The situated function - behaviour - structure framework. Gero (ed.) Artificial Intelligence in Design, 89--104.
• 5: John S. Gero, Design prototypes: a knowledge representation schema for design, AI Magazine, v.11 n.4, p.26-36, Winter 1990
• 6: Goldschmidt, G. 2003. The backtalk of self-generated sketches. Design Issues 19, 1 (Winter), 72--88.
• 7: Gross, M. D. 1986. Design as Exploring Constraints. PhD thesis, Massachusetts Institute of Technology.
• 8: Janssen, P. H. 2006. The role of preconceptions in design: Some implications for the development of computational design tools. In Design Computing and Cognition '06, Springer Verlag, J. S. Gero, Ed., 365--383.
• 9: JI, X., and Xiao, J. 2001. Planning motion compliant to complex contact states. International Journal of Robotics Research 20, 6 (June), 446--465.
• 10: Leo Joskowicz , Elisha P. Sacks, Computational kinematics, Artificial Intelligence, v.51 n.1-3, p.381-416, Oct. 1991 [doi>10.1016/0004-3702(91)90115-Z]
• 11: Jean-Claude Latombe, Robot Motion Planning, Kluwer Academic Publishers, Norwell, MA, 1991
• 12: Lawson, B. 2004. Schemata, gambits and precedent: some factors in design expertise. Design Studies: Expertise in Design 25, 5 (September), 443--157.
• 13: Maher, M. L., and Tang, H.-H. 2003. Co-evolution as a computational and cognitive model of design. Research in Engineering Design 14, 1 (February), 47--63.
• 14: Mukerjee, A., and Bhatia. 1995. A qualitative discretization for two-body contacts. In Proc. of the 14th IJCAI, vol. 1, 915--921.
• 15: Pahl, G., and Beitz, W. 1988. Engineering Design:A Systematic Approach. The Design Council/Springer-Verlag, London/Berlin, 199--400.
• 16: Poon, J., and Maher, M. L. 1997. Co-evolution and emergence in design. Artificial Intelligence in Engineering 11, 3 (July), 319--327.
• 17: Suwa, M., Gero, J., and Purcell, T. 2000. Unexpected discoveries and s-invention of design requirements: important vehicles for a design process. Design Studies 21, 6 (November), 539--567.
• 18: Jan Wolter , Periannan Chandrasekaran, A concept for a constraint-based representation of functional and geometric design knowledge, Proceedings of the first ACM symposium on Solid modeling foundations and CAD/CAM applications, p.409-418, June 05-07, 1991, Austin, Texas, United States [doi>10.1145/112515.112576]

INDEX TERMS

Primary Classification:
  J. Computer Applications
  J.6 COMPUTER-AIDED ENGINEERING
      Subjects: Computer-aided design (CAD)

Additional Classification:
  F. Theory of Computation
  F.2 ANALYSIS OF ALGORITHMS AND PROBLEM COMPLEXITY
      F.2.2 Nonnumerical Algorithms and Problems
          Subjects: Computations on discrete structures; Geometrical problems and computations

  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.5 Computational Geometry and Object Modeling

General Terms:
Algorithms, Design