Expert System for Tool Selection

Fabrication Methods and Tooling (M&T) personnel typically use manual methods for selecting the tools to make a cut with a numerically controlled machine tool. The outcome of the selection process may or may not be the optimum tool assembly because of inadequacies in the “knowledge” of the M&T person and the manuals used. The solution falls directly within the scope of a rule-based expert system.

The expert system designed at Texas Instruments for this problem is written in Pascal and uses the decision and classification (DCLASS) information system as the representation language. DCLASS was written in Fortran by Brigham Young University in 1976 and represents rules in the form of decision trees and tree manipulation functions. The manipulation functions are the basis of the “if … then …” processing found in conventional rule-based expert systems. The functions perform well-defined forward-chain processing, which limits the usage scope of the product but handles the tool selection problem nicely.