Expert Tower Analysis and Design System. I: Architecture and Heuristics

Abstract

This paper reports the development of EXTASY—an expert system for analysis and design of microwave towers. The three inputs given to a tower designer are the tower height, its geographical location, and details about the antennae the tower is to support. Based on these inputs, the overall configuration of the tower has to be fixed by the designers. Expert designers basically rely on heuristics (acquired from experience by designing many towers) to choose parameters such as the base width, the top width, the type of bracing, spacing of the panels, etc., for the tower configuration. The final cost of the tower is sensitive to these initial decisions. These heuristics are incorporated in the form of IF‐THEN‐WITH rules. Knowledge acquisition for these rules is automated and the system relies on previously generated solutions for making new design decisions. A blackboard architecture is used as the fundamental problem‐solving strategy. The paper is presented in two parts. The first gives an introduction to the nature of the problem, the architecture adopted for problem solving, the nature of the heuristics involved and the knowledge acquisition module. The various search strategies implemented and “learning” in EXTASY are described in the second part of the paper. A sample session with EXTASY is included. The system is implemented on an IBM PC‐AT with MS‐DOS. The languages used are PROLOG, FORTRAN and BASIC.