### Abstract

The development of solid modeling to represent the geometry of designed parts and the development of parametric modeling to control the size and shape have had significant impacts on the efficiency and speed of the design process. Designers now rely on parametric solid modeling, but surprisingly often are frustrated by a problem that unpredictably causes their sketches to become twisted and contorted. This problem, known as the "multiple solution problem" occurs because the dimensions and geometric constraints yield a set of non-linear equations with many roots. This situation occurs because the dimensioning and geometric constraint information given in a CAD model is not sufficient to unambiguously and flexibly specify which configuration the user desires. This paper first establishes that only explicit, independent solution selection declarations can provide a flexible mechanism that is sufficient for all situations of solution selection. The paper then describes the systematic derivation of a set of "solution selector" types by considering the occurrences of multiple solutions in combinations of mutually constrained geometric entities. The result is a set of eleven basic solution selector types and two derived types that incorporate topological information. In particular, one derived type "concave/convex" is user-oriented and thought to be very useful.

Original language | English (US) |
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Title of host publication | Proceedings of the ASME Design Engineering Technical Conference |

Pages | 203-213 |

Number of pages | 11 |

Volume | 2 |

State | Published - 2001 |

Event | 2001 ASME Design Engineering Technical Conference and Computers and Information in Engineering Conference - Pittsburgh, PA, United States Duration: Sep 9 2001 → Sep 12 2001 |

### Other

Other | 2001 ASME Design Engineering Technical Conference and Computers and Information in Engineering Conference |
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Country | United States |

City | Pittsburgh, PA |

Period | 9/9/01 → 9/12/01 |

### Fingerprint

### ASJC Scopus subject areas

- Engineering(all)

### Cite this

*Proceedings of the ASME Design Engineering Technical Conference*(Vol. 2, pp. 203-213)

**Solution selectors : A user-oriented answer to the geometric constraint multiple solution problem.** / Bettig, Bernhard; Shah, Jami.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*Proceedings of the ASME Design Engineering Technical Conference.*vol. 2, pp. 203-213, 2001 ASME Design Engineering Technical Conference and Computers and Information in Engineering Conference, Pittsburgh, PA, United States, 9/9/01.

}

TY - GEN

T1 - Solution selectors

T2 - A user-oriented answer to the geometric constraint multiple solution problem

AU - Bettig, Bernhard

AU - Shah, Jami

PY - 2001

Y1 - 2001

N2 - The development of solid modeling to represent the geometry of designed parts and the development of parametric modeling to control the size and shape have had significant impacts on the efficiency and speed of the design process. Designers now rely on parametric solid modeling, but surprisingly often are frustrated by a problem that unpredictably causes their sketches to become twisted and contorted. This problem, known as the "multiple solution problem" occurs because the dimensions and geometric constraints yield a set of non-linear equations with many roots. This situation occurs because the dimensioning and geometric constraint information given in a CAD model is not sufficient to unambiguously and flexibly specify which configuration the user desires. This paper first establishes that only explicit, independent solution selection declarations can provide a flexible mechanism that is sufficient for all situations of solution selection. The paper then describes the systematic derivation of a set of "solution selector" types by considering the occurrences of multiple solutions in combinations of mutually constrained geometric entities. The result is a set of eleven basic solution selector types and two derived types that incorporate topological information. In particular, one derived type "concave/convex" is user-oriented and thought to be very useful.

AB - The development of solid modeling to represent the geometry of designed parts and the development of parametric modeling to control the size and shape have had significant impacts on the efficiency and speed of the design process. Designers now rely on parametric solid modeling, but surprisingly often are frustrated by a problem that unpredictably causes their sketches to become twisted and contorted. This problem, known as the "multiple solution problem" occurs because the dimensions and geometric constraints yield a set of non-linear equations with many roots. This situation occurs because the dimensioning and geometric constraint information given in a CAD model is not sufficient to unambiguously and flexibly specify which configuration the user desires. This paper first establishes that only explicit, independent solution selection declarations can provide a flexible mechanism that is sufficient for all situations of solution selection. The paper then describes the systematic derivation of a set of "solution selector" types by considering the occurrences of multiple solutions in combinations of mutually constrained geometric entities. The result is a set of eleven basic solution selector types and two derived types that incorporate topological information. In particular, one derived type "concave/convex" is user-oriented and thought to be very useful.

UR - http://www.scopus.com/inward/record.url?scp=1542436120&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=1542436120&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:1542436120

VL - 2

SP - 203

EP - 213

BT - Proceedings of the ASME Design Engineering Technical Conference

ER -