Accession Number:

ADA162555

Title:

The Use of Quantitative Databases in Aladin, an Alloy Design System.

Descriptive Note:

Interim rept.,

Corporate Author:

CARNEGIE-MELLON UNIV PITTSBURGH PA ROBOTICS INST

Report Date:

1985-09-01

Pagination or Media Count:

18.0

Abstract:

The Aluminum Alloy Design Inventor Aladin is an expert system that aids in the design of new alloys. The system uses traditional, rule based, qualitative methods as well as quantitative calculations. Our approach is to model the design process as a collaboration among several different bodies of expertise composition in terms of elements to be added properties of known alloys internal sturcture, ranging from solid phases and microstructure down to the crystal lattice structure and thermo-mechanical processing of the metal. The inference mechanism is a variant of hypothesize-and-test. The present implementation combines the Carnegie Representation Language CRL and OPS5 along with Lisp. A database of metallurgical knowledge and data on known alloys is built in the form of CRL schemata. The execution of the system is controlled by OPS productions and most of the data produced in a specific run is represented by OPS working memory elements. This paper gives a preliminary overview of the architecture of Aladin with emphasis on the couplng of symbolic and numeric computations. We breifly describe the knowledge representation of Alloys, Phase diagrams and Microstructure information. We explain how qualitative reasoning is used to define the variables to be dealt with quantitatively and how regression among known alloys is used. We describe multidimensional constraints and how they are used to deal with interaction between variables, to implement a least commitment strategy and how they at the same time provide criteria for search termination and backtracking.

Subject Categories:

  • Properties of Metals and Alloys
  • Computer Programming and Software
  • Computer Hardware

Distribution Statement:

APPROVED FOR PUBLIC RELEASE